• Journal of Korea Water Resources Association
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• v.41 no.1
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• pp.1-15
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• 2008

The purpose of this study is to propose a procedure that will be able to find the most efficient sets of weight coefficients for the Geum-River basin in Korea. The result obtained from multi-objective optimization model is inherently sensitive to the weight coefficient on each objective. In multi-objective reservoir operation problems, the coefficient setting may be more complicated because of the natural variation of inflow. Therefore, for multi-objective reservoir operation problems, it may be important for modelers to provide reservoir operators with appropriate sets of weight coefficients considering the inflow variation. This study presents a procedure to find an appropriate set of weight coefficients under the situation that has inflow variation. The proposed procedure uses GA-CoMOM to provide a set of weight coefficient sets. A DEA-window analysis and a cross efficiency analysis are then performed in order to evaluate and rank the sets of weight coefficients for various inflow scenarios. This proposed procedure might be able to find the most efficient sets of weight coefficients for the Geum-River basin in Korea.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.5
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• pp.747-755
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• 2009

The feed resource for animals is a major cost determinant for profitability in livestock production enterprises, and thus any effort at improving the efficiency of feed use will help to reduce feed cost. Feed conversion ratio, expressed as feed inputs per unit output, is a traditional measure of efficiency that has significant phenotypic and genetic correlations with feed intake and growth traits. The use of ratio traits for genetic selection may cause problems associated with prediction of change in the component traits in future generations. Residual feed intake, a linear index, is a trait derived from the difference between actual feed intake and that predicted on the basis of the requirements for maintenance of body weight and production. Considerable genetic variation exists in residual feed intake for cattle and pigs, which should respond to selection. Phenotypic independence of phenotypic residual feed intake with body weight and weight gain can be obligatory. Genetic residual feed intake is genetically independent of its component traits (body weight and weight gain). Genetic correlations of residual feed intake with daily feed intake and feed conversion efficiency have been strong and positive in both cattle and pigs. Residual feed intake is favorably genetically correlated with eye muscle area and carcass weight in cattle and with eye muscle area and backfat in pigs. Selection to reduce residual feed intake (excessive intake of feed) will improve the efficiency of feed and most of the economically important carcass traits in cattle and pigs. Therefore, residual feed intake can be used to replace traditional feed conversion ratio as a selection criterion of feed efficiency in breeding programs. However, further studies are required on the variation of residual feed intake during different developmental stage of production.

• Fisheries and Aquatic Sciences
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• v.4 no.3
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• pp.150-158
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• 2001

A study on the amount, distribution and item of bottom litter on the sea-bed was conducted by the bottom trawl net at 5 sections in Chinhae Bay over a year. The number and weight of litter found per unit of swept area (1 hectare) in each section were estimated as the range of 8.76-80.63 pieces, 3.51-108.39kg, respectively. The seasonal variation of high (Aug., '97) and low season (Feb., '98) in quantity was small, and it was about 2 times as the range of 24.58- 52.61 pieces/ha between them. But the weight variation between high (Apr., '98) and low season (Aug., '97) was very large, about 30 times as the range of 4.06-119.64kg/ha. The largest and second composition on the weight of bottom litter in Chinhae Bay are $76\%$ in other-litter with compound and bulky materials, and $93\%$ in fishing gear, respectively. The relationship between quantity and weight of bottom litter was not occurred due to the variety of specific gravity. Of the fishing gear, fishing nets was portioned to be 2.571kg/ha in weight and $84.9\%$ in composition. So these results prove that fishing nets were discarded as the most part of fishing gear during fishing activity in the bay. The largest composition of the soiled state classified into 3 styles in overall bottom litter was $69\%$ in very soiled state, and the second one of $28\%$ in the soiled state. On the other hand, new state is very small and portioned in $3.0\%$ of all. Chinhae Bay was estimated to be about 10 times in quantity and about 36 times in weight of Tokyo Bay. Therefore, these suggest that Chinhae Bay is a very serious polluted estuary caused by the bottom litter such as heavy and bulky wastes, fishing gear.

• Asian-Australasian Journal of Animal Sciences
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• v.30 no.9
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• pp.1234-1238
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• 2017

Objective: The vertebral number is associated with body length and carcass traits, which represents an economically important trait in farm animals. The variation of vertebral number has been observed in a few mammalian species. However, the variation of vertebral number and quantitative trait loci in sheep breeds have not been well addressed. Methods: In our investigation, the information including gender, age, carcass weight, carcass length and the number of thoracic and lumbar vertebrae from 624 China Kazakh sheep was collected. The effect of vertebral number variation on carcass weight and carcass length was estimated by general linear model. Further, the polymorphic sites of Vertnin (VRTN) gene were identified by sequencing, and the association of the genotype and vertebral number variation was analyzed by the one-way analysis of variance model. Results: The variation of thoracolumbar vertebrae number in Kazakh sheep (18 to 20) was smaller than that in Texel sheep (17 to 21). The individuals with 19 thoracolumbar vertebrae (T13L6) were dominant in Kazakh sheep (79.2%). The association study showed that the numbers of thoracolumbar vertebrae were positively correlated with the carcass length and carcass weight, statistically significant with carcass length. To investigate the association of thoracolumbar vertebrae number with VRTN gene, we genotyped the VRTN gene. A total of 9 polymorphic sites were detected and only a single nucleotide polymorphism (SNP) (rs426367238) was suggested to associate with thoracic vertebral number statistically. Conclusion: The variation of thoracolumbar vertebrae number positively associated with the carcass length and carcass weight, especially with the carcass length. VRTN gene polymorphism of the SNP (rs426367238) with significant effect on thoracic vertebral number could be as a candidate marker to further evaluate its role in influence of thoracolumbar vertebral number.

• Journal of the Korean Society of Clothing and Textiles
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• v.17 no.2
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• pp.301-306
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• 1993

Since the underquilt has an important role of supporting the human body in sleeping, it needs to sustain ample degrees of hardness, elasticity, humidity absorption, and warmth retention property and also to have the two ergonimical requirements : It should not be too soft to allow human bodies to sink in, and that it should be comfortable for humans to tum over in sleeping. This study aims to investigate the effect of the thermal insulation of the variation in weight applied to the underquilt. For this purpose, six items were selected as filling materials for the underquilt : cotton, wool, silk, down, polyester, cotton/ployester. Various weights were applied to each of the underquilts to survey the reduction tendency of its thermal insulation effect. The results are as follow : 1. The Thermal insulation effect of each underquilt decreased in an exponetial function as the weight on the underquilt was increased. 2. The thermal reduction curves according to the load weight insrease were shown to be constant in shape regardless of the weight increase. 3. At the weight of more than $25kg/m^2$ the degree of the thermal insulation effect of each underquilt was found to be in order of down>cotton>silk>polyester>wool>cotton/ployester. 4. The variation in load weight applied to each underquilt was shown to be in reverse correlation with the thermal insulation effect. An estimated regression formula can be made on the data.

• Journal of Korea Game Society
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• v.20 no.1
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• pp.13-22
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• 2020

This study is about the VR controller that can provide an enhanced experience in VR by augmenting the sense of weight. In this study, the method of changing the center of gravity of the controller was used as a means of transmitting the sense of weight. The experiment was carried out with a device that could change the center of gravity to find the minimum distance at which people can perceive the difference in weight. The results showed that the weight difference between the two stimuli can be perceived at a distance of about 5 cm regardless of the position of the starting stimulus.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.54 no.1
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• pp.24-28
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• 2009

This study was conducted to evaluate the growth characters and yield components of 18 collected sesame cultivars to get basic information on the variation for the sesame breeding using principal component analysis. All characters except days to flowering, days to maturity and 1,000 seed weight showed significantly different. Seed weight per 10 are showed higher coefficient of variance. Capsule bearing stem length and liter weight showed positive correlation with seed yield per 10 are. The principal components analysis grouped the estimated sesame cultivars into four main components which accounted for 83.7% of the total variation at the eigenvalue and its contribution to total variation obtained from principal component analysis. The first principal component ($Z_1$) was applicable to increase plant height, capsule bearing stem length and 1,000-seed weight. The second principal component ($Z_2$) negatively correlated with days to flowering and maturity by which it was applicable to shorten flowering and maturity date of sesame. At the scatter diagram, Yangbaek, Ansan, M1, M2, M4, M7 and M9 were classified as same group, but M10, Yanghuk, Kanghuk, M5, M6, M12 and M13 were classified as different group. This results would be helpful for sesame breeder to understand genetic relationship of some agronomic characters and select promising cross lines for the development of new sesame variety.

• Journal of the Korean GEO-environmental Society
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• v.11 no.4
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• pp.19-24
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• 2010

Generally, slope behavior is analyzed by 2-dimensional creep model. Creep behavior shows the deformation variation as time goes by without stress increment. Convention 2-dimensional creep analysis does not have the term of stress variation, it means creep analysis could not figure out the relationship of shear strength variation according to the stress variation and displacement. The slope weight and shear strength is directly related and interlocked to the safety variation and displacement of slope, therefore, this phenomenon could be treated and analyzed as combining the hysteresis and creep, the iteration of this process will result in the slope safety. Furthermore, the combined analysis will be the slope analysis considering shear stress, displacement and shear strength with time variation. In real case, because the variation of shear stress and strength happen at the same time, they should be changed into safety factor which is function of them. This paper shows the 3-dimensional variation of unit weight of soil with hybrid analysis considering creep and hysteresis on the seepage and drainage of rainfall, futhermore variations of shear stress and strength which make the safety factor change.

• Health Policy and Management
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• v.14 no.1
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• pp.148-168
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• 2004

To investigate the effect of parents' social class on birthweight in Korea during the period of transition to a market economy, 1995-2001. Methods: All births resulting from pregnacies reported in 1995-22001(n=4,298,374) were studied with respect to social variation in birthweight. The results were adjusted for maternal age, parity, parents' education, gestational age, total births, the dead births among total births, the number of births in one delivery. Results: Between 1995 and 2001, mean birth weight was 3271g and low birth rate was 3.41%. Maternal education, faternal education, parents' occupation, the number of birth in one delivery, total births, gestational age, and the number of deaths among. total births were all independently related to the birthweight. Parents with lower education showed higher low-birthweight rates compared with parents with university level of education(OR: 2.16 for mother and 1.68 for father). Especially, mother's education showed stronger relationship with birthweight than fathers' education. The differences in birth weight by parents' social class, especially parents' educational level became stronger between 1995 and 2001. Discussion: This study suggests that the social differences of birth weight were increasing in order 1995 to 2001. Especially, this increasing tendency in variation in birth weight by social class was shown after economic crisis, 1998.

• International Journal of Industrial Entomology and Biomaterials
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• v.4 no.2
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• pp.149-153
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• 2002

Induction of non-diapause eggs and manifestation of quantitative characters were studied in different seasons by low temperature incubation of eggs of a low yielding diapause with coloured cocoons silkworm breed, RDI of Bombyx mori. Hundred percent of nandiapause eggs were induced when the egg incubation was carried out at 15$^{\circ}C$ followed by incubation initially at $25^{\circ}C$ and then at $15^{\circ}C$. The diapause-nondia-pause relation was found to be reversible. Analysis of variance study demonstrated significant variation in all the quantitative characters whereas significant variation due to different incubation treatments was observed for larval span, fifth instar larval span, cocoon yield/10,000 larvae by weight, cocoon weight, cocoon shell weight, and cocoon shell ratio. study on hybrid vigour skewed significant heterosis over mid parent value for four economic characters viz., cocoon weight, cocoon shell weight, cocoon shell ratio and filament length in a Fl hybrid between RD1 with diapause eggs and Japanese type bivoltine $NB_{4} D_{2}$.