• Title/Summary/Keyword: Overturn

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Simulation of Sideways Overturning of Agricultural Tractor-Trailer Systems (농용(農用)트랙터-트레일러 시스템의 횡전도(橫轉倒) 시뮬레이션)

  • Jung, S.Y.;Kim, K.U.
    • Journal of Biosystems Engineering
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    • v.15 no.4
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    • pp.298-309
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    • 1990
  • A mathematical model was developed to simulate sideways overturning of agricultural tractor-trailer systems. Sideways overturn of a tractor-trailer system was described by oscillatory motions of the tractor with respect to the first and second tipping axes, and of the trailer with respect to the drawbar hitch point when either the tractor or trailer rides over an obstacle on slopes. By a computer simulation, critical slope angles of the ground on which the tractor-trailer system is likely to sideways overturn were evaluated under the given operational conditions. Validity of the proposed mathematical model was proved by comparing the results of computer simulation and experiment with a model tractor-trailer system. A close agreement was observed between the two results.

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Combined Effect of Lidocaine Hydrochloride with Some Surfactants ( I ) (유화제(乳化劑)와 Lidocaine.HCl의 병용효과에 관(關)한 연구(硏究)( I ))

  • Kim, Yong-Hyoun;Yeum, Chul-Ho;Choi, Jun-Shik
    • Journal of Pharmaceutical Investigation
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    • v.12 no.2
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    • pp.31-36
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    • 1982
  • The effect of some surfactants, such as tween 40, tween 80, span 80, and triethanolamine, on the absorption of lidocaine was studied using goldfish as a model of absorption kinetics. This model was believed that reciprocal overturn time and death time were the occurrence of biological effect versus drug absorption. The results were as follows; The threshold concentration of lidocaine was significantly reduced by the surfactants. Overturn time and death time of goldfish in the lidocaine solution were reduced by such surfactants as tween 40, tween 80, span 80 and triethanolamine, and more reduced with increasing concentration of surfactants except tween 40 and tween 80. The plots of reciprocal death time versus lidocaine concentration were linear relationship with a positive concentration intercept such as minimum effective concentration (0.2-0.8%). As results it is believed that these surfactants may form complexes with lidocaine or affect the goldfish membrane to make more permeable to lidocaine, which is adsorbed more rapidly.

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A Study on the Natural Wind Measurement to Assess the Risk of Train Overturn due to the Strong Wind (강풍 시 열차전복위험도 평가를 위한 자연풍 측정에 관한 연구)

  • Kwon, Hyeok-Bin;Nam, Seong-Won;You, Won-Hee;Hong, You-Na
    • Proceedings of the KSR Conference
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    • 2006.11b
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    • pp.123-129
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    • 2006
  • The measurement method of natural wind to understand the characteristics of the natural wind along the railway lines in Korea has been investigated to be used in the assessment of the risk of train overturn. The weather information service provided by Korea Meteorological Administration has been employed to outline the broad characteristic of natural wind in Korea. Anemometers using CDMA telecommunication for data transfer have been installed near the railway lines to measure velocities and directions of natural wind and the data processing method has been studied using the measured data.

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Mobile Crane Ground-Fixing System (이동식 크레인의 접지설계 시스템)

  • Ho, Jong-Kwan;Seo, Jong-Min;Kim, Sun-Kuk
    • KIEAE Journal
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    • v.7 no.6
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    • pp.83-90
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    • 2007
  • A mobile crane has been more frequently used to deal with the increased capital-intensive projects in line with the economic growth, but the operation is still heavily dependent on personal experience in the past, resulting in severe overturn accidents that cause the loss of lives and damage to the properties. A crane shall be installed in a systematic manner that proved to be safe in engineering aspect, and should the installation and operation be blindly dependent on experience alone, it would apparently cause a great risk. Particularly the mobile crane, among others, frequently causes a severe overturn accident due to poor ground-fixing device. The study therefore focused on fixing system of mobile crane and the outcome is highly expected to make a great commitment to selecting the optimal type of crane for the project as well as to securing the safety during construction.

Structural Safety Analysis on Car Body at Overturn (전복시 차체에 대한 구조 안전 해석)

  • Cho, Jae-Ung;Kim, Key-Sun;Lee, Eun-Jong
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.12 no.1
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    • pp.32-37
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    • 2011
  • In this study, the changes of displacement and stress are investigated by structural analysis according to the thickness of car body in case of overturn. In case of 5 mm thickness, the maximum displacement of 7.5024 mm at its right ceiling and the maximum equivalent stress of 113.69 MPa at the left lower part are occurred on the elapsed time of 2 second. In case of 10 mm thickness, the maximum displacement of 1.2557 mm at its right ceiling and the maximum equivalent stress of 15.134 MPa at the left lower part are occurred on the elapsed time of 2 second. In case of 15 mm thickness, the maximum displacement of 0.426067 mm at its right ceiling and the maximum equivalent stress of 4.4842 MPa at the left lower part are occurred on the elapsed time of 2 second. As stress and displacement are uniformly distributed according to time in this case, the design of car body can be stabilized.

A Design for Summer Safety Shoes for Agricultural Work Using a Survey

  • Lee, Kyung Suk;Kim, Do Hee;Oh, Young Soon;Oh, Sae Loom;Chae, Hye Seon;Kim, Kyung Ran
    • Journal of the Ergonomics Society of Korea
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    • v.35 no.1
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    • pp.1-10
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    • 2016
  • Objective: This study aimed to find good design for summer functional farm shoes under the agricultural environment and working characteristics, which can help safe farm work and further promote the efficiency of working. Background: Most accidents at farms were overturn accidents caused by slipping or falling, and it was found that the main factors which caused the overturn accidents were inappropriate work shoes for the working conditions. These inappropriate work shoes often cause overturn accidents in the rural areas with steep paths. Method: A survey on work shoes was conducted with 174 farmers, and the outcome of this survey was used to find problems of work shoes and improvement ideas for the design of work shoes which can be used at farms. Results: Regarding the form of farm shoes, the ankle height was set at 6 inches to prevent the bending of the ankle and the inflow of foreign substances. The size and groove of the pattern of the outsole were extended to prevent catching of foreign substances. In the upper part, polyurethane and cordura were used in combination to secure air permeability, which was pointed out as the reason for the discomfort during the work wearing existing work shoes. Conclusion: Since farmers felt discomfort with the shoes which they were currently wearing, this study suggested a design of farm shoes by analyzing the important matters of the work shoes in development in order to improve such discomfort. Application: This study can help develop farm shoes that would practically ease farmers' burden of working at farm worksites and keep them safe.

Long Term Behavior of Permanent Rock Anchorages in Large Spatial Span Structures (대공간구조물에 시공된 영구앵커의 장기거동)

  • Yoo, Nam-Jae;Kim, Dae-Hak;Park, Byung-Soo;Kim, Jae-Il;Lee, Jong-Yong
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.10 no.6
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    • pp.123-135
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    • 2006
  • Most of all, large spatial span structures are the symbol of cities but have to get to supply the purpose of structure simultaneously, therefore their foundations are designed to get rolls of structure support, structure shape maintenance or overturn prevention, buoyancy resistance, etc. Accordingly various type foundations have been introduced, and after anchorage power is introduced for double structures shape maintenance and overturn prevention, change of anchorage power checked in the construction process is reviewed, comparing of playground case. Case1 anchors for the control of horizontal power worked outside hemisphere type roof, Case2 anchors for the overturn prevention of cantilever roof examined in this example. The examination has been executed by the analysis of anchorage power introduction process, related test results and anchorage power monitoring results for 2 examples.

An Overturn disease of Cultured Mud Loach (Misgurnus mizolepis) (미꾸라지 (Misgurnus mizolepis)의 뒤집힘병에 관한 연구)

  • Park, Seong-U;Park, Hyeon-Tae;Choe, Seon-Nam
    • Journal of fish pathology
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    • v.17 no.1
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    • pp.21-28
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    • 2004
  • In late summer of 2001, a new disease "overturn disease" occurred among mud loach (Misgurnus mizolepis) cultured in a farm Chonbuk Province. The fish exhibited a lethargic, erratic and spiral swimming at the water surface. Affected fish showed swollen abdomen with accumulation of air bubbles in the intestinal canal. The bubbles were much larger in the anterior part than in the posterior part. Hematological and histopathological examinations were done. No significant differences were found in RBC count, Ht value and Hb concentration between the diseased and the healthy fish. Gill filaments showed proximal hyperplasia of the respiratory epithelia and fusing of the gill lamella. Hemorrhage and necrosis occurred in the intestinal epithelia and within the lamina propria, and the mucosal epithelia were separated from the muscularis. Hepatocytes underwent atrophy. In the fish experimentally tied between the annal fin and the anus by a thread to confirm accumulation of air bubbles within intestine, accumulation of air bubbles was confirmed. This disease in mud loach appeared to be induced by circulatory disturbances in the intestinal wall owing to accumulation of air bubbles in the alimentary canal after fed high protein diet throughout all culturing period.

The Effect of the Gust of Wind on Safety of Driving Vehicles in Higher Speed Freeways (강한 바람이 고속도로 차량 주행 안전성에 미치는 영향 분석)

  • Kim, Sang-Youp;Choi, Jai-Sung;Hwang, Kyung-Sung;Hwang, Kyung-Soo
    • International Journal of Highway Engineering
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    • v.11 no.2
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    • pp.45-54
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    • 2009
  • Despite vehicle instability problems caused by gusts of wind on freeways located in mountain or seaside areas, current national highway design standards overlook their detrimental effects, and if higher design speed freeways being proposed now by the government are in operation, the strong effect of the gust of wind becomes a highway alignment design issue. This paper presents the vehicle movements and their resulting safety effects by checking vehicle sliding and overturn based on vehicle dynamic analysis for the case when a gust of wind blows to vehicles negotiating curves on higher speed freeways. In this analysis, vehicle types, curve radii, motorist responsive time to vehicle driving path changes, and vehicle speeds are systematically arranged to get vehicle sliding and overturn values in each different conditions. The results showed that there were little overturn possibilities when wind speed would stay in 50m/sec with higher than 600 meter curve radii. Interestingly it was also found in sliding checks that, although being safe at less than 15.0m/sec wind speed levels, there appeared the need of vehicle travel prohibitions when the wind speed could exceed 25.0m/sec level. The findings in this research is of information in future higher speed freeway designs, and particularly useful when designing freeways passing frequent gust wind areas.

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