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电弧喷涂系统最优控制参数选择方法探讨 被引量:5
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作者 李鹤岐 陈爱军 《甘肃工业大学学报》 1999年第2期1-4,共4页
针对电弧喷涂单片机控制系统的不足和再扩展能力,对其功能和控制算法进行了扩充和改进,实现了电弧喷涂工艺参数自适应控制,达到了喷涂工艺参数优化的目的,并得到了良好的涂层质量.
关键词 电弧喷涂 数字控制 最优控制 参数选择法
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基于split-and-conquer和非参数向前选择法的变量选择
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作者 李顺勇 赵永胜 《云南民族大学学报(自然科学版)》 CAS 2019年第6期576-580,623,共6页
变量选择是统计学界研究的重要课题之一.当处理高维数据时,一些常用的变量选择方法大多比较耗时,因此提出了一种既能筛选出高维数据中的变量又能节省时间的方法:基于split-and-conquer的非参数向前选择法.首先使用split-and-conquer方... 变量选择是统计学界研究的重要课题之一.当处理高维数据时,一些常用的变量选择方法大多比较耗时,因此提出了一种既能筛选出高维数据中的变量又能节省时间的方法:基于split-and-conquer的非参数向前选择法.首先使用split-and-conquer方法将数据进行拆分,然后使用B样条函数逼近的非参数向前选择法进行研究.实验结果表明:基于split-and-conquer的非参数向前选择法可以较好地将变量选择出来,并且节省了大量时间. 展开更多
关键词 变量选择 参数可加性模型 参数向前选择 B样条函数 线性回归
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中国乳腺癌自然史参数选择的优化方法
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作者 尹娟 王乐 +7 位作者 白晓宁 李燕婕 王鑫 张在坤 李炳照 李扬 石菊芳 李庆娜 《中国科学:数学》 CSCD 北大核心 2023年第6期895-913,共19页
乳腺癌是女性最常见的恶性肿瘤之一。为了提出有效的筛查策略并评估其效果,一个基本且重要的步骤是在中国乳腺癌自然史模型中选择合适的参数,即转移概率.选择合理的转移概率有两个挑战.首先,由于乳腺癌的流行病学特性,其他国家使用的转... 乳腺癌是女性最常见的恶性肿瘤之一。为了提出有效的筛查策略并评估其效果,一个基本且重要的步骤是在中国乳腺癌自然史模型中选择合适的参数,即转移概率.选择合理的转移概率有两个挑战.首先,由于乳腺癌的流行病学特性,其他国家使用的转移概率不一定适用于中国.其次,可用的筛查样本数据很少,这使得传统的基于统计的方法(如极大似然估计法)失效.本文从优化角度提出一种乳腺癌自然史参数选择的方法,基于公布的统计数据建立数学优化模型.该模型的挑战在于目标函数高度非线性且无显式表达式,本文提出一种坐标下降算法来处理这个挑战.最后,本文提出一种最佳匹配方法来估计每个转移概率的分布.本文所提出的方法为进一步提出合理的中国乳腺癌筛查策略和分析乳腺癌的经济负担提供了坚实的基础. 展开更多
关键词 乳腺癌 自然史 参数选择黄金分割 无导数 坐标下降
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Extrapolated Tikhonov method and inversion of 3D density images of gravity data
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作者 王祝文 许石 +1 位作者 刘银萍 刘菁华 《Applied Geophysics》 SCIE CSCD 2014年第2期139-148,252,共11页
Tikhonov regularization(TR) method has played a very important role in the gravity data and magnetic data process. In this paper, the Tikhonov regularization method with respect to the inversion of gravity data is d... Tikhonov regularization(TR) method has played a very important role in the gravity data and magnetic data process. In this paper, the Tikhonov regularization method with respect to the inversion of gravity data is discussed. and the extrapolated TR method(EXTR) is introduced to improve the fitting error. Furthermore, the effect of the parameters in the EXTR method on the fitting error, number of iterations, and inversion results are discussed in details. The computation results using a synthetic model with the same and different densities indicated that. compared with the TR method, the EXTR method not only achieves the a priori fitting error level set by the interpreter but also increases the fitting precision, although it increases the computation time and number of iterations. And the EXTR inversion results are more compact than the TR inversion results, which are more divergent. The range of the inversion data is closer to the default range of the model parameters, and the model features and default model density distribution agree well. 展开更多
关键词 Gravity data inversion 3D inversion extrapolated Tikhonov regularization method extrapolated Tikhonov parameter selection
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Parameter selection of pocket extraction algorithm using interaction interface 被引量:1
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作者 KIM Chong-Min WON Chung-In +3 位作者 RYU Joonghyun CHO Cheol-Hyung BHAK Jonghwa KIM Deok-Soo 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2006年第9期1492-1499,共8页
Pockets in proteins have been known to be very important for the life process. There have been several studies in the past to automatically extract the pockets from the structure information of known proteins. However... Pockets in proteins have been known to be very important for the life process. There have been several studies in the past to automatically extract the pockets from the structure information of known proteins. However, it is difficult to find a study comparing the precision of the extracted pockets from known pockets on the protein. In this paper, we propose an algorithm for extracting pockets from structure data of proteins and analyze the quality of the algorithm by comparing the extracted pockets with some known pockets. These results in this paper can be used to set the parameter values of the pocket extraction algorithm for getting better results. 展开更多
关键词 POCKET PROTEIN Interaction interface Protein interaction Voronoi diagram
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A FUZZY CLOPE ALGORITHM AND ITS OPTIMAL PARAMETER CHOICE 被引量:1
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作者 Li Jie Gao Xinbo Jiao Licheng 《Journal of Electronics(China)》 2006年第3期384-388,共5页
Among the available clustering algorithms in data mining, the CLOPE algorithm attracts much more attention with its high speed and good performance. However, the proper choice of some parameters in the CLOPE algorithm... Among the available clustering algorithms in data mining, the CLOPE algorithm attracts much more attention with its high speed and good performance. However, the proper choice of some parameters in the CLOPE algorithm directly affects the validity of the clustering results, which is still an open issue. For this purpose, this paper proposes a fuzzy CLOPE algorithm, and presents a method for the optimal parameter choice by defining a modified partition fuzzy degree as a clustering validity function. The experimental results with real data set illustrate the effectiveness of the proposed fuzzy CLOPE algorithm and optimal parameter choice method based on the modified partition fuzzy degree. 展开更多
关键词 Data mining Cluster analysis Cluster validity Categorical attributes Optimal parameter choice
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Kinetic Characteristics of Nitrate Uptake by Wheat and Rape and Their Determination 被引量:2
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作者 ZHANGLI-GAN XUANJIA-XIANG 《Pedosphere》 SCIE CAS CSCD 1993年第2期127-132,共6页
15-day old seedlings of wheat and rape were grown in a series of solutions with different concentrations of KNO3 for a definite period of time. The changes in NO3- concentration of the solutions were determined by the... 15-day old seedlings of wheat and rape were grown in a series of solutions with different concentrations of KNO3 for a definite period of time. The changes in NO3- concentration of the solutions were determined by the double ion-selective electrode method, and then the amount of NO3- taken up by the plants was estimated and values of Km and Imax of the Michealis-Menten equation were calculated. Results show that both the method and conditions of determination affected the values of Km and Imax. For example, the Km value was appreciably reduced when the volume of culture solution was increased or when the duration of nutrient uptake was shortened; the Km value obtained with short-term depletion method was higher than that obtained with long-term one. Similar Variations were found for the values of Imax. There was a considerable difference in the characteristics of uptake kinetics between wheat and rape when determined under the same conditions of determination. The isotherm of NO3- uptake by wheat could be separated into saturated and unsaturated parts, and when the concentration of NO3- exceeded 180 uuuuuuuuuuuuM, the relationship between the rate of NO3- uptake and NO3- concentration tended to be linear. However, the isotherm of NO3- uptake by rape was found to fit the Michealis-Menten equation and no linear relationship could be found. 展开更多
关键词 double ion-selective electrode method kinetic parameter NITRATE
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Study on Collision Between Two Ships Using Selected Parameters in Collision Simulation 被引量:2
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作者 Dong-Myung Bae Aditya Rio Prabowo +2 位作者 Bo Cao Ahmad Fauzan Zakki Gunawan Dwi Haryadi 《Journal of Marine Science and Application》 CSCD 2016年第1期63-72,共10页
In the present analysis, several parameters used in a numerical simulation are investigated in an integrated study to obtain their influence on the process and results of this simulation. The parameters studied are el... In the present analysis, several parameters used in a numerical simulation are investigated in an integrated study to obtain their influence on the process and results of this simulation. The parameters studied are element formulation, friction coefficient, and material model. Numerical simulations using the non-linear finite element method are conducted to produce virtual experimental data for several collision scenarios. Pattern and size damages caused by collision in a real accident case are assumed as real experimental data, and these are used to validate the method. The element model study performed indicates that the Belytschko-Tsay element formulation should be recommended for use in virtual experiments. It is recommended that the real value of the friction coefficient for materials involved is applied in simulations. For the study of the material model, the application of materials with high yield strength is recommended for use in the side hull structure. 展开更多
关键词 ship collision collision accident non-linear finite element collision parameter hull structure
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Multi-strategy Differential Evolution Algorithm for QoS Multicast Routing
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作者 Xi Li Yang Zhao 《International Journal of Technology Management》 2013年第8期90-92,共3页
This paper studies the difference algorithm parameters characteristic of the multicast routing problem, and to compare it with genetic algorithms. The algorithm uses the path of individual coding, combined with the di... This paper studies the difference algorithm parameters characteristic of the multicast routing problem, and to compare it with genetic algorithms. The algorithm uses the path of individual coding, combined with the differential cross-choice strategy and operations optimization. Finally, we simulated 30 node networks, and compared the performance of genetic algorithm and differential evolution algorithm. Experimental results show that multi-strategy Differential Evolution algorithm converges faster and better global search ability and stability. 展开更多
关键词 QOS multi-strategy difference differential evolution genetic algorithm
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Novel robust approach for constructing Mamdani-type fuzzy system based on PRM and subtractive clustering algorithm 被引量:1
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作者 褚菲 马小平 +1 位作者 王福利 贾润达 《Journal of Central South University》 SCIE EI CAS CSCD 2015年第7期2620-2628,共9页
A novel approach for constructing robust Mamdani fuzzy system was proposed, which consisted of an efficiency robust estimator(partial robust M-regression, PRM) in the parameter learning phase of the initial fuzzy syst... A novel approach for constructing robust Mamdani fuzzy system was proposed, which consisted of an efficiency robust estimator(partial robust M-regression, PRM) in the parameter learning phase of the initial fuzzy system, and an improved subtractive clustering algorithm in the fuzzy-rule-selecting phase. The weights obtained in PRM, which gives protection against noise and outliers, were incorporated into the potential measure of the subtractive cluster algorithm to enhance the robustness of the fuzzy rule cluster process, and a compact Mamdani-type fuzzy system was established after the parameters in the consequent parts of rules were re-estimated by partial least squares(PLS). The main characteristics of the new approach were its simplicity and ability to construct fuzzy system fast and robustly. Simulation and experiment results show that the proposed approach can achieve satisfactory results in various kinds of data domains with noise and outliers. Compared with D-SVD and ARRBFN, the proposed approach yields much fewer rules and less RMSE values. 展开更多
关键词 Mamdani-type fuzzy system robust system subtractive clustering algorithm outlier partial robust M-regression
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改进的自适应加法算法及其在衍射光学元件设计中的应用 被引量:6
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作者 温昌礼 季家镕 +1 位作者 窦文华 宋艳生 《光学学报》 EI CAS CSCD 北大核心 2010年第9期2473-2477,共5页
随着激光的广泛应用,在许多场合都需要对其进行光束整形,其中最重要的整形元件就是衍射光学元件(DOE)。引用了自适应加法(AA)算法,并且对其进行了改进,一方面克服了AA算法的两个缺陷,另一方面提高了AA算法的精度。在AA算法中加入自动选... 随着激光的广泛应用,在许多场合都需要对其进行光束整形,其中最重要的整形元件就是衍射光学元件(DOE)。引用了自适应加法(AA)算法,并且对其进行了改进,一方面克服了AA算法的两个缺陷,另一方面提高了AA算法的精度。在AA算法中加入自动选取参数λ的环节,使得不必采用尝试法确定参数,减小了DOE设计的工作量。此外,还提出了三种克服分母出现零点的方法。应用AA算法设计了整形高斯光束的DOE以及一维光栅分束器,并得到理想的结果。对比了AA算法和高斯(GS)算法,说明AA算法具有优势和潜力,可以简单高效地应用于DOE的设计。 展开更多
关键词 光学设计 衍射光学元件 自适应加 参数选择法
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Multi-parameter Tikhonov Regularization—An Augmented Approach
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作者 Kazufumi ITO Bangti JIN Tomoya TAKEUCHI 《Chinese Annals of Mathematics,Series B》 SCIE CSCD 2014年第3期383-398,共16页
We study multi-parameter regularization(multiple penalties) for solving linear inverse problems to promote simultaneously distinct features of the sought-for objects. We revisit a balancing principle for choosing regu... We study multi-parameter regularization(multiple penalties) for solving linear inverse problems to promote simultaneously distinct features of the sought-for objects. We revisit a balancing principle for choosing regularization parameters from the viewpoint of augmented Tikhonov regularization, and derive a new parameter choice strategy called the balanced discrepancy principle. A priori and a posteriori error estimates are provided to theoretically justify the principles, and numerical algorithms for efficiently implementing the principles are also provided. Numerical results on deblurring are presented to illustrate the feasibility of the balanced discrepancy principle. 展开更多
关键词 Multi-parameter regularization Augmented Tikhonov regularization Balanced discrepancy principle
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