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Scheduling System (scheduling + system)

Distribution by Scientific Domains

Engineering	57%
Medical Sciences	14%

Selected Abstracts

Segregation and scheduling for P2P applications with the interceptor middleware system

CONCURRENCY AND COMPUTATION: PRACTICE & EXPERIENCE, Issue 6 2008
Cosimo Anglano
Abstract Very large size peer-to-peer systems are often required to implement efficient and scalable services, but usually they can be built only by assembling resources contributed by many independent users. Among the guarantees that must be provided to convince these users to join the P2P system, particularly important is the ability of ensuring that P2P applications and services run on their nodes will not unacceptably degrade the performance of their own applications because of an excessive resource consumption. In this paper we present the Interceptor, a middleware-level application segregation and scheduling system, which is able to strictly enforce quantitative limitations on node resource usage and, at the same time, to make P2P applications achieve satisfactory performance even in face of these limitations. A proof-of-concept implementation has been carried out for the Linux operating system, and has been used to perform an extensive experimentation aimed at quantitatively evaluating the Interceptor. The results we obtained clearly demonstrate that the Interceptor is able to strictly enforce quantitative limitations on node resource usage, and at the same time to effectively schedule P2P applications. Copyright © 2007 John Wiley & Sons, Ltd. [source]

Performance prediction for a code with data-dependent runtimes

CONCURRENCY AND COMPUTATION: PRACTICE & EXPERIENCE, Issue 3 2008
S. A. Jarvis
Abstract In this paper we present a predictive performance model for a key biomedical imaging application found as part of the U.K. e-Science Information eXtraction from Images (IXI) project. This code represents a significant challenge for our existing performance prediction tools as it has internal structures that exhibit highly variable runtimes depending on qualities in the input data provided. Since the runtime can vary by more than an order of magnitude, it has been difficult to apply meaningful quality of service criteria to workflows that use this code. The model developed here is used in the context of an interactive scheduling system which provides rapid feedback to the users, allowing them to tailor their workloads to available resources or to allocate extra resources to scheduled workloads. Copyright © 2007 John Wiley & Sons, Ltd. [source]

A new task scheduling method for distributed programs that require memory management

CONCURRENCY AND COMPUTATION: PRACTICE & EXPERIENCE, Issue 9 2006
Hiroshi Koide
Abstract In parallel and distributed applications, it is very likely that object-oriented languages, such as Java and Ruby, and large-scale semistructured data written in XML will be employed. However, because of their inherent dynamic memory management, parallel and distributed applications must sometimes suspend the execution of all tasks running on the processors. This adversely affects their execution on the parallel and distributed platform. In this paper, we propose a new task scheduling method called CP/MM (Critical Path/Memory Management) which can efficiently schedule tasks for applications requiring memory management. The underlying concept is to consider the cost due to memory management when the task scheduling system allocates ready (executable) coarse-grain tasks, or macro-tasks, to processors. We have developed three task scheduling modules, including CP/MM, for a task scheduling system which is implemented on a Java RMI (Remote Method Invocation) communication infrastructure. Our experimental results show that CP/MM can successfully prevent high-priority macro-tasks from being affected by the garbage collection arising from memory management, so that CP/MM can efficiently schedule distributed programs whose critical paths are relatively long. Copyright © 2005 John Wiley & Sons, Ltd. [source]

Conception of self-construction production scheduling system

ELECTRONICS & COMMUNICATIONS IN JAPAN, Issue 1 2010
Hai Xue
Abstract With the high speed innovation of information technology, many production scheduling systems have been developed. However, a lot of customization according to individual production environment is required, and then a large investment for development and maintenance is indispensable. Therefore now the direction to construct scheduling systems should be changed. The final objective of this research aims at developing a system which is built by it extracting the scheduling technique automatically through the daily production scheduling work, so that an investment will be reduced. This extraction mechanism should be applied for various production processes for interoperability. Using the master information extracted by the system, production scheduling operators can be supported to accelerate the production scheduling work easily and accurately without any restriction of scheduling operations. By installing this extraction mechanism, it is easy to introduce a scheduling system without a lot of expense for customization. In this paper, first a model for expressing a scheduling problem is proposed. Then the guideline to extract the scheduling information and use the extracted information is shown and some applied functions are also proposed based on it. © 2009 Wiley Periodicals, Inc. Electron Comm Jpn, 93(1): 19,29, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecj.10188 [source]

Decision aids in routine practice: lessons from the breast cancer initiative

HEALTH EXPECTATIONS, Issue 3 2006
Kerry A. Silvia BA
Abstract Background, Many decision aids have been developed to help patients make treatment and screening decisions; however, little is known about implementing them into routine clinical practice. Objective, To assess the feasibility of implementing a patient decision aid (PtDA) for the early stage breast cancer surgical decision into routine clinical care. Design, Structured individual interviews. Setting and participants, A convenience sample of providers from nine sites, including two community resource centres, a community hospital and six academic centres. Main outcome measures, Usage data, barriers to and resources for implementing the PtDAs. Results, Six of the nine sites were using the PtDAs with patients. Two sites were primarily using a scheduling system and four sites relied on a lending system. For the academic centres, the keys to successful implementation included integrating the PtDA into the flow of patients through the centre and having physicians who recommended it to patients. At the community centres, the keys to successful implementation included an informed staff and the flexibility to get the PtDAs to patients in different ways. Barriers that limited or prevented sites from using the PtDA included a lack of clinical support, a lack of system support, competing priorities and scheduling problems. Conclusions, It is feasible to implement a breast cancer PtDA into routine clinical care at academic centres and community resource centres. Future research should assess the effectiveness of PtDAs in routine clinical care as well as resources and barriers to their implementation in community hospitals. [source]

Automation of paratransit reservation, routing, and scheduling

JOURNAL OF ADVANCED TRANSPORTATION, Issue 2 2000
T. Chira-Chavala
Santa Clara County, California experienced a sharp growth in demand-responsive paratransit ridership for individuals with disabilities, as a result of the passage of the 1990 Americans With Disabilities Act (ADA). This paper describes an automated paratransit system for the ADA-type paratransit operation implemented in Santa Clara County. It automated paratransit reservation, scheduling, and routing functions. The key components of this system were a digital geographic database (DGD) and an automated trip scheduling system (ATSS). Empirical evidence after one year of operation indicates numerous benefits of this automation. There were significant reductions in the paratransit operating costs and an increase in the percent shared rides. The savings in operating costs far exceeded the annualized capital cost of automation. A user survey indicates that these improvements were achieved without degradation to service quality such as vehicle on-time performance, invehicle travel times, vehicle response to open return, and ride comfort. [source]

Keynote Address: Closing the Research-to-practice Gap in Emergency Medicine

ACADEMIC EMERGENCY MEDICINE, Issue 11 2007
Carolyn M. Clancy MD
Emergency medicine in the United States is facing tremendous challenges due to recent public health emergencies, continuing threats of bioterrorism, and an increasing and unprecedented demand for emergency department services. These challenges include overcrowding; long waiting times; "boarding" of patients; ambulance diversion; a need for better, more reliable tools for triaging patients; and medical errors and other patient safety concerns. These challenges and concerns were brought to the forefront several years ago by the Institute of Medicine in several landmark reports that call for closing the research-to-practice gap in emergency medicine. The Agency for Healthcare Research and Quality is funding a number of projects that address many of the concerns raised in the reports, including the use of an advanced access appointment scheduling system to improve access to care; the use of an electronic medical record system to reduce waiting times and errors and improve patient and provider satisfaction; and the refinement of the Emergency Severity Index, a five-level triage scale to get patients to the right resources at the right time. The agency's Healthcare Cost and Utilization Project is gathering data that will allow researchers to examine a broad range of issues affecting the use, quality, and cost of emergency services. Although progress has been made over the past few years in closing the research-to-practice gap in emergency medicine, many challenges remain. The Agency for Healthcare Research and Quality has supported and will continue to support a broad portfolio of research to address the many challenges confronting emergency medicine, including ways to improve emergency care through the application of research findings. [source]

Conception of self-construction production scheduling system

A framework for developing intelligent real-time scheduling systems

HUMAN FACTORS AND ERGONOMICS IN MANUFACTURING & SERVICE INDUSTRIES, Issue 4 2006
Ronald F. McPherson
The authors describe the adaptation of a hierarchical management-control framework to the design of intelligent real-time scheduling systems. Originally developed for the analysis of organizations where dynamics are governed solely by the reactions of human decision makers, the control framework provides insights concerning design requirements for decision systems that react in human-like fashion within narrow domains of expertise. The framework emphasizes the dynamic balance of autonomy and decentralization required to achieve planned goals within a hierarchical organization. Applying this framework, design specifications for knowledge-based scheduling systems are developed, which are responsive to organizational dynamics as required for schedule control and replanning. An illustration is given that addresses kitchen scheduling in full-service restaurants. © 2006 Wiley Periodicals, Inc. Hum Factors Man 16: 385,408, 2006. [source]

Constructing robust crew schedules with bicriteria optimization

JOURNAL OF MULTI CRITERIA DECISION ANALYSIS, Issue 3 2002
Matthias Ehrgott
Abstract Optimization-based computer systems are used by many airlines to solve crew planning problems by constructing minimal cost tours of duty. However, today airlines do not only require cost effective solutions, but are also very interested in robust solutions. A more robust solution is understood to be one where disruptions in the schedule (due to delays) are less likely to be propagated into the future, causing delays of subsequent flights. Current scheduling systems based solely on cost do not automatically provide robust solutions. These considerations lead to a multiobjective framework, as the maximization of robustness will be in conflict with the minimization of cost. For example crew changing aircraft within a duty period is discouraged if inadequate ground time is provided. We develop a bicriteria optimization framework to generate Pareto optimal schedules for the domestic airline. A Pareto optimal schedule is one which does not allow an improvement in cost and robustness at the same time. We developed a method to solve the bicriteria problem, implemented it and tested it with actual airline data. Our results show that considerable gain in robustness can be achieved with a small increase in cost. The additional cost is mainly due to an increase in overnights, which allows for a reduction of the number of aircraft changes. Copyright © 2003 John Wiley & Sons, Ltd. [source]