• 조명전기설비학회논문지
• /
• 제24권4호
• /
• pp.95-102
• /
• 2010

전력산업이 경쟁적 시장체제로 옮겨가면서 기존의 수직통합체제에서와는 다른 운영 메카니즘을 필요로 하게 되었다. 기존의 급전 알고리듬은 최적화 모델에 기반 하여 비용 최소화 목적함수 및 물리적 재무적 제약조건을 정식화하여 최적의 발전량을 산출하는 개념인데, 현재의 상용 시장 시뮬레이터들은 대부분 이러한 기존 급전 알고리듬에 근거하여 시장가격을 추정하게 된다. 이러한 방법을 분석적 방법이라고 하는데, 이러한 방법으로 시장가격을 추정하기 위해서는 다양한 데이터들이 정확히 입력되고 시장의 구조적 모델로 상세히 수립되어야 정확한 결과를 예측할 수 있다. 수직 통합적 체제에서는 모든 데이터들이 단일의사결정 주체에 집중되므로 이러한 방법이 적합하지만, 경쟁적 시장체제에서는 많은 정보가 상업적 기밀로 분류되기 때문에 발전사업자 입장에서 이러한 방법으로 가격을 예측하는데 한계가 있을 수밖에 없다. 따라서 본 논문에서는 이러한 분석적 방법을 적용하기 힘든 상황에서, 시장의 과거 데이터와 공개 정보를 이용한 실험적 방법에 근거하여 확률과정 기반의 가격모델을 수립하고 그로부터 시장가격의 궤적을 추정하는 방법을 제안하고자 한다. 이러한 확률과정론 기반의 가격 모델은 장기적인 설비계획과 장기계약을 수립하는데 유용하게 사용될 수 있으리라 전망된다.

• KIEE International Transactions on Power Engineering
• /
• 제5A권3호
• /
• pp.260-268
• /
• 2005

This paper proposes an improved investment pnonty decision method of facilities considering the reliability of distribution networks. The proposed method decides an investment order of the facilities combining, by fuzzy rules, the investment priority decision by KEPCO and that by reliability evaluation indices. The reliability evaluation indices are SAIFI (System Average Interruption Frequency Index) and SAIDI (System Average Interruption Duration Index). The reliability analysis method of distribution networks applied in this paper utilizes the analytic method, where the used reliability data is the historical data of KEPCO. Particularly, we assumed that the failure rate increases as the equipment ages. To verify the performance of the proposed method, we applied it with the planned projects to reinforce the weak electrical facilities in KEPCO in 2004. The evaluation result showed that, under a limited budget, the reliability of KEPCO in the Busan region using the proposed method could be enhanced if used rather than the conventional method typically in place. Therefore, the results verify that the proposed method can be efficiently used in the actual priorities method for investing in the electrical facilities.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2003년도 추계학술대회 논문집 전력기술부문
• /
• pp.488-490
• /
• 2003

This paprer presents the evlauation method for transmission marginal loss factors(MLFs) considering the electrical distance. Generally, MLFs are represented as the sensitivity of transmission losses, which is computed from the change of generation by the change of the load. MLFs are classified as load-focused MLFs and generator-focused MLFs. The existing evaluation method for generator focused MLFs has the limit not reflecting the characteristic of power systems since the method has been introduced the assumption which the output of a generator is supplied to all of the load buses on the power system. Therefore, to overcome the limit of evaluation method for generator-focused MLFs, we have applied the process, which it approximately can find the load buses that supplied a generator to the method. We have applied the proposed method to the simple 5-bus system because the proposed method is not analytic but the hybrid method incorporated the Kirschen and Bialek's algorithm to the existing analytic method to find the load buses supplied by a generator.

• Journal of Mechanical Science and Technology
• /
• 제16권6호
• /
• pp.785-798
• /
• 2002

A reliable analytic model that predicts the surface profile of the exit cross section of workpiece in round-oval (or oval-round) pass sequence is established. The presented model does not require any plasticity theory but needs the only geometric information on workpiece and roll groove. Formulation is based on the linear interpolation of the radius of curvature of an incoming workpiece and that of roll groove in the roll axis direction when the maximum spread of workpiece is known beforehand. The validity of the analytic model is examined by hot rod rolling experiment with the roll gap, specimen size, design parameter of oval groove and steel grade changed. Results revealed that the cross sectional shapes predicted by the model were in good agreement with those obtained experimentally. We found that the analytic model not only has simplicity and accuracy for practical usage but also saves a large amount of computational time in comparison with finite element method.

• 시스템엔지니어링학술지
• /
• 제9권2호
• /
• pp.1-6
• /
• 2013

Developing Build-Own (or Operate)-Transfer (BOT) nuclear power project carrying large capital in the long term requires initially well-made multi-decision which it prevents sorts of risks from unexpected situation of target countries. In order to analyze the feasibility of project country, the Analytic Hierarchy Process is adopted. Firstly, the factors influencing the success of BOT nuclear power project in overseas countries were investigated through the literature survey for the country risk and were evaluated by expert interview for estimating comparative weight through pairwise comparison between such factors. Finally, it is developed comparative database of alternate countries with respect to each factor. This analytic method enables the developer to select and focus on the country which has preferable circumstance so that it enhances the efficiency of the project promotion. Also, it enables the developer to quantify the qualitative factors so that it diversifies the project success strategy and policy for the target country.

• 한국해안해양공학회지
• /
• 제19권3호
• /
• pp.183-193
• /
• 2007

부분반사 전면 및 완전반사 후면을 갖는 반무한 방파제 및 방파제 개구부에 의한 파의 산란 현상에 대한 해석 해를 유도하였다. 이는 수심이 일정하고 파가 방파제에 직각으로 입사하는 경우에 적용 가능하며, 선형파 이론에 근거하여 변수 변환 및 좌표 변환을 통해 지배 방정식을 상미분 방정식으로 전환하여 구하였다. 본 연구에서 유도된 해석 해는 유한 요소 수치 모델의 결과와 비교하여 그 정확도를 비교하였는데, 꽤 정확한 결과를 보인다는 것을 알 수 있었다. 유도된 해석 해를 이용하여 방파제에서의 반사율에 따른 항 입구에서의 정온도에 미치는 효과를 조사하였다.

• 한국인터넷방송통신학회논문지
• /
• 제10권6호
• /
• pp.47-53
• /
• 2010

본문은 단일 교차로의 주기시간을 결정하는 시간 간격을 계층분석방법(Analytic Hierachy Process)을 이용하여 도출하여 내었다. 주어진 불확실한 상황 가운데 결정적인 도출물을 얻기위해서는 비선형특성의 퍼지 적분이나 적응 계수를 사용하여 얻어내어야 하는데 이를 기반으로한 방법이 계층분석방법이다. 계층분석방법을 사용한 제어기와 고정시간 제어를 한 교통제어기와의 비교를 위하여 모의 실험을 통한 결과를 가지고서 비교 검토하였다.

• ETRI Journal
• /
• 제34권6호
• /
• pp.978-981
• /
• 2012

We present an analytic solution to the projector pose estimation problem for the pinhole projection model in which the source image is a centered rectangle with an unknown aspect ratio. From a single quadrilateral given as a target image, our solution gives the position and orientation of a projector as well as the aspect ratio of a source image. The proposed method decomposes the problem into two pose estimation problems of coupled line projectors aligned at each diagonal of the given quadrilateral and then computes the common solution that satisfies the relevant geometric constraints. The solution is formulated as simple analytic equations. We also provide a determinant of projectability of an arbitrary quadrilateral.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 1996년도 Proceedings of the Korea Automatic Control Conference, 11th (KACC); Pohang, Korea; 24-26 Oct. 1996
• /
• pp.64-68
• /
• 1996

In this note, we propose the discrete model reduction method over disc-type analytic domains. We define Hankel singular value over the disc that is mapped by standard bilinear mapping. And GSPA(generalized singular perturbation approximation) and DT(direct truncation) are generalized to GSPA and DT over a disc. Furthermore we show that the reduced order model over a smaller domain has a smaller L$_{\infty}$ norm error bound..

• 한국공간구조학회논문집
• /
• 제2권4호
• /
• pp.53-60
• /
• 2002

An analytic study on the bond stress between steel tube and concrete in concrete filled steel(CFT) rectangular column is presented in this paper. Recently buildings need members which are enhanced durability and ductility. Concrete filled rectangular column system is proposed as alternative plan. In this paper, ABAQUS/Standard Version 5.8 which is identified as usefulness for finite element analysis and has various element library is used. The variables in this study are the location and type of shear-connector. The modeling on contact problem practiced by Contact Pair and Contact Pressure method. In the step of physical bond, it is practiced by Change friction option After yielding of models, analytic results is less than that of experimental results.