• Journal of the Korean Ceramic Society
• /
• v.47 no.1
• /
• pp.47-53
• /
• 2010

Ceramics with perovskite-type structure are interesting functional materials for several energy conversion processes due to their flexible structure and a variety of properties. Prominent examples are electrode materials in fuel cells and batteries, thermoelectric converters, piezoelectrics, and photocatalysts. The very attractive physical-chemical properties of perovskite-type phases can be modified in a controlled way by changing the composition and crystallographic structure in tailor-made soft chemistry synthesis processes. Improved thermoelectric materials such as cobaltates with p-type conductivity and n-type manganates are developed by following theoretical predictions and tested to be applied in oxidic thermoelectric converters.

• 제어로봇시스템학회:학술대회논문집
• /
• 2001.10a
• /
• pp.137.2-137
• /
• 2001

We have been developed an intelligent mobile robot with an artificial olfactory function to recognize odours and to track odour source location. This mobile robot also has been installed an engine for speech recognition and synthesis, and is controlled by wireless communication. An artificial olfactory system based on array of 7 gas sensors has been installed in the mobile robot for odour recognition, and 11 gas sensors also are located in the bottom of robot to track odour sources. 3 optical sensors are also included in the intelligent mobile robot, which is driven by 2 D.C. motors, for clash avoidance in a way of direction toward an odour source. Throughout the experimental trails, it is confirmed that the intelligent mobile robot is capable of not only the odour recognition using artificial neural network algorithm, but also the tracking odour source using the step-by-step approach method ...

• Journal of Institute of Control, Robotics and Systems
• /
• v.8 no.5
• /
• pp.401-406
• /
• 2002

As product lifecycles become shorter, factories are pushed to develop small batches of many different products. The highly flexible control systems has become a necessity. The majority of existing automated industrial systems are controlled by programmable logic controllers(PLCs). In most cases, the control programs for PLCs are developed based on ladder diagrams(LDs). However, it is difficult to debug and maintain those LDs because the synthesis of LD itself mainly depends on the experience of the industrial engineer via trial-and-error methods. Hence, in this paper, we propose a discrete event model conversion algorithm for systematic analysis of LDs. The proposed discrete event model conversion algorithm is illustrated by an example of a conveyor system.

• 제어로봇시스템학회:학술대회논문집
• /
• 1988.10b
• /
• pp.981-986
• /
• 1988

A controller synthesis procedure for precise tracking of reference inputs in the sense of spheres is applied to a 3 d.o.f. robotic manipulator. This methodology applies to a class of nonlinear systems with input uncertainty and parameter uncertainty. The 3 d.o.f. manipulator to be controlled is subjected to varying payloads and is required to follow specified joint trajectories to within prespecified tolerances. The design procedure above lends itself naturally to this type of control problem. The appeal of such a design procedure lies on a special decomposition which exploits linear control theory on the one hand and facilitates a separate treatment of the effects of nonlinearities and the uncertainties on the other.

• Applied Science and Convergence Technology
• /
• v.26 no.5
• /
• pp.129-132
• /
• 2017

We report a chemical vapor deposition approach and optimized growth condition to the synthesis of single layer molybdenum disulfide ($MoS_2$). Obtaining large grain size with continuous $MoS_2$ atomically thin films is highly responsible to the growth distance between molybdenum trioxide source and receiving silicon substrate. Experimental results indicate that triangular shape $MoS_2$ grain size could be enlarged up to > 80um with the precisely controlled the source-to-substrate distance under 7.5 mm. Furthermore, we demonstrate fabrication of a memory device by employing poly(methyl methacrylate) (PMMA) as insulating layer. The fabricated devices have a PMMA-$MoS_2$/metal configuration and exhibit a bistable resistance switching behavior with high/low-current ratio around $10^3$.

• Biotechnology and Bioprocess Engineering:BBE
• /
• v.8 no.1
• /
• pp.9-18
• /
• 2003

The most challenging and emerging field of biotechnology is the tailoring of proteins to attain the desired characteristic properties. In order to increase the stability of proteins and to study the function of proteins, the mechanism by which proteins fold and unfold should be known. It has been debated for a long time how exactly the linear form of a protein is converted into a stable 3-dimensional structure. The literature showed that many theories support the fact that protein folding E5 a Thermodynamically controlled process. It is also possible to predict the mechanism of protein deactivation and Stability to an extent from thermodynamic studies. This article reviewed various theories that have been proposed to explain the process of protein folding after its biosynthesis in ribosomes. The theories of the determination of the thermodynamic properties and the interpretation of thermodynamic data of protein stability are 3150 discussed in this article.

• Journal of Electrical Engineering and Technology
• /
• v.6 no.3
• /
• pp.414-417
• /
• 2011

Indium tin oxide (In:$SnO_2$) nanoparticles were synthesized employing a sol-gel combustion method followed by annealing. The TG, XRD, XPS and SEM results of the precursor powders and calcinated In:$SnO_2$ nanoparticles were investigated. Crystal structures were examined by powder XRD, and those results show shaper intensity peak at $25.6^{\circ}$ ($2{\theta}$) of $SnO_2$ by increased annealing temperature. A particle morphology and size was examined by SEM, and the size of the nanoparticles was found to be in the range of 20~30nm. In:$SnO_2$ films could controlled by nanoparticle material at various annealing temperature. The sol-gel combustion method was offered simple and effective route for the synthesis of In:$SnO_2$ nanoparticles.

• Proceedings of the Korean Society of Broadcast Engineers Conference
• /
• 2012.11a
• /
• pp.60-61
• /
• 2012

최근들어 초고화질 방송인 UHDTV 의 오디오 규격으로 다채널 오디오에 대한 관심이 높아지고 있으며, 이를 효과적으로 재생하기 위해 여러 연구기관과 대학에서 음장합성기법(WFS)과 스피커어레이에 관한 연구가 이루어지고 있다. 음장합성기법에 대한 여러가지 알고리즘과 청취조건을 시험할 때, 직관적인 인터페이스와 실시간 상호작용이 가능하다면 실험시간을 단축하고, 효과적인 청취시험을 할 수 있다. 이를 위해서 본 논문에서는 이를 위해서 MAXMSP 외부 오브젝트를 이용하여 음장합성기법으로 음원을 재생하고 스피커 어레이를 제어하는 방법에 대해 소개한다. 본 논문에서 구현한 시스템을 통해서 손쉽게 실시간으로 음장합성시의 오브젝트의 위치 제어하고 멀티채널 음원을 재생할 수 있다.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2012.02a
• /
• pp.535-535
• /
• 2012

We present a new synthetic route and characterization for ultra small sized PbS quantum dots in extreme quantum confinement with 1.5 to 2.9 nm in diameter. We obtained a series of nanocrystals with first absorption wavelength ranging from 580 to 820 nm (2.1-1.5 eV). To get this result, PbS quantum dots size is finely controlled by adjusting the growth temperature in the range of $70-95^{\circ}C$. We demonstrate that photoluminescence (PL) shows a red shift with respect to the first absorption peak that increases with decreasing PbS quantum dots size and ranges from about 500 to 125 meV as the mean PbS quantum dots diameter increases from 1.5 to 2.9 nm. We further created the assembled PbS quantum dot solids and investigated the transport properties for energy applications.

• Journal of Powder Materials
• /
• v.13 no.2 s.55
• /
• pp.108-111
• /
• 2006

Aluminum hydroxides were synthesized by a simple electrolytic reaction of aluminum plates. The aluminum hydroxide, boehmite (AlO(OH)), was predominantly formed in the application of electrical potential at and above 30V, while the mixture of bayerite ($Al(OH)_3$) and boehmite (AlO(OH)) phases were formed below 20V. The boehmite has a clear fibrous structure controlled on nanometer scale. On the contrary, the bayerite consists of the typical hourglass or semi-hourglass shaped coarse crystals as a result of aggregation of various crystals stacked together. The specific surface area of the boehmite nanofiber was markedly high, approaching at about $302\;m^2/g$.