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The problem of efficient resource management in large cloud data centres is well recognised in the cloud management community. With the rising demand for cloud services and expansion of the size and distribution of data centres, the repercussions of not taking into account all parameters of interest while allocating resources are becoming significant. Hence, one of the major issues today is how to...
A current trend in networking and cloud computing is to provide compute resources at widely distributed sites; this is exemplified by developments such as network function virtualization. This paves the way for wide-area service deployments with improved service quality: e.g., user-perceived response times can be reduced by offering services at nearby sites. But always assigning users to the nearest...
In recent decades, due to limitation of radio spectrum and increasing users in wireless networks, spectral efficiency has been a considerable issue in literatures. In addition, energy consumption is rapidly increasing in wireless communications due to growing demand for wireless technologies especially cellular networks. Therefore, energy efficiency has become an important issue in such networks....
A distributed optimization algorithm is presented for resource allocation in wireless relay networks. This algorithm is particularly useful in multiple-source, multiple-relay wireless networks employing fractional cooperation, in which each relay contributes only a fraction of its resources to each source; in this case, the algorithm is used to find the optimal fractions. The advantage of this distributed...
Energy consumption in wireless communication system is rapidly increasing due to the growth in wireless multimedia access. Combating the adverse effects of excessive energy consumption demands for energy-aware system design called green communication, which has become the major focus of many researchers recently. In this paper, we propose user selection and power allocation schemes for a multi-user...
In this paper, we formulate an optimization problem for resource allocation and scheduling in orthogonal frequency division multiple access (OFDMA) half-duplex decode-and-forward (DF) relay assisted networks. Our problem formulation takes into account artificial noise generation to combat a multiple antenna eavesdropper. The secrecy data rate, power, and sub-carrier allocation policies are optimized...
Consider the problem of selecting the best simulated system with high probability, from a finite and huge set of alternative systems. The best system might be the one that has the maximum or minimum performance measure. In this paper, we present a sequential method that uses the Ordinal Optimization procedure to select randomly a subset that overlaps with the set of the actual best m% systems with...
Environmental concerns on the negative impact and depletion of fossil fuels have triggered a search for alternative energy sources. Biofuels are recognised as one of the most potential renewable alternatives. In order to have a sustainable production of biofuels, a processing facility (i.e., biorefinery) that converts biomass into value-added products is needed. As the first and second generations...
This study presents an optimization model using constraint programming (CP) for project selection and scheduling problems with time-dependent resource constraints. The proposed model aims to maximize total profit from selected projects, while scheduling the projects with various resource constraints with specified time intervals, including consumed and renewable resources. The optimization model integrates...
Distributed systems usually provide services with varying criticalities. Failures of core services lead to catastrophic consequences to the system. Maintaining system core services' availability with limited resources has become a challenging issue, especially when system operates in an adversary environment and face malicious under attack. This paper discusses the attacker-defender problem and analyzes...
Summary form only given. In this paper we propose a video coding optimization strategy for H.264/AVC encoder which uses HVS (Human Visual System) theory to improve the visual quality. It is based on a basic rule that sensitivity of distortion is different according to the image property. Most existing coding strategies which allocate fixed parameters to each unit within a frame are not reasonable...
Radio frequency spectrum in wireless communication is a common resource shared by all collocated devices. Most spectrum management schemes rely on a centralized base station-receiver station relaying architecture. In contrast, infrastructure-less systems including wireless ad hoc networks require a scalable, distributed methodology. Moreover, the access has to be coordinated among the nodes in the...
MIMO, OFDMA and cooperative relaying are the key technologies in future wireless communication systems. However, under the usage of these technologies, resource allocation becomes a more crucial and challenging task. In multi-user MIMO-OFDMA relay-enhanced cellular networks, we formulate the optimal instantaneous resource allocation problem including user group selection, path selection, power allocation,...
Energy-efficient link adaptation is studied based on minimizing the total energy consumption per transmitted bit in a mobile terminal. It is shown that the optimal power allocation is water-filling; the optimal energy consumption per bit is a function of the power amplifier efficiency, the circuit power rate dependence, and a cutoff channel to noise ratio (CNR). For a given transceiver architecture,...
We investigate the channel assignment problem in a cluster-based multi-channel cognitive radio sensor network in this paper. Due to the inherent power and resource constraints of sensor networks, energy efficiency is the primary concern for network design. An R-coefficient is developed to estimate the predicted residual energy using sensor information (current residual energy and expected energy consumption)...
In this work we study adaptive resource allocation for uplink transmission of correlated video sources. We consider a framework where multiple wireless sources transmit correlated information via a common base station. We introduce an optimization problem for sources to maximize the weighted sum of received quality of all videos, when source correlation can be used at the decoder in case of missing...
This paper presents a novel resource allocation procedure for OFDMA downlinks, which stems from an hybridization of the Harmony Search and the Differential Evolution heuristic algorithms. In this setup it is known that optimum subcarrier and power allocation is achieved through 1) assigning each subcarrier to the user with highest channel gain at the given frequency, and 2) a Water-Filling procedure...
For delivering multimedia services over (wireless) networks it is important that the mechanisms which negotiate and optimize content delivery under resource constraints take into account user perceived quality in order to improve user satisfaction. Within the scope of the IP Multimedia Subsystem (IMS) architecture a novel application server may be added which handles multi-user multi-flow Quality...
In this paper, resource allocation and scheduling in an orthogonal frequency division multiple access (OFDMA) downlink network is studied. The considered problem is modeled as an optimization problem which takes into account a multiple antenna eavesdropper and artificial noise generation for secure communications. Power, secrecy data rate, and subcarrier allocation are optimized for maximization of...
In this paper, we deal with a scheduling algorithm to fulfil a qualified end-to-end video service in terms of fairness and energy efficiency over multi-hop wireless sensor networks. For this goal, we explore to optimize the routing and power allocation via cross-layer optimization by utilizing a game-theoretic approach. In order to reduce computational complexity, we also propose a distributed optimization...
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