• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.19 no.2
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• pp.62-73
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• 2020

Access management is aimed at preserving the road's high intercity mobility. In urbanized areas, immoderate acceleration lane-length requirements restrict the accessibility of land. Therefore, there are many opinions to revise the minimum acceleration lane-length requirement. For this purpose, it is important to diagnose the effects of slow vehicles on the mainline. This study analyzed a single merging vehicle's total delay occurrence depending on the mainline traffic flow rate and merging speed. A linear relationship was observed between the mainline traffic flow rate and total delay. As a merging speed increases gradually from 40km/h to 100km/h in 20km/h intervals, the total delay decreases by 5.0, 1.6, and 5.1 times, respectively. This shows that the ideal condition with the total delay is less than 0.5 vehicle·sec when there is no speed difference between the mainline and merging vehicle. On the other hand, given the one-second response time of drivers, the total delay occurrence was slightly low when the speed difference between the mainline and merging vehicle was less than 20km/h.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.20 no.2
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• pp.58-71
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• 2021

The number of elderly people worldwide is rapidly increasing and the mobility handicapped suffering from inconvenient public transportation service is also increasing. In Korea and abroad, various policies are being implemented to provide high-quality transportation services for the mobility handicapped, and budget support and investment related to mobility facilities are being expanded. The mobility handicapped spends more time for transit transfer than normal users and their satisfaction with transit service is also lower. There exist transfer inconvenience points of the mobility handicapped due to various factors such as long transfer distances, absence of transportation facilities like elevators, escalators, etc. The purpose of this study is to find transfer inconvenience points for convenient transit transfer of the mobility handicapped using Smart card Big data. This study process traffic card transaction data and construct transfer travel data by user groups using smart card big data and analysis of the transfer characteristics for each user group ; normal, children, elderly, etc. Finally, find transfer inconveniences points by comparing transfer patterns between normal users and the mobility handicapped. This study is significant in that it can find transfer inconvenience points for convenient transit transfer of the mobility handicapped using Smart card Big data. In addition, it can be applicated of Smart card Big data for developing public transportation polices in the future. It is expected that the result of this study be used to improve the accessibility of transit transportation for mobility handicapped.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.11 no.2
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• pp.89-94
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• 2011

Today, the utilization of communication devices is being increased including information terminals, cell phones, handheld personal digital assistants (PDA) caused by the development of information and communication technology. The development of information and services is speeding up, whereas most communication devices have provided a inefficient hierarchical menu and sequential searching structure. In this study, the Adaptive User Interface is applied to the Bus Information Terminal(BIT) which is one of communication equipment installed in the bus stop. It will be based on analysis of unspecified individuals' preferences and user's directly personalization in the BIT prototype. We expect the results of this study to be possible to provide users with efficient and convenient information acquisition and contribute to the development of public transport use by improving the accessibility and usability of BIT.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.36 no.3
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• pp.127-134
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• 2018

Electric transmission towers are facilities to transport electrical power from a plant to an electrical substation. The towers are connected using power lines that are installed with a proper sag by loosening the cable to lower the tension and to secure the sufficient clearance from the ground or nearby objects. The power line sag may extend over the tolerance due to the weather such as strong winds, temperature changes, and a heavy snowfall. Therefore the periodical mapping of the power lines is required but the poor accessibility to the power lines limit the work because most power lines are placed at the mountain area. In addition, the manual mapping of the power lines is also time-consuming either using the terrestrial surveying or the aerial surveying. Therefore we utilized multiple overlapping images acquired from a low-cost drone to automatically reconstruct the power lines in the object space. Two overlapping images are selected for epipolar image resampling, followed by the line extraction for the resampled images and the redundant images. The extracted lines from the epipolar images are matched together and reconstructed for the power lines primitive that are noisy because of the multiple line matches. They are filtered using the extracted line information from the redundant images for final power lines points. The experiment result showed that the proposed method successfully generated parabolic curves of power lines by interpolating the power lines points though the line extraction and reconstruction were not complete in some part due to the lack of the image contrast.

• The Korean Journal of Ecology
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• v.28 no.4
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• pp.181-188
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• 2005

Methods used to study carbon sequestration by soil aggregates have often excluded the concentric spatial variability and other dynamic processes that contribute to resource accessibility and solute transport within aggregates. We investigated the spatial gradients of carbon (C) and nitrogen (N) from the exterior to interior layers within macroaggregates, $6.3\sim9.5$ mm, sampled from conventional tillage (CT) and no tillage (NT) sites of a Hoytville silt clay loam. Spatial gradients in C accumulation within macroaggregates were related to the differences in C dynamics by determining the sizes and the turnover rates of fast C and slow C pools in the concentric layers of aggregates. Aggregate exteriors contained more labile C and were characterized by greater C mineralization rates than their interiors in both management systems. In contrast, C in the interior layers of aggregates was more resistant in both systems. These results indicated the spatial differentiation of C dynamics within macroaggregates, i.e., exterior layers as a reactive site and interior layers as a protective site. Greater total C distribution in the exterior layers of NT aggregates indicated more influx of C from the macropores in interaggregate space than C. mineralization (net gain of C), whereas lower C distribution within the exterior layers of CT aggregates indicated net loss of C by greater C mineralization than C influx. We found total C increased approximately 1.6-fold by the conversion of CT soils to NT management systems for a period of 36 years. Differences in total accumulation and the spatial distribution of C within aggregates affected by management were attributed to the differences in aggregate stability and pore networks controlling the spatial heterogeneities of resource availability and microbial activity within aggregates.

• Korean Journal of Agricultural Science
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• v.42 no.4
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• pp.341-346
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• 2015

This study was conducted to investigate the awareness tendency of the government employees who manage forest roads about problems of forest road use and how to improve them in the future using surveys. The results show there are more silvicultural operations than harvesting operations using forest roads. The main purpose of using forest roads is to transport workers; however, the road will be used more for harvesting operations in the future. The respondents wanted to be accessibility for forest operations within 200 m from road in both present and future. For silvicultural operations 1-ton vehicle is used at present, and 5-ton vehicles are expected to be used in the future. For harvesting operations 5-ton vehicle is used at present, and 10-ton vehicles are will be used in the future. The roadway width is 3 - 4 m at present, but should be 4 - 4.5 m in the future. The longitudinal gradient of roads is 7 - 10% at present, and will be below 10% in the future. The minimum curve radius of roads is 12 - 15 m at present, and will be 15 - 20 m in the future. The results provide basic data for making future forest road policies.

• Nuclear Engineering and Technology
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• v.52 no.8
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• pp.1784-1791
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• 2020

The 14 MeV neutron generator facility is being developed by the Institute for Plasma Research India to conduct the lab scale experiments related to Indian breeding blanket system for ITER and DEMO. It will also be utilized for material testing, shielding experiments and development of fusion diagnostics. Occupational radiation exposure control is necessary for the all kind of nuclear facilities to get the operational licensing from governing authorities and nuclear regulatory bodies. In the same way, the radiation exposure for the 14 MeV neutron generator facility at the occupational worker area and accessible zones for general workers should be under the permissible limit of AERB India. The generator is designed for the yield of 10¹² n/s. The shielding assessment has been made to estimate the radiation dose during the operational time of the neutron generator. The facility has many utilities and constraints like ventilation ducts, accessible doors, accessibility of neutron generator components and to conduct the experiments which make the shielding assessment challenging to provide proper safety for occupational workers and the general public. The neutron and gamma dose rates have been estimated using the MCNP radiation transport code and ENDF -VII nuclear data libraries. The ICRP-74 fluence to dose conversion coefficients has been used for the assessment. The annual radiation exposure has been assessed by considering 500 h per year operational time. The provision of local shield near to neutron generator has been also evaluated to reduce the annual radiation doses. The comprehensive results of radiation shielding capability of neutron generator building and local shield design have been presented in the paper along with detailed maps of radiation field.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.35 no.3
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• pp.671-678
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• 2015

When evaluating the feasibility of construction projects of large-scaled transportation facilities such as roads or railways based solely on the result of the economic analysis, less development indicators are politically reflected on the investment decision-making because regions whose socio-economic indicators are poor may be disadvantaged or underserved for the projects. Existing less development indicators, however, does not consider the transportation connectivity which indicates how effective the transportation networks are established for the transport of people and goods. In this study, travel time contour maps, travel distance and travel time between regions, and a route curvature were utilized to define new indices which reflect transportation connectivity on the less development indicators. When the new indices are applied, the existing rankings of under-developedness were changed, which means that transportation connectivity could effect on the political decision. In this study, we also suggested the necessity of considering the transportation connectivity when evaluating less development indicators, developed measures of inter-regional linkages, and performed the whole procedures of combining existing and new indices to evaluate the less development indicators.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.5
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• pp.3240-3250
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• 2014

This study aims to draw a correlation in the choice of automobiles as the preferred mode of personal transport in relation to three factors: 5Ds, urban form and individual-level characteristics. The analysis result shows that the control at the individual level is required to analyze effective urban character and urban form elements to decrease the car choice and the 5Ds demonstrate meaningful relation to decreasing the car choice. However, it may be concluded that the density and the diversity, well-known elements in decreasing the car choice among Western cities do not show relatively large impact on Korean cities.

• The Journal of the Korea Contents Association
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• v.19 no.6
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• pp.359-367
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• 2019

As a strategy for strengthening local competitiveness, efficient use of regional assets is becoming more and more important. The key to regional identity and competitiveness is local assets. The purpose of this study is to derive the priority region for development by evaluating local assets. The analysis methods used in this study are Geographic Information System analysis, Big Data Trend analysis, and Analytic Hierarchy Process analysis. To assess the potential of local assets, the preference of assets, historical value, cluster of resources, wide-area transport accessibility, and population density were set as analysis indicators and itemized weights were applied using AHP to reflect the importance of each item. As a result of analyzing Yeongju city in Gyeongsangbuk-do, eight major points such as Buseoksa Temple, Sosu Seowon, Huibangsa Temple, Punggi Hot Spring Resort, Punggi Station, National Center for Forest Therapy, Yeongju east region and Museom Village were derived.