• Journal of the Ergonomics Society of Korea
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• v.32 no.5
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• pp.413-420
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• 2013

Objective: The objective of this study was to compare one-hand and two-hands lowering activity in terms of biomechanical stress for the range of lowering heights from knuckle height to 10cm above floor level. Background: Even though two-hands lifting/lowering activity of manual materials handling tasks are prevalent at the industrial site, many manual materials handling tasks which require the worker to perform one-hand lifting/lowering are also very common at the industrial site and forestry and farming. Method: Eight male subjects were asked to perform lowering tasks using both a one-handed as well as a two-handed lowering technique. Trunk muscle electromyographic activity was recorded while the subjects performed the lowering tasks. This information was used as input to an EMG-assisted free-dynamic biomechanical model that predicted spinal loading in three dimensions. Results: It was shown that for the left-hand lowering tasks, the values of moment, lateral shear force, A-P shear force, and compressive force were increased by the average 6%, as the workload was increased twice from 7.5kg to 15kg. For the right-hand lowering task, these were increased by the average 17%. For the two-hands lowering tasks, these were increased by the average 14%. Conclusion: Even though the effect of workload on the biomechanical stress for both one-hand and two-hands lowering tasks is not so significant for the workload less than 15kg, it can be claimed that the biomechanical stress for one-hand lowering is greater than for two-hands lowering tasks. Therefore, it can be concluded that asymmetrical lowering posture would give greater influence on the biomechanical stress than the workload effect for one-hand lowering activity. Application: The result of this study may be used to provide guidelines of recommended safe weights for tasks involved in one-hand lowering activity.

• Journal of Electrical Engineering and Technology
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• v.9 no.5
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• pp.1774-1779
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• 2014

It is known that muscle strength of human body can alter or deteriorate as aging. In this study, we present an inverse dynamics simulation to investigate the effect of muscle strength on performing the daily activities. A 3D musculoskeletal model developed in this study includes several segments of whole body, long and short muscles, ligaments and disc stiffness. Five daily activities such as standing, flexion, finger tip to floor, standing lift close and lifting flexed were simulated with varying the maximum muscle force capacities (MFC) of each muscle fascicles from 30 to $90N/cm^2$ with an increment of $30N/cm^2$. In the result, no solution can be obtained for finger tip to floor and lifting flexed with $30N/cm^2$. Even though the solution was available for standing lift close activity in case of $30N/cm^2$ capacity, many of muscle fascicles hit the upper bound of muscle strength which means that it is not physiologically possible to perform the acvities in reality. For lifing flexed, even the case of $60N/cm^2$ capaciy, represents the moderate healthy people, was not able to find the solutions, showing that 18 muscles among 258 muscle fascicles reached 100% of muscle capacity. The estimated results imply that people who have low muscle strength such as elders or rehabilitation patients were required higher muscle work to perform and maintain the same daily activities than healthy one.

• PNF and Movement
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• v.9 no.1
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• pp.65-73
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• 2011

Background : This study was to investigate effect of hot and cold water for the hand dexterity. Methods : A total of 37 subjects having hemiplegia(men=6, women=11) and normal(men=10, women=10) were participated in this study. After both hands was soaked in the small tube for 1 minute, we measured 'making dots in circles(BOTMP)', 'lifting small objects(JHFT)', 'disk turning(MMDT)' test. Results : In the case of normal's dominant hand, there were statistically significant differences in all tests after soaked in the hot water but there were statistically significant differences in 'disk turning' test after soaked in the cold water. In the case of hemiplegia's unaffected hand, there were statistically significant differences in 'disk turning' test after soaked in the hot water but there were statistically significant differences in 'making dots in circles', 'disk turning' test after soaked in the cold water. In the case of hemiplegia's affected hand, there were statistically significant differences in 'lifting small objects', 'disk turning' test after soaked in the hot water but there were statistically significant differences in 'making dots in circles', 'disk turning' test after soaked in the cold water. Conclusion : The hot and cold water were affected in the hand dexterity. Especially, in the case of both normal and hemiplegia, there were statistically significant differences in 'disk turning' test after soaked in the cold and hot water. Therefore, We were founded that affected in gross movement than fine movement.

• Journal of the Korea institute for structural maintenance and inspection
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• v.12 no.4
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• pp.98-106
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• 2008

The strengthening in terms of efficiency, easy, economics is very popular method when it is applied to a damaged structures. The purpose of this study develops anchorage system that supports enough strengthening effect without any damage. In addition it is checked whether the method can be conveniently applied to structures. To verify strengthening effect a flexural experiments were performed. Four concrete beams were constructed and tested. Deflections, strains and modes of failure were recorded to examine strengthen of beams. Comparing crack load of each experimental data, yielding load, ultimate load, ductility index, and tendon stress were analyzed.

• Transactions of the Korean Society of Automotive Engineers
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• v.5 no.2
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• pp.197-204
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• 1997

In order to investigate the relationship between the ring gap ratio and oil consumption, the axial motion of piston ring was measured by capacitance technique. The pressures of each land and the motions of each ring were calculated by orifice-volume method in which it is assumed that the ring gaps are the only gas leakage paths. The calculated results were compared with the measured ones. Consequently, it is known that the increase of ring gap ratio has the effect of lifting the first ring. The calculated results were roughly in accordance with those measured. Therefore, it is possible to predict the effect of design variables on the pattern of ring motion. It is known that the lift off of first ring accompanied by the increase of ring gap ratio make rise of oil consumption.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.49 no.2
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• pp.169-176
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• 2023

In this study, stem cells were extracted from the callus derived from the aloe cambium, and the antioxidant activity and effect of skin elasticity improvement were assessed. The aloe cambium-derived stem cell extract, AloStem and callus showed the survival rate of each 98.27% and 71.31%. In the results of the DPPH antioxidant activity of AloStem and aloe extract, it was confirmed that the antioxidant effect of AloStem was more than twice that of Aloe extract. AloStem did not affect the cytotoxicity of normal human dermal fibroblasts (NHDF) cells up to 0.25% concentration. Also, AloStem increased elastin, COL1A1 and HAS2 mRNA expression levels dose-dependently. Furthermore, to examine lifting effect of skin elasticity using a sheet mask containing AloStem, 21 adult men and women applied the sheet mask in the face, once a day for 2 weeks. As a result, after 2 weeks the skin length was 116.75 ± 5.58 mm before the use of the sheet mask, but after 2 weeks of use, it was confirmed that 0.59% increased to 117.44 ± 5.17 mm. Thus, we concluded that the sheet mask containing AloStem can help the lifting effect of skin elasticity.

• Journal of the Ergonomics Society of Korea
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• v.33 no.6
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• pp.465-475
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• 2014

Objective: The aim of this study is to investigate the effect of workload on musculoskeletal degeneration. Background: It is important that workers maintain a health body for a long time as a measure of aging workers. In order do so, it is necessary to find out if workload can effect on musculoskeletal degeneration. Method: Epidemiological studies on workload or occupation and disc degeneration, osteoarthritis of knee were identified through database and bibliography searches. Results: Epidemiological studies showed that workload certainly effect on musculoskeletal degeneration. But we couldn't know which of individual factors and occupational factors further contribute to the musculoskeletal degeneration. And we could find that studies on workload and genetic factors were very few. In addition, there was also very few studies that it was possible interaction between individual factors as obesity and occupational factors as heavy manual lifting. Conclusion: Our reviews suggest that it need to conduct study between workload and genetic factors for musculoskeletal degeneration. This further study can identify attributable risk of workload for musculoskeletal degeneration, and contribute to the measure of aging workers. Application: This paper can help to establish research plan for the measure of aging workers.

• Korean Journal of Construction Engineering and Management
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• v.19 no.2
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• pp.50-60
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• 2018

Recently, modular construction method has been widely applied to projects with repetitive processes including dormitory, the residential facility, and the hotel construction due to reduced labor input and shortened construction schedule. Generally, about 40% of total on-site construction cost excluding unit installation cost, is put on exterior finishing work, and thus management of finishing work is deemed important in maintaining the targeted schedule and cost. Since limited equipment is shared so that subsequent activities are not affected while carrying out on-site installation and finishing work, lifting plan becomes more important for modular projects with greater portion of finishing work load. In this regard, tower crane operation plan may take the form of a single cycle or multiple cycles in which equipment efficiency can be affected. However, difficulties exist in evaluating alternatives to tower crane operation plans supporting unit installation and finishing work. Therefore, this study aims to evaluate the alternative of tower crane operation method according to the cyclic period setting in modular building site to determine the effect on T/C uptime and process by parameterizing lifting time for unit and exterior finishing material, lift cycle for unit and exterior finishing material and time required for finishing work. Accordingly, this study develops a simulation model that can increase the tower crane efficiency by controlling the work speed. An academic contribution of this study is to suggest a resource leveling method applying the concept of lifting cycle, and further is expected to be managerially used as a basis for an alternative evaluation of equipment plan.

• The Journal of Korean Physical Therapy
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• v.27 no.5
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• pp.299-303
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• 2015

Purpose: The objective of this study was to examine the changes in muscle activity on the anterior deltoid muscle depending on the stretch rate of kinesio tape when applying kinesio tape in healthy adult subjects. Methods: This study was a single-blind randomized controlled trial, including 22 healthy participants (male 15, female 7) with no pathology or past history of shoulder who participated voluntarily. Participants applied a different stretch rate of the kinesio tape, and the functional activity was tested. The stretch rate of kinesio tape was 0%, 10%, and 20%. Subjects lifted a weight (5% of their body weight) to their shoulder height. Subjects lifted a weight up to an angle of 90 degrees in the sagittal plane, and muscle activities (biceps brachii, anterior deltoid, middle deltoid, upper trapezius) were assessed using EMG (electromyography). Analysis of muscle activity was divided into two parts (lift weight and keep holding). The EMG activity of each muscle was normalized to the value of reference voluntary contraction (%RVC) and explored using repeated ANOVA. Results: There were no significant differences in muscle activity depending on the ratio of tape stretch when lifting a weight (p>0.05). There were no significant differences in muscle activity depending on the ratio of tape stretch when holding a weight (p>0.05). Conclusion: According to the results of this study, in the case of applying kinesio taping therapy for healthy people, it was found that the stretch rate of the tape does not have an effect on muscle activity.

• 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.