• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2009.01a
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• pp.799-802
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• 2009

We have been studying the next generation of video creation solution based on TVML (TV program Making Language) technology. TVML is a well-known scripting language for computer animation and a TVML Player interprets the script to create video content using real-time 3DCG and synthesized voices. TVML has a long history proposed back in 1996 by NHK, however, the only available Player has been the one made by NHK for years. We have developed a new TVML Player from scratch and named it T2V (Text-To-Vision) Player. Due to the development from scratch, the code is compact, light and fast, and extendable and portable. Moreover, the new T2V Player performs not only a playback of TVML script but also a Text-To-Vision conversion from input written in XML format or just a mere plane text to videos by using 'Text-filter' that can be added as a plug-in of the Player. We plan to make it public as freeware from early 2009 in order to stimulate User-Generated-Content and a various kinds of services running on the Internet and media industry. We think that our T2V Player would be a key technology for upcoming new movement.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.19 no.1
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• pp.111-119
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• 1994

In this paper we propose a reversible image coding methods with progressive build-up function by bit-plane of multi-lavel image. Firstly, the differencial conversion is applied to reduce the entropy of source images. Then the bit-plane sequences of converted images are coded by means of the newly designed VFRL(Variable to Fixed Run-Llength) code and the RDHC(Run-length Dynamic Huffman Coding). We aim to the simple construction to reduce the complexity. The computer simulated results show that the proposed methods are very effective to the multi-level digital images. For "GIRL" and "COUPLE" of 1EEE monochromatic standard images, the compressibility are superior to the results obtained by the well-known universal codes.own universal codes.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2004.11a
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• pp.99-102
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• 2004

본 논문에서는 SIMD 명령어를 이용하여 H.264 복호화기의 역 정수 변환 과정과 역 양자화 과정을 고속으로 처리 할 수 있는 방법을 제안한다. 제안하는 고속 역 변환 방법을 ZERO 블록에 대하여 역 변환과 역 양자화 과정을 수행하지 않음으로써 속도 향상을 얻을 수 있다. 움직임이 적은 Akiyo 영상에서는 QP=0일 때 참조 코드(reference code)의 역 정수 변환과 역 양자화 과정에 비하여 7.52배, QP=24인 경우 8.1배의 속도 향상을 얻을 수 있다. 또한 움직임이 많은 Stefan 영상에 대해서는 QP=0일 때 고속 역 변환 방법이 참조 코드의 역 정수 변환과 역 양자화 과정에 비하여 6.7배. QP=36인 경우 7.83배의 속도 향상을 얻을 수 있다

• The Journal of the Korea institute of electronic communication sciences
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• v.12 no.6
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• pp.1099-1106
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• 2017

In this paper, a three phase inverter control methodology for photovoltaic generation system, which is a renewable energy source, was studied. The voltage source inverter type of the constant voltage supply type was selected as the three phase photovoltaic inverter, and SWPM method was selected as control technique. a small capacity three phase photovoltaic inverter system, which has a DSP with powerful high speed data processing ability as the main controller and a solar controller as current controller to supply a certain amount of current to charge the battery, was made and tested for SPWM function.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.12 no.2
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• pp.168-175
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• 1987

In this paper, a FFH-SS hybrid communication method using digital frequency synthesizer is proposed. This can simultaneously share the same frequency band with conventional band limited communication method without interference. In the experiment the selective hopping pattern is attained by some conbination of serial to parallel conversion of maximal code from pseudo random noise generater, and it is observed that the selective hopping band transition can be more easily achieved when the hop interval is nonuniform than it is uniform. Digital frequency synthesizer is now reported to have very poor spurious suppression ability below 50~60dB, the reason of this is observed from the experimental result, and the way of how to solve this problem is presneted.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2004.04a
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• pp.18-21
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• 2004

A GFRP based composite blade was developed for a 750kW wind energy conversion system of type class I. The blade sectional geometry was designed to have a general shell-spar structure. The load cases specified in the IEC61400-1 international specification were considered. For withstanding all relevant extreme loads, the structural analysis for the complete blade was performed using a commercial FEM code. The static load carrying capacity, buckling stability, blade tip deflection and natural frequencies at various rotational speeds were evaluated to satisfy the strength requirements in accordance with the IEC61400-1 and GL Regulations. For designing a lightweight blade, the thickness and the lay-up pattern of the skin-foam sandwich structures were optimized iteratively using the DOT program T-bolts were used for joining the blade root and the hub, which were modeled using a 3D FE volume model. In order to confirm the safety of the root connection, the static stresses of the thick root laminate and the steel. bolts were predicted by taking account of the bolt pretension and the root bending moments. The calculated stresses were compared with the material strengths.

• Interaction and multiscale mechanics
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• v.6 no.2
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• pp.173-195
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• 2013

Meshfree methods are known to have the capability to overcome the strict regularization requirements and numerical instabilities that encumber the finite element method (FEM) in large deformation problems. They are also more naturally suited for problems involving material perforation and fragmentation. To take advantage of the high efficiency of FEM and high accuracy of meshfree methods, a coupled finite element (FE) and reproducing kernel (RK, one of the meshfree approximations) formulation is described in this paper. The coupling of FE and RK approximation is implemented in an evolutionary fashion, where the extent and location of the evolution is dependent on a triggering criteria provided by the material constitutive laws. To enhance computational efficiency, Gauss quadrature is applied to integrate both FE and RK domains so that no state variable transfer is required when mesh conversion is performed. To control the hourglassing that might occur with 1-point integrated hexahedral grids, viscous type hourglass control is implemented. Meanwhile, the FEM version of the K&C concrete (KCC) model was modified to make it applicable in both FE and RK formulations. Results using this code and the KCC model are shown for the modeling of concrete responses under quasi-static, blast and impact loadings. These analyses demonstrate that fragmentation phenomena of the sort commonly observed under blast and impact loadings of concrete structures was able to be realistically captured by the coupled formulation.

• JSTS:Journal of Semiconductor Technology and Science
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• v.15 no.3
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• pp.427-435
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• 2015

This paper presents a high-throughput low-complexity decoder architecture and design technique to implement successive-cancellation (SC) polar decoding. A novel merged processing element with a one's complement scheme, a main frame with optimal internal word length, and optimized feedback part architecture are proposed. Generally, a polar decoder uses a two's complement scheme in merged processing elements, in which a conversion between two's complement and sign-magnitude requires an adder. However, the novel merged processing elements do not require an adder. Moreover, in order to reduce hardware complexity, optimized main frame and feedback part approaches are also presented. A (1024, 512) SC polar decoder was designed and implemented using 40-nm CMOS standard cell technology. Synthesis results show that the proposed SC polar decoder can lead to a 13% reduction in hardware complexity and a higher clock speed compared to conventional decoders.

• The KSFM Journal of Fluid Machinery
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• v.11 no.3
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• pp.22-29
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• 2008

Clean and renewable energy technologies using ocean energy give us non-polluting alternatives to fossil and nuclear-fueled power plants to meet establishment of countermeasures against the global warming and growing demand for electrical energy. Among the ocean energy resources, wave power takes a growing interest because of its enormous amount of potential energy in the world. Therefore, various types of wave power conversion system to capture the energy of ocean waves have been developed. However, suitable turbine type is not normalized yet because of relatively low efficiency of the turbine systems. The purpose of this study is to investigate the internal flow and performance characteristics of a cross-flow type hydro turbine, which will be built in a caisson for wave power generation. Numerical simulation using a commercial CFD code is conducted to clarify the effects of the turbine rotation speed and flow rate variation on the turbine characteristics. The results show that the output power of the cross-flow type hydro turbine with symmetric nozzle shape is obtained mainly from Stage 2. Turbine inlet configuration should be designed to obtain large amount of flow rate because the static pressure and absolute tangential velocity are influenced considerably by inlet flow rate.

• Nuclear Engineering and Technology
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• v.48 no.2
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• pp.330-338
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• 2016

The U-Zr or U-TRU-Zr cylindrical metallic fuel slug used in fast reactors is known to swell significantly and to grow during irradiation. In neutronics simulations of metallic-fueled fast reactors, it is assumed that the slug has swollen and contacted cladding, and the bonding sodium has been removed from the fuel region. In this research, a realistic burnup-dependent fuel-swelling simulation was performed using Monte Carlo code McCARD for a single-batch compact sodium-cooled breed-and-burn reactor by considering the fuel-swelling behavior reported from the irradiation test results in EBR-II. The impacts of the realistic burnup-dependent fuel swelling are identified in terms of the reactor neutronics performance, such as core lifetime, conversion ratio, axial power distribution, and local burnup distributions. It was found that axial fuel growth significantly deteriorated the neutron economy of a breed-and-burn reactor and consequently impaired its neutronics performance. The bonding sodium also impaired neutron economy, because it stayed longer in the blanket region until the fuel slug reached 2% burnup.