• Title/Summary/Keyword: Field condition

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Thin Bonded Concrete Overlay for Concrete Pavement Rehabilitation (콘크리트포장의 박층 콘크리트 덧씌우기공법)

  • 윤경구;이형준;엄주용;서영찬
    • Proceedings of the Korea Concrete Institute Conference
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    • 1997.04a
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    • pp.635-642
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    • 1997
  • This research focused on the development of concrete overlay and test, which was conducted at 88 Highway 105k, 2 lanes of 290 m. The field application test consists of 6 cm and 10 cm bonded concrete overlay and 25 cm unbonded concrete overlay, using the slag cement for opening lanes for traffic early. The overlay were placed in a day. The whole period of traffic closing wes 8 day and it was reopened to traffic after concrete overlay has cured for 3 day. 5 cracks were founded when the field test section was investigated after 1 month, but all these may not make significant problems to overlay because these initiated and growed at the same line of repair section. The rideability and skid resistance become much better like in the new pavement after overlay. The structural capacity against deflection was much. which were verified by FWD(Falling Weight Deflectometer). The field test section is being used in a good condition and the results of field application and pavement performance analysis are encouraging. This rehabilitation methods may be adopted in Korea after a more field performance verifications.

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Field Applicability Of Emergency Road Repair Material Using the CAC (CAC를 이용한 긴급도로 보수재의 현장 적용성)

  • Hyun, Ji-Soo;Kim, Jin-Man;Choi, Hong-Beom;Lee, Ha-Na;Koo, Ja-Sul
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2015.05a
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    • pp.154-155
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    • 2015
  • This study was to review the basic characteristics in order to evaluate field application of the emergency road repair materials for development of CAC(Calcium Aluminate Composite) usage. The experiment was conducted with two phases of field and laboratory conditions and the laboratory experiment consisted indoor and outdoor tests for compressive and flexural strength. In the result of an experiment, for the compressive strength test, the specimens that cured in the laboratory conditions were not satisfied the requirement of standards, while the specimens that cured in the field conditions were well satisfied with those. For flexural strength test, the result value was satisfied with the requirement on the standards only in outdoor curing condition of laboratory experiment. Based on these results, it is expected that the CAC can be used as an emergency road repair material for field conditions.

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The Insulation Characteristics by Conducting Particle in GIS (GIS내 금속이물 존재시 절연특성)

  • Cho, Kook-Hee;Kim, Jae-Chul;Kwak, Hee-Ro
    • Proceedings of the KIEE Conference
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    • 2004.05b
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    • pp.105-108
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    • 2004
  • This paper describes the influence of conducting particle in the coaxial cylindrical electrodes under alternating voltage condition investigated using breakdown electric field and electro magnetics simulation method. Simulated particle-location in GIS chamber were the particle on electrode, the particle on enclosure and free moving particle. As results, it was founded that in case of breakdown electric field of the GIS chamber, breakdown electric field of particle on electrode was the lowest, that of free moving particle was middle and that of particle on enclosure was the highest. And in case of the electric field analysis with particle locations, electric field of particle on electrode was the highest that of lifted particle was middle and that of particle on enclosure was the lowest. This results can offer a practical reference ra the insulation design of domestic GIS.

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Multi-modal Sensor System and Database for Human Detection and Activity Learning of Robot in Outdoor (실외에서 로봇의 인간 탐지 및 행위 학습을 위한 멀티모달센서 시스템 및 데이터베이스 구축)

  • Uhm, Taeyoung;Park, Jeong-Woo;Lee, Jong-Deuk;Bae, Gi-Deok;Choi, Young-Ho
    • Journal of Korea Multimedia Society
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    • v.21 no.12
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    • pp.1459-1466
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    • 2018
  • Robots which detect human and recognize action are important factors for human interaction, and many researches have been conducted. Recently, deep learning technology has developed and learning based robot's technology is a major research area. These studies require a database to learn and evaluate for intelligent human perception. In this paper, we propose a multi-modal sensor-based image database condition considering the security task by analyzing the image database to detect the person in the outdoor environment and to recognize the behavior during the running of the robot.

Growth Characteristics and Occurrence Rate of Disease and Pest According to the Forest Field in Panax ginseng C. A. Meyer (인삼 임간재배시 병해충 발생율 및 생육 특성)

  • Cheong, Seong-Soo;Park, Jong-Suk;Yang, Jae-Choon;Ryu, Jeong;Kim, Hee-Jun;Lim, Ju-Rak;Kim, Dong-Won
    • Korean Journal of Medicinal Crop Science
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    • v.15 no.4
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    • pp.261-265
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    • 2007
  • A climatic feature, growth condition and incidence phase of disease and pest in Korean ginseng (Panax ginseng C. A. Meyer) were surveyed, both the conventional cultivation and culture in the forest located in Jinan. The results were as follows. The forest field was lower $1^{\circ}C$ in the air temperature, lower $1.9^{\circ}C$ in the soil temperature and 11.8% lower in the soil temperature compared with the conventional field. The wind velocity of the forest field was three times slower, but the dew condensation time was 3.3 hours longer than the conventional field. Particularly, the amounts of solar radiation in the forest was remarkably lower, while the rainfall was little lower with no significance. The incidence of disease and pest in the forest field was severe compared with that of the conventional field. Among them, Colletotrichum gloeosporioides, Cylindrocarpon destructans, and Alternaria panax was severe in the forest field while, Botrytis cinerea was severe in the conventional field. The growth condition of forest field in Panax ginseng C. A. Meyer was 50% worse in general and the root weight was 87.2% less than the 3-year-old ginseng in the conventional field.

Air Corridor Planning Strategy based on the Wind Field and Air Corridor Simulation - A Case Study of Pan-Gyo New Town Development Area - (바람통로 예측모델링을 통한 바람통로 계획전략 - 성남판교 신도시 개발지구를 중심으로 -)

  • 황기현;송영배
    • Journal of the Korean Institute of Landscape Architecture
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    • v.31 no.5
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    • pp.43-57
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    • 2003
  • This paper presents the air corridor planning strategy based on simulation with MUKLMO_3 (Micro-scale Urban Climate Model) to investigate the wind field and air corridor caused by the land-use change of the New Town Development Area in Pan-Gyo. In the first part, the most frequently observed wind field in the New Town Development Area was measured and used as an initial value to simulate a more realistic wind field and air corridor. Several experiments with different initial values of wind fields were carried out to investigate the wind field change affected by the New Town Development. The results show the features of the wind field of the neutral stability condition in the urban canopy layer with a high resolution near the ground. The wind speed is weakened at this level due to the New Town Development. It was found that the wind field and air corridor are influenced by the land-use change. After the development of the New Town, the speed of the wind field decreased and the main wind directions and air corridor changed. In this study, this model is found to be a useful tool for evaluating air corridor and change of wind field in speed and direction.

Seed Quality of Soybean Produced from Upland and Drained-Paddy Field

  • Kim Sun-Lim;Park Keum-Yong;Lee Yeong-Ho;Ryu Yong-Hwan
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.49 no.4
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    • pp.309-315
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    • 2004
  • This study was carried out to evaluate the seed quality of soybeans produced from upland and drained-paddy fields. Soybeans from drained-paddy field showed significantly higher in the 100 seeds weight and greater in the size of seed length than those from upland fields. However, there are no significant differences in seed width and thickness between upland and paddy fields. In case of Hunter's color value, the lightness (L) was significantly higher in the upland soybeans, but the a (redness) and b (yellowness) values were higher in the drained-paddy field soybeans. Seed appearance of drained-paddy field was poor than that of upland field. Soybeans produced from the drained-paddy field showed higher protein content, whereas, lipid and ash contents were higher in the upland field. Soybeans from upland field had lower contents of total amino acids compared to drained-paddy fields. No statistical differences were found in palmitic, linoleic, and linolenic, but stearic, oleic, saturated fatty acids (SFA), and unsaturated fatty acids (USFA) showed significant differences between soybean seeds from upland and drained-paddy fields. Genistein content was higher in the drained-paddy fields, while daidzein and glycitein contents were higher in the upland fields. This result suggested that the soil condition of drained-paddy field is more favorable to synthesis genistein than daidzein and glycitein.

A Survey on Science Field Study for Elementary School Science in 7th Korean School Curriculum (제7차 교육과정기의 초등 과학교과 현장학습 실태조사)

  • Kim, Eun-Jin;Lim, Chae-Seong
    • Journal of Korean Elementary Science Education
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    • v.22 no.2
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    • pp.173-180
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    • 2003
  • The purpose of this study was to investigate about current status of science field study in elementary schools. A total of 72 elementary teachers in Busan and Gyungnam districts were involved and the data from questionnaire was gathered. The questionnaire was comprised two parts: items on general level include the epistemological aspect and actual condition and items on concrete level according to chapters of elementary school science curriculum. The major findings are as follows: 1. Many teachers cognize the requirement of science field study in 7th Korean elementary school science curriculum is larger than 6th one. But they respond the actual number of science field study in 7th curriculum is nearly equal to 6th. 2. In analysis to grades, the actual number of field study decrease as grade is high. 3. In the science content aspects, the requirement of field study is the largest on biology domain and earth science domain. 4. Many teachers have pointed out “the difficulty of administration for field study” and “inappropriated surrounding of their school” as the problems of science field study in elementary school.

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Quantitative Analysis of a Steel Billet Surface Flaw Detection System by Means of a Finite Element Method

  • Bae, Sungwoo;Lee, Hongyeob
    • Journal of Electrical Engineering and Technology
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    • v.11 no.6
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    • pp.1729-1734
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    • 2016
  • The surface inspection of a steel billet is a common practice in the steel manufacturing process prior to hot rolling to produce steel wire for tire cord. This billet surface inspection is an important process because flaws on the surface may cause major failures during the product manufacturing phase. This paper presents a computer simulation based on a finite element method for a magnetic flaw detector with a function of the current intensity, the number of coil turns, and the billet proceeding speed during the production phase based on the typical condition of conventional apparatus. Based on the simulation result, the magnitude of the electromagnetic field on the surface diminished with distance from the electromagnet. In addition, the increased current intensity and the increased number of coil turns actually induced a stronger electromagnetic field on the billet surface. On the other hand, the proceeding speed of a billet in its production line had no significant effects. The result in this study may assist to reduce trial and error and to minimize the opportunity costs during the optimization process by applying the findings of this study into the operation condition in the steel billet production line.

Diurnal changes of Tissue Water Relations in Two Allopatric Tree Species (이소적 두 수종의 수분관계 일변화)

  • Park, Yong-Mok
    • The Korean Journal of Ecology
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    • v.19 no.5
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    • pp.453-463
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    • 1996
  • Diurnal changes of microclimatic conditions and tissue water relations were measured at two sites where Carpinus laxiflora and C. cordata were allopatrically distributed. The microclimatic conditions at a site where C. laxiflora was distributed produced severe water stress condition during summer months. Daily maximum temperature reached $30.4^\circC$ and the highest vapor pressure deficit was 1.31 KPa when 13 rainless days were continued. During this period soil water content decreased to below the field capacity even at a depth of 20 cm and xylem pressure potential also decreased to ­2.04 MPa. However, turgor potential was maintained more than 0.4 MPa. Patterns of stomatal conductance were changed with evaporative demand and soil water availability. On the other hand, microclimatic conditions at a site where C. cordata was distributed were moderate water strees condition compared with those at a site C. laxiflora was distributed. Though soil water content was maintained above field capacity C. cordata showed a remarkable decrease in turgor potential and stomatal conductance throughout the experiment. These results indicate that there is a difference in habitat characteristics between the two species and C. laxiflora is more resistant than C. cordata to water stress.

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