• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
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• pp.508-510
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• 2003

Land cover change has been recognized as one of the most important factors influencing the occurrence of rainfall-triggered landslides. Satellite remote sensing provides detailed information regarding the spatial distribution and extent of land cover/use changes. This study describes the land cover changes in Nagasaki City, Japan and Kangnung City, South Korea. The former has been suffered from rainfall-triggered disasters for long term and latter was damaged by Typhoon Rusa in 2002. The results obtained from both study areas clearly show that land cover changes have occurred in the last decade as a result of both natural forces and human activities.

• 한국군사과학기술학회지
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• 제22권4호
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• pp.452-459
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• 2019

In order to design and manufacture structures such as a guided missile, assembly process with fastener is an essential method of fabrication. In this study, the dynamic characteristics of a cylindrical structure with bolted joints were studied using experimental methods. The change of the natural frequency of the structure with the change of the fastening method and the tightening torque were measured by the test and the finite element analysis was performed using the stiffness model of the fastening part according to the fastening method and compared with the test results.

• 대한건축학회논문집:구조계
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• 제34권2호
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• pp.3-10
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• 2018

Damage location and extent of structure could be detected by the inverse analysis on dynamic response properties such as frequencies and mode shapes. In practice the measured difference of natural frequencies represent the stiffness change reliably, however the measured mode shape is insensitive for stiffness change, but provides spatial information of damage. The damage detection index on shear building structures is formulated in this study. The damage detection index could be estimated from mode shape and srory stiffness of undamaged structure and frequency difference between undamaged and damaged structure. For the verification of the observed damage detection method, the numerical analysis of Matlab and MIDAS and shacking table test were performed. In results, the damage index of damaged story was estimated so higher than undamaged stories that indicates the damaged story apparently.

• Advances in nano research
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• 제10권2호
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• pp.115-128
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• 2021

In this article, free vibration behavior of electro-magneto-thermo sandwich Timoshenko beam made of porous core and Graphene Platelet Reinforced Composite (GPLRC) in a thermal environment is investigated. The governing equations of motion are derived by using the modified strain gradient theory for micro structures and Hamilton's principle. The magneto electro are under linear function along the thickness that contains magnetic and electric constant potentials and a cosine function. The effects of material length scale parameters, temperature change, various distributions of porous, different distributions of graphene platelets and thickness ratio on the natural frequency of Timoshenko beam are analyzed. The results show that an increase in aspect ratio, the temperature change, and the thickness of GPL leads to reduce the natural frequency; while vice versa for porous coefficient, volume fractions and length of GPL. Moreover, the effect of different size-dependent theories such as CT, MCST and MSGT on the natural frequency is investigated. It reveals that MSGT and CT have most and lowest values of natural frequency, respectively, because MSGT leads to increase the stiffness of micro Timoshenko sandwich beam by considering three material length scale parameters. It is seen that by increasing porosity coefficient, the natural frequency increases because both stiffness and mass matrices decreases, but the effect of reduction of mass matrix is more than stiffness matrix. Considering the piezo magneto-electric layers lead to enhance the stiffness of a micro beam, thus the natural frequency increases. It can be seen that with increasing of the value of WGPL, the stiffness of microbeam increases. As a result, the value of natural frequency enhances. It is shown that in hc/h = 0.7, the natural frequency for WGPL = 0.05 is 8% and 14% less than its for WGPL = 0.06 and WGPL = 0.07, respectively. The results show that with an increment in the length and width of GPLs, the natural frequency increases because the stiffness of micro structures enhances and vice versa for thickness of GPLs. It can be seen that the natural frequency for aGPL = 25 ㎛ and hc/h = 0.6 is 0.3% and 1% more than the one for aGPL = 5 ㎛ and aGPL = 1 ㎛, respectively.

• 한국가정과교육학회지
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• 제20권2호
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• pp.61-73
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• 2008

본 연구는 고등학교 1학년 기술 가정 교과 "직물을 이용한 생활용품 만들기" 단원에 천연염색과 조각보 만들기를 적용하여 전통이미지에 대한 인식의 변화를 알아보고 학생들의 기술 가정 교과에 대한 흥미도와 태도를 향상시키는데 그 목적이 있다. 연구 결과를 요약하면 다음과 같다. 첫째, 천연염색과 조각보 만들기에서 LT 협동학습 모형을 적용한 교수-학습 지도안 및 학습 자료를 개발하였다. 둘째, 개발된 교수-학습 지도안을 적용한 후 기술 가정 교과에 대한 학습흥미도와 태도 변화를 조사한 결과, 매우 긍정적으로 향상되었다. 또한 천연염색과 조각보 만들기 수업을 실시한 후 전통이미지 인식의 변화를 분석한 결과, 전통에 대한 관심과 흥미가 매우 긍정적으로 향상되었다. 이러한 결과로 볼 때, 천연염색과 조각보 제작을 통한 수업은 학습 흥미도와 태도를 향상시킬 뿐만 아니라 전통이미지인식의 변화에 매우 긍정적인 효과가 있음을 알 수 있으며, 개발된 교수-학습 지도안과 학습 자료들은 교육현장에서 전통문화에 대한 교육내용으로 활용 가능성이 높다고 할 수 있다.

• 한국의류산업학회지
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• 제10권4호
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• pp.560-565
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• 2008

Plantae of the natural material has been broadly used on cloth dyeing by it's specific properties such as eco-friendly and innoxious. However dyeing with natural material on synthetic fiber is nearly impossible due to poor affinity between natural material and synthetic fiber. The method which is binding with micro-capsulized natural material to cloth, used in this study, has low change on quality by external influence. Also this method has high ability in spray effect by broken capsule which comes to pressure and friction when the treated cloth was dressed. And this method is applicable widely from natural fiber to synthetic fiber. The purpose of this study is to develop the multi-functional synthetic material with micro-capsulized Ginseng on PET. Moreover, it was driven by comparison of colormetric properties and fastness between regular dip-dyeing method and binding with micro-capsulized material method. Dyeability showed a little bit low exhaustion but the PET treated by micro-capsule was more or less better than the dip dyed PET. Through the SEM(Scanning Electron Microscope) of PET treated by micro-capsule, it has good residence of capsules even after 5 or 10 times washing. Wash and light fastness were revealed some different grades by each condition but showed high level, in most and the micro-capsulized PET was more improver than regular dip dyed PET.

• 한국실내디자인학회논문집
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• 제16권3호
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• pp.102-110
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• 2007

According to change a generation, in modern society the view which looks at the nature the people and the space is changing. As recognition which the environment is the most important factor in our society, there are researches that environment has to preserve and there are methods that the environment is related with the human, therefore, in the space ecology design views that similar to modern society are being shift. Museum of natural environment is public and popular space that it is designed and composed by a method of ecology space design. Hence, on this study, the museum of natural environment is defined public space by ways of characteristics of ecology design and a design characteristic which the museum of natural environment basically has to arrange are examined. Gallery of natural environment is most related with subsidiarity of mutuality, unity of the totality and stablity and will need other factors such as diversity & balance and suitability. Characteristic of museum of natural environment will be understood method for extension of a sustainable and mutual public space based on the this study, and it will become a process that we will have to advance for not only the present day but also the future.

• 한국공간구조학회논문집
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• 제17권1호
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• pp.49-58
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• 2017

The result of the previous work leads to the idea that the inner area of the hyperbolic shell generator should be minimized for the cooling tower with higher first natural frequency. In this study the inner area of the hyperbolic shell generator was graphically established under varying height of the throat and angle of the base lintel. From the graph, several shell geometries were selected and analysed in the aspect of the natural frequency. Three representative towers reinforced differently due to different first natural frequencies were analysed non-linearly and evaluated using a damage indicator based on the change of natural frequencies. The results demonstrated that the damage behaviour of the tower reinforced higher due to a lower first natural frequency was not necessarily advantageous than the others.

• Advances in nano research
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• 제6권1호
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• pp.57-80
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• 2018

In this study, the thermal loading effect on free vibration characteristics of carbon nanotubes (CNTs) with multiple cracks is studied. Various boundary conditions for nanotube are taken in to account. In order to take the small scale effect, the nonlocal elasticity of Eringen is employed in the framework of Euler-Bernoulli beam theory. This theory states that the stress at a reference point is a function of strains at all points in the continuum. A cracked nanotube is assumed to be consisted of two segments that are connected by a rotational spring which is located in the position of the cracked section. Hamilton's principle is used to achieve the governing equations. Influences of the nonlocal parameter, crack severity, temperature change and the number of cracks on the system frequencies are investigated. Also, it is found that at room or lower temperature the natural frequency for CNT decreases as the value of temperature change increases, while at temperature higher than room temperature the natural frequency of CNT increases as the value of temperature change increases. Various boundary conditions have been applied to the nanotube.

• 복식
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• 제39권
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• pp.91-98
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• 1998

This paper is to study the development background of casual Korean clothes through the consideration of the style change of traditional clothes. The purpose of this study is to present the method for the settlement of casual Koran clothes as everyday clothes and to present the direction which casual Koran clothes follow in the future. The development. The development backgrounds of casual Korean clothes are as followings. 1) the self-awakening for the importance of national culture. 2) practical aspects 3) the change of life style accompanied with economic growth 4) the development of mass media Casual Korean clothes in the future should be studied and developed in following aspects. 1) practical aspects by developing design for easy activity 2) environmental aspects by natural dyeing which is harmless to human body and the nature 3) emotional aspects by regarding traditional beauty as importance 4) color sense aspects according to scarcity of as form change of the Korean clothes 5) production aspects by mass production of ready-made clothes not order clothes 6) diplomatic aspects as folk costume which is corresponding with international trend 7) scientific aspects by developing many patterns according to various bodies 8) economic aspects by low price through the mass cultivation of natural materials 9) fashionable aspects by subdividing traditional clothes to ceremonial clothes, everyday clothes, working clothes.