• Title/Summary/Keyword: Road field

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Noise reduction of Asphalt Concrete Pavement : Techniques and their performance evaluation (아스팔트 저소음 포장의 개발 및 공용성 평가)

  • Ock, Chang-Kwon;Kim, Jin-Hwan;Lee, Jong-Sup
    • International Journal of Highway Engineering
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    • v.12 no.1
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    • pp.29-37
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    • 2010
  • Porous pavements can provide road users with beneficial characteristics such as skid resistance and surface water drainage under rainy condition, and they cause less tire-road noise than conventional hot mix asphalt(HMA) pavements. However, voids of porous pavements are easily clogged by road debris at early stages, which leads to frequent maintenance works. Therefore, this study focused on the way of minimizing void clogging in porous pavements. During mixture design, the quantity of coarse aggregate has been increased to form many straight void conduits (SVCs) in porous HMAs. These SVCs were found to be effective resisting the void clogging problems. Four different porous HMAs(19mm, 13mm, 10mm, and 8mm) were developed and placed on highway roads. Their performances were validated with field tests during the past four years.

Steering Control for Autonomous Electric Vehicle using Magetic Fields (자기장을 이용한 자율주행 전기자동차의 조향제어)

  • Kim, Tae-Gon;Son, Seok-Jun;Ryoo, Young-Jae;Kim, Eui-Sun;Lim, Young-Cheol
    • Journal of Sensor Science and Technology
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    • v.10 no.2
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    • pp.134-141
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    • 2001
  • This paper describes a method to steer an autonomous electric vehicle using magnetic fields. Magnets are embeded along the center of the road and a magneto-resistive sensor is mounted beneath the front bumper of the vehicle. As the vehicle moves along the road neural network controller controls the vehicle using measured magnetic field variation. Based on a single magnets modeling equation, we analyzed three dimensional magnetic field distributions of embeded magnets in series on the center of the road and performed a computer simulation using this results. In simulation study, straight and curved road was configured. The steering controller for the vehicle was designed using neural network and experiment was performed on the real embeded magnets using real autonomous electric vehicle. At the experiment we compensated the earth's magnetic fields and showed a good result driving an autonomous vehicle using proposed method.

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Installation Status of Information Facilities and Condition of Walking Road Influencing to Psychological Safety of Walking Tourists - Focusing on the Course No. 16 of Jeju Olle Trail, Sarabong·Byeoldobong Walkway in Jeju and the Course No. 8 of Bougil, Gyeongpo Lake Walkway in Gangneung - (도보여행자의 심리적 안전에 영향을 미치는 도보길 환경과 정보시설물의 설치 현황 - 제주올레 16코스와 사라봉·별도봉 산책로, 강릉바우길 8구간과 경포호 산책로를 대상으로 -)

  • Byun, Kyeonghwa;Kim, Young-duk
    • Journal of the Korean Institute of Rural Architecture
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    • v.18 no.3
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    • pp.25-34
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    • 2016
  • The purpose of this study is to investigate installation status of information facilities and condition of walking road influencing to psychological safety of walking tourists. For this purpose, four roads for walking tour are selected; the course no. 16 of Jeju Olle Trail, Sarabong Byeoldobong walkway in Jeju and the course no. 8 of Bougil, Gyeongpo Lake walkway in Gangneung. Facilities installed on roads for walking tour are classified into four facilities; safety facility, information facility, amenity facility, local cultural facility. In order to consider installation status of information facilities and condition of walking road influencing to psychological safety of walking tourist, a field experiment was conduced focusing on the course no. 16 of Jeju Olle Trail. Thirteen cases were happened as confusing situation while walking tour. Of the 13 cases, the situation of being lost and wandering on the trail accounted for six cases. In contrast to the expectation that the situation of being lost and wandering would occur only at a crossroads, it is not that such situation took place at specific places like a crossroads or where direction signs were inaccurate. Walking tourists of this field experiment also confronted situations of having lost confidence about continuing the ongoing direction, of having anxiety over walking a walking trail, of feeling discomfort caused by walking and of being offended by uncomfortable or messy areas of walking trial. These confusing situations are happened inappropriate installation of direction sign, so direction sign is needed to install more carefully and detailed.

The Freezing Characteristics of Pavement Layer Using the Field Road Model Test (현장도로 모형실험을 이용한 포장구성층의 동결 특성 분석)

  • Shin, Eun-Chul;Ryu, Byung-Hyun;Park, Jeong-Jun
    • Journal of the Korean Geotechnical Society
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    • v.26 no.7
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    • pp.71-80
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    • 2010
  • Korea is considered to be a seasonal frozen soil area that thaws in the spring, and freezes in winter. In the current design codes for anti-freezing layer, the thickness of anti-freezing layer is calculated by the depth frozen due to the temperature condition. Therefore, there is a tendency of over-design and applying uniform thickness without the consideration of thermal stability, bearing capacity and frost susceptibility of materials. So, it is essential to study the structural appropriateness of pavement layer and bearing capacity besides the seasonal and mechanical properties of pavement materials to take an appropriate and reasonable design of the road structure. In this paper, the evaluation of frost susceptibility on subgrade, ant-freezing layer, subbase was conducted by means of the mechanical characteristics and model experiment. The temperature, heaving amount, unfrozen water contents and freezing depth of soil samples, the subgrade, anti-freezing layer, subbase soils of road construction site were measured to determine the frost susceptibility.

Analysis of Health Status of Street Trees and Major Affecting Factors on Deogyeong-daero in Suwon (수원시 덕영대로의 가로수 건강성 평가 및 주요 영향요인 분석)

  • Kim, Eun-Young;Jung, Kyung-Min
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.22 no.2
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    • pp.49-57
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    • 2019
  • The street trees increase the liveability of cities by reducing stormwater runoff, improving air quality, storing carbon, providing shade, and ameliorating the urban heat-island effect. In this study, the health status of street trees in Suwon was evaluated, and the factors affecting the growth of the trees were also derived. In order to evaluate the growth and health of street trees, field survey was carried out on a total of 125 trees in 25 sections of the Deogyeong-daero where is through the city. During the field survey, the following items were examined: Street trees health status (i.e. species, height, DBH (diameter at breast height), planting types, vigor, etc.), soil factors (i.e. soil temperature, humidity, pH, hardness, etc.), and environmental factors (i.e. landuse, road width, etc.). As the results of field survey, the main species of the street trees was Zelkova serrata, which was healthy in most of the sections. The factors such as planting types, soil temperatures, tree root cover, road extension, distance from the road were derived to affect the growth and health of street trees, and the differences were significant. The results of this study were derived the following conclusions for vigorous street trees: First, it is important to install and maintain the protection facilities like tree root cover for the growth of trees. Second, it is necessary to discuss how to plant multiple trees in narrow spaces like a street green space. Third, it is important to provide appropriate soil conditions continuously for growth of threes. Finally, it should be utilized as a mitigation measure of urban heat island effects.

X-RAY ASTRONOMY EXPERIMENT ON THE INDIAN SATELLITE IRS-P3

  • AGRAWAL P. C.;PAUL B.;RAO A. R.;SHAH M. R.;MCKERJEE K.;VARIA M. N.;YADAV J. S.;DEDHIA D. K.;MALKAR J. P.;SHAH P.;DAMLE S. V.;MARAR T. M. K.;SEETHA S.
    • Journal of The Korean Astronomical Society
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    • v.29 no.spc1
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    • pp.429-432
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    • 1996
  • An x-ray astronomy experiment consisting of three collimated proportional counters and an X-ray Sky Monitor (XSM) was flown aboard the Indian Satellite IRS-P3 launched on March 21, 1996 from SHAR range in India. The Satellite is in a circular orbit of 830 km altitude with an orbital inclination of $98^{\circ}$ and has three axis stabilized pointing capability. Each pointed-mode Proportional Counter (PPC) is a multilayer, multianode unit filled with P-10 gas ($90\%$ Ar + $10\%\;CH_4$) at 800 torr and having an aluminized mylar window of 25 micron thickness. The three PPCs are identical and have a field of view of $2^{\circ}{\times}2^{\circ}$ defined by silver coated aluminium honeycomb collimators. The total effective area of the three PPCs is about 1200 $cm^2$. The PPCs are sensitive in 2-20 keV band. The XSM consists of a pin-hole of 1 $cm^2$ area placed 16 cm above the anode plane of a 32 cm$\times$32 cm position sensitive proportional counter sensitive in 3-8 keV interval. The position of the x-ray events is determined by charge division technique using nichrome wires as anodes. The principal objective of this experiment is to carry out timing studies of x-ray pulsars, x-ray binaries and other rapidly varying x-ray sources. The XSM will be used to detect transient x-ray sources and monitor intensity of bright x-ray binaries. Observations of black-hole binary Cyg X-1 and few other binary sources were carried out in early May and July-August 1996 period. Details of the x-ray detector characteristics are presented and preliminary results from the observations are discussed.

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Development of Vehicle Environment for Field Operational Test Data Base of Driver-vehicle's Behaviour (운전자 거동에 대한 필드 데이터베이스 구축을 위한 차량 환경 개발)

  • Kim, Jinyong;Jeong, Changhyun;Jeong, Minji;Jung, Dohyun;Woo, Jinmyung
    • Transactions of the Korean Society of Automotive Engineers
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    • v.21 no.1
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    • pp.1-8
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    • 2013
  • Recently, the automotive technology has developed with electronics and information technology as convergence technology while vehicles had been regarded as machines. Moreover, vehicles are becoming more intelligent and safer devices, assembly of advanced technologies by customers' demand. Even though all of installations of vehicle have attracted as diverting devices, it cause drivers' mistakes like delay of response on traffic condition. Here, we proposed the Field Operational Test (FOT) environment which could be used as driving and road conditions collector(Vehicle motion, Traffic condition, Driver input, Driver state, etc.) for researches about Driver Friendly Intelligent System(SCC, LDWS, etc.), Human Vehicle Interface(Driving Workload, etc.) and Economic Drive Model. Furthermore driving patten and fuel consumption patten of drivers were analyzed by measured data and direction of future research was suggested.

Investigation of Domestic Application for Soil Impact Hammer(SIH) (동적 지반물성측정장치(SIH, Soil Impact Hammer)의 국내 적용성 평가)

  • 박재영;석정우;황대진;양구승
    • Proceedings of the Korean Geotechical Society Conference
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    • 2002.10a
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    • pp.411-418
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    • 2002
  • In domestic road construction sites, the compaction control based on strength are widely performed through the direct method with high accuracy, such as Plate Loading Test or Field CBR test. It is impossible to manage all construction sites using the direct method because the direct method requires heavy reaction loads and long measurement time. Therefore, it is necessary to apply the indirect method that could control the relative density of construction sites on the whole. Indirect methods, such as Cone Penetration Test and Fall Cone Test, require extra time for data analyzing and fixed area for test device. In this paper, the field applicability of Soil Impact Hammer (SIH) was investigated comparing with the results of field measurement tests and laboratory compaction tests. SIH developed by Japan Construction Administration and Asanuma Ltd., is a kind of indirect methods for compaction checking. According to the results of SIH performed in domestic road construction site, the subgrade reaction modulus obtained from SIH are similar to that from Plate loading tests in the range of 10 to 40. In comparison with laboratory compaction test, similar compaction line are shown in the dry side of optimum moisture contents.

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Forecasting of Green Technologies on Intelligent Transportation System using Patent Analysis (특허 분석을 활용한 ITS 녹색 기술 예측)

  • Lee, Joo-Hyeon;Lee, Chul-Ung
    • Journal of the Korea Society of Computer and Information
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    • v.19 no.2
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    • pp.233-241
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    • 2014
  • In this paper, it predicts green technology in the future with "Co-word" which is patent analysis, "technology road-map, life cycle graph of patent activation and trend analysis. Analysis result shows that it would help environment preservation because development of ITS green technology makes carbon emission effectiveness and ITS green technology is especially expected to develop in fuel saving field. In addition, fuel saving field is predicted to be advance more practically technology field with convergence with IT.

Drone Operation Scheme for Patrolling & Inspecting Power Transmission Lines and on Public Drone Road Construction (송전선로 드론 순시·정밀점검 운용 및 공공용 드론길 구축방안에 대한 연구)

  • Woo, Jung-Wook;Park, Joon-Young;Kim, Seok-Tae;Lee, Jae-Kyung;Ryu, Seo-Hyeon
    • KEPCO Journal on Electric Power and Energy
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    • v.6 no.3
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    • pp.271-278
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    • 2020
  • KEPCO Research Institute developed a GIS-based autopilot drone inspection system for electric power facilities and since its pilot application in 2017, it has been successfully used to detect defects in power transmission lines. This paper presents how to operate this system in the field of power line inspection. Power transmission lines are located in a wide variety of environments such as plains, mountains, river crossings, sea crossings, and industrial areas. Among these, some transmission lines are difficult for human workers to access because of their geographies and some should be checked more often due to their severe contamination. Considering these field conditions, we classified drone operation in two categories to increase its effectiveness and efficiency - patrol surveillance and detailed inspection tasks. This paper describes the detailed procedures of the two tasks above and their field application experiences. In addition, this paper newly proposes how to construct public drone roads by using the information of KEPCO's power transmission lines.