• Journal of Mechanical Science and Technology
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• v.18 no.6
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• pp.955-960
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• 2004

Some characteristics of the eigenvalue sensitivities have been found for beams in the paper. For cantilever beams and simply supported beams, the sensitivities of the eigenvalues to the stiffness correction factor of one element are equal and opposite to the sensitivities to the mass correction factor of the symmetrically positioned element. For beams with other boundary conditions, however, the relationship does not hold. The relationship has been proven analytically for simply supported beams.

• The Journal of Korean Obstetrics and Gynecology
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• v.24 no.3
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• pp.146-155
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• 2011

Objectives: Since early developed measurement of Postpartum depression(PPD) doesn't reflect physical symptoms, we need to find out how PPD and related physical disorders are expressed in functional medical methods. The study was conducted to find out characteristics of 7 Zone diagnosis and postpartum physical symptoms on PPD. Methods: To 216 postpartum women who did normal delivery, we measured 7-zone-diagnosis Factor AA's height on 5th day and 15th day postpartum. And we surveyed EPDS and postpartum physical symptoms question on 15th day postpartum. Subjects were divided into normal and depression group by EPDS score. And we compared Factor AA's height between two groups and Factor AA's height change in each group. Results: In depression group, Factor AA's height was higher than normal group on 5th day and 15th day postpartum. In both groups Factor AA's height was decreased on 15th day compared to 5th day postpartum. In normal group 2, 6, 7 zone were significantly decreased and in depression group only 6 zone was significantly decreased. Conclusions: These results demonstrate that postpartum depression group has low recuperative power. And these can be judged by Factor AA's height change.

• Journal of Climate Change Research
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• v.8 no.4
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• pp.347-355
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• 2017

Methane and nitrous oxide are main greenhouse gases from agricultural system and their global warming potential are 25 and 258 times stronger than that of $CO_2$, respectively. In 2016, the emission was $21,290Gg\;tone\;CO_2-eq$. which was emitted from agriculture sector and about 3.1% of total GHG emission of Korea. Those guidelines that were published by IPCC have methodology for GHGs emission calculation as well as emission factor and so on. For recent 5 years, GHGs emissions in Korea have calculated by MRV which has been improved every year based on IPCC guidelines. Analysis as estimating method improvement showed that the methane emissions from rice cultivation were the lowest on 2012 methodology, and the highest on 2014 methodology. On the other hand, the emissions of agricultural soils were the lowest on 2015 methodology and the highest on 2012 methodology. Total emissions from agriculture sector were the lowest on 2015 methodology and the highest on 2012 methodology. Compared with 2016 methodology, the GHGs emitted as few as $-1,865Gg\;tone\;CO_2-eq$ and as many as $2,717Gg\;tone\;CO_2-eq$. GHGs emissions can vary greatly, depending on how to use the emission factor and activity data. Therefore, it need constantly a detailed analysis for methodology and GHGs emission in the future.

• The Journal of the Acoustical Society of Korea
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• v.18 no.4E
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• pp.10-19
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• 1999

Psychophysical approaches to the room acoustics have been made in number of researches. The present study is looking at whether the listener's perception of frequency change in rooms are dependent on the acoustics of a listening environment. P(C)s for frequency change in short tones were measured in different listening conditions. Two experiments were carried out to investigate the influence of room acoustics on the listener's perception of frequency change, and its implication for evaluating the acoustics of listening environments were examined and discussed. It was found that the temporal and spectral contents of reflections from room surfaces might be an important factor which influenced the listener's perception of frequency change in a reverberant sound field. This implicates that psychophysical approach by measuring listener's frequency change perception might be an useful tool for evaluating room acoustics. However, cares should be taken, since some individual differences were found to exist with respect to the direction of frequency change.

• Journal of Climate Change Research
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• v.7 no.2
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• pp.193-203
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• 2016

The importance of forecasting agricultural production is receiving attention while climate change is accelerating. This study suggested three types of crop yield forecasting model for major vegetable crops by using downscaled meteorological information of main production area on farmland level, which identified as limitation from previous studies. First, this study conducted correlation analysis with seven types of farm level downscaled meteorological informations and reported crop yield of main production area. After, we selected three types of meteorological factors which showed the highest relation with each crop species and regions. Parameters were deducted from meterological factor with high correlation but crop species number was neglected. After, crop yield of each crops was estimated by using the three suggested types of models. Chinese cabbage showed high accuracy in overall, while the accuracy of daikon and onion was quiet revised by neglecting the outlier. Chili and garlic showed differences by region, but Kyungbuk chili and Chungnam, Kyungsang garlic appeared significant accuracy. We also selected key meteorological factor of each crops which has the highest relation with crop yield. If the factor had significant relation with the quantity, it explains better about the variations of key meteorological factor. This study will contribute to establishing the methodology of future studies by estimating the crop yield of different species by using farmland meterological information and relatively simplify multiple linear regression models.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.10a
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• pp.33-37
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• 1995

A side-cut grinding generates a machining error by the decrease of the quill rigidity. In this paper, The effect on the grinding force, machining error and surface roughness due to the change of the quill rigidity is investigated experimentally. The slenderness ratio of the quill is a significant factor to analyse the change of the grinding force and machining error.

• Journal of Family Resource Management and Policy Review
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• v.21 no.2
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• pp.95-117
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• 2017

The purpose of this study was to examine the level of anxiety about economic change in middle-aged and elderly people and to analyze the factors that influence this anxiety. The data, derived from Korean General Social Survey(KGSS) were collected from Survey Research Center of Sung Kyun Kwan University. The samples included 821 people over the age of 40, including 529 middle-aged people who were from 40 to 59, and elderly people who were over 60. Multiple regression analysis was used to analyze the research model. The findings from the analysis showed that age and subjective economic status had crucial effects on the entire group's anxiety about unemployment and poverty, housing prices, financial markets, and economic recession in the older life. For the middle-aged group, age in particular had crucial effects on all the components of its anxiety about economic change. For the elderly group, geographical region was the most critical factor that affected its anxiety about economic change, the elderly people who were living in metropolitan area and towns had more anxiety than those who were living in rural areas. In particular, region was the only factor that affected the elderly group's anxiety about financial markets, and economic recession. These results showed that specific age of middle-aged and elderly people had the crucial effects while their sex, educational level, and the employment status of their spouse had no effects on their anxiety about economic change. Objective economic indices such as their earned-income and other income including savings and pensions had no effects on their anxiety level. While as noted above subjective economic indices such as their standard of living compared with their parents, projected economic status, and level of socio-economic success had an effect on anxiety about economic change.

• Journal of the Korean Data and Information Science Society
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• v.18 no.2
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• pp.289-300
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• 2007

The stock return is changed by factors of inside and outside or is changed by factor of market system. But most studies have not considered the changes of stock return distribution when estimate the VaR. Such study may lead us to wrong conclusion. In this paper we calculate the VaR of price-to-earnings ratios by the distribution that have considered the change point and used transformation to satisfy normal distribution.

• Journal of Climate Change Research
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• v.7 no.4
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• pp.513-520
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• 2016

Korea's energy consumption has been constantly increasing. Final energy consumption was increased by an annual average of 2.9% compared to 2010. The consumption of all energy sources except for its oil was increased during the same time. While electric demand has increased coal consumption increased rapidly. Therefore, calorfic value and carbon emission factor development can improve the quality of Korea's greenhouse gas inventory. Calorific value is the amount of heat generated while burning coal. Caloric value is one of the most important factors in the development of carbon emission factors. Calorific value is used as the basis for the analysis of the various energy statistics. This study has calculated the other bituminous coal and coking coal's calorfic value by the data received from domestic coal-fired power plants and steel manufacturer. Calorofic value's trend analysis period is the year of 2010~2014. Through analyzing the carbon content it was calculated the carbon emission factor. The bituminous coal and coking coal's uncertainty analysis was performed using a Monte Carlo simulation.

• Journal of Climate Change Research
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• v.8 no.2
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• pp.145-151
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• 2017

Korea's energy consumption has been constantly increasing. Final energy consumption was increased by anannual average of 2.9% compared to 2010. The consumption of all energy sources except for its oil was increased during the same time. While electric demand has increased coal consumption increased rapidly. Therefore, calorfic value and carbon emission factor development can improve the quality of Korea's greenhouse gas inventory. Calorific value is the amount of heat generated while burning coal. Caloric value is one of the most important factors in the development of carbon emission factors. Calorific value is used as the basis for the analysis of the various energy statistics. This study has calculated the sub-bituminous coal's calorfic value by the data received from domestic coal-fired power plants. Calorofic value's trend analysis period is the year of 2011~2015. Through analyzing the carbon content it was calculated the carbon emission factor. The sub-bituminous coal's uncertainty analysis was performed using a Monte Carlo simulation.