• Journal of Power Electronics
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• 제15권1호
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• pp.96-105
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• 2015

In recent years, the multilevel converters have been given more attention due to their modularity, reliability, failure management and multi stepped output waveform with less total harmonic distortion. This paper presents a novel symmetric multilevel inverter topology with reduced switching components to generate a high quality stepped sinusoidal voltage waveform. The series and parallel combinations of switches in the proposed topology reduce the total number of conducting switches in each level of output voltages. In addition, a comparison between the proposed topology with another topology from the literature is presented. To verify the proposed topology, the computer based simulation model is developed using MATLAB/Simulink and experimentally with a prototype model results are then compared.

• 한국운동역학회지
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• 제33권4호
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• pp.185-195
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• 2023

Objective: The purpose of this study is to improve TPI OnBaseU Power Test and golf performance by conducting CrossFit power training. Method: Three male golf players from University B participated in this study. They had 3 to 4 years of golf experience and participated in 8 weeks of CrossFit power training. Results: OnBaseU Power Test: There was a lot of improvement in Sit up throw (27.9%) and Chest pass (10.58%), but there was not much improvement in Baseline Toss (R5.9, L9.8%) and Vertical Jump (4.1%). Golf shot data: There was a very statistically significant difference in Club speed, Ball speed, and Total Length, which are related to speed, and there was no difference in Club path and Smash factor, which are related to accuracy and posture. Conclusion: CrossFit power training was effective in improving TPI OnBaseU Power Test and golf performance (Club speed, Ball speed, Total Length).

• 비파괴검사학회지
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• 제18권4호
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• pp.321-329
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• 1998

발전설비의 건전성은 원자력발전소의 안전운영을 위하여 필수적이며 이를 위하여 원자력발전소의 안전 규제법에서는 원전사업자 책임하에 신뢰성있는 가동중검사를 주기적으로 수행하도록 규정하고 있다. 따라서 한전은 국내 유일의 원전사업자로서 가동중검사의 정확도 및 신뢰성을 높이기 위한 기술개발에 최선을 다하고 있으며, 전력연구원은 한전의 기술개발 및 연구업무의 중추적 역할을 담당하는 부서로서 효율적인 원전 가동중검사 수행을 위하여 종합지원체계 (total support system : TSS)를 확립하고, 국내기술자립을 위한 요소기숱개밭은 물론 검사요원의 교육 및 자격인증체계 확립에 만전을 기하고 있다. 이 논문은 이와 같은 원자력발전소의 발전설비 건전성 진단을 위하여 현재 전력연구원에서 수행중인 가동중검사 기술개발업무 전반에 관해 상세하게 설명하기 위한 것이다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 A
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• pp.262-263
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• 2006

This paper presents a scheme to solve the congestion problem with phase-shifting transformer(PST) and power generation using linear programming method. A good design of PST and power generation control can improve total transfer capability(TTC) in interconnected systems. This paper deals with an application of optimization technique for TTC calculation. linear programming method is used to maximize power flow of tie line subject to security constraints such as voltage magnitude and real power flow. The proposed method is applied to 10 machines 39 buses model systems to show its effectiveness.

• 조명전기설비학회논문지
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• 제24권4호
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• pp.17-24
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• 2010

송변전설비들이 점점 중부하로 운용되어짐에 따라 송전용량이 전력회사에서 중요한 문제로 부각되어 왔다. 한전 시스템의 경우 전체송전용량은 주로 전압 안정도에 의해 제한을 받고 있으며, 이의 향상을 위한 연구들이 계속하여 수행되어 오고 있다. 본 논문에서는 전압안정도 관점에서의 전체송전용량을 향상시키기 위하여 STATCOM 설비를 설치하는 위치를 효과적으로 선택하기 위한 송전용량지수가 제시된다. 이 지수를 소규모 전력시스템인 IEEE 39모선 시스템에 적용하여 제시된 지수의 효과를 보여준다. 그리고, 이 소규모 시스템을 활용하여 부하가 증가할 때 전체송전용량에 전압안정도뿐 만이 아니라 과도안정도가 미치는 영향을 분석한다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1995년도 하계학술대회 논문집 B
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• pp.528-530
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• 1995

In the conventional power flow calculations, the slack bus is assumed to undertake the total transmission loss for the convenience of numerical computation. This is an unrealistic assumption because, in real power system, the transmission loss is supplied by all the generators and makes the power flow calculation results somewhat distorted. This paper proposes a new loss redistribution algorithm that can reduce the distortion of power flow results. In the proposed method, the system power loss redistribution algorithm is added to the conventional power flow equations and jacobian elements that are related the real power are newly constructed. In each iteration step, the power output of each generator is updated to consider the effect of calculated total power losses. Finally the usefulness of proposed method are tested through the some appropriate case studies.

• 대한물리의학회지
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• 제3권4호
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• pp.225-233
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• 2008

Purpose : The purpose of this study was to investigate changes of muscle strength, ROM and proprioceptive function as before & after ankle taping in soccer players. For this study fifteen sports club whose had no ankle injuries were volunteered. Methode : Fifteen healthy male in soccer players participated in this study. Biodex pro system3 was used to measure isokinetic muscle strengths at $60^{\circ}$/sec angular velocity. Performances of ankle joint were measured peak torque, total work, average power, total work. To measure proprioceptive function used goniometer. Results : 1. proprioceptive sensation error were significantly differences by before & after taping(p<.05). 2. Compare of total work of dorsi flexion plantar flexion weren't significantly differences by before & after taping(p>.05). 3. Compare of average power of dorsi flexion weren't significantly differences by before & after taping(p>.05). 4. Compare average power of plantar flexion were significantly differences by before & after taping(p<.05). 5. Compare average peak torque of dorsi flexion weren't significantly differences by before & after taping(p>.05). 6. Compare average peak torque of plantar flexion were significantly differences by before & after taping(p<.05). Conclusion : Taping can have propriocetive aberrative angular measure, power & peak torque of plantar flexion were significantly differences. But, total work of dorsi flexion plantar flexion and power & peak torque of dorsi flexion weren't significantly differences.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2011년도 제42회 하계학술대회
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• pp.191-192
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• 2011

The transmission capacity has been highlighted as a problem in the power company according to operated heavy loaded of transmission facility. The total transfer capability in the KEPCO power system is determined mainly by the voltage stability limit and many approaches for enhancement of the total transfer capability has been consistently performed. This paper proposes a study on determination of the adequate var sizing of power compensator regarding the transfer capability enhancement in power system. This method was controlled power compensator in substation becasue of the voltage stability. It was simulated power system using EMS peak data.

• 교육녹색환경연구
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• 제12권2호
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• pp.61-70
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• 2013

As the existing school building power consumption is expressed by total power consumption, in the view of energy saving is disadvantage. The the power consumption of school building is divided as cooling, heating, lighting and others. The cooling power consumption, heating power consumption, lighting power consumption can be calculated using real total power consumption that gained from Korea Electric Power Corporation(KEPCO). The power consumption for cooling and heating can be calculated using heat transmittance, wall area and floor area, and for lighting is calculated by artificial lighting calculation. but this calculation methods is difficult for laymen. This study was carried out in order to establish the regression equation for cooling power consumption, heating power consumption, lighting power consumption and other power consumption in school building. In order to verify the validity of the regression equation, it is compared regression equation results and calculation results based on real power consumption. As the results, difference between regression result and calculation results for cooling and heating power consumption showed 0.6% and 3.6%.

• 동력기계공학회지
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• 제17권6호
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• pp.102-107
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• 2013

In this paper, the performance analysis for evaporation capacity, total work and efficiency of the ocean thermal energy conversion(OTEC) power system using mixed refrigerant(R32,R152a) is conducted to find the effect of hot wasted water on OTEC power system. The system in this study is applied with two stage turbine, regenerator, cooler and separator on Organic Rankine Cycle. The commercial program HYSYS is used for the performance analysis. The main results were summarized as follows : The efficiency of the OTEC power cycle has a largely effect on the evaporation capacity and total work. As increasing temperature of heat source water, evaporator's capacity is decreased but total work increase. Otherwise, using hot wasted water bring effects not only increasing system efficiency but also declining evaporator's capacity. Thus With a thorough grasp of these effect, it is necessary to find way to use hot wasted water emitted by power plant and so on.