• Journal of Korean Society of Transportation
• /
• v.18 no.6
• /
• pp.89-99
• /
• 2000

To cope with the limits of conventional O-D trip matrix collecting methods, several approaches have been developed. One of them is bilevel Programming method Proposed by Yang(1995), which uses Sensitivity Analysis Based(SAB) algorithm to solve Generalized Least Square(GLS) problem. However, the SAB a1gorithm has revealed two critical short-comings. The first is that when there exists a significant difference between target O-D matrix and true O-D matrix, SAB algorithm may not produce correct solution. This stems from the heavy dependance on the historical O-D information, in special when gravel Patterns are dramatically changed. The second is the assumption of iterative linear approximation to original Problem. Because of the approximation, SAB algorithm has difficulty in converging to Perfect Stackelberg game condition. So as to avoid the Problems. we need a more robust and stable solution method. The main purpose of this Paper is to show the problem of the dependency of Previous models and to Propose an alternative solution method to handle it. The Problem of O-D matrix estimation is intrinsically nonlinear and nonconvex. thus it has multiple solutions. Therefore it is necessary to require a method for searching globa1 solution. In this paper, we develop a solution algorithm combined with genetic algorithm(GA) , which is widely used as probabilistic global searching method To compare the efficiency of the algorithm, SAB algorithm suggested by Yang et al. (1992,1995) is used. From the results of numerical example, the Proposed algorithm is superior to SAB algorithm irrespective of travel patterns.

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.10 no.5
• /
• pp.23-35
• /
• 2011

The pedestrian green time is usually long at wide width intersections. This sometimes causes the increase of delay on the whole intersection because of long cycle length and thus small g/C ratio on some direction. In this paper, to improve these problems, staggered pedestrian crossing was evaluated on the vehicular and pedestrian aspects. The results were gained by using both TRANSYT-7F and VISSIM model. The vehicle control delay of the staggered pedestrian crossing was estimated to be decreasing than that of the general pedestrian crossing by 14.9% to 85.6%. The pedestrian average delay of two pedestrian crossing systems was examined by analytical method and VISSIM. According to the analytical method there was no significant difference between each pedestrian crossing system. The pedestrian delay of staggered pedestrian crossing was from 13.4% to 22.3% than the general pedestrian crossing by VISSIM. In conclusion, the staggered pedestrian crossing was more effective than general pedestrian crossing for both the vehicle and the pedestrian. However this conclusion was resulted from micro simulation where traffic volume condition, v/c, was from 0.8 to 1.1.

• Journal of Arbitration Studies
• /
• v.19 no.3
• /
• pp.93-119
• /
• 2009

Nowadays the number of crimes is increasing rapidly and society is getting more and more dangerous. Recently the criminal aspect of our society, the intelligence, diversity, localized area, as well as for the crime victims also difficult to predict the damage recovery is not easy to change their level of pain and are also serious. This phenomenon is increasingly expected to intensify, the proper response is a factory. The more so if the victim of murder. The criminal mediation working on the operational adjustments Borrower payment, Construction charges, investments and financial transactions due to interpersonal conflicts that occurred as a fraud, embezzlement, breach of trust property crimes such accused, individuals between the defamatory, offensive, encroachment, violating intellectual property rights and private Disputes about the complaint case and other criminal disputes submitted to mediation to resolve it deems relevant to the case who are accused. But the core of a detective control adjustment, adjust the members' representative to the region, including front-line player or a lawyer appointed by the attorney general at this time by becoming parties to this negative view may be ahead. Some scholars are criticizing the current criminal justice system for the absence of proper care for the criminal victims, as an alternative to the traditional criminal justice system. The introduction of the summary trial and related legal cases, the command structure, compensation system, crime victims' structural system can be seen as more classify, crime subject to victim's complaint, By case with a criminal misdemeanor in addition to disagree not punish criminal, minor offense destination, traffic offenders, regular property crime, credit card theft, intellectual property rights violators can be seen due to more categories can try. They sued in law enforcement, Prosecution case has been received and if any one party to the criminal detective Arbitration request arbitration by the parties can agree to immediately contact must be referred to arbitration within 15 days of when the arbitration case will be dismissed. These kinds of early results of the case related to, lawyers are involved directly in the arbitration shall be excluded. Arbitration system is the introduction of criminal justice agencies working to help resolve conflicts caused by adjustment problems will be able to. This article does not argue that we should stick to the traditional justice system as a whole. Instead it argues that the restrictive role of the traditional justice is to be preserved.

• Journal of the Korean Geosynthetics Society
• /
• v.15 no.2
• /
• pp.45-54
• /
• 2016

Double deck tunnels are considered to have a large demand in a near future for solving traffic congestion problems and overcoming the limitations in constructing new tunnels. This study presents a numerical investigation using finite element (FE) analysis on the behaviors of the tunnels and the stability of pillars in a divergence section where single tunnel is diverged from a main line double deck tunnel. The effects of the separation distance between the diverged and the main tunnels and the ground condition were examined through the FE analysis by varying the separation distance from 0.1D to 2.0D (D: diameter of main tunnel) and the rock class from class I to V, respectively, and the analysis results were compared with those using empirical methods, strength-stress ratio, and the volume of interference. The FE analysis results indicated that the separation distance has a larger effect on tunnel behaviors, compared with the rock strength, and a single tunnel with a large cross section is more favorable than two separated tunnels for tunnel stability when the separation distance is below 0.7D.

• Journal of Broadcast Engineering
• /
• v.25 no.4
• /
• pp.609-619
• /
• 2020

In accordance with a demand for high quality video streaming, it needs high data rate in limited bandwidth and more traffic congestion occurs. In particular, when providing real time video service, packet loss rate and bit error probability increase significantly. To solve these problems, a raptor code, which is one of FEC(Forward Error Correction) techniques, is pervasively used in the application layers as a method for improving real-time service quality. In this paper, we propose a method of determining image transmission parameters based on various deep neural networks to increase transmission efficiency at a similar level of image quality by using raptor codes. The proposed neural network uses the packet loss rate, video encoding rate and data rate as inputs, and outputs raptor FEC parameters and packet sizes. The results of the proposed method present that the throughput is 1.2% higher than that of the existing multimedia transmission technique by optimizing the transmission efficiency at a PSNR(Peak Signal-to-Noise Ratio) level similar to that of the existing technique.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.18 no.10
• /
• pp.559-568
• /
• 2017

recent times, the monthly rent in the Jongno-gu Historical and Cultural Street in Seoul has rapidly increased, because of the presence of large-scale franchises and the entry of private investment into the traditional and local businesses focusing on Bukchon, Seochon, Insa-dong, and Samcheong-dong. As a result, the business environment for these merchants has worsened, due to the increasing economic burden. In order to maintain the business environment of the merchants, it is necessary to evaluate the potential for establishing a regional commercial area, in order to resolve the problems of the existing commercial areas and to improve the locational, economic, cultural and political environment. This study analyzed the factors influencing the merchants' satisfaction with the business environment as a function of their age, by considering three age groups, viz. 30-49, 50-59, and more than 60, considering the locational, economic, cultural and political environment of the merchants. Among the factors influencing the satisfaction with the business environment, the merchants in their 30s and 40s placed more emphasis on the traffic accessibility, floating population, store premium and monthly rent than the other age groups. Among the factors influencing the satisfaction with the business environment, the merchants in their 50s placed more emphasis on the cultural organization, artist activities, expansion of community support facilities, and banning of franchises in certain locations than the other age groups. Among the factors influencing the satisfaction with the business environment, the merchants over 60 years old placed more emphasis on the walking accessibility, monthly sales, merchant community, preservation of historical and cultural landscape, and commercial protection of the government than the other age groups.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.16 no.10
• /
• pp.6604-6610
• /
• 2015

In this paper, an efficient Wireless Access in Vehicular Environment (WAVE) packet transmission scheme for railroad communication is proposed. WAVE communication is a wireless local area network (WLAN) based communication and it is developed to be suitable for vehicular communication. There has been a lot of study on WAVE's applicability to Intelligent Transport System (ITS). As one of main transportation methods, by using WAVE, quality of railroad communication including WLAN based Communication Based Train Control (CBTC) can be enhanced and variety of railroad communication systems can be integrated into WAVE. However, there are technical challenges to adopt WAVE in railroad communications. For the simplest single-PHY WAVE, time division alternation of 50ms between Control Channel (CCH) and Service Channel (SCH) is required. Since there are delay sensitive railroad traffic types, alternation operation of CCH and SCH may cause performance degradation. In this paper, after identifying a couple of problems based on detailed analysis, a novel packet transmission scheme under railroad environment is proposed. In order to verify if the proposed scheme meets the requirement of railroad communication, WAVE transmission is mathematically modeled.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.21 no.3
• /
• pp.246-252
• /
• 2020

Safety accidents have been reported due to falling accumulated snow from cables of cable-supported bridges. In addition to the direct damage caused by falling snow, secondary damage, such as traffic accidents, can occur. Various methods have been proposed to prevent these accidents, but there are still problems in safety and practicality. In this study, a cable robot type was selected as one of the active methods for removing accumulated snow on cables. An attempt was made to increase the climbing ability of the robot to improve the efficiency of snow removal. In addition, the available range of cable diameter for the robot can be adjusted flexibly to be applied to cables used in the field. A high-resolution camera was also installed to check the surface condition of the cable in real time to increase the utility, and be used as a cable inspection robot. A three-axis accelerometer and a tension conversion algorithm were added to measure the tension force of cables. To verify the performance, indoor and field experiments were conducted, and future improvements for the inspection robot were proposed.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.35 no.3
• /
• pp.607-616
• /
• 2015

The demand for cars has been so steadily increasing based on the economic growth that the number of registered cars reached 18,870,000 as of the end of December, 2012. Due to this, the demand for the parking lots also rises continuously. Because of the limited ground space, the buildings ever becoming larger, and the trend of underground parking spaces, recent parking spaces are generally constructed underground. Accordingly, the parking lot ramps slope is limited to less than 17% by relevant laws to ensure the driver safety. However, when a driver enters a parking lot ramps whose slope is slightly steep, he frequently experiences his car body colliding with ramp brackets and often sees the scratches on ramp floor. Thus, this study is intended to prevent any damage to a structure and to contribute to ensuring the riding comfort and safety of drivers and passengers by presenting the details of proper vertical curve to prevent the collision of vehicles with ramp brackets through a vertical analysis of the first and last parts of a parking lot ramps. Because it is necessary to decide the appropriate and suitable vertical slope of a parking lot ramps, this study first identified the problems through site inspection, targeting the parking lot ramps of large buildings frequently that are used by many random people. Next, the possibility of mutual collision was assessed through a theoretical analysis of the first and last parts of a parking lot ramps. Lastly, the vertical curve of a parking ramp was analyzed to estimate its details, which was presented in this study. In conclusion, if the vertical curve presented through this study is used, it will help prevent any damage to the cars and structures, ensure the riding comfort and safety of the drivers, and further reestablish the criteria for vertical installation of a parking lot ramps.

• Journal of Korean Society of Transportation
• /
• v.25 no.2 s.95
• /
• pp.17-26
• /
• 2007

Because the prime objective of the current preemption methods at signalized intersections near highway-railroad grade crossings(IHRGCs) is to clear the crossing, secondary objectives such as safe pedestrian crossing time and minimized delay often are given less consideration or are ignored completely during the preemption. Under certain circumstances state-of-the-practice traffic signal preemption strategies may cause serious pedestrian safety and efficiency problems at IHRGCs. An improved transition preemption strategy(ITPS) that is specifically designed to improve intersection performance while maintaining or improving the current level of safety was developed by Cho and Rilett. Even if the new transition preemption strategy improved both the safety and efficiency of IHRGCs, the performance of the strategy is affected by train speed. Understanding the impact of this factor is essential in order to implement ITPS. In this paper, the effects of train speed were analyzed using a VISSIM simulation model which was calibrated to field conditions. It was concluded that the delay is affected more by train speed than the transitional preemption strategy and the safety of the intersection is not affected by train speed once an advanced preemption warning time(APWT) is equal to or greater than 90 seconds.