• Transactions of the Korean Society of Mechanical Engineers
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• v.17 no.7 s.94
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• pp.1678-1685
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• 1993

This paper considers a time delay control of noncolocated flexible mechanical systems in discrete time domain. A stability criterion suggested in the previous paper is,extended in the consideration of infinite mode property of flexible systems and finite control sampling frequency. Based on the stability criterion, the one step advanced discrete time derivative control is suggested, which can stabilize infinite number of modes of a flexible system. The sensitivity analysis shows the robustness of the one step advanced control to the system parameter uncertainties and time delay errors. Application to a simply supported beam verifies the extended stability criterion and the effectiveness of the one step advanced D-control.

• Journal of Haehwa Medicine
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• v.12 no.2
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• pp.63-70
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• 2004

• 건강소식
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• v.3 no.5 s.20
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• pp.24-27
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• 1975

이른바「질」자가 붙는 병치고 잘 낫는 병이 없다. 그렇다고 죽지도 않는다. 병의 형태도 가지가지 이고, 치료법도 가지가지다-치질도 그런 병의 한 가지. 그러면 치질은 왜 생기며, 완전하게 고칠 수도 있을가.

• Journal of Haehwa Medicine
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• v.13 no.1
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• pp.19-25
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• 2004

• Journal of Haehwa Medicine
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• v.7 no.2
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• pp.305-325
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• 1999

• Journal of Haehwa Medicine
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• v.7 no.2
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• pp.337-360
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• 1999

• Journal of the Korean GEO-environmental Society
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• v.10 no.4
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• pp.65-71
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• 2009

Hydraulic fracturing technology has been widely applied in the industry for the recovery of the natural resources such as gas, oil and geothermal heat from hot dry rock. During hydraulic fracturing stimulation, multiple cracks are created resulting in mechanical interaction between cracks. Such an interaction influences obtaining hydraulic fracturing key parameters (crack opening, length, and borehole net pressure). The boundary collocation method (BCM) has been proved to be very effective in considering mechanical interaction. However, for better confidence, it needs to be verified by comparison with analytical solutions such as stress intensity factors. In this paper, three cases, single fracture in remote uniaxial tension, single fracture in remote shear stress field and two arbitrary segments in an infinite plane loaded at infinity are considered. As a result, the BCM is proved to be valid technique to consider mechanical interaction between cracks and can be used to estimate the hydraulic fracturing parameters such as opening of the fracture, and so on.

• Journal of Korea Multimedia Society
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• v.11 no.4
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• pp.554-565
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• 2008

The French neo-impressionist painter, George Seurat, introduced pointillism under the theory that the individual pigments of colors on the canvas are reconstructed on the human retina. Pointillism is a painting technique in which many small brush strokes are combined to form a picture in the canvas. When such a painting is seen from a far, the individual stroke color are unnoticeable and they are seen as intermixed colors. This is called juxtaposed color mixture. In this paper, we present a painterly rendering method for generating the pointillism images. For expressing countless separate dots which shown in the pointillism works, we propose a hierarchical points structure using Wang The method. Also a user defined palette is constructed based on the usage that Neo-Impressionist painter works on his palette. Lastly, based on this, a probability algorithm will be introduced, which divides the colors in the image(sampled by hierarchical point structure) into juxtaposed colors. A hierarchical points set which undergone juxtaposed color division algorithm is converted into brush strokes.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.42 no.2
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• pp.151-162
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• 2022

Prefab members have attracted attention because they can be mass-produced in factories through smart construction technology. For prefab prestressed concrete girders, it is important to manage the shapes of the girders properly from production to the pre-installation stage for consistency with the prefab floor plate during the erection process. This paper presents a camber reconstruction method using collocated strain measurements from the top and bottom of the prefab girder. In particular, the camber reconstruction method is applied to measured strain data in which the time-dependent behavior of concrete is considered after the introduction of prestress. Through Monte Carlo numerical simulations, the statistical accuracy of the reconstructed camber for a limited number of sensors, measurement errors, and nonlinear time-dependent behaviors are analyzed and validated.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.30 no.2
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• pp.130-141
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• 2012

This study examines the characteristics of landscape elements and the reappearance techniques of traditional landscape image in Chinatown of the Shanghai Street in Busan, Korea. The subjects of the study are commercial buildings owned by Chinese residents, commercial buildings' naming design and environmental sculptures in the Shanghai Street. The results are as follows: First, the design methods of the front side of commercial buildings were classified into two parts: facede design of buildings and signboard design. The design form of the buildings' facades were classified into five types, there are: emphasis type on Chinese characters' signboard, addition type on decorative signboard, introduction type of traditional patterns, imitation type of traditional architectures and modern architectures' modes. The signs of chinese commercial buildings were observed mostly as having a traditional Chinese font in yellow/white on a red background. It has been found that this style was the most popular method of sign design. Secondly, The commercial buildings' naming design was analyzed into design methods and meanings. Design methods were classified into three types: a combination of meaning and place, a combination of season and atmosphere and tourist attractions. The meaning of the commercial buildings' names was divided into three kinds: the wishes of the prosperity, elegant type and the appropriation of local attractions. Thirdly, the environmental sculptures of Shanghai Street were found to have been influenced by both through out Chinese culture with mixed Korean culture. Finally, as for characteristics of landscape elements, we found three reappearance techniques - addition, replacement, juxtaposition. The technique of addition is added new face to the base map by just two methods - extending and overlapping area. Replacement is created new faces from base map by the action of replacing, it has three types - local replacement, package replacement, successive replacement. Juxtaposition is the fact of two or more things placed together with contrasting effect, it also has three types - the same kind juxtaposition, a different kind juxtaposition, topological juxtaposition. This study is the basic research which is analyzing the landscape design in chinatown. But the research only on Shanghai Street may have some limits in scope. It is considered an necessary study to add, which is about chinatown in other city such as Incheon, Jeonju. Then it is expected that the results of this study can be used for the basic data of the landscape plans, that municipalities are actively progressing their respective development projects of Chinatown.