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Statistically robust design of linear filter for non-regenerative MIMO relay systems
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作者 WANG Ying LI Gen GONG Feng 《The Journal of China Universities of Posts and Telecommunications》 EI CSCD 2011年第3期34-40,共7页
This paper addresses the robust linear filter design issues for non-regenerative multiple input multiple output (MIMO) relay systems with imperfect channel state information (CSI) in both or partial hops. By consi... This paper addresses the robust linear filter design issues for non-regenerative multiple input multiple output (MIMO) relay systems with imperfect channel state information (CSI) in both or partial hops. By considering statistical Kronecker channel model involving channel mean and antenna correlation, the robust linear processing schemes in imperfect CSI scenario for both hops are first derived based on mean squared error (MSE) criterion. In addition to this, the result is also extended to two practical scenarios, i.e. imperfect CSI for relay link with perfect CSI for access link and imperfect CSI for access link with perfect CSI for relay link. Simulation results show that the proposed scheme is capable of mitigating the performance degradation caused by the imperfect CSI. 展开更多
关键词 MIMO RELAY linear filter robust design
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Radiation dose reduction with application of non-linear adaptive filters for abdominal CT 被引量:3
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作者 Sarabjeet Singh Mannudeep K Kalra +2 位作者 Mi Kim Sung Anni Back Michael A Blake 《World Journal of Radiology》 CAS 2012年第1期21-28,共8页
AIM:To evaluate the effect of non-linear adaptive filters (NLAF) on abdominal computed tomography (CT) images acquired at different radiation dose levels.METHODS:Nineteen patients (mean age 61.6 ± 7.9 years,M:F=8... AIM:To evaluate the effect of non-linear adaptive filters (NLAF) on abdominal computed tomography (CT) images acquired at different radiation dose levels.METHODS:Nineteen patients (mean age 61.6 ± 7.9 years,M:F=8:11) gave informed consent for an Institutional Review Board approved prospective study involving acquisition of 4 additional image series (200,150,100,50 mAs and 120 kVp) on a 64 slice multidetector row CT scanner over an identical 10 cm length in the abdomen.The CT images acquired at 150,100 and 50 mAs were processed with the NLAF.Two radiologists reviewed unprocessed and processed images for image quality in a blinded randomized manner.CT dose index volume,dose length product,patient weight,transverse diameters,objective noise and CT numbers wererecorded.Data were analyzed using Analysis of Variance and Wilcoxon signed rank test.RESULTS:Of the 31 lesions detected in abdominal CT images,28 lesions were less than 1 cm in size.Subjective image noise was graded as unacceptable in unprocessed images at 50 and 100 mAs,and in NLAF processed images at 50 mAs only.In NLAF processed images,objective image noise was decreased by 21% (14.4 ± 4/18.2 ± 4.9) at 150 mAs,28.3% (15.7 ± 5.6/21.9 ± 4) at 100 mAs and by 39.4% (18.8 ± 9/30.4 ± 9.2) at 50 mAs compared to unprocessed images acquired at respective radiation dose levels.At 100 mAs the visibility of smaller structures improved from suboptimal in unprocessed images to excellent in NLAF processed images,whereas diagnostic confidence was respectively improved from probably confident to fully confident.CONCLUSION:NLAF lowers image noise,improves the visibility of small structures and maintains lesion conspicuity at down to 100 mAs for abdominal CT. 展开更多
关键词 Noise REDUCTION filterS COMPUTED TOMOGRAPHY radiation dose REDUCTION ABDOMINAL COMPUTED TOMOGRAPHY image quality NON-linear adaptive filterS
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A NEW ALGORITHM FOR ADAPTIVE LATTICE FILTERAND ITS APPLICATION IN THE SPEECH LINEARPREDICTIVE SYNTHESIS 被引量:1
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作者 Jiang Taihui (institute of Information Science, Wuji University Jiangmen, Guangdong 529020) 《Journal of Electronics(China)》 1996年第4期325-332,共8页
In this paper, an adaptive line spectral pair filter is derived from an adaptive lattice filter. A least-mean-square(LMS) type adaptive algorithm used to calculate directly the line spectral pair(LSP) coefficients on ... In this paper, an adaptive line spectral pair filter is derived from an adaptive lattice filter. A least-mean-square(LMS) type adaptive algorithm used to calculate directly the line spectral pair(LSP) coefficients on a stage-by-stage basis is presented. Experimental results show that the algorithm has higher convergence rate and lower misadjustment as compared with the other algorithms. The LSP coefficients calculated by the algorithm have been used to carry out speech linear predictive synthesis, resulting in better results than PARCOR coefficients. 展开更多
关键词 Line SPECTRAL PAIR filter Adaptive LATTICE filter linear prediction LMS algorithm
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Reduced-order Kalman filtering for state constrained linear systems 被引量:1
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作者 Chaoyang Jiang Yongan Zhang 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2013年第4期674-682,共9页
This paper aims at solving the state filtering problem for linear systems with state constraints. Three classes of typical state constraints, i.e., linear equality, quadratic equality and inequality, are discussed. By... This paper aims at solving the state filtering problem for linear systems with state constraints. Three classes of typical state constraints, i.e., linear equality, quadratic equality and inequality, are discussed. By using the linear relationships among different state variables, a reduced-order Kalman filter is derived for the system with linear equality constraints. Afterwards, such a solution is applied to the cases of the quadratic equality constraint and inequality constraints and the two constrained state filtering problems are transformed into two relative constrained optimization problems. Then they are solved by the Lagrangian multiplier and linear matrix inequality techniques, respectively. Finally, two simple tracking examples are provided to illustrate the effectiveness of the reduced-order filters. 展开更多
关键词 state constraint state filtering reduced-order Kalman filter linear matrix inequality (LMI).
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The Marginal Rao-Blackwellized Particle Filter for Mixed Linear/Nonlinear State Space Models 被引量:16
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作者 Yin Jianjun Zhang Jianqiu Mike Klaas 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2007年第4期346-352,共7页
In this paper, the marginal Rao-Blackwellized particle filter (MRBPF), which fuses the Rao-Blackwellized particle filter (RBPF) algorithm and the marginal particle filter (MPF) algorithm, is presented. The state... In this paper, the marginal Rao-Blackwellized particle filter (MRBPF), which fuses the Rao-Blackwellized particle filter (RBPF) algorithm and the marginal particle filter (MPF) algorithm, is presented. The state space is divided into linear and non-linear parts, which can be estimated separately by the MPF and the optional Kalman filter. Through simulation in the terrain aided navigation (TAN) domain, it is demonstrated that, compared with the RBPF, the root mean square errors (RMSE) and the error variance of the nonlinear state estimations by the proposed MRBPF are respectively reduced by 29% and 96%, while the unique particle count is increased by 80%. It is also found that the MRBPF has better convergence properties, and analysis has shown that the existing RBPF is nothing more than a special case of the MRBPF. 展开更多
关键词 signal processing marginal Rao-Blackwellized particle filter SIMULATION mixed linear/nonlinear terrain aided navigation
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Filtering Function Method for the Cauchy Problem of a Semi-Linear Elliptic Equation 被引量:2
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作者 Hongwu Zhang Xiaoju Zhang 《Journal of Applied Mathematics and Physics》 2015年第12期1599-1609,共11页
A Cauchy problem for the semi-linear elliptic equation is investigated. We use a filtering function method to define a regularization solution for this ill-posed problem. The existence, uniqueness and stability of the... A Cauchy problem for the semi-linear elliptic equation is investigated. We use a filtering function method to define a regularization solution for this ill-posed problem. The existence, uniqueness and stability of the regularization solution are proven;a convergence estimate of H?lder type for the regularization method is obtained under the a-priori bound assumption for the exact solution. An iterative scheme is proposed to calculate the regularization solution;some numerical results show that this method works well. 展开更多
关键词 ILL-POSED PROBLEM CAUCHY PROBLEM SEMI-linear Elliptic Equation filterING Function Method Convergence Estimate
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Comparison of Signal to Noise Ratios by Stochastic Resonance Device and by Optimal Linear Filter
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作者 龚德纯 秦光戎 +1 位作者 温孝东 胡岗 《Science China Mathematics》 SCIE 1993年第4期431-436,共6页
The signal to noise ratio (SNR) obtained by the devices for manifesting stochastic resonance (SR) can be larger than that by the optimal linear filter. The essential reason for this fact is that there is an energy tra... The signal to noise ratio (SNR) obtained by the devices for manifesting stochastic resonance (SR) can be larger than that by the optimal linear filter. The essential reason for this fact is that there is an energy transfer from noise to signal under the SR condition which is absent in the linear case. 展开更多
关键词 SIGNAL to noise RATIO STOCHASTIC RESONANCE deviee OPTIMAL linear filter.
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An Improved H∞ Filter Design for Nonlinear System with Time-delay via T-S Fuzzy Models 被引量:1
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作者 HUANG Sheng-Juan ZHANG Da-Qing HE Xi-Qin ZHANG Ning-Ning 《自动化学报》 EI CSCD 北大核心 2010年第10期1454-1459,共6页
关键词 非线性系统 自动化系统 研究 模糊性
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Fault detection filter design for linear discrete time-varying systems with multiplicative noise 被引量:1
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作者 Yueyang Li Maiying Zhong 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2011年第6期982-990,共9页
The problem of fault detection for linear discrete timevarying systems with multiplicative noise is dealt with.By using an observer-based robust fault detection filter(FDF) as a residual generator,the design of the ... The problem of fault detection for linear discrete timevarying systems with multiplicative noise is dealt with.By using an observer-based robust fault detection filter(FDF) as a residual generator,the design of the FDF is formulated in the framework of H ∞ filtering for a class of stochastic time-varying systems.A sufficient condition for the existence of the FDF is derived in terms of a Riccati equation.The determination of the parameter matrices of the filter is converted into a quadratic optimization problem,and an analytical solution of the parameter matrices is obtained by solving the Riccati equation.Numerical examples are given to illustrate the effectiveness of the proposed method. 展开更多
关键词 fault detection filter(FDF) linear discrete time-varying(LDTV) system multiplicative noise Riccati equation.
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Properties of Gauss-Newton filter in linear cases
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作者 BAO Zhichao JIANG Qiuxi 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2018年第5期899-907,共9页
This paper presents the derivation of Gauss-Newton filter in linear cases and an analysis of its properties. Based on the minimum variance theorem, the Gauss-Newton filter is constructed and derived, including its sta... This paper presents the derivation of Gauss-Newton filter in linear cases and an analysis of its properties. Based on the minimum variance theorem, the Gauss-Newton filter is constructed and derived, including its state transition equation, observation equation and filtering process. Then, the delicate relationship between the Gauss-Aitken filter and the Kalman filter is discussed and it is verified that without process noise the two filters are equivalent. Finally, some simulations are conducted. The result shows that the Gauss-Aitken filter is superior to the Kalman filter in some aspects. 展开更多
关键词 Gauss-Newton filter linear case target tracking
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NOVEL LINEAR TRANSFORMATION SWITCHED-CAPACITOR FILTER DESIGN
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作者 高岩 王文煊 谷群山 《Journal of Electronics(China)》 1989年第1期19-33,共15页
This paper presents a novel method that is applied to realize the Linear Transformation(LT)Switched-Capacitor Filter(SCF).It adopts the Voltage Control Voltage Source(VCVS)equalized transfor-mation to revise the origi... This paper presents a novel method that is applied to realize the Linear Transformation(LT)Switched-Capacitor Filter(SCF).It adopts the Voltage Control Voltage Source(VCVS)equalized transfor-mation to revise the original LC ladder filter and induce it into 16 basic sections and then extend the princi-ple of the LT in order to fit active and 3 port networks and give out switched-capacitor circuits corre-sponding to the 16 basic sections,which can realize all four kinds of filters——LP,HP,BP,BS filters.De-signed examples are given here.An Nth order filter only requires N amplifiers and the circuit is insensitive toparasitic capacitances.The experimental results of a 3rd order elliptic LP and a 6th order elliptic BP are giv-en and agree with the theory. 展开更多
关键词 SWITCHED-CAPACITOR filter linear TRANSFORMATION VOLTAGE control VOLTAGE SOURCE
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Reliable H∞Filter Design for Discrete-time Systems with Sector-bounded Nonlinearities: an LMI Optimization Approach 被引量:3
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作者 GUO Xiang-Gui YANG Guang-Hong 《自动化学报》 EI CSCD 北大核心 2009年第10期1347-1351,共5页
关键词 H∞ filtering reliable filtering Lyapunov function sensor failure linear matrix inequality (LMI)
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Exponential passive filtering for a class of nonlinear jump systems 被引量:3
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作者 He Shuping Liu Fei 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2009年第4期829-837,共9页
The exponential passive filtering problem for a class of nonlinear Markov jump systems with uncertainties and time-delays is studied. The uncertain parameters are assumed unknown but norm bounded, and the nonlineariti... The exponential passive filtering problem for a class of nonlinear Markov jump systems with uncertainties and time-delays is studied. The uncertain parameters are assumed unknown but norm bounded, and the nonlinearities satisfy the quadratic condition. Based on the passive filtering theory, the sufficient condition for the existence of the mode-dependent passive filter is given by analyzing the reconstructed observer system. By using the appropriate Lyapnnov-Krasovskii function and applying linear matrix inequalities, the design scheme of the passive filter is derived and described as an optimization one. The presented exponential passive filter makes the error dynamic systems exponentially stochastically stable for all the admissible uncertainties, time-delays and nonlinearities, has the better abilities of state tracking and satisfies the given passive norm index. Simulation results demonstrate the validity of the proposed approach. 展开更多
关键词 nonlinear Markov jump systems UNCERTAINTIES TIME-DELAYS passive filter exponentially stochastically stable linear matrix inequalities.
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A New Design Approach for Nearly Linear Phase Stable IIR Filter using Fractional Derivative 被引量:1
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作者 Nikhil Agrawal Anil Kumar Varun Bajaj 《IEEE/CAA Journal of Automatica Sinica》 EI CSCD 2020年第2期527-538,共12页
In this paper,a new design method for digital infinite impulse response(IIR)filters with nearly linear-phase response is presented using fractional derivative constraints(FDCs).In the proposed method,design problem of... In this paper,a new design method for digital infinite impulse response(IIR)filters with nearly linear-phase response is presented using fractional derivative constraints(FDCs).In the proposed method,design problem of an IIR frlter is constructed as the minimization of phase error between the desired and designed phase response of an allpass filter(APF)such that the designed lowpass filter(LPF)or highpass frlter(HPF)yields less passband(ep),and stopband errors(es)with optimal stopband attenuation(As).In order to have accurate passband(pb)response,FDCs are imposed on appropriate reference frequency,where the optimality of these FDCs are ensured by using a new greedy based sorting mechanism.The simulated results reflect the efficiency of the proposed method in term of improved passband response along with better transition width.However,small reduction in^is observed within the allowable limit,when compared to noin-fractional design approach,but the designed filter remains immune to wordlength(WL)effect. 展开更多
关键词 Fractional derivative constraint(FDC) infinite impulse response(IIR)filter least squared linear phase QUANTIZATION
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非定常Stokes/Darcy模型一种新的time filter算法的分析
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作者 王阳 李剑 +1 位作者 李祎 秦毅 《数学物理学报(A辑)》 CSCD 北大核心 2023年第3期829-854,共26页
首先,在非定常Stokes/Darcy模型的线性多步法的一阶θ-格式的基础上,该文结合time filter算法在几乎不增加计算量的情况下有效地将线性多步法的收敛阶由一阶提高到二阶,从而提出一种新的高效数值算法.其次,该文分别对耦合和解耦的线性... 首先,在非定常Stokes/Darcy模型的线性多步法的一阶θ-格式的基础上,该文结合time filter算法在几乎不增加计算量的情况下有效地将线性多步法的收敛阶由一阶提高到二阶,从而提出一种新的高效数值算法.其次,该文分别对耦合和解耦的线性多步法加time filter算法的稳定性和误差估计进行了理论分析.最后,数值实验进一步展示了耦合和解耦算法的有效性,收敛性和高效性. 展开更多
关键词 Stokes/Darcy 模型 线性多步法 TIME filter 算法 二阶收敛
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Krein space approach to robust H_∞ filtering for linear uncertain systems
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作者 Jin Feng Fei Yu +2 位作者 Na Yang Pengyu Zhang Wei Gao 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2012年第4期596-602,共7页
A novel Krein space approach to robust H∞ filtering for linear uncertain systems is developed. The parameter uncertainty, entering into both states and measurement equations, satisfies an energy-type constraint. Then... A novel Krein space approach to robust H∞ filtering for linear uncertain systems is developed. The parameter uncertainty, entering into both states and measurement equations, satisfies an energy-type constraint. Then a Krein space approach is used to tackle the robust H∞ filtering problem. To this end, a new Krein space formal system is designed according to the original sum quadratic constraint (SQC) without introducing any nonzero factors into it and, consequently, the estimate recursion is obtained through the filter gain in Krein space. Finally, a numerical example is given to demonstrate the effectiveness of the proposed approach. 展开更多
关键词 linear uncertain system sum quadratic constraint(SQC) robust H∞ filtering Krein space linear estimation.
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THE REALIZATION OF LINEAR SHIFT-VARIANT FILTERS THROUGH STATE FEEDBACK
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作者 冯志彪 沈永昌 R.Unbehauen 《Journal of Electronics(China)》 1991年第3期259-267,共9页
In this paper a new method to realize rational generalized transfer functions of linearshift-variant digital filters through state feedback is presented In some practical applications therequired characteristics of th... In this paper a new method to realize rational generalized transfer functions of linearshift-variant digital filters through state feedback is presented In some practical applications therequired characteristics of the filter change slowly.Under these circumstances,the proposedmethod is very effective and the resulting filter structure is simple.A numerical example isprovided to show the performance of the method. 展开更多
关键词 linear shift-variant digital filter Shift-variant IMPULSE response Generalized transfer function
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Comparative Study of Linear and Non-Linear Controls of Three-Phase Shunt Active Filters for Improving the Quality of Electrical Energy
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作者 Mamane Adamou Nabil Alkassoum +1 位作者 André Foulani Amadou Seidou Maiga 《Energy and Power Engineering》 2019年第3期149-166,共18页
The aim of this work is to comparatively study two types of control of a three-phase shunt active filter (TSAF) in order to realize a system of depollution of electrical networks so as to improve the quality of electr... The aim of this work is to comparatively study two types of control of a three-phase shunt active filter (TSAF) in order to realize a system of depollution of electrical networks so as to improve the quality of electrical energy. We used two TSA control models which differ in the method of disturbed currents detection, one linear and the other non-linear. The results show that the non-linear control method, although with high calculation blocks, gives more promising results than the linear control method. When connecting a non-linear load (televisions, lamps, variable speed drives, etc.) directly to the public distribution network, the non-linear nature of the load causes the source current to be deformed due to the presence of harmonic currents and voltages. These harmonics thus generate a high reactive power, and therefore considerable electrical losses in the network. One of the solutions to reduce losses on the electricity grid is to incorporate an electronic circuit called a filter into the electricity grid. This work carried out a comparative study of two types of control of a three-phase shunt active filter (TSAF) in order to carry out a system for cleaning up electricity networks in order to improve the quality of electrical energy. We used two TSA control models that differ in the method of detecting disturbed currents, one linear and the other non-linear. The results show that the non-linear control method, although with high calculation blocks, gives better results than the linear control method. 展开更多
关键词 Power QUALITY Active THREE-PHASE SHUNT filter NON-linear CONTROL linear CONTROL
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Commissioning of TrueBeamTM Medical Linear Accelerator: Quantitative and Qualitative Dosimetric Analysis and Comparison of Flattening Filter (FF) and Flattening Filter Free (FFF) Beam 被引量:4
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作者 Ravindra Shende Gourav Gupta +1 位作者 Ganesh Patel Senthil Kumar 《International Journal of Medical Physics, Clinical Engineering and Radiation Oncology》 2016年第1期51-69,共19页
Motive of the study is to present quantitative and qualitative analysis and comparison of beam data measurement with FF (flattening filter) and FFF (flattening filter free) beam in a Varian TrueBeam<sup>TM</s... Motive of the study is to present quantitative and qualitative analysis and comparison of beam data measurement with FF (flattening filter) and FFF (flattening filter free) beam in a Varian TrueBeam<sup>TM</sup> Medical Linear Accelerator. Critique of beam characterization and evolution of dosimetric properties for 6 MV, 10 MV, 15 MV FF beam and 6 MVFFF, 10 MVFFF FFF beam has been carried out. We performed the comparison of photon beam data for two standard FF photon energy 6 MV, 10 MV verses 6 MVFFF, and 10 MVFFF FFF beam. Determination and comparison of parameter involved PDD (Percentage depth dose), Depth dose profile, Symmetry, Flatness, Quality index, Relative output factor, Penumbra, Transmission factor, DLG (Dosimetric leaf gap), in addition to degree of Un-flatness and off-axis ratio of FFF beam. Outcomes of presenting study had shown that change of various parameters such as Percentage depth dose curves, Shape of the depth dose profile, Transmission, Value of quality index and significant rise in surface dose for FFF in comparison with FF beam. Differences in the output factor at lower and higher field sizes for FFF beam compared to that of FF beam were found. The maximum output factor deviation between 6 MV and 6 MVFFF was found to be 4.55%, whereas in 10 MV and 10 MVFFF was 5.71%. Beam quality TPR20/10 for FFF beam was found to be lesser in magnitude, 5.42% for 6 MVFFF whereas 4.50% for 10 MVFFF compared to 6 MV and 10 MV FF beam respectively. Jaw transmission and interleaf leakage for FFF beam were found to be lesser than FF beam. Also DLG for FFF beam was found to be lesser in magnitude comparable to that of flattened beam. This study is mainly inclined towards evaluation and comparison of the FF and FFF beam. It has been observed that, the outcome of a commissioning beam data generation fully complies with vendor specification and published literature. 展开更多
关键词 True Beam Medical linear Accelerator Commissioning Photon Beam Data Flattening filter Flattening filter Free
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H_∞ Filter Design for Linear Systems with Delays
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作者 薛红 《科技信息》 2011年第9期I0217-I0217,I0226,共2页
This paper focuses on the problem of H∞ filter design for linear delayed systems.A new approach of filter design is proposed by using Lyapunov stability theory together with linear matrix inequality(LMI) approach.Som... This paper focuses on the problem of H∞ filter design for linear delayed systems.A new approach of filter design is proposed by using Lyapunov stability theory together with linear matrix inequality(LMI) approach.Some sufficient conditions for the existence of H∞ filter are established based on the solutions of a set of LMIs.Finally,two examples are given to demonstrate the effectiveness of the proposed method. 展开更多
关键词 自动化系统 线性系统 最优控制 函数
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