• Structural Engineering and Mechanics
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• 제52권6호
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• pp.1177-1191
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• 2014

Reinforced concrete (RC) shear walls are one of the most commonly used lateral-load resisting systems in high-rise buildings. RC Parallel redundancy walls studied herein consist of two parts nested to each other. These two parts have different mechanical behaviors and energy dissipation mechanisms. In this paper, experimental studies of four 1/2-scale specimens representing this concept, which are subjected to in-plane cyclic loading, are presented and test results are discussed. Two specimens consist of a wall frame with barbell-shaped walls embedded in it, and the other two consist of a wall frame and braced walls nested each other. The research mainly focuses on the failure mechanism, strength, hysteresis loop, energy dissipation capacity and stiffness of these walls. Results show that the RC parallel redundancy wall is an efficient lateral load resisting component that acts as a "dual" system with good ductility and energy dissipation capacity. One main part absorbs a greater degree of the energy exerted by an earthquake and fails first, whereas the other part can still behave as an independent role in bearing loads after earthquakes.

• 전기전자학회논문지
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• 제14권3호
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• pp.205-209
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• 2010

본 논문에서는 W-CDMA에서 사용 무선 중계기에서 사용 가능한 간섭신호 제거 알고리즘을 제안하였다. 기존의 방법인 1개의 긴 필터를 이용하여 간섭신호를 제거하는 알고리즘 대신 여러 개의 짧은 병렬형 필터를 이용하여 수렴속도를 줄일 수 있음을 분석하였다. 제안된 알고리즘은 실제 성능 시험 조건 하에서 시뮬레이션을 통해 기존 방법보다 수렴 속도가 빨라짐을 확인하였다.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2003년도 봄 학술발표회 논문집
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• pp.521-528
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• 2003

This paper presents the results of a cooperative research on remote parallel pseudo-dynamic testing on a base-isolated bridge with multiple piers using Internet between KAIST, Korea and Kyoto Univ., Japan. Experimental facilities located at two institutions were parallelly used to test the nonlinear behavior of the base-isolators. Two data communication schemes for parallel tests were developed and the performance is compared. The results indicate that the elapsed time may vary widely depending on the data communication and testing schemes : i.e. 1-25sec for each time step. But it is fairly comparable with the time required for pseudo-dynamic testing. The testing method can become more powerful, as the data communication and monitoring techniques through Internet improve further.

• 대한산업공학회지
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• 제26권3호
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• pp.249-256
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• 2000

Bond immunization model is used to minimize interest rate risk for investing in fixed-income market, the model equalizes asset and liability values using the duration which is the sensitivity of portfolio value with respect to the interest rate. However this model might generate an error in practice because the model is based on unreal hypothesis, so called "Parallel Shift Term Structure". In this paper, we use the neural network approach to overcome the parallel shift term structure and try to employ this term structure function to the traditional immunization model. Finally, we present some computational test results that show the superiority of the partial immunization model to the traditional methods.

• International Journal of Precision Engineering and Manufacturing
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• 제8권2호
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• pp.3-8
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• 2007

A machining system that generates accurate relative motions between the tool and workpiece is required to realize ultra precise machining or measurements. Accuracy improvements for each element of the machine are also required. This paper proposes a machining system that uses a compensation device for the six-degree-of-freedom (6-DOF) motion error between the tool and workpiece. The compensation device eliminates elastic and thermal errors of the joints and links due to temperature fluctuations and external forces. A hexapod parallel kinematics mechanism installed between the tool spindle and surface plate is passively actuated by a conventional machine. Then the parallel mechanism measures the 6-DOF motions. We describe the conception and fundamentals of the system and test a passively extensible strut with a compensation device for the joint errors.

• 전기학회논문지
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• 제66권3호
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• pp.599-604
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• 2017

Nowadays reactance method is being used as a technique for fault location in parallel feeding AC traction power system. However, implementation of this method requires a large number of field tests(ground fault) which is a huge burden on the operators. This paper presents a new estimation technique using quadratic interpolation to reduce number of times for field test and improves the accuracy of fault location. To verify a new technique, we solve AT feeding circuit and model it using PSCAD/EMTDC. Finally this paper conducts a comparative analysis of usefulness between a new technique and real field data.

• 대한안전경영과학회지
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• 제25권2호
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• pp.1-8
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• 2023

This paper is proposing a novel machine scheduling model for the unrelated parallel machine scheduling problem without setup times to minimize the total completion time, also known as "makespan". This problem is a NP-complete problem, and to date, most approaches for real-life situations are based on the operator's experience or simple heuristics. The new model based on the Memetic Algorithm, which was proposed by P. Moscato in 1989, is a hybrid algorithm that includes genetic algorithm and local search optimization. The new model is tested on randomly generated datasets, and is compared to optimal solution, and four scheduling models; three rule-based heuristic algorithms, and a genetic algorithm based scheduling model from literature; the test results show that the new model performed better than scheduling models from literature.

• 조명전기설비학회논문지
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• 제25권12호
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• pp.107-112
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• 2011

Multiple ground rods are commonly used to obtain the low ground impedance, but they will not reduce the ground impedance unless the spacings between the ground rods are sufficient. This paper presents the experimental results of frequency-dependent resultant ground impedance of two ground rods in parallel. The resultant ground impedance of two ground rods in parallel were measured as functions of the spacing and length of ground rods and the frequency of test currents and were discussed based on the potential interferences. As a consequence, the frequency-dependent ground impedance of single ground rod and two combined ground rods give capacitive. It was found that the effect of potential interference on the ground impedance is directly associated with the frequency-dependent ground impedance and is strong in low frequency. Also, in order to reduce the increasing rate of resultant ground impedance of two ground rods due to potential interference to within 10(%), two ground rods in parallel will be placed over one rod length apart.

• 한국지반공학회논문집
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• 제19권6호
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• pp.181-187
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• 2003

이 연구는 기존터널과 근접하여 새로운 터널을 시공할 경우 이에 따른 터널의 상호거동에 대한 연구이다. 특히 이 연구는 연약지반내에서의 근접터널 시공에 따른 기존터널 라이닝의 변위 및 응력 영향에 대하여 수행되었다. 이와 같은 터널거동을 연구하기 위하여 시험실 모형시험을 수행하였다. 이 시험 결과는 터널의 상호 거동에 대한 보다 정확한 결과를 얻기 위한 시뮬레이숀 기법 개발을 위하여 유한요소기법을 이용하여 수치해석을 수행하여 비교 분석하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 하계학술대회 논문집 A
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• pp.169-171
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• 2002

The western route of KEPCO's 765kV transmission line has been tentatively operating as 345kV voltage before commercial operation. After finishing the test operation of 765kV substation in 2002. KEPCO decided to operate the 765kV line for commercial operation. During the applying of 765kV voltage to the transmission line, double circuit transmission line will be operated with two voltage grades of 765kV and 345kV. Because the earthing switch is installed on both end of transmission line, we had estimated the electrostatic induction voltage and electromagnetic induction current before the line energizing in order to confirm the ratings of earthing switch. The induced voltage and current is very important for the maintenance of parallel circuit. This paper describes the simulation study of electrical phenomena such as electrostatic induction voltage from the parallel line and electromagnetic induction current from the parallel circuit. The transmission line model was developed by EMTP (Electro-Magnetic Transient Program).