• 한국경제지리학회지
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• 제16권3호
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• pp.344-358
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• 2013

베트남이 세계 제2의 커피 생산국으로 도약하는 데에는 닥락(Dak Lak) 성(省)을 포함한 중부고원지대의 농업 발달이 있었으며 그러한 농업 발달에 연안지역에서 내륙고원지대로의 이주가 중요한 역할을 수행하였다. 기존 연구는 이러한 이주의 중요성을 인지하면서 계획 이주와 자발적 이주로 나누어 논의를 전개해 왔다. 하지만 이들 연구는 계획이주와 자발적 이주 간의 연계 관계를 명확히 파악하지 못했으며 이들의 연계 관계가 커피의 생산 현장이라 할 수 있는 꼬뮨 단위에서 차별적으로 구현되었는지 밝히지 못했다. 이에 본 연구는 닥락 성으로의 이주 흐름을 통계자료로 분석하고 Ea H'Ding 꼬뮨과 Doan Ket 꼬뮨을 사례지역으로 선정하여 전문가와의 면담 그리고 농가 설문과 면담을 통해 이주 과정을 비교 분석하였다. 그 결과 닥락 성 스케일에서 계획 이주가 초기에는 많았다가 점차 감소하였으나, 대신 자발적 이주가 점차 증가하면서 꾸준한 인구 유입이 이루어져 이 지역이 커피 생산지로 발돋움할 수 있었다. 하지만 커피 생산의 구체적 현장이라 할 수 있는 소지역 스케일에서는 계획 이주와 자발적 이주 간 연계 관계가 서로 다른 민족 구성, 정주 시기, 정부 개발 프로그램, 이주민 폭증 시기를 갖는 꼬뮨별로 상이하게 구현되었음이 밝혀져 국지적 맥락의 중요성을 확인할 수 있었다.

• Biotechnology and Bioprocess Engineering:BBE
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• 제11권5호
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• pp.402-407
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• 2006

Vascular endothelial cells release proteinases that degrade the extracellular matrix (ECM), thus enabling cell migration during angiogenesis and vasculogenesis. Sildenafil citrate stimulates the nitric oxide-cyclic guanosine monophosphate pathway through inhibition of phosphodiesterase type V (PDE5). In this report, we examined the mechanisms underlying sildenafil citrate-induced cell migration using cultured mouse aortic endothelial cells (MAECs). Sildenafil citrate induced migration and proteinase secretion by murine endothelial cells. Sildenafil citrate induced the secretion of matrix metalloproteinase-2 (MMP-2) and MMP-9, which is inhibited by $NF-{\kappa}B$ inhibitors. Sildenafil citrate also induced the secretion of plasmin, which is inhibited by PI 3'-kinase inhibitors. It is suggested that sildenafil citrate-induced migrating activity in endothelial cells may be accomplished by increased secretion of proteinases.

• 한국산학기술학회논문지
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• 제17권9호
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• pp.737-744
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• 2016

본 연구는 지역간 인구이동보다는 내부 인구이동이 증가하고 있는 수도권을 대상으로 전출입 인구현황을 파악하고, 도시유형을 분석한 후 유형별 인구이동 영향요인을 분석하였다. 수도권 시 군 구별 전출입 인구를 분석한 결과, 서울시는 송파구, 인천시는 서구, 남동구, 경기도는 용인시, 화성시 등으로 인구가 집중하였다. 수도권 시 군 구간 전출입 현황에서는 수원시에서 화성시, 성남시에서 용인시로 이동하는 인구가 많았다. 고용밀도와 인구밀도를 변수로 한 도시유형분석에서는 4개의 도시유형(도심형, 자족형, 주거형, 도농형)으로 분류되었다. 도심형인 유형1은 전세가격, 도로연장, 지하철역 수, 자족형인 유형2는 총소득 증가율, 주택보급률, 도로연장, 주거형인 유형3은 주택보급률, 도시공원면적, 전세가격, 인구밀도, 도농형인 유형4는 사업체밀도, 주택보급률, 주택공급, 지하철역 수, 교육시설 등이 인구이동에 영향을 주는 것으로 분석되었다. 이중 주택보급률은 전입인구에 긍정적인 영향을 미쳤으나 인구밀도의 경우 전출인구에 영향을 주었다. 도로, 지하철역 수의 경우 도심형은 전출인구에 영향을 주었으나, 자족형과 도농형에서는 전입인구에 영향을 미치는 것으로 나타나 유형별로 각기 다른 영향을 보였다.

• Journal of the Korean Physical Society
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• 제73권9호
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• pp.1219-1224
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• 2018

We investigate the evolutionary dynamics and the phase transitions of the island model which consists of subdivided populations of individuals confined to two islands. In the island model, the population is subdivided so that migration acts to determine the evolutionary dynamics along with selection and genetic drift. The individuals are assumed to be haploid and to be one of two species, X or Y. They reproduce according to their fitness values, die at random, and migrate between the islands. The evolutionary dynamics of an individual based model is formulated in terms of a master equation and is approximated by using the diffusion method as the multidimensional Fokker-Planck equation (FPE) and the coupled non-linear stochastic differential equations (SDEs) with multiplicative noise. We analyze the infinite population limit to find the phase transitions from the monomorphic state of one type to the polymorphic state to the monomorphic state of the other type as we vary the ratio of the fitness values in two islands and complete the phase diagram of our island model.

• Food Science and Biotechnology
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• 제15권1호
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• pp.133-137
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• 2006

Wheat gluten-chitosan composite film (WGCCF) can prevent moisture migration and enhance the antimicrobial properties of gluten in intermediate-moisture foods like sandwiches. To mimic the structure of actual sandwich-type products we developed multi-layer food models, where moisture content and water activity differ. Water activity gradients direct moisture migration and therefore determine product characteristics and product stability. A 10% wheat gluten film-forming solution was mixed with chitosan film-forming solution (0-3%, w/w) and evaporated to generate WGCCF. Addition of 3% chitosan enhanced the mechanical properties of the film composite, lowered its water vapor permeability, and improved its ability to protect against both, Streptococcus faecalis and Escherichia coli, in a 24 hr sandwich test (reduction of 1.3 and 2.7 log cycles, respectively, compared to controls). Best barrier and antimicrobial performance was found for 3% chitosan WGCCF at pH 5.1. Film of this type may find application as barrier film for intermediate-moisture foods.

• 물과 미래
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• 제25권2호
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• pp.79-87
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• 1992

본 연구는 굴곡도(sinuosity)가 작은 정현파형(SWR)하천에서 사행 이행의 크기와 방향 및 제방부근의 하상세굴 위치와 크기를 예측할 수 있는 이행특성 모형을 운동량 방정식, 질량보존법칙, 하상 안정식을 적용하여 개발하였다. 본연구에서 황방향 하상계수 B'와 질량 이송계수 a 는 SWR 하천에서 중요한 역할을 하는 변수임이 확인되었으며, 그 값은 각각 B'는 4.0, a는 0.40이 합리적인 값으로 나타났다. 본 모형은 SWR 하천 유역의 개발계획 및 설계시 유용한 정보를 제공해 줄 것이다.

• 한국환경복원기술학회지
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• 제14권3호
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• pp.157-168
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• 2011

In order to promote efficiency of upstream and downstream migration of fishes, this study has developed a combined fishway of herring-bone bottom baffle type and brush type fishways. The results obtained are as follows : 1. In a channel with constant incline, the velocity of current generally shows a distinct tendency of acceleration as it goes down the stream. But in the hydraulic experiment of herring-bone bottom baffle type fishway, the velocity reached its maximum only at 0.4m/sec, and it tended to be stable without any acceleration. 2. The velocity in the brush type fishway showed a distinct tendency of acceleration as the discharge increased. But its greatest velocity was only 0.3m/sec, and its velocity change according to the discharge increase was only 0.15m/sec at maximum. 3. The maximum velocity in the combined type fishway was less than half of the blast speed of the poorest swimmer, the juvenile eel with 90mm of body length. So any species of fishes are supposed to be able to migrate upstream from the estuary through this combined type fishway. 4. The field experiment of upstream migration showed that the combined type fishway can promote efficiency of upstream and downstream migration of any species of fishes.

• Membrane and Water Treatment
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• 제14권2호
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• pp.95-106
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• 2023

In the developing country like India, groundwater is the main sources for household, irrigation and industrial use. Its contamination poses hydro-geological and environmental concern. The hazardous waste sites such as landfills can lead to contamination of ground water. The contaminants existing at such sites can eventually find ingress down through the soil and into the groundwater in case of leakage. It is necessary to understand the process of migration of pollutants through sub-surface porous medium for avoiding health risks. On this backdrop, the present paper investigates the behavior of pollutants' migration through porous media. The laboratory experiments were carried out on a soil-column model that represents porous media. Two different types of soils (standard sand and red soil) were considered as the media. Further, two different solutes, i.e., non-reactive and reactive, were used. The experimental results are simulated through numerical modeling. The percentage variation in the experimental and numerical results is found to be in the range of 0.75- 11.23 % and 0.84 - 1.26% in case of standard sand and red soil, respectively. While a close agreement is observed in most of the breakthrough curves obtained experimentally and numerically, good agreement is seen in either result in one case.

• The Korean Journal of Physiology and Pharmacology
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• 제19권6호
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• pp.499-506
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• 2015

Angiotensin II (Ang II), a key mediator of hypertensive, causes structural changes in the arteries (vascular remodeling), which involve alterations in cell growth, vascular smooth muscle cell (VSMC) hypertrophy. Ang II promotes fibrotic factor like IGFBP5, which mediates the profibrotic effects of Ang II in the heart and kidneys, lung and so on. The purpose of this study was to identify the signaling pathway of IGFBP5 on cell proliferation and migration of Ang II-stimulated VSMC. We have been interested in Ang II-induced IGFBP5 and were curious to determine whether a Pitavastatin would ameliorate the effects. Herein, we investigated the question of whether Ang II induced the levels of IGFBP5 protein followed by proliferation and migration in VSMC. Pretreatment with the specific Angiotensin receptor type 1 (AT1) inhibitor (Losartan), Angiotensin receptor type 2 (AT2) inhibitor (PD123319), MAPK inhibitor (U0126), ERK1/2 inhibitor (PD98059), P38 inhibitor (SB600125) and PI3K inhibitor (LY294002) resulted in significantly inhibited IGFBP5 production, proliferation, and migration in Ang II-stimulated VSMC. In addition, IGFBP5 knockdown resulted in modulation of Ang II induced proliferation and migration via IGFBP5 induction. In addition, Pitavastatin modulated Ang II induced proliferation and migration in VSMC. Taken together, our results indicated that Ang II induces IGFBP5 through AT1, ERK1/2, P38, and PI3K signaling pathways, which were inhibited by Pitavastatin. These findings may suggest that Pitavastatin has an effect on vascular disease including hypertension.

• 한국농공학회논문집
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• 제52권3호
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• pp.1-7
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• 2010

The ichthyofauna and passing efficiency of fishways were surveyed in Geumgang estuary from May to October in 2009. The fishes collected were classified into 24 species, 23 genera belonging to 8 families. These 24 species consist of 17 freshwater fish species, 3 migration fish species and 4 peripheral freshwater fish species. Seasonal function of fishways showed the migration from May to June and returning to the reservoir of fishes be washed out to sea when sluice gate open by rainfall in July and August. Most of the fishes catched in fishways moved from middle tide to high tide except for July. Fishes ascended fishways between the middle ebb tide and the ebb tide only July, because small freshwater swim against the fishway for leaching the reservoir through the newly formed flow when the water level at the fishway kept dropping. Small fishes that body length less than 200 mm mainly used gabion type fishways and fishes over 200 mm utilized a cascade type fishways. Based on the total individuals collected, the efficiency of the fishway was 1 % for the anadromous fish and over 80 % for freshwater fish. Therefore, it is concluded that ecological function of the fishway in the Geumgang estuary dike be very important not only for fish migration but also freshwater fishes's returning.