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1.
The literature reports many scientific works on the use of artificial intelligence techniques such as neural networks or fuzzy logic to predict surface roughness. This article aims at introducing Bayesian network-based classifiers to predict surface roughness (Ra) in high-speed machining. These models are appropriate as prediction techniques because the non-linearity of the machining process demands robust and reliable algorithms to deal with all the invisible trends present when a work piece is machining. The experimental test obtained from a high-speed milling contouring process analysed the indicator of goodness using the Naïve Bayes and the Tree-Augmented Network algorithms. Up to 81.2% accuracy was achieved in the Ra classification results. Therefore, we envisage that Bayesian network-based classifiers may become a powerful and flexible tool in high-speed machining.  相似文献   

2.
The main objective of this paper is to present a new method of detection and isolation with a Bayesian network. For that, a combination of two original works is made. The first one is the work of Li et al. [1] who proposed a causal decomposition of the T2 statistic. The second one is a previous work on the detection of fault with Bayesian networks [2], notably on the modeling of multivariate control charts in a Bayesian network. Thus, in the context of multivariate processes, we propose an original network structure allowing to decide if a fault has appeared in the process. This structure permits the isolation of the variables implicated in the fault. A particular interest of the method is the fact that the detection and the isolation can be made with a unique tool: a Bayesian network.  相似文献   

3.
Drilling process is one of the most important operations in aeronautic industry. It is performed on the wings of the aeroplanes and its main problem lies with the burr generation. At present moment, there is a visual inspection and manual burr elimination task subsequent to the drilling and previous to the riveting to ensure the quality of the product. These operations increase the cost and the resources required during the process. The article shows the use of data mining techniques to obtain a reliable model to detect the generation of burr during high speed drilling in dry conditions on aluminium Al 7075-T6. It makes possible to eliminate the unproductive operations in order to optimize the process and reduce economic cost. Furthermore, this model should be able to be implemented later in a monitoring system to detect automatically and on-line when the generated burr is out of tolerance limits or not. The article explains the whole process of data analysis from the data preparation to the evaluation and selection of the final model.  相似文献   

4.
王占孔  王学丽 《软件》2011,32(4):87-90
本文以SNMP网络管理模型的管理信息库(MIB)为基础,在不同层次上构建了用于故障判别与定位的贝叶斯网络。对MIB变量采用自适应自回归(AAR)模型建模分析,构建与其相关协议之间的贝叶斯网络,推断协议功能是否发生异常。分析各个协议之间的功能依赖关系,构建协议间的贝叶斯网络,定位协议间的故障根源。考虑网络中故障传播构建了基于网络拓扑的贝叶斯网,定位故障根源节点。最后,对构建的模型进行了实验仿真,并分析了模型的优点和缺点。  相似文献   

5.
Selecting tourist attractions to visit at a destination is a main stage in planning a trip. Although various online travel recommendation systems have been developed to support users in the task of travel planning during the last decade, few systems focus on recommending specific tourist attractions. In this paper, an intelligent system to provide personalized recommendations of tourist attractions in an unfamiliar city is presented. Through a tourism ontology, the system allows integration of heterogeneous online travel information. Based on Bayesian network technique and the analytic hierarchy process (AHP) method, the system recommends tourist attractions to a user by taking into account the travel behavior both of the user and of other users. Spatial web services technology is embedded in the system to provide GIS functions. In addition, the system provides an interactive geographic interface for displaying the recommendation results as well as obtaining users’ feedback. The experiments show that the system can provide personalized recommendations on tourist attractions that satisfy the user.  相似文献   

6.
International Journal of Information Security - Due to the continuous evolution of adversary tactics, strategies, and processes, the contemporary digital universe is confronted with new obstacles...  相似文献   

7.
The burrs at the hole exit degrade the performance in precision part and affect the reliability of the product. Hence, it is essential to select the optimal process parameters for minimal burr size at the manufacturing stage so as to reduce the deburring cost and time. This paper illustrates the application of particle swarm optimization (PSO) to select the best combination values of feed and point angle for a specified drill diameter in order to simultaneously minimize burr height and burr thickness during drilling of AISI 316L stainless steel. The burr size models required for the PSO optimization were developed using artificial neural network (ANN) with the drilling experiments planned as per full factorial design (FFD). The PSO optimization results clearly indicate the importance of larger point angle for bigger drill diameter values in controlling the burr size.  相似文献   

8.
针对贝叶斯信念网络应用于话题识别进行了研究, 提出了新的话题识别模型。模型的拓扑结构包括新报道、报道术语、事件术语、话题四层节点, 用弧标明索引关系。在贝叶斯概率和条件独立性假设的基础上, 模型运用条件概率计算新报道和已有话题簇的相似度, 从而实现话题识别。考虑到核心报道、核心事件的重要性, 对不同层次的权重计算进行了调整。实验采用DET曲线评测法对模型性能进行测试, 实验结果显示, 调整后的权重计算可在一定程度上提高新模型的性能, 与向量空间模型相比, 在相同阈值下新模型的漏报率与误报率有所降低。  相似文献   

9.
崔惠萍  徐英卓 《计算机工程与设计》2007,28(21):5308-5310,5313
根据石油钻井作业的特点,提出开发一个由计算机网络支持的钻井事故诊断与处理系统,为后方基地的多方专家进行会诊提供了支撑平台.该平台可以将分散在不同地点的有关专家或软件系统聚集在网上一起协同工作,从而提高钻井事故诊断与处理的科学性和实时性.对系统的结构与功能模型、组网方法以及主要设计技术包括数据传输协议栈、数据包格式、数据交互等进行了详细描述.  相似文献   

10.
In this paper, an effective strategy for fault detection of sludge volume index (SVI) sensor is proposed and tested on an experimental hardware setup in waste water treatment process (WWTP). The main objective of this fault detection strategy is to design a system which consists of the online sensors, the SVI predicting plant and fault diagnosis method. The SVI predicting plant is designed utilizing a fuzzy neural network (FNN), which is trained by a historical set of data collected during fault-free operation of WWTP. The fault diagnosis method, based on the difference between the measured concentration values and FNN predictions, allows a quick revealing of the faults. Then this proposed fault detection method is applied to a real WWTP and compared with other approaches. Experimental results show that the proposed fault detection strategy can obtain the fault signals of the SVI sensor online.  相似文献   

11.
针对依据专家知识推断贝叶斯网络中条件概率表(CPT)时存在的个体推断信息缺乏完备性和精确性以及整体集成结果缺乏科学性的问题,提出了基于证据理论/层次分析法(DS/AHP)的能够从专家推断信息中提取最优条件概率的方法.首先,通过引入DS/AHP方法中的知识矩阵提出了有利于实现判断对象更直观、判断方式更完善的推断信息提取机制;其次,在此基础上遵循由前至后的推断顺序提出了贝叶斯网络的构建过程;最后,应用传统方法与提出方法对同一贝叶斯网络中的缺失条件概率表进行了推断.数值对比分析表明,所提方法能够在提高计算效率的同时将累计总偏差降低41%,验证了所提方法的科学有效性和应用可行性.  相似文献   

12.
A Bayesian discriminating features method for face detection   总被引:18,自引:0,他引:18  
This paper presents a novel Bayesian discriminating features (BDF) method for multiple frontal face detection. The BDF method, which is trained on images from only one database, yet works on test images from diverse sources, displays robust generalization performance. The novelty of this paper comes from the integration of the discriminating feature analysis of the input image, the statistical modeling of face and nonface classes, and the Bayes classifier for multiple frontal face detection. First, feature analysis derives a discriminating feature vector by combining the input image, its 1D Harr wavelet representation, and its amplitude projections. While the Harr wavelets produce an effective representation for object detection, the amplitude projections capture the vertical symmetric distributions and the horizontal characteristics of human face images. Second, statistical modeling estimates the conditional probability density functions, or PDFs, of the face and nonface classes, respectively. While the face class is usually modeled as a multivariate normal distribution, the nonface class is much more difficult to model due to the fact that it includes "the rest of the world." The estimation of such a broad category is, in practice, intractable. However, one can still derive a subset of the nonfaces that lie closest to the face class, and then model this particular subset as a multivariate normal distribution.  相似文献   

13.
A Bayesian approach to the Hough transform for line detection   总被引:1,自引:0,他引:1  
This paper explains how to associate a rigorous probability value to the main straight line features extracted from a digital image. A Bayesian approach to the Hough Transform (HT) is considered. Under general conditions, it is shown that a probability measure is associated to each line extracted from the HT. The proposed method increments the HT accumulator in a probabilistic way: first calculating the uncertainty of each edge point in the image and then using a Bayesian probabilistic scheme for fusing the probability of each edge point and calculating the line feature probability.  相似文献   

14.
15.
提出了一种利用BP神经网络仿真、利用贝叶斯决策修正仿真结果的人脸检测方法.讨论了单纯使用BP神经网络作人脸的检测判定的不足,并在此基础上提出利用贝叶斯决策对神经网络的仿真结果进行第二次判定的方法.共使用MITEx人脸库的4 000个人脸与非人脸图像进行实验分析,正确率平均提升了3.63%,表明了神经网络的良好判定性能和使用贝叶斯决策进行修正的有效性和必要性.  相似文献   

16.
基于卡方检验的贝叶斯网络入侵检测的分析   总被引:1,自引:0,他引:1  
朴素贝叶斯(NB)入侵检测没有考虑其入侵行为所涉及的数据属性间的差别.引入卡方检验改进传统的NB模型,利用它来对网络连接数据的属性进行特征选择,并删除一些冗余的属性,达到优化NB入侵检测模型的目的.实验结果表明,卡方检验对NB模型有一定的优化作用,相对神经网络模型有更高的检测率.  相似文献   

17.
In this paper the fault detection problem is solved using an alternative methodology based on a fuzzy/Bayesian strategy combining a Bayesian network and the fuzzy set theory. The new important issue in this proposed methodology is to address uncertainties in the input of the Bayesian Network. This contribution is possible since the fuzzy set theory is used as the knowledge representation. To illustrate the technique, the fault detection problem in induction machine stator-winding is considered. Specifically, the faults in the induction machine stator-winding are detected by a state change of stator current. Simulation results are presented to illustrate the advance of the proposed methodology when compared to standard Bayesian network.  相似文献   

18.
The presence of antipatterns can have a negative impact on the quality of a program. Consequently, their efficient detection has drawn the attention of both researchers and practitioners. However, most aspects of antipatterns are loosely specified because quality assessment is ultimately a human-centric process that requires contextual data. Consequently, there is always a degree of uncertainty on whether a class in a program is an antipattern or not. None of the existing automatic detection approaches handle the inherent uncertainty of the detection process. First, we present BDTEX (Bayesian Detection Expert), a Goal Question Metric (GQM) based approach to build Bayesian Belief Networks (BBNs) from the definitions of antipatterns. We discuss the advantages of BBNs over rule-based models and illustrate BDTEX on the Blob antipattern. Second, we validate BDTEX with three antipatterns: Blob, Functional Decomposition, and Spaghetti code, and two open-source programs: GanttProject v1.10.2 and Xerces v2.7.0. We also compare the results of BDTEX with those of another approach, DECOR, in terms of precision, recall, and utility. Finally, we also show the applicability of our approach in an industrial context using Eclipse JDT and JHotDraw and introduce a novel classification of antipatterns depending on the effort needed to map their definitions to automatic detection approaches.  相似文献   

19.
20.
A hybrid inversion technique based on Bayesian network is proposed for estimating the biochemical and biophysical parameters of land surface vegetation from remotely sensed data. A Bayesian network is a unified knowledge-inferring process that can incorporate information derived from multiple sources including remote sensing and information derived from a priori knowledge. Using this inversion approach, content of chlorophyll a and chlorophyll b (Cab) and leaf area index (LAI) of winter wheat were estimated from data derived from simulations as well as field measurements. Estimations from the simulated data proved accurate, with root mean square errors (RMSEs) of 0.54 m2/m2 in LAI and 4.5 μg/cm2 in Cab. In validating the estimates against field measurements, it was found that prior knowledge of target parameters improved the accuracy of estimates, in terms of RMSEs from 0.73 to 0.22 m2/m2 in LAI and 9.6 to 4.0 μg/cm2 in Cab. Bayesian inference in this hybrid inversion scheme produces a posterior probability distribution, which can reveal such properties of the inferred results as updated information contained in the inversion result. Using entropy, the revision of posterior information about the parameters of interest was calculated. Including more data may allow more information to be retrieved about parameters in general. Exceptions were also observed where data from some viewing angles slightly reduced the information on the parameters of interest. It was also found that data from these viewing angles were less sensitive to the parameters. The method proposed here was also validated using LandSat ETM+ imagery provided by the BigFoot project. When used for mapping LAI with ETM+ imagery, the proposed method with an RMSE of 0.70 and a correlation of 0.67 produced a slightly better result than that from empirical regression.  相似文献   

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