• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.6D
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• pp.1025-1032
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• 2006

Sensor modeling of high-resolution satellites is a prerequisite procedure for mapping and GIS applications. Sensor models, describing the geometric relationship between scene and object, are divided into two main categories, which are rigorous and approximate sensor models. A rigorous model is based on the actual geometry of the image formation process, involving internal and external characteristics of the implemented sensor. However, approximate models require neither a comprehensive understanding of imaging geometry nor the internal and external characteristics of the imaging sensor, which has gathered a great interest within photogrammetric communities. This paper described a comparison between rigorous and various approximate sensor models that have been used to determine three-dimensional positions, and proposed the appropriate sensor model in terms of the satellite imagery usage. Through the case study of using IKONOS satellite scenes, rigorous and approximate sensor models have been compared and evaluated for the positional accuracy in terms of acquirable number of ground controls. Bias compensated RFM(Rational Function Model) turned out to be the best among compared approximate sensor models, both modified parallel projection and parallel-perspective model were able to be modelled with a small number of controls. Also affine transformation, one of the approximate sensor models, can be used to determine the planimetric position of high-resolution satellites and perform image registration between scenes.

• The KIPS Transactions:PartB
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• v.14B no.7
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• pp.513-522
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• 2007

Clustering is to divide given data and automatically find out the hidden meanings in the data. It analyzes data, which are difficult for people to check in detail, and then, makes several clusters consisting of data with similar characteristics. On-Line Document Clustering System, which makes a group of similar documents by use of results of the search engine, is aimed to increase the convenience of information retrieval area. Document clustering is automatically done without human interference, and the number of clusters, which affect the result of clustering, should be decided automatically too. Also, the one of the characteristics of an on-line system is guarantying fast response time. This paper proposed a method of determining the number of clusters automatically by geometrical information. The proposed method composed of two stages. In the first stage, centers of clusters are projected on the low-dimensional plane, and in the second stage, clusters are combined by use of distance of centers of clusters in the low-dimensional plane. As a result of experimenting this method with real data, it was found that clustering performance became better and the response time is suitable to on-line circumstance.

• Journal of the Korean Society of Floral Art and Design
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• no.42
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• pp.3-21
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• 2020

In this paper, the funeral was defined as a culture of death and, on the most important ideological basis, the biological death was not recognized as the end of the world, but as a starting point for another life. Various funeral cultures were investigated and the funeral floral design was analyzed through the case. Based on this, it was concluded that Korea's funeral floral design was an impediment to the development of funeral floral design, similar to the use of limited materials. Storytelling, a communicative concept through the exchange of emotions and opinions, rather than unilaterally conveying a message as an answer, is one of the most effective marketing strategies in the emotional consumption era. Based on this, the target person was selected to analyze life and draw suggestions from his life. Accordingly, the production of the work was attempted by applying storytelling to the funeral floral design. The painting design applied to storytelling expressed the symbol and meaning of the painting design material, and the color and form of the floral design in various forms and colors of pastel line, which are based on peach color that symbolizes the deceased, in a departure from the traditional funeral painting design with the solemn atmosphere of the geometric design centered on the white chrysanthemum material.

• Journal of the Korea Society for Simulation
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• v.19 no.1
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• pp.23-31
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• 2010

Due to the fact that fisheye lens can provide super wide angles with the minimum number of cameras, field-of-view over 180 degrees, many vehicles are attempting to mount the camera system. Not only use the camera as a viewing system, but also as a camera sensor, camera calibration should be preceded, and geometrical correction on the radial distortion is needed to provide the images for the driver's assistance. In this thesis, we introduce a geometric correction technique to minimize the loss of the image data from a vehicle fish-eye lens having a field of view over $180^{\circ}$, and a asymmetric distortion. Geometric correction is a process in which a camera model with a distortion model is established, and then a corrected view is generated after camera parameters are calculated through a calibration process. First, the FOV model to imitate a asymmetric distortion configuration is used as the distortion model. Then, we need to unify the axis ratio because a horizontal view of the vehicle fish-eye lens is asymmetrically wide for the driver, and estimate the parameters by applying a non-linear optimization algorithm. Finally, we create a corrected view by a backward mapping, and provide a function to optimize the ratio for the horizontal and vertical axes. This minimizes image data loss and improves the visual perception when the input image is undistorted through a perspective projection.

• Archives of design research
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• v.17 no.2
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• pp.311-322
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• 2004

The purpose of this study is to ascertain pattern design element in traditional palaces among those in the neighboring three nations of East Asia, notably Korea, China and Japan. The basic assumption underlying this study is that these northeastern Asian states have been developed a unique inter-cultural ties over long periods of time in history, culminating in their respective design cultures. Undoubtly the ultimate goal to be pursued, by so doing, has to be inquiry into the identical prototype of Korean pattern design element. In the West, the pattern is appreciated by an aesthetic level, but the East Asian pattern is a symbolic alphabet deeply rooted in religious and folk beliefs. The difference of the respective country comes from the expression style of the pattern the Chinese express the magnificent pattern with various color, the Korean do the moderate pattern with harmonious color with the nature and the Japanese do the stylized pattern with the material color. To sum up similarities and dissimilarities among the design element in traditional palaces of Korea, China, and Japan is as the following : It is to be noticed that the mainly common characteristics of the artistic design are 'naturalism', 'harmonious ideas 'and 'confucianism'. But the representation style of the design element is differed from the country.

• Journal of Wetlands Research
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• v.6 no.3
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• pp.71-81
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• 2004

In recent, the heavy rainfall is frequently occurred and the damage tends to be increased. So, more careful hydrologic analysis is required for the designs of the hydraulic or disaster prevention structures. The time distribution of a rainfall is one of the important factors for the estimation of peak flow in hydrologic and hydraulic designs. This study is to suggest a methodology for the estimation of a rainfall time distribution which can reflect the meteorologic and topographical characteristics of Daejeon area. We collect the 34 years' rainfall data recorded in the range of 1969 to 2002 for Daejeon area and we performed the rainfall analysis with the data in between May and October of each year. According to the Huff method, the collected data corresponds to the first quartile which the rainfall is concentrated in the primary stage but the suggested method shows the different rainfall distribution with the Huff method in time. The reason is that the Huff method determines the quartile in each storm event while the suggested one determines it by estimating the dimensionless distribution of rainfall in duration after the accumulation of rainfall in time. The rainfall distributions estimated by two methodologies were applied to the Gabcheon basin in Daejeon area for the estimation of flood flow. Here we use the SCS method for the effective rainfall and unit hydrograph for the flood discharge. As the results, the peak flow for 24-hour of 100-year frequency was estimated as a $3421.20m^3/sec$ by the Huff method and $3493.38m^3/sec$ by the suggested one. We can see the difference of $72.18m^3/sec$ in between two methods and thus we may carefully determine the rainfall time distribution and compute the effective rainfall for the estimation of the peak flow.