• Korean journal of applied entomology
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• v.60 no.4
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• pp.339-355
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• 2021

Aphids can damage plants directly by absorbing their phloem sap and indirectly by transferring plant viruses and causing sooty mold. We compared the thermal effect on the development, survivorship, and reproduction of four cereal crop-damaging aphid species, Rhopalosiphum padi, Aulacorthum solani, Aphis craccivora, and Acyrthosiphon pisum using a life table analysis method. We investigated the stage-specific development period, survivorship, adult longevity, and fecundity of the above mentioned four aphids at 10, 15, 20, 25, and 30℃, respectively, and analyzed their life table parameters using the age-stage, two-sex life table analysis. A. solani nymphs could not complete their development to adulthood at 30℃. The intrinsic increase rate of R. padi was the highest at all tested temperatures except for that at 15℃ (0.12, 0.34, 0.47, and 0.32 at 10, 20, 25, and 30℃, respectively), and that of A. pisum displayed negative values at 30℃ (-0.04). It is speculated that R. padi would be a dominant species under high temperature conditions and A. solani is a highly adaptive species at low temperatures through the comparative analysis of the life table parameters of four aphid species damaging to cereal crops.

• Journal of the Korea Furniture Society
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• v.27 no.4
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• pp.325-334
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• 2016

This study explores developing a large round table with Bosang flower pattern for a contemporary meeting room made by a cabinet maker, Kim Byeung-soo, who has built the traditional Korean furniture in Korean Western Gyeongnam Province since after his elementary school. He uses the post finger joint from one of the middle level of his education process based on the traditional Korean technique, develops it into flower stem joint, and adds flower patterns' carving decoration called Bosang flower patterns. Hence, the table makes the table be strong, useful, and beautiful. Therefore, the modernized round table will be able to make the people access more easily and to make more demand on the traditional Korean furniture and the adopted furniture than ever.

• Animal cells and systems
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• v.6 no.1
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• pp.19-22
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• 2002

Life table studies were conducted in the laboratory for the eulophid gregarious pupal parasitoid, Tetrastichus sp., on Hyphantria cunea Drury at a constant temperature of 28.2$\pm$2$^{\circ}C$, 50-60% RH to evaluate their impact on the host and their potential biological control. Development of immature stage took 20.1$\pm$2.7 d: adult females lived for 23.2$\pm$2.2 (range, 16-27)d and produced a mean of 53.6$\pm$26.6 adult progeny per female, with a sex ratio of 1: 9.5 (M:F). The intrinsic rate of natural increase (r$_{m}$) was 0.178/ female/day; the net reproductive rate (R$_{o}$), 46.74; the capacity for increase (r$_{c}$) 0.177; the finite rate of increase (λ) 1.19/female/day; thus each female contributed 46.74 individuals to the population in a mean generation time of 21.6 d. Biological factors in determining the life history trait variation of the parasitoid were discussed.d.d.d.

• International Journal of Human Ecology
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• v.3 no.1
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• pp.37-54
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• 2002

This study examines longitudinal patterns of financial kin support and welfare given to single mother families using life table techniques. Drawing on the 1985-1993 Panel Study of Income Dynamics(PSID), I followed 560 single mothers from the time they began a single motherhood spell. About 30 percent of these single mothers received financial support from relatives, and 40 to 50 percent received AFDC and Food Stamps, respectively. Results indicate that kin support is more likely to be given in a transitional period and tends to decrease over time. In comparison, receiving welfare appears positively time-dependent.

• Journal of the East Asian Society of Dietary Life
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• v.2 no.2
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• pp.251-262
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• 1992

Eum Sik Check is a cooking book written in old Korean by a woman called Dan Yang Daek. In this study, the contents of the book are interpreted in modern Korean, and are analyzed, compared, and examined in the point of view of cooking. The book shows 1) the methods of the setting of a large table, of a table for ancestor-memorial services, of decorative seasonings, 2) 11 methods for making rice cakes, 3) 21 methods for side dishes, and 4) 7 methods for berwing rice wine.

• The Journal of the Korean life insurance medical association
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• v.22
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• pp.171-181
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• 2003

• Survey Research
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• v.12 no.1
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• pp.65-88
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• 2011

This study analyzed the work and retirement behavior of middle- and old-aged Koreans using panel-data based multi-state life table models. Compared to previous studies that have mainly focused on gender differences in the work and retirement behavior, this study also analyzed educational differences in the retirement life course. With respect to the heterogeneity of work and retirement experiences, this study finds that the retirement life course of men and women differs substantially. Despite their longer life spans, women are expected to have shorter working life expectancies but live in a non-working state longer, resulting in a substantially higher proportion of non-working state in their lives. In terms of educational differences, this study finds that there is little difference in the expected length of stay in the labor force across educational levels but that poorly educated persons are more likely to spend a greater proportion of their lives in the labor force due to their shorter non-working life expectancies.

• Journal of agriculture & life science
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• v.46 no.6
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• pp.43-49
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• 2012

This study was conducted to develop a stem volume table for the Robinia pseudoacacia using stem taper equations. Specifically, Kozak's model was used in the estimation of each model parameter. The fitness of the estimated model was statistically verified and results of the residual analysis were found significant. Therefore, this model is considered applicable in the preparation of stem volume table for R. pseudoacacia. Furthermore, volume with bark and without bark table were developed based on the bark thickness estimation equation. The bark thickness estimation equation was also statistically significant, The stem volume table developed for R. pseudoacacia, which was first in Korea, is vital in managing these forests.

• Korea journal of population studies
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• v.11 no.2
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• pp.22-32
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• 1988

This study was conducted in order to compare the sequential changes of marital partnership and average marital life expectancy in Korea using Korean marriage life table for 1970, 1980, and 1985. The marriage life table was constructed by the Wolfbein-Wool method of constructing a working life table. Data used in this study was obtained from the Population Census Reports of Korea and the Korean Abridged life Tables. Some of the finding may be summarized as follows : 1. The marital partnership findings showed that males in the 40-44 age group in 1970 and in 1980 and those in the 45-49 bracket in 1985 have the highest rates of any other age interval, the percentages were 97.5% 97.3% and 96.9% respectively. The highest marital partnership rates for females were those aged 30-34 in 1970 and in 1980 and 35-39 in 1985:these were 94.6% 94.3% and 93.30% respectively. 2. The marital rate of the youngest age group has decreased due to the increasing amount of people marrying at older ages. On the other hand, the marital rates of the elderly has increased slightly due to the decreasing mortality rate. 3. The enterance rate of marriage at the 15-19 female age group ad the 20-24 male age group has decreased. 4. The secession rate of marriage has gradually decreased due to the decrease in the mortality rate. The main reason of secession for males is his own death. For females, the main reasons are divorce and the death of her spouse. 5. Korean average marital life expectancy has improved in general. In 1985 the average marital life expectancy for males was higher by 4-5 years than for females. The average difference of marital expectancy and life expectancy is about 1.4 - 1.5 years for males and about 11-14 years at the age groups below 60 years for females.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.13 no.5
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• pp.107-115
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• 2014

Highly functional mill turrets have been developed and continuously improved to shorten the manufacturing time and enable multiple uses. Among these, a mill turret with B-axis rotary table was developed. The B-axis rotary table should be evaluated for structural integrity. Moreover, its worm and worm gear for transmitting power should be able to endure fatigue damage. Therefore, this article presents a structural analysis of this type of B-axis rotary table and confirms its static stability by comparing the stress results to the allowable stress levels. Next, the dynamic stability of the rotary table was investigated via a mode analysis and a harmonic analysis in a range determined by the results of a modal analysis. Finally, a worm gear set, the main part that drives the rotary table, is analyzed for fatigue and to estimate its lifetime. The results of the fatigue analysis allowed a prediction of the life of the worm gear set. The analytical results show that the B-axis rotary table has good structural integrity.