• KSCE Journal of Civil and Environmental Engineering Research
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• v.38 no.2
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• pp.283-294
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• 2018

An accurate pedestrian-delay model is essential for the pedestrian-oriented evaluation of signalized intersection (SI). The crossing behaviors of pedestrians at signalized pedestrian crosswalks (SPCs) are various, and their arrival behaviors consist of two types, random and platoon. It is natural, hence, that the behaviors of pedestrian crossing and arrival should be considered in order to estimate accurate pedestrian delay. Despite this necessity, a simple pedestrian-delay model that cannot explain these behaviors of pedestrian movements is still recommended in Highway Capacity Manual (HCM). For these reasons, a pedestrian-delay model, suitable for various SPCs and SIs, is required to make pedestrian-oriented decisions on the design and operation of various SPCs and SIs. This paper proposes a novel pedestrian-delay model that is based on the behaviors of pedestrian crossing and arrival. The proposed model consists of two sub models: the one for SPC and the other for SI. The SPC delay model was developed based on the behaviors of pedestrian crossing during pedestrian green time. The SI delay model was designed based on the behaviors of pedestrian crossing and platoon arrival. The results of a numerical simulation showed that the proposed delay model can successfully overcome the under- and overestimation problems of the HCM model with explaining various behaviors of pedestrian crossing and arrival.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.10 no.1
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• pp.27-41
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• 2011

This research proposes new tram signal coordination model, called MAXBAND MILP-Tram for a passive tram signal priority strategy. The proposed model was formulated based on the MAXBAND model that was a traditional arterial signal optimization model. The model could calculate the bandwidth solutions for both general-purpose-lane traffic and median-tram-lane traffic. Lower progression speed are applied for the tram traffic considering lower running speed and dwell time at the stations. A phase sequence procedure determines the green times and left-turn phase sequences for tram traffic in median tram lane. To estimate the performance of the MILP-Tram model, the control delay of trams were estimated using the micro simulation model, VISSIM. The analysis results showed 57 percent decrease of the tram compared to the conventional signal timing model. The delay for car, however, increased 18 percent. The sensitivity analysis indicated that the passive tram signal priority strategy using the offset and phase sequence optimization was effective in reducing the person delay under the congested traffic condition.

• Journal of KIISE:Computing Practices and Letters
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• v.12 no.5
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• pp.312-325
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• 2006

Integration applications, such as EAI, B2Bi, need stable massive data processing systems during overload state cause by service request congestion in a short period time. In this paper, we propose the PLC (Peak Load Control)-based Worker-Linker pattern, which can effectively and stably process massive I/O transactions in spite of overload state generated by service request congestion. This pattern uses the delay time algorithm for the PLC mechanism. In this paper, we also show the example of applying the pattern to business-business integration framework and the experimental result for proving the stability of performance. According to our experiment result, the proposed delay time algorithm can stably control the heavy overload after the saturation point and has an effect on the controlling peak load.

• Journal of the Korean Society of Radiology
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• v.17 no.6
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• pp.993-999
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• 2023

Bio materials of fibrinogen and collagen are widely used in tissue regeneration engineering. In this study, I aim to create a new dual-structure support using these two materials. Strategically, tissue regeneration takes priority over blood vessel regeneration, so by forming a fibrinogen support that helps blood vessel formation on the outside of the double support and placing collagen, which is more effective in tissue regeneration, in the center, a synergistic effect in new tissue regeneration is expected. Although these two materials have been used interchangeably in previous studies, there has been no report yet on making a support through the formation of a support structure for the core system. Therefore, the core of this study, the double scaffold, is to propose a method for manufacturing a core structure with a collagen scaffold on the inside and fibrinogen on the outside. The experimental results showed that the fibrinogen located on the outside of the scaffold resulted in rapid biodegradation and drug release due to strategic biodegradation of the dual structure scaffold. On the other hand, collagen scaffolds were found to be able to maintain drug release time relatively longer than fibrinogen scaffolds. In conclusion, it is believed that applying the method of creating a double scaffold will have a synergistic effect on defective tissue regeneration.

• The Journal of the Korea Contents Association
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• v.16 no.8
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• pp.671-680
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• 2016

This research suggested a new real-time traffic signal control algorithm using fusion data of the travel time and the occupancy rate. This research applied the travel time data of traffic information system to traffic signal operation, and developed the signal control process using the degree of saturation that was estimated from the travel time data. This algorithm estimates a queue length from the travel time based on a deterministic delay model, and includes the process to change from the queue length to the degree of saturation. In addition, this model can calculate the traffic signal timings using fusion data of the travel time and the occupancy rate based on the saturation degree. The micro simulation analysis was conducted for effectiveness evaluation. We checked that the average delay decreased by up to 27 percent. In addition, we checked that this signal control algorithm could respond to a traffic condition of oversaturation and detector breakdown effectively and usefully. This research has important contribution to apply the traffic information system to traffic signal operation sectors.

• Journal of the Korea Convergence Society
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• v.8 no.7
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• pp.305-313
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• 2017

The purpose of this study is to investigate the effect of the level of participation in sports for the disabled on the community attachment. The subjects of this study were 227 persons with physical disabilities in D city. The analysis method was analyzed by factor analysis, frequency analysis, independent t-test, one-way ANOVA and multiple regression analysis using SPSS 21.0 program. The results of this study are as follows: First, there is a high level of community attachment to male(sex), 40's and 50's(by age group) and 1st and 2nd grade(by disability grade). Second, in the degree of participation, the duration of exercise and duration of exercise, duration of exercise in dependency, and duration of exercise and intensity of exercise were found to have a positive effect on identity. As a result, it affected the consciousness of local community. In future research, it is necessary to study the psychological effect connected with community.

• Journal of Korean Society of Transportation
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• v.19 no.3
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• pp.115-131
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• 2001

The Purpose of this study is to develop a simulation model for large-scale network with interrupted flow as well as uninterrupted flow. The Cell Transmission(CT) theory is used to simulate traffic flow. Flow transition rules have been newly developed to simulate traffic flows at merging and diverging sections, and signalized intersections. In the model, it is assumed that dynamic OD table is exogenously given. Simulation results for toy network shows that the model can explain queue dynamics not only in signalized intersections of urban arterials, but also in merging and diverging sections of freeway. In case study, the model successfully simulated traffic flows of 145,000 vehicles on CBD network of city of Seoul with 74 traffic zones, 133 signalized intersections among 395 nodes and 1110 links.

• International Journal of Highway Engineering
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• v.11 no.3
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• pp.121-128
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• 2009

This study has proposed the signal operating system to use both semi-actuated signal control and pedestrian push-button as a way to make up for the problems of 3 leg intersections which are operated inefficiently in the signal operation, one of the methods of traffic operations. In case of the semi-actuated signal control, it can reduce delay inside the intersection by serving to uncongested traffic on the main road where there is not much traffic volume on the secondary road and push-button signal can reduce unnecessary waiting time it could happen to vehicles by operating it though there is no pedestrian. Quantitative analysis was tried regarding the average delay reduction per vehicle using VISSIM, microscopic simulation program regarding how much effect it has compared with the existing signal control system and semi-actuated signal control system when the above two advantages are collected. The field test was performed for one three-leg intersection of Incheon. According to respectively signal control method pedestrian traffic changed and executed a sensitivity analysis. The result which compares the average delay time per a vehicle of scenarios, the signal control method of using the pedestrian push-button system in comparison with the fixed signal control method showed to decrease effect of a minimum 3.7 second (10%), a maximum 5.8 second (16%). When the pedestrian traffic volume was 20% or less of the measurement traffic volume, The signal control method of using the pedestrian push-button system appeared to be more efficient the semi-actuated signal control with object intersection.

• Journal of Korean Society of Transportation
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• v.33 no.5
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• pp.488-496
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• 2015

The main reason to install pedestrian pushbuttons is improving traffic operations. The current guideline for the installation of signal systems with pedestrian pushbuttons is car-oriented. It is difficult to clearly understand the guideline because there isn't an in-depth study to compare the pros and cons of the pedestrian- and vehicle-oriented methods in terms of waiting time. Thus, this study aims to estimate the waiting times of pedestrians and vehicles. The two delay times are compared considering the hypothetical circumstances such as geometry, pedestrian crossing time, pedestrian/vehicle counts and arrival distribution. The results show that when the pedestrian traffic volume exceeds 97 ped/h in the case of a two-lane road (one lane in each direction) the pushbutton system is effective and beneficial to pedestrians. It means that the total waiting time of pedestrians is less than the one of vehicles. Additional four scenarios are designed and tested by varying the number of lanes and design speeds. In conclusion, the pushbutton signal is more beneficial for pedestrians when the number of pedestrians is less than or equal to 85, 70, and 70 ped/h for the three-lane scenario, the four-lane with the design speed of 80km/h scenario, and the four-lane with the design speed of 100km/h, respectively.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.3
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• pp.927-935
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• 2013

In this study, reservoir routings for 1 hour-50 year precipitation frequency were carried out at the Engineering Water Fall and the Amphitheater located at the downstream of Seoul National University Dam. Main analysis was focus on the following matters: (1) storage amount by the tank; (2) reduction of the outflow and the peak water surface elevation; (3) change of phase lag time; and (4) design of new boxes at the inlet and outlet of storage tank. As for the storage tank of $25,000m^3$ built in the Amphitheater area, the tank induced 49.43 % storage effect, 28 min. phase lag time, and reduced the peak outflow by 49.64 %. In addition, the peak water surface elevation was lowered by 35 cm compared with that of $15,000m^3$ storage tank. It is concluded that combined management of previous storage facility and new underground storage tank would control the excessive rainfall runoff efficiently.