应用科技
應用科技
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YING YONG KE JI
2013年
5期
18-23
,共6页
压缩感知%稀疏重构%光滑l0范数%修正牛顿法%混合优化
壓縮感知%稀疏重構%光滑l0範數%脩正牛頓法%混閤優化
압축감지%희소중구%광활l0범수%수정우돈법%혼합우화
compressive sensing%sparse recovery%smoothed l0 norm%revised Newton method%hybrid optimization
研究压缩感知的重构算法,分析了平滑l0(smoothed l0, SL0)的理论基础。 SL0算法通过利用平滑的高斯函数去逼近l0范数,将重构中的l0范数最小化问题转化为求解光滑函数最小值的最优化问题。针对算法中最速下降法存在“锯齿现象”和收敛速度慢等缺点,引入数值最优化理论中的混合优化算法,提出了一种基于混合优化的 SL0重构算法(HOSL0)。该算法结合了最速下降法和修正牛顿法的优点,提高了算法的重构精度和速度。仿真实验表明,HOSL0算法与同类算法相比性能有明显提高,同时在重构速度上比BP算法快了2个数量级。
研究壓縮感知的重構算法,分析瞭平滑l0(smoothed l0, SL0)的理論基礎。 SL0算法通過利用平滑的高斯函數去逼近l0範數,將重構中的l0範數最小化問題轉化為求解光滑函數最小值的最優化問題。針對算法中最速下降法存在“鋸齒現象”和收斂速度慢等缺點,引入數值最優化理論中的混閤優化算法,提齣瞭一種基于混閤優化的 SL0重構算法(HOSL0)。該算法結閤瞭最速下降法和脩正牛頓法的優點,提高瞭算法的重構精度和速度。倣真實驗錶明,HOSL0算法與同類算法相比性能有明顯提高,同時在重構速度上比BP算法快瞭2箇數量級。
연구압축감지적중구산법,분석료평활l0(smoothed l0, SL0)적이론기출。 SL0산법통과이용평활적고사함수거핍근l0범수,장중구중적l0범수최소화문제전화위구해광활함수최소치적최우화문제。침대산법중최속하강법존재“거치현상”화수렴속도만등결점,인입수치최우화이론중적혼합우화산법,제출료일충기우혼합우화적 SL0중구산법(HOSL0)。해산법결합료최속하강법화수정우돈법적우점,제고료산법적중구정도화속도。방진실험표명,HOSL0산법여동류산법상비성능유명현제고,동시재중구속도상비BP산법쾌료2개수량급。
This paper researches the reconstruction algorithm of compressive sensing, analyzes the theoretical basis of smoothed l0 algorithm (SL0). Through the use of a sequence of smoothed Gauss functions to approximate the l0 norm, the problem of minimization of the l0 norm in the reconstruction can be transformed into a convex optimization problem for the smoothed function. This paper proposes a new reconstruction algorithm to overcome the shortcomings of the gradient method, such as"notched effect"and the slow convergence. The algorithm using Smoothed l0 based on Hybrid Optimization algorithm (HOSL0) combines the advantages of the gradient method and the revised Newton method to improve the accuracy and speed of sparse recovery. The numerical simulation results show that the proposed algorithm has fast convergence and better accuracy compared with some existing similar methods. It is experimentally shown that HOSL0 algorithm is about two orders of magnitude faster than backpropagation algorithm under the same conditions.