Research efforts in quality of service (QoS) management have usually addressed the problem under the network infrastructure perspective whereas a business-oriented perspective, named service quality management (SQM), ...
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Research efforts in quality of service (QoS) management have usually addressed the problem under the network infrastructure perspective whereas a business-oriented perspective, named service quality management (SQM), is being considered by industry. This paper point out differences and similarities between two approaches and addresses the main issues arising under SQM perspective. Here, QoS indicators and corresponding service levels are defined to provide a common understanding of service delivery, and a critical issue is to provide an effective way to evaluate them. Two evaluation modes are used: off-line and on-line. Off-line methods compute indicators values at the end of a pre-defined evaluation period, whereas on-line methods do it when a related event occurs. This work proposes an architecture for SQM systems and discusses the mechanisms for both off-line and on-line evaluation modes.
In this paper we describe the extensions to the RVision tool to support hardware performance counters monitoring at system level. This monitoring tool is useful for system administrators to detect applications that ne...
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In general, two types of resource reservations in computer networks can be distinguished: immediate reservations which are made in a just-in-time manner and advance reservations which allow to reserve resources a long...
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In general, two types of resource reservations in computer networks can be distinguished: immediate reservations which are made in a just-in-time manner and advance reservations which allow to reserve resources a long time before they are actually used. Advance reservations are especially useful for grid computing but also for a variety of other applications that require network quality-of-service, such as content distribution networks or even mobile clients, which need advance reservation to support handovers for streaming video. With the emerged MPLS standard, explicit routing can be implemented also in IP networks, thus overcoming the unpredictable routing behavior which so far prevented the implementation of advance reservation services. The impact of such advance reservation mechanisms on the performance of the network with respect to the amount of admitted requests and the allocated bandwidth has so far not been examined in detail. We show that advance reservations can lead to a reduced performance of the network with respect to both metrics. The analysis of the reasons shows a fragmentation of the network resources. In advance reservation environments, additional new services can be defined such as malleable reservations and can lead to an increased performance of the network. Four strategies for scheduling malleable reservations are presented and compared. The results of the comparisons show that some strategies increase the resource fragmentation and are therefore unsuitable in the considered environment while others lead to a significantly better performance of the network. Besides discussing the performance issue, the software architecture of a management system for advance reservations is presented.
Centralized approaches to Network Management have demonstrated a clear inadequacy for efficient management of large and heterogeneous computer networks. Considerable research is being carried out on decentralized appr...
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Concepts and principles of TINA (Telecommunications Information Networking Architecture) are introduced with the objective of correcting problems of centralized service control and service data model existent in INs (...
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Concepts and principles of TINA (Telecommunications Information Networking Architecture) are introduced with the objective of correcting problems of centralized service control and service data model existent in INs (...
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ISBN:
(纸本)0780367197
Concepts and principles of TINA (Telecommunications Information Networking Architecture) are introduced with the objective of correcting problems of centralized service control and service data model existent in INs (intelligent networks). Now, it is becoming clear that future sophisticated services breaking away from the simple telephony call model, e.g., multimedia, multi-party conferencing, etc., will need to be rapidly and efficiently introduced, deployed, operated and managed. In this context, TINA developed a comprehensive architecture for multi-service networks that will support multimedia services. On the other hand, the provisioning of all the service management functionality for TINA services (i.e. FCAPS) is still an open research question. In this paper, we discuss accounting features and requirements, security of accounting management, and issues for their integration in a TINA-based service environment. A prototype has been implemented to validate the concepts and results are also presented.
作者:
Wu, BCYoung, GSSchmidt, WChoppella, KDr. Bi-Chu Wu:received a PhD in Mechanical Engineering from the University of Maryland
College Park in 1991. She has worked on projects involving naval architecture design optimization solid mechanics and database development. Presently a senwr engineer with Angle Incorporated Dr Wu's research interests are in design optimization and fuzzy logic applications. Dr. Gin-Shu Young:
a senior engineer with Angle Incorporated holds a PhD in Mechanical Engineering from the University of Maryland College Park. As a guest researcher with National Institute of Standards and Technologies from 1990 to 1993 he worked on vision-based navigation for autonomous vehicles. His experience also includes applications of optimization fuzzy logic neural network and genetic algorithm methods to engineering system design Mr. William Schmidt:co-founded Angle Incorporated in 1990 and has served as Vice PresidentlChiefScientist during this tame. He holds a B.Sc. in Applied Science from the Naval Acadt?my and an M.Sc. in Physics from the Naval Post Graduate School. He has cner 20 years experience in technical leadership
material and personnel management. He has led the application of computer aided design (CAD) and Product Model Information Exchange to the shipbuilding industry. His experience also includes leading the amlication of model based operational analysis to support the Live Fire Test Program for DDG 51 Class Destroyers. Mr. Krishna M. Choppella:is a Sofware Engineer at Eidea Laboratories
Incotporated where he works on componentbased distributed enterpvise frameworks. He has been involved in creating data analysis tools for the US Nay by integrating CAD modeis databases and graphical front ends. His work in the Masters degree program in Mechanical Engineering at the University of Texas at Austin was in di0ddase.r spectroscopy of combustion products in porous-matri burners. He received his Bachelors degree in Electrical Engineering in India. He was a Research Associate at the Centre for Laser Technology and Project Engi
Ship design is often multidisciplinary involving several design elements with various types of objectives and constraints (O/C) some easily described as mathematical formulas, others better modeled as descriptive asse...
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Ship design is often multidisciplinary involving several design elements with various types of objectives and constraints (O/C) some easily described as mathematical formulas, others better modeled as descriptive assertions. This paper describes a method based on fuzzy functions and an integrated performance index to model O/C using descriptive assertions to be used with mathematical formulas in optimization. Another issue addressed in this paper concerns the coordination of design elements when sequentially coupled, that is, when one leads the other and the performance of the follower depends greatly on the design of the leader. Based on neuro-fuzzy techniques, the method described here coordinates and optimizes sequentially coupled elements. The two methods are applied to machinery arrangement (MA) and pipe routing (PR). Preliminary models for optimization of MA and PR are described considering convenience, producibility: engine room size, interference and location as factors in the O/C set. Some test results from MA/PR applications are presented and discussed. The methods are generic and can be extended to other elements in ship design. They are mutually independent and may be used separately Two advantages of their use are an improvement in overall performance and a reduction in the need for redesign of elements.
作者:
PAIGE, KKCONVERSE, RAUSNLCdr. Kathleen K. Paige
USN:graduated with a BA from the University of New Hampshire in 1970. She received her commission from Officer Candidate School in April 1971 and performed her first tour of duty with VFP-63 NAS Miramar. LCdr. Paige then received her MS from the Naval Post Graduate School in June 1976 and returned to San Diego to serve as Head Support Software Division at the Fleet Combat Direction System Support Activity. In May 1981 she reported to NA VSEA (PMS-408) where she served initially as Chairman of the NAVMAT Software Engineering Environment Working Group. She has been assigned as Deputy AN/UYK-43 Acquisition Manager since October 1981. LCdr. Paige was designated a fully qualified Engineering Duty Officer in December 1983. Robert A. Converse:is presently the Acquisition Manager for the Ada Language System/Navy (ALS/N) for the Naval Sea Systems Command Tactical Embedded Computer Resources Project. As such
he is responsible for the definition and development of the ALS/N to be provided as a Navy standard computer programming system for Navy mission critical applications. Mr. Converse received a Bachelor of Science degree in Physics from Wheaton College Wheaton II. He spent fourteen years with the Naval Underwater Systems Center Newport Rhode Island during which time he designed and developed the Fortran compiler for the Navy Standard AN/UYK-7 computer. Also during that period he received a Master of Science degree in Computer Science from the University of Rhode Island. His thesis for that degree was entitled “Optimization Techniques for the NUSC Fortran Cross-Compiler”. Mr. Converse started his involvement with the Ada program in 1975 with the initial “Strawman” requirements review. Subsequently he was named as the Navy Ada Distinguished Reviewer and was intimately involved in the selection and refinement of the Ada language as it evolved to become ANSI/MIL-STD-1815A.
The U.S. Navy introduced the use of digital computers in mission critical applications over a quarter of a century ago. Today, virtually every system in the current and planned Navy inventory makes extensive use of co...
The U.S. Navy introduced the use of digital computers in mission critical applications over a quarter of a century ago. Today, virtually every system in the current and planned Navy inventory makes extensive use of computer technology. computers embedded in mission critical Navy systems are integral to our strategic and tactical defense capabilities. Thus, the military power of the U.S. Navy is inextricably tied to the use of programmable digital computers. The computerprogram is the essential element that embodies the system “intelligence”. In addition, it provides the flexibility to respond to changing threats and requirements. However, this very flexibility and capability poses a host of difficulties hindering full realization of the advantages. This paper describes the lessons learned about computerprogram development over the past twenty five years and discusses a software engineering process that addresses these lessons. It then describes how Ada and its related Ada programming Support and Run-Time Environments foster this software engineering process to improve computerprogram productivity and achieve greater system reliability and adaptibility. Finally, the paper discusses how the use of Ada and its environments can enhance the interoperability and transferability of computerprograms among Navy projects and significantly reduce overall life cycle costs for Navy mission critical computerprograms.
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