• Advances in nano research
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• v.10 no.3
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• pp.221-234
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• 2021

During the previous few years, phenomenon of bioconvection along with the use of nanoparticles showed large number of applications in technological and industrial field. This paper analyzed the bioconvection phenomenon in magnetohydrodynamic boundary layer flow of a Powell-Eyring nanoliquid past a stretchable cylinder with Cattaneo-Christov heat flux. In addition, the impacts of chemical reaction and heat generation/absorption parameter are considered. By the use of appropriate transformation, the governing PDEs (nonlinear) have been transformed and formulated into nonlinear ODEs. The resulting nonlinear ODEs subjected to relevant boundary conditions are solved analytically through homotopy analysis method which is programmed in Mathematica software. Graphical and numerical results versus physical quantities like velocity, temperature, concentration and motile microorganism are investigated under the impact of physical parameters. It is noted that velocity profile enhances as the curvature parameter A and Eyring-Powell fluid parameter M increases but a decline manner for large values of buoyancy ratio parameter Nr and bio-convection Rayleigh number Rb. In the presence of Prandtl number Pr, Eyring-Powell fluid parameter M and heat absorption parameter ��, temperature profile decreases. Nano particle concentration profile increases for increasing values of magnetic parameter Ha and thermophoresis parameter Nt. The motile density profile has revealed a decrement pattern for higher values of bio-convection Lewis number Lb and bio-convection peclet number Pe. This study may find uses in bio-nano coolant systems, advance nanomechanical bio-convection energy conversion equipment's, etc.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.64 no.4
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• pp.256-260
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• 2015

In this paper, achieved rise temperature distribution about degradation phenomenon of 24 MVA distribution cast resin transformer using CFD(Computational Fluid Dynamics). Usually, life of transformer is depended on temperature distribution of specification region than thermal special quality of transformer interior. Specially, life of transformer by decline of dielectric strength decreases rapidly in case rise by strangeness transformer interior hot spot temperature value permits. Because calculating high-voltage(HV) winding and low-voltage(LV) winding of cast resin transformer and Joule's loss of core for improvement these life, forecasted heat source, and HV winding and LV winding of cast transformer rise temperature distribution of core for supply of electric power and temperature distribution of highest point on the basis of the results. Also, calculated temperature rise limit of cast resin transformer and permission maximum temperature using analysis by electromagnetic heat source. Calculated and forecasted rise temperature distribution by heat source of thermal analysis with calculated result.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2000.11a
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• pp.107-118
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• 2000

For the last several decades, the fate of organic pollutants has been extensively studied in natural environments with emphasis on sorption and desorption phenomena. Although the mechanisms involved are not clear yet there is a consensus about the existence of hysteresis in the sorption and desorption of organic pollutants. Furthermore, it is found that hysteresis is the outcome of slow nonequilibrium sorption of organic pollutants, which results in the formation of desorption-resistant fractions of the pollutants. Desorption-resistant fractions may increase as a function of the residence time of the pollutants in the environments. Field monitoring data show a slow but continuous decline of chemicals applied to soil, followed by little or no subsequent disappearance. One plausible explanation for such resistance to biodegradation, desorption, or extraction can be attributed the gradual movement of organic pollutants to less accessible remote sites inside the matrix with time. This phenomenon has been termed sequestration or aging. The fact that some pollutants are sequestered in soil with time may have a great impact on bioremediation and risk assessment, Some portion of the resistant pollutants may still be present in the environments after bioremediation. It requires vigorous means to completely remove the aged portion that may not be further bioavailable. However, precaution should be taken since aging is not always evident. Aging seems to be soil and chemical specific.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.305-306
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• 2006

In process for production of Rubber Scheme Product that have the most inferior Working Environment is Medicine mixture and Scheme processing. Applying automation and Environment Treatment technology to the hazardous chemical and mixture processing, Through developed 'Mixture Automatic Machine for hazardous chemical Interruption type that is occurred at mixing rubber medicines', we try to decline worker's intensity of labour, Also overcomes solution of work evasion phenomenon and manpower supply and demand's difficulty by forming agreeable working environment and through the automatic scheme and mixture processing by preventing that hazardous chemical had known as disease causes of various importance disease is exposed to worker during the work. and we plan to do so that production of high added value product may be available.

• Health Policy and Management
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• v.6 no.1
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• pp.59-84
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• 1996

It is generally believed that the medical profession in Korea is an well-paid field along with legal profession. In this vein, the nursing is regarded one of well-paid profession. The actual data, however, reveals that nurses belong to low income bracket. We carefully compare the nurse's earnings with those of other professions. We selected 58 professions, which are similar in vocational characteristics and education background to nurses and conduct a regression analysis to estimate earning functions. Using the estimated coefficients, we project an optimum salary level for nurse, and compare it with the actual salary level. The estimated results show that the nurses are underpaid : their actual salary is less than the optimum level. We provide several explanations for this phenomenon : a tradition based on Confucian value, wage discrimination for women, and wage inequality among hospitals. Undercompensation will result either ratard professional development, or block the motivation for high quality of nursing care. If the current underpaying situation is not improved, a shortage of nurses along with an noticeable decline in the quality of medical services are expected. Therefore an adequate compensation for nurses must be properly assessed and addresed not only be health care authorities but also by legislators. Further research is needed to explain why there is such as wide salary inequality among nurses, and to find what cause it.

• Korea journal of population studies
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• v.6 no.1
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• pp.70-89
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• 1983

China's population and family planning program has heen successful. Women's fertility as measured by total fertility rate (TFR) has declined from 5.8 in 1970 to 2.3 in 1990, accordingly the annual crude birth rate(CBR) has declined from 34 per thousand in 1970 to 21 per thousand in 1989, and the annual natural growth rate from 2.6 percent in 1970 to 1.4 percent in 1989 (Coale and Chen, 1987; SSB, 1991; Gu, 1994). While this is indeed an astonishing achievement for a developing country to have its fertility down to replacement within a short period, some new issues emerging along with the rapid fertility decline require careful considerations. One of them is the uprising of the sex ratio at birth in China. The 1990 population census reported the sex ratio at birth in China of 113.8 in 1989, which is ohviously much higher than the acceptable level of normal ratio around 106. It has received since then a lot of tention in China and abroad, among demographic professionals and governmental agencies alike (Hull, 1990; Johansson and Nygren, 1991; Xuand Guo, 1991; Tu, 1993; Gu and Xu, 1994; among others). Based on the available demographic data and research results this paper will first have a review of the patterns and trends of sex ratio at birth in China, then turn to the immediate causes of abnormal sex ratio at birth and the determinants of the son preference, followed with a conceptual framework for understanding of the phenomenon, and finally the policy implications and recommendations will be discussed.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.43 no.3
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• pp.204-215
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• 2020

Efforts on the continued increase of local government's fiscal spending related to improving the residential environment are desirable to counter the declining phenomenon of urban decline. At the same time, however, it is also important to know how to operate limited finances more efficiently to improve the residential environment. This study aims to contribute to the rational allocation of fiscal expenditure and the creation of productive results for the improvement of the settlement environment. To this end, this study analyzed the efficiency of financial expenditure related to the improvement of the residential environment in 225 local governments nationwide. The relationship between financial expenditure and residential environmental performance was also measured and the CCR, BCC and SBM models were used to measure efficiency. The analysis showed that most local governments need to scale back their fiscal spending related to improving the government environment. In addition, it was required to prepare feasible spending plans by bench-marking the processes of residential environment improvement projects in areas such as Haman-gun, Jongno-gu, Seoul, and Seocho-gu, which are considered to be under efficient operation.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2006.11a
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• pp.133-137
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• 2006

Can examine cause that the construction industry is faced in crisis of skill exhaustion in two sides. One is the tribe of actuality production manpower by entry evasion and graying of young man class specially new manpower to the tribe of skill manpower. Another is qualitative decline of skill manpower. Generally, problem of the systematic knowledge tribe and the picking up tribe about new technology etc, exists because learn skill for shoulder beyond in spot. In cutting phenomenon of skill that is depended on personal relationships availability with skilled worker in hereafter, problem that worker who is old or enter through rain skilled worker does not learn all life skill is detected. These problems institute entry of young man class and necessity of systematic vocational education training specially new human strength strongly. This study does presentation of way to promote construction industry entry of young man class and improvement way of vocational education training system that can do to train these by function manpower by purpose.

• Journal of Biomedical Engineering Research
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• v.29 no.1
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• pp.17-24
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• 2008

The aim of this paper is to report our preliminary results of investigating the spatial focalization of Zen-meditation EEG (electroencephalograph) in alpha band (8-13 Hz). For comparison, the study involved two groups of subjects, practitioners (experimental group) and non-practitioners (control group). To extract EEG alpha rhythm, wavelet analysis was applied to multi-channel EEG signals. Normalized alpha-power vectors were then constructed from spatial distribution of alpha powers, that were classified by Fuzzy C-means based algorithm to explore various brain spatial characteristics during meditation (or, at rest). Optimal number of clusters was determined by correlation coefficients of the membership-value vectors of each cluster center. Our results show that, in the experimental group, the incidence of frontal alpha activity varied in accordance with the meditation stage. The results demonstrated three different spatiotemporal modules consisting with three distinctive meditation stages normally recognized by meditation practitioners. The frontal alpha activity in two groups decreased in different ways. Particularly, monotonic decline was observed in the control group, and the experimental group showed increasing results. The phenomenon might imply various mechanisms employed by meditation and relaxation in modulating parietal alpha.

• Korea journal of population studies
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• v.17 no.2
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• pp.116-135
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• 1994

China's population and family planning program has heen successful. Women's fertility as measured by total fertility rate (TFR) has declined from 5.8 in 1970 to 2.3 in 1990, accordingly the annual crude birth rate(CBR) has declined from 34 per thousand in 1970 to 21 per thousand in 1989, and the annual natural growth rate from 2.6 percent in 1970 to 1.4 percent in 1989 (Coale and Chen, 1987; SSB, 1991; Gu, 1994). While this is indeed an astonishing achievement for a developing country to have its fertility down to replacement within a short period, some new issues emerging along with the rapid fertility decline require careful considerations. One of them is the uprising of the sex ratio at birth in China. The 1990 population census reported the sex ratio at birth in China of 113.8 in 1989, which is ohviously much higher than the acceptable level of normal ratio around 106. It has received since then a lot of tention in China and abroad, among demographic professionals and governmental agencies alike (Hull, 1990; Johansson and Nygren, 1991; Xuand Guo, 1991; Tu, 1993; Gu and Xu, 1994; among others). Based on the available demographic data and research results this paper will first have a review of the patterns and trends of sex ratio at birth in China, then turn to the immediate causes of abnormal sex ratio at birth and the determinants of the son preference, followed with a conceptual framework for understanding of the phenomenon, and finally the policy implications and recommendations will be discussed.