Dynamic Resource Allocation in Wireless Heterogeneous Networks

Deployment of low power basestations within cellular networks can potentially increase both capacity and coverage. However, such deployments require efficient resource allocation schemes for managing interference from the low power and macro basestations that are located within each other’s transmission range. In this dissertation, we propose novel and efficient dynamic resource allocation algorithms in the frequency, time and space domains. We show that the proposed algorithms perform better than the current state-of-art resource management algorithms. In the first part of the dissertation, we propose an interference management solution in the frequency domain. We introduce a distributed frequency allocation scheme that shares frequencies between macro and low power pico basestations, and guarantees a minimum average throughput to users. The scheme seeks to minimize the total number of frequencies needed to honor the minimum throughput requirements. We evaluate our scheme using detailed simulations and show that it performs on par with the centralized optimum allocation. Moreover, our proposed scheme outperforms a static frequency reuse scheme and the centralized optimal partitioning between the macro and picos. In the second part of the dissertation, we propose a time domain solution to the interference problem. We consider the problem of maximizing the alpha-fairness utility over heterogeneous wireless networks (HetNets) by jointly optimizing user association, wherein each user is associated to any one transmission point (TP) in the network, and activation fractions of all TPs. Activation fraction of a TP is the fraction of the frame duration for which it is active, and together these fractions influence the interference seen in the network. To address this joint optimization problem which we show is NP-hard, we propose an alternating optimization based approach wherein the activation fractions and the user association are optimized in an alternating manner. The subproblem of determining the optimal activation fractions is solved using a provably convergent auxiliary function method. On the other hand, the subproblem of determining the user association is solved via a simple combinatorial algorithm. Meaningful performance guarantees are derived in either case. Simulation results over a practical HetNet topology reveal the superior performance of the proposed algorithms and underscore the significant benefits of the joint optimization. In the final part of the dissertation, we propose a space domain solution to the interference problem. We consider the problem of maximizing system utility by optimizing over the set of user and TP pairs in each subframe, where each user can be served by multiple TPs. To address this optimization problem which is NP-hard, we propose a solution scheme based on difference of submodular function optimization approach. We evaluate our scheme using detailed simulations and show that it performs on par with a much more computationally demanding difference of convex function optimization scheme. Moreover, the proposed scheme performs within a reasonable percentage of the optimal solution. We further demonstrate the advantage of the proposed scheme by studying its performance with variation in different network topology parameters.

The socioeconomic gradient in health: The role of intra-household resource allocation

This paper aims to analyse the impact of different household financial regimes on the health status of males and females in a number of European countries. Using the EU-SILC 2010 on intra-household sharing of resources, we find that each member of the couple is worse off if his/her partner has most decision-making responsibilities. Additionally, the presence of children in the household plays a role in the effect that household financial regimens exert on individual self-assessed health, especially among females. We conclude that family arrangements regarding resource allocation and decision-making have important consequences and should be given some attention in the task of identifying individuals predisposed to health problems.

Robust control for power sharing in microgrids with low-inertia wind and PV generators

This paper presents a robust control design scheme for a multidistributed energy resource (DER) microgrid for power sharing in both interconnected and islanded modes. The scheme is proposed for micgrogrids consisting of photovoltaic (PV) units and wind turbine driven doubly fed induction generators (DFIGs). A battery is integrated with each of the wind and solar DER units. The control scheme has two levels: 1) one centralized multi-input–multi-output robust controller for regulating the set reference active and reactive powers and 2) local real and reactive power droop con-trollers, one on each DER unit. The robust control scheme utilizes multivariable H1 control to design controllers that are robust to the changes in the network and system nonlinearities. The effectiveness of the proposed controller is demonstrated through large-distur-bance simulations, with complete nonlinear models, on a test micro-grid. It is found that the power sharing controllers provide excellent performance against large disturbances and load variations during islanding transients and interconnected operation.

A secure and efficient data sharing framework with delegated capabilities in hybrid cloud

Hybrid cloud is a widely used cloud architecture in large companies that can outsource data to the publiccloud, while still supporting various clients like mobile devices. However, such public cloud data outsourcing raises serious security concerns, such as how to preserve data confidentiality and how to regulate access policies to the data stored in public cloud. To address this issue, we design a hybrid cloud architecture that supports data sharing securely and efficiently, even with resource-limited devices, where private cloud serves as a gateway between the public cloud and the data user. Under such architecture, we propose an improved construction of attribute-based encryption that has the capability of delegating encryption/decryption computation, which achieves flexible access control in the cloud and privacy-preserving in datautilization even with mobile devices. Extensive experiments show the scheme can further decrease the computational cost and space overhead at the user side, which is quite efficient for the user with limited mobile devices. In the process of delegating most of the encryption/decryption computation to private cloud, the user can not disclose any information to the private cloud. We also consider the communication securitythat once frequent attribute revocation happens, our scheme is able to resist some attacks between private cloud and data user by employing anonymous key agreement.

Interoperable Resource Brokering with Policy-based Provisioning and Job Allocation

The increasing needs for computational power in areas such as weather simulation, genomics or Internet applications have led to sharing of geographically distributed and heterogeneous resources from commercial data centers and scientific institutions. Research in the areas of utility, grid and cloud computing, together with improvements in network and hardware virtualization has resulted in methods to locate and use resources to rapidly provision virtual environments in a flexible manner, while lowering costs for consumers and providers. However, there is still a lack of methodologies to enable efficient and seamless sharing of resources among institutions. In this work, we concentrate in the problem of executing parallel scientific applications across distributed resources belonging to separate organizations. Our approach can be divided in three main points. First, we define and implement an interoperable grid protocol to distribute job workloads among partners with different middleware and execution resources. Second, we research and implement different policies for virtual resource provisioning and job-to-resource allocation, taking advantage of their cooperation to improve execution cost and performance. Third, we explore the consequences of on-demand provisioning and allocation in the problem of site-selection for the execution of parallel workloads, and propose new strategies to reduce job slowdown and overall cost.

WIPO and the Reinforcement of the Nagoya Protocol: Towards Effective Implementation of an Access and Benefit Sharing Regime for the Protection of Traditional Knowledge Associated with Genetic Resources

Traditional knowledge associated with genetic resources (TKaGRs) is acknowledged as a valuable resource. Its value draws from economic, social, cultural, and innovative uses. This value places TK at the heart of competing interests as between indigenous peoples who hold it and depend on it for their survival, and profitable industries which seek to exploit it in the global market space. The latter group seek, inter alia, to advance and maintain their global competitiveness by exploiting TKaGRs leads in their research and development activities connected with modern innovation. Biopiracy remains an issue of central concern to the developing world and has emerged in this context as a label for the inequity arising from the misappropriation of TKaGRs located in the South by commercial interests usually located in the North. Significant attention and resources are being channeled at global efforts to design and implement effective protection mechanisms for TKaGRs against the incidence of biopiracy. The emergence and recent entry into force of the Nagoya Protocol offers the latest example of a concluded multilateral effort in this regard. The Nagoya Protocol, adopted on the platform of the Convention on Biological Diversity (CBD), establishes an open-ended international access and benefit sharing (ABS) regime which is comprised of the Protocol as well as several complementary instruments. By focusing on the trans-regime nature of biopiracy, this thesis argues that the intellectual property (IP) system forms a central part of the problem of biopiracy, and so too to the very efforts to implement solutions, including through the Nagoya Protocol. The ongoing related work within the World Intellectual Property Organization (WIPO), aimed at developing an international instrument (or a series of instruments) to address the effective protection of TK, constitutes an essential complementary process to the Nagoya Protocol, and, as such, forms a fundamental element within the Nagoya Protocol’s evolving ABS regime-complex. By adopting a third world approach to international law, this thesis draws central significance from its reconceptualization of biopiracy as a trans-regime concept. By construing the instrument(s) being negotiated within WIPO as forming a central component part of the Nagoya Protocol, this dissertation’s analysis highlights the importance of third world efforts to secure an IP-based reinforcement to the Protocol for the effective eradication of biopiracy.