• Proceedings of the Korea Society for Simulation Conference
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• 1997.04a
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• pp.81-85
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• 1997

In a virtual environment, agents must demonstrate some degree of realism and interactivity. This paper discusses the algorithm that enables agents to navigate a virtual road network realistically and interactively. The road description files written in this language provide the information of road environments to the navigating agents and the scene visualizer. We call this navigating agent in the road an ambient car. The ambient cars must follow the traffic rules as human does. To do this, the ambient car should continuously check its circumstances, such as, the traffic lights, lanes, road signs, and other ambient cars. Because of the huge scale of road network and the large number of ambient cars, the algorithm considers only the area where the participant is currently located. By this locality, the performance of the whole system does not fluctuate much in different situations. The behavior of ambient cars according to the predefined rules may appear monotonous. We added probability distribution functions to introduce some randomness. We implemented the above idea on silicon Graphics Indigo 2 workstation. The ambient car exhibited its awareness of lanes, traffic lights, and other cars. The participants could hardly distinguish between a human-controlled car and computer-controlled ambient car generated by the algorithm.

• Proceedings of the KSRS Conference
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• 2002.10a
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• pp.775-779
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• 2002

Currently, high-resolution satellite imagery such as KOMPSAT and IKONOS has been tentatively utilized to various types of urban engineering problems such as transportation planning, site planning, and utility management. This approach aims at software development and followed applications of remotely sensed imagery to transportation geographic analysis. At first, GDPA (Gradient Direction Profile Algorithm) and main modules in it are overviewed, and newly implemented results under MS visual programming environment are presented with main user interface, input imagery processing, and internal processing steps. Using this software, road network are automatically generated. Furthermore, this road network is used to transportation geographic analysis such as gamma index and road pattern estimation. While, this result, being produced to do-facto format of ESRI-shapefile, is used to several types of road layers to urban/transportation planning problems. In this study, road network using KOMPSAT EOC imagery and IKONOS imagery are directly compared to multiple road layers with NGI digital map with geo-coordinates, as ground truth; furthermore, accuracy evaluation is also carried out through method of computation of commission and omission error at some target area. Conclusively, the results processed in this study is thought to be one of useful cases for further researches and local government application regarding transportation geographic analysis using remotely sensed data sets.

• Proceedings of the National Institute of Ecology of the Republic of Korea
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• v.2 no.4
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• pp.274-278
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• 2021

Road structures play an important role in collisions involving vehicles and wildlife. Our study aimed to determine the effect of various types of road structures on the risk associated with roadkill. We surveyed 50 previously identified roadkill hotspots, ranked from one to five according to roadkill density. We collected nine types of road structure data on each hotspot road section. Structures with similar characteristics were grouped together, resulting in five categories, namely, median barrier, high edge barrier, low edge barrier, speed, and visibility. We examined the existence of each road structure category at each hotspot rank. The cumulative link model showed that the absence of bottom blocked median barrier increased the roadkill hotspot rank. Our study concluded that a visual obstacle in the middle of roads by the median barrier decreases wildlife road crossing attempts and roadkill risk. We suggest that future roadkill mitigation plans should be established considering these characteristics.

• International conference on construction engineering and project management
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• 2022.06a
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• pp.261-268
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• 2022

In road work zones, pedestrian workers' habituated inattention to warning alarms from construction vehicles can lead to fatal accidents. Previous studies have theorized that human factors such as personality traits may affect workers' inattentiveness to workplace hazards. However, there has been no study that directly examined how road construction workers' personality traits affect their attention to warning alarms within a work zone and the likelihood of engagement in a struck-by accident. This study examines how workers' sensation-seeking (especially boredom susceptibility) is related to inattention to warning alarms while performing a task in road work zones. An experiment with actual road construction workers was conducted using a virtual road construction environment. Workers' attention to repeatedly presented warning alarms was measured using eye-tracking sensors. In response to workers' frequent inattentive behaviors, a virtual accident was simulated. Results revealed a significant association between boredom susceptibility and workers' engagement in the virtual accident, a consequence of inattentiveness to warning alarms. The findings suggest that workers' personality traits predispose them to tune out warning alarms and become vulnerable to accidents in road work zones. The findings of this study can be used to develop targeted interventions aimed at preventing workers' inattention to repeatedly exposed workplace hazards, thereby contributing to reducing fatal accidents in road work zones.

• Journal of Korean Society of Rural Planning
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• v.23 no.2
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• pp.55-65
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• 2017

This study is to estimate the circuity factors which can be used to assess for public facilities accessibility and analyze traffic in the area. We set the range of the administrative districts by Si Gun Gu unit and Eup Myeon Dong unit (more subdivided unit than Si Gun Gu unit). The average circuity factor in Si Gun Gu unit is 1.364 (maximum 2.953 and minimum 1.711). The region indicated the highest value of circuity factor is wando-gun in jeollanam-do, which area consists of 4 island and is connected to the bridges. Having to use the bridges for using public facilities hinders its accessibility. In the case of Eup Myeon Dong unit, the average circuity factor is 1.353 (maximum 2.950 and minimum 1.154). The region indicated the highest value of circuity factor is buksan-myeon in chuncheon-si, Gangwon-do. This region also has to use bridges for using public facilities because there is the largest lake, called Soyangho. This circuity factor is used to analyze the location of public facilities and assess vulnerability of accessibility. And also the factor can be applied to some policies, such as rural public service planning based on spatial big data.

• Journal of the Korean earth science society
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• v.25 no.2
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• pp.94-108
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• 2004

In order to clarify the efficiency of ground level change in Ice-valley on atmospheric circulation, numerical experiment was carried out. The circulations over the slope in North and South are different due to the topography and short wave radiation in Ice-valley. Therefore the circulations in both side are asymmetric and the asymmetric circulations are kept on at 1800 LST. A small difference of the atmospheric circulations formation is made due to the road construction at night. The reason may be the weakness of sensible heat flux from the road and other factors except that the sensible heat is not a principal factor in road construction. The construction of road is associated with growing of sensible heat from the road surface. For this reason, in case of daytime, ascending wind in north slope is more stronger with the road than that without road. The maximum wind speed becomes 4.67 m/s after road construction. And the position of the road is also an important factor in estimation of mesoscale circulation in mountainous area.

• Journal of Environmental Science International
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• v.33 no.1
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• pp.75-85
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• 2024

An intensive observing period (IOP) of heatwaves in the urban region of Seoul in the summer of 2023 was carried out to understand the changes in air temperature and road temperature induced by environmental conditions. The temperature observed at eight points with different urban environmental conditions was compared with the temperature by the KMA/AWS to analyze the characteristics of change in air temperature by height and the change in road temperature according to environmental conditions and road sprinkler. The comparison of the average temperature observed in different urban environmental conditions with the temperature observed at KMA/AWS showed that the air temperature in asphalt and open space sites was 0.7 to 2.3℃ higher and that the one in bus stops was 0.9 to 2.3℃ higher. In terms of temperature deviations depending on residential type, the temperature in highly populated areas was about 0.1 to 0.8℃ higher than that of apartment complexes. In addition, regardless of the size of a park, the temperature in the park was lower than the temperature in dense housing areas and apartment complexes. In asphalt and residential areas, the road temperature was higher than the temperature at a height of 150 cm, Conversely, road temperature was lower than air temperature in a shaded shelter and large park. In addition, after spraying a surface road, the road temperature immediately dropped by about 3 to 4℃; however, after about 20 minutes, it rose again to the previous road temperature. This change in road temperature appeared only for the temperature of 30 cm height.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.31 no.4
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• pp.269-275
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• 2013

Recently, importance of pedestrian road network is getting emphasized as it is possible to provide mobile device users with both route guidance services and surrounding spatial information. However, it costs a tremendous amount of budget for generating and renovating pedestrian road network nationally, which hinder further advances of these services. Hence, algorithms extracting pedestrian road network automatically based on raster data are needed. On the other hand, road dataset generated from raster data usually has unnecessary vertices which lead to maintenance disutility such as excessive turns and increase in data memory. Therefore, this study proposed a method of selecting a proper threshold automatically for separate road entity using not only Douglas-Peucker algorithm but also road attribute data of digital map in order to remove redundant vertices, which maximizes line simplification efficiency and minimizes distortion of shape of roads simultaneously. As a result of the test, proposed method was suitable for automatic line simplification in terms of reduction ratio of vertices and accuracy of position.

• Journal of Korean Society for Atmospheric Environment
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• v.24 no.1
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• pp.72-82
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• 2008

Benzene is a very harmful and toxic compound known as human carcinogen by all routes of exposure. Owing to the risky feature of benzene, several countries such as Japan, UK and EU have established the ambient air quality standard and protect from that risk of it. Korea also has designated it as one of the criteria air pollutants and established the concentration limit ($5\;{\mu}g/m^3$) in the air and is going to apply the standard from 2010. Benzene is emitted from various sources such as combustion plants, production processes, waste treatment facilities and also automobiles. Mobile source is known as one of the major emission sources of benzene. In this study, we estimated the domestic emissions of benzene from mobile source and compared the results with those of advanced countries. Mobile source was divided into 2 categories, Le., on-road source and non-road source. The total emissions of benzene from mobile source were estimated as 3,106 tons/yr and 1,612 tons/yr was emitted from on-road source and 1,494 tons/yr was from non-road source. Emission ratio of benzene from on-road source showed that 80.0% was from passenger cars, 10.1% was from taxis, 7.2% was from light-duty vehicles, 2.5% was from heavy-duty vehicles and 0.2% was from buses. In the case of non-road source, the distribution showed that 66.3% was from construction machineries, 14.5% was from locomotives, 11.7% was from ships, 7.1% was from agriculture equipments and 0.5% was from aircrafts. The cold-start emissions were estimated as 942 tons/yr and this value was almost 1.5 times greater than that for hot engine emissions (608 tons/yr). In addition, the fuel-based distribution was 65.9%, 31.1% and 2.8% from gasoline, LPG and diesel vehicles, respectively. The emission ratio from mobile source occupied 65% and 30% of total benzene emissions in USA and UK, respectively. In case of Korea, the emission ratio of benzene from mobile source occupied 29% (15% from on-road source, 14% from non-road source) which showed similar value with UK.

• Korean Journal of Construction Engineering and Management
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• v.15 no.6
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• pp.83-91
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• 2014

The global community demands the reduction of environmental pollution such as greenhouse gas and carbon dioxide emissions. According to these requirements, the road construction project in the highest energy consuming industry is required the efficient way of reducing environmental pollution emissions. In this study, during the whole life cycle process, an environment impact assessment was performed for the several road construction projects in order to evaluate environmental stress through the road construction process. This study provides a proper process of environment impact assessment for life cycle assessment (LCA) analysis of road construction project, and figures the environmental stress regarding to the major construction materials for the case projects. In addition, this study conducted a sensitivity analysis for the key materials of environmental stress through the quantity analysis of major materials for the 1km section of a road construction. By this sensitivity analysis of total environmental stress change from the different volumes of constructing materials, it would be useful information for the environment impact assessment for the future road construction project.