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为提高分类性能,提出了一种新的基于数据离散化和选择性集成的SVM集成学习算法。该算法采用粗糙集和布尔推理离散化方法处理数据集,构造有差异的个体SVM以提高集成学习的性能。在训练得到一批SVM之后,算法采用了选择性集成提高性能并减小集成规模。实验结果表明,所提算法能取得比传统集成学习方法Bagging和Adaboost更好的性能。 相似文献
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Clustering-based selective neural network ensemble 总被引：1，自引：0，他引：1
INTRODUCTION Neural network ensemble is becoming a hot spot in machine learning and data mining recently. Many researchers have shown that simply combining the output of many neural networks can generate more accurate predictions than that of any of the individual networks. Most previous work either focused on how to combine the output of multiple trained networks or how to directly design a good set of neural networks. Theoretical and empirical work showed that a good ensemble is one wh… 相似文献
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Pan and Wollack (PW) proposed a machine learning method to detect compromised items. We extend the work of PW to an approach detecting compromised items and examinees with item preknowledge simultaneously and draw on ideas in ensemble learning to relax several limitations in the work of PW. The suggested approach also provides a confidence score, which is based on an autoencoder to represent our confidence that the detection result truly corresponds to item preknowledge. Simulation studies indicate that the proposed approach performs well in the detection of item preknowledge, and the confidence score can provide helpful information for users. 相似文献
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To improve the accuracy of sand-dust storm forecast system, a sand-dust storm ensemble forecast model based on rough set (RS) is proposed. The feature data are extracted from the historical data sets using the self-organization map (SOM) clustering network and single fields forecast to form the feature values with low dimensions. Then, the unwanted attributes are reduced according to RS to discretize the continuous feature values. Lastly, the minimum decision rules are constructed according to the remainder attributes, namely sand-dust storm ensemble forecast model based on RS is constructed. Results comparison between the proposed model and the back propagation neural network model show that the sand-storm forecast model based on RS has better stability, faster running speed, and its forecasting accuracy ratio is increased from 17.1% to 86.21%. 相似文献
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Ensemble learning HMM for motion recognition and retrieval by Isomap dimension reduction 总被引：1，自引：0，他引：1
XIANG Jian WENG Jian-guang ZHUANG Yue-ting WU Fei 《浙江大学学报(A卷英文版)》2006,7(12):2063-2072
INTRODUCTION Now more and more motion capture systems are used to acquire realistic human motion data. Due to the success of the Mocap systems, realistic and highly detailed motion clips are commercially available and widely used for producing animations of human-like characters in a variety of applications, such as simu- lations, video games and animation files. Therefore an efficient motion data recognition and retrieval technique is needed to support motion data processing, such as mot… 相似文献
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LIU Jiao-min WANG Jing-hong 《浙江大学学报(A卷英文版)》2007,8(3):469-474
The switching arc that occurs in contact gap when contact of low voltage apparatus closes or breaks in electric circuit is harmful to the contacts, insulation, and reliability of electrical gear because of its very high temperature. As arcing time is very short in switching gear, it is very difficult to observe arc phenomena directly for researchers. Therefore, visualization of switching arc is important for understanding arc phenomena, to analyze the arc features, and to improve the design and reliability of switching gear. Based on analyzing the visualization methods proposed by researchers, a new switching arc capturing approach is introduced in this paper. Arc image acquisition, and image processing techniques were studied. A switching arc image acquisition and visual simulation software based on high speed CCD camera hard ware system was designed and implemented to yield en- hanced arc image with good visual effect. 相似文献
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通过将多个光动量变换到三能级原子系综,提出了基于双光子达到海森堡极限超辐射高精度的位移测量方案.利用2N个相干脉冲可制备双激发狄拉克态的叠加态,每个狄拉克态由包含4N个分立光动量的超辐射态构成.结果表明,两态间的相位差与原子系综整体位移有关,其测量精度可高达1/8N.同时,利用拉姆齐干涉仪,简单说明了在晶体中本方案实现的可行性. 相似文献
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考察当前社会危机实际,试图提出一种结合本体论实现社会危机领域信息管理的方法．探讨了本体构建的方法、技术和工具,着重研究了基于本体论方法的社会危机信息本体的设计和构建,并实现了可视化展示,以期能改进当前系统不足,更好为社会危机工作服务． 相似文献
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Think aloud interview protocols from three high school post-physics students who interacted with a relative motion computer simulation presented in a predict-observe-explain format are analysed. Evidence is presented for: qualitative and quantitative difficulties with apparently simple one-dimensional relative motion problems; students' spontaneous visualization of relative motion problems; the visualizations facilitating solution of these problems; and students' memory of the on-line simulation used as a framework for visualization of post-test problems solved off-line. Instances of successful and unsuccessful mapping of remembered simulation features onto target problems are presented. Evidence from hand motions and other indicators suggesting that the subjects were using dynamic imagery in mental simulations during the treatment and post-test is presented. On the basis of these observations, it is hypothesized that for successful students, dissonance between their incorrect predictions and simulations displayed by the computer initiated the construction of new ways of thinking about relative motion, and that the memory of certain simulations acted as an analogue 'framework for visualization' of target problems solved off-line after the intervention. In such cases we find that interaction with a computer simulation on-line can facilitate a student's appropriate mental simulations off-line in related target problems. Implications for design and use of educational computer simulations are discussed. 相似文献
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Computed tomography(CT) blurring caused by point spread function leads to errors in quantification and visualization. In this paper, multichannel blind CT image restoration is proposed to overcome the effect of point spread function. The main advantage from multichannel blind CT image restoration is to exploit the diversity and redundancy of information in different acquisitions. The proposed approach is based on a variable splitting to obtain an equivalent constrained optimization formulation, which is addressed with the alternating direction method of multipliers and simply implemented in the Fourier domain. Numerical experiments illustrate that our method obtains a higher average gain value of at least 1.21 d B in terms of Q metric than the other methods, and it requires only 7 iterations of alternating minimization to obtain a fast convergence. 相似文献
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1 Introduction The degree of malignancy in brain glioma[1]domi-nates the way of treatment .In case of gradeⅠorⅡaccording to Kernohan,the success rate of operationis satisfactory. Otherwise ,for gradeⅢor IV,the sur-gical risk is high ,and poor life qual… 相似文献
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Reduction of roll and pitch motions is critical in improving the safety and operability of a ship. In this paper, a predictive controller for a ship equipped with two pairs of active fins is proposed for joint pitch-roll stabilization. The proposed controller is developed on the basis of ship motion and hydrodynamic force prediction (SMHFP). The SMHFP controller consists of a short-term predictor, a force estimator, and a fin angle allocator. The short-term predictor adopts an autoregressive (AR) approach and serves to forecast ship motions. Then, predicted ship motions are used in an external hydrodynamic force estimator to evaluate the expected stabilizing forces. Finally, the optimal attack angles for active fins are allocated based on external hydrodynamic forces forecasts. The control system of the stabilizing fins and SMHFP controller is integrated into the sea-keeping program. The program was developed based on a weakly nonlinear 2.5D method, which shows better efficiency and accuracy compared with conventional 2D and 3D methods. To evaluate the performance of the proposed controller, numerical simulations of the joint pitch-roll stabilization under various sea states were investigated on a ship model. The results suggest that the SMHFP controller shows satisfactory performance in reducing pitch and roll motions simultaneously. 相似文献
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为了直观认识随机变量概率分布的特性及其经验分布拟合的动态变化,提出了基于MATLAB GUI的可视化思想,通过算例说明了该程序的编制与实现方法. 相似文献
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The intemational standard ISO 10303.called STEP.has been used to deal with problems in the ex change of product models and the associated data between difierent computer-aided systems.A platform based on STEP for managing product information is presented.This platform includes three components:a product geometry information model,a product feature model and a product visualization model.An information extracting pattern,in which information is extracted from low level elements to high level ones,is adopted in establishing the product geometry information model.Relative elements lists are created based on the extracted product information.With the traversing of these lists,feature extraction methods are proposed,which take advantage of boundary information in product model and avoid the determination of concavity and convexity of curves.Information correlating to features iS stored in a structure named as feature block and the product visualization model iS founded from it.The feature block is used in the platform for information communication and synchronous update among the three components. 相似文献
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A dynamic velocity feed-forward compensation control (DVFCC) approach with RBF neural network (RBF-NN) dynamic model identification was presented for the adaptive trajectory tracking of industrial robots.The proposed control approach combined the advantages of traditional feedback closed-loop position control and computed torque control based on inverse dynamic model.The feed-forward compensator used a nominal robot dynamics as accurate dynamic model and on-line identification with RBF-NN as uncertain part to improve dynamic modeling accuracy.The proposed compensation was applied as velocity feed-forward by an inverse velocity controller that can convert torque signal into velocity in the standard industrial controller.Then,the need for a torque control interface was avoided in the real-time dynamic control of industrial robot.The simulations and experiments were carried out on a gas cutting manipulator.The results show that the proposed control approach can reduce steady-state error,suppress overshoot and enhance tracking accuracy and efficiency in joint space and Cartesian space,especially under highspeed condition. 相似文献
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量子存储在量子信息领域中具有相当重要的地位,类似于光子回波技术,一种基于可逆非均匀展宽的光量子存储方法可通过控制外部场的变化,达到对光信号的量子存储和提取。通过数值计算,对用于描述系统的海森堡方程进行求解,可知光信号被原子系统吸收后逐渐变小,光信号的量子信息转化为原子的极化属性,这样光量子信息就存储于原子系统中,其存储在原子系统的效率取决于系统的光学深度。 相似文献
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Kuo-En Chang Lin-Jung Wu Shing-Chuang Lai Yao-Ting Sung 《Interactive Learning Environments》2016,24(4):916-934
The purpose of this research is to develop a hands-on spatial geometry learning system to facilitate the learning of geometry. The development of this system was based on Duval's four critical elements of geometric learning: perceptual apprehension, sequential apprehension, operative apprehension, and discursive apprehension. The system offers support to high school students in the process of spatial geometry problem-solving. It provides a hands-on approach for manipulating spatial figures, thereby developing the students' visualization skills and ability to conceptualize images. The experiment comprised a total of 58 participants from different classes with the experimental group using the proposed learning system, whereas the control group using the traditional pencil-and-paper approach. The study investigated the effects of the hands-on system on the perceptual, sequential, and operative apprehension, and on overall spatial geometry scores and learning attitude. The results indicated improvements on effective learning and a higher level of sequential, operative apprehension, and overall spatial geometry scores from the experimental group. 相似文献
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朱明 《佳木斯教育学院学报》2012,(6):443+447
可视化最早是用于科学计算领域的,是为了方便人们发现事物之间相互联系,而提供的一种在视觉上比较直观的方式。按照信息的不同形式,目前主要有数据可视化、空间信息可视化、案例可视化等分类。 相似文献
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An approach for generating interactive 3D graphical visualization of the genetic architectures of complex traits in multiple environments is described. 3D graphical visualization is utilized for making improvements on traditional plots in quan- titative trait locus (QTL) mapping analysis. Interactive 3D graphical visualization for abstract expression of QTL, epistasis and their environmental interactions for experimental populations was developed in framework of user-friendly software QTLNetwork (http://ibi.zju.edu.cn/software/qtlnetwork). Novel definition of graphical meta system and computation of virtual coordinates are used to achieve explicit but meaningful visualization. Interactive 3D graphical visualization for QTL analysis provides geneticists and breeders a powerful and easy-to-use tool to analyze and publish their research results. 相似文献