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System Resources (system + resource)
Selected AbstractsConcepts for computer center power managementCONCURRENCY AND COMPUTATION: PRACTICE & EXPERIENCE, Issue 2 2010A. DiRienzo Abstract Electrical power usage contributes significantly to the operational costs of large computer systems. At the Hypersonic Missile Technology Research and Operations Center (HMT-ROC) our system usage patterns provide a significant opportunity to reduce operating costs since there are a small number of dedicated users. The relatively predictable nature of our usage patterns allows for the scheduling of computational resource availability. We take advantage of this predictability to shut down systems during periods of low usage to reduce power consumption. With interconnected computer cluster systems, reducing the number of online nodes is more than a simple matter of throwing the power switch on a portion of the cluster. The paper discusses these issues and an approach for power reduction strategies for a computational system with a heterogeneous system mix that includes a large (1560-node) Apple Xserve PowerPC supercluster. In practice, the average load on computer systems may be much less than the peak load although the infrastructure supporting the operation of large computer systems in a computer or data center must still be designed with the peak loads in mind. Given that a significant portion of the time, systems loads can be less than full peak, an opportunity exists for cost savings if idle systems can be dynamically throttled back, slept, or shut off entirely. The paper describes two separate strategies that meet the requirements for both power conservation and system availability at HMT-ROC. The first approach, for legacy systems, is not much more than a brute force approach to power management which we call Time-Driven System Management (TDSM). The second approach, which we call Dynamic-Loading System Management (DLSM), is applicable to more current systems with ,Wake-on-LAN' capability and takes a more granular approach to the management of system resources. The paper details the rule sets that we have developed and implemented in the two approaches to system power management and discusses some results with these approaches. Copyright © 2009 John Wiley & Sons, Ltd. [source] Network-aware selective job checkpoint and migration to enhance co-allocation in multi-cluster systems,CONCURRENCY AND COMPUTATION: PRACTICE & EXPERIENCE, Issue 13 2009William M. Jones Abstract Multi-site parallel job schedulers can improve average job turn-around time by making use of fragmented node resources available throughout the grid. By mapping jobs across potentially many clusters, jobs that would otherwise wait in the queue for local resources can begin execution much earlier; thereby improving system utilization and reducing average queue waiting time. Recent research in this area of scheduling leverages user-provided estimates of job communication characteristics to more effectively partition the job across system resources. In this paper, we address the impact of inaccuracies in these estimates on system performance and show that multi-site scheduling techniques benefit from these estimates, even in the presence of considerable inaccuracy. While these results are encouraging, there are instances where these errors result in poor job scheduling decisions that cause network over-subscription. This situation can lead to significantly degraded application performance and turnaround time. Consequently, we explore the use of job checkpointing, termination, migration, and restart (CTMR) to selectively stop offending jobs to alleviate network congestion and subsequently restart them when (and where) sufficient network resources are available. We then characterize the conditions and the extent to which the process of CTMR improves overall performance. We demonstrate that this technique is beneficial even when the overhead of doing so is costly. Copyright © 2009 John Wiley & Sons, Ltd. [source] System Complexity As a Measure of Safe Capacity for the Emergency DepartmentACADEMIC EMERGENCY MEDICINE, Issue 11 2006Daniel J. France PhD Objectives System complexity is introduced as a new measure of system state for the emergency department (ED). In its original form, the measure quantifies the uncertainty of demands on system resources. For application in the ED, the measure is being modified to quantify both workload and uncertainty to produce a single integrated measure of system state. Methods Complexity is quantified using an information-theoretic or entropic approach developed in manufacturing and operations research. In its original form, complexity is calculated on the basis of four system parameters: 1) the number of resources (clinicians and processing entities such as radiology and laboratory systems), 2) the number of possible work states for each resource, 3) the probability that a resource is in a particular work state, and 4) the probability of queue changes (i.e., where a queue is defined by the number of patients or patient orders being managed by a resource) during a specified time period. Results An example is presented to demonstrate how complexity is calculated and interpreted for a simple system composed of three resources (i.e., emergency physicians) managing varying patient loads. The example shows that variation in physician work states and patient queues produces different scores of complexity for each physician. It also illustrates how complexity and workload differ. Conclusions System complexity is a viable and technically feasible measurement for monitoring and managing surge capacity in the ED. [source] An operational algorithm for residential cogeneration systems based on the monitored daily-basis energy demandELECTRICAL ENGINEERING IN JAPAN, Issue 2 2010Yuka Yamagishi Abstract Residential cogeneration systems with PEFC are promising as distributed power system resources with the ability to improve energy system efficiency. However, it is important to develop an efficient algorithm for operation because the energy demand at each house differs greatly from day to day. In this paper, we propose an operational algorithm and evaluate it from the viewpoint of energy conservation and economic effectiveness based on the energy demand characteristics. In the algorithm, the hot water and electricity demand on the next day are estimated based on the average of past data. The results of simulations using actually monitored energy demand data indicate that (1) the greater the electrical demand of a household, the more effective this algorithm becomes with respect to energy conservation; (2) the greater the hot water demand of a household, the more effective this algorithm becomes with respect to economic effectiveness. © 2009 Wiley Periodicals, Inc. Electr Eng Jpn, 170(2): 37,45, 2010; Published online in Wiley InterScience (www.interscience.wiley. com). DOI 10.1002/eej.20892 [source] An Approach to Fulfilling the Systems-based Practice Competency RequirementACADEMIC EMERGENCY MEDICINE, Issue 11 2002David Doezema MD The Accreditation Council for Graduate Medical Education (ACGME)-identified core competency of systems-based practice requires the demonstration of an awareness of the larger context and system of health care, and the ability to call on system resources to provide optimum care. This article describes an approach to teaching and fulfilling the requirement of this core competency in an emergency medicine residency. Beginning residents are oriented to community resources that are important to the larger context of care outside the emergency department. Each resident completes a community project during his or her residency. Readings and discussions concerning community-oriented medical care and the literature of research and injury prevention in emergency medicine precede the project development. Several projects are described in detail. Such projects help to teach not only awareness of the community resources of the greater context of medical practice outside the emergency department, but also how to use those resources. Projects could be a main component of a resident portfolio. This approach to teaching the core competency of systems-based practice is proposed as an innovative and substantial contribution toward satisfying the requirement of the core competency. [source] The concept of work compatibility: An integrated design criterion for improving workplace human performance in manufacturing systemsHUMAN FACTORS AND ERGONOMICS IN MANUFACTURING & SERVICE INDUSTRIES, Issue 4 2004S. Abdallah In this paper, we present the concept of work compatibility as an integrated work design criterion that simultaneously improves human health and safety, productivity, and work quality in manufacturing systems. In this respect, we have modeled work compatibility as a work design parameter that mathematically integrates the energizing (i.e., system resources) and the demand (i.e., system requirements) forces in the work system. A mathematical equation has been derived for the work compatibility matrix. Furthermore, an operating zone has been developed in which there is a region of optimality for the employee to function on practical grounds with a good degree of efficiency and sustainability. An application example is provided to demonstrate the potential of work compatibility to improve productivity and quality along with improvement in worker safety and health. © 2004 Wiley Periodicals, Inc. Hum Factors Man 14: 379,402, 2004. [source] A network-centric approach for access and interface selection in heterogeneous wireless environmentsINTERNATIONAL JOURNAL OF COMMUNICATION SYSTEMS, Issue 5 2008George Koundourakis Abstract In this paper, we introduce a network-based approach for access and interface selection (AIS) in the context of resource management in heterogeneous wireless environments (UMTS, WLAN and DVB-T). We focus on the optimization of resource utilization, while ensuring acceptable quality of service (QoS) provision to the end users. Our objective is to optimally manage the overall system resources and minimize the possibility of QoS handovers (non-mobility handovers). The adopted architecture applies to typical heterogeneous environments and network entities (Access Routers) are enhanced with extra functionalities. We propose an AIS algorithm that exploits the multihoming concept and globally manages network resources at both radio access and IP backbone networks. The algorithm can estimate near-optimal solutions in real time and we also introduce a novel triggering policy. We present simulation results of typical scenarios that demonstrate the advantages of our approach. System performance metrics, derived from the simulations, show minimum degradations in high load and congestion situations. Copyright © 2007 John Wiley & Sons, Ltd. [source] A dynamic bandwidth resource allocation based on neural networks in euroskyway multimedia satellite systemINTERNATIONAL JOURNAL OF COMMUNICATION SYSTEMS, Issue 1 2003P. Camarda Abstract Advanced traffic management based on the dynamic resource assignment allows a broadband satellite system such as euroskyway (ESW) to dynamically assign the resources of connections. The mechanisms of the dynamic assignment exploit variations of burstiness exhibited by real time and non-real time variable bit rate traffic sources to perform an optimized resource redistribution. The efficiency of the dynamic bandwidth allocation capability (DBAC) depends on the accuracy of the traffic source description; inaccurate assessment of the arrival process will cause an overhead and a degraded utilisation of system resources. In this paper a flexible traffic burstiness predictor for dynamic bandwidth resource allocation based on neural network is presented. The approach is able to perform an online estimation of expected resource requests implementing traffic resource assignment by using a sub-symbolic adaptive representation of the traffic source. The achieved results prove that the flexible approach is more effective than the ones based on fixed schemes designed using analytical traffic source description when applied on the satellite terminal ESW system component. Copyright © 2003 John Wiley & Sons, Ltd. [source] A feedback suppression algorithm for reliable satellite multicast based on spatial,temporal prediction of the satellite channelINTERNATIONAL JOURNAL OF SATELLITE COMMUNICATIONS AND NETWORKING, Issue 2 2009Markos P. Anastasopoulos Abstract The major problem limiting the scalability of large-scale multicast satellite networks is feedback implosion that arises whenever a large number of users simultaneously transmit feedback messages (FBMs) through the network, thus occupying a significant portion of satellite system resources. In satellite networks operating above 10,GHz, attenuation due to rain constitutes the dominant fading mechanism deteriorating the quality of service. In this paper, a novel scheme for providing large-scale reliable multicast services through a star-based geostationary satellite topology is presented incorporating accurate channel modeling of the propagation phenomena. The new protocol is based on the selection of an area representative that provides quick FBMs aiming at suppressing FBMs originating from the rest of the network users. The scheme provides a timely reaction to changes of either the channel conditions or the network topology by properly updating the selection of representatives. Through appropriate simulations, comparisons and examples it is demonstrated that the new approach suppresses FBMs very effectively. Copyright © 2009 John Wiley & Sons, Ltd. [source] Factors Associated with Home Versus Institutional Death Among Cancer Patients in ConnecticutJOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 6 2001William T. Gallo PhD OBJECTIVE: To assess the relationships between home death and a set of demographic, disease-related, and health-resource factors among individuals who died of cancer. DESIGN: Prospective cohort study. SETTING: All adult deaths from cancer in Connecticut during 1994. PARTICIPANTS: Six thousand eight hundred and thirteen individuals who met all of the following criteria: died of a cancer-related cause in 1994, had previously been diagnosed with cancer in Connecticut, and were age 18 and older at the time of death. MEASUREMENT: Site of death. RESULTS: Twenty-nine percent of the study sample died at home, 42% died in a hospital, 17% died in a nursing home, and 11% died in an inpatient hospice facility. Multivariate analysis indicated that demographic characteristics (being married, female, white, and residing in a higher income area), disease-related factors (type of cancer, longer survival postdiagnosis), and health-resource factors (greater availability of hospice providers, less availability of hospital beds) were associated with dying at home rather than in a hospital or inpatient hospice. CONCLUSIONS: The implications of this study for clinical practice and health planning are considerable. The findings identify groups (men, unmarried individuals, and those living in lower income areas) at higher risk for institutionalized death,groups that may be targeted for possible interventions to promote home death when home death is preferred by patients and their families. Further, the findings suggest that site of death is influenced by available health-system resources. Thus, if home death is to be supported, the relative availability of hospital beds and hospice providers may be an effective policy tool for promoting home death. J Am Geriatr Soc 49:771,777, 2001. [source] The Business of Emergency Medicine: A Nonclinical Curriculum Proposal for Emergency Medicine Residency ProgramsACADEMIC EMERGENCY MEDICINE, Issue 9 2009Thomas Falvo DO Abstract Over the course of their postgraduate medical education, physicians are expected not only to acquire an extensive knowledge of clinical medicine and sound procedural skills, but also to develop competence in their other professional roles as communicator, collaborator, mediator, manager, teacher, and patient advocate. Although the need for physicians to develop stronger service delivery skills is well recognized, residency programs may underemphasize formal training in nonclinical proficiencies. As a result, graduates can begin their professional careers with an incomplete understanding of the operation of health care systems and how to utilize system resources in the manner best suited to their patients' needs. This article proposes the content, educational strategy, and needs assessment for an academic program entitled The Business of Emergency Medicine (BOEM). Developed as an adjunct to the (predominantly) clinical content of traditional emergency medicine (EM) training programs, BOEM is designed to enhance the existing academic curricula with additional learning opportunities by which EM residents can acquire a fundamental understanding of the nonclinical skills of their specialty. [source] | |||||||||||||