This study explores a stable model order reduction method for fractional-order systems. Using the unsymmetric Lanczos algorithm, the reduced order system with a certain number of matched moments is generated. To obtai...
详细信息
This study explores a stable model order reduction method for fractional-order systems. Using the unsymmetric Lanczos algorithm, the reduced order system with a certain number of matched moments is generated. To obtain a stable reduced order system, the stable model order reduction procedure is discussed. By the revised operation on the tridiagonal matrix produced by the unsymmetric Lanczos algorithm, we propose a reduced order modeling method for a fractional-order system to achieve a satisfactory fitting effect with the original system by the matched moments in the frequency domain. Besides, the bound function of the order reduction error is offered. Two numerical examples are presented to illustrate the effectiveness of the proposed method.
In this study, a strategy based on the particle swarm optimization (PSO) algorithm is developed to control the microstructures of a Ni-based superalloy during hot forging. This strategy is composed of three parts, nam...
详细信息
In this study, a strategy based on the particle swarm optimization (PSO) algorithm is developed to control the microstructures of a Ni-based superalloy during hot forging. This strategy is composed of three parts, namely, material models, optimality criterions, and a PSO algo rithm. The material models are utilized to predict microstructure information, such as recrystallization volume fraction and average grain size. The optimality crite? non can be determined by the designed target microstructures and random errors. The developed strategy is resolved using the PSO algorithm, which is an intelligent optimal algorithm. This algorithm does not need a derivable objective function, which renders it suitable for dealing with the complex hot forging process of alloy components. The optimal processing parameters (deformation temperature and strain rate) are obtained by the developed strategy and validated by the hot forging experiments. Uniform and fine target microstructures can be obtained using the optimized processing parameters, which indicates that the developed strategy is effective for controlling the microstructural evolution during the hot forging of the studied superalloy.
OBJECTIVE To define selection criteria for pelvic lymph node dissection (PLND) based on a contemporary Australian cohort of men with clinically localised prostate cancer undergoing radical prostatectomy (RP) with PLND...
详细信息
OBJECTIVE To define selection criteria for pelvic lymph node dissection (PLND) based on a contemporary Australian cohort of men with clinically localised prostate cancer undergoing radical prostatectomy (RP) with PLND, as stage migration of prostate cancer has led to re-evaluation of the role of PLND at the time of RP. PATIENTS AND METHODS In all, 200 consecutive men treated by one surgeon between 2000 and 2005 with open RP and PLND. The clinical and pathological data were extracted by retrospective chart review. Associations between clinical predictors and LN positivity were assessed by logistic regression analysis. RESULTS Overall, there were LN metastases were in 10 95%) men. The LN positivity rate was signifi cantly associated with biopsy Gleason score, preoperative prostate-specifi c antigen 9PSA) concentration and percentage of positive cores 9PPC), with respective odds ratios 9OR) 995% confi dence interval [ CI]) of 3.70 91.98-6.92), 1.11 91.04-1.19) and 1.04 91.01-1.06) Trend toward signifi cant association with clinical stage 9OR 1.75, 95% CI 0.97-3.13) On multivariate analysis, PSA concentraion and biopsy Gleason score were signifi cant predictors of LN disease. All 10 men with LN metastases came from a high-risk group of 96, identifi able by having at least one of the following: stage = cT2b, biopsy Gleason score = 4 + 3, PSA concentration of = 10 ng/mL or PPC of = 38%. CONCLUSIONS The risk of LN metastases depends upon well-defined clinical risk factors of stage, biopsy Gleason score, PSA concentration and PPC The present data suggests a simple risk- stratifi cation method, using these risk factors, of identifying men to have PLND at the time of RP
Crystal structure prediction has been widely used to accelerate the discovery of new materials in recent *** to this day,it remains a challenge to predict the stable stoichiometries and structures of ternary or more c...
详细信息
Crystal structure prediction has been widely used to accelerate the discovery of new materials in recent *** to this day,it remains a challenge to predict the stable stoichiometries and structures of ternary or more complex systems due to the explosive increase of the size of the chemical and configurational *** novel materials with a series of unique characteristics are expected to be found in this virgin territory while new algorithms to predict crystal structures in complex systems are urgently called *** by co-evolution in biology,here we propose a co-evolutionary algorithm,which we name COPEX,and which is based on the well-known evolutionary algorithm *** this proposed algorithm,a few USPEX calculations for ternary systems and multiple for energetically-favored pseudobinary or fixed-composition systems are carried out in parallel,and coevolution is achieved by sharing structural information on the fittest individuals among different USPEX sub-processes during the joint *** have applied the algorithm to W–Cr–B,Mg–Si–O,and Hf–Ta–C,three very different systems,and many ternary compounds have been *** results clearly demonstrate that the COPEX algorithm combines efficiency and reliability even for complex systems.
Due to the stochastic and correlated attributes of natural inflows, the mid-term generation scheduling problem for cascaded hydro systems is a very challenging *** paper proposes a novel stochastic optimization algori...
详细信息
Due to the stochastic and correlated attributes of natural inflows, the mid-term generation scheduling problem for cascaded hydro systems is a very challenging *** paper proposes a novel stochastic optimization algorithm using Latin hypercube sampling and Cholesky decomposition combined with scenario bundling and sensitivity analysis(LC-SB-SA) to address this *** deal with the uncertainty of natural inflows, Latin hypercube sampling is implemented to provide an adequate number of sampling scenarios efficiently, and Cholesky decomposition is introduced to describe the correlated natural inflows among cascaded *** addition, to overcome the difficulties in solving the objectives of all the scenarios, scenario bundling and sensitivity analysis algorithms are developed to improve the computational *** results from both two-station and tenstation systems indicate that the proposed method has the merits in accuracy as well as calculation speed for the midterm cascaded hydro generation *** consideration of natural inflow correlation makes the formulated problem more realistic.
In nanoparticle sizing using the ultrafast image-based dynamic light scattering (UIDLS)method,larger impurities and dark noise from the complementary metal-oxide-semiconductor (CMOS)detector affect measurement *** sol...
详细信息
In nanoparticle sizing using the ultrafast image-based dynamic light scattering (UIDLS)method,larger impurities and dark noise from the complementary metal-oxide-semiconductor (CMOS)detector affect measurement *** solve this problem,a two-dimensional self-adapting fast Fourier transform (2D-SAFFT)algorithm is proposed for *** light scattering images of nanoparticles are processed using 2D fast Fourier transforms,and a high-frequency threshold and a low-frequency threshold are then set using the self-adapting algorithm to eliminate the effects of the dark noise of the CMOS detector and the *** signals caused by the dark noise of the CMOS detector and the impurities are cut off using the high-frequency threshold and the low-frequency *** signals without the high- and low-frequency components are then processed again using an inverse Fourier transform to obtain new images without the dark noise and impurities *** mean diameters of the measured nanoparticles can be obtained from images obtained using *** standard latex nanoparticles (46,100, 203,508,994nm)and commercial nanoparticles (antimony-doped tin oxide,indium tin oxide,TWEEN- 80,nano-Fe,and nano-Al2O3)were measured using this new *** show that 2D-SAFFT can effectively eliminate the effects of dark noise from the CMOS detector and the impurities.
Quantum algorithms are emerging tools in the design of functional materials due to their powerful solution space search *** to balance the high price of quantum computing resources and the growing computing needs has ...
详细信息
Quantum algorithms are emerging tools in the design of functional materials due to their powerful solution space search *** to balance the high price of quantum computing resources and the growing computing needs has become an urgent problem to be *** propose a novel optimization strategy based on an active learning scheme that combines the Quantum-inspired Genetic algorithm(QGA)with machine learning surrogate model *** Random Forests as the surrogate model circumvents the time-consuming physical modeling or experiments,thereby improving the optimization ***,a genetic algorithm embedded with quantum mechanics,combines the advantages of quantum computing and genetic algorithms,enabling faster and more robust convergence to the *** the design of planar multilayer photonic structures for transparent radiative cooling as a testbed,we show superiority of our algorithm over the classical genetic algorithm(CGA).Additionally,we show the precision advantage of the Random Forest(RF)model as a flexible surrogate model,which relaxes the constraints on the type of surrogate model that can be used in other quantum computing optimization algorithms(e.g.,quantum annealing needs Ising model as a surrogate).
This study concerns with the design optimization of steel skeletal structures thereby utilizing both a real-life specification provisions and ready steel profiles named hot-rolled I sections. For this purpose, the enh...
详细信息
This study concerns with the design optimization of steel skeletal structures thereby utilizing both a real-life specification provisions and ready steel profiles named hot-rolled I sections. For this purpose, the enhanced genetic algorithm methodology named EGAwMP is utilized as an optimization tool. The evolutionary search mechanism of EGAwMP is constituted on the basis of generational genetic algorithm (GGA). The exploration capacity of EGAwMP is improved in a way of dividing an entire population into sub-populations and using of a radial basis neural network for dynamically adjustment of EGAwMP’s genetic operator parameters. In order to improve the exploitation capability of EGAwMP, the proposed neural network implementation is also utilized for prediction of more accurate design variables associating with a new design strategy, design codes of which are based on the provisions of LRFD_AISC V3 specification. EGAwMP is applied to determine the real-life ready steel profiles for the optimal design of skeletal structures with 105, 200, 444, and 942 members. EGAwMP accomplishes to increase the quality degrees of optimum designations Furthermore, the importance of using the real-life steel profiles and design codes is also demonstrated. Consequently, EGAwMP is suggested as a design optimization tool for the real-life steel skeletal structures.
In order to solve the springback problem in sheet metal forming, the trial and error method is a widely used method in the factory, which is time-consuming and costly for its non-direction and non-quantitative. Finite...
详细信息
In order to solve the springback problem in sheet metal forming, the trial and error method is a widely used method in the factory, which is time-consuming and costly for its non-direction and non-quantitative. Finite element simulation is an e ective method to predict the springback of complex shape parts, but its precision is sensitive to the simulation model, particularly material model and boundary conditions. In this paper, the simple iterative method is introduced to establish the iterative compensation algorithm, and the convergence criterion of iterative parameters is put forward. In addition, the new algorithm is applied to the V-free bending and stretch-bending processes, and the convergence of curvature and bending angle is proved theoretically and verified experimentally. At the same time,the iterative compensation experiments for plane bending show that, the new method can predict the next compensaantido tnh ev atlaureg ebta cseurdv oatnu trhe ew sitphri tnhgeb earcrko ro fo fe laecshs ttehsat,n s0 o. 5 th%a ta rteh eo btatraigneet db aefntedri n2 g-3 a nitgelrea tiwoitnhs.t Thhei se rrreosre aorf clhe sps rtohpaons e±s 0 a.1%new iterative compensation algorithm to predict springback in sheet metal forming process, where each compensation value depends only on the iteration parameter di erence before and after springback for the same forming process of same material.
An algorithm for plotting two-dimensinal EEG histograms in amplitude-frequency coordinates of the waves forming the curve with the aid of a computer is described. The EEG is presented for coding as a series of extrema...
详细信息
An algorithm for plotting two-dimensinal EEG histograms in amplitude-frequency coordinates of the waves forming the curve with the aid of a computer is described. The EEG is presented for coding as a series of extrema, the times of their appearance being recorded. The appropriateness of the algorithm is confirmed by examples.
暂无评论