• Title/Summary/Keyword: Local Slope

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Pressure Distribution Analysis for After Bush Bearing of Ship Propulsion Shaft (선박 추진축 선미 베어링 압력 분포 해석)

  • 신상훈;최익흥
    • Journal of the Society of Naval Architects of Korea
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    • v.41 no.3
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    • pp.35-40
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    • 2004
  • Since the scale of vessels is growing up recently, some troubles between the shaft and after bush bearing are frequently reported. Generally, mean pressure on bush bearing is used as a design criterion. However, in some case of the long bearing such as after bush bearing of the propulsion shaft, it might be liable to be locally under high pressure. As for the main engine bearings and the intermediate shaft bearing, it is reasonable to take the mean pressure as a design criterion. But, in case of after bush bearing, it is not sufficient because of the possibility of high pressure caused by local contact. In this study, Hertzian contact condition was applied to evaluation of the local pressure for after bush bearing. To reduce the local maximum pressure, the height of the after bush bearing was controlled. It was found that local maximum pressure could be reduced effectively by taking a partial slope on the white metal of the aft bush bearing.

A Study on Selected Transverse Bed Slope Models in Channel Bend (유로만곡부의 횡방향 하상경사 산정 모형에 관한 연구)

  • Song, Jai Woo;Choi, In Ho;Kim, Ji Ho
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.14 no.6
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    • pp.1395-1404
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    • 1994
  • Transverse bed slope in bend is a subject of scientific investigation since it provides the necessary information for channel design and protection of hydraulic structures (bank, bridge, etc), and study of river morphology. In this paper, selected models were examined and compared for the value of prediction of the transverse bed slope in curved alluvial channels(project area), by using field data, and fitting model was proposed. All models that related the local transverse bed slope to mean flow characteristics were alike in the sense that they predicted the local transverse bed slope to be proportional to the ratio between depth and radius of curvature. The difference among the models was related with the factor of proportionality, K. Also, measured transverse bed slope was correlated to mean velocity, maximum depth, and density Froude number in channel bend. In this paper selected models were compared for the prediction of the transverse bed slope using Odgaard's experiment (obtained in Sacramento River bend), so Odgaard89 model was closely related with real transverse bed slope.

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Evaluation of unsaturated soil slope stability by incorporating soil-water characteristic curve

  • Zhai, Qian;Tian, Gang;Ye, Weimin;Rahardjo, Harianto;Dai, Guoliang;Wang, Shijun
    • Geomechanics and Engineering
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    • v.28 no.6
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    • pp.637-644
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    • 2022
  • Loess soils are unsaturated and widely distributed in the northwest zone in China. Many steep slope of unsaturated are observed are observed to be naturally stable. However, a low factor of safety (FoS) for these slopes would be computed from the slope stability analysis following local code practices. It seems that the analyzed results following the local code practices do not agree with the real condition as observed in the field. It is commonly known that soil suction plays an important role in slope stability due to a higher shear strength of the unsaturated soil as compared with that of the saturated soil. In this paper, it is observed that the computed FoS can also be affected by unsaturated unit weight of the soil. However, the effect of unsaturated unit weight of the soil on the slope stability is commonly ignored in engineering practice. Therefore, both the effects of shear strength and unit weight of the unsaturated soil on the computed FoS of unsaturated soil slope are investigated in this study. It is observed that the unsaturated unit weight of soil on the computed FoS increases with increase in slope angle. It is also observed that the effects of the unsaturated shear strength and unsaturated unit weight on the computed FoS are more significant than the effect of 3D analyses compared to the 2D analyses on the FoS.

Stability Evaluation of Progressive Failure Slope in Biotite Granite Area of Andong (안동 흑운모화강암 지역의 진행성 파괴사면 안정성 평가)

  • Baek, Seung-Cheol
    • Journal of the Korean Society of Safety
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    • v.15 no.2
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    • pp.103-110
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    • 2000
  • This paper deal with the stability evaluation and suggestion of progressive failure slope in biotite granite area of Andong. Based on geological site investigation and field test, stability analysis of slope was performed in conjunction with limit equilibrium methods and stereographic projection. Additionally, initial design and construction procedure was critically evaluated. Series of the slope stability analysis reveals the detection of local wedge and plane failure under the current slope condition. It is additionally appeared that a certain synthetic behavior of circle and plane failure exists on the right spot where the overall failure's going in progress. In order to construct more stable slope based on the suitability for the real state of the slope circumstances, this study issues a solution to eliminate the primary factors which cause the instability, by means of the grade of weathering and RMR classification of rock mass.

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Palmprint Verification Using Multi-scale Gradient Orientation Maps

  • Kim, Min-Ki
    • Journal of the Optical Society of Korea
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    • v.15 no.1
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    • pp.15-21
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    • 2011
  • This paper proposes a new approach to palmprint verification based on the gradient, in which a palm image is considered to be a three-dimensional terrain. Principal lines and wrinkles make deep and shallow valleys on a palm landscape. Then the steepest slope direction in each local area is first computed using the Kirsch operator, after which an orientation map is created that represents the dominant slope direction of each pixel. In this study, three orientation maps were made with different scales to represent local and global gradient information. Next, feature matching based on pixel-unit comparison was performed. The experimental results showed that the proposed method is superior to several state-of-the-art methods. In addition, the verification could be greatly improved by fusing orientation maps with different scales.

The Monitoring System Using Multi Antenna GPS for Weak Slope (Multi Antenna GPS를 이용한 취약사면 상시모니터링 시스템)

  • Noh, Won-Seok;Kim, Wan-Jong;Jang, Hyun-Ick;Kim, Hak-Soo
    • Proceedings of the Korean Geotechical Society Conference
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    • 2009.09a
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    • pp.677-694
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    • 2009
  • While the budget has been allocated more for repairs and reinforcements, casualties are gradually increased due to slope disaster. Slope disaster causes road damaged as well as casualties. It also causes significant social and economic loss. The measurement device, which is installed inside ground of slope like inclinometer, has the high loss rate when slope is being slided. The electric type and the vibrating wire type have low durability because of corrosion. To cover the demerit of the present slope monitoring, the measurement method using the Multi-Antenna GPS has been developed. The Multi-Antenna GPS has been installed in the local slope as the regular monitoring system for slope. Although the initial cost of the Multi-Antenna GPS for installation is high, the additional cost is low. So it is the suitable method for large slope. The regular monitoring system using the Multi-Antenna GPS is the suitable measurement method for watching slope collapse, which is occurred widely, because it is economical, has high durability, and collects data with high resolution.

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Design for the Kangwonland Ski Resort (강원랜드 스키장 설계)

  • 이준복
    • Journal of the Korean Institute of Landscape Architecture
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    • v.32 no.1
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    • pp.92-103
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    • 2004
  • This design was submitted to an invited competition for the Ski Resort of Kangwon Land which was held by Kangwon Land Resort in August, 2003. The site is located at 1∼17 Gohan-ri Gohan-eup Jungsungun Kangwon-do and has an area of 5,000,000$m^2$. The objectives of this project were to revitalize the local economy of Sabuk, Gohan which is well Down for deserted coal mines, by creating a resort complex for family group users with an environmentally friendly ski facility. This design scheme addresses three areas of concerns: First, how to boost the local economy through the proposed ski resort. By limiting lodging facilities in the ski resort, we could induce more development in the nearby towns. In order to balance the economical benefit to towns of Sabuk and Gohan, we decided to have two separate ski base facilities in each town boundary. Second, how to encourage family-oriented use of the ski resort by designing user-friendly ski slope, especially for beginner skiers. We designed 50% more beginner-level ski slope compared to average ski resorts. Third, how to make environmentally-friendly ski resort by respecting the original land form. We minimized the damage to the natural environment by protecting valuable tree groves. Also, ski slopes are designed to reduce unnecessary earth movement. This was designed under the assumption that more valley-oriented slopes would result in less cutting and banking of earthwork; this assumption was verified in comparison with other ski resorts. It is expected that this desist would serve environmentally-friendly designs in ski slopes.

Characteristics of Median Frequency According to the Load During Fatiguing Isometric Exercise (등척성 운동시 운동강도에 따른 중앙주파수의 특성)

  • Lee, Su-Young;Shin, Hwa-Kyung;Cho, Sang-Hyun
    • Physical Therapy Korea
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    • v.10 no.3
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    • pp.141-149
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    • 2003
  • Median frequency can be regarded as a valid indicator of local muscle fatigue. As local muscle fatigue develops, the muscle fiber conduction velocity decreases, the fast twitch fibers are recruited less, and consequently the median frequency shifts toward the lower frequency area. The aim of this study was to test the characteristics of the median frequency according to exercise load (30% and 60% of MVC on the biceps brachii, 40% and 80% of MVC on the vastus lateralis) during the fatiguing isometric exercise. Thirteen healthy male volunteer students of Yonsei University were recruited. After the testing maximal voluntary isometric contraction, three variables (initial median frequency, regression slope, fatigue index) from the regression line of MDF data were measured in each exercise load. The results showed that the regression slope and fatigue index were significantly different for the biceps brachii, but not for the vastus lateralis initial MDF was not significant difference according to the exercise load on both muscles. The regression slope and fatigue index could monitor physiologic muscle change during fatiguing isometric exercise. The results showed that two MDF variables reflect the local muscle fatigue according to the exercise load.

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Development of Mobile Equipment for Local Risk Factors Detecting of Road Slope (도로사면의 국부적 위험요인 검지를 위한 이동형 장비 개발)

  • Kim, Yong-Soo;Jung, Soo-Jung;Ahn, Sang-Ro
    • Proceedings of the Korean Geotechical Society Conference
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    • 2008.10a
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    • pp.938-945
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    • 2008
  • Rockfall and landslide bring about a great social loss with loss of property such as obstruction of traffic and damage of the crops as well as casualty. The purpose of this study is to develop a mobile equipment for local risk factors detecting of road slope. The mobile equipment is designed to receive the sensing data from the measurement sensors, which are installed to detect the dangerous signs from the slopes, as loaded on a vehicle which is moving around to the places where the sensors are installed. In general, more than one mandatory data logger, which is very expensive, must be installed at each slope for the automatic measuring system, but in case of this developmental system, the inexpensive routine measurement can be performed regardless of the number of slopes due to the single unit of information gathering vehicle. This study is going to develop technologies that are expected to be applied to not only slope but also tunnel and bridges which might have the partial risk and need measuring.

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The study on the statue of hazard area related to slopes in Korea (국내 사면관련 재해위험지역 현황조사)

  • Lee, Su-Gon;Lee, Kyoung-Su;Jung, Sang-Hun;Kang, Byoung-Ho
    • Proceedings of the Korean Geotechical Society Conference
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    • 2008.03a
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    • pp.1298-1303
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    • 2008
  • In Korea, the management and remedial system of the slope near national road and highway has been studied actively. But in case of the slopes exist at the residential area and local government, there is not exact record of them. So in this study, we carried out analysis about nearly 14000 slopes which were reported by local government as the dangerous area. and went to the field work some of them.

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