• Journal of the Ergonomics Society of Korea
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• v.31 no.5
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• pp.637-646
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• 2012

Objective: The aim of this study was to develop the adaptive device for severe physical disabilities using smart device in the driving simulator and its performance evaluation. Development of appropriate driving adaptive device for the people with serious physical limitation could contribute to maintain their community mobility. Background: There is lack of adaptive driving devices for the people with disabilities in Korea. However, if smart device systems like iPod and iPhone are used for driving a car, the people with serious physical limitations can improve their community mobility. Method: Both gyroscope and accelerometer from iPod were used to measure the tilted angle of the smart device for driving. Customized Labview program was also used to control three axis motors for steering wheel, accelerator and brake pedals. Thirteen subjects were involved in the experiment for performance evaluation of smart device in simulator. Five subjects had driver licenses. Another four subjects did not have driver licenses. Others were people with disabilities. Results: Average driving score of the normal group with driver license in the simulator increased 46.6% compared with the normal group without driver license and increased 30.4% compared with the disabled group(p<0.01). There was no significant difference in the average driving score between normal group without driver license and disabled group(p>0.05). Conclusion: The normal group with driver license showed significantly higher driving score than other groups. The normal group without driver license and disabled group could improve their driving skills with training in simulator. Application: If follow-up studies would be continued and applied in adapted vehicle for on road environment, many people with more severe disabilities could drive and improve the quality of life.

• Journal of the Ergonomics Society of Korea
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• v.23 no.2
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• pp.1-12
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• 2004

The purposes of this study were to investigate the relationship between anthropometric data of foot and other body sizes. to categorize the foot shape of elementary school boys and to find out determinant factors related the foot that enable us to deduce the foot shape and size for the design of more comfortable shoes. Subjects of this study were 249 elementary school boys of age ranged from 6 to 11 residing Seoul and lncheon area. Anthropometric sizes were measured with the direct measurement method using Martin scales and the indirect measurement method using digital photos. Pearson's correlation, factor analysis. cluster analysis. analysis of variance, post-hoc test, and cross tabs were performed for statistical analysis of the data by SPSS program. From the investigation on the relationship between foot-related items and body items, most items of foot measure were significantly related to body size items. However, angle of the foot did not related to other body sizes although other height items and mass items of the foot did have relationships with other body sizes. Results of ANOVA indicated there were significant differences in foot-related items except for items of foot angle and all body anthropometric items by subjects' age. This implicates big toe angle, little toe angle and foot ratio factors are required in sizing shoes besides foot length. On the basis of cluster analysis using factor scores. three different foot shapes were categorized. Type 1 was large and wide foot, Type 2 was small and narrow foot with large toe angle. and Type 3 was medium foot with no deformity on big toe. These three groups show significant differences in almost all measurement items. However, Rorher index and foot angle didn't show any significant differences among groups. This implicates the foot shape can be a determinant of shoe size.

• Journal of the Ergonomics Society of Korea
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• v.29 no.5
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• pp.751-762
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• 2010

The purpose of this study was to investigate the job stress factors of aircraft composite material part manufacturing workers using survey based on 'Job stress factors evaluation tool for Koreans' that was developed by KOSHA in 2003. Two hundred and fifty workers participated in this study, and among them 204 responses were analyzed for this study due to the unreliability and insincerity of responses. The eight job stress factors which are physical environment, job autonomy, job insecurity, organizational system, workplace culture, unfair compensation, relationship conflict, and job requirement were analyzed. The results showed that the stress level of the six job stress factors which are physical environment, job autonomy, job insecurity, organizational system, workplace culture, unfair compensation was relatively higher than that of other industry workers. Generally, all eight job stress factors showed higher stress with temporary workers than with permanent workers, and especially job autonomy, job insecurity, organizational system, and unfair compensation factors showed statistically significant differences (p<0.05). Since the temporary workers are insecure with their job, weak position in organization, having little self-control for the job and lower pay level than that of permanent workers though the job is as same as permanent workers', the stress level of above job stress factors would be much higher than that of the other factors. The group of unsatisfactory with workplace showed higher job stress than group of satisfactory with workplace in all job stress factors, as expected, at the statistically significance level (p<0.05). From the results of this study, the work loss due to the job stress could be prevented, and accurate stress factors could be removed at the workplace. Also the job stress management program can be implemented to improve the work efficiency and the workers' quality of life.

• Journal of the Ergonomics Society of Korea
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• v.31 no.6
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• pp.705-713
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• 2012

Objective: The aim of this study is to predict human visual target search using ACT-R cognitive architecture in real scene images. Background: Human uses both the method of bottom-up and top-down process at the same time using characteristics of image itself and knowledge about images. Modeling of human visual search also needs to include both processes. Method: In this study, visual target object search performance in real scene images was analyzed comparing experimental data and result of ACT-R model. 10 students participated in this experiment and the model was simulated ten times. This experiment was conducted in two conditions, indoor images and outdoor images. The ACT-R model considering the first saccade region through calculating the saliency map and spatial layout was established. Proposed model in this study used the guide of visual search and adopted visual search strategies according to the guide. Results: In the analysis results, no significant difference on performance time between model prediction and empirical data was found. Conclusion: The proposed ACT-R model is able to predict the human visual search process in real scene images using salience map and spatial layout. Application: This study is useful in conducting model-based evaluation in visual search, particularly in real images. Also, this study is able to adopt in diverse image processing program such as helper of the visually impaired.

• Journal of the Ergonomics Society of Korea
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• v.29 no.2
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• pp.225-239
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• 2010

A high prevalence of farmer's work-related musculo-skeletal disorders (MSDs) have been reported in precedent studies. Risk factors - physical, chemical, biological, ergonomic risk factor etc. - in farm-work were identified by previous studies. To prevent farmers from exposing to them and reduce, Agricultural Safety Technology were introduced and used on farm. The purpose of this study is to review and summarize the agricultural safety technology on farm in Korea. According to strategy principles, this technology is classified as four criteria - workload reduction by reducing awkward posture, workload reduction by using manual material handling aids, Comfort improvement by protecting worker from hot, cold environment and work efficiency improvement by workplace redesign and cultivation modification. This technology includes transporting tools, working cloth, personal protective equipment, and pesticide-proof Clothing. Anthropometric study of Korean farmers was also carried out to support the development of equipment and clothes. In long terms, it needs to precaution activity from risk factors by using cultivation modification and working improvement. Although working condition gets better and workload reduce by this technology, it required customized safety technology in each crops - rice cultivation, horticulture and livestock farming. And farmers should use the assistive technology and participate voluntarily in ergonomic intervention program.

• Journal of the Ergonomics Society of Korea
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• v.26 no.4
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• pp.147-152
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• 2007

The aim of this study was to evaluate the musculo-skeletal symptomatic features of municipal sanitation workers and to compare differences of the musculo-skeletal symptoms by work types. We conducted descriptive cross-sectional survey concerning the musculo-skeletal symptomatic features of 315 street cleaners in Seoul and GyeongGi Province, Korea, during 2 weeks of September 2006. Questionnaires were consisted of general characteristics, occupational characteristics and musculo-skeletal symptoms. And we observed their works and evaluated their movement and posture by REBA. For work types, tools and subjective physical work loading, there were statistical difference whether or not NIOSH symptom positive on upper limb. Musculo-skeletal symptoms on upper limb were claimed from 43.2% of street cleaners, more than in 32.4% of cleaners. Musculo-skeletal symptoms on upper limb were reported higher in the group who felt their subjective physical work loading severe than in the otherwise group. The REBA results were over 'high risk stage' in street cleaners. Street cleaners had more repetitive motions than solid waste collectors on upper limbs. Works according to the criteria of musculoskeletal burdened work by the Ministry of Labor results were over 'high risk stage' of No. 2 and No. 4 in street cleaners. We found that street cleaners complained musculo-skeletal symptoms on upper limb more than solid waste collectors. This study suggests that it is necessary for street cleaners to carry out the prevention program of musculo-skeletal diseases. For street cleaner, the measure plans such as job rotation, automatic street sweepers, reducing work hours are helpful in preventing musculoskeletal symptoms on the upper limb.

• Journal of the Ergonomics Society of Korea
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• v.26 no.4
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• pp.25-31
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• 2007

The purpose of this study was to investigate the strength and endurance of the deep neck flexor muscles in individuals with work-related neck pain. Subjects consisted of two groups: twenty industrial workers with neck pain and twenty age-matched healthy subjects. To evaluate the strength and endurance of deep cervical flexors, maximum voluntary contractile strength (MVCS) and a sustained time at sub-maximal voluntary contractile strength (SMVCS) (80% and 50% of MVCS) were measured using a pressure biofeedback unit and a stop watch in supine. The MVCS of deep neck flexor muscles was 29.67${\pm}$4.56 in neck pain group and 54.27${\pm}$6.78㎜Hg in normal group. The sustained time at 80% SMVCS was 12.42${\pm}$2.64 seconds and 55.12${\pm}$12.76 seconds in the groups with and without neck pain. The sustained time at 50% SMVCS was 25.40±5.88 seconds and 109.70${\pm}$31.50 seconds in the groups with and without neck pain. The difference of the lower jaw position was 16.75${\pm}$3.57㎜ and 23.03${\pm}$2.51㎜. The MVCS, endurance at the two sub-maximal levels and the difference of the lower jaw position were significantly greater in the group without neck pain than with neck pain (p$<$0.05). The findings indicate that the maximal strength and endurance of the deep neck flexors were decreased in the workers with neck pain compared to those without neck pain. Therefore, it is necessary to include strengthening and endurance exercises of the deep neck flexor muscles in therapeutic program of work-related musculoskeletal disorders involving neck pain.

• Journal of the Ergonomics Society of Korea
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• v.35 no.2
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• pp.97-109
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• 2016

Objective: The aim of this study is to identify the domestic and foreign laboratory safety management system and to suggest domestic laboratory safety management policy priority. Background: Various types of accidents are occurred in research laboratories according to a variety of laboratory safety risks. However, there are only lists of incidents without any precise accident analysis. Method: We analyzed statistically the survey on current status of laboratory safety management of universities, research institutes, and industrial research institutions carried out by Ministry of Science, ICT and Future Planning in Korea. We also investigated laboratory safety management systems and safety organization carried out mainly in overseas countries such as USA, Japan, Switzerland and France. In addition, we analyze the UCLA College laboratory explosion occurred in the US in 2010. Results: More than 75 percent of 2015 domestic laboratory accidents were occurred in the field of operation management and chemistry research. Also, approximately 55% of accidents took place due to careless use mechanical instruments & dangerous chemicals. In addition, common difficulties of lab safety act applicable organizations are overlapping and comprehensive application of legal requirements. Conclusion: There is a need for laboratory safety professional organizations. Also, the high frequency of use of hazardous substances in the high-risk, such as the chemical field must be strengthened the laboratory safety management. In addition, it is needed to minimize the problems of the research organizations through close cooperation between related ministries and government support policy such as professional development program. Application: The result of this analysis might help to present a differentiated safety management policy and advanced safety management system in laboratory.

• Journal of the Ergonomics Society of Korea
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• v.32 no.6
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• pp.495-501
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• 2013

Objective: The purpose of this study was to survey of the subjective health status of the elderly farmer. Background: With increase of aged population, the health of the elderly farmer has become main concerns of the elderly in the rural community. For the effects of the factors related to quality of life, subjective health condition showed the largest influence. Method: The survey was conducted by 326 elderly farmers aged 50 and older in rural areas through structured questionnaires. Survey questionnaire consisted items of general characteristics, health-related life habits, levels of stress(SF-PWI), symptom of musculoskeletal diseases and general level of health(SF-36). For the data analysis, SPSS 19.0K was used, and analysis was conducted by using frequency, percentage, mean, and standard deviation. For the symptom prevalence of musculoskeletal disorders and comparison of average level of health, chi-square test and t-test were used. Results: The results of the study are as follows. It was shown that the symptom prevalence of musculoskeletal disorders had a significant difference in gender (p<0.01). Frequency analysis on presence of musculoskeletal symptoms in each part of body showed that leg/knee region was 28.1%, back region was 26.6%, shoulder region was 18.0%, arm/elbow region was 11.9%, hand/wrist region was 8.2% and neck region was 7.2%. According to comparison of average level of health, a social functioning were the highest as score 87.3, followed by mental health(65.6) and role limitation-emotional(65.5). Conclusion: Health promotion program for the elderly and female in the rural are needed. Application: The survey of the subjective health status of the elderly should be used for planning factors to make a health improvement plan in elderly farmer.

• Journal of the Ergonomics Society of Korea
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• v.33 no.1
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• pp.15-25
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• 2014

Objective: This study aims to analyze the factors that affect the ability to maintain dynamic sitting balance (DSB), biomechanical characteristics, and physical characteristics in spinal cord injuries (SCI) patients. Background: Virtual ski training systems, ski equipment, and training protocols for disabled skiers are being studied to spread awareness. However, few studies have been reported on the sitting balance ability associated with chair mono skiing. Method: A dynamic sitting balance border system was built to investigate the ability to maintain dynamic sitting balance in SCI patients. Trunk muscle activity was evaluated by electromyogram while conducting dynamic sitting balance tests. The trunk muscle strength was tested with a portable handheld dynamometer. Physical activity scores were measured with the physical activity recall assessment. Results: There were high levels of correlation between the ability to maintain DSB and trunk flexor strength, extensor strength, rotator strength, and physical activity score. However, height, weight, and injury level in SCI patients were not correlated with the ability to maintain DSB. Additionally, strong negative correlations were found between muscle activities of the external oblique and lumbar erector spinae muscles and the ability to perform the backward tilt test. Trunk extensor muscle activity during the ball lifting test was significantly higher than in other tests. Conclusion: The results indicate that improving trunk muscle strength and physical activity can increase the ability to maintain DSB. Application: The findings of a close relationship between trunk strength, physical activity, and the ability to maintain DSB need to be reflected in the chair mono ski training program.