• 한국정보과학회논문지:시스템및이론
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• 제29권6호
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• pp.340-345
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• 2002

본 논문에서는 기관위치설정 문제 중에서, 이차원 평면에 주어진 n개의 점들로 구성된 집합 P에 대한 이산 2-중심 문제를 다룬다. P의 있는 서로 다른 두 점을 중심으로 선택하는 데, P의 다른 점들은 두 중심 중에서 가까운 중심가지의 거리의 최대값과 두 중심 사이의 거리의 합이 최소가 되도록 선택하는 것이 목적이다. 본 논문에서는 Ο(n$^2$logn) 시간에 이산 2-중심을 구하는 알고리즘을 제시한다.

• 한국생물물리학회:학술대회논문집
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• 한국생물물리학회 1996년도 정기총회 및 학술발표회
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• pp.10-10
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• 1996

High-resolution solution conformation of a novel conotoxin, [Pro 7,13] $\alpha$A-conotoxin $P_{IVA}$, GCCGSYPNAACHPCSCKDROSYCGQ-N $H_2$, has been determined by two-dimensional $^1$H nmr methods in combination with distance geometry calculation to rmsd values of 0.90 $\AA$ and 1.16 $\AA$ for the backbone and heavy atoms, respectively. Total of 324 NOE-derived interproton distance restraints including 33 long-range NOE restraints a well as 11 $\Phi$ and 7 $\chi$$^1$ torsion angle restraints were used for computation of structures. (omitted)d)

• 한국철도학회:학술대회논문집
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• 한국철도학회 2004년도 추계학술대회 논문집
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• pp.430-434
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• 2004

The geometric parameters between wheel and rail change wheel/rail contact geometry characteristics, and this influence dynamic behavior of rolling stock. So, the selections of optimum geometric parameters between wheel and rail is important for planning of railway system. In this study, we have analyzed the influence of geometric parameters like wheel flange-back distance, gage, and rail inclination to the equivalent conicity relating dynamic behavior. The analyses show the following results. The widening of wheel flange-back distance increase the equivalent conicity, the widening of gage, rail inclination 1/20 compared with rail inclination 1/40 decrease the equivalent conicity.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 추계학술대회 논문집 전기물성,응용부문
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• pp.133-134
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• 2006

In this paper, a novel method is presented for efficient calculation of the spatial-domain Green's functions of 2D electromagnetic problems. This method combines spectral and spatial domain calculation schemes and prevents the Green's functions from diverging at the singularities that complicate the process of the Method of Moment(MoM) application. For the validation of this proposed method, fields will be evaluated along the spatial distance including zero distance for 2D free-space and periodic homogeneous geometry. The numerical results show the validity of the prosed method and correspondng physics.

• Bulletin of the Korean Chemical Society
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• 제16권7호
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• pp.649-653
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• 1995

Solution-state structure of native F430 was determined by using NMR methods and NMR-based distance geometry (DG) computations. Structures were generated with loose NOE-derived interproton distance restraints (2.0-2.5 Å, 2.0-3.5 Å and 2.0-4.5 Å for strong, medium, and weak NOE cross-peak intensities, respectively). 2D NOESY back-calculations of structures were subsequently carried out for establishing the consistence between experimental data and DG-model structures. The back-calculated 2D NOESY spectra of resulting DG structures were well consistent with experimental 2D NOESY spectra. Superposition of 20 independent structures with macrocyclic ring atoms and all atoms of F430 afforded pairwise root mean square deviations (RMSD) of 0.025-0.125 Å and 0.64-1.3 Å, respectively. The macrocyclic rings of structures are well converged to a unique conformation with saddle-shaped deformation whereas most of side chains are not converged. The average dihedral angle (N1-N2-N3-N4, 27.78±1.50°) of 20 DG-structures exhibits that the macrocyclic ring conformation is puckered as much as 12,13-diepimeric F430 (28.75±4.07°).

• 항공우주시스템공학회지
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• 제12권4호
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• pp.81-89
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• 2018

본 연구에서는 초음속 유동장 내 연료 분사시 연소기의 공간적인 제한 조건을 고려하여 복수의 분사기간 배치 간격을 변화시키고 그에 따른 유동 구조, 연료의 침투 거리 및 연료-공기의 혼합 특성을 비교 분석하였다. 이를 위하여 널리 알려진 단일 분사구를 이용한 실험 조건을 모사하여 적용된 수치 모델을 검토하였으며, 동일한 분사 조건을 갖는 복수의 분사기를 이용하여 비반응 유동 해석을 수행하였다. 해석 결과를 바탕으로 분사구 간 거리에 따라 전압력 손실, 침투 거리, 및 혼합 성능 등을 정량적으로 비교하였다. 해석 결과 분사구 간 배치 거리가 매우 짧은 경우 분사 연료가 서로 융합되면서 유동장이 2차원 특성을 나타내었고 전반적으로 낮은 혼합 효율 특성과 높은 전압력 손실을 발생하였다. 분사구 간 거리가 멀어짐에 따라 분사 가스간의 상호작용이 감소하면서 혼합 효율이 증가하고 전압력 손실이 낮아지는 것이 관찰되었다.

• 한국도로학회논문집
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• 제9권3호
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• pp.29-38
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• 2007

본 연구의 목적은 운전자의 행태를 통한 시선유도시설의 효과를 검증하고, 도로의 기하구조에 따라 어떤 시선유도시설의 효과가 우수한지에 대해 그 결과를 제시하고자 함이며, 이를 위해 GPS가 장착된 차량을 이용하여 시선유도시설의 인지거리와 측방이격 폭을 측정하였다. 실험결과 첫째로 야간에 운전자는 시선유도시설이 설치될 경우 도로선형 인지에 긍정적인 영향을 미치는 것으로 나타났으며, 둘째로 직선구간에서는 표지병보다 시선유도표지의 인지거리가 길고 곡선부에서는 차이가 없는 것으로 나타났다. 또한 갈매기표지는 곡선부에서 인지거리가 가장 큰 것으로 나타났으며, 표지병은 인지거리와 측방위치에서 큰 차이를 보이지 않았다. 따라서 직선부에서는 시선유도표지가, 곡선부에서는 갈매기표지의 설치가 권장된다.

• Nuclear Engineering and Technology
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• 제54권1호
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• pp.84-96
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• 2022

In the worst case, a temporary ignition source (also known as transient combustibles) between two electrical panels can damage both panels. Mitigation strategies for electrical panel fires were previously developed using fire modeling and risk analysis. However, since they do not comply with deterministic fire protection requirements, it is necessary to analyze the boundary values at which combustibles may damage targets depending on various factors. In the present study, a sensitivity analysis of input variables related to the damage threshold of two electrical panels was performed for dimensionless geometry using a Fire Dynamics Simulator (FDS). A new methodology using a damage evaluation map was developed to assess the damage of the electrical panel. The input variables were the distance between the electrical panels, the vertical height of the fuel, the size of the fire, the wind speed and the wind direction. The heat flux was determined to increase as the vertical distance between the fuel and the panel decreased, and the largest heat flux was predicted when the vertical separation distance divided by one half flame length was 0.3-0.5. As the distance between the panels increases, the heat flux decreases according to the power law, and damage can be avoided when the distance between the fuel and the panel is twice the length of the panel. When the wind direction is east and south, to avoid damage to the electrical panel the distance must be increased by 1.5 times compared to no wind. The present scale model can be applied to any configuration where combustibles are located between two electrical panels, and can provide useful guidance for the design of redundant electrical panels.

• Journal of Welding and Joining
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• 제30권6호
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• pp.49-55
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• 2012

The tandem welding process is one of the most efficient welding processes widely used in material joining technique such as manufacturing of strong and durable structures. It facilitates high rate of joint filling with little increase in the overall rate of heat input due to the simultaneous deposition from two electrode wires. The two electrodes in tandem welding process helps in high-efficiency and high productive of welding process. In this study a automated tandem welding system is developed to determine the correlation between cathode and anode and compared with current ratio of the two electrode torch. Three different inter-electrode distances were chosen, 25mm, 35mm and 45mm to perform the experiment with three different current ratio. From the experiment results, the current ratio between two torch has a large impact on width, height and depth of penetration. In addition, a stable bead geometry is obtained when inter-electrode distance is 35mm.

• 한국초전도ㆍ저온공학회논문지
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• 제25권2호
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• pp.19-24
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• 2023

Recently, interest in renewable energy such as solar and wind power has increased as an alternative to fossil fuels. Renewable energy sources such as large wind farms require long-distance power transmission because they are located inland or offshore, far from the city where power is required. High-Temperature Superconducting (HTS) power cables have more than 5 times the transmission capacity and less than one-tenth the transmission loss compared to the existing cables of the same size, enabling large-capacity transmission at low voltage. For commercialization of HTS power cables, unmanned operation and long-distance cooling technology of several kilometers is essential, and pressure drop characteristic is important. The cryostat's spiral corrugation tube is easier to bend, but unlike the round tube, the pressure drop cannot be calculated using the Moody chart. In addition, it is more difficult to predict the pressure drop characteristics due to the irregular surface roughness of the binder wound around the cable core. In this paper, a CFD model of a spiral corrugation tube with a core was designed by referring to the water experiments from previous studies. In the four cases geometry, when the surface roughness of the core was 10mm, most errors were 15% and the maximum errors were 23%. These results will be used as a reference for the design of long-distance HTS power cables.