• Title/Summary/Keyword: Heavy Lifting

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The Erection Method of Starter Segment for Cable Stayed Bridge using Asymmetric System and Cable (케이블과 비대칭 구조를 이용한 사장교 주두부 시공 방법)

  • Cho, Seo-Kyung;Yoon, Tae-Seob;Jeong, Seung-Wook;Lee, Jea-Chan;Eo, Jun
    • Proceedings of the Korea Concrete Institute Conference
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    • 2002.05a
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    • pp.1031-1038
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    • 2002
  • In this paper the erection method of the Seohae Bridge starter is presented. The erection method of starter for cable stayed bridge was changed from conventional bracket supported erection to heavy lifting supported directly by stays. There was the need to reduce the erection time drastically. The cost saving was obtained as a bonus.

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Structure of Mesoscale Heavy Precipitation Systems Originated from the Changma Front (장마전선 상에서 발생한 중규모 호우계 구조에 대한 연구)

  • Park, Chang-Geun;Lee, Tae-Young
    • Atmosphere
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    • v.18 no.4
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    • pp.317-338
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    • 2008
  • Analyses of observational data and numerical simulations were performed to understand the mechanism of MCSs (Mesoscale Convective Systems) occurred on 13-14 July 2004 over Jindo area of the Korean Peninsula. Observations indicated that synoptic environment was favorable for the occurrence of heavy rainfall. This heavy rainfall appeared to have been enhanced by convergence around the Changma front and synoptic scale lifting. From the analyses of storm environment using Haenam upper-air observation data, it was confirmed that strong convective instability was present around the Jindo area. Instability indices such as K-index, SSI-index showed favorable condition for strong convection. In addition, warm advection in the lower troposphere and cold advection in the middle troposphere were detected from wind profiler data. The size of storm, that produced heavy rainfall over Jindo area, was smaller than $50{\times}50km^2$ according to radar observation. The storm developed more than 10 km in height, but high reflectivity (rain rate 30 mm/hr) was limited under 6 km. It can be judged that convection cells, which form cloud clusters, occurred on the inflow area of the Changma front. In numerical simulation, high CAPE (Convective Available Potential Energy) was found in the southwest of the Korean Peninsula. However, heavy rainfall was restricted to the Jindo area with high CIN (Convective INhibition) and high CAPE. From the observations of vertical drop size distribution from MRR (Micro Rain Radar) and the analyses of numerically simulated hydrometeors such as graupel etc., it can be inferred that melted graupels enhanced collision and coalescence process of heavy precipitation systems.

Cause Analysis of Cone Roof Tank Collapse during Plant Construction (플랜트 공사 중 발생한 Cone Roof Tank 붕괴 사고 원인 분석)

  • Kim, Seung-Han;Kim, Byung-Suk
    • Journal of the Korea Safety Management & Science
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    • v.18 no.3
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    • pp.71-80
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    • 2016
  • This study is on safety improvement measures through analysis of accident cases during plant storage tank construction. Storage tank is a general term for artificial ground facility constructed to store oil, water, gas, and other chemicals. Some companies have clustered storage tanks (tank farm). The construction methods vary according to the component and types of fluids. Because most of the construction procedures include lifting heavy weight materials using heavy construction equipment and are carried out at high places, storage tank construction contains more risk factors than normal aerial construction. Recently, major accidents such as storage tank collapse have occurred often, and cost many lives due to the characteristics of the structure. In this study we would like to analyze the cause of these accidents and propose measures to improve safety.

Study on the Impact Coefficient of the Lifting System (조금구의 충격계수에 관한 연구)

  • 하대환
    • Journal of the Korean Professional Engineers Association
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    • v.34 no.3
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    • pp.64-67
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    • 2001
  • In resent the weight of structure is heavier and bigger than before. Engineers use many heavy equipments to erect buildings and bridges. The heavy equipment is very useful to lift any weight. But most engineers do not know the impact of the weight when the equipment lifts the weight. In this study one researched into the impact of the weight in the crane work which lifts the weight in the construction site. Also along the number of pulley sheave the impact of the weight was researched. From the impact field test the impact coefficient of a single pulley sheave crane was 0.65 and the four pulley sheaves crane was 0.13. The result shows that the impact coefficient of a single pulley crane is more than 5 time of the impact coefficient of the four pulley sheaves crane and that engineers must consider the impact effect of the crane work in the construction site.

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Analysis on Ga-Rak market workers' disease and treatment of Traditional Korean Medicine(TKM) (pilot study) (가락시장 근로자의 병증과 한의학적 치료에 대한 예비 분석)

  • Yoo, Jae-Ryong;Song, Ho-Sueb
    • Journal of Pharmacopuncture
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    • v.7 no.2
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    • pp.109-119
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    • 2004
  • Objective : To broaden our understanding on occupational disease of market workers and to evaluate the effect of TKM treatment focusing on acupuncture and herb medicine and to promote base studies and clinical trials on occupational disease. Materials and Methods : Analysis was done on 33 Ga-Rak market workers' chart which had been selected through investigation of 1508 outpatient's chart of Kyung Won University Hospital from Jun. 1st, 2002 to May. 31th, 2003. Results : 1. Out of 33 patients, Men had more occupational diseases than women had and Most people were in their forties. 2. Major cause of the disease include repetitve bending, heavy weight lifting and overwork. 3. Past History of patients mostly include frequent lumbar sprain, periarthritis of shoulder, lumbar HNP 4. The patients with occupational disease were diagnosed as lumbar sprain, periarthritis of shoulder, lumbar HNP, degenerative spondylosis, spinal stenosis and their chief complaints were low back pain, omalgia, back pain with radicular pain. 5. The duration of treatment was mostly within a week. 6. Acupuncture, Bee Venom Acupuncture, moxibustion, Herb-medicine, extract, taping therapy, physical therapy were used as treatment methods. 7. Applied herb medicine were composed of 8 kinds of prescriptions and extract were made up of 6 prescriptions 8. Applied acupoints belonged mainly to 14 meridians 9. The treatment of herb medicine combined with acupuncture proved effective in treating the ocupational disease. Conclusion : The occupational disease of patients working in Ga-Rak market were closely related with overwork, especially with repetitive bending and heavy weight lifting and TKM treatment focusing on acupuncture combined with herb medicine was effective in treating occupational disease.

Occupational Safety and Health Among Young Workers in the Nordic Countries: A Systematic Literature Review

  • Hanvold, Therese N.;Kines, Pete;Nykanen, Mikko;Thomee, Sara;Holte, Kari A.;Vuori, Jukka;Waersted, Morten;Veiersted, Kaj B.
    • Safety and Health at Work
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    • v.10 no.1
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    • pp.3-20
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    • 2019
  • This review aimed to identify risk factors for occupational accidents and illnesses among young workers in the Nordic countries and to attain knowledge on specific vulnerable groups within the young working force that may need special attention. We conducted a systematic review from 1994 to 2014 using five online databases. Of the 12,528 retrieved articles, 54 met the review criteria and were quality assessed, in which data were extracted focusing on identifying occupational safety, health risk factors, and vulnerable groups among the young workers. The review shows that mechanical factors such as heavy lifting, psychosocial factors such as low control over work pace, and organizational factors such as safety climate are all associated with increased injury risk for young Nordic workers. Results show that exposures to chemical substances were associated with skin reactions, e.g., hand eczema. Heavy lifting and awkward postures were risk factors for low back pain, and high job demands were risk factors for mental health outcomes. The review identified young unskilled workers including school drop-out workers as particularly vulnerable groups when it comes to occupational accidents. In addition, apprentices and young skilled workers were found to be vulnerable to work-related illnesses. It is essential to avoid stereotyping young Nordic workers into one group using only age as a factor, as young workers are a heterogeneous group and their vulnerabilities to occupational safety and health risks are contextual. Politicians, researchers, and practitioners should account for this complexity in the education, training and organization of work, and workplace health and safety culture.

Development of the Air Cushion Carrier Equipment for Carrying Heavy Loads (중량물 운반을 위한 에어쿠션 이송장비의 개발)

  • Yun, Dongwon;Park, Hee-Chang;Kim, Byung-In;Lee, Sung-Hwi;Jang, Seung-Ik;Hong, Ik-Pyo
    • Journal of Power System Engineering
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    • v.19 no.5
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    • pp.17-24
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    • 2015
  • In this paper, the development of an air cushion transporter has been studied. To do this, theoretical analysis is introduced to design the equipment and computational fluid dynamics is also conducted. Design of an air cushion transporter for heavy load carriage is completed and a prototype is manufactured. Through the analysis and experiment of the developed the prototype, it can be known that the developed transporter can levitate the load of about 1 ton at the applied pressure of 0.2 MPa and the maximum lifting height at this condition is 17mm.

Observation on the Low Back Pain with Myofascial Pain Syndrome (근막동통 증후군의 요통환자에 대한 고찰)

  • Her, Young-Gu
    • Journal of Korean Physical Therapy Science
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    • v.1 no.2
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    • pp.235-241
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    • 1994
  • Myofascial pain syndrome is a common cause of physical disability and reduces the activity of the patient. The purpose of this study was review and analysis efficiency of myofascial pain syndrome with low back pain on 50 case who were treated at the Tae Jon Nam, Myung Ho rehabilitation clinic, from January 1, 1994 to May 31, 1994. The results of this study are as follows : 1. of the 50 cases, 24(48.0%) were male and 26(52.0 %) were female. The most common age group was 40 to 30 years old. 2. The most common duration of the treatment and onset were more than 25 months with 22(44.0 %) and less : 3. As for a major causative disease of low back pain with myofascial pain sndrome, without known cause(30.0 %), lifting object(16.0 %), post exercise(14.0 %) and heavy work(12.0 %). 4. Involved muscle with low back pain reviewed I. C. L(31.0 %), Q. L, Gluteus and others muscle(23.0 %). 5. Disease history and treatment duration were proportioned. 6. Involved muscle distribution for causative disease was 26.0 % post exercise to I. C. L, 33.5 % lifting object to Q. L, 40.0 % without known to gluteus. 7. Low back pain with syndrome was buttock and thigh Pain with 44.0 %, only low back pain with 36.0 %. 8. The improvement by physical therapy on the low back pain was good 24.0 %, fair 56.0 % etc respectively. * I.C.L : Iliocostalis lumborum * Q.L : Quadratus lumborum.

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Risk Assessment and Intervention of Ergonomic Risk Factor in Beekeeping (양봉 작업의 인간공학적 위험성평가 및 개선 사례)

  • Lee, Chanhwi;Kang, Taesun
    • Journal of agricultural medicine and community health
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    • v.44 no.3
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    • pp.138-143
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    • 2019
  • Objectives: The purpose of this study was to assess the ergonomic risk factors in beekeeping, and to evaluate the effectiveness of assistive device hive lift. Methods: This study included 30 subjects of beekeeper in Pocheon, Korea. We assessed the ergonomic risk of main task in beekeeping with NLE, OWAS and evaluate the effectiveness of hive lift. We also surveyed prevalence of musculoskeletal symptoms among the subjects based on the Korea Working Condition Survey. Results: Moving to different floral origin, internal inspection of beehives, feeding syrup is the most burdensome to musculoskeletal system (NLE LI value=2~3. OWAS action category=4). The prevalence of musculoskeletal symptoms (lower and upper extremities) among the subjects was over 80 %. The introduction of assistive devices in the three hazardous tasks has dramatically reduced the risk by removing manual lifting hives (OWAS action category<1). Conclusions: Beekeeping is a heavy workload on the musculoskeletal system because it has a lot of manual lifting task. As a result of applying the hive lift, the burden could be reduced.

Comparative Study of Low Back Pain between White Collar Workers and Blue Collar Workers (사무직 근로자와 육체 노동자의 요통특성에 관한 비교 고찰)

  • Park Ji-whan
    • The Journal of Korean Physical Therapy
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    • v.3 no.1
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    • pp.123-149
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    • 1991
  • This study has been attempted to be helpful for the back rehabilization of Korean workers by analyzing the general, occupational, social aspects of low back pain and to identify possible risk factors for back pain in White and Blue collar workers. The primary data were collected from 380 workers in Seoul city by means of a Questionnaire with random which was distributed from March 10 to 31, 1990. For the test of statistical significance, chi-square analysis was used to compare the back pain characteristics between above two groups. The results were as follows : 1. The incidence of low back pain in all walkers studied was $79.7\%$. The incidence of Blue collar with low back pain $(87.2\%)$ was higher than that of White collars $(75.0\%)$. 2. With regard to the relationship of back pain to the occupational characteristics, statistically significant differences were observed between workers with and without back pain concerning the job factors on work-time, job satisfaction, mental stress, chair fittness, work posture, work rotation, weight lifting, monotonous repetitive movements, vibration, and heavy noise (p<0.05). 3. With regard to the relationship of back pain to the social characteristics, there were no differences with respect to having car, personality types, drinking habits, and leisure-time activities. However, significant differences were showed between no pain and pain groups for the using bed, sleeping posture, traffic time amount, walking health state, smoking habits, and physical exercise (p<0.05). 4. The comparative analysis of back pain related to work factors showed highly significant differences with respect to mental stress, chair fittness, work posture, trunk rotation, weight lifting, monotonous repetitive work in White collar group (p<0.01) ; and job satisfaction, mental stress, trunk rotation, weight lifting, monotonus repetitive work, exposure to vibration and heavy noise in Blue collar group(p<0.01). 5. The comparative analysis of social factors in two groups showed differences with respect to the using bed, sleeping posture, walking amount, health state, physical exercise, smoking habits in White cellar group (p<0.05) ; and walking amount, traffic time amount, health state, smoking habits, physical exercise in Blue cellar group (p<0.05). 6. In regard to the general aspects of back pain between two groups, there were differences concerning etiolgy of back pain, counselling partners, treatment types, and sick-leaves(p<0.05), except pain duration, and awareness of back pain.

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