• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2007.12a
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• pp.373-375
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• 2007

출입항로에서 중요한 역할을 하는 등부표는 주로 항로를 표시하거나 위험 장소를 표시한다. 등부표를 적절한 간격으로 배치하여 항해자가 자연스럽게 이용할 수 있도록 하는 것이 다른 항법시스템이 없더라도 안전을 확보할 수 있는 길이 될 것이다. 이런점에 고려하여 이 논문에서는 동부표의 적절한 배치(이하 '최적 배치'라 한다.)를 하기 위한 원칙을 제시하려고 한다. 이 원칙을 먼저 항만의 수역 설계와 관련한 규정을 검토하고, 면담 및 설문 조사에서 얻은 결론, 실측한 등부표 시인거리, 마지막으로 개개의 항만에 어떻게 적용되는가를 탑 혹은 풀미션 선박조종시물레이터으로 검증하는 방법으로 진행하려고 한다.

• Proceedings of the KAIS Fall Conference
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• 2011.05a
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• pp.201-203
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• 2011

본 논문은 지상에 배치된 의사위성의 배치에 따른 측위 정확도 분석에 대한 연구결과이다. 의사위성의 배치 간격에 따라 수신기에서의 측위 정확도(DOP, Dilution of Precision)가 결정된다. 본 논문에서는 다양한 배치에 따른 측위 정확도를 이론적인 연구결과를 이용하여 분석한 결과를 제시하였다. 특히 의사위성의 배치 시 디지털 지형 지도를 이용하여 정확한 위치에서 계산 될 수 있도록 하였고 측위정확도를 계산하기 위한 프로그램을 구현하였다.

• Journal of Korean Society of Transportation
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• v.27 no.5
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• pp.145-153
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• 2009

Although an interest in higher design speeds continues to increase to promote more efficient travel on expressways, the current Korean design guidelines do not provide criteria for design values. An arising issue associated with higher design speeds is how to effectively ensure traffic safety under such high speed traffic conditions. In particular the safety issue would become more significant in determining the interchange spacing. This study proposes a methodology for determining freeway interchange spacing under higher speed traffic conditions. A microscopic traffic simulator, VISSIM, was used to evaluate the effects of various interchange spacings on traffic conditions in terms of safety. In this study, the acceleration noise was used as an index to represent the stability of traffic conditions, which is a potential indicator to quantify the level of safety. It was found based on simulation evaluations that 5-km interchange spacing would be a feasible alternative under higher speed traffic conditions (around 160 km/h).

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.15 no.2
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• pp.7-12
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• 2001

In this paper, the optical arrangement of LED lamps was studied using an optical design software for illumination applications. A standard source was constructed, and then simulated its light distribution characteristics of the basic arrangements by shape, by angle, and by displacement. And the color variation circuit was constructed to obtain stabilized light and color output in consideration of the electrical and optical characteristics of high brightness RGB LEDs.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.19 no.3
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• pp.57-65
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• 2005

No matter how well the equally spaced grounding grid is designed, there we questions keep rising, such as leakage of current from comer conductor, high voltage of touch voltage in comers of grid than in center, and high material cost for grounding grid. The best-fitted design for unequally spaced grounding grid is a part that must be considered. Explain advantages of unequally spaced grounding grid and lead formula by dividing the number of grid division, j, into 20, instead of 7. Then, present Dij, which is optimum rate for unequally spaced grounding grid and verify safety and economy of the unequally spaced grounding grid by computer simulation with a poly-nominal function form.

• Proceedings of the Korean Geotechical Society Conference
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• 1991.10a
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• pp.348-361
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• 1991

When reinforcing strip footing on a sand 8round with reticulated root piles, reinforcing effect depends on the length , number, cross sectional area, penetration angle, spacing, and Young's modulus of piles. the mode of action of reinfocement tendons in soil isn't one of carring developed tensile stresses but of anisotropic(uni-directional) reduction or even supression of one normal strain rate. R. H. Bassett and N. C. Last proposed that the reinforcement should be located on the direction of minor strain rate which coincides with the tensile strain rate in the velocity characteristics. Based on this proposal the author carried out a series of 2 - dimentional finite element analysis which varies the parameters mentioned above.

• Proceedings of the Korea Water Resources Association Conference
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• 2021.06a
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• pp.433-433
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• 2021

본 연구는 개수로 흐름에서 조류발전단지의 터빈 최적 배열의 거시적 특성에 관한 연구를 수행하였다. 천수방정식을 통해 직사각형 개수로의 흐름장을 해석하였고, 상류와 하류단에 대해 각각 유입경계조건(inlet boundary condition)과 Flather 형식의 개방경계조건(open boundary condition)을 부여하여 일정 유량으로 흐르는 개수로 흐름을 구현하였다. 더불어, Strickler의 법칙을 확장한 반력공식을 연계하여, 개수로 흐름에 대한 조류 터빈의 영향을 반영하였다. 주어진 상류의 흐름 조건에 대해 조류발전량을 최대로 하는 최적 배열을 구하기 위해 터빈 반력모형을 연계한 천수방정식, 터빈간 최소간격, 그리고 발전단지영역을 제한조건으로 하는 발전량 최대화 문제를 구성하였다. 여기서 조류 터빈의 위치를 나타내는 벡터를 설계변수로 두었는데, 설계되는 터빈의 수가 증가함에 따라 최적화 문제의 계산량이 증가하지 않도록 수반법(adjoint method)을 경사도기반법(gradient-based method)에 연계한 방법이 이용되었다. 다수의 터빈초기배치로 상당한 수치실험이 수행되었고, 발전량 최대화를 이루도록 최적화된 터빈의 배치들이 큰 규모에서 고유한 형상으로 수렴함을 확인하였다. 이러한 특성은 발전단지의 너비와 터빈의 최소간격의 함수로 정의된 무차원수 E를 바탕으로 설명되었다. 구체적으로, E가 1보다 작을 때에는 선형배열이 최적배열로 나타났고, E가 1을 넘어 점차 커짐에 따라 하류에 오목한 형상을 보이다가 V-형태로 발전하는 양상을 보였다. 또한, 어느 임계 수 이상의 터빈이 배치되는 경우 일열 배열을 유지하지 못하고 이열 배열로 분리됨이 관찰되었다.

• Geotechnical Engineering
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• v.10 no.2
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• pp.57-68
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• 1994

To find out the most efficient arrangement of root piles reinforcing sandy soil under a strip footing, a series of model tests for the patten A of by R.H. Bassett and N.C. Last are carried out. In the model test, the variables adopted are a pile length, longitudinal spacing, and the number of rows of piles. According to the results, the most efficient longitudinal spacing of piles is six times of a pile diameter. When the pile length exceeds five times of footing width, no further increase of reinforcing effect is observed. In the pattern A, piles of second row exhibit the largest reinforcing effect and the fifth row show no significant reinforcing effect on the soil.

• Journal of Korean Society of Steel Construction
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• v.16 no.3 s.70
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• pp.365-375
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• 2004

This paper presents the numerical results in strength and stress distribution behavior for the connections of corrugated steel plates (CSP). The results obtained using the finite element method indicate that the CSP with =30mm of longitudinal edge lap, by the current standard specification, has very conservative values. The results also indicate the difference of strength behavior from the bolt arrangement. The strength behavior of standard corrugated type with staggered holes is only affected by circumferential edge lap, but the edge lap and bolthole spacing have an effect on the strength behavior for the deeply corrugated type with parallel holes. Based on these results, this paper examines the current specification of the connections for CSP.

• Journal of the Korea institute for structural maintenance and inspection
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• v.18 no.4
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• pp.67-76
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• 2014

In this study, the behavior of Steel Plate Concrete (SC) walls subjected to shear and axial forces to investigate the effects of shape and arrangement spacing of studs on the design of SC walls was analytically reviewed. For this purpose, 9 cases of finite element analyses considering the different shape and spacing of studs in SC wall were performed. The results showed that the steel plate was yielded at the lower load than the second yielding shear force of the design skeleton curve when the spacing of stud is excessively far from each other. It is also found that the shape of the stud did not affect the shear behavior of SC wall but, the spacing influenced to its composite action. In this study, it was also proven that the inclined shaped stud resists more effectively to the bucking load than the general shaped stud in SC wall.