• Journal of the Korean GEO-environmental Society
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• v.5 no.4
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• pp.33-45
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• 2004

In the present study, more systematic laboratory model tests under various conditions are carried out to investigate load-sharing characteristics among the granular pile and adjacent soils and bearing capacity characteristics with different pile lengths. Further to evaluate effects of both a loading area and a spacing of pile installation on the bearing capacity and bearing capacity characteristics of each pile in group, model test results are also analyzed for the purpose of an efficient design of granular compaction piles. From the analysis of the model test results, it is found that the ultimate capacity of granular compaction group piles increases with a decrease in the installation distance among granular piles. It is also found that the dominant failure mode of the granular compaction piles is bulging failure. It is further realized that the length of a granular pile could not significantly affect on the ultimate granular pile capacity.

• Journal of Environmental Policy
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• v.12 no.4
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• pp.45-69
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• 2013

This study estimates baseline greenhouse gas emissions from transport sector when a new town is developed. It has adopted a general greenhouse gas estimation model developed by Schipper, celine, Roger(2000) for the estimation, and showed how various transport related statistics can be utilized in detail. Particularly, it has produced unit greenhouse gas emission factor per vehicle types, vehicle-km, and trip-km. To evaluate effects of greenhouse gas reduction policies, it has calculated how much emissions will be reduced from bicycle promotion. It has turned out that about 369 thousand tons of carbon dioxide will be emitted from transport sector once the 1st Geomdan New Town is developed in Incheon metropolitan city. If the policy of bicycle promotion can attract people to use bicycle as much as 5% of total trips, then it can reduce about 1,869 tons of carbon dioxide.

• Journal of Korean Society of Steel Construction
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• v.26 no.6
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• pp.499-509
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• 2014

This study focuses on mixing steel fiber in the concrete to improve the ductility and toughness of the columns. The purpose of the study is to evaluate the load capacity and deformation capacity associated with the amount of steel fiber and loading condition and to analyze the interplay between the steel fiber reinforced concrete and the welding built-up square tube in terms of structure and fire resistance performance. Reinforcement of concrete with steel fiber(Vf=0.375%), when cross-section shape and boundary condition (load ratio) remained unchanged, improved fire resistance performance by 1.1~1.3 times. It is deemed that the area resisting thermal load increased and fire resistance performance was improved since the concrete reinforced with steel fiber restrained cracking. In addition, the fact that the cross-sections of the concrete were barely damaged indicates that load share capacity was greatly improved.

• Journal of Korean Society of Transportation
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• v.28 no.3
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• pp.7-17
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• 2010

Bicycle is one of the most important eco-friendly transport mode which can cope with global warming. ICTs(information and communication technologies) on bicycles became a dominant factor for success to the spread of bicycles to public as we experienced Public Bike System. In this paper, conceptualization and classification of u-Bike services are fulfilled and its priority was examined using AHP method. Group capabilities technique of ECII, a computer fool of AHP was invited to minimize bias on appraisal. 12 u-Bike services were conceptualized. U-service with highest adoptability was 'bike and ride' service which can link bicycle to public transportation. 'Prevention system from abandonment and theft' and 'public bike system' similar to Velib system in Paris are also considered to be very important services in u-City.

• Journal of Korean Society of Transportation
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• v.29 no.6
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• pp.7-16
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• 2011

This study investigates the degree of dependency on freeways when auto travelers make route choices in the Seoul Metropolitan Area. The investigation is conducted based on aggregated auto trip data, defining the degree of dependency as the proportion of auto trips selecting freeways in their travel paths. The analyses reveal that the trips departing from the areas with higher accessibility to freeways tend to exhibit higher dependency on freeways. In addition, the dependency is significantly affected by the travel time differences between two paths including and excluding freeways, respectively. The number of service interchanges was found to be one of significant factors for trips to Incheon and Gyenggi areas. The finding indicates that the factors affecting the degree of dependency on freeways may vary depending on the areas' characteristics. The findings would enhance the understanding of drivers' route choice behavior in Seoul at an aggregate level.

• Journal of Korean Society of Transportation
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• v.32 no.3
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• pp.280-292
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• 2014

A tram has been the focus of a new public transportation that can solve a traffic jam, decreasing of public transit usage and environmental problem in recent years. This study aims to develop a signal optimization model for considering the traffic signal progression of tram and vehicles, when they are operated simultaneously in the same signalized intersections. This research developed the KS-SIGNAL-Tram model to obtain a minimum tram bandwidth and to minimize a vehicle's delay to perform a tram passive signal priority, it is based on the KS-SIGNAL model and is added to the properties of a tram and it's system. We conducted a micro simulation test to evaluate the KS-SIGNAL-Tram model, it showed that the developed optimization model is effective to prevent a tram's stop on intersection, to reduce a tram's travel time and vehicle's delay.

• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2012.03a
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• pp.65-65
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• 2012

The air texturing공정은 노즐에서 전달되는 초음속 에어기류에 의해 overfeed를 수반하여 yarn속 fiber가 뒤얽혀 loop와 crimp를 발달시키는데, 고강력 고탄성율 고내열성 내절단성 등의 특성을 가지는 아라미드섬유를 에어 가공사로 가공 할 경우 가공 전 필라멘트 상태일 때 보다 표면에 생기는 loop로 인하여 촉감이 좋아지고 또한 타 소재와 접착 시 접착제 담지 성능이 향상 되어 접착력이 상승되고, 이를 통해 보강재로서의 기능이 강화되는 반면 역학물성이 기존의 아라미드 보다 저하되는 약점을 가지고 있어 최근 ATY 공정조건이 ATY 사의 구조와 물성변화에 미치는 영향에 대한 많은 연구결과가 발표되고 있다. 본 연구에서는 Aiki air jet texturing machine에서 $Heracron^{(R)}$ para-aramid(840, 1000d, 1500d)를 사용하여 ATY nozzle의 직경을 0.6, 0.75, 1, 1.2mm로 변화를 주어 12개의 para-aramid ATY 시료를 제조하여 이들의 섬도, 강신도, 초기탄성률, 열수축률 그리고 형태불안정성(instability)등의 물성변화를 분석하여 다음과 같은 결과를 얻었다. 노즐의 직경이 증가함에 따라 사 내의 filament간의 움직임이 자유로워 교락이 증가하고 루프가 형성되어 단위길이 당 mass가 커지므로 섬도가 미세하게 증가하는 것을 볼 수 있다. 또한 직경이 증가할수록 절단강도와 초기탄성률은 감소하고 절단신도가 증가하는 경향을 볼 수 있는데 이는 축 방향으로의 배열이 적어져 하중을 분담하는 portion이 감소하고 사의 loop형성이 많아짐으로서 상대적으로 인장력에 대응하는 fiber의 수가 적어지기 때문으로 사료된다. 이는 현미경 관찰로 확인할 수 있는데 직경이 증가함에 따라 사의 loop의 엉킴이 증가하고 filament가 조밀한 것을 확인할 수 있다. 직경 변화에 따른 건 습열 수축률은 1% 미만의 매우 낮은 값으로 영향을 받지 않는 것을 확인 할 수 있는데 para-aramid의 열적특성의 안정성에 기인하는 것으로 사료되며 ATY의 불안정성은 노즐 직경 증가에 따른 어떤 경향성을 찾아볼 수 없었지만 840d, 1000d, 1500d로 섬도가 증가함에 따라 사의 불안정성이 증가하였다.

• Journal of the Korean Geotechnical Society
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• v.29 no.1
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• pp.109-120
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• 2013

This paper presents the results of a laboratory investigation into a study on undrained characteristics of a geogrid-encased stone column (GESC) installed in soft clay under cyclic load. In order to analyze behavior of settlement, pore water pressure, stress concentration ratio and strain of the GESC compared to a stone column, a series of reduced-scale laboratory tests were performed. The model tests show that GESC provides a simple and effective method of deformation resistance and settlement restraint when a short-term cyclic load is applied. The maximum strain of geogrid occurred at 1.2D and 1.5D from the top of the column. This paper highlights the importance of considering overlay effect and replacement ratio on cyclic load supporting GESC.

• Journal of Korea Multimedia Society
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• v.9 no.10
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• pp.1322-1331
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• 2006

Concurrency control is one of the important factors to maintain consistent conditions of a game because most participants of the game should be shared information to play the game through a distributed network system. replay delay times should establish in every event and the received event should be saved and performed simultaneously for Concurrency Control. However, it is not easy to practice the event with same speed in environment having various moving speed. Therefore, expansion have to be provided. In other words, one of the most important factors of a game's efficiency is the process of bandwidth and delay. the process of concurrency control method based on scalable prediction for Multi-platform games would minimize the loss rate of a event and then would improve the interaction capacity of a game. It also might get reliability between clients. This paper analyzes some problems in terms of a layout of a game that integrates a cable and a wireless system. In addition, this paper provides methods to expand bandwidth and delay that might be an obstacle of a On-line game and to ensure reliability between a server and a client.

• Proceedings of the KSR Conference
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• 2009.05a
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• pp.1269-1278
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• 2009

The Seoul metropolitan area is generated the transportation problems of traffic congestion, delay of travel time, etc due to the increase of traffic demand at Seongnam area, Koyang/Paju area, Incheon/Bucheon area, etc, because that have not provided the urban surrounding railway network and live to be concentrated about 49% of the population of Korea. The Koyang/Paju route axis is required the urban surrounding railway network because the share percentage of public transportation is 51%, the automobiles is 48.8% and the subway is 27.3% and the housing development plan for 530,000 persons have provided. According to the result of the study for the introduction of the express railway between Kangnam to Ilsan of 37.8Km, in case of operation of 150Kmm at express railway, the scheduled speed between Kangnam to Ilsan is 103Km/h, the running time is about 23 minutes. The demand of traffic of this project was forecasted about 237,000persons by traffic analysis. This project which was analysed B/C of 1.08 by the result of the feasibility study have a economic feasibility.