• Journal of Korean Society of Transportation
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• v.19 no.1
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• pp.115-129
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• 2001

The purpose of this study is to develop a cycle-free signal timing model for minimizing delays based on Third-generation control concept using Genetic Algorithm. A special feature of this model is its ability to manage delays of turning movements on the cycle basis. The model produces a cycle-free based signal timing(cycles and green times) for each intersection to minimize delays of turning movements on the cycle basis. The performance of cycle-free signal timings was evaluated on normal (v/c = 0.7) and oversaturated (v/c=1.0) conditions. The performance measures are throughput and the number of queued vehicles at the end of green time. The result shows that the cycle free signal timing is superior to the fixed signal timing to manage traffic flows of intersections; (1) the proposed model accomplishes the basic objective of the research, producing cycle free signal timings on the cycle basis, (2) on normal conditions, cycle free signal timings produce less queued vehicles at the end of green time, and (3) on oversaturated conditions, the cycle free signal timing is superior to the fixed signal timing to manage saturated traffic flows of intersections.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.8 no.1
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• pp.47-55
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• 2014

Almost of alternate computer access devices which assist people with disabilities to utilize the computer connected to computer by some cables or installed in as a S/W program. These devices have some spatial limitations to the people with disabilities, it can't guarantee the free and diverse access to the computer. For these reasons, in this paper, an Android-based mouse program for alternative computer access was developed. A people with physical disabilities who has some limitation of hand movements can use it in anywhere and anytime using only the fine motor skill of the upper limbs. The developed device recognizes the user's point touch and transforms it into the location of mouse cursor. The location information transferred to the computer via Bluetooth communication module equipped in smart devices. Also the group scanning method which can reduce the user's fatigue degree was employed and click, double click, drag & drop functions by hand's movements were equipped. The developed device will help the people with disabilities to use computer with brief touch and convenient operation without spatial limitation.

• Journal of Digital Contents Society
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• v.13 no.3
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• pp.335-342
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• 2012

The purpose of the study was to develop a computer access assessment system for improving computer access of individuals with physical disabilities for the first time in Korea. Korea-Computer Access Assessment System (K-CAAS) presented in this article tests five user skills of aim, drag, menu, scan, and switch. Skill levels of the five test areas could be set as low, middle, and high according to individuals' characteristics. All tests have their default set in each level, and skill levels can be selected and controlled by the abilities and goals of a user. Tests could be selected for users' training and their results could be traced and shown. Therefore, the K-CAAS is a training program to improve computer access skills as well as an assessing program. It would help users with physical disabilities operate a computer by themselves as improving their computer access skills.

• Proceedings of the Korean Society for Information Management Conference
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• 2012.08a
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• pp.33-36
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• 2012

인터넷 발달로 인한 정보격차는 장애인들의 문화지체현상을 가속화 시키고 있다. 이에 웹사이트의 원스톱 서비스에 있어 경험에 기초한 디자인과 보편적 디자인을 기반으로 접근성을 확장해 나가야 할 것이다. 본 연구에서는 문헌을 통해 장애인을 위한 접근성 필수항목 7가지, 즉 콘텐츠구성, 키보드접근, 마우스접근, 이미지처리, 텍스트처리, 색, 코드를 선정하고 이를 근거로 장애인 자료실이 있는 공공도서관과 그렇지 못한 공공도서관, 해외 공공도서관의 웹사이트를 대상으로 평가하였다. 이를 토대로 접근성 확장을 위해 메인페이지 개선, 사용자 경험을 기초한 콘텐츠 구성, 콘텐츠의 접근성, 의미 있는 마크업, 이용자를 위한 맞춤형 콘텐츠, 제작 권장사항 등을 제안하였다. 앞으로 장애인을 포함한 모든 이용자를 위한 웹 접근성 지침은 경험적 데이터와 보편적 디자인에서 이루어져야 할 것이다.

• Water for future
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• v.28 no.4
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• pp.155-169
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• 1995

Three types of methods are used to determine the lag time which is an important parameter in estimating the geomorphological instantaneous unit hydrograph (GIUH) and their results are anlyzed hydrologically in this study. The first method uses only the average velocity and second one uses the combination of the stream length and the average velocity. The third method employs the relationship between watershed area and lag time obtained from the empirical coefficients of Boyd and Singh. To verify the applicabilities of such methods to the actual river basin, the obtained lag times were tested by using the observed data. The results showed that the first method was applicable to small watershed area but not to larger area. The several other hydrologic characteristics beside the watershed area should be considered for the third method because the accuracy of the lag time was not good. Finally, the second method gave the most similar simulation results and the best agreements to the observed runoff data than any other method.

• 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.

• Journal of Korean Society of Transportation
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• v.27 no.5
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• pp.179-187
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• 2009

This study develops a real-time signal control algorithm based on sectional travel times and includes a field test and evaluation. The objective function of the signal control algorithm is the equalization of delay of traffic movements, and the main process is calculating dissolved time of the queue and delay using the sectional travel time and detection time of individual vehicles. Then this algorithm calculates the delay variation and a targeted red time and calculates the length of the cycle and phase. A progression factor from the US HCM was applied as a method to consider the effect of coordinating the delay calculation, and this algorithm uses the average delay and detection time of probe vehicles, which were collected during the accumulated cycle for a stabile signal control. As a result of the field test and evaluation through the application of the traffic signal control algorithm on four consecutive intersections at 400m intervals, reduction of delay and an equalization effect of delay against TOD control were confirmed using the standard deviation of delay by traffic movements. This study was conducted to develop a real-time traffic signal control algorithm based on sectional travel time, using general-purpose traffic information detectors. With the current practice of disseminating ubiquitous technology, the aim of this study was a fundamental change of the traffic signal control method.

• Journal of Korean Society of Transportation
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• v.23 no.8 s.86
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• pp.181-191
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• 2005

This study developed an algorithm for real-time signal control based on the detection system that can collect sectional travel time. The signal control variable is maximum queue length per cycle and this variable has a sectional meaning. When a individual vehicle pass through the detector, we can gather the vehicle ID and the detected time. Therefor we can compute the travel time of an individual vehicle between consecutive detectors. This travel time informations were bisected including the delay and not. We can compute queue withdrawing time using this bisection and the max queue length is computed using the deterministic delay model. The objective function of the real-time signal control aims equalization of queue length for all direction. The distribution of the cycle is made by queue length ratios.

• Journal of Music and Human Behavior
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• v.1 no.1
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• pp.33-46
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• 2004

Mentally disable children feel as failure because they have difficulty in restricted and undifferentiated communications with others. It also makes the counter-partner feel frustrated. Therefore, in the aspects of language acquirement and communication activities, it is essential to let the disable children learn and communicate voluntarily. Music provides the unthreatening and interesting stimulus as non-language communication vehicle. Musical experiences for mentally disable children's are multi-stimulating experiences that make a positive influence in speech and language development and development of variety of talents. There are many communication intervention and method to treat the mentally disable children. One of the most effective treatments for mentally disable children to acquire communication techniques by expressing the language more naturally and joyfully is the musical therapy. This study analyzes children's communication technique referring to response action and attempt action through video tape observation. Also, this study measured the receptive and expressive language by PRES(Preschool Receptive-Expressive Language Scale) as a test tool in order to examine the pre-post language ability for respective children as pre-post period of therapy activity. First result of this study showed that music therapy with song was effective for mentally disable children in enhancing the communication techniques centered with communication response and in attempt action by increasing the communication action incidence. Secondly, pre-post comparison test with PRES showed that the music therapy with song was effective on improvement the receptive and expressive language ability of 4 children.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.18 no.2
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• pp.77-92
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• 2019

TPCLT is a advanced signal system that serves twice left turn phases during the same cycle. TPCLT can be a useful where the left turn traffic volume is high and the length of the left turn lane is short. This study examined the effectiveness of TPCLT in reducing delay for a signalized three-Leg intersection and proposed the application of TPCLT signal system. 108 scenarios with different traffic volumes were created. This study analyzed the control delay of the three-Leg intersection in case TPCLT is operated and non-TPCLT is operated. As a result of analysis, it was shown that TPCLT was effective in most of the scenarios. When traffic volume ratio of the left turn is 30~40%, TPCLT was more effective at reducing the control delay. The study result shows significant delay reduction for the left turning traffic and it is approximately 50 seconds. The opposing movement's average control delay increased 2 seconds. The effect of TPCLT on the length of left turn lane was analyzed. As a result, it is found that TPCLT is effective when the length of left turn lane is 30%~60% compared to that of conventional three leg intersection operations.