• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.22 no.2
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• pp.29-43
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• 2023

It is necessary to grasp the characteristics of traffic flow passing through a specific road section and the topological structure of the road in advance in order to quickly prepare a movement management strategy in the event of a disaster or disaster. It is because it can be an essential basis for road managers to assess vulnerabilities by microscopic road units and then establish appropriate monitoring and management measures for disasters or disaster situations. Therefore, this study presented spatial density, time occupancy, and betweenness centrality index to evaluate vulnerabilities by road link in the city department and defined spatial-temporal and topological vulnerabilities by clustering analysis based on distance and density. From the results of this study, road administrators can manage vulnerabilities by characterizing each road link group. It is expected to be used as primary data for selecting priority control points and presenting optimal routes in the event of a disaster or disaster.

• ETRI Journal
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• v.34 no.5
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• pp.771-774
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• 2012

Typical channel allocation algorithms for secondary users do not include processes to reduce the frequency of switching from one channel to another caused by random interruptions by primary users, which results in high packet drops and delays. In this letter, with the purpose of decreasing the number of switches made between channels, we propose a nonparametric channel allocation algorithm that uses robust kernel density estimation to effectively schedule idle channel resources. Experiment and simulation results demonstrate that the proposed algorithm outperforms both random and parametric channel allocation algorithms in terms of throughput and packet drops.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.2
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• pp.247-255
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• 2021

The Ulsan anchorage has not secured a sufficient area than the anchorage demand, and the criteria for objective evaluation are not clearly defined. In this study, a general formula to solve the problems of the current anchorage density and occupancy concept was derived, and new adequacy evaluation criteria were proposed. The proposed criteria were applied to the Ulsan E anchorage to evaluate the suitability of the anchorage. The anchorage density and occupancy of the E1 anchorage were 129 % and 122 %, respectively, showing that both evaluation techniques exceeded 100 %, requiring anchorage expansion according to the evaluation criteria. A plan to expand the anchorage was reviewed considering the traffic pattern and the distance from the pilot boarding point. Therefore, a plan to open 35˚ on a sector at the end of the Ulsan No. 1 fairway was developed, and its suitability was verified. Base on the verification results, there was a part of the overlap between the extended area and the traffic track on the south of the E3 anchorage, but the possibility of affecting the marine traffic was minimal. In addition, it was confirmed that anchorage adequacy was achieved.

• Journal of the Korean housing association
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• v.20 no.6
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• pp.111-118
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• 2009

In modern Asia major cities had same problem with lack of affordable housing for families. So they had to concentrate to the mass supply of housing and made some physical counter effects like high density of cities, limitation of parking space. Also people who lived in those cities could suffer from broken traditional community culture. To rebuild traditional community and increase land usage, Block housing is suggested as a new kind of multi-family housing for old town redevelopment. Now some governments are trying to make urban code to give some initiative for new block housing development in old city blocks. They expect this new housing type can help to solve serious problems like lack of parking area, green space and context of block. Also they hope that block housing development can help to increase safety of town and reduce cost of development. The purpose of this study is to review the establishment and development process of Block Housing and to confirm the aspect which has been changed with urban organization together. Also this study tried to find out the intentional characteristics of similarities and differences with comparison of Korea and Japan. And as a result we could find critical physical viewpoint, and provide considerations for future study and plan. Several cases of block housing in Korea and Japan were reviewed for comparative study and Post Occupancy Evaluation (POE) survey was examined to find satisfaction factors and problems which were expected to improved.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2009.11a
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• pp.115-120
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• 2009

Since the middle of 1990, "High Rise Residential Complex" has been started to construct to fulfill the use of high density land use. In addition, it bacame a major solution for a rehabilitation project to achieve a high volume ratio, which in turn brings a good business. In this study, POE is applied to secure residential satisfaction level between Apartment and High Rise Residential complex. Also life style differences are investigated between the two type of complexes. It was resulted that recent High Rise Residential Complex is quite acceptable in most respects, however interior vetillation and direct wind flow from living space through dining - kitchen to ease the cooking scent is not a satisfactory level. These two factors are most highly demanded for future design of High Rise Complex in considering specialties in our cultural life style.

• Journal of Korean Society of Transportation
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• v.30 no.1
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• pp.75-83
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• 2012

This study is to find a shortcoming embedded in the current Korean Highway Capacity Manual (KHCM) on reflecting a heavy vehicle effect to the highway capacity. The KHCM suggests to handle the percent heavy vehicle to deal with its effect to a capacity regardless of density levels. Authors hypothesized in this study that the effect of heavy vehicles would vary at different levels of traffic density - the effect would be comparably insignificant when a density is low and it becomes comparably significant when it becomes high. Field data from a freeways located in Seoul were collected for 360 hours (15 days) and categorized them into a set of operation conditions grouped by 15 minutes and by the LOS density levels. Comparison between the field measured and the estimated by the KHCM method showed that the KHCM method overestimated the effect of heavy vehicles in LOS B and C but underestimated in LOS E. The results suggested that there be a difference pattern from the one the KHCM expected and brought discussion on further studies.

• International Journal of Highway Engineering
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• v.18 no.5
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• pp.117-125
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• 2016

PURPOSES : The density in uninterrupted traffic flow facilities plays an important role in representing the current status of traffic flow. For example, the density is used for the primary measures of effectiveness in the capacity analysis for freeway facilities. Therefore, the estimation of density has been a long and tough task for traffic engineers for a long time. This study was initiated to evaluate the performance of density values that were estimated using VDS data and two traditional methods, including a method using traffic flow theory and another method using occupancy by comparing the density values estimated using vehicular trajectory data generated from a radar detector. METHODS : In this study, a radar detector which can generate very accurate vehicular trajectory within the range of 250 m on the Joongbu expressway near to Dongseoul tollgate, where two VDS were already installed. The first task was to estimate densities using different data and methods. Thus, the density values were estimated using two traditional methods and the VDS data on the Joongbu expressway. The density values were compared with those estimated using the vehicular trajectory data in order to evaluate the quality of density estimation. Then, the relationship between the space mean speed and density were drawn using two sets of densities and speeds based on the VDS data and one set of those using the radar detector data. CONCLUSIONS : As a result, the three sets of density showed minor differences when the density values were under 20 vehicles per km per lane. However, as the density values become greater than 20 vehicles per km per lane, the three methods showed a significant difference among on another. The density using the vehicular trajectory data showed the lowest values in general. Based on the in-depth study, it was found out that the space mean speed plays a critical role in the calculation of density. The speed estimated from the VDS data was higher than that from the radar detector. In order to validate the difference in the speed data, the traffic flow models using the relationships between the space mean speed and the density were carefully examined in this study. Conclusively, the traffic flow models generated using the radar data seems to be more realistic.

• Journal of the Society of Disaster Information
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• v.9 no.4
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• pp.413-422
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• 2013

This study evaluated the fire safety code elements through analyze the loss of life when the fire occurred in the facility sprinklers installed evaluated. And through comparison with national fire safety code elements and standards of NFPA 13 in the United States, Was looking for ways to improve for Life and property damage. In the United States, in some cases, if you do not install the sprinkler are installed as per the fire death rate compared to 83 % lower. By contrast, If the domestic rate of 280 % fatalities were 3.37 times than the United States. This lack of fire performance were analyzed uniform occupancy classification, the amount of source of water supply, live not consider the density according to the standard number and the horizontal distance that causes the installation of sprinkler facilities were analyzed.

• International Journal of Highway Engineering
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• v.10 no.3
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• pp.19-31
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• 2008

Video image processing systems(VIPS) offer numerous benefits to transportation models and applications, due to their ability to monitor traffic in real time. VIPS based on wide-area detection, i.e., multi-lane surveillance algorithm provide traffic parameters with single camera such as flow and velocity, as well as occupancy and density. However, most current commercial VIPS utilize a tripwire detection algorithm that examines image intensity changes in the detection regions to indicate vehicle presence and passage, i.e., they do not identify individual vehicles as unique targets. If VIPS are developed to track individual vehicles and thus trace vehicle trajectories, many existing transportation models will benefit from more detailed information of individual vehicles. Furthermore, additional information obtained from the vehicle trajectories will improve incident detection by identifying lane change maneuvers and acceleration/deceleration patterns. The objective of this research was to relate traffic safety to VIPS tracking and this paper has developed a computer vision system of monitoring individual vehicle trajectories based on image processing, and offer the detailed information, for example, volumes, speed, and occupancy rate as well as traffic information via tripwire image detectors. Also the developed system has been verified by comparing with commercial VIP detectors.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2013.04a
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• pp.80-81
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• 2013

최근 제정 시행되고 있는 지하연계 복합건축물에 대한 다양한 연구가 진행되고 있다. 그러나 화재위험성이 높은 지하 공간의 경우, 아직까지 관련 규정의 근거가 미약하여 현실적인 피난안전 설계에 어려움을 가지고 있다. 본 연구에서는 피난 계획을 위한 로우 데이터를 확보하고자 현재 사용 중인 선큰을 대상으로 실제 유동인구를 측정하여 재실자 밀도를 분석하였다. 선큰으로 연결되는 출입구들의 유동인구와 함께 유동계수를 측정하였으며 선큰내의 재실자 밀도 산정을 통하여 선큰의 대피기능을 위한 연구 진행의 토대를 마련하였다.