• Title/Summary/Keyword: rail joint

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Data Analysis of International Joint Road and Sea Transportation Tests Under Normal Conditions of Transport (국제공동 육해상 정상운반시험의 데이터 분석)

  • Lim, JaeHoon;Cho, Sang Soon;Choi, Woo-seok
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.18 no.2_spc
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    • pp.275-289
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    • 2020
  • In 2017, multimodal transportation tests for evaluating road, sea, and rail transport were performed by research institutes in the US, Spain, and the Republic of Korea. In this study, acceleration and strain data determined through road and sea tests were analyzed. It was investigated whether the load generated for each transport mode was amplified or attenuated according to the load transfer path. From the results, it was confirmed that the load transfer characteristics differed according to the transportation mode and loading path. The effects of strain determined through each test on the structural integrity of the spent nuclear fuel were also investigated. It was found that the magnitude of the measured strain had a negligible effect on the structural integrity of the spent nuclear fuel, considering its fatigue strength. The results for the acceleration and strain data analyses obtained in this study will be useful for scheduled domestic transportation tests under normal transport conditions.

Beach-chair lateral traction position using a lateral decubitus distracter in shoulder arthroscopy

  • Kim, Kyung-Cheon;Rhee, Kwang-Jin;Shin, Hyun-Dae;Byun, Ki-Yong
    • The Academic Congress of Korean Shoulder and Elbow Society
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    • 2008.03a
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    • pp.164-164
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    • 2008
  • The beach-chair traction position is designed to allow the use of traction while allowing the surgeon to orient the shoulder in an upright position and convert to an open procedure, if necessary. The patient is placed in the beach-chair position under general anesthesia. A three-point shoulder holder (Arthrex, Naples, Florida) is attached to the rail of the operating table on the same side as the surgeon, whereas it is placed on the side opposite the surgeon in the lateral decubitus position. A shoulder traction and rotation sleeve (Arthrex) are affixed to the arm following the manufacturer's instructions. Positioning the thumb toward the closed side of the sleeve ensures a field for the anterior portion of the rotator cuff and prevents the tendency of the suspension apparatus to place the arm in internal rotation. The arm is maintained in 30 to 40 degree abduction and 30 to 40 degree flexion by controlling the length and height of the bar and the location of the universal clamp. The universal clamp allows multiple planes of adjustment to control abduction and forward movement of the arm. The sleeve is attached to the longitudinal traction cable using a sterile hook, and a lateral strap is secured around the proximal portion of the sleeve to the overhead traction cable to ensure a field for glenohumeral reconstruction. The use of a lateral strap permits ideal shoulder positioning for improved access to the anterior and inferior glenohumeral joint. The lateral strap can be released or removed to widen the subacromial space during subacromial decompression or rotator cuff repair. A 10-lb weight is attached to the longitudinal traction cable for an average-sized person.

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Motion Planning of Building Maintenance Robot System for Reducing Jerk Effect (빌트인형 BMR 시스템의 이동 중 충격완화를 위한 모션제어)

  • Lee, Seunghoon;Kang, Min-Sung;Kang, Sungpil;Hwang, Soonwoong;Kim, YoungSoo;Moon, Sung-Min;Hong, Daehie;Han, Chang-Soo
    • Journal of the Korean Society for Precision Engineering
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    • v.30 no.4
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    • pp.368-374
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    • 2013
  • Maintenance works for current high-rise buildings significantly depend on human labor, unlike other construction processes that are gradually being automated. Herein, this paper proposes robotic building maintenance system using motion control, in specific, reducing a system jerk which is directly subjected to improve the process performance and economic feasibility. The sensor for detecting straight and curvature section of the building facade, moreover rail-joint segment can be detected and be utilized for reducing jerk of the system. Analysis of the proposed system error caused by excessive vibration, e.g. jerk motion is introduced. To enhance the stability and safety of the system, herein, the strategy is proposed for enhancing the performance of the system based on anti-jerk motion control algorithm which comes out increasing the stability and sustainability of the integrated system, as well.

Performance Measurement of Split PC Sleepers for Safety in Maintenance Work (분절형 PC침목의 안전성 확보를 위한 성능평가 시험)

  • Eum, Ki-Young;Um, Ju-Hwan;Sin, Seung-Kwon;Lee, Chang-Hun
    • Journal of the Korean Society of Hazard Mitigation
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    • v.6 no.4 s.23
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    • pp.1-6
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    • 2006
  • In terms of the speed-up of the conventional line, the research for a improved turnout was carried out continually around world. A turnout is known that it is the most unstable equipment structurally in the rail system. So, the turnout is needed more stable structure. An accurate assembly of turnout affects traveling qualify of turnout area and running safety. Therefore, a turnout which is pre-assembled at a factory by using the split PC sleeper is transported to construction site recently in advanced countries. In this paper, the performance measurements which estimate the safety of the split PC sleepers which are adopted for the first time to improve performance of turnout are implemented indoors. The split PC sleeper is one of components of the improved turnout. The test is considered of the worst ballast condition under the maintenance work as like STT(Swithc Tie Tamper) or MTT(Multiple Tie Tamper). These experiments results indicate that structural safety for the expansion joint of the split PC sleepers.

CONSTRUCTION MANAGEMENT OF TUNNELLING IN SEVERE GROUNDWATER CONDITION

  • Young Nam Lee;Dae Young Kim
    • International conference on construction engineering and project management
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    • 2005.10a
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    • pp.655-661
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    • 2005
  • For a hydro power plant project, the headrace tunnel having a finished diameter of 3.3m was constructed in volcanic rocks with well-developed vertical joint and high groundwater table. The intake facility was located 20.3 km upstream of the powerhouse and headrace tunnel of 20 km in length and penstock of 440 m in height connected the intake and the powerhouse. The typical caldera lake, Lake Toba set the geology at the site; the caving of the ground caused tension cracks in the vertical direction to be developed and initial stresses at the ground to be released. High groundwater table(the maximum head of 20 bar) in the area of well-connected vertical joints delayed the progress of tunnel excavation severely due to the excessive inflow of groundwater. The excavation of tunnel was made using open-shield type TBM and mucking cars on the rail. High volume of water inflow raised the water level inside tunnel to 70 cm, 17% of tunnel diameter (3.9 m) and hindered the mucking of spoil under water. To improve the productivity, several adjustments such as modification of TBM and mucking cars and increase in the number of submersible pumps were made for the excavation of severe water inflow zone. Since the ground condition encountered during excavation turned out to be much worse, it was decided to adopt PC segment lining instead of RC lining. Besides, depending on the conditions of the water inflow, rock mass condition and internal water pressure, one of the invert PC segment lining with in-situ RC lining, RC lining and steel lining was applied to meet the site specific condition. With the adoption of PC segment lining, modification of TBM and other improvement, the excavation of the tunnel under severe groundwater condition was successfully completed.

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Study for Progress Rate of Standard Deviation of Irregularity Based on Track Properties for the Railway Track Maintenance Cycle Analysis (궤도 유지보수 주기 예측을 위한 구간 특성에 따른 궤도틀림 표준편차 진전정도 분석)

  • Jeong, Min Chul;Kim, Jung Hoon;Lee, Jee Ha;Kang, Yun Suk;Kong, Jung Sik
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.16 no.3
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    • pp.31-40
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    • 2012
  • The irregularity of railway track affects not only the comfort of ride such as noise or vibration but also the safety of train operation. For this reason, it is an interesting research area to design a reliable and sustainable railway track system and to analyze the train movement mechanism based on systematic approaches considering reasons of track irregularity possible in a specific local environment. Irregularity data inspected by EM-120, an railway inspection system in Korea includes unavoidable incomplete and erratic information, so it is encountered lots of problem to analyse those data without appropriate pre-data-refining processes. In this research, for the efficient management and maintenance of railway system, progress rate of standard deviation of irregularity is quantified. During the computation, some important components of railways such as rail joint, ballast, roadbed, and fastener have been considered. Probabilistic distributions of irregularity growth with respect to time are computed to predict the remaining service life of railway track and to be adapted for the safety assessment.

Tunneling in Severe Groundwater Inflow Condition (지하수 과다유입 조건하에서의 터널굴착)

  • Lee, Young-Nam;Kim, Dae-Young
    • Journal of the Korean GEO-environmental Society
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    • v.7 no.2
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    • pp.67-76
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    • 2006
  • For a hydro power plant project, the headrace tunnel having a finished diameter of 3.3 m was constructed in volcanic rocks with well-developed vertical joint and high groundwater table. The intake facility was located 20.3km upstream of the powerhouse and headrace tunnel of 20km in length and penstock of 440m in height connected the intake and the powerhouse. The typical caldera lake, Lake Toba set the geology at the site the caving of the ground caused tension cracks in the vertical direction to be developed and initial stresses at the ground to be released. High groundwater table(the maximum head of 20bar) in the area of well-connected vertical joints delayed the progress of tunnel excavation severely due to the excessive inflow of groundwater. The excavation of tunnel was made using open-shield type TBM and mucking cars on the rail. High volume of water inflowraised the water level inside tunnel to 70cm, 17% of tunnel diameter (3.9m) and hindered the mucking of spoil under water. To improve the productivity, several adjustments such as modification of TBM and mucking cars and increase in the number of submersible pumps were made forthe excavation of severe water inflow zone. Since the ground condition encountered during excavation turned out to be much worse, it was decided to adopt PC segment lining instead of RC lining. Besides, depending on the conditions of the water inflow, rock mass condition and internal water pressure, one of the invert PC segment lining with in-situ RC lining, RC lining and steel lining was applied to meet the site specific condition. With the adoption of PC segment lining, modification of TBM and other improvement, the excavation of the tunnel under severe groundwater condition was successfully completed.

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Analysis on Barriers and Resolution Priority of Sea-Rail Multimodal Logistics among Korea and Eurasia Nations (한국-유라시아간 해륙복합운송 문제점 및 해결 우선순위 분석)

  • Lee, Eon-Kyung;Lee, Suyoung;Kim, Bokyung;Euh, Seungseob
    • Journal of Korea Port Economic Association
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    • v.35 no.2
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    • pp.109-126
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    • 2019
  • The Panmunjom Declaration adopted by the leaders of South and North Korea on April 27, 2018, has created an environment conducive for peace and cooperation in the Korean Peninsula. In the June of last year, South Korea has joined the Organization for Cooperation between Railways (OSJD). The membership of OSJD has established a solid foundation for restoring a multimodal logistics system that connects the Korean peninsula to Eurasia countries, including China and Russia. In this paper, a questionnaire survey targeting working-level experts was conducted to find the barriers in constructing multimodal logistics that efficiently connect the port-continental railways of the Korean peninsula and the Eurasian nations. Survey items were divided into five categories-border crossing procedures, technology, facilities, operation, and government support. As a result, among the most important problems of international multimodal logistics in Eurasia that need to be solved on priority include improving transshipment facilities, eliminating inspection carried out at every country for transit, simplifying documents for customs clearance, and minimizing the changes in freight rates. In conclusion, for vitalizing the connection between the Korean peninsula and the continental railways, it is necessary to develop a transshipment system to facilitate the changes in tracks at the borders by making a joint effort with the international community. Second, railway and operational systems in South Korea, North Korea, China, and Russia should be standardized. Third, international cooperation among South Korea, North Korea, China, and Russia is essential for simplifying customs clearance at borders, priority departure of domestic cargo, sharing information about the changes in freight rates, and so on. Finally, the government should come up with measures to secure the quantity of cargo required to form block trains, while developing new business models.