• 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.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2011.04a
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• pp.538-543
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• 2011

In this paper, optimal spot weld layout design of the shock tower structure is performed for increasing fatigue life of spot weld and fatigue life of shock tower simultaneously. To predict the fatigue life, linear static analysis is conducted then fatigue analysis is performed by applying random vibration load. To optimize the spot weld layout, design variables that have an effect on spot weld fatigue life are selected. Based on the DOE table, spot weld fatigue analysis is conducted. Finally, response surface model is made from fatigue analysis results and optimized spot weld layout model which increases fatigue life of sport weld and fatigue life of shock tower is determined.

• 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.

• Korean Journal of Social Welfare
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• v.31
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• pp.87-118
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• 1997

• Journal of Korean Society of Rural Planning
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• v.20 no.2
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• pp.45-56
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• 2014

There are direct and indirect approaches to measure the quality of rural life with comparison of urban. One of the direct approach is to survey living satisfaction of rural residents. Survey result is also important factor for the understanding of local needs in rural development. Rural Development Adminstration(RDA) has developed a survey table with 71 survey items for measuring the satisfaction of rural residents. In rural field forum which have conducted for finding the direction of rural development, the understanding of local needs with measuring the satisfaction of rural residents is important. But developed survey table is difficult to be applied in rural field forum not only many survey items but also overlapping in survey range. The purpose of this study is to suggest a field-applicable survey table in rural field forum based on results of RDA. Survey items were selected based on the importance score of RDA survey table, and weighting values were applied to each survey items. Finally, we suggested 31 items based on results with principle component and reliability analysis.

• Korea journal of population studies
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• v.13 no.2
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• pp.1-18
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• 1990

This is a study which attempt to analyze changing patierns of economic active popu-lation, t o estimato- future patterns, and exa- mine vartons problems arises by changing c ire u mst ances of t he labor force market in- clunging soici al, economic ic, heathl th and demoi-graph ic aspects. We have constructed series of wotking life table which are useful in syt uiolyioig the lirocess of growth and structural change of labor force. Work i ng life tables represent ihie life eyele of econrmic' activity in hi ypothetical cohorts, that is. gen-erat i on of men Sn bject at eat' b period ot f their lives th given ra to's o mor tali it y and of par-- tici pation in economic activities. The tabloes prot' ide measorues of the alvet'age he ng t able of economically aeti \- e life. and agespecific rates of en trannee' into and retirement from the hahn' force. In const routing working life tables, age-specific activity rates and life tabole popula- titoto which represents contemporary condi-tions of moortality in Korea au'e the basic' maltoerials. We have derived the age-specific rates foorm economically active population survey, whoich were conducted by the Bureau of Statistics, Economic Planning Borard of the Korean government. Working life tables are constructed for men wtable these materi- als in the year of 1970, 1980 and 1988 by a modified Wolfbein-Wool's method. Some of the findings may be summerized as follow : 1) A central part of constructing working life table is calculation of stationary' economic active population, which represents the number of men in the stationtary population extoected to be in the labor force at each age group in the life span. The stationary economic active population by age have generally a universal pattern, where they rise sharply in the early twenties, approach its' peak in the thirties decline thereafter. at first graolually and then more rapidly at an advanced age. Korean men show the same general pa ttern of age distribution of stationary eco-- nomic active population with sharp increase hegining from the age interval of 20 to 24, reaching to maximum level at older age. The population. however, presumably, increased substantially due to increaseing school atte endance rates. Another difference exiSts in the youngest age groups, that is the activity rate in the year of 1988 is lower than that of Japan. The table shows an analysis of changes in the age distrihution of labor force between 1970, 1980 and 1988. 2) It was shown an analysis of changes in the age distribution and cause of separation from labor force. The entrance rate to labor force has increased from 18~\5 persons to 299 persons per 1000 head of stationary population between that of 1980 than that of 1988 for Korean men in 20~24 age group. The entrace rate to labor force shows a rapid entrance appearance concentrated on the 15~24 age group. The separation rate from labor force by retirment in Korea in the year of 1988 shows a great difference of the about four times as much as that of Japan. 3) The functions of table illustrate the patterns of working life of males in Korea in 1970, 1980 and 1988. The average remaining number of economically active years, e at age 15 in 1988 is 46.39 which is 2.12 years of increase compared with that of at age 15 in 1970,1980 and 1988 are 43.90,44.27 and 46.39 respectively, showing steadily increase dur- ing the past double decade the increase in the length of economically active life various age may be considered to have come both from extention of general life expectancy and from increasing entrance rate to economic activity in high age that of working is far greater in 1988 than that of 1980. The gaps between expectation of life and average remaining years of economically active widened due to rapid improvement of mortality level in Ko- rea. This observation together with the population pressure by the appearance of a group of younger population implies that constant increase of economically inactive population among older age group.

• Journal of Biomedical Engineering Research
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• v.29 no.6
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• pp.484-492
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• 2008

Sit to stand(STS) movement is one of the most common activity in daily life. In addition, Korean traditionally stand up from various sitting heights in one's daily life compared to other foreigners. As Korea enter rapidly to the aging society, needs of the elderly's independent life are increasing. Therefore the importance of research about the analysis of elderly's activity in daily life is rapidly increasing. In this study, we analyzed joint movements and changes of muscle length during STS(sit-to-stand) at various sitting heights(table seat, bath seat, bottom) in the Korean elderly's daily life by using the motion analysis and musculoskeletal modeling. Ten Korean elderly and young were participated in this experiment. Three heights of sitting posture which could represent typical sitting in Korean daily life were chosen as table seat(42cm), bath seat(21cm) and bottom(0cm). As the results, the elderly showed both smaller knee/hip flexion and larger trunk flexion relatively in comparison to the young during table seat STS. The elderly also showed larger dorsiflexion and smaller ROM of knee, hip, trunk compared to the young during bath seat STS. Additionally, the elderly showed larger plantarflexion, hip flexion, smaller knee flexion and trunk flexion during the first half of bottom STS and larger knee flexion, hip flexion and trunk flexion during the second half of bottom STS. In addition, we could know contraction and relaxation characters of major muscles in lower limb during various STS through the analysis of changes in muscle length by musculoskeltal modeling.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.21 no.6
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• pp.67-73
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• 2022

Industrial inverters are used in a variety of fields for electric power supply. They may be exposed to vibration and heat once they are installed. This study focused on a framework of accelerated life testing of an industrial inverter considering fatigue damage as the primary source of deterioration. Instead of analyzing detailed failure mechanisms and the product's vulnerability to them, the potential of fatigue failure is considered using the fatigue damage spectrum calculated from the environmental vibration signals. The acceleration and temperature data were gathered using field measurement and spectral analysis was conducted to calculate the vibration signal's power spectral density (PSD). The fatigue damage spectrum is then calculated from the input PSD data and is used to design an accelerated fatigue life testing. The PSD for the shaker table test is derived that has the equivalent fatigue damage to the original input signal. The tests were performed considering the combined effect of random vibration and elevated temperature, and the product passed all the planned tests. It was successfully demonstrated that the inverter used in this study could survive environmental vibration up to its guarantee period. The fatigue damage spectrum can effectively be used to design accelerated fatigue life testing.

• The Journal of Korean Physical Therapy
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• v.32 no.5
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• pp.295-301
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• 2020

Purpose: The purpose of this study was to compare the electromyographic activity and onset time of the gluteus maximus (GM) and hamstring (HAM), lumbopelvic kinematics during three different prone table hip extension exercises in healthy individuals. Methods: Twenty subjects were participated. Electromyography device was used to measure the muscle activities and onset time of the GM and HAM muscles. An electromagnetic tracking motion device was used to measure lumbopelvic compensations. The subjects were asked to perform three different prone table hip extension [Prone table hip extension with the abdominal drawing-in maneuver on a chair (PTHEA), PTHEA with the ipsilateral knee flexion (PTHEAF), PTHEAF with hip 30 abduction (PTHEAFA)]. One-way repeated measures analysis of the variance and a Bonferroni post hoc test were used. Results: The electromyographic activity and onset time were significantly different among three conditions (PTHEA vs. PTHEAF vs. PTHEAFA)(p<0.01). The GM muscle activity and onset time were significantly greater and reduced during the PTHEAFA compared to PTHEA and PTHEAF (p<0.01). However, The HAM muscle activity and onset time were significantly smaller and delayed during the PTHEAFA compared to PTHEA and PTHEAF (p<0.01). Conclusions: PTHEAFA exercise can be recommended to facilitate the muscle activity and efficient muscle firing time of GM without HAM dominance.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.60 no.4
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• pp.470-474
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• 2015

This study was carried out to compare botanical and amylogram characteristics including table quality in waxy corn kernel. The used materials in this experiment were producted and evulated at Corn Breeding Laboratory, Coll. of Agri. & Life Sci., in CNU. In botanical characteristics CNU H09-26 among used hybrids was highest in stem height as 228.5 cm, but that of CNU H09-30 was lowest. Ear height was highest in CNU H09-23 as 78.2 cm, but that of CNU H09-30 was lowest. Ear length among hybrids were also variable as 21.2 cm to 10.8 cm. in amylogram analysis CNU H09-23 hybrid was lowest in pasting temperature, while break down of this hybrid was highest These results appeared highly in table quality. Accordingly we thought that this hybrid will be adapted as a leading variety for edible waxy corn.