• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.10a
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• pp.651-654
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• 2008

협대역 다중접속 방식의 한계를 벗어난 Ultra-wide band(UWB) 기술이 고속 데이터 전송을 위해 많이 개발되어지고 있다. UWB 시스템은 방사전력 제한을 두고 있어서 근거리 실내 무선통신 분야에서 활용 범위가 확대되고 있다. 하지만 실내 무선 환경에서는 벽, 천장, 바닥 그리고 실내에 위치한 장애물 등에 의한 다중경로 페이딩 영향으로 초고속 실내 무선통신 서비스를 제공하는데 어려움이 있다. 이러한 실내 다중경로 성분에 의한 페이딩을 경감시키는 여러 가지 방법 중에서 원형편파를 이용하면, 상대적으로 긴 지연을 갖는 강한 다중경로 성분을 효과적으로 제거할 수가 있기 때문에 수신신호의 RMS 지연 감소, 페이딩 경감 및 신호강도 개선효과 등을 얻을 수 있다. 본 논문에서는 원형편파를 고려한 수정된 UWB 채널의 파라미터를 수정 정립하였고, 수정된 채널모델을 UWB 시스템에 적용하여 성능 개선을 시도하였다.

• Proceedings of the Korea Information Processing Society Conference
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• 2021.05a
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• pp.560-563
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• 2021

본 논문에서는 사각형 실내 공간에서 점군 데이터를 기반으로 빠르고 정확하게 바닥, 천장, 벽면에 대한 평면 정보를 획득할 수 있는 시스템을 제안한다. 기존의 방법은 관측되지 않은 공간에 대한 평면을 예측할 수 없으며, 노이즈에 취약하고, 모든 점에 대한 기저 정보를 알아야하기 때문에 많은 연산량을 요구한다. 제안 방법은 기존의 평면 검출 방식에서 벗어나 Bounding Box 형상을 예측하는 기술을 활용한다. 또한, 제안 시스템은 구면 파노라마 비디오를 기반으로 적은 수의 프레임으로도 빠르게 실시간 점군 데이터를 확장해나간다. 제안 방법은 실험을 통해 기존의 방법보다 월등히 빠르고, 노이즈 등 환경 제약 요소에 강건함을 보인다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.26 no.3
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• pp.449-455
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• 2022

In this paper, we propose a position measuring system using trilateration based on the illuminance of a light-emitting diode (LED). Three LEDs are located on the ceiling of the virtual space, and each fixed coordinate is inputted to the monitoring program, and Length to the illuminance sensor is drawn through the relational expression of the length and illuminance value from the respective LED. Based on the derived length, the trilateration method is used to find object location information in virtual space. By using the least square equation to minimize the error of the length drawn to trilateration, the error is reduced to the utmost. Unlike the existing indoor positioning system using visible light communication (VLC), the proposed system does not require synchronization between the transmitter and the receiver, so the system can be configured simply.

• Journal of the Korean Institute of Intelligent Systems
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• v.15 no.5
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• pp.560-566
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• 2005

In this paper, a practical technique for correction of a distorted image for vision-based localization of ubiquitous mobile robot. The localization of mobile robot is essential and is realized by using camera vision system. In order to wide the view angle of camera, the vision system includes a fish-eye lens, which distorts the image. Because a mobile robot moves rapidly, the image processing should he fast to recognize the localization. Thus, we propose the practical correction technique for a distorted image, verify the Performance by experimental test.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2011.05a
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• pp.242-244
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• 2011

최근 넓은 창고에서 물품들을 좀 더 효율적으로 관리하기 위해 RFID(Radio Frequency Identification)를 이용한 창고관리시스템(Warehouse Management System)에 대한 연구가 활발히 진행되고 있다. 창고관리시스템에서 중요한 요소 중 하나는 물품의 정확한 위치파악이다. 특히 냉동 창고에서는 물품 보관을 하는 coldroom의 안팎 온도차이로 인한 물품의 적재위치 오류는 물품의 변질을 가져오게 하므로 실시간 정확한 위치를 파악하는 것이 중요한 요소가 된다. 기존의 연구방법들에서는 coldroom 입구에 RFID리더기를 설치하여 물품이 인식될 때 단지 그곳에 적재되는 것으로 인식하였다. 그러나 이러한 방법으로는 물품이 coldroom으로 들어가다 다시 돌아 나오는 경우, 반대로 물품이 밖으로 나가다 다시 들어오는 경우 등과 같은 상황에서는 물품의 위치가 잘못된 정보를 가지게 된다. 본 논문에서는 냉동 창고관리시스템에서 2대의 RFID리더기가 설치된 지게차를 이용하여 물품의 적재위치 정확성을 높이기 위한 방법을 제안한다. 지게차에 설치된 2개의 RFID리더기는 각각 천장에 부착된 태그로부터 위치데이터와 지게차에 적재된 물품데이터를 획득한다. 2개의 리더기로부터 수집된 데이터를 분석하여 물품의 입/출고 상황정보와 물품의 이동경로정보를 실시간으로 모니터링 할수 있다. 이를 통해 실시간 냉동 창고 적재위치 오류를 감지해 냄으로써 냉동 창고관리시스템의 물품보관에 대한 효율성을 높일 수 있게 된다.

• Fire Science and Engineering
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• v.25 no.6
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• pp.39-43
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• 2011

In this research, full-scale fire test was performed on a real house for the evaluation of the performance of waterworks direct-coupled sprinkler system. The fire was set to occur as spontaneous combustion as the cooking oil overheats. The size of house is $56m^2$ and it consists of a living room, a kitchen, and a room. In order to verify the performance of waterworks direct-coupled sprinkler system, it was installed in the kitchen. The result of the test showed that the fire started from the kitchen enlarged up to its ceiling but it was soon exhausted as the sprinkler started to work. The pressure of the waterworks was 0.28 MPa when the sprinkler operated, by which it verified that fire could go out even by waterworks pressure of the general residence.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2006.05a
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• pp.430-433
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• 2006

Wireless sensor network plays a prominent role in tracking the location of the target outdoor and indoor. This paper describes the implementation of the passive indoor location tracking system using ultrasonic and RF technologies that provides accurate location in the form of user space and position in three dimensions. Our system used a combination of RF and ultrasonic technologies to provide a location-support service to users and applicants. Ceiling-mounted beacons were spread through the building, publishing location information on an RF signal. The person carried a listener and the listener determined the location by calculating the distance from three beacons using triangulation algorithm.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.6
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• pp.1119-1123
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• 2006

Wireless sensor network plays a prominent role in tracking the location of the target outdoor or indoor. This paper describes the implementation of the passive indoor location tracking system using ultrasonic and RF technologies that provides accurate location in the form of user space and position in three dimensions. Our system used a combination of RF and ultrasonic technologies to provide a location-support service to users and applicants. Ceiling-mounted beacons were spread through the building, publishing location information on an RF signal. The person carried a listener and the listener determined the location by calculating the distance from three beacons using triangulation algorithm.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• autumn
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• pp.402-405
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• 2003

As Remodeling is proceed in the limited condition that is utilization of existing resource, the selection of remodeling objects and scope are affected by the correlation of building systems. Unexpected problems have occurred in construction phase by lack of the consideration about correlation of building systems; increasing of cost, delaying of schedule etc. Therefore, this research suggests the Building System Correlation Diagram Model and the method for selecting the alternative reasonably in remodeling project.

• Applied Chemistry for Engineering
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• v.20 no.5
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• pp.547-552
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• 2009

When fiber reinforced plastics (FRP) products are manufactured, dust and odor materials are inevitably generated in a workplace. To improve the bad condition of the workshop, we developed the Hybrid Bag Filter attached activated carbon fiber (ACF) and installed the system at two companies producing FRP goods. In order to raise the efficiency of dust collection, we set the ducts both on the ceiling and at the bottom of the wall and according to the circumstances of the workshop's space, moving dust collector also adopted as a different type of flexible duct. Pulse Jet Type Bag Filter is also equipped to operate the system more effectively, for the improved fine environment because of high dust removal efficiency. Finally, we investigated the removal tendency of the dust and odor when operating the System of Hybrid Bag Filter.