• Title/Summary/Keyword: Golden Section

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자연.인간, 그리고 황금분할 I

  • 안가경;한정순
    • Journal for History of Mathematics
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    • v.16 no.4
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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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    • v.18 no.3
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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.

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

  • Kim, Yeong-Sang;Lee, Seung-Rae;Kim, Yun-Tae
    • Geotechnical Engineering
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    • v.13 no.4
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    • pp.95-108
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    • 1997
  • For normally consolidated clay, several researchers have developed a number of theoretical time factors to determine the coefficient of consolidation However, depending on the assumptions and analytical techniques, it could considerably vary even for a specific degree of consolidation. In this paper, a method is proposed to determine a consistent coefficient of consolidation over all ranges of degree of consolidation by applying the concept of the Optimum Design Technique. The initial excess pore pressure distribution is assumed to be obtainable by the successive spherical cavity expansion theory. The dissipation of pore pressure is simulated by means of two dimensional linear-uncoupled axisymmetric consolidation analysis. The minimization of the differences between the measured and the predicted excess pore pressures was carried by BFGS unconstrained optimum design algorithm with one dimensional golden section search technique. By analyzing numerical and real field examples, it can be found that the adopted optimum technique gives a consistent and convergent results.

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

  • 이진렬;홍정표;김진아
    • Archives of design research
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    • v.15 no.2
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    • pp.115-124
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    • 2002
  • There has been no enough consistency about the question of 'Is it possible for golden section to be applied to product design\ulcorner'In addition, There has been no near answer about 'What is proportion\ulcorner and 'How can proportion be approached\ulcorner About this matter, this study identified various types of proportion through experiment design and consumer surrey. According to the results of this study, various and different types of proportion exist in product design and therefore, proportion in product design couldn't be considered by one-dimensional aesthetic element. This kind of study about the types of proportion could give an good answer abort the matter of 'Is it possible for golden section to be applied to product design\ulcorner'and it's expected practically to give a useful insight to the approach of Product design in Which proportion is considered. In addition, preferred proportion structure is different according to the consumer characteristic, successful design strategy such as niche market penetration could be performed if designers classify consumer characteristic systematically.

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Kansei Comparison of Form-ratio between Cubic Model and Refrigerator

  • Nishino, Tatsuo;Nagamachi, Mitsuo
    • Proceedings of the Korean Society for Emotion and Sensibility Conference
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    • 2000.04a
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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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    • v.16 no.9
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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.

Numerical optimization via ALM method (ALM방법에 의한 수치해석적 최적화)

  • 김민수;이재원
    • Journal of the korean Society of Automotive Engineers
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    • v.11 no.2
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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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A Study on Design and Construction of Anap Pond with a Comparative Study of Ancient Palace Ponds in Korea, China and Japan (한.중.일 고대 원지 비교 분석을 통한 안압지 조영계획의 연구)

  • 박경자;양병이
    • Journal of the Korean Institute of Landscape Architecture
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    • v.29 no.3
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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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A Study on Numerical Optimization Method for Aerodynamic Design (공력설계를 위한 수치최적설계기법의 연구)

  • Jin, Xue-Song;Choi, Jae-Ho;Kim, Kwang-Yong
    • The KSFM Journal of Fluid Machinery
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    • v.2 no.1 s.2
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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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    • v.9 no.1
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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.