• Journal of Korean Tunnelling and Underground Space Association
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• v.18 no.1
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• pp.41-52
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• 2016

When the queue length of congestion vehicles in tunnel fire is extended beyond tunnel length, the capacity of smoke control system needs to be increased in line with ventilation resistance. However, the vehicle queue length is not defined, so a rational equation is necessary in current fire prevention guideline. This study is intended to propose an equation to calculate the queue length considering the number of vehicles in queue in tunnel fire and evaluate the applicability by tunnel length as well. When it comes to normal tunnel, it is necessary to compare the vehicle queue length with tunnel length up to the length of 1,200 m in a bid to avoid applying the vehicle queue length excessively in case of fire. As a result of evaluation of applicability to model a tunnel, saving the number of jet fan for smoke control appeared to be effective. Besides, quantitative approach to explain the vehicle queue length through the relationship between the percentage of large vehicles and tunnel length was presented. Consequently, when the queue length of the congestion vehicles exceeds the tunnel length in determining the capacity of smoke control system in case of fire, the number of vehicles beyond the tunnel length needs to be excluded from estimating the ventilation resistance by vehicles.

• KIISE Transactions on Computing Practices
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• v.21 no.1
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• pp.19-28
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• 2015

In this paper, we proposed an algorithm for the identification of relieving or worsening current traffic congestion using historic traffic congestion patterns. Historical congestion patterns were placed in an adjacency list. The patterns were constructed to represent spatial and temporal length for status of a congested road. Then, we found information about historical traffic congestions that were similar to today's traffic congestion and will use that information to show how to change traffic congestion in the future. The most similar pattern to current traffic status among the historical patterns corresponded to starting section of current traffic congestion. One of our experiment results had average error when we compared identified changes of the congestion for one of the sections in the congestion road by using our proposal and real traffic status. The average error was 15 minutes. Another result was for the long congestion road consisting of several sections. The average error for this result was within 10 minutes.

• Journal of Korean Society of Transportation
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• v.23 no.5 s.83
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• pp.169-176
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• 2005

This paper introduces the dynamic control of acceleration lanes at freeway-ramp junctions. The feasibility of operation with flexible length of acceleration lane was tested with most possible traffic conditions. The operational qualify was also evaluated using average speed and total thru-put at both ramp section and freeway section. A CORSIM microscopic simulation model was used to evaluate the operation quality with a variety or volume conditions and three acceleration lanes, each representing different length categories. In addition, tollgate O-D data including travel times were obtained for two sections on the Gyeong-bu Freeway where an effective merging distance has been largely reduced. Its effect was analyzed and compared to the simulation results. Finally, the effects of acceleration lane are discussed and operational improvement at junctions is presented as research findings.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.5
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• pp.2170-2177
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• 2012

The ratio of index finger length to ring finger length(2D:4D) is an index of prenatal testosterone and/or estrogen exposure. The aim of this study is to investigate digit ratio and the type of gender-role orientation, to identify the correlation between 2D:4D and gender-role orientation in health and medical students. Participants were 120 male and 146 female university students majoring in health or medicine. After filling in KSRI(Korean Sex Role Inventory), 2nd and 4th finger lengths were measured on both hands using vernier callipers with photocopy. This study showed 2D:4D in the males was 0.95, and that in the females was 0.96 (p<0.01). 38.3% male students revealed androgyny, on the other hand, 35.6% female students revealed undifferentiated type from KSRI. And also, there was a significant difference in masculinity score between male and female but not in feminity score. There was no significant difference in 2D:4D according gender role orientation. The KSRI masculinity score was negatively related to 2D:4D of left hand in male (p<0.05). The results of this study suggest that a more masculine gender role orientation in males is associated with low 2D:4D revealing higher testosterone and/or lower estrogen level in utero. However, more research in 2D:4D ratio to Korean is needed for support of this result.

• Journal of the Korean Society of Radiology
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• v.15 no.2
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• pp.201-210
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• 2021

This study was conducted not only to find out the effect of straight body exercise on neck pain, necks disability and neck length change of turtle neck syndrome patients but also to provide fundamental data for this field in the future. Number of 60 persons were selected by pre-test and divided to 21 persons in straight body exercise group, 19 persons in exercise group and 20 persons in control group(non-exercise group). 5 kinds of straight body exercise were applied in straight body exercise group, 8 kinds of strengthening cervical vertebral exercise were applied in exercise group and no exercise was applied in control group. Neck pain, necks disability index and neck length were measured before and after exercise and 10 weeks later as well. The data were analyzed by SPSS(v18.0). In straight body exercise group and exercise group, neck length, neck pain and necks disability index were significantly decreased after eight weeks of exercise and there was no significant difference in control group. Neck length which was checked every week in straight body exercise group and exercise group was significantly decreased and there were significant differences after 3 weeks.. After 2 weeks of 8 weeks exercise, neck length, neck pain and necks disability were checked again in post test and those results were maintained just like 8 weeks exercise status. As above results, it was more efficient in the straight body exercise group than exercise group and control group to decrease neck pain, necks disability and neck length of turtle neck syndrome patients. Furthermore, after 2 weeks of 8 weeks exercise, the results were maintained just like 8 weeks exercise status. Therefore, the author consider that straight body exercise will be effective exercise for turtle neck syndrome patients, and this study would provide fundamental data for this field in the future.

• Journal of Korea Water Resources Association
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• v.37 no.8
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• pp.623-630
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• 2004

In this paper, the hydraulic model tests are conducted for the hydraulic characteristics at channel junctions. The experiments are examined through the variation of approaching angle, discharge in the upstream main channel and the discharge ratio between the main channel and the tributary. The experiments are conducted in the channel model having the length of 450cm, the widths of 40cm and 32cm. Four water tanks and pumps are installed in the experimental channel. The length of stagnation zone is increased by Increasing of approaching angle and the discharge in the upstream channel. The length of stagnation increase with the discharge ratio between the main channel and the tributary. However, the variation of the stagnation zone near the channel junctions is little at the same approaching angles and the discharge ratioes between the main channel and tributary. However, the variation of the stagnation zone near the channel junctions is little at the same approaching angles and the discharge ratioes between the main channel and tributary. Accelerating zone of the velocity is occurred in the middle of the channel in the small approaching angle. However, the influence zone of the accelerating velocity is increased by increasing the approaching angle.

• Journal of Korean Society of Transportation
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• v.32 no.5
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• pp.522-530
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• 2014

Spatio-temporal congestion evolution pattern can be reproduced using the VDS(Vehicle Detection System) historic speed dataset in the TMC(Traffic Management Center)s. Such dataset provides a pool of spatio-temporally experienced traffic conditions. Traffic flow pattern is known as spatio-temporally recurred, and even non-recurrent congestion caused by incidents has patterns according to the incident conditions. These imply that the information should be useful for traffic prediction and traffic management. Traffic flow predictions are generally performed using black-box approaches such as neural network, genetic algorithm, and etc. Black-box approaches are not designed to provide an explanation of their modeling and reasoning process and not to estimate the benefits and the risks of the implementation of such a solution. TMCs are reluctant to employ the black-box approaches even though there are numerous valuable articles. This research proposes a more readily understandable and intuitively appealing data-driven approach and developes an algorithm for identifying congestion patterns for recurrent and non-recurrent congestion management and information provision.

• Journal of the Korea Society of Computer and Information
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• v.28 no.4
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• pp.83-91
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• 2023

In this paper, we propose a robustness sensitivity index (RSI) of highway networks to analyze the effect of congestion in a specific section on the entire highway. The newly proposed RSI is defined as the change in the total mileage of the transportation network per extended unit length when the length of a particular section is extended. When the RSI value is large, traffic congestion in the section has a worse effect on the entire network than in other sections. The existing network robustness index (NRI) simply observes changes in transportation networks with and without specific sections, but the RSI proposed in this study is a kind of performance indicator that allows quantitative analysis of the ripple effect of the entire network according to the degree of congestion in a specific section. While changing the degree of congestion in a particular section, it is possible to calculate how the traffic volume increases, decreases, and the size and location of the congestion section change. This analysis proves the superiority of RSI as it cannot be analyzed with NRI. Various properties of RSI are analyzed using data from the domestic highway network. In addition, using the RSI concept, it is shown that the ripple effect on other sections in which a change in the degree of congestion of a specific section occurs can be analyzed.

• Proceedings of the Korea Water Resources Association Conference
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• 2010.05a
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• pp.561-564
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• 2010

하천의 본류와 1개 이상의 지류가 만나는 합류부에서는 본류 흐름과 지류 흐름이 충돌함에 따른 흐름 정체가 빈번하게 일어난다. 이로 인하여 태풍이나 집중호우 시 유속저하와 수위증가로 통수능이 크게 저감되어 홍수피해위험이 크게 증가하는 경향을 보인다. 도류제는 흐름의 원활한 소통을 위하여, 흐름방향을 조정해주는 인공구조물로서 수제의 한 종류이며, 합류부에서의 흐름 정체현상을 해소할 수 있는 한 방법으로 알려져 있으나, 국내에서는 도류제의 적용이 주로 해안의 사빈방지 등에 이루어지고 있으며, 하천의 합류부에서의 적용사례를 찾아 보기는 힘들다. 이 연구에서는 본류와 지류가 만나는 합류구간을 지닌 자연형 사행하천을 대상으로 한 수리모형 실험장치를 이용하여, 도류제의 합류부의 흐름개선 효과를 분석하였다. 수리모형실험의 조건은 도류제 설치 전 후, 도류제 길이 변화에 따라 구성되었으며, 실험결과 도류제의 설치는 본류흐름, 지류흐름, 합류 후 흐름의 수위, 유속, 흐름방향 등의 흐름 특성을 변화시켰다. 특히, 실험조건에 따라 하도의 통수능 증대효과가 다르게 나타났으며, 도류제 설치길이에 따른 변화를 확인하였다. 본 연구 결과를 통해 하천 합류부에 도류제 등의 홍수저감시설을 적용할 시 합류부의 수위 및 유속 등의 수리특성 변화를 예측함으로 합류부 흐름개선을 위한 하천개수계획 등에 유용한 자료로 활용될 것으로 사료된다.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.20 no.7
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• pp.2267-2276
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• 1996

Twin-fluid atomization has been widely used in combustors and process industries because of its high performance and simple structure. Flow visualization and pressure measurements were conducted to investigate the effects of gas flow in twin-fluid atomization. Schlieren photographs showed that changes in atomizing gas pressure, altered the wave patterns, and the lengths of both recitrculating toroid (impinging stangnation point) nad supersonic flow region in the jet. A longer supersonic wave pattern like net-shape wqas observed as atomizing gas pressure increased. The disintegration phenomenon of liquid delivery tube. The variation of spray angles with gas pressures were obtained by visualization using laser sheet beam. Suction pressuresat the nozzle orifice exit and recirculating region are shown to be used to estimate the stable atomization condition of a twin-fluid atomizer.