• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.1A
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• pp.75-89
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• 2006

This paper presents a practical and realistic Life-Cycle Cost (LCC) optimum design methodology of steel bridges considering time effect of bridge reliability under environmental stressors such as corrosion and heavy truck traffics. The LCC functions considered in the LCC optimization consist of initial cost, expected life-cycle maintenance cost and expected life-cycle rehabilitation costs including repair/replacement costs, loss of contents or fatality and injury losses, road user costs, and indirect socio-economic losses. For the assessment of the life-cycle rehabilitation costs, the annual probability of failure which depends upon the prior and updated load and resistance histories should be accounted for. For the purpose, Nowak live load model and a modified corrosion propagation model considering corrosion initiation, corrosion rate, and repainting effect are adopted in this study. The proposed methodology is applied to the LCC optimum design problem of an actual steel box girder bridge with 3 continuous spans (40 m+50 m+40 m=130 m), and various sensitivity analyses of types of steel, local corrosion environments, average daily traffic volume, and discount rates are performed to investigate the effects of various design parameters and conditions on the LCC-effectiveness. From the numerical investigation, it has been observed that local corrosion environments and the number of truck traffics significantly influence the LCC-effective optimum design of steel bridges, and thus realized that these conditions should be considered as crucial parameters for the optimum LCC-effective design.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2022.05a
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• pp.171-173
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• 2022

The 4th industrial revolution technology is developing people's lives more efficiently. GIS provided on the Internet services such as traffic information and time information makes people getting more quickly to destination. National geographic information service(NGIS) and each local government are making basic data to investigate SOC accessibility for analyzing optimal point. To construct the shortest distance, the accessibility from the starting point to the arrival point is analyzed. Applying road network map, the starting point and the ending point, the shortest distance, the optimal accessibility is calculated by using Dijkstra algorithm. The analysis information from multiple starting points to multiple destinations was required more than 3 steps of manual analysis to decide the position for the optimal point, within about 0.1% error. It took more time to process the many-to-many (M×N) calculation, requiring at least 32G memory specification of the computer. If an optimal proximity analysis service is provided at a desired location more versatile, it is possible to efficiently analyze locations that are vulnerable to business start-up and living facilities access, and facility selection for the public.

• Korean Journal of Culture and Social Issue
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• v.22 no.3
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• pp.387-410
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• 2016

This study conducted a review of the existential and psychological perspective about the risks and safe. The risk was identified as existential task through the existential philosophy and psychology discussed were the safety regulations as existential need. As existential anxiety that is caused by unmet and insufficiency of the existential needs and the existential task that was presented to identify the subjective risk. Subjective risk as existential anxiety, and suggested that serves as a compass to advance to the completion and the facing the existential. In addition, existential anxiety as a subjective function as a signal that can identify the problem conditions that expressed phenomena. Problematic aspect of a subjective risk was suggested that it can be adjusted through a method for supplying information that can be recognized by an experienced and symmetrical state with the direction of the expressed symptoms. The attempt to determine the existence of and psychological point of view, it gave provided the underlying psychological spokesman for the analysis of human society, including the Sewol ferry of Korea-type disaster. There are also presented some implications that can be applied effectively to give more psychological approach to future risk reduction and safety enhancement. In addition, this study through the various views presented by a comprehensive existential subject of several ways to adjust the status Theme conditioning method (Theme Condition Adjustment Theory: TCAT) to establish a theoretical basis for expecting it to be that.

• Information Systems Review
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• v.25 no.4
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• pp.113-130
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• 2023

Due to economic development and increasing gross national income, the number of automobiles continues to rise, leading to a serious issue of illegal parking due to limited road conditions and insufficient parking facilities. Illegal parking causes significant inconvenience and displeasure to people and can even result in accidents and loss of lives. The severity of accidents and their consequences, related to the growing number of vehicles and illegal parking, is escalating, particularly in the metropolitan areas. Consequently, efforts are being made to address this problem as a cause of social issues and come up with measures to reduce illegal parking. In particular, half of the public complaints in the metropolitan area are related to illegal parking, and the highest physical and human damage occurs in Gyeonggi. Thus, this study aims to use machine learning techniques based on data related to illegal parking in Suwon city, Gyeonggi, to categorize regional characteristics and propose effective measures to crack down on illegal parking. Additionally, practical, social, policy, and legal measures to decrease illegal parking in the metropolitan area are suggested. This study has academic significance in that it solved the problem of illegal parking, which is mentioned as one of the social problems that cause traffic congestion, by classifying regional characteristics using K-prototype, a machine learning algorithm. Furthermore, the results of this study contribute to practical and social aspects by providing measures to decrease illegal parking in the metropolitan area.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.22 no.5
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• pp.182-199
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• 2023

Since 2021, government departments have been promoting Automated Driving Technology Development and Innovation Project as national research and development(R&D) project. The automated vehicles and service technologies developed as part of these projects are planned to be subsequently provided to the public at the selected Living Lab City. Therefore, it is important to determine a spatial area and operation section that enables safe and stable automated driving, depending on the purpose and characteristics of the target service. In this study, the static Operational Design Domain(ODD) elements for Level 4 automated driving services were reclassified by reviewing previously published papers and related literature surveys and investigating field data. Spatial analysis techniques were used to consider the reclassified ODD elements for level 4 in the real area of level 3 automated driving services because it is important to reflect the spatial factors affecting safety related to real automated driving technologies and services. Consequently, a total of six driving mode changes(disengagement) were derived through spatial information analysis techniques, and the factors affecting the safety of automated driving were crosswalk, traffic light, intersection, bicycle road, pocket lane, caution sign, and median strip. This spatial factor analysis method is expected to be useful for determining special areas for the automated driving service.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.23 no.2
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• pp.1-14
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• 2024

The most optimal route-search algorithm thus far has introduced a method of applying node labels and link labels. Node labels consider two nodes simultaneously in the optimal route-search process, while link labels consider two links simultaneously. This study proposes a turn-label-based optimal route-search technique that considers two turns simultaneously in the process. Turn-label-based optimal route search guarantees the optimal solution of dynamic programming based on Bellman's principle as it considers a two-turn search process. Turn-label-based optimal route search can accommodate the advantages of applying link labels because the concept of approaching the limit of link labels is applied equally. Therefore, it is possible to reflect rational cyclic traffic where nodes allow multiple visits without expanding the network, while links do not allow visits. In particular, it reflects the additional cost structure that appears in two consecutive turns, making it possible to express the structure of the travel-cost function more flexibly. A case study was conducted on the metropolitan urban railway network consisting of transportation card terminal readers, aiming to examine the scalability of the research by introducing parameters that reflect psychological resistance in travel with continuous pedestrian transfers into turn label optimal path search. Simulation results showed that it is possible to avoid conservative transfers even if the travel time and distance increase as the psychological resistance value for continuous turns increases, confirming the need to reflect the cost structure of turn labels. Nevertheless, further research is needed to secure diversity in the travel-cost functions of road and public-transportation networks.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.17 no.1
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• pp.31-37
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• 2024

In this study, we propose a machine vision-based pedestrian signal detection algorithm that operates efficiently even in computing resource-constrained environments. This algorithm demonstrates high efficiency within limited resources and is designed to minimize the impact of ambient lighting by sequentially applying HSV color space-based image processing, binarization, morphological operations, labeling, and other steps to address issues such as light glare. Particularly, this algorithm is structured in a relatively simple form to ensure smooth operation within embedded system environments, considering the limitations of computing resources. Consequently, it possesses a structure that operates reliably even in environments with low computing resources. Moreover, the proposed pedestrian signal system not only includes pedestrian signal detection capabilities but also incorporates IoT functionality, allowing wireless integration with a web server. This integration enables users to conveniently monitor and control the status of the signal system through the web server. Additionally, successful implementation has been achieved for effectively controlling 50W LED pedestrian signals. This proposed system aims to provide a rapid and efficient pedestrian signal detection and control system within resource-constrained environments, contemplating its potential applicability in real-world road scenarios. Anticipated contributions include fostering the establishment of safer and more intelligent traffic systems.

• International Journal of Highway Engineering
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• v.7 no.4 s.26
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• pp.151-162
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• 2005

Variable Message Sign (VMS), which provides drivers with direct information about state of traffic congestion and for prevent an accident, is the most effective method among the methods of providing information in Advanced Transportation Management System. Currently establishment and the VMS which is operated foundation lets in Guidelines on the use of Variable message sign (a book of the VMS) of 1999 November the Ministry Construction & Transportation, these contents mean main viewpoint on physical part such as message special quality variable (font, character size and line space, word interval) and position mainly among standard about establishment in general. But, it is true that using without effect verification on the character of VMS display and that using mode of stationary-centered. In this paper, it executed significance test to effort verification on the character of VMS display for more practical and effective information transmission based on the driver viewpoint For the researches; develop 3D-Simulation, select characteristics of driver's visual cognition behavior (the conspicuity, the legibility and the comprehensibility), evaluation each issue (day or night, 80km/h or 100km/h). Especially, that used the Eye Marker Recorder to measure of reading-time (legibility) thus, confirmed objectivity and reduce an observational error. The results showed that the conspicuity is Flashing> Stationary>Scroll. The legibility is not deference that Flashing between stationary form. Also the comprehensibility result showed that Flashing> Stationary>Stroll form.

• Journal of Korean Society of Transportation
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• v.35 no.6
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• pp.499-510
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• 2017

Traffic accident fatalities in Korea in 2016 was 4,292 and 1,732 cases were deaths of elderly people. In spite of this, the researches on behaviors of the elderly when crossing roads, are rather limited. The purpose of this study is to investigate and analyze road crossing behavior characteristics of the elderly, when crossing roads, especially focusing on the characteristics of pedestrians and vehicles. Cross-sectional data was collected from six different sites in two regions and the following results was identified. First, at road crossings, 528 cases(84.3%) out of 626 conflict situations of the elderly and 303 cases(63.3%) out of 478 conflict situations of the non-elderly pedestrians were found to be dangerous, respectively. The elderly tend to face a statistically significant risk of 3.11 times higher than that of non-elderly people. Second, 519 cases(82.9%) of jaywalking occurred in 626 conflict cases of the elderly and 375 cases(78.5%) of jaywalking in 478 conflict events of non-elderly persons, which indicates the elderly's 1.34 times higher trend compared with the non-elderly's. Third, the pedestrian safety margin (PSM) analysis showed that the PSM of the elderly and the non-elderly were 3.33 seconds and 4.04 seconds respectively, which is 17.5% high. Fourth, the difference in pedestrian safety interval was examined by dividing the speed of approaching vehicle into less than 30km/h, above 30km/h and less than 50km/h, and over 50km/h. There was no significant difference between the PSM of coming vehicles with the speed less than 30km/h and the PSM of approaching with the speed 30km/h~50km/h, but the conflicts with vehicle of the speed above 50km/h show significantly lower PSM than with vehicle speed of 30km/h~50km/h. Finally, when the risk threshold is set to less than 2.5 seconds, the analysis shows that older pedestrians tend to cross roads dangerously 1.59~2.53 times than younger pedestrians. The results set forth here can be used as a basis for constructing the elderly safety measures at present and a potential basis for autonomous vehicle safety application in the future for solving the issue of the difference in crossing behavior between elderly and non-elderly pedestrians.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.28 no.4
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• pp.120-126
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• 2010

As the importance of an historical area is getting increased in these days, the reconstruction of an bell chamber in Namhansansung has significant historial, educational and cultural meaning. The purpose of this study, as a study on an bell chamber in Namhansansung, is to assume an original location of the bell chamber and identify the size and shape of the original bell chamber through literature study, site inspection, and analysis on old maps. In addition, this study could provide useful information when new bell chamber is constructed. According to the literature study, site inspections(5 times) and analysis on old maps, the original bell chamber is assumed to locate near current Oroji tea house at the rotary, where was in the area of Hanggung. With regard to the traffic system, it is assume that there was an old road along with the current local road No.342 connecting the South Gate with North Gate and a Y or T shape intersection connecting the site of old bell chamber with the north. In addition, there was a government office street from the old bell chamber to Hanggung. The shape of old bell chamber is assumed to have Paljak or Woojingak roof. Samo roof was not found in all the five maps. Regarding the direction of bell chamber, three maps indicate that it faces the East and two maps show that it faces the South. Therefore, it is assumed that the length and width of the roof have similar size. However, a new bell chamber should face the East, which is the same direction with Hanggung. As there is a record which states that a bell in the Cheonheoungsa, Seonggeosan, Cheonan was used as a Namhansansung's bell when the Cheonheoungsa was closed, this study suggests that new Namansansung's bell should be built, considering histroical value and artistry of Cheonheoungsa's bell. This study is a basic research for the reconstruction of Namhansansung in 2009. However, as reconstruction of historical assets should be based on thorough historical evidences. Therefore, more detail researches by a indicator analysis are left for the topic of future studies.