• 한국전기전자재료학회논문지
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• 제27권5호
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• pp.322-327
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• 2014

Internal corrosion of the distribution line can be detected in order to develop techniques of non-destructive inspection methods that operate only on the metal track eddy current diagnosis is possible by applying the technique investigated. Sensor for the production of a finite element method modeled by using an eddy current sensor, a distribution line by using an accelerated aging samples of sodium hydroxide was prepared. Sheathed cables for internal corrosion studies detected using an eddy current sensor is considered to be possible.

• Journal of applied mathematics & informatics
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• 제14권1_2호
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• pp.343-351
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• 2004

In order to maintain load balancing in a distributed system, we should obtain workload information from all the nodes on network. This processing requires $O(v^2)$ communication overhead, where v is the number of nodes. In this paper, we present a new synchronous dynamic distributed load balancing algorithm on a (v, k ＋ 1, 1)-configured network applying a symmetric balanced incomplete block design, where $v\;=\;k^2$\;＋\;k\;＋\;1$. Our algorithm needs only $O(\sqrt[v]{v})$ communication overhead and each node receives workload information from all the nodes without redundancy. Therefore, load balancing is maintained since every link has the same amount of traffic for transferring workload information.

• Journal of Electrical Engineering and information Science
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• 제2권4호
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• pp.37-45
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• 1997

With rapid increase of information requirements from various application areas, there has been much research on dynamic information storage structures that effectively support insertions, deletions and updates. In this appear we evaluate the performance of he existing dynamic signature file methods such as the S-tree, Quick Filter and HS file and provide guidelines for the most effective usage to a given operational environment. We derive analytic performance evaluation models of the storage structures based on retrieval time, storage overhead and insertion time. We also perform extensive experiments with various data distributions such as uniform, normal and exponential distributions. The relationships among various performance parameters are throughly investigated. We show through performance comparison based on analytic models and experiments that regardless of data distribution, the HS file significantly improves performance in both the retreival time and the storage overhead over S-tree and Quick Filter.

• 정보처리학회논문지:컴퓨터 및 통신 시스템
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• 제4권3호
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• pp.85-90
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• 2015

본 논문에서는 새로운 병렬 이벤트구동 로직 시뮬레이션 기법을 제안한다. 제안한 예측에 기반한 병렬 이벤트구동 시뮬레이션 기법은 병렬 이벤트구동 시뮬레이션에서 다른 로컬시뮬레이션과의 연동 과정에서 사용되는 입력값과 출력값에 실제값과 예측값을 함께 사용함으로써 성능 향상의 제약 요소인 동기 오버헤드 및 통신 오버헤드를 크게 감소시킬 수 있다. 본 논문에서 제안한 예측기반 병렬 이벤트구동 로직 시뮬레이션의 유용함은 다수의 디자인들에 적용한 실험을 통하여 확인할 수 있었다.

• 한국전자통신학회논문지
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• 제2권2호
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• pp.99-105
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• 2007

MANET(Mobile Ad-hoc network) have recently attracted a lot of attention in the research community as well as in industry. Although the previous research mainly focused on various of MANET in routing, we consider, in this paper, how to efficiently support applications such as variable geocasting basd on MANET. The goal of a geocasting protocol is deliver data packet to a group of nodes that are located within a specified geocasting region. Previous research that support geocast service in mobilie computing based on MANET have the non-optimization problem of data delivery path, overhead by frequent reconstruction of the geocast tree, and service disruption problem. In this paper, we propose the mobility pattern based geocast technique using variable service range according to the mobility of destination node and resource reservation to solve this problem. The experimental results show that our proposed mechanism has improved performance of Accessibility & Network Overhead than previous research.

• 한국통신학회논문지
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• 제21권4호
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• pp.926-938
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• 1996

In this paper, we proposed a new multicast algorithm which is efficiently applicable to overlapped process group environments where one process may be involved in several process groups. Unlike the esisting algorithms, the proposed one provides an efficient group communication mechanism by generating the processgroup information in two-level tree. Using this algorithm, we improved the shortcoming of the existing algorithms by reducing the overhead in passing through unnecessary processes for message ordering. We have provided the causal ordering method as well as the total ordering method in group communication environments. As a result, we allow one process to deliver message to other processes with a short delay time, and reduced the overhead required for the message ordering. Also, we logically proved the proposed causal ordering method, and compared the performance of the proposed algorithm with ones of other existing algorithms by computer simulation.

• 한국정보처리학회논문지
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• 제7권3호
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• pp.799-807
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• 2000

In this paper, object replication Client/server under distributed computing system is design and implementation. Today many end-users have a computer communication by using internet in the distributed system of client/server. If many users request services to a specific remote server, the server should have got a overhead for hat service processing, delayed the speed for replay, and bring a bottleneck in communication network. Therefore object replication method was proposed to solve this problems. The growth of internet works and distributed applications has increased the need for large scale replicated systems. However, existing replication protocols do not address scale and autonomy issues adequately. Further, current application protocol require consistency of different levels, and therefore should be the selection function of consistency in them, in order to have particular semantics of each level. In this paper, server overhead and bottleneck happening in remote procedure call be using server object replication. Therefore access transparency can be improved by sharing object duplicately. So it will Keep up with the consistency within the replicated objects.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 C
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• pp.2345-2347
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• 2005

In this paper, impedance characteristics of overhead medium-voltage (MV) power lines is reported for power line communication (PLC) over an MV power line network. For analysis, a two-port equivalent network model of MV power lines is derived. By applying the transmission line theory, reflection behavior and impedance of power lines are investigated. For verification, impedance of power lines is measured at a test field for an MV PLC. The results show that impedance of MV power lines is between $200{\Omega}$ and $300{\Omega}$ and converges to a half of their characteristic impedance.

• 전기학회논문지
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• 제62권4호
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• pp.474-481
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• 2013

It is anticipated that AC distribution system can be replaced by DC distribution system in the near future because of the operation of various distributed source or microgrid system. However DC distribution system replacing 22.9kV AC distribution line is not sufficiently studied still. This paper describes lightning overvoltage analysis among many research fields should be studied to realize DC overhead distribution systems. DC distribution system is modeled using EMTP and overvoltage is analyzed according to interval of arrestor location, earth interval of overhead grounding wire and grounding resistance. It is evaluated that analysis results can be effectively used to design of future DC distribution system.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1999년도 하계종합학술대회 논문집
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• pp.857-860
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• 1999

It is made possible a removal of the preamble for carrier recovery and symbol-timing recovery by storing a burst in memory with low overhead QPSK demodulation and this demodulation method also effects frame efficiency improved by processed synchronization performance. In this paper, we have proposed that new algorithm for arc-tangent look-up table which transform the input I, Q data by phase. This I, Q data plays an important role in demodulation and makes demodulator with low-overhead by storing a burst in memory. To evaluate proposed new algorithm and symbol-timing recovery method, function simulation and timing verification have been done by using synopsys VHDL tool.