• KIEE International Transactions on Power Engineering
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• 제5A권3호
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• pp.280-285
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• 2005

This paper proposes a novel method for determining the kind and rating of power quality solutions. To determine the kind of solution, event cause and direction are utilized. According to the event cause and direction, an adequate type of solution is determined for effective compensation. To rate the required capacity of solution, the concept of lost energy is adopted. Lost voltage, lost power and lost energy are calculated and the rating of the solution is determined to compensate a specific event. The rating method that utilizes the result of stochastic diagnosis is also proposed. A power quality index such as CP95 is adopted for solution suggestion. The method developed in this paper is applied to the test system and proved to be useful for enhancing the power quality of the customer system. It can provide customers with information pertaining to what is a proper and cost-effective solution among various compensating devices.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2000년도 추계학술대회 논문집
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• pp.53-56
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• 2000

This paper discusses the horizontally rotaling wind power generator. Quasi static analysis are applied to performance. Translational velocity. which varies on the distance from the rotating wind power generator is effective in speed. In high rotation. the reverse torque reduces the total effective troque. It is recommended to giver efforts to redutorque for the acceptavle performance of the horizontallv rogatting tvpe generator.

• 한국항행학회논문지
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• 제17권1호
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• pp.56-62
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• 2013

최근 차세대 이동통신 시스템은 스마트폰을 시작으로 다양한 멀티미디어 콘텐츠 서비스를 지원하고 있다. 따라서, 음성통화를 목적으로 한 시스템 사용에 비해 멀티미디어 서비스를 위한 시스템 사용이 점차 증가하고 있다. 멀티미디어 서비스의 증가는 사용자의 시스템 사용시간을 증가시키고, 시스템의 정해진 전력에 비해 사용 시간을 단축시킴으로 효율적인 전력사용에 대한 연구가 필요하다. 또한 도시 집중화 환경에 의한 음영지역의 출현으로 인한 불필요한 전력소모가 발생되고 있으며, 이러한 문제는 차세대 이동통신 시스템의 사용 시간 단축에 큰 영향을 미친다. 본 논문에서는 차세대 이동통신 시스템의 통신망 구조를 살펴보고, 음영지역에서의 불필요한 전력사용을 살펴본 후, 효율적인 전력사용을 위한 방법을 제안하고 시뮬레이션을 통해 차세대 이동통신 시스템의 효율적인 전력사용에 대해 분석했다.

• 복식
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• 제42권
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• pp.223-230
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• 1999

Dressmaking which is defined as the process of changing two-dimensional cloth into three-dime-nsional clothes needs a lot of joining parts. Particularly sleeve needs a more curved surface than other joining parts owing to shape of the top of arms. Easing is used to control the fullness along the seam-line to create the fullness curved shape of the sleeves and it plays an important role in increasing three-dimensional constru-ction power. unfortunately sufficient data regarding effective easing conditions to increase three-dimensional construction power of sleeve are not available. Therefore the author tried to investigate the effective easing conditions to increase three-dimensional construction power of sleeve by cap height. Easing construction power of sleeve by cap height. Easing contraction made by different angles on the sleeve cap curve line previous work were examined and the effective easing conditions according to the variation of angles were determined. This study contains the following objectives. Firstly to obtain the easing contraction ratio in sleeve according to the above easing conditions. Secondly to investigate the three-dimensional construction power or sleeve by the factors of easing contraction. Thirdly to determine for each sleeve the effective easing conditions on the basis of the calcuative easing contraction ratio in the sleeve patterns by cap heights.

• 한국재료학회지
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• 제14권2호
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• pp.152-156
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• 2004

We have studied the effective optical absorption power of Si solar cell with $SiO_2$-antireflection layer based on a mathematical modelling of AM(air mass)1 spectrum and Si refractive index in the wavelength range(0.4 $\mu\textrm{m}\leq$λ$\leq$$0.97\mu\textrm{m}$). The effective optical absorption power obtained from the theoretical calculation was 450 and 520 W/$\m^2$ for the Si solar cells with $SiO_2$-antireflection layer of 500$\AA$ and 1000$\AA$, respectively. The optimum thickness of $SiO_2$-antireflection layer showing the minimum reflection loss was about 1000$\AA$ in the computer simulation. Two kinds of Si solar cells named EBS(500$\AA$) and EBS(l000$\AA$) were fabricated to evaluate the effect of $SiO_2$-antireflection layer thickness on the optical absorption. The epitaxial base Si cell with $SiO_2$-antireflection layer of 1000$\AA$ [EBS(l000$\AA$)] showed the output power improvement of about 15% upon the EBS(500$\AA$) cell due to larger absorption of effective optical power under illumination of AM1, 1 sun.

• 전기학회논문지
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• 제59권1호
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• pp.26-32
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• 2010

This paper proposes a new effective installed reserve rate in order to evaluate reliability of power system considering renewable generators, which include uncertainty of resource supply. It is called EIRR(effective installed reserve rate) in this paper. It is developed with considering capacity credit based on ELCC by using LOLE reliability criterion. While the conventional installed reserve rate index yields over-evaluation reliability of renewable generators, the proposed EIRR describes actual effective installed reserve rate. However, it is not the probabilistic reliability index as like as LOLE or EENS but another deterministic effective reliability index. The proposed EIRR is able to evaluate the realistic contribution to the reliability level for power system considering wind turbine generators and solar cell generators with high uncertainty in resource supply. The case study in model system as like as Jeju power system size presents a possibility that the proposed EIRR can be used practically as a new deterministic reliability index for generation expansion planning or operational planning in future.

• 한국산업융합학회 논문집
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• 제22권3호
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• pp.251-257
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• 2019

This paper proposes a new measurement method using virtual power concept to measure the effective value of 3-phase voltage with variable frequency. The conventional effective value measurement method uses a method of integrating data sampled during one or half cycle of the power voltage and averaging it. In this method, since the effective voltage is calculated every cycle, a time delay occurs in the measured effective voltage and it is s a problem to measure the effective value of a device whose frequency varies from time to time, such as a generator. The proposed 3-phase voltage rms measurement method has an advantage that it can measure accurate voltage RMS value regardless of measurement frequency variation. In particular, there is an advantage in that it is possible to measure a 3-phase effective voltage rather than an average value of the effective voltage of each phase in a 3-phase unbalance voltage. In addition, the validity of the proposed method is verified by using the Psim simulation tool and the experimental results are analyzed by applying the proposed measurement algorithm to the actual three phase synchronous generator voltage measurement experiment.

• 한국심리학회지 : 문화 및 사회문제
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• 제13권3호
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• pp.1-21
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• 2007

본 연구에서는 1) 원자력 발전소 지역 주민들의 안전체감을 구성하고 있는 하위요인들을 규명하고, 2) 그 구성요소들의 측정을 통해 주민들의 안전체감지수를 산출하며, 3) 주민들이 체감하는 안전의 정도와 발전소 직원들이 추측하는 주민들의 안전 체감 정도를 비교하였다. 이를 위해 원자력 발전소 지역주민 800명을 대상으로 연구 1과 발전소 직원 187명을 대상으로 연구 2가 수행되었다. 연구 결과에 따르면, 안전체감은 커뮤니케이션, 신뢰, 발전소 위험대응역량, 그리고 응급대응역량의 4가지 요소로 구성되어 있는 것으로 밝혀졌다. 개발된 안전체감 지수에 따르면 발전소 지역 주민들의 안전체감 수준은 매우 낮았으며(100점 만점에 38.22점), 이 점수는 발전소 지역에 따라 다른 것으로 나타났다. 또한 원자력 발전소의 직원들은 주민들이 실제로 체감하고 있는 것보다 주민들이 발전소를 훨씬 더 안전하게 지각하고 있을 것이라고 착각하고 있는 것으로 나타났다. 이 결과의 시사점 및 후속 연구에 대해 논의하였다.

• 한국마린엔지니어링학회:학술대회논문집
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• 한국마린엔지니어링학회 2011년도 후기공동학술대회 논문집
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• pp.75-75
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• 2011

This paper has been studied that ocean wave vibration power generator is composed of buoy and vibration generator to make effective use of ocean wave energy. We designed buoy to can occur resonance for dominant frequency with ocean wave. And then we fitted the natural frequency of vibration system with vibration power generator to buoy's natural frequency. And we can show that the amplitude of ocean wave up and down motion is decreased, on the other hand, the displacement of vibration system with vibration power generator is increased. Therefore, ocean wave vibration power generator which is proposed in this paper has merits not only securing its stability from surroundings but also producing more electronic power by using ocean wave energy.

• 대한전기학회논문지:전력기술부문A
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• 제49권4호
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• pp.195-198
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• 2000

This paper illustrates a new method for constructing composite power system effective load duration curve(CMELDC) at load points. The main concept of proposed method is that the CMELDC can be obtain from convolution integral processing of the outage probabilistic distribution function of not supplied power and the load duration curve given at each load point. The effective load duration curve (ELDC) at HLI plays an important part in probabilistic production simulation, reliability evaluation, outage cost assessment and power supply margins assesment for power system planning and operation. And also, the CMELDC at HLII will extend the application areas of outage cost assessment and reliability evaluation at each load point. The CMELDC at load points using the Monte Carlo method and a DC load flow constrained LP have already been developed by authors. The effective load concept at HLII, however, has not been introduced sufficiently in last paper although the concept is important. In this paper, the main concept of the effective load at HLII which is proposed in this study is defined in details as the summation of the original load and the probabilistic loads caused by the forced outage of generators and transmission lines at this load point. The outage capacity probabilistic distribution function at HLII can be obtained by combining the not supplied powers and the probabilities of the not supplied powers at this load point. It si also expected that the proposed CMELDC can be applied usefully to research areas such as reliability evaluation, probabilistic production cost simulation and analytical outage cost assessment, etc. at HLII in future. The characteristics and effectiveness of this methodology are illustrated by case study of IEEE-RTS.