Francois Belletti, Evan Sparks, Michael J. Franklin, Alexandre M. Bayen · 5 authors
Linear causal analysis is central to a wide range of important application spanning finance, the physical sciences, and engineering. Much of the existing literature in linear causal analysis operates in the time domain. Unfortunately, the direct application of time domain linear causal analysis to many real-world time series presents three critical challenges: irregular temporal sampling, long range dependencies, and scale. Moreover, real-world data is often collected at irregular time intervals across vast arrays of decentralized sensors and with long range dependencies which make naive time domain correlation estimators spurious. In this paper we present a frequency domain based estimation framework which naturally handles irregularly sampled data and long range dependencies while enabled memory and communication efficient distributed processing of time series data. By operating in the frequency domain we eliminate the need to interpolate and help mitigate the effects of long range dependencies. We implement and evaluate our new work-flow in the distributed setting using Apache Spark and demonstrate on both Monte Carlo simulations and high-frequency financial trading that we can accurately recover causal structure at scale.
The fiscal incentives literature emphasizes how the design of transfer systems has a significant implication on the behavior of local governments within decentralized systems. The empirical findings on the relationship between intergovernmental transfers and the incentives they create for local revenue generation are inconclusive and differ from country to country. Given the lack of data on local public finances, this type of study rarely involves developing countries. Using a unique and rich socio-economic and public finance data covering a large set of Moroccan municipalities over the period 2005 to 2009, this paper contributes to the new generation of fiscal federalism literature by assessing the fiscal incentive effects of two types of transfers: general purpose transfers (unconditional) defined by a formula and specific purpose transfers (conditional) allocated on an ad-hoc basis. After correcting for the endogeneity problem, our findings support the existence of a significant incentive effect of unconditional transfers and a less robust effect of conditional transfers. Suggesting that transfers from the central government complement local own revenues by encouraging Moroccan municipalities to collect more revenues.
O Bitcoin e um sistema de pagamento totalmente digital independente de uma entidade centralizadora como bancos ou governos. O projeto foi criado e publicado em 2008 atraves da Internet. Entretanto apenas em 2009 a rede tornou-se operacional. O Bitcoin e um protocolo de codigo aberto e uma rede ponto a ponto de participantes que e responsavel pelo funcionamento do sistema. Seguranca criptografica, ausencia de taxas e de custos de instalacao sao fatores que convenceram varias empresas do mundo a adota-lo como alternativa de pagamento. Apesar dos trabalhos acerca da moeda digital, pouco ainda se sabe sobre sua topologia e caracteristicas, principalmente pela otica de ciencia de redes. Nesse sentido, o presente trabalho apresenta o estudo da dinamicidade de suas principais variaveis no seu funcionamento diario. No decorrer do trabalho sao apresentadas duas formas de extracao de dados da rede Bitcoin para futuras analises.
In this explorative study, we examine the economy and transaction network of the decentralized digital currency Bitcoin during the first four years of its existence. The objective is to develop insights into the evolution of the Bitcoin economy during this period. For this, we establish and analyze a novel integrated dataset that enriches data from the Bitcoin blockchain with off-network data such as business categories and geo-locations. Our analyses reveal the major Bitcoin businesses and markets. Our results also give insights on the business distribution by countries and how businesses evolve over time. We also show that there is a gambling network that features many very small transactions. Furthermore, regional differences in the adoption and business distribution could be found. In the network analysis, the small world phenomenon is investigated and confirmed for several subgraphs of the Bitcoin network.
This article provides a comprehensive critique of current corporate foreign exchange risk management (FXRM) practices. The authors characterize much of FXRM as a “legacy” activity, a set of outdated, often decentralized and “earnings‐driven” methods and procedures that have not been subjected to rigorous cost‐benefit analysis at the enterprise level. And according to the authors, the costs of poorly designed and executed FXRM have increased sharply in recent decades because of the growing demand by analysts and investors for cost‐efficiency, transparency, and predictability. After discussing six ways in which the FX policy of most large multinationals fails to serve the interests of their investors and other important stakeholders, the authors offer the following: (1) a restatement of the goals of FXRM; (2) an illustration of various ways of implementing a largely (if not completely) centralized approach to FXRM; (3) a proposal for aligning performance evaluation and executive pay with the goals of FXRM; (4) suggestions for improving decision‐support tools in relation to FXRM; (5) proposals for integrating FXRM into an enterprise‐wide risk management system, which include shifting responsibility for FXRM from the Finance/Treasury group to a centralized risk committee (typically under a Chief Risk Officer who reports to the board of directors); and (6) suggestions for improving communication of a company's risk management policies and practices to investors and other stakeholders.
Revealed a variety of approaches and concepts ethnogeny of the Ukrainian people in the context of its primary mentality. Within historiosophical Ukrainian mentality paradigm study describes key milestones ethnogeny of Ukrainians. Emphasized on the bright tilling discovered the nature of Tripoli culture — protocultural Ukrainian, which defined the original features of their mentality. Ants state is seen as the first proto-Ukrainian political community, which laid the mental qualities that find their further development in the political mentality of the Ukrainians: democracy, decentralization, regionalism and more. The article made the following conclusions. To solve the problem of Ukrainian ethnogeny finally and clearly, convincingly and consistently play its period features and is quite a difficult task given the complex dynamic processes ethnogeny. The process of the emergence of ethnicity is not always adequate and comprehensive reflection of scientific sources. But we can talk about the possibility and the need to find the most acceptable and scientifically correct hypotheses concerning Ukrainian ethnogeny. In this connection, the indigenous-origin Ukrainians autonomous version looks like is that most meets the requirements. Summarizing some moments Ukrainian ethnogeny should pay attention to the specific features of the formation of primitive mentality of pre Ukrainians who subsequently receive proper development of the mentality of the Ukrainian people. Prolonged existence of matriarchal clan system in the distant predecessors Ukrainian ensured the dominance of women in their mentality primary which is fixed at the time of Tripoli culture in the cult of the earth-mother, typical, however, for all grain-growing nations. Surely this time there is a future mental dominant Slavs — female archetype of the Earth Mother. The emergence of a day of metals territorial community where there is communal land ownership, and processing is carried out a separate family, on the one hand, determines saving big role family (actually a mother) in the education and life of a particular individual, and withother hand, reinforces sedentary, propensity to a certain piece of land that forms the mentality of a no-aggressive expansionist motivations and as a result — peacefulness. The latest feature best manifested in Ukrainian, which for all its history never won one but, however, were themselves the object of permanent conquest. The existence of modern Ukrainian territory ScythianSkolot, Ants States is representative of the capacity of the substrate to the proto-Ukrainian political organization. Study of the socio-political system Ants state, which M. S. Grushevsky generally believed the first Ukrainian state formation, and to determine certain characteristics of political mentality of their own immediate ancestors Ukrainian. The decisive role of tribal assembly, which later transformed into Kiev Rus in the council, shows immanence democratic guidelines original Ukrainian mentality. At the same time the actual exercise of functions among convening meetings of tribal council of elders, which often had the sole head — his head, which writes the same M. S. Grushevsky [6, p. 33], indicating both the propensity to collective forms of governance, and in disregard of the principle of autocracy and a mistrust or neglect their own authorities. The latter attitude will develop in a typical Ukrainian political mentality and will be called «egalitarian negativity» with respect to their political leaders and the political elite. Polycentric state system Ants state determines the political and mental focus our ancient predecessors decentralism that evolutionary regionalism to Ukrainian
Bitcoin is a peer to peer decentralized virtual currency, released online through a research paper in 2008 by the unknown Satoshi Nakamoto . Around the world, many countries have cautiously taken minor initiatives to address the regulatory issues, due to its rising popularity. The regulation is not seen as complete, due to the nascent and novel outlook of bitcoins, requiring time for analysis and empirical evidence. The main research question that needs to be answered, is how can governance ideas be conceptualized to support technological decentralization while protecting against illegal activities? To answer this question a literature review is performed across academia, digital media and conferences/ independent authors. From this study, ideas for frameworks are consolidated, to effectively regulate bitcoins through coalitions, analyzed with game theory. This is complemented with a theoretical understanding of the technical, political, economical and ethical issues surrounding the bitcoin ecosystem. The thesis is broadly divided into seven chapters, where initially an introduction is presented which presents the structure of the thesis, along with the research problem and its motivation. This is followed by an exploration of bitcoin's current framework, which forms the most important theoretical part of the thesis. Here, its system design, strengths, challenges and solutions to regulatory issues are detailed. Also, how bitcoin is being perceived globally across twenty nations, is presented. Being an economic system, there has been reasonable skepticism, as to its validity as a money system. This is presented in the next chapter, where its economic structure is first explored, which is followed by an analysis of bitcoin from the perspective of both Austrian economics and Keynesian economics. Further, to understand the overall validity of a new system, the ethical impacts must be considered. This has been analyzed through two frameworks in this thesis. Firstly, as a large social experiment and secondly through a standard ethical impact assessment. Also, bitcoin has always been portrayed in the popular press, as promoting only decentralization. This is critically analyzed, from classical ideas of noted humanitarian M.K Gandhi and British economist M.F Schumacher. As a follow up, a modern exponential technology framework presented by Singularity University, is offered as a comparison. It is observed that bitcoin excels in the material aspect of decentralization (while requiring centralized intermediaries), but struggles in the spiritual aspect, as detailed. The major regulatory solution offered in this thesis, is through coalitions among stakeholders. For clarity, seven crisis situations are highlighted with the different payoff's (relative power) among the different members assigned, with proper reasoning and a demo game explained. Finally, conclusions and favorable recommendations are drawn , along with sections on research limitations, future research and reflections. Also, an appendix section on the major digital media outlook, is presented for two years (Aug'13- Sep'15), to explain its popular portrayal and the opinion of the general audience. Overall, it can be said that it is still early days for bitcoin and there are major critics in every domain. Consistent issues with taxation, anonymity tools like TOR promoting illegal activities, its inherent economic value and price volatility exist. The internet as an information medium, is probably the only suitable precedent for bitcoin which has been far more successful than anticipated. The benefits of bitcoin from exponentially lower transaction fees, global banking outreach, framework for decentralized asset ownership transfer and its ability to impact the Monetary Policy of ruling governments have been appreciated. Further, as a practical lesson, policy makers could see mainstream bitcoin as promoting a balance of centralized and decentralized intermediaries. Any effort at promoting an extreme ideology could have long term negative effects. Also, offering technologies like bitcoin a fair trial run would be far more appropriate than inviting legally controversial use. With over hundred competing digital currencies, the question is certainly not if, but when they would be competitive with fiat currencies.
<ns4:p>Trust in scientific research is diminished by evidence that data are being manipulated. Outcome switching, data dredging and selective publication are some of the problems that undermine the integrity of published research. Methods for using blockchain to provide proof of pre-specified endpoints in clinical trial protocols were first reported by Carlisle. We wished to empirically test such an approach using a clinical trial protocol where outcome switching has previously been reported. Here we confirm the use of blockchain as a low cost, independently verifiable method to audit and confirm the reliability of scientific studies.</ns4:p>
Since 1980, municipalities are in the center of decentralization policy in Côte d'Ivoire. More than thirty years later, the elected representatives are still in search of strategy to satisfy needs for the populations. In spite of the difficulties of financing, investments were realized. These boosted the local development to Alépé through the metamorphosis of the urban landscape, the dynamism of economic activities, the increase of infrastructures and equipments, etc. But, they do not take into account concerns of the populations. Where from their disappointment.
Sébastien Philippe, R.J. Goldston, Alexander Glaser, Francesco d’Errico
Zero-knowledge proofs are mathematical cryptographic methods to demonstrate the validity of a claim while providing no further information beyond the claim itself. The possibility of using such proofs to process classified and other sensitive physical data has attracted attention, especially in the field of nuclear arms control. Here we demonstrate a non-electronic fast neutron differential radiography technique using superheated emulsion detectors that can confirm that two objects are identical without revealing their geometry or composition. Such a technique could form the basis of a verification system that could confirm the authenticity of nuclear weapons without sharing any secret design information. More broadly, by demonstrating a physical zero-knowledge proof that can compare physical properties of objects, this experiment opens the door to developing other such secure proof-systems for other applications.
Eleftherios Kokoris-Kogias, Philipp Jovanovic, Nicolas Gailly, Ismail Khoffi · 6 authors
While showing great promise, Bitcoin requires users to wait tens of minutes for transactions to commit, and even then, offering only probabilistic guarantees. This paper introduces ByzCoin, a novel Byzantine consensus protocol that leverages scalable collective signing to commit Bitcoin transactions irreversibly within seconds. ByzCoin achieves Byzantine consensus while preserving Bitcoin's open membership by dynamically forming hash power-proportionate consensus groups that represent recently-successful block miners. ByzCoin employs communication trees to optimize transaction commitment and verification under normal operation while guaranteeing safety and liveness under Byzantine faults, up to a near-optimal tolerance of f faulty group members among 3f + 2 total. ByzCoin mitigates double spending and selfish mining attacks by producing collectively signed transaction blocks within one minute of transaction submission. Tree-structured communication further reduces this latency to less than 30 seconds. Due to these optimizations, ByzCoin achieves a throughput higher than PayPal currently handles, with a confirmation latency of 15-20 seconds.
Eleftherios Kokoris-Kogias, Philipp Jovanovic, Nicolas Gailly, Ismail Khoffi · 6 authors
While showing great promise, Bitcoin requires users to wait tens of minutes\nfor transactions to commit, and even then, offering only probabilistic\nguarantees. This paper introduces ByzCoin, a novel Byzantine consensus protocol\nthat leverages scalable collective signing to commit Bitcoin transactions\nirreversibly within seconds. ByzCoin achieves Byzantine consensus while\npreserving Bitcoin's open membership by dynamically forming hash\npower-proportionate consensus groups that represent recently-successful block\nminers. ByzCoin employs communication trees to optimize transaction commitment\nand verification under normal operation while guaranteeing safety and liveness\nunder Byzantine faults, up to a near-optimal tolerance of f faulty group\nmembers among 3f + 2 total. ByzCoin mitigates double spending and selfish\nmining attacks by producing collectively signed transaction blocks within one\nminute of transaction submission. Tree-structured communication further reduces\nthis latency to less than 30 seconds. Due to these optimizations, ByzCoin\nachieves a throughput higher than PayPal currently handles, with a confirmation\nlatency of 15-20 seconds.\n
Although it is still in early stages, many commentators have been quick to note the revolutionary potential of next-generation or Bitcoin 2.0 technology. While some have expressed fear that the widespread application of these technologies may engender the rise of a Terminator-style Skynet, others believe that it represents the coming of a decentralized autonomous society (DAS) in which humans are freed from centralized forms of power through the proliferation of distributed autonomous organizations or DAOs. Influenced by neoliberal theory that stresses privatization, open markets, and deregulation, Bitcoin 2.0 technologies are implicitly working on the assumption that 'freedom' means freedom from the state. This neglects, however, that within capitalist societies, the state can also provide freedom from the vagaries of the market by protecting certain things from commodification. Through an analysis of (1) class and the role of the state; (2) the concentration and centralization of capital; and (3) the role of automation, I argue that the vision of freedom that underpins Bitcoin 2.0 tech is one that neglects the power that capital holds over us in both organizing the structure of our lives, and informing our idea of what it means to be human. In neglecting these other forms of power, I claim that the DAS might be a far more dystopian development than its supporters comprehend, making possible societies that are commodities all the way down.
In most countries, the central bank is required to hold reserve assets as a means of providing credibility for the value of the fiat currency. These assets can be in the form of gold, foreign exchange or some other internationally recognised reserve asset and are held to permit the country to engage in international transactions. Within recent years, cryptocurrencies have been increasingly utilised for international transactions, and it is possible that the use of these cryptocurrencies might expand in the future. This paper therefore examines the potential role of digital currency balances as part of the portfolio of external assets held by a central bank. Using the case of Barbados, the paper also provides a simulation of the effect holding some proportion of their asset-base would have had on the stability of the foreign reserves as well as the return on the portfolio of assets.
version anglaise de Crowdfunding baseado em blockchain: qual seu impacto sobre a produção artística e o consumo de arte?, Observatorio/ITAU cultural,n°19
Atalay Mert İleri, Halil Ibrahim Ozercan, Alper Gundogdu, Ahmet K. Senol · 6 authors
Rate of growth of the amount of data generated using the high throughput sequencing (HTS) platforms now exceeds the growth stipulated by Moore's Law. The HTS data is expected to surpass those of other "big data" domains such as astronomy, before the year 2025. In addition to sequencing genomes for research purposes, genome and exome sequencing in clinical settings will be a routine part of health care. The analysis of such large amounts of data, however, is not without computational challenges. This burden is even more increased due to the periodic updates to reference genomes, which typically require re-analysis of existing data. Here we propose Coin-Application Mediator Interface (Coinami) to distribute the workload for mapping reads to reference genomes using a volunteer grid computer approach similar to Berkeley Open Infrastructure for Network Computing (BOINC). However, since HTS read mapping requires substantial computational resources and fast analysis turnout is desired, Coinami uses the HTS read mapping as proof-of-work to generate valid blocks to main its own cryptocurrency system, which may help motivate volunteers to dedicate more resources. The Coinami protocol includes mechanisms to ensure that jobs performed by volunteers are correct, and provides genomic data privacy. The prototype implementation of Coinami is available at http://coinami.github.io/.
Nesrine Khernane, Maria Potop-Butucaru, Claude Chaudet
Advances in wearable and implementable of wireless sensors have enable the development of tiny and intelligent sensors called body sensors. Monitoring the vital body parameters in real-time using wireless body area network (WBAN) has shown great potential in improving healthcare quality not only for patients but also for medical staff. However, security and privacy are still an important issue in WBANs especially in multi-hop architectures. Considering the constraints of the body sensors (namely energy, memory, computational power, etc.). In this paper, we propose and present the design and the evaluation of a secure lightweight and energy efficient authentication scheme BANZKP based on an efficient cryptographic protocol, Zero Knowledge Proof (ZKP) and a commitment scheme. ZKP is used to confirm the identify of the sensor nodes, with small computational requirement, which is favorable for body sensors given their limited resources, while the commitment scheme is used to deal with replay attacks and hence the injection attacks by committing a message and revealing the key later. BANZKP reduces the memory requirement by 56,13% compared to TinyZKP [10], the comparable alternative so far for Body Area Networks. Also, the simulation results demonstrate that our proposed scheme is 17 and 5 times more efficient in term of execution time, and uses 94.11% and 80% less energy compared to TinyZKP and W-ECDSA [16], respectively.
As a fiscal policy within the framework of regional autonomy, the allocation of DAU is an act that very important. It was meant to address financing capability gap between regions. The reason is because the DAU is the largest component of balance funds, namely the lack of 26% of the net domestic income in the state budget the amount of DAU scheme is not limiting, because it can only grow with the size of the authority delegated to the regions. DAU legal standing as a regional income in the financial relationship between the center and the regions based on the principle of autonomy is as a subsidy coming from the state revenue in the state budget that is allocated to local revenue in the budget based on fiscal decentralization. Keywords: General Allocation Fund, autonomy, regional autonomy
Nesrine Khernane, Maria Potop-Butucaru, Claude Chaudet
-Wireless body area network(WBAN) has shown great potential in improving\nhealthcare quality not only for patients but also for medical staff. However,\nsecurity and privacy are still an important issue in WBANs especially in\nmulti-hop architectures. In this paper, we propose and present the design and\nthe evaluation of a secure lightweight and energy efficient authentication\nscheme BANZKP based on an efficient cryptographic protocol, Zero Knowledge\nProof (ZKP) and a commitment scheme. ZKP is used to confirm the identify of the\nsensor nodes, with small computational requirement, which is favorable for body\nsensors given their limited resources, while the commitment scheme is used to\ndeal with replay attacks and hence the injection attacks by committing a\nmessage and revealing the key later. Our scheme reduces the memory requirement\nby 56.13 % compared to TinyZKP [13], the comparable alternative so far for Body\nArea Networks, and uses 10 % less energy.\n
The money is a widely accepted commodity, by means of which it is possible to determine the economic value of purchased goods and services and make payments. Over the centuries, "money" has evolved many times. Their constantly changing character, generates questions on their future aspect. In the reference to the cryptocurrencies questions are focused on their nature and compliance with the definition of money.