检索结果-内蒙古大学图书馆

International Conference on Parallel Processing (ICPP)

作者： J. Jonsson K.G. Shin Department of Computer Engineering Chalmers University of Technology Goteborg Sweden Real-Time Computing LaboratoryDepartment of Elec. Engineering and Computer Science University of Michigan Ann Arbor MI USA

In this paper we experimentally evaluate the performance of a parametrized branch-and-bound (B&B) algorithm for scheduling real-time tasks an a multiprocessor system. The objective of the B&B algorithm is to minimize the maximum task lateness in the system. We show that a last-in-first-out (LIFO) vertex selection rule clearly outperforms the commonly used least-lower-bound (LLB) rule for the scheduling problem. We also present a new adaptive lower-bound cost function that greatly improves the performance of the B&B algorithm when parallelism in the application cannot be fully exploited on the multiprocessor architecture. Finally, we evaluate a set of heuristic strategies, one of which generates near-optimal results with performance guarantees and another of which generates approximate results without performance guarantees.

关键词： Processor scheduling Multiprocessing systems Real time systems Polynomials Cost function Parallel processing Artificial intelligence Fault tolerant systems Application software computer science

来源：评论

学校读者我要写书评

暂无评论

Deadline assignment in distributed hard real-time systems with relaxed locality constraints

Deadline assignment in distributed hard real-time systems wi...

引用

International Conference on Distributed Computing Systems

作者： J. Jonsson K.G. Shin Department of Computer Engineering Chalmers University of Technology Goteborg Sweden Real-Time Computing Laboratory Department of Elec. Engr. and Computer Science University of Michigan Ann Arbor MI USA

In a real time system, tasks are constrained by global end to end deadlines. In order to cater for high task schedulability, these deadlines must be distributed over component subtasks in an intelligent way. Existing methods for automatic distribution of end to end deadlines are all based on the assumption that task assignments are entirely known beforehand. This assumption is not necessarily valid for large real time systems. Furthermore, most task assignment strategies require information on deadlines in order to make good assignments, thus forming a circular dependency between deadline distribution and task assignment. We present a heuristic approach that performs deadline distribution prior to task assignment. The deadline distribution problem is presented in the context of large distributed hard real time systems with relaxed locality constraints, where schedulability analysis must be performed offline, and only a subset of the tasks are constrained by predetermined assignments to specific processors. Using experimental results we identify drawbacks of previously proposed techniques, and then show that our solution provides significantly better performance for a large variety of system configurations.

关键词： Real time systems Processor scheduling computer science Software maintenance Performance analysis Distributed computing Application software Software reusability Parallel processing Sensor systems

来源：评论

学校读者我要写书评

暂无评论

Database design for machining cell level product specification

Database design for machining cell level product specificati...

引用

International Conference on Industrial Electronics, Control and Instrumentation

作者： S.-A. Andreasson A. Adlemo M. Fabian P. Gullander B. Lennartson Department of Computing Science Chalmers University of Technology Goteborg Sweden Department of Computer Engineering Chalmers University of Technology Goteborg Sweden Control Engineering Laboratory Chalmers University of Technology Goteborg Sweden Department of Production Engineering Chalmers University of Technology Goteborg Sweden

To create a flexible machining cell control system a control algorithm is required that is based on models of products and resources. The scope of this paper is to present the database structure of a model used to des... 详细信息

关键词： Machining Object oriented modeling Relational databases Control systems Control system synthesis Manufacturing systems Control engineering Robots Design methodology Control engineering computing

来源：评论

学校读者我要写书评

暂无评论

Two-dimensional analysis of bandwidth of open hard surface

Two-dimensional analysis of bandwidth of open hard surface

引用

Antennas and Propagation Society International Symposium

作者： Z. Sipus P.-S. Kildal J. Salomonsson Department of Microwave Technology Chalmers University of Technology Goteborg Sweden Faculty of Electrical Engineering and Computer Science University of Zagreb Zagreb Croatia

The field caused by a filament current located on a dielectric slab has been calculated from a full wave solution. The results show that the slab provides that ideally hard boundary condition on the dielectric surface when d=/spl lambda/o/(4/spl radic/(/spl epsi//sub r/-1)), which means that the grounded slab works as an artificial PMC when the E-field is tangential to it. The radiation fields approach the omnidirectional radiation pattern of a PMC when d decreases, i.e. /spl epsi/r increases. The bandwidth of the hard surface is shown to decrease when the length of it increases.

关键词： Bandwidth Corrugated surfaces Dielectrics Surface waves Slabs Surface impedance Microwave technology Tellurium Cutoff frequency Boundary conditions

来源：评论

学校读者我要写书评

暂无评论

Communication Protocols and Failure Semantics in a Material-Driven Intelligent Manufacturing Systems

Communication Protocols and Failure Semantics in a Material-...

引用

1994 AAAI Spring Symposium

作者： Adlemo, Anders Andréasson, Sven-Arne Department of Computer Engineering Chalmers University of Technology GöteborgS-412 96 Sweden Department of Computing Science Chalmers University of Technology GöteborgS-412 96 Sweden

The paper describes a series of protocols that increases the ability to automatically cope with failures in a computerized manufacturing system. In order to achieve better automatic failure solutions the behavior of a subsystem must be more precisely defined regarding the possible failure modes. This is called to give the subsystem a stronger failure semantics. Then, regarding the systems specific failure semantics, an algorithm to cope with the corresponding failures can be given. In this paper material-driven systems, so called Push systems, are considered. To get more precise failure resolution protocols with one or two acknowledgment messages from the receiver are defined. A protocol with acknowledgment messages from an intelligent material transportation network is also described. copyright © 1994, AAAI (***). All rights reserved.

关键词： Fault tolerance

来源：评论

学校读者我要写书评

暂无评论

Communication protocols and failure semantics in intelligent manufacturing systems

Communication protocols and failure semantics in intelligent...

引用

IEEE International Conference on Robotics and Automation (ICRA)

作者： A. Adlemo S.-A. Andreasson Department of Computer Engineering Chalmers University of Technology Gothenburg Sweden Department of Computer Science Chalmers University of Technology Gothenburg Sweden

This paper describes a series of protocols that increases the ability to automatically cope with failures in a computerized manufacturing system. In order to achieve better automatic failure solutions the behavior of a subsystem must be more precisely defined regarding the possible failure modes. This is called to give the subsystem stronger failure semantics. Then, regarding the systems specific failure semantics, an algorithm to cope with the corresponding failures can be given.< >

关键词： Protocols Intelligent manufacturing systems computer errors Fault tolerant systems computer aided manufacturing Manufacturing systems Client-server systems Production systems Modems Fault tolerance

来源：评论

学校读者我要写书评

暂无评论

Fault tolerance aspects in computerized systems

Fault tolerance aspects in computerized systems

引用

Mediterranean Electrotechnical Conference (MELECON)

作者： A. Adlemo S.-A. Andreasson Department of Computer Engineering Chalmers University of Technology Goteborg Sweden Department of Computer Science Chalmers University of Technology Goteborg Sweden

Fault tolerance has become a very important aspect when designing computerized systems. It was first implemented for basic elements, such as hardware and software modules, but has more recently been implemented for complex systems, such as databases, process control, transaction applications, telephone exchanges, aeroplanes and manufacturing. The reason for introducing fault tolerance has been to improve the reliability and availability of the systems, thus minimizing the risks of human and economical losses. The paper briefly describes some basic fault tolerance concepts and also illustrates how fault tolerance has been implemented in different applications, such as hardware, software, computer systems and manufacturing systems.< >

关键词： Fault tolerant systems Hardware Application software Transaction databases Process control Telephony Manufacturing processes Availability Humans Software systems

来源：评论

学校读者我要写书评

暂无评论

Two Strategies for Improved Availability in Partitioned computerized Systems

引用

IFAC Proceedings Volumes 1994年第5期27卷 749-754页

作者： A. Adlemo S.-A. Andréasson Chalmers University of Technology Department of Computer Engineering S-412 96 Göteborg Sweden Chalmers University of Technology Department of Computing Science S-412 96 Göteborg Sweden

Many modern computerized systems are built as distributed, autonomous systems. Distributed systems have many advantages, e.g., the lack of a centralized control system. However, one situation that could lead to problems in a distributed system is when the data network partitions due to, e.g., a gateway failure. Such a partition can cause a stop in the execution of an isolated node, resulting in a reduction of performability and availability of the enure system. This paper proposes two strategies to handle data network partitions. Both strategies are based on the use of caches. The difference between them is that the first strategy uses a static cache while the second strategy uses a dynamic cache. The paper describes the difference between the caches and how the use of one, or both, caches increases the system’s performability and availability. The approach is illustrated with the help of an intelligent manufacturing system and a distributed database system.

关键词： Availability caches degradable systems distributed database systems intelligent manufacturing systems network partitions

来源：评论

学校读者我要写书评

暂无评论

A 40 GHz integrated quasi optical slot HFET mixer

A 40 GHz integrated quasi optical slot HFET mixer

引用

Microwave, MTT-S International Symposium

作者： H. Zirath C.-Y. Chi N. Rorsman G.M. Rebeiz Department of Microwave Technology Chalmers University of Technology Goteborg Sweden NASA/Center for Space Terahertz Technoloy Electrical Engineering and Computer Science Department University of Michigan Ann Arbor MI USA

We present for the first time a quasi optical mixer realized as a resistive HFET mixer with an integrated slot antenna. The mixer circuit conversion loss, defined as the measured IF-power in the 50 ohm load divided by the RF-power available at the slot-antenna terminals, is approximately 7 dB at an LO-power of 10.5 dBm when the mixer is fundamentally pumped, and 16 dB for subharmonically pumping at 10 dBm LO-power.< >

关键词： Integrated optics HEMTs MODFETs Optical pumping Slot antennas Optical losses Antenna measurements Loss measurement Integrated circuit measurements

来源：评论

学校读者我要写书评

暂无评论

Fault tolerance in partitioned manufacturing networks

引用

Journal of Systems Integration 1993年第1期3卷 63-84页

作者： Adlemo, Anders Andréasson, Sven-Arne Department of Computer Engineering Chalmers University of Technology Göteborg S-412 96 Sweden Department of Computer Science Chalmers University of Technology Göteborg S-412 96 Sweden

Fault tolerance is especially important for computer systems that require a high degree of confidence. computer Integrated Manufacturing (CIM) is an area where computer systems must not be disturbed by uncontrolled failures. This article deals with two problems that are related to fault tolerance and network partitions in automated manufacturing systems. The first problem relates to the distribution of information in partitioned data networks in CIM systems. We indicate how to overcome this problem by using the material network as a redundant data network: The second problem relates to fault detection and diagnosis in manufacturing systems. The problem is whether the indication of a fault means that a production unit itself has actually broken down, or that the indication is instead due to disturbances in the transmission of material. That is, the production unit continues to operate propcrly despite indications to the contrary. We describe how the material network can be used for detection and diagnosis. © 1993 Kluwer Academic Publishers.

关键词： Caches computer integrated manufacturing distributed computing systems dynamic configuration fault detection fault diagnosis fault tolerance network partitioning quasi-partitioning

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：