• Journal of the Computational Structural Engineering Institute of Korea
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• v.27 no.4
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• pp.313-320
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• 2014

A tensegrity structure consists of a set of continuous cables in tension and a set of discontinuous struts in compression. The tensegrity structure can be classified into self-stressed and pre-stressed pin-jointed structure. A key step in the design of tensegrity structures is the determination of their equilibrium configuration, known as form-finding. In this paper, three effective methods are presented for form-finding of tensegrity structures. After performing form-finding process, a set of force density and corresponding topology results can be obtained. Then the force density method combined with a genetic algorithm is adopted to uniquely define a single integral feasible set of force densities. Numerical examples are presented that demonstrate the excellent performance of the algorithms.

• Journal of Korea Water Resources Association
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• v.36 no.2
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• pp.325-343
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• 2003

In this study, several types of rainfall time distribution of the probabilistic rainfall amount have been applied to the Sihwa Lake, located in Gyounggi Province, Korea and their runoff characteristics, obtained by the Hec-Hms program, according to the rainfall distribution types, were compared and analysed. And then, the influences of the above rainfall distribution types of the highest water level of the reservoir, computed through the reservoir flood routing, were analysed. The tidal variation was considered, performing the flood routing and, in addition, the new program, called “IWSEA”, which can compute the reservoir water level, was developed. To conclude, when the Mononobe type of the rainfall distribution was used, the largest inflow flood discharge into the reservoir was performed and the highest reservoir water level was obtained when the Pilgrim-Cordery type of the rainfall distribution was applied.

• Journal of Korea Game Society
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• v.3 no.2
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• pp.12-18
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• 2003

A good game comes from an original and unique scenario. Game development must precede with the game's scenario because this is where the contents of the game are expressed. Scenario planing brings the result of the game scenario. scenario planning is the draft for game development. The circumstances of gaming today, from the company which produce games to the academic world which educate game development, do not have planning for their game scenarios. A habit that many Korean game developers have is to just insert a rough scenario into a game or even worse no proper form for one at all. The Purpose of this book is to simply search for a scenario planning method and suggest the contents for game planning. paper, we researched technical considerations in initial game software planning, focusing on platform, game engine, game service, network infrastructure.

• Proceedings of the KIEE Conference
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• 2005.07c
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• pp.1971-1973
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• 2005

We fabricated an alumina membrane with nano-sized pore array by anodic oxidation using the thin film aluminum deposited on silicon wafer. It is important that the sample prepared by metal deposition method has a flat aluminum surface and a good adhesion between the silicon wafer and the thin film aluminum. The oxidation time was controlled by observation of current variation. The nano-sized pores with diameter of $60{\sim}120nm$ was obtained by $40{\sim}80$ voltage. The pore widening process was employed for obtaining the flat surface because the pores of the alumina membrane prepared by the fixed voltage method shows the structure of rough surface. Finally, the sample was immersed to the phosphoric acid with 0.1M concentration to etching the barrier layer. The sample will be applied to electronic sensors, field emission display, and template for nano- structure.

• The Journal of the Korea Contents Association
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• v.13 no.9
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• pp.10-19
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• 2013

This Paper proposed the development of new magnetic sensor and recognition system to expendite pattern recognition of a handwriting character. Received character graphics should be performed the session and balancing and no extraction of end points, bend points and juntions separately. The Artifical intelligence algorithm is adapted to structure snalysis and recognition process by individual basic letter dictionary except for the handwriing character graphic dictionaryimproving error of recognition algorithm and enomous dictionary for generalization. In this Paper, recognition rate of the received character are compared with pre registered character at letter dictionary for performance test of magnetic ball sensor. As a result of unicode conversion and eomparison, the artificial intelligence study have recognition rate more than 95% at initial recognition rate of 70%.

• Journal of Biosystems Engineering
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• v.34 no.2
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• pp.89-94
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• 2009

Aerial application using an agricultural unmanned helicopter was suggested for an alternative against current pesticide application methods. Centrifugal clutches play important roles in the performance and safety of the helicopter operation. A previous study analyzed and verified the power transfer theory of the guide type centrifugal clutch. Based on the clutch theory, optimal designs of the clutch became possible and feasible using a simulation method. Design criteria of the clutch were the power transfer capacity of 24.66 kW(33.5 PS) at the rated engine speed and the engaging range speed of 3,000${\sim}$3,500 rpm. Various designs were accomplished using the simulation. An optimal clutch was simulated by determining the values of spring constant and mass of friction sector, which were 94,700 N/m and 123.7 g, respectively. The design performed the power capacity of 24.86 kW(33.8 PS) and engagement speed of 3,069 rpm, meeting the design criteria. Using the designed clutch, an efficient transfer of the power would be possible for the unmanned agricultural helicopter.

• Journal of Broadcast Engineering
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• v.13 no.2
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• pp.172-178
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• 2008

Orthogonal Frequency Division Multiplexing (OFDM) is one of the most promising technologies for high data rate wireless communications. OFDM has been adopted in wireless standards such as digital audio/video broadcasting. The combination of OFDM and cooperative diversity techniques can provide the diversity gain and/or increased capacity. In this paper, the cooperative coding using cyclic delay diversity (CDD) for multiuser OFDM systems is introduced. To improve the beneficial effects of relays's cooperation, CDD is adopted in cooperative transmission of relays. Simulation results show the bit error rate (BER) for various consideration. The proposed scheme provides improved performance compared to delay.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.06a
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• pp.136-137
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• 2007

LCD 패널의 전기전도에 대한 물량여부를 측정하기 위한 프르브 유니트의 핵심소자 중 하나인 블레이드 타입의 핀을 제작하는데 있어서 주 소재인 베릴륨니켈 박판의 식각 조건에 대하여 연구하였다. 사용된 베릴륨니켈 기판의 두께는 $20{\mu}m$이며, DFR을 이용하여 패터닝하였고 염화제이철 및 황산을 첨가한 용액을 이용하여 침전법으로 단면 식각을 실시하였다. 베릴륨니켈 박판은 2mol의 염화제이철에 1mol의 황산을 첨가한 용액으로 $40^{\circ}C$의 온도에서 식각하였을때 가장 빠른 식각을 보였으며, 그에 따라 식각된 면의 상태도 매우 깨끗하고 수직 가까운 식각면이 나타남을 알 수 있었다.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1522-1523
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• 2007

MEMS(Micro Electro Mechanical Systems)기술과 니켈 전기도금 공정을 이용하여 수십 내지 수백개의 탐침소자를 갖는 프르브디바이스(probe device)를 제작하였다. 사용된 기판은 $4000{\AA}$의 oxide가 있는 p-type 실리콘 웨이퍼로서, 기판위에 NiCr과 Au를 증착한 후 PR 패터닝을 통하여 니켈을 전기도금법으로 도금하고 니켈 도금층을 제외한 부분의 NiCr과 Au를 식각함으로서 전류가 흐르는 라인(line)배선과 탐침소자가 세워질 라인을 형성하였다. 그 후 후막의 PR을 코팅하고 탐침소자가 세워질 부분을 패터닝 한 후 전기도금법을 이용하여 니켈 탐침소자를 제작하였다. 제작된 탐침소자 하나의 크기는 $60{\mu}m$의 폭과 $70{\mu}m$의 높이를 보이며, 탐침소자 전체의 크기는 $250{\mu}m$이고 탐침소자와 탐침소자 사이의 간격은 $50{\mu}m$로 제작되었다. 본 연구에서 제작된 탐침소자의 수는 25*2line으로서 총 50개 이지만 이러한 공정방식을 이용하고 탐침소자의 크기를 작게 제작한다면 하나의 프르브 디바이스에 수백 내지수천 개의 탐침소자를 제작할 수 있을 것이다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.07a
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• pp.471-474
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• 2000

A flat type microgas sensor was fabricated on the p-type silicon wafer with low stress S $i_3$ $N_4$, whose thickness is 2${\mu}{\textrm}{m}$ using MEMS technology and its characteristics were investigated. W $O_3$thin film as a sensing material for detection of N $O_2$gas was deposited using a tungsten target by sputtering method, followed by thermal oxidation at several temperatures (40$0^{\circ}C$~$600^{\circ}C$) for one hour. N $O_2$gas sensitivities were investigated for the W $O_3$thin films with different annealing temperatures. The highest sensitivity when operating at 20$0^{\circ}C$ was obtained for the samples annealed at $600^{\circ}C$. As the results of XRD analysis, the annealed samples had polycrystalline phase mixed with triclinic and orthorhombic structures. The sample exhibit higher sensitivity when the system has less triclinic structure. The sensitivities, $R_{gas}$ $R_{air}$ operating at 20$0^{\circ}C$ to 5 ppm N $O_2$of the sample annealed at $600^{\circ}C$ were approximately 90. 90.