• Geotechnical Engineering
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• v.14 no.2
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• pp.107-126
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• 1998

Ground settlements induced by tunnel excavation cause the foundations of the neighboring building structures to deform. An expert system called NESASS( Neural network Expert System for Adjacent Structure Safety analysis) was developed to analyze the structural safety of such building structures. NESASS predicts the trend of ground settlements resulting from tunnel excavation and carries out a safety analysis for building structures on the basis of the predicted ground settlements. Using neural network technique. the NESASS learns the database consisting of the measured ground settlements collected from numerous actual fields and infers a settlement trend at the field of interest. The NESASS calculates the magnitudes of angular distortion, deflection ratio, and differential settlement of the structure. and in turn, determines the safety of the structure. In addition, the NESASS predicts the patterns of cracks to be formed in the structure, using Dulacska model for crack evaluation. In this study, the ground settlements measured from Seoul subway construction sites were collected and classified with respect to the major factors influencing ground settlement. Subsequently, a database of ground settlement due to tunnel excavation was built. A parametric study was performed to select the optimal neural network model for the database. A comparison of the ground settlement predicted by the NESASS with the measured ones indicates that the NESASS leads to reasonable predictions. The results of confidence evaluation for safety evaluation system of the NESASS are presented in this paper.

• Proceedings of the KIEE Conference
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• 2008.04a
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• pp.182-183
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• 2008

환기시설이 열악한 도시 지하철역 내의 대기환경은 지상보다 열악할 수밖에 없다. 현재 지하철역을 주로 사용하는 시민들의 안전을 보호 하고 지하철의 대기환경을 개선하기 위해 스크린 도어, 자동 제어 환기시설, 종합 영상 감지시스템 등 다양한 노력을 기울이고 있다. 하지만 일부 지하철역에 설치되어 있는 공기질 모니터링 시스템은 수입품에 의존하고 고가의 장비이므로 초기설치 비용뿐만 아니라 유지보수의 어려움을 겪고 있다. 본 논문에서는 이러한 문제점을 해결하기 위해 무선 센서 네트워크 기술을 적용하여 저가형 대기환경 모니터링 시스템을 개발했다. 이 시스템의 구성은 센서노드(ZED : ZigBee End Deice), 네트워크 코디네이터(ZCM : ZigBee Coordinator Modem), 수신서버로 구성된다. 지하철역 내부의 미세먼지, CO2, CO, 온습도, VOCs 데이터를 센싱할 수 있는 확장 센서보드를 설계한 후, 지하공간에서의 열악한 통신환경에서 QoS를 보장할 수 있도록 ZigBee 라우팅 기술을 이용한 센서노드(ZED)를 인터페이스하여 하나의 통합된 대기환경 센서 노드(ZED)를 개발했다. 또한 수신서버에 USB방식으로 연결되어 각각의 ZED로부터 데이터를 수신하는 센서노드(ZCM)과 전송된 데이터를 저장 및 처리하여 언제 어디서나 누구든지 인터넷을 통해 확인 가능하도록 지하철 대기환경 모니터링을 위한 수신서버를 개발했다.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.9 no.5
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• pp.53-63
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• 2009

This paper is to develop WiMAX CPE(wireless AP) that can provides Wi-Fi terminal with wireless Internet service by connecting to Wibro wireless network. This AP aims to support WiBro in upstream interface basically, and Wi-Fi and 100M Ethernet interface in downstream. So, we has developed the equipment for business that wireless ISP can provide many Internet customers with wireless Internet service by using Wi-Fi terminal in subway, car, ship, and so on, and the equipment for users that a user can purchase and then install in person. For the latter, multiple Wi-Fi terminals that be registered in WiBro service can be connected to Internet simultaneously.

• Korean Institute of Interior Design Journal
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• v.19 no.2
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• pp.15-23
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• 2010

First appeared in the 1970s, the underground shopping mall has been spreading across the country, and there reportedly exist 77 malls in the 2010. After over 30 decades operation, many underground shopping malls are now under the planning phase for renovation in many cities. This study considers the renovation issue of the underground shopping mall in the perspective of spatial re-configuration. A case is taken from Kangnam TerminalUnderground Shopping Mall in Seoul for detailed observation and suggestion. The monotonous and confusingspatial layout of the existing mall is investigated by observation methods. Based on the observation, a modifiedplan is suggested and evaluated by means of computer simulation program, Depth Map. The program mainly deals with visual network analysis in order to quantify the optical exposure in a given space. It is argued in this paper that the enhanced visual connectedness could affect the pedestrian performance positively in the shopping mall, and this leads to an easy and quick access to each shops in users' stand point. It is thought that this configurational solution for the remodelling of a specific case would be an effective reference for other malls in the country which are facing the similar problems.

• The KIPS Transactions:PartC
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• v.18C no.1
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• pp.45-50
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• 2011

Due to advances in wireless communications and portable terminals, any-time, any-where, and any-device Internet access is possible. In particular, Internet access in moving vehicles is an emerging and challenging issue. Even though a variety studies have been conduced for vehicular networks, little attention is paid to vehicular Wi-Fi networks where a Wi-Fi access point (AP) is installed at the vehicle and the AP is connected to an external base station (BS). In this paper, we conduct a measurement study on the uplink and downlink throughput for Internet access in vehicular Wi-Fi networks. We consider diverse network environments: high-speed train, car, and subway. Measurement results demonstrate that current Internet access in vehicular Wi-Fi networks are not satisfactory for interactive multimedia applications. Therefore, in-depth study on resource management in vehicular Wi-Fi networks is strongly required.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.3
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• pp.492-497
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• 2015

An overhead rigid conductor system is mainly applied to the subway and recently studies on the rigid system have been conducted for applications such as tunnels of high-speed line and speed improvement of a conventional lines up to 250km/h. Power feeding performance which is the most important in a rigid system can be measured by contact force and characteristics of this contact force are related to the shape and material of the R-BAR. In this paper, we analyze the measurements of contact force, current heating temperature, impedance of a rigid conductor which was developed in Korea, after that we compare static characteristics of home and abroad rigid conductors which have various shapes and materials.

• Proceedings of the KSR Conference
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• 2005.11a
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• pp.964-968
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• 2005

The standardization of information communication is doing a Internal each other connection and each other characteristic stability operation security in objective. From the low-speed network of the subway operation beginning currently it changes with the superhigh speed digital information transmission communication service environment which is a quality service, the hazard which plans the quality improvement of the efficient communication service use which hits to here and passenger service the standardization of the technical standard which stands and the improvement which hits to an engineering standard and facility must come to accomplish. The facility which existing is been old or the enclosure communication equipments which are insufficient. it improves, establishment itexpands efficiently, like this facilities it is stabilized and it is economic and rationally use maintenance it manages with the plan for the inside and outside of the country information communication relation technical standard and engineering standard service feature improvement and future expandability and economical efficiency, the possibility of having a pliability in order to be, rational technical standard and standard it takes a triangular position, efficient characteristic security of information communication service there is a place objective which promises the rational development of course city railroad communication system with character. Function improvement of enclosure communication base equipment, against an improvement and standardization plan it described trom the prosecution which it sees.

• Proceedings of the KSR Conference
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• 2006.11b
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• pp.407-413
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• 2006

Railways are very important to get stability of railway structure as transportation system carrying a lot of passengers and freight. These days the construction of underground railway crossing such as expansion of new roads, construction of subway and gas pipe is increasing because of economic and social development. But these kinds of construction didn't take into account Cost-benefit analysis of railway which has the most important aspects of railway safety, so the results of construction didn't get a good evaluation. This study adapt Cost-benefit analysis to evaluate the economic validity of underground railway crossing. This study adjust about Cost-benefit analysis of railway part, and analyze the new method and technology of underground railway crossing constructed by Korean National Railroad and Railway Network Authority. Also this study divide between high frequency line and low frequency lineusing B/C, NPV, and IRR analysis. After analysis, B/C ratio method is the most suitable method among B/C, NPV, and IRR analysis method. Therefore this study can express economic benefit quantitatively and decrease the cost by adapting Cost-benefit analysis, and can clearly express the construction feasibility and investment effects of construction of underground railway crossing method.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.29 no.1
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• pp.165-174
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• 2019

They are frequently used today in public places such as street, subway, school or library. Since users can sometimes print documents that contain confidential data using Printer Kiosks, the devices should store and manage the documents securely. In this paper, we identify potential security threats in Printer Kiosks and suggest practical attack scenarios that can take place. To show the feasibility of suggested attack, we analyzed network traffic that were generated by the real Printer Kiosk device. As a result of our analysis, we have found that attackers can access other users' scanned files and access other users' documents from Printer Kiosk's home page. We confirmed that using our attack, we could retrieve other users' personal data.

• Journal of the Korean Institute of Intelligent Systems
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• v.15 no.2
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• pp.149-162
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• 2005

This paper suggest a way to detect a specific wanted figure in public places such as subway stations and banks by comparing color face images extracted from the real time CCTV with the face images of designated specific figures. Assuming that the characteristic of the surveillance camera allows the face information in screens to change arbitrarily and to contain information on numerous faces, the accurate detection of the face area was focused. To solve this problem, the normalization work using subsampling with $20{\times}20$ pixels on arbitrary face images, which is based on the Perceptron Neural Network model suggested by R. Rosenblatt, created the effect of recogning the whole face. The optimal linear filter and the histogram shaper technique were employed to minimize the outside interference such as lightings and light. The addition operation of the egg-shaped masks was added to the pre-treatment process to minimize unnecessary work. The images finished with the pre-treatment process were divided into three reception fields and the information on the specific location of eyes, nose, and mouths was determined through the neural network. Furthermore, the precision of results was improved by constructing the three single-set network system with different initial values in a row.