• Title/Summary/Keyword: adaptive iterative strategy

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An Adaptive Iterative Algorithm for Motion Deblurring Based on Salient Intensity Prior

  • Yu, Hancheng;Wang, Wenkai;Fan, Wenshi
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.13 no.2
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    • pp.855-870
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    • 2019
  • In this paper, an adaptive iterative algorithm is proposed for motion deblurring by using the salient intensity prior. Based on the observation that the salient intensity of the clear image is sparse, and the salient intensity of the blurred image is less sparse during the image blurring process. The salient intensity prior is proposed to enforce the sparsity of the distribution of the saliency in the latent image, which guides the blind deblurring in various scenarios. Furthermore, an adaptive iteration strategy is proposed to adjust the number of iterations by evaluating the performance of the latent image and the similarity of the estimated blur kernel. The negative influence of overabundant iterations in each scale is effectively restrained in this way. Experiments on publicly available image deblurring datasets demonstrate that the proposed algorithm achieves state-of-the-art deblurring results with small computational costs.

Multiscale Adaptive Wavelet-Galerkin Method for Membrane Eigenvalue Analysis (박막 고유치 해석을 위한 멀티스케일 적응 웨이블렛-갤러킨 기법)

  • Yi, Yong-Sub;Kim, Yoon-Young
    • Proceedings of the KSME Conference
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    • 2003.11a
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    • pp.1291-1296
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    • 2003
  • The objective of the present research is to develop a wavelet-based multiscale adaptive Galerkin method for membrane eigenvalue analysis. Since approximate eigensolutions at a certain resolution level can be good guesses, which play an important role in typical iterative solvers, at the next resolution level, the multiresolution iterative solution approach by wavelets can improve the solutionconvergence rate substantially. The intrinsic difference checking nature of wavelets can be also utilized effectively to develop an adaptive strategy. The present wavelet-based approach will be implemented for the simplest vector iteration method, but some important aspects, such as convergence speedup, and the reduction in the number of nodes can be clearly demonstrated.

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Adaptive Random Testing through Iterative Partitioning with Enlarged Input Domain (입력 도메인 확장을 이용한 반복 분할 기반의 적응적 랜덤 테스팅 기법)

  • Shin, Seung-Hun;Park, Seung-Kyu
    • The KIPS Transactions:PartD
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    • v.15D no.4
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    • pp.531-540
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    • 2008
  • An Adaptive Random Testing(ART) is one of test case generation algorithms, which was designed to get better performance in terms of fault-detection capability than that of Random Testing(RT) algorithm by locating test cases in evenly spreaded area. Two ART algorithms, such as Distance-based ART(D-ART) and Restricted Random Testing(RRT), had been indicated that they have significant drawbacks in computations, i.e., consuming quadratic order of runtime. To reduce the amount of computations of D-ART and RRT, iterative partitioning of input domain strategy was proposed. They achieved, to some extent, the moderate computation cost with relatively high performance of fault detection. Those algorithms, however, have yet the patterns of non-uniform distribution in test cases, which obstructs the scalability. In this paper we analyze the distribution of test cases in an iterative partitioning strategy, and propose a new method of input domain enlargement which makes the test cases get much evenly distributed. The simulation results show that the proposed one has about 3 percent of improvement in terms of mean relative F-measure for 2-dimension input domain, and shows 10 percent improvement for 3-dimension space.

Low Complexity Iterative Detection and Decoding using an Adaptive Early Termination Scheme in MIMO system (다중 안테나 시스템에서 적응적 조기 종료를 이용한 낮은 복잡도 반복 검출 및 복호기)

  • Joung, Hyun-Sung;Choi, Kyung-Jun;Kim, Kyung-Jun;Kim, Kwang-Soon
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.36 no.8C
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    • pp.522-528
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    • 2011
  • The iterative detection and decoding (IDD) has been shown to dramatically improve the bit error rate (BER) performance of the multiple-input multiple-output (MIMO) communication systems. However, these techniques require a high computational complexity since it is required to compute the soft decisions for each bit. In this paper, we show IDD comprised of sphere decoder with low-density parity check (LDPC) codes and present the tree search strategy, called a layer symbol search (LSS), to obtain soft decisions with a low computational complexity. In addition, an adaptive early termination is proposed to reduce the computational complexity during an iteration between an inner sphere decoder and an outer LDPC decoder. It is shown that the proposed approach can achieve the performance similar to an existing algorithm with 70% lower computational complexity compared to the conventional algorithms.

Integrated Design System using MDO and Approximation Technique (MDO 통합 설계 시스템을 위한 근사기법의 활용)

  • 양영순;박창규;장범선;유원선
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2004.04a
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    • pp.275-283
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    • 2004
  • The paper describes the integrated design system using MDO and approximation technique. In MDO related research, final target is an integrated and automated MDO framework systems. However, in order to construct the integrated design system, the prerequisite condition is how much save computational cost because of iterative process in optimization design and lots of data information in CAD/CAE integration. Therefore, this paper presents that an efficient approximation method, Adaptive Approximation, is a competent strategy via MDO framework systems.

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Study on an Approximation Technique using MDO (MDO에서 적용가능한 근사기법의 활용에 관한 연구)

  • Park, Chang-Kyu
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.6
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    • pp.3661-3666
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    • 2015
  • The paper describes the integrated design system using MDO and approximation technique. In MDO related research, final target is an integrated and automated MDO framework systems. However, in order to construct the integrated design system, the prerequisite condition is how much save computational cost because of iterative process in optimization design and lots of data information in CAD/CAE integration. Therefore, this paper presents that an efficient approximation method, Adaptive approximation, is a competent strategy via MDO framework systems.

Radioactive waste sampling for characterisation - A Bayesian upgrade

  • Pyke, Caroline K.;Hiller, Peter J.;Koma, Yoshikazu;Ohki, Keiichi
    • Nuclear Engineering and Technology
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    • v.54 no.1
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    • pp.414-422
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    • 2022
  • Presented in this paper is a methodology for combining a Bayesian statistical approach with Data Quality Objectives (a structured decision-making method) to provide increased levels of confidence in analytical data when approaching a waste boundary. Development of sampling and analysis plans for the characterisation of radioactive waste often use a simple, one pass statistical approach as underpinning for the sampling schedule. Using a Bayesian statistical approach introduces the concept of Prior information giving an adaptive sample strategy based on previous knowledge. This aligns more closely with the iterative approach demanded of the most commonly used structured decision-making tool in this area (Data Quality Objectives) and the potential to provide a more fully underpinned justification than the more traditional statistical approach. The approach described has been developed in a UK regulatory context but is translated to a waste stream from the Fukushima Daiichi Nuclear Power Station to demonstrate how the methodology can be applied in this context to support decision making regarding the ultimate disposal option for radioactive waste in a more global context.

A Power Control for OFDM Transmission Scheme in a Cochannel Interference Environment (동일 채널 간섭 환경에서 OFDM 전송 방식을 위한 송신 전력 제어)

  • Park, Jin-Kyu;Lim, Chang-Heon
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.32 no.3A
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    • pp.271-280
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    • 2007
  • This paper presents a power control scheme for OFDM based wireless communication systems in a multicell environment with co-channel interference which enables each system to achieve its target level of transmission bit rate. Generally, the optimal or near optimal power control scheme for multicarrier systems is Down to control the power level of each subcarrier in accordance with the associated channel status, which may be found in WF(waterfilling) and WF(iterative waterfilling) schemes. However, this requires the channel state information associated with every subchannel to be fed back from the receiver to its transmitter for successful power control. If the wireless channel exhibits relatively fast fading or the number of subcarriers is large, this may result in a considerable overhead. Here, in order to alleviate this problem, we propose a power control strategy for an OFDM systems maintaining the same power level over all the subcarriers. Also we prove its convergence, compare its complexity with that of the existing IWF algorithm, and examine its convergence characteristic through computer simulations.