Towards a green cluster through dynamic remapping of virtual machines

Since power is one of the major limiting factors for a data center or for large cluster growth, the objective of this study is to minimize the power consumption of the cluster without violating the performance constraints of the applications. We propose a runtime virtual machine (VM) mapping framework in a cluster or data center to save energy. The new framework can make reconfiguration decisions on time with the consideration of a low influence on the performance. In the GreenMap framework, one probabilistic, heuristic algorithm is designed for the optimization problem: mapping VMs onto a set of physical machines (PMs) under the constraint of multi-dimensional resource consumptions. Experimental measurements show that the new method can reduce the power consumption by up to 69.2% over base, with few performance penalties. The effectiveness and performance insights are also analytically verified.     

CyberGuarder: A virtualization security assurance architecture for green cloud computing

As the sizes of IT infrastructure continue to grow, cloud computing is a natural extension of virtualisation technologies that enable scalable management of virtual machines over a plethora of physically connected systems. The so-called virtualisation-based cloud computing paradigm offers a practical approach to green IT/clouds, which emphasise the construction and deployment of scalable, energy-efficient network software applications (NetApp) by virtue of improved utilisation of the underlying resources. The latter is typically achieved through increased sharing of hardware and data in a multi-tenant cloud architecture/environment and, as such, accentuates the critical requirement for enhanced security services as an integrated component of the virtual infrastructure management strategy. This paper analyses the key security challenges faced by contemporary green cloud computing environments, and proposes a virtualisation security assurance architecture, CyberGuarder, which is designed to address several key security problems within the ‘green’ cloud computing context. In particular, CyberGuarder provides three different kinds of services; namely, a virtual machine security service, a virtual network security service and a policy based trust management service. Specifically, the proposed virtual machine security service incorporates a number of new techniques which include (1) a VMM-based integrity measurement approach for NetApp trusted loading, (2) a multi-granularity NetApp isolation mechanism to enable OS user isolation, and (3) a dynamic approach to virtual machine and network isolation for multiple NetApp’s based on energy-efficiency and security requirements. Secondly, a virtual network security service has been developed successfully to provide an adaptive virtual security appliance deployment in a NetApp execution environment, whereby traditional security services such as IDS and firewalls can be encapsulated as VM images and deployed over a virtual security network in accordance with the practical configuration of the virtualised infrastructure. Thirdly, a security service providing policy based trust management is proposed to facilitate access control to the resources pool and a trust federation mechanism to support/optimise task privacy and cost requirements across multiple resource pools. Preliminary studies of these services have been carried out on our iVIC platform, with promising results. As part of our ongoing research in large-scale, energy-efficient/green cloud computing, we are currently developing a virtual laboratory for our campus courses using the virtualisation infrastructure of iVIC, which incorporates the important results and experience of CyberGuarder in a practical context.     

Power-efficient video encoding on resource-limited systems: A game-theoretic approach

Most mobile video applications are often deployed on battery-operated devices. With limited power supply, it is a challenging issue to support video applications with high resolution due to the complex functionality and high resource requirements. Thus, power-efficient design is important in computation intensive applications especially for mobile video terminals. Previous works on power-efficient control in video encoding systems focus on the low complexity design while typically ignoring the impact of scalable design by considering various power consumption involved in the encoding process. This paper is dedicated to developing a power-scalable video encoding (PSVE) strategy for energy-limited mobile terminals. PSVE can help the video encoding terminal to adjust its power consumption budget efficiently so as to enhance the power-scalable capability in mobile video terminals. This paper first establishes game theoretical analysis to model the power consumption problem as a bargaining problem. Then, the tradeoff between encoding effect and power consumption achieved by the use of game theory. The scalable and low power video encoding system based on Nash equilibrium solution is derived through the analysis on the power consumption and encoding effect. Experimental results demonstrate the efficiency of the proposed approach.     

Balancing energy consumption with mobile agents in wireless sensor networks

For Wireless Sensor Networks (WSNs), an unbalanced energy consumption will decrease the lifetime of network. In this paper, we leverage mobile agent technology to investigate the problem of how to balance the energy consumption during data collection in WSNs. We first demonstrate that for a sensor network with uniform node distribution and constant data reporting, balancing the energy of the whole network cannot be realized when the distribution of data among sensor nodes is unbalanced. We design a method to mitigate the uneven energy dissipation problem by controlling the mobility of agents, which is achieved by an energy prediction strategy to find their positions. Finally, we propose energy balancing cluster routing based on a mobile agent (EBMA) for WSNs. To obtain better performance, the cluster structure is formed based on cellular topology taking into consideration the energy balancing of inter-cluster and intra-cluster environments. Extensive simulation experiments are carried out to evaluate EBMA with several performance criteria. Our simulation results show that EBMA can effectively balance energy consumption and perform high efficiency in large-scale network deployment.     

QoS enhancements for global replication management in peer to peer networks

Replica Management is a key issue to reduce the bandwidth consumption, to improve data availability and to maintain data consistency in large distributed systems. Global Replica Management (GRM) means to maintain the data consistency across the entire network. It is preferable particularly for multi-group distributed systems. On the other hand, GRM is not favorable for many applications because a very large number of message passes is needed for replica management processes. In this paper, in order to reduce the number of message passes needed to achieve the efficient GRM strategy, an interconnection structure called the Distributed Spanning Tree (DST) has been employed. The application of DST converts the peer network into logical layered structures and thereby provides a hierarchical mechanism for replication management. It is proved that this hierarchical approach improves the data availability and consistency across the entire network. In addition to these, it is also proved that the proposed approach reduces the data latency and the required number of message passes for any specific application in the network.     

Visual understanding industrial workflows under uncertainty on distributed service oriented architectures

Service Oriented Architecture (SOA) is an evolution of distributed computing based on the request/reply design paradigm for synchronous and asynchronous applications. In such architectures, application developers or system integrators can build scenarios by composing one or more services without knowing the services’ underlying implementations. In this paper, we adopt a SOA framework for on-line scheduling complex industrial workflows. The proposed SOA consists of three main layers; the input layer, the benchmarking layer, the prediction layer and the scheduler. The main innovation of our SOA architecture is the prediction layer that supports computer vision tools able to visually observe how an industrial workflow is actually executed. This way, we can automatically estimate the actual execution time for a process. In particular a new self-initialized visual tracker algorithm is proposed in this paper to robustly trace workers’ trajectory in a plant via visual observations. Then, part-to-whole curve matching is presented so as to find correspondences among the traced curve and the ideal one and thus improving scheduler efficiency. The input layer interoperably describes industrial operations using the XPDL (an XML-based) format. The benchmarker evaluates much faster than real-time and in an off-line mode how long it takes for an industrial workflow to be executed on a given resource guaranteeing an almost real-time implementation of the video processing algorithms on the plant. The last component of the proposed SOA is the scheduler with the goal to assign the workflows to the available resources. In this paper, a Maximum Benefit First (MBF) scheduler is presented which maximizes the total gain received by the industry when completing execution of all the beneficial operations with minimum violations of their delivery deadlines (that is with the minimum compensations). Experiments have been conducted on a real-world industrial plant of Nissan Iberica automobile construction indicating the efficiency of the proposed system.     

Palmprint based recognition system using phase-difference information

This paper presents an efficient palmprint based human recognition system. Each palmprint is divided into several square overlapping blocks. Reconstruction error using principle component analysis (PCA) is used to classify these blocks into either a good block or a non-palmprint block. Features from each good block of a palmprint are obtained by binarising the phase-difference of vertical and horizontal phase. The Hamming distance is used to compute the matching score between the features of corresponding good blocks of enrolled and live palmprint. These matching scores are fused using weighted sum rule, where weights are based on the average discriminating level of a block relative to other blocks. The performance of the proposed system is analysed on different datasets of hand images and it has been observed that it achieves a Correct Recognition Rate of 100% with a low Equal Error Rate for all the datasets. The system is also evaluated for noisy and bad palmprint images. It is found to be robust as long as the noise density is less than 50% or the bad region is less than 64% of the images.     

User-configurable semantic home automation

The ideas of smart home and home automation have been proposed for many years. However, when discussing homes of the future, related studies have usually focused on deploying various smart appliances (or devices) within a home environment and employing those appliances automatically by pre-defined procedures. The difficulties of supporting user-configurable automation are due to the complexity of various dynamic home environments. Moreover, within their home domains, users usually think semantically; for example, “I want to turn off all the lights on the second floor”. This paper proposes a semantic home automation system, USHAS (User-configurable Semantic Home Automation System), which adopts Web Service and WSBPEL for executing automated process; OWL and OWL-S for defining home environments and service ontology; and a self-defined markup language, SHPL (Semantic Home Process Language), for describing semantic processes.     

Heuristic algorithms for two-dimensional uplink burst construction in IEEE 802.16 networks

Many burst construction algorithms have been proposed for Orthogonal Frequency Division Multiple Access (OFDMA). However, none meets the burst structure characteristics required by the IEEE 802.16 standard. In this study, two heuristic algorithms, Best Corner Oriented (BCO) and Best Subchannel Oriented (BSO), are proposed to provide high throughput for uplink burst construction in IEEE 802.16 networks. The BCO maintains all available slots as a continuous area and attempts to construct each burst from one of the two ending slots of this area. The BSO, however, constructs each burst in its best quality subchannels to adopt a better modulation coding scheme (MCS). The simulation results under a heavy load indicate that BSO and BCO achieve 2 and 1.5 times, respectively, the throughput achieved by Raster, the conventional algorithm. However, the superior performance of BSO is achieved at the expense of increased time complexity.