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991.
992.
993.
In this paper, we present a 600‐V reverse conducting insulated gate bipolar transistor (RC‐IGBT) for soft and hard switching applications, such as general purpose inverters. The newly developed RC‐IGBT uses the deep reactive‐ion etching trench technology without the thin wafer process technology. Therefore, a freewheeling diode (FWD) is monolithically integrated in an IGBT chip. The proposed RC‐IGBT operates as an IGBT in forward conducting mode and as an FWD in reverse conducting mode. Also, to avoid the destructive failure of the gate oxide under the surge current and abnormal conditions, a protective Zener diode is successfully integrated in the gate electrode without compromising the operation performance of the IGBT. 相似文献
994.
Concepts of submerged floating tunnels (SFTs) for land connection have been continuously suggested and developed by several researchers and institutes. To maintain their predefined positions under various dynamic environmental loading conditions, the submerged floating tunnels should be effectively moored by reasonable mooring systems. With rational mooring systems, the design of SFTs should be confirmed to satisfy the structural safety, fatigue, and operability design criteria related to tunnel motion, internal forces, structural stresses, and the fatigue life of the main structural members. This paper presents a feasibility study of a submerged floating tunnel moored by an inclined tendon system. The basic structural concept was developed based on the concept of conventional cable-stayed bridges to minimize the seabed excavation, penetration, and anchoring work by applying tower-inclined tendon systems instead of conventional tendons with individual seabed anchors. To evaluate the structural performance of the new type of SFT, a hydrodynamic analysis was performed in the time domain using the commercial nonlinear finite element code ABAQUS–AQUA. For the main dynamic environmental loading condition, an irregular wave load was examined. A JONSWAP wave spectrum was used to generate a time-series wave-induced hydrodynamic load considering the specific significant wave height and peak period for predetermined wave conditions. By performing a time-domain hydrodynamic analysis on the submerged floating structure under irregular waves, the motional characteristics, structural stresses, and fatigue damage of the floating tunnel and mooring members were analyzed to evaluate the structural safety and fatigue performance. According to the analytical study, the suggested conceptual model for SFTs shows very good hydrodynamic structural performance. It can be concluded that the concept can be considered as a reasonable structural type of SFT. 相似文献
995.
Jin-Hee Lee Eikyu Choi Minseok Song Byeong-Seok Shin 《Multimedia Tools and Applications》2014,68(2):305-319
We designed and implemented an edutainment platform, Dreamware. It effectively helps education, sensibility treatment and intelligence training for children with developmental disability. We developed special toy-like hardware and software tools: a content authoring tool that makes a variety of multimedia content operating on the hardware, a management tool that provides training results to instructors, and a real-time monitoring tool to observe the current state of learning. The hardware is designed to consider the characteristics of children with developmental disability. It can provide sensibility training, such as visual, auditory, and tactile senses to them. The easy-to-use authoring tool enables teachers and non-specialists to make educational content conveniently. In addition, the real-time monitoring tool helps observe the user’s status, even outside the classroom. The management tool stores training results and provides the result for further steps. Efficient repetitive training is possible without restriction of time and location using this platform. We can recognize that our system is effective in improving their concentration and learning. 相似文献
996.
We propose an efficient framework to realistically render 3D faces with a reduced set of points. First, a robust active appearance model is presented to detect facial features in the projected faces under different illumination conditions. Then, an adaptive simplification of 3D faces is proposed to reduce the number of points, yet preserve the detected facial features. Finally, the point model is rendered directly, without such additional processing as parameterization of skin texture. This fully automatic framework is very effective in rendering massive facial data on mobile devices. 相似文献
997.
998.
Richard Hahnkee KimSeok Ju Kang Insung BaeYeon Sik Choi Youn Jung ParkCheolmin Park 《Organic Electronics》2012,13(3):491-497
In this study, we investigated the molecular and microstructures of thin poly(vinylidene fluoride-chlorotrifluoro ethylene) (PVDF-CTFE) copolymer films with three different CTFE compositions of 10, 15, 20 wt% with respect to PVDF in relation with their ferroelectric properties. All PVDF-CTFE annealed at 130 °C showed consecutive TTTT trans conformation with β type crystals while films molten and re-crystallized from a temperature above their melting points exhibited α type crystals with characteristic TGTG conformation. Microstructures of the films treated with the two different thermal histories also supported the formation of β and α type crystals with hundreds of nanometer scale sphere caps and micron level spherulites, respectively. Interestingly, PVDF-CTFE films with both α and β type crystals gave rise to relatively high remnant polarization of approximately 4 μC/cm2 in metal/ferroelectric/metal capacitors regardless of the composition of CTFE. The ferroelectric polarization of a PVDF-CTFE film independent of thermal processing history allowed a wide processing window and easy fabrication protocol, resulting in a non-volatile ferroelectric field effect transistor memory which exhibited saturated hysteresis loops with the current ON/OFF ratio of approximately 103 at ±60 V sweep and reliable data retention. 相似文献
999.
Yaping Liu Manabu Tanaka Sooseok Choi Takayuki Watanabe 《Journal of Thermal Spray Technology》2012,21(5):863-872
In-flight particle measurements of the surface temperature and velocity are important for understanding of melting behavior of glass particles during in-flight melting by multi-phase AC arc plasma. However, the use of optical pyrometry for particle surface temperature has inevitable uncertainties due to non-thermal emissions signals from the plasma plume. This work presents spectroscopic measurements of the non-thermal signals which were found to be caused mainly by the plasma emissions scattered by the particles and the radiation emitted by vapor. After that, the accuracy of thermal radiation measurement was estimated and surface temperature of in-flight glass particle was corrected. 相似文献
1000.
Jae-Kook Park O-Pil Kwon Eun-Young Choi Chan-Keun Jung Suck-Hyun Lee 《Synthetic Metals》2010,160(7-8):728-731
We report the enhanced electrical conductivity of polyaniline (PANI) films produced in a low magnetic field using polyaniline that was synthesized by a self-stabilized dispersion polymerization (SSDP). The sample PANI film prepared with a low magnetic field of 1.4 T showed a 1.85-fold increase in electrical conductivity. Moreover, the film using the polyaniline prepared using the SSDP method showed greater conductivity enhancement than the conventionally prepared sample. In addition, the PANI films exhibited considerable anisotropy of the electrical conductivity depending on the direction of the applied magnetic field. This was attributed to the non-negligible contribution of the orientation of the polyaniline backbone segment and the face-to-face π–π stacking of the main-chains by the magnetic field. 相似文献