• Journal of Broadcast Engineering
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• v.21 no.4
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• pp.592-608
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• 2016

Recently, many researches on digital holograms, which retain almost perfect 3 dimensional image information, have been performed actively that it seems for them to be serviced soon. Accordingly, this paper proposes a data compression technique for a digital hologram video for this service. It uses H.265/HEVC, the most recent international 2 dimensional video compression standard, for which we consider various domain transform methods to increase the correlation among the pixels in a digital hologram. Also we consider the various parameters on H.265/HEVC. The purpose of this paper is to find empirically the optimal condition for the domain transform method, the size of transform unit, and the H.265/HEVC parameters. The proposed method satisfying the optimal parameter set found is compared to the existing methods to prove that ours shows better performance.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.1
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• pp.119-126
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• 2012

H.264/AVC can use three transforms depending on types of residual data which are to be coded. H.264/AVC always executes $4{\times}4$ DCT transform. In $16{\times}16$ intra mode only, $4{\times}4$ Hadamard transform for luma DC coefficients and $2{\times}2$ Hadamard transform for chroma DC coefficients are performed additionally. Quantization is carried out to achieve further data compression after transform coding is completed. In this paper, the hardware implementation for DCT transform, Hadamard transform and quantization is studied. Especially, the proposed architecture adopting the pipeline technique can output a quantized result per clock cycle after 33-clock cycle latency. The proposed architecture is coded in Verilog-HDL and synthesized using Xilinx 7.1i ISE tool. The operating frequency is 106MHz at SPARTAN3S-1000. The designed IP can process maximum 33-frame at $1920{\times}1080$ HD resolution.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2008.10a
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• pp.333-336
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• 2008

The groove rolling is a process that transforms the bloom or billet into a shape with circular section through a series of rolling. Inhibition of surface defect generation in groove rolling is a matter of great importance and therefore many research groups proposed a lot of models to find the location of surface defect initiation. In this study, we propose a model for maximum shear stress ratio over equivalent strain to catch the location of surface defect onset. This model is coupled with element removing method and applied to box groove rolling of POSCO No. 3 Rod Mill. Results show that proposed model in this study can find the location of surface defect initiation during groove rolling when finite element analysis results is compared with experiments. The proposed criterion has been applied successfully to design roll grooves which inhibits the generation of surface defect.

• Coupled systems mechanics
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• v.9 no.4
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• pp.325-342
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• 2020

A mathematical model of electro-thermoelasticity subjected to memory-dependent derivative (MDD) heat conduction law is applied to a one-dimensional problem of a thermoelectric spherical cavity exposed to a warm stun that is an element of time in the presence of a uniform magnetic field. Utilizing Laplace transform as an instrument, the issue has been fathomed logically within the changed space. Numerical inversion of the Laplace transform is carried for the considered distributions and represented graphically. Some comparisons are shown in the figures to estimate the effects of MDD parameters and thermoelectric properties on the behavior of all considered fields.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.2
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• pp.283-290
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• 2002

In this paper, we consider the dynamic electromechanical behavior of an eccentric Yoffe permeable crack in a piezoelectric ceramic strip sandwiched between two elastic orthotropic materials under the combined anti-plane mechanical shear and in-plane electrical loadings. Fourier transforms are used to reduce the problem to the solution of two pairs of dual integral equations, which are then expressed to a Fredholm integral equation of the second kind. The initial crack propagation orientation for PZT-5H piezoceramics is predicted by maximum energy release rate criterion.

• 제어로봇시스템학회:학술대회논문집
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• 1991.10a
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• pp.844-849
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• 1991

A high speed control system for a telerobot using DSP is developed. The system is designed to resolve computational burden in advanced algorithms. The design is assumed to h ave no specific algorithm and robot configuration. The system is composed of a teaching box, a DSP board, a set of servo drivers and 16 bit microcomputer system. The teaching box is designed as a man-machine interface, which has two joysticks with three degrees of freedom for velocity generation in Cartesian space. The DSP board, i.e. DSP56000ADS based on a 10.25MIPS digital signal processor, DSP56001, computes the inverse Jacobian matrix which transforms Cartesian velocity into joint velocity. A resolved motion rate control algorithm for a 5 degrees of freedom manipulator was implemented. About 100 Hz sampling rate was achieved in this system.

• ETRI Journal
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• v.24 no.5
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• pp.391-397
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• 2002

This paper presents digital signal processor (DSP) instructions and their data processing unit (DPU) architecture for high-speed fast Fourier transforms (FFTs) in orthogonal frequency division multiplexing (OFDM) systems. The proposed instructions jointly perform new operation flows that are more efficient than the operation flow of the multiply and accumulate (MAC) instruction on which existing DSP chips heavily depend. We further propose a DPU architecture that fully supports the instructions and show that the architecture is two times faster than existing DSP chips for FFTs. We simulated the proposed model with a Verilog HDL, performed a logic synthesis using the 0.35 ${\mu}m$ standard cell library, and then verified the functions thoroughly.

• Journal of the Korean Society for Precision Engineering
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• v.14 no.7
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• pp.126-136
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• 1997

This paper describes a task level cell programming environment that deals with difficulties in programming Flexible Manufacturing Cells (FMCs), and consists of the cell programming editor and the automatic generation module. In the cell programming editor, cell programs can be developed with task- oriented cell specifications that reduces the amount of details to be considered by cell programmers. The automatic generation module transforms task specifications into executable programs used by cell constituents. The development tool in designing the environment is an object-oriented approach which provides a simple to use and intuitive user interface, and allows for an easy development of object models associated with the environment. Test results are illustrated in order to demonstrate the applicability of the developed envifonment.

• International Journal of Reliability and Applications
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• v.10 no.2
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• pp.109-118
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• 2009

Crankshaft, the core element of the engine of a vehicle, transforms the translational motion generated by combustion to rotational motion. Its failure will cause serious damage to the engine so its reliability verification must be performed. In this study, the S-N data of the bending and torsion fatigue limits of a crankshaft are derived. To evaluate the reliability of the crankshaft, reliability verification and analysis are performed. For the purpose of further evaluation, the bending and torsion tests of the original crankshaft are carried out, and failure mode analysis is made. The appropriate number of samples, the applied load, and the test time are computed. On the basis of the test results, Weibull analysis for the shape and scale parameters of the crankshaft is estimated. Likewise, the $B_{10}$ life under 50% of the confidence level and the MTTF are exactly calculated, and the groundwork for improving the reliability of the crankshaft is laid.

• Proceedings of the KSME Conference
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• 2001.06a
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• pp.304-309
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• 2001

In this paper, we consider the dynamic electromechanical behavior of an eccentric Yoffe permeable crack in a piezoelectric ceramic strip sandwiched between two elastic materials under the combined anti-plane mechanical shear and in-plane electrical loadings. Fourier transforms are used to reduce the problem to the solution of two pairs of dual integral equations, which are then expressed to a Fredholm integral equation of the second kind. The initial crack propagation orientation for PZT-5H piezoceramics is predicted by maximum energy release rate criterion.