• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.23 no.1
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• pp.26-41
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• 2024

To ensure safer road conditions, understanding the human factors influencing driving behavior is crucial. However, there are many difficulties in deriving the characteristics of individual human factors that affect actual driving behaviors. Therefore, this study analyzes self-reported dangerous-driving propensities in order to explore potential correlations with drivers' behaviors. The goal is to propose a method for assessing driving tendencies based on varying traffic scenarios. The study employed a questionnaire to gauge participants' propensity to drive dangerously, utilizing a simulator to analyze their driving behaviors. The aim is to determine any notable connections between dangerous-driving propensity and specific driving behaviors. Results indicate that individuals exhibiting a high propensity for reckless driving, as identified by the Korean DBQ, tend to drive at higher speeds and display more aggressive acceleration patterns. These findings contribute to a potential method for assessing reckless driving drivers.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2004.11a
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• pp.73-80
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• 2004

Recently, many maritime accidents have been increased and the collisions due to human error are given a great deal of proportions out if them We develop the Real-time Collision Risk Monitoring System (CRMS) for the navigational officers to cope with the emergency situation promptly and thus to reduce the probability if casualty. In this study, the risk of collision is evaluated by two kinds if method. The first method is based on Fuzzy algorithm, which evaluates the risk of collision between traffic ships. The second method is based on Environmental Stress (ES) Model, where the total risk if collision is evaluated by the environmental stress felt by human. The developed real-time CRMS has been installed to the ship handling simulator system and its capabilities have been tested through simulator experiments.

• Journal of Korean Society of Transportation
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• v.29 no.4
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• pp.65-71
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• 2011

It is practically hard to measure vehicle fuel consumption required to evaluate the energy-related governmental policies and traffic management strategies; the existing methods are too simplified due to the limited field data available. Existing methods are even unable to reflect the amount of fuel consumed when vehicles accelerate and decelerate, and such technical limitations have reduced the quality of the policy evaluation. This study proposes a new fuel consumption model that simultaneously considers the effects of both cruising speed and acceleration/deceleration of vehicles. A new fuel consumption model was developed based on the simulation data generated by AVL Cruise, a vehicle simulation program. The estimated by the proposed model was compared against the one from the existing method. Comparison results showed that the proposed model provided much reliable estimate (fuel consumption) than the other did.

• KIISE Transactions on Computing Practices
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• v.20 no.12
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• pp.688-693
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• 2014

With the advent of ubiquitous environments, the smart phone has come into wide use and the demand for various content increases. Thus, in order to efficiently utilize limited resources cognitive radio technology is regarded as a possible solution. Besides spectrum sensing or access schemes, the provision of VoIP traffic service for secondary users with limited spectrum resources is a very important issue. In this paper, a resource allocation and control system for VoIP QoS provision in cognitive radio networks is proposed. Firstly, as the system model, the time structure of the network is addressed and, according to the structure, a bandwidth broker is proposed. In addition, based on available bandwidth estimated by the bandwidth broker, a connection admission control for secondary users is developed. It is demonstrated that the provision of VoIP QoS is greatly affected by channel utilization, the number of channels, and the length of timeslot.

• Journal of Korean Society of Transportation
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• v.30 no.5
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• pp.3-10
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• 2012

This study dealt with traffic accidents occurring within roundabouts. The objective was to develop roundabout accident models for different driving types by using simultaneous equations. In pursuing the above, this study used a statistical program SPSS 17.0 to accommodate data from 148 accidents occurred within 39 roundabouts of Korea. In addition, the 2SLS(2 stage least square) estimation method was adopted to calibrate the models. The main results are as follows. First, both the number of accidents and the EPDO were evaluated to have bilateral relationships. Second, all 6 different simultaneous equation models according to driving types were found to be statistically significant. Third, the developed models were compared to each other with respect to either common or specific variables. Finally, variables such as ADT, conflicting rate, heavy vehicle ratio, circulatory roadway width, number of circulatory roadway lane, approach lane width, average approach lanes, parking places, and bus stops were selected as independent variables for the models.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.10
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• pp.2263-2268
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• 2015

This paper describes packet scheduling techniques that can be used to alleviate the impact of interference. The mechanism is consisted of interference estimation and master delay police. Proposed scheduling police is effective in reducing packet loss and delay. Another advantage worth mentioning, are the additional saving s in the transmitter power since packet are not transmitted when channel is bad. This paper gives that scheduling policy works only with data traffic since voice packets need to be sent at fixed intervals. However, if the delay variance is constant and the delay can be limited to a slot, it may be worthwhile to use DM packet for voice.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.24 no.4
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• pp.351-358
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• 2006

The farming and fishing village roads is located in a mountainous geographical feature, a resident's movement zone is followed by many restrictions in economic activities or social activities. Establishment of general planning gets into guide of long-term development direction for road in farming and fishing villages area. This study examined and analyzed a regional characteristics such as a regional environment and traffic condition, etc. and an actual condition of farming and fishing village roads, selected a factor affecting a priority to open a road, calculated a weight per each factor by AHP & Statistical analysis techniques, converted it into GIS database, and determined a priority for paying forming and fishing village roads. It is that development precedence and estimation calculation are decided applying result of research, GIS and AHP and statistical processing techniques.

• The Journal of Korean Institute of Next Generation Computing
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• v.13 no.5
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• pp.104-112
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• 2017

The CRE (Cell Range Expansion) that selects the small cell with more efficient uplink resources has been developed by 3GPP to relieve the problem of the traffic imbalance due to the power differences between macro and small cells in HetNet. In addition, ABS (Almost Blank Subframes) has been proposed to resolve the signal interference problem due to the operation CREs. This paper proposes an effective method to calculate the ABS ratio by considering the proportion of the number of UEs in CRE and macro cell ranges, as well as the number of small cells in a macro cell. The proposed method has been implemented on the LTESim simulator, and compared with previously proposed methods. The experimental results show that the proposed method can improve the throughput and packet loss ratio performances. In particular, it is also shown that CRE bias values affect those performances, and there exist effective CRE bias values to derive the best performances.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.3A
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• pp.291-303
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• 2006

In this paper, we analyze functional requirements of the IEEE 802.22 WRAN, and propose a downlink 프레임 structure satisfying the requirements. The proposed downlink 프레임 structure maximizes e transmission efficiency by adopting the cognative radio to assign the sub-channel by reflecting the channel environment of WRAN. We also calculate the signalling overhead for both downlink and uplink, and analyze the performances of time synchronization, frequency synchronization and cell identification based on the 프리앰블 in downlink and suggest the channel estimation method tough 프리앰블 or pilot. As a final result, e stationary beamforming (SBF) algorithm with dynamic channel allocation(DCA) is proposed. The proposed OFDMA downlink 프레임 structure with channel adaptive sub-channel allocation for cognitive radio applications is verified to meet the requirements of IEEE 802.22 WRAN, by computer simulations.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.21 no.2
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• pp.74-84
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• 2022

Vehicle average speed information which measured at a point or a short section has a problem in that it cannot accurately provide the speed changes on an actual highway. In this study, segment separation method based on vehicle big data for accurate micro-speed estimation is proposed. In this study, to find the point where the speed deviation occurs using location-based individual vehicle big data, time and space mean speed functions were used. Next, points being changed micro-scale speed are classified through gradual segment separation based on geohash. By the comparative evaluation for the results, this study presents that the link-based speed is could not represent accurate speed for micro-scale segments.