• Journal of the Korean Society for Precision Engineering
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• v.23 no.8 s.185
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• pp.163-170
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• 2006

By removing sacrificial layer through ashing process, movable MEMS structure on substrate can be fabricated in surface micromachining. However, MEMS structure includes, during the ashing process, the warping or buckling effects due to stress gradient along the vertical direction of thin film. In this study, we presented method for counteracting the unwanted deflection of MEMS structure and designed using character of deposit process to overcome limited design conditions. Unit cell patterns were designed with character of deposit shape, and their final shapes were adopted using Finite Element Method. Finally, RF MEMS switch was fabricated by surface micro machining as test vehicles. We checked out that alleviation effect for deformation of switch improved by 35%.

• Journal of the Korean Institute of Landscape Architecture
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• v.40 no.3
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• pp.60-68
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• 2012

The purpose of this research is to identify green roofs based on how to utilize the diverse space. This research also aims to discover the correlation between the use of the green roof and the overall level of the public's health condition, through which it is intended to grasp the health effects by means of the space of the green roof. The current use patterns of the green roof have been identified generally to have more than 60% accessibility, less than 30 minutes of short-tenn use, relaxation or removing stress, enjoy the view of the surrounding, smoking, walking and exercise. It will be highly effective to furnish facilities and plants for tree planting, and to get financial maintenance & management subsidy for the purpose of revitalizing the green roof. It is expected that if the green roof is created in educational institutes, hospitals and shopping centers, where the current level of health conditions is generally low, it will contribute in promoting the city dwellers' health benefits. In addition, the physical environmental renovation through establishing the green roof will bring about producing a healthy city because the emotional health benefits also will make a positive impact upon physical health.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1999.04a
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• pp.203-209
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• 1999

In this study, the structural deflection analysis of robot manipulator for removing nuclear fuel rod from nuclear reactor vessel is performed by using general purpose finite element code (ANSYS). The structural deflection analysis results reported in this study is very required for the accurate design of robot system. The structural deflection analysis for the manipulator's structural status at which the gripper grasps and draws up the nuclear fuel rod is done, For this beginning structural status of robot manipulator's removing motion, the reaction forces at each joint have static maximum values as reported in the reference(6), and so these forces may cause the maximum deflection of robot structure. The structural deflection analysis is performed for selected four working cases of the proposed structural model and results on deformation, stress for the manipulator's solid body and the deflection at the end of robot manipulator's gripper are calculated. And further, the same analysis is performed for the slenderer manipulator with cross section reduced by one-fifth of each side length of proposed model. The analysis is performed not only for the nuclear fuel rod with weight load of 300kg but also for nuclear fuel rods with weight loads of 100kg, 200kg, 400kg and 500kg. The static structural deflection analysis results show that the deflection value increases as the load increases and the largest value (corresponding to the weight load of 500kg in case 1) is much smaller than the gap distance between nuclear fuel rods. but the largest value for the slenderer manipulator is almost as large as the gap distance, Hence, conclusively, the proposed manipulator's structural model is acceptably safe for mechanical design of robot system.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.5
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• pp.3298-3303
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• 2014

In order to recycle the waste bumper, techniques removing coated paint on a bumper is crucial. Chemical methods are known to be much more effective in removing the paint compared to physical methods. However, the chemical methods generally use toxic solvents and consequently cause environmental pollution. In this study, we tested a new method which combines the chemical and physical method to reduce the amount of solvent and increase the paint removal efficiency. We found that mechanical stirring increases the paint removal efficiency in soaking stage of solvent. When solid particles as a stress transfer media are incorporated into the solvent and high mechanical stirring is applied, the paint removal efficiency is very high. It was proved that the combined method can accomplish high level of the paint removal efficiency maintaining low amount of solvent consumed.

• The Journal of the Convergence on Culture Technology
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• v.7 no.4
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• pp.163-170
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• 2021

The purpose of this study is to identify the harmful factors of teacher's job stress and occupational-related musculoskeletal diseases, and to investigate according to job types to seek solutions and improvement measures for removing harmful factors. A total of 168 elementary and high school teachers in Seoul were surveyed. As a result, the average RULA score of the teacher was 4.2 points, and the average RULA score of the teacher who did not complain of musculoskeletal diseases was 4.3 points. In addition, the average job stress score of the teacher was 58.9 points, and the stress score by factor was in the order of student guidance, work burden, loss of authority, organizational structure and curriculum, treatment and welfare, human relations. As a result of analyzing the teacher's RULA score and job stress, it was possible to derive a correlation between musculoskeletal disorders and job stress caused by occupation.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.21 no.9
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• pp.1392-1399
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• 1997

In order to determine the Mode I stress intensity factor ($K_1$) experimentally by means of the alternating current potential drop(ACPD) technique, the change in potential drop due to load for a ferromagnetic material containing a two-dimensional surface crack was examined. The cause of the change in potential drop and the effect of the magnetic flux on the change in potential drop were clarified by using the measuring systems with and without removing the magnetic flux from the circumference of the specimen. To remove the magnetic flux, a new measuring system was made by utilizing the characteristic of coaxial transmission line. The change in potential drop in the case without magnetic flux in the air was caused by the change in electromagnetic properties near the crack tip due to magnetization. The relationship between the change in potential drop and the change in $K_I$ was linealized by demagnetization and was found to be independent of the crack length.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.16 no.3
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• pp.259-272
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• 1994

The authors reviewed the etiology and essential treatment of temporomandibular disorders. The principal etiology was thought to the the myospasm of masticatory musculatures by stress (major cause) and dental irritation. Therefore, we attempted to control the myospasm by stress management, isometric exercise and regular daily physical exercises (walking, Jogging, bycycling, rope skipping, swimming & gymnastic exercise). The result was more favorable (95% success rate) without recurrence in 123 patients, who was referred to our department of dentistry(Oral & Maxillofacial surgery), Wonju Christian Hospital.

• Molecules and Cells
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• v.40 no.9
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• pp.607-612
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• 2017

When mammalian cells and animals face a variety of internal or external stresses, they need to make homeostatic changes so as to cope with various stresses. To this end, mammalian cells are equipped with two critical stress responses, autophagy and cellular senescence. Autophagy and cellular senescence share a number of stimuli including telomere shortening, DNA damage, oncogenic stress and oxidative stress, suggesting their intimate relationship. Autophagy is originally thought to suppress cellular senescence by removing damaged macromolecules or organelles, yet recent studies also indicated that autophagy promotes cellular senescence by facilitating the synthesis of senescence-associated secretory proteins. These seemingly opposite roles of autophagy may reflect a complex picture of autophagic regulation on cellular senescence, including different types of autophagy or a unique spatiotemporal activation of autophagy. Thus, a better understanding of autophagy process will lead us to not only elucidate the conundrum how autophagy plays dual roles in the regulation of cellular senescence but also helps the development of new therapeutic strategies for many human diseases associated with cellular senescence. We address the pro-senescence and anti-senescence roles of autophagy while focusing on the potential mechanistic aspects of this complex relationship between autophagy and cellular senescence.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.35 no.5
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• pp.1191-1198
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• 2015

In this study, vehicle/track interaction analysis by the Saemaul powered vehicle was carried out. The prediction equation for the bending stress of rail was estimated using the rail bending stress by the rail surface irregularities at welds. Also, the fatigue analysis using a S-N curve of welds in the conventional railway was carried out. We estimated the fatigue life of CWR by the fracture probability. By the rail grinding, the fatigue life of CWR was evaluated in consideration to reduce the rail bending stress through removing the rail surface irregularities. Therefore, it presented the fatigue life of CWR according to the rail grinding execution plan in the conventional railway.

• Korean Journal of Human Ecology
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• v.21 no.6
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• pp.1095-1110
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• 2012

The purpose of this study was to examine pathways between job characteristics and job satisfaction among local officials in the child care sector. Participants of this study comprised of 128 local officials who worked in the child care sectors. Structural equation modeling was used to test the direct and indirect effects of job characteristics on job satisfaction through job stress and job burnout. Results confirmed the initial model that assumed there would be an indirect effect of job characteristics based on job satisfaction. The path involving three variables of job characteristics, however, were not statistically significant. The initial model was modified by removing the job characteristics variables. The modified model that confirmed the initial model showed that job stress of local officials in the child care sector was likely to increase job burnout; in turn, the job burnout tended to decrease job satisfaction.