• Proceedings of the Korean Operations and Management Science Society Conference
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• 2002.05a
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• pp.285-292
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• 2002

A cluster tool for semiconductor manufacturing is an integrated device that consists of several single wafer processing modules and a wafer transport module based on a robot. The distributed module controllers are integrated by an inter-module communication network and coordinated by a centralized controller, called a cluster tool controller (CTC). Since the CTC monitors and coordinates the distributed complex module controllers for advanced process control, complex commuication messaging and services between the CTC and the module controllers are required. A SEMI standard, CTMC(Cluster Tool Module Communication), specifies application-level communication service requirements for inter-module communication. We propose the use of high-level fieldbuses, for instance. PROFIBUS-FMS, for implementing CTMC since the high-level fieldbuses are well suited for complex real-time distributed manufacturing control applications. We present a way of implementing CTMC using PROFIBUS-FMS as the communication enabler. We first propose improvements of a key object of CTMC for material transfer and the part transfer protocol to meet the functional requirements of modem advanced cluster tools. We also discuss mapping objects and services of CTMC to PROFIBUS-FMS communication objects and services. Finally, we explain how to implement the mappings.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1999.10a
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• pp.89-90
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• 1999

• Journal of Korea Multimedia Society
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• v.10 no.12
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• pp.1679-1686
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• 2007

In this paper, we introduce the sharable and reusable learning objects which are suitable for XML Web services in e-learning systems. These objects are extracted from the principles of pedagogical paradigms for reusable learning units. We call them LIO (Learning Item Object) objects. Existing models, such as Web-hosted and ASP-oriented service model, are difficult to cooperate and integrate among the different kinds of e-learning systems. So we developed the LIO objects that are suitable for XML Web services. The reusable units that are extracted from pedagogical paradigms are tutorial item, resource, case example, simulation, problems, test, discovery and discussion. And these units correspond to the LIO objects in our learning object model. As a result, the proposed model is that learner and instruction designer should increase the power of understanding about learning contents that are based on pedagogical paradigms. By using XML Web services, this guarantees the integration and interoperation of the different kinds of e-learning systems in distributed environments and so educational organizations can expect the cost reduction in constructing e-learning systems.

• International Journal of Contents
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• v.4 no.2
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• pp.19-23
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• 2008

This paper presents a novel method to construct a personalized e-Learning system based on dynamic estimations of item parameters and learners' abilities, where the learning content objects are of the same intrinsic quality or homogeneously distributed and the estimations are carried out using IRT(Item Response Theory). The system dynamically connects the test and the corresponding learning procedures. Test results are directly applied to estimate examinee's ability and are used to modify the item parameters and the difficulties of learning content objects during the learning procedure is being operated. We define the learning unit 'Node' as an amount of learning objects operated so that new parameters can be re-estimated. There are various content objects in a Node and the parameters estimated at the end of current Node are directly applied to the next Node. We offer the most appropriate learning Node for a person's ability throughout the estimation processes of IRT. As a result, this scheme improves learning efficiency in web-base e-Learning environments offering the most appropriate learning objects and items to the individual students according to their estimated abilities. This scheme can be applied to any e-Learning subject having homogeneous learning objects and unidimensional test items. In order to construct the system, we present an operation scenario using the proposed system architecture with the essential databases and agents.

• Journal of KIISE:Computing Practices and Letters
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• v.6 no.6
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• pp.555-568
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• 2000

The World Wide Web has become the largest virtual system that is almost universal in scope. In recent research, it has become effective to utilize idle hosts existing in the World Wide Web for running applications that require a substantial amount of computation. This novel computing paradigm has been referred to as the advent of global computing. In this paper, we implement and propose a mobile object-based global computing framework called Tiger, whose primary goal is to present novel object-oriented programming libraries that support distribution, dispatching, migration of objects and concurrency among computational activities. The programming libraries provide programmers with access, location and migration transparency for distributed and mobile objects. Tiger's second goal is to provide a system supporting requisites for a global computing environment - scalability, resource and location management. The Tiger system and the programming libraries provided allow a programmer to easily develop an objectoriented parallel and distributed application using globally extended computing resources. We also present the improvement in performance gained by conducting the experiment with highly intensive computations such as parallel fractal image processing and genetic-neuro-fuzzy algorithms.

• The KIPS Transactions:PartC
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• v.12C no.3 s.99
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• pp.449-456
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• 2005

Optical burst switching (OBS) overcomes the inefficient resource usage of optical circuit switching and minimizes the optical buffering requirement of optical packet switching. General switch management protocol (GSMP) is an open interface between a label switch and a controller, and it provides connection, configuration, performance, event management and synchronization. GSMP open interface in the OBS network allows the implementation of OBS switch to be simple by separating the data forward plane from the control plane. We defined managed objects to support connection, configuration, performance, and fault management for the management of OBS network in the GSMP open interface. We proposed the network management model, in which the above managed objects are distributed in a controller and an OBS switch according to network management functions. We verified the possibility of connection management using distributed network management model in the GSMP open interface of OBS network by implementing GSMP and network management functions with managed objects of OBS.

• Proceedings of the KIEE Conference
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• 2002.07d
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• pp.2531-2533
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• 2002

In this paper, we evaluate feasibility of an object-oriented method in a distributed real-time control environment through the prediction of delay expected. We adopt CAN as the distributed network and the application layer of the CAN is composed of client/server communication model of COM and surroundings for the support of real-time capability of the COM. Mathematical models formalizing delays which are predicted to invoke in the COM architecture are proposed. Sensors and actuators which are widely used in distributed network-based systems are represented by COM objects in this paper. It is expected that the mathematical models can be used to protect distributed network-based systems from violation of real-time features by the COM.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.6 no.1
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• pp.133-139
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• 2002

For efficiently providing distributed services, distributed computing environments are specified the requirements of various services and distributed object platforms applied an object-oriented technology by TINA Consortium and OMG CORBA. Because applications are becoming large and distributing, their servicing and managing interfaces among objects are being complicated. In order to solve these defects, it is necessary to suggest a new object grouping model and specify object service/management requirements can be introduced under the object groups.

• Journal of Korea Spatial Information System Society
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• v.10 no.4
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• pp.11-19
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• 2008

Recently, advances in mobile devices and wireless communication technologies require research on various location-based services. As a result, many studies on processing k-nearest neighbor query, which is most im portant one in location-based services, have been done. Most of existing studies use pre-computation technique to improve retrieval performance by computing network distance between POIs and nodes beforehand in spatial networks. However, they have a drawback that they can not deal with effectively the update of POIs to be searched. In this paper, we propose a distributed grid scheme using S-GRID to overcome the disadvantage of the existing work as well as to manage the location information of a large number of moving objects in efficient way. In addition, we describe a k-nearest neighbor(k-NN) query processing algorithm for the proposed distributed grid scheme. Finally, we show the efficiency of our distributed grid scheme by making a performance comparison between the k-NN query processing algorithm of our scheme and that of S-GRID.

• Journal of Internet Computing and Services
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• v.10 no.1
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• pp.101-110
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• 2009

Multi-agent systems are mostly used to integrate the intelligent and distributed approaches to various systems for effective sharing of resources and dynamic system reconfigurations. Object replication is usually used to implement fault tolerance and solve the problem of unexpected failures to the system. This paper presents the intelligent multi-agent distributed platform based on the dynamic object group management and proposes an object search technique based on the proposed filtered k-means (Fk-means). We propose Fk-means for the search mechanism to find alternative objects in the event of object failures and transparently reconnect client to the object. The filtering range of Fk-means value is set only to include relevant objects within the group to perform the search method efficiently. The simulation result shows that the proposed mechanism provides fast and accurate search for the distributed object groups.