• Journal of Ship and Ocean Technology
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• v.11 no.3
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• pp.1-13
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• 2007

A semi-submersible drilling rig is regarded as one of the typical offshore structures operated in the field with moderate environments such as the Gulf of Mexico, Brazil, and West Africa. Its typical roll and pitch natural periods are around 30 seconds, which avoids prevailing regions of the wave energy spectrum, and their responses in waves are quite acceptable for common operation conditions. But large roll and pitch motions can be induced by wave difference frequency energy spectrum if the metacentric heights of a semi-submersible decrease to small values in some loading conditions, and it is because the roll and pitch natural periods increase and approach to the region where the spectral density of the low frequency wave drift moment has significant value. This paper describes the low frequency roll motion of a semi-submersible that are excited by the wave 2nd order difference frequency energy by a series of model experiments. From the model tests with several different initial metacentric heights (GM), it was observed that a semi-submersible can experience large roll motion due to the wave group spectrum.

• Korean System Dynamics Review
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• v.8 no.2
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• pp.235-252
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• 2007

This study focused on the analysis of the abilities and characteristics of the systems thinking for pre-service elementary teachers. Systems thinking is defined as the ability to see the world as a complex system in which one understands that everything is connected to everything else. For this study, 345 subjects carrying of the 2nd grade were selected and participated in making out the protocol developed by Sweeney and Sterman(2000) for the estimating ability of the systems thinking. As a result, the proportion of the correct answers based on the total points of view was 63%. However, the proportion of correct answer was considerably different according to the gender. The women group showed 53%, while the men group was 76%. Especially, there was a great difference in the rates of correct answer depending on their academic tracks of the humanities or natural science courses in the high school. The average rates of the correct answers for the natural science and the human science were 84 and 46%, respectively. Consequently, the ability of the systems thinking for pre-service elementary teachers is highly related with their gender and learning experience in the high school. The results of this study may contribute the practical use of the systems thinking in the area of the science education.

• Korean Journal of Computational Design and Engineering
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• v.16 no.4
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• pp.277-284
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• 2011

In tangible augmented reality (AR) environments for virtual prototyping, the user interacts with virtual products by manipulating tangible objects with his or her hands, but the user often encounter awkward situations in which his or her hands are occluded by augmented virtual objects, which reduces both immersion and ease of interaction. In this paper, we present how to resolve such hand region occlusion in order to enhance natural interaction and immersive visualization. In the AR environment considered, we use two types (product-type and pointer-type) of tangible objects for tangible user interaction with a virtual product of interest. Holding the tangible objects with his or her hands, the user can create input events by touching specified regions of the product-type tangible object with the pointer-type tangible object. We developed a method for resolving hand region occlusion frequently arising during such user interaction, It first detect hand region in a real image and refines the rendered image of the virtual object by subtracting the hand region from the rendered image, Then, it superimposes the refined image onto the real image to obtain an image in which the occlusion is resolved. Incorporated into tangible AR interaction for virtual prototyping of handheld products such as cellular phones and MP3 players, the method has been found by a preliminary user study that it is not only useful to improve natural interaction and immersive visualization of virtual products, but also helpful for making the users experience the products' shapes and functions better.

• The Research Journal of the Costume Culture
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• v.4 no.3
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• pp.349-359
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• 1996

The research was designed to find out the effects of design elements ; ①color, ②pattern, on image perception of clothing by using a qualitative depth interview method. The subjects were 40 women who lived in Taejon and aged 20 to 40. The interview results were both hand recorded and tape recorded for further analysis by researchers and judge groups. And the results were as follows. 1. The most preferred colors appeared to be blue and black, while stripes, checks and flowers were most favorite patterns. 2. There were individual difference in color and pattern perception, however the color image of yellow was brightness, red was dashing, green comfortable, blue cool, and black tightness. The image of geometric pattern was modesty and natural motif pattern was dynamics. 3. The tow major forces which affected the image of design elements were appeared as followed : 1) Color images affected by the image of natural objects which obtained the color. 2) Individuals past experience and emotional status also affected the personal image perception. 4. The color and pattern preference for the Koran traditional customes and Western tow piece were significantly different and this result imply cultural stereotyping on image perception of design elements. On conclusion, the results supported the research model of form perception and image evaluation.

• Fashion & Textile Research Journal
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• v.22 no.5
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• pp.561-569
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• 2020

In this study, the dyeing of Chrysanthemum indicum Linne alone and the combined dyeing of Chrysanthemum indicum Linne and onion shell were first performed to compare dyeing properties. A combination extract of Chrysanthemum indicum Linne and onion shell can be expected to improve coloration. A Hanbok design for children used a natural dyeing fashion dyeing method to make the Chrysanthemum pattern. Chrysanthemum indicum Linne is a type of wild chrysanthemum with various medicinal effects for headache and stress relief, skin diseases, insomnia and depression. Widely used onion shells have medicinal properties that help prevent and treat various adult diseases. The colors of silk dyed exclusively by Chrysanthemum indicum Linne, and the colors of silk dyed by Chrysanthemum indicum Linne and onion shell extract are yellow; in addition, silk dyed by Chrysanthemum indicum Linne and onion shell extracts were almost all unchanged. Four hanboks, which are comfortable for children to wear and use, were produced using Chrysanthemum indicum Linne and onion shell extracts. If children wear hanbok fashion products with auspicious patterns, they can provide a chance to simultaneously experience the traditional symbolism of Korean patterns and culture. In addition, it is expected to develop pride in traditional dress culture.

• Clinical and Experimental Pediatrics
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• v.48 no.11
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• pp.1153-1161
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• 2005

As known by other name(natural immunity), the innate immune system comprises all those mechanisms for dealing with infection that are constitutive or built in, changing little with age or with experience of infection. Though in some ways less sophisticated than adaptive immunity, innate immunity should not belittled, since it has evidently protected thousands of species of invertebrates sufficiently to survive for up to 2 billion years. In the innate immune system, molecules of both cellular and humoral types are involved, corresponding to the need to recognize and dispose of different types of pathogen, to promote inflammatory responses and to interact to the adaptive immune system. A major features of innate immunity are the presence of the normal gut flora, complements, macrophages, dendritic cells, natural killer cells and many cytokines that can block the establishment of infection. Both phagocytic cells and complement system have tremendous potential for damaging host cells, but fortunately they are normally only triggered by foreign materials, and usually most of their destructive effects are focussed on the surface of these or in the safe environment of the phagolysosome. This article addreses the comprehensive mechanisms of the major components of the innate immune system to prevent the infection.

• Smart Structures and Systems
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• v.13 no.3
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• pp.473-500
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• 2014

Tuned mass dampers (TMDs) have been installed in many high-rise buildings, to improve their resiliency under dynamic loads. However, high-rise buildings may experience natural frequency changes under ambient temperature fluctuations, extreme wind loads and relative humidity variations. This makes the design of a TMD challenging and may lead to a detuned scenario, which can reduce significantly the performance. To alleviate this problem, the current paper presents a proposed approach for the design of a robust and efficient TMD. The approach accounts for the uncertain natural frequency, the optimization objective and the input excitation. The study shows that robust design parameters can be different from the optimal parameters. Nevertheless, predetermined optimal parameters are useful to attain design robustness. A case study of a high-rise building is executed. The TMD designed with the proposed approach showed its robustness and effectiveness in reducing the responses of high-rise buildings under multidirectional wind. The case study represents an engineered design that is instructive. The results show that shear buildings may be controlled with less effort than cantilever buildings. Structural control performance in high-rise buildings may depend on the shape of the building, hence the flow patterns, as well as the wind direction angle. To further increase the performance of the robust TMD in one lateral direction, active control using LQG and fuzzy logic controllers was carried out. The performance of the controllers is remarkable in enhancing the response reduction. In addition, the fuzzy logic controller may be more robust than the LQG controller.

• Advances in Energy Research
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• v.7 no.1
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• pp.53-66
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• 2020

Before the industrial revolution architecture has been shaped by the natural and cultural inputs. Local constraints become more effective determinants of architecture in the rural contexts because by being disengaged from the webs of transportation and communication, rural settlements have achieved sustainability in difficult conditions. The examples of rural settlement and architecture have provided sustainability through integration with natural inputs within the geographical context because they have reached the goals of ecological design within the local constraints. Although this feature of the rural cultural landscapes has been emphasized frequently, tangible standards could not be developed in order to interpret their ecological design principles from the perspectives of the contemporary building sector and planning. However, the historical experience indicates that the sustenance of ecological performance can be possible as a result of integrated planning at the overall scale of the settlement. Therefore, the existing standards are not qualified for interpreting the rural contexts. This study develops a method for analysing, interpreting and evaluating traditional rural settlements and certifying new implementations in the rural environments in the light of the given literature review, discussion and methodological proposal.

• The Journal of Natural Sciences
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• v.16 no.1
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• pp.77-86
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• 2005

The study was designed to learn about features of landscape trees and shrubs on an exclusive area-specific outer space planting plan in Noeun Apartment Complex in Daejeon Metropolitan City. the exclusive areas were no more than $60m^2$ and $85m^2$ and the landscape areas ranged from 15% and 30%, respectively according to exclusive area-to-plottage ratios. The study showed that trees were likely to be more densely planted in exclusive areas not exceeding $60m^2$ than in exclusive areas over $85m^2$. It also found that the greater the exclusive areas were, the larger the number of species became. Regardless of the size of an exclusive use, however, the species number of evergreen trees and shrubs remained small, while there was no remarkable difference in vegetation due largely to a massive influx of special trees or shrubs such as Eastern white pines (Pinus strobus) and Korean azaleas (Rhododendron yedoensis var. poukhanense). The introduction of trees with the height over four meters and the diameter of breast height (DBH) exceeding 15 meters was strictly limited to Japanese red pins (Pinus densiflora) and Japanese zelkovas (Zelkova serrata). In conclusion, it is necessary for us to introduce fresh species of trees and especially develop evergreen trees and shrubs to make the environment of the apartment complex more comfortable and make a vegetation experience feasible.

• Journal of the Korean Society for Precision Engineering
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• v.12 no.1
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• pp.87-96
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• 1995

A new fungivle material named Epoxy-Granite composite is applied to the column structure of drilling center in order to investigate the advanced dynamic charateristics comparing with a conventional cast iron material. The dimensions of new column structure are adjusted to keep the same stiffness (EI value) and the manufacturing conditions are formulated based on the preceeding research experience about the development of Epoxy-Granite structural material. The two kinds of experiments are set up, one of which is for the measurement of natural mode and frequency using experimental modal analysis, and the other one is for the measurement of vibration amplitude during idling operation of a machine tool. The comparison of maximum accelerance values at each natural frequency of bending mode shows a Epoxy-Granite column have larger modal damping ratios(over 2times) than a cast iron column. The vibration amplitude of Epoxy-Granite column measrued on the bed, motor base, and top of column are also much smaller (up to 12%) than the case of cast iron column. It is therefore confirmed that a Epoxy-Granite material exhibits a good anti- vibrational propderty even if it is used under the actual operational environments of machine tool as a practical structural element.