• Journal of applied mathematics & informatics
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• v.28 no.1_2
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• pp.193-207
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• 2010

In this paper, a predator-prey model with stage structure and distributed delay is investigated. Mathematical analyses of the model equation with regard to boundedness of solutions, nature of equilibria, permanence, extinction and stability are performed. By the comparison theorem, a set of easily verifiable sufficient conditions are obtained for the global asymptotic stability of nonnegative equilibria of the model. Taking the product of the per-capita rate of predation and the rate of conversing prey into predator as the bifurcating parameter, we prove that there exists a threshold value beyond which the positive equilibrium bifurcates towards a periodic solution.

• Proceedings of the IEEK Conference
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• 2003.11b
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• pp.3-6
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• 2003

In this paper, we conduct a performance analysis for the composite scheme that is obtained by combining the data distribution and the data replication schemes usually used for the implementation of distributed directory service systems. The analysis results reveal that the composite model is a viable option to overcome the performance trade-off between the data distribution and the data replication model. In this paper, we present the performance model developed for the composite model by appling queuing modelling. Using the performance model, performance values for a variety of system execution environments are suggested which enable us to bring an efficient design for high performance distributed directories.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.496-497
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• 2008

This paper presents development of the long and mid term power expansion planing for distributed generation. This planing model reflect WADE Economic Model's advantage that special quality of DG(Decentralized Generation) and WASP Model's advantage that special quality of CG(Centralized Generation) each other. Through these synergy, we develop better the Plan of Long and Mid Term Distributed Generation then existent model.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.23 no.9A
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• pp.2258-2270
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• 1998

Recently, the distributed processing environments provide various open multimedia serivces through telecommunication network and have been developing into information networking structure based on object oriented concepts and distributed systems which can apply new services with a few changes the existing networks. This paper proposes the object group model which is the collection of objects and can functionally and efficiently manage the individual object. this paper presents the analysis of the requirement and the function specifications to propose the object group model, and depicts the functional structure in details using its analysis. The goal of this paper is to decrease the complexity of the object's management and to voercome the limitations of among the components of object group for management and service functions based on our proposed the object group model and show interaction procedures to eTD (event tracing diagram)s and finally we design the object group model by TINA-ODL.

• International Journal of Aeronautical and Space Sciences
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• v.18 no.3
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• pp.574-578
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• 2017

In order to achieve iterative design in early R&D period, a Distributed and Real-time Integrated Simulation System for avionics based on a Model-Based Systems Engineering (MBSE) method is proposed. The proposed simulation system includes driver, simulation model, monitor, flight visual model and aircraft external model.The effect of this simulation system in iterative design and system verification is testified by several use cases. The result shows that the simulation system, which can play an important role in iterative design and system verification, can reduce project costs and shorten the entire R&D period.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.18 no.33
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• pp.1-10
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• 1995

The allocation of files is essential to the efficiency and effectiveness of a distributed system that must meet geographically dispersed data processing demands. In this paper, we address an optimization model that generates optimal file migration policies in distributed database systems. The proposed model is a more generalized model that includes system's capacity constraints - computing sites' storage capacity and communication networks' capacity - which have not taken into consideration in previous researches. Using this model, we can establish initial file allocation, file reallocation and file migration polices that minimize a system operating cost under system's capacity constraints at an initial system design or reorganization point The proposed model not only can be adopted by small-sized systems but also provides a foundation for effective and simple heuristics for adaptive file migration in large systems.

• ETRI Journal
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• v.13 no.2
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• pp.34-41
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• 1991

In this paper, a new distributed parallel algorithm for pattern classification based upon Self-Organizing Neural Network(SONN)[10-12] is developed. This system works without any information about the number of clusters or cluster centers. The SONN model showed good performance for finding classification information, cluster centers, the number of salient clusters and membership information. It took a considerable amount of time in the sequential version if the input data set size is very large. Therefore, design of parallel algorithm is desirous. A new distributed parallel algorithm is developed and experimental results are presented.

• International Journal of Reliability and Applications
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• v.1 no.2
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• pp.105-113
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• 2000

This paper discusses some problems of the TMN-based architecture of integrated network management systems and presents a CORBA-based architecture of distributed network management system with reliability, which maintains location transparency of distributed managed objects and provides an interoperability among heterogeneous networks and systems. In this paper, the proposed distributed management system model has been applied to the TMN based management systems and then considered for qualitative evaluation of system performance. Two different types of implementation models have been proposed: one is a system using a CORBA gateway and the other is a pure CORBA system, which maps all managed objects into CORBA objects. The characteristics of two system model have been compared in the respect of system implementation

• Journal of the Korea Computer Industry Society
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• v.2 no.8
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• pp.1099-1108
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• 2001

In this paper, we proposed an efficient method of management in which various design objects in the environments for distributed software development. Those design objects are created in the environments for distributed software development based on Unified Modeling Language as well as versions of source codes. In this research, a version control technique has been specially focused that is based on our proposed version rules to consistently control versions from web-based distributed software development which enables developers to independently manage distributed objects from the software development platform. Based on the version control technique, we have designed a web-based rule-control version management model that has been proposed here.

• Korean Journal of Computational Design and Engineering
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• v.5 no.1
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• pp.12-22
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• 2000

Network and Internet technology opens up another domain for building future CAD/CAM environment. The environment will be global, network-centric, and spatially distributed. In this paper, we present an approach for network-centric feature-based modeling in a distributed design environment. The presented approach combines the current feature-based modeling technique with distributed computing and communication technology for supporting product modeling and collaborative design activities over the network. The approach is implemented in a client/server architecture, in which Web-enabled feature modeling clients, neutral feature model server, and other applications communicate with one another via a standard communication protocol. The paper discusses how the neutral feature model supports multiple views and maintains naming consistency between geometric entities of the server and clients. Moreover, it explains how to minimize the network delay between the server and client according to incremental feature modeling operations.