The aim of this research is to advance understanding of how mathematical knowledge functions in the proving in geometry. We focus on the rules whose mobilization is due rather to the mathematical knowledge at stake than to the proof. We observed students who are asked to solve construction problem and proving problem. The problems require to mobilize the “same ” rule from the theoretical point of view. The first result is that even if the students can construct correctly a symmetric and are conscious of the necessity of perpendicular and equal distance, it doesn’t mean that they can use the rule appropriate in proving.
We consider a continuous-time version of fictitious play (FP), in which interacting players evolve their strategies in reaction to their opponents' actions without knowledge of their opponents' utilities. It is known that FP need not converge, but that convergence is possible in certain special cases including zero-sum games, identical interest games, and two-player/two-move games. We provide a unified proof of convergence in all of these cases by showing that a Lyapunov function previously introduced for zero-sum games also can establish stability in the other special cases. We go on to consider a two-player game in which only one player has two-moves and use properties of planar dynamical systems to establish convergence.
The severe acute respiratory syndrome (SARS) crisis in China revealed not only the failures of the Chinese health-care system but also some fundamental structural deficiencies. A decentralized and fragmented health system, such as the one found in China, is not well-suited to making a rapid and coordinated response to public health emergencies. The commercial orientation of the health sector on the supply-side and lack of health insurance coverage on the demand-side further exacerbate the problems of the under-provision of public services, such as health surveillance and preventive care. For the past 25 years, the Chinese Government has kept economic development at the top of the policy agenda at the expense of public health, especially in terms of access to health care for the 800 million people living in rural areas. A significant increase in government investment in the public health infrastructure, though long overdue, is not sufficient to solve the problems of the health-care system. China needs to reorganize its public health system by strengthening both the vertical and horizontal connections between its various public health organizations. China's recent policy of establishing a matching-fund financed rural health insurance system presents an exciting opportunity to improve people's access to health care.
We present a protocol for verification of ``no such entry'' replies from databases. We introduce a new cryptographic primitive as the underlying structure, the keyed hash tree, which is an extension of Merkle's hash tree. We compare our scheme to Buldas et al.'s Undeniable Attesters and Micali et al.'s Zero Knowledge Sets.
In recent years, formation flying has become an enabling technology for several mission concepts at both NASA and the Department of Defense. In most cases, a multiple-satellite approach is required in order to accomplish the large-scale geometries imposed by the sensing objectives. In general, the paradigm shift of using a multiple-satellite cluster rather than a large, monolithic spacecraft has also been fueled by the objectives of increased robustness, greater flexibility, and reduced cost. However, the operational costs of monitoring and commanding a large fleet of close-orbiting satellites is likely to be unreasonable unless the onboard software is sufficiently autonomous, robust, and reconfigurable. This paper presents the prototype of a system that addresses these objectives – a decentralized guidance and control system that is distributed across spacecraft using a multipleteam framework. The system is designed to provide a high-level of autonomy, to support clusters with large numbers of satellites, to enable the number of spacecraft in the cluster to change post-launch, and to provide for on-orbit software modification. The real-time distributed system will be implemented in C++ using the MANTA environment (Messaging Architecture for Networking and Threaded Applications). In this architecture, tasks may be remotely added, removed or replaced post-launch to increase mission flexibility and robustness. This built-in adaptability will allow significant or simple software modifications to be made on-orbit in a robust manner. The prototype system, which is implemented in Matlab, emulates the task-based and message-passing features of the MANTA software. In this paper, the multiple-team organization of the cluster is described, and the relative dynamics in circular and eccentric reference orbits is reviewed. Families of periodic, relative trajectories are identified and represented with static geometric parameters. An analytic solution for impulsive maneuvering is used for whole orbit-period control in circular orbits, and linear programming techniques are used to find time-weighted, minimum-fuel control solutions. Finally, the decentralized guidance law design is presented, with a comparison between the optimal and a sub-optimal assignment algorithm.
A.J. Chakravarti, Gerald Baumgartner, Mario Lauria
Desktop grids have recently been used to perform some of the largest computations in the world and have the potential to grow by several more orders of magnitude. However, current approaches to utilizing desktop resources require either centralized servers or extensive knowledge of the underlying system, limiting their scalability. We propose a biologically inspired and fully-decentralized approach to the organization of computation that is based on the autonomous scheduling of strongly mobile agents on a peer-to-peer network. In a radical departure from current models, we envision large-scale desktop grids in which agents autonomously organize themselves so as to maximize resource utilization. By encapsulating computation and behavior into agents, the organization of the computation can be customized for different classes of applications. At the same time, the design of the underlying infrastructure is greatly simplified, resulting in a system that naturally lends itself to a true peer-to-peer implementation where each node can be at the same time provider and user of the computing utility infrastructure. We demonstrate this concept with a reduced-scale proof-of-concept implementation that executes a data-intensive independent-task application on a set of heterogeneous, geographically distributed machines. We present a detailed exploration of the design space of our system and a performance evaluation of our implementation using metrics appropriate for assessing self-organizing desktop grids.
"A silent, and in my opinion revolutionary, reform of the budget, to truly become a management tool and an instrument for short-term economic and social programming." This is how the participatory budget was cataloged by a senior official from the Ministry of Economy and Finance. "They are a disaster, with this spending has been atomized... In addition, the MEF has acted against the law", affirms emphatically and harshly -and as a balance, a year later- the main person in charge of the National Decentralization Council (CND).
Significant changes in the Indonesian political system have affected most aspects of its government and community. First, there is an effort to implement democracy in terms of ideology as well as political practices. Second, the government system is transforming from centralization to decentralization, as the development process is delegated to regional governments (cities and kabupatens). Third, there is an effort to build community consciousness through community participation in national and regional development.Participating in the development process, citizens should be supported with relevant public information. It is the government's task to provide information regarding governmental issues and public interests. As communication and information have been delegated to regional governments, they should execute this task based on good governance principles.However, providing fair and balanced information is not simple. Large populations and regions separated by water and mountains make the task harder. Therefore, regional governments must adopt advanced information technology systems, which functioned to transfer information to the public as well as to receive public feedback medium in an efficient and effective way. To meet those qualifications, regional governments endeavor to implement e-government as a tool for democratizing communication and information.After almost 3 years, there are indications that e-government has not been properly implemented by regional governments. They have faced many problems, including lack of financing, poor technical skill, lack of human resources and infrastructure, and the political will of the government elite itself.Nevertheless, there are many ways to overcome these problems. Standardizing the application of e-government, establishing the regulation of e-government, involving other stakeholders, and developing human resources may aid in the implementation of e-government. In addition, lessons learned from other regions, for example, Kutai Timur or Gorontalo, are also recommended.
What are the social, political and institutional conditions for organizational heterogeneity and the production of new organizational forms? I address this question using historical methods and time series analyses of 3145 mutual fire insurers — important cooperative alternatives to markets and hierarchies. Developing politically oriented neo-institutional arguments, I show that mutuals were vehicles by which property owners and agrarian interests resisted corporate consolidation and secured conditions for autonomous economic development. Mutuals embodied a vision of a decentralized, “cooperative commonwealth” of farmers, merchants and independent producers. And they rested on a socio-industrial order characterized by political struggles against corporations; anti-monopoly social movements; immigrants and other cultural carriers of mutual organizing templates; and an institutional infrastructure of protestant churches and local movements.
This article argues for three linked conceptions. First is a conception of ‘a text’ as characterized by three features: a text is symbolic; it is inscribed as symbols on a relatively permanent, ‘readable’ medium such as paper or CD; and it has a coherent enough structure to be dealt with by interpretive processes or technologies such as financial processing. The second conception is that of an organization as a stable relational system grounded in the capacity to ‘“bracket space–time”... via the reflexive monitoring of system reproduction and the articulation of discursive history’ (Giddens, 1987b: 153). I argue that this capacity depends on the specific properties of ‘a text’ mentioned above. Third, ‘agency’ is conceptualized in line with Giddens’ ‘internalist’ model of agentive powers, which are ones necessary to engage with a text as organization members do. The paper argues that other conceptions risk blinding us to the features and relationships shown to be crucial here.
An original approach to establish a computationally secure and robust conference key between multiple users is presented, which is built on known secret sharing schemes and requires the authenticated and encrypted point-to-point channels between servers and users. By running of the protocol, every honest user of a given conference can get a common key, even if a minority of the servers malfunction or misbehave. This scheme does not rely on any unproven cryptographic assumptions or on the availability of any tamper-proof hardware. By using zero knowledge proof, any corrupted information and incorrect results can be detected. And by distributing the sensitive security information across several servers and never reconstructing any key at a single location, the compromise of a few servers will not compromise the privacy of any key. Analysis shows that under the assumption of a Diffie-Hellman decisional problem, a passive adversary gets zero knowledge about the conference key, and in the random oracle model, an active adversary cannot impersonate successfully. We have implemented the scheme in a distributed environment. By conducting a number of experiments in the fault-free case and various fault scenarios, we show that it has an acceptable performance of practicability.
The burden of proof is a central feature of all systems of adjudication, yet one that has been subject to little normative analysis. This Article examines how strong evidence should have to be in order to assign liability when the objective is to maximize social welfare. In basic settings, there is a tradeoff between deterrence benefits and chilling costs, and the optimal proof requirement is determined by factors that are almost entirely distinct from those underlying the preponderance of the evidence rule and other traditional standards. As a consequence, these familiar burden of proof rules have some surprising properties, as do alternative criteria that have been advanced. The Article also considers how setting the proof burden interacts with other features of legal system design: the determination of enforcement effort, the level of sanctions, and the degree of accuracy of adjudication. It compares and contrasts a variety of legal environments and methods of enforcement, explaining how the appropriate proof requirements differ qualitatively across contexts. Most of the questions raised and answers presented differ in kind — as well as in result — from those in prior literature.
Wallace Oates is one of the most important scholars in both environmental economics and public finance and this new volume of his essays brings together his recent research in both these areas, covering theory, research and policy. The first half of the book includes papers on the political economy of environmental policy, the analysis of environmental regulation and environmental federalism. The second half deals with fiscal and regulatory competition, state and local government finance and fiscal federalism. This new collection will be essential reading for scholars and students in both environmental economics and public finance.
Wallace Oates is one of the most important scholars in both environmental economics and public finance and this new volume of his essays brings together his recent research in both these areas, covering theory, research and policy. The first half of the book includes papers on the political economy of environmental policy, the analysis of environmental regulation and environmental federalism. The second half deals with fiscal and regulatory competition, state and local government finance and fiscal federalism. This new collection will be essential reading for scholars and students in both environmental economics and public finance.
Wallace Oates is one of the most important scholars in both environmental economics and public finance and this new volume of his essays brings together his recent research in both these areas, covering theory, research and policy. The first half of the book includes papers on the political economy of environmental policy, the analysis of environmental regulation and environmental federalism. The second half deals with fiscal and regulatory competition, state and local government finance and fiscal federalism. This new collection will be essential reading for scholars and students in both environmental economics and public finance.
An Internet accounting system, where transactions are entered on the spot and business data created by transactions are distributed to appropriate staff of the company, becomes more important for companies operating worldwide. The Internet accounting system described in this paper consists of a three-tier structure: Web, application and database servers. The accounting system provides complete accounting functions including general ledger, accounts payable, accounts receivable, purchase order, sales order, inventory management, fixed assets, temporary payment, multi-users, multi-currencies, multi-companies, and multi-languages allowing customer relation management, partner relation management, supply chain management and performance analysis. A prototype system has been completed and a full-scale system is now under development.
This paper concerns redistribution and public good provision in an economic federation with two levels of government: a local government in each locality and a (first mover) central government. Each locality is characterized by two ability-types, and the ability-distribution differs across localities. The central government redistributes via a nonlinear income tax and a lump-sum transfer to each local government, while the local governments use proportional income taxes and provide local public goods. We show how the redistributive role of taxation is combined with a corrective role, and how the central government can implement the second best resource allocation. Copyright 2008 Blackwell Publishing, Inc..
This study investigated the multilevel dimensionality of socioeconomic status and its relationship to reading achievement in 23 countries. Different factor structures of SES were found at different levels’ observations and in different countries. The study showed that the cultural dimension strongly related to student reading performance, while the school general capital dimension explained a large part of the between-school reading achievement differences. Most interestingly, the factor relationship between SES and reading achievement at the school level varies greatly across countries. It was argued that these variations might be due to the differences in the centralized versus decentralized educational finance, tracking mechanism and some social characteristics in different countries.
School Choice and Performance
Parental Involvement in Education
Intergenerational and Educational Inequality Studies
This study aims at assessing the performance of local government in Palestine in regard to fiscal and administrative decentralization. Data was gathered from the Ministry of Local Government, Ministry of Finance and a questionnaire was sent to 12 municipalities' key officials. It was found that the government is organized into the central government headed by the president, the cabinet, the governorates, mayors and village councils. The main functions of the local governments are to provide the necessary needed services. It was found that there is a degree of decentralization in providing the intended services as the functions of each level is clearly defined by the law, even though there is an overlapping amongst these functions due to the current situation instability The study explains several aspects including organization of the local government, decision making process, functional responsibilities, partnership among local government and the performance of these partnerships, employment, training programs, the most urgent issues regarding decentralization process, local government finances, financial standing of municipalities, relationship between central and local governments, and decentralization reforms under preparation, The study ends up with conclusions and recommendations. تهدف هذه الدراسة إلى تقييم أداء الهيئات المحلية في فلسطين فيما يتعلق باللامركزية الإدارية والماليـة. وقد تم جمع البيانات اللازمة للدراسة من وزارة الحكم المحلي ووزارة المالية، إضافة الى استبانة كانت قد أرسلت إلى 12 مسئولاً من مسئولي 12 بلدية. وتبين من البحث أن التنظيم الإداري للحكومة يتكون من الحكومة المركزية والمحافظات والبلديات والمجالس القروية. ووجد أن وظائف الهيئات المحلية تتركز في تقديم الخدمات الأساسية للمواطنين. وتبين أن لدى هذه الهيئات درجة كبيرة من اللامركزية في تقديمها لهذه الخدمات، لأن وظائف هذه الهيئات محددة بشكل واضح في قانون الحكم المحلي الفلسطيني، إلا أن هناك بعض التداخل في بعض الصلاحيات نتيجة للظروف الحالية. وأوضحت الدراسة العديد من القضايا الخاصة باللامركزية المالية والإدارية منها: التنظيم الإداري للهيئات المحلية، وعملية اتخاذ القرارات، والمسئوليات الوظيفية، والتعاون بين الهيئات المحلية في تقديم الخدمات، القوى العاملة في الهيئات المحلية والتدريب والحوافز، والقضايا الملحة فيما يتعلق باللامركزية، وتمويل الهيئات المحلية، والأوضاع المالية لهذه الهيئات وعلاقاتها بالحكومة المركزية، والإصلاحات الجارية الخاصة باللامركزية. وانتهت الدراسة بالخلاصة وعدد من التوصيات.
Decentralized countries around the world use different institutional set-ups to assure that the system of local government finances achieves the objectives sought by the public sector through the decentralized delivery of public services. In many centralized countries, the Ministry of Local Government is tasked with the exclusive responsibility to monitor and coordinate all aspects of intergovernmental relations, including local government finances. While the Ministry of Local Government generally also plays a role in more decentralized countries, it is not unusual for broad-based or inter-ministerial commissions to be tasked with tracking and considering local government finance issues in more decentralized countries. In contrast, other decentralized countries rely more heavily on local government associations or even the legislative branch to monitor and analyze the system of local government finances and to represent local government interests at the national level to assure a balanced system of intergovernmental relations. Finally, there are a small number of decentralized countries around the world that lack a formal intergovernmental mechanism to coordinate local government finance issues altogether.