• Title/Summary/Keyword: Safe speed

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Determination of Proper Design Speed at Inter-Change Ramp in a Highway (입체교차로 유.출입 접속부의 적정 설계속도 결정)

  • Choi, Seok-Keun;Lee, Seon-Gyu;Lee, Jae-Kee
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.24 no.5
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    • pp.425-431
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    • 2006
  • Recently, the government has adjusted the 4th National Master Plan in an effect to achieve balanced national land development. However, the current traffic accident index ranks among the lowest in OECD countries, ranking 25th out of 29 countries. Therefore, this study is aimed at indicating problems with National Expressway and local roads developing a solution by analyzing the problems and suggesting the most appropriate design speed for inter-changes where the traffic accidents occur frequently. With the results, it is to obtain a design speed decision formula at interchange branch points to prevent traffic accidents, secure safe and optimal road conditions and maximize traffic load capability.

Core Technologies of Superconducting Magnet for High-speed Maglev and R&D Activities in Korea (초고속 Maglev용 초전도 마그넷 요소 기술 및 국내 연구 개발 현황)

  • Lee, Chang-Young;Kang, Bu-Byoung;Han, Young-Jae;Sim, Ki-Deok;Park, Dong-Keun;Ko, Tae-Kuk
    • Proceedings of the KSR Conference
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    • 2009.05a
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    • pp.1454-1460
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    • 2009
  • Ultra-speed tube train, which runs in vacuum atmosphere to overcome aero-dynamic dragging force, is considered as a high-speed ground transportation system to back up long-distance air travel. To realize the ultra-speed tube train, feasibility study of currently available Maglev technologies especially for propulsion and levitation system is needed. Propulsion by linear synchronous motor(LSM) and levitation by electro-dynamic suspension(EDS) which are utilized in the Japan's MLX system could be one of candidated technologies for ultra-speed tube train. In the LSM-EDS system, the key component is superconducting magnet, and its reliability and performance is very important to guarantee the safe-operation of Maglev. As the initiative of the feasibility study, this paper deals with the basic structure of superconducting magnet and core technologies to design and operate it. And by surveying the current R&D achievement in Korea, the nation's capability to develop advanced superconducting magnet for Maglev is presented.

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A new look at the restrictions on the speed and magnitude of train loads for bridge management

  • Aflatooni, Mehran;Chan, Tommy H.T.;Thambiratnam, David P.
    • Structural Engineering and Mechanics
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    • v.53 no.1
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    • pp.89-104
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    • 2015
  • In current bridge management systems (BMSs), load and speed restrictions are applied on unhealthy bridges to keep the structure safe and serviceable for as long as possible. But the question is, whether applying these restrictions will always decrease the internal forces in critical components of the bridge and enhance the safety of the unhealthy bridges. To find the answer, this paper for the first time in literature, looks into the design aspects through studying the changes in demand by capacity ratios of the critical components of a bridge under the train loads. For this purpose, a structural model of a simply supported bridge, whose dynamic behaviour is similar to a group of real railway bridges, is developed. Demand by capacity ratios of the critical components of the bridge are calculated, to identify their sensitivity to increase of speed and magnitude of live load. The outcomes of this study are very significant as they show that, on the contrary to what is expected, by applying restriction on speed, the demand by capacity ratio of components may increase and make the bridge unsafe for carrying live load. Suggestions are made to solve the problem.

An Empirical Study on method to Reduce of Human Error of High-Speed Train Drivers (고속철도 운전직무의 휴먼에러 감축방안을 위한 실증적 연구)

  • Joo, Chang Hoon;Kim, Tae Gil;Lim, Jeong Oun;Kang, Kyung Sik
    • Journal of the Korea Safety Management & Science
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    • v.16 no.2
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    • pp.1-9
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    • 2014
  • This study tried to propose plan to prevent human error of railroad driver among human error of railroad worker which takes great share in railroad accident. For this, in order to maintain correlation between the accident actually occurred after the opening of high-speed railroad and experience of accident that did not happened, survey on respondent was analyzed by conducting survey on KTX captain who is working in driving work of high-speed railroad, and instruction management team manager who manages KTX captain and captain. This thesis classified the factors by human factor, job factor, environment factor, organization factor, and established human error management model by comparing and analyzing how each factors have spatial interrelations with a railroad accident. The purpose of this study is to contribute to make safe railroad, and reliable railroad by preventing human error accident by minimizing human error of high-speed railroad drivers, and improving driving workers to cope accurately and fast with irregularities through various institutional improvement, improvement of driving facilities, improvement of operating room environment, and improvement of education system.

Prevention System for Real Time Traffic Accident (실시간 교통사고 예방 시스템)

  • Hong You-Sik
    • Journal of the Korea Society of Computer and Information
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    • v.11 no.4 s.42
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    • pp.47-54
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    • 2006
  • In order to reduce traffic accidents, many researchers studied a traffic accident model. The Cause of traffic accidents is usually the mis calculation of traffic signals or bad traffic intersection design. Therefore, to analyse the cause of traffic accidents, it takes effort. This paper, it calculates the optimal safe car speed considering intersection conditions and weather conditions. It will recommend calculation of 1/3 in vehicle speed when there are rainy days and snow days. But the problem is that it will always display the same speed limit when whether conditions change. In order to solve these problems, in this paper, it is proposed the calculation of optimal safety speed algorithm uses weather conditions and road conditions. Computer simulations is prove that it computes the traffic speed limit correctly, which proposed considering intelligent traffic accident prediction algorithms.

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Running safety of high-speed train on deformed railway bridges with interlayer connection failure

  • Gou, Hongye;Liu, Chang;Xie, Rui;Bao, Yi;Zhao, Lixiang;Pu, Qianhui
    • Steel and Composite Structures
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    • v.39 no.3
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    • pp.261-274
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    • 2021
  • In a railway bridge, the CRTS II slab ballastless track is subjected to interlayer connection failures, such as void under slab, mortar debonding, and fastener fracture. This study investigates the influences of interlayer connection failure on the safe operation of high-speed trains. First, a train-track-bridge coupled vibration model and a bridge-track deformation model are established to study the running safety of a train passing a deformed bridge with interlayer connection failure. For each type of the interlayer connection failure, the effects of the failure locations and ranges on the track irregularity are studied using the deformation model. Under additional bridge deformation, the effects of interlayer connection failure on the dynamic responses of the train are investigated by using the track irregularity as the excitation to the vibration model. Finally, parametric studies are conducted to determine the thresholds of additional bridge deformations considering interlayer connection failure. Results show that the interlayer connection failure significantly affects the running safety of high-speed train and must be considered in determining the safety thresholds of additional bridge deformation in the asset management of high-speed railway bridges.

Estimation Desirable Safety Speed based on Driving Condition on Rural Highways (도로환경특성을 고려한 안전속도 산정에 관한 연구)

  • Kim, Keun-Hyuk;Lim, Joon-Beom;Lee, Soo-Beom;Kang, Dong-Soo;Hong, Ji-Yeon
    • International Journal of Highway Engineering
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    • v.14 no.4
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    • pp.149-162
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    • 2012
  • PURPOSES : The causes of traffic accidents can be classified into the factors of highway users, vehicles, and driving environments. Traffic accidents result from the deficiency in single or combination of these three factors. The objective of this study is to define the "potentially hazardous sections of highway" in terms of traffic safety considering these three factors. METHODS : The test drivers performed repeated driving on these highway sections. The drivers and passengers recorded the sections on which the driving was uncomfortable, and the speeds on the sections excluding the uncomfortable sections were used for the development of the model. RESULTS : The model is composed of three sub-models for each of the horizontal curve, tangent, and the section where the curve starts/ends. The safe driving behavior coefficients by the horizontal curvature were derived by comparing the maximum operating speeds at which the vehicle may slide or deviate and the speeds at which the drivers feel comfort. The safety speeds on tangent were derived by the length of tangent section considering the driver's desired speeds under the traffic condition on which the drivers hardly influenced by the other vehicles. For the sections where the curve starts/ends, the driving behaviors were classified by the distances between the curves, and the safe acceleration/deceleration speeds were derived on which the drivers enter/exit the curve sections safely. CONCLUSIONS : Safety speed could then be regarded that the model suggested in this study may be useful to define the potentially hazardous highway section and contribute the improvement of highway safety.

Development of a Lane Departure Warning Application on a Smartphone (스마트폰용 차선이탈경보 애플리케이션 개발)

  • Ro, Kwang-Hyun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.12 no.6
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    • pp.2793-2800
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    • 2011
  • The purpose of this research is to develop and optimize a lane departure warning application based on a smartphone which can be applicable as a new platform for various mobile information applications. Recently, a lane detection warning system which is a representative application among safe driving assistant solutions is being commercialized. Due to the necessity of powerful embedded hardware platform and its price, its market is still not growing. In this research, it is proposed to develop and optimize a lane departure warning application on iPhone 3GS. OpenCV is used for efficient image processing, and for lane detection a heuristic algorithm based on Hough Transform is proposed. The application was developed under Macintosh PC platform with Xcode 3.2.4 development tools, downloaded to the iPhone and has been tested on the real paved road. The experimental result has shown that the detection ratio of the straight lane was over 90% and the processing speed was 1.52fps. For the enhancement of the speed, a few optimization methods were introduced and the fastest speed was 3.84fps. Through the improvement of lane detection algorithm, additional optimization works and the adoption of a new powerful platform, it will be successfully commercialized on smartphone application market.

Prediction of Wildfire Spread and Propagation Algorithm for Disaster Area (재난 재해 지역의 산불 확산경로와 이동속도 예측 알고리즘)

  • Koo, Nam-kyoung;Lee, Kang-whan
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.20 no.8
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    • pp.1581-1586
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    • 2016
  • In this paper, we propose a central disaster monitoring system of the forest fire. This system provides the safe-zone and detection to reduce the suppression efforts. In existing system, it has a few providing the predicting of wildfire spread model and speed through topography, weather, fuel factor. This paper focus on the forest fire diffusion model and predictions of the path identified to ensure the safe zone. Also we have considering the forest fire of moving direction and speed for fire suppression and monitering. The proposed algorithm could provide the technique to analyze the attribute information that temperature, wind, smoke measured over time. This proposed central observing monitoring system could provide the moving direction of spred out forecast wildfire. This observing and monitering system analyze and simulation for the moving speed and direction forest fire, it could be able to predict and training the forest fire fighters in a given environment.

A Light-weight PKM Mutual Authentication Protocol for Improving Initial Authentication in WiMAX (WiMAX 초기 인증을 향상시킨 경량화된 PKM 상호 인증 프로토콜)

  • Jeong, Yoon-Su;Kim, Yong-Tae;Park, Gil-Cheol;Lee, Sang-Ho
    • The KIPS Transactions:PartC
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    • v.16C no.2
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    • pp.257-266
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    • 2009
  • Now a days, as increased the use of mobile units like a laptop computer and PDA, the demand for high speed internet service is increasing. On the other hand, PKMv2 which is provided from IEEE 802.16e cannot support fully on the security of high speed internet service. This paper proposes light-weight mutual authentication protocol which solved security problem of PKMv2 related to integrity of mobile node for transmission of safe high speed data of mobile node operating in mobile WiMAX environment. Proposed mutual authentication protocol increases the efficiency as the user in network can move in network safely without additional procedure of authentication between subscriber and base station after user's initial authentication. Also, the proposed mutual authentication protocol is safe from the security attack (the man-in-the-middle attack and reply attack) between subscriber and base station by generating a key adopt to PRF() function using random number and secret value in order to secure certification.