• 제목/요약/키워드: golden section

검색결과 73건 처리시간 0.021초

주먹 돌도끼에 나타난 황금비 (Golden Section Found in Hand Axe)

  • 한정순
    • 한국수학사학회지
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    • 제19권1호
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    • pp.43-54
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    • 2006
  • 본고에서는 $\ulcorner$자연$\cdot$인간, 그리고 황금분할 I$\lrcorner$([1])의 후속연구로 인간의 미의식과 정신적 모형과 약 1백만 년 전 석기시대의 주먹 돌도끼에 나타나는 황금비와, 오늘날도 다방면에서 선호하여 사용되어지고 있는 황금비에 관하여 연구한다. 연구결과 특히 1백만 년 전의 주먹 돌도끼는 인류가 당시에 후일의 예술과 수학의 전제조건이 되는 중요한 능력을 가지고 있었다는 것을 보여주는 것이었으며, 펜, 종이, 자 등의 도움 없이도 정신적인 모형이 존재하여 기본적인 수학적 변환을 가능하게 하였음을 보여준다. 다양한 크기의 주먹도끼를 동일한 황금비를 유지하면서 제작하였다는 것은 수십만 년 후에 나타난 유클리드의 $\ulcorner$기하학 원론$\lrcorner$에서 다루어진 원리를 최초로 보여준 예라고 생각된다.

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수정된 황금분할 탐색법을 이용한 사출성형 설계인자의 최적화 (Optimization of Design Variable for Injection Molding Using a Modified Golden Section Search Method)

  • 박종천;김경모
    • 한국기계가공학회지
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    • 제16권1호
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    • pp.63-69
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    • 2017
  • The golden section search method is widely used to optimize a single design variable in many fields due to its superior advantages of search. In this paper, a new direct search method is proposed by modifying the search structure of the golden section search method; thus, it can be adapted in the optimization of a single design variable for the injection molding process. This proposed method is applied to determine an optimal gate position for the injection molding of a bezel of an automated teller machine for minimizing the injection pressure. Thus, an optimal gate position where the injection pressure is decreased by 4.5 MPa to that of the initial position was obtained with a small number of simulations. It is anticipated that the current proposed search method can be utilized as a practical tool for optimizing single variables for injection molding design.

Tracking Control of Robotic Manipulators based on the All-Coefficient Adaptive Control Method

  • Lei Yong-Jun;Wu Hong-Xin
    • International Journal of Control, Automation, and Systems
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    • 제4권2호
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    • pp.139-145
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    • 2006
  • A multi-variable Golden-Section adaptive controller is proposed for the tracking control of robotic manipulators with unknown dynamics. With a small sample time, the unknown dynamics of the robotic manipulator are denoted equivalently by a characteristic model of a 2-order multivariable time-varying difference equation. The coefficients of the characteristic model change slowly with time and some of their valuable characteristic relationships emerge. Based on the characteristic model, an adaptive algorithm with a simple form for the control of robotic manipulators is presented, which combines the multi-variable Golden-Section adaptive control law with the weighted least squares estimation method. Moreover, a compensation neural network law is incorporated into the designed controller to reduce the influence of the coefficients estimation error on the control performance. The results of the simulations indicate that the developed control scheme is effective in robotic manipulator control.

BACKPROPAGATION BASED ON THE CONJUGATE GRADIENT METHOD WITH THE LINEAR SEARCH BY ORDER STATISTICS AND GOLDEN SECTION

  • Choe, Sang-Woong;Lee, Jin-Choon
    • 한국지능시스템학회:학술대회논문집
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    • 한국퍼지및지능시스템학회 1998년도 The Third Asian Fuzzy Systems Symposium
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    • pp.107-112
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    • 1998
  • In this paper, we propose a new paradigm (NEW_BP) to be capable of overcoming limitations of the traditional backpropagation(OLD_BP). NEW_BP is based on the method of conjugate gradients with the normalized direction vectors and computes step size through the linear search which may be characterized by order statistics and golden section. Simulation results showed that NEW_BP was definitely superior to both the stochastic OLD_BP and the deterministic OLD_BP in terms of accuracy and rate of convergence and might sumount the problem of local minima. Furthermore, they confirmed us that stagnant phenomenon of training in OLD_BP resulted from the limitations of its algorithm in itself and that unessential approaches would never cured it of this phenomenon.

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살오징어(Todarodes pacificus)와 갑오징어(Sepia esculenta)에 대한 광대역 음향산란특성의 비교 (Comparison of Broadband Acoustic Scattering Characteristics Between Japanese Flying Squid Todarodes pacificus and Golden Cuttlefish Sepia esculenta)

  • 이대재
    • 한국수산과학회지
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    • 제52권6호
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    • pp.709-718
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    • 2019
  • Cephalopods, such as the Japanese flying squid Todarodes pacificus and golden cuttlefish Sepia esculenta, are an important food source for all toothed whales, particularly bottlenose dolphins in costal and offshore waters around the Korean Peninsula. A controlled laboratory experiment was conducted to investigate the broadband acoustic backscattering from live individuals of these two cephalopod species using linear chirp signals (100-200 kHz). The backscattered echo signal was measured at about 1° intervals from -45° (head down) to +45° (head up) in the dorsal plane. The species-specific, frequency-dependent scattering characteristics were investigated by comparing the relationship between the wavelength-normalized backscattering cross-section (σ/λ2) and the wavelength-normalized fish length L/λ for each species. The estimated σ/λ2 value for Japanese flying squid was 9.51 at an L/λ range of 12.79-30.27 (mean, 21.26). This was approximately 7% of the σ/λ2 value (136.1) for golden cuttlefish at an L/λ range of 9.07-25.49 (mean, 15.77).

A Study on the Collision Accident between Ferry Golden Jindo and Ferry Princess

  • Kim Jin Kwon
    • 한국항해항만학회지
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    • 제29권2호
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    • pp.119-126
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    • 2005
  • Ferry Golden Jindo collided with Ferry Princess near the No.7 light buoy of Incheon Port No.1 Passage in restricted visibility due to dense fog. The result was that Ferry Golden Jindo got a hole at the starboard midship section shell plating and Ferry Princess sustained damages at the starboard bow and 25 persons injured The aim of this paper is to investigate this collision accident, to clarify its causes, and to prevent such accident from occurring again In short, this collision resulted from Princess' high speed in restricted visibility, Golden Jindo's carelessness of watchkeeping, lack of proper safety training of crew, lack of instruction of supervisor, carelessness af PTMS Center and indifference of Korea Shipping Association, etc.

인적정보의 고유기능과 계량화 방안에 관한 연구 (A Study on the Eigen Ethnic Function and Mathematical Processing Method of Human Information)

  • 김홍재;서윤정
    • 산업경영시스템학회지
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    • 제19권40호
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    • pp.329-339
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    • 1996
  • This study presents the eigen ethnic function and mathematical processing method of human information. Human information can be definded as the overlap area taking the superposition property composed of intuition and sensory in stimulus/response (S/R) model, In S/R model, the intuition and sensory eigen ethnic function acts on the forming of perception. Perception process by the superposition property of intuition and sensory analogy to the basic neural network model. This analogy model extends to the analysis method. As an analysis method, optimal ratio number induced to the golden section ratio. Golden section ratio drived out by diverse source and implicated to the sensory and intuitive context such as beauty, harmony, optimality etc. This numerical orders can be applied to analysing the Perception process and extended to pursue the Potential human behavior, On the basic of proposed applying method, an illustrative mathematical examples are presented.

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유체기계 임펠러의 최적 역설계 기법 (Optimization Inverse Design Technique for Fluid Machinery Impellers)

  • 김종섭;박원규
    • 한국전산유체공학회지
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    • 제3권1호
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    • pp.37-45
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    • 1998
  • A new and efficient inverse design method based on the numerical optimization technique has been developed. The 2-D incompressible Navier-Stokes equations are solved for obtaining the objective functions and coupled with the optimization procedure to perform the inverse design. The steepest descent and the conjugate gradient method have been applied to find the searching direction. The golden section method was applied to compute the design variable intervals. It has been found that the airfoil and the pump impellers are well converged to their targeting shapes.

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기능경사 내열 복합재의 체적분율 최적화에 관한 연구 (Study on the Volume Fraction Optimization of Functionally Graded Heat-Resisting Composites)

  • 조진래;하대율
    • 대한기계학회논문집A
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    • 제25권6호
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    • pp.988-995
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    • 2001
  • Functionally graded materials(FGMs) are highlighted to be suitable for high temperature engineering due to their continuous distribution of material properties. In this paper, an optimal design is executed for determining the optimal material volume distribution pattern that minimizes the steady-state thermal stress of FGM heat-resisting composites. The interior penalty function method and the golden section method are employed as optimization techniques while the finite element method is used for thermal stress analysis. Through numerical simulations we suggest the volume fraction distributions that considerably improve initial thermal stress distributions.