A robust self-organized public key management for mobile ad hoc networks

A mobile ad hoc network (MANET) is a self-organized wireless network where mobile nodes can communicate with each other without the use of any existing network infrastructure or centralized administration. Trust establishment and management are essential for any security framework of MANETs. However, traditional solutions to key management through accessing trusted authorities or centralized servers are infeasible for MANETs due to the absence of infrastructure, frequent mobility, and wireless link instability. In this paper, we propose a robust self-organized, public key management for MANETs. The proposed scheme relies on establishing a small number of trust relations between neighboring nodes during the network initialization phase. Experiences gained as a result of successful communications and node mobility through the network enhance the formation of a web of trust between mobile nodes. The proposed scheme allows each user to create its public key and the corresponding private key, to issue certificates to neighboring nodes, and to perform public key authentication through at least two independent certificate chains without relying on any centralized authority. A measure of the communications cost of the key distribution process has been proposed. Simulation results show that the proposed scheme is robust and efficient in the mobility environment of MANET and against malicious node attacks

Redistribution spurs growth by using a portfolio effect on human capital

We demonstrate by mathematical analysis and systematic computer simulations that redistribution can lead to sustainable growth in a society. The human capital dynamics of each agent is described by a stochastic multiplicative process which, in the long run, leads to the destruction of individual human capital and the extinction of the individualistic society. When agents are linked by fully-redistributive taxation the situation might turn to individual growth in the long run. We consider that a government collects a proportion of income and reduces it by a fraction as costs for administration (efficiency losses). The remaining public good is equally redistributed to all agents. We derive conditions under which the destruction of human capital can be turned into sustainable growth, despite the losses from the random growth process and despite the administrative costs. Sustainable growth is induced by redistribution. This effect could be explained by a simple portfolio-effect which re-balances individual stochastic processes. The findings are verified for three different tax schemes: proportional tax, taking proportional more from the rich, and proportionally more from the poor. We discuss which of these tax schemes is optimal with respect to maximize growth under a fixed rate of administrative costs, or with respect to maximize the governmental income. This leads us to some general conclusions about governmental decisions, the relation to public good games, and the use of taxation in a risk taking society.Comment: 12 pages, plus 8 Figures, plus matlab-code to run simulation and produce figur

Improving Transportation Construction Project Performance: Development of a Model to Support the Decision-Making Process for Incentive/Disincentive Construction Projects, MTI Report 09-07

This research presents a project time and cost performance simulation model to assist project planners and managers by providing a complete picture during the Incentive/Disincentive (I/D) contracting decision-making process of possible performance outcomes with probabilities based on historical data. This study was performed by collecting transportation construction project data. The collected project data from the Florida Department of Transportation were evaluated using time and cost performance indices and then statistical data analysis was performed to identify important factors that influence construction project time performance. Using Monte Carlo simulation procedures, this study demonstrated a methodology for developing an I/D project time and cost performance prediction model. User-friendly visual interfaces were developed to perform the simulation and report results using Visual Basic Application programming. The developed model was validated using additional cases of transportation construction projects. Based on statistical analysis, this research found that several project factors influence I/D contracting performance. The important factors that had significant impacts on project performance were the effects of contract type, project type, district, project size, project length, maximum incentive amount, and daily I/D amount. In conclusion, the developed model applied to I/D contracting projects will be a useful tool to assist the project planners and managers during the decision-making process and will promote the efficient use of I/D contracting, which will benefit the traveling public by saving their travel time from construction delays. With additional project data, the developed model can be updated easily and the more data used for the model, the better the accuracy of prediction that can be expected

Risk Adjustment and Reinsurance: A Work Plan for State Officials

Outlines the decisions and actions states need to take to implement the risk adjustment and reinsurance provisions of the 2010 health reform law, including risk adjustment model, reinsurance parameters, stakeholder engagement, and program administration

National Security Pedagogy: The Role of Simulations

This article challenges the dominant pedagogical assumptions in the legal academy. It begins by briefly considering the state of the field of national security, noting the rapid expansion in employment and the breadth of related positions that have been created post-9/11. It considers, in the process, how the legal academy has, as an institutional matter, responded to the demand. Part III examines traditional legal pedagogy, grounding the discussion in studies initiated by the American Bar Association, the Carnegie Foundation, and others. It suggests that using the law-writ-large as a starting point for those interested in national security law is a mistake. Instead, it makes more sense to work backwards from the skills most essential in this area of the law. The article then proposes six pedagogical goals that serve to distinguish national security law: (1) understanding the law as applied, (2) dealing with factual chaos and uncertainty, (3) obtaining critical distance—including, inter alia, when not to give legal advice, (4) developing nontraditional written and oral communication skills, (5) exhibiting leadership, integrity, and good judgment in a high-stakes, highly-charged environment, and (6) creating continued opportunities for self-learning. Equally important to the exercise of each of these skills is the ability to integrate them in the course of performance. These goals, and the subsidiary points they cover, are neither conclusive nor exclusive. Many of them incorporate skills that all lawyers should have—such as the ability to handle pressure, knowing how to modulate the mode and content of communications depending upon the circumstances, and managing ego, personality, and subordination. To the extent that they are overlooked by mainstream legal education, however, and present in a unique manner in national security law, they underscore the importance of more careful consideration of the skills required in this particular field. Having proposed a pedagogical approach, the article turns in Part IV to the question of how effective traditional law school teaching is in helping to students reach these goals. Doctrinal and experiential courses both prove important. The problem is that in national security law, the way in which these have become manifest often falls short of accomplishing the six pedagogical aims. Gaps left in doctrinal course are not adequately covered by devices typically adopted in the experiential realm, even as clinics, externships, and moot court competitions are in many ways ill-suited to national security. The article thus proposes in Part V a new model for national security legal education, based on innovations currently underway at Georgetown Law. NSL Sim 2.0 adapts a doctrinal course to the special needs of national security. Course design is preceded by careful regulatory, statutory, and Constitutional analysis, paired with policy considerations. The course takes advantage of new and emerging technologies to immerse students in a multi-day, real-world exercise, which forces students to deal with an information-rich environment, rapidly changing facts, and abbreviated timelines. It points to a new model of legal education that advances students in the pedagogical goals identified above, while complementing, rather than supplanting, the critical intellectual discourse that underlies the value of higher legal education

Teaching Substantive Environmental Law and Practice Skills Through Interest Group Role-Playing

Most law students take their first introductory course in environmental law during their second year of law school. The traditional first-year curriculum does little to prepare students for the complex statutory and regulatory models for most environmental regulation. Law students at the end of their first year often have had little exposure to statutory interpretation. Further, they often have no exposure to administrative law and regulatory implementation. These students may expect statutes to provide clear statements of rules rather than guidelines for administrative rulemaking. They also tend to view the lawmaking and interpretive process through the traditional lens of congressional legislation and common-law-style judicial interpretation in a bipolar scheme of implementation--where the regulatory agencies and the regulated industries are the only players. In fact, environmental regulatory programs constantly evolve through a complex interaction of legislative amendment, administrative rulemaking, and judicial interpretation. Influencing these programs are the multipolar interaction of regulated industries, environmental groups, state agencies, and federal regulators. Law students accustomed to the bipolar model of common-law legal development and who expect statutory law to consist of a simple reading of clear statutory texts can find this interest group pluralist model of law development bewildering. One way to help give context to this complex interaction is to place students in the roles of the various advocates and decision-makers in the environmental law processes. Assigning students to adopt the perspective of various distinct players in the regulatory process, such as agency lawyer, industry lawyer, and environmental NGO lawyer, helps make this complex interaction more accessible to students. This also provides an introduction into the skills of statutory interpretation and regulatory implementation. At Pace Law School, we have had considerable success integrating this approach into an Environmental Law Skills course. This course combines a comprehensive study of the Clean Water Act (CWA) regulatory program with skills-based exercises in administrative rulemaking, judicial review, regulatory permitting, negotiation, and enforcement. The course was added to the curriculum in the 1990s in response to the growing recognition by the legal academy that the traditional case-oriented method of instruction failed to result in law graduates with basic competencies expected of lawyers. The course has been refined over the years to incorporate the Carnegie Report\u27s more recent critiques: the legal education\u27s failure to foster students\u27 development of their professional identities and their understanding of lawyers\u27 role in representing clients. By integrating role-playing, problem solving, and doctrinal instruction, the course seeks to engage students in active learning and professional identity development. The course also seeks to implement recommendations for the improvement of legal instruction contained in Professor Stuckey\u27s influential 2007 report, Best Practices for Legal Education. In particular, the course seeks to “teach doctrine, theory, and practice as part of a unified, coordinated program of instruction” as recommended in that report

Improving the Power Electronics Laboratory teaching/learning process: an interactive web tool

European Higher Education Area; Power Electronics Laboratory; educational methods Resumen: The forthcoming European Higher Education Area implies an important change in the teaching/learning process: it is necessary to get students more involved as well as to promote their independence and active participation. To achieve this objective, the new teaching methodologies aimed at more effective and appropriate learning for professional practice involve the use of audiovisual, computer and multimedia tools on the part of lecturers. Therefore, a web tool, based on a content management system, has been developed for the teaching in Power Electronics Laboratory. Moreover, the use of these multimedia tools makes possible to promote the students independence. Finally, the use of this web tool results in a very significant increase in the motivation students.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech