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1.
We consider an online string matching problem in which we find all the occurrences of a pattern of m characters in a text of n characters, where all the characters of the pattern are available before processing, while the characters of the text are input one after the other. We propose a space-time optimal parallel algorithm for this problem using a neural network approach, This algorithm uses m McCulloch-Pitts neurons connected as a linear array. It processes every input character of the text in one step and hence it requires at most n iteration steps. 相似文献
2.
In this paper, we develop an artificial neural network method for machine setup problems. We show that our new approach solves a very challenging problem in the area of machining i.e. machine setup. A review of machine setup concepts and methods, along with feedforward artificial neural network is presented. We define the problem of machine setup to assessing the values of machine speed, feed and depth of cut (process inputs) for a particular objective such as minimize cost, maximize productivity or maximize surface finish. We use cutting temperature, cutting force, tool life, and surface roughness (process outputs) rather than objective functions to communicate with the decision maker. We show the relationship between process inputs to process outputs. This relationship is used in determining machine setup parameters (speed, feed, and depth of cut). Back propagation neural network is used as a decision support tool. The network maps, the forward relationship, and backward relationship between process inputs and process outputs. This mapping facilitates an interactive session with the decision maker. The process input is appropriately selected. Our method has the advantage of forecasting machine setup parameters with very little resource requirement in terms of time, machine tool, and people. Forecast time is almost instantaneous. Accuracy of the forecast depends on training and a well determined training sample provides very high accuracy. Trained network replaces the knowledge of an experienced worker, hence labor cost can be potentially reduced. 相似文献
3.
This paper presents a new approach based on the Hopfield model of artificial neural networks to solve the routing problem in a context of computer network design. The computer networks considered are packet switching networks, modeled as non-oriented graphs where nodes represent servers, hosts or switches, while bi-directional and symmetric arcs represent full duplex communication links. The proposed method is based on a network representation enabling to match each network configuration with a Hopfield neural network in order to find the best path between any node pair by minimizing an energy function. The results show that the time delay derived from flow assignment carried out by this approach is, in most cases, better than those determined using conventional routing heuristics. Therefore, this neural-network approach is suitable to be integrated into an overall topological design process of moderate-speed and high-speed networks subject to quality of service constraints as well as to changes in configuration and link costs. 相似文献
4.
提出了一种适用于大规模特征集的快速匹配算法——SRS算法,该算法性能优异,在特征集达到100 000条时,匹配速度比经典算法快10倍以上。该算法适用于内容过滤、防病毒、反垃圾邮件、短信过滤、网络入侵检测和防御等众多领域。 相似文献
5.
An enterprise resource planning (ERP) software selection is known to be multi attribute decision making (MADM) problem. This problem has been modeled according with analytic network process (ANP) method due to fact that it considers criteria and sub criteria relations and interrelations in selecting the software.Opinions of many experts are obtained while building ANP model for the selection ERP then opinions are reduced to one single value by methods like geometric means so as to get desired results. To use ANP model for the selection of ERP for a new organization, a new group of expert’s opinions are needed. In this case the same problem will be in counter. In the proposed model, when ANP and ANN models are setup, an ERP software selection can be made easily by the opinions of one single expert. In that case calculation of geometric mean of answers that obtained from many experts will be unnecessary. Additionally the effect of subjective opinion of one single decision maker will be avoided. In terms of difficulty, ANP has some difficulties due to eigenvalue and their limit value calculation.An ANN model has been designed and trained with using ANP results in order to calculate ERP software priority. The artificial neural network (ANN) model is trained by results obtained from ANP. It seems that there is no any major difficulty in order to predict software priorities with trained ANN model. By this results ANN model has been come suitable for using in the selection of ERP for another new decision. 相似文献
6.
The objective of this paper is to find a sequence of jobs in the flow shop to minimize makespan. A feed forward back propagation
neural network is used to solve the problem. The network is trained with the optimal sequences of completely enumerated five,
six and seven jobs, ten machine problem and this trained network is then used to solve the problem with greater number of
jobs. The sequence obtained using artificial neural network (ANN) is given as the initial sequence to a heuristic proposed
by Suliman and also to genetic algorithm (GA) as one of the sequences of the population for further improvement. The approaches
are referred as ANN-Suliman heuristic and ANN-GA heuristic respectively. Makespan of the sequences obtained by these heuristics
are compared with the makespan of the sequences obtained using the heuristic proposed by Nawaz, Enscore and Ham (NEH) and
Suliman Heuristic initialized with Campbell Dudek and Smith (CDS) heuristic called as CDS-Suliman approach. It is found that
the ANN-GA and ANN-Suliman heuristic approaches perform better than NEH and CDS-Suliman heuristics for the problems considered. 相似文献
7.
One of the imperative problems in the realm of wireless sensor networks is the problem of wireless sensors localization. Despite the fact that much research has been conducted in this area, many of the proposed approaches produce unsatisfactory results when exposed to the harsh, uncertain, noisy conditions of a manufacturing environment. In this study, we develop an artificial neural network approach to moderate the effect of the miscellaneous noise sources and harsh factory conditions on the localization of the wireless sensors. Special attention is given to investigate the effect of blockage and ambient conditions on the accuracy of mobile node localization. A simulator, simulating the noisy and dynamic shop conditions of manufacturing environments, is employed to examine the neural network proposed. The neural network performance is also validated through some actual experiments in real-world environment prone to different sources of noise and signal attenuation. The simulation and experimental results demonstrate the effectiveness and accuracy of the proposed methodology. 相似文献
8.
In a biometric-based security system, rather than depending on the system configuration itself, failure rate also relies upon feature extraction and its related statistics. In this paper, a significant approach is being presented to minimize the failure rate and maintain high recognition accuracy and uniformity for non-symmetrical feature points. This work contributes a detailed analysis of stable parameters of captured biometric feature points by using a flexible learning model named as adopted Artificial Neural Network (ANN). The paper also discusses a comparative study of different global and local methods of Histogram of an Equivalent Pattern (HEP) technique for facial feature detection and extraction. The HEP, is further classified by using adopted ANN model, which depends on partitioning the feature area of a predefined image. This task has been accomplished by providing the appropriate definition of local and global functions based on pixel intensities. The literature available for face detection shows many shortcomings such as false acceptance and rejection rates. Among all defined global and local techniques, this paper primarily endorsed an adopted method of Improved Local Binary Pattern (ILBP) which works on local pixel values of a facial image for feature extraction. The classification and recognition task are performed by adopted ANN for various defined global and local features. The paper also derives a detailed comparison with the other existing techniques. As a result, the proposed ILBP technique ensures the consistency of acceptable results in unpredictable variations in the dataset. 相似文献
9.
自适应滤波器能够适应系统和环境的动态变化,具有较高的滤波精度。介绍了一种利用ADALINE神经网络进行自适应滤波的方法,根据自适应噪声抵消原理建立了ADALINE自适应神经滤波器模型,并使用该模型将发动机高压油管振动信号中的机体振动噪声滤除,提高了信噪比,为利用高压油管振动信号进行喷油器故障的精确诊断奠定了基础。 相似文献
10.
An artificial neural network tester for the satisfiability problem of propositional calculus is presented. Satisfiability is treated as a constraint satisfaction optimization problem and, contrary to most of the existing satisfiability testers, the expressions are converted into disjunctive normal form before testing. The artificial neural network is based on the principles of harmony theory. Its basic characteristics are the simulated annealing procedure and the harmony function; the latter constitutes a measure of the satisfiability of the expression under the current truth assignment to its variables. The tester is such that: (a) the satisfiability of any expression is determined; (b) a truth assignment to the variables of the expression is output which renders true the greatest possible number of clauses; (c) all the truth assignments which render true the maximum number of clauses can be produced. © 2001 John Wiley & Sons, Inc. 相似文献
11.
The Hollis-Paulos artificial neural network (1990) [HPANN] is convenient in terms of its possibility for realization of variable weight artificial neural networks in VLSI by MOS transistor circuits, though it is nondynamical and not driven by external inputs. Here we introduce dynamics and inputs into the HPANN and show that over the range of operation covered by the Hollis-Paulos theory the system has an inverse. In particular, we derive that inverse, in semistate form, and give simulation results on its operation, showing how well the input to the original HPANN can be recovered from the output of the HPANN when fed into the inverse system. A comparison is made with the previous inverse of the Hopfield ANN. Possible applications of these inverse systems are to decoding of transmitted ANN signals and to inverse filtering for the extraction of input signals from processed signals. 相似文献
12.
With the current rapid growth in multimedia technology, there is an imminent need for efficient techniques to search and query large image databases. Because of their unique and peculiar needs, image databases cannot be treated in a similar fashion to other types of digital libraries. The contextual dependencies present in images, and the complex nature of two-dimensional image data make the representation issues more difficult for image databases. An invariant representation of an image is still an open research issue. For these reasons, it is difficult to find a universal content-based retrieval technique. Current approaches based on shape, texture, and color for indexing image databases have met with limited success. Further, these techniques have not been adequately tested in the presence of noise and distortions. A given application domain offers stronger constraints for improving the retrieval performance. Fingerprint databases are characterized by their large size as well as noisy and distorted query images. Distortions are very common in fingerprint images due to elasticity of the skin. In this paper, a method of indexing large fingerprint image databases is presented. The approach integrates a number of domain-specific high-level features such as pattern class and ridge density at higher levels of the search. At the lowest level, it incorporates elastic structural feature-based matching for indexing the database. With a multilevel indexing approach, we have been able to reduce the search space. The search engine has also been implemented on Splash 2-a field programmable gate array (FPGA)-based array processor to obtain near-ASIC level speed of matching. Our approach has been tested on a locally collected test data and on NIST-9, a large fingerprint database available in the public domain 相似文献
13.
Similarity matching in video databases is of growing importance in many new applications such as video clustering and digital video libraries. In order to provide efficient access to relevant data in large databases, there have been many research efforts in video indexing with diverse spatial and temporal features. However, most of the previous works relied on sequential matching methods or memory-based inverted file techniques, thus making them unsuitable for a large volume of video databases. In order to resolve this problem, this paper proposes an effective and scalable indexing technique using a trie, originally proposed for string matching, as an index structure. For building an index, we convert each frame into a symbol sequence using a window order heuristic and build a disk-resident trie from a set of symbol sequences. For query processing, we perform a depth-first traversal on the trie and execute a temporal segmentation. To verify the superiority of our approach, we perform several experiments with real and synthetic data sets. The results reveal that our approach consistently outperforms the sequential scan method, and the performance gain is maintained even with a large volume of video databases. 相似文献
14.
An architecture-adaptive intelligent self-tuning control system is presented. The system is composed of the supervisor module,
the model refinement module, the process plant and the database. In the supervisor module, the user prescribes the desired
curve for the plant dynamic process. The model refinement module is in parallel with the process plant, and consists of the
self-tuning process model, which contains an architecture-adaptive neural network. The model refinement module could learn
intelligently the real process plant by the prompt adjustments based on the difference of the outputs of the two modules,
and its learned model is also refined gradually. This diagram is especially versatile in the complex nonlinear and time-variant
systems in practice. 相似文献
15.
针对在线模块化神经网络难以实时有效划分样本空间,提出一种改进的在线自适应模块化神经网络.首先,基于距离与密度实时更新样本局部密度及RBF神经元中心,实现样本空间在线划分;然后,将子网络模块数根据划分样本空间的个数进行自适应增减,每个子网络模块对属于对应样本空间的样本进行学习;最后,集成模块对子网络模块的输出结果进行集成,输出最终结果.针对在线梯度下降法要求样本有足够的随机性问题,提出一种具有固定记忆的在线梯度下降法对网络进行在线学习.通过对典型非线性时变系统及污水处理过程中出水氨氮浓度进行预测,验证了该模块化神经网络能够实时有效地更新RBF神经元中心,并减少学习过程中子网络模块不必要的增减,且网络结构更加简洁,能够准确预测不同的时变系统. 相似文献
16.
A spatial relation graph (SRG) and its partial matching method are proposed for online composite graphics representation and recognition. The SRG-based approach emphasizes three characteristics of online graphics recognition: partial, structural, and independent of stroke order and stroke number. A constrained partial permutation strategy is also proposed to reduce the computational cost of matching two SRGs, which is originally an NP-complete problem as is graph isomorphism. Experimental results show that our proposed SRG-based approach is both efficient and effective for online composite graphics recognition in our sketch-based graphics input system - SmartSketchpad.Received: 13 March 2003, Accepted: 13 March 2004, Published online: 1 June 2004 相似文献
17.
本文总结了现有的软件水印算法并给出了水印系统的形式化定义,继而提出一种新的基于神经网络的软件水印实现方案,并对其进行了简单的性能分析。 相似文献
18.
基于神经网络的基本结构和算法,该文建立了一个用于高压电磁式互感器故障诊断的人工神经网络。其中采用了有效的网络学习算法,旨在全面、快速和准确地实现互感器故障诊断,以提高互感器及电力系统运行的可靠性。根据互感器的故障特征,该文建立一个3层前向神经网络,采用误差逆传播学习算法进行了讨论,并由仿真计算结果加以论证。 相似文献
19.
Reducing fuel consumption of ships against volatile fuel prices and greenhouse gas emissions resulted from international shipping are the challenges that the industry faces today. The potential for fuel savings is possible for new builds, as well as for existing ships through increased energy efficiency measures; technical and operational respectively. The limitations of implementing technical measures increase the potential of operational measures for energy efficient ship operations. Ship owners and operators need to rationalise their energy use and produce energy efficient solutions. Reducing the speed of the ship is the most efficient method in terms of fuel economy and environmental impact. The aim of this paper is twofold: (i) predict ship fuel consumption for various operational conditions through an inexact method, Artificial Neural Network ANN; (ii) develop a decision support system (DSS) employing ANN-based fuel prediction model to be used on-board ships on a real time basis for energy efficient ship operations. The fuel prediction model uses operating data – ‘Noon Data’ – which provides information on a ship’s daily fuel consumption. The parameters considered for fuel prediction are ship speed, revolutions per minute (RPM), mean draft, trim, cargo quantity on board, wind and sea effects, in which output data of ANN is fuel consumption. The performance of the ANN is compared with multiple regression analysis (MR), a widely used surface fitting method, and its superiority is confirmed. The developed DSS is exemplified with two scenarios, and it can be concluded that it has a promising potential to provide strategic approach when ship operators have to make their decisions at an operational level considering both the economic and environmental aspects. 相似文献
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