Joint Energy Efficient and QoS-aware Path Allocation and VNF Placement for Service Function Chaining

Service Function Chaining (SFC) allows the forwarding of a traffic flow along a chain of Virtual Network Functions (VNFs, e.g., IDS, firewall, and NAT). Software Defined Networking (SDN) solutions can be used to support SFC reducing the management complexity and the operational costs. One of the most critical issues for the service and network providers is the reduction of energy consumption, which should be achieved without impact to the quality of services. In this paper, we propose a novel resource (re)allocation architecture which enables energy-aware SFC for SDN-based networks. To this end, we model the problems of VNF placement, allocation of VNFs to flows, and flow routing as optimization problems. Thereafter, heuristic algorithms are proposed for the different optimization problems, in order find near-optimal solutions in acceptable times. The performance of the proposed algorithms are numerically evaluated over a real-world topology and various network traffic patterns. The results confirm that the proposed heuristic algorithms provide near optimal solutions while their execution time is applicable for real-life networks.Comment: Extended version of submitted paper - v7 - July 201

Human-Robot Trust Integrated Task Allocation and Symbolic Motion planning for Heterogeneous Multi-robot Systems

This paper presents a human-robot trust integrated task allocation and motion planning framework for multi-robot systems (MRS) in performing a set of tasks concurrently. A set of task specifications in parallel are conjuncted with MRS to synthesize a task allocation automaton. Each transition of the task allocation automaton is associated with the total trust value of human in corresponding robots. Here, the human-robot trust model is constructed with a dynamic Bayesian network (DBN) by considering individual robot performance, safety coefficient, human cognitive workload and overall evaluation of task allocation. Hence, a task allocation path with maximum encoded human-robot trust can be searched based on the current trust value of each robot in the task allocation automaton. Symbolic motion planning (SMP) is implemented for each robot after they obtain the sequence of actions. The task allocation path can be intermittently updated with this DBN based trust model. The overall strategy is demonstrated by a simulation with 5 robots and 3 parallel subtask automata

A review of personal communications services

This article can be accessed from the link below - Copyright @ 2009 Nova Science Publishers, LtdPCS is an acronym for Personal Communications Service. PCS has two layers of meaning. At the low layer, from the technical perspective, PCS is a 2G mobile communication technology operating at the 1900 MHz frequency range. At the upper layer, PCS is often used as an umbrella term that includes various wireless access and personal mobility services with the ultimate goal of enabling users to freely communicate with anyone at anytime and anywhere according to their demand. Ubiquitous PCS can be implemented by integrating the wireless and wireline systems on the basis of intelligent network (IN), which provides network functions of terminal and personal mobility. In this chapter, we focus on various aspects of PCS except location management. First we describe the motivation and technological evolution for personal communications. Then we introduce three key issues related to PCS: spectrum allocation, mobility, and standardization efforts. Since PCS involves several different communication technologies, we introduce its heterogeneous and distributed system architecture. IN is also described in detail because it plays a critical role in the development of PCS. Finally, we introduce the application of PCS and its deployment status since the mid-term of 1990’s.This work was supported in part by the National Natural Science Foundation of China under Grant No. 60673159 and 70671020; the National High-Tech Research and Development Plan of China under Grant No. 2006AA01Z214, and the Engineering and Physical Sciences Research Council (EPSRC) of UK under Grant EP/E060722/1

Energy-Efficient Management of Data Center Resources for Cloud Computing: A Vision, Architectural Elements, and Open Challenges

Cloud computing is offering utility-oriented IT services to users worldwide. Based on a pay-as-you-go model, it enables hosting of pervasive applications from consumer, scientific, and business domains. However, data centers hosting Cloud applications consume huge amounts of energy, contributing to high operational costs and carbon footprints to the environment. Therefore, we need Green Cloud computing solutions that can not only save energy for the environment but also reduce operational costs. This paper presents vision, challenges, and architectural elements for energy-efficient management of Cloud computing environments. We focus on the development of dynamic resource provisioning and allocation algorithms that consider the synergy between various data center infrastructures (i.e., the hardware, power units, cooling and software), and holistically work to boost data center energy efficiency and performance. In particular, this paper proposes (a) architectural principles for energy-efficient management of Clouds; (b) energy-efficient resource allocation policies and scheduling algorithms considering quality-of-service expectations, and devices power usage characteristics; and (c) a novel software technology for energy-efficient management of Clouds. We have validated our approach by conducting a set of rigorous performance evaluation study using the CloudSim toolkit. The results demonstrate that Cloud computing model has immense potential as it offers significant performance gains as regards to response time and cost saving under dynamic workload scenarios.Comment: 12 pages, 5 figures,Proceedings of the 2010 International Conference on Parallel and Distributed Processing Techniques and Applications (PDPTA 2010), Las Vegas, USA, July 12-15, 201

Coping with crises : why and how to protect employment and earnings

Events of the past two years are a reminder that crises are a recurring phenomenon with deep and often protracted impacts on labor markets. This paper examines the challenges inherent in crafting policy responses, with particular attention to developing countries. It focuses on the potential tradeoffs between offsetting adverse short-term impacts and preserving incentives for economic recovery and future growth, and between protecting the most vulnerable and compensating those most immediately impacted. It also highlights how policymakers’ room for maneuver is constrained in crisis times by deteriorating fiscal space, limited institutional capacity, and mounting political pressures. Based on empirical evidence from previous crises, the paper asserts that taking a myopic and reactive approach may be costly and counterproductive. Instead, it advocates a more comprehensive approach, designed to build institutions - such as automatic stabilizers and safety nets - that can deliver a coordinated and coherent policy package. This approach will make crises catalysts for institutional changes and long-run growth.Labor Markets,Labor Policies,Safety Nets and Transfers,Banks&Banking Reform,Population Policies

Implications Of Bulk Water Transfer On Local Water Management Institutions: A Case Study of the Melamchi Water Supply Project in Nepal

To mitigate a drinking water crisis in Kathmandu valley, the Government of Nepal initiated the Melamchi Water Supply Project in 1997, which will divert water from the Melamchi River to Kathmandu city's water supply network. In the first phase, the Project will divert 170,000 cubic meters of water per day (at the rate of 1.97M3/sec), which will be tripled using the same infrastructure as city water demand increases in the future. The large scale transfer of water would have farreaching implications in both water supplying and receiving basins. This paper analyzes some of the major changes related to local water management and socioeconomics brought about by the Project and in particular the changes in the local water management institutions in the Melamchi basin. Our study shows that traditional informal water management institutions were effective in regulating present water use practices in the water supplying basin, but the situation will vastly change because of the scale of water transfer, and power inequity between the organized public sector on one side and dispersed and unorganized marginal water users on the other. The small scale of water usage and multiple informal arrangements at the local level have made it difficult for the local users and institutions to collectively bargain and negotiate with the central water transfer authority for a fair share of project benefits and compensation for the losses imposed on them. The process and scale of project compensation for economic losses and equity over resource use are at the heart of the concerns and debates about the Melamchi water transfer decision. The Project has planned for a one-time compensation package of about US$18 million for development infrastructure related investments and is planning to share about one percent of revenue generated from water use in the city with the supplying basin. The main issues here are what forms of water sharing governance, compensation packages, and water rights structures would emerge in relation to the project implementation and whether they are socially acceptable ensuring equitable distribution of the project benefits to all basin communities. In addition, these issues of the Melamchi project discussed in this paper are equally pertinent to other places where rural to urban water transfer projects are under discussion

RCTS: A flexible environment for sensor integration and control of robot systems; the distributed processing approach

Most robot systems lack a suitable hardware and software environment for the efficient research of new control and sensing schemes. Typically, engineers and researchers need to be experts in control, sensing, programming, communication and robotics in order to implement, integrate and test new ideas in a robot system. In order to reduce this time, the Robot Controller Test Station (RCTS) has been developed. It uses a modular hardware and software architecture allowing easy physical and functional reconfiguration of a robot. This is accomplished by emphasizing four major design goals: flexibility, portability, ease of use, and ease of modification. An enhanced distributed processing version of RCTS is described. It features an expanded and more flexible communication system design. Distributed processing results in the availability of more local computing power and retains the low cost of microprocessors. A large number of possible communication, control and sensing schemes can therefore be easily introduced and tested, using the same basic software structure

The republic of Congo's infrastructure : a continental perspective

Infrastructure contributed half a percentage point to the Republic of Congo's annual per capita GDP growth from 2001 to 2006. If the country's infrastructure were improved to the level seen in Mauritius, the regional leader, it could contribute more than 3 percentage points to annual per capita growth. The Republic of Congo's existing infrastructure is concentrated in the developed south, reflecting the country's urbanization patterns. Links spread from there to the less-developed north, where there are vast areas of underexploited dense forest. The Republic of Congo's power sector offers the greatest potential for infrastructure-based economic growth, but major inefficiencies need to be addressed. Transit improvements would also make significant contributions to growth by improving connections to the north and to neighboring countries. Additional opportunities include rehabilitating the fixed-line telephone operator to spread Internet access. The country's water and sanitation infrastructure is in relatively good shape. Spending on infrastructure was $460 million per year in the Republic of Congo during the mid-2000s. Based on these spending levels, if all inefficiencies were eliminated, the country would face an infrastructure funding gap of$270 million a year and would not meet infrastructure targets for 31 years. Spending rose to $550 million per year in 2008-09. If the Republic of Congo could maintain these higher spending levels, the funding gap would essentially disappear. The nation could further reduce the funding gap by adopting lower-cost technologies to meet infrastructure targets.Transport Economics Policy&Planning,Infrastructure Economics,Public Sector Economics,Banks&Banking Reform,Energy Production and Transportation