• Title/Summary/Keyword: Lifting device

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Quantitative Risk Assessment based on Fault Tree Analysis for Gangform Accident (갱폼 재해의 FTA를 통한 정량적 위험성 산정에 관한 연구)

  • Ham, Young Jong;Kee, Jung Hun;Park, Jong Yil
    • Journal of the Korean Society of Safety
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    • v.35 no.4
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    • pp.40-47
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    • 2020
  • Although gangform has good workability due to the integration of outer wall forms and working platforms, 22 workers were died from 21 gangform related accidents during 2012 to 2016. Quantitative risk assessment is required for evident based prevention measure selection. In this study, based on 52 accident data from 2004 to the first half of 2019, FTA is conducted for probabilities of direct causes and their contribution to accidents. Three stages are considered; gangform installation, dismantling and lifting, and using. The effectiveness of countermeasures is evaluated through minimum cut set, RAW and RRW. Complete assembly of gangform on the ground level, detailed planning, and fall prevention device are suggested as prevention measures for installation, dismantling and lifting, and using stages, respectively.

Ergonomic Verification of Suitability of the 4-Wheeled Hand Cart to Transfer a Projectile for Towed Howitzer (견인곡사포용 이동대차형 포탄 이송장치의 인간공학적 적합성 검증)

  • Park, Sung Ho
    • Journal of Korean Institute of Industrial Engineers
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    • v.42 no.3
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    • pp.165-172
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    • 2016
  • The purpose of this study is to investigate the ergonomic verification of suitability of the 4-wheeled hand cart to prevent musculoskeletal problems in the firing test range. Because of the increasing amount of firing test, the needs to develop a projectile transferring device such as 4-wheeled hand cart has been increased. For the 4-wheeled hand cart, the lifting and carrying activity in the manual handling method were transformed to pushing activity. The risk of low back pain for lifting and carrying the projectile by manual was estimated by NLE and 3D SSPP. On the other hand, the risk for pushing the 4-wheeled hand cart was estimated by psychophysical and biomechanical method such as Mital's equation, Snook's table and 3D SSPP. It was shown that the 4-wheeled hand cart reduced the risk of low back pain drastically with higher efficiency and design compatibility.

Monitoring-Evaluation System for Lifting Heavy Structures using 3D Location Data (3차원 위치좌표를 이용한 대형 구조물 양중을 위한 계측 - 평가 시스템)

  • Lee, Myung Ho;Chun, Sung Chul;Oh, Bohwan
    • Journal of Korean Society of Steel Construction
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    • v.21 no.4
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    • pp.413-420
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    • 2009
  • Heavy structures such as large roof structures and superbeams were lifted using hydraulic jacks. Moreover, member verticality and horizontality checks were performed at every construction stage to monitor the measuring tapes for their structural safety, using CCTV. When the relative displacement exceeded the predetermined limit, the hydraulic systems were terminated. After adjusting the relative displacement manually, lifting was resumed. The accuracy of the relative displacement was found not to be reliable, however, due to eye check using CCTV, and it took a long time due to manual adjustment. Moreover, real-time monitoring was impossible. To address these problems, the monitoring-evaluation system for the stable lifting of heavy structures was proposed, using the total station of the automatic-target-recognition type, laser-distance-measuring devices, a data logger, a strain gauge, and others. After developing a program for the operation of the system and for the acquisition of data, a mock-up test was conducted in a large-scale structural laboratory to evaluate the accuracy and applicability of the system. The stable acquisition and applicability of data was confirmed in the test.

Design of Fuzzy Controller for a 2-Dimensional Wire-Driven Heavy Material Lifting System (2차원 와이어 구동식 중량물 권양 시스템을 위한 퍼지제어기 설계)

  • Lee, Yong-Chan;Lee, Hyeng-Jun;Lee, Yun-Jung
    • Journal of the Korean Institute of Intelligent Systems
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    • v.25 no.2
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    • pp.97-104
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    • 2015
  • A fuzzy controller and a 2-dimensional wire-driven heavy material lifting system helping human operator are proposed in this paper. The 2-dimensional wire-driven heavy material lifting system is a kind of human-assistive systems in which a human is involved in the control loop. Most of the existing human-assistive control systems cannot consider human operator's characteristic. To consider human operator's characteristic, human's operating motion and requirement of reducing operator's force to lift a heavy material are considered in the design process of the proposed fuzzy controller. The performance of the proposed system is verified by experiments.

A study on the toilet lifting seat for the elderly (노약자를 위한 변기 리프팅 시트 연구)

  • Minseo Kim;Hyemin Son;Jinho Cho;Sang-Hyun Kim
    • The Journal of the Convergence on Culture Technology
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    • v.10 no.1
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    • pp.459-464
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    • 2024
  • The purpose of this study is to design a toilet lifting seat to prevent falls accidents in the elderly while using the toilet. Prior to design, laws and national standards related to restroom use were investigated and the available space for the assistive devices to be installed was determined. In additions, considering the body size and operating range of the elderly, the optimal final position of the toilet seat is set so that users can use it more safely and conveniently without external help. Moreover, in order to provide an effective standing assistance function, a complex 4-bar link structure was applied to enable simultaneous seat elevation and angle adjustment when operating the device, and the appropriate link shape and dimensions were determined using a linkage program and UG NX. FEA analysis using ANSYS Workbench is performed to ensure the robustness of the stretched linkage and the feasibility of the lifting seat is verified through fabrication.

A Study on the Safety and Performance Test Guideline of Low Intensity Therapeutic Ultrasound Device (저강도 초음파 치료기기의 안전성 및 성능평가 가이드라인 수립을 위한 연구)

  • Kim, Ju-Young;Kim, Jae-Young;Noh, Si-Cheol;Choi, Heung-Ho
    • Journal of Biomedical Engineering Research
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    • v.36 no.5
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    • pp.162-168
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    • 2015
  • In this study, we suggested the performance and safety testing guideline for low intensity pulsed ultrasound (LIPUS) represented by the ultrasound fracture treatment device and cartilage treatment device and low intensity focused ultrasound (LIFU) represented by ultrasonic face lifting device. For these study, the international standards and management regulations of Korea, Japan and United State were analyzed. And the usefulness and applicability were evaluated by testing with commercial equipment and reflecting the views of the industry and experts. As a result of this study, the safety and performance test guidelines for low intensity therapeutic ultrasound device were proposed by presenting the 10 items for LIPUS and 12 items for LIFU. The suggested guidelines are considered a high utilization in the domestic testing and approval authorities. And they are also thought to be useful to new technology development.

A Study on Interface for Image Compression Based on SOPC (SOPC 기반 영상압축을 위한 인터페이스 연구)

  • Jung, Jae-Wook;Son, Hong-Bum;Park, Seong-Mo
    • Proceedings of the IEEK Conference
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    • 2006.06a
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    • pp.687-688
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    • 2006
  • This paper presents implementation of the lifting based DWT processor interface which the process of JPEG2000. The proposed architecture uses Excalibur device produced Altera. This study describes CIS(CMOS Image Sensor), DMA(Direct Memory Access) and DWT control logic

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The Design and Development of An Oil Palm Fresh Fruit Bunch Cutting Device

  • Ahmad, Desa
    • Proceedings of the Korean Society for Agricultural Machinery Conference
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    • 1996.06c
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    • pp.458-468
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    • 1996
  • The Oil Palm industry has developed tremendously with the increasing of planted area from 54,000 hectaresin 1960 to about 2.28 million hectares in 1995. This is expected to increase further to 2.5 million hectares by the year 2000. However, there has been an increasing difficulty in obtaining sufficient labour for the oil palm plantations. At present , harvesting of oil palm fresh fruit is facing an acute shortage of workforce as the workers are much more attracted to the better working environment and salary in the industrial sector. Harvesting of short palm is easily done by using a chisel attached to a short steel pole. Cutting is done by moving the tool at high speed to the target. The weight of the tool coupled with the speed of throwing will produce enough energy to cut the bunch stalk. In this cutting method, sharpness of the cutting device, weight of tool and the speed of throwing contribute to the efficiency of the tool . For the tall palms, a sickle attached to a ong pole is used and the job is more difficult compared to the short palms. Lifting of pole and cutting jobs require great effort and skills. This paper describes the basic design needs in developing an appropriate device that is practical for field use. A prototype design was developed and tested.

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Development of Hanging Type Circular-patterned System for Strawberry Cultivation (행거식 순환형 딸기 재배시스템 개발)

  • Sewoong An;Dong Eok Kim;Soonjung Hong;Dong Hyeon Kang
    • Journal of Practical Agriculture & Fisheries Research
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    • v.26 no.2
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    • pp.25-30
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    • 2024
  • This study was conducted to develop the hanging type circular-patterned system that at maximizing the spatial efficiency of strawberry cultivation to increase yields, while also reducing labor and improving energy efficiency. The system consists of a cultivation bed units, longitudinal moving device, bed lifting device, front and rear transfer devices, lateral transfer device, nutrient supply device, and control unit. Performance testing revealed that the operational motor for longitudinal movement should have a torque of at least 0.1Nm based on the design weight and traction force of the cultivation bed unit. The power consumption required to move one cycle was calculated to be approximately 149Wh when performing harvesting or maintenance tasks for all 10 cultivation beds. Vibration angles measured during bed movement showed that the lateral transfer resulted in a roll angle ranging from -0.62° to 0.68° and a pitch angle ranging from -3.79° to 5.26°. For longitudinal transfer, the roll angle ranged from -3.37° to 3.36°, and the pitch angle ranged from -0.45° to 0.49°.

Difference of Lumbar & Lower Extremity Muscle Activity when Patients are Transferred by Physical Therapists

  • Hur, Jin-Gang;Park, Chong-Uk;Lee, Ju-Sang
    • Journal of the Ergonomics Society of Korea
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    • v.30 no.5
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    • pp.613-619
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    • 2011
  • Objective: The purpose of this study is to compare the muscle activities of lumbar and lower extremity muscles between left and right sides using EMG(Electromyogram) when patients are transferred by physical therapists. Background: Asymmetrical lift was recognized as a major cause of musculoskeletal disorder. Several studies show that physical therapists' transferring patients needs caution as it could cause a lumbar pain to patients but there is not sufficient data to support. Method: Forty healthy rehabilitation hospital physical therapists joined for this study. The subjects were transferred from wheelchair to treatment mat(from left to right) by connecting the EMG device to the patients' body both on erector spine and rectus fermoris. At the moment when subjects were being transferred, the EMG device collected data from both erector spine and rectus femoris and it was normalized as %MVC. Then the EMG data was statistically analyzed using paired t-tests. Results: The EMG data show that the left erector spinae and rectus femoris are more activated than right erector spinae and rectus femoris in all position(p<.05) in a significant degree. Conclusion: The result implies that physical therapists' asymmetrical lifting when patients are transferred by them has a potential cause of musculoskeletal disorder of patients. Further studies will be conducted to find out a same tendency in other muscles of a body and to see if there are other factors to affect to patients during asymmetrical lifting. Application: These results can be used to provide baseline information for more understanding to asymmetrical lift loading.