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排序方式: 共有6014条查询结果,搜索用时 11 毫秒
41.
In this paper, regression analyses (RA) are presented for the neutronic calculation of ThO2 mixed 244CmO2 fuel with different neutronic parameters for various coolants, natural lithium, Li20Sn80 and Flinabe, respectively. The tritium breeding ratio (TBR), energy multiplication factor (M), total fission rate (Σf) and 232Th(n, γ) reaction is computed by XSDRNPM. In addition, this numerical results are estimated by RA depends on neutronic parameters and the empirical equations for neutronic performance are acquired. The results obtained by using XSDRNPM and the results of the RA, obtained empirical equations, are compared. The empirical equations indicate that RA can successfully be used for the prediction of the neutronic performance parameters in the hybrid reactor with a high degree of accuracy. In addition, correlation matrix is calculated to determined statistical relationships between variables TBR, M, Σf, and 232Th(n, γ). 相似文献
42.
Sustainable supply chain management (SSCM) provides economic, social end environmental requirements in material and service flows occurring between suppliers, manufacturers and customers. SSCM structure is considered as a prerequisite for a sustainable success. Thus designing an effective SCM structure provides competitive advantages for the companies. In order to achieve an effective design of this structure, it is possible to apply quality function deployment (QFD) approach which is successfully applied as an effective product and system development tool. This study presents a decision framework where analytic network process (ANP) integrated QFD and zero-one goal programming (ZOGP) models are used in order to determine the design requirements which are more effective in achieving a sustainable supply chain (SSC). The first phase of the QFD is the house of quality (HOQ) which transforms customer requirements into product design requirements. In this study, after determining the sustainability requirements named customer requirements (CRs) and design requirements (DRs) of a SSC, ANP is employed to determine the importance levels in the HOQ considering the interrelationships among the DRs and CRs. Furthermore ZOGP approach is used to take into account different objectives of the problem. The proposed method is applied through a case study and obtained results are discussed. 相似文献
43.
The interactive whiteboard (IWB) has become a popular technology for instructors over the last decade. Though research asserts that the IWBs facilitate learning in different ways, there is a lack of studies examining actual IWB use in classroom settings based on learners’ perspectives by means of valid instruments. The purpose of this study is to develop a valid and reliable interactive whiteboard student survey in order to evaluate the IWB use based on perceptions of students who have been taught with IWBs. In establishing the theoretical base of the survey, the Technology Acceptance Model (TAM) and constructivist learning theories were considered. In addition, with respect to IWB use in classrooms, a number of studies emanated from countries such as the UK, the USA, and Australia were examined, and similar research questionnaires and findings and also reflections of students about IWBs were utilized to create an item pool. A 39-item survey was conducted among middle school students (N = 263) from the city of Istanbul in Turkey. Collected data was exposed to exploratory factor analysis and resulted in a 26-item, three-factor survey, whose factors were named as the perceived efficiency of IWB, perceived learning contribution and motivation, and the perceived negative effects of IWB. The results of the analyses illustrated that this new IWB student scale, which explains 50% of the total variance with a good level of Cronbach’s Alpha coefficient (0.93) is a valid and reliable instrument designed specifically for measuring the use of IWBs in real classroom settings. Besides, theoretical foundations of interactive whiteboard use, the development process of the instrument, and results of validity and reliability analyses were discussed in detail. 相似文献
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46.
Autonomous use of legged robots in unstructured, outdoor settings requires dynamically dexterous behaviors to achieve sufficient
speed and agility without overly complex and fragile mechanics and actuation. Among such behaviors is the relatively under-studied
pronking (aka. stotting), a dynamic gait in which all legs are used in synchrony, usually resulting in relatively slow speeds but
long flight phases and large jumping heights. Instantiations of this gait for robotic systems have been mostly limited to
open-loop strategies, suffering from severe pitch instability for underactuated designs due to the lack of active feedback.
However, both the kinematic simplicity of this gait and its dynamic nature suggest that the Spring-Loaded Inverted Pendulum
model (SLIP) would be a good basis for the implementation of a more robust feedback controller for pronking. In this paper,
we describe how template-based control, a controller structure based on the embedding of a simple dynamical “template” within a more complex “anchor” system, can
be used to achieve very stable pronking for a planar, underactuated hexapod robot. In this context, high-level control of
the gait is regulated through speed and height commands to the SLIP template, while the embedding controller ensures the stability
of the remaining degrees of freedom. We use simulation studies to show that unlike existing open-loop alternatives, the resulting
control structure provides explicit gait control authority and significant robustness against sensor and actuator noise. 相似文献
47.
In this paper, a novel classification rule extraction algorithm which has been recently proposed by authors is employed to
determine the causes of quality defects in a fabric production facility in terms of predetermined parameters like machine
type, warp type etc. The proposed rule extraction algorithm works on the trained artificial neural networks in order to discover
the hidden information which is available in the form of connection weights in them. The proposed algorithm is mainly based
on a swarm intelligence metaheuristic which is known as Touring Ant Colony Optimization (TACO). The algorithm has a hierarchical
structure with two levels. In the first level, a multilayer perceptron type neural network is trained and its weights are
extracted. After obtaining the weights, in the second level, the TACO-based algorithm is applied to extract classification
rules. The main purpose of the present work is to determine and analyze the most effective parameters on the quality defects
in fabric production. The parameters and their levels which give the best quality results are tried to be discovered and evaluated
by making use of the proposed algorithm. It is also aimed to compare the accuracy of proposed algorithm with several other
rule-based algorithms in order to present its competitiveness. 相似文献
48.
M. Bilginer Gülmezoğlu Rifat Edizkan Semih Ergin Atalay Barkana 《Expert systems with applications》2011,38(4):3690-3696
In this paper, the subspace based classifier, common vector approach (CVA), with the center of gravity (COG) method is used for isolated word recognition. Since the CVA classifier is sensitive to shifts through the time axis, endpoint detection becomes extremely important for the recognition of isolated words. The COG method eliminates the need for endpoint detection. The effects of the COG method and a classical endpoint detection algorithm on the recognition rates of isolated words are investigated. The experimental results show that the COG method yields slightly higher recognition rates than the endpoint detection method in the TI-digit database when CVA is used. 相似文献
49.
In this paper, an automatic diagnosis system for diabetes on Linear Discriminant Analysis (LDA) and Morlet Wavelet Support Vector Machine Classifier: LDA–MWSVM is introduced. The structure of this automatic system based on LDA-MWSVM for the diagnosis of diabetes is composed of three stages: The feature extraction and feature reduction stage by using the Linear Discriminant Analysis (LDA) method and the classification stage by using Morlet Wavelet Support Vector Machine (MWSVM) classifier stage. The Linear Discriminant Analysis (LDA) is used to separate features variables between healthy and patient (diabetes) data in the first stage. The healthy and patient (diabetes) features obtained in the first stage are given to inputs of the MWSVM classifier in the second stage. Finally, in the third stage, the correct diagnosis performance of this automatic system based on LDA–MWSVM for the diagnosis of diabetes is calculated by using sensitivity and specificity analysis, classification accuracy, and confusion matrix, respectively. The classification accuracy of this system was obtained at about 89.74%. 相似文献
50.
Tarık Çakar 《Journal of Intelligent Manufacturing》2011,22(4):481-490
A neuro-dominance rule (NDR) for single machine total weighted tardiness problem with unequal release date is presented by
the author. To obtain the NDR, backpropagation artificial neural network (BPANN) has been trained using 10,000 data and also
tested using 10,000 another data. Inputs of the trained BPANN are starting date of the first job (t), processing times (pi and pj), due dates (di and dj), weights of the jobs (wi and wj) and ri and rj release dates of the jobs. Output of the BPANN is a decision of which job should precede. Training set and test set have
been obtained using Adjusted Pairwise Interchange method. The proposed NDR provides a sufficient condition for local optimality.
It has been proved that if any sequence violates the NDR then violating jobs are switched according to the total weighted
tardiness criterion. The proposed NDR is compared to a number of competing heuristics (ATC, COVERT, EDD, SPT, LPT, WDD, WSPT,
WPD, CR, FCFS) and meta heuristics (simulated annealing and genetic algorithms) for a set of randomly generated problems.
The problem sizes have been taken as 50, 70, 100. NDR is applied 270,000 randomly generated problems. Computational results
indicate that the NDR dominates the heuristics and meta heuristics in all runs. Therefore, the NDR can improve the upper and
lower bounding schemes. 相似文献