• Title/Summary/Keyword: dropping slope

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A Study on the Design of Flow Control Valve Attached to Vane Pump for Power Steering (파워 스티어링용 베인 펌프 유량 제어부 설계에 관한 연구)

  • 이윤태
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.9 no.5
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    • pp.87-95
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    • 2000
  • The numerical analysis and the experiments are carried out to develop the design program for the flow control valve attached to the vane pump for power steering. The factors affecting the flow rate characteristics are analyzed by the experiments and the numerical analysis. The results are summarized as follows; (1) the main factors affecting to the first and second control flow rate are the diameter of big and small rod of the spool. (2) the cut off is mainly affected by the main spring constant, the initial displacement of main spring and the small diameter of the spool. (3) the dropping slope characteristics are decided by the chamfer of spool and the dynamic characteristics of the spool.

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Automatic Analysis Model for Support Emergency Medical Helicopter Landing Zone Using Geographic Information System (GIS를 이용한 비상 의료지원 헬리콥터 착륙지점 자동 분석 모델)

  • Park, Jong-kook;Lee, Eun-seok;Kim, Jong-hee;Kim, Jeong-su;Kim, Jong-bae
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2014.05a
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    • pp.338-340
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    • 2014
  • The purpose of this research is to support decision making of emergency rescue system with GIS which selects landing point of emergency rescue for emergency situation on mountains and dropping point when landing is impossible. The area of research was limited to Pocheon-si, Gyeonggi-do. The results were divided into two values; landing point of helicopter on mountains and dropping point. Digital map, forest type map and forest soil map were utilized as fundamental data. Factors of landing point were slope, topographical characteristics, vegetation characteristics and area of helicopter landing point by helicopter data. And, for dropping point, slope and vegetation characteristics were divided as factors and GIS intersect function was utilized for the analysis. But, this research was conducted by excluding factor values of wind direction, wind velocity, etc. In the future, it's necessary to improve effectiveness of the analysis more by making a connection with Meteorological Agency DB.

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Landslide prediction system by wireless sensor network (무선센서 네트워크를 이용한 산사태 모니터링 기초기술 연구)

  • Kim, Hyung-Woo
    • 한국정보통신설비학회:학술대회논문집
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    • 2007.08a
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    • pp.191-195
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    • 2007
  • Recently, landslides frequently happen at a natural slope during period of intensive rainfall. With rapidly increasing population of steep terrain in Korea, landslides have become one of the most significant natural hazards. Thus, it is necessary to protect people from landslides and to minimize the damage of houses, roads and other facilities. To accomplish this goal, many landslide prediction methods have been developed in the world. In this study, a simple landslide prediction system that enables people to escape the endangered area is developed. The system is focused to debris flows which happen frequently during periods of intensive rainfall at steep slopes in Kangwondo. This system is based on the wireless sensor network that is composed of sensor nodes, gateway, and server system. Sensor nodes that are composed of sensing part and communication part are newly developed to detect sensitive ground movement. Sensing part is designed to measure tilt angle and acceleration accurately, and communication part is deployed with Bluetooth (IEEE 802.15. I) module to transmit the data to the gateway. To verify the feasibility of this landslide prediction system, a series of laboratory tests is performed at a small-scale earth slope supplying rainfall by artificial rainfall dropping device. It is found that sensing nodes installed at slope can detect the ground motion when the slope failure starts. It is expected that the landslide prediction system by wireless senor network can provide early warnings when landslides such as debris flow occurs, and can be applied to ubiquitous computing city (U-City) that is characterized by disaster free.

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Characteristics of the Body Shape of Korean Woman Farmers by Crops (주 재배 작목별 한국 여성 농업인 체형 특성)

  • Baek, Yoon-Jeong;Lee, Kyung-Suk
    • Journal of the Korean Society of Clothing and Textiles
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    • v.32 no.10
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    • pp.1584-1594
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    • 2008
  • This study was to research the characteristics of the body shape of Korean woman farmers by the major crops. Four hundred ninety-five Korean woman farmers from 9 different area such as Kumi, Damyang, Iksan, Injae, Chungju, Choongju, Haman, Whasung, and Whasoon volunteered for this study. Their major crops were the rice, the pepper, the water melon, the strawberry, the wild rocambole, the sweet persimmon, the grapes, the mushroom, and the chrysanthemums. Twelve body angles were measured from archived the somatotype photographs of the front, the side, and the back. Questionnaires of SF-36 and the farmer's symptom, and the farm-work related movements were surveyed. The results were as follows; 1. Farmers had lower health levels in physical role limit, pain, vitality, and physical function than other occupational workers. 2. Most farmers acted the high-risk ergonomics motions when they worked in the farm. 3. There were significantly different on the both shoulder angles, the hip tangential line slope, the hip breadth angel, in frontal ankle-knee angle, the bending back angle, the dropping breast slope, the abdominis media angle, under the abdominis media angle, the glutea angle, under the glutea angle, and the sideward knee angle(p<.05). 4. Farmers cultivating the low plants such as the water melon, the strawberry, and the wild rocambole showed more banded vertebralis and side knee angles. Farmers cultivating the red pepper showed the dropping the left shoulder and O shape legs. Farmers cultivating the fruit trees such as the sweet persimmon and the grapes showed the less banded side knee angles than other farmer groups. 5. On comparing the same age, farmers showed the older's body shape in earlier and much more than the old living in the city.

A study on Orientation and Morphology of clasts in Rockfall Talus in the Sukam area, Bukpyoung-eup, Gangwon-do, South Korea (테일러스 역의 방향성 및 형태 분포에 대한 연구 - 강원도 정선군 북평읍 숙암리 지내 사면을 중심으로 -)

  • Kim, Seung-Hyun;Koo, Ho-Bon;Baek, Yong
    • Proceedings of the Korean Geotechical Society Conference
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    • 2003.03a
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    • pp.469-474
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    • 2003
  • Talus topography is that rock clasts that is weathered is accumulated dropping in steep slope to action of gravity. Rock fall talus is formed by the accumulation of rock debris falling as individual particles from a cliff. If the collapse is produced in talus slope, it will be possible the loss of manpower and country. Despite correct access about talus is required, domestic research was scientific access about talus short. The aim of the present study is to review and compare fabric data derived from rock fall talus about orientation, distribution and morphology in Sukam area. These deposits tend to have approximately equal amounts of clasts oriented parallel and perpendicular to the dip direction of the slope. And, platy-shaped clasts dominate the proximal and intermediate parts of the talus, whereas blocky-shaped clasts is more common in the distal part.

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Viscous fluid characteristics of liquefied soils and behavior of pile subjected to flow of liquefied soils (액상화된 지반의 점성 유체 특성과 그 흐름이 말뚝의 거동에 미치는 영향 분석)

  • Hwang, Jae-Ik;Kim, Chang-Yeob;Chung, Choong-Ki;Kim, Myoung-Mo
    • Proceedings of the Korean Geotechical Society Conference
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    • 2004.03b
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    • pp.722-729
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    • 2004
  • The horizontal movement of sloping ground due to flow liquefaction has caused many pile foundations to fail, especially those in ports and harbor structures. In this study, a virtual case is assumed in which flow liquefaction is induced by earthquake loads in a fully saturated infinite sand slope with a single pile installation. Under the assumption that the movement of liquefied ground is viscous fluid flow, the influence of ground movement due to flow liquefaction on the pile behavior was analyzed. Since the liquefied soil is assumed as a viscous fluid, its viscosity must be evaluated, and the viscosity was estimated by the dropping ball method ,md the pulling bar method. Finally, the influence of the flow of liquefied soil on a single pile installed in an infinite slope was analyzed by a numerical method.

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Landslide Detection using Wireless Sensor Networks (사면방재를 위한 무선센서 네트워크 기술연구)

  • Kim, Hyung-Woo;Lee, Bum-Gyo
    • 한국방재학회:학술대회논문집
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    • 2008.02a
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    • pp.369-372
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    • 2008
  • Recently, landslides have frequently occurred on natural slopes during periods of intense rainfall. With a rapidly increasing population on or near steep terrain in Korea, landslides have become one of the most significant natural hazards. Thus, it is necessary to protect people from landslides and to minimize the damage of houses, roads and other facilities. To accomplish this goal, many landslide prediction methods have been developed in the world. In this study, a simple landslide prediction system that enables people to escape the endangered area is introduced. The system is focused to debris flows which happen frequently during periods of intense rainfall. The system is based on the wireless sensor network (WSN) that is composed of sensor nodes, gateway, and server system. Sensor nodes comprising a sensing part and a communication part are developed to detect ground movement. Sensing part is designed to measure inclination angle and acceleration accurately, and communication part is deployed with Bluetooth (IEEE 802.15.1) module to transmit the data to the gateway. To verify the feasibility of this landslide prediction system, a series of experimental studies was performed at a small-scale earth slope equipped with an artificial rainfall dropping device. It is found that sensing nodes installed at slope can detect the ground motion when the slope starts to move. It is expected that the landslide prediction system by wireless senor network can provide early warnings when landslides such as debris flow occurs.

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Current Increase Effect and Prevention for Electron Trapping at Positive Bias Stress System by Dropping the Nematic Liquid Crystal on the Channel Layer of the a-InGaZnO TFT's

  • Lee, Seung-Hyun;Heo, Young-Woo;Kim, Jeong-Joo;Lee, Joon-Hyung
    • Proceedings of the Korean Vacuum Society Conference
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    • 2015.08a
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    • pp.163-163
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    • 2015
  • The effect of nematic liquid crystal(5CB-4-Cyano-4'-pentylbiphenyl) on the amorphous indium gallium zinc oxide thin film transistors(a-IGZO TFTs) was investigated. Through dropping the 5CB on the a-IGZO TFT's channel layer which is deposited by RF-magnetron sputtering, properties of a-IGZO TFTs was dramatically improved. When drain bias was induced, 5CB molecules were oriented by Freedericksz transition generating positive charges to one side of dipoles. From increment of the capacitance by orientation of liquid crystals, the drain current was increased, and we analyzed these phenomena mathematically by using MOSFET model. Transfer characteristic showed improvement such as decreasing of subthreshold slope(SS) value 0.4 to 0.2 and 0.45 to 0.25 at linear region and saturation region, respectively. Furthermore, in positive bias system(PBS), prevention effect for electron trapping by 5CB liquid crystal dipoles was observed, which showing decrease of threshold voltage shift [(${\delta}V$]_TH) when induced +20V for 1~1000sec at the gate electrode.

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An Experimental Study on the Behavior of Muddy Water Lumps Caused by Dropping Soil in Coastal Areas (해역에서 토사침하에 따른 탁수괴 거동에 관한 연구)

  • 신문섭;이종남
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.2 no.4
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    • pp.223-230
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    • 1990
  • Suspended materials during maritime construction works may cause surrounding environmental changes Therefore, it is important to know the behavior of the muddy water lumps caused by dropping soil in coastal areas. Two-dimensional behaviors of the muddy water moving along the inclined boundaries are investigated experimentally, which are the change of height, length, and moving velocity, the properties of movement at the head of muddy water, the coefficient of entrainment and shape, and the accumulation shape. The shape of the muddy water lumps was similar with the slope thermal. Therefore, the moving characteristics were found to be described using turbulence theory.

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Wetness Index Estimate and Suggestion of the Criteria of the Rockfall Protective Barrier in Talus slope (테일러스 사면의 습윤지수 산정 및 낙석방호시설 설치 기준 제안)

  • Kim, Seung-Hyun;Koo, Ho-Bon;Baek, Yong;Kim, Sung-Wook;Kim, In-Soo
    • Proceedings of the Korean Geotechical Society Conference
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    • 2004.03b
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    • pp.592-599
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    • 2004
  • Talus topography is that weathered rock clasts were accumulated dropping in steep slope to action of gravity. Rock fall talus is formed by the accumulation of rock debris falling as individual particles from a cliff. If the collapse is produced in talus slope. it will be possible the loss of manpower and country. Despite correct access about talus is required, domestic research was scientific access about talus short because of short resolution of aerophoto and difficulties of research about huge talus. In this Study, Our research team analgize the wetness index using the geomorphogical data. Lineament through wetness index is simillar with distribution of the talus. And, the aim of the present study is to review and compare fabric data derived from rock fall talus about orientation, distribution and morphology. These deposits tend to have approximately equal amounts of clasts oriented parallel and perpendicular to the dip direction of the slope. And, platy- shaped clasts dominate the proximal and intermediate parts of the talus, wheres blocky-shaped clasts is more common in the distal part. we carry out Rock Fall Simulation. And, We install criteria of the rockfall protective barrier using talus and geomorphological characteristics.

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