• 전기전자학회논문지
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• 제24권4호
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• pp.982-990
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• 2020

Groundwater is essential source of the freshwater. Groundwater is stored in the body of the rocks or sediments, called aquifer. Finding an aquifer is a very important part of the geophysical survey. The best method to find the aquifer is to make a borehole. Single borehole is not a suitable method if the aquifer is not located in the borehole drilled area. To overcome this problem, a cross borehole method is used. Using a cross borehole method, we can estimate aquifer location more precisely. Electrical impedance tomography is use to estimate the aquifer location inside the subsurface using the cross borehole method. Electrodes are placed inside each boreholes and area between these boreholes are analysed. An aquifer is a non-uniform structure with complex shape which can represented by the truncated Fourier series. Deep neural network is evaluated as an inverse problem solver for estimating the aquifer boundary coefficients.

• 복식문화연구
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• 제17권3호
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• pp.499-511
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• 2009

As the demand of the consumer for high-sense clothing, relation with materials is becoming important even in clothing construction. Especially, the cutting angle of materials is becoming an crucial element in the formation of silhouette, and drape of Hem line, of skirts. Accordingly, in this study, Hem line shapes between real clothing and 3D virtual clothing of "i-Designer" were analyzed by manufacturing semi-flare skirts of polyester 100% according to a cutting angle, and the results are as follows. As a result of comparison of silhouette between the real clothing and the virtual clothing, the real and the virtual have a similar feeling regardless of a cutting angle. In case of drape shapes, both the front and the lateral side were represented in almost similar shapes. The back side, however, the real and the virtual showed a great difference in case of grain direction. And in the whole silhouette, the real and the virtual were represented similarly. It could be known that with regard to Hem-line drape shapes between the real clothing and the virtual according to a cutting angle, the real clothing is represented in a location farther from the body than the virtual clothing and, the location or number of node was similarly showed in the real and the virtual.

• Archives of Plastic Surgery
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• 제45권5호
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• pp.425-431
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• 2018

Background The umbilicus makes an important contribution to the natural appearance of the abdomen. To date, studies on its position in Korean women are lacking, and no standards have been established. The purpose of this study was to investigate the position of umbilicus in Korean women and to review changes in its position after ipsilateral pedicled rectus abdominis musculocutaneous (IP-RAM) flap. Methods This research consisted of two studies. In first study, 100 females who visited the emergency department with gastroenteritis between 2007 and 2011 were included. In second study, 40 women who underwent IP-RAM flap in the same period were included. Using abdominal computed tomography, we measured the distance between xiphoid process and umbilicus, represented by value a, and the distance between umbilicus and symphysis pubis, represented by value b. Thus, the location of the umbilicus was represented by the ratio a/b. The data were analyzed using Pearson correlation test and paired t-test. Results In study 1, the mean value of a/b was 1.07. Pearson correlation test revealed a significant correlation between age and a/b. In study 2, the mean value of a/b was 1.16 in preoperative measurements and 1.01 in postoperative measurements. The paired t-test showed a significant difference between preoperative and postoperative measurements, indicating cephalic migration of the umbilicus after surgery. Conclusions The natural position of the umbilicus showed caudal migration with aging. Additionally, in a comparison of preoperative and postoperative measurements in patients who underwent IP-RAM flap, cephalic migration of the umbilicus was observed after surgery.

• Spatial Information Research
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• 제19권5호
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• pp.75-86
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• 2011

실세계의 도시에 대한 3차원 모델링은 도시계획과 의사결정을 하기 위하여 필수적인 작업이다. 또한 무선인터넷 발달과 함께 이용자의 위치를 파악하여 정보를 제공하는 위치기반서비스에 대한 소비자 증가로 많은 3차원 도시모델이 개발되고 있다. 특히 우리나라 도심지역의 경우에는 초고층 건물들의 밀집으로 실외뿐만 아니라 실내공간 모델링에 대한 연구가 필요하며, 공간 모델을 통해서 최단경로 등의 공간 분석이 통한 위치기반서비스가 제공될 수 있어야 한다. 지금까지 많은 연구가 진행된 3차원 도시모델들은 피처 모델로, 기본요소들(primitives)을 조합하여 공간을 표현하고, 관계성은 공유하는 기본요소들을 찾아야지만 표현할 수 있기 때문에 복잡한 3차원 공간 객체들 사이에서는 관계성을 정의하기 힘들다. 따라서 최단경로와 같이 공간간의 관계성을 기반으로 도출되는 공간 분석을 하기 위해서는 공간간의 관계성 표현이 필요하다. 본 연구에서는 복잡한 3차원 실내공간간의 관계성을 효율적으로 표현하는 네트워크 기반의 위상학적 데이터 모델인 보행 공간 관계 모델을 개발하였다.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2011년도 추계학술대회
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• pp.91-94
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• 2011

기존의 SNS(Social Networking Service)서비스에 LBS(Location-Based Service)서비스가 부가된 LBSNS(Location-Based Social Networking Service)서비스들이 상용화되면서 큰 인기를 얻고 있다. 트위터는 그러한 서비스의 대표적인 예라고 볼 수 있다. 트위터의 현재 위치기반서비스는 자신이 원하는 지역정보와 상관없는 정보를 구독하게 하는 구조로 되어 있다. 팔로잉한 사용자는 단순히 개인적인 선호도에 의해 지역정보가 추가된 메시지를 트윗하지만 구독하는 입장의 팔로워는 자신이 원하지 않는 지역정보를 받아 볼 수도 있다. 이러한 사항을 개선하기 위해 공간조인을 이용한 필터링 기법이 제안되었다. 필터링 기법을 위한 우선적인 작업은 바로 각각의 사용자와 트윗들에 위치정보가 추가되어져야 한다. 여기서 위치정보는 MBR(Minimum Bounding Rectangle)로 표현된다. 위치정보는 동적속성 또는 정적속성으로 나누어진다. 동적인 경우를 예를 들어보면 사용자가 지속적으로 움직이는 상황을 들 수 있다. 이 때 발생되는 대량의 연속질의는 사용자가 많은 SNS의 특성상 서버에 많은 부하를 줄 수 있다. 본 논문에서는 구글 맵 상에서 Virtual Grid를 생성하여 문제를 해결 하였고 성능 평가 결과 Virtual Grid를 사용하지 않았을 때 보다 질의 발생 빈도수가 줄어들었다.

• 지역연구
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• 제11권1호
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• pp.31-60
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• 1995

The distribution of economic activity over a mutually exclusive and exhaustive categorical industry-region matrix is modeled as a composition of two random components: the probability-like share distribution of jobs and the dynamic evolution of absolute aggregates. The former describes the individual activity location choice by comparing the predicted profitability of the current industry-region pair against that of all other alternatives based on the available information on industry-specific, region specific, or activity specific attributes. The latter describes the time evolution of macro-level aggregates using a dynamic reduced from model. With the seperation of micro choice behavior and macro dynamic aggregate constraint, the usual independence and identicality assumptions become consistent with the activity share distribution, hence multi-regional industrial migration can be represented by a set of probability evolution equations in a conservative Markovian from. We call this a Micro-Macro Composition Approach since the product of the aggregate prediction and the predicted activity share distribution gives the predicted activity distribution gives the predicted activity distribution which explicitly considers the underlying individual choice behavior. The model can be applied to interesting practical problems such as the plant location choice of multinational enterprise, the government industrial ploicy to attract international firms, and the optimal tax-transfer mix to influence activity location choice. We consider the latter as an example.

• 한국군사과학기술학회지
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• 제17권2호
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• pp.248-257
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• 2014

As observed in the recent war, suppression of enemy air defense operation is one of the major tactics, simultaneously conducted with high payoff target. Specifically, our air defense operation should be properly constructed, since the operating environment of our forces mostly consists with mountainous terrain, which makes detections of the enemy difficult. The effective arrangements of low altitude air defense radars can be suggested as a way of improving the detection capability of our forces. In this paper, we consider the location problem of low altitude air defense radar, and formulate it as an Integer Programming. Specifically, we surveyed the previous researches on facility location problems and applied two particularly relevant models(MCLP, MEXCLP) to our problem. The terrain factor was represented as demand points in the models. We verified the optimal radar locations for operational situations through simulation model which depicts simple battle field. In the simulation model, the performance of optimal radar locations are measured by the enemy detection rate. With a series of experiments, we may conclude that when locating low altitude air defense radars, it is important to consider the detection probability of radar. We expect that this finding may be helpful to make a more effective air defense plan.

• Journal of Ecology and Environment
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• 제47권3호
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• pp.146-156
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• 2023

Background: Endemic species are important components in the flora of most world regions. Most of these species have become threatened and exposed to extinction within the last few years. The present study aims to evaluate the ecosystem services offered by the endemic plant taxa in Egypt and the threats that affect them. Twenty-five field visits were conducted during summer 2018 to spring 2022 to several locations all over Egypt. In each location, the main habitats, national distribution, abundance, goods and threats were recorded. Results: Egypt has 41 endemic taxa belonging to 36 genera and 20 families inhabiting 10 main habitats. Rocky surfaces and sandy formations have the highest number of endemic species. The relation between the number of endemic taxa and the abundance categories indicated that 2 taxa are rare (4.9% of the total taxa), while the remaining were very rare (95%). The most represented offered good was the medicinal uses (32 taxa = 78%), while fuel plants were only represented by 2 taxa (2 taxa = 4.9%). Besides, 14 taxa (34.1% of the total studied taxa) have at least 1 environmental service. Soil fertility (7 taxa = 50%) was the most represented, followed by sand accumulations (6 taxa out of 14 taxa = 43%), while shading plant was the least (1 taxon = 7.1%) (Rosa arabica). The most represented threat is over-cutting and over-collecting (38 taxa = 92.7%), while mining and quarrying is the least represented (4 taxa = 9.8%). Conclusions: The potential and actual goods, services and threats of the endemic taxa were assessed as follows; field observation, information collected from local inhabitants and herbalists, and a literature review. The present study recommended planning a strategy about the importance, threats and conservation of endemic taxa in Egypt that would help in the protection and rescue of these plants and increase awareness about the importance of these plants.

• 산업경영시스템학회지
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• 제24권66호
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• pp.37-45
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• 2001

Because the structure of the economy is being changed from product-oriented and company-centered economy to service-oriented and customer-centered economy, and the market competition is varying with the competition of non-price factors, the importance for customer service of logistics system is being increased. Thus, the level of customer service should be represented as an element of the logistics decision and the facility location decision. The level of customer service provided by logistics system has an effect on customers\` purchase decisions, hence on the market demand. That is, the market demand is elastic for customer service as it is influenced by product price. Considering the effect of customer service on demand, this study develops the market area which each facility will serve. That area is circular, and distance norm is considered Euclidean and Rectilinear (or Manhattan) distance norm. The market demand for product at a particular area is affected by the level of customer service that facility provides, and the relationship between the market demand and the level of customer service is represented with a mathematical function.

• 한국CDE학회논문집
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• 제5권2호
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• pp.168-174
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• 2000

A biarc is a curve connecting two circular arcs with the constraints of tangent continuity so that it can represent the free form currie approximately connecting several biarcs with the tangent continuity. Since a biarc consists of circular arcs, the offset curve of the curve represented by biarcs can be easily obtained. Besides. if the tool path is represented by biarcs, the efficiency of machining is improved and the amount of data is decreased. When approximating a curve with biarcs, the location of the point where two circular arcs meet each other plays an important part in determining the shape of a biarc. In this thesis, the optimum point where two circular arcs meet is calculated using the tangent information of the curve to approximate so that it takes less calculation time to approximate due to the decrease of the number of iterations.