• Proceedings of the KSR Conference
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• 2003.10b
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• pp.247-252
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• 2003

본 논문은 철도안전운행을 위하여 능동적으로 철도차량을 제어를 지리정보시스템기법을 활용하는 방안을 제시하고 있다. 이를 위해서는 철도차량의 위치를 얼마나 정확하게 추적 및 표출이 가능한지를 검토해 보았다. 구체적으로는 GIS의 정의와 기능을 살펴보고 GIS기법을 활용한 능동적 철도차량제어의 에시를 정리하였다. 능동적 철도차량을 제어를위한 핵심요소인 철도차량 위치자료의 정확성을 수치지도의 축적별로 분석하였다. 최종적으로는 능동적으로 철도차량을 제어를 지리정보시스템기법을 활용하기 위해 칠요한 주요쟁점사항을 정리하였다.

• The Journal of the Korea Contents Association
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• v.22 no.9
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• pp.85-94
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• 2022

In modern society, environmental and energy problems have caused to replace cars with environment friendly energy. Vehicles with internal combustion engine which use petroleum are one of the factors that influence global pollution due to environment problems such as fine dust and ozone layer destruction. In addition use of energies for automobile making resources to become depleted. To solve this limited oil energy problem by using other energy sources. To the problem using electric energy and green energy as alternative for a solution. Among environment friendly energies this paper studies the possibility of drive service for autonomous vehicles that self-charges using only solar energy and whether they can be used as pollution free and alternative energy for automobiles. Studies was researched based on published literature review, data from ministry of transportation and automobile companies. Also case of electric vehicle and prototype automobile using only solar energy and the theory of near future technologies. Many automakers are using electric cars as alternative energy. Also making efforts to use solar energy as an substitute energy source and as a way to supplement electricity. Results show that there is a potential on operating autonomous vehicle using only solar energy. Furthermore, it will be possible to use automobiles actively, also use and supply solar energy. This paper suggest the possibility of contributing to the future of the automotive industry.

• Journal of Korean Society of Transportation
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• v.19 no.5
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• pp.85-97
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• 2001

In this study, the purpose behind this research is to propose index to be used for classification of functional the urban streets and to select the feasible length of special management link by the index. This special management link help decision makers found a transportation policy. In order to perform functional classification, index such as average traveled distance, link VKT and VKT per length-lane are use at the study. Average traveled distance index is average traveled distance divided by length of Path k and VKT per length-lane is trip volume characteristic considering lanes and length of Path k. Special management links on which major part of the vehicle are selected with using Path-VKT which represents how many long-distance touring vehicles are on the arterial road. The selection of special management links are performed with network composed of 14 paths (arterial roads) in seoul The total distance of special management links resulted from the above analysis is 141km(35.0% of the whole paths length) and total VKT of the special management links is 4,152,475 VKT(45.2% of the whole paths VKT)

• Journal of the Korean Society for Nondestructive Testing
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• v.36 no.5
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• pp.345-352
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• 2016

As aircrafts are being operated at high altitude, wing structures experience various fatigue loadings under cryogenic environments. As a result, fatigue damage such as a crack could be develop that could eventually lead to a catastrophic failure. For this reason, fatigue damage monitoring is an important process to ensure efficient maintenance and safety of structures. To implement damage detection in real-world flight environments, a special cooling chamber was built. Inside the chamber, the temperature was maintained at the cryogenic temperature, and harmonic fatigue loading was given to a wing structure. In this study, piezoelectric active-sensing based guided waves were used to detect the fatigue damage. In particular, a beamforming technique was applied to efficiently measure the scattering wave caused by the fatigue damage. The system was used for detection, growth monitoring, and localization of a fatigue crack. In addition, a sensor diagnostic process was also applied to ensure the proper operation of piezoelectric sensors. Several experiments were implemented and the results of the experiments demonstrated that this process could efficiently detect damage in such an extreme environment.

• Journal of the Economic Geographical Society of Korea
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• v.14 no.4
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• pp.540-552
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• 2011

Freight travel pattern has been less studied comparing with the field of passenger travel. Nonetheless, the importance of the freight travel has been increasing in urban travel sector, and the research needs on the freight travel demand hence is increasing. The current paper aims to identify, by tons of freight trucks and cargos, the characteristics of mean travel pattern, efficiency or performance, and the characteristics of freight trip chain regarding destination location, destination type and freight type. The study analyzed the nation-wide data of freight travel behavior survey. This study intended to set the starting framework of decision-making principle in freight travel, which has already been popular in passenger travel study. Findings suggest that those characteristics are clearly distinguished among trucks and cargos of different sizes of tons. The results are expected to provide important insight to the development of relevant transportation policy measures.

• Journal of Korean Society of Transportation
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• v.22 no.6
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• pp.145-157
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• 2004

Microscopic freeway simulation models project the uncertain values of performance measures for subject traffic conditions by explaining drivers' driving behavior with lane changing and car-following models. However, the existing lane changing models are limited to gap acceptance oriented passive behavior of drivers and not able to capture more-or-less aggressive driving behavior(e.g. cut-in lane changing) ordinarily obseved in field. This paper suggests the definition of cut-inlane changing and presents its characteristics based on the findings from two different freeway on- and off-ramp sections. In addition, this paper proposes a new lane changing model capable of handling both passive and active drivers' driving behavior for better performance of simulations. The proposed lane changing model was tested with Hanyang Simulatin (HYTSIM), a microscopic freeway simulation program developed for this study. The HYTSIM simulation results reflecting the performance of the proposed lane changing model were compared against the field data. The test results showed that the distribution of gaps collected when vehicles change lanes were statistically identical to the field data at 95% confidence level.

• The Journal of the Korea Contents Association
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• v.14 no.9
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• pp.45-53
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• 2014

In this study, we analyzed the next generation ITS (C-ITS) technology trends, focusing on the national and international C-ITS projects. Based on the promotion practices of developed countries, we pointed out the lack of linkages with the existing ITS infrastructure. As a way to overcome this problem, we proposed the three-direction to enable the existing ITS infrastructure corresponding to the C-ITS. First one is developing a technique to improve the performance of the existing ITS infrastructure and automate the performance management (Performance-enhanced ITS). Second, developing active sensors or fusion sensor which along with V2X communication technology implement of an active safety driving support system (Safety-enhanced ITS). Third, we need to develop a technology that generate the new advanced traffic data by integrating the collected data from existing ITS infrastructure and nomadic device (Cloud-ITS). By improving the function of the existing ITS infrastructure for adaptation to the new V2X communication environment, we enhanced the efficiency of maintenance performance and would maximize the benefit of the introduction of C-ITS.

• Journal of Korean Society of Transportation
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• v.20 no.6
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• pp.115-128
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• 2002

Traffic engineers have developed and implemented various microscopic simulation models to verify the traffic performance and to prevent the expected problems. The existing microscopic simulation models categorize drivers into several types to reflect various drivers' driving patterns but miss the dynamics of drivers' behavior changed based upon the traffic conditions. It was found from the field data collected from two different merging sections on an urban freeway in Seoul, Korea, that the drivers' critical gap distributions are changed based on (1) the traffic density on the adjacent lane to the acceleration lane and (2) the opportunities left to merge in terms of distance to the end of acceleration lane. It was also found from the study that the drivers' critical gap distributions follow the Normal distribution. and its mean and variance change while a vehicle progresses on an acceleration lane. This paper proposes a new gap-acceptance model developed based on a set of drivers' critical gap distributions from each segment on the acceleration lanes. Through the comparison study between the field data and the results from the simulation utilizing the proposed model, it was verified that (1) the distribution of merging points on an acceleration lane to the adjacent main lane at different density levels, (2) the size of the gap accepted for merging and (3) the speed difference between the merging vehicle and the trailing vehicle at the time of merging are statistically identical to the field data at 95% confidence level.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.11
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• pp.2002-2007
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• 2006

The path search method in the telematics system should consider traffic flow of the roads as well as the shortest time because the optimal path with minimized travel time could be continuously changed by the traffic flow. The existing path search methods are not able to cope efficiently with the change of the traffic flow. The search method to use traffic information also needs more computation time than the existing shortest path search. In this paper, a method for efficiency improvement of path search is implemented and its performance is evaluated. The method employs the fixed grid for adjustable heuristic to traffic flow. Moreover, in order to simplify the computation of estimation values, it only adds graded decimal values instead of multiplication operation of floating point numbers with due regard to the gradient between a departure and a destination. The results obtained from the experiments show that it achieves the high accuracy and short execution time as well.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2006.11a
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• pp.261-264
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• 2006

지능형 차량정보 시스템은 21세기 교통체계로 기대를 모으고 있는 ITS(Intellligent Transport System)의 구축에 핵심이 되는 시스템이다. 이러한 시스템을 구현하기 위해서 종래의 네비게이션, 차량용 무선통신, 차량진단 등의 단일화된 시스템을 통합적으로 수행하며, 계측 또는 수집된 데이터를 분석하여 지능적으로 차량의 주행 상태를 분석 / 진단함으로써 차량에서의 안전한 운행과 운전자 및 승객들이 요구하는 정보 또는 다양한 서비스를 제공하기 위한 새로운 모듈의 개발이 절실히 필요한 실정이다. 따라서, 본 논문에서는 CAN(Controller Area Network) BUS을 이용한 차량의 상태수집 모듈과 능동 데이터베이스에 관해 기술하고 이를 통합하기 위한 임베디드 보드를 이용한 CAN BUS연계형 차량용 복합통신모듈의 프로토타입 H/W을 구성하여 실용화 가능성 및 유용성을 제시하고자 하였다.