• Journal of the Korea Institute of Information and Communication Engineering
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• v.23 no.8
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• pp.923-929
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• 2019

The stability of the propulsion system is crucial for the autonomous vessel. Multiple power generation and propulsion systems should be provided for the stability of the propulsion system. High power generation capacity is calculated for stability, resulting in economical decline due to low load operation. To solve this problem, we need to optimize the power system. In this paper, an OPMS for electric propulsion ship is constructed. The OPMS consists of a hybrid power generation system, an energy storage system, and a control load system. The power generation system consists of a dual fuel engine, the energy storage system is a battery, and the control load system consists of the propulsion load, continuous load, intermittent load, cargo part load and deck machine load. The power system was constructed by modeling the characteristics of each system. For the experiment, a scenario based on ship operation was prepared and the stability and economical efficiency were compared with existing electric propulsion ships.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.2 no.3
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• pp.83-92
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• 1999

To investigate the influence of forest road characteristics and site conditions on the stability of forest-road in granite area, four forest roads had been selected in Kyongbuk regions. The total of 13 road characteristic variables were evaluated by the discriminant analysis. The factors influencing the stability of forest road were bed rock, slope length, coverage, hardness, side-ditch erosion and road width. But aspect and soil texture were not significant for the stability in this area. In the correlation between forest environment and road structure, hardness and bed rock was highly significant in stability group, and coverage and side-ditch erosion was highly significant in instability group. 75 of 175 segments were instable whereas the others were stable. The centroids value by discriminant function in the stability and instability were estimated to 3.0585 and -1.9116, respectively. The stability criterion of forest road was discriminated from the centroids value of the each group. The main factors contributing the stability of forest road were significant in order of side-ditch erosion, coverage, soil texture, elevation, gradient, slope length and construction year. The prediction rate of discriminant function for stability evaluation of forest road was as high as 97.44%. In conclusion, the forest road structure factors such as length, coverage and slope gradient were controlled by construction techniques. If the factors like those should be considered in design, construction and forest road management, the stability of forest road may increase more. And also, it is necessary to take slope protection measures like small terraces and retaining walls for stability of cut slope.

• Journal of Service Research and Studies
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• v.11 no.2
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• pp.106-117
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• 2021

This study is a descriptive survey study using a self-reported survey method to find out the job value and intention of career choice of college students in the medical management field. This study was conducted on university students in medical management at three four-year universities located in Busan Metropolitan City. A total of 139 effective questionnaires were used as statistical analysis data. As a result of the analysis, social dedication and stability were significantly displayed in the selection of jobs for hospital administration and administrative positions, and social dedication and stability were significantly displayed in the selection of jobs as medical recorders. In choosing a career as an international medical tourism coordinator, the focus on human relations, maintaining face, and pursuing stability have been significant. Only social commitment was significantly shown in the choice of occupation as a health educator. A comparison of job values according to general characteristics showed that there was a difference in the pursuit of knowledge and social commitment. In the case of grades, there was a difference in social dedication and stability. There was no significant difference in the case of religious or non-religious matters. In the case of economic level, only economic priorities differed. Through this study, we would like to present basic data so that college students in medical management who prepare to take the first step into a professional medical management society can recognize the need for recognition of job value and move in a better direction in choosing a job.

• Proceedings of the Safety Management and Science Conference
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• 2013.04a
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• pp.263-270
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• 2013

• International Journal of Knowledge Content Development & Technology
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• v.2 no.2
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• pp.31-45
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• 2012

This study prepared a foundation to provide high-quality services in a stable and effective way to meet the customer expectations, by building up and establishing an ISO 20000 certified IT service management system and protecting the information assets from various threats through effective system operation that meets the requirements of international standards, in order to ensure the reliability and stability of NDSL public services provided by KISTI Information Service Center and to enhance the customer satisfaction.

• Management & Information Systems Review
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• v.31 no.1
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• pp.183-203
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• 2012

This paper investigates how small-medium firms deploy organizational culture, job stability and environmental uncertainty for technological innovation(product and process innovation). This paper suggests that organizational culture has significant effects on technological innovation, that job stability and environmental uncertainty moderate relationship between organizational culture and technological innovation. To test the hypotheses, data were collected from small-medium firms. The survey data of 258 firms were collected and integrated as the empirical base for testing the hypotheses. Major results are as follows: Firstly, when organizational culture as well as control variables are considered, organizational culture had significant and positive effects on product innovation. This result implies that organizational culture is an important means by which small-medium firms can promote innovation. Secondly, the interaction between organizational culture and job stability had a positive and significant effects on product innovation. Thirdly, the interaction between organizational culture and environmental uncertainty had a positive and significant effects on product innovation and process innovation. This paper suggests implications and several future researches need to overcome the limitations of this paper.

• Journal of the Ergonomics Society of Korea
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• v.29 no.3
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• pp.347-356
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• 2010

The purpose of this study is to analyze the spine stability by comparing muscle activation in various scaffold working conditions. The independent working conditions were designed by two levels of working height, existence and absence of safety handrail, and the two levels of expertise. The corresponding activities of the agonist and antagonist muscles of spine were simultaneously recorded by using EMG. As results, novice worker showed increased muscle activity while doing the task on the 2nd floor, absence of handrail. And expert showed the increase of co-contraction while working on the 2nd floor without handrail. Such co-contraction was found to increase the spine stability when the working condition become risky. On the other hand, the co-contraction was prolonged, the spine muscle fatique and disc pressure could be increased, which would increase the risk of musculo-skeletal disorder. The results of co-contraction in this study indicates that the motor control system responds to maintain the stability of the spine particularly when workers cognitively recognize the danger of falling or imbalance. This study also quantitatively accounted for the biomechanical cause of LBP among workers who has to prevent themselves from falling. Therefore, if can be said that safe environment preventing falling can also prevent workers from MSDs as well. Such knowledge can be applied to design ergonomic workplace environment as well as movable scaffold.

• Journal of the Korean Applied Science and Technology
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• v.28 no.1
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• pp.95-101
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• 2011

We estimated on the stability of W/O type emulsified fuel using by capacitance sensor, so it concluded the following conclusions. For the first 24 hours, prepared emulsified fuel reveals phase separation ratio of 5%, maintains stable status which verifies the stability of emulsified fuel. Adding more water increases the phase separation ratio rapidly, and adding more surfactant displays stable emulsification. Adding water causes larger size of water droplet diameter, and adding surfactant mixture causes smaller size of water droplet diameter. In conclusion, the size of W/O type emulsified fuel water droplet diameter is directly related to the volume of surfactant, and density of water droplet diameter changes thedistribution according to water contents.

• The Journal of Korean Physical Therapy
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• v.16 no.4
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• pp.11-22
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• 2004

The concept of segmental stabilization has been one of the most exciting advancements in the field of physical therapy. Specific deep stabilizing muscle have proven to reverse motor control deficits that occurs after back injury. After an injury, a new motor programming strategy is adopted and there is excessive recruitment of the large , strong , global muscular system works instead of small segmental deep muscle recruitment for stability. Many physical therapists and doctors mistakenly prescribe therapeutic exercise for low back pain to use larger, superficial musculature to strengthen the spine for stability and pain control. But motor control coordination of local segmental muscle is actually the key to stability and pain control, not strengthening of global muscle. A recent focus in physiotherapy management of patients with chronic back pain has been the specific training of muscles surrounding the lumbar spine whose primary role is considered to be the provision of dynamic stability and segmental control to the spine. These are the deep transverse abdominis muscle and lumbar multifudus.

• Structural Engineering and Mechanics
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• v.85 no.6
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• pp.809-823
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• 2023

In this work, dynamic stability analysis of the ball after contacting with the earth in the volleyball game is presented. Via spherical shell coordinate, the governing equations and general boundary conditions of the ball after contacting with the earth in the volleyball game is studied. Via Comsol multi-physics simulation, some results are presented and a verification between the outcomes is studied. Harmonic differential quadrature method (HDQM) is utilized to solve the dynamic equations with the aid of boundary nodes of the current spherical shell structure. Finally, the results demonstrated that thickness, mass of the ball and internal pressure of the ball alters the frequency response of the structure. One important results of this study is influence of the internal pressure. Higher internal pressure causes lower frequency and hence reduces the stability of the ball.