Energy-aware Load Balancing Policies for the Cloud Ecosystem

The energy consumption of computer and communication systems does not scale linearly with the workload. A system uses a significant amount of energy even when idle or lightly loaded. A widely reported solution to resource management in large data centers is to concentrate the load on a subset of servers and, whenever possible, switch the rest of the servers to one of the possible sleep states. We propose a reformulation of the traditional concept of load balancing aiming to optimize the energy consumption of a large-scale system: {\it distribute the workload evenly to the smallest set of servers operating at an optimal energy level, while observing QoS constraints, such as the response time.} Our model applies to clustered systems; the model also requires that the demand for system resources to increase at a bounded rate in each reallocation interval. In this paper we report the VM migration costs for application scaling.Comment: 10 Page

Issues on packet transmissioin strategies in a TDD-TD/CDMA scenario

This paper presents a packet transmission scheme that deals with the problems of a TDD CDMA scenario with different levels of frame structure asymmetry in adjacent base stations by distributing the users in the slots depending on their Time Advance. A multiple access protocol and a scheduling algorithm are also proposed to provide a certain degree of Quality of Service.Peer ReviewedPostprint (published version

A QoS-enabled resource management scheme for F-HMIPv6 micro mobility approach

In the near future, wireless networks will certainly run real-time applications with special Quality of Service (QoS) requirements. In this context micro mobility management schemes such as Fast Handovers over Hierarchical Mobile IPv6 (F-HMIPv6) will be a useful tool in reducing Mobile IPv6 (MIPv6) handover disruption and thereby to improve delay and losses. However, F-HMIPv6 alone does not support QoS requirements for real-time applications. Therefore, in order to accomplish this goal, a novel resource management scheme for the Differentiated Services (DiffServ) QoS model is proposed to be used as an add-on to F-HMIPv6. The new resource management scheme combines the F-HMIPv6 functionalities with the DiffServ QoS model and with network congestion control and dynamic reallocation mechanisms in order to accommodate different QoS traffic requirements. This new scheme based on a Measurement-Based Admission Control (MBAC) algorithm is effective, simple, scalable and avoids the well known traditional resource reservation issues such as state maintenance, signaling overhead and processing load. By means of the admission evaluation of new flows and handover flows, it is able to provide the desired QoS requirements for new flows while preserving the QoS of existing ones. The evaluated results show that all QoS metrics analyzed were significantly improved with the new architecture indicating that it is able to provide a highly predictive QoS support to F-HMIPv6

Taxonomic classification of planning decisions in health care: a review of the state of the art in OR/MS

We provide a structured overview of the typical decisions to be made in resource capacity planning and control in health care, and a review of relevant OR/MS articles for each planning decision. The contribution of this paper is twofold. First, to position the planning decisions, a taxonomy is presented. This taxonomy provides health care managers and OR/MS researchers with a method to identify, break down and classify planning and control decisions. Second, following the taxonomy, for six health care services, we provide an exhaustive specification of planning and control decisions in resource capacity planning and control. For each planning and control decision, we structurally review the key OR/MS articles and the OR/MS methods and techniques that are applied in the literature to support decision making

An improved multi-agent simulation methodology for modelling and evaluating wireless communication systems resource allocation algorithms

Multi-Agent Systems (MAS) constitute a well known approach in modelling dynamical real world systems. Recently, this technology has been applied to Wireless Communication Systems (WCS), where efficient resource allocation is a primary goal, for modelling the physical entities involved, like Base Stations (BS), service providers and network operators. This paper presents a novel approach in applying MAS methodology to WCS resource allocation by modelling more abstract entities involved in WCS operation, and especially the concurrent network procedures (services). Due to the concurrent nature of a WCS, MAS technology presents a suitable modelling solution. Services such as new call admission, handoff, user movement and call termination are independent to one another and may occur at the same time for many different users in the network. Thus, the required network procedures for supporting the above services act autonomously, interact with the network environment (gather information such as interference conditions), take decisions (e.g. call establishment), etc, and can be modelled as agents. Based on this novel simulation approach, the agent cooperation in terms of negotiation and agreement becomes a critical issue. To this end, two negotiation strategies are presented and evaluated in this research effort and among them the distributed negotiation and communication scheme between network agents is presented to be highly efficient in terms of network performance. The multi-agent concept adapted to the concurrent nature of large scale WCS is, also, discussed in this paper

Costs of alternative treatments for incomplete abortion

Unsafely performed abortion is one of the five leading causes of maternal deaths worldwide. Many women who have undergone unsafe abortions enter the healthcare system to seek help for the resulting complications, including incomplete abortion. This human and financial cost of this health problem is tremendous, especially in the developing world. This study examined the potential for reducing costs to healthcare systems by changing the standard method of treatment for incomplete abortion. Vacuum aspiration (VA) has been shown to be safer than dilation and curettage (D&C) for uterine evacuation; the World Health Organization includes VA as an essential service at the first referral level. The technique most commonly used for treating first-trimester incomplete abortion in developing countries, however, is D&C. This study examined the hypothesis that use of manual vacuum aspiration (MVA) - a variation of VA - would be less costly than D&C and thus advantageous to healthcare systems with limited resources. The purpose of the study was to identify and, where possible, to explain the factors that contributed to cost differences between MVA and D&C for treatment of first-trimester incomplete abortion. To achieve this objective, researchers observed patient management and documented resource use at hospital sites in Ecuador, Kenya, and Mexico. In most cases, treatment with MVA required a shorter patient stay and fewer hospital resources than D&C, as the two techniques were practiced at the various study sites. The policy decision to adopt MVA, supported by procurement of instruments and incorporation of training in its use, is the chief prerequisite for achieving these improvements. But the full advantages of MVA are realized only if it is introduced in conjunction with certain changes in patient-management practices, such as offering outpatient treatment of incomplete abortion. Further, decentralizing MVA services can maximize the benefits of the technique, facilitating (hospitals'and) healthcare systems'efforts to decrease the cost of delivery service and improve the quality of care.Health Monitoring&Evaluation,Gender and Health,Health Systems Development&Reform,Information Technology,Business Environment

A centralized feedback control model for resource management in wireless networks

In a wireless environment, guaranteeing QoS is challenging because applications at multiple devices share the same limited radio bandwidth. In this paper we introduce and study a resource management model for centralized wireless networks, using feedback control theory. Before applying in practice, the proposed model is evaluated using the well-known 20-sim dynamic system simulator. The experimental results show that flexible and efficient resource allocation can be achieved for a variety of system parameters and WLAN scenarios; however, care should be taken in setting the control parameters and coefficients

Reference costs and the pursuit of efficiency in the 'new' NHS

Both the White Paper, The New NHS, and the later consultation document, A National Framework for Assessing Performance, stress the need to develop new instruments to tackle inefficiency in the NHS. Among these instruments it has been proposed to benchmark Trusts, and by association Health Authorities, using Healthcare Resource Group (HRG) costs. The NHS Executive has published plans for a system of ‘Reference Costs’ that will itemise the cost of every treatment in every Trust. These reference costs will be derived from costing HRGs and are to be used for many purposes: benchmarking cost improvement, measuring relative efficiency, identifying best practice, funding transfers and costing health improvement programmes. This paper examines the construction of reference costs, considers incentives to use the information appropriately and asks whether a single accounting construct, the costed HRG, can be expected to contribute successfully to its many intended functions of regulation and management.performance measures; costing

Permanent Legal Immigration to the United States: Policy Overview

Four major principles currently underlie U.S. policy on legal permanent immigration: the reunification of families, the admission of immigrants with needed skills, the protection of refugees, and the diversity of admissions by country of origin. These principles are embodied in federal law, the Immigration and Nationality Act (INA) first codified in 1952. The Immigration Amendments of 1965 replaced the national origins quota system (enacted after World War I) with per-country ceilings, and the statutory provisions regulating permanent immigration to the United States were last revised significantly by the Immigration Act of 1990. The critiques of the permanent legal immigration system today are extensive, but there is no consensus on the specific direction the reforms of the law should take. As the Congress considers comprehensive immigration reform (CIR), many maintain that revision of the legal immigration system should be one of the major components of a CIR proposal. This primer on legal permanent immigration law, policies, and trends provides a backdrop for the policy options and debates that may emerge as Congress considers a revision of the legal immigration system