• Title/Summary/Keyword: Long-distance migration

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The Urbanization and Migration in the Period of the Japanese Occupation (일제 강점기 도시화와 인구이동: 1930년 부(府)와 지정면(指定面) 지역을 중심으로)

  • Lee, Chung Sup
    • Journal of the Korean Geographical Society
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    • v.52 no.1
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    • pp.105-122
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    • 2017
  • The purpose of this study is to understand the urbanization process and identify the Origin-Destination(O-D) of migration in the period of the Japanese occupation, based on the census data about Bu and Jijung-myeon. For this, the study analysed the types and the location of the immigrants' origin(birthplace) whose headed for an urban area. In 1930, as the destinations in the inter-regional migration, the urban areas could be divided into three categories according to the distance: long-, medium- and short-distance. The new urban areas which developed for effective colonial rule by Japanese pulled the long distance immigrant across the Korean Peninsula, and the Chosun Dynasty's traditional cities had the inflow of population from the near and hinterland. All in all, it is proposed that the dual settlement systems of colonial and traditional structures, is the key to understand the Korean urbanization processes basedd on the inter-regional migration during Japanese colonial period.

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A Model to Estimate Population by Sex, Age and District Based on Fuzzy Theory

  • Pak. Pyong-Sik;Kim, Gwan
    • 제어로봇시스템학회:학술대회논문집
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    • 2002.10a
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    • pp.42.1-42
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    • 2002
  • A model to predict population by sex, age and district over a long-range period is proposed based on fuzzy theories. First, a fuzzy model is described. Second, a method to estimate the social increase by sex and age in each district is proposed based on a fuzzy clustering method for dealing with long-range socioeconomic changes in population migration. By the proposed methods, it became possible to predict the population by sex, age and district over a long-range period. Third, the structure and characteristics of the three models of employment model, time distance model, and land use model constructed to predict various socioeconomic indicators, which are require...

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A Study on the Metallic ion Migration Phenomena of PCB (PCB의 금속 이온 마이그레이션 현상에 관한 연구)

  • Hong Won Sik;Kang Bo-Chul;Song Byeong Suk;Kim Kwang-Bae
    • Korean Journal of Materials Research
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    • v.15 no.1
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    • pp.54-60
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    • 2005
  • Recently a lots of problems have observed in high densified and high integrated electronic components. One of them is ion migration phenomena, which induce the electrical short of electrical circuit. ion migration phenomena has been observed in the field of exposing the specific environment and using for a long tin e. This study was evaluated the generation time of ion migration and was investigated properly test method through water drop test and high temperature high humidity test. Also we observed direct causes and confirmed generation mechanism of dendritic growth as we reproduced the ion migration phenomena. We utilized PCB(printed circuit board) having a comb pattern as follows 0.5, 1.0, 2.0 mm pattern distance. Cu, SnPb and Au were electroplated on the comb pattern. 6.5 V and 15 V were applied in the comb pattern and then we measured the electrical short time causing by ion migration. In these results, we examined a difference of ion migration time depending on pattern materials, applied voltage and pattern spacing of PCB conductor.

Development of a model to forecast the external migration rate in development projects reflecting city characteristics

  • Kim, Ki-Bum;Park, Joon;Seo, Jee-Won;Yu, Young-Jun;Hyun, In-Hwan;Koo, Ja-Yong
    • Environmental Engineering Research
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    • v.23 no.4
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    • pp.406-419
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    • 2018
  • In planning public service systems such as waterworks, the design population is very important factor. Owing to the limitations of the indirect method, two new models, which take into consideration urban characteristics, were developed to accurately predict external migration rate (EMR), which is an essential component in estimating reliably the design population. The root mean square error (RMSE) between the model values and observed values were 10.12 and 15.58 for the metropolitan cities and counties respectively and were lower compared to RMSE values of 27.31 and 28.79 obtained by the indirect method. Thus, the developed models provide a more accurate estimate of EMR than the indirect method. In addition, the major influencing factors for external migration in counties were development type, ageing index, number of businesses. On the other hand, the major influencing migration factors for cities were project scale, distance to city center, manufacturing size, population growth rate and residential environment. Future medium and long-term studies would be done to identify emerging trends to appropriately inform policy making.

The Characteristics of Population Flows in kwangju Metropolitan Area (光州 中心의 人口移動 特性에 관한 硏究)

  • Chouh, Hae-Chong
    • Journal of the Korean Geographical Society
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    • v.28 no.1
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    • pp.40-57
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    • 1993
  • This paper aims to show the various aspects of migration in Kwangju merropolitan area, southwestern Korea, for a period of years 1980-1985. Migratory patterns are spatially extensive in countryside around Kwanfju, and due to high accessibility to the metropolitan area urban implosion emerges in the city. In Chonnam province where Kwangju is loca-ted, all cities and counties except for such in-dustrial areas as Yochon, and Kwangyang are experiencing population losses in terms of net migration by survival rate methods. Kwangju is the exceptionally one of in-migration areas in Chonnam, though its central part(Dong-Gu) is also an out-migrated area. Predominantly in-migration urban areas have high proportions of a student age group between 15-19 years, and that reflects the importance of the educational factor in migration analysis. The municipal authorities of Kwangju are planning to block the way of the middle sxhool students who live in the outskirts of Kwangju to entrance to high school in the city. Thant may stir up migrations into Kwangju for the elementary and middle school students, because the city id expected to provide educational opportunities higher and better than remaining Chonnam areas. Population of Kwangju would, therefore, grow as the students migrate into the city. The findings on the residential intra-city movement in selected 5 Dongs indicate that implications of a short-distance movement re noteworthy; neighbour to neighbour, and the nearest stop in the way from the outer Kwangju as well. Trends in a short-distance movement are in accord with Ravensteins's "law of migra-tion". But in casw of the inter-provincial migra-tion to Kwangju, the number of in-migrants from remoter Seoul is more than that from nearer Chonbuk province. Therefore it supports the fact that the movement between capital region and far off local cities overcomes a distance barrier. The temporary mobility for a day has been increased as the standard of living has improved and it reaches a peak on weekend or on con-secutive holidays. The number of temporal movers to Kwangju from capital region and Yongnam area, southeastern Korea has a greatincrease in terms of the frequency of the passengers' mobility, in particular on Myongjol(the ethnic and traditional festival day) in com-parison with on weekdays. By comparison with two largest Myongjols, the number of movers is more on Chusok(The Full Moon festival on lunar August) than on Sol (lunar new year's day). Annual peak point of weekday movers appears in August because of summer vacation. But the lowest one appears in June, which is related to the busy farming season. A patients' move for medical services in on the increase with a change of living conditions. It is especially true in the industrial counties such as Kwangyang and Yochon. By way of conclusion, it should be pointed out that one of the problems we face in survey of migration volume by the survival rate method is that the survival rate somtimes exceeds the value 1.0, in normal states of which should be under 1.0. it may be due to the shortcoming from the census statistics. We should not give therefore too much stress on the importance of migrations or moves as an element of changes in spatial pattern. In cinclusion, the results of the study show some geographic facts as the followings: 1. One of the outstanding phenomena in all types of movement is the seletivity of ages. The most important factors are related to education and employment. 2. Short-distance movement is carried out in accordance with Ravenstein's law, but in case long-distance movement, in-migration from capital region is prominent in spite of remoten-ces. The gravity between large cities such as Kwangju and Seoul, which has a frequent human movenent, causes urban implosion of small cities between those cities. 3. The temporary mobility for a day, in con-trast to that of permanent movement, is more related to transportation, and its volumes and annual variations are a large-scale. 4. Passengers' mobility is high in industrial cities. And the scope of patients' mobility is narrower than passengers'.

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Electrochemical Ion Migration Sensitivity of Printed Circuit Board Plated with Sn-3.0Ag-0.5Cu and Sn-37Pb (Sn-3.0Ag-0.5Cu, Sn-37Pb 표면처리 기판의 전기화학적 이온 마이그레이션 민감도)

  • Hong, Won-Sik;Park, No-Chang;O, Cheol-Min;Kim, Gwang-Bae
    • Proceedings of the KWS Conference
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    • 2006.10a
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    • pp.136-138
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    • 2006
  • Recently a lots of problems have observed in high densified and high integrated electronic components. One of them is ion migration phenomena, which induce the electrical short of electrical circuit. Ion migration phenomena has been observed in the field of exposing the specific environment and using for a long time. Also as the RoHS restriction was started in July 1st, 2006, Pb-free solder was utilized in electronics assemblies. In this case, it is very important to compatible between components and printed circuit board(PCB), thus surface treatment materials of PCB was changed to Sn, Sn-3.0Ag-0.5Cu, Cu. Therefore these new application become to need to reevaluate the sensitivity about electrochemical ion migration. This study was evaluated the occurrence time of electrochemical ion migration using by water drop test. We utilized PCB(printed circuit board) having a comb pattern as follows 0.1, 0.318, 0.5, 1.0 mm pattern distance. Sn-3.0Ag-0.5Cu and Sn-37Pb were electroplated on the comb pattern. 6.5V and 15.0V were applied in the comb pattern and then we measured the electrical short time causing by occurring the ion migration. In these results, we evaluate the sensitivity and derived the prediction models of ion migration occurrence time depending on the pattern materials, applied voltage and pattern spacing of PCB conductor.

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A Trial Using a Micro Chip for Horse Identification (경주마에 있어서 개체감별을 위한 Micro Chip의 이용에 대하여)

  • Lim Young-Jae;Lee Soo-Deuk;Lee Shi-Young;Bak Ung-Bok
    • Journal of Veterinary Clinics
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    • v.9 no.1
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    • pp.317-322
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    • 1992
  • This trial is concerned with practical application of a M. C. that was injected Into the horse's muscle in order to make a effective identification by computer compatible. Following results were obtained through the study of histopathologic changes, migration of M. C. and possible problems about practical application. 1. Muscle romboideus cervicalis(site 'A') was thought to be the best Injection site of M. C. in the horse. 2. There were no the exact interface between the M. C. and surrounding tissue. It seemed to be why the implanted transponder was located in the muscle fascia. 3. No evidence of migration in the tissues was found through the radiographs taken after implantation 4. There were no clinical disorder and interference with racing performance. 5. ID 100 from Trovan, Co. had some advantages comparing with TX 1400 L from Destron, Co. These are, for instance, the long readout distance and the easy application of computer in the field practive.

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A Study on the Effects of Migration History on Tenure Choice : Focusing on the Determinants and Relationship between Migration Typology and Housing Choice (이주 유형이 자가소유에 미치는 영향에 관한 연구 : 결정요인과 이동유형 별 주거선택과의 연계성을 중심으로)

  • Chun, Jin-Hong;Lee, Seong-Woo
    • Journal of the Korean association of regional geographers
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    • v.13 no.6
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    • pp.651-673
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    • 2007
  • In the studies on residential move, there has been tendency of dichotomy where short distance moves are largely caused by housing to adjust to changes in households while long distance moves are induced by shift in labor market. However, some empirical studies have proven that residential move is so complex process that the simple dichotomy should be elaborated. In this sense, the present study seeks to identify compounded course of residential move in Korea. In determining migration history, families with younger householders, renters, householders with higher educational attainment and smaller households show a higher probability to move. In case of mobility, women were more prone to move compared to man. Women compared to man, older age augmented the probability to own a house after migration. Families with householders following an occupation of sales and technical service showed lowest tendency to own houses while it marked the highest in the group of professionals. Higher land price of a region was negatively related to owning houses after migration. The present study revealed that factors in macro level as well as micro level significantly affect the move of individuals with varying effects in accordance with migration history.

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Spatio-temparal Pattern Formation of Abdominal Muscle in Xenopus Iaevis

  • Ko, Che-Myong;Chung, Hae-Moon
    • Animal cells and systems
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    • v.1 no.2
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    • pp.329-335
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    • 1997
  • The final pattern of the skeletal muscle of a vertebrate depends on the position-specific behavior of the muscle precursor cells during early developmental process and the abdominal muscle is made of cells which migrate a relatively long distance from their original tissue, myotome of dorsal mesoderm. We report the spatia-temporal migration pattern of abdominal muscle in Xenopus laevis by in situ hybridization and immunohistological studies. Shortly after hatching tadpole stage (stage 31/32), a group of myotomal cells detaches from the lower tip of the second somite and migrates ventrally to the lower position of abdomen. At stage 34/35, a second cell group migrates away from the third somite. Total 7 myotomal cell groups migrate ventrally one by one from the second to eighth myotome along their own pathways through the cell free space located between epidermis and subepidermal layer of the abdomen. During migration, the sizes of the cell groups (abdominal muscle anlagens) are increased to several tens fold. Around stage 40 all the abdominal muscle anlagens reaches their final positions and are interconnected side by side rostrocaudally. They are also connected to other types of muscles, forming a large multisegmented abdominal muscle. Heat shock study suggests that the disruption of segmentation of somites does not block the detachment of abdominal muscle anlagen, though the treatment gave stage- and dosagedependent effects on the migration speed.

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The use of animal models in rheumatoid arthritis research

  • Jin-Sun Kong;Gi Heon Jeong;Seung-Ah Yoo
    • Journal of Yeungnam Medical Science
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    • v.40 no.1
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    • pp.23-29
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    • 2023
  • The pathological hallmark of rheumatoid arthritis (RA) is a synovial pannus that comprises proliferating and invasive fibroblast-like synoviocytes, infiltrating inflammatory cells, and an associated neoangiogenic response. Animal models have been established to study these pathological features of human RA. Spontaneous and induced animal models of RA primarily reflect inflammatory aspects of the disease. Among various induced animal models, collagen-induced arthritis (CIA) and collagen antibody-induced arthritis (CAIA) models are widely used to study the pathogenesis of RA. Improved transplantation techniques for severe combined immunodeficiency (SCID) mouse models of RA can be used to evaluate the effectiveness of potential therapeutics in human tissues and cells. This review provides basic information on various animal models of RA, including CIA and CAIA. In addition, we describe a SCID mouse coimplantation model that can measure the long-distance migration of human RA synoviocytes and cartilage destruction induced by these cells.