• Journal of the Computational Structural Engineering Institute of Korea
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• v.23 no.5
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• pp.535-541
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• 2010

In this paper, we have derived a continuum-based adjoint design sensitivity of general performance functionals with respect to Young' modulus and heat conduction coefficient for steady-state nonlinear thermoelastic problems. An adjoint equation for temperature and displacement fields is defined for the efficient computation of the coupled field design sensitivity. Through numerical examples, we investigated the mesh dependency of the topology optimization method in the thermoelastic problems. Also, comparing the dominant loading cases of thermal and mechanical ones, the loading dependency of topology design optimization in coupled multi-physics problems is investigated.

• Proceedings of the KIEE Conference
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• 2007.04c
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• pp.234-236
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• 2007

Even though the existing train route controlling method, using track circuits, ensures the sufficient number of operation, it still has problems such as discordance between train numbers which was planned for operating and train numbers being operated on the track, and allowing only one train entering for one route. To solve those problems, we study and develop the Smart train route controlling system which uses the real-time informations of train positions. This system enables improve the coefficient of utilization in a certain train route controlling section, and the safety level of train route controlling, but we should ensure satisfying reliability of data about tracks operated by trains. In addition, there is a need to protect accidents caused by erroneous information of train position, by reflecting changes of tracks, for example maintenance, improvement, expansion of tracks. In this paper, we describes data structure of a developed program which required to change CAD files to wiring diagrams and to generate them to data of tracks. And we show the result that the simulator, using the data structure, controls speed and route of trains without problems.

• Korean Journal of Occupational Health Nursing
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• v.20 no.2
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• pp.163-171
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• 2011

Purpose: This study is to investigate the job stress and presenteeism of nurses with work shift. Methods: The data were collected through questionnaires from 281 clinical nurses working for a university hospital located in D city from 13 to 28 of February, 2009. The data were analyzed by descriptive statistics, t-test, ANOVA, Scheffe verification test, Pearson correlation coefficient and multiple linear regression using SPSS/WIN 16.0. Results: The mean score of job stress was 3.47. Work overload and psychological burden scored the highest point as the sub-category of work stress factor. Work performance loss out of presenteeism showed 26.89 and perceived productivity, 79.79. Also 94.7% of respondents answered they had health problems. A significantly positive correlation was found among job stress, work performance loss and health issue. To determine the factors affecting presenteeism, work performance loss was associated with work overload and perceived productivity with interpersonal relationship conflict. Conclusion: Based on the findings of the study, job stress is positively correlated with work performance loss, and health problems. Therefore, health problems of nurses with work shift need to be considered and plans to manage their job stress affecting presenteeism need to be developed at an earlier stage.

• Journal of Ocean Engineering and Technology
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• v.12 no.2 s.28
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• pp.1-21
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• 1998

In this paper, a non-conforming 3-D 8-node solid element(MQM10) has beets applied to the analyses of static and dynamic bending problems of laminated composite plates The QM10 element exhibits stiffer bending stiffness which is caused by the reduction of degree of freedom from Q11 element. As an effective way to correct the relative stiffness stiffening phenomenon the modification of Gauss sampling points for composite plates is proposed. The quantity of modification is a function of material properties. Also, another two modified equations are obtained, one is modification for stress, and the other is modification of coefficient of shear modulus in free vibration. It is noted that MQM10 element can analyse the static and free vibration problems of various 3-dimensional composite plates composed of unidirectional laminae, woven laminae or braided laminae. The results of MQM10 element are in good agreement with those of 20-node element.

• Research in Community and Public Health Nursing
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• v.28 no.2
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• pp.118-128
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• 2017

Purpose: The purpose of this study is to measure health-related quality of life (HRQoL) and to investigate the affecting factors according to gender in older adults by using the 2012 Korea Health Panel data. Methods: The Korea Health Panel data 2012 were collected from February to August 2012 by Korea Institute for Health and Social Affairs and National Health Insurance Corporation and the number of respondents were 1,921. The data were analyzed by t-test, chi-square, Pearson correlation coefficient and multiple regression using SPSS/WIN program. Results: The limitation of activity was the most influential factor for health-related quality of life of both male and female. For male, the affecting factors on HRQoL were hearing problems and frustration. For female, the affecting factors on HRQoL were eating problems, depression and suicidal impulses. Drinking, moderate physical activities, vision problems and stress had a significant effect on HRQoL for both male and female. Conclusion: Health care providers should consider the differences between male and female when they design a program in order to improve HRQoL of older people.

• Journal of Environmental Science International
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• v.1 no.1
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• pp.35-43
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• 1992

Handling the emergency problems such as Chemobyl accident require real time prediction of pollutants dispersion. One-point real time sounding at pollutant source and simple model including turbulent-radiation process are very important to predict dispersion at real time. The stability categories obtained by one-dimensional numerical model (including PBL dynamics and radiative process) are good agreement with observational data (Golder, 1972). Therefore, the meteorological parameters (thermal, moisture and momentum fluxes; sensible and latent heat; Monin-Obukhov length and bulk Richardson number; vertical diffusion coefficient and TKE; mixing height) calculated by this model will be useful to understand the structure of stable boundary layer and to handling the emergency problems such as dangerous gasses accident. Especially, this simple model has strong merit for practical dispersion models which require turbulence process but does not takes long time to real predictions. According to the results of this model, the urban area has stronger vertical dispersion and weaker horizontal dispersion than rural area during daytime in summer season. The maximum stability class of urban area and rural area are "A" and "B" at 14 LST, respectively. After 20 LST, both urban and rural area have weak vertical dispersion, but they have strong horizontal dispersion. Generally, the urban area have larger radius of horizontal dispersion than rural area. Considering the resolution and time consuming problems of three dimensional grid model, one-dimensional model with one-point real sounding have strong merit for practical dispersion model.al dispersion model.

• Journal of Ship and Ocean Technology
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• v.9 no.4
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• pp.35-46
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• 2005

The performance of optimisation methods, based on penalty functions, is highly problem- dependent and many methods require additional tuning of some variables. This additional tuning is the influences of penalty coefficient, which depend strongly on the degree of constraint violation. Moreover, Binary-coded Genetic Algorithm (BGA) meets certain difficulties when dealing with continuous and/or discrete search spaces with large dimensions. With the above reasons, Real-coded Micro-Genetic Algorithm (R$\mu$GA) is proposed to find the global optimum of continuous and/or discrete nonlinear constrained engineering problems without handling any of penalty functions. R$\mu$GA can help in avoiding the premature convergence and search for global solution-spaces, because of its wide spread applicability, global perspective and inherent parallelism. The proposed R$\mu$GA approach has been demonstrated by solving three different engineering design problems. From the simulation results, it has been concluded that R$\mu$GA is an effective global optimisation tool for solving continuous and/or discrete nonlinear constrained real­world optimisation problems.

• Journal of Home Health Care Nursing
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• v.26 no.1
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• pp.72-80
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• 2019

Purpose: This study aimed to measure health-related quality of life (HRQoL) and investigate the relevant factors for middle aged women using the 2014 Korea Health Panel data. Methods: The Korea Health Panel data 2014 were collected from February to August 2014 by the Korea Institute for Health and Social Affairs and the National Health Insurance Corporation and included 2,075 people who responded to the questionnaire. Using SPSS WIN program, the data were analyzed by t-test, ANOVA, Pearson correlation coefficient, and multiple regression analysis. Results: Limited activity was the most influential factor for the health-related quality of life of middle-aged women. For health behavior, the factors affecting HRQoL were drinking, sleeping time, and physical activity. For physical health, factors affecting HRQoL were vision problems, eating problems, and hearing problems. For mental health, the factors affecting HRQoL were suicidal impulse, stress, and frustration. Conclusion: These results indicated that to improve HRQoL for middle-aged women, limited activity and suicidal impulses should be addressed.

• Journal of muscle and joint health
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• v.28 no.2
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• pp.152-160
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• 2021

Purpose: This study, using the International Classification for Nursing Practice, aimed to identify the phenomenon of family nursing care, and the factors affecting it, for high-risk and frail older persons who have a significant need for home healthcare services. Methods: This study was conducted using secondary data collected by students who interviewed 93 healthcare subjects in a health center. The data was used to analyze the general characteristics, health-related characteristics, and confirmed problems of family nursing phenomena of the subjects. Independant t-test, Pearson correlation coefficient, and multiple linear regression were used for the data analysis. Results: The mean age of the subjects was 82.4±6.3 years. The most common problem of the family nursing phenomenon were unhealthy lifestyle, disturbance in family communication, and lack of family interaction in the community. People with greater family nursing phenomenon problems reported a higher degree of frailty and depression, lower quality of life and self-rated health. The factors that influence the family nursing phenomenon of frail older persons are the problems of mobility and hearing. Conclusion: Physical and psychological problems associated with aging can cause not only personal, but family functional problems as well. Therefore, a comprehensive family-oriented support program is required.

• Journal of Korean Port Research
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• v.10 no.2
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• pp.17-29
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• 1996

It is required to consider pricing and non-pricing factors and external economy in order to achieve the objects of physical distribution system in a port. Recently, among the three factors, much attention has been paid to non-pricing factor in the system. Although physical distribution service in a port(PDSP)has been frequently mentioned in documents and literature related to port and shipping studies, few study on it has not been systematically and scientifically made due to the following problems; $\circ$ there are not proper criteria to evaluate level and quality of PDSP and as a result it is difficult to set up a unified standard for doing so. $\circ$ algorithms to evaluate problems with complex and ambiguous attributes and multiple levels in PDSP are not available. This thesis aims to establish a paradigm to evaluate PDSP and to abvance existing decision making methods to deal with complex and ambiguous problems in PDSP. To tackle the first purpose, extensive and thorough literature survey was carried out on general physical distribution service, which is a corner stone to handle PDSp. In addition, through interviews and questionnaire to the expert, it have extracted 82 factors of physical distribution service in a port. They have been classified into 6 groups by KJ method and each group defined by the expert's advice as follows; a. Potentiality b. Exactness c. safety d. Speediness e. Convenience f. Linkage Prior to the service evaluation, many kinds of its attributes must be identified on the basis of rational decision owing to complexity and ambiguity inherent in PDSP. An analytical hierarchy process (AHP) is a method to evaluate them but it is not applicable to PDSP that have property of non-additivity and overlapped attributes. Therefore, probablility measure can not be used to evaluate PDSP but fuzzy measure is required. Hierarchical fuzzy integral method, which is merged AHP with fuzzy measure, is also not effective method to evaluate attributes because it has vary complicated way to calculate fuzzy measure identification coefficient of attributes. A new evaluation algorithm has been introduced to solve problems with multi-attribute and multi-level hierarchy, which is called hierarchy fuzzy process(HFP).Analysis on ambiguous aspects of PDSP under study which is not easy to be defined is prerequisite to evaluate it. HFP is different from algorithm existed in that it clarified the relationship between fuzzy measure and probability measure adopted in AHP and that it directly calculates the family of fuzzy measure from overlapping coefficient and probability measure to treat and evaluate ambiguous and complex aspects of PDSP. A new evaluation algorithm HFP was applied to evaluate level of physical distribution service in the biggest twenty container port in the world. The ranks of the ports are as follows; 1. Rotterdam Port, 2. Hamburg Port, 3. Singapore Port, 4. Seattle Port, 5. Yokohama Port, 6. Long beach Port, 7. Oakland Port, 8. Tokyo Port, 9. Hongkong Port, 10. Kobe Port, 11. Los Angeles Port, 12. New york Port, 13. Antwerp Port, 14. Felixstowe Port, 15. Bremerhaven Port, 16. Le'Havre Port, 17. Kaoshung Port, 18. Killung Port, 19. Bangkok Port, 20. Pusan Port