• Title/Summary/Keyword: Tunnel environments

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Analysis and Investigation of International(UIC, EN, IEC) and Domestic Standards(Test Methods) for Climatic Wind Tunnel Test of Rolling Stock (철도차량 기후환경시험을 위한 국제 규격(UIC, EN, IEC) 및 국내 규격(시험방법) 분석 및 고찰)

  • Jang, Yong-Jun;Chung, Jong-Duk;Lee, Jae-Cheon
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.21 no.12
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    • pp.782-789
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    • 2020
  • The demand for the development of rolling stock technology to maintain the best performance in various climatic environments has increased to expand the overseas market of rolling stock. In this study, international and domestic standards that must be applied to build a harsh climatic environment test system were investigated and compared. The way of improvement for domestic standards is proposed. The wind velocities and temperatures are specified in the UIC, EN, and IEC standards for climatic wind tunnel, and EN 50125-1 provides the velocity test up to 180km/h, the largest wind speed. UIC and EN provide the lowest temperature of -45℃, and IEC 62498-1 provides the highest temperature 55℃. The solar radiation test was specified up to 1200W/m2 in the UIC, EN, and IEC. The IEC, EN, and KS R 9145 provide the water tightness standards, which are different from each other in water capacity, pressure, and methods. The snow test method was not well specified. KRTS-VE-Part 31 provides pressurization test methods. The airtightness standards for high-speed rolling stock are defined and regulated for internal pressure change rate in UIC 660 and 779-11. The domestic standard for the wind tunnel test was not well prepared, and the solar radiation test and snow test do not exist in Korea. Therefore, it is necessary to improve domestic standards to an international level for the climatic wind tunnel test of rolling stock.

Development of a Acoustic Acquisition Prototype device and System Modules for Fire Detection in the Underground Utility Tunnel (지하 공동구 화재재난 감지를 위한 음향수집 프로토타입 장치 및 시스템 모듈 개발)

  • Lee, Byung-Jin;Park, Chul-Woo;Lee, Mi-Suk;Jung, Woo-Sug
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.22 no.5
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    • pp.7-15
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    • 2022
  • Since the direct and indirect damage caused by the fire in the underground utility tunnel will cause great damage to society as a whole, it is necessary to make efforts to prevent and control it in advance. The most of the fires that occur in cables are caused by short circuits, earth leakage, ignition due to over-current, overheating of conductor connections, and ignition due to sparks caused by breakdown of insulators. In order to find the cause of fire at an early stage due to the characteristics of the underground utility tunnel and to prevent disasters and safety accidents, we are constantly managing it with a detection system using image analysis and making efforts. Among them, a case of developing a fire detection system using CCTV-based deep learning image analysis technology has been reported. However, CCTV needs to be supplemented because there are blind spots. Therefore, we would like to develop a high-performance acoustic-based deep learning model that can prevent fire by detecting the spark sound before spark occurs. In this study, we propose a method that can collect sound in underground utility tunnel environments using microphone sensor through development and experiment of prototype module. After arranging an acoustic sensor in the underground utility tunnel with a lot of condensation, it verifies whether data can be collected in real time without malfunction.

Characteristic Analysis of Wireless Channels to Construct Wireless Network Environment in Underground Utility Tunnels (지하공동구 내 무선 네트워크 환경구축을 위한 무선채널 특성 분석)

  • Byung-Jin Lee;Woo-Sug Jung
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.24 no.3
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    • pp.27-34
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    • 2024
  • The direct and indirect damages caused by fires in underground utility tunnels have a great impact on society as a whole, so efforts are needed to prevent and manage them in advance. To this end, research is ongoing to prevent disasters such as fire flooding by applying digital twin technology to underground utility tunnels. A network is required to transmit the sensed signals from each sensor to the platform. In essence, it is necessary to analyze the application of wireless networks in the underground utility tunnel environments because the tunnel lacks the reception range of external wireless communication systems. Within the underground utility tunnels, electromagnetic interference caused by transmission and distribution cables, and diffuse reflection of signals from internal structures, obstacles, and metallic pipes such as water pipes can cause distortion or size reduction of wireless signals. To ensure real-time connectivity for remote surveillance and monitoring tasks through sensing, it is necessary to measure and analyze the wireless coverage in underground utility tunnels. Therefore, in order to build a wireless network environment in the underground utility tunnels. this study minimized the shaded area and measured the actual cavity environment so that there is no problem in connecting to the wireless environment inside the underground utility tunnels. We analyzed the data transmission rate, signal strength, and signal-to-noise ratio for each section of the terrain of the underground utility tunnels. The obtained results provide an appropriate wireless planning approach for installing wireless networks in underground utility tunnels.

Numerical Analysis of Peak Uplift Resistance of Buried Pipeline in Sand and Soft Clay (연약 점토와 사질토에 묻힌 파이프라인의 극한 인발저항력 산정)

  • Kwon, Dae-Hean;Seo, Young-Kyo
    • Journal of Ocean Engineering and Technology
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    • v.31 no.3
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    • pp.227-232
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    • 2017
  • Subsea pipelines are one of the most important structures used to transport fluids such as oil and natural gas in offshore environments. The uplift behavior of the pipeline caused by earthquakes and buoyancy can result in a pipeline failure. The objective of this study is to examine the peak uplift resistance through parametric studies with numerical modeling by PLAXIS 3D Tunnel. The effects of the embedment ratio and pipe diameter were first examined for uplift resistance in sand and soft clay conditions. Then the length of geogrid layers and the number of geogrid layers were examined in terms of ability to resist uplift behavior.

A Study on the Evacuation Time by the Influence of Decreasing Visibility on Fire (화재시 가시도 변화에 따른 대피속도 산정에 관한 연구)

  • Rie, Dong-Ho;Park, Jong-Seung
    • Journal of the Korean Society of Safety
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    • v.22 no.5
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    • pp.21-26
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    • 2007
  • The computer program is developed to simulate the evacauation time for a building which is made geometrically complex. The program is intended for use both as a search and a design tool to analyze the evacuation safety through a wide range of structure environments. The computer program has a function of importing FDS's result to each individual resident in the building. These attributes include a walking speed reduction by producing visibility reduction for each person on the fire. $A^*$ pathfinding algorithm is adopted to calculate the simulation of escape movement, overtaking, route deviation, and adjustments to individual speeds due to the proximity of crowd members. Finally, a case study for a theater is presented to compared the calculated evacuation time with SIMULEX in detail. This program contribute to a computer program that evaluates the evacuation time of individual occupants as they walk towards, and through the exits especially for building, underground spaces like a subway or tunnel.

Development of LED Traffic Light Lens with snow removing function (제설 기능을 갖는 LED 신호등 렌즈 개발)

  • Lee, Dongeun;Seol, Dongyoul
    • Journal of Korea Society of Digital Industry and Information Management
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    • v.13 no.4
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    • pp.41-48
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    • 2017
  • It is necessary to develop an LED traffic light lens having a snow removal function capable of clearly providing a traffic signal to the driver even when a traffic light is blurred due to heavy snow and wind in the winter season. This study is focused on the research and development of the traffic light lens in the process of developing the LED traffic light with the snow removal function. In the developed traffic light lens, instead of attaching the film heater, the coated nichrome wire was wound into a coil shape and inserted directly into the groove in the lens. The developed heater system facilitates the insertion of the heating wire with high elasticity into a curved lens and can provide a sufficient heat without deformation of the PC lens. The proposed traffic lights were tested in various external environments and the test results showed that complete snow removal is possible without tunnel effect.

TBM considerations for soft-ground tunnels

  • Rozgonyi T. G.;Kieffer D. S.;Maidl U.;Bald Cernal
    • 한국지구물리탐사학회:학술대회논문집
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    • 2003.11a
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    • pp.42-51
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    • 2003
  • The global demand for underground facilities has increased substantially in the past decades, and a substantial number of underground projects have had to deal with challenging ground conditions in urban environments. Particularly challenging are weak and unstable water bearing soils. Advancements in shielded TBM tech-nology have led to significant improvements regarding the ability to control ground deformations in soft ground. Nonetheless, ground collapse may occur even when the most advanced TBM designs are employed if unexpected adverse ground conditions are encountered or if insufficient stabilizing pressure is transferred to the tunnel face. This paper reviews common approaches for face stability and face pressure transmission calculations, and provides an overview of some of the latest technological developments and considerations for soft ground TBM applica-tions.

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PRELIMINARY MODELING FOR SOLUTE TRANSPORT IN A FRACTURED ZONE AT THE KOREA UNDERGROUND RESEARCH TUNNEL (KURT)

  • Park, Chung-Kyun;Lee, Jae-Kwang;Baik, Min-Hoon;Jeong, Jong-Tae
    • Nuclear Engineering and Technology
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    • v.44 no.1
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    • pp.79-88
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    • 2012
  • Migration tests were performed with conservative tracers in a fractured zone that had a single fracture of about 2.5 m distance at the KURT. To interpret the migration of the tracers in the fractured rock, a solute transport model was developed. A two dimensional variable aperture channel model was adopted to describe the fractured path and hydrology, and a particle tracking method was used for solute transport. The simulation tried not only to develop a migration model of solutes for open flow environments but also to produce ideas for a better understanding of solute behaviours in indefinable fracture zones by comparing them to experimental results. The results of our simulations and experiments are described as elution and breakthrough curves, and are quantified by momentum analysis. The main retardation mechanism of nonsorbing tracers, including matrixdiffusion, was investigated.

Experimental Studies for Solar Drying System of Agricultural Products(I) - Solar drying characteristics for radish - (태양열 건조 시스템에 관한 실험적 연구(I) - 무우절편의 태양열 건조 특성 -)

  • Koh, Hak-Kyun;Kim, Yong-Hyeon;Song, Dae-Bin;Kim, Man-Soo
    • Solar Energy
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    • v.11 no.3
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    • pp.9-20
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    • 1991
  • Experiments for drying radish were carried out to analyze the drying characteristics and quality evaluation between solar heated-air drying and natural air drying system. Solar heated-air drying system consists of a small fan, a solar air heater and a tunnel dryer. Simulation model for thermal environments of solar collector was developed to investigate the effect of solar radiation and airflow rate on thermal performance.

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A Study on the improvement of Track Circuit measurement equipment for High speed Line (고속선 궤도회로 검측설비 개량을 위한 방안 연구)

  • Kwak, Woo-Hyun;Kim, Yong-Kyu;Lee, Jong-Woo
    • Proceedings of the KSR Conference
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    • 2006.11b
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    • pp.832-837
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    • 2006
  • ATC facility manipulates ground-on-board information, which transmits speed limit, varying as wayside environments - safety facility, track gradient, inclination, bridge and tunnel and other factors, installed for safe operation of trains on wayside. Efficientiation and automatification of operation and maintenance is being realized, by measuring if there are any erroneous information, using a measuring car. In this paper, we study in priority the methods for measuring accurately distinctive properties of internal malfunctions of track circuits, the performance decrease of condensers, and the unbalance of return cables, which are actually required for functionality improvement of high-speed line signal measure facilities, by measuring the unbalance of return current given because of damaged factors of external track circuits.

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