• Journal of Korean Society of Transportation
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• v.26 no.5
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• pp.185-194
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• 2008

The objective of this paper is to design the dynamic route guidance system(DRGS) and develop an ant algorithm based on routing mechanism for finding the multiple shortest paths within limited time in real traffic network. The proposed ant algorithm finds a collection of paths between source and destination considering turn-restrictions, U-turn, and P-turn until an acceptable solution is reached. This method can consider traffic constraints easily comparing to the conventional shortest paths algorithms.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.8 no.6
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• pp.1673-1681
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• 2007

The u-Learning just begins to emerge as the next-generation knowledge-based business. Since it has a great potential to become a high value-added industry, there is much attention paid in this field. In this work, we first summarized the concept of the u-Learning where the architecture of various u-learning areas has been identified. Then we investigated the current status and problems of the u-Learning industry. Through the SWOT analysis, we have extracted the political strategies that will be essential for the rapid industrialization of u-Learning which will, in turn, contribute much to enhance the competitiveness of national economy.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.3
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• pp.663-668
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• 2010

In driving a car, turns such as left turns, right turns, or u-turns, make the speed of the car decrease considerably. A more straight path, therefore, is probably faster to arrive at the destination than zig-zag path with same distance. In this paper, we have newly proposed the turn heuristic to make more straight path. The path navigation algorithm with turn heuristic(called as TA* algorithm) could enhance the straightness of a path by putting the turned-edges to the turn cost. It requires higher cost to use TA* algorithm than traditional A* algorithm because the straight-edge first searching have increased the search space. We have improved the TA* algorithm into the variable TA* algorithm(called as VTA* algorithm) which adopt the turn-heuristic during the a portion of the whole path.

• 한국정보통신설비학회:학술대회논문집
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• 2008.08a
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• pp.277-280
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• 2008

Starting from 2005, as the new city paradigm, the term 'u-City' was created in Korea. U-City service, as defined in "u-City law", is a service that connects and intermediates among government, traffic, welfare, environment, disaster mitigation, etc., and their data based on ubiquitous city technology and infrastructure. According to the survey executed by local governments, the improvements in the standard of living of citizens have in turn increased the needs for anti-mitigation services. Such trend is bolstered with the recent disasters such as the conflagration of Korean Soong-rae Gate and the devastating earthquake of Sichuan province. This article describes a concept of the u-City disaster prevention service and looks into the activities and planning of u-City disaster prevention service of local governments. This paper also briefly looks into the law and policies to derive the needs of u-City disaster prevention service as well as the current technologies and u-City disaster prevention services of local governments. Ultimately, this paper offers the strategic direction of developing u-Disaster Prevention City.

• The Journal of the Korea institute of electronic communication sciences
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• v.11 no.5
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• pp.531-538
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• 2016

Driving behaviors such as speeding and illegal u-turn which violate traffic rules are main causes of car accidents, and they can lead to serious accidents. Bus drivers are less aware of dangers of illegal u-turn, and infrastructures such as traffic enforcement equipment and watchmen are deficient. This research aims to develop technology for estimating driving behaviors based on map-matching in order to prevent illegal u-turns. For this research, 23,782 of u-turn permit data and 146,000 of speed limit data are collected nationwide, and an estimation algorithm is built with these data. Then, an application based on android is developed, and finally, tests are conducted to assess the accuracy in data computations and GPS data map-matching, and to extrapolate driving behavior. As a result of the tests, the accuracy results in the map-matching is 86% and the assessment of driving behavior is 83%, while the display of the data output yielded 100% accuracy. Additional research should focus on improvement in accuracy through the development of a robust monitoring system, and study of service scenarios for technology application.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2010.04a
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• pp.363-365
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• 2010

In this study, based on numerical map GIS-T Dataset build and by using ArcGIS Network Analysis emergency vehicle's reach time were analyzed. AutoCad using 1: 50,000 based on roads and hospitals of numerical map were creating a Polyline and Point and Network Dataset made using ArcCatalog. ArcGIS Analysis setting the interval for the period reached 3 minutes, 5 minutes, 15 minutes was set and then U-Turn was set to not allow because U-turn takes a long time to calculate and does not happen often on the real road. Intersection of the passage of time, considering that the emergency vehicles were set to 3 seconds. To expand by taking advantage of this facility on Vulnerable area will be used as base material. If we focus on analyzing the emergency activity to convert little data, To prepare for disaster and disaster will be able to use the materials.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.8 no.3
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• pp.454-462
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• 1998

Mechanisms and conditions for rounding of AUC particles were examined during AUC precipitation. Rounding of AUC particle was possible only by external circulation using pump, not by internal circulation using agitator. The rate of AUC rounding $(dn_p/dt)$ was proporational to operation conditions such as magma density $(M_t:g-U/{\iota}l)$, turn over ratio $(T_o)$ and impeller tip velocity of pump (U); $ dn_p/dt{\propto}M_t{\cdot}T_o{\cdot}U^2$. The validity of this relationship was qualitatively confirmed by comparing the expermental results. Two rounding mechanisms were suggested. One is crack formation mechanism and the other etch-pit formation mechanism on the surface of AUC particle. It was found that the crack formation is more dominant at the initial stage and the etch-pit formation at the final stage of the AUC precipitation.

• Journal of Korean Society of Transportation
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• v.16 no.2
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• pp.157-167
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• 1998

건설된 도로를 효율적으로 이용하고, 통행자의 편리성을 향상시키기 위해 첨단 여행자 정보체계(ATIS)를 활용할 수 있다. ATIS 체계하에서 노선정보를 통행자에게 제공하기 위해서는 교차로에서의 회전으로 인한 지체를 정확하게 반영할 수 있는 효율적인 최단경로 알고리즘이 필요하다. 하지만 기존의 최단경로탐색 알고리즘은 좌회전 금지, U-turn, P-turn 등 교차로에서의 회전으로 인한 지체를 정확히 반영 못한다는 단점을 갖고 있다. 그러므로 본 논문에서는 이러한 단점을 극복하기 위해 수정형 덩굴망 알고리즘을 재발하였다. 수정형 덩굴망 알고리즘은 노드표지(node labelling) 방법에 있어서는 기존의 덩굴망 알고리즘의 노드표지 방법과 개념적으로 동일하여 이용상의 편리성을 갖도록 하였으며, 최단경로 탐색기능에 있어서는 링크탐색알고리즘(혹은 링크표지기법)이 갖고 있는 장잠을 다 반영할 수 있는 기법으로 개발하였다. 수정형 덩굴망 알고리즘은 노드표지에 있어 특정 노드로 유입하는 방향에 따라 노드표지를 별도로 기록하였다. 따라서 교차로에서의 좌회전, 우회전 및 직진은 물론 U-turn의 경우에도 추가적인 절차 없이 현실적인 최단 경로를 탐색할 수 있도록 하였다. 또한 본 논문은 최단경로의 역추적 방법을 개선하여 좌회전 금지, U-turn, P-turn 및 기타 회전에 의한 지체등을 각 교차로마다 정확히 반영함으로써 비합리적인 최단경로가 추적되는 것을 근본적으로 차단하도록 하였다. 따라서 본 연구에서 개발한 수정형 덩굴망 최단경로탐색 알고리즘은 교차로에서의 회전지체 및 회전금지를 현실적으로 잘 반영함으로써 정확한 노선정보를 요구하는 ATIS체계를 분석하는데 유용하게 활용될 수 있는 기법이다.장자료를 통해 구하기란 현실적으로 불가능하므로, 본 연구에서는 이러한 제약점을 극복할 수 있는 근사적인 지체시간을 계산하는 방법을 제시한 점에서 의미를 갖을 수 있다.수들은 직업의 선택이나 소득을 예측하기 위한 요소들로 포함될 수 없었다. 따라서 후속연구에서는 이를 보완해야 할 것이며, 최근 들어 우리 나라에서도 재택근무에 대한 관심이 대두되고 있으나 아직 개념정의나 그 중요성과 가치, 그리고 실태 파악과 같은 연구가 활발히 이루어지지 못하고 있으므로 이에 대한 심층적인 연구가 행해져야 할 것이다.d similar flower proceeding dates in all branches. but "Daepung" showed similar flower proceeding dates in all branches.est in HB. Mean period of wetting duration was in the order of DS＞HB＞MB, while the dew point depression was greatest in DS.ANCOVA, Pearson correlation을 이용하여 분석하였으며, 그 결과는 다음과 같다. 캠프 프로그램은 소아 당뇨병 환자의 자기 효능을 증진시키고 환자 역할 행위 이행을 높여주는데 효과적 이었다. 소아 당뇨병 환자의 자기 효능은 환자 역할 행위 이행과 순 상관 관계가 있어, 자기 효능이 증진될수록 환자 역할 행위 이행 정도가 높아졌다. 무조건 사주지 않는다(8.0%), 무조건 사준다(3.1%)로 식품광고에 나오는 식품 요구시 부모의 70.3%가 거절하는 것으로 나타났다. 거절 이유는 건강에 나쁘다는 것이 가장 큰 이유였으며 강남과 강북 어린이간에 유의적인 차이가 있었다

• Journal of Korean Society of Transportation
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• v.19 no.4
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• pp.73-84
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• 2001

Korean Highway Capacity Manual applies 7 adjustment factors to estimate saturation flows at signalized intersections. Among the adjustment factors, the right-turn adjustment factor uses equation hard to understand and requires complicated computing process comparing other adjustment factors. Thus. this study was conducted in order to suggest a new technique of estimating the right-turn adjustment factor which is easy to understand and simple to computer by having reasonable degree of accuracy. In this study the right-turn saturation flow ratios which are important in estimating the factor are suggested and the equation to estimate the volume of right-turn on red signal(RTOR) is developed based on observed data. The right-turn saturation flow rates can be estimated according to turning radius and number of lanes of crossing road dividing right-turn lanes into canalized and uncanalized lanes. The RTOR volume is estimated using the proportion of the time during which RTOR is possible to the whole time of red signal according to the through traffic volume per lane of the approach at signalized intersections. The technique of estimating the right-turn adjustment factor suggested in this study, which follows the HCM2000 of U.S. in principal, first judges the right-turn lane to be used exclusively for right-turn or not by employing the RTOR factor and the judging equation developed in this study. Next, if the right-turn lane is not exclusive right-turn lane, the shared right-turn lane is classified into single lane approach or multi lane approach. Thus, a total of three methods of estimating the right-turn adjustment factor to the three cases are suggested in this study.

• Proceedings of the KIEE Conference
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• 1996.07c
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• pp.1547-1549
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• 1996

The electrical and optical switching characteristics of gold-doped silicon p-i-n diodes have been investigated. The device shows a dark switching voltage of about 500 V. The switching voltage decreases rapidly when the illumination level is increased. The differential sensitivity of optical gating over linear region is $d(V_{Th}/V_{Tho})/dP_{Ph}$=0.25/uW. The turn-on delay time and the turn-on rise time decrease with increasing optical pulse power. The turn-off delay and the fall time are negligible.