• 제어로봇시스템학회:학술대회논문집
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• 1992.10b
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• pp.112-117
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• 1992

The Real-time Distributed Control Systems(RDCS) consist of several distributed control processes which share a network medium to exchange their data. Performance of feedback control loops in the RDCS is subject to the network-induced delays from sensor to controller and from controller to actuator. The network-induced delays are directly dependent upon the data sampling times of the control components which share a network medium. In this study, a scheduling algorithm of determining data sampling times is developed using the window concept, where the sampling data from the control components dynamically share a limited number of windows.

• The Journal of Information Systems
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• v.4
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• pp.85-104
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• 1995

In a loosely-coupled distributed database server system, a server failure and/or a communication failure can be masked by a resiliency mechanism. Recognizing that a distributed transaction executes at several servers during its lifetime, we propose a resiliency mechanism which allows continuous transaction processing in distributed database server systems in the presence of a server failure. The resiliency mechanism for transaction processing is achieved by keeping redundant information using a primary/backup approach. The purpose of this paper is to analyze the performance improvement opportunities with the resiliency mechanism and to present the design of the proposed system.

• The KIPS Transactions:PartD
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• v.13D no.1 s.104
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• pp.139-146
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• 2006

This paper describes the design and implementation details of a distributed transactional workflow monitoring system. There have been prevalent research and development trends in the workflow literature - workflow systems tend to be completely distributed architectures to support very large-scale workflow applications on object-oriented and internet-based infrastructures. That is, the active (object), distributed (architecture), system-oriented (transaction), and large-scale (application) workflow systems are the key targets in terms of the research and development aspects. While the passive, centralized, human-oriented, and small/medium scale workflow systems are the typical instances of the traditional workflow systems. Unlike in the traditional (the client-server architecture) workflow systems, the workflow monitoring features should not be easily supported in the recent (the fully distributed architecture) workflow systems. At the same time, they need a set of additional monitoring features, such as gathering and displaying statistical (or overload status) information of the workflow architectural components dispersed on the internet. We, in this paper, introduce the additional workflow monitoring features that are necessarily required for the recent workflow systems, and show how to embed those features into a web-based distributed workflow system.

• Journal of Korea Society of Digital Industry and Information Management
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• v.14 no.3
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• pp.39-44
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• 2018

Communication in real-time distributed system should have high reliability. To develop group communication Protocol with high reliability, potential fault should be known and when fault occurs, it should be detected and a necessary action should be taken. Existing detection method by Ack and Time-out is not proper for real time system due to load to Ack which is not received. Therefore, group communication messages from real-time distributed processing systems should be communicated to all receiving processors or ignored by the message itself. This paper can make be sure of transmission of reliable message and deadline by suggesting and experimenting fault detection technique applicable in the real time distributed system based on ring, and analyzing its results. The experiment showed that the shorter the cycle of the heartbeat signal, the shorter the time to propagate the fault detection, which is the time for other nodes to detect the failure of the node.

• Journal of Korean Port Research
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• v.13 no.2
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• pp.289-302
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• 1999

As the size and complexity of network increase Distributed System Management (DSM) will be significant issue within information network in order to increase the high reliability and to improve the flexibility of network management. The OSI management model has several problems. The key problems are that it does not fully address the problem of how to develop communication protocol in support of DSM and how to classify the management connection criteria. In this paper to solve first problem described above this paper propose the connectionless CMIP to accomplish for effectively managing the distributed management managing systems to handle the dynamic informations. To work out second problem we introduce the connection criteria in the hierarchy of management system and finally evaluate the efficiency of a suggested protocol during cooperative negotiation among the managing system.

• Journal of Institute of Control, Robotics and Systems
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• v.13 no.6
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• pp.596-602
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• 2007

Recently, many ECUs(Electronic Control Units) have been used to enhance the vehicle safety, which leads to a distributed real-time control system. The distributed real-time control system requires to reduce the network delay for dependable real-time performance. There are two different paradigms by which a network protocol operates: event-triggered and time-triggered. This paper focuses on implementation of a time-triggered protocol. i.e. TTP/C(Time-Triggered Protocol/class C). This paper presents a design method of TTP control network and performance evaluation of distributed real-time control system using TTP protocol.

• IE interfaces
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• v.16 no.1
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• pp.1-7
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• 2003

Today's manufacturing enterprise relies heavily on the collaboration and coordination among the distributed manufacturing systems. The effective exchange of the various manufacturing information among the distributed organizations contributes a great deal to their productivity. An Internet-Based Manufacturing Desk is developed for the production of the press dies in the automobile industry in order to solve the manufacturing problems among the distributed organizations, to maintain their smooth and immediate information flow, and to increase their productivity finally. The CBR(Case-Based Reasoning) method is applied to achieve those effects. Using the method, the solutions and methods of the predetermined case-bases are retrieved and applied to solve a newly introduced problem. The developed system is implemented and applied successfully.

• Asia pacific journal of information systems
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• v.7 no.3
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• pp.23-37
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• 1997

Although numerous models and solution algorithms to design efficient distributed databases have been developed, very few have been validated for their effectiveness. In this paper, we develop a simulation system which can be used to analyze and validate the average response time of distributed database designs. Our simulation system models comprehensive query processing strategies such as semijoin as well as a concurrency control mechanism We analyze and validate an average response time distributed database design model using our simulation system.

• International Journal of Contents
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• v.3 no.1
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• pp.34-38
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• 2007

Load redistribution is a critical resource in computer system. In sender-initiated load redistribution algorithms, the sender continues to send unnecessary request messages for load transfer until a receiver is found while the system load is heavy. These unnecessary request messages result in inefficient communications, low CPU utilization, and low system throughput in distributed systems. To solve these problems, we propose a genetic algorithm based approach for improved sender-initiated load redistribution in distributed systems. Compared with the conventional sender-initiated algorithms, the proposed algorithm decreases the response time and task processing time.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.88.1-88
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• 2001

The paper describes a new approach to the organization of an artificial brain for mobile multi-robot systems, where individual robots are not considered as independent entities, but rather forming together a universal parallel and distributed machine capable of processing both information and physical matter in distributed worlds. This spatial machine, operating without any central control, is driven on top by distributed mission scenarios in WAVE-WP language. The scenarios can be written on a variety of levels, and any mixture of them, supporting the needed system flexibility and freedom ...