Blockchain Papers

Hoeteck Wee

No abstract is available for this record.

Hirotada Kobayashi

This paper studies the complexity classes QZK and HVQZK of problems having a quantum computational zero-knowledge proof system and an honest-verifier quantum computational zero-knowledge proof system, respectively. The results proved in this paper include: (a) HVQZK = QZK, (b) any problem in QZK has a public-coin quantum computational zero-knowledge proof system, (c) any problem in QZK has a quantum computational zero-knowledge proof system of perfect completeness, and (d) any problem in QZK has a three-message public-coin quantum computational zero-knowledge proof system of perfect completeness with arbitrarily small constant error in soundness. All the results above are unconditional and do not rely any computational assumptions. For the classes QPZK, HVQPZK, and QSZK of problems having a quantum perfect zero-knowledge proof system, an honest-verifier quantum perfect zero-knowledge proof system, and a quantum statistical zero-knowledge proof system, respectively, the following new properties are proved: (e) HVQPZK = QPZK, (f) any problem in QPZK has a public-coin quantum perfect zero-knowledge proof system, (g) any problem in QSZK has a quantum statistical zero-knowledge proof system of perfect completeness, and (h) any problem in QSZK has a three-message public-coin quantum statistical zero-knowledge proof system of perfect completeness with arbitrarily small constant error in soundness. It is stressed that our proofs are direct and do not use complete promise problems or those equivalents. This gives a unified framework that works well for all of quantum perfect, statistical, and computational zero-knowledge proofs, and enables us to prove properties even on the computational and perfect zero-knowledge proofs for which no complete promise problems are known.

Gilles Brassard, Claude Crépeau

A zero-knowledge interactive proof is a protocol by which Alice can convince a polynomially-bounded Bob of the truth of some theorem without giving him any hint as to how the proof might proceed. Under cryptographic assumptions, we give a general technique for achieving this goal for every problem in NP. This extends to a presumably larger class, which combines the powers of non-determinism and randomness. Our protocol is powerful enough to allow Alice to convince Bob of theorems for which she does not even have a proof: it is enough for Alice to convince herself probabilistically of a theorem, perhaps thanks to her knowledge of some trap-door information, in order for her to be able to convince Bob as well, without compromising the trap-door in any way. These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Dario Catalano, Ivan Visconti

No abstract is available for this record.

Arthur C. Danto

>The translator into Hungarian of several of my writings on art theory recently sent me a catalog of the work of a young artist from her country, Ágnes Eperjesi.1 The translator—Eszter Babarczy—is a gifted critic in her own right, and I cannot do better than quote from her letter, which explains why she felt I would be especially interested in Eperjesi's art. She thought your ideas about transfiguration and the commonplace applied to her work, and she took inspiration from your essays. Hers is a remarkable and long journey from experimental photography to an absolutely unique venture of collecting wrappings of household products, and taking the humble sign language of ordinary household chores, and recreating them as objects of beauty and irony. The products, like dishwashers and vacuum cleaners—or underwear—were in all likelihood intended for export to countries anywhere in the world, which implies that they will fit into forms of life that must be much the same the world over. So the images must themselves belong to the sign language of globalism, necessarily universal in that they have to be legible to consumers who cannot be counted on to have a common language. The signs show what the consumers need to know about the products they have purchased—which side of a pair of underpants is front and which side is back, for example. In many, though not, all cases, they are pictograms or even isotypes—an acronym for “International System of Typographic Picture Education”—signs of a kind initially invented in 1936 by the Logical Positivist, Otto Neurath, who may have been influenced by Wittgenstein's so‐called picture theory of language. Neurath anticipated globalism in saying: “The visual method becomes the basis for a common cultural life and a common cultural relationship.”2 Just consider their international use in giving traffic directions to drivers who may or may not be able to read the language of the country in which they are traveling, or in guiding us through foreign airports. Isotypes are among the rare practical and positive contributions made by modern philosophy to the common life of humankind. When these pictograms are recycled—or transfigured—into works of art, their implied universality is elevated to a portrait of the society in which the products are to be used. I would not altogether follow Babarszy in calling Eperjesi's works beautiful and, in truth, I am somewhat at a loss to describe them aesthetically. But I can appreciate that in transfiguring the isotype into an artwork, an interesting reversal of Walter Benjamin's famous distinction has taken place: the art of mechanical reproduction has acquired, through transfiguration, an aura, and in virtue of that the images may acquire an aesthetic interest they heretofore lacked. At least, as art, we look at them as critics, and notice their aesthetic qualities, such as they are. Just knowing that an object is intended as a piece of fine art may trigger the sense that it must be beautiful. Or better, we use this standard term of aesthetic commendation in connection with them that we would hardly use in characterizing the pictograms on which they are based. The term ‘beautiful’ may simply be a compliment paid to art as art, without really being descriptive of the art at all. The goal of trans‐cultural communication may mean that features that imply ethnic differences will be erased—the persons are depicted neither as white nor black nor red nor yellow—leaving figures that are abstractly human, which in a way look quite “modern.” But is “looks modern” an aesthetic characterization or a stylistic one? Modernist design strove for a kind of simplification through its distaste for ornament, and this led to stylization in modernist pictography. This does not explain why the isotypical pictograms are stylized as they are, which comes, rather, from globalist imperatives—so “looks modern” is façon de parler. But in any case, the pictogram has undergone some sort of aesthetic transformation in the course of its artistic transfiguration, however we finally describe it. Eperjesi's aesthetic enhancement of workaday images is as distinctive as Andy Warhol's transformations of Polaroids into portraits. As to Eszter Bararcszy's description of the work as “ironic,” that is true—but it is due more to Eperjesi's titles—or perhaps they are captions—than to the images themselves: the covers of The New Yorker Magazine have titles, the cartoons have captions. Either way, the titles/captions express thoughts that the images alone do not. Eperjesi has often selected her images with the intention of using them to convey how women in contemporary Hungary regard themselves, and how they think about the housework for which the product designated by the image is intended to be used—usually by women as a matter of course. One of her images shows a man, a woman, and a child on bicycles. It is difficult to determine what product it stands for, though I would guess that it belongs to what we might think of as the secret life of women. The image could show a woman living a full active life, thanks to the product in question. Whatever its rhetorical aim, Eperjesi captions it this way: “My new boyfriend gets along fine with my daughter. I hope it's not just a show for now” (Figure 1). This is interesting because the woman is evidently a single mother, looking for a new relationship. The irony derives from the implication that while women in contemporary society have been greatly liberated, they remain in a disadvantageous position in relationship to men, as much so in Hungary as in America or western Europe. They are the ones left to do the housework, and to hope that men are not just out to exploit them sexually. Ágenes Eperjesi. The irony goes well beyond the power of isotypes. The three figures could, after all, just represent a family. Interestingly, most of the women are in Western clothing, which has become fairly isotypical: I imagine that the isotype on the door of women's' toilets, shown with a short flaring skirt, would be recognized in airports everywhere in the world, even by women who wear burkhas. In any case, the titles/captions have to be translated, as the artist has done, from Hungarian into the language of the country in which they are to be shown—English, for example, in the catalog I saw. English itself is not, for all it ubiquity, isotypical. Even if it were universally used, as Latin once was, there would be a distinction between pictures and words, which means that while isotypes may validate the picture theory of language, they do so in ways having nothing to do with natural languages as spoken or written. The semantics of sentences in a natural language differ from the semantic of a sentence used pictorially, as in a quotation. But even quotations have to be translated. Tempting as it is to dwell on the artistic semantics of Eperjesi's pictures, my immediate purpose in using her work has to do with its extreme contemporaneity, and to the way it illustrates the pluralistic structure that has increasingly come to define the production of contemporary art, especially since the 1960s when artists first began to explore the possibility of using vernacular imagery. I have already touched on the question of their indeterminate aesthetic qualities, but I want ultimately to discuss this with reference to the problems that artistic pluralism has raised for aesthetic theory, and especially for Kantian aesthetic theory, which more or less dominated discussion until the decade when pluralism became a driving force in art. I understand “Kantian” to mean the view that artistic excellence is one with aesthetic excellence, which is understood to be a matter of pleasure and value distinct from the pleasure of sensual gratification, and internally connected with an ideal of disinterested contemplation. It concerns what the classical aestheticians designated “taste,” and the main features of the theory are laid out in the section of the Critique of Aesthetic Judgment titled “The Analytic of Taste,” which served as the great empowering text for aesthetic theory in modern times, especially, at least in America, in the critical thought and practice of Clement Greenberg. Immanuel Kant's initial interest was in natural beauty, which it was easy enough to relate to the visual arts, understood—the decorative arts apart, which were appraised in terms of “free beauty”—either as accurate representations of natural beauty, or else as beautified representations of natural objects that in reality fell short of beauty. For what would be the point of making pictures of aesthetically repellent or deficient motifs? Greenberg had no such interest, as far as I can tell, and his chief focus was on abstract painting, which could be treated in terms of “free” beauty. This had the advantage for him that he could treat even representationalist art as if abstract, and hence subject to formalist analysis. That is to say, he appreciated painting in terms of what we might call the aesthetics of medium, since painterly excellence is determined by what pertains to properties essential to that medium, namely, in Greenberg's view, relationships between flat forms, irrespective of what the forms may signify. Aesthetic value is what these forms convey to visual perception, in which all concepts are put out of play. Kant of the pleasure taken in an object of any For the alone with he or she may put for the in The of the artist was to from painting not the The was the production of beauty for The of Greenberg's modernist aesthetics on so‐called art in the was is is how pluralism have at all when the had all the power and in the at least so far as contemporary visual art was But for that an I am to the aesthetic began to way in the and became just when Greenberg his most in his The implied by in in the catalog for the at the of was to the between art and would have spoken of the between art and reality so far as were In artistic that the of giving to art out of of had become the it was was not when in the but the kind of aesthetic by the making for what one may think of as a pluralism of aesthetic for a aesthetic that is the of the kind of aesthetic excellence Kant and Greenberg took for It is the aesthetics of and as in he the and in which the work applied as it was used by to an object of use in connection with which and are in or as by what once as is the aesthetic of by and there is question that a for it can be and even by and to young with themselves through a of Kant's main was to what one might call a pluralism of by which I mean the common and somewhat view that beauty is in the of the and that differences in are to differences in Kant to show that beauty is and to be the same for all. This was a kind of aesthetic view that so‐called were simply aesthetically in their was the for the of Western in what to be Greenberg was that his critical practice was by Kant's Critique of Aesthetic which he often the on art. In truth, the of might have in the the remarkable of Greenberg's critical could be taken to have a of on Kant's abstract which a from a of painting hardly in his own of Kant's to Greenberg's which to aesthetic that in the New there was Kant's that of beauty are and that they are universally that they are in no sense Greenberg of beauty. interest was in what he in art, which that his could not be to the aesthetics of which would of course have been of interest to In Greenberg that in art can be neither nor by or alone in this the so to of Greenberg's view is that is what is Greenberg Kant for how it was to be or in of aesthetic not think one had to know of the kind that art concerns itself with in to be or about art. he that had the possibility of of art that we or art has nothing to do with once that though he about art, he would be able to out the or three in a They need not be by the by which themselves such but that was because they were by that had to do with aesthetic as he understood was to say, in front of a piece of art, beyond an But that in no sense that one was as Greenberg's in philosophy would have having come to the view that aesthetic is That it was, on the is by Greenberg's way of his and them when the work to be was in front of the as if a the had to to by way of was what aesthetic Greenberg's was through his in artistic in at a when there was on the of to abstract art as This would have art on the New at the New and at the New the to on abstract art, because they have not taken the to of it. enough to be able to the from the in abstract art, no one has the to be on this were who to with Greenberg on could I have been using for Greenberg was the New to in the that made The of his of had about it the of a It him as well as great power in the Greenberg and, more Kant was in their to that there is a of aesthetic qualities, that to be recognized when of language touched on the of aesthetics at about the same that Greenberg dominated critical in I have in an of much it is to be we could for a while about the beautiful and to the and the this in his in his for as this out the that we to use the of ordinary language some interesting were made by such as who to that aesthetic were not It would have been interesting to out if this was the for aesthetic as a for if not, what if there are. not in Greenberg's was But aesthetics took a in the decade to the philosophy of art, I am to say, with my “The which was by and to a by the work of and especially of the became the of art, and that has more or less been the for the philosophy of art was interesting was how a aesthetics in that as as the aesthetic in artistic production and in the increasingly art world, in the and but in and finally everywhere that art was to the The artists that were and the and the in work aesthetics was of since the of art had to with the and the in which aesthetic were at there was a question of aesthetics had really to do with art at all. This was a that from the it had that aesthetic pleasure was what art was all I was fairly about the of aesthetics for art. In my main work in the philosophy of art, The of the I with what I thought of as for a of art is about and hence and that an its which is what art I this by calling works of art In my The of I more or less that aesthetics is than had been and if there were not a namely, that to be a work of art, has to have some aesthetic not beauty, say, not I the that art need have any aesthetic at all. I a distinction between and beauty, and, by between and when stands for any aesthetic that may is what I by beauty. The beauty of an is when it to the I several of this from contemporary art, for the and in In a I thought a was the use that made of beauty in painting the of as beautiful in which like a from the The beauty of was like the beauty of and the of the painting was that for the who must the of this by their the beauty is not in a work of art it which means that it in Kant's “free and In my was to from the aesthetic of and an aesthetics of It is at this point that one might that the distinction the of aesthetic to which and the ordinary language aestheticians in the us consider once In is a had just the that the work was When first the of in it was a for was so and and made so much he was to It was simply a world from my it was like a that In a from that on was the of a made of and from a Kantian to an as when he applied as his for the that they have the of aesthetic that they neither pleasure nor to the They were from the of of they were aesthetic from the that was to in the when aesthetic became an aesthetic to the of the and itself a matter of the way had been for one might say, an aesthetic of of the kind out of which Ágnes Eperjesi her art. It is not easy to describe this but it is easy enough to and it is due to the of itself due to the of making the images easy to read and to understand everywhere in the to a an recognized aesthetic in the images of the that Andy used in his first in in the of on They were the kind of that were on in for and like of the It is the aesthetics of by the need to the that would to the product But that aesthetic gets to be to the works made of as the aesthetics of images gets to be to the work Ágnes Eperjesi on of work show their and from this is not the of The of this is that the to the question of aesthetics into the of pluralism is and It is if we are of the aesthetic of and disinterested contemplation. It is if we are of the way in which aesthetic qualities, of them to as by Kant and are to the of works of art as In the of pluralism has to the of aesthetic far far than aesthetics was able to I would say, that of these aesthetic is as as Kant beauty is in the of the but in the way in which sense are in the of the just as they are. in in the he but this in no sense it from as and and all qualities, not in but in the The is the same with beauty and virtue and This however no more from the reality of the than from that of the were to in the would or be less or is a in the and of to all these the objects of art and and to have the on life and taken the matter to this I must some to view on works of art a in a section of the the of the that he his of The Kant of is not the Kant of Kantian which is on the of I it to to show how my are to his in this section of his the of which shows how Kant was the in that the of was from that alone was not the when it to of products of which we that they at least in as beautiful art, they are without we nothing to in them on the of he means of the and this he goes on to say, no than the of It is of Kant that he will a kind of in to for a when the one might say, is really is as it an that has been in the way it was used by it to what is to is is that he has that is to sense and we a through the than a or a or a Kant as an one of the which we are to that Kant is as a sort of the when in the its does that often one by The in the of ones life and without through the image of a beautiful This is a quite commonplace use of and has nothing to do with as Kant to it “The is one through as in irony or in that the in this Kant's is about the course of a as a way of about the course of a It is a beautiful which need have nothing to do with the beauty of the The just after from the visual is as an in its and as a as a with The power of is made through the that is not than can be a being of must have The image us more than is all alone the of power that an to the to itself a of representations that more thought than can be in a determined by It is in regard to the of that Kant of and of as from the of and as in reference to the of the This was much in the in the when he his In for example, a of for the of of which he was at the must have to the of an namely, that there are no in It in from this that we cannot the practice of painting on the of or on any of text with a to the of the to in full without and to use means for them from the that shows them the way to this or that of text a from the that his work to the of his work, but it a about art. art a and is not that can be ideas have nothing much to do with the aesthetics of and they are what is from Greenberg's who of in his of in art. In a which has to natural and beauty, has to do with art, which in was in the in of what were felt to be of classical beauty. is of that in his one these are hardly of ideal beauty. the of but I to for this work, in the de he for a to and is taken to be the of there is no using painting for of a to and to be in any Greenberg would have this as having nothing essential to do with art at all. was a term of critical in Greenberg's and in formalist own view is that the relationship of aesthetics to art was and The of pluralism has nothing in this But the theory of art as the of it how aesthetic can to the of the work that This I am is what when he at the of his on why artistic beauty is to natural beauty. It is because natural beauty is Kant could have since for him natural beauty is a of and us the sense that the world is not to for has a kind of as the has recently in his natural beauty, as in the of the was an to this kind of But its in works is to their beauty as art. One can that without for a that itself is in the of and The works of Andy I of convey they have as aesthetic what belongs to through their They convey the of the and the that for a will be and that and will finally come Ágnes Eperjesi in the in which products are are of the society in which products are used. They are or better, as her a picture of what like a in her may in be the of a of a woman with a in a while gets into my I can of my (Figure even image of a woman with a is into a of and a on for the of Ágenes Eperjesi.

IRS Reddy

Respected chair persons and members of the Indian Psychiatric Society (IPS), I am extremely happy and privileged to be here at the 59th Annual Conference, before an enlightened gathering to preside over the prestigious IPS. It is a rare honour and it shall be my endeavour to prove myself worthy of being chosen for this prestigious and highly coveted honour among the psychiatrists. I know my limitations but I am also aware of the great role that can be played by our society and I make bold to place before you many of my experiences in the field to exhort my fellow psychiatrists that we have a great responsibility ahead. From what I have observed during these years of my active practice, I have no doubt in my mind that the psychiatry as a profession is slowly gaining ground and in the years to come it will play an effective role in disabusing the minds of the public of their wrong and ill conceived notions. I shall endeavour my best with the cooperation and support of all my fellow psychiatrists. There were quite a few topics that I short listed for my presidential address. Finally, I zeroed in on this topic titled “MAKING PSYCHIATRY A HOUSEHOLD WORD” as I feel the art and science of psychiatry has a great deal to offer society apart from treating the “crazy people”. To make that contribution, psychiatrists must continue to tackle society's most pressing problems and also raise the visibility of psychiatry and its perceived relevance to solving a wide range of personal, social and family problems. The image of psychiatry has been tarnished in the eyes of common man, thanks to the battering that the profession has received at the hands of the media, not to mention the apathy of the policy makers. Here is an example to prove my point. At the recently held conference at Jaipur, I was walking outside the convention center when I heard two young women talking to each other. One said to the other: “My God!!!…. He's so weird! He really should see one of those psychiatrists who are walking around here.” “That's it!” I thought. “People think you have to be ‘weird’ to see a psychiatrist.” The public tends to view psychiatrists narrowly, associating us chiefly with our expertise in mental illness. In reality, psychiatrists can promote coping and wellness in addition to diagnosing and treating mental illness. Many people today have significant stress in their lives and we all undergo crises and life-stage transitions as a normal part of life. Psychiatrists can help people assess how they are coping with current stresses and develop new skills and strategies. A lot of people find that their stress levels have increased in this era of wars, terrorism and natural disasters. We, as psychiatrists, could do much more to prevent problems by helping people learn to cope and build their resilience. I wondered what it would take to normalize our public image, that set me thinking and I looked into dentistry, which changed the public image of its profession in the 1980s when it teamed up with Colgate toothpaste in a public education campaign that promoted the idea of the dental check-up. This campaign led to major changes not only in the public image of dentistry but also in the very nature and public impact of dental practice. Dentistry moved from a focus on restorative dentistry to an emphasis on preventive dentistry. We have all witnessed the success of this transition. People no longer wait for a toothache to visit the dentist and employers routinely include preventive examinations and cleanings as a dental benefit. I am envisaging a day when people similarly take appointments for a “psychological check-up” akin to a general health check -up and when that day comes one can rest assured that the community has truly embraced our profession. At these check-ups they could address such matters as their stress level, their relationships, how they are caring for their children and ageing parents and health basics such as diet, nutrition, sleep and exercise. In my 30 years of practising psychiatry, I have had a unique vantage point from which to both observe and reflect on, the process whereby psychiatry responds to urgent societal needs and how these needs thus influence the evolution of psychiatry. As I see it, the scope of psychiatric practice is expanding and diversifying into new areas. In short, the stage is set for the public's as well as policymakers and health care payers' full embrace of our field and for the true integration of psychiatry into health care, Only if we make them aware of our scientific knowledge and professional skills. DISABILITY AND MENTAL ILLNESS The burden of mental illness on health and productivity throughout the world has long been profoundly underestimated. Data developed by the massive Global Burden of Disease study conducted by the World Health Organization, the World Bank and Harvard University, reveal that mental illness, including suicide, accounts for over 15 percent of the burden of disease in established market economies, such as the United States. This is more than the disease burden caused by all cancers.[1] This Global Burden of Disease study developed a single measure to allow comparison of the burden of disease across many different disease conditions by including both death and disability. This measure was called Disability Adjusted Life Years (DALYs). DALYs measure lost years of healthy life regardless of whether the years were lost to premature death or disability. The disability component of this measure is weighted for severity of the disability. For example, disability caused by major depression was found to be equivalent to blindness or paraplegia whereas active psychosis seen in schizophrenia produces disability equal to quadriplegia. The World Health Organization's Global Burden of Disease study reported that mental disorders comprise four of the top five sources of premature death and disability in 15-44 year olds in the Western world. Using the DALYs measure, major depression ranked second only to ischemic heart disease in magnitude of disease burden in established market economies. Schizophrenia, bipolar disorder, obsessive-compulsive disorder, panic disorder and post-traumatic stress disorder also contributed significantly to the total burden of illness attributable to mental disorders. The projections show that with the aging of the world population and the conquest of infectious diseases, psychiatric and neurological conditions could increase their share of the total global disease burden by almost half, from 10.5 percent of the total burden to almost 15 percent in 2020. Major depression is the leading cause of disability (measured by the number of years lived with a disabling condition) worldwide among persons age 5 and older. For women throughout the world as well as those in established market economies, depression is the leading cause of DALYs. In established market economies, schizophrenia and bipolar disorder are also among the top 10 causes of DALYs for women. The above stated facts, hopefully will be an eye-opener for all the concerned parties. From our side, we should do all that we can in whichever small way to reduce this enormous disease burden. My presidential address, I hope, will serve as an initiative to formulate ways and means to achieve this objective. IMPEDIMENTS IN MAKING PSYCHIATRY A HOUSEHOLD WORD There have been a lot of impediments in making psychiatry a household word. The main culprits are the age old concept of mind-body dualism and lack of integration of mental health care into primary health care, stigma, psychiatrists themselves, the apathy of the policy makers, failure of Consultation - Liaison psychiatry and media. I will make an attempt to briefly detail what resulted in these hindrances and some plausible solutions to overcome them. MIND-BODY DUALISM The earlier concepts of health glorifying mind-body dualism are bankrupt now and mind-body dualism has an enormous negative impact on our health care system. Because of it, our health care system does not systematically attend to the many psychological risk factors for both morbidity and mortality and it virtually ignores the psychosocial pathways that lead to unnecessary utilization of medical and surgical services. In addition, the psychological impact of a medical illness is not well by the health care is the that many people from a illness have psychological illness. Finally, the share of mental health problems are by primary care take a at some of the of the top health risk factors are diet, suicide, and of the leading causes of death have significant At as much as of all to primary care medical are for problems with a psychological those who with mental health problems and those who or for problems with a psychological component those with such as those with and those with medical one study found that than of had and A number of have that health care the utilization of medical and surgical The of people mental health are for by medical with in mental is a of the of psychological in a wide range of health including both and disease system and and In addition to being these are than across a wide of and including and that mental health can be in primary health care with and on but it is whether this is true of for persons with and mental illness. There is a long of in for persons with mental disorders that would be a single system of care that to medical and mental health services. Many mental health problems are seen as and thus the general health is a natural point for and treating mental health problems. Many also continue to find care for psychiatric problems more when by their primary care The and mental health care in an system also a that common and mental disorders will be and that and among will reduce and common of of The concept of a number of that are at the of health care them are the and A significant is that not be in a highly system of As medical are to be more and they have to to each and to know the and to the of problems that Because with conditions are and to their and they will not be with disabling mental illness will have to with who more and to deal with by and of these problems has but they are not can be to and with mental but this is a and can be to increase the of health care to disabling illness, but this must with many in an of new and practice by of public and is but effective in this objective. the that mental health for ill can be into the general health a and that are on at for the The is for persons with more and disorders. - A Psychiatrists should have been seen as and as an as they are so few in In are only psychiatrists for a population of over of psychiatrists to the of is which is quite Psychiatrists are seen in negative by the of the have been are seen as disease and not are seen as being seen as are seen as a on the most in the are seen as the to as not in and thus could them of their and being a are seen as making a a to their view are seen as not scientific psychiatrists in and are seen as are seen as only and not the have been up over and mental health of of and of including have contributed to these of by help has matters The of and of view has it from the the of psychiatrists themselves, the to formulate and not the focus from negative to and not our have it We of the of mental and disease in the but are not to prevent We of mental health but do not or we do not have or for mental health at the professional or We of well being and on The and do not have psychiatrists as the but are to our We would be to of and for but not in at the to preventive and health strategies. We can be if we are to The community of which is a part would be to allow us to lead if we have for and which are effective and We would have to hands with and community with to long solutions for the population than at a of only those who have extremely and We to be for the mental health needs of the and not only the for It is only that psychiatrists in and psychiatry in general would its place and a - PSYCHIATRY of the to with are and are for the cooperation and for effective is a on the part of some to the place of factors in the of the This be to and conditions that are to observe and or to is that mental health have long had a for The or at was in the many people the field in to their psychological problems. it and such an are to The that be and the of psychiatric The on of or at in many is with and One by many including psychiatrists, is that a will come in that the has a more disorder than the one and that the is on should the for psychiatric the the moved to this is not an the two care This is to the of if the psychiatric The should that lack expertise outside of and with psychiatrists is a that must be over a of the most here is to make but when called for an This reduce by the and allow to up in the psychiatrists have a for diagnosing as or the that they be to have some psychiatric problems of their The is not as many psychiatrists and mental health in make of fellow them or their A general way to many of these is for the to be in and to the of and medical and should that the is a in which the will have the The of with psychological problems in with should be and not The should not be or or that will be as very by the He should also be aware of the of the and than a take it or it I have found that with when I am by and does not medical the can find ways to make to the medical He should with and take the of these It is also to attend medical The of knowledge of one by psychiatrists and can during before such and can lead to the also the with an to the and of with their and AND MENTAL of people with mental disorders has throughout It is by to or or people with mental disorders such as It to and and to and It the public from and to In its most and in and it people of their and with their full in for in from the mind and by of in the of the mental health system in the United from the of an influence on and in the world. In the the public mental illness as a and an of mental illness. were not to as when with of who would have been said to be ill to the professional of the The public was not at mental illness from and and to see only of mental illness. illness great social stigma, with of and a that had scientific of mental illness. the in knowledge not social in comparison with the the public's of mental illness more This was true among those who mental illness to include psychosis view held by of the The also how of those with mental illness by The public was more to an with schizophrenia as mental illness than an with This people with mental disorders truly more some public but the of is The risk of is from those who have who have a mental disorder as well as a There is a small in risk of from with mental disorders if they are with their the risk of is much for a than for a family or who is to the with mental In is very risk of or to a from with an who has a mental Because the is to whether who is has of these or in the natural is to be to this all in the of mental disorders to the total of in society is Because most people should have to from those with mental illness, in its most is of so focus on and One of found that the public's and mental illness and people to from those with mental disorders. of the common with from psychiatric disorders are listed of mental illness of of It is not that psychiatry has a in its to mental illness, but that it has also to address its current of the psychiatry in their There is a of psychiatric on and and a to the are some in psychiatry, which are in minds and a great deal to the in psychiatry. A IN PSYCHIATRY and of and and for and help for mental disorders of all people with mental disorders do not the of mental health is among the many that people from to be in in to or and for mental disorder of is in the public's to for mental health services. to for mental health or has been public held in of the public a to for for with mental such as schizophrenia and than for conditions such as and the public to support for its support the that or would be In the of the to for mental illness is to be The public for mental disorders that for There is no or single to the with mental illness. was to with increased knowledge of mental illness, but the in some ways over the years of mental illness by to knowledge be to public is to that negative mental illness can be by on the and mental to of public education and with persons with mental illness and societal way to is to find causes and effective for mental disorders. this to be of and to are of mental disorders for which has The of an infectious and of led to the of when was to a and with was the was in the developed world. with had been in mental in the before its was no one has the of public these conditions over the and of this disease of its these also a more that the mental health field was when causes and were As were each was from the mental health field to medical For over of was moved to and in and over mental disorders was moved to The of this to is that mental health field over the years the for mental disorders was This the mental health field to by their medical that psychiatry was not part of and that psychiatric practice on and that for disorders them or the mental disorders not only but be by to mental health care only those conditions causes or To point this is not to that in mental health should be should be and The here is to some of the of the the general health and mental health that will continue to effective for mental disorders to be an effective people that mental disorders are not the of or will but are that are to much of the negative to to to be developed and science has much to to the and of As a in public should People should to should more to its most they should more to the that are the of this mental health and mental illness are part of the of health and they are a for all to would be the of the to who to mental illness regardless of from the of has been a in the success of on and AND MENTAL and medical profession have been in in the media. psychiatry and psychiatrists have not been so than the profession has been by media. illness has been the for and which the in the minds of the public mental illness and the the old some of the have psychiatry in extremely Psychiatrists are as who and for the most are not in their of mental illness. as as if is not in the minds of The is not in its of psychiatry and psychiatrists. I an by the which in the on the the no longer as a the Indian Psychiatric to do of that and it a measure of the of the profession of psychiatry in if you to a This of will the most from of psychiatric have been some of mental illness, the and both of which have been into the It is to that these have been well and psychiatrists are in a of will well for the mental health profession and for psychiatrists as a There are no to tackle this It is for all of as psychiatrists, to a to this It is our responsibility to more in the mental illness. For we should no as the of this can be of you must have seen in the and for public health causes you seen psychiatry in which I think of a when mental illness and the impact that will have on the common I feel that is a and we in are some to that I all members of to the and come more with a and the psychiatry and do all that you can to the image of psychiatry, which is for the public to embrace our IN PSYCHIATRY In this I would briefly some of the success in the field of mental The that come to my mind are the by the psychiatrists in the of the The has a lot of for psychiatry and psychiatrists. This is significant as this of will a long way in making the public more and in psychiatry. The by psychiatrists during the and and the so called in the Indian of and is a in point. a long way in the with the policy and the public I also the of and that is on in the and I also the of all the psychiatrists who have in the community mental illness and to the PSYCHIATRY IN must a with a as its more than psychiatry at the of a of has such a of as psychiatry This of both and is our and we must not up one for the of the other. health must more for Indian and psychiatry do not develop in a but they develop in a social psychiatric of and and to are all on This is not a very for a with its no has the of the and the of mental the way we have in we continue to concepts and these are in our We to on these and a truly to mental from such an will more with ground in of is its and psychological well being of the community for a and of the and we as mental health should that MENTAL I of this has a to a and an which to an of and family community and care or or in the that of mental health care with primary health care into the and of mental illness and into the of and effective and overcome the with mental illness public and Health to effective must be the for people with mental illness as for medical to mental health care should be across including the and to be with and should be to and to an of psychiatrists, to the current and needs of the population I psychiatry as my profession with a lot of and I am very happy I do feel to the way in which psychiatrists are in the society A day should come when we should be to that am a and in are psychiatrists and are psychiatry. This will if we to offer solutions to a wide range of personal, family and pressing social in and and the of in some of our role in We should make the that their health the to their should be on long solutions for the population than at a of only those who are extremely and We should make the community what we are is what our minds are the which the To this the with a the is a the mind is so to it is that we it to the is the medical profession to the with such emphasis on the In this who the of by in the is by and has to a to at the of the mind and all that it has I a day not in when people make appointments for general health check We to be for the mental health needs of the community and not only the for In these of I would to the the that you to see in the we play our role as psychiatrists, I a when psychiatry in general and psychiatrists in would their place and a household word. My to all of you is that each one of you needs to in this of a household one and all IPS.

Gerald V. Post

The current political climate has almost ruled out the use of Internet voting.Many politicians, led by vocal computer scientists, are pushing for voter verified paper receipts; which is likely to push us even further away from even electronic voting systems.On the other hand, cryptographers have created homomorphic encryption and non-interactive zero-knowledge proofs with features that can support Internet voting.Adding a few more protocols, including an extended voting period and repeat voting can solve the remaining problems need to make Internet voting at least as secure as existing systems.

Amitabh Saxena

In this paper, we study the opacity property of verifiably encrypted signatures (VES) of Boneh et al. (proposed in Eurocrypt 2003). Informally, opacity implies that although some given aggregate signatures can verified, no useful information about the individual signatures is leaked. However, the very fact that an aggregate signature can be verified leaks certain information- that the individual signature is indeed well-formed. Apart from this, is there any other information leaked? In this paper, we show that there is absolutely no other information leaked about the individual signatures when the aggregation contains only two signatures. In more formal terms, we show that VES are Zero-Knowledge (ZK). We then extend the ZK property of VES to propose efficient Additive Non-Interactive Witness-Indistinguishable (A-NIWI) proofs. Intuitively an A-NIWI proof can be considered as a Proof of Knowledge (PoK) of another A-NIWI proof. 1

José Cláudio do Nascimento, Rubens Viana Ramos

Zero-knowledge proof system is an important protocol that can be used as a basic block for construction of other more complex cryptographic protocols. An intrinsic characteristic of a zero-knowledge systems is the assumption that is impossible for the verifier to show to a third part that he has interacted with the prover. However, it has been shown that using quantum correlations the impossibility of transferring proofs can be successfully attacked. In this work we show two new protocols for proof transference, being the first one based on teleportation and the second one without using entangled states.

Shien Jin Ong, Salil Vadhan

No abstract is available for this record.

Ivan Damgård, Rune Thorbek

We present two universally composable and practical protocols by which a dealer can, verifiably and non-interactively, secret-share an integer among a set of players. Moreover, at small extra cost and using a distributed verifier proof, it can be shown in zero-knowledge that three shared integers a, b, c satisfy ab = c. This implies by known reductions non-interactive zero-knowledge proofs that a shared integer is in a given interval, or that one secret integer is larger than another. Such primitives are useful, e.g., for supplying inputs to a multiparty computation protocol, such as an auction or an election. The protocols use various set-up assumptions, but do not require the random oracle model.

Yehuda Lindell, Benny Pinkas

Abstract. We show an efficient secure two-party protocol, based on Yao’s construction, which provides security against malicious adversaries. Yao’s original protocol is only secure in the presence of semi-honest adversaries. Security against malicious adversaries can be obtained by applying the compiler of Goldreich, Micali and Wigderson (the “GMW compiler”). However, this approach does not seem to be very practical as it requires using generic zero-knowledge proofs. Our construction is based on applying cut-and-choose techniques to the original circuit and inputs. Security is proved according to the ideal/real simulation paradigm, and the proof is in the standard model (with no random oracle model or common reference string assumptions). The resulting protocol is computationally efficient: the only usage of asymmetric cryptography is for running O(1) oblivious transfers for each input bit (or for each bit of a statistical security parameter, whichever is larger). Our protocol combines techniques from folklore (like cut-and-choose) along with new techniques for efficiently proving consistency of inputs. We remark that a naive implementation of the cut-and-choose technique with Yao’s protocol does not yield a secure protocol. This is the first paper to show how to properly implement these techniques, and to provide a full proof of security. Our protocol can also be interpreted as a constant-round black-box reduction of secure two-party com-putation to oblivious transfer and perfectly-hiding commitments, or a black-box reduction of secure two-party computation to oblivious transfer alone, with a number of rounds which is linear in a sta-tistical security parameter. These two reductions are comparable to Kilian’s reduction, which uses OT alone but incurs a number of rounds which is linear in the depth of the circuit [18]. 1

Ivan Damgård, Jesper Buus Nielsen, Daniel Wichs

We introduce a new notion called `-isolated proofs of knowledge (`-IPoK). These are proofs of knowledge where a cheating prover is allowed to exchange up to ` bits of communication with some external adversarial environment during the run of the proof. Without any additional setup assumptions, no witness hiding protocol can be an `-IPoK for unbounded values of `. However, for any pre-defined threshold `, and any relation in NP and we construct an `-IPoK protocol for that relation. The resulting protocols are zero knowledge (ZK) in the standard sense, i.e., w.r.t. a verifier that communicates only with the prover during the proof. The cost of having a large threshold ` is a large communication complexity of the constructed protocol. We analyze these costs and present a solution that is asymptotically optimal. If a cheating verifier is allowed to communicate arbitrarily with an external environment, it is not possible to construct an `-IPoK that is also ZK with respect to such a verifier. As another new notion, we define `-isolated zero knowledge (`-IZK) where the verifier is `-isolated. For every relation in NP and every `, we construct an `-IPoK protocol that is also `-IZK. We describe several applications of `-IPoK protocols under the physical assumption that one can `isolate a prover for the duration of the proof phase. Firstly, we can use a witness indistinguishable (WI) `-IPoK to prevent “man-in-the-middle” attacks on identification schemes. Prior results for this scenario required all verifiers to register keys under a PKI, or the ability to fully isolate the prover. Secondly, a partially isolated prover can register a public key and use a WI `-IPoK to prove knowledge of the corresponding secret key to another party acting as a verifier. This allows us to set up a PKI where the key registrant does not need to trust the Certificate Authority. The PKI is not perfect since the proof is only witness indistinguishable and not zero knowledge. In a companion paper, we show how to set up such a PKI and use it to implement arbitrary multiparty computation securely in the UC framework without relying on any trusted third parties.

Mole

Okay, kids, you can come back in; Uncle Mole is in a better mood now. If you're just joining us, you should know that I was in a very foul temper, because I'd only just found out that a prominent scientist, whose work I'd valued, had been exposed as a fake. His lovely work wasn't simply flawed, it was made up. My whole faith in science has been shaken, and I want to fix it. Instead, I've watched TV.I've just seen one of my favorite episodes of the old Twilight Zone. In `It's a Good Life' we meet a mind-reading, omnipotent monster who is terrorizing a small town. The monster is a six-year-old body played by Billy Muni, who would later gain quasi-immortality as the youngest member of the Robinson family on Lost in Space (as in, `Danger, Will Robinson!'). But in this Twilight Zone story by Jerome Bixby, he is a small boy who can do anything, and when he is displeased, he can transform townspeople into horrors, or make them disappear altogether, by `sending them to the cornfield'. So I imagined doing this to our scientific fraud, and I felt better. Maybe this wasn't the point of the story, but it made me feel better.The problem of scientific fraud isn't new, but it seems as though our efforts to eradicate it have not worked. We get tougher, but the fakers just get better at faking. Perhaps we need to further tighten security - remove your shoes and laptops prior to submission...There are two views of this problem, and the one we take will dictate what we should do. The `tip of the iceberg' position says that the fraud that has been exposed represents only the tiniest bit of a problem that is rotting science from the inside. Some have advocated a zero-tolerance policy, and have taken it on themselves to act, vigilante fashion, to publicize any discrepancies they find in publications, demanding satisfaction. The standard operating procedure here seems to be to contact the journal and the community, via emails for example, intimating that every questionable figure is evidence of fakery - mistakes cannot be tolerated. I know of one investigator who is being hounded to explain two identical images in a paper, which he asserts is a post-proof printing error (and was immediately corrected) but he can't prove it. But the vigilantes contend that zero tolerance demands that everyone subject themselves to a `trust no-one' process in the hope that we'll weed out the worst offenders.Don't get me wrong, I do think that there is a lot of fudging in the literature. My old Oxford English Dictionary defines fudge in this context as “to fit together or adjust in a clumsy, makeshift or dishonest manner”. (The most romantic etiology traces this to one Captain Fudge, c1664, a.k.a. Lying Fudge, who was probably a real person, although he may have made himself up.) In science, fudging data can be elimination of compelling results that don't fit the hypothesis (which may be for perfectly valid reasons or not) or adjusting the results, say, when molecular weight markers seem off. It occurs because researchers are under tremendous pressure to publish on a timetable - the need to publish any work that has used up time and resources, however questionable the conclusions. Journals promote this problem by demanding additional results that are conditions for publication, usually on even shorter timetables. Fudging seems inevitable. I am not forgiving it; I'm only saying why I think it happens. But when it goes too far it becomes fakery, and it is unforgivable. The tip of the iceberg view is that much of what we see is not simply fudged; it is faked.The alternative view, to which I subscribe, is that true fraud is exceedingly rare. Mistakes, misinter - pretations, and wishful thinking are more common - and problematic - but I think we can deal with them. But outright fabrication is rare enough to be news.Can I prove this second view? No. But I can demonstrate that it is a useful and profitable position to take. And the demonstration points to a route to the solution, not only for fraud, but also for errors and other problems.Unless you live in a cave and, for that matter, a cave without an internet connection, you know about eBay, the massively successful online auction system. Anyone can buy or sell anything on eBay (including, apparently, fabulously expensive grilled-cheese sandwiches) and can do so with a remarkable level of confidence. It is based on a seemingly naive, but ultimately profound, precept: most people are honest. This is backed up by a readily accessible rating system, where buyers and sellers provide feedback on their transactions, thereby exposing problems if and when they arise. The system is largely transparent: those who lie are quickly flamed, and anyone who gives inordinate numbers of negative comments is discredited. It is freewheeling, but for the most part it is wildly successful.Once, when science was conducted by an elite, feedback occurred in the literature and at meetings. This still happens, but in a manner that is difficult to assess unless one is in the center of the action (again, one of the elite). High-impact journals have no interest in publishing work that refutes other work, regardless of the rigor of the refutation, and the group psychology among researchers translates this into `high impact = true, low impact = less true'. Even when we think that everyone knows that a particular finding is flawed, one only has to take a stroll into a related but different venue, such as the department upstairs, to find that others who might be peripheral to the field can evince surprise at our suspicions. We need a feedback system that everyone can access.I propose that we take a cue from eBay. Link a system to PubMed, for example, by which we can identify a paper and offer feedback (“we repeated this finding, but couldn't reproduce that one” or “this result may be an artifact for the following reasons”). It must be transparent - commentators are registered and their identities known, and we can similarly access their other reviews. Vigilantes who only find fault will find their comments of less value than those from reviewers who are balanced in their views. And, of course, the authors will be able to respond to criticism if it is especially important. We will have a way to evaluate the experiences of the community, far beyond a paper's `impact', which is more likely to reflect the extent to which a finding is easy to mention. I think we'll gain confidence in the literature, we'll expose fudges, and we'll find very little fraud.For this to work, however, we need a fundamental change in the community of scientists. We need to realize that making mistakes is common and that honesty requires that errors be owned up to. We need to reward, not punish, those individuals who can say that they got it wrong. It happens all the time, and we pretend it doesn't, and, as a consequence, the fudging goes on. We can make it stop, but only if we take away the pressure not to admit to it.But what of the real monsters who are out there? The ones who simply make it up? Such allegations are serious and must be dealt with by informed investigation, as we do now, and evidence of genuine misconduct must come from close to home (fellow researchers with intimate knowledge of the lab and methods). We can deal with this, and only open such investigations when the evidence is overwhelming. But why do they do it, this outright fakery that is so antithetical to the entire process of scientific inquiry? I think I know, because I've just been watching the Twilight Zone.The monster in `It's a Good Life' can do anything, knows everything and, because he is only a child, has no goals but his own desires. He understands only that whatever he wants to happen, happens. When a bright, young, and very ambitious scientist begins his or her career, one of two things occur early on. They can chance on a set of ideas that happen to be correct, and their experiments flow effortlessly towards a happy conclusion. And if this is an important conclusion, rewards come quickly. Or, alternatively, they can be wrong, and they learn at this formative stage that no matter how wonderful an idea may be, and how much they need it to be true, it can still be wrong. This is an extremely important lesson that our first, lucky researcher may not learn, unless, of course, we teach them. The successful student guesses again, and again may be right - more rewards. By the time they come up against something that they cherish that turns out to be mistaken, they may have already become our monster-their idea, their need to be right, exceeds all other goals. It doesn't happen all at once - but someone who is always right begins to believe that they are special, and does not realize that luck is a major factor in all of this. So they make it right. They have made the leap to quasi-omnipotence. I once met a monster like this, and it was truly frightening.'It's a Good Life' was remade, years later, as a vignette in The Twilight Zone Movie. In the rewritten work, the ending was changed: a teacher takes on the task of educating the monster/child, who is desperate for guidance. And this, of course, is what we need to do with our most gifted, lucky young scientists. We have to teach them that ideas are frequently wrong, and this is fundamental to science. And we have to stop stressing that being right brings rewards, while being wrong brings despair. Let's stop giving awards for best poster, best thesis, best student. Science is a reward. We don't need more monsters. Let them be wrong sometimes.Otherwise, I'll want to send you to the cornfield.

Marc Girault, Guillaume Poupard, Jacques Stern

No abstract is available for this record.

Mehmet Tahir Sandıkkaya, Bülent Örencik

Many electronic voting systems, classified mainly as homomorphic cryptography based, mix-net based and blind signature based, appear after the eighties when zero knowledge proofs were introduced. The common ground for all these three systems is that none of them works without real time cryptologic calculations that should be held on a server. As far as known, the agent-based approach has not been used in a secure electronic voting system. In this study, an agent-based electronic voting schema, which does not contain real time calculations on the server side, is proposed. Conventional cryptologic methods are used in the proposed schema and some of the requirements of an electronic voting system are constructed within the schema. The schema seems quite secure if the used cryptologic methods and agents are secure. In this paper, proposed schema will be explained and compared with already known electronic voting systems.

Authors unavailable

The past decade has been a period of introspection in the radiological protection community. The International Commission on Radiological Protection (ICRP) has set out to produce a new set of recommendations; a draft document has been produced and made available on the ICRP web site. That draft has been widely reviewed and support for the proposed recommendations has been muted to say the least [1]. A subsequent draft is now being reviewed. As we wait for the final version it seems worthwhile to reaffirm the fundamental base for radiological protection as we practise it. The base is the set of three principles; justification, protection of the individual, and optimization of protection (the ALARA principle). Their importance seemed to be lost in the detail of the initial draft recommendations. I feel that without a clear statement of their primacy in the protection system we are in danger of the minutiae of the recommendations being applied in a far too arbitrary and restrictive way. There was a hint of this in the draft ICRP document on optimization that was available for review earlier this summer, in which it was argued that the so-called precautionary principle had been the driver for the evolution of the ICRP's thinking [2]. Some argue, correctly I believe, that this is not really a principle; it is more a poorly-defined and open-ended method of handling or reacting to uncertainties in our knowledge of risk. We see the precautionary principle rather loosely invoked in some risk management decisions as justifying arbitrary safety factors. `Applying the precautionary principle' sounds more substantial and scientific than just saying `to be on the safe side'. The influence of the principle is far more widespread though. The idea behind the precautionary principle originated in Germany in the 1960s but it was not until 1982 that it was endorsed internationally when the UN included it in the World Charter for Nature. It gained prominence in European treaties and was advocated by the UN Rio Declaration on Environment and Development in 1992. Initially the idea was that `uncertainty does not justify inaction'. The idea evolved and precaution began to take the place of science-based risk assessment and management. By the late 1990s the idea was that uncertainty also required shifting the burden and standard of proof [3]. The principle became `When an activity raises threats of harm to human health or the environment, precautionary measures should be taken even if some cause and effect relationships are not fully established scientifically. In this context, the proponent of an activity, rather than the public, should bear the burden of proof.' [4,5] In other words, uncertain risk requires forbidding the potentially risky activity until the proponent of the activity demonstrates that it poses no (or acceptable) risk. We are all aware of the impossibility of proving a zero but this wording may sound reasonable provided that the parenthetic `or acceptable' is the operative qualifier. For many though, it is not. Adams has described what he calls the {\it environmentalist paradigm}, in which possibility replaces probability as a criterion for protection regulation, and any agent harmful at high doses is considered harmful at exceedingly low doses [6]. Only zero risk is then acceptable when the precautionary principle is applied. This is a stultifying situation. Morris comments, in a broad-ranging critique, that the precautionary principle not only lacks any clear guidance on when and how it does apply, but perhaps more importantly it is devoid of any limitations of when it does apply [7]. Without such limitations, he notes, the precautionary principle will be a vacuum that can consume any and all products and technologies, since some risk and uncertainty is associated with every human activity. We could conclude that in radiological protection we would have no optimizing; no applying the ALARA principle. Radiation regulations based on the three fundamental ICRP principles have achieved an acceptable level of protection for decades. We should not abandon them to the arbitrariness of the precautionary principle when we have a sound basis for radiological protection in the clearly-enunciated principles of justification, individual dose limitation and optimization of protection. Radiological protection based on these principles includes elements of precaution. Why do we need a precautionary principle? This has been indirectly answered by asking: What if we were to apply the precautionary principle to itself? Its application carries the burden of untold risks and uncertainties. Thus, by its own definition, it should be abandoned [4]. This is not to argue that we should throw caution to the wind. The key is reasonableness. As Nilsson points out, though it is certainly better to be safe than sorry, it is important to distinguish unjustified precautionary action from justifiable precautionary action based on sound science and an appropriate assessment of the costs and benefits of taking action [8]. The precautionary principle fails to distinguish between the two, by elevating to the status of universal `principle' a notion that is only narrowly applicable. In Canada we are fortunate that we have sensible wording in the Federal Nuclear Safety and Control Act that provides the framework for many of the radiological protection regulations in Canada [9]. Part of its stated purpose is the limitation, to a reasonable level , of the risks to the health and safety of persons and the environment. The ICRP principle of dose limitation and the ALARA principle are coherent with this. Further, the Federal Government's Privy Council Office (PCO) has published guidance for its agencies on the application of precaution in science-based decision-making that reinforces the approach we have been taking in radiological protection and, in particular, emphasizes the importance of what is in essence the ALARA principle [10]. It notes that sound scientific information and its evaluation must be the basis for applying precaution. Peer review represents a concrete test for the practical application of precaution to decision making. A peer-review process can assess the soundness of the scientific evidence and its inherent credibility within the scientific community. Scientific advisors should give weight to peer-reviewed science and aim at sound and reasonable evidence on which to base their judgments. Moreover, the science function can be further supplemented by formal, structured and, where warranted, independent advisory processes that include widely recognized and credible individuals. I believe we can heartily subscribe to this. The guidance document lays out five principles that should guide the application of precautionary measures. They should be: Subject to reconsideration, on the basis of the evolution of science, technology and society's chosen level of protection. Proportional to the potential severity of the risk being addressed and to society's chosen level of protection. Non-discriminatory and consistent with measures taken in similar circumstances. Cost-effective, with the goal of generating an overall net benefit for society at least cost, and efficiency in the choice of measures. Finally, where more than one option reasonably meets the above characteristics, then the least trade-restrictive measure should be applied. We can see all three radiological protection principles reflected in this guidance. Particularly important is the emphasis on the link to scientific knowledge, rather than the whims of activist groups, together with the exhortation to assess the real and potential impacts of making a precautionary decision (whether to act or not to act), including social, economic and other relevant factors and risk-risk trade-offs. Apply the ALARA principle in other words. The guidance concludes with the expectation that Canadian agency officials will consider its guiding principles in decision-making and will work together in developing, in consultation with their stakeholders, guidance for the application of precaution in t

Rahul Jain, Alexandra Kolla, Gatis Midrijānis, Ben W. Reichardt

Let L be a language decided by a constant-round quantum Arthur-Merlin (QAM)\nprotocol with negligible soundness error and all but possibly the last message\nbeing classical. We prove that if this protocol is zero knowledge with a\nblack-box, quantum simulator S, then L in BQP. Our result also applies to any\nlanguage having a three-round quantum interactive proof (QIP), with all but\npossibly the last message being classical, with negligible soundness error and\na black-box quantum simulator.\n These results in particular make it unlikely that certain protocols can be\ncomposed in parallel in order to reduce soundness error, while maintaining zero\nknowledge with a black-box quantum simulator. They generalize analogous\nclassical results of Goldreich and Krawczyk (1990).\n Our proof goes via a reduction to quantum black-box search. We show that the\nexistence of a black-box quantum simulator for such protocols when L notin BQP\nwould imply an impossibly-good quantum search algorithm.\n

Patrick McLaren, R Paul Beveridge

The following provides a review, discussion, and description of how sediment transport pathways are obtained. It excludes the details of the mathematical proof, demonstrating the changes in grain size distributions that occur with transport as contained in McLaren and Bowles (1985). Sediment trend analysis (STA) requires for its data the grain size distributions of sediments collected on regular grid spacing over the aquatic site of interest. The sampled sediments are described in statistical terms (by the moment measures of mean, sorting, and skewness), and the basic underlying assumption is that processes causing sediment transport will affect the statistics of the sediments in a predictable way. For this purpose, a grain size distribution defines for any size class the probability of the sediment being found in that size class. Size classes are defined in terms of the well-known ϕ (phi) unit, where d is the effective diameter (diameter of the sphere with equivalent volume) of the grain in millimeters. Given that the grain size distribution g(s), where s is the grain size in phi units, is a probability distribution, then In practice, grain size distributions do not extend over the full range of s and are not continuous functions of s. Instead, discretized versions of g(s) with estimates of g(s) in finitesized bins of 0.5ϕ widths are used. Selection of the bin width is largely empirically derived. An increase in width can result in losing information contained in the distribution, whereas a decrease in width can produce an increasingly noisy distribution (a discussion of this dilemma is found in Bowles and McLaren [1985]). Three parameters related to the first 3 central moments of the grain size distribution are of fundamental importance in STA. They are defined here, both for a continuous g(s) and for its discretized approximation with N size classes. The 1st parameter is the mean grain size (m), defined as The 2nd parameter is sorting (s), which is equivalent to the variance of the distribution, defined as Finally, the coefficient of skewness (k) is defined as With the removal of r(s) from g(s), the remaining sediment (a lag) has a new distribution denoted by l(s) (Figure A1) where The function t(s) is defined as a sediment transfer function and is described in exactly the same manner as a grain size probability function except that it is not normalized. It can be thought of as a function that incorporates all sedimentary and dynamic processes that result in initial movement and transport of particular grain sizes. Data from flume experiments show that distributions of transfer functions change from having a high negative skewness to being nearly symmetrical (although still negatively skewed) as the energy of the eroding/transporting process increases. These 2 extremes in the shape of t(s) are termed low-energy and high-energy transfer functions, respectively (Figure A2). The shape of t(s) is also dependent not only on changing energy levels of the process involved in erosion and transport, but also on the initial distribution of the original bed material, g(s) (Figure A1). The coarser g(s) is, the less likely it is to be acted on by a high-energy transfer function. Conversely, the finer g(s) is, the easier it becomes for a high-energy transfer function to operate on it. In other words, the same process can be represented by a high-energy transfer function when acting on fine sediments and by a low-energy transfer function when acting on coarse sediments. The terms high and low energy are, therefore, relative to the distribution of g(s) rather than to the actual process responsible for erosion and transport. Sediment transport model to develop a lag deposit (see the text for a definition of terms). That t(s) appears to be mainly a negatively skewed function results in r(s), the sediment in transport, always becoming finer and more negatively skewed than g(s). The function 1 — t(s) (Figure A1) is, therefore, positively skewed, with the result that l(s), the lag remaining after r(s) has been removed, will always be coarser and more positively skewed than the original source sediment. McLaren and Bowles (1985) provide the mathematical proof for these statements. If t(s) is applied to g(s) many times (i.e., n times, where n is large), then the variance of both g(s) and l(s) will approach zero (i.e., sorting will become better). Depending on the initial distribution of g(s), it is mathematically possible for variance to become greater before eventually decreasing. In reality, an increase in variance in the direction of transport is rarely observed. Given 2 sediments whose distributions are, d1(s) and d2(s), and d2(s) is coarser, better sorted, and more positively skewed than d1(s), it might be possible to infer that d2(s) is a lag of d1(s) and that the 2 distributions were originally the same (Table A1, case A). Consider a sequence of deposits d1(s), d2(s), d3(s), … dn(s) that follows the direction of net sediment transport (Figure A3). Each deposit is derived from its corresponding sediment in transport according to the 3-box model shown in Figure A1. Each dn(s) can be considered a lag of each rn(s). Thus, dn(s) will be coarser, better sorted, and more positively skewed than rn(s). Similarly, each rn(s) is acted on by its corresponding tn(s), with the result that the sediment in transport becomes progressively finer, better sorted, and more negatively skewed. Any 2 sequential deposits (e.g., d1[s] and d2[s]) can be related to each other by a function X(s) (Eqn. 9). As illustrated in Figure A3, d2(s) can also be related to d1(s) by The function X(s) combines the effects of 2 transfer functions, t1(s) and t2(s) (Eqn. 10b). It could also be considered a transfer function in that it provides the statistical relationship between the 2 deposits and it incorporates all of the processes responsible for sediment erosion, transport, and deposition. The distribution of deposit d2(s) will, therefore, change relative to d1(s) according to the shape of X(s), which in turn is derived from the combination of t1(s) and t2(s) as expressed in Equation 10b. It is important to note that X(s) can be derived from the distributions of the deposits d1(s) and d2(s) (Eqn. 10a), and it provides the relative probability of any particular sized grain being eroded from d1, transported, and deposited at d2. With the use of empirically derived t(s) functions, it can be shown that when the energy level of the transporting process decreases in the direction of transport (i.e., t2[si] < t1[si]) and both are low-energy functions, then X(s) is always a negatively skewed distribution (Figure A4). This will result in d2(s) becoming finer, better sorted, and more negatively skewed than d1(s). Therefore, given 2 sediments (d1 and d2), where d2(s) is finer, better sorted, and more negatively skewed than d1(s), it might be possible to infer that the direction of sediment transport is from d1 to d2 (Table A1). Diagram showing the extremes in the shape of transfer functions t(s). In the event that t1(s) is a high-energy function and t2(si) > t1(si) (i.e., energy is decreasing in the direction of transport), the result of Equation 10b will produce a positively skewed X(s) distribution (Figure A4). Therefore, d2(s) will become coarser, better sorted, and more positively skewed than d1(s) in the direction of transport. When these changes occur between 2 deposits, it might be possible to infer that the direction of transport is from d1 to d2 (Table A1). Sediment coarsening along a transport path will be limited by the ability of t1(s) to remain a high-energy function. As the deposits become coarser, it will be less and less likely that the transport processes will maintain high-energy characteristics. With coarsening, the transfer function will eventually revert to its low-energy shape (Figure A2), with the result that the sediment must become finer again. Cases A and C produce identical grain size changes between d1 and d2 (Table A1). Generally, however, the geological interpretation of the environments being sampled will differentiate between the 2 cases. The above model indicates that grain size distributions of sedimentary deposits will change in the direction of net sediment transport according to either case B or case C (Table A1 and Figure A5). Thus, if any 2 samples (d1 and d2) are compared sequentially (i.e., at 2 locations within a sedimentary facies) and their distributions are found to change in the described manner, the direction of net sediment transport can be inferred. Sediment transport model relating deposits in the direction of transport. Summary diagram of t1 and t2 and corresponding X distribution (Eqn. 10b) for cases B and C (Table A1). Changes in grain size descriptors along transport paths. In reality, perfect sequential changes along a transport path as determined by the model and summarized in Figure A5 are rarely observed. This is because of a variety of uncertainties that can be introduced in sampling, in the analytical technique to obtain grain size distributions, in the assumptions of the transport model, and in the statistics used in describing the grain size distributions. These uncertainties are discussed in further detail (see Uncertainties section). One approach that appears to be successful in minimizing uncertainty is a simple statistical method whereby the case (Table A1) is determined among all possible sample pairs contained in a specified sequence. Given a sequence of n samples, (n2 - n)/2 directionally orientated pairs can exhibit a transport trend in one direction and an equal number of pairs in the opposite direction. When any 2 samples are compared with respect to their distributions, the mean can become finer (F) or coarser (C), the sorting can become better (B) or poorer (P), and the skewness can become more positive (+) or more negative (-). These 3 parameters provide 8 possible combinations (Table A2). In STA, if it is postulated that a certain relationship exists among the set of n samples and that this relationship is evidenced by particular changes in sediment size descriptors between pairs of samples, then the number of pairs for which the trend relationship occurs should exceed the number of pairs that would be expected to occur at random by a sufficient amount to state confidently that the trend relationship exists. Suppose that the probability of any trend existing between any pair of samples, if the trend relationships were established randomly, is p. Since there are 8 possible trend relationships among 3 sediment descriptors, and it is assumed that each of these is equally likely to occur, the p value is set to 0.125. To determine whether the number of occurrences of a particular case exceeding the random probability of 0.125, the following 2 hypotheses are tested: H0: p > 0.125 with no preferred direction H1: p < 0.125 and transport occurs in the preferred direction. The Z statistic is considered valid for N < 30 (i.e., a large sample). Thus, for this application, a suite of 8 or 9 samples is the minimum required to evaluate a transport direction. To assess the validity of any transport line, we use the Z score and an additional statistic, the linear correlation coefficient R2, defined as The value of R2 can range from 0 to 1. The definition of R2 is based on the use of a model to relate a dependent parameter y to 1 or more independent parameters (x1, x2, …). In this case, the model used is linear, which can be written as The data (y, x1, x2) are grain size distribution statistics, and the parameters (a0, a1, a2) are from the data with a The dependent parameter is defined as the and the independent parameters are the mean size and the An assumption is that distributions from samples along a transport if in in Figure would to be along a The of the line, which are the would on the of transport or there is no to a linear relationship among the 3 descriptors, there is also no any other of according to the of the relationship for the not to be except from a in of R2 with a high value of the Z score provide in the validity of the transport A low R2 can occur, when the Z score statistic is the of the of many sediment trend from many it appears that low R2 can result when sediments on an assumed transport path are, in reality, from and valid trend statistics the sediments are from a but the sequence is only a approximation of the actual transport and sediments been introduced the transport as in the case of R2, therefore, is and can provide information on the sediment transport The Z score and R2 statistics for each of the sample (Figure used to determine the sediment transport in the are in The McLaren and Bowles (1985) model requires that the grain size distributions of the sampled sediments be described in statistical terms (by the moment measures of mean, sorting, and The basic underlying assumption is that sequential deposits following the of net sediment transport will affect the statistics of the size distributions of the sediments in a predictable way. from this the size distributions of the sediments provide the data with which to for of net sediment transport. in the transport method is used to requires a model of the sediment transport The model is based on the assumption that are more than (i.e., the probability of transport, on a phi as grain size this it can be shown that erosion and of sediments will change the moments of their size distributions in a predictable in the direction of transport. as in transfer functions from sediment data in flume this assumption might not always be the transfer function over only a of the grain before to contained within the assumption is a further assumption that the probability of transport of 1 particular grain size must be independent of the transport of other grain sizes. as whereby the of can the transport of an increase in the of the finer or a decrease in the ability of the process to additional with all that the transport process is a function related to the sediment distribution and the of the erosion Thus, the of the the that the probability of transport must increase over a large range of in the deposits to produce the As and the technique to determine net transport pathways in a variety of and environments has been empirically the use of that an assumption be size distribution of a particular can be the result of sediment from and at It is assumed that is sampled is the of all the sediment derived from an number of The transport direction might not to that for a with a transport In STA, it is assumed that a sample provides a of a sediment facies) with no the to which the sample any that the sample in the for a of many Each might a particular transport and event at a might be from that of the transport as a The can be determined by the in a that a sufficient number of are the sample to the assumption that the sample an of the The distribution of all the the can be compared with a sample on the To provide d1 might be a sample an over whereas d2 of deposition. The trend analysis whether a possible sediment transport relationship or between the 2 deposits exists. might be to transport With between sample locations an of sediments by transport. in further detail in the indicates that to a continuous with samples, the must be sampled at the contained in the This would that for STA, sample could only transport over a in the of or over less than would as or could transport pathways the process of In practice, of a sample spacing must the number of environments likely to affect the the of the sediment and the shape and of the and samples will be by random These can in the the effects of and a sediment and random Sediment trend analysis is, in many to In the information is to a where a is that both the information as as The must be of the information from the noisy In sedimentary the information is the transport direction and the is the sediment The of is to the information from the noisy In the information can be by the from the an approach that in because the of the information and the are both This however, will be in because the of the information the is A large of analytical has been to in These 2 and For in the is as a a the all other than the The then for the to the original the the level of the to the to be the it easier to because of of the It is important to note that is being for is of importance in the would not be sufficient to the In STA, with no to the other of might to the in is with the use of that the level for the range of the If these of the the will the of the and the can be that increase the to The in is not as because the is not and the of the is only In this by can be because the can however, statistical might be to the In a sedimentary can be considered in 2 sample and in a sediment samples can be by One to this would be to many samples in and to produce a method that to this is For there has been on the use of a to sediments because it appears to provide a to many deposits and to the of STA, it has been shown that parameters of the distribution should change in the of erosion or and It that erosion and the parameters of the distribution to in particular when on the shape of the distribution and all however, are that distributions provide information (e.g., and and McLaren whether or is based on the assumption that sediments distributions. a to the sedimentary it is assumed that that do not on the are and are In this if in sediments do to the If do then the process as as a could be more noisy than the original In the approach of STA, the of are because only the data of each sediment grain size distribution are used from which the moments are sediment is over a can be To this of of samples could be used. of the by are, in reality, to in this manner (i.e., the Z as described or the of and These of of samples, which is not If the of the and the information is not the of samples can the information more than it the is to random by a number of samples from the same to a better distribution of that In STA, the assumption is that is and to the trend as the after these might in might provide more and In it is to the from the (i.e., a that over to the which the of the (i.e., the amount of the that is by all of the this is with a which the its the an is to the to the In sediment the rather than but exactly the same analysis can be In this case, the data grain size distributions of the sediment can be represented as a of with a the is a of the sedimentary deposits that how over For 1 would the of changes over a over a that the sample as discussed will set as to can be the in this the to be how is it is In the information is it it would be if not to in a simple analysis of the sedimentary data (e.g., the in the mean grain it is that a transport direction would be To the it is to an assumption as to is being It is then possible to the data to this and whether in a corresponding to the assumption is For a transport process that would produce the of sediments over a To this a can be and all with of less than could be An of the data would then over the The important of this approach in the approach discussed is the use of many sample to the transport direction. This the level of The however, is that it is to because the number of possible transport in a given can be large to The of a transport direction be and can only be to a level and information from other (e.g., In the Z score statistic, however, a transport trend can be determined whereby all possible pairs in a sample sequence are compared with each When either a case B or case C trend random probability within the sample the direction of net sediment transport can be inferred. As the grid spacing must be with the and the number of environments likely to be the shape of the and the statistical of the For it has been found for in sample spacing should not exceed 1 in spacing can be to For (e.g., to determine the transport for a sample spacing will be that a minimum number of samples can be to has also shown that samples should be over of (e.g., and in which the regular grid is to (e.g., and the direction of transport over an many sample this the sediment that should at the sample the with the Z score statistic from the grain size distributions of the and the assumed direction and the the is from the when a and of transport pathways is that or nearly of the samples, the assumption that information transport is contained in the grain size has been the to all the uncertainties that might be It must be that the actual processes responsible for the transport of along the derived pathways are They might in one be in a in the and in still the effects of one of the in the transport is to assess the processes that are likely to The shape of the X distribution is important in the of transport of the along a the of X is Consider a transport N X is then defined as in Equation d2 in one pair is d1 in and of d2 and d1 are with Equation that X is not defined as the of the mean value of d2 by the mean value of d1, the results of the 2 are For of d1, and X are before in there is no to that the of the X distribution should be X(s) can be thought of as a function that the relative probability of each being from d1 and deposited at d2. of X distributions from a large number of environments has shown that basic are when compared with the distributions of the deposits d1(s) and d2(s) (Figure 1. shape of the X distributions d1(s) and The relative probability of being transported, therefore, is a distribution to the actual Thus, the probability of a particular sized grain in the deposit is equal to the probability of its transport and (i.e., there must be a along the transport The bed is and is, therefore, in dynamic An X distribution dynamic can be found in either case B or case C transport, a fine between erosion and when environments are both case B and case C can be along the sample sequence. This is to as a and when this it is that the transport is also a state of dynamic of the 3 distributions are but the of X is finer than the of d1(s) and The of X can be thought of as the size that is the the of the deposits are coarser than these are more deposited than The therefore, must be in a state of net can only be in case B transport. Summary of the given to the of X distributions relative to the d1 and d2 the of the 3 distributions are but the of X is coarser than of d1(s) and This is the of net the size is coarser than the As a the deposits are erosion along the transport erosion can only be in case C transport. of the of d1(s) and d2(s), the X distribution more or less over the size range of the Sediment must fine in the direction of transport however, the bed is no it is a of sediment that with from transport The of is to sediments. X only in fine sediments when the mean grain size is a fine or the X distribution can be sediments are found from their and the of the X distribution that their is no related to size In other words, all an equal probability of being This of the X distribution 1st in the deposits of a and is described in McLaren the occur in fine in which any changes in the distributions are X distributions can be found in both case B and case C R2 is the correlation coefficient derived from the mean, sorting, and skewness of each sample pair a This is a relative of how the samples are related by transport. becoming finer, better sorted, and more negatively skewed in the direction of transport. becoming coarser, better sorted, and more positively skewed in the direction of transport. N is the number of possible pairs in the of X is the number of pairs a particular trend in a direction. Z is the Z score at the level are indicates transport in the direction. indicates transport in the direction. defines the dynamic of the sediments the of samples (i.e., 1 for a

Giorgi Japaridze

No abstract is available for this record.

Sagar Sen, Sagar Sen, Hans Agarwal, Sagar Sen · 5 authors

No abstract is available for this record.

Keiji Matsumoto

Watrous had presented the first proof of zero-knowledge property of a proof system against a quantum verifier. The key of the proof is the construction of a quantum simulator. In the construction, the 'failure state' is rotated to the 'success' state by a tricky operation which is initially developped for the amplification of QMA proof systems. This manuscript presents a new and simpler construction of a simulator. In the construction, we simply amplify the success probability of a classical simulator using Grover's amplification.

Oded Schramm

Many mathematical models of statistical physics in two dimensions are either known or conjectured to exhibit conformal invariance. Over the years, physicists proposed predictions of various exponents describing the behavior of these models. Only recently have some of these predictions become accessible to mathematical proof. One of the new developments is the discovery of a one-parameter family of random curves called stochastic Loewner evolution or SLE. The SLE curves appear as limits of interfaces or paths occurring in a variety of statistical physics models as the mesh of the grid on which the model is defined tends to zero. The main purpose of this article is to list a collection of open problems. Some of the open problems indicate aspects of the physics knowledge that have not yet been understood mathematically. Other problems are questions about the nature of the SLE curves themselves. Before we present the open problems, the definition of SLE will be motivated and explained, and a brief sketch of recent results will be presented.

David Avis, Hiroshi Imai, Tsuyoshi Ito

The cut polytope of a graph arises in many fields. Although much is known about facets of the cut polytope of the complete graph, very little is known for general graphs. The study of Bell inequalities in quantum information science requires knowledge of the facets of the cut polytope of the complete bipartite graph or, more generally, the complete k-partite graph. Lifting is a central tool to prove certain inequalities are facet inducing for the cut polytope. In this paper we introduce a lifting operation, named triangular elimination, applicable to the cut polytope of a wide range of graphs. Triangular elimination is a specific combination of zero-lifting and Fourier-Motzkin elimination using the triangle inequality. We prove sufficient conditions for the triangular elimination of facet inducing inequalities to be facet inducing. The proof is based on a variation of the lifting lemma adapted to general graphs. The result can be used to derive facet inducing inequalities of the cut polytope of various graphs from those of the complete graph. We also investigate the symmetry of facet inducing inequalities of the cut polytope of the complete bipartite graph derived by triangular elimination.