• 한국정보통신학회논문지
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• 제11권2호
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• pp.422-429
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• 2007

위치 인식 기능은 U-city를 구성하는 핵심 요소로서 U-city 기반 아파트 단지 등에서 상용화를 목적으로 활발히 연구, 개발되고 있다. 능동태그를 부착한 거주자나 자동차가 단지 내를 이동할 때 태그는 주기적으로 자신의 식별자를 방송하고 이를 받은 수신기들은 RSSI를 이용하여 태그의 위치를 계산한다. 문제는 수천세대 규모의 아파트 단지의 경우 동시 사용되는 태그수가 수 만개에 이르며 배터리 교체 없이 1년 이상 사용될 수 있어야 하므로 저전력 소모가 매우 중요하다는 것이다. 본 논문에서는 이러한 문제점을 고려한 U-city의 1) 위치 인식 시스템의 구성을 제안하고, 2) 능동 태그 방식으로 구현할 때 기술적 이슈를 제시하며, 3) 특히, 수만개의 태그들이 동작할 때의 성능을 수학적으로 모델링하고 실제 실험을 통해 비교 분석하였다. 이를 통하여 능동태그 시스템에서 발생하는 충돌확률의 이론적 최저값을 구하고 현장 적용시 적정 수준의 태그의 갯수를 제시하였다. 연구결과는 실제 U-city 위치인식 시스템의 상세 설계에 활용될 수 있다.

• Journal of Korean Neurosurgical Society
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• 제62권4호
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• pp.432-441
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• 2019

Objective : Few studies have reported direct comparative data of lumbar spine angles between direct lateral interbody fusion (DLIF) and oblique lateral interbody fusion (OLIF). The purpose of this study was to investigate the clinical and radiological outcomes of DLIF and OLIF, and determine influential factors. Methods : The same surgeon performed DLIF from May 2011 to August 2014 (n=201) and OLIF from September 2014 to September 2016 (n=142). Radiological parameters, cage height, cage angle (CA), cage width (CW), and cage location were assessed. We checked the cage location as the distance (mm) from the anterior margin of the disc space to the anterior metallic indicator of the cage in lateral images. Results : There were significant differences in intervertebral foramen height (FH; $22.0{\pm}2.4$ vs. $21.0{\pm}2.1mm$, p<0.001) and sagittal disc angle (SDA; $8.7{\pm}3.3$ vs. $11.3{\pm}3.2^{\circ}$, p<0.001) between the DLIF and OLIF groups at 7 days postoperatively. CA ($9.6{\pm}3.0$ vs. $8.1{\pm}2.9^{\circ}$, p<0.001) and CW ($21.2{\pm}1.6$ vs. $19.2{\pm}1.9mm$, p<0.001) were significantly larger in the OLIF group compared to the DLIF group. The cage location of the OLIF group was significantly more anterior than the DLIF group ($6.7{\pm}3.0$ vs. $9.1{\pm}3.6mm$, p<0.001). Cage subsidence at 1 year postoperatively was significantly worse in the DLIF group compared to the OLIF group ($1.0{\pm}1.5$ vs. $0.4{\pm}1.1mm$, p=0.001). Cage location was significantly correlated with postoperative FH (${\beta}=0.273$, p<0.001) and postoperative SDA (${\beta}=-0.358$, p<0.001). CA was significantly correlated with postoperative FH (${\beta}=-0.139$, p=0.044) and postoperative SDA (${\beta}=0.236$, p=0.001). Cage location (${\beta}=0.293$, p<0.001) and CW (${\beta}=-0.225$, p<0.001) were significantly correlated with cage subsidence. Conclusion : The cage location, CA, and CW seem to be important factors which result in the different-radiological outcomes between DLIF and OLIF.

• 지역연구
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• 제39권3호
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• pp.13-34
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• 2023

제주도는 전국 1% 수준에 불과한 지역내총생산(GRDP)을 증가시키고자 기업 육성 및 유치를 위해 다각적인 노력을 지속하고 있다. 기업의 입지 선택은 기업 성장에 영향을 미칠 수 있는 중대한 결정이다. 한 지역에 기업 입지가 집중된다면 그것은 그 지역 특성이 기업 이윤극대화에 도움이 된다는 것을 의미한다. 따라서, 기업이 선호하는 지역의 특성을 분석하고 그것을 기업 유치 정책에 반영할 수만 있다면 지역의 혁신과 발전을 유도하는데 도움이 될 것이다. 이에 본 연구는 제주지역 기업들의 입지분포를 살펴보고, 조건부 로짓 모형을 이용하여 제주도 읍면동별 지역 특성이 기업 입지 결정에 미치는 영향을 분석하였다. 분석 결과, 업종과 무관하게 제주지역 모든 기업은 다양한 업종의 기업이 밀집되어 있고, 경제활동인구가 많고, 인구밀도가 낮으며, 대중교통 혼잡도가 낮은 지역의 입지를 선호하는 것으로 나타났다. 그리고, 지식기반산업에 속한 기업은 동종기업들이 많이 위치한 지역을 선호하는 것으로 나타나, 집적 외부성을 중시하는 지식기반산업 특징이 제주지역 기업들에게도 나타나고 있음을 확인할 수 있었다. 본 연구는 그간 전무 하였던 제주지역을 대상으로 한 기업 입지 요인분석으로, 향후 제주지역의 기업·산업 육성 및 지역 발전 정책 수립을 위한 기초분석을 실시하였음에 의미를 찾을 수 있겠다.

• 산업경영시스템학회지
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• 제36권2호
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• pp.17-24
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• 2013

This paper is to analyze the picking lead time for picking batch size in a warehouse system and to get minimum picking batch size that is the warehouse system feasible. The warehouse system consists of aisles and racks, which two racks face each other through aisle. The products are picked from the storage locations by batch size. The probability that items are picked in the each row of the rack in the aisle for order picking activity is derived. The picking lead time for picking batch size is the time passed from the first picking location to arrival at starting location in aisle picking all items included in a batch size. The picking lead time for picking batch size in an aisle is analyzed. The picking lead time for picking batch size in the whole warehouse system is obtained. The warehouse system is feasible if all items that customers order are picked from the storage locations for same period. The picking batch size that is the warehouse system feasible is obtained. The problem is analyzed, a solution procedure is developed, and a numerical example is shown to explain the problem.

• 한국정보통신학회논문지
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• 제15권11호
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• pp.2419-2425
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• 2011

현재 스마트폰 가입자는 1500만 명을 넘어 연말까지 2천만 명을 넘길 것으로 예상하고 있다. 스마트폰의 보급은 새로운 패러다임과 긍정적인 결과도 주었지만, 대인 관계를 멀리하고 스마트폰에만 열중하는 결과를 양산해냈다. 본 논문에서는 안드로이드 OS를 기반으로 개개인의 위치 정보를 이용해 동일한 애플리케이션을 이용하는 사용자간의 관계 형성 서비스를 설계하고 구현한다.

• 디지털융복합연구
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• 제11권12호
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• pp.821-828
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• 2013

본 논문에서 제안한 문화유산 체험학습에 최적화된 스마트폰 APP인 CHELS-App은 단순한 관광지안내 서비스를 벗어나 스마트폰을 활용하여 문화유산을 체험하고 제시되는 퀘스트를 통하여 미션을 즐기면서 학습과 관광을 동시에 체험할 수 있도록 구성하였다. CHELS-App은 세계문화유산으로 지정되어 있는 종묘를 대상으로 위치기반 서비스를 이용한 안내지도와 이벤트 푸쉬기능을 이용한 현장에서의 다양한 문화해설(해설, 사진, 퀴즈, 게임, 카툰)을 제공하고 이러한 체험을 통한 발도장 기능, 체험일지 작성 기능을 구성하였다.

• 디지털산업정보학회논문지
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• 제12권3호
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• pp.157-166
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• 2016

This paper presents the interior space information using 6D-360 degree immersive media video information. And we implement the augmented reality, which includes a variety of information such as position information, movement information of the specific location in the interior space GPS signal does not reach the position information. Augmented reality containing the 6D-360 degree immersive media video information provides the position information and the three dimensional space image information to identify the exact location of a user in an interior space of a moving object as well as a fixed interior space. This paper constitutes a three dimensional image database based on the 6D-360 degree immersive media video information and provides augmented reality service. Therefore, to map the various information to 6D-360 degree immersive media video information, the user can check the plant in the same environment as the actual. It suggests the augmented reality service for the emergency escape and repair to the passengers and employees.

• 한국주거학회논문집
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• 제21권2호
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• pp.41-48
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• 2010

This study shows how the water space outside the housing impacts the indoor thermal environment. CFD simulation was used for this experiment to analyze the interior environment focusing on the effect of temperature control and the thermal comfort. A shape of perfect square, which creates the very basic space formation, was used and the simulation was processed looking at the size, distance, and the location of the water space. The results of the experiment are as follows. Firstly, introducing a water space with the same floor area size of the simulation model decreased the indoor temperature by 1 Celsius (3.72%). It was determined the interior environment was considered as a comfort zone when the water space was greater than 70% of the floor area. Secondly, there was not much influence to the level of thermal comfort of the interior environment when the distance to the water space from the housing was greater than 2 meters. Lastly, interpreting the location of water space, the effect of controlling the total areas' temperature was the greatest following with the surrounding of the formation. There barely was any change to the temperature considering the side and the rear of the area.

• 한국가구학회지
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• 제20권4호
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• pp.281-289
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• 2009

This research examined the technical feasibility of composite that had two layers of fiberglass reinforcement to enhance the load carrying capacity of lumber. Specimens were prepared from standard lumber made of thinning crop trees such as Larix kaempferi, Pinus koraiensis, and P. rigida. Results indicated that bending properties, hardness, and wood screw withdrawal load of low density lumber from the P. koraiensis increased as the number of layers of fiberglass reinforcement increased. Composite produced by VARTM method showed the MOE increased in all specimens, while the MOR differed on the location, whether the 2-layers of FRP is put on tensile zone or compressive zone. The MOR of high density lumber from Larix kaempferi and P. rigida decreased when they placed into tensile zone, but low density lumber from P. koraiensis increased in same location. The bending toughness only increased high density lumber of Larix kaempferi as the number of layers of fiberglass reinforcement increased. The technique developed by this study may increase an opportunity to use small diameter log with low density for commercial purposes.

• Design & Manufacturing
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• 제2권6호
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• pp.49-55
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• 2008

Double-injection molding can inject two different materials or two colors in the same mold and process. If this injection process use, product has ability because the base part maintain strength and specified part can inject soft-material. It makes the cost down by single operation automatically for saving wages. In this paper, we designed double-injection mold for automobile remote control to inject secondary using this part as insert after inject external appearance of product. CAE analysis was progressed gate location and runner size as variable and analysis result is reflected in mold design process. As a result, it could solved badness that is generated at the conventional mold. Additionally, cost is downed by reducing loss of runner as well as could omit painting process because surface of finished product is improved through new mold.