• Journal of Digital Convergence
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• v.11 no.10
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• pp.255-262
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• 2013

Data envelopment analysis(DEA) is a linear programming procedure designed to evaluate the relative efficiency of a set of peer entities called decision making units which use the same inputs to produce the same outputs. It has been widely employed in a variety of disciplines as an efficiency or performance measurement tool for comparing a set of entities such as firms, banks, hospitals, nations and organizations. The method, however, cant's make the priority of their performance when many units have efficiency score of unity or 100 percent. In this paper, we propose a new approach which combine qualitative method(graphical approach using network analysis) and quantitative method(super-efficient analysis using DEA), and present the results of an empirical analysis using the data of the Korean professional baseball players. As a result, there were 12 DMU that priority is hardly realized through DEA. However, this problem could be solved with super-efficiency analyzing. Also, more in-depth interpretation was able through integrating results of dendrogram and super-efficiency analyzing and prospecting it in qualitative, quantitative ways.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.45 no.5
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• pp.38-47
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• 2008

The most commonly used location recognition system is the GPS-based approach. However, the GPS is inefficient for an indoor or urban area where high buildings shield the satellite signals. To overcome this problem, this paper propose the indoor positioning method using wavelet and neural network. The basic idea of proposed method is estimated the location using the received signal strength from wireless APs installed in the indoor environment. Because of the received signal strength of wireless radio signal is fluctuated by the environment factors, a feature that is strength of signal noise and error and express the time and frequency domain is need. Therefore, this paper is used the wavelet coefficient as the feature. And the neural network is used for estimate the location. The experiment results indicate 94.6% an location recognition rate.

• Child Health Nursing Research
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• v.8 no.2
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• pp.164-173
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• 2002

The vision disturbances of school-age children has been recognized as and important school health problem. The purpose of this study is to describe the current status of the visual health and to explore the related factors for the decrease in visual acuity in the elementary school age children. The study subjects were 697 children (Boys: 338, Girls: 359) of 4th to 6th grade in two school in urban area. The visual acuity data of the school health examination in 1999 and 2000 were utilized for analysis. The questionnaire for children and parents was used for survey. The findings were as follows. 1. The prevalance rate of the children with the visual acuity less than 0.7 on the left eye were 26.84％ ( Grade 4), 31.30％ (Grade 5), and 38.39％ (Grade 6). The rate on the right eye were 28.31％ (Grade4), 30.37％ (Grade 5), and 37.92％ (Grade 6). There was a significant difference in the rate of the visual acuity less than 0.7 according to grade (p<.01). 2.The rate of visual acuity decrease was 40.12％. 3. The factors related to the decrease in the visual acuity were grade, sex, genetic factor, posture, and the awareness of the visual acuity. There was more decrease in the visual acuity when the children were in higher grade (O.R= 1.06), girls (O.R=2.29). Children having parents with better vision (Father: O.R=1.26; Mother O.R= 1.25) showed better vision. On the other hand, when the children have siblings with glasses, there was more decrease in the visual acuity (O.R=2.31). Students with good posture during study (sitting on the chair) and watching TV to the lower direction showed less decrease in the visual acuity. Also, when the students know their visual acuity, the rate of decrease were lower. The variables which odds ratio were statistically significant were sex (p<.01), siblings with glasses (p <.01), and awareness of visual acuity (p<.01).

• Land and Housing Review
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• v.1 no.1
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• pp.51-57
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• 2010

The importance of seismic design is greatly emphasized recently in Korea, resulting in an increase in the number of dynamic analysis being performed. One of the most important input parameters for the dynamic seismic analysis is input ground motion. However, it is common practice to use recorded motions from U.S. or Japan without considering the seismic environment of Korea or synthetic motions generated in the frequency domain. The recorded motions are not suitable for the seismic environment of Korea since the variation in the duration and energy with the earthquake magnitude cannot be considered. The artificial motions generated in frequency domain used to generated design response spectrum compatible ground motion has the problem of generating motions that have different frequency characteristics compared to real recordings. In this study, an algorithm that generates target response spectrum compatible ground motions in time domain is used to generate a suite of input ground motions. The generated motions are shown to preserve the non-stationary characteristics of the real ground motion and at the same, almost perfectly match the design response spectrum.

• Land and Housing Review
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• v.11 no.3
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• pp.49-59
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• 2020

The Seoul's 2030 Youth-Housing is a policy to promote the development of private sector-built rental housing in a Station Influence Area (SIA). It is a representative policy to resolve a housing problem for the youth in Seoul. The Seoul Metropolitan Government has made continuous policy improvements to respond to earlier criticisms on the policy. In December 2018, the Seoul Metropolitan Government enlarged the possible spatial boundaries of the SIA that the private sector developer can carry out the housing development projects. This study attempts to assess the potential sites available in Seoul by considering the youth's demand. This study used the suitability modelling technique to evaluate the potential sites. In detail, we established three sub-models by reflecting rent, accessibility to living areas of the youth, and accessibility to living SOC for the youth's demand. According to the results, the Hanyang City Wall area, which was newly included by the recent policy revision, showed moderate scores to fit the housing projects, while some Gangbuk areas, which have high accessibility and relatively lower rents, showed the best scores appropriate for the projects. The age group of 20s preferred university districts, while the age group of 30s preferred to locate near Seoul's main office areas. We suggest that the Seoul metropolitan government develops better ways to guage and reflect the demand for differing youth groups and the demand by age groups.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.20 no.1
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• pp.1-11
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• 2002

This study set up a purpose in the efficient utilization of security target objects. This purpose is the following: Firstly, this study analyzed problem about deleted areas for security described on aerial photography image. Secondly, this study made clustering and labeling to recognize censored areas of image. Finally, this study tried to maximize various utilizability of digital image data through postprocessing algorithm. Based on these courses, the results of this study appeared that brightness value of image increased depending on topography and quantities of topographic features. It was estimated that these was able to utilized by useful estimative data in judging information of topography and topographic features included in the total image. Besides, in the image recognition and postprocessing, the better result value was not elicited than in a mountainous region. Because it was included that a lots of topography and topographic features was similarly recognized with the process for deletion of the existing security target objects in urban and suburb region. This result appeared that the topography and quantities of topographic features absolutely affected the recognition and processing of image.

• Journal of the Korean Society for Railway
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• v.19 no.2
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• pp.234-242
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• 2016

In express operation plans for urban trains, it is effective for the reduction of the number of sidetracks to apply a high performance train that has improved acceleration/deceleration ability and a regular train to local and express trains, respectively. In this research, based on a plan to use a high performance train for a local train, an optimization methodology is suggested to reduce the number of sidetracks and the operation time of the local train simultaneously. The optimization solver applied in this research is a genetic algorithm; headway, location of sidetrack and waiting time at the sidetrack are considered as design variables in the optimization problem. Consequently, by applying this system to Seoul metro line no.7, the effect of the suggested methodology was verified by obtaining the proper optimum solution.

• KIEAE Journal
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• v.10 no.5
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• pp.159-164
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• 2010

High-rising buildings are a sort of solution to recent cities. Till now real estate development was concentrated in new development on vacant lots, and it resulted urban sprawl. Generally large cities are confronted with the exodus of industry and population from city. High-rising buildings solve many problems associated with this problem. The purpose of this research is to identify the effect of super high-rise mixed use building project process on apartment price. For this study, the hypothesis is that price of apartments is influenced by project process of super high-rise mixed use building. The study concerned 4 variations of project process that is building permits stage, sale stage, construction starting stage and stage of moving into building. The target projects of buildings are selected by number of floor(over 40 floors) and construction time. And 48 apartment complex are selected around super high-rise mixed use building. This study uses hedonic price function to analysis effect of project process of super high-rise mixed use building. A price of apartments is defined as a dependent variable. Characteristics of residence, complex, district and super high-rise building are defined as independent variables. The results are as follows; first, there is no error in price model of this study. Second, it is found that apartment price was influenced negatively by building permit stage and sale stage of super high-rise mixed use building. But that was influenced positively by construction starting stage and stage of moving into building of that. Third, as the project process of super high-rise mixed use building was proceeded, price of apartments was increased.

• KIEAE Journal
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• v.11 no.2
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• pp.75-82
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• 2011

In Korea, the ratio of population in urban areas used to be only 50.1% in 1970, but with the value risen to 90.8% in 2009, urbanization is going on rapidly. Urbanization, which occurs by the rampantly planted buildings, has become major source of raising building density, changing wind direction and reducing wind amount, and such reductions are affecting even inside the building. In each year, among the total energy consumption in Korea, residential portion takes up significant ratio, and specifically the ratio of apartment house is shown to be highest. In order to solve such problem, many studies are being conducted for the improvement of natural ventilation performance. The natural ventilation performance of apartment house are significantly determined by the characteristics of external and internal structure, but in macroscopic perspective, the performance is established fundamentally by the layout characteristics of the main building of the apartment house in preparation for wind conditions. So far researches on raising the thermal comfort through elevation of ventilation performance have been conducted actively, but many of them propose only theoretical concepts deduced through wind path analysis, and do not include any indicator to measure ventilation performance simply only with area data from layout planning stage. Therefore, in this study, gap ratio a wind field measuring indicator was developed, and after the ventilation characteristics by layout types and main building uniformity were identified, the scope of gap ratio efficient for ventilation and that of uniformity were clarified, followed by verification through simulation.

• Korean Institute of Interior Design Journal
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• v.16 no.6
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• pp.136-143
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• 2007

In case of commercial area of underground commercial area that occupy large amount of space among underground space, the lighting plays a very important role in terms of user's psychological and physiological side. The purpose of this research is to suggest the direction of lighting design of underground commercial area for revitalization of urban function. Spacial scope of this research were adjusted as 8 underground commercial area in Seoul. Scope of content of this research is about lighting plan of underground commercial area. Research methods are as follows: First, we identified the psychological and physiological problem of the underground space which appears in preceding research and the literature. In order to make the design element which is necessary to an underground space it executed this research method. By this research method we made the design element which is necessary to an underground space. Second, Through site visits, illumination level and lighting plans were studied by each category. Third, we presented the direction of illumination plan of each space in underground commercial area We could conclude a conclusion as following through this research. First, lighting plan of underground commercial area should solve user's psychological, physiological problems and should take advantage of the traits of each space. Second, the usage of space of underground commercial area changes as time pass, a lighting plan is needed in order to cope with this. Third, a lighting plan is needed for user's rest within underground commercial area. Fourth, detailed lighting plan is needed for space users of underground commercial area.