• Journal of Korean Society of Transportation
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• v.27 no.3
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• pp.161-168
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• 2009

The ubiquitous transportation system environments make it possible to collect each vehicle's position and velocity data and to perform more sophisticated traffic flow management at individual vehicle or platoon level through V2V and V2I communication. It is necessary to develop a new traffic management paradigm to take advantage of the ubiquitous transportation system environments. This paper proposed a preventive congestion management algorithm for uninterrupted flow, whose goal is to minimize the incident potential and maximize the productivity by maintaining traffic flow stability. The algorithm includes the following steps: Processing the raw data to produce the 3-dimension speed/flow/density profile and to produce the platoon profile and the shock wave profile, Determining the traffic state and the flow stability based on the processed data, Deciding the desirable speed the according the traffic flow state, and finally Providing the desirable speed information. It remains as further work to perform field experiments and calibrate the algorithm parameters.

• Journal of Korean Society of Transportation
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• v.17 no.1
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• pp.131-139
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• 1999

The quality of progression at signalized intersection has the largest potential effect. TRANSYT-7F is widely used to estimate the signal progression delay, but the progress of collecting and executing the compute program appears to be rather cumbersome. The research is to develop the analytical and progressing platoon delay model that is as simple as the methodology of HCM and familiar with the output of simulation model. The general approach to this research was conducted to examine the Rouphail and NCHRP 339 methodology together with the existing progression delay model (TRANSYT-7F. HCM). The scope is contained to be applicable only to cycles with no overflow queue and to obtain a comprehensive evaluation of the effects of changes in the quality of traffic signal progression on stopped delay and to be analyzed a simple mathematical method. The principle assumption for this model is that secondary flows is dispersed and partly mixed with average flow of the primary progressed flow. A second assumption is that through flow is consisted with the part of saturation flow at the front of it and the part of average flow at the rear of it. The delay equations vary for two arrival. The conclusion of this study could be summarized as 1)The evaluation of this model was consistently similar to that of TRANSYT-7F, 2) Platoon pattern has the real traffic flow characteristics. 3) The computing process of progression delay is made to have simple logic and easy calculation by integration, 4) This model could be estimated to be applied in almost all case.

• Convergence Security Journal
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• v.11 no.1
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• pp.49-56
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• 2011

Recently, the army make plans for the development of new conceptual military vehicles. As the development of military vehicles, we need selecting of considerable factors for solution of user's additional requirements, systematic and efficient development management of military vehicles. For this study, we made up questions from 4 specialist's groups about military vehicles as manager group, operator group, maker group, researcher group. There were 22 selected factors in the result of gathering the specialists' opinions and the result of this study will useful for hereafter development of military vehicles.

• 한국ITS학회:학술대회논문집
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• 2005.11a
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• pp.25-28
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• 2005

• Journal of Intelligence and Information Systems
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• v.16 no.1
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• pp.57-69
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• 2010

The ubiquitous transportation system environments make it possible to collect each vehicle's position and velocity data and to perform more sophisticated traffic flow management at individual vehicle or platoon level through V2V and V2I communication. It is necessary to develop a new data processing methodology to take advantage of the ubiquitous transportation system environments. This paper proposed to build 3-dimension data profiles to maintain the detailed traffic flow information contained in the individual vehicles' data and at the same time to keep the profiles from the meaningless fluctuations. Also methods to build the platoon profile and the shock wave speed profile are proposed, which have not been possible under ITS(Intelligent Transportation System) environments.

• Journal of the korean Society of Automotive Engineers
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• v.18 no.3
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• pp.34-44
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• 1996

IVHS(Intelligent Vehicle Highway System)는 현재 개별적으로 움직이는 차량들을 도로의 상황과 연계하여 종합적으로 통제하는 시스템으로서 차세대 차량 주행기술의 핵심이 될것으로 믿고 있다. IVHS는 운행중인 차량 또는 차량군의 위치, 속도, 목표점 등과 도로의 상황, 교통상태 등의 정보를 수집하고 필요한 조치를 실시간으로 시행하기 위하여 GPS(Global Positioning System), 차량-차량간, 차량-중앙 통제소간 또는 차량-도로간 센싱 및 송수신 기술을 필연적으로 활용하여야 한다. 이를 위하여 자동차 선진국들은 막대한 비용과 시설 투자를 하고 있으며, 실용성 검토를 위하여 1997년경에는 미국서부에 시험용 자동화 고속도로(AHS) 도로 건설도 계획중이다. 그러나 IVHS를 추구함에 있어서 중요한 사실은 완전 자동화된 고속도로 시스템을 구축하기까지 기술적으로, 사회적으로, 문화적으로 해결해야 될 많은 문제점들이 남아 있고 이들의 현실화까지는 수십 년이 소요될 지도 모른다는 것이다. 본 기고에서는 우선 IVHS 연구에 대한 포괄적인 설명에 이어서 단기간의 연구를 통해 부분적으로 상품화되고 있거나 될 수 있는 기술들을 몇가지 소개하고자 한다.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.5
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• pp.137-144
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• 2000

In this paper, a longitudinal control of the lead vehicle for a platoon in IVHS Regulation Layer is proposed. The backstepping method has been used for the controller design. This method has an advantage in that its stability need not be proven since the controller is designed based on the Lyapunov Function. The control object is that the lead vehicle tracks a reference velocity and maintains a safe distance between the inter-platoons while the followers are keeping the speed of the lead vehicle of a platoon. The coordinate of system is transformed to a new coordinate system for its convenience to design controller. The new coordinate system is composed of error and new error variable. The error is the difference between the safe distance and the actual distance of inter-platoons. A new error variable is the difference between the velocity of vehicle and the estimated state of a system operated by the virtual input. The Lyapunov function is obtained based on the variables of new coordinate system. In the computer simulation, several cases have been studied such as when the lead vehicle is tracking the optimal speed. or a lead vehicle of the following platoon tracks the velocity of the previous platoon while maintaining a safe distance. Also a nonlinear engine time constant case has been investigated. All the simulation results show that the designed controller satisfies the control object sufficiently.

• Journal of Korean Society of Transportation
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• v.26 no.3
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• pp.179-186
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• 2008

It is crucial in traffic flow management to maintain productivity and the traffic stability at the same time especially under congested traffic conditions. This issue has not been explicitly addressed under the intelligent transportation system environments. However, the ubiquitous transportation system environments make it possible to collect the data for each vehicle's position and velocity and to perform more sophisticated traffic flow management at individual vehicle or platoon level through V2V and V2I communications. In this paper, a preventive traffic flow management scheme is proposed, in which the objective is to maintain traffic flow stability while the productivity of the system is not decreased. The management scheme is proposed based on Greenshield's model because it is simple and easy to handle. It is considered that further research should be performed to evaluate the various traffic flow models.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.6
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• pp.2473-2481
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• 2013

The two characteristics of two-lane-and-two-way traffic flow are platoon and overtaking triggered by low-speed vehicle. It is crucial to develop a robust model which simultaneously generates the behaviors of platoon by low-speed vehicle and overtaking using opposite lane. Hence, a microscopic two-lane and two-way vehicle model was introduced (B. Yoon, 2011), which is based on CA (Cellular Automata) which is one of discrete time-space models, in Korea. While the model very reasonably explains the behaviour of overtaking low-speed vehicle in stable traffic flow below critical density, it has shortcomings to the overtaking process in unstable traffic flow above the critical density. Therefore, the objective of this study is to develope a vehicle model to more realistically explain overtaking process in unstable traffic flow state based on the model developed in the previous study. The experimental results revealed that the car-following model robustly generates the various macroscopic relationships of traffic flow generating stop-and-go traffic flow and the overtaking model reasonably explains the behaviors of overtaking under the conditions of both opposite traffic flow and stochastic parameter to consider overtaking in unstable traffic flow state. The vehicle model presented in this study can be expected to be utilized for the analysis of two-lane-and-two-way traffic flows more realistically than before.

• Journal of Energy Engineering
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• v.28 no.1
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• pp.30-36
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• 2019

The military has developed and operated a variety of military vehicles. Among them, medium tactical vehicles are developed as vehicles suitable for transporting troops, replacing existing military trucks, which have a significant impact on infantry forces' combat capability. Applying technology to increase fuel efficiency to these critical weapons systems, medium tactical vehicles, increases the distance range, which can reduce effective operational performance and oil costs. In this study, a measure was taken to improve the distance range of Medium Tactical Vehicles by applying an oil temperature control strategy to increase fuel efficiency.