• The KIPS Transactions:PartA
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• v.17A no.6
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• pp.259-264
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• 2010

In case of scheduling tasks with shared resources in multiprocessor systems, Global Earliest Deadline First (GEDF) algorithm, equally applied Earliest Deadline First (EDF) which runs scheduling with deadline criterion, makes schedulability decline because GEDF typically does not have a specific process in order to handle tasks with shared resources. In this paper, we propose Earliest Deadline First with Partitioning (EDFP) for tasks with shared resources which partitions a task into two kinds of subtasks that include critical sections to access to shared resources, gives their own deadline respectively and manages them. As a result of simulations, EDFP shows better performance than GEDF for tasks with shared resources since system load goes up and the number of processor increases.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.3 no.1
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• pp.37-43
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• 2003

Current Internet system of the entrance exam information to the university that is depending on searching key to solve the overloaded problem in the network and DB server or other tools to support HTML edit, haven't satisfied user's wants by supplying uniformed searching system. So this thesis will establish EEIS(Entrance Examination Information System) to prevent database overload phenomena when many users request a great amount of data at the same time and improve the decrease of speed and overload problem in DB server. EEIS playa role of bridge between outside client and DB server by placing VVS(Virtual View Server) between web server and DB server. By that method this system give users several usefulness in convenience and variety by supplying realtime data searching function to user. EEIS also give inner system manager more efficiency and speed in control the management system by solving those problem. This system is design and implementation to satisfy user's desire and give them more convenience and bring up the confidence of university that adopt this system at the end.

• Proceedings of the Korea Society for Simulation Conference
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• 1999.04a
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• pp.242-250
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• 1999

The objective of this paper is to propose an Extended AND-OR Graph (EAOG)-driven inferential simulation mechanism with which decision makers engaged in electronic commerce (EC) can effectively deal with complicated decision making problem. In the field of traditional expect systems research, AND-OR Graph approach cannot be effectively used in the EC problems in which real-time problem-solving property should be highly required. In this sense, we propose the EAOG inference mechanism for EC problem-solving in which heurisric knowledge necessary for intelligent EC problem-solving can be represented in a form of matrix. The EAOG method possesses the following three characteristics. 1. Realtime inference: The EAOG inference mechanism is suitable for the real-time inference because its computational mechanism is based on matrix computation.2. Matrix operation: All the subjective knowledge is delineated in a matrix form, so that inference process can proceed based on the matrix operation which is computationally efficient.3. Bi-directional inference: Traditional inference method of expert systems is based on either forward chaining or based on either and computational efficiency. However, the proposed EAOG inference mechanism is generically bi-directional without loss of both speed and efficiency.We have proved the validity of our approach with several propositions and an illustrative EC example.

• Journal of the Korean Institute of Intelligent Systems
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• v.7 no.5
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• pp.1-7
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• 1997

In this paper, a neuro-contouring control scheme for the high precision machining of CNC machine tools is descrihed. The proposed control system consists of a conventional controller for each axis and an additional neuro-controller. For contouring control, the contour error must be computed during realtime motion, but generally the contour error for nonlinear contours is difficult to he directly computed. We, therefore, propose a new contour error model to approximate real error more exactly, and here we also introduce a cost function for better contouring performance and derive a learning law to adjust the weights of the neuro-controller. The derived learning law guarantees good contouring performance. Usefulness of the proposed control scheme is demonstrated hy computer simulations.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.25 no.1
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• pp.29-34
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• 1989

Recently microcomputers have come into wide use in the field of the control. They are used not only as monitors and as controllers in the various plant control systems but also as the Computer Aided Design of control systems. As an example of the design and the realtime control of the control system using Microcomputer, the optimal design of the control system of which the numerator of the transfer function is constant have been reported by authors. In this paper, author proposes a method to design the optimal controller about the control system of which the numerator of the transfer function is not constant, and develops the program of the response simulation.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.10a
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• pp.241-244
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• 2009

Recently car navigation systems which are widely spreaded and provide routes exactly have been evolved. The systems use various information and techniques as follows. In order to provide shortest path with good flow, realtime traffic information provided by DMB is used. Augmented reality technique is also introduced to give the sense of real to driver by displaying real images captured by camera during driving. But these operate well when the GPS receives data normally. Exact information about the position of vehicles becomes a base that supports the above function with realities. This paper proposes a method for compensating a given path. It uses various information by integrated vehicle networks when the GPS does not operates normally.

• Journal of Korea Society of Industrial Information Systems
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• v.14 no.4
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• pp.65-74
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• 2009

The risk of health impairment due to poor ventilation, fire and explosion by inflammable materials, and other unintended occurrences is always present in dangerous workplaces such as manholes, underground septic tanks, storage tanks and confined areas. Therefore, it a system which can monitor harmful working environment through sensors in workplace on a realtime basis and keep workers safe from the risk is needed. This paper has attempted to design an inference engine to monitor harmful environments in the workplace. The proposed inference engine has a rule-based system structure using JESS. This system is not confined to a particular computing platform and is easily interlocked with OSGi-based middleware.

• Journal of the Korea Institute of Military Science and Technology
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• v.11 no.4
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• pp.46-58
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• 2008

Naval combat management system is a kind of complex weapon systems performing naval ship's warfare mission by integrating various types of system including sensor systems, weapon systems and many kinds of communication system. Recently, there are many studies to apply commercial high-level communication middleware to naval combat system development to integrate and interoperate various kinds of heterogeneous on-board systems efficiently. An initial discovery mechanism is required for application modules to start communication with their relevant modules to apply middlware technology in developing naval combat system, which is characterized by large-scale, complex and real-time system. This paper suggests a fast hybrid discovery mechanism which combines static and dynamic discovery mechanism and confirms its adaptability by an experiment on testing environment.

• Journal of KIISE:Computer Systems and Theory
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• v.36 no.6
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• pp.463-475
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• 2009

Flash memory is suitable for real time systems because of its consistent performance for random access, low power consumption and shock resistance. However, flash memory needs blocking time to perform a garbage collection to reclaim invalidated pages. Moreover, the worst-case garbage collection time is significantly longer than the best-case garbage collection time. In this paper, we propose a FTL (Flash Translation Layer) mapping scheme called KAST (K-Associative Sector Translation). In the KAST scheme, user can control the maximum association of the log block to limit the worst-case garbage collection time. Performance evaluation using simulation shows that not only KAST completes the garbage collection within the specified time but also provides about 10~15% better average performance than existing FTL schemes.

• Journal of the Korea Society of Computer and Information
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• v.12 no.6
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• pp.297-306
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• 2007

Bar-code based airway logistics systems have many problems like freight loss and data management error due to semiskilled air-cargo process and individual information system. To solve these problems, this paper analyzed how to process an air-cargo practically and designed and implemented the RFID-based airway logistics system. This system has an information service system which manages data from RFID systems in realtime and provides a communication interface for data sharing. And, this system precesses data queries from capture applications and access applications to provide various services to users such as the freight track and trace service. Also, this system includes a H/H reader agent to integrate existing bar-cord systems. It allows us to realize automation and information-oriented air-cargo process and achieve improvement of air-cargo services with reduction of freight loss and management error.