• Proceedings of the KIEE Conference
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• 1987.07b
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• pp.1347-1351
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• 1987

This thesis aims at studying laplacian pyramid vector quantization which keeps a simple compression algorithm and stability against various kinds of image data. To this end, images are devied into two groups according to their statistical characteristics. At 0.860 bits/pixel and 0.360 bits/pixel respectively, laplacian pyramid vector quantization is compared to the existing spatial domain vector quantization and transform coding under the same condition in both objective and subjective value. The laplacian pyramid vector quantization is much more stable against the statistical characteristics of images than the existing vector quantization and transform coding.

• Proceedings of the KWS Conference
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• 2000.10a
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• pp.260-263
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• 2000

A methodology is developed and many used to evaluate the response sensitivity of the thermal systems to variations in their design parameters. Technique for computing the sensitivity of temperature distributions to changes in processing parameters needed for deciding the more effective laser input parameters for laser surface hardening treatment are considered. In this study, a state equation governing the heat flow in laser surface treatment is analyzed using a three-dimensional finite element method and sensitivity data of the processing parameter obtained using a direct differentiation method applied for sensitivity analysis. The interesting processing parameter is taken as the laser scan velocity and characteristic beam radius( $r_{b}$) of the sensitivity of the temperature T versus v and $r_{b}$ is analyzed. And these sensitivity results obtained in another parameters are fixed condition. To verifying the numerical analysis results, hardened layer dimensions (width and depth) of the numerical analysis compared with the results of an experimental data.ata.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2006.05a
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• pp.168-171
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• 2006

Hot deformation behavior of A350 LF2 alloy was characterized by compression tests in the temperature range of 800-$1250^{\circ}C$ and the strain rate range of $0.001-10s^{-1}$. The microstructural evolution during hot compression was investigated and deformation mechanisms were analyzed by constructing processing map. Processing maps were generated using the dynamic material model (DMM). The combination of dynamic material model and Ziegler's instability criterion was applied to predict an optimum condition and unstable regions for hot forming.

• Proceedings of the Korean Society of Community Living Science Conference
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• 2011.10a
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• pp.112-113
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• 2011

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2005.10a
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• pp.398-401
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• 2005

The characteristic of sheet metal process is the few loss of material during process, the short processing time and the excellent price and strength. Such press-forming process are the used machine ability and the characteristic, used material, the accuracy of the part which becomes processing and side condition of a process are considered and the designed. The purpose of this study is apply efficiently sheet metal forming processing by 3D formation-analyzed program simulations in the site. By a study, forming process was simulation to drawing and trimming and cam process using static-implicit method software. By making apply this to an industrial site the productivity improvement and cost reduction etc. effect able was predicted.

• Textile Coloration and Finishing
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• v.16 no.1
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• pp.1-4
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• 2004

This research surveys the twisting and untwisting tensions according to the various processing conditions of belt type texturing such as draw ratio, 1st heater temperature and velocity ratio. The 1st heater temperature was changed from 1606{\circ}C\; to\; 220^{\circ}C$, draw ratio was changed from 1.6 to 1.9 and velocity ratio was changed from 1.4 to 1.8. The twisting and untwisting tensions are measured with the variation of these processing conditions, in addition, the untwisting tension(T2) and tension ratio(T2/Tl) according to the various processing conditions are analysed with the false twist mechanism which is affected to the physical properties of draw textured yams.

• Journal of the Korean Magnetics Society
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• v.5 no.5
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• pp.610-613
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• 1995

The effect of processing parameters such as milling, additives and sintering atmoshpere on the magnetic properties of Mn-Zn ferrite was investigated. The experiment was followed by general ceramic fabrication process and added additives were $CaCO_{3}$, $SiO_{2}$, $V_{2}O_{5}$, $ZrO_{2}$, and $Nb_{2}O_{5}$. The effects of additives could be divided into three categories which were formation ofliquid phase, substitution in lattice and inducing stress. Core loss smong the magnetic properties was dependent mainly on the additives and also correlated with processing parameters. As a result, an optimum condition of preparing process for a high quality Mn-Zn ferrite was suggested by controlling the correlation of each processing parameters.

• Nuclear Engineering and Technology
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• v.54 no.4
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• pp.1153-1160
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• 2022

The application of video processing techniques are useful for the safety of nuclear power plants by tracking the people online on video to estimate the dose received by staff during work in nuclear plants. Nuclear reactors remotely visually controlled to evaluate the plant's condition using video processing techniques. Internal reactor components should be frequently inspected but in current scenario however involves human technicians, who review inspection videos and identify the costly, time-consuming and subjective cracks on metallic surfaces of underwater components. In case, if any frame of the inspection video degraded/corrupted/missed due to noise or any other factor, then it may cause serious safety issue. The problem of missing/degraded/corrupted video frame estimation is a challenging problem till date. In this paper a systematic literature review on video processing techniques is carried out, to perform their suitability analysis for NPP applications. The limitation of existing approaches are also identified along with a roadmap to overcome these limitations.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.26 no.6_spc
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• pp.651-659
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• 2016

Condition monitoring (CM) encounters a large data problem due to sensors that measure vibration data with a continuous, and sometimes, high sampling rate. In this study, compressive sensing approaches for condition monitoring are proposed to demonstrate the efficiency in handling a large amount of data and to improve the damage detection capability of the current condition monitoring process. Compressive sensing is a novel sensing/sampling paradigm that takes much fewer samples compared to traditional sampling methods. For the experiments a built-in rotating system was used and all data were compressively sampled to obtain compressed data. Optimal signal features were then selected without the reconstruction process and were used to detect and classify damage. The experimental results show that the proposed method could improve the data processing speed and the accuracy of condition monitoring of rotating systems.

• Journal of KIISE:Databases
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• v.33 no.6
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• pp.620-630
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• 2006

Event-detection is an important application of sensor networks. Join operations can facilitate event-detection with a condition table predefined by a user. When join operations are used for event-detection, it is desirable, if possible, to do in-network join processing to reduce communication costs. In this paper, we propose an energy-efficient in-network join algorithm, called PBA. In PBA, each partition of a condition table is stored along the path from each node to the base station, and then in-network joins are performed on the path. Since each node can identify the parts to store in its storage by its level, PBA reduces the cost of disseminating a condition table considerably Moreover, while the existing method does not work well when the ratio of the size of the condition table to the density of the network is a little bit large, our proposed method PBA does not have such a restriction and works efficiently in most cases. The results of experiments show that PBA is efficient usually and especially provides significant cost reduction over existing one when a condition table is relatively large in comparison with the density of the network, or the routing tree of the network is high.