• Journal of Wetlands Research
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• v.21 no.1
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• pp.16-26
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• 2019

Wetlands that provide diverse ecosystem services, such as habitat provision and hydrological control of flora and fauna, constitute ecosystems through interaction between wetlands existing in a wetlandscape. Therefore, to evaluate the wetland functions such as resilience, it is necessary to analyze the ecological connectivity that is formed between wetlands which also show hydrologically dynamic behaviors. In this study, by defining wetlands as ecological nodes, we generated ecological networks through the connection of wetlands according to the dispersal model of wetland species. The characteristics of these networks were then analyzed using various network metrics. In the case of the dispersal based on a threshold distance, while a high local clustering is observed compared to the exponential dispersal kernel and heavy-tailed dispersal model, it showed a low efficiency in the movement between wetlands. On the other hand, in the case of the stochastic dispersion model, a low local clustering with high efficiency in the movement was observed. Our results confirmed that the ecological network characteristics are completely different depending on which dispersal model is chosen, and one should be careful on selecting the appropriate model for identifying network properties which highly affect the interpretation of network structure and function.

• Land and Housing Review
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• v.13 no.3
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• pp.69-81
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• 2022

Unplanned land use, that is, unplanned development, causes various negative externalities. In the past, Korea has experienced significant socio-economic costs due to reckless development centered on the boundary between urban and non-urban areas.. Unplanned land use can be viewed as a result of the interaction of various factors.. Therefore, it is difficult to develop in areas where unplanned land use occurs intensively. It is necessary to strengthen legal and institutional measures so that negative externalities do not persis. In this study, we present a spatial analysis methodology to effectively find spatial clusters where unplanned land use is concentrated. By demonstrating and applying this to individual development activities that occurred in Asan City, we examine the usefulness of information to support decision making when establishing mid-to-long-term growth management strategies at the local government level.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.4D
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• pp.671-678
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• 2006

In this study, to describe vehicle-structure dynamic interaction phenomena with 1/4 vehicle model, nonlinear Hertzian contact spring and nonlinear contact damper are adopted. The external loads acting on 1/4 vehicle model are selfweight of vehicle and geometry information of running surface. The constraint equation on contact surface is implemented by the Penalty method with stabilization and the reaction from constraint violation. To describe pitching motion of various vehicles two types of the displacement constraint equations are exerted to connect between car bodies and between bogie frames, i.e., the rigid body connection and the rigid body connection with pin, respectively. For the time integration of dynamic equations of vehicles and structure Newmark time integration scheme is adopted. To reduce the error caused by inadequate time step size, adaptive time-stepping technique is also adopted. Thus, it is expected that more versatile dynamic interaction phenomena can be described by this approach and it can be applied to various railway dynamic problems with low computational cost.

• Journal of the Korean Association of Geographic Information Studies
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• v.22 no.1
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• pp.1-18
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• 2019

This research measured and visualized the spatial dependency and the spatial heterogeneity of the small business in Cheonan-si, Asan-si with $100m{\times}100m$ grids based on global and local spatial autocorrelation. First, we confirmed positive spatial autocorrelation of small business in the research area using Moran's I Index, which is ESDA(Exploratory Spatial Data Analysis). And then, through Getis-Ord $GI{\ast}$, one kind of LISA(Local Indicators of Spatial Association), local patterns of spatial autocorrelation were visualized. These verified that Spatial Regression Model is valid for the location factor analysis on small business commercial buildings. Next, GWR(Geographically Weighted Regression) was used to analyze the spatial relations between the distribution of small business, hourly mobile traffic-based floating population, land use attributes index, residence, commercial building, road networks, and the node of traffic networks. Final six variables were applied and the accessibility to bus stops, afternoon time floating population, and evening time floating population were excluded due to multicollinearity. By this, we demonstrated that GWR is statistically improved compared to OLS. We visualized the spatial influence of the individual variables using the regression coefficients and local coefficients of determinant of the six variables. This research applied the measured population information in a practical way. Reflecting the dynamic information of the urban people using the commercial area. It is different from other studies that performed commercial analysis. Finally, this research has a differentiated advantage over the existing commercial area analysis in that it employed hourly changing commercial service population data and it applied spatial statistical models to micro spatial units. This research proposed new framework for the commercial analysis area analysis.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.37 no.6
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• pp.417-426
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• 2019

Conventional visualization of PM (Particulate Matter)10 flows applies superimposition of concentration distribution maps and wind field maps. This method is efficient for small scale maps where only macro flow trends are of interest. However, in the case of urban areas, local flows are difficult to model at micro level using wind fields, and therefore different methods of flow extraction is deemed necessary. In this study, flow information is extracted and visualized directly from the PM10 density data by using the gravity model. This method has the advantage that additional information such as wind field is not necessary for estimating the intensity and direction of PM10 flow. The extracted spatio-temporal flow patterns of PM10 are analyzed with relation to traffic information.

• Archives of design research
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• v.14 no.3
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• pp.117-125
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• 2001

The 2D based-web contents are limited to implement interactive elements for the users even though the contents are offered in various styles. Using the mouse and keyboards users chose any web contents for themselves beyond the limitation of time and space. They want more interactive style as they become familiar with convenience of web contents. The 3 dimensional web contents integrated with interactive technologies are one of the ways for them There are many researches and commercialization of the interactive web 30 for the past years because it has a lot of user benefits in terms of immersion, realistic expression, and interactivity. It has two types of implementation; one is for 3D polygon based objects, the other is for virtual worlds. This research is focus of on the concept of web interactive 3D, the technical aspects, design elements, and the proposal of navigation methods for the purpose of creating new type of web interactive contents.

• Proceedings of the Korea Water Resources Association Conference
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• 2007.05a
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• pp.296-300
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• 2007

우리나라에 내리는 대부분의 강수량은 6월${\sim}$8월의 장마기간 혹은 태풍의 영향으로 인해 발생한다. 특히 국지적으로 발생하는 집중호우로 인해 많은 인명, 재산 피해 등이 발생한다. 우리나라에서 집중호우로 인한 피해는 거의 매년 발생하고 있으며, 집중호우의 발생 지역은 특정 지역에 국한되어 있지 않다. 따라서 집중호우 발생으로 인한 피해 방지를 위해 사전에 충분한 준비를 해야 한다. 2006년 7월 8일부터 10일까지 3일 동안 진주지역 306.5mm, 합천지역 259.5mm, 산청지역 366.0mm의 집중호우가 발생하였으며, 이 기간 동안 이들 지역 외에도 전국적으로 태풍 에위니아(EWINIAR)의 영향으로 많은 호우가 발생하였다. 본 연구에서는 2006년 7월 진주지역 집중호우 특성 연구를 위해 진주지역 시강우 자료를 이용하여 자료를 분석하였다. 시강우 자료를 이용하여 진주지역 재현기간별 확률강우량을 산정하였고 2006년 7월 8일부터 10일까지의 강우분포형태를 설계강우분포형과 비교하였다. 또한 2006년 7월 발생했던 진주지역 집중호우의 무차원 누가곡선을 작성하여 분석을 실시하였다. 분석 결과 일최대 강우량의 경우 그 크기가 50년 혹은 80년 이내였으며, 강우분포형의 경우 하천정비기본계획의 경우 Mononobe 중앙집중형이였지만, 지난 호우의 경우 후방위의 강우가 연속적으로 발생한 형태였다. 또한 대부분의 강우가 6시간 이내에 내려 첨두홍수 발생에 많은 영향을 미쳤을 것으로 판단된다. 앞으로 이상기후와 같은 자연 현상에 대비하기 위해서는 단시간 호우에 대한 정확한 분석과 강우분포에 대한 연구가 더욱 필요할 것으로 생각된다.적자색의 미려한 결정이 석출되므로 이 결정을 여과하여 ethanol로 세척하고 진공 desiccator중에서 건조시켰다. 수득량 1.2~1.3g.)와의 조환가는 11.9565의 상인연소현상을 보였다. 삭과색(Y) 경색(R) 유전자간에는 어느것이나 연소현상이 보이지 않았다. 4. 단일반응성의 변이는 연소적이며 우성은 거의 인정되지 않았고 인자간의 상호작용도 인정되지 않았으며 상가적 유전을 보였다. 광의와 협의의 유전력은 각각 89.50%로서 실용적으로 대단히 높은 것으로 생각되었으며 단일반응성에 관여하는 유전자수는 2대의 인자로 추정하였고 다시 양친의 유전자형을 aabb AABB라고 측정하여 각인자의 작용가는 11.136일로 산출되었고 분해법에 의한 유전분석결과 유전자형의 관찰빈도분포와 이론빈도분포는 서로 잘 적합되었다. 단일반응성에 있어서 유전력이 대단히 높았으므로 비교적 초기세대에서 본 형질의 선발이 가능할 것 같았다. 5. 단일반응성과 엽형 및 엽병색 유전자와의 사이에 $F_2$, $BC_1$ 및 $BC_2$에서 각각 유의적인 상관관계를 볼 수 있었으므로 이들 형질간에 연소가 있는 것으로 인정되었다. 더욱 엽형과 엽병색과의 연소가 있는 것으로 인정되는 이상단일반응성 유전자와의 사이에 연소군이 인정된다. 6. 섬유중 유전자와 엽병색 및 엽형유전자와의 사이에 $F_2$$BC_1$ 및 $BC_2$에서 각각 유의적 상관관계를 볼 수 있었으므로 이를 형질간에 연소가 있는 것으로 인정되었다. 더욱 엽형과 엽병색과의 연소가 있는 것으로 인정되는 이상 섬유중 유전

• Ecology and Resilient Infrastructure
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• v.7 no.1
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• pp.1-14
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• 2020

In fluvial and riparian ecosystems, biogeomorphological research has considered the complex, multi-way relationships between biological and hydro-geomorphological components over a wide range of spatial and temporal scales. In this review, we discussed the scope and processes of fluvial biogeomorphology by explaining (1) the multi-lateral interactions between organisms and hydrogeomorphic conditions, (2) the relationships between biodiversity and habitat heterogeneity, and (3) the effects of disturbance on ecosystem patterns. Over time, an organism-landform complex along streams transitions in the sequences of geomorphic, pioneer, biogeomorphic, and ecological stages. Over space, water flow and sediment distributions interact with vegetation to modify channel topography. It is the habitat heterogeneity in streams that enhances riparian biodiversity. However, in the areas downstream of a dam, habitat types and conditions are substantially damaged and biodiversity should be reduced. In South Korea, riparian vegetation flourishes in general and, in particular, invasive species actively colonize in accordance with the changes in the fluvial conditions driven by local disturbances and global climate change. Therefore, the importance of understanding reciprocal relationships between living organisms and hydrogeomorphic conditions will ever increase in this era of rapid climate change and anthropogenic pressure. The fluvial biogeomorphic framework reviewed in this article will contribute to the ecological management and restoration of streams in Korea.

• Journal of Korea Water Resources Association
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• v.34 no.4
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• pp.347-356
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• 2001

Even though the increase of greenhouse gases such as $CO_2$ is thought to be the main cause for global warming, its impact on global climate has not been revealed clearly in rather quantitative manners. However, researches using Genral Circulation Model(GCM) has shown that the accumulation of greenhouse gases increases the global mean temperature, which in turn impacts on the global water circulation pattern. A climate predictive capability is limited by lack of understanding of the different process governing the climate and hydrologic systems. The prediction of the complex responses of the fully coupled climate and hydrologic systems can be achieved only through development of models that adequately describe the relevant process at a wide range of spatial and temporal scales. These models must ultimately couple the atmospheres, oceans, and lad and will involve many submodels that properly represent the individual processes at work within the coupled components of systems. So far, there are no climate and related hydrologic models except local rainfall-runoff models in Korea. The purpose of this research is to predict the change of temperature in Korean Peninsula using regional scale model(IRSHAM96 model) and GCM data obtained from the increasing scenarios of $CO_2$ Korean Peninsula increased by $2.5^{\circ}C$ and the duration of Winter in $lxCO_2$ condition would be shorter the $2xCo_2$ condition due to global warming.

• Journal of the Korean association of regional geographers
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• v.23 no.2
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• pp.403-419
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• 2017

This study analyzed the forces to drive the change of urban green spaces in Daegu from 1989 to 2009. First, the loss and fragmentation of green spaces in the past 20 years were spatially identified by performing the hot spots analysis for the cell-based spatial metrics quantifying the size and diversity of green spaces. Next, seven drivers such as slope, distance to roads, land price, population density, ratios of residential, commercial, and industrial areas were selected based on the previous studies and the direction of the association between the loss and fragmentation of green spaces and seven drivers was analyzed with the stepwise logistic regression. Finally, the relative importance of the seven drivers and their interactions in the past 20 years were analyzed with the geographical detector. The results show that the loss of green spaces was concentrated on a part of the Anshim housing development district from 1989 to 2009 and green spaces were highly fragmented around the housing development districts such as Seongseo, Anshim, Dalseong-gun and Chilgok. The forces to drive the loss and fragmentation of green spaces in these areas were different at the administrative levels, but the drivers such as slope and ratios of residential and industrial areas were commonly significant. These drivers were positively correlated with largest patch index(LPI) quantifying the loss of green spaces while they were negatively correlated with Shannon's diversity index(SHDI) measuring the fragmentation of green spaces. In other words, the loss and fragmentation of urban green spaces in Daegu appeared around such regions with lower slope and lower ratios of residential and industrial areas. The relative importance of drivers for LPI was listed as ratio of industrial area, land price, and ratio of commercial area in descending order whereas that of drivers for SHDI was listed as ratio of industrial area, land price, and distance to roads in descending order. Also, the interaction between slope and ratio of residential area had a great impact on LPI and SHDI. The ratio of industrial area was a single driver to most significantly explain the loss and fragmentation of urban green spaces in Daegu in the past 20 years. The interaction between slope and ratio of residential area was greater than the independent influence of a single driver. This study will provide the base data to build a sustainable urban green policy for the city of Daegu in the near future.