• Journal of Korean Society of Transportation
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• v.20 no.4
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• pp.123-134
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• 2002

감응식 신호운영변수 설계에 관한 연구는 정주기식 신호운영변수 설계의 그것보다 그 수준이 현저히 미비하며 이는 감응식 신호운영 특성을 반영한 평가방법의 부재로 감응식 운영변수의 평가가 불가능하였기 때문이다. 본 논문은 최근에 소개된 평균 감응현시 녹색시간 추정 수리모형을 이용하여 Highway Capacity Manual (HCM) 지체도를 최소화하는 최대녹색시간의 설계방안을 제시한다. - '최소녹색시간'과 '단위연장시간'은 보행자 횡단시간 및 차량 차두시간 등 지역별 운전자/보행자의 특성과 관련이 있어 일반적인 최적화 설계 수리모형의 적용에 무리가 있어 제외한다. 제안된 설계방안은 감응식 운영논리를 토대로 감응현시 군의 평균녹색시간과 평균주기를 산정하며, HCM 지체도를 평가하고, 가능한 대안 중 지체를 최소화하는 최대녹색시간 운영변수 군을 '혼혈 유전자 알고리즘'으로 도출한다. 현장실험을 통해 도출이 불가능한 실제 최적치를 Corridor Simulation(CORSIM)모형을 이용하여 추정하였고 이를 제안된 설계방안으로 도출된 최대녹색시간 운영변수' 값들과 비교하였다. 비교결과 교차로 v/c 비율이 1.0 보다 낮을 시는 제안된 방법을 통해 설계된 최대녹색시간 운영변수 군이 최소 CORSIM 지체도를 산출하는 최대녹색시간 운영변수 군과 동일한 것으로, v/c비율이 1.0보다 높을 시는 다른 것으로 결과되었다. v/c비율이 1.0 보다 높은 경우는 정주기식 교차로 운영에 효율적이라 감응식 운영의 필요를 벗어나므로 제안된 최대녹색시간 설계방안은 감응식 신호운영 필요범위 내에서 효율적이다. 기존의 최대녹색시간 설계는 정수기식 최적녹색시간을 기준으로 최대녹색시간을 추정하며, 그러한 과정을 돕기 위하여 추정범위(설계자가 범위 내에서 임의로 선택함)를 제시하는 것이 기존의 연구임을 비교하면 본 연구에서 제안하고 있는 설계방법의 의미가 크다.

• Journal of Korean Society of Transportation
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• v.20 no.5
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• pp.23-31
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• 2002

The headway of vehicles entering an intersection is closely related with the saturation flow rate and is a basic parameter required for determining the saturation headway and the start-up lost delay. Since such headway value reflects the drivers' behaviors and features of the intersection, all intersections don't have an equal value, but are affected by number and location of their lanes, changing types, local characteristics and time zone. Accordingly, this study attempted to suggest proper values on the basis of data by investigating headway in lanes. Number of exclusive through lanes was divided into single lane, double lanes and triple lanes, the locations of lanes were divided into inside lane, central lane and outside lane. As a result of investigating the headway, single through lane, double through lanes-inside lane, and triple through lane-outside lane showed as 1.73 sec., 1.71 sec. and 1.93sec., respectively. The result of calculating the area factor of business areas by fixing 1.00 for the residental area and applying relation between headway and saturation flow rate was 0.96. In the case of start-up lost delay lead dual left turn and directional separation were 1.41 sec. and 3.27 sec., respectively, showing the great difference. Therefore, different start-up lost delay according to changing type should be applied.

• Korean Journal of Construction Engineering and Management
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• v.6 no.1 s.23
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• pp.65-72
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• 2005

The 3D objects far representing artificial element in building project can be easily organized in 4D system. However, the civil engineering projects need a composing technology of irregular triangulate network because the projects generally include earthwork of large scale that consists of cutting, filling, and excavating work. It Is very difficult to represent earthwork status as 3D object type because the earthwork in highway or railway projects is being progressed on the natural geographical features. That is, a composing technology of irregular triangulate networks necessary function to simulate natural site condition as 3D object in 4D system. This study suggests a new composing technology of irregular triangulate network that 3D objects can be automatically generated by attribute in each layer.

• Journal of the Korean Society for Railway
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• v.18 no.5
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• pp.426-438
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• 2015

Train speed controlling systems are now changing from wayside systems to onboard signaling systems. Locomotive engineers refer to wayside markers to decide on a braking point when the train speed appears to be lower than the current speed. However, in the onboard signaling systems that have been installed recently, the braking point is not determined by the wayside signal but by an onboard value. In this paper, we studied braking points and methods for deciding on such points by engineers using the onboard systems. An optimized braking point is proposed via simulation of decelerating velocity to control the velocity in the signaling system through a predefined point; Gaussian distributions are used to simulate the actual situation. We estimated and demonstrated how to obtain braking parameters in order to satisfy the interval of permitted error.

• International Commerce and Information Review
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• v.14 no.2
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• pp.317-346
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• 2012

Korea's export economy across all industries are affected by the rise of China. The field of cosmetics can not be an exception. Expansion of the export of Chinese cosmetic goods can bring a greater concern to the export of Korea. Therefore, comparing the competitiveness of cosmetics in China and Korea will propose Implications for export growth strategy. To this end, comparing Korea cosmetic product's competitiveness with China, Revealed Comparative Advantage Index (RCA), Trade Specialization Index (TSI) and the status of import and export countries were comprehensively analyzed. In the case of Korea, items that have a competitive over China were No. 330499 and No. 330510. The following items in proportion were No. 330430 and No. 330590. By strengthening its position of these four items as major export items of Korea Cosmetics, export growth strategy in China and other markets around the world is needed.

• Journal of Navigation and Port Research
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• v.37 no.6
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• pp.719-725
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• 2013

Northeast Asia region is becoming the hub of world trade with China as the center. Integration of this region's economy is now visualized, domestic trade and international division of labor will be more invigorated. Especially on electrical and electronics industry is a large proportion of the trading volume between Korea and China and now, Present condition of electrical and electronics trading industry can effect on whole trading industry. In this study, conducting analysis of the current Korea-China electrical and electronics industry trading and advanced research, and find out the implication to trading volume with the panel analysis. As the results Korean/Chinese GDP, revealed comparative advantage, and foreign direct investment have an effect on the trading volume.

• Journal of Korean Society of Transportation
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• v.24 no.5 s.91
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• pp.123-133
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• 2006

Seoul and many large cities in Korea have implemented Median Exclusive Bus Lane(MEB). But exclusive bus lane in the middle of the road caused new contradictions between left turn movement and through bus movement and several signal operation techniques like 'left turn Protected' and 'overlap phase' couldn't be applied in intersections on MEB. We suggest 'Bus-only Signal for median lane technique as solution of these problems This study presents optimum signal time design process and detailed algorithms for intersections where bus-only signals are installed. As a test field. we took Yang-Je intersection where Median Exclusive Bus Lane go through. and have large gap in volume of left turn in main direction. And we verified that revised optimum signal time including overlap phase can reduce average delay time of vehicle through before and after simulation.

• International Area Studies Review
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• v.18 no.3
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• pp.205-229
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• 2014

Global production networks (GPNs) emerged as multinational companies strategically relocated different stages of their value chain over many regions. Since GPNs require moving materials, parts, components and finished products across national borders multiple times, as well as coordinating it efficiently, they are intensified further within an integrated region. Within the region, developed countries which enjoy a comparative advantage in higher value-added tasks specialize in the production of ICT parts and components and exhibit high export RCA indices while developing countries show high import RCA indices. But, as developing countries upgrade technological capabilities and achieve industrial upgrading through participation in GPNs, their level of sophistication improves. East Asian countries have participated in GPNs to a greater degree when compared to countries in other regions because of a variety of factors. They have benefited much as shown by a significant increase in the level of ICT sophistication and export shares, which in turn led to uneven regional developments of GPNs in the ICT parts and components industry.

• International Area Studies Review
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• v.13 no.2
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• pp.643-666
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• 2009

When it comes to current balance, both of Korea and China enjoy the trade surplus in goods while both countries suffer trade deficit in service. This facts demonstrate that two countries have comparative disadvantages in service industry. In order to identify the international competitiveness of trade in service between Korea and China, several indexes such as TSI, RSCA and IMS was calculated, using the IMF's balance of payments (BOP) statistics as proxy. The results of this analysis are as follows. Korea has a comparative advantage in four sectors (Transportation services, Financial services, Royalties & license fees and Personal cultural recreation), while China has a comparative advantage in five sectors (Travel, Communication services, Insurance services, Computer & information services and Other Business services). Construction services are indeterminate. However, the competitiveness of the two sectors-communication and computer & information-which China has a comparative advantage will be transferred to Korea if some effort to reinforce the competitiveness is added because the gap is being narrowed.

• Journal of the korean Society of Automotive Engineers
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• v.7 no.1
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• pp.12-17
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• 1985

주위기체와 다른 기체를 간헐적으로 또는 단발로 분사한 경우, 분류내의 분사체의 농도는 시간에 따라 급격히 변화한다. 수ms인 전자식기체 채취밸브를 이용해서 기체를 채취하고, 가스마토그 라프 등에 의해 가스분석을 행하는 방법이 있고 주로 피스톤식 내연기관의 연소실내 농도의 측 정에 이용되고 있다. 이 방법은 밸브 열립시간을 단축시켜도 약 1ms가 한도이고 시간분해능력도 1ms정도가 최단시간이다. 또 동일한 장소에서 농도의 시간경과를 얻는 데에는 각각의 시간에 대해서 기체의 채취와 분석을 행하지 않으면 안되어 실제시간의 농도측정이 불가능하다는 결점이 있다. 최근 레이저 응용기술의 진보에 의해 라만산란, 레리산란, CARS법 등의 농도순간측정이 가능해지고 있고, 점차 현실화되어가고 있다. 이들의 방법은 국소의 순간농도뿐만 아니라 온도의 동시측정도 가능하게 하는 특징을 갖고있다. 그러나 레이저에 의한 측정장치는 현시정에서는 아직 가격이 고가이고 광학계의 설치 등, 실험상의 조작이 복잡한 것 등의 결점을 갖고 있다. 본 고에서는 최근 진전이 현저하고 실용화에 대한 확신을 갖고 있는 열선농도Probe에 의한 순간농 도의 측정방법을 소개하고자 한다.