• Journal of the Society of Naval Architects of Korea
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• v.39 no.4
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• pp.17-23
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• 2002

The present paper describes the optimum inverse design of 2-D linear cascade airfoil. The pressure coefficient of an airfoil surface is taken as the objective function, and non-orthogonal incompressible Navier-Stokes equation is applied to calculate the pressure coefficient. Both of steepest descent and conjugate gradient method have been used to make the objective function go to zero. The 1st order finite differential method is applied to the searching direction and the golden section method is used to compute the searching distance. As a result of the present work, a good convergence to the target airfoil has been obtained.

• Journal of Electrical Engineering and Technology
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• v.13 no.3
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• pp.1326-1336
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• 2018

This paper proposes a numerical approach to predict the critical flashover voltages of air gaps under lightning impulses. For an air gap, the impulse voltage waveform features and electric field features are defined to characterize its energy storage status before the initiation of breakdown. These features are taken as the input parameters of the predictive model established by support vector machine (SVM). Given an applied voltage range, the golden section search method is used to compute the prediction results efficiently. This method was applied to predict the critical flashover voltages of rod-rod, rod-plane and sphere-plane gaps over a wide range of gap lengths and impulse voltage waveshapes. The predicted results coincide well with the experimental data, with the same trends and acceptable errors. The mean absolute percentage errors of 6 groups of test samples are within 4.6%, which demonstrates the validity and accuracy of the predictive model. This method provides an effectual way to obtain the critical flashover voltage and might be helpful to estimate the safe clearances of air gaps for insulation design.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2000.04a
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• pp.248-252
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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. We conducted two kinds of kansei experiments of cubic model and refrigerator varied from 1:1:1 to 1:1:3.66 on the scale of x:y:z. The subjects evaluate the form-ratios of 3-dimensional cubes and virtual products with SD-scale Kansei words(feelings and images). We applied the factor analysis to identify semantic space in cube model and virtual products. Finally, we compared with kansei structure of cube model and virtual product.

• Korean Institute of Interior Design Journal
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• no.39
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• pp.45-53
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• 2003

The purpose of this study is to grasp how B la Bartok's 'Music for Strings, Percussion and Celesta' was expressed in 'Stretto House' of Steven Holl. In conclusion, it is found that phenonenological temporality was expressed through the following equation: (equation omitted). More specifically, it is clarified that the stretto of the musical piece was expressed in the spatial overlapping of the house; the inversion, in the form change of the plan and section of the guest house; the symmetrical proportion and Golden Section, in the same proportion of the house section; the melody of theme, in the shape of the roof. This shows the possibility of approach to the substance of interior and architectural design through music.

• Fire Science and Engineering
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• v.33 no.3
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• pp.138-142
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• 2019

By securing golden time, this study analyzed the effects of an emergency vehicle priority system in Cheongju, North Chungcheong province. Until the scene of a fire is reached, severe obstacles in the street, such as traffic congestion, cars coming forward, non-cooperative vehicles etc., are significant. To solve these problems of road obstacles, it is essential to adopt an emergency vehicle priority system. From April 2017 to June 2018 (1 year and 2 months, 426 days), the dispatch time and date, fire truck moving distance and required time, traffic signal control section and pass time, and shortening time, were measured. This study selected 140 cases consisting of five heavy traffic and frequent dispatch routes out of 293 cases. The effects of the emergency vehicle priority system were excellent. Overall, it took 3 min 3 s to pass 1 km on an uncontrolled traffic signal section. On the other hand, it took 1 min 23 s to pass 1 km on the same section that was controlled. The shortening time to pass 1 km was 1 min 40 s, showing a 45.4% reduction. This means that the 15 min driving time can be reduced to 6 min and 49 s. From this result, an emergency vehicle priority system should be implemented nationwide as soon as possible.

• Journal of Korean Society for Quality Management
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• v.12 no.2
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• pp.33-36
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• 1984

This paper is concerned with the optimal replacement policy of auto-scale with increasing error-variance. This optimization model is to minimize the sum of the cost of defective and excess weight allowance for a target value. The numerical example for the proposed problem is solved by Golden-Section Search and Simpsons's rule.

• Proceedings of the KIEE Conference
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• 1991.07a
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• pp.437-439
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• 1991

This paper deals with the development of computer programs that can be used for fuse and relay coordination in power station and also with the characteristics of these protective devices. The coordination of protective devices is determined by caculation from the lowest voltage level back to the power source. The minimum time difference between two different characteristics on the time- current curves is determined by the Golden Section searching routine.

• Journal for History of Mathematics
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• v.16 no.4
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• pp.59-68
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• 2003

Mathematics and arts are reflection of the spirit of the ages, since they have human inner parallel vision. Therefore, in ancient Greek ages, the artists' cannon was actually geometric ratio, golden section. However, in middle ages, the Euclidean Geometry was disappeared according to the Monastic Mathematics, then the art was divided two categories, one was holy Christian arts and the other was secular arts. In this research, we take notice of Renaissance Painting and Perspective Geometry, since Perspective Geometry was influenced by Renaissance notorious painter, Massccio, Leonardo and Raphael, etc. They drew and painted works by mathematical principles, at last, reformed the paradigm of arts. If we can say Euclidean Geometry is tactile geometry, the Perspective Geometry can be called by visual geometry.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 1999.11a
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• pp.256-261
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• 1999

본 연구는 감성의 정보적 측면 즉 감성정보를 인지과학적 관점에서 유도하였다. 감성정보는 인간행동의 내부와 외부의 변환과정을 주도하는 감성의 정보적 측면이라 할 수 있다. 이 감성정보와 인지과학의 인터페이스를 근간으로 하여 감성정보의 고유기능특성을 고찰하여 해석하고자 한다. 나아가 인간의 감성정보를 황금비(Golden section ratio)와 유비(Analogy)시켜 수리적 적응을 도모하고자 한다. 이러한 적응은 인간 감성이 미치는 제 대상에 새로운 방안을 제공하므로서 응용폭의 확대를 기대할 수 있다고 사료된다.

• Journal of Korean Society of Transportation
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• v.26 no.3
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• pp.17-29
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• 2008

A volume-delay function(VDF) has been used to describe the relation between traffic volumes and delay experienced by travelers on the roads traveling from origin to destination, which has been usually adopted in traffic assignment. For the purpose of more precise description of traffic pattern, we have to estimate the parameters of VDF in advance. This paper presents a methodology for estimating the parameters, which combined with golden section method. By using the method we have estimated the parameters with real data based on KTDB(2006), and validated them. Compared to the existing values of the parameters, newly estimated values are found to be closer to real world.