• Journal of Labour Economics
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• v.35 no.2
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• pp.79-115
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• 2012

In the study, we try to get reliable estimates of intergenerational income mobility in Korea. At first, we show that the low estimates of previous studies are mainly due to sample selection problem. The direct estimations using OLS after correcting this problem show higher values than previous estimates. We also compute the attenuation bias by decomposing the variances of earnings into the variances of permanent and transitory components of earnings by the results of the regression. Additionally, we try to estimate the range of intergenerational mobility by comparing the OLS results with the results of the two samples instrumental variable estimation and the three samples instrumental variable estimation. The results of these estimations are a little higher than or similar to OLS results.

• Journal of the KSME
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• v.44 no.6
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• pp.48-52
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• 2004

과거 10여 년 간 Electro-Active Polymer(EAP) 분야는 큰 변형을 낼 수 있는 지능재료들이 출현함에 따라 인공근육을 만들 수 있는 가능성으로 인해 많은 관심이 모아지고 있다. EAP는 외부의 자극에 따라 큰 변위를 생성할 뿐만 아니라 근육과 같이 탄력성이 있는, 다른 재료기술들이 낼 수 없는 특성과 성능을 가지고 있다. EAP가 갖는 생체근육과 같은 작동을 할 수 있는 가능성은 곧 공상과학의 꿈을 이루고자하는 희망을 갖게 하며 인류의 문명발전에 크게 기여할 것이다. EAP는 차세대 마이크로 로봇, 오락산업 또는 초소형 비행체의 구동과 같은 인공근육 작동기의 응용분야를 창출하고 있다. EAP 작동기의 응용성은 폭넓으며 새로운 기술혁신의 기대를 불러 일으키고 있다. (중략)

• Korean Journal of Environment and Ecology
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• v.35 no.4
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• pp.424-434
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• 2021

People who face retirement in aging society experience changes in resilience and psychological depression. As the baby boomer generation, which has played a central role in Korea's economic and social sectors, begins retiring, interest in their post-retirement lives has also increased. Thus, this study investigates the effects of a forest healing program using forest healing factors of ecological forests on the resilience and depression of baby-boomer retirees. This experiment divided 58 subjects in the baby boomer generation into three groups and examined differences among the groups. The result showed that the subjects in the forest healing program group (FHPG) had a very significant increase in resilience and a statistically significant decrease in depression compared to those in the forest healing program non-participation group (FHNG) and the daily life group (DLG). Therefore, it can be said participating in the forest healing program is more effective for retirees than voluntary forest activities. The results of this study can be used as basic data for research on the resilience and depression of retirees.

• Journal of Christian Education in Korea
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• v.70
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• pp.11-35
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• 2022

The purpose of this article is to suggest nine types of educational ministry based on the practical theology in Christian Education. For the purpose this article emphasizes an individual dimension including church, society dimensions. An individual dimension is based on the spirit of post digital era within sociocultural area in different with personal-existential area of the philosophical and theological perspective and life cycle theology area of the developmental psychological perspective. Post digital era means the humanization of digital, digital friendly, and emotional digital cultural characteristics. Post digital generation means child, youth, young adults those who are accustomed with post digital cultural of the post digital era. The educational ministry for the post digital generations categorized into nine types according to correlation with individual, church, and society as a field of ministry and critical scientific method, critical confessional method, and critical correlational method as an interdisciplinary which are composed of Christian tradition and contemporary science. Representative key competencies of nine types in the educational ministry are media literacy, relational identity, communication, high touch, discipleship, making and using media, integrative vocation, collaboration abilities, and home, school, and social resilience in relation with multicultural generations.

• Journal of the Korean Society of Food Culture
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• v.14 no.4
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• pp.371-383
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• 1999

This report gave analysis of food demand both in Korea and Japan through introducing the concept of cohort analysis to the conventional demand model. This research was done to clarify the factors which determine food demand of the household. The traits of the new model for demand analysis are to consider and quantify those effects on food demand not only of economic factors such as expenditure and price but also of non-economic factors such as the age and birth cohort of the householder. The results of the analysis can be summarized as follows: 1) The comparison of the item-wise elasticities of food demand demonstrates that the expenditure elasticity is higher in Korea than in Japan and that the expenditure elasticity is -0.1 for cereal and more than 1 for eating-out in both countries. In respect to price elasticity, the absolute values of all the items except alcohol and cooked food are higher in the Korea than in Japan, and especially the price elasticities of beverages, dairy products and fruit are predominantly higher in Japan. In this way, both expenditure and price elasticities of a large number of items are higher in Korea than in Japan, which may be explained from the fact that the level of expenditure is higher in Japan than in Korea. 2) In both of Korea and Japan, as the householder grows older, the expenditure for each item increases and the composition of expenditure changes in such a way that these moves may be regarded as due to the age effect. However, there are both similarities and differences in the details of such moves between Korea and Japan. Those two countries have this trait in common that the young age groups of the householder spend more on dairy products and middle age groups spend more on cake than other age groups. In the Korea, however, there can be seen a certain trend that higher age groups spend more on a large number of items, reflecting the fact that there are more two-generation families in higher age groups. Japan differs from Korea in that expenditure in Japan is diversified, depending upon the age group. For example, in Japan, middle age groups spend more on cake, cereal, high-caloric food like meat and eating-out while older age groups spend more for Japanese-style food like fish/shellfish and vegetable/seaweed, and cooked food. 3) The effect of the birth cohort effect was also demonstrated. The birth cohort effect was introduced under the supposition that the food circumstances under which the householder was born and brought up would determine the current expenditure. Thus, the following was made clear: older generations in both countries placed more emphasis upon stable food in their composition of food consumption; the share of livestock products, oil/fats and externalized food was higher in the food composition of younger generation; differences in food composition among generations were extremely large in Korea while they were relatively small in Japan; and Westernization and externalization of diet made rapid increases simultaneously with generation changes in Korea while they made any gradual increases in Japan during the same time period. 4) The four major factors which impact the long-term change of food demand of the household are expenditure, price, the age of the householder, and the birth cohort of the householder. Investigations were made as to which factor had the largest impact. As a result, it was found that the price effect was the smallest in both countries, and that the relative importance of the factor-by-factor effects differed among the two countries: in Korea the expenditure effect was greater than the effects of age and birth cohort while in Japan the effects of non-economic factors such as the age and birth cohort of householder were greater than those of economic factors such as expenditures.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.8B
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• pp.691-700
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• 2006

Based on the destination IP address of incoming packets, the Internet routers determine next hops and forward packets toward final destinations through If address lookup. The bandwidth of communication links increases exponentially fast as well as the routing table size grows significant as the number of single host networks attached to the Internet increases. Since packets should be processed at wire-speed, the increased link speed reduces the processing time of a packet in routers, and hence more efficient and fast IP address lookup algorithms and architectures are required in the next generation routers. Most of the previous IP lookup schemes compare routing prefixes of shorter length first with a given input IP address. Since IP address lookup needs to find the most specific route of the given input, search continues until the longest matched prefix is found while it keeps remembering the current test matching prefix. In this paper, based on binary search on prefix length, we proposed a new IP address lookup algorithm which compares longer prefixes first. The proposed scheme is consisted of multiple tries with prefixes on leaves only. The trie composed of the longest prefixes is primarily searched whether there is a match with the given input. This processing is repeated for the trio of the next longer prefixes until there finds a match. Hence the proposed algorithm provides the fast search speed. The proposed algorithm also provides the incremental update of prefixes while the previous binary search on length scheme does not provide the incremental update because of pre-processing requirement. In this paper, we performed extensive simulations and showed the performance comparisons with related works.