• Proceedings of the KIEE Conference
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• 2000.11c
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• pp.425-427
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• 2000

We describe the preparation of a cobalt oxide in which the solid-pore architecture of the material is controllably varied. All $CoO_2$ gels derived from $CoCl_2$-based sol-gel synthesis, but exhibit markedly different final pore structures based on how the pore fluid is removed from forces that result from extraction are either low or nonexistent. These nanoscale mesoporous materials have higher $CoO_2$ crystallites. Controlling both the pore and solid architecture on the nanoscale offers a strategy for the design of new supercapacitor and charge-storage materials.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.12 no.4
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• pp.622-629
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• 2001

An engineering model VCO with a good phase noise for Ku-band satellite transponder is designed using a nonlinear design methodology. It generates frequencies from 1,745 and 1,755 MHz with control voltages from 0 to 5 V DC. This unit requires 7 mA of current from 5 V DC supply voltage. Phase noise characteristics of the manufactured VCO exhibit -114 dBc/Hz @10 kHz offset and -131 dBc/Hz @100 kHz of offset and its output power is 5 dBm.

• Structural Engineering and Mechanics
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• v.12 no.4
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• pp.363-376
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• 2001

Sandwich plates are widely used in lightweight design due to their high strength and stiffness to weight ratio. Due to the heterogeneous structure of sandwich plates, they can exhibit local instabilities (wrinkling), which lead to a sudden loss of stiffness in the structure. This paper presents an analytical solution to the wrinkling problem of sandwich plates. The solution is based on the Rayleigh-Ritz method, by assuming an appropriate deformation field. In contrast to the other approaches up to now, this model takes arbitrary and different orthotropic face layers, finite core thickness and orthotropic core material into account. This approach is the first to cover the wrinkling of unsymmetric sandwiches and sandwiches composed of orthotropic FRP face layers, which are most common in advanced lightweight design. Despite the generality of the solution, the computational effort is kept within bounds. The results have been verified using other analytical solutions and unit cell 3D FE calculations.

• Bulletin of the Society of Naval Architects of Korea
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• v.25 no.1
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• pp.56-62
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• 1988

Artificial Intelligence(AI) is that branch of computer science that deals with designing computer system that exhibit some of the characteristics associated with intelligence on human behaviors such as, understanding natural language, reasoning, solving problems, robotics and so on. The most developed component of artificial intelligence today is probably the expert system. An expert system is defined as a computer program that embodies organized knowledge concerning some specific domain of human expertise and programmed to perform convincingly as an advisory consultant in the given domain with self-explanation of reasoning on demand. This paper describes general concept of artificial intelligence and expert system and investigates applicability of expert system to ship design.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.11a
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• pp.9-12
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• 2004

Coupling beams subject to cyclic loads exhibit different behavioral characteristics and energy dissipation capacity varying with re-bar layouts. In the present study, nonlinear analysis method was developed using analogous truss model. Using the numerical method, parametric studies were performed to investigate the behavioral characteristics and the energy dissipation mechanism of coupling beams with various re-bar layouts subject to cyclic loading. Based on the investigation, a simple and practical method for evaluating the energy dissipation capacity of coupling beams was developed and verified by experiments. The proposed method accurately predicted the dissipated energy during cyclic loading addressing design parameters such as re-bar layouts, re-bar ratio, and deformation. The proposed method can be easily applied to nonlinear static and dynamic methods for seismic analysis and design.

• Journal of Communications and Networks
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• v.9 no.2
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• pp.167-176
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• 2007

In multimedia communication systems, efficient transmission system design should incorporate the use of matching unequal error protection (UEP), since source coders exhibit unequal bit error sensitivity. In this paper, we present UEP schemes which exploit differences in bit error protection levels in orthogonal frequency division multiplexing (OFDM) systems over frequency selective fading channels. We introduce an UEP scheme which improves the link performance with multiple transmit and receive antennas. Especially, we propose a new receiver structure based on two stage Maximum Likelihood detection (MLD) schemes which can approach the performance of a full search MLD receiver with much reduced computational complexity. In the performance analysis, we derive a generalized pairwise error probability expression for the proposed UEP schemes. Simulation results show that the proposed schemes achieve a significant performance gain over the conventional equal error protection (EEP) scheme.

• Proceedings of the Korean Institute of Interior Design Conference
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• 2005.05a
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• pp.154-158
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• 2005

The purpose of exhibition is not putting exhibits on display but communicating the information and message of them to people effectively. The exhibition evaluation is very important because it allows the whole process of exhibit development to be reviewed. The purpose of this study is to examine the exhibition evaluation method into preceding research and to grope the proper evaluation method through analyze visitors behavior on the Permanent Exhibition in National Science Museum.

• Proceedings of the Korean Institute of Interior Design Conference
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• 2005.05a
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• pp.182-186
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• 2005

The purpose of this research is to develop subject of up-to-date scientific technology, according with science museum, and to deviate from the old style, simply-seeing display, and the passive display which simply support narrative styles by one-way action. In addition, for motivating audience to take part in the display, this study is to analyze displaying technique, key marks of an exhibit and then to create the way which science museum should follow in order to plan interactive scenario and display technique. By analysis and consideration of museums, which I took for a sample, this study will work out display scenario, based on interactive concept, and experience display technique. Moreover, this study will suggest alternatives and basis in order to develop display technique of up-to-date science in science museum.

• Proceedings of the PSK Conference
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• 2003.04a
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• pp.241.1-241.1
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• 2003

Apio nucleosides whose 4'-hydroxymethyl group moves to 3'-position exhibit interesting biological activity such as antitumor or antiviral activity. On the other hand, neplanocin A and aristeromycin are the representative of the carbocyclic nucleosides and have been recognized as potent inhibitors of S-adenosylhomocysteine hydrolase. Based on these findings. it was of great interest to design apio analogues of neplanocin A and aristeromycin. (omitted)

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2002.03a
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• pp.250-257
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• 2002

Pseudo dynamic test is an on-line computer control method to achieve the realism of shaking table test with the economy and versatility of the conventional quasi-static approach Pseudo dynamic tests of six full-size RC bridge piers have been carried out to investigate their seismic performance. For the purpose of precise evaluation, the experimental investigation was conducted to study the seismic performance of the real size specimen, which is constructed for highway bridge piers in Korean peninsula. Since it is believed that Korea belongs to the moderate seismicity region, five test specimens were designed in accordance with limited ductility design concept. Another one test specimen was nonseismically designed according to a conventional code. Important test parameters were transverse reinforcement and lap splicing. Lap splicing was frequently used in the plastic hinge region of many bridge columns. Furthermore, the seismic design code is not present about lap splice in Korean Roadway Bridge Design Code. The results show that specimens designed according to the limited ductility design concept exhibit higher seismic resistance. Specimens with longitudinal steel lap splice in the plastic hinge region appeared to significantly fail at low ductility level.