Agile manufacturing capabilities require fast responses in workshops to cope with different demands in product geometrical features and qualities in fabricating moulds. Therefore, direct machining of complex mould fea...
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Agile manufacturing capabilities require fast responses in workshops to cope with different demands in product geometrical features and qualities in fabricating moulds. Therefore, direct machining of complex mould features using simple shape machined electrodes with the electro-discharge machining (EDM) process, empowers the flexibility and the capacity of the enterprises and dramatically reduces lead times resulting in much more efficient production processes. In the case of machining geometrical features with characteristic dimensions in the order of few millimeters, the EDM process requires further understanding. This article focuses on investigating the influence of EDM parameters and electrode geometry on feature micro-accuracy in tool steel for mould fabrication purposes. A set of designed experiments with varying EDM process parameters such as pulsed current, open voltage, pulse time, and pulse pause time is carried out in H13 steel using differently shaped copper electrodes. Microdimensional and geometrical accuracies are the measures of response. artificialneuralnetwork and regression models have been constructed to capture the influence of the process parameters on the geometrical feature quality such as flatness, depth, slope, width, and dimension variation between the entrance and the exit (DVEE).
The goal was to use an artificialneuralnetwork model to predict the plasma concentration of aminoglycosides in burn patients and identify patients whose plasma antibiotic concentration would be sub-therapeutic based...
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The goal was to use an artificialneuralnetwork model to predict the plasma concentration of aminoglycosides in burn patients and identify patients whose plasma antibiotic concentration would be sub-therapeutic based on the patients' physiological data and taking into account burn severity. Physiological data and some indicators of burn severity were collected from 30 burn patients who received arbekacin. A three-layer artificialneuralnetwork with five neurons in the hidden layer was used to predict the plasma concentration of arbekacin. Linear modeling for prediction of plasma concentration and logistic regression modeling for the classification of patients were also used and the predictive performance was compared to results from the artificialneuralnetwork model. Dose, body mass index, serum creatinine concentration and amount of parenteral fluid were selected as covariates for the plasma concentration of arbekacin. Area of burn after skin graft was a good covariate for indicating burn severity. Predictive performance of the artificialneuralnetwork model including burn severity was much better than linear modeling and logistic regression analysis. An artificialneuralnetwork model should be helpful for the prediction of plasma concentration using patients' physiological data, and burn severity should be included for improved prediction in burn patients. Because the relationship between burn severity and plasma concentration of aminoglycosides is thought to be nonlinear, it is not surprising that the artificialneuralnetwork model showed better predictive performance compared to the linear or logistic regression models. (C) 2004 Elsevier SAS. All rights reserved.
A review about the application of response surface methodology (RSM) in the optimization of analytical methods is presented. The theoretical principles of RSM and steps for its application are described to introduce r...
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A review about the application of response surface methodology (RSM) in the optimization of analytical methods is presented. The theoretical principles of RSM and steps for its application are described to introduce readers to this multivariate statistical technique. Symmetrical experimental designs (three-level factorial, Box-Behnken, central composite, and Doehlert designs) are compared in terms of characteristics and efficiency. Furthermore, recent references of their uses in analytical chemistry are presented. Multiple response optimization applying desirability functions in RSM and the use of artificialneuralnetworks for modeling are also discussed. (C) 2008 Published by Elsevier B.V.
The solid nature of coal presents greater difficulties in measuring and controlling the combustion process compared to gas and oil fired power plants. Knowing the composition and energy content of coal can be very use...
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The solid nature of coal presents greater difficulties in measuring and controlling the combustion process compared to gas and oil fired power plants. Knowing the composition and energy content of coal can be very useful for combustion control in coal-fired power utilities. In this work, an attempt is made to establish relationships between the hydrogen composition of coal and available data from the proximate analysis. In the present work, artificialneuralnetwork based model is developed for the prediction of hydrogen content. For practical implications, a combustion control system utilising the neuralnetwork based model is also proposed to show the potential for coal-fired utilities. (C) 2008 Elsevier B.V. All rights reserved.
Generally, in nature, non-human creatures perform adaptive behaviors to external environment they are living in. i.e. animals have to keep alive by improving there behavioral ability to be adaptable to there living en...
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ISBN:
(纸本)9781934272312
Generally, in nature, non-human creatures perform adaptive behaviors to external environment they are living in. i.e. animals have to keep alive by improving there behavioral ability to be adaptable to there living environmental conditions. This paper presents an investigational comparative overview on adaptive behaviors associated with two diverse (neural and Non-neural) biological systems. Namely, intelligent behavioral performance of Ant Colony System (ACS) to reach optimal solution of Traveling Sales-man Problem (TSP). That is investigated versus concepts of adaptive behavioral learning concerned with some animals (cats, dogs and rats), in order to keep survive. More precisely, investigations of behavioral observations tightly related to suggested animals, supposed to obey discipline of biological information processing. So, artificialneuralnetwork (ANN) modeling is a relevant tool to investigate such biological system observations. Moreover, an illustrative brief of ACS optimal intelligent behaviors to solve TSP is presented. Additionally, considering effect of noisy environment on learning convergence an interesting analogy between both proposed biological systems is introduced. Finally, performance of three learning algorithms shown to be analogously in agreement with behavioral concepts of both suggested biological systems' performance.
Recent biological experimental findings have announced so, me interesting results concerned with evaluation of brain functions (teaming an it memory). Herein main attention delivered to Construct an ANN model to simul...
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ISBN:
(纸本)9781934272244
Recent biological experimental findings have announced so, me interesting results concerned with evaluation of brain functions (teaming an it memory). Herein main attention delivered to Construct an ANN model to simulate the activity of transference short term memory (STM) into long term memory (LTM). This memorization function basically depends upon the adaptation and selectivity of synaptic plasticity. That observed as two phenomena of long term potentiation LTP, and long term depression LTD. This paper introduces a modified version model of an over- simplified memorization function model (Grand mother cells network). The proposed model is spatial- temporal and characterized by some biological features such as dynamical adaptation, selectivity and fault tolerance. So, it seems to simulate realistically the role performed by transcription gene factor namely CREB. That as it selects some synapses to be strengthened and neglect others on the basis of LTP and LTD respectively. More over, the effect of forgetting factor on presented model performance is evaluated. Finally, However, the proposed model seems to be will inspired by biology, this paper opens future research work to construct more biologically plausible models based on pulsed neuralnetworks or equivalently spike- timing- dependent- plasticity.
artificialneuralnetworks (ANNs) are used for classification and prediction of enzymatic activity of ethylbenzene dehydrogenase from EbN1 Azoarcus sp. bacterium. Ethylbenzene dehydrogenase (EBDH) catalyzes stereo-spe...
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artificialneuralnetworks (ANNs) are used for classification and prediction of enzymatic activity of ethylbenzene dehydrogenase from EbN1 Azoarcus sp. bacterium. Ethylbenzene dehydrogenase (EBDH) catalyzes stereo-specific oxidation of ethylbenzene and its derivates to alcohols, which find its application as building blocks in pharmaceutical industry. ANN systems are trained based on theoretical variables derived from Density Functional Theory (DFT) modeling, topological descriptors, and kinetic parameters measured with developed spectrophotometric assay. Obtained models exhibit high degree of accuracy (100% of correct classifications, correlation between predicted and experimental values of reaction rates on the 0.97 level). The applicability of ANNs is demonstrated as useful tool for the prediction of biochemical enzyme activity of new substrates basing only on quantum chemical calculations and simple structural characteristics. Multi Linear Regression and Molecular Field Analysis (MFA) are used in order to compare robustness of ANN and both classical and 3D-quantitative structure-activity relationship (QSAR) approaches.
Some models closely related to animal psycho-learning, and a swarm intelligent system, are comparatively presented. More specifically, three introduced models are inspired by creatures' behavioral learning phenome...
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ISBN:
(纸本)0780393139
Some models closely related to animal psycho-learning, and a swarm intelligent system, are comparatively presented. More specifically, three introduced models are inspired by creatures' behavioral learning phenomenon, observed in nature. Two of presented models based on Pavlov's and Thorndike's excremental work. Pavlov's dog learns how to associate two inputs sensory stimuli (audible, and visual signals). Thorndike's cat behavioral learning that to get out from a cage for obtaining food. Each of behavioral learning models improves its performance by minimizing response time period. Additionally, other third model motivated by ant colony system ACS. optimized performance. That model simulates a swarm (ant) intelligent system used for solving optimally traveling sales man problem TSP. That by bringing food from different food sources to store (in cycles) at ant's nest. Moreover, three other learning models based on pulsed neurons criterion, parallel genetic algorithmic programming, and modified Hebbian learning paradigm (Oja's rule). Interestingly, those models shown to behave analogously to previously suggested;Pavlov's, Thorndike's and ACS models.
artificialneuralnetworks (ANN) was evaluated and compared with Response Surface Model (RSM) results using growth response data for E. coli O157:H7 as affected by 5 variables: pH, sodium chloride, and nitrite concent...
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artificialneuralnetworks (ANN) was evaluated and compared with Response Surface Model (RSM) results using growth response data for E. coli O157:H7 as affected by 5 variables: pH, sodium chloride, and nitrite concentrations, temperature, and aerobic/anaerobic conditions. The best ANN obtained, where the 2 kinetic parameters, growth rate and lag-time, were estimated jointly, contained 17 parameters and displayed a slightly lower Standard Error of Prediction (% SEP) than those obtained with RSM. Mathematical lag-time validation with additional data gave a lower %SEP for ANN (18%) than for RSM (27%), although growth-rate values were the same (22%). ANN thus should provide the innovative possibility of obtaining a single predictive model for the estimation of several kinetic parameters.
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