• 대한전기학회논문지:전력기술부문A
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• 제49권11호
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• pp.558-565
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• 2000

In this paper, we propose a method for mitigating for mitigating the effect of voltage of voltage sag in radial power distribution systems using load transfer switching (LTS). The term of LTS is defined that the weakness load points for voltage sag transfer to the alternative source during the fault clearing practices. The sequenced of proposed LTS method is divided into the search of weakness points for voltage sag using the risk assessment model and transfer behavior of weakness points. The search of weakness point is carried out using the risk assessment model of voltage sag and Monte Carlo simulation method and the historical reliability data in Korea Electric Power Corporation (KEPCO) are also used. Through the case studies, we verify the effectiveness of proposed LTS method and present the searching method of effective application points of LTS method using the risk assessment model.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 추계학술대회 논문집 학회본부 A
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• pp.208-210
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• 2000

In this paper, we present a method for mitigating the effect of voltage sag in radial power distribution systems using load transfer switching (LTS). The term of LTS is defined that the weakness load points for voltage sag transfer to the alternative source during the fault clearing practices. The sequences of proposed LTS method is divided into the search of weakness points for voltage sag using the risk assessment model and transfer behavior of weakness points. Through the case studies, we verify the effectiveness of proposed LTS method and present the searching method of effective application points of LTS method using the risk assessment model.

• 무역상무연구
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• 제59권
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• pp.3-26
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• 2013

The purpose of this paper is to examine the several points at issue in international technology transfer contract from licensor's and licensee's perspectives, and to refer them when the licensor and the licensee draw up the contract. This author analyzed the critical points of the related provisions of ICC Model International Technology Transfer Contract(2009) by citing the explanations of the Introduction of the Model Contract. The provisions of the Model Contract are generally divided into two categolies; specific conditions and general conditions. This author selected four topics in the specific conditions; Contents of the Contract, Royalty, Modification and/or Improvements of Products, and Territory and Competition. Likewise this author selected three topics in the general conditions; Resolutions of Disputes, Applicable Law and Taxes. Both parties need to be mindful of the following points in the above topics, when they draw up the contract. First, both parties should make the definitions of special terminologies clear, which are included in the Contract. Second, before the parties sign the Contract, they should check any approvals to be necessary by the both countries' governments. Third, for the calculation of the royalty, they should clear the criteria, the scope, and the object. Fourth, as the local laws or regional laws regarding the territory limitation and taxation are mandatory, any provisions of the Contract should not be inconsistent with them. Therefore, both parties should check before-hand the local laws or rules related with the provisions of the Contract. Fifth, when the parties draw up the Contract, they should examine the Provisions of Dispute Resolution in consideration of the Governing Law. Thus both parties decide to make the technology transfer contract, the three aspects namely profitability, legal conflict with mandatory rules, and sustainability of the business resulting from the Contract should be examined in advance, and then proceed the business using the technology transfer.

• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 2005년도 연구개발 발표회 논문집
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• pp.185-190
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• 2005

This work presents a numerical procedure to optimize the elliptic-shaped pin fin arrays to enhance turbulent heat transfer. The response surface method is used as an optimization technique with Reynolds-averaged Navier Stokes analysis of flow and heat transfer. Shear stress transport (SST) turbulence model is used as a turbulence closure. Computational results for average heat transfer rate show a reasonable agreement with the experimental data. Four variables including major axis length, minor axis length, pitch and the pin fin length nondimensionalized by duct height are chosen as design variables. The objective function is defined as a linear combination of heat transfer and friction-loss related terms with weighting factor. D-optimal design is used to reduce the data points, and, with only 28 points, reliable response surface is obtained. Optimum shapes of the pin-fin arrays have been obtained in the range from 0.0 to 0.1 of weighting factor.

• 한국ITS학회 논문지
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• 제20권2호
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• pp.58-71
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• 2021

전 세계적으로 고령인구가 급증하고 이에 따라 이동에 불편을 겪는 교통약자의 수도 증가하고 있다. 이러한 추세에 따라 국내에서는 이동편의시설 설치 확대 등 교통약자에 대한 양질의 대중교통 서비스 제공을 위해 다양한 정책을 시행 중이다. 기존 대중교통 이동편의시설 설치는 역사의 면적, 층수, 시설 미확보역 등의 양적인 측면을 기준으로 우선적 확대·설치되고 있다. 하지만 양적 기준 보다는 실제 이용자 기준의 설치 필요 지역에 이동편의시설을 확보하는 것이 교통약자의 이동편의 증진에 더 효과적일 것으로 사료된다. 본 연구에서는 이용자 기반의 교통카드 빅데이터 분석을 통해 교통약자의 환승취약지점을 도출하고자 했다. 스마트카드 거래내역 데이터를 가공하여 환승통행데이터를 구축하고 이용자별 환승통행패턴 분석 및 환승통행시간 차이가 큰 경로를 기준으로 환승취약지점을 도출했다. 분석 결과 일반 이용자보다 교통약자의 환승시간이 오래 걸리는 것으로 나타났다. 일반과 교통약자의 환승통행시간 차이와 시설물 개수와의 상관관계는 미약한 것으로 나타났는데 현장 조사 결과 환승통행시간 차이는 시설물의 단순 개수보다는 해당 환승최단경로 내 이동편의시설의 부재로 인해 발생하는 것으로 나타났다. 향후 교통약자를 위한 이동편의시설 확대 시 실질적 이용자 기반 데이터 분석을 통한 환승취약지점을 기준으로 우선적 시설 확보 시 교통약자의 이동편의가 보다 더 향상될 것으로 사료된다.

• Journal of Computational Design and Engineering
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• 제3권2호
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• pp.132-139
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• 2016

In this paper, a minimum time path planning strategy is proposed for multi points manufacturing problems in drilling/spot welding tasks. By optimizing the travelling schedule of the set points and the detailed transfer path between points, the minimum time manufacturing task is realized under fully utilizing the dynamic performance of robotic manipulator. According to the start-stop movement in drilling/spot welding task, the path planning problem can be converted into a traveling salesman problem (TSP) and a series of point to point minimum time transfer path planning problems. Cubic Hermite interpolation polynomial is used to parameterize the transfer path and then the path parameters are optimized to obtain minimum point to point transfer time. A new TSP with minimum time index is constructed by using point-point transfer time as the TSP parameter. The classical genetic algorithm (GA) is applied to obtain the optimal travelling schedule. Several minimum time drilling tasks of a 3-DOF robotic manipulator are used as examples to demonstrate the effectiveness of the proposed approach.

• 대한산업공학회지
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• 제35권1호
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• pp.73-86
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• 2009

This paper discusses a method of determining the optimal design of a block. A horizontal layout of blocks is assumed in which transfer points are located at a side of the block. Each block has several transfer points (TPs) each of which is assigned to a group of adjacent bays and located at the center of the assigned group. The goal is to find the optimal size of a block and the optimal number of TPs while minimizing the total cost consisting of the fixed and operational cost of yard cranes (YCs), the operational cost of internal trucks, and the installation cost of TPs. Constraints on the maximum expected system time of trucks are imposed for the optimization. Formulas for estimating handling operation cycle times of a YC are derived analytically. Numerical experiments are conducted to illustrate optimal block designs for a given set of data.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 춘계학술대회논문집
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• pp.253-259
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• 2002

The rigid body characteristics (value of mass, Position of center of mass, moments and products of inertia) of mechanical systems can be identified from FRF data or vibration spectra of rigid body motion. Therefore the accuracy of rigid body characteristics is connected directly with the accuracy of measured data for rigid body motions. In this paper, a method of improving accuracy of measurement of rigid body motion is presented. Applying rigid body theory, ail translational and rotational displacements at a tentative point on the rigid body are calculated using the measured translational displacements for several points and transfer matrix. Then the estimated displacements for the identical points are calculated using the 6 displacements of the tentative Point and transfer matrix. By using correlation coefficient between measured and estimated displacements, we can detect the existence of errors that are contained in a certain measured displacement. Consequently, the improved rigid body motion with respect to a tentative point can be obtained by eliminating the contaminated data.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2010년도 춘계학술대회 논문집
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• pp.123-125
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• 2010

As the exterior noise emitted by a vehicle is getting more and more attention, simulated pass-by measurements become more important. This well established method provides information about the total noise emitted by the vehicle. For a vehicle manufacturer it is not only interesting to know about the total noise but also to know how this total exterior noise is composed of different contributions, such as for example the contribution of the engine, the intake or exhaust system. Transfer path analysis (TPA) provides a separation of these contributions for each of the pass-by microphones alongside the track. Presented is a method for fast and efficient determination of the contributions of multiple sources using operational transfer path analysis (OTPA). The calculation of the transfer characteristics between the reference measurement points on the vehicle and the corresponding response points of both microphone lines are carried out while operation of the vehicle. As result of the contribution analysis from operational transfer path analysis, the characteristic noise level as function of the covered distance is displayed for all individual sound sources, thus providing in depth information for sound quality engineering.

• International Journal of Fluid Machinery and Systems
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• 제9권3호
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• pp.229-236
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• 2016

Exergetic analysis was introduced in optimization of a rotating equilateral triangular internal cooling channel with staggered square ribs to maximize the net exergy gain. The objective function was defined as the net exergy gain considering the exergy gain by heat transfer and exergy losses by friction and heat transfer process. The flow field and heat transfer in the channel were analysed using three-dimensional Reynolds-averaged Navier-Stokes equations under the uniform temperature condition. Shear stress transport turbulence model has been selected as a turbulence closure through the turbulence model test. Computational results for the area-averaged Nusselt number were validated compared to the experimental data. Three design variables, i.e., the angle of rib, the rib pitch-to-hydraulic diameter ratio and the rib width-to-hydraulic diameter ratio, were selected for the optimization. The optimization was performed at Reynolds number, 20,000. Twenty-two design points were selected by Latin hypercube sampling, and the values of the objective function were evaluated by the RANS analysis at these points. Through optimization, the objective function value was improved by 22.6% compared to that of the reference geometry. Effects of the Reynolds number, rotation number, and buoyancy parameter on the heat transfer performance of the optimum design were also discussed.