Unsolicited e-mail has brought much annoyance to users, thus, making e-mail less reliable as a communication tool. This has happened because current email architecture has key limitations. For instance, while it allows senders to send as many messages as they want, it does not provide adequate capability to recipients to prevent unrestricted access to their mailbox. This research develops a new approach to equip recipients with ability to control access to their mailbox.<p>This thesis builds an ownership-based approach to control mailbox usage employing the CyberOrgs model. CyberOrgs is a model that provides facilities to control resources in multi-agent systems. We consider a mailbox to be a precious resource of its owner. Any access to the resource requires its owner's permission. Thus, we give recipients a capability to manage their valuable resource - mailbox. In our approach, message senders obtain a permission to send messages through negotiation. In this negotiation, a sender makes a proposal and the intended recipient evaluates the proposal according to their own policies. A sender's desired outcome of a negotiation is a contract, which conducts the subsequent communication between the sender and the recipient. Contracts help senders and recipients construct a long-term relationship.<p>Besides allowing individuals to control their mailbox, we consider groups, which represent organizations in human society, in order to allow organizations to manage their resources including mailboxes, message sending allowances, and contracts.<p>A prototype based on our approach is implemented. In the prototype, policies are separated from the mechanisms. Examples of policies are presented and a public policy interface is exposed to allow programmers to develop custom policies. Experimental results demonstrate that the system performance is policy-dependent. In other words, as long as policies are carefully designed, communication involving negotiation has minimal overhead compared to communication in which senders deliver messages to recipients directly.

Unsolicited e-mail has brought much annoyance to users, thus, making e-mail less reliable as a communication tool. This has happened because current email architecture has key limitations. For instance, while it allows senders to send as many messages as they want, it does not provide adequate capability to recipients to prevent unrestricted access to their mailbox. This research develops a new approach to equip recipients with ability to control access to their mailbox.<p>This thesis builds an ownership-based approach to control mailbox usage employing the CyberOrgs model. CyberOrgs is a model that provides facilities to control resources in multi-agent systems. We consider a mailbox to be a precious resource of its owner. Any access to the resource requires its owner's permission. Thus, we give recipients a capability to manage their valuable resource - mailbox. In our approach, message senders obtain a permission to send messages through negotiation. In this negotiation, a sender makes a proposal and the intended recipient evaluates the proposal according to their own policies. A sender's desired outcome of a negotiation is a contract, which conducts the subsequent communication between the sender and the recipient. Contracts help senders and recipients construct a long-term relationship.<p>Besides allowing individuals to control their mailbox, we consider groups, which represent organizations in human society, in order to allow organizations to manage their resources including mailboxes, message sending allowances, and contracts.<p>A prototype based on our approach is implemented. In the prototype, policies are separated from the mechanisms. Examples of policies are presented and a public policy interface is exposed to allow programmers to develop custom policies. Experimental results demonstrate that the system performance is policy-dependent. In other words, as long as policies are carefully designed, communication involving negotiation has minimal overhead compared to communication in which senders deliver messages to recipients directly.

Current web browsers are ill-prepared to manage execution of scripts embedded in web pages, because they treat all JavaScript code executing in a page as one unit. All code shares the same namespace, same security domain, and shares uncontrolled access to the same heap; some browsers even use the same thread for multiple tabs or windows. This lack of isolation frequently causes problems that range from loss of functionality to security compromises. ScriptSpace is an abstraction that provides separate, isolated execution environments for parts or all of a web page. Within each ScriptSpace, we maintain the traditional, single-threaded JavaScript environment to provide compatibility with existing code written under this assumption. Multiple ScriptSpaces within a page are isolated with respect to namespace, CPU, and memory consumption. The user has the ability to safely terminate failing scripts without affecting the functionality of still-functional components of the page, or of other pages. We implemented a prototype of ScriptSpace based on the Firefox 3.0 browser. Rather than mapping ScriptSpaces to OS-level threads, we exploit a migrating-thread model in which threads enter and leave the ScriptSpaces associated with the respective sections of the document tree during the event dispatching process. A proportional share scheduler ensures that the number of bytecode instructions executed within each ScriptSpace is controlled. Our prototype can isolate resource-hogging gadgets within an iGoogle Mashup page as well as across multiple pages loaded in the browser and still retain interactive response. / Master of Science

In the near future, demand for Heterogeneous Wireless Networking (HWN) is expected to increase. HWNs are formed by integration of different communication technologies, for example the integration of wireless LAN and cellular networks, to support mobile users. QoS provisioning in these networks is a challenging issue given the diversity in wireless technologies and the existence of mobile users with different communication requirements. In this thesis, we consider optimal resource planning and dynamic resource management for HWNs. In the first part of this thesis, we examine the optimal deployment of such networks. We propose a mobility-aware network planning optimization in which the objective is to minimize the rate of upward vertical handovers while maximizing the total number of users accommodated by the network. The optimal placement of Access Points (AP) with respect to these two objectives is formulated as an integer programming problem. Our results show that considering the mobility pattern in the planning phase of network deployment can significantly improve infrastructure performance. In the second part, we investigate optimal admission control policies employed in maintaining QoS in HWNs. Here we consider two cases: integration of cellular overlay with a single WLAN AP, and integration with a WLAN mesh network. A decision theoretic framework for the problem is derived using a dynamic programming formulation. In the case of single WLAN AP and cellular overlay, we prove that for this two-tier wireless network architecture, the optimal policy has a two-dimensional threshold structure. Furthermore, this structural result is used to design two computationally efficient algorithms, Structured Value Iteration and Structured Update Value Iteration. These algorithms can be used to determine the optimal policy in terms of thresholds. Although the first one is closer in its operation to the conventional Value Iteration algorithm, the second one has a significantly lower complexity. In the second case where the underlay is a complex WLAN mesh network, we develop a Partially Observable Markov-Modulated Poisson Process (PO-MMPP) traffic model to characterize the overflow traffic from the underlaying mesh to the overlay. This model captures the burstiness of the overflow traffic under the imperfect observability of the mesh network states. Then, by modeling the overlay network as a controlled PO-MMPP/M/C/C queueing system and obtaining structured decision theoretic results, it is shown that the optimal control policy for this class of HWNs can be characterized as monotonic \emph{threshold curves}. Moreover, these results are used to design a computationally efficient algorithm to determine the optimal policy in terms of thresholds. Extensive numerical observations suggest that, in both cases and for all practical parameter sets, the algorithms converge to the overall optimal policy. Additionally, numerical results show that the proposed algorithms are efficient in terms of time-complexity and in achieving optimal performance by significantly reducing the probability of dropped and blocked calls.

In the near future, demand for Heterogeneous Wireless Networking (HWN) is expected to increase. HWNs are formed by integration of different communication technologies, for example the integration of wireless LAN and cellular networks, to support mobile users. QoS provisioning in these networks is a challenging issue given the diversity in wireless technologies and the existence of mobile users with different communication requirements. In this thesis, we consider optimal resource planning and dynamic resource management for HWNs. In the first part of this thesis, we examine the optimal deployment of such networks. We propose a mobility-aware network planning optimization in which the objective is to minimize the rate of upward vertical handovers while maximizing the total number of users accommodated by the network. The optimal placement of Access Points (AP) with respect to these two objectives is formulated as an integer programming problem. Our results show that considering the mobility pattern in the planning phase of network deployment can significantly improve infrastructure performance. In the second part, we investigate optimal admission control policies employed in maintaining QoS in HWNs. Here we consider two cases: integration of cellular overlay with a single WLAN AP, and integration with a WLAN mesh network. A decision theoretic framework for the problem is derived using a dynamic programming formulation. In the case of single WLAN AP and cellular overlay, we prove that for this two-tier wireless network architecture, the optimal policy has a two-dimensional threshold structure. Furthermore, this structural result is used to design two computationally efficient algorithms, Structured Value Iteration and Structured Update Value Iteration. These algorithms can be used to determine the optimal policy in terms of thresholds. Although the first one is closer in its operation to the conventional Value Iteration algorithm, the second one has a significantly lower complexity. In the second case where the underlay is a complex WLAN mesh network, we develop a Partially Observable Markov-Modulated Poisson Process (PO-MMPP) traffic model to characterize the overflow traffic from the underlaying mesh to the overlay. This model captures the burstiness of the overflow traffic under the imperfect observability of the mesh network states. Then, by modeling the overlay network as a controlled PO-MMPP/M/C/C queueing system and obtaining structured decision theoretic results, it is shown that the optimal control policy for this class of HWNs can be characterized as monotonic \emph{threshold curves}. Moreover, these results are used to design a computationally efficient algorithm to determine the optimal policy in terms of thresholds. Extensive numerical observations suggest that, in both cases and for all practical parameter sets, the algorithms converge to the overall optimal policy. Additionally, numerical results show that the proposed algorithms are efficient in terms of time-complexity and in achieving optimal performance by significantly reducing the probability of dropped and blocked calls.

ABSTRACT The Niger Delta region of Nigeria has in recent years been a hotbed of conflict. The region has been embroiled in turmoil over the struggle for the control of the vast resources of the region. There has arisen a controversy over the cause of the struggle. Closely associated with this controversy is the confusion over the terms ‘resource control’ and ‘increase in revenue’. Though the Supreme Court, the apex court in Nigeria has delivered a landmark judgment on the issue of resource control, the last is yet to be heard on the matter. There is a lacuna in the law as an appropriate revenue allocation formula is yet to be fixed for Nigeria. This work examines whether the people of the Niger Delta region of Nigeria are entitled to the right to resource control. It will examine the Supreme Court’s decision in A.G. Federation v. A.G. Abia & 35 ors. and discuss on the possibility of fashioning out an acceptable revenue allocation formula for Nigeria.

Il existe de nombreuses approches développées par la communauté Implicit Computational Complexity (ICC) permettant d'analyser les ressources nécessaires à la bonne exécution des algorithmes. Dans cette thèse, nous nous intéressons plus particulièrement au contrôle des ressources à l'aide d'interprétations sémantiques. Après avoir rappelé brièvement la notion de quasi-interprétation ainsi que les différentes propriétés et caractérisations qui en découlent, nous présentons les différentes avancées obtenues dans l'étude de cet outil : nous étudions le problème de la synthèse qui consiste à trouver une quasi-interprétation pour un programme donné, puis, nous abordons la question de la modularité des quasi-interprétations. La modularité permet de diminuer la complexité de la procédure de synthèse et de capturer un plus grand nombre d'algorithmes. Après avoir mentionné différentes extensions des quasi-interprétations à des langages de programmation réactifs, bytecode ou d'ordre supérieur, nous introduisons la sup-interprétation. Cette notion généralise la quasi-interprétation et est utilisée dans des critères de contrôle des ressources afin d'étudier la complexité d'un plus grand nombre d'algorithmes dont des algorithmes sur des données infinies ou des algorithmes de type diviser pour régner. Nous combinons cette notion à différents critères de terminaison comme les ordres RPO, les paires de dépendance ou le size-change principle et nous la comparons à la notion de quasi-interprétation. En outre, après avoir caractérisé des petites classes de complexité parallèles, nous donnons quelques heuristiques permettant de synthétiser des sup-interprétations sans la propriété sous-terme, c'est à dire des sup-interprétations qui ne sont pas des quasi-interprétations. Enfin, dans un dernier chapitre, nous adaptons les sup-interprétations à des langages orientés-objet, obtenant ainsi différents critères pour contrôler les ressources d'un programme objet et de ses méthodes / There are several approaches developed by the Implicit Computational Complexity (ICC) community which try to analyze and control program resources. In this document, we focus our study on the resource control with the help of semantics interpretations. After introducing the notion of quasi-interpretation together with its distinct properties and characterizations, we show the results obtained in the study of such a tool: We study the synthesis problem which consists in finding a quasi-interpretation for a given program and we tackle the issue of quasi-interpretation modularity. Modularity allows to decrease the complexity of the synthesis procedure and to capture more algorithms. We present several extensions of quasi-interpretations to reactive programming, bytecode verification or higher-order programming. Afterwards, we introduce the notion of sup-interpretation. This notion strictly generalizes the one of quasi-interpretation and is used in distinct criteria in order to control the resources of more algorithms, including algorithms over infinite data and algorithms using a divide and conquer strategy. We combine sup-interpretations with distinct termination criteria, such as RPO orderings, dependency pairs or size-change principle, and we compare them to the notion of quasi-interpretation. Using the notion of sup-interpretation, we characterize small parallel complexity classes. We provide some heuristics for the sup-interpretation synthesis: we manage to synthesize sup-interpretations without the subterm property, that is, sup-interpretations which are not quasi-interpretations. Finally, we extend sup-interpretations to object-oriented programs, thus obtaining distinct criteria for resource control of object-oriented programs and their methods

Social dominance is an inherent component of human social organization (Hawley, 1999, Ryff & Singer, 2000; Uchino, Cacioppo, & Kiecolt-Glaser, 1996). Some behaviors typically associated with gaining dominance (e.g., bullying, aggression), have been linked with maladaptive outcomes (Hawley, 2016). However, Resource Control Theory (RCT) highlights the adaptive role of the prosocial (e.g., sharing, cooperating) and the coercive (e.g., taking, threatening) strategies that youth use to gain resources within their peer group (Hawley, 2003a). These behaviors may have important implications for individuals’ physiological stress reactivity, particularly during middle childhood when youth are undergoing rapid cognitive and social development (Parker et al., 2006). The overall goal of the current study was to examine whether patterns of prosocial and coercive resource control strategy use were associated with autonomic nervous system reactivity in a sample of 9-12 year old children. Specifically, this study used person-centered analyses to investigate whether membership in groups based on resource control strategy use was associated with measures of autonomic nervous system reactivity (i.e., skin conductance [SCL-R], heart rate [HR-R], and systolic and diastolic blood pressure [SBP-R, DBP-R, respectively]). This study also utilized variable-centered analyses to investigate whether coercive resource control strategies were associated with these measures of autonomic nervous system reactivity, and whether this relationship was moderated by prosocial resource control strategies. This study also investigated whether these associations were present in the context of social and non-social stressor tasks. One hundred children (50% female, Mage = 10.47 years) and one of their parents participated in the current study and were recruited from the community in a small northeastern city. Participants’ SCL-R, HR-R, SBP-R, and DBP-R were assessed using a stress protocol during which they discussed an experience of relational victimization (e.g., being left out), played an online ball-tossing game designed to mimic social exclusion experiences, and completed a mirror-tracing task. Levels of prosocial and coercive resource control strategy use were gathered using parent report. Findings suggested that, during the discussion of a relational victimization experience, the association between coercive control strategies and HR-R was moderated by prosocial control strategies. Specifically, for those low in prosocial control strategies, lower coercive control strategies were associated with increased HR-R. In contrast, in the context of the online ball-tossing game, the associations between coercive control strategies and both SBP-R and DBP-R, respectively, were moderated by prosocial control strategies. Specifically, for those low in prosocial control strategies, higher coercive control strategies were associated with both increased SBP-R and DBP-R. No other outcome measures were associated with main effects of resource control strategies or an interaction between coercive and prosocial control strategies. These patterns suggest that resource control strategy use may be differentially related to HR-R and blood pressure reactivity. Additionally, this pattern may have resulted from differences in the characteristics of the social stressor tasks. Though more research is needed, this study provides the first step in investigating the associations between resource control strategies and long-term physical health in children. This may have important implications for the development of intervention and prevention programs that will help improve the physical health of youth.

A state of conflict has existed in the Niger Delta for fifty years. The nature of the conflict, whether it is terrorism or civil insurrection, has not been resolved by the respective legislative entities. This qualitative case study was designed to explore the nature of the Niger Delta conflict from the perspective of several members of the Nigerian National Assembly and determine whether terrorism in Nigeria is related to the general conflict. Social conflict theory provided the basis for the exploration. An ancillary question explored whether antiterrorism legislation in 2006 alleviated the Niger Delta conflict. Interview data were collected from 1 senator and 5 representatives of the Nigerian National Assembly. These data were inductively coded and manually analyzed for major themes, and then triangulated with a review of internal and public documents pertaining to the relevant legislation. The study established that the root causes of the Niger Delta conflict were economic inequities. Three conclusions were drawn from the case study and data regarding legislative attempts to address the conflict: (1) the antiterrorism legislation of 2006 did not criminalize the Niger Delta conflict, (2) the legislation did not have an impact on fiscal resource allocations to the region, and (3) no link between the conflict and current terrorism activities in Nigeria was evident. Recommendations are given for the Nigerian state to engage in fiscal federalism as a means of equitable allocations of resources to the region, thereby contributing to positive social change.

The runtime environments provided by application-level virtual machines such as the Java Virtual Machine or the .NET Common Language Runtime are attractive for Internet application providers because the applications can be deployed on any platform that supports the target virtual machine. With Internet applications, organisations as well as end users face the risk of viruses, trojans, and denial of service attacks. Virtual machine providers are aware of these Internet security risks and provide, for example, runtime monitoring of untrusted code and access control to sensitive resources. Our work addresses two important security issues in runtime environments. The first issue concerns resource or release control. While many virtual machines provide runtime access control to resources, they do not provide any means of limiting the use of a resource once access is granted; they do not provide so-called resource control. We have addressed the issue of resource control in the example of the Java Virtual Machine. In contrast to others’ work, our solution builds on an enhancement to the existing security architecture. We demonstrate that resource control permissions for Java-mediated resources can be integrated into the regular Java security architecture, thus leading to a clean design and a single external security policy. The second issue that we address is the usabilityhttps://www.diva-portal.org/liu/webform/form.jsp DiVA Web Form and security of the setup of security policies for runtime environments. Access control decisions are based on external configuration files, the security policy, which must be set up by the end user. This set-up is security-critical but also complicated and errorprone for a lay end user and supportive, usable tools are so far missing. After one of our usability studies signalled that offline editing of the configuration file is inefficient and difficult for end users, we conducted a usability study of personal firewalls to identify usable ways of setting up a security policy at runtime. An analysis of general user help techniques together with the results from the two previous studies resulted in a proposal of design guidelines for applications that need to set up a security policy. Our guidelines have been used for the design and implementation of the tool JPerM that sets the Java security policy at runtime. JPerM evaluated positively in a usability study and supports the validity of our design guidelines.