• Earthquakes and Structures
• /
• 제7권2호
• /
• pp.159-178
• /
• 2014

Although the family methods with unconditional stability and numerical dissipation have been developed for structural dynamics they all are implicit methods and thus an iterative procedure is generally involved for each time step. In this work, a new family method is proposed. It involves no nonlinear iterations in addition to unconditional stability and favorable numerical dissipation, which can be continuously controlled. In particular, it can have a zero damping ratio. The most important improvement of this family method is that it involves no nonlinear iterations for each time step and thus it can save many computationally efforts when compared to the currently available dissipative implicit integration methods.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2009년도 추계학술대회 논문집
• /
• pp.238-238
• /
• 2009

In this work, we investigated the effect of the Zn complex concentration and growth temperature on the growth of ZnO nanorod by hydrothermal method. The ZnO nanorods were performed at condition of the various Zn complex concentration and growth temperature, 0.02 ~ 0.08 M and 60 ~ 80 $^{\circ}C$, respectably. We found from the SEM results that the diameter and length of ZnO nanorods were with increasing the growth temperature and Zn complex concentration. However, the growth condition in the two parameters wasmore than sensitive compared to Zn complex concentration on increasing the growth rate. From photoluminescence(PL) analysis, the strong band-edge emission for ZnO nanorod grown at 80 $^{\circ}C$ with 0.08 M indicated the fine crystallinity. Therefore, the diameter and length of ZnO nanorods have been able to control through the control of front growth parameters. Also, these ZnO nanorods grown low temperature will be available as building block for transparence flexible device applications.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
• /
• pp.1541-1544
• /
• 1997

The rehailitation robot, one of the service robot, is the important area in the service automation. In the paper, we describe the overall configuration of KARES(KAIST Rehabilitation Engineering System), which is an intellingent rehabilitaion robotic system designed to assist the independent livelihood of the handicapped and the eldrly. KARES consists of the 6 degree of freedom robot arm mounted on a wheelchair, the controller ofr the arm, sensors to perceive environment, and user interface. Basic desired hobs in KARES are gripping the target object and moving it to the user's face for eating, drinking, or cooperation work wiht the mouth. Currently, the manual operation of the arm is available for gripping to target objects. The autonomous functionality will be ginven for the facilities of the human operator.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
• /
• pp.756-759
• /
• 1997

Multi-arm cooperation robot system is required for more specific and dextrous jobs such as transferring very large or heavy objects, or grasping work piece while processing on it. There is little research on 3-dimensional multi-arm robot. Here we propose two performance indices presenting isotropy of end-effector's acceleration and velocity capabilities with constraints of joint torques, that is Isotropic Acceleration Radius [IAR] and Isotropic Velocity Radius [IVRI. Also the procedure to find 3-dimensional IAR, IVR is proposed, where available acceleration set concept is used. The case of 3-dimensional two 3 joint robot system was simulated and the distributions of IAR, IVR was studied.

• 대한화학회지
• /
• 제40권8호
• /
• pp.549-556
• /
• 1996

항생물질 tetracycline(TC)과 여러 가지 다양한 활성도를 보이는 flavonoid화합물들의 단순유도체들(13, 25, 26, 27)을 새로운 벙법으로 합성하였다, 먼저, 1,3-cyclohexanedione 유도체로부터 분자내 benzoyl group의 이동 반응을 이용하여 TC의 A, D ring이 유사한 bicyclic compound 13를 합성하였고, 0-methoxy benzaldehyde로부터 TC의 A, C ring이 유사한 bicyclic compound, 25와 chromone을 모핵으로 하는 flavonoid유도체, 26과 27을 합성하였다.

• 복식문화연구
• /
• 제19권2호
• /
• pp.316-323
• /
• 2011

This research aim concerns questioning how we can generate environments suggestive of nature fused with built environments through textiles. Through literature reviews and experiments with available the 3D imaging techniques of Holography, Lenticular and other new technologies. We also have researched towards finding the most effective method for 3D imaging techniques for textile applications. The advantage of the combining technique is to create the possibility of seeing a number of different floating 3D illusory images, depending on the viewing angle. This objective is to produce intriguing textile patterns and images in which the objects and colours change as viewpoints change. Experimental work was carried out in collaboration with professional textile researchers, scientists, artists and designers conducting research in this field.

• Computers and Concrete
• /
• 제2권3호
• /
• pp.215-238
• /
• 2005

This work is based on a nonlinear finite-element model with proven capacity for yielding realistic predictions of the response of reinforced-concrete structures under static monotonically-increasing loading. In it, the material description relies essentially on the two key properties of triaxiality and brittleness and, thus, is simpler than those of most other material models in use. In this article, the finite-element program is successfully used in investigating the behaviour of a series of RC walls under static cyclic loading. This type of loading offers a more strenuous test of the validity of the proposed program since cracks continuously form and close during each load cycle. Such a test is considered to be essential before attempting to use the program for the analysis of concrete structures under seismic excitation in order to ensure that the solution procedure adopted is numerically stable and can accurately predict the behaviour of RC structures under such earthquake-loading conditions. This is achieved through a comparative study between the numerical predictions obtained presently from the program and available experimental data.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• 제42권2호
• /
• pp.67-76
• /
• 2016

Dracunculiasis, otherwise known as guinea worm disease (GWD), is caused by infection with the nematode Dracunculus medinensis. This nematode is transmitted to humans exclusively via contaminated drinking water. The transmitting vectors are Cyclops copepods (water fleas), which are tiny free-swimming crustaceans usually found abundantly in freshwater ponds. Humans can acquire GWD by drinking water that contains vectors infected with guinea worm larvae. This disease is prevalent in some of the most deprived areas of the world, and no vaccine or medicine is currently available. International efforts to eradicate dracunculiasis began in the early 1980s. Most dentists and maxillofacial surgeons have neglected this kind of parasite infection. However, when performing charitable work in developing countries near the tropic lines or other regions where GWD is endemic, it is important to consider GWD in cases of swelling or tumors of unknown origin. This paper reviews the pathogenesis, epidemiology, clinical criteria, diagnostic criteria, treatment, and prevention of dracunculiasis. It also summarizes important factors for maxillofacial surgeons to consider.

• Advances in aircraft and spacecraft science
• /
• 제5권1호
• /
• pp.107-128
• /
• 2018

Thermo-mechanical vibration of sandwich beams with a stiff core and face sheets made of functionally graded carbon nanotube-reinforced composite (FG-CNTRC) is investigated within the framework of Timoshenko beam theory. The material properties of FG-CNTRC are supposed to vary continuously in the thickness direction and are estimated through the rule of mixture and are considered to be temperature dependent. The governing equations and boundary conditions are derived by using Hamilton's principle and are solved using an efficient semi-analytical technique of the differential transform method (DTM). Comparison between the results of the present work and those available in literature shows the accuracy of this method. A parametric study is conducted to study the effects of carbon nanotube volume fraction, slenderness ratio, core-to-face sheet thickness ratio, and various boundary conditions on free vibration behavior of sandwich beams with FG-CNTRC face sheets. It is explicitly shown that the vibration characteristics of the curved nanosize beams are significantly influenced by the surface density effects.

• Advances in nano research
• /
• 제6권2호
• /
• pp.135-145
• /
• 2018

This work represents the study of the vibration response of the double walled carbon nanotubes (DWCNT) for various boundary conditions. The inner and outer carbon nanotubes are modeled as two individual Euler-Bernoulli's elastic beams interacting each other by Van der waals force. Differential transform method (DTM) is used as a numerical method to solve the governing differential equations and associated boundary conditions. The influence of Winkler elastic medium on vibration frequency is also examined and results are interpreted. MATLAB is used as a tool for solving the governing differential equations. The fundamental natural frequencies are validating with those available in literature and observed a good agreement between them.