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Lee J.-M.,Korea Land and Housing Corporation | Hyun K.-H.,Korea Land and Housing Corporation | Choi J.-S.,Korea Land and Housing Corporation | Yoon Y.-J.,Konyang University | Geronimo F.K.F.,Kongju National University
Desalination and Water Treatment | Year: 2012

Urban development is the primary cause of the expansion of impervious areas. Urbanization reduces infiltration of rainwater, increases runoff volume, and finally has an effect on the hydro-logical cycle and urban environment. To solve these problems, Low Impact Development (LID) methods have been used to restore the natural hydrology of predevelopment sites using site design techniques such as infiltration, evaporation, and retention. SWMM5 has been developed as a model to analyze the hydrologic impacts of LID facilities. This study performed hydrologic analysis and evaluated the flood reduction effect of the Jangjae Stream watershed by the design of LID facilities of the rainwater management demonstration district of AsanTangjung New Town (Korea). LID facilities in this study were comprised of infiltration trench, rain barrel, vegetation swale, etc. SWMM5 was calibrated using rainfall data of the 7th and the 14th of July, 2011 and was verified using rainfall data of the 10th and the 11th of August, 2011. This study analyzed flood reduction effect on 50 to 100 y return period. Based on the results of this study, the reduction of flood peak discharge by each return period of storms was estimated to be about 7 to 15%. © 2012 Desalination Publications. All rights reserved.

Lim S.-H.,Korea Land and Housing Corporation | Joo S.J.,Seoul National University | Yang K.-C.,Kongju National University
Journal of Ecology and Environment | Year: 2015

To clarify the effects of forest fire on the carbon budget of a forest ecosystem, this study compared the seasonal variation of soil respiration, net primary production and net ecosystem production (NEP) over the year in unburned and burned Pinus densiflora forest areas. The annual net carbon storage (i.e., NPP) was 5.75 t C ha-1 in the unburned site and 2.14 t C ha-1 in the burned site in 2012. The temperature sensitivity of soil respiration (i.e., Q10 value) was higher in the unburned site than in the burned site. The annual soil respiration rate was estimated by the exponential regression equation with the soil temperatures continuously measured at the soil depth of 10 cm. The estimated annual soil respiration and heterotrophic respiration (HR) rates were 8.66 and 4.50 t C ha-1 yr-1 in the unburned site and 4.08 and 2.12 t C ha-1 yr-1 in the burned site, respectively. The estimated annual NEP in the unburned and burned forest areas was found to be 1.25 and 0.02 t C ha-1 yr-1, respectively. Our results indicate that the differences of carbon budget and cycling between both study sites are considerably correlated with the losses of living plant biomass, insufficient nutrients and low organic materials in the forest soil due to severe damages caused by the forest fire. The burned Pinus densiflora forest area requires at least 50 years to attain the natural conditions of the forest ecosystem prior to the forest fire. © 2015 The Ecological Society of Korea. All rights are reserved.

Jang S.Y.,Korea Railroad Research Institute | Kim B.S.,Korea Land and Housing Corporation | Oh B.H.,Seoul National University
Cement and Concrete Research | Year: 2011

The purpose of the present study is to explore the diffusion characteristics of cracked concrete according to the width of cracks. Major test variables include crack width, concrete strength, fly ash addition, and maximum aggregate size. The diffusion characteristics have been measured by steady-state migration test. The present study indicates that the diffusion coefficients do not increase with increasing crack widths up to the so-called "threshold crack width." The threshold crack width for diffusion is found to be around 55-80 μm. Above this threshold value, the diffusion coefficients start to increase with crack width. A composite model with the introduction of "crack geometry factor" was derived to identify the diffusion coefficient in cracked concrete. It was shown that the crack geometry factor ranges from 0.067 to 0.206. Finally, the effects of concrete strength, fly ash addition and maximum aggregate size on diffusion coefficients are also discussed. © 2010 Elsevier Ltd.

Lee K.,Land and Housing Institute | Lee T.,Korea Land and Housing Corporation
2011 7th Asia-Pacific International Conference on Lightning, APL2011 | Year: 2011

This paper verified the electrical continuity of steelwork and tested the endurance of the steel bars' connection for lightning current in reinforced concrete apartments. It was proven that the steelwork in reinforced concrete apartment has electrical continuity with low resistance(below than 0.2 Ω. Also the installation of the steel bars as down-conductor must be very carefully implemented since it was proven that a poor connection between two reinforcement bars can easily cause serious damage of the concrete even with impulsive current of 50kA, 10/350 μs. © 2011 IEEE.

Choi J.,Korea Land and Housing Corporation | Lee D.,Catholic University of Pusan | Jung H.,Korea Institute of Science and Technology
Lecture Notes in Electrical Engineering | Year: 2014

Different information related to knowledge should be collected and filtered by system in order to discover and integrate knowledge in multiple knowledge representation environment. Especially, various information exist in multiple forms and in separate spaces, such as geographic information, housing statistics, and policy statements, in housing planning doamin. Housing policy support system is needed to make a proper spatial decision for supply housing when housing demand is occured. Thus, this paper proposes a conceptual design of system for knowledge discovery and integration in housing planning support. This system uses GIS based Housing Demand and Supply Mapping Model (HDSMM) to support policy decision using housing statistics and geographic information and to be composed of multi-dimension analysis, policy monitoring functionalities. © Springer-Verlag Berlin Heidelberg 2014.

Kim H.T.,Korea Land and Housing Corporation | Kim S.B.,Chung Ang Aerosurvey co. | Go J.S.,Chung Ang Aerosurvey co. | Eo Y.D.,Konkuk University | Lee B.K.,Kyonggi University
Journal of Convergence Information Technology | Year: 2010

3D geospatial information is information which presents the real world, and contributes to quantitative analysis and decision making support of construction, forestry, disaster management etc. using integrated orthophoto, DEM, attribute data, 3D modeling and visualizing information. Multi-looking Aerial photogrammetric method, which is more efficient than traditional one, can save the expenditure of public sector and increase their efficiency, and can be applied to diverse applications of private sector. It is expected to be a one of the valuable national projects in time.

Lee S.,Oregon State University | Dazkir S.S.,Georgia Southern University | Paik H.S.,Korea Land and Housing Corporation | Coskun A.,Middle East Technical University
Applied Ergonomics | Year: 2014

Healthcare facilities are often complex and overwhelming for visitors, and wayfinding in healthcare facilities can be challenging. As there is an increasing number of global citizens who travel to seek medical care in another country, it is critical to make wayfinding easy for visitors who are not familiar with the language in a foreign country. Among many wayfinding aids, symbols are helpful for those visitors who have limited ability to understand written language. This study tested universal healthcare symbols in the United States, South Korea, and Turkey to compare the comprehension of symbols cross-country and identify predictors of the correct comprehension. To explore statistically significant relationships between symbol comprehension and countries, Pearson's Chi-square tests, logistic regression, and ANOVA were conducted. The test results showed that ten symbols among 14 tested have significant relationship with countries. Results of this study demonstrate that symbol comprehension can be varied significantly in different countries. © 2013 Elsevier Ltd and The Ergonomics Society.

Lee H.,University of Texas at Arlington | Lee B.,Korea Land and Housing Corporation | Park K.,University of Texas at Arlington | Elmasri R.,University of Texas at Arlington
International Journal of Digital Content Technology and its Applications | Year: 2010

Information fused by multi-sensors is an important factor for obtaining reliable contextual information in smart spaces which use the pervasive and ubiquitous computing techniques. Adaptive fusion improves robust operational system performances then makes a reliable decision by reducing uncertain information. However, these fusion techniques suffer from problems regarding the accuracy of estimation or inference. No commonly accepted approaches exist currently. In this survey, we introduce the advantages and disadvantages of fusion techniques which can be used in specific applications. Second, we categorize well-known models, algorithms, systems, and applications depending on the proposed approaches. Finally, we discuss the related issues for fusion techniques within the smart spaces then suggest research directions for improving the decision-making in uncertain situation.

Lee J.-M.,Korea Land and Housing Corporation | Hyun K.-H.,Korea Land and Housing Corporation | Choi J.-S.,Korea Land and Housing Corporation
Water Science and Technology | Year: 2013

An analysis of the impact of a low impact development (LID) on runoff was performed using a Storm Water Management Model 5 (SWMM5)-LID model. The SWMM5 package has been developed to facilitate the analysis of the hydrologic impacts of LID facilities. Continuous simulation of urban stormwater runoff from the district which included the LID design was conducted. In order to examine the impact of runoff in the LID district the first, second and third highest ranked flood events over the past 38 years were analyzed. The assessment estimated that a LID system under historical storm conditions would reduce peak runoff by approximately 55-66% and runoff volume by approximately 25-121% in comparison with that before the LID design. The impact on runoff was also simulated under 50, 80 and 100 year return period conditions. Under these conditions, the runoff reductions within the district were estimated to be about 6-16% (peak runoff) and 33-37% (runoff volume) in comparison with conditions prior to the LID. It is concluded from these results that LID is worthy of consideration for urban flood control in future development and as part of sewer and stormwater management planning. © IWA Publishing 2013.

Lee S.,Purdue University | Paik H.S.,Korea Land and Housing Corporation
Building and Environment | Year: 2011

The rapid industrial and economic development in the recent several decades has caused serious environmental problems in Korea. The country has very limited carrying capacity; the population density in Korea is 481 people per km2, ranking the third-highest in the world [1]. In 1995, the Korean government implemented a volume-based waste fee system (unit pricing system) that required every household to purchase certified plastic bags for waste disposal [2]. Consequently, since the introduction of this regulation, household solid waste in Korea has been substantially decreased, and household recycling has been increased. This study is to examine current Korean household recycling and waste management behavior and explore factors that affect those behaviors. Data was gathered though a survey conducted in Seoul, Korea. For the data analysis, 196 responses were used. The impacts of several factors on recycling and waste management behaviors including NEP (New Environmental Paradigm), attitudes for recycling and waste management, and the respondents' demographic variables were examined. To analyze the data, correlations and multiple regressional analyses were conducted using SPSS 16. The results showed that environmental attitudes affected recycling and waste management behaviors significantly along with several demographic variables. © 2010 Elsevier Ltd.

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