• 제목/요약/키워드: Lifting-scheme

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Dual-rate Digital Controller Design for Continuous-time Linear Systems

  • Park, Poo-Gyeon;Ko, Jeong-Wan
    • 제어로봇시스템학회:학술대회논문집
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    • 2003.10a
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    • pp.468-472
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    • 2003
  • The lifting technique is a standard control procedure that is commonly applied to dual-rate systems, where a critical difficulty is that care must be taken so that the resulting equivalent system preserves the causality constraint between the control signal and the measured output. To overcome this difficulty, the most attractive result has been suggested by defining control time sequences as the union of sample and hold time sequences. However, the sacrifice of regular control period scheme results in some serious disadvantages; restrictions on the implementation to hardware and the corresponding inefficient control scheme. On the contrary, this paper proposes a novel dual-rate control technique, which redescribes the system as a control-rate-based system having regular control period and designs the controller, with no causality constraint, through Linear Matrix Inequality (LMI) formulation.

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A Study on the Data Compression Algorithm for Just-in-Time Rendering of Concentric Mosaic (동심원 모자이크의 실시간 표현을 위한 데이터 압축 알고리즘에 관한 연구)

  • Jee, Inn-Ho;Ahn, Hong-Yeoung
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.10 no.1
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    • pp.91-96
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    • 2010
  • Concentric mosaics are made with arranging and summing of video frames by using common spacial standards. Compared with previous works on 3-D wavelet transform coding, we have made important design considerations to enable flexible partial decoding and bit-stream random access. A just-in-time(JIT) rendering engine of the compressed concentric mosaic is developed. However, computationally, it is still demanding to accomplish the real-time rendering. Only the contents for specific scene representation are need to be decoded by maintaining compressed data. Thus our proposed algorithm is able to render real concentric mosaic by using lifting scheme instead of wavelet transform.

Defect Detection of Flat Panel Display Using Wavelet Transform (웨이블릿 변환을 이용한 FPD 결함 검출)

  • Kim, Sang-Ji;Lee, Youn-Ju;Yoon, Jeong-Ho;You, Hun;Lee, Byung-Gook;Lee, Joon-Jae
    • Journal of the Korean Society for Industrial and Applied Mathematics
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    • v.10 no.1
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    • pp.47-60
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    • 2006
  • Due to the uneven illumination of FPD panel surface, it is difficult to detect the defects. The paper proposes a method to find the uneven illumination compensation using wavelets, which are done based on multi-resolution structure. The first step is to decompose the image into multi-resolution levels. Second, elimination of lowest smooth sub-image with highest frequency band removes the high frequency noise and low varying illumination. In particular, the main algorithm was implemented by lifting scheme for realtime inline process.

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Deep Face Verification Based Convolutional Neural Network

  • Fredj, Hana Ben;Bouguezzi, Safa;Souani, Chokri
    • International Journal of Computer Science & Network Security
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    • v.21 no.5
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    • pp.256-266
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    • 2021
  • The Convolutional Neural Network (CNN) has recently made potential improvements in face verification applications. In fact, different models based on the CNN have attained commendable progress in the classification rate using a massive amount of data in an uncontrolled environment. However, the enormous computation costs and the considerable use of storage causes a noticeable problem during training. To address these challenges, we focus on relevant data trained within the CNN model by integrating a lifting method for a better tradeoff between the data size and the computational efficiency. Our approach is characterized by the advantage that it does not need any additional space to store the features. Indeed, it makes the model much faster during the training and classification steps. The experimental results on Labeled Faces in the Wild and YouTube Faces datasets confirm that the proposed CNN framework improves performance in terms of precision. Obviously, our model deliberately designs to achieve significant speedup and reduce computational complexity in deep CNNs without any accuracy loss. Compared to the existing architectures, the proposed model achieves competitive results in face recognition tasks

Adaptive Update-Predict Structure Based on Template Matching Method in Wavelet Transform (템플릿 매칭 기반 적응적 갱신-예측 구조 웨이블렛 변환 기법)

  • Park, Sang-Jae;Kim, Sung-Jei;Choe, Yoon-Sik
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 2009.11a
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    • pp.295-298
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    • 2009
  • 웨이블렛 변환(Wavelet Transform)은 영상압축에 효율적인 방법으로 알려져 있으며 lifting scheme을 이용해서 쉽게 구현이 가능하다. 가장 널리 쓰이는 방법으로는 Daubechies 5/3 필터가 있고, 이를 바탕으로 하여 영상의 기하학적인 특성을 이용한 적응적 예측 방법이 많이 소개되었다. 본 논문에서는 적응적 예측을 위해 템플릿 매칭을 적용한 새로운 알고리즘을 제안하였다.

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Wavelet Algorithms for Remote Sensing

  • CHAE Gee Ju;CHOI Kyoung Ho
    • Proceedings of the KSRS Conference
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    • 2004.10a
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    • pp.224-227
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    • 2004
  • From 1980's, the DWT(Discrete Wavelet Transform) is applied to the data/image processing. Many people use the DWT in remote sensing for diversity purposes and they are satisfied with the wavelet theory. Though the algorithm for wavelet is very diverse, many people use the standard wavelet such as Daubechies D4 wavelet and biorthogonal 9/7 wavelet. We will overview the wavelet theory for discrete form which can be applied to the image processing. First, we will introduce the basic DWT algorithm and review the wavelet algorithm: EZW (Embedded Zerotree Wavelet), SPIHT(Set Partitioning in Hierarchical Trees), Lifting scheme, Curvelet, etc. Finally, we will suggest the properties of wavelet algorithm; and wavelet filter for each image processing in remote sensing.

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A Study on Turning Gait for a Quadruped Walking Robot (사각 보행로보트의 회전 걸음새에 관한 연구)

  • ;;Zeungnam Bien
    • Journal of the Korean Institute of Telematics and Electronics B
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    • v.28B no.11
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    • pp.886-896
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    • 1991
  • In this paper a new turning gait is proposed for a quadruped walking robot. The proposed scheme makes it possible to control the translation and orientation of the walking robot simultaneously. At first the feasible leg sequences which can guarantee a positive longitudinal gait stability margin for each direction of movement are found. A method for finding the lifting time of each leg of a feasible leg sequince and selecting an optimal gait among feasible gaits is then suggested. The proposed gait can be appled to control the posture of walking robots and to generate an optimal gait for a desired movement of translation and rotation of the walking robot systematically.

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Numerical Simulation of Wave Motions in Ideal Fluid of a Finite Depth (유한수심인 이상유체에서의 자유표면파의 수치모사)

  • Protopopov, Boris Ye.
    • Journal of the Society of Naval Architects of Korea
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    • v.32 no.1
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    • pp.58-69
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    • 1995
  • The present paper is devoted to constructing a numerical algorithm for solving un steady problems on generation, propagation and interaction of nonlinear waves at a surface of ideal fluid, within the framework of the potential-flow model. The numerical scheme is implicit. with non-linearity iteration at every step of time. the finite-difference method with boundary-fitted coordinates are presented in favor for validity and high efficiency of the numerical model developed. Among these arguments, there are the results of calculations of two test problems-on stretching of a liquid ellipse and on wave generation by lifting a portion of a bottom.

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Theoretical and Computational Analyses of Bernoulli Levitation Flows (베르누이 부상유동의 이론해석 및 수치해석 연구)

  • Nam, Jong Soon;Kim, Gyu Wan;Kim, Jin Hyeon;Kim, Heuy Dong
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.37 no.7
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    • pp.629-636
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    • 2013
  • Pneumatic levitation is based upon Bernoulli's principle. However, this method is known to require a large gas flow rate that can lead to an increase in the cost of products. In this case, the gas flow rate should be increased, and the compressible effects of the gas may be of practical importance. In the present study, a computational fluid dynamics method has been used to obtain insights into Bernoulli levitation flows. Three-dimensional compressible Navier-Stokes equations in combination with the SST k-${\omega}$ turbulence model were solved using a fully implicit finite volume scheme. The gas flow rate, workpiece diameter,and clearance gap between the workpiece and the circular cylinder were varied to investigate the flow characteristics inside. It is known that there is an optimal clearance gap for the lifting force and that increasing the supply gas flow rate results in a larger lifting force.

A Fast Processor Architecture and 2-D Data Scheduling Method to Implement the Lifting Scheme 2-D Discrete Wavelet Transform (리프팅 스킴의 2차원 이산 웨이브릿 변환 하드웨어 구현을 위한 고속 프로세서 구조 및 2차원 데이터 스케줄링 방법)

  • Kim Jong Woog;Chong Jong Wha
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.42 no.4 s.334
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    • pp.19-28
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    • 2005
  • In this paper, we proposed a parallel fast 2-D discrete wavelet transform hardware architecture based on lifting scheme. The proposed architecture improved the 2-D processing speed, and reduced internal memory buffer size. The previous lifting scheme based parallel 2-D wavelet transform architectures were consisted with row direction and column direction modules, which were pair of prediction and update filter module. In 2-D wavelet transform, column direction processing used the row direction results, which were not generated in column direction order but in row direction order, so most hardware architecture need internal buffer memory. The proposed architecture focused on the reducing of the internal memory buffer size and the total calculation time. Reducing the total calculation time, we proposed a 4-way data flow scheduling and memory based parallel hardware architecture. The 4-way data flow scheduling can increase the row direction parallel performance, and reduced the initial latency of starting of the row direction calculation. In this hardware architecture, the internal buffer memory didn't used to store the results of the row direction calculation, while it contained intermediate values of column direction calculation. This method is very effective in column direction processing, because the input data of column direction were not generated in column direction order The proposed architecture was implemented with VHDL and Altera Stratix device. The implementation results showed overall calculation time reduced from $N^2/2+\alpha$ to $N^2/4+\beta$, and internal buffer memory size reduced by around $50\%$ of previous works.