• Proceedings of the KIEE Conference
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• 1999.07c
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• pp.1101-1103
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• 1999

Deregulation and restructuring of electric industry change the fundamental nature of electric business which will be coordinated by the evolved market structures such as spot market with pool and bilateral transaction structure, forward market and future market. Introduction of competition can significantly change the system operation in near-terms as well as long-run generation expansion planning Previous centralized planning by monopoly utilities which was guided for the public service purpose will be replaced by decentralized investments plan by individual generation companies in response to commercial incentives. This paper reviews WASP model as a centralized planning tool and presents a methodological analysis of generation expansion planning in deregulated power systems. It stresses how affects the process of planning new generation investments by the introduction of competition and how maintains proper fuel mix and continuously sustains system reliability under deregulated environments.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.2A
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• pp.134-141
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• 2010

In this paper, we propose a scheduling algorithm to improve the performance of IEEE 802.16 based wireless mesh networks using directional antenna. The performance is presented in terms of throughput of system and delay between each node by varying number of users. The result show that proposed scheduling algorithm improving the performance by reducing the delay of mesh network system. Our work may be useful as a guideline to control the fairness between SSs for multi-hop systems such as multi-hop relay and mesh networks.

• Journal of Information Processing Systems
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• v.10 no.1
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• pp.36-54
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• 2014

Resource sharing is a major advantage of distributed computing. However, a distributed computing system may have some physical or virtual resource that may be accessible by a single process at a time. The mutual exclusion issue is to ensure that no more than one process at a time is allowed to access some shared resource. The article proposes a token-based mutual exclusion algorithm for the clustered mobile ad hoc networks (MANETs). The mechanism that is adapted to handle token passing at the inter-cluster level is different from that at the intra-cluster level. It makes our algorithm message efficient and thus suitable for MANETs. In the interest of efficiency, we implemented a centralized token passing scheme at the intra-cluster level. The centralized schemes are inherently failure prone. Thus, we have presented an intra-cluster token passing scheme that is able to tolerate a failure. In order to enhance reliability, we applied a distributed token circulation scheme at the inter-cluster level. More importantly, the message complexity of the proposed algorithm is independent of N, which is the total number of nodes in the system. Also, under a heavy load, it turns out to be inversely proportional to n, which is the (average) number of nodes per each cluster. We substantiated our claim with the correctness proof, complexity analysis, and simulation results. In the end, we present a simple approach to make our protocol fault tolerant.

• Journal of the Korean association of regional geographers
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• v.16 no.4
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• pp.355-368
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• 2010

This study is to make a framework of newly interpretating the dynamic change of regional or local landscape rapidly occurred after the establishment of the nation state and capitalistic system. The basic concepts of making an interpretative framework are power, subjectivity, and performativity. The framework of closely interrelating the three concepts developed in the near future will be applied to the interpretation of variety of (de)centralized landscapes in regions or locals. A centralized political power under the nation state has destroyed or marginalized the historically developed landscapes, traditional culture, and subjects' values in regions or locals by the political implementation of the nation state, the establishment of national identity, a centralized economic development, and so on. The landscapes produced by the political power of the nation state can take a role as a cause of conflicts in regions or locals in terms of a historical perspective. Landscapes are being made by various subjects, and the produced landscapes also positively or negatively will influence the emotion, cognition, and behavior of the subjects particularly in a performative perspective. The dynamics interrelation between subjects and landscapes has been disguised or marginalized by reason/rationality, totality/collectivity, the separation between reason and emotion mainly made by modernism, the nation state, a capitalistic system. The interrelation between landscapes and subjects is especially emphasized on people's resistibility and creativity. Lastly, landscape is not a concept given as a priori or (re)presented objectively. It is not also a material or an object independently existed from a subject's emotion and cognition. It should be interpreted through a performative relation with subjects. Performativity will take an active role of combining the materiality of landscape, power, and subjectivity. It is also important to understand the active role of landscapes.

• KIPS Transactions on Software and Data Engineering
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• v.3 no.5
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• pp.169-178
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• 2014

In this paper, we present a research utilizing decentralized LTL specifications for ensuring a quality for interaction-centralized system. In this system, for ensuring the quality, we need to validate interactions between modules of the system and then we should check whether the system achieves the expected requirements. This task remains difficult and labor-intensive and requires an expert. In this paper, we present a method to assist such a task. First of all, the requirements of the system is written as multiple LTL specifications. Interactions between modules mean that behaviors of one module are related with other one's behavior. We generate the automaton model fully achieving specification through GR(1) synthesis. And we simulate them using the simulator based on the software agent for checking behaviors of the system. Finally, we validate the whole system whether it achieves given requirements.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.12
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• pp.2252-2258
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• 2016

CCMP(centralized conferencing manipulation protocol) enables adding and removing conference participants, changing their roles, adding and removing media streams in conference system. In this paper, by using extended CCMP, a new distributed conference system architecture which can be used to multiple servers distributed conference system in SIP(session initiation protocol) environment has been presented. In this study, according to increasing number of participants, a new extended CCMP architecture which can distribute conference system loads to multiple servers dynamically to decrease loads of servers has been designed. This extended CCMP architecture also can add dynamically new servers from the prepared servers pool. Furthermore, new conference information data format which can represent extended CCMP has been designed, and exchange procedures of extended CCMP control messages which can distribute loads between servers have also been presented. The performance of the proposed system has been analysed by simulation.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.10a
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• pp.889-890
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• 2016

Existing machine-to-machine collaboration system is a centralized structure system fo built OpenWrt and a Web server on the router. But scarce resources of the router are getting more requests from the collaboration client when a problem has occurred with increasing probability of a client object, the higher the traffic. In this paper, in order to solve the problem, we propose a distributed system utilizing Machine Socialization cooperation algorithm. The MCU attached to the machine to minimize the traffic occurrence probability and loss of the data by processing to distribute the data between the server and the client. Also improve the response speed between the server and the client and the operation stop caused by the loss of data. The proposed system will be utilized if the IoT field will be high efficiency compared to existing systems.

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 1986.10a
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• pp.59-63
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• 1986

This paper presents a basic planning of CMDSS(Centrallized Maintenance Decision Support System)for future operation and maintenance of telecommunication network, the main components of CMDSS are MDB, MMB, DSDB, MDBMS, MMAMS, and IGMS. ANd the efficiency and the effectiveness depend on the adequate design of the decision procedure to assisy operation and maintenance persinnels.

• 제어로봇시스템학회:학술대회논문집
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• 1991.10a
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• pp.322-326
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• 1991

A real time process control package was developed in an INTEL 80386 based PC and MS OS/2 environment using MS-C and MS-FORTRAN. RTACS(Real Time Advanced Control System), process control computer software for distributed or centralized architectures, is a package which meets functional requirements specified for typical continuous process applications like chemical processes. The package consists of 5 parts, which are DB(data base), OCF(Operator Console Functions), CL (Control logic Library), MSM(Multitasking and Scheduling, Manager) and UAI(User Applications Interface), based upon a table and function block architecture to improve the system performance.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.217-217
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• 2000

A decentralized robust EA(eigensoucture assignment) controller is designed for an active suspension system of a vehicle based on a full car model with 7-degree of freedom. Using overlapping decomposition, the full car model is decentralized by two half car models. For each half car model, a robust eigenstructure assignment controller can be obtained by using optimization approach. The performance of the decentralized robust EA controller is compared with that of a conventional centralized EA controller through computer simulations.