• Korean Journal of Social Welfare
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• v.63 no.2
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• pp.233-260
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• 2011

This study intends to analyze the trend of employment rate of men aged 55~64 in 15 OECD countries from 1980 to 2005. Furthermore, this study means to examine the determinants of men aged 55~64 in 15 OECD countries to support the labor force participation among them. The analysis is based on the data of OECD, ILO and LIS. The analysis method is Arellano and Bond(1981)'s difference GMM which used instrumental variables by dynamic panel model which estimates state dependency of labor market participation and individual panel's heterogeneity. The main results from this analysis are summarized in three points. First, the employment rates of men aged 55~64 had decreased until the middle of the 1990s, while that has been increasing since 1995. Second, the sate dependency strongly worked in the employment rates of 55~64 men and positive period effect was observed for 1980~2005. This study cannot find the pull effect of public pension, while labor market push effect have negatively affected. Third, temporary work rates had contributed to increase the employment rate of men aged 55~64 for 1996~2005. The poverty has become the mechanism of the labor.

• Tunnel and Underground Space
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• v.15 no.6 s.59
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• pp.432-440
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• 2005

Baehuryeong tunnel connects Chuncheon with Hwacheon in Kangwon, Korea, This tunnel is a single tunnel with 5,057 m long and two bidirectional lanes which will be extended into low lanes in the future. The estimated construction period of Baehuryeong tunnel is approximately 55 months. This tunnel will become the longest bidirectional roadway tunnel in Korea. Compared to a twin tunnel, a bidirectional single tunnel has two major disadvantages with regard to the ventilation system and ease of escape during fire. For these reasons, a service tunnel and the transverse ventilation system are planned first time in Korea. In case of fire, the tunnel ventilation design aims to maintain a smoke free layer for passenger evacuation. The geology of Baehuryeong tunnel site is mainly composed of gneiss and granite. Baehuryeong fault is a mainly large scale fault which stands vertical and parallels with tunnel direction. The influenced zone of this fault is within 70 m. Baehuryeong tunnel was designed that it was separated with the distance of more than 100 m from Baehuryeong fault for its safety.

• The Korean Journal of Zoology
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• v.38 no.3
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• pp.348-355
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• 1995

This Investigation was carried out to map the morphological development of serotonin-immunoreactive neurons in the larval brain of the cabbage butterfly, Artogeia rapae, during five larval stages. Both the first instar larva and the second instar larva contained twenty serotonin-immunoreactive (5-HTi) neurons in each brain. The fibres of 5-HTI commissure was interconnected to two cerebral hemispheres in both brains. However, the 5-HTi commissural fibres was Increased in number in the second-instar larva brain. In the brain of the second Insar larva these 5-HTi fibres formed rich arborization in contralateral neuropils, especially In the posterior parts of it. The third-Instar larva braIn, which Included twenty two 5-HTi neurons, had three groups of 5-HTi commissural fibres. In the fourth Instar larva, the number of 5-HTi fibres as well as 5-HTi cell bodies increased in the brain. The fifth-instar larva brain, which contained fifty four 5-HTi cell bodies, showed the largest number of 5-HTi cell bodies In developing larval brains. The 5-HTi fibres formed richest commissural fibres and some of them run parallel to anteroposterior axis.

• Survey Research
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• v.12 no.2
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• pp.1-26
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• 2011

Mortality for oldest-old age (aged 80 or over) in Korea has never been studied mainly due to lack of data leaving its quality aside. The rapid aging recently occurring in Korea, which no other country has never experienced, must introduce a drastic change in the structure of future population pyramid, requring a careful investigation on mortality level, pattern, and trend for the oldest-old age in Korea. For mortality trend, we need to extend the past mortality data, which has provided only an open-ended age interval 80 or 85 years and over, to age-specific mortality up to 115 years old. A prerequisite for such an extension is constructing a Korean standard mortality by which one can figure out the mortality level and pattern of the oldest-old age. A Korean standard mortality is proposed by applying one relational model and eleven functions from which we select best models for each sex in terms of three measures of fits and three consistencies of mortality. Then we extend the mortality of the open-ended age intervals by providing a method to avoid the longitudinal consistency of mortality.

• Korean journal of applied entomology
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• v.27 no.4
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• pp.219-224
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• 1988

Rearing of Spodoptera litura fed on arfificial diet basically formulated with kindby bean powder was much promisible for production of S. litura nuclear polyhedrosis virus(SINPV) than that on kidney bean leaves. The $LC_{50}$ of SINPV against 3rd and 5th instar were $4.48{\times}10^{3}$ PIB/ml and $4.52{\times}10^{4}$ PIB/ml, respectively. The $LC_{50}${/TEX} of SINPV varied from 5.8 days to 7.7 days at higher inocula in the testes. The larval growth of 1st and 3rd instar larvae fed on virus were much delayed and the larval were killed within 4th instar in the former and within 5th instar in latter. S. litura larvae were very susceptible to multinucleocapsid nuclear polyhedsosis virus (MNPV) of Autographa californica, S. littoralis and Trichoplusia ni.

• Korean Journal of Heritage: History & Science
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• v.53 no.2
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• pp.156-179
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• 2020

The Preservation Decree (1933) is the basic law relevant to the conservation of cultural property of colonial Chosun, and invoked clauses from the Old History Preservation Act (1897), the Historic Scenic Sites Natural Monument Preservation Act (1919), and the National Treasure Preservation Act (1929), which were all forms of Japanese Modern Cultural Heritage Law, and actually used the corresponding legal text of those laws. Thus, the fact that the Preservation Decree transplanted or imitated the Japanese Modern Cultural Heritage Law in the composition of the constitution can be proved to some extent. The main features and characteristics of the Preservation Decree are summarized below. First, in terms of preservation of cultural property, the Preservation Decree strengthened and expanded preservation beyond the existing conservation rules. In the conservation rules, the categories of cultural properties were limited to historic sites and relics, while the Preservation Decree classifies cultural properties into four categories: treasures, historic sites, scenic spots, and natural monuments. In addition, the Preservation Decree is considered to have advanced cultural property preservation law by establishing the standard for conserving cultural property, expanding the scope of cultural property, introducing explicit provisions on the restriction of ownership and the designation system for cultural property, and defining the basis for supporting the natural treasury. Second, the Preservation Decree admittedly had limitations as a colonial cultural property law. Article 1 of the Preservation Decree sets the standard of "Historic Enhancement or Example of Art" as a criteria for designating treasures. With the perspective of Japanese imperialism, this acted as a criterion for catering to cultural assets based on the governor's assimilation policy, revealing its limitations as a standard for preserving cultural assets. In addition, the Japanese imperialists asserted that the cultural property law served to reduce cultural property robbery, but the robbery and exporting of cultural assets by such means as grave robbery, trafficking, and exportation to Japan did not cease even after the Preservation Decree came into effect. This is because governors and officials who had to obey and protect the law become parties to looting and extraction of property, or the plunder and release of cultural property by the Japanese continued with their acknowledgement,. This indicates that cultural property legislation at that time did not function properly, as the governor allowed or condoned such exporting and plundering. In this way, the cultural property laws of the Japanese colonial period constituted discriminative colonial legislation which was selected and applied from the perspective of the Japanese government-general in the designation and preservation of cultural property, and the cultural property policy of Japan focused on the use of cultural assets as a means of realizing their assimilation policy. Therefore, this suggests that the cultural property legislation during the Japanese colonial period was used as a mechanism to solidify the cultural colonial rules of Chosun and to realize the assimilation policy of the Japanese government-general.

• The Korean Journal of Pesticide Science
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• v.17 no.3
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• pp.206-212
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• 2013

This study was examined for activity of aggregation pheromone fish net trap with residual effect of insecticides against Riptortus pedestris. Time of escape was from aggregation pheromone fish net trap researched 49.74 min ($ET_{99}$) and 65.01 min ($ET_{99}$) with 1st and 2nd instar nymph respectively. Six insecticides for the stink bugs were treated to 3 different materials (wood, metal and plastic). Bifenthrin and fenitrothion were showed 100% insecticidal activity at 48 h to all developmental stage of R. pedestris. Residual effect of bifenthrin and fenitrothion on plastic material were showed 100% insecticidal activity over 15 day after treatment with 1st, 3rd instar nymphs and adults except 5th instar nymph. In field test using plastic material trap with two pesticides, 1st instar nymphs and adults were showed 100% mortality until 10 day after treatment. These results indicate that R. pedestris might be managed using aggregation pheromone trap with insecticides.

• Korean journal of applied entomology
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• v.51 no.4
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• pp.461-467
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• 2012

Developmental characteristics of Geocoris pallidipennis were investigated at a constant temperature ($20{\pm}1$, $25{\pm}1$, $30{\pm}1$, $35{\pm}1$, $37.5{\pm}1$ and $40{\pm}1^{\circ}C$), under long day illumination 16:8 (L:D) and constant relative humidity ($80{\pm}10%$). From egg to adulthood, the lower developmental threshold and the effective accumulative temperature were $14.8^{\circ}C$ and 399.1 day-degree, respectively. The experimental results at $35^{\circ}C$ were as follows. The egg period was 5.6 days (hatchability: 81.1%) and the nymphal period was 14.3 days (1st: 3.2, 2nd: 2.2, 3rd: 2.7, 4th: 2.7, 5th: 3.6). Female longevity was 33.8 days and the oviposition period was 29.2 days. Total egg production was 111.2 eggs and the maximum daily egg production was 14.8 eggs (in 7th days). However, although some eggs and nymphs developed at $37.5^{\circ}C$, G. pallidipennis could not develop at $40^{\circ}C$, The total egg production at $40^{\circ}C$ was only 22.1 eggs. When G. pallidipennis was fed on Bemisia tabaci pupae, daily prey consumption by nymphs (1st, 3rd and 5th) and adults was 1.9, 7.3, 18.7 and 29.5, respectively.

• Journal of agriculture & life science
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• v.50 no.1
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• pp.117-124
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• 2016

Researches on soil microbial community are increasing to assess ecosystem responses to anthropogenic disturbances and to provide an indicator of ecosystem recovery. Microbial communities are able to respond more rapidly to environmental changes than plants and therefore they may provide an early indication of the ecosystem recovery trajectory. This study was conducted using 16S rRNA gene pyrosequencing of soil samples to compare soil bacterial community composition between artificially covered soils of the Baedudaegan ridgeline and their adjacent forest soils in two restoration project sites, Ihwaryeong and Yuksimnyeong, which were completed in 2012 and 2013, respectively. Richness of the Phylum level was 29.3 in Ihwaryeong and 32.3 in Yuksimnyeong. Significant difference in the richness between artificial restored soils and adjacent forest soils(p<0.01) was observed, however no significant difference was observed for site location and soil depth. Acidobacteria(37.3%) and Proteobacteria(31.1%) were more abundant than any other phylum in collected soil samples. Also, we found the significant difference in the relative abundance of the two abundant phyla between artificially restored soils and their adjacent forest soils (Proteobacteria, 38.1% in restored soils vs 24.2% in adjacent forest soils, p<0.01; Acidobacteria, 55.4% in restored soils vs 19.2% in adjacent forest soils, p<0.001). The results support the previous researches indicating that soil bacterial community composition is affected by nutritional status of soils and that Acidobacteria is also strongly influenced by pH, thus favoring soils with lower pH. This study could be utilized to monitor and evaluate restoration success of forest soil environment quantitatively.

• Journal of Life Science
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• v.18 no.12
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• pp.1728-1732
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• 2008

This study was performed to investigate the bionomical characteristics of Luciola lateralis in Korea. Imago's longevity of female was $17.5{\pm}0.7$ and male was $20.6{\pm}1.0$ days at $23^{\circ}C$, R.H. 80%, and significant difference was not occurred in breeding density. Pre-oviposition period was a pair $2.8{\pm}1.5$, two pairs $2.5{\pm}1.5$, three pairs $1.7{\pm}0.7$, four pairs $1.3{\pm}0.5$ days and pre-oviposition period was shorten in higher breeding density. The mean of laying eggs was $248.9{\pm}80.7$, was not related breeding density. Daily oviposition rate was 1st day 20.8%, 2nd 17.3%, 3rd 14.3%, 4th 12.7%, 5th 7.0%, the rate was highest in 1st day and gradually reduced. Egg period was $21.8{\pm}0.7$ days and hatchability was $95.5{\pm}4.8%$. Larval instar was identified the 9th instar, the evidence was able to its skin and marking pattern. Larval period of each instar was 1st $1.0{\pm}0.1$, 2nd $3.3{\pm}0.2$, 3rd $10.2{\pm}1.0$, 4th $6.8{\pm}0.5$, 5th $6.9{\pm}2.0$, 6th $15.4{\pm}4.1$, 7th $18.3{\pm}5.9$, 8th $25.8{\pm}8.7$, 9th $31.2{\pm}13.2$ days. Matured 9th larva was made of cocoon during $2.8{\pm}0.8$ days and pre-pupal, pupal period was $4.6{\pm}0.9$, $5.6{\pm}0.7$ days. Imago was made hard hind wing during $3.8{\pm}0.4$ days in cocoon and come out.