• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.25 no.4
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• pp.472-481
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• 2015

Objectives: Welding is a major task in shipbuilding yards that generates welding fumes. A significant amount of welding in shipbuilding yards is done on steel. Inevitably, manganese is present in the base metals being joined and the filler wire being used and, consequently, in the fumes to which workers are exposed. The objective of this work was to characterize manganese exposure associated with work area, total and particle size-selective mass concentration, and compare the mass concentrations obtained using a three-piece cassette sampler, size-selective impactor sampler and blood manganese concentrations. Materials: All samples were collected from the main work areas at one shipbuilding yard. We used a three piece cassette sampler and the eight stage cascade impactor sampler for the airborne manganese mass concentration of total and all size fractions, respectively. In addition, we used the results of health examination of workers sampled for airborne manganese. Results: The oder of high concentration of airborne manganese in shipbuilding processes was as follows; block assembly, block erection, outfitting installation, steel cutting, and outfitting preparation. The percentages of samples that exceeded the OES of the ministry of employment and labor by the cassette sampling method was 12.5%, however 59.1% of sampled workers by the impactor sampling method exceeded the TLV of the ACGIH. Conclusions: Even though the manganese concentrations in blood of workers exposed to higher airborne manganese concentration were higher than among those exposed to lower concentrations, there was no difference in blood manganese concentrations among work duration. The data analyzed here by characterizing size-selective mass concentrations indicates that the inhaled manganese of welders in shipbuilding yards could be mostly manganese-containing respirable particle sizes.

• Journal of Preventive Medicine and Public Health
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• v.32 no.3
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• pp.374-382
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• 1999

Objectives: Organizational culture has beer important in field of organizational behavior research for the past decade. Although there has been a growing interest in the organizational culture and organizational effectiveness, there is few research in health care field. This study was carried out to investigate the relationship of organizational culture and organizational effectiveness at general hospital. Methods: Data was collected by self-administrated questionares. Organizational cultures were measured by using Likert scale. A general hospital in Kyunggi-Do was selected and survey was conducted to 675 workers. Data was analyzed with computer package, PC-SPSS. Results: There were four types of organizational culture in this hospital consensual culture, developmental culture, hierarchical culture, rational culture. Many workers recognized their culture as rational culture and developmental culture. This finding showed that the hospital had both human related and task related climate. There were some differences in recognition of sub-organizational culture by occupational group, but perceived organizational culture was in accordance with sub-organizational culture in general. Multiple regression analysis and multiple logistic regression analysis were conducted to find the relationship of organizational culture and organizational effectiveness. As a result, developmental culture showed a strong relationship with organizational commitment and job-satisfaction. Conclusions: These results showed that types of organizational culture were significantly related to organizational effectiveness and understanding the existing culture is essential to develope their organizational effectiveness.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.21 no.1
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• pp.11-24
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• 2011

Working in a research laboratory means exposure to a wide range of hazardous substances. Several studies indicated that laboratory workers, especially working with chemicals, might have an increased risk of certain cancers. However, exposure assessment data in laboratory settings are scarce. This study was performed to examine several approaches for quantitatively assessing the exposure levels to volatile organic compounds (VOCs) among workers in chemistry laboratories. The list of 10 target VOCs, including ethanol, acetone, 2-propanol, dichlormethane, tetrahydrofuran, benzene, toluene, n-hexane, ethyl acetate, chloroform, was determined through self-administered questionnaire for six chemistry research laboratories in a university, a government-funded research institute, or private labs. From September to December 2008, 84 air samples were collected (15 area samples, 27 personal time weighted samples, 42 personal task-basis short-term samples). Real time monitors with photo ionization detector were placed during the sampling periods. In this study, benzene was observed exceeding the action levels, although all the results were below the American Conference of Governmental Industrial Hygienists (ACGIH) Threshold Limit Value (TLV). From the air sampling results, we concluded that (1) chemicals emitted during experiments could directly affect to neighbor office areas (2) chemical exposures in research laboratories showed a wide range of concentrations depending on research activities (3) area samples tended to underestimate the exposures relative to personal samples. Still, further investigation, is necessary for developing exposure assessment strategies specific to laboratories with unique exposure profiles.

• The Journal of Korean Physical Therapy
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• v.25 no.5
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• pp.273-281
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• 2013

Purpose: The purpose of this study is to determine the effect of motor imagery training on residual upper extremity strength and activities of daily living of chronic cervical spinal cord injury patients. Methods: Twelve ASIA A B patients, who had more than a 12-month duration of illness and C5 or 6 motor nerve injury level, were randomly divided into experimental group (n=6) and control group (n=6). Patients in the experimental group performed motor imagery training for five minutes prior to general muscle strengthening training, while those in the control group performed general muscle strengthening training only. The training was performed five times per week, 30 minutes per day, for a period of four weeks. General muscle strengthening training consisted of a progressive resistive exercise for residual upper extremity. Motor imagery training consisted of imagining this task performance. Before and after the training, EMG activity using BTS Pocket Electromyography and Spinal Cord Independent Measure III(SCIM III) were compared and analyzed. Results: The residual upper extremity muscle strengths showed improvement in both groups after training. Comparison of muscle strength improvement between the two groups showed a statistically significant improvement in the experimental group compared to the control group (p<0.05). SCIM III measurements showed significant improvement in the scores for Self-care and Transfer items in the experimental group. Conclusion: Motor imagery training was more effective than general muscle strengthening training in improving the residual upper extremity muscle strength and activities of daily living of patients with chronic cervical spinal cord injury.

• Journal of Korean Physical Therapy Science
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• v.20 no.1
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• pp.43-49
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• 2013

Background and purpose : The shoulder joints permit the greatest mobility of any joint area carries out the important function of stabilization for hand use. Research has now shown that grip strength has proven to be a reliable indicator for quality of life at an older age. The purpose of this study was to investigate the effects of testing posture and shoulder position on grip strength for repetitive gripping task. Methods : Forty(20male, 20female) college adult volunteers with no known shoulder dysfunction participated subject in two testing posture(sitting and standing) and three positions with shoulder flexion: (1) shoulder $0^{\circ}$ flexion (2) shoulder $90^{\circ}$ flexion (3) shoulder $180^{\circ}$ flexion. The paired t-test was used to determine any significant difference in grip strength between the testing posture and shoulder position. Results : The higher grip strength gained in the sitting with the shoulder $180^{\circ}$ flexion and the higher grip strength gained in the standing with the shoulder $180^{\circ}$ flexion. The second experiment showed that the grip strength was significant for sitting, standing position of shoulder $0^{\circ}$ flexion( p<0.05). Grip strength goes up as increase height and weight. Conclusion : These findings demonstrate that the theory does not fit with, because of the influence of gravity, a measure from the shoulder joint is the most high, $0^{\circ}$. And sitting posture and stance in the grip of a difference when compared SIT $0^{\circ}$ and standing position $0^{\circ}$ significant difference in indicated but, $90^{\circ}$ and $180^{\circ}$ in the sitting position and stance in the grip of the difference was not significant difference. To demonstrate the universality of this study's results, future studies should have a larger and more subject as well as a more even distribution of male and female subject. Therefore future research is needed to refine the definition and identify optimal methods of measuring this grip strength.

• Physical Therapy Rehabilitation Science
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• v.4 no.2
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• pp.87-93
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• 2015

Objective: Balance is a preceding task for functional activities in daily activities as well as community-dwelling activities. To learn skilled and functional activities, it is also necessary to imagine an appropriate and effective movement representation used to plan and execute the functional activities. The purpose of this study was to evaluate the effects of balance imagery of semi-tandem stance on a flat floor and balance beam on balance abilities for elderly and young adults. Design: Cross-sectional study. Methods: Fifteen elderly and thirty-four young adults were enrolled in this study. In order to determine whether there is a change in postural control ability according to the different imagery training methods used, standing static balance measurements were performed. According to the therapist's instructions, participants were to stand in a semi-tandem position on the Good Balance System for 1 minute while imagining that they were standing on a balance beam, and while the postural control abilities was assessed. Results: Postural control was significantly different in balance ability of semi-tandem stance on a flat floor compared to on a balance beam in both geriatrics and young adults. Postural sway was more significantly decreased in young adults than older adults during balance imagery of semi-tandem stance on a flat floor as well as on balance beam (p<0.05). Conclusions: The results of this study suggest that the ability to mentally represent their actions was similar in older adults compared to young adults, although older adults showed a drop in efficiency of postural control more than young adults.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.23 no.4
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• pp.412-420
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• 2013

Objectives: This study was conducted in order to evaluate personal and area exposure to airborne total dust and endotoxin during harvest and planting tasks at cucumber, yellow melon and potato farms Materials and Methods: Total dust was measured with NIOSH method 0500. Endotoxin were measured using a 37 mm glass fiber filter which was connected to an air pump calibrated to 2 LPM, and then analyzed with a Turbidmetric kinetic method. Results: The average(arithmetic mean) concentrations of total dust in the personal samples were $0.10-3.81mg/m^3$ for cucumbers, $0.21-1.19mg/m^3$ for yellow melon, and $0.08-2.72mg/m^3$ for potato. There was a significant difference in the harvest task among the three farm types(p=0.019 of personal sample, p=0.048 of area sample), in which the air concentration for potatoes was higher than with cucumbers and yellow melons. Conclusions: It was found that potatoes(planting and harvest) should be considered the first priority for studying and reducing total dust exposure.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.19 no.4
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• pp.328-334
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• 2009

There are various methods for welding fume control. These methods can be divided into local exhaust system, general ventilation system and integrated control system. With the general ventilation system, we should have a good prediction tool for testing various appropriate control options. But, until now there are not many studies about how to predict the welding fume concentrations. Especially, the prediction of welding fume concentration is not a very easy task because welding fume is the particulate matters. In this study, we tried to measure $CO_2$ concentrations and welding fume concentrations in a small single room with a small ventilation opening. Using commercially available CFD (Computational Fluid Dynamics) software, we tried to predict $CO_2$ concentrations under the exactly same conditions. Then, we tried to compare the numerical $CO_2concentrations$ with the experimental results to know whether we could predict $CO_2$ concentrations. Then we tried to compare $CO_2$ concentrations with experimental welding fume concentrations to know whether we can use the numerical $CO_2concentrations$ to predict the welding fume concentration indirectly.

• The Journal of Korean Physical Therapy
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• v.26 no.6
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• pp.436-441
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• 2014

Purpose: The objective of this study was to offer clinical primary data that it's aims to examine effects of transcranial direct current stimulation (tDCS) on cognitive function and biochemical change of rat with alzheimer's disease(AD) induced by injecting scopolamine. Methods: Subjects were instructed cognitive dysfunction model, rat of Sprague-Dawley system was injected with scopolamine and each experimental group was classified into three; group I (n=16) is non-treatment groups; group II (n=16) is applied with the tacrine; group III (n=16) is applied with the tDCS. The ziggurat task test was conducted to observe behavioral changes and cognitive function ability and 7, 14, 21, 28 days after the model. Acetylcholine Esterase (Ach E) activity was examined for biochemical assessment of which the results are followed. Results: Participants showed as to behavioral change, tacrine application group was the most significantly responded, following tDCS application group. As to biochemical change, same as above, tacrine application group was the most significantly responded, following tDCS application group. Conclusion: From these results, confirm that tDCS application to rat with alzheimer's disease leads to positive effects on behavioral, cognitive function changes, and biochemical changes, lasting for certain period of time. This study, in particular, tDCS, which can change excitability of brain cells non-invasively, could provide basic data that is useful as a new treatment way for the patients with cognitive dysfunction.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.29 no.2
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• pp.159-166
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• 2019

Objectives: The purpose of this study was to evaluate the personal exposure to $PM_{10}$ by body parts for the development of dust monitoring wearable device for swine farmers. Methods: Tasks were classified by using motion pictures taken by action cameras attached to swine farmers. Concentrations of $PM_{10}$ were measured by attaching direct-reading instruments at the head, neck and waist of worker. Differences of $PM_{10}$ exposure between body parts were analyzed with linear regression. Results: We identified three tasks(vaccination, moving pigs, and manure treatment). $PM_{10}$ concentration during vaccination was the highest among the tasks, and the body part showing the highest concentration of $PM_{10}$ was the waist regardless of task. In all tasks, the closer distance between the body parts, the higher were the R-squared values(vaccination 0.4221, moving pigs 0.6990, and manure treatment 0.2164). Conclusions: We presumed that $PM_{10}$ concentrations were affected by the parts of the body in which they were measured. In order to develop swine farmer's wearable device for monitoring dust concentration in air, the determination of the positions of monitoring sensor to ensure accurate measurement is essential. Considering the results of this study, wearable sensor should be positioned at the waist.