• 한국시뮬레이션학회논문지
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• 제30권4호
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• pp.21-29
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• 2021

역합성개구면레이다(ISAR) 영상은 표적의 주요 산란 부위를 보여주는 강력한 도구이다. 표적을 식별 및 분류하는데 주로 사용된다. ISAR 영상의 산란점 정보를 찾는 것은 표적 특징을 모델링하는데 중요하다. 본 논문에서는 ISAR 영상 데이터와 모델링 함수와의 근사오차를 최소화함으로서 산란점 정보를 추출하는 모델링 방법을 제안한다. 여기서 추출된 산란점 정보는 시뮬레이션에서 사용될 표적의 산란점 위치뿐만 아니라 표적 산란점의 오차요소를 고려하는 시뮬레이션에 사용될 수 있는 표적 산란점 위치오차의 통계적 정보도 포함한다. 또한 제안된 방법에 의해서 얻어진 산란점 정보로부터 영상을 재구성하고 원래의 ISAR 영상을 잘 근사하는지 확인하였다.

• Journal of Positioning, Navigation, and Timing
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• 제9권3호
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• pp.157-167
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• 2020

Fingerprinting method is useful when estimating the location of a requestor based on LTE signals in an urban area. To do this, it is necessary to acquire location-based signals everywhere in the service area for fingerprint DB generation in advance. However, there may be signal uncollected area within a wide service area, which may cause a problem that the positioning accuracy of the requestor is low. In order to solve this problem, in this paper, signal propagation modeling is performed based on the obtained measurements, and based on this model, the signal information in the non-acquisition region is estimated. To this end, techniques for modeling signal propagation according to a method using measurements are proposed. The performance of the proposed techniques is verified based on the measurements obtained on a test bed selected as Seocho-gu, Seoul. As a result, it can be seen that signal propagation modeling performed based on multidivision segmented measurements has the most performance improvement.

• 대한기계학회논문집B
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• 제25권12호
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• pp.1784-1792
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• 2001

Numerical analysis on a parallel flow heat exchanger(PFHE) is performed using 2 dimensional turbulent porous modeling. This modeling can consider three-dimensional configuration of passage (flat tube with micro-channels), and the stability and accuracy of numerical results are improved. The geometrical parameters(e.g., the position of separators, inlet/outlet, and porosity of passages of a PFHE) are varied in order to examine the flow and thermal characteristics and flow distribution of the single phase multiple passages system. The flow non-uniformities along the paths of the PFHE are observed to evaluate the thermal performance of the heat exchanger. The location of inlet affects the heat transfer, and the location of outlet affects the pressure drop. The porosity with the optimum thermal performance is around 0.53.

• Architectural research
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• 제12권2호
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• pp.15-22
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• 2010

Our prediction model is based on the development of "Semantic Location Model." It embodies geometrical and topological information which can increase the efficiency in prediction and make it easy to manipulate the prediction model. Data mining is being implemented to extract the inhabitant's location patterns generated day by day. As a result, the self-learning system will be able to semantically predict the inhabitant's location in advance. This context-aware system brings about the key component of the ubiquitous computing environment. First, we explain the semantic location model and data mining methods. Then the location prediction model for the ubiquitous computing system is described in details. Finally, the prototype system is introduced to demonstrate and evaluate our prediction model.

• Wind and Structures
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• 제20권4호
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• pp.489-508
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• 2015

In this paper, a novel methodology is proposed to obtain optimum location of outriggers. The method utilizes genetic algorithm (GA) for shape and size optimization of outrigger-braced tall structures. In spite of previous studies (simplified methods), current study is based on exact modeling of the structure in a computer program developed on Matlab in conjunction with OpenSees. In addition to that, exact wind loading distribution is calculated in accordance with ASCE 7-10. This is novel since in previous studies wind loading distributions were assumed to be uniform or triangular. Also, a new penalty coefficient is proposed which is suitable for optimization of tall buildings. Newly proposed penalty coefficient improves the performance of GA and results in a faster convergence. Optimum location and number of outriggers is investigated. Also, contribution of factors like central core and outrigger rigidity is assessed by analyzing several design examples. According to the results of analysis, exact wind load distribution and modeling of all structural elements, yields optimum designs which are in contrast of simplified methods results. For taller frames significant increase of wind pressure changes the optimum location of outriggers obtained by simplified methods. Ratio of optimum location to the height of the structure for minimizing weight and satisfying serviceability constraints is not a fixed value. Ratio highly depends on height of the structure, core and outriggers stiffness and lateral wind loading distribution.

• 경영과학
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• 제12권2호
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• pp.63-75
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• 1995

The uncapacitated facility location problem considered here is to determine facility location sites, minimizing the total cost of establishing facilities and serving customer demand points which require primary and back-up services. To solve this problem effectively, we propose two things in this study. First, we propose an idea of Benders' decomposition approach as a solution method of the problem. Second, we implement the problem on GAMS. Using GAMS (general Algebraic Modeling System) can utilize an mixed-integer programming solver such as ZOOM/XMP and provide a completely general automated implementation with a proposed solution method.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2003년도 가을 학술발표회 논문집
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• pp.663-666
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• 2003

Using numerical analysis modeling of Multi-electrode Array that could be applied to the corrosion state measurement of a reinforcing steel bar in concrete, the steel bar location inside concrete can be probed by the investigation of the change of the measured impedance from concrete surface determined by the electrical impedance of interface between the steel bar and concrete, the electrical resistivity of concrete, the array of electrodes and the relative location and diameter of the steel bar.

• 한국측량학회:학술대회논문집
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• 한국측량학회 2010년 춘계학술발표회 논문집
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• pp.359-361
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• 2010

This research is thing about location choice of solar power generation equipment to increase efficiency of solar power generation equipment. In the case of current solar power generation equipment, location of large scale solar power generation equipment facilities choice or, have localized in small scale equipment by individual. This research uses various climatic elements of small scale area for efficient location choice of solar power generation facilities and quantity of solar radiation did back-tracking.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 A
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• pp.218-219
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• 2006

This paper is about modeling on 1500V DC electric railroad system. Electric railroad systems have peculiar characteristics against other electric system. The characteristics arc that the railroad systems have electric vehicle loads which are power-varying and location-varying with time. Because of this load characteristic, the electric railroad system modeling which reflects its own characteristics on EMTDC simulation could not be achieved. However, to reflect load characteristic on EMTDC, this paper suggests electric railroad system modeling by using TPS (Train Performance Simulator) that was developed in Korea Railroad Research Institute. A TPS program has various kinds of input data, such as operation condition, vehicle condition, and power system condition. By these data, TPS calculates mechanical power consumption and location, especially it decide electric power consumption on the basis of the fact that consumed electric and mechanical power are equal. Moreover, on this paper, movement of vehicle is reflected on EMTDC simulation as variation of feeder impedance. Also, an electric vehicle load is modeled as time-varying constant power load model.

• 한국콘텐츠학회논문지
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• 제11권4호
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• pp.440-447
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• 2011

적지선정은 이용목적에 적합한 공간 또는 속성조건을 인자로 정하고 이를 만족하는 지역을 선정하는 것으로 체계적으로 수행되어야 한다. 본 연구는 계층적 분석과정과 GIS분석 모델링 방법을 이용하여 주거지 개발의 합리적인 적지선정을 시도한 것이다. 연구에서 적지선정을 위해 공간적 속성적 분석방법을 계층화하였으며 단계 별 효율적 결과도출을 위해 GIS분석 모델을 사용하였다. 다음 단계로, 적지선정 조건과 의사결정요소들을 유기적으로 고려하여 정량적 정성적인 평가지표를 만들고 요소들의 경중에 따라 가중치를 적용하였다. 특히, 주관적 평가요소인 경관에 대한 심미적인 요소를 반영하기 위해 3차원 지형모델의 시뮬레이션기법을 사용하였으며 계층적기법을 도입한 정성적인 평가요소로 고려하였다. 연구결과, 계층적 GIS모델분석으로 신속, 정확하게 복합적인 요구조건을 만족하는 적지를 선정할 수 있었다.