• The Journal of the Acoustical Society of Korea
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• v.18 no.1
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• pp.72-77
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• 1999

In this paper, we propose a wavelet VQ approach to modeling VBR broadcast video traffic. The proposed method decomposes video traffic into two parts via wavelet transformation, and models each part separately. The first part, which is modeled by an AR(1) process, serves to capture the long-term trend of the traffic; the second part, classified via vector quantization, addresses the short-term behavior of the traffic. Compared with other VBR video models, our model has three advantages. First, it allows the separate modeling of long- and short-term behavior of the video traffic; second, it preserves the periodic coding structure in traffic data; and third, it provides an unified approach for the frameand slice-level traffic modeling. We demonstrate the validity of our model by statistical measurements and network performance simulation.

• International Journal of Highway Engineering
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• v.14 no.4
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• pp.163-173
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• 2012

PURPOSES : The purpose of this study is to check the possibilities of traffic pattern analysis using MatSIM for urban road network operation in incident case. METHODS : One of the stochastic dynamic models is MatSIM. MatSIM is a transportation simulation tool based on stochastic dynamic model and activity based model. It is an open source software developed by IVT, ETH zurich, Switzerland. In MatSIM, various scenario comparison analyses are possible and analyses results are expressed using the visualizer which shows individual vehicle movements and traffic patterns. In this study, trip distribution in 24-hour, traffic volume, and travel speed using MatSIM are similar to those of measured values. Therefore, results of MatSIM are reasonable comparing with measured values. Traffic patterns are changed according to incident from change of individual behavior. RESULTS : The simulation results and the actual measured values are similar. The simulation results show reasonable ranges which can be used for traffic pattern analysis. CONCLUSIONS : The change of traffic pattern including trip distribution, traffic volumes and speeds according to various incident scenarios can be used for traffic control policy decision to provide effective operation of urban road network.

• Journal of the Ergonomics Society of Korea
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• v.29 no.4
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• pp.619-624
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• 2010

The traffic accidents of the aged are increasing because old people generally experience a decline of physical functions and judgment but their dependence on automobiles increases. In order to investigate the older drivers' response to traffic signs and surrounding environment according to changing driving brightness, this study measured the visual cognitive behavior, driving behavior, and subjective evaluation while the driving brightness was changed using a driving simulator. Furthermore, the drivers who recognized traffic signs and those who did not were compared. As a result, it was found that some older drivers had declined ability of cognition, some failed to adapt to rapid brightness change even if sufficient attention was given to traffic sign, and some could not safely control the vehicle when approaching intersections. Therefore, the development of support systems for aged drivers in traffic environment is necessary in the future.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.33A no.4
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• pp.68-77
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• 1996

In this paper, we investigate the effect of a LAN traffic on the performance of a shared buffer ATM switch andIWF (interworking function )on a LAN environment through simulations. Firstly, the delay and the buffer occupancy of the switch and IWF are mesured according to the proportion of the LAN traffic to the traffic generated by gernoulli process. Secondly, we investigate the behavior of the switch in the case that LAN traffic is concentrated to a connectionless server, and the effect of LAN traffic shaping at IWF on the delay and the buffer occupancy of the switch.

• Korean Journal of Culture and Social Issue
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• v.9 no.spc
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• pp.57-73
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• 2003

This paper attempts to identify that the speeding behavior is the important factor in traffic accident by analysing the background and process of speeding behavior. The structure of hurried behavior is reviewed to explain the relationship between the speeding behavior and hurried behavior. And the process of speeding behavior which becomes his own attitude and behavior in driving by social customs approval is analysed by risk homeostasis theory. The results of attitude survey show that drivers speeding behavior is not changing even though they know that speeding behavior is main factor in traffic accident. The influence structure among hurried behavior, background and process of speeding behavior should be analysed to understand the actual speeding behavior in driving.

• Journal of Korean Society of Transportation
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• v.25 no.2 s.95
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• pp.95-105
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• 2007

Speeding and drunken driving make drivers fail to detect hazards and cope with various driving situations. These behaviors also raise the possibility of being involved in traffic accidents and tend to increase the number of fatalities. The authors compared the driving behavior determinants of a rockless drivers group, consisting of individuals who have committed traffic accidents or offended regulations through drunken driving, with a normal drivers group. In the results, the reckless drivers group showed high scores of 'speeding' and 'drunken driving', and they also stated that they had more experiences of speeding, drunken driving and traffic accidents. In the path analysis study, it was found that the impacts of the rockless drivers group's 'risk sensitivity' and 'situational adaptability' on traffic accidents were stronger than those of normal drivers. This means 'risk sensitivity' and 'situational adaptability' can explain the origins of traffic accidents better in the reckless drivers group than accidents of the normal drivers group.

• Korean Security Journal
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• no.7
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• pp.155-189
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• 2004

The mission of the police as described by law is to guard the life, body and property of all citizens. Such duties should be accurately performed based on legal and democratic procedures because the works of the police are directively influencing the overall lives of the citizens by restricting their freedom. We are frequently watching the traffic police on the street or road. Traffic policing aims to reduce crime and the opportunities for criminal activity in relation to the use of roads, that is to improve road user behavior in order to reduce accidents. The characteristics of traffic accident change is not similar in each traffic condition. The purpose of this study is to analysis a type characteristics of traffic accident change, such as number of deaths and wounded persons by the time, the vehicle, the type the road, the age group. Based on the characteristics of traffic accident change, traffic accident countermeasures are proposed, in which some variable of traffic policies such as traffic facilities, traffic regulation, and traffic safety education.

• Journal of the Ergonomics Society of Korea
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• v.29 no.3
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• pp.337-345
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• 2010

The purpose of this study was to investigate the effects of sleep/wake behavior for shiftwork in air traffic controllers (ATCs) using wrist actigraph for ten workers on a continuous full-day three-team three-shift system of forward rotation including on-duty and off-duty periods. The wrist actigraph data were recorded for three days (one shift cycle) for each subject. The mean activity counts during an on-duty period progressively increased from the night, the swing, to the morning shifts. The doze length during on-duty periods showed decreases in the morning and swing shifts as compared to the night shift. Total sleep time (TST) and sleep efficiency (SE) during off-duty periods increased in the morning-1 and swing-night shift compared to the morning-2 shift. Finally, I discussed the role of doze-taking during the burden on night shift ATCs.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1996.04a
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• pp.543-546
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• 1996

Recently, some research has been done to analyze the asymptotic behavior of queue length distribution in ATM (Asynchronous Transfer Mode) multiplexer. In this paper, we relate this asymptotic behavior with the asymptotic behavior of decreasing cell loss probability when the buffer capacity is increased. We find with reasonable assumptions that the asymptotic rate of queue length distribution is the same as that of decreasing cell loss probability. Even under different priority control schemes and traffic classes, we find that this asymptotic rate of the individual cell loss probability of each traffic class does not change. As a consequence, we propose the upper bound of cell loss probability of each traffic class when a priority control scheme is employed. This bound is computationally feasible in a real-time. The numerical examples will be provided to validate this finding.

• Journal of the Korean GEO-environmental Society
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• v.5 no.1
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• pp.65-73
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• 2004

The analysis of corrugated steel pipes is depending on a second dimension frame analysis or compressed ring model. This is the analysis not to consider the behavior of soil-structure interaction. The behavior of load resistance system is varied according to the depth of cover and the spacing of corrugated steel pipes structure. Therefore, the behavior characteristic of corrugated steel pipes was confirmed through finite element analysis to consider the activity of soil-structure interaction. If soil cover is filled up to the more of optimal depth, behavior of corrugated steel pipes are similar to those of ductile steel pipes according to the earth pressure distribution and effects of traffic loads are decreased. But, If soil cover is filled up to the less of optimal depth, corrugated steel pipes can't behave completely as ductile steel pipes because the passive earth pressure acting on side of corrugated steel pipes is decreased according to the decrement of vertical earth pressure, and the traffic loads influence on the section forces is increased, so that the traffic loads dominated the behavior of corrugated steel pipes.