• Journal of Korea Water Resources Association
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• v.44 no.7
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• pp.511-522
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• 2011

Two-dimensional shallow water model based on the cut cell and the adaptive mesh refinement techniques is presented in this paper. These two mesh generation methods are combined to facilitate modeling of complex geometries. By using dynamically adaptive mesh, the model can achieve high resolution efficiently at the interface where flow changes rapidly. The HLLC Reimann solver and the MUSCL method are employed to calculate advection fluxes with numerical stability and precision. The model was applied to simulate the extreme urban flooding experiments performed by the IMPACT (Investigation of Extreme Flood Processes and Uncertainty) project. Simulation results were in good agreement with observed data, and transient flows as well as the impact of building structures on flood waves were calculated with accuracy. The cut cell method eased the model sensitivity to refinement. It can be concluded that the model is applicable to the urban flood simulation in case the effects of sewer and stormwater drainage system on flooding are relatively small like the dam brake.

• Journal of Korea Water Resources Association
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• v.45 no.10
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• pp.1023-1034
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• 2012

Linear regression technique has been used widely in water resources field as well as various fields such as economics and statistics, and so on. Using fuzzy regression technique, it is possible to quantify uncertainty and reflect them to the regression model. In this study, fuzzy regression model is developed to compute design floods in any place in Pyeongchang River basin. In ungaged basins, it is usually difficult to obtain data required for flood discharge analysis. In this study, basin characteristics elements are analyzed spatially using GIS and the technique of estimating design flood in ungaged mountainous basin is studied based on the result. Fuzzy regression technique is applied to Pyeongchang River basin which has mountainous basin characteristics and well collected rainfall and runoff data through IHP test basin project. Fuzzy design flood estimation equations are developed using the basin characteristics elements for Pyeongchang River basin. The suitability of developed fuzzy equations are examined by comparing the results with design floods computed in 9 locations along the river. Using regional regression method and fuzzy regression analysis, the uncertainties of the design floods occurred from the data monitoring can be quantified.

• Land and Housing Review
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• v.6 no.3
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• pp.117-127
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• 2015

Korean government has launched a new public rental housing policy for younger generation suffering from instable housing conditions in CBD area. This paper is to analyze the financial feasibility of urban public rental housing projects, based on its cash flows. Urban rental housing projects should find out the way to reduce costs and to secure cheap land, because of the high land price in CBD area and complex relationship of legal rights. Project types are categorized by the land acquisition method and district characteristics. For 10 sample projects, financial feasibility was analyzed. Cash flows were calculated on the design plan and 16 scenarios were made by combining 4 important variables. The variables are increase rate of land price, increase rate of monthly rents, ratio of public and market rents, and the interest rate of National Housing Fund. The findings are as follows. Government land rent-type can reduce initial costs because it is not necessary to buy land. However, total NPV is lowered at the time of liquidation due to the land return. Private land acquisition-type require more initial costs. But the NPV at liquidation time increases with land disposal. To improve financial feasibility, acquisition-type should be preferred in high land-price area and rent-type should be preferred in low land-price area. Among influencing variables, the rate of increase in land price and the ratio of public and market rents turned out to be the most important. Although the ratio of public and market rents can be controllable, high ratio will cause the burden of tenants. Therefore, interest rate adjustment of National Housing Fund is more desirable.

• Land and Housing Review
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• v.5 no.1
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• pp.11-24
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• 2014

The expected launching countries are selected based on the state and strategy of businesses undertaking by LH, then the legal systems for urban development of those countries are investigated and analyzed to be used as basic data for advancing to oversea urban development. The results are showing as follows. First, on the basis of the advancing priority, and the level and obtaining possibility of legal system for urban developments, Bangladesh, Thailand, Dominican Republic, and Venezuela are selected to be investigated among the countries of Central and South America and Asia to where expected to be advanced. Second, most of the selected countries establish and promote the national housing policies by their own National Housing Authority. For example, First-Home Policy and National Housing Development Strategy, etc. are established in Thailand, and National Housing Authority takes charge of the housing development for low-income bracket. Third, the laws and project procedures are investigated, then compared to the similar laws of Korea. The common "Land Allocation Act" is legislate in Bangladesh and Thailand, for example, "Land Allocation Act" and "Town and City Planning Act" are enacted in Thailand. On the other hand, the laws for urban and housing developments vary from country to country those are located in Central and South America. Meanwhile, it is verified that "Act on Planning and Use of National Territory" of Korea is similar to the "Town and City Planning Act" of Thailand.

• 한국HCI학회:학술대회논문집
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• 2009.02a
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• pp.876-883
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• 2009

Learning Diagnosis & Prescription Service(LDPS) in Cyber Home Learning System is a educational service which provides customized learning contents based on student's academic level and individualized counseling and comments after diagnosing learner's study habits beyond the past e-Learning systems which offer the same contents to different students. For a national point of view, it is a crucial project in public education to achieve the goals of the next-generation e-Learning service by making a lot efforts both in time and money. However, those efforts has been made, not in terms of providing a better quality of service and a better user experience in a effective and enjoyable way, but in terms of developing the technology-driven system. Therefore, in this study, two types of usability evaluations has been conducted in order to enhance a user experience on the LDPS. One is the expert reviews by utilizing the usability evaluation tools (heuristics) which was focused on educational contexts developed by Suh Young-suhk(2007). The other is the user testing with students who have done think-aloud during the evaluation, remembering their retrospective experience with LDPS, and the interview with teachers & service operators were conducted. As the implications on the research, this is an effort to provide an user-friendly educational system for the students nationwide.

• Korean Journal of Construction Engineering and Management
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• v.7 no.6
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• pp.112-120
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• 2006

Although waste management in construction industry has a significant impact on both economical and environmental issues, the current level of waste management performance in Korean construction is reported as relatively low. To improve any type of management performance, it is necessary to diagnose the current status of the performance level. In this context, this research is aimed to identify important factors in influencing the waste management performance and to develop an evaluation tool for the purpose of assessing the level of the performance for a particular construction site. In this paper, 59 influential factors have been identified and categorized into five classes, i.e., manpower, material, method, management, and policy, in terms of the characteristics of the factors. In addition, an evaluation tool has been developed in order to effectively quantify all the 59 factors based on a thorough industry survey. The output of the Tool, which is Waste Management Index, effectively assess the level of waste management performance for a particular project and provide with the most leveraged factors in need for improvement in waste management performance.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• autumn
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• pp.73-81
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• 2003

The construction industry has been experiencing a major challenge in its work force, 'the shortage of skilled craft workers.' This problem has been caused by several factors such as the poor image of the construction industry, lack of training and education, unclear career path, declining wages, and changing work force demographics. A 'step-change' approach called the 'Two-Tier Work Force Strategy' has been proposed by the Center for Construction Industry Studies (CCIS) to deal with the work force related issues in a radical way. It is composed of two separate strategies, Tier I and II. The Tier I strategy uses less skilled and task trained craft workers, and has a larger administrative site management team than the Tier II strategy. The Tier II strategy utilizes fewer, better-educated, and higher skilled workers who perform some lower-management functions in addition to craft functions. They are paid more, but produce more through higher skills, stay on the job longer through multi-skilling, and deliver improved project performance in safety, quality, schedule, and cost The Two-Tier Work Force Strategy has the potential to resolve the current work force problems and foster a better work force environment in the future.

• Tunnel and Underground Space
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• v.15 no.4 s.57
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• pp.275-287
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• 2005

At the planning and design stages of a development of underground space or tunneling project, the information regarding ground conditions is very important to enhance economical efficiency and overall safety In general, the information can be expressed using RMR or Q-system and with the geophysical exploration image. RMR or Q-system can provide direct information of rock mass in a local scale for the design scheme. Oppositely, the image of geophysical exploration can provide an exthaustive but indirect information. These two types of the information have inherent uncertainties from various sources and are given in different scales and with their own physical meanings. Recently, RMR has been estimated in unsampled areas based on given data using geostatistical methods like Kriging and conditional simulation. In this study, simulated annealing(SA) is applied to overcome the shortcomings of Kriging methods or conditional simulations just using a primary variable. Using this technique, RMR and the image of geophysical exploration can be integrated to construct the spatial distribution of RM and to evaluate its uncertainty. The SA method was applied to solve an optimization problem with constraints. We have suggested the practical procedure of the SA technique for the uncertainty evaluation of RMR and also demonstrated this technique through an application, where it was used to identify the spatial distribution of RMR and quantify the uncertainty. For a geotechnical application, the objective functions of SA are defined using statistical models of RMR and the correlations between RMR and the reference image. The applicability and validity of this application are examined and then the result of uncertainty evaluation can be used to optimize the tunnel layout.

• Journal of Environmental Science International
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• v.22 no.12
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• pp.1671-1681
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• 2013

The study selected 10 regions among major Korean cities. Then the study classified the yearly change of relative humidity of those regions for 37 years based on 1996 (from 1974 to 2011) aimed at high temperature days, and examined them by stage regarding daily maximum temperature. For large cities and small cities, in general relative humidity had been likely to increase at high temperatures of $30^{\circ}C$ or over before 1996, whereas it has decreased since 1996. For suburban areas, relative humidity had been prone to diminish before 1996, whereas it has been likely to either increase since 1996 or rarely some of the cities have not shown any change. The increasing tendency of relative humidity before 1996 in large cities and small cities is believed to be because of an increase of the latent heat of vaporization by the supply of steam from cooling towers established in downtown areas. Meanwhile, the decreasing tendency from 1996 is concluded to be caused by the change from counter-current circular cooling towers, which produce a great quantity of steam including arsenic acid, to cross-flow cooling towers, which produce hardly any steam containing arsenic acid. This change was in accordance with the modification and pursuit of an urban planning law that ordered cooling towers that had been installed on rooftops be installed in the basement of buildings in consideration of a "Green network creation" project by the Ministry of Environment, urban beautification, concerns since 1996 over building collapses, and according to an argument that steam containing arsenic acid could be harmful to human health owing to chemicals contained in the water in the cooling tower in summer.

• Korean Institute of Interior Design Journal
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• v.20 no.3
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• pp.127-134
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• 2011

Interior design has diverse functions and roles according to recent changes in life and cultural style. As the meaning of space varies, the furniture as another element of the space should also be planned and included in the beginning of the project to accomplish its functional role on the finished space and not only be placed. The relationship between Interior space and furniture should be studied and understood at the same realm because they have a complementary relationship. The final destination of design, which is very challenging to accommodate people, the designer needs to approach to the interior space and furniture in a cognitive view. The study of Semiotics views in a knowledgeable and epistemological way every element as a sign and by the relationship of their characters it makes to understand the structure of the signs. Charles Sanders Peirce, a leader of Semiotics in USA, classified the structure of Sign into Representamen, Object and Interpretant to complete the theory which could systematically describe physical characteristic and function of the Sign and its significance in practical use. Peirce stated that all nine types of Sign would be generated if each structure of Sign in combined with three categories of Sign such as Firstness, Secondness, and Thirdness. In this study, based on Peirce's nine types of Sign, the interrelationship between space and furniture in interior design was investigated with examples in Living Space, Office Space, and Commercial Space, respectively. In the category of Representamen, which can be classified into Qualisign, Sinsign, and Legisign, it is a feature of Living Space to be expressed in harmonized and stabilized ways. In Office Space vertical/horizontal elements and open expression are differently showed depending on fields. And splendid and interesting expressions are showed in Commercial Space. In the category of Object, which can be classified into Icon, Index, and Symbol, each function of Sign has distinctly been showed as Symbol in Living Space, Index in Office Space, and Icon in Commercial Space, respectively. In the category of Interpretant, which can be classified into Rheme, Dicisign, and Argument, it was found that space image of Living Space is transferred to human being, Office Space regulates human bing, and Commercial Space binds human being with the space. In conclusion the function of the interior space and the furniture could be explained in another way with re-interpretation of interrelationship among interior space elements in the concept of Semiotics. It is expected that interpretation with Semiotics in interior design will grow to new theory of design.