• Journal of the Ergonomics Society of Korea
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• v.30 no.4
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• pp.481-489
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• 2011

Objective: The aim of this study was to develop an ergonomic checklist (AULA: Agricultural Upper-Limb Assessment) which can assess the risks of the work-related upper limb disorders of farming tasks in Korea. Background: There are few assessment tools that reflect the current condition of agricultural works as of now. Method: AULA was developed as following three stages. First of all, a physiological experiment was conducted with selected 14 upper limb postures which are frequently occurred in farming tasks and then, an ergonomic checklist was developed with determining risk levels of each body posture based on the experimental findings. Lastly, the ergonomic checklist was validated by comparing with the existing assessment tools. Results: When comparing the AULA which was developed in this study with the existing assessment tools, it was found that the AULA may get over limits of the existing ones which are sensitive to particular postures, but aren't sensitive to the rest of them. Conclusion: It is predicted that the developed upper limb posture assessment tool which gets over the existing tools' limits and is proper for domestic farm work conditions, will help to reduce musculoskeletal disorders caused by farm works, by assessing farm works more easily and objectively. Application: By further developing the theoretical groundwork on the induction of muscular skeletal system symptoms relating to agricultural works, it is expected to improve the level of preventing and managing such muscular skeletal system symptoms in the field of agricultural and farming works, which is relatively less advanced in terms of labor difficulties.

• Journal of Korea Multimedia Society
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• v.3 no.4
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• pp.389-398
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• 2000

The focus of this study is to investigate how personal display system - Head Mounted Display(HMD) and VDU-affect to the body in virtual environments. This prediction was tested by a comparing of playing 3D games while wearing a HMD and monitoring a VDU for an hour. As quantitative measuring and analyzing tools, SSQ, RSSQ, pre and post posture stability test and vision test are used. The results showed that SSQ and RSSQ total score (TS) are related with the results of pre and post posture stability test and SSQ and RSSQ TS of HMD is higher than TS of VDU by one point five times. Especially, TS of MRG3C, having large field of view, has a possibility by two times of simulator sickness (SS). And in order to investigate the degree of SS regarding to the simulator control condition, two conditions, subjective-passive and subjective-active environments were compared. However, there was no significant difference between two environments. The repetition of the same environment has no effect to reduce the SS. Disorientation and oculomotor scores of the SSQ and RSSQ are higher than that of another symptoms. In addition, RSSQ score of strain/confusion is higher than that of nausea. Therefore, we assume that personal fear could possibly increase the simulator sickness in virtual environments.

• Korean Journal of Rural Living Science
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• v.8 no.2
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• pp.111-117
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• 1997

In this study we tried to give a decision on propriety of working conditions, to present ideas on reducing work loads. and to grope for efficiency of agricultural works. For this we examined the actual conditions of working environment, farmer's clothes, working posture, working methods, working time, resting state, fatigue recovery methods during cultivating lettuce in the winter greenhouse. And Ive improved harmful factors that affect farmer's health by considering results of previous study and farmer's subjective sensation. And we measured, compared, and analyzed the farmer's work loads before and after improvement. The results of this study are as follows ; 1. According to examine the actual conditions of cultivating lettuce in the winter greenhouse, farmers have experienced physical and mental chronic fatigue on the basis of the hot and humid crops-centered working environment, the rough ground condition, inconsistent arrangement of working stand and sorter, heavy-weared habits. and unsuitable working posture. 2. When we improved harmful factors that affect farmer's health, conformed the positive effects on important work efficiency index such as heart rate, electromyovolume, body temperature, and microclimate inside clothing and work loads were decreased by improving the hot and humid working environment, eliminating the hillock and obstacles of working path. deliver way, arranging the working stand and sorter consistantly, decreasing the clothing weight, improving the working postures and methods as using assistant appliances, alloting the working time and sequence effectively and presenting the light gymnastic exercises and rest for fatigue restoration.

• Journal of Distribution Science
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• v.14 no.3
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• pp.55-62
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• 2016

Purpose - Average using time of smart-phone for Korean people is 3 hours 39 minutes and most people who are using a computer at home and their workplace can be affected over force to neck and shoulder due to unstable body posture. musculoskeletal disorders which caused by unstable body posture can affect strongly to decrease work efficiency. So this research is designed to measure the effect of using computer & smart-phone on decreased work efficiency due to musculoskeletal disorders and mediating effect between decreased work efficiency and musculoskeletal disorders. Research Design, Data, and Methodology - The author has developed a questionnaire with 6 hypothesis on the basis of previous research result with 5 constructs. The questionnaires were also made by interview and E-mail. 300 copies of questionnaires were distributed and 282 questionnaire were used for the analysis as valid data responses. SPSS ver.21.0 were used and made Cronbach's α and reliability test, correlation, Baron & Kenny 3 step mediated regression analysis. Result - Cronbach's α shows 0.770~0.954 and C.R. is 0.963~0.997 which is higher than 0.7. and AVE was 0.867~0.933. So the data are all acceptable condition. Using for a long time of a computer & smart-phone has a positive effect on musculoskeletal disorders. This means, it can cause musculoskeletal disorders if people use a computer & smart-phone for a long time due to unstable body posture. And musculoskeletal disorders can effect strongly decrease work efficiency. This study also found out that a long time of using computer can cause musculoskeletal disorders rather than using smart-phone a long time. To check mediate effect of musculoskeletal disorders between using a computer & smart-phone and Decreased Work Efficiency, author used 3-step mediated regression analysis of Baron & Kenny (1986). Using a computer for a long time mediate partially and using a smart-phone for a long time mediate completely. This means that using a smart-phone a long time is not the actual reason to decrease work efficiency. But using level of smart-phone is increasing rapidly day by day. So we need to make additional research about this matter seriously. Conclusion - Nowadays, people can not live on without a computer & smart-phone even a moment. But, using a computer for a long time will affect to cause musculoskeletal disorders and it will effect strongly to decrease work efficiency. Before, we thought over that musculoskeletal disorders were diseases of elder people. But, we found out from this study that musculoskeletal disorders can be happen to any people, even children, or workers in heavy industry or engaged in brain work. So we need to be careful when we use a computer for a long time. People also need to be careful to keep correct body posture when using both a computer and smart-phone since a smart-phone became more popular and using time level became longer. Due to increased income and living standard of people, physical growth of young people is so rapid. But the physical environment of society is not suitable for them since it can not follow up the speed of growth. Suitable work table is very important to prevent musculoskeletal disorder which can affect decrease work efficiency. For a person, a society or country, increased productivity is very important since it can directly connected to the job satisfaction. Education and reeducation for the people is also important, but to teach them how to keep good condition of health will be more important since it can increase the quality of work efficiency and quality of life. Computer and Smart-phone is one the best invention of modern society, but it can cause mental and physical disease which can affect decrease work efficiency and productivity. So it is necessary to observe attentively for the situation continually.

• Physical Therapy Korea
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• v.23 no.1
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• pp.87-93
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• 2016

Background: Posture balance control is the ability to maintain the body's center of gravity in the minimal postural sway state on a supportive surface. This ability is obtained through a complicated process of sensing the movements of the human body through sensory organs and then integrating the information into the central nervous system and reacting to the musculoskeletal system and the support action of the musculoskeletal system. Motor function, including coordination, motor, and vision, vestibular sense, and sensory function, including proprioception, should act in an integrated way. However, more than half of stroke patients have motor, sensory, cognitive, and emotional disorders for a long time. Motor and sensory disorders cause the greatest difficulty in postural control among stroke patients. Objects: The purpose of this study is to determine the effect of visual and somatosensory information on postural sway in stroke patients and carrying out a kinematic analysis using a tri-axial accelerometer and a quantitative assessment. Methods: Thirty-four subjects posed four stance condition was accepted various sensory information for counterbalance. This experiment referred to the computerized dynamic posturography assessments and was redesigned four condition blocking visual and somatosensory information. To measure the postural sway of the subjects' trunk, a wireless tri-axial accelerometer was used by signal vector magnitude value. Ony-way measure analysis of variance was performed among four condition. Results: There were significant differences when somatosensory information input blocked (p<.05). Conclusion: The sensory significantly affecting the balance ability of stroke patients is somatosensory, and the amount of actual movement of the trunk could be objectively compared and analyzed through quantitative figures using a tri-axial accelerometer for balance ability.

• International Journal of Advanced Culture Technology
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• v.1 no.1
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• pp.1-5
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• 2013

This network system for home care realized communication by the bio-physical signal, to convey physical rhythm. Four function of displacement had point of a Vision, Somatosensory, Vestibular and CNS. Bio-physical signal was decided to design a maximum points and minimum points with 0.01unit in reference level. Bio-physical signal was checked to compound physical condition of body posture for sensory organ. There detected a measurement of Vision, Somatosensory, Vestibular, CNS and BMI. The service of network system of home can be used to support a health care system for health assistant in health care center. It will expect to manage a physical parameter for network communication.

• Journal of the Korean housing association
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• v.3 no.1
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• pp.85-92
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• 1992

A floor system have played a major part in the living in Korean house. It is an essential element in the residential houses. Uufortunately, a design method of the floor heating system for the human thereat comfort has not established in Korea system. This paper aims to review the previous researches to find the issue for the futher study of comfort floor heating design. The following results were obtained: 1) Nevins et at conducted experiments on the effect of the comfortable of floor and air temperatures on the psychological responses by a large number of subjects. Its objective was to find the combined condition to obtain thermal comfort for sedentary posture.7here has never been researches regarding a sitting Person on the heated floor. 2) Some investigation in Japan on the effect of floor heating system on a sitting person on the floor have been conducted for these years, but they are net based on the human heat balance but on only psychological responses. 3) Hirayama et al developed an indication method of the effect of heat conduction on the sedentary person.4) There are few researches on the human thermal comfort compared whth indoor environmental researches on mechanical controls in Korea. Thus, the further study on the followings in needed the estimaiing of heat conduction between tile hunman body and a floor, developing an index expressed the combined effect of convection, radiation and conduction and its associated experiments.

• The Journal of Korean Physical Therapy
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• v.27 no.5
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• pp.292-298
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• 2015

Purpose: The purpose of this study was to examine the effects of dual tasks on balance and postural control during standing in patients with cerebellar ataxia (CA). It was hypothesized that CA patients would exhibit different sway characteristics of the center of mass (COM) depending on the complexity of the secondary cognitive tasks compared with normal control subjects. Methods: A total of 8 patients with CA and age-matched healthy control subjects participated in this study. They were instructed to perform two balance tasks (non-dual and dual movement) with 3 different complexity of dual tasks. Range, variability, and velocity of COMs were measured. Results: According to the results CA patients showed deficits in balance and postural control with increased dual-task complexity during the static balance task in saggital sway movements. However, there was no significant difference in static balance in frontal sway. With higher difficulty in the cognitive task, CA patients took longer to stabilize their body center, while normal control subjects showed no change between conditions. In addition, CA patients had a greater COM resultant velocity during recovery in the dual-task condition compared with the single-task condition. These findings indicate that CA patients had defendable compensatory strategies in performing dual tasks. Conclusion: In conclusion, CA patients appeared to manage the priority to balance and postural control. Particularly in a situation with a postural threat such as when potential consequences of the loss of stability increase, they appeared to prioritize the control of balance and posture over the performance of the secondary task.

• Journal of the Korean Society of Clothing and Textiles
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• v.22 no.1
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• pp.149-158
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• 1998

The purpose of this study was to investigate the effect of age on the human thermoregulatory responses and to obtain the basic information of the Korean thermophysiological characteristics under the traditional Korean floor heating system-Ondol. The participants consisted of 10 elderly women, 4 elderly men(over 65 years), 10 young women and 5 young men(in twenties). They were exposed to temperature-controlled Ondol room(20$\pm$1$^{\circ}C$, 50$\pm$5%R.H., floor surface temperature: 30$\pm$1$^{\circ}C$) for 60 minutes and wore the same experimental clothing. The postures were performed sitting and supine on the floor. In each pose, rectal temperature, skin.temperature of 10 areas, mean skin temperature, clothing microclimate, body fat were measured. The results were as follows; 1. The rectal temperature gradually decreased and mean skin temperature gradually increased in young and old groups in both supine and sitting pose on heated Ondol floor for 60 minutes. 2. Rectal temperature was different in each pose. The rectal temperature decreased 0.1$^{\circ}C$ in both groups under the condition of sitting and decreased 0.2'c in elderly group under the condition of supine. In supine pose, elderly group was more declined than young group. Mean skin temperature increased 0.5$^{\circ}C$ in both poses, both groups.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.33 no.4
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• pp.38-44
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• 2010

We investigated the effects of trunk twist on postural stability during manually handling flat ties. Ten male subjects participated in this study. While handling 5kgf and 10kgf bundles of flat ties respectively, their centers of pressure (COPs) were measured under two levels of body position (twisted and fixed), two levels of direction (left and right), and three levels of object position ($30^{\circ}$, $45^{\circ}$, and $60^{\circ}$). Subjects' postural stability was quantified by calculating the sway length. Results showed that the effect of different object position was significant on postural sway length in subject's medio-lateral axis. Post-hoc multiple comparions revealed that, under the 5kgf load condition, the sway length was increased significantly as the object position increased to $45^{\circ}$. Under the 10kgf load condition, however, the sway length was increased significantly at the object position of $60^{\circ}$. Actual or potential applications of this research include guidelines for the design of working posture evaluation techniques.