• Korean Journal of Social Welfare Studies
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• no.39
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• pp.315-342
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• 2008

The aim of this study was to examine growth trajectories of delinquent behaviors during adolescence. In addition, the effects of protective and risk factors that might account for individual difference in the level of delinquent behaviors and in the rate of change were examined. Four waves of data in the Korea Youth Panel Survey(KYPS) were used to analyze the linear growth modeling. The sample consisted of 3346 adolescents who were assessed at 4 measurement waves with approximately 1-year intervals. The results showed significant individual differences in both final level of delinquent behaviors and in the rate of change across 3 measurement occasions. Adolescent gender, family's socioeconomic background predicted the final level and the rate of change of delinquent behaviors. The protective effects of positive parenting and self-control were significantly associated with problem behaviors and the risk effects of the association with deviant peers and negative stigma were significant on the final level of delinquency. Self-control and deviant peer affiliation had differential influences over time significantly. Practice and policy implications as well as further research topic were discussed in the light of searching for important factors in preventing adolescent problem behaviors.

• The Journal of the Convergence on Culture Technology
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• v.5 no.4
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• pp.373-378
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• 2019

In the marine area, the salt concentration in the soil increases, and the inland heavy metal pollution increases the damage of plants. In the inland industrial development area, researches on the genetic resources of plants together with the heavy metal accumulation of Co, Ni, Zn, and so on are required. Both of these problems have caused scientists to work hard to find plants that are likely to cause stress in plant roots. In this study, seeds of Arabis stelleri var. japonica collected near the shore were used for germination. The growth and development and tolerance of both Arabis and Arabidopsis seeds were investigated under laboratory culture conditions. As a result, Arabis showed resistance about 3 times in 250 mM nickle and cobalt, and more than 4 times in 1 mM zinc when compared to Arabidopsis. The tolerance of Arabis to Na salts increased by 20% or more at 50 mM concentration and Arabis was resistant to heavy metals and salt concentration. The accumulation of Na ions in the body was measured as a preparation for studying the intracellular mechanism. As a result, it showed a further decrease in resistance to ground water roots. It is considered that the activity of the exporting gene is important rather than the mechanism of accumulation.

• The Journal of Korean Academy of Prosthodontics
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• v.57 no.4
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• pp.483-489
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• 2019

With development of digital dentistry, the 3-dimensional (3D) manufacturing industry using computer-aided design and computer-aided manufacturing (CAD/CAM) has grown dramatically in recent years. Denture fabrication using digital method is also increasing due to the recent development of digital technology in dentistry. The 3D manufacturing process can be categorized into 2 types: subtractive manufacturing (SM) and additive manufacturing (AM). SM, such as milling is based on cutting away from a solid block of materal. AM, such as 3D printing, is based on adding the material layer by layer. AM enables the fabrication of complex structures that are difficult to mill. In this case, additive manufacturing method was applied to the fabrication of the resin-based complete denture to a 80 year-old patient. During the follow-up periods, the denture using digital method has provided satisfactory results esthetically and functionally.

• Journal of Sericultural and Entomological Science
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• v.43 no.2
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• pp.77-82
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• 2001

This study was investigated to know the effects of diflubenzuron(DFB) on the larval silkgland development of the silk-worm, Bombyx mori (L.). It has been known as a prohibitor of chitin synthesis mostly on the species of the Order Lepidoptera. In this work, the effects of the DFB concentrations (2.5$\times$10$\^$-1/,2.5$\times$10$\^$-2/, and 2.5$\times$10$\^$-3/$\mu\textrm{g}$/$\mu$l on the various larval stages, were investigated in terms on the silkgland. The macro- and microstructure of cell membrane of silkgland, and the differences of silkgland weight and water contents treated by DFB are also surveyed. As the tesults, the silkgland weight depended sensitively on not the DFB concentration but the DFB treatment period. The longer DFB treatment period, the lighter dried silkgland weight and the heavier water content of the silkgland. White opaque(WO) emerged in the middle silkgland of DFB treated larva. From the scanning election microscope observation, the cell membrane of silkgland of DFB treated larva was distinctly more compact compared to that of control. The WO was evidently resulted from the obstacles of normal transformation of silk protein through the cell membrane of middle silkgland.

• Journal of Life Science
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• v.31 no.7
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• pp.641-653
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• 2021

The purpose of this study was to confirm the antifungal activity, plant growth-promoting activity, and mineral solubilizing activity of 18 types of bacteria isolated purely from rhizosphere soil. The potential of isolates of the genus Bacillus and Pseudomonas as biocontrol agents was confirmed through the antifungal activity of these isolates. This activity has been determined to be due to various hydrolytic enzymes on the cell wall of plant pathogenic fungi and the production of siderophores in isolates. In addition, most of the isolates have been found to have aminocyclopropane-1-carboxylate deaminase production activity, indole-3-acetic acid production activity, and nitrogen fixation activity. These characteristics are believed to have a positive effect on root development, growth, and the productivity of crops via a reduction in the concentration of ethylene under conditions of environmental stress, to which plants are commonly exposed. In addition, on testing for the solubilizing activity of the isolates for phosphoric acid, silicon, calcium carbonate, and zinc, some isolates were found to have mineral solubilizing activities. Inoculation of these isolates during plant growth is expected to assist plant growth by converting nutrients necessary for growth into usable forms that can be absorbed by plants. The 18 isolated strains can be used as biocontrol agents due to their antifungal activity, plant growthpromoting activity, and mineral solubilizing activity.

• Journal of vocational education research
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• v.35 no.4
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• pp.109-129
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• 2016

Korea has recently invested much of its effort in fostering talents in scientific fields to establish a foundation for sustainable future growth. From this perspective, the ministry of education has come up with a special rule aimed at achieving the substantiality of engineering schools in universities. The ministry has been providing educational support by providing a tech-innovation center, industry-oriented education, and policies such as PRIME. Despite this support, most students in the natural science field end up being hired in fields not related to their majors. There has been a growing opinion regarding the need for career education for these students. In this research, based on a social cognitive career theory (SCCT) model that provides a comprehensive understanding of career development, this research would like to practically examine the relationship among college students' career preparation behaviors and influencing variables, such as grit, career decision-making self-efficacy, outcome expectation, and major interest. Data from 153 natural-science majors at A college in Korea were collected and analyzed using path analysis. The result was that the data strongly supported the model explaining the relationship between career preparation behaviors and influencing variables. Based on this result, we propose that career education that can promote grit, career decision-making self-efficacy, outcome expectation, and major interest is required to encourage students in the field of the natural sciences to pursue career preparation behaviors related to their majors.

• Korean Journal of Breeding Science
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• v.43 no.5
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• pp.457-463
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• 2011

Plant specific gene family, NAC (NAM, ATAF, and CUC) transcription factors have been characterized for their roles in plant growth, development, and stress tolerance. In this study, we isolated OsNAC69 gene and analyzed expression level by inoculation of bacterial leaf blight pathogen, Xanthomonas oryzae pv. oryzae (Xoo). NAC transcription factor family can be divided into five groups (I-V). On the basis of phylogenetic analysis, OsNAC69 was fall into group II. OsNAC69 was strongly induced 1 hr after infected with Xoo. To investigate its biological function in the rice, we constructed vector for overexpression in rice, and then generated transgenic rice lines. Gene expression of OsNAC69-overexpressed transgenic rice lines were analyzed by northern blot. Analysis of disease resistance to pathogen Xoo, nine OsNAC69-overexpressed transgenic rice lines showing high expression level of OsNAC69 were shown more resistant than wild type. These results suggest that OsNAC69 gene may play regulatory role during pathogen infection.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.3
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• pp.291-297
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• 2019

The world's leading industrialized nations are improving their national science and technology capacity through the continuous expansion of national R&D investment and the improvement of performance in accordance with the trend of the fourth industrial revolution. As rapid technological development following technological convergence necessitates a preemptive response to a new paradigm, the importance of securing high technology that affects the national competitiveness is increasing day by day. Core technologies and future new technologies that affect national competitiveness can be seen as a measure to upgrade the nation's innovative capabilities. In particular, the core technologies and future new technologies to prepare for changes in a security environment and future battlefields are very important in the defense sector that develops weapons systems. In the defense sector, the core technologies based on the military weapons systems are identified, and future new technologies that use the best technologies of the private sector for national defense, not on the needs of develops weapons systems, are derived. This study examined the characteristics of core technology and future new technology of defense ground unmanned systems, conducted a comparative study through empirical analysis, and concluded that strategic technology planning and research and development are needed according to the core technology and future new technology characteristics.

• Resources Recycling
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• v.27 no.6
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• pp.23-29
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• 2018

Recently rapid economic growth and technological development have led to an increase in the generation of waste electrical and electronic equipment (WEEE). As the amount of electric and electronic waste generated increases, the importance of processing waste printed circuit boards (PCB) is also increasing. Various studies have been conducted to recycle various valuable metals contained in a waste PCB in an environmentally friendly and economical manner. To get anode slime containing Ag and Au, Anode copper prepared from PCB scraps was used by means of electro-refining. Ag and Au recovery was conducted by leaching, direct reduction, and ion exchange method. In the case of silver, the anode slime was leached at 3 M $HNO_3$, 100 g/L, $70^{\circ}C$, and Ag was recovered by precipitation, alkali dissolution, and reduction method. In the case of gold, the nitrate leaching residues of the anode slime was leached at 25% aqua regia, 200 g/L, $70^{\circ}C$, and Au was recovered by pH adjustment, ion exchange resin adsorption, desorption and reduction method. The purity of the obtained Au and Ag were confirmed to be 99.99%.

• Journal of Korea Port Economic Association
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• v.35 no.2
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• pp.21-36
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• 2019

To ensure that Korea continues to grow, past governments have been consistent in following a policy of advancing into Russia, Mongolia, and Eurasia. The northern economy can expect to achieve synergistic growth because its economic structure complements that of Korea, which has high energy demand and industrial development. There is also an opportunity to accelerate the growth of the China-Russia-Mongolia economic corridor, which is based on Russia's Look East Policy, China's One Belt One Road, and the Mongolian Steppe Road initiative. The Korean government is pursuing a New Northern Policy to achieve the goal of economic cooperation and peace building with other nations, including North Korea; this policy succeeds the Northern Policy pursued by the previous government. As international economic cooperation requires transportation infrastructure, the demand for shipping, which offers more advantages than road and rail transportation, will increase; thus, it is necessary to prepare for it. Korea's port cities, which have a port that serves as the nodal point for maritime transportation, need to prepare for the New Northern Policy. In this paper, the long-term development of Seosan-Daesan port in the was planned and the North Korea's opening-op plan was considered in accordance with the New Northern Policy. Because international cooperation between the government and the provincial cities is required, cooperation with the Port Authority is needed, along with the proactive attitude of Seosan City, Chungcheongnam-do. The Seosan-Daesan port, which is the center of the liquid energy cargo center, can become the base of the New Northern Policy Region; further, the port can be an opportunity to establish its position as a peaceful economic hub on the west coast of Korea.