• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 춘계학술대회 논문집
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• pp.1927-1930
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• 2007

This study describes the consideration of environmental impact in the preliminary environment investigation and EIA of railroad work. In the stage of preliminary environment investigation, it is important to choose the railroad line and location which minimizes the environmental impact due to the operation of railroad work, and EIA includes the prediction and reduction plan of environmental impact according to the construction and management of railroad.

• 한국산학기술학회논문지
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• 제19권2호
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• pp.530-547
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• 2018

본 연구는 사회 경제적 여건의 변화에 따라 급변하는 의료환경 속에서 중소병의원의 개원 및 운영과 관련하여 고객입장에서 입지환경의 중요성에 주목하고 입지 및 교통, 입주건물의 매력도와 고객만족도 간의 관련성을 분석한 실증연구이다. 내원환자 350여명에 대해 2017년 7월부터 8월까지 약 40일간 설문조사를 수행하고 회수된 343부중 결측치 8부를 제외한 335부에 대해 SPSS와 AMOS 통계패키지를 활용하여 분석하였다. 주요 연구결과는 다음과 같다. 첫째, 건물매력도가 고객만족도에 유의적인 정(+)의 영향을 미칠 것이라는 가설은 채택되었다. 둘째, 교통인프라가 고객만족도에 유의적인 정(+)의 영향을 미칠 것이라는 가설은 기각되었다. 셋째, 건물매력도가 입지시장성에 유의적인 정(+)의 영향을 미칠 것이라는 가설은 채택되었다. 넷째, 교통인프라가 입지시장성에 유의적인 정(+)의 영향을 미칠 것이라는 가설은 채택되었다. 다섯째, 입지시장성이 고객만족도에 유의적인 정(+)의 영향을 미칠 것이라는 가설은 채택되었다. 여섯째, 건물매력도와 고객만족도 간의 관계를 입지시장성이 매개할 것이라는 가설은 부분매개역할이 있음이 확인되어 채택되었다. 일곱째, 교통인프라와 고객만족도 간의 관계를 입지시장성이 매개할 것이라는 가설은 완전매개역할이 있음이 확인되어 채택되었다. 본 연구는 서울지역의 중소병의원만을 대상으로 하고 있어서 지방 중소병의원의 입지 및 교통인프라, 건물매력도에 대한 환자들의 인식까지 아우르지 못하고 있다. 또한 병의원의 매출, 순이익 등 재무적 경영성과에 대한 객관적 자료 대신 고객만족도라는 환자들의 인식만을 분석대상으로 하고 있다는 한계를 가지고 있다. 본 연구의 결과는 향후 의료서비스 시설의 입지선정을 위한 기초를 제공하는데 응용할 수 있을 것이다.

• 지역연구
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• 제9권2호
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• pp.27-40
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• 1993

Most studies on regional economic impact have utilized employment or employment income data. Recently, a few scholars have noticed the importance of nonemployment income sources in urban economies. Using decennial census data on Arizona towns from 1970 to 1990, this paper first examines the increasing importance of nonempolyment income sources in urban economies and the associations of nonemployment income sources with elderly population and metropolitan location. Then, this paper investigates the impact of nonemployment income on urban growth in the framework of economic base model. The regression results show that the impact of nonemployment income is significant in the increase of nonbasic income and becomes greater over time, and that the impact of transfer over time, and that the impact of transfer income on nonbasic income of transfer income on nonbasic income is stronger in smaller towns and the impact of investment income is stronger in larger towns.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2008년도 춘계학술대회논문집
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• pp.383-388
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• 2008

A modeling method for the impact analysis of plate structures employing Hertzian contact theory is presented in this paper. Since local deformation as well as bending deflection of the plate occurs due to the collision, it has to be considered for the impact analysis. When the coefficient of restitution is employed for the impact analysis, the local deformation is not considered. For more accurate and reliable impact analysis, however, the local deformation should be considered. The effects of the location of collision and the collision mass on the impact duration time and the contact force magnitude are investigated through numerical studies employing Hertzian contact theory.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2003년도 추계학술대회논문집
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• pp.324-329
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• 2003

An air-conditioner has various noise sources such as cooling fan noise, pumping noise, flow noise and impact noise. Among these, impact noise is the most unpleasant source. This is because the noise is produced in indoor unit of air-conditioner. To control the noise source effectively, first we must identify the noise sources. When we identify impact noise source, the measurement have to be carried out simultaneously. So we use beamforming method that requires less measurement points than intensity method and acoustic holography. The objective of this paper is to estimate the location of impact source. This objective can be achieved by using minimum variance cepstrum that is able to detect impulse embedded in noise. In this study, modified beamforming method based on cepstrum domain is proposed. Then this method applied to air-conditioner noise sources which produce impact noise.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2012년도 추계학술대회 논문집
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• pp.715-722
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• 2012

A structural health monitoring (SHM) technique for locating impact position in a composite plate is presented in this paper. The technique employs a single sensor and spatial focusing properties of time reversal (TR) and inverse filtering (IF). We first examine the focusing effect of back-propagated signal at the impact position and its surroundings through simulation. Impact experiments are then carried out and the localization images are found using the TR and IF signal processing, respectively. Both techniques provide accurate impact location results. Compared to existing techniques for locating impact or acoustic emission source, the proposed methods have the benefits of using a single sensor and not requiring knowledge of material properties and geometry of structures. Furthermore, it does not depend on a particular mode of dispersive Lamb waves that is frequently used in the SHM of plate-like structures.

• 대한산업공학회지
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• 제7권2호
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• pp.19-26
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• 1981

A special case of the probabilistic multi-location problem is studied in a two-echelon logistic system for deteriorating items. The objective is to determine the location of the minimum number of supply centers among a discrete set of location sites of supply centers, such that the probability each retailer being covered by some supply center is not less than a specified value. A logistic cost is introduced as performance measure of the system, and leads us to analyze the impact of deterioration rate on the location problem. The results obtained from numerical examples are discussed, which provides effective guidelines that can be used for the logistic managerial decisions.

• 대한산업공학회지
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• 제26권4호
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• pp.384-391
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• 2000

Most of the previous works on classical location models are based on the assumption that the value(or utilities) of inventory remains constants over time. In this study a special case of location problem is studied for both ameliorating and deteriorating items in two-echelon supply-chain management such as agricultural and fishery products. The objective of this study is to determine the minimum number of storage facilities among a discrete set of location sites so that the probability for each customer to be covered is not less than a critical value. We have formulated this problem using stochastic set-covering problem which can be solved by 0-1 programming method. Also we developed a computer program and applied to a set of problems for fish culture storage and distribution centers and the sample results well show the impact of ameliorating and deteriorating rate on the location problem. For the further study, a graphical user-interface with visualization for input and output is needed to be developed.

• 한국멀티미디어학회논문지
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• 제17권8호
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• pp.977-987
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• 2014

Many of the recent performance evaluation of clustering schemes in wireless sensor networks considered one sink node operation and fixed sink node location without mentioning about any network application requirements. However, application environments have variable requirements about their networks. In addition, network performance is sufficiently influenced by different sink node location scenarios in multi-hop based network. We also know that sink location can influence to the sensor network performance evaluation because of changed multipath of sensor nodes and changed overload spots in multipath based wireless sensor network environment. Thus, the performance evaluation results are hard to trust because sensor network is easily changed their network connection through their routing algorithms. Therefore, we suggest that these schemes need to evaluate with different sink node location scenarios to show fair evaluation result. Under the results of that, network performance evaluation results are acknowledged by researchers. In this paper, we measured several clustering scheme's performance variations in accordance with various types of sink node location scenarios. As a result, in the case of the clustering scheme that did not consider various types of sink location scenarios, fair evaluation cannot be expected.

• Journal of Communications and Networks
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• 제14권4호
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• pp.396-409
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• 2012

With the proliferation of diverse wireless devices, there is an increasing concern about the security of location information which can be spoofed or disrupted by adversaries. This paper investigates the characterization and detection of location spoofing attacks, specifically those which are attempting to falsify (degrade) the position estimate through signal strength based attacks. Since the physical-layer approach identifies and assesses the security risk of position information based solely on using received signal strength (RSS), it is applicable to nearly any practical wireless network. In this paper, we characterize the impact of signal strength and beamforming attacks on range estimates and the resulting position estimate. It is shown that such attacks can be characterized by a scaling factor that biases the individual range estimators either uniformly or selectively. We then identify the more severe types of attacks, and develop an attack detection approach which does not rely on a priori knowledge (either statistical or environmental). The resulting approach, which exploits the dissimilar behavior of two RSS-based estimators when under attack, is shown to be effective at detecting both types of attacks with the detection rate increasing with the severity of the induced location error.