Modeling security and cooperation in wireless networks using game theory

This research involves the design, development, and theoretical demonstration of models resulting in integrated misbehavior resolution protocols for ad hoc networked devices. Game theory was used to analyze strategic interaction among independent devices with conflicting interests. Packet forwarding at the routing layer of autonomous ad hoc networks was investigated. Unlike existing reputation based or payment schemes, this model is based on repeated interactions. To enforce cooperation, a community enforcement mechanism was used, whereby selfish nodes that drop packets were punished not only by the victim, but also by all nodes in the network. Then, a stochastic packet forwarding game strategy was introduced. Our solution relaxed the uniform traffic demand that was pervasive in other works. To address the concerns of imperfect private monitoring in resource aware ad hoc networks, a belief-free equilibrium scheme was developed that reduces the impact of noise in cooperation. This scheme also eliminated the need to infer the private history of other nodes. Moreover, it simplified the computation of an optimal strategy. The belief-free approach reduced the node overhead and was easily tractable. Hence it made the system operation feasible. Motivated by the versatile nature of evolutionary game theory, the assumption of a rational node is relaxed, leading to the development of a framework for mitigating routing selfishness and misbehavior in Multi hop networks. This is accomplished by setting nodes to play a fixed strategy rather than independently choosing a rational strategy. A range of simulations was carried out that showed improved cooperation between selfish nodes when compared to older results. Cooperation among ad hoc nodes can also protect a network from malicious attacks. In the absence of a central trusted entity, many security mechanisms and privacy protections require cooperation among ad hoc nodes to protect a network from malicious attacks. Therefore, using game theory and evolutionary game theory, a mathematical framework has been developed that explores trust mechanisms to achieve security in the network. This framework is one of the first steps towards the synthesis of an integrated solution that demonstrates that security solely depends on the initial trust level that nodes have for each other.^

The United States Congress and Venezuela's Hugo Chávez

The Soviet Union's dissolution in December 1991 marks the end of the Cold War and the elimination of the United States' main rival for global political-economic leadership. For decades U.S. foreign policymakers had formulated policies aimed at containing the spread of Soviet communism and Moscow's interventionist policies in the Americas. They now assumed that Latin American leftist revolutionary upheavals could also be committed to history. This study explores how Congress takes an active role in U.S. foreign policymaking when dealing with revolutionary changes in Latin America. This study finds that despite Chávez's vitriolic statements and U.S. economic vulnerability due to its dependence on foreign oil sources, Congress today sees Chávez as a nuisance and not a threat to U.S. vital interests. Devoid of an extra-hemispheric, anti-American patron intent on challenging the United States for regional leadership, Chávez is seen by Congress largely as a threat to the stability of Venezuela's institutions and political-economic stability. Today both the U.S. executive and the legislative branches largely see Bolivarianism a distraction and not an existential threat. The research is based on an examination of Bolivarian Venezuela compared to revolutionary upheaval and governance in Nicaragua over the course of the twentieth century. This project is largely descriptive, qualitative in approach, but quantitative data are used when appropriate. To analyze both the U.S. executive and legislative branches' reaction to revolutionary change, Cole Blasier's theoretical propositions as developed in the Hovering Giant: U.S. Responses to Revolutionary Change in Latin America 1910-1985 are utilized. The present study highlights the fact that Blasier's propositions remain a relevant means for analyzing U.S. foreign policymaking.

The United States Congress and Venezuela's Hugo Chávez

The Soviet Union's dissolution in December 1991 marks the end of the Cold War and the elimination of the United States' main rival for global political-economic leadership. For decades U.S. foreign policymakers had formulated policies aimed at containing the spread of Soviet communism and Moscow's interventionist policies in the Americas. They now assumed that Latin American leftist revolutionary upheavals could also be committed to history. This study explores how Congress takes an active role in U.S. foreign policymaking when dealing with revolutionary changes in Latin America. This study finds that despite Chavez's vitriolic statements and U.S. economic vulnerability due to its dependence on foreign oil sources, Congress today sees Chavez as a nuisance and not a threat to U.S. vital interests. Devoid of an extra-hemispheric, anti-American patron intent on challenging the United States for regional leadership, Chavez is seen by Congress largely as a threat to the stability of Venezuela's institutions and political-economic stability. Today both the U.S. executive and the legislative branches largely see Bolivarianism a distraction and not an existential threat. The research is based on an examination of Bolivarian Venezuela compared to revolutionary upheaval and governance in Nicaragua over the course of the twentieth century. This project is largely descriptive, qualitative in approach, but quantitative data are used when appropriate. To analyze both the U.S. executive and legislative branches' reaction to revolutionary change, Cole Blasier's theoretical propositions as developed in the Hovering Giant: U.S. Responses to Revolutionary Change in Latin America 1910- 1985 are utilized. The present study highlights the fact that Blasier's propositions remain a relevant means for analyzing U.S. foreign policymaking.

Disciplining democracy: United Nations peacekeeping, international security and democratization in the post -Cold War era

After the end of the Cold War, democratization and good governance became the organizing concepts for activities of the United Nations, regional organizations and states in the fields of peace, development and security. How can this increasing interest in democratization and its connection with international security be explained? This dissertation applies the theoretical tools developed by Michel Foucault in his discussions of disciplinarity and government to the analysis of the United Nations debate on democracy in the 1990s, and of two United Nations pro-democracy peacekeeping operations and their aftermath: the United Nations interventions in Haiti and Croatia. It probes “how” certain techniques of power came into being and describes their effects, using as data the texts that elaborate the United Nations understanding of democracy and the texts that constitute peacekeeping. ^ In the face of the proliferation of unpredictable threats in the last decades of the twentieth century a new form of international power emerged. Order in the international arena increasingly was maintained through activities aimed at reducing risk and increasing predictability through the normalization of “rogue” states. The dissertation shows that in the context of these activities, which included but were not limited to UN peacekeeping, normality was identified with democracy, non-democratic regimes with international threats, and democratization with international security. “Good governance” doctrines translated the political debate on democracy into the technical language of functioning state institutions. International organizations adopted good governance as the framework that made democratization a universal task within the reach of their expertise. In Haiti, the United Nations engaged in efforts to transform punishment institutions (the judiciary, police and the prison) into disciplined and disciplinary machines. In Croatia, agreements signed in the context of peacekeeping established in detail the rules of functioning of administrations and the monitoring mechanisms for their implementation. However, in Haiti, the institutions promoted were not sustainable. And in Croatia reforms are stalled by lack of consensus. ^ This dissertation puts efforts to bring about democracy through peacekeeping in the context of a specific modality of power and suggests caution in engaging in universal normalizing endeavors. ^

Comparison of coronary heart disease risk factors in foreign -born and United States-born Afro Caribbean Americans and African Americans in south Florida

In a cross-sectional study design, risk factors for coronary heart disease (CHD) were evaluated in three groups: 66 Afro Caribbeans (FBCA) living in the US for less than 10 years, 62 US-born Afro Caribbean (USBCA) and 61 African American (AA) adults (18–40 years), with equal numbers of males and females in each group. Socio-demographic, dietary, anthropometric and blood pressure data were collected. Fasting blood glucose, blood lipids and high-sensitivity C-reactive protein (hs-CRP) were determined. ^ The USBCA and AA participants compared to the FBCA participants consumed significantly (p < 0.05) more mean total fat (g) (66.3 ± 41.7 and 73.0 ± 47.8 vs. 52.8 ± 32.3), saturated fat (g) (23.1 ± 14.9 and 24.9 ± 15.8 vs. 18.6 ± 11.5), percent energy from fat (%) (33.1 ± 6.5 and 31.4 ± 6.4 vs. 29.3 ± 6.8), fat servings (1.8 ± 1.2 and 1.5 ± 1.0 vs. 1.2 ± 0.9), dietary cholesterol (mg) (220.4 ± 161.9 and 244.1 ± 155.0 vs. 168.8 ± 114.0) and sodium (mg) (2245.2 ± 1238.3 and 2402.6 ± 1359.3 vs. 1838.0 ± 983.4) and less than 2 servings of fruits per day (%) (86.9 and 94.9 vs. 78.5). These differences were more pronounced in males compared to females and remained after correcting for age. Also, the percentages of USBCA and AA participants who were obese (17.1% and 23.0%, respectively) were significantly (p < 0.05) higher compared to FBCA (7.6%) participants. More USBCA and AA than FBCA individuals smoked cigarettes (4.8% and 6.6% vs. 0.0%) and consumed alcoholic beverages (29.0% and 50.8% vs. 24.2%). The mean hs-CRP level of the AA participants (2.2 ± 2.7 mg/L) was significantly (p < 0.01) higher compared to the FBCA (1.1 ± 1.3 mg/L) and USBCA (1.3 ± 1.6 mg/L) participants. ^ The FBCA participants had a better CHD risk profile than the USBCA and AA participants. Focus should be placed on the ethnic and cultural differences in a population to better understand the variations in health indicators among different ethnic groups of the same race. This focus can provide healthcare professionals and policy planners with the opportunity to develop culturally sensitive programs and strategies for the improvement of health outcomes. ^

The effect of an enriched learning community on success and retention in chemistry courses

Since the mid-1990s, the United States has experienced a shortage of scientists and engineers, declining numbers of students choosing these fields as majors, and low student success and retention rates in these disciplines. Learning theorists, educational researchers, and practitioners believe that learning environments can be created so that an improvement in the numbers of students who complete courses successfully could be attained (Astin, 1993; Magolda & Terenzini, n.d.; O'Banion, 1997). Learning communities do this by providing high expectations, academic and social support, feedback during the entire educational process, and involvement with faculty, other students, and the institution (Ketcheson & Levine, 1999). ^ A program evaluation of an existing learning community of science, mathematics, and engineering majors was conducted to determine the extent to which the program met its goals and was effective from faculty and student perspectives. The program provided laptop computers, peer tutors, supplemental instruction with and without computer software, small class size, opportunities for contact with specialists in selected career fields, a resource library, and Peer-Led Team Learning. During the two years the project has existed, success, retention, and next-course continuation rates were higher than in traditional courses. Faculty and student interviews indicated there were many affective accomplishments as well. ^ Success and retention rates for one learning community class ( n = 27) and one traditional class (n = 61) in chemistry were collected and compared using Pearson chi square procedures ( p = .05). No statistically significant difference was found between the two groups. Data from an open-ended student survey about how specific elements of their course experiences contributed to success and persistence were analyzed by coding the responses and comparing the learning community and traditional classes. Substantial differences were found in their perceptions about the lecture, the lab, other supports used for the course, contact with other students, helping them reach their potential, and their recommendation about the course to others. Because of the limitation of small sample size, these differences are reported in descriptive terms. ^

Human Security and Crime in Latin America: The political Capital and Political Impact of Criminal Groups and Belligerents Involved in Illicit Economies

Organized crime and illegal economies generate multiple threats to states and societies. But although the negative effects of high levels of pervasive street and organized crime on human security are clear, the relationships between human security, crime, illicit economies, and law enforcement are highly complex. By sponsoring illicit economies in areas of state weakness where legal economic opportunities and public goods are seriously lacking, both belligerent and criminal groups frequently enhance some elements of human security of the marginalized populations who depend on illicit economies for basic livelihoods. Even criminal groups without a political ideology often have an important political impact on the lives of communities and on their allegiance to the State. Criminal groups also have political agendas. Both belligerent and criminal groups can develop political capital through their sponsorship of illicit economies. The extent of their political capital is dependent on several factors. Efforts to defeat belligerent groups by decreasing their financial flows through suppression of an illicit economy are rarely effective. Such measures, in turn, increase the political capital of anti-State groups. The effectiveness of anti-money laundering measures (AML) also remains low and is often highly contingent on specific vulnerabilities of the target. The design of AML measures has other effects, such as on the size of a country’s informal economy. Multifaceted anti-crime strategies that combine law enforcement approaches with targeted socio-economic policies and efforts to improve public goods provision, including access to justice, are likely to be more effective in suppressing crime than tough nailed-fist approaches. For anti-crime policies to be effective, they often require a substantial, but politically-difficult concentration of resources in target areas. In the absence of effective law enforcement capacity, legalization and decriminalization policies of illicit economies are unlikely on their own to substantially reduce levels of criminality or to eliminate organized crime. Effective police reform, for several decades largely elusive in Latin America, is one of the most urgently needed policy reforms in the region. Such efforts need to be coupled with fundamental judicial and correctional systems reforms. Yet, regional approaches cannot obliterate the so-called balloon effect. If demand persists, even under intense law enforcement pressures, illicit economies will relocate to areas of weakest law enforcement, but they will not be eliminated.

Consolidating Security and Development in Colombia: Lessons for Peru and Panama

Colombia's increasingly effective efforts to mitigate the power of the FARC and other illegitimately armed groups in the country can offer important lessons for the Peruvian government as it strives to prevent a resurgence of Sendero Luminoso and other illegal non-state actors. Both countries share certain particular challenges: deep economic, social, and in the case of Peru ethnic divisions, the presence of and/or the effects of violent insurgencies, a large-scale narcotics production and trafficking, and a history of weak state presence in large tracts of isolated and scarcely-populated areas. Important differences exist, however in the nature of the insurgencies in the two countries, the government response to them and the nature of government and society that affects the applicability of Colombia's experience to Peru. The security threat to Panama from drug trafficking and Colombian insurgents --often a linked phenomenon-- are in many ways different from the drug/insurgent factor in Colombia itself and in Peru, although there are similar variables. Unlike the Colombian and Peruvian cases, the security threat in Panama is not directed against the state, there are no domestic elements seeking to overthrow the government -- as the case of the FARC and Sendero Luminoso, security problems have not spilled over from rural to urban areas in Panama, and there is no ideological component at play in driving the threat. Nor is drug cultivation a major factor in Panama as it is in Colombia and Peru. The key variable that is shared among all three cases is the threat of extra-state actors controlling remote rural areas or small towns where state presence is minimal. The central lesson learned from Colombia is the need to define and then address the key problem of a "sovereignity gap," lack of legitimate state presence in many part of the country. Colombia's success in broadening the presence of the national government between 2002 and the presence is owed to many factors, including an effective national strategy, improvements in the armed forces and police, political will on the part of government for a sustained effort, citizen buy-in to the national strategy, including the resolve of the elite to pay more in taxes to bring change about, and the adoption of a sequenced approach to consolidated development in conflicted areas. Control of territory and effective state presence improved citizen security, strengthened confidence in democracy and the legitimate state, promoted economic development, and helped mitigate the effect of illegal drugs. Peru can benefit from the Colombian experience especially in terms of the importance of legitimate state authority, improved institutions, gaining the support of local citizens, and furthering development to wean communities away from drugs. State coordinated "integration" efforts in Peru as practiced in Colombia have the potential for success if properly calibrated to Peruvian reality, coordinated within government, and provided with sufficient resources. Peru's traditionally weak political institutions and lack of public confidence in the state in many areas of the country must be overcome if this effort is to be successful.

Effects of cooperative and individual integrated learning system on attitudes and achievement in mathematics

This study compares the effects of cooperative delivery (CD) and individual delivery (ID) of integrated learning system (ILS) instruction in mathematics on achievement, attitudes and behaviors in adult (16-21 yrs.) high school students (grades 9-13). The study was conducted in an urban adult high school in Miami-Dade County Public Schools using a pre-test/post-test design. Achievement was measured using the Test of Adult Basic Education (TABE) by CTB MC-Graw-Hill and Compass Learning. An attitudinal survey measured attitudes towards mathematics, the computer-related lessons, and attitudes toward group activities. Behavior was assessed using computer lab observations. ^ Two-way analyses of variance (ANOVA) were conducted on achievement (TABE and Compass) by group and time (pre and post). A one-way ANOVA was conducted on the overall attitude by group on the five components (i.e., content mathematics, delivery/computers, cooperative, partners, and self efficacy) and a one-way ANOVA was conducted on the on-task behavior by group. ^ The results of the study revealed that CD and ID students working on mathematics activities delivered by the ILS performed similarly on achievement tests of the TABE. The CD-ILS students had significantly better overall mathematics attitudes than the ID-ILS students and the ID-ILS group was on-task significantly more than the CD-ILS group. This study concludes that regularity and period of time over which the ILS is used may prove to be important variables although there were insufficient data to fully investigate the impact of models of use. Additionally, a minimum amount of time-on-system is necessary before gains can become apparent in innumeracy and increasing exposure to the system may have beneficial effects on learning. ^

Effect of the Florida A+ Plan on curriculum and instruction in Title I public elementary schools

The purpose of this research was to study the effect of the Florida A+ Plan accountability program on curriculum and instruction in four Title I public elementary schools in the Miami-Dade County Public Schools system. It focused on the experiences of the school principals and the classroom teachers of the four schools as they related to curriculum and instruction. The study included an analysis of the school improvement plans in curriculum and instruction for each school during the school years 1998-2004. ^ The study was conducted in the format of interviews with the school principals and principal selected classroom teachers who taught third, fourth, or fifth grade during the first six years of the Florida A+ Plan. The analysis of the school improvement plans focused on the implementation of curriculum and instruction for each of the four schools. It focused on the goals and measurable objectives selected by each school to improve its instructional program in the academic subjects of reading, mathematics, writing, and science. ^ The findings indicated that under the pressure to improve their school grade on the Florida A+ Plan, each of the target schools, based on individual needs assessments, and restructured their instructional program each school year as documented in their school improvement plans. They altered their programs by analyzing student performance data to realign curriculum and instruction. The analysis of the interviews with the principals and the teachers showed that each school year they restructured their program to align it with the FCAT content. This realigning was a collaborative effort on the part of the administration and the instructional staff. ^

Effects of Cooperative and Individual Integrated Learning System on Attitudes and Achievement in Mathematics

The purpose of this study was to determine the effects of a computer-based Integrated Learning Systems (ILS) model used with adult high school students engaging mathematics activities. This study examined achievement, attitudinal and behavior differences between students completing ILS activities in a traditional, individualized format compared to cooperative learning groups.

Current Research on Immigration and Transnationalism in the Americas: Main Problems, Approaches, and Methods [Colloquium]

This flyer provides the full program for the colloquium “Current Research on Immigration and Transnationalism in the Americas: Main Problems, Approaches, and Methods”.

Computer interaction : its effect on attitude and performance in older adults

This study examined the interaction of age, attitude, and performance within the context of an interactive computer testing experience. Subjects were 13 males and 47 females between the ages of 55 and 82, with a minimum of a high school education. Initial attitudes toward computers, as measured by the Cybernetics Attitude Scale (CAS), demonstrated overall equivalence between these older subjects and previously tested younger subjects. Post-intervention scores on the CAS indicated that attitudes toward computers were unaffected by either a "fun" or a "challenging" computer interaction experience. The differential effects of a computerized vs. a paperand- pencil presentation format of a 20-item, multiple choice vocabulary test were examined. Results indicated no significant differences in the performance of subjects in the two conditions, and no interaction effect between attitude and performance. These findings suggest that the attitudes of older adults towards computers do not affect their computerized testing performance, at least for short term testing of verbal abilities. A further implication is that, under the conditions presented here, older subjects appear to be unaffected by mode of testing. The impact of recent advanced in technology on older adults is discussed.

Reaganomics and its effects on pricing and participation in the regular paying sector of the National School Lunch Program in Dade County public high schools

Problem: This research proposes to examine the effects of Reaganomics on pricing and participation in the regular paying sector of the National School Lunch Program in Dade County Public High Schools. Subproblems: The first subproblem is to examine the effects of Reaganomics on pricing in the regular paying sector of the National School Lunch Program in Dade County Public High Schools. The second subproblem is to examine the effects of Reaganomics on participation in the regular paying sector of the National School Lunch Program in Dade County Public High Schools. Hypotheses: The first hypothesis is that Reaganomics has resulted in price increases to the regular paying sector of the National School Lunch Program in Dade County Public High Schools. The second hypothesis is that Reaganomics has decreased the percentage of the regular paying sector participating in the National School Lunch Program in Dade County Public High Schools.

Hands-On Activities and Engagement in Kindergarten Students

The purpose of this action research study is to investigate the effectiveness of implementing hands-on activities for increasing the engagement of kindergarten students. Participants will be the teacher/researcher’s 18 kindergarten students in a charter school. It is hypothesized that hands-on activities will increase students’ engagement in the class.