• Journal of Korea Water Resources Association
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• v.33 no.5
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• pp.561-568
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• 2000

The dimension of the fishlock at the Youngam Lake is 6.6m wide and 30m long, and it has been used for both fish migration and ship passage. The capacity of attraction freshwater is $0.172\;\textrm{m}^3/s$, and the water depth of the fishlock varies between 1.9m - 5.7m due to the tide. Fishes were sampled weekly by using 3m wide maze net from April to June, 1999, and by using purse seine covering the entire space of fishlock from July to November, 1999. 116,014 samples were comprised of 25 species, and 99.5% of the samples were 10 kinds of diadromous fishes. The order of the diadromous fishes in abundance was Hemirhamphus kurumeus, Hypomesus olidus, Coilia ectens, and Mugil cephalu, where these four species consist 99% of the individuals, and the other six species contribute only a few of individuals. Each species had unique peak migration period. The peak migration of Hypomesus olidus, Mugil cephalus, Coilia ectens, and Hemirhamphus kurumeus happened on July 20, July 15, May 10, and May 1, respectively.tively.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.46 no.5
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• pp.649-652
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• 2013

Distribution and migration of larval and juvenile sandfish Arctoscopus japonicus in the coastal waters off Gangwondo were determined monthly from samples collected by a rectangular bottom net in the coastal waters off Gangwondo from March to July, 2011. Fish were collected in abundance from the northern waters from March to June. The average total length (${\pm}SD$) was $11.5{\pm}1.6$ mm in March increased up to $53.5{\pm}3.3$ mm in June. The size distribution of sandfish by depth suggested that the fish grew waters less than 50 m deep until June, before moving deeper waters of around 100 m.

• Journal of Technology Innovation
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• v.13 no.2
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• pp.71-95
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• 2005

This study aims to explore and understand the role of return migrants in the regional innovation system of a transition economy (China) by analyzing the activities of returning entrepreneurs in two emerging high-tech industries in Shanghai. The empirical analysis is based on in-depth interviews with founders of high-tech companies and experts in Shanghai. The results of the analysis reveal that return migrants are a significant factor for the Shanghai innovation system, which is presently in a transition from a former manufacturing site to a metropolitan region comprising a range of industries (including high-tech) and services. First of all, return migrants are important for the Shanghai RIS in terms of numbers. Second, they engage in activities in the medium range of high-tech which reflects prevailing weaknesses of the framework conditions for innovation in Shanghai. However, due to their international background, returning entrepreneurs are able to overcome these weaknesses, and thus contribute to the development of high-tech industries in Shanghai and to a reduction of the technological lock-in.

• The Journal of the Korean dental association
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• v.55 no.6
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• pp.388-399
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• 2017

Generalized aggressive periodontitis cause intrabony pocket, loss of teeth, and severe alveolar bone defect. As a result, pathologic tooth migration occurs and esthetic problem happens according to this, especially on the anterior teeth of maxilla. The purpose of this study was to assess the multidisciplinary treatment including periodontics, orthodontics and prosthetics of a patient caused by generalized aggressive periodontitis. This study presents a case using full mouth periodontal treatment, immediate orthodontic treatment for 5 months, implantation with guided bone regeneration and free gingival graft, and prosthetic treatment. Treatments took totally 14 months. Periodontal indicators such as probing pocket depth, bleeding on probing, tooth mobility improved. Also, the patient was satisfied with the esthetic and functional improvement.

• Journal of Agricultural Extension & Community Development
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• v.18 no.4
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• pp.729-764
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• 2011

The purpose of this study is to look into current situations of urban-to-rural migrants' community participation and its relationship with rural life satisfaction. This topic is important because one of the main barriers to migration decision is job availability, especially in rural areas. Besides, rural areas need more human resources to support aging communities, as rural population is constantly decreasing. For this study, we used the methods of survey and in-depth interview with structured questionnaire. We met 121 respondents who were in community participation activities by the snowball sampling method in 10 counties nationwide. As a result, we identified community participation activities could contribute to urban-to-rural migrants' stable settlement and improving their satisfaction with rural lives.

• Nuclear Engineering and Technology
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• v.40 no.5
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• pp.429-438
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• 2008

The objective of the present study is the depth and layout optimizations of a single layer, high level radioactive waste repository in a discontinuous rock mass with special joint set arrangements. A single layer repository model, considering variations in the repository depths, pitches, and tunnel spacings, is used to analyze the thermomechanical interaction behavior. It is assumed that the repository is constructed in saturated granite with joints; the PWR spent fuel in a disposal canister is installed in a deposition drift which is then sealed with compacted bentonite; and the backfill material is filled in the repository tunnel. The decay heat generated by the high level radioactive wastes governs the thermomechanical behavior of the near field rock mass of the repository. The temperature and displacement behavior of the repository is influenced more by the pitch variations than the tunnel spacing and repository depth. However, the stress behavior is influenced more by the repository depth variations than the pitch and tunnel spacing. For the final selection of the tunnel spacing, pitch, and repository depth, other aspects such as the nuclide migration through a groundwater flow path, construction costs, operation costs, and so on should be considered.

• Korea journal of population studies
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• v.31 no.2
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• pp.133-155
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• 2008

The purpose of this study is to examine the pattern and characteristics of population movement in Kangwon province. The data for this study were drawn from in- out- migration data established by Korea National Statistical Office(KNSO) between 2000 and 2007. Sample survey and depth interview were also used. The results showed that the population of all Si and Gun except Choonchun and Wonju declined. This decline of population in Kangwon province persisted during the last decades. The decline started with the industrialization in the 1960s and 1980s. The decline of population in Kangwon province continued in the 1990s and 2000s with the open agriculture policy rooted in UR and FTA. All Si and Gun can be classified into five groups in terms of population movement in Kangwon province between 2000 and 2007. The first group(Group B) is where in-migration from other Si and Gun and out-migration to Seoul and Kyunggi continues in the period. Choonchun, Wonju, and Sokcho belong to this category. The second group(Group C) is where out-migrarion to Seoul and Kyunggi is larger the in-migration. It includes Cholwon, Taebaek, Donghae, and Samchok. The third group(Group D) is where out-migration to Group B is larger than that of other places. Hwachun, Pyungchang, Hoegsung, Gosung, and Hongchun are included in this group. The fourth group(Group E) is where out-migration to both Group B and Seoul & Kyunggi is large. Youngwol, Gangnung, and Chungsun belong to this category. The fifth group(Group F) is where few population movement occurs. It includes Yangyang, Yanggu, and Injae. The findings also shows that the extent of population movement to Choonchun and Wonju is larger than that of Seoul and Kyunggi in recent period. This finding indicates that the effect of base city like Choonchun and Wonju has become in recent years.

• Korean Journal of Ecology and Environment
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• v.42 no.1
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• pp.58-66
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• 2009

The telemetry of eight adult manchurian trouts (Brachymystax lenok tsinlingensis) in the upper part of the Nakdong River, which is the southern limit of distribution of manchurian trout on the Korean peninsula, was used to examine migration patterns and evaluate characteristics of over-wintering and the spawning season between December, 2007 and May, 2008. Based on the tracking data, the tagged fish showed a limited migration between adjacent pools, moving only up to $8.6m\;day^{-1}$ during the winter season (December to February). Hydraulic conditions of over-wintering pool areas were, ca. 1m depth, slow moving surface water with areas of sand and gravel. The migration of tagged individuals was successful, moving up to $96.2m\;day^{-1}$ during the spawning season. Two tagged individuals (BL4, BL6) exhibited upstream migration, whereas others showed downstream movements. The timing of upstream migration of the two individuals was consistent with an increasing phases of water level and discharge. The fishes migrating toward the down stream moved to the wide pool areas downstream, where they spent the summer season for the growth.

• Journal of the Korean Regional Science Association
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• v.36 no.3
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• pp.17-27
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• 2020

Baby boomers are the population group born between 1955 and 1974 in South Korea. They are the generation to grow up in the rural areas and it has been reported in the previous literature that a large part of baby boomers now hopes to return their hometowns after their retirement. The purpose of this study is to investigate factors that obstruct the baby boomers' residential relocation to their hometowns by in-depth interviews with three different types of baby boomers: returners, soon-to-be returner, and wanna-be returner. Findings of this study show that the reasons behind the hesitation to the migration may be grouped into four categories: concerns about insufficient jobs, lack of medical services, concerns about social relation network and poor cultural environment in their hometown.

• Journal of the Korean Vacuum Society
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• v.9 no.3
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• pp.221-226
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• 2000

After manufacturing the electrochromic device (structure: ITO glass/$WO_3$/electrolyte/$V_2O_5$/ITO;glass) by using of sol-gel process and evaporation, optical properties and migration effect were investigated. The result shows that electrochromic device with heat treated (at water vapor ambient, $500^{\circ}C$, 1 hour) sol-gel coated $WO_3$ and $V_2O_5$ films had the highest transmittance variance. Electrochromic devices are based on the reversible insertion of guest atoms into structure of the host solid. But after cyclic operation, we find that the tungsten in $WO_3$ film and the indium in ITO film were migrated with each other. For the purpose of blocking migration, tungsten barrier film is inserted between ITO and $WO_3$ film. The result of cyclic voltamogram and the Auger depth profile show that the peak separation of cyclic voltamogram is reduced to below 1/10 and we could effectively block the indium and tungsten migration that is caused by flow of Li ions.