• Journal of agriculture & life science
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• v.44 no.3
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• pp.99-110
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• 2010

This paper builds a system of indicators representing rural regional development level. Indicators were classified into two groups, that is, living environment indicator group and regional vitality indicator group. Living environment indicator group consists of four indicators including housing, road, water supply, and sewage system, while regional vitality indicator group consists of five indicators including regional economy, public finance, and demography. Real data of the year 2002 and 2006 were used to do the basic statistical analysis and estimate the suitable statistical distributions for each indicator. Data were applied for the three city/county type, general city, urban-rural combined city, and county. General cities have the strongest urbanization tendency among the three types, while counties have the weakest tendency. General cities turned out to be superior in housing condition, road density, water supply system and sewage system. Indicators of employment and local finance showed the highest levels in counties. The results of this analysis are expected to provide local governments with the appropriate reference for their rural regional development policy.

• International Journal of Highway Engineering
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• v.14 no.3
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• pp.131-140
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• 2012

Lane markings such as edgelines, centerlines, and lines that delineate lanes generally provide drivers with the various information for safe driving. Drivers can easily recognize the lane markings through the color differences between the markings and road surfaces during the daytime. However, it is a bit difficult for drivers to perceive them during the nighttime due to the lack of artificial lights. Although the glass beads with the 1.5-refractive index have been used to improve the visibility of the lane markings during the nighttime, it is still difficult for drivers to recognize the lane markings properly, especially during the rainy nighttime, which may often lead to traffic accidents. To improve the retroreflectivity and visibility of the lane markings during the rainy nighttime, the high refractive beads with the 2.4-refractive index are essentially required, but they do not work appropriately during the dry nighttime. Thus, the mixed materials with the 1.5, 1.9, and 2.4-refractive beads should be considered for the satisfactory implementation of the lane markings. This study reveals the best mixing rates of the beads by conducting benefit-cost analysis under various weather conditions in Korea. The analysis results show that the lane markings with the 100% of the 2.4-refractive beads provide the highest visibility of lane markings regardless of the roadway conditions, but the benefit-cost (B/C) ratio of the bead mixture is merely 0.46. The best mixing rate of the beads, from the highest B/C ratio viewpoint, was identified as the mixture with a 80% of 1.5-refractive beads and a 20% of 2.4-refractive beads. Some limitations and future research agenda have also been discussed.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.1D
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• pp.83-90
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• 2011

A need still exists that the unsaturated condition is to be considered when evaluating the infiltration and drainage capacity for compacted geomaterials in road foundation or embankments. For this reason, numerical analysis were used to analyze the time-dependent unsaturated infiltration and drainage condition depending on various geomaterial types. Therefore, laboratory data from the soil-water characteristic curve tests on geomaterials were adopted from previous studies. In addition, the unsaturated permeability was estimated using SWCC. Then the infiltration and drainage performance of unsaturated compacted soils were evaluated under various conditions based on the proposed method. The results demonstrated that the effect of initial suction and SWCC path on each material could be substantial and the proper application on analysis is very important to enhance the prediction on each capacity.

• Analytical Science and Technology
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• v.18 no.3
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• pp.241-249
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• 2005

In this study, instrumental neutron activation analysis was used to measure the concentrations of about 30 trace elements in airborne particulate (PM2.5) samples at urban area of Daejeon city located in the southwestern region of Korea. An inspection of the measurement data indicates that the distribution patterns of trace elements could clearly distinguish the elements with their concentrations ranging over five orders of magnitude. The mean values for Lu and Dy were found to be the lowest at values of 0.01 and $0.04ng/m^3$, while those for K and Fe showed the highest value of 671 and $653ng/m^3$, respectively. The results of correlation analysis showed that PM2.5 concentrations can exhibit much more enhanced correlations with the elements of earth crustal components. The results of factor analysis further indicated that there are no more than six factors with statistical significance, which may exert dominant roles in regulating the elemental concentration levels in the study area. Enrichment factor analysis supports explicit interpretation of results found by this factor analysis.

• Proceedings of the Korea Water Resources Association Conference
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• 2006.05a
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• pp.1256-1260
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• 2006

하천 복개나 하상 도로 등 교각이 밀집된 군교각은 홍수시에 큰 수위 상승을 유발할 수 있다. 이런 군교각에 의한 배수위 효과를 분석하기 위해 다양한 경우에 대한 실험과 2차원 수치 모의를 수행하였다. 수리 실험은 수치 모형의 정확도를 검증하기 위해 수행되었으며, 다양한 종류의 교각 배치 경우에 대해서는 수치 모의를 위주로 분석하였다. 수리 모형 실험을 통하여 2차원 수치 모형인 RMA-2의 신뢰성에 대해 검토한 결과 이 모형은 교각에 의한 수위 상승 효과를 상당한 정확도로 모의할 수 있음을 알 수 있었다. 군교각에 의한 수위상승 인자를 흐름 횡단면 교각 수, 흐름 방향의 교각 간격, 흐름방향의 교각 수로 선정하여 이들 변수들을 조합하여 다양한 경우에 대하여 수리 실험과 수치 모의를 병행하였다. 단일 횡단면의 교각 수 증가에 따른 배수위 상승은 횡단면의 차단율 증가에 따라 선형적으로 증가한다. 그러다가 차단율이 어느 정도 이상에 이르면 수위 상승이 매우 급격히 증가하는 경향을 보인다. 또한 흐름방향 교각 수 증가에 따라 배수위는 선형적으로 증가함을 알 수 있는데, 이는 교각에 의한 상호 간섭 및 중첩에 의한 것으로 생각된다. 흐름방향 교각 간격을 증가시켜도 배수위 상승이 크게 증가하였으나, 교각의 지름의 약 9배 (9D) 이상 떨어진 다음부터는 배수위 상승량이 감소하는 것을 알 수 있다. 이런 점에서 볼 때, 군교각은 교각 지름의 9배 정도 떨어진 경우 배수위 상승 효과가 중첩되지 않음을 알 수 있었다.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.21 no.1
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• pp.51-63
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• 2022

Convoy driving is one of the technologies of multi-vehicle cooperation driving along with platoon driving. All over the world, research on vehicle control mechanisms to maintain vehicle formation during convoy driving convoy driving has been actively conducted and in Europe's Autonet 2030 project has developed and demonstrated convoy driving services for highways. But, even the concept of convoy driving is still insufficient in Korea. Therefore, in this study, the concept of convoy driving service was established and scenarios and communication messages for service application on urban roads were developed. And its effectiveness was verified through simulation analysis. As a result of comparing and analyzing individual vehicle cooperative driving and convoy driving for the blind spot support service and dilemma zone safety support service, which are representative V2I cooperative driving services on urban roads, the number of conflicts(indicator of traffic safety) and delays and stops(indicator of traffic efficiency) are significantly improved in convoy driving compared to individual vehicle cooperative driving.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.2D
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• pp.235-242
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• 2008

Due to the lack of judgement in an information processing on road sign, older drivers usually are having a hard time driving than young group. Furthermore, according to increasing in aging population, older drivers in Korea have been growing much faster. That means research for older drivers' characteristics and the number of guide name for road sign should be needed. In accordance with suggestions, this study was carried out the number of guide names for road sign with a variety of ages from the twenties to the seventies. For the sake of this study, statistical verification was conducted to confirm a change of speed, a reading time and a misreading rate with Driving Simulator and Electrooculogram tool. As the results of study, change of speed in the age range has shown that the higher the proportion of age, the lower the rate of velocity. Also reading time in the age range with regression analysis found that the higher the proportion of age, the higher the rate of reading time by 0.106sec. Finally, a binary logistic model was used to find the main factors. As the results, 4 number of guide names for road sign have been the best of them for older driver. The result of this study verified the importance of ideal guide numbers on road sign for older driver and proved itself to be an effective method to determine the road safety for the road signs.

• The Journal of Engineering Geology
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• v.21 no.1
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• pp.25-34
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• 2011

We applied a slope-stability analysis method, considering infiltration by rainfall, to the construction site where an express highway is being extended. Slope stability analysis that considers infiltration by rainfall can be classified into three methods: a method that considers the downward velocity of the wetting front, a method that considers the upward velocity of the groundwater level, and a method that considers both of these factors. The results of slope stability analysis using $Bishop^{\circ}{\Phi}s$ simplified method indicate that the safety factor due to the downward velocity of the wetting front decreases more rapidly than that due to the upward velocity of the groundwater level. For the third of the above methods, the safety factor decreases more rapidly than for the other two methods. Therefore, slope stability during rainfall should be analyzed with consideration of both the downward velocity of the wetting front and the upward velocity of the groundwater level.

• Journal of Korean Society for Geospatial Information Science
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• v.23 no.2
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• pp.69-77
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• 2015

In Korea, local governments have decided the location of shelters as part of their disaster planning. However, no quantitative standards, such as assuming different hazard and shelter types, shelters' capacity, are specified in that planning. To propose the direction of disaster evacuation policy, first of all, the current state of shelters' location and evacuation area is needed to be analyzed. In addition, considering topographical condition such as road slope and physical strength by age are important factors to measure optimal evacuation route. The purpose is to suggest a new methodology of estimating optimal evacuation route considering resistance of road slope and difference of walking speed by age. Moreover, as a case study of Seoul, Korea, using coverage analysis of GIS analysis tool, the accessible area (or vulnerable area) to the shelters is evaluated based on the spatial distribution of disaster evacuation shelters and their accommodation capacity, according to evacuation time within 7.5, 15 and 30 minutes. The main results are summarized as follows: 1) The average area of disaster evacuation shelter per person is calculated as 0.45 square meters. Considering that the minimum shelters' area per person is 1 square meters, only 45% of people in Seoul can be accommodated. 2) The ratio of inhabitants who live in accessible area within 7.5 minutes presents only 33% of all. Furthermore, the ratio of inhabitants by age group of 5~9 or over 65 years old shows significantly lower percentage in comparison with 15~49 years old people.

• International Journal of Highway Engineering
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• v.13 no.1
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• pp.107-118
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• 2011

This study carries out to evaluate the value of introducing the road guard system that merges the function of a fence that induces wild animals and a grass inhibitor to an existing guard rail that acts as road safety facilities. For this purpose, we surveyed that road user's willingness-to-pay and recognition characteristics for road safety facilities using contingent valuation Method. By establishing a willingness-to-pay assumption model, the average willingness-to-pay was 5,018 won, which was higher than the average proposed amount of 3,883 won and shows that the road guard system is an appropriate alternative facility to increase road safety and reduce road kills. Therefore, it would be prudent to review the introduction of the road guard system to newly constructed roads or current roads in operation as a way of reducing road kills. In the future, the road guard system must be tested in areas that are highly susceptible to road kills after consulting with the relevant highway managing authorities to conduct a comparison study on the before and after installation effect of the road guard system to investigate its operation and the current status of road kills to clearly identify its effectiveness.