• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.15 no.2
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• pp.63-73
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• 2016

On January 16 to May 31, 2012, Korea Expressway Corporation was carried out an pilot overweight enforcement using high-speed weigh-in-motion at Gyeongbu expressway 195.0k (Gimcheon) and Jungbunaeryuk expressway 119.5k (Seonsan). In this study, it is attempted to analyze the practical effect of high-speed weigh-in-motion by comparing the average total weight and traffic volume of eight weeks before and after the these overweight enforcement, respectively. The main results are as follows: First, the result of analysis of the change in average total weight and traffic volume, it was found that it did not differ after as in previous traffic volume, and the total weight is reduced. This means that the total weight is not reduced by decreasing freight traffic, but by decreasing the total weight. Therefore, it can be seen that there is an effect of pilot overweight enforcement using high-speed weigh-in-motion. Second, the average total weight and total weekly traffic volume decreased rapidly starting from the start of the overweight enforcement, but there was showing a tendency to increase gradually again.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.21 no.6
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• pp.87-96
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• 2022

The traffic vulnerable, including elderly pedestrians, have a relatively low walking speed and slow cognitive response time due to reduced physical ability. Although a smart crossing system has been developed and operated to improve problem, it is difficult to operate a signal that reflects the appropriate walking speed for each pedestrian. In this study, a neural network model and a multiple regression model-based traversing speed estimation model were developed using image information collected in an area with a high percentage of traffic vulnerability. to support the provision of optimal walking signals according to real-time traffic weakness. actual traffic data collected from the urban traffic network of Paju-si, Gyeonggi-do were used. The performance of the model was evaluated through seven selected indicators, including correlation coefficient and mean absolute error. The multiple linear regression model had a correlation coefficient of 0.652 and 0.182; the neural network model had a correlation coefficient of 0.823 and 0.105. The neural network model showed higher predictive power.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.22 no.4
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• pp.14-34
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• 2023

The purpose of this study was to calculate the appropriate yellow-signal time for intersections, to find out the relationship between the approach speed and intersection width when calculating the time, and to secure safety by minimizing conflicts and dilemma sections in intersections that change according to the signal operation. For this purpose, 6,824 data points from 5 intersections were collected and analyzed. The main results of the study are as follows. First, the approach speed of individual vehicles in different lanes was analyzed, and the width of an intersection was defined by considering the conflict in each direction. Second, we developed a multiple regression model based on the approach speed and conflict points, which compensated for the problems of an existing formula. Third, a standard table is presented for applying the appropriate yellow-signal time according to the approach speed and intersection width based on a development formula. A method is also presented to determine the safety of the length of the dilemma according to the change in the yellow-light time by presenting a calculation table that can cross-analyze the yellow-signal time and a dilemma section using the relationship.

• Journal of Korean Society of Transportation
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• v.23 no.4 s.82
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• pp.7-16
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• 2005

Rejected Takeoff Accidents are not common. but if occurred, it leads to big disaster From the year of 1959, when Jet Transport service opened, to the year of 2000, Rejected Takeoff accidents/incidents occurred total of 94 cases. All cases led to overrun, and major cause is to initiate stopping maneuvers over $V_1$, takeoff decision speed, according to National Transport Safety Board of America. Similar results are represented in Aviation Safety Reporting System of National Aeronautics and Space Administration. So I believe that it is worth studying if Airplane Flight Manual, which is the reference Performance criteria, is appropriate to operations of line pilots. The definition of $V_1$ has been revised a couple of times and Rejected Takeoff Certification Standards for Transport Airplanes was changed in 1998. It shows that up to now there are some portions unreasonable. This study focused on gathering the pilot's tendency for current Rejected Takeoff Procedures of K airlines and analyze the factors they concern. I chose B777 airplane and actually measured the recognition and reaction time of the rejected takeoff transitions through Simulators. And compared the results with the data of flight test and Airplane Flight Manual.

• Journal of the Society of Disaster Information
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• v.16 no.4
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• pp.650-657
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• 2020

Purpose: In this study, the effectiveness of pilot project of PLSP (Priority Lane and Signal Preference) system, which was operated in Cheongju City, was analyzed. Method: The priority signal was operated by a police officer switching to a blue signal when approaching a fire truck through CCTV, and the priority lane of emergency vehicles was displayed on the road to enable preferential traffic. VISSIM simulation analysis was performed for the 1.2km section (3.8km) of the pilot project section and vehicle data was analyzed for some of the test operation sections. Result: Simulation analysis shows that the moving speed of the emergency vehicle can be increased by 42 km/h with the introduction of PLSP, which can be increased by approximately twice the speed. Travel time was reduced by about 3 minutes, and considerable improvements of 69% compared to cities that are not operating was analyzed. The pilot operation of Cheongju City showed a time-shortening effect of about two minutes on average, with the average time reaching 4 minutes and 14 seconds in the first period and the average time reaching 5 minutes and 40 seconds in the second period. Conclusion: The system has been shown to be effective in minimizing time-to-site arrival of emergency vehicles.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.15 no.6
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• pp.80-89
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• 2016

The median exclusive bus lanes with the purpose of improving public transport as part of a public transport promoting policy propel to improves the speed of the bus and guarantee punctuality security of public transportation for citizen satisfaction. In Median Exclusive bus lanes, Intersection operational methods are classified as turn prohibition, left turn, left turn U-Turn after turn prohibition. However, there are not clear criteria for applying for turn left U-Turn and related researches. The purpose of this study is to search a method for more safely operation when we operate turn left U-Turn in median exclusive bus lanes intersection. As a result, Bus stop in median exclusive bus lane should set back 12m for left turn, 17m for left turn U-turn during 60km/h and set back 13m for left turn, 17m for left turn U-turn during 50km/h.

• Journal of the Korean Society of Clothing and Textiles
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• v.19 no.1
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• pp.36-50
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• 1995

The purpose of this study was 1) to estimate the improvement of thermal storage/release and moisture transport properties of PEG-treated acrylic athletic socks and suggest the optimum add-on for PEG treatment, 2) to investigate wear performance of untreated cocks and two kinds of socks treated with PEG of minimum and optimum add-on respectively, and 3) to consider the effect of thermal storage/release and moisture transport properties of PEG- treated socks on the wear performance and the subjective comfort zone. Thermal activities of specimens treated by PDC were evaluated on a DSC by measuring the heat of fusion on heating and the heat of crystallization on cooling. Moisture regain, absorption speed, wickability, water retenti on value, and water-vapor permeability were measured. In the wear trials that the subjects performed a subsequent exercise protocol wearing three differently treated socks in a conditioned environment ($14\pm2^{\circ}C$, 65$\pm$2% R.H.), microclimate temperature and humidity, and subjective wear sensations including thermal sensation, wettedness, softness, fit, and overall comfort were obtained. PEC-treated specimens with more than 20% add-on showed thermal storage on heating and thermal release on cooling by a DSC and the heat contents of treated ones were generally proportional to the add-ons. Moisture transport properties were highly improved after PEG treatment and increased rapidly with increasing add-on. The tendencies were, however, relaxed above 50% add-on and the treated knits were much stiffer above that add-on. In the wear trials of untreated, PEG add-on 20%, and 50% acrylic socks, the changes of microclimate temperature of 50% socks were significantly less than that of 20% socks. PEG add-on 50% socks showed significantly less changes of microclimate humidity than other two kinds of socks. Three kinds of socks showed significant differences in overall comfort and add-on 50% socks were accepted more comfortable than other two kinds of socks. Comfort zone of foot was extended after PEG treatment on socks and it implied that the subjects wearing PEG- treated socks felt comfortable in wider ranges of microclimate temperature and humidity.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.1 no.1
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• pp.21-33
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• 1997

This dissertation deals with the design and VLSI implementation of the MTP(Multimedia Transport Protocol) protocol for the high speed networks. High throughput, functional diversity and flexible adaptation are key requirements for the future transport protocol. However it is very difficult to satisfy all these requirements simultaneously. Fortunately, the future networks will be very reliable. It means that the future transport protocol will usually perform some fixed functions without the protocol state information. According to this concept, we proposed and designed the MTP protocol that is consisted of Information Plane and Control Plane. Information Plane performs some fixed functions that are independent of the protocol state information as far as no error. However Control Plane manages the protocol state information and controls the operation of Information Plane. Our MTP protocol was finally implemented as an FPGA chip using the VHDL. We built a testbed for verification of the implemented protocol, and it was shown that the MTP protocol worked correctly and made a throughput of about 800 Mbps. Our future works include the addition of multiplexing and multicasting capabilities to our protocol for multimedia applications.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.14 no.6
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• pp.21-36
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• 2015

These days Automated Vehicle(AV) has been receiving attention as a fundamental solution to resolve the various transportation problems and various researches related to the benefits of AV have been done. However, previous researches mainly analyzed the effects in the virtual network. The purpose of this research is to predict and to find out the benefits by introducing the Automated Vehicle to present road traffic system. Thus, the study analyzes the traffic-flow changes of Gyeongbu freeway Seoul-Singal basic section which is planned for setting the test-bed. The results show that Automated Vehicle can have negative effects on the traffic-flow in low volume of LOS A and B. However, the average speed increases and the traffic density decreases in more than LOS C, the traffic volume increase. Therefore, the introduction of Automated Vehicle achieves positive effect on various transportation problems such as the traffic congestion.

• Journal of Environmental Science International
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• v.11 no.2
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• pp.111-120
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• 2002

Asian dust(or yellow sand) occurs mainly in spring and occasionally in winter in east Asia, when the weather conditions are under an upper trough/cut-off low and surface high/low pressure system during blocking episode days associated with the stationary patterns of the upper level jet stream. The transport mechanism for Asian dust during the blocking episode days in spring 2001 was analyzed using the TOMS aerosol index and meteorological mesoscale model 5(MM5). Based on the E vector, an extension of an Eliassen-Palm flux, the blocking episode days were found to be associated with the development of an upper cut-off low and surface cyclones. Concurrently, the occurrence of dust storms was also determined by strong cold advection at the rear of a jet streak, which exhibited a maximum wind speed within the upper jet stream. As such, the transport mechanism for Asian dust from China was due to advection of the isentropic potential vorticity(IPV) and isentropic surfaces associated with tropopause folding. The transport heights for Asian dust during the blocking episode days were found to be associated with the distribution of the isentropes below the IPV At the same time, lee waves propagated by topography affected the downward motion and blocking of Asian dust in China. The Asian dust transported from the dust source regions was deposited by fallout and rain-out with a reinforcing frontogenesis within a surface cyclone, as determined from satellite images using TOMS and GMS5. Accordingly, these results emphasize the importance of forecasting jet streaks, the IPV, and isentropes with geopotential heights in east Asia.