• Journal of the Korean Society of Safety
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• v.20 no.2 s.70
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• pp.169-174
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• 2005

Traditionally, keyboards have been one of the most frequently used input devices for information processing using computers. As most computers adopt the Microsoft Windows for their operating system however, the usage of mouse has recently increased to a great extent. Moreover, the mouse has been used as the leading input device in such areas as industrial design and computer aided design. Excessive uses of mouse may cause a severe pain and fatigue on neck and upper limb due to the intensive and repetitive use of corresponding muscles, which renders a decline in efficiency and leads to musculoskeletal disorders. The main purpose of this study is to find the best working conditions to prevent musculoskeletal disorders when using mouse in a neutral posture. Utilizing electromyogram amplitude and Borg's scale, the role change and strength imposed on the muscles were measured and analyzed with and without the forearm support concerned. Also investigated were the effects of changes in elbow forearm supporter.

• Journal of Society of Preventive Korean Medicine
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• v.6 no.1
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• pp.1-14
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• 2002

The proportion and role of public sector in health care industry is very small in Korea. Asymmetric distribution of health care resources is one of the major health care concerns. This issue is so important that it raises a question of accessibility, availability, continuity of care and equity of rural area people's health care utilization. To solve these problems and to satisfy the basic demand of oriental medical service in rural areas, the oriental public health doctors were placed in rural health centers since 1998. The main objectives of this study are twofold: to measure the cognition and attitude of health center directors on the strategies for utilizing oriental public health doctors and to provide basic data for improving the health manpower management program. Data have been collected by way of the self-administrative questionnaires. Developing the questionnaire, the literature review on the previous studies and delphi method were carried out. The response rate was 38.7%. The results of this study are summarized as follows; 1. community people respond positively on the oriental medical service activity in health center. 2. In regard to workloads of oriental public health doctor, 'appropriate' was 81.1% and 'burdensome' was 18.2%, respectively. 3. The 94.0% of respondents thought that the oriental medical service will be continued. 4. To activate oriental medical service in health center, the sufficient budget and provision of aid workers is a necessity. 5. The 75.5% of health center directors respond positively on the allocation of oriental public health doctor to health sub-centers. 6. Health center directors agreed that oriental public health doctor should perform the clinical service as well as prevention and health promotion activity. These results recommend that oriental medical service in health center should be continued gradually, and oriental public health doctors working at health center perform their work efficiently. Undoubtedly, their activity should be more focused on health promotion and disease prevention than daily patient care. For achieving this objective, more support of governmental policy is essential for utilizing oriental public health doctor and better health of the rural area community people.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.11
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• pp.254-263
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• 2020

This study developed indexes of farmers' acceptance factors for new farming technologies and evaluated the importance of the developed. For this study, farming technologies were classified according to the criteria established by the Rural Development Administration, and the Delphi technique was applied to evaluate the importance of the indexes. The indexes were composed of two tiers and evaluated by the analytic hierarchy process (AHP). Results showed that the importance of the first tier was finance and profitability with 43.9%, technology affairs 23.6%, labor environments 22.4%, and related industries and service system 10.1%. The importance of the second tier was the ease of technology acceptance 64.9% and technology completion 35.1% for technology affairs in the first tier, labor intensity 53.7%, work hazard 26.7%, working hours 19.6% for labor environment, farm income increment 69.9% and new fund required 30.1% for finance and profitability, and training and service system 66.7% and activation of related industries 33.7% for related industry and service system. This study may contribute to farmers' acceptance of new farming technologies and increase the efficiency and effectiveness of agricultural research and extension activities by the Rural Development Administration.

• Journal of Electrical Engineering and Technology
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• v.10 no.4
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• pp.1621-1625
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• 2015

Power quality has always been a concern of power engineers. Certainly an argument can be successfully made that most parts of power engineering have the ultimate objective to improve power quality. AC motors were widely used in industrial and domestic applications. Generally, AC motors were of two types: Induction and Synchronous motors. In motor many parameters like different load cycling, switching, working in hot weather and unbalances creates harmonics which creates major reasons for temperature rise of the motors. Due to high peak value of voltage, harmonics can weaken insulation in cables, windings and capacitors and different electronic components. Higher value of harmonics increase the motor current and decrease the power factor which will reduce the life time of the motor and increase the overall rating of all electrical equipments. Harmonics reduction of all the motors in India will save more power. Coating of windings of the motor with nano fillers will reduce the amount of harmonics in the motor. Based on the previous project works, actions were taken to use the enamel filled with various nano fillers for the coating of the windings of the different AC motors. Ball mill method was used to convert the micro particles of Al₂O₃, SiO₂, TiO₂, ZrO₂ and ZnO into nano particles. SEM, TEM and XRD were used to augment the particle size of the powder. The synthesized nano powders were mixed with the enamel by using ultrasonic vibrator. Then the enamel mixed with the nano fillers was coated to the windings of the several AC motors. Harmonics were measured in terms of various indices like THD, VHD, CHD and DIN by using Harmonic analyzer. There are many other measures and indices to describe power quality, but none is applicable in all cases and in many instances, these indices may hide more than they show. Sometimes power quality indices were used as a basis of comparison and standardization. The efficiency of the motors was increased by 5 – 10 %. The thermal withstanding capacity of the motor was increased by 5º to 15º C. The harmonics of the motors were reduced by 10 – 50%.

• Korean Journal of Psychosomatic Medicine
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• v.25 no.1
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• pp.12-18
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• 2017

Objectives : Psychiatric staffs may experience excessive work stress, burnout, and reduced job satisfaction in clinical settings. This can increase chances of diminishing their overall working efficiency or having difficulty managing their own mental health. The purpose of this study was to investigate the effect of group mindfulness-based cognitive therapy(MBCT) on job stress, burnout, self-efficacy, resilience, and job satisfaction. Methods : Twenty eight psychiatric staffs who agreed to participate in the study were included. Self-report questionnaires were used to measure job stress, burnout, resilience, self-efficacy, and job satisfaction. To examine the effects of group MBCT, the scores were compared before and after MBCT. Results : Work stress and burnout scale scores were significantly decreased after group MBCT. Resilience, job satisfaction, and self-efficacy scale scores were significantly increased after group MBCT. Conclusions : In the current study, group MBCT for psychiatric staffs helped to reduce their work stress and burnout, and, as well, helped to improve resilience, self-efficacy, and job satisfaction. This suggests that, in mental health treatment settings, psychiatric staffs can improve their mental health through group MBCT. Improving mental health of psychiatric staff may also have a positive impact on their patients.

• Journal of the Korea Organic Resources Recycling Association
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• v.10 no.4
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• pp.112-117
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• 2002

This study was conducted to induce the optimal composting conditions of pig manure mixed with sawdust and dried paper-mill sludge in the composting for production of high quality compost. Pig manure contains high water content and How C/N ratio because of comparatively high nitrogen content than sawdust and dried paper-mill sludge. Therefore the addition of dried paper-mill sludge and sawdust to the raw materials helps controlling the C/N and the water content of compost pile. The composting system used in the experiment was agitated static bed system. The physical properties of the mixed raw materials was not good at the working conditions in the early stage of composting. The temperature of compost heap reaches at $60^{\circ}C$within 5 day after starting composting in P-2 treatment mixed with pig manure and sawdust(56.6 : 43.4). Then the water content of P-2 was 58%. The pH in all treatments were slowly decreased as the composting was proceeded. Although the changes of T-C and T-N were not extended because of the short composting experiment period. Reduction rates of T-C in treatments were 5-12% without special difference. By considering the efficiency of composting in each of five treatments with pig manure the optimal water contents was about 57% level. Mixing a sawdust as a bulking agent was more positive than dried paper-mill sludge from a viewpoint of compost quality.

• Proceedings of KOSOMES biannual meeting
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• 2006.11a
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• pp.71-74
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• 2006

Currently offshore fisheries are one of shrinking industries and fishermen are getting older. Moreover it is difficult to work fisheries for decreasing fishermen as the time goes. Two people per a boat work together at least for proper fisheries. If the unskilled fisherman boards on boat, it will make some troubles to speak each other and diminish the efficiency of working because one person should control the boat. So it need to study the remote control system for leasure and outboard engine that can control and work at the same time. The remote control system is consisted of engine revolution, steering gear and forward reverse neutral gear controls. These three controls are made by position and speed control using DC motor, and microprocessor is used to communicate and control the engine speed This system can be controled and worked alone and we tested the system at sea and confirmed that the system works properly.

• Magazine of the Korean Society of Agricultural Engineers
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• v.17 no.4
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• pp.3897-3920
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• 1975

Since the most of Korean dairy and cattle raising farms are too small to introduce western mechanized farming, it is necessary to develope small size equipments. This study has been carried to develop a rotary mower as on attachment of 8 to 10 horse powertiller which is widely spread in rural area. It will not ony be helpfull for the farmers to harvesting hay grass but also desirable to increase the power tiller utility. The protto type rotary mower designed through the fundamental investigations, has been modified and improved through the field trials, and a series of field tests has been carried to investigate its performance and economic feasibility comparing with existing vailable harvesting equipments. The results are as follows; 1. To increase the stability, two guide wheels are attached to both side of the protto type rotary mower. 2. To prevent the clinging of tall grasses, the vertical driving shafts are covered with cylindrical protectors. 3. The cutting height is adjustable in 8 steps from 2.5 to 20 centimeters by changing the length of guide wheel legs. 4. The practical Critical cutting speed were always higher than theoretical value in both case of single cutting blade and three when the cutting depth was 25 millimeter. 5. The peripheral speed of cutting blade was varied in response to the change of engine speed, mean while the peripheral speed was adequate as it was changhed from 25 to 35 meter per second when the power tiller is operated in proper working ground speed. 6. The time requirement to harvest 10 a were 88.7, 54.6 and 41.4 minutes for the first, second and third stage of ground speed respectively, and because of the difficulty of delivery, it was observed that operating with fourth stage of ground speed was not recomanendable when the grass height is taller than 90 centimeters. 7. The performance of rotary mower were 1.1-1.7, 1.4-4.0, 3.8-11.8 and 7.4-22.0 times of reciprocating mower, portable disc type cutter, hay scythe and ordinary sickle respectively. 8. When the slope exceeds, 20 degree the downward harvesting operation was impossible because of the excessive front end weight, while less than 5 degree of land slope did not effect in field operation. 9. Increased traveling spee caused higher cutting height and slight cutting failure, but seems not to effect to the gross yield, and the efficiency of cutting width were from 83 to 94 precent. 10. Tn rank of economy were rotary mower (3,2 stage operation), reciprocating mower, hay scythe, portable disc type cutter and sickle in order when the annul operation exdeeds 100 hours. From the above results, it is convinced that the protto type rotary mower is good enough to the livestock farmers as a hay harvesting equipment because of its economy, hardiness in operating and its out standing performance and hopefully it will contribute to the extension of Korean livestock farming.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.7
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• pp.54-62
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• 2016

The most efficient system for converting heat to electricity, AMTEC (Alkali Metal Thermal-to-Electric Convertor), is a device that directly converts heat energy to electricity using an alkali metal (sodium) as the working fluid. The AMTEC consists of a low pressure chamber, high pressure chamber, BASE (Beta-Alumina Solid Electrolyte), and artery wick. The main heat loss of the AMTEC system occurs in the low pressure chamber. A high power generation rate is thought to be obtainable by using a high temperature in the BASE. Therefore, to reduce the radiation heat loss, 6 types of radiation shields were examined to reduce the radiative heat loss in the low pressure chamber. The power generation rate of the AMTEC varied depending on the shape of the radiation shield. CFD (Computational Fluid Dynamics) analyses were carried out to optimize the shape of the radiation shield. As a result, the optimum radiation shield was found to consist of a curvature formed at the vertical point, in which case the dimensionless temperature (condenser temperature/BASE temperature) is approximately 0.665 and the maximum power generated is calculated to be 17.69W. Increasing the distance beween the BASE and condenser leads to an increase in the power generated, and the power generated with the longest distance was 17.58 W. The shields with multiple holes and multiple horizontal layers showed power reduction rates of 0.91 W and 2.06 W, respectively.

• Korean Security Journal
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• no.12
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• pp.309-333
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• 2006

These days, the majority of public service area presents increment of utilizing a contracting-out with the following reasons such as cost-efficiency, maintenance of population changes in flexible manner, and convenience of management. The social changes have influence on policing structure and regional security system as well as problems associated with accepting the contracting-out in the public policing sector. However, many issues such as limited contracting-out sector, difficulty of encouragement of participation to private sector, and limitation of making a contract with contracting-out would be brought up when initiate contracting-out to the public policing sector. Changing security system to lower budget, planning restructure of organization, developing alterable partial contracting-out, establishing private and public cooperate system and rationalizing contract system are the suggestions to solve and modify the raising problems. This study suggests a differentiate regulation of policing services compare to currently existing contracting-out method to consider a distinctive working environment. The suggestions are as follows: 1. develop a security segregate model, 2. build a cooperative system between private and public policing sector, 3. broaden opportunity of participation of private policing sector, 4. open-competition among qualified private tender to make a contract. The private contracting-out in the public security service sector should be manage in different manner compare to other private contracting-out in government-oriented public service sector. Since work performance of each private contracting-out agency is strongly bond to safety of every civilian in the nation, it is essential to increase its standard of qualification of each agency.