• Proceedings of the Korea Water Resources Association Conference
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• 2011.05a
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• pp.183-187
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• 2011

본 연구에서는 3차원 수리해석과 함께 유사의 이송, 침식, 퇴적 현상을 연동하여 모의할 수 있는 유한차분 수치모형인 EFDC(Environmental Fluid Dynamics Code)를 이용하여 주운하천 구간으로 유입되는 다입경 혼합유사의 입경별 시 공간적 퇴적분포 특성을 고찰하고, 하상변동 예측에 있어서 유사의 밀도와 모델의 유한차분 격자 구조에 의한 불확실성 해석을 수행하였다. 유입 유사의 입경별 공간적 퇴적특성은 하천 하류부와 단면 확대부에서 발생하는 3차원적 수리현상과 매우 밀접한 상관성을 보였으며, 굴포천과 합류하는 주운수로 유입부에서는 대부분 입경이 큰 비점착성 유사($63{\mu}m$ 이상)인 사질(sand)입자들이 주로 퇴적되는 것으로 나타났으며, 주운하천 합류부로부터 하류구간까지는 $4\sim63{\mu}m$ 입자의 실트질(silt) 유사가 대부분 이송되어 퇴적되는 것으로 분석되었다. 점착성 유사인 $4{\mu}m$ 이하의 점토(clay)는 단면이 확대되어 유속이 매우 느린 구간이나 사수역을 중심으로 퇴적되는 것으로 나타났다. 단면 횡방향 분포특성은 굴포천과 주운하천이 합류하는 합류부 구간의 주흐름 방향 남쪽에서 흐름의 정체구간이 발생되어 퇴적이 발생하고, 단면 급확대부 양안에서 사수역이 형성되므로 퇴적이 지배적으로 발생되었다. 하상변동 예측의 불확실성 해석을 위해 유사 밀도값에 대한 민감도 분석결과, 하상변동량은 유사밀도($1.3ton/m^3\sim2.65ton/m^3$)가 감소됨에 따라 약 2배까지 증가하는 것으로 분석되어 민감도가 매우 크게 나타났다. 또한 수치격자 구조의 민감도 분석결과, 수층을 3개 층으로 분석한 결과가 단일층 분석결과보다 최대 6배의 하상변동량이 많게 산정되었다. 이는 수심방향의 유속과 부유사 농도의 불균등 분포특성이 실제 자연현상에 더 가깝게 모의되기 때문으로 판단되었다.

• Journal of the Korean association of regional geographers
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• v.1 no.1
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• pp.23-43
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• 1995

This paper is the first part of a research which looks into the regional development process and the quality of life of Youngnam area, and which suggests a prospect and tasks for the future development of the region. Youngnam region has grown rapidly on the basis of labor-intensive light industries and standardized Fordist lage-scale heavy industries through the industrialization and urbanization of South Korea from the 1960s; but recently it has shown a relatively downward trend. The recent economic stagnation of Youngnam region can be seen as a result of uneven regional development in the national scale, which has brought out the increasing subcontracting relation within the region, the geographically excessive concentration of firms, the lack of growth potentiality of high-tech industries, the weakness of producer service, and the shortage of financial activities for capital flows. In addition, construction of physical and social infrastructures and management of urban central functions could not meet properly the rapid economic and urban growth of the region. Because of these problematics inherent in the economy of Yougnam region, the occupational status of regional dwellers is more or less unstable, and the wage level of employee as a whole in Youngnam region is lower than those of Seoul, although the wage level of labourers in manufacturing is relatively high. Moreover, the quality of life of dwellers in the region has some difficulties in the use of resources and ecological environment as well as the unequal provision of means of living and welfare facilities, even though it has been improved materially.

• Journal of Korean Society of Environmental Engineers
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• v.35 no.12
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• pp.918-928
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• 2013

The inequitable flow distribution to flocculation basins is an important problem faced in many water treatment plants. This is caused by the structure of a distribution channel, the height differences of outlet weirs etc. But, a modified approach for the structures has no effectiveness to achieve flow equality. The aim of this study is to reduce the inequality by adopting optimized inlet valve opening (%) of the flocculation basins using DOE (Design of Experiments) and RSA (Response Surface Analysis). The inlet valve openings (%) and inflow distributions (%) of 6 paralleled basins were set as factors (X) and characteristics(Y) respectively. 2 level factorial experiments and RSA were conducted for optimization and regression analysis (Y = f(X) + Const.). Adopting the optimized inlet valve opening (%) at field, standard deviation of flow distribution (%) and effluent turbidity was declined from 3.80% to 0.42% and from 0.29 NTU to 0.03 NTU respectively.

• Journal of the Korean Geographical Society
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• v.47 no.1
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• pp.13-36
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• 2012

This paper is to reconsider comprehensively and systematically major issues on transnational immigrants, increased rapidly since the beginning of the 1990s, and their impacts on socio-spatial changes in S. Korea. Foreign immigrants who have moved on the contexts of unevenness of globalization and advancces in transport & telecommunication technology on the global level and of economic development and shortage of cheap and unskilled workers have been distributed unevenly, concentrating on the Capital region and local areas with industrial complexes. Foreign workers seems to have some negative influences on regional economies in the long-term, though positive in the short-term. Domestic people seem to have an ambivalent attitude which accepts necessity of multi-culture, while simultaneously continues to be self-confident on ethnic homogeneity. The Korean government has launched multicultural policies for foreign immigrants by the mid-2000, but still continues some policies with assimilationism and differential exclusionism, marginalizing them socio-spatially, while lacking local government's policy and programmes. In conclusion, in order to resolve these problems and to transfer multicultural societal space of Korea, a geography of transnational migration which promotes especially discourse and policy with authentic multiculturalism, extending roles of local government, and ensuring glocal citizenships.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.1A
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• pp.105-113
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• 2008

Solar radiation induces non-uniform temperature distribution in the bridge structure depending on the shape of the structure and shadows cast on it. Especially in the case of curved steel box girder bridges, non-uniform temperature distribution caused by solar radiation may lead to unusual load effects enough to damage the support or even topple the whole curved bridge structure if not designed properly. At present, it is very difficult to design bridges in relation to solar radiation because it is not known exactly how varying temperature distribution affects bridges; at least not specific enough for adoption in design. Standard regulations related to this matter are likewise not complete. In this study, the thermal behavior of curved steel box girder bridges is analyzed while taking the solar radiation effect into consideration. For the analysis, a method of predicting the 3-dimensional temperature distribution of curved bridges was developed. It uses a theoretical solar radiation energy equation together with a commercial FEM program. The behavior of the curved steel box girder bridges was examined using the developed method, while taking into consideration the diverse range of bridge azimuth angles and radii. This study also provides reference data for the thermal design of curved steel box girder bridges under solar radiation, which can be used to develop design guidelines.

• Journal of the Korean Association of Geographic Information Studies
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• v.13 no.2
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• pp.1-10
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• 2010

The purpose of this research is to establish location models for public service facilities considering efficiency as well as equity. And it suggests the method of spatial evaluation reflected the real world. Finally, this research is applied to the analysis on the optimum location of cultural facilities in Geumsan. This research adopts the expert survey for site selection factors and applys AHP for the relative weights. Secondly, it assorts the urban area by satellite image for the spatial analysis on the real world. Next, it adopts the Location-Allocation Model for the location evaluation and embodies the unequal population distribution according to the location model establishment. Finally, it conducts the more specific spatial analysis reflected the real world through the two methods applications; both spatial analysis(Grid analysis) and Network analysis.

• Journal of the Korean Geographical Society
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• v.45 no.1
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• pp.119-143
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• 2010

Local administrative districts in Japan have extensively reformed over the last 10 years and have decreased by 40 percent. This study examines the process of the municipal mergers in Japan from the perspective of the politics of space, in addition to a focus on the formation of Tobichi (enclaves). The background and progress of municipal mergers in Japan revealed that the reformation of administrative districts progressed under 'restruction' rather than 'decentralization' to manage a financial crisis of government. As a result, the municipal mergers of Japan have progressed in spatiotemporal inequality. The municipal mergers of the study areas are analyzed in multi-dimensional spatial politics composed of financial and demographic properties, locationality, territoriality, placeness, and the politics of decision making. Administrative districts have a spatial property; the reformation of them should be considered with the specialty and generality of the region.

• The Korean Journal of Ecology
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• v.17 no.1
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• pp.59-67
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• 1994

Differences in physicochemical characteristics of sediment and changes in density, height and dry matter of shoots along different water depths were investigated in the stands of Zizania latifolza populations of the littoral zone of Lake Paltangho, Korea. Any significant differences in sediment chemistry were not found along water depth, although sand content decreased slightly with increasing depth. Shoot density of Zizania latqolia decreased with increasing water depth. In shallower water, many of the short shoots died in the early growth stages. The morphology of shoots was taller and heavier in deeper water. The distributions of shoot heights became negatively skewed and leptokurtic as plants grew, and these changes occurred in the earlier growth stages in deeper water. The standing crop of shoots increased with increasing water depth. These results suggest that Zizania lattfolia has a growth strategy for adjustment to deep water through decreasing shoot density and increasing height.

• Composites Research
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• v.17 no.3
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• pp.23-28
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• 2004

A method of calculating the natural frequency corresponding to the first mode of vibration of beams and tower structures, with irregular cross sections and with arbitrary boundary conditions was developed and reported by Kim, D. H. in 1974. In this paper, the result of application of this method to the three span continuous reinforced concrete bridge with elastic intermediate supports is presented. Such bridge represents either concrete or sandwich type three span bridge on polymeric supports for passive control or on actuators for active control. The concrete slab is considered as a special orthotropic plate. Any method may be used to obtain the deflection influence surfaces needed for this vibration analysis. Finite difference method is used for this purpose, in this paper, The influence of the modulus of the foundation and $D_{22}$, $D_{12}$, $D_{66}$ stiffnesses on the natural frequency is thoroughly studied.

• Journal of the Economic Geographical Society of Korea
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• v.25 no.4
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• pp.484-498
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• 2022

The purpose of this study is to analyze the location, distribution and its change of photovoltaic power generation in the scale of municipality(Si-Gun-Gu). First the distribution of photovoltaic power generation was analyzed in 2020, and second, from 2017 to 2021, we tracked the increase in capacity of power generation facilities in each Si-Gun-Gu. As a result, the distribution and increase of photovoltaic power generation were concentrated in some regions and the unequal distribution of photovoltaic power generation has been identified through Gini coefficient.