• 제목/요약/키워드: Collective migration

검색결과 22건 처리시간 0.032초

한국(韓國)의 급격(急激)한 이촌향도형(離村向都型) 인구이동(人口移動)과 농촌경제(農村經濟) (Rapid Rural-Urban Migration and the Rural Economy in Korea)

  • 이번송
    • KDI Journal of Economic Policy
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    • 제12권3호
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    • pp.27-45
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    • 1990
  • 이촌향도형(離村向都型) 인구이동(人口移動) 농촌지역경제(農村地域經濟)에 미치는 영향(影響)에 관해 두가지 상반(相反)된 견해(見解)가 있다. 신고전학파적(新古典學派的) 낙관론(樂觀論) 따르면 이농현상(離農現象)은 농촌지역(農村地域)의 소득(所得)이나 후생수준(厚生水準)을 저해(沮害)하지 않는다고 보는 반면 Lipton (1980)은 그 반대의 견해(見解)를 취하고 있다. 본고(本稿)에서는 비교역재(非交易財)(nontraded goods)에 대한 국제무역이론(國濟貿易理論)과 화란병(和蘭病)(Dutch Disease)의 이론(理論)을 원용하여 농촌(農村)에서 도시(都市)로의 인구이동모형을 개발했다. 이 모형은 이농인구이동(離農人口移動)이 농촌지역(農村地域)의 소득(所得)과 후생수준(厚生水準)을 저해(沮害)한다는 점에서는 Lipton의 견해(見解)와 일치하나 소득(所得)을 감소(減少)시키는 요인들은 Lipton의 모형(模型)에서 지적(指摘)된 것들과는 다르다. 본고(本稿)는 이농현상(離農現象)이 농촌소득(農村所得)을 감소(減少)시키는 이유가 농업생산성(農業生産性)의 하락(下落) 때문이 아니라 농촌노동 및 소비인구의 격감으로 인한 농업부문(農業部門)의 이윤감소(利潤減少)와 농촌(農村) 서비스부문(部門)와 쇠퇴(衰退)때문이라고 주장한다. 1966, 1970, 1975, 1980 및 1985년의 한국인구(韓國人口)센서스 통계자료(統計資料)를 이용하여 주요가설(主要假說)들에 대해 실증분석(實證分析)을 한 결과 신고전학파(新古典學派)의 주장(主張)이나 Lipton의 견해(見解)보다 본(本) 연구모형(硏究模型)의 설명력(說明力)이 더 높은 것으로 밝혀졌다.

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이온화 클러스터 빔 증착의 박막 형성 기구에 관한 연구 (A Study on the Film-Formation Mechanism by Ionized Cluster Beam Deposition)

  • 신치범;이경호;황경순;문상흡;조원일;윤경석
    • 공업화학
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    • 제7권3호
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    • pp.464-472
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    • 1996
  • 이온화 클러스터 빔 증착에 의한 박막 형성 기구를 연구하였다. 가속전압, 기판온도, 표면이동 활성화에너지, 임계핵 크기 등이 박막의 결정입자크기 및 표면 평활도에 미치는 영향을 조사하기 위하여 Monte-Carlo방법에 근거한 전산 모사 프로그램을 개발하였다. 클러스터의 운동에너지가 박막형성에 미치는 영향을 관찰함으로써 높은 가속전압이 입자들의 표면이동에너지를 증가시키며 단결정막의 생성을 용이하게 함을 알 수 있었다. 기판온도가 증가함에 따라 입자의 운동에너지 소산(dissipation)속도는 느려지고 따라서 결정입자의 크기가 커졌다. 이러한 효과는 임계핵 크기가 클수록 두드러졌다. 표면이동 활성화에너지는 입자와 기판간의 상호작용력과 운동에너지 소산속도에 영향을 미침이 발견되었다. 가속전압, 기판온도, 표면이동 활성화에너지는 박막의 평활도에 복합적인 영향을 미치는 것을 알 수 있었다.

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History, Trauma, and Motherhood in a Korean Adoptee Narrative: Marie Myung-Ok Lee's Somebody's Daughter

  • Koo, Eunsook
    • 영어영문학
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    • 제55권6호
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    • pp.1035-1056
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    • 2009
  • Korean adoptee narratives have proliferated over the last ten years as adopted Koreans have begun to represent their own experiences of violent dislocation, displacement and loss in various forms of literary and artistic works, including poems, autobiographical works, novels, documentaries and films. These narratives by Korean adoptees have intervened in the current diaspora discourse to question further the traditional categories of race, ethnicity, culture and nation by representing the unique experiences of the forced and involuntary migration of adopted Koreans. For a long time, the adoption discourse has been mostly constructed from the perspectives of adoptive parents. Therefore the voice of adoptees as well as that of the birth mothers have not been properly heard or represented in adoption discourse. According to Hosu Kim, the U. S. adoption discourse, feeling pressured to deal with the stigma of the commodification of children, changed from viewing the adoptees as children who had been rescued from poverty and abandonment to considering them as a gift from the birth mothers. With the emergence of the gift rhetoric in transnational adoption, the birth mothers erased from adoption discourse have begun to be acknowledged as one of the central characters in the adoption triad. If Korean adoptees are the "the ghostly children of Korean history," the birth mothers are their "ghostly doubles" who "bear the mark of a repressed national trauma." Somebody's Daughter represents the female experiences of becoming an adopted child and of being a birth mother. In particular, the novel makes a birth mother, the forgotten presence in adoptee narratives, into a central figure in the triangular relationship created by international adoption. The novel historicizes the experiences of a Korean adoptee growing up in America as well as those of a mother who had suffered silently from feelings of unbearable loss, guilt, grief and from unforgettable memories. In addition, narrating the birth mother's story is a way to give humanity back to these forgotten women in Korean adoption history. Revisiting the site of loss both for a mother and a daughter through the novel is an act of collective mourning. The narratives about and by Korean adoptees force Korean intellectuals to reflect seriously upon Korean society and its underlying ideology which prevents a woman from mothering her own baby, and to take an ethical and political stand on this current social and political issue.

The self induced secular evolution of gravitating systems.

  • Pichon, Christophe
    • 천문학회보
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    • 제42권2호
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    • pp.37.1-37.1
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    • 2017
  • Since the seminal work of Perrin, physicists have understood in the context of kinetic theory how ink slowly diffuses in a glass of water. The fluctuations of the stochastic forces acting on water molecules drive the diffusion of the ink in the fluid. This is the archetype of a process described by the so-called fluctuation-dissipation theorem, which universally relates the rate of diffusion to the power spectrum of the fluctuating forces. For stars in galaxies, a similar process occurs but with two significant differences, due to the long-range nature of the gravitational interaction: (i) for the diffusion to be effective, stars need to resonate, i.e. present commensurable frequencies, otherwise they only follow the orbit imposed by their mean field; (ii) the amplitudes of the induced fluctuating forces are significantly boosted by collective effects, i.e. by the fact that, because of self-gravity, each star generates a wake in its neighbours. In the expanding universe, an overdense perturbation passing a critical threshold will collapse onto itself and, through violent relaxation and mergers, rapidly converge towards a stationary, phase-mixed and highly symmetric state, with a partially frozen orbital structure. The object is then locked in a quasi-stationary state imposed by its mean gravitational field. Of particular interests are strongly responsive colder systems which, given time and kicks, find the opportunity to significantly reshuffle their orbital structure towards more likely configurations. This presentation aims to explain this long-term reshuffling called gravity-driven secular evolution on cosmic timescales, described by extended kinetic theory. I will illustrate this with radial migration, disc thickening and the stellar cluster in the galactic centre.

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Southeast Asia in International History: Justification and Exploration

  • Gin, Ooi Keat
    • 수완나부미
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    • 제12권2호
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    • pp.81-118
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    • 2020
  • Despite its centrality at a pivotal crossroads of both land and sea of East-West trade, communications and travel, the region now known as Southeast Asia provides very few scholarly works situating or featuring it in an international context. Because of this paucity, there is immense scope for exploration. But prior to further explorations, justification is needed to establish that Southeast Asia, as a region, is a subject of interest, relevance, and significance in a global context. Southeast Asia was home to several empires whose reach transcended the region and beyond. Southeast Asia in, and as part of international history as an area of study is therefore justifiable. Moreover, other factors come into play, viz. geography, resources, migration, diffusion of ideas and beliefs from without and accommodation from within, shared experience of imperialism and colonialism, decolonization, and the Cold War, and the collective fate under the Association of Southeast Asian Nations (ASEAN), that further bolster its rationalization as a component of international history. Explorations, on the other hand, examine issues and obstacles that contribute to the paucity of works on Southeast Asia in international history. Furthermore, in contextualizing Southeast Asia in international history, there might appear challenges that need to be identified, confronted, and resolved.

Push-Pull-Mooring 모델을 이용한 전기자동차로의 사용자 전환의도에 관한 연구 (A Study on User Conversion Intention to Electric Vehicle Using Push-Pull-Mooring Model)

  • 우징원;김석태
    • 무역학회지
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    • 제47권6호
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    • pp.71-96
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    • 2022
  • This research will study the conversion intention of the users in China from fuel vehicle to new energy vehicles through the empirical methods. To this end, a questionnaire survey was conducted with car users as the object, combined with the theory of user migration and the PPM model to analyze the impact of fuel vehicle users' conversion intention to new-energy vehicles factor. The results showed that purchase experience contains the moderating effect, in which perceived risk and switching costs had a greater impact on the groups without purchase experience, whereas social identity, perceived value, personal attitude, and willingness to switch had a greater impact on groups with the purchase experience. Among all five factors, perceived risk had no discernible impact on the switching intention, but social identity, perceived value, attitude toward switching, and switching costs all had discernible impact on the switching intention. This study expects to come out with sustainable advises for the future growth of new energy vehicles from the study of car users' switching intention and the collective difference test of purchasing experience.

A Feasible Role of Neuropilin Signaling in Pharyngeal Pouch Formation in Zebrafish

  • Chong Pyo Choe
    • 한국발생생물학회지:발생과생식
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    • 제27권3호
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    • pp.137-147
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    • 2023
  • Pharyngeal pouches are an important epithelial structure controlling facial skeletal development in vertebrates. A series of pouches arise sequentially in the pharyngeal endoderm through collective cell migration followed by rearrangement of pouch-forming cells. While crucial transcription factors and signaling molecules have been identified in pouch formation, a role for Neuropilins (Nrps) in pouch development has not yet been analyzed in any vertebrates. Nrps are cell surface receptors essential for angiogenesis and axon guidance. In all vertebrates, the two Nrp family members, Nrp1 and Nrp2, are conserved in the genome, with two paralogs for Nrp1 (Nrp1a and Nrp1b) and Nrp2 (Nrp2a and Nrp2b) being identified in zebrafish. Here, I report a potential requirement of Nrp signaling in pouch development in zebrafish. nrp1a and nrp2b were expressed in the developing pouches, with sema3d, a ligand for Nrps, being expressed in the pouches. Knocking down Nrps signaling in the pharyngeal endoderm led to severe defects in pouches and facial cartilages. In addition, blocking Mitogen-activated protein kinase (MAPK) activities, a downstream effector of Nrp signaling, in the pharyngeal endoderm caused similar defects in pouches and facial skeleton to those by knocking down Nrps signaling. My results suggest that Nrp signaling acts for pouch formation through MAPK.

덴마크와 스웨덴 코하우징의 물리적 특성에 대한 연구 (A Study on the Physical Feature of Cohousing Projects in Denmark and Sweden)

  • 한민정;최정신;이상호
    • 한국주거학회논문집
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    • 제16권5호
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    • pp.57-66
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    • 2005
  • Korea has experienced serious changes during the last several decades of industrialization. Limited land resources and excessive rural-to-urban migration inevitably resulted high-rise apartment housing development. However, apartment housing couldn't follow up social change and residents' needs. Turning into the 21st century, there are great demands for the diversification of housing style and amenity of housing, which include enhancing community lift through proper collective environment. To solve these problems, cohousing has been introduced in Scandinavian countries. A primary goal of cohousing is the desire of residents to live in a socially supportive setting. People can do housework together and also can promote active mutual relationship among residents in the community. Physical feature of cohousing, in combination with social organization factors, may serve to enhance or support the sense of community sought by residents. In this point of view, the purpose of this study is to find out the physical feature of cohousing in Denmark and Sweden. First, it is to figure out the background and development of cohousing in Denmark and Sweden. Then, by making clear physical features between similarity and difference of two countries of cohousing through case study; such as housing type, the circulation patterns, common facilities and etc. This paper could suggest a possibility of application of cohousing in Korea to present how they encourage emphasize design aspects that increase the possibilities for social contacts and the sense of community. Also, it goes on to suggest that the educational program and the support from the government.

기억의 초국적 이동과 이민자 집단의 정치: 미국 위안부 소녀상을 사례로 (Transnational Migration of Memory and Politics of Immigrant Community: The Case of Comfort Women Memorials in the U.S.)

  • 윤지환
    • 한국경제지리학회지
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    • 제21권4호
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    • pp.393-408
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    • 2018
  • 본 연구는 특정 집단의 기억이 공간적 스케일을 넘어 확산되는 과정에 주목하며 이의 원인과 지리적 함의를 찾고자 한다. 위안부의 역사는 한반도를 넘어 미국의 한인사회를 중심으로 회자되기 시작하여 2010년 뉴저지 주 팰리세이즈파크 공립 도서관 마당에 미국 최초의 위안부 기림비가 건립되는 결실로 이어졌다. 위안부 할머니들이 겪었던 전쟁 범죄의 피해 경험이 제한된 스케일을 넘어 미국으로 확산되는 과정은 다양한 주체들에 의한 다층적 과정 및 정치적 목적이 내포되었음을 이해해야 한다. 본 연구는 위안부 기억의 초국적 확산 과정에 있어 미국 내 한인 이민자 집단의 역할에 대해 조명하며 그들의 미국 내 정치적 입지 확대 및 타 민족과의 정서적 연대에 있어 기억의 이식이 어떻게 개입되었는지를 분석하였다.

Expression and Functional Analysis of cofilin1-like in Craniofacial Development in Zebrafish

  • Jin, Sil;Jeon, Haewon;Choe, Chong Pyo
    • 한국발생생물학회지:발생과생식
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    • 제26권1호
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    • pp.23-36
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    • 2022
  • Pharyngeal pouches, a series of outgrowths of the pharyngeal endoderm, are a key epithelial structure governing facial skeleton development in vertebrates. Pouch formation is achieved through collective cell migration and rearrangement of pouch-forming cells controlled by actin cytoskeleton dynamics. While essential transcription factors and signaling molecules have been identified in pouch formation, regulators of actin cytoskeleton dynamics have not been reported yet in any vertebrates. Cofilin1-like (Cfl1l) is a fish-specific member of the Actin-depolymerizing factor (ADF)/Cofilin family, a critical regulator of actin cytoskeleton dynamics in eukaryotic cells. Here, we report the expression and function of cfl1l in pouch development in zebrafish. We first showed that fish cfl1l might be an ortholog of vertebrate adf, based on phylogenetic analysis of vertebrate adf and cfl genes. During pouch formation, cfl1l was expressed sequentially in the developing pouches but not in the posterior cell mass in which future pouch-forming cells are present. However, pouches, as well as facial cartilages whose development is dependent upon pouch formation, were unaffected by loss-of-function mutations in cfl1l. Although it could not be completely ruled out a possibility of a genetic redundancy of Cfl1l with other Cfls, our results suggest that the cfl1l expression in the developing pouches might be dispensable for regulating actin cytoskeleton dynamics in pouch-forming cells.