• 제목/요약/키워드: golden section

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자연.인간, 그리고 황금분할 I

  • 안가경;한정순
    • 한국수학사학회지
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    • 제16권4호
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    • pp.69-78
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    • 2003
  • In this paper, we examine human perception and mentality on the shape, and study the correlation of golden section with nature and human being.

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Dual-Algorithm Maximum Power Point Tracking Control Method for Photovoltaic Systems based on Grey Wolf Optimization and Golden-Section Optimization

  • Shi, Ji-Ying;Zhang, Deng-Yu;Ling, Le-Tao;Xue, Fei;Li, Ya-Jing;Qin, Zi-Jian;Yang, Ting
    • Journal of Power Electronics
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    • 제18권3호
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    • pp.841-852
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    • 2018
  • This paper presents a dual-algorithm search method (GWO-GSO) combining grey wolf optimization (GWO) and golden-section optimization (GSO) to realize maximum power point tracking (MPPT) for photovoltaic (PV) systems. First, a modified grey wolf optimization (MGWO) is activated for the global search. In conventional GWO, wolf leaders possess the same impact on decision-making. In this paper, the decision weights of wolf leaders are automatically adjusted with hunting progression, which is conducive to accelerating hunting. At the later stage, the algorithm is switched to GSO for the local search, which play a critical role in avoiding unnecessary search and reducing the tracking time. Additionally, a novel restart judgment based on the quasi-slope of the power-voltage curve is introduced to enhance the reliability of MPPT systems. Simulation and experiment results demonstrate that the proposed algorithm can track the global maximum power point (MPP) swiftly and reliably with higher accuracy under various conditions.

피에조 콘 시험을 이용정회원, 한국과학기술원 토목공학과 부교수, 정회원, 한국과학기술원 토목공학과 박사 후 과정한 망일계수 결정시 최적화 기법의 적용 (Application of Optimum Design Technique in Determining the Coefficient of Consolidation Using Piezocone Test)

  • 김영상;이승래;김윤태
    • 한국지반공학회지:지반
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    • 제13권4호
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    • pp.95-108
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    • 1997
  • 피에조 콘의 소산시험을 이용한 정규 압밀 지반의 압밀계수 추정은 그간 많은 연구자들에 의하여 연구되어 왔으나 각 연구자들의 가정 사항과 해석 방법에 따라 특정한 압밀도에 대해서도 매우 넓은 범위의 이론적인 해들이 제시되어 왔다. 본 연구에서는 보다 현실적이면서 전 범위의 압밀도에 걸쳐서 일관성 있는 압밀계수를 구할 수 있도록 최적화 기법을 적용하였다. 콘 관입효과를 고려하기 위해 연속적인 구형 공동확장을 적용하므로써 이론적으로 얻어지는 간극수압의 분포와 관입 간극수압으로부터 초기 과잉간극수압의 분포를 결정하였으며 축대칭 선형비혼합 압밀이론을 사용하여 유발된 과잉간극수압의 소산효과를 모사하였다. 이와 같이 계산된 소산곡 선과 실제 계측된 소산곡선의 차이를 최소화시키기 위하여 비구속 최적화 알고리듬인 BFGS가 사용되었고 golden section 일차원 탐색법이 사용되었다. 검증 예제를 통하여 적용된 최적화 기법의 안정된 수렴성을 확인하였고 실제 예제에 적용함으로써 제안된 방법이 넓은 범위의 압밀도 범위에서 계측된 소산곡선과 잘 일치하는 압밀계수를 산정함으로써 매우 효과적임을 확인 할 수 있었다.

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제품형태에 있어서 비례의 유형에 관한 연구 (A Study on Typology of Proportion in Product Form)

  • 이진렬;홍정표;김진아
    • 디자인학연구
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    • 제15권2호
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    • pp.115-124
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    • 2002
  • '제품디자인에 있어서 황금비례의 적용이 가능한가' 라는 논제에 대하여 기존의 연구들이 이에 대한 의견의 일치를 보이고 있지 못하고 있다. 아울러 기존연구들에서는 과연 비례란 무엇이며 또한 어떻게 이해하고 접근해야 하는가라는 문제에 대해서도 명확한 해답을 내리고 있지 못하고 있다. 이에 대하여 본 연구는 실험 설계와 설문조사를 통하여 다양한 비례의 유형을 파악하였다. 본 연구의 결과에 따르면 제품유형마다 상이한 비례구조를 지니고 있으며 따라서 비례는 단순히 일차원적인 심미적 요소로만 다루어져서는 안된다. 이러한 비례의 유형에 대한 고찰은 '제품디자인에 있어서 황금 비례의 적용이 가능한가'라는 주제에 대한 해답을 제시해 줄 수 있으며 실무적으로도 심미적 조형요소로서 비례를 다루는데 있어서 바람직한 제품디자인접근법에 대한 유용한 통찰력을 제시해 줄 수 을 것으로 예상된다. 또한 소비자의 특성에 따라 선호하는 비례구조가 다르기 때문에 소비자의 특성을 체계적으로 분류한다면 틈새시장 공략 등 성공적인 디자인전략을 수행할수 있을 것으로 예상된다.

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Kansei Comparison of Form-ratio between Cubic Model and Refrigerator

  • Nishino, Tatsuo;Nagamachi, Mitsuo
    • 한국감성과학회:학술대회논문집
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    • 한국감성과학회 2000년도 춘계 학술대회 및 국제 감성공학 심포지움 논문집 Proceeding of the 2000 Spring Conference of KOSES and International Sensibility Ergonomics Symposium
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    • pp.133-137
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    • 2000
  • Form-ratio means the ratio of Height/Width/Depth in 3-dimensions. The golden ratio or golden section is included as one of the form-ratio. Kansei Engineering System has some basic design databases. Form-ratio and color are basic design elements and they are very important for designing various products in viewpoint of Kansei Engineering. The subjects evaluate the form-ratios of 3-dimensional cubes and virtual products (refrigerator) with SD-scale kansei words(feelings and images). The golden ration was evaluated as "not beautiful" in refrigerator. We compared with the kansei of cube model and virtual product, and obtained databases of the relationship between the form-ratio and kansei.

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Configuration Interaction Theory and van der Waals Predissociation

  • 이천우
    • Bulletin of the Korean Chemical Society
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    • 제16권9호
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    • pp.850-858
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    • 1995
  • Golden-rule like formulas have been used without theoretical basis to calculate the resonance lifetimes and final state distributions in the predissociation of van der Waals molecules. Here we present their theoretical basis by extending Fano's configuration interaction theory. Such extensions were independently done by Farnonux [Phys. Rev. 1985, 25, 287] but his work, unfortunately, was not well known outside some small group of people in the field of Auger spectroscopy. Since my extension is easier to understand than his, it is presented here. Theoretical basis of Golden rule like formulas used in the predissociation of van der Waals molecules was obtained by using such extensions. Factors responsible for several aspects of predissociation dynamics, such as variations of dynamics as functions of resonance lifetimes, or variations in shapes of final quantum state distributions of photofragments around resonances, were identified. Parameters, or dynamical information that could be obtained from the measurement of partial cross section spectra were accordingly determined. The theory was applied to the vibrational predissociation of triatomic van der Waals molecules and its result was compared with those calculated by close-coupling method. An example where Golden-rule like expression fails and branching ratios vary greatly around a resonance was considered.

ALM방법에 의한 수치해석적 최적화 (Numerical optimization via ALM method)

  • 김민수;이재원
    • 오토저널
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    • 제11권2호
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    • pp.24-33
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    • 1989
  • 본 고에서는 이러한 추세에 따라서, 보다 효율적인 optimization program에 대해서 소개하고자 한다. 사용한 최적화 알고리즘은 ALM(augmented lagrange multiplier) 방법을 적용해서 구속조건이 있는 문제를 구속조건이 없는 문제로 변환한 후, self-scaling BFGS(broydon-flecher-goldfarb-schanno)를 적용한다. BFGS의 각 descent 방향에서의 step 길이는, sequential search로 unimodal point를 구해서, golden section 방법으로 refine을 한후, cubic approximation을 적용해서 구한다.

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한.중.일 고대 원지 비교 분석을 통한 안압지 조영계획의 연구 (A Study on Design and Construction of Anap Pond with a Comparative Study of Ancient Palace Ponds in Korea, China and Japan)

  • 박경자;양병이
    • 한국조경학회지
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    • 제29권3호
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    • pp.1-9
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    • 2001
  • The purpose of this article is to study the design and construction of Anap pond with a comparative study of ancient palace ponds in Korea, China and Japan. Anap pond was excavated in 1975-6 and is the oldest orignal pond to be found among Koran garden sites. Anap pond was made just before Shilla drove out Tang, after Shilla ruined Paekjae and Koguryo with the Tang army. This was a time Shilla enjoyed a multi-cultural situation due to interaction with Paekjae and Koguryo refugees, as well as information provided by the ambassadors sent to Tang who were well aquainted with Tang culture. Anap pond shows the influence of not only the indigenous mountain-god myth, but also the theoretical background common among Korea, China and Japan. But it also depicts the special form of space inbued with the exquisite aesthetic taste of Shilla people, which started with Anap pond hardened in Gaen temple, and which bloomed in Sukgulam. Scenery structure analysis gives a supposition of the center building on the western coatland, and sequential analysis gives the feeling of being at sea, analysised by root square shape analysis, equal ratio square shape and golden section, sow we can see the planned space organization by speculated planning. Thus, Anap pond is a garden of Shilla in which the cultural exchange has been inculturated and made our own, and the special aesthetic taste embodied.

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공력설계를 위한 수치최적설계기법의 연구 (A Study on Numerical Optimization Method for Aerodynamic Design)

  • 김설송;최재호;김광용
    • 한국유체기계학회 논문집
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    • 제2권1호
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    • pp.29-34
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    • 1999
  • To develop the efficient numerical optimization method for the design of an airfoil, an evaluation of various methods coupled with two-dimensional Naviev-Stokes analysis is presented. Simplex method and Hook-Jeeves method we used as direct search methods, and steepest descent method, conjugate gradient method and DFP method are used as indirect search methods and are tested to determine the search direction. To determine the moving distance, the golden section method and cubic interpolation method are tested. The finite volume method is used to discretize two-dimensional Navier-Stokes equations, and SIMPLEC algorithm is used for a velocity-pressure correction method. For the optimal design of two-dimensional airfoil, maximum thickness, maximum ordinate of camber line and chordwise position of maximum ordinate are chosen as design variables, and the ratio of drag coefficient to lift coefficient is selected as an objective function. From the results, it is found that conjugate gradient method and cubic interpolation method are the most efficient for the determination of search direction and the moving distance, respectively.

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Experimental study on hydrodynamic coefficients for high-incidence-angle maneuver of a submarine

  • Park, Jong-Yong;Kim, Nakwan;Shin, Yong-Ku
    • International Journal of Naval Architecture and Ocean Engineering
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    • 제9권1호
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    • pp.100-113
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    • 2017
  • Snap rolling during hard turning and instability during emergency rising are important features of submarine operation. Hydrodynamics modeling using a high incidence flow angle is required to predict these phenomena. In the present study, a quasi-steady dynamics model of a submarine suitable for high-incidence-angle maneuvering applications is developed. To determine the hydrodynamic coefficients of the model, static tests, dynamic tests, and control surface tests were conducted in a towing tank and wind tunnel. The towing tank test is conducted utilizing a Reynolds number of $3.12{\times}10^6$, and the wind tunnel test is performed utilizing a Reynolds number of $5.11{\times}10^6$. In addition, least squares, golden section search, and surface fitting using polynomial models were used to analyze the experimental results. The obtained coefficients are presented in tabular form and can be used for various purposes such as hard turning simulation, emergency rising simulation, and controller design.