• Journal of Korean Society of Steel Construction
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• v.10 no.1 s.34
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• pp.1-10
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• 1998

The temporary steel bridges which are constructed for detour and constructional expediency are consisted of H-beams(as superstructure) and H-piles(as substructure). Because these members are fastened by high-tension bolts, there are no expansion joints in these bridges. So, these kinds of bridges have no system which can relieve the excessive thermal stress. In this investigation, monitoring system was set up at temporary steel bridge and stress and temperature changes of H-beam are monitored. From these measured data, it is analyzed that the relationship between ambient and main-girder temperature change, between temperature and stress change. With these analyses, it is resulted that the thermal stress take main part of stress variation in this bridge and the restrain of thermal longitudinal displacement of H-pile. In addition, because the connection part of H-beam to H-beam is weak in the continuous spans, the sub-modelling is well apt to reflect the effect of thermal stress.

• Journal of Korean Society of Transportation
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• v.24 no.5 s.91
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• pp.77-88
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• 2006

The purpose of this study is to Propose the time dependent K-least time path algorithm applicable to a real-time based operation strategy in multi-modal transportation network. For this purpose, we developed the extended method based on entire path deletion method which was used in the static K-least time path algorithm. This method was applied to time dependent K-least time path algorithm to find k least time paths in order based on both time dependant mode-link travel time and transfer cost In particular, this algorithm find the optimal solution, easily describing transfer behavior, such as walking and waiting for transfer by applying a link-based time dependent label. Finally, we examined the verification and application of the Proposed algorithm through case study.

• Journal of Korean Society of Transportation
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• v.30 no.2
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• pp.93-100
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• 2012

This study dealt with the critical gap of roundabouts in Korea. The objective was to develop a model to derive critical gaps by analyzing gap acceptance patterns. In this context, the present study had a particular emphasis on collecting the data for accepted or rejected gaps. The main contributions of the study were as follows. First, accepted or rejected gaps were counted and measured through video frame analysis on the traffic patterns of 20 roundabouts in Korea. Based on the data, a gap acceptance model, guaranteeing the statistical significant in their parameters, was developed in the framework of the Logit model. Second, the critical gap calculated from the developed model was evaluated to be 2.584 seconds as a whole. Also, the critical gap in urban areas was estimated to be 2.744 seconds, whilst the critical gap in rural areas was estimated to be 2.416 seconds. Finally, critical gaps of roundabout in Korea were found to be smaller than those in foreign countries by about 1.5~2.5 seconds.

• Journal of Korean Society of Transportation
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• v.28 no.5
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• pp.77-87
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• 2010

In the last five years, Korea has supplied many more bicycle facilities than in the last several decades combined. However, have bicyclists increased in proportion to investment? If bicyclists are avoiding existing bicycle related facilities, including off-road bicycle facilities, it could be because suppliers did not consider bicyclists' preferences in their planning process. In this paper, the authors tried to understand the bicyclists' behavioral and route choice characteristics using stated preference surveys and a logit model, using commuting time in Daejeon Metropolitan City, Korea. The results show that nine factors affect the route choice behavior of bicyclists. In particular, bicyclists preferred sub-arterial roads to off-road, dedicated bicycle facilities in residential area. It means that bicyclists like a seamless bicycle route and that a buffer zone between car lanes and bicycle lanes or 50 km/h speed limits for cars are necessary for bicycle lanes that are not physical separated.

• Journal of Korean Society of Transportation
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• v.27 no.5
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• pp.195-208
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• 2009

A network design problem (NDP) formulated as a mathematical program is generally used to find an optimum value to minimize or to maximize some objectives such as total travel time, social benefit, or others. NDP has, however, some limits of describing components of travel patterns like activities and trip generation due to its modeling simplicity, and also it has difficulty in including attributes of regional planning. In order to cope with such limits, this paper extends NDP to the urban planning field and proposes a mathematical program which can describe the interactions between urban social activities and transportation planning. Based on this model the authors try to optimize both urban activities and the transportation system. The model developed in this paper is tested to assess its application with a real-size regional transportation network.

• Proceedings of the Korea Water Resources Association Conference
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• 2018.05a
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• pp.135-135
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• 2018

한강의 잠수교는 평상시에는 사람과 차의 통행이 가능하나 예측수위가 5.5m일 경우, 보행자통제, 6.2m일 경우, 차량통제를 실시한다. 잠수교는 국토교통부의 홍수예보 지점은 아니지만 그 특수성으로 인해 정확한 홍수위 예측을 통해 선행시간을 확보할 필요가 있다. 일반적으로 하천 홍수위 예측을 위해서는 강우-유출 모형과 하도추적을 위한 수리모형을 결합한 모델링이 요구되나 잠수교는 하류부 조위로 인한 배수 및 상류부 팔당댐 방류량의 영향을 받아 물리적 수리 수문모형의 구축이 상당히 제약적이다. 이에 본 연구에서는 딥러닝 오픈 라이브러리인 Tensorflow 기반의 LSTM 심층신경망(Deep Neural Network) 모형을 구축하여 잠수교의 수위예측을 수행한다. LSTM 모형의 학습과 검증을 위해 2011년부터 2017년까지의 10분단위의 잠수교 수위자료, 팔당댐의 방류량과 월곶관측소의 조위자료를 수집한 후, 2011년부터 2016년까지의 자료는 신경망 학습, 2017년 자료를 이용하여 학습된 모형을 검증하였다. 민감도 분석을 통해 LSTM 모형의 최적 매개변수를 추정하고, 이를 기반으로 선행시간(lead time) 1시간, 3시간, 6시간, 9시간, 12시간, 24시간에 대한 잠수교 수위를 예측하였다. LSTM을 이용한 1~6시간 선행시간에 대한 수위예측의 경우, 모형평가 지수 NSE(Nash-Sutcliffe Efficiency)가 1시간(0.99), 3시간(0.97), 6시간(0.93)과 같이 정확도가 매우 우수한 것으로 분석되었으며, 9시간, 12시간, 24시간의 경우, 각각 0.85, 0.82, 0.74로 선행시간이 길어질수록 심층신경망의 예측능력이 저하되는 것으로 나타났다. 하천수위 또는 유량과 같은 수문시계열 분석이 목적일 경우, 종속변수에 영향을 미칠 수 있는 가용한 모든 독립변수를 데이터화하여 선행 정보를 장기적으로 기억하고, 이를 예측에 반영하는 LSTM 심층신경망 모형은 수리 수문모형 구축이 제약적인 경우, 홍수예보를 위한 활용이 가능할 것으로 판단된다.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.39 no.1
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• pp.45-53
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• 2019

As the urbanization progresses, the demand for parking in large cities surges compared with that for parking lots. However, the space for securing a parking lot in a large city is physically limited and a budget problem also arises. Therefore, a shared parking system that can utilize existing parking lots is becoming important. This study was carried out to analyze the parking area efficiently for the residents parking area. As a result of the questionnaire survey, it was the most frequent passage to work / commuting and business purposes. The most important factors in parking were 'Parking charge', 'Walking distance to the destination after parking', 'Parking lot searching time' Approximately 46 % of the respondents were female. As a result of the quantitative analysis of the factors influencing the potential use of the intention to use as a dependent variable, it was analyzed that the policy was effective to reduce the parking fee to less than 500 won per 10 minutes and take about 3-6 minutes to search.

• Journal of the Korea Convergence Society
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• v.12 no.8
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• pp.93-104
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• 2021

In the process of the sustainable development of the world economy, the change and construction of urban living environment has always been the focus of people's attention. Therefore, the purpose of this study is to find out the potential safety hazards in residential areas, and put forward feasible improvement plans under the framework of CPTED theory.One is to collect the necessary literature. Secondly, according to the field investigation and questionnaire survey, sorting out the existing security risks. Finally, this paper puts forward the corresponding improvement and suggestion to this research. The conclusion is as follows: First, based on the six principles of CPTED theory, problems existing in Gamcheon Cultural Village, which is subject to research, were investigated. Second, six of the most serious safety issues (safety handle, landscaping, entrance control, signs, empty space, monitoring) were objectively analyzed, and designs were presented in terms of increasing safety stairs, installing automatic entrances, open access view, unifying signs, and building leisure areas.

• Journal of the Korea Society of Computer and Information
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• v.26 no.4
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• pp.85-91
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• 2021

Some sections of the highway are closed due to disasters and accidents. In this situation, it analyzes what kind of situation occurs due to functional failure in the highway network. The domestic highway network can be expressed as a graph. Blocking some sections of the highway can turn into a national disaster. In this paper, we analyze the robustness of the domestic highway network. The robustness of expressways refers to the degree to which the traffic conditions of the domestic expressway network deteriorate due to the blockage of some sections. The greater the robustness, the smaller the effect of some blocking appears. This study is used to evaluate the congestion level of one section of the transportation network, and a value obtained by dividing the section traffic volume (V) by the section traffic volume (C) is used. This study analyzes the robustness of highways by using the actual traffic volume data of the departure and arrival points of domestic highways, and analyzes the changes in traffic volume due to partial blockage through experimental calculations. Although this analysis cannot reflect the exact reality of domestic highways, it is judged to be sufficient for the purpose of confirming the basic robustness of the overall network.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.22 no.3
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• pp.116-130
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• 2023

Expressways play pivotal roles in cargo transportation because of their superior accessibility and mobility compared to rail and air. On the other hand, there is a limit to the accurate calculation of cargo transportation performance using existing highways owing to the mixture of vehicle types and difficulty in identifying cargo loads of individual cargo vehicles. This paper presents an algorithm for calculating more reliable cargo transportation performance using big data. The traffic performance (veh·km/day) was derived using the data collected from Toll Collecting System. The average tolerance weight for each vehicle type and the cargo load unit (ton/unit) considering it was calculated using vehicle specification information data and high-speed and low-speed axis data. This study calculated the cargo transportation performance by section and type using various online integrated highway data and presented a method for calculating the transportation performance by linking open business offices and private highways.