• Title/Summary/Keyword: time compression method

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Evaluation on Uniaxial Compression Strength of SSG Method with Curing Condition (양생조건에 따른 SSG공법의 일축압축강도 평가)

  • Choi, Yong-Sung;Kim, Byoung-Il;Moon, In-Jong;Heo, Jun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.17 no.2
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    • pp.15-20
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    • 2016
  • The grouting method, which can be used to effectively improve small areas within a short amount of time, may have different injection effects depending on the ground conditions and the levels of a water table. In particular, for ground with a relatively large permeability, the strength of the ground and the water proof ability can decrease over time due to the leaching process. To solve this problem, a "self-healing smart grouting (SSG) method", which was designed to maintain the initial strength of the ground by minimizing the leaching process, was developed recently. In this study, uniaxial compression tests were carried out on SSG samples to understand the strength of SSG over curing time where two different curing temperatures have been applied for comparison. The uniaxial compression strength of SSG was further compared with the samples prepared using conventional methods (LW and SGR). The test results showed that the uniaxial compression strength of SSG was higher at both high and low curing temperatures compared to that of the samples prepared using conventional methods. The initial strength of SSG was also relatively higher.

Comparison of Manual Chest Compression and Chest Compression Using AutoPulseTM Device in Pre-Hospital Simulation Cardiac arrest

  • Ko, Jang-Sik;Kim, Yong-Seok;Lim, Se-Young;Kim, Soo-Tae;Kim, Keun-Hee;Hwang, Sung-Hoon;Cho, Byung-Jun
    • Journal of the Korea Society of Computer and Information
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    • v.23 no.10
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    • pp.151-156
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    • 2018
  • The purpose of this study was to find more effective method through comparison of manual chest compression and chest compression using $AutoPulse^{TM}$ device in pre-hospital simulation cardiac arrest. In order to achieve the purpose of the study, ambulance workers did two different style CPR in pre-hospital simulation cardiac arrest. Data analyzed by T test and ANOVA. Findings of this study are as follows. Firstly, manual chest compression is more effective than chest compression using $AutoPulse^{TM}$ device on scene. Secondly, chest compression using $AutoPulse^{TM}$ device is more effective manual chest compression in ambulance and in elevator. In conclusion, these findings provide strong evidence for the importance of hands off time and stable CPR before hospital arrival in explaining patient's prognosis. Therefore, strategies to conduct precise hands off time and stable CPR are needed to improve patient's prognosis.

The Compression of Normal Vectors to Prevent Visulal Distortion in Shading 3D Mesh Models (3D 메쉬 모델의 쉐이딩 시 시각적 왜곡을 방지하는 법선 벡터 압축에 관한 연구)

  • Mun, Hyun-Sik;Jeong, Chae-Bong;Kim, Jay-Jung
    • Korean Journal of Computational Design and Engineering
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    • v.13 no.1
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    • pp.1-7
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    • 2008
  • Data compression becomes increasingly an important issue for reducing data storage spaces as well as transmis-sion time in network environments. In 3D geometric models, the normal vectors of faces or meshes take a major portion of the data so that the compression of the vectors, which involves the trade off between the distortion of the images and compression ratios, plays a key role in reducing the size of the models. So, raising the compression ratio when the normal vector is compressed and minimizing the visual distortion of shape model's shading after compression are important. According to the recent papers, normal vector compression is useful to heighten com-pression ratio and to improve memory efficiency. But, the study about distortion of shading when the normal vector is compressed is rare relatively. In this paper, new normal vector compression method which is clustering normal vectors and assigning Representative Normal Vector (RNV) to each cluster and using the angular deviation from actual normal vector is proposed. And, using this new method, Visually Undistinguishable Lossy Compression (VULC) algorithm which distortion of shape model's shading by angular deviation of normal vector cannot be identified visually has been developed. And, being applied to the complicated shape models, this algorithm gave a good effectiveness.

A New Controller for Improvement of Response Time by Data Compression Using Color Space Conversion

  • Koo, Sung-Jo;Kim, Chang-Gon;An, Jong-Ki;Park, Man-Hyo;Yeo, Sang-Deog
    • 한국정보디스플레이학회:학술대회논문집
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    • 2005.07b
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    • pp.863-864
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    • 2005
  • In recent years, we use overdriving scheme to improve the response time of the liquid crystal. Since conventional overdriving scheme uses memory to perform ideal processing, it is desired to reduce system cost by decreasing the data stored in these SDRAMs. As a general compression method, quantization, sub-sampling and Block Truncation Coding ( BTC ) are used, which process data in block base and cause block effect. So we proposed new data compression method by color space conversion. Because this method compresses luminance and chrominance signal by different ratio, it can efficiently reduce error of block effect in decompression image.

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Finite Element Analysis of Compression Holding Step Considering Solidification for Semi-Solid Forging (반용융 단조에서 응고 현상을 고려한 가압유지 단계의 유한요소해석)

  • 최재찬;박형진;조해용
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1997.04a
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    • pp.597-601
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    • 1997
  • The technology of Semi-Solid Forging(SSF) has been actively developed to fabricate near-net shape products using light and hardly formable materials. Generally, the SSF process is composed of slug heating,forming,compression holding and ejecting step. After forming step in SSF, the slug is comperssed during a certain holding time in order to be completely filled in the die cavity and be accelerated in solidification rate. This paper presents the analysis of temperature,solid fraction and shrinkage at compression holding step for a cylindrical slug,then predicts the solidification time to obtain the final shaped part. Enthalpy-based finite element analysis is performed to solve the heat transfer problem considering phase change in solidification.

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Finite Element Analysis of Compression Holding step Considering Solidification for Semi-Solid Forging (반용융 단조에서 응고 현상을 고려한 가압유지 단계의 유한요소해석)

  • Park, J.C.;Park, H.J.;Cho, H.Y.
    • Journal of the Korean Society for Precision Engineering
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    • v.14 no.10
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    • pp.102-108
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    • 1997
  • The technology of Semi-Solid Forging (SSF) has been actively developed to fabricate near-net- shape products using light and hardly formable materials. Generally, the SSF process is composed of slug heating, forming, compression holding and ejecting step. After forming step in SSF, the slug is compressed during a certain holding time in order to be completely filled in the die cavity and be accelerated in solidification rate. This paper presents the analysis of temperature, solid fraction and shrinkage at compression holding step for a cylindrical slug, then predicts the solidification time to obtain the final shaped part. Enthalpy-based finite element analysis is performed to solve the heat transfer problem considering phase change in solidification.

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A Study on Prediction and Application of ECG Data Compression Rate at Zero-Oder Compression (Zero-Order 압축 방식에서 ECG 데이터 압축률 예측과 적용에 관한 연구)

  • 안형민;김영길
    • Proceedings of the IEEK Conference
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    • 1999.11a
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    • pp.513-516
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    • 1999
  • I here are many kinds of method to compress data. To very simple methods from very complex methods, a kind is various. In this study, the simplest form of the Tolerance-Comparison method, zero-order method is used. Using this method, despite using low speed CPUs, it is possible to compress real time data. So this method is suitable for ECG holler system. In this study, to complement zero-order method, it is needed to develop prediction technique and to research ways to apply the technique.

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A Study on the sand mold compression strength of the N-process mold mixed with JA-EUN-DO sand. (자은도사(慈恩島砂)를 이용(利用)한 N-Process의 주형강도(鑄型强度)에 관(關)한 연구(硏究))

  • Lee, Won-Sik
    • Journal of Korea Foundry Society
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    • v.4 no.2
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    • pp.102-107
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    • 1984
  • The variations of the mold compression strength were studied by varing the contents of the silicon powder and water glass, silion purities, and molecule rates of the water glass, when domestic JA EUN DO sand is mixed with water glass (sodium silicate) and metallic silicon or ferro - silicon powder by the self - hardening N - PROCESS method. The results obtained from this experiment are as follows; 1) The compression strength of the mold used with metalic powder was higher and more stable than to be used ferro - silicon powder. 2) 6% water glass of 2.8 molecule rate and 1.5% of ferro - silicon of 75% purity for the N - PROCESS used with JA EUN DO sand was suitable mixing rate. 3) The compression strength increased with self - hardening time, and the PH values of the mixture of silicon powder and water glass did not change after 2 hours, but the compression strength increased steadily due to the reaction of remained silicon. 4) It is recommended to take 24 hours for self - hardening time at least.

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A Still Image Compression Algorithm based on JPEG Systems (JPEG 시스템을 기반으로 한 정지 영상 압축 알고리즘)

  • 이철원;임인칠
    • Journal of the Korean Institute of Telematics and Electronics B
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    • v.31B no.7
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    • pp.9-15
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    • 1994
  • This paper proposes a image compression algorithm which stores and transmites image data efficiently. The proposed compression algorithm modify enhances compression rate by modified ZIG-ZAG Scanning in JPEG standard algorithm which is based on 2D-DCT. And the up-compatible method of proposed algorithm can solve compatible problem with JPEG that is cased by modified ZIG-ZAG Scanning. And this paper presentes a block diagram of hardware for real-time processing.

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High Efficient Entropy Coding For Edge Image Compression

  • Han, Jong-Woo;Kim, Do-Hyun;Kim, Yoon
    • Journal of the Korea Society of Computer and Information
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    • v.21 no.5
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    • pp.31-40
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    • 2016
  • In this paper, we analyse the characteristics of the edge image and propose a new entropy coding optimized to the compression of the edge image. The pixel values of the edge image have the Gaussian distribution around '0', and most of the pixel values are '0'. By using this analysis, the Zero Block technique is utilized in spatial domain. And the Intra Prediction Mode of the edge image is similar to the mode of the surrounding blocks or likely to be the Planar Mode or the Horizontal Mode. In this paper, we make use of the MPM technique that produces the Intra Prediction Mode with high probability modes. By utilizing the above properties, we design a new entropy coding method that is suitable for edge image and perform the compression. In case the existing compression techniques are applied to edge image, compression ratio is low and the algorithm is complicated as more than necessity and the running time is very long, because those techniques are based on the natural images. However, the compression ratio and the running time of the proposed technique is high and very short, respectively, because the proposed algorithm is optimized to the compression of the edge image. Experimental results indicate that the proposed algorithm provides better visual and PSNR performance up to 11 times than the JPEG.