• 한국터널지하공간학회 논문집
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• 제17권1호
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• pp.1-9
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• 2015

본 논문은 터널 조명 시스템을 적절하게 운영하기 위하여, 터널 내부/외부의 휘도를 측정하는 영상휘도계의 개발 내용을 소개한다. 터널을 측정하는 국제규격 CIE88의 L20법 및 광막법이 구현 가능하도록 개발하였으나 현재 주로 적용되는 L20법을 위주로 실험하였다. 독립적 운영을 위하여 컴퓨터가 내장되었으며 외부와는 이더넷 통신으로 연결된다. 내부에 자동 온도조절 기능과 앞면유리의 열선과 와이퍼 시스템이 구축되었다. 정확한 휘도 측정을 위하여 노출시간과 휘도량에 따른 비선형 특성을 보정하는 수식이 적용되었다. 개발된 휘도계의 공인기관 교정결과는 1%미만의 오차를 보여주었다. 개발된 휘도계를 이용하여 실제 터널에서 실험을 하였고, 실험결과 기준 휘도계측기들과 유사한 특성을 보였으며, 매우 안정적으로 작동함을 볼 수 있었다. 다만, 부분적 고휘도로 인한 센서 포화에 의한 측정오차를 해결하는 과제는 남아 있다.

• World Technopolis Review
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• 제2권2호
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• pp.96-108
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• 2013

Egypt has been known as the light house of science and innovation not only in the Middle East but to the world across ages. Recently, there have been many ups and downs that positioned Egypt in a lower rank that it actually deserves according to its long history. This review entitles the current condition of science, technology and innovation in Egypt and the consequent setting up of best practices of science and technology parks (STPs) experiences. Egypt's science, technology and innovation (STI) system is highly centralized and dominated by the public sector, with R&D happening mostly in state-run universities and research centers supervised by the Ministry of Higher Education and Ministry of Scientific Research. R&D indicators state that Egypt ranking is 40th worldwide for the published articles (around 10,000 papers in 2011), while the numbers of issued patents (350 local and 50 international in 2011) is still far beyond expected. STPs in Egypt are addressed in this review by three examples; smart village in Cairo, Investment zone in Borg El-Arab City and Technology Valley in Ismailia. The three models are discussed in details and a suggested road map for developing more STPs is estimated.

• Composites Research
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• 제26권4호
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• pp.223-229
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• 2013

본 연구에서는 자동차가 불규칙한 노면을 주행 시 받게 되는 충격으로 인하여 마운트 상단에 발생하는 영구변형을 방지하고자 하이브리드 복합재료를 사용한 스트럿 타워를 설계하였다. 타이어와 현가장치에서 흡수 가능한 에너지량을 초과하였을 시 잔류 충격은 마운트로 전이되며, 특히 고속주행성능을 향상시키기 위하여 강직한 현가장치를 도입한 경우, 에너지 흡수량 저하로 인하여 기존의 스트럿 타워가 쉽게 변형될 수 있다. 유한요소해석을 통하여 압연강판과 탄소섬유 복합재료로 이루어진 하이브리드 복합재료 스트럿 타워의 최적설계를 진행하였으며, 낙하충격시험을 실시하여 동적 거동을 연구하였다. 또한 3차원 형상측정과 초음파 비파괴 검사방법을 이용하여 스트럿 타워의 손상 유무를 확인하였다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제10권6호
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• pp.2483-2503
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• 2016

Traffic congestion is a severe problem in many modern cities around the world. Real-time and accurate traffic congestion identification can provide the advanced traffic management systems with a reliable basis to take measurements. The most used data sources for traffic congestion are loop detector, GPS data, and video surveillance. Video based traffic monitoring systems have gained much attention due to their enormous advantages, such as low cost, flexibility to redesign the system and providing a rich information source for human understanding. In general, most existing video based systems for monitoring road traffic rely on stationary cameras and multiple vehicle tracking method. However, most commonly used multiple vehicle tracking methods are lack of effective track initiation schemes. Based on the motion of the vehicle usually obeys constant velocity model, a novel vehicle recognition method is proposed. The state of recognized vehicle is sent to the GM-PHD filter as birth target. In this way, we relieve the insensitive of GM-PHD filter for new entering vehicle. Combining with the advanced vehicle detection and data association techniques, this multiple vehicle tracking method is used to identify traffic congestion. It can be implemented in real-time with high accuracy and robustness. The advantages of our proposed method are validated on four real traffic data.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 1999년도 가을 학술발표회 논문집
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• pp.293-300
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• 1999

Soilcrete has been the traditional material for the paving and soft ground improvement techniques. But because the durability is not excellent and the quality is not homogeneous, it has not been used for the various purposes up to date. And because the quality of soilcrete is apt to be changed by the content of water and soil stabilizer, and the kind of soil and soil stabilizer, it is not free of cares. But with the increase of naturally oriented needs for the light traffic road such as pedestrian roads of the garden, golf courses and sidewalks, the cases of soilcrete paving has been increased recently. This study aims at making the reference table of the mix design in accordance with the required design specifications for the soilcrete admixtures by the FGC soil stabilizer by using the statistical experiment method. The treated soil is the clay which are widely spreaded in Korea. As the results of this study we can derive the effective reference mix design table for the clay soil treated by the FGC soil stabilizer in accordance with the compressive strength of 50∼200kg/$\textrm{cm}^2$ soilcrete with respect to the contents of water, soil stabilizer and fine sand.

• 한국수소및신에너지학회논문집
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• 제17권1호
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• pp.55-61
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• 2006

신규 $Nb_2Zr_6O_{17-x}N_x$ 광촉매를 고상합성법처리(solid state synthesis) 후 암모니아가스($NH_3$)에 의한 기상처리법(ammonolysis)으로 합성하였다. 합성된 신규 광촉매 및 이를 다시 Pt 및 $RuO_2$를 도핑 하여 $H_2S$를 광분해하여 수소를 발생 실험을 수행하였다. 이 신규 oxynitrid계 광촉매는 가시광하에서 $H_2S$를 광분해하여 수소를 발생하는(Quantum yield = 13.5 %) 우수한 광촉매 활성을 보여주었다.

• International Journal of Aeronautical and Space Sciences
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• 제17권1호
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• pp.29-36
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• 2016

Tensairity girder is a light weight inflatable fabric structural concept which can be used in road emergency transportation. It uses low pressure air to stabilize compression elements against buckling. With the purpose of obtaining the comprehensive target of minimum deflection and weight under ultimate load, the cross-section and the inner pressure of tensairity girder was optimized in this paper. The Variable Complexity Modeling (VCM) method was used in this paper combining the Kriging approximate method with the Finite Element Analysis (FEA) method, which was implemented by ABAQUS. In the Kriging method, the sample points of the surrogate model were outlined by Design of Experiment (DOE) technique based on Optimal Latin Hypercube. The optimization framework was constructed in iSIGHT with a global optimization method, Multi-Island Genetic Algorithm (MIGA), followed by a local optimization method, Sequential Quadratic Program (SQP). The result of the optimization gives a prominent conceptual design of the tensairity girder, which approves the solution architecture of VCM is feasible and efficient. Furthermore, a useful trend of sensitivity between optimization variables and responses was performed to guide future design. It was proved that the inner pressure is the key parameter to balance the maximum Von Mises stress and deflection on tensairity girder, and the parameters of cross section impact the mass of tensairity girder obviously.

• International Journal of Automotive Technology
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• 제6권6호
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• pp.671-676
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• 2005

Spring is one of major suspension part of the light commercial vehicle (LCV). In the manufacturing process it is shot-peened to improve its fatigue strength. In this paper, residual stresses by shot peening were calculated through finite element analysis, and the effects of these residual stresses on fatigue strength of leaf spring were evaluated. Fatigue tests were performed with two kinds of specimens; one is actual leaf spring assembly, and the other is simulated 3-point bending specimen. Fatigue tests were performed under the loading condition that was measured on the proving ground. From the results, the maximum load-fatigue life relation of leaf spring was defined, and test results of 3 point bending specimen are in good agreement with those of leaf spring assembly. The effects of residual stresses by shot peening on fatigue strength of leaf spring is not large in the high load range, however, in the low load range, its effects were not negligible.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 춘계학술대회 논문집
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• pp.233-237
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• 2002

Vehicle Dynamics Control(VDC) has been a breakthrough and become a new terminology for the safety of a driver and improvement of vehicle handling. This paper examines the usefulness of a brake steer system (BSS), which uses differential brake forces for steering intervention in the context of VDC. In order to help the car to turn, a yaw moment can be achieved by altering the left/light and front/rear brake distribution. The steering function achieved through BSS can then be used to control lateral position in an unintended road departure system. A 8-DOF non-linear vehicle model including STI tire model will be validated using the equations of motion of the vehicle, and the non-linear vehicle dynamics. Since Fuzzy logic can consider the nonlinear effect of vehicle modeling, Fuzzy controller is designed to explore BSS feasibility, by modifying the brake distribution through the control of the yaw rate of the vehicle. The control strategies developed will be tested by simulation of a variety of situation; the possibility of VDC using BSS is verified in this paper.

• 대한교통학회지
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• 제14권3호
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• pp.45-59
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• 1996

The shortest path algorithm for route guidance is implicitly required not only to support geometrical variations of transportation network such as U-TURN or P-TURN but to efficiency search reasonable routes in searching mechanism. The purpose of this paper is to integrate such two requirements ; that is, to allow U-TURN and P-TURN possibilities and to cut down searching time in locating routes between two points (origin and destination) in networks. We also propose a new type of link searching algorithm which can solve the limitation of vine building algorithm at consecutively left-turn prohibited intersections. The test site is a block of Gangnam road network that has some left-turn prohibited and allowed U-TURN intersections. Four models have been identified to be comparatively analyzed in terms of searching efficiency. The Models are as follows : (i) Model 1 - Link Searching Dijkstra Algorithm without Searching Area Extraction (SAE) ; (ii) Model 2 - Link Searching Dijkstra Algorithm with SAE ; (iii) Model 3 - Link Searching Bidirectional Dijkstra Algorithm without SAE ; and (iv) Model 4 - Link Searching Bidirectional Dijkstra Algorithm with SAE. The results of comparative evaluation show that Model 4 can effectively find optimum path faster than any other models as expected. Some discussions and future research agenda have been presented in the light of dynamic route guidance application of the urban ATIS.