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Machine learning-based performance predictions for steels considering manufacturing process parameters:a review
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作者 Wei Fang Jia-xin Huang +2 位作者 Tie-xu Peng Yang Long Fu-xing Yin 《Journal of Iron and Steel Research International》 SCIE EI CAS CSCD 2024年第7期1555-1581,共27页
Steels are widely used as structural materials,making them essential for supporting our lives and industries.However,further improving the comprehensive properties of steel through traditional trial-and-error methods ... Steels are widely used as structural materials,making them essential for supporting our lives and industries.However,further improving the comprehensive properties of steel through traditional trial-and-error methods becomes challenging due to the continuous development and numerous processing parameters involved in steel production.To address this challenge,the application of machine learning methods becomes crucial in establishing complex relationships between manufacturing processes and steel performance.This review begins with a general overview of machine learning methods and subsequently introduces various performance predictions in steel materials.The classification of performance pre-diction was used to assess the current application of machine learning model-assisted design.Several important issues,such as data source and characteristics,intermediate features,algorithm optimization,key feature analysis,and the role of environmental factors,were summarized and analyzed.These insights will be beneficial and enlightening to future research endeavors in this field. 展开更多
关键词 STEEL Manufacturing process Machine learning performance prediction Algorithm
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Composition optimization and performance prediction for ultra-stable water-based aerosol based on thermodynamic entropy theory
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作者 Tingting Kang Canjun Yan +6 位作者 Xinying Zhao Jingru Zhao Zixin Liu Chenggong Ju Xinyue Zhang Yun Zhang Yan Wu 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第3期437-446,共10页
Water-based aerosol is widely used as an effective strategy in electro-optical countermeasure on the battlefield used to the preponderance of high efficiency,low cost and eco-friendly.Unfortunately,the stability of th... Water-based aerosol is widely used as an effective strategy in electro-optical countermeasure on the battlefield used to the preponderance of high efficiency,low cost and eco-friendly.Unfortunately,the stability of the water-based aerosol is always unsatisfactory due to the rapid evaporation and sedimentation of the aerosol droplets.Great efforts have been devoted to improve the stability of water-based aerosol by using additives with different composition and proportion.However,the lack of the criterion and principle for screening the effective additives results in excessive experimental time consumption and cost.And the stabilization time of the aerosol is still only 30 min,which could not meet the requirements of the perdurable interference.Herein,to improve the stability of water-based aerosol and optimize the complex formulation efficiently,a theoretical calculation method based on thermodynamic entropy theory is proposed.All the factors that influence the shielding effect,including polyol,stabilizer,propellant,water and cosolvent,are considered within calculation.An ultra-stable water-based aerosol with long duration over 120 min is obtained with the optimal fogging agent composition,providing enough time for fighting the electro-optic weapon.Theoretical design guideline for choosing the additives with high phase transition temperature and low phase transition enthalpy is also proposed,which greatly improves the total entropy change and reduce the absolute entropy change of the aerosol cooling process,and gives rise to an enhanced stability of the water-based aerosol.The theoretical calculation methodology contributes to an abstemious time and space for sieving the water-based aerosol with desirable performance and stability,and provides the powerful guarantee to the homeland security. 展开更多
关键词 Ultra-stable Water-based aerosol Thermodynamic entropy Composition optimization performance prediction
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Two-Way Neural Network Performance PredictionModel Based onKnowledge Evolution and Individual Similarity
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作者 Xinzheng Wang Bing Guo Yan Shen 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第2期1183-1206,共24页
Predicting students’academic achievements is an essential issue in education,which can benefit many stakeholders,for instance,students,teachers,managers,etc.Compared with online courses such asMOOCs,students’academi... Predicting students’academic achievements is an essential issue in education,which can benefit many stakeholders,for instance,students,teachers,managers,etc.Compared with online courses such asMOOCs,students’academicrelateddata in the face-to-face physical teaching environment is usually sparsity,and the sample size is relativelysmall.It makes building models to predict students’performance accurately in such an environment even morechallenging.This paper proposes a Two-WayNeuralNetwork(TWNN)model based on the bidirectional recurrentneural network and graph neural network to predict students’next semester’s course performance using only theirprevious course achievements.Extensive experiments on a real dataset show that our model performs better thanthe baselines in many indicators. 展开更多
关键词 COMPUTER EDUCATION performance prediction deep learning
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A Stacking Machine Learning Model for Student Performance Prediction Based on Class Activities in E-Learning
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作者 Mohammad Javad Shayegan Rosa Akhtari 《Computer Systems Science & Engineering》 2024年第5期1251-1272,共22页
After the spread of COVID-19,e-learning systems have become crucial tools in educational systems worldwide,spanning all levels of education.This widespread use of e-learning platforms has resulted in the accumulation ... After the spread of COVID-19,e-learning systems have become crucial tools in educational systems worldwide,spanning all levels of education.This widespread use of e-learning platforms has resulted in the accumulation of vast amounts of valuable data,making it an attractive resource for predicting student performance.In this study,we aimed to predict student performance based on the analysis of data collected from the OULAD and Deeds datasets.The stacking method was employed for modeling in this research.The proposed model utilized weak learners,including nearest neighbor,decision tree,random forest,enhanced gradient,simple Bayes,and logistic regression algorithms.After a trial-and-error process,the logistic regression algorithm was selected as the final learner for the proposed model.The results of experiments with the above algorithms are reported separately for the pass and fail classes.The findings indicate that the accuracy of the proposed model on the OULAD dataset reached 98%.Overall,the proposed method improved accuracy by 4%on the OULAD dataset. 展开更多
关键词 STACKING E-LEARNING student performance prediction machine learning CLASSIFICATION
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Numerical Research on Performance Prediction for Centrifugal Pumps 被引量:15
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作者 TAN Minggao YUAN Shouqi LIU Houlin WANG Yong WANG Kai 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2010年第1期21-26,共6页
Performance prediction for centrifugal pumps is now mainly based on numerical calculation and most of the studies merely focus on one model. Therefore, the research results are not representative. To make an improveme... Performance prediction for centrifugal pumps is now mainly based on numerical calculation and most of the studies merely focus on one model. Therefore, the research results are not representative. To make an improvement of numerical calculation method and performance prediction for centrifugal pumps, performance of six centrifugal pump models at design flow rate and off design flow rates, whose specific speed are different, were simulated by using commercial code FLUENT. The standard k-t turbulence model and SIMPLEC algorithm were chosen in FLUENT. The simulation was steady and moving reference frame was used to consider the impeller-volute interaction. Also, how to dispose the gap between impeller and volute was presented and the effect of grid number was considered. The characteristic prediction model for centrifugal pumps is established according to the simulation results. The head and efficiency of the six models at different flow rates are predicted and the prediction results are compared with the experiment results in detail. The comparison indicates that the precision of head and efficiency prediction are all less than 5%. The flow analysis indicates that flow change has an important effect on the location and area of low pressure region behind the blade inlet and the direction of velocity at impeller inlet. The study shows that using FLUENT simulation results to predict performance of centrifugal pumps is feasible and accurate. The method can be applied in engineering practice. 展开更多
关键词 centrifugal pump performance prediction numerical research
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Prediction of roadheaders' performance using artificial neural network approaches (MLP and KOSFM) 被引量:11
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作者 Arash Ebrahimabadi Mohammad Azimipour Ali Bahreini 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2015年第5期573-583,共11页
A pplication o f m echanical excavators is one o f th e m o st com m only used excavation m eth o d s because itcan bring th e p ro ject m ore productivity, accuracy and safety. A m ong th e m echanical excavators, ro... A pplication o f m echanical excavators is one o f th e m o st com m only used excavation m eth o d s because itcan bring th e p ro ject m ore productivity, accuracy and safety. A m ong th e m echanical excavators, roadhead ers are m echanical m iners w h ich have b een extensively u se d in tu n n elin g , m ining an d civil indu stries. Perform ance pred ictio n is an im p o rta n t issue for successful ro a d h e a d e r application andgenerally deals w ith m achine selection, p ro d u ctio n rate an d b it consu m p tio n . The m ain aim o f thisresearch is to investigate th e c u ttin g p erfo rm an ce (in stan tan eo u s c u ttin g rates (ICRs)) o f m ed iu m -d u tyro ad h ead ers by using artificial neural n etw o rk (ANN) approach. T here are d ifferent categories forANNs, b u t based o n train in g alg o rith m th e re are tw o m ain k in d s: supervised and u n su p erv ised . Them u lti-lay er p ercep tro n (MLP) an d K ohonen self-organizing feature m ap (KSOFM) are th e m o st w idelyused neu ral netw o rk s for supervised an d u n su p erv ised ones, respectively. For gaining this goal, ad atab ase w as prim arily provided from ro ad h e a d e rs' p erfo rm an ce an d geom echanical characteristics o frock form ations in tu n n els and d rift galleries in Tabas coal m ine, th e larg est an d th e only fullymech an ized coal m ine in Iran. T hen th e datab ase w as analyzed in o rd e r to yield th e m ost im p o rtan tfactor for ICR by using relatively im p o rta n t factor in w hich G arson eq u atio n w as utilized. The MLPn etw o rk w as train ed by 3 in p u t p ara m e te rs including rock m ass pro p erties, rock quality d esignation(RQD), in tact rock p ro p erties such as uniaxial com pressive stre n g th (UCS) an d Brazilian ten sile stren g th(BTS), and o n e o u tp u t p a ra m e te r (ICR). In o rd e r to have m ore v alidation o n MLP o u tp u ts, KSOFM visualizationw as applied. The m ean square e rro r (MSE) an d regression coefficient (R ) o f MLP w e re found tobe 5.49 an d 0.97, respectively. M oreover, KSOFM n etw o rk has a m ap size o f 8 x 5 and final qu an tizatio nan d topographic erro rs w e re 0.383 an d 0.032, respectively. The results show th a t MLP neural n etw orkshave a strong capability to p red ict an d ev alu ate th e perfo rm an ce o f m ed iu m -d u ty ro ad h ead ers in coalm easu re rocks. Furtherm ore, it is concluded th a t KSOFM neural n etw o rk is an efficient w ay for u n d e rstand in g system beh av io r an d know ledge extraction. Finally, it is indicated th a t UCS has m ore influenceo n ICR b y applying th e b e st train ed MLP n etw o rk w eig h ts in G arson eq u atio n w h ich is also confirm ed byKSOFM. 展开更多
关键词 Artificial neural network(ANN) performance prediction ROADHEADER Instantaneous cutting rate(ICR) Tabas coal mine project
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Predictive performance of'Diprifusor'TCI system in patients during upper abdominal surgery under propofol/fentanyl anesthesia 被引量:7
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作者 李玉红 徐建红 +2 位作者 杨建军 田婕 徐建国 《Journal of Zhejiang University-Science B(Biomedicine & Biotechnology)》 SCIE CAS CSCD 2005年第1期43-48,共6页
Objective:To evaluate the predictive performance of‘Diprifusor’TCI(target-controlled infusion)system for its betterapplication in clinical anesthesia.Methods:The predictive performance of a‘Diprifusor’TCI system w... Objective:To evaluate the predictive performance of‘Diprifusor’TCI(target-controlled infusion)system for its betterapplication in clinical anesthesia.Methods:The predictive performance of a‘Diprifusor’TCI system was investigated in 27Chinese patients(16 males and 11 females)during upper abdominal surgery under total intravenous anesthesia(TIVA)withpropofol/fentanyl.Measnred arterial propofol concentrations were compared with the values predicted by the TCI infusion system.Performance was determined by the median performance error(MDPE),the median absolute performance error(MDAPE),thedivergence(the percentage change of the absolute PE with time),and the wobble(the median absolute deviation of each PE fromthe MDPE).Results:The median(range)values of 14.9%(-21.6%~42.9%)for MDPE,23.3%(6.9%~62.5%)for MDAPE,-1.9%h^(-1)(-32.7%~23.0% h^(-1))for divergence,and 18.9%(4.2%~59.6%)for wobble were obtained from 227 samples from all patients.For the studied population,the PE did not increase with time but with increasing target propofol concentration,particularly fol-lowing induction.Conclusions:The control of depth of anaesthesia was good in all patients undergoing upper abdominal surgicaloperation and the predictive performance of the‘Diprifusor’target controlled mthsion system was considered acceptable forclinical purposes.But the relatively bigger wobble showed that the pharmacokinetic model is not so suitable and requires im-provement. 展开更多
关键词 Target-controlled infusion(TCI) ‘Diprifusor’TC1 system Predictive performance assessment Wobble INFUSION
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Improving MapReduce Performance by Balancing Skewed Loads 被引量:4
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作者 FAN Yuanquan WU Weiguo XU Yunlong CHEN Heng 《China Communications》 SCIE CSCD 2014年第8期85-108,共24页
MapReduce has emerged as a popular computing model used in datacenters to process large amount of datasets.In the map phase,hash partitioning is employed to distribute data that sharing the same key across data center... MapReduce has emerged as a popular computing model used in datacenters to process large amount of datasets.In the map phase,hash partitioning is employed to distribute data that sharing the same key across data center-scale cluster nodes.However,we observe that this approach can lead to uneven data distribution,which can result in skewed loads among reduce tasks,thus hamper performance of MapReduce systems.Moreover,worker nodes in MapReduce systems may differ in computing capability due to(1) multiple generations of hardware in non-virtualized data centers,or(2) co-location of virtual machines in virtualized data centers.The heterogeneity among cluster nodes exacerbates the negative effects of uneven data distribution.To improve MapReduce performance in heterogeneous clusters,we propose a novel load balancing approach in the reduce phase.This approach consists of two components:(1) performance prediction for reducers that run on heterogeneous nodes based on support vector machines models,and(2) heterogeneity-aware partitioning(HAP),which balances skewed data for reduce tasks.We implement this approach as a plug-in in current MapReduce system.Experimental results demonstrate that our proposed approach distributes work evenly among reduce tasks,and improves MapReduce performance with little overhead. 展开更多
关键词 MAPREDUCE cloud computing skewed loads performance prediction supportvector machines
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THREE-DIMENSIONAL COUPLED IMPELLER-VOLUTE SIMULATION OF FLOW IN CENTRIFUGAL PUMP AND PERFORMANCE PREDICTION 被引量:28
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作者 ZHAO Binjuan YUAN Shouqi +1 位作者 LlU Houlin TAN Minggao 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2006年第1期59-62,共4页
A three-dimensional turbulent flow through an entire centrifugal pump is simulated using k-ε turbulence model modified by rotation and curvature, SIMPLEC method and body-fitted coordinate. The velocity and pressure f... A three-dimensional turbulent flow through an entire centrifugal pump is simulated using k-ε turbulence model modified by rotation and curvature, SIMPLEC method and body-fitted coordinate. The velocity and pressure fields are obtained for the pump under various working conditions, which is used to predict the head and hydraulic efficiency of the pump, and the results correspond well with the measured values. The calculation results indicate that the pressure is higher on the pressure side than that on the suction side of the blade; The relative velocity on the suction side gradually decreases from the impeller inlet to the outlet, while increases on the pressure side, it finally results in the lower relative velocity on the suction side and the higher one on the pressure side at the impeller outlet; The impeller flow field is asymmetric, i.e. the velocity and pressure fields arc totally different among all channels in the impeller; In the volute, the static pressure gradually increases with the flow route, and a large pressure gratitude occurs in the tongue; Secondary flow exists in the rear part of the spiral. 展开更多
关键词 Centrifugal pump Numerical simulation performance prediction Secondary flow
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Tunnelling performance prediction of cantilever boring machine in sedimentary hard-rock tunnel using deep belief network 被引量:2
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作者 SONG Zhan-ping CHENG Yun +1 位作者 ZHANG Ze-kun YANG Teng-tian 《Journal of Mountain Science》 SCIE CSCD 2023年第7期2029-2040,共12页
Evaluating the adaptability of cantilever boring machine(CBM) through in-depth excavation and analysis of tunnel excavation data and rock mass parameters is the premise of mechanical design and efficient excavation in... Evaluating the adaptability of cantilever boring machine(CBM) through in-depth excavation and analysis of tunnel excavation data and rock mass parameters is the premise of mechanical design and efficient excavation in the field of underground space engineering.This paper presented a case study of tunnelling performance prediction method of CBM in sedimentary hard-rock tunnel of Karst landform type by using tunneling data and surrounding rock parameters.The uniaxial compressive strength(UCS),rock integrity factor(Kv),basic quality index([BQ]),rock quality index RQD,brazilian tensile strength(BTS) and brittleness index(BI) were introduced to construct a performance prediction database based on the hard-rock tunnel of Guiyang Metro Line 1 and Line 3,and then established the performance prediction model of cantilever boring machine.Then the deep belief network(DBN) was introduced into the performance prediction model,and the reliability of performance prediction model was verified by combining with engineering data.The study showed that the influence degree of surrounding rock parameters on the tunneling performance of the cantilever boring machine is UCS > [BQ] > BTS >RQD > Kv > BI.The performance prediction model shows that the instantaneous cutting rate(ICR) has a good correlation with the surrounding rock parameters,and the predicting model accuracy is related to the reliability of construction data.The prediction of limestone and dolomite sections of Line 3 based on the DBN performance prediction model shows that the measured ICR and predicted ICR is consistent and the built performance prediction model is reliable.The research results have theoretical reference significance for the applicability analysis and mechanical selection of cantilever boring machine for hard rock tunnel. 展开更多
关键词 Urban metro tunnel Cantilever boring machine Hard rock tunnel performance prediction model Linear regression Deep belief network
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Evaluation of boring machine performance with special reference to geomechanical characteristics 被引量:1
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作者 K. Goshtasbi M. Monjezi P. Tourgoli 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2009年第6期615-619,共5页
The duration of tunneling projects mostly depends on the performance of boring machines. The performance of boring machines is a function of advance rate, which depends on the machine characterizations and geomechanic... The duration of tunneling projects mostly depends on the performance of boring machines. The performance of boring machines is a function of advance rate, which depends on the machine characterizations and geomechanical properties of rock mass. There were various theoretical and empirical models for estimating the advance rate. In this paper, after determining the geomechanical properties of rock mass encountered in the Isfahan metro tunnel, the performance of the roadheader and tunnel boring machine (TBM) were then evaluated using various models. The calculation results show that the average instantaneous cutting rate of the roadheader in sandstone and shale are 42.8 and 74.5 m^3/h respectively. However the actual values in practice are 34.2 and 51.3 m^3/h. The operational cutting rate of the roadheader in sandstone and shale are 8.2 and 9.7 m^3/h respectively, but the actual values are 6.5 and 6.7 m^3/h. The penetration rate of the TBM in shale is predicted to be 50-60 mm/round. 展开更多
关键词 performance prediction ROADHEADER cutting rate specific energy tunnel boring machine penetration rate
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Intelligent prediction on performance of high-temperature heat pump systems using different refrigerants 被引量:1
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作者 YU Xiao-hui ZHANG Yu-feng +4 位作者 ZHANG Yan HE Zhong-lu DONG Sheng-ming MA Xue-lian YAO Sheng 《Journal of Central South University》 SCIE EI CAS CSCD 2018年第11期2754-2765,共12页
Two new binary near-azeotropic mixtures named M1 and M2 were developed as the refrigerants of the high-temperature heat pump(HTHP).The experimental research was used to analyze and compare the performance of M1 and M2... Two new binary near-azeotropic mixtures named M1 and M2 were developed as the refrigerants of the high-temperature heat pump(HTHP).The experimental research was used to analyze and compare the performance of M1 and M2-based in the HTHP in different running conditions.The results demonstrated the feasibility and reliability of M1 and M2 as new high-temperature refrigerants.Additionally,the exploration and analyses of the support vector machine(SVM)and back propagation(BP)neural network models were made to find a practical way to predict the performance of HTHP system.The results showed that SVM-Linear,SVM-RBF and BP models shared the similar ability to predict the heat capacity and power input with high accuracy.SVM-RBF demonstrated better stability for coefficient of performance prediction.Finally,the proposed SVM model was used to assess the potential of the M1 and M2.The results indicated that the HTHP system using M1 could produce heat at the temperature of 130°C with good performance. 展开更多
关键词 high-temperature heat pump experimental performance support vector machine back propagation neural network performance prediction
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Predicting configuration performance of modular product family using principal component analysis and support vector machine 被引量:1
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作者 张萌 李国喜 +1 位作者 龚京忠 吴宝中 《Journal of Central South University》 SCIE EI CAS 2014年第7期2701-2711,共11页
A novel configuration performance prediction approach with combination of principal component analysis(PCA) and support vector machine(SVM) was proposed.This method can estimate the performance parameter values of a n... A novel configuration performance prediction approach with combination of principal component analysis(PCA) and support vector machine(SVM) was proposed.This method can estimate the performance parameter values of a newly configured product through soft computing technique instead of practical test experiments,which helps to evaluate whether or not the product variant can satisfy the customers' individual requirements.The PCA technique was used to reduce and orthogonalize the module parameters that affect the product performance.Then,these extracted features were used as new input variables in SVM model to mine knowledge from the limited existing product data.The performance values of a newly configured product can be predicted by means of the trained SVM models.This PCA-SVM method can ensure that the performance prediction is executed rapidly and accurately,even under the small sample conditions.The applicability of the proposed method was verified on a family of plate electrostatic precipitators. 展开更多
关键词 design configuration performance prediction MODULARITY principal component analysis support vector machine
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Performance prediction of gravity concentrator by using artificial neural network-a case study 被引量:3
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作者 Panda Lopamudra Tripathy Sunil Kumar 《International Journal of Mining Science and Technology》 SCIE EI 2014年第4期461-465,共5页
In conventional chromite beneficiation plant, huge quantity of chromite is used to loss in the form of tailing. For recovery these valuable mineral, a gravity concentrator viz. wet shaking table was used.Optimisation ... In conventional chromite beneficiation plant, huge quantity of chromite is used to loss in the form of tailing. For recovery these valuable mineral, a gravity concentrator viz. wet shaking table was used.Optimisation along with performance prediction of the unit operation is necessary for efficient recovery.So, in this present study, an artificial neural network(ANN) modeling approach was attempted for predicting the performance of wet shaking table in terms of grade(%) and recovery(%). A three layer feed forward neural network(3:3–11–2:2) was developed by varying the major operating parameters such as wash water flow rate(L/min), deck tilt angle(degree) and slurry feed rate(L/h). The predicted value obtained by the neural network model shows excellent agreement with the experimental values. 展开更多
关键词 Chromite Artificial neural network Wet shaking table performance prediction Back propagation algorithm
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Assessment of Model Predictive Control Performance Criteria 被引量:1
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作者 Rafael Lopes Duarte-Barros Song Won Park 《Journal of Chemistry and Chemical Engineering》 2015年第2期127-135,共9页
The current highly competitive environment has driven industries to operate with increasingly restricted profit margins. Thus, it is imperative to optimize production processes. Faced with this scenario, multivariable... The current highly competitive environment has driven industries to operate with increasingly restricted profit margins. Thus, it is imperative to optimize production processes. Faced with this scenario, multivariable predictive control of processes has been presented as a powerful alternative to achieve these goals. Moreover, the rationale for implementation of advanced control and subsequent analysis of its post-match performance also focus on the benefits that this tool brings to the plant. It is therefore essential to establish a methodology for analysis, based on clear and measurable criteria. Currently, there are different methodologies available in the market to assist with such analysis. These tools can have a quantitative or qualitative focus. The aim of this study is to evaluate three of the best current main performance assessment technologies: Minimum Variance Control-Harris Index; Statistical Process Control (Cp and Cpk); and the Qin and Yu Index. These indexes were studied for an alumina plant controlled by three MPC (model predictive control) algorithms (GPC (generalized predictive control), RMPCT (robust multivariable predictive control technology) and ESSMPC (extended state space model predictive controller)) with different results. 展开更多
关键词 Predictive controller performance minimum variance CAPABILITY MPC GPC ESSMPC (extended state space model predictive controller).
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PREDICTION OF THE AERODYNAMIC PERFORMANCE OF HORIZONTAL AXIS WIND TURBINES IN CONDITION OF UNIFORM WIND 被引量:1
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作者 Wang Tongguang Tang Ruiyuan Nanjing Aeronautical Institute Nanjing 210016, P.R. of China 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 1991年第2期207-213,共7页
The classical momentum-blade element theory is improved by using the empirical formula while part of rotor blades enters into the turbulent wake state, and the performance of a horizontal-axis wind turbine (HAWT) at a... The classical momentum-blade element theory is improved by using the empirical formula while part of rotor blades enters into the turbulent wake state, and the performance of a horizontal-axis wind turbine (HAWT) at all speed ratios can be predicted. By using an improved version of the so-called secant method, the convergent solutions of the system of two-dimensional equations concerning the induced velocity factors a and a' are guaranteed. Besides, a solving method of multiple solutions for a and a' is proposed and discussed. The method provided in this paper can be used for computing the aerodynamic performance of HAWTs both ofrlow solidity and of high solidity. The calculated results coincide well with the experimental data. 展开更多
关键词 WIND AXIS PREDICTION OF THE AERODYNAMIC performance OF HORIZONTAL AXIS WIND TURBINES IN CONDITION OF UNIFORM WIND
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SEM-Based Method for Performance Evaluation of Wired LANs
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作者 Qi Xiaogang Xu Chunxia Liu Lifang 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI CSCD 2018年第3期403-412,共10页
For wired local area networks(LANs),their effectiveness and invulnerability are very critical.It is extraordinarily significant to evaluate the network performance effectively in the design of a reasonable network top... For wired local area networks(LANs),their effectiveness and invulnerability are very critical.It is extraordinarily significant to evaluate the network performance effectively in the design of a reasonable network topology and the performance improvement of the networks.However,there are many factors affecting the performance of the networks,and the relation among them is also complicated.How to evaluate the performance of the wired LANs more accurately has been a heavy challenge in the network research.In order to solve the problem,this paper presents a performance evaluation method that evaluates the effectiveness and invulnerability of the wired LANs.Compared to traditional statistical methods,it has the distinct advantage of being able to handle several dependent variables simultaneously and tolerates the measurement errors among these independent variables and dependent variables.Finally,the rationality and validity of this method are verified by the extensive experimental simulation. 展开更多
关键词 wired local area networks(LANs) structural equation model(SEM) node contribution performance prediction network topology
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Performance Prediction Model for Parallel Computing on Network of Workstation
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作者 Zhang, Jianjun Ru, Guobao 《Wuhan University Journal of Natural Sciences》 EI CAS 1998年第3期61-64,共4页
In order to effectively program Parallel Computing on NOW (Network of workstation),users must be able to evaluate how well the system performs for a given application.In this paper,we present an framework that can be... In order to effectively program Parallel Computing on NOW (Network of workstation),users must be able to evaluate how well the system performs for a given application.In this paper,we present an framework that can be used to evaluate tree structured computing on NOW.Based on this framework,we derive a model for the famous parallel programming paradigm divide and conquer.We discuss how this model can be used to evaluate performance and how it can be used to restructure the application to improve performance. 展开更多
关键词 parallel computing programming paradigm divide and conquer performance prediction
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Performance Predictable ServiceBSP Model for Grid Computing
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作者 TONG Weiqin MIAO Weikai 《Wuhan University Journal of Natural Sciences》 CAS 2007年第5期871-874,共4页
This paper proposes a performance prediction model for grid computing model ServiceBSP to support developing high quality applications in grid environment. In ServiceBSP model, the agents carrying computing tasks are ... This paper proposes a performance prediction model for grid computing model ServiceBSP to support developing high quality applications in grid environment. In ServiceBSP model, the agents carrying computing tasks are dispatched to the local domain of the selected computation services. By using the IP (integer program) approach, the Service Selection Agent selects the computation services with global optimized QoS (quality of service) consideration. The performance of a ServiceBSP application can be predicted according to the performance prediction model based on the QoS of the selected services. The performance prediction model can help users to analyze their applications and improve them by optimized the factors which affects the performance. The experiment shows that the Service Selection Agent can provide ServiceBSP users with satisfied QoS of applications. 展开更多
关键词 grid computing QOS AGENT ServiceBSP performance prediction
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Performance Prediction of Packet Mobile Communication through Wireless Multipath Fading Channel Modeling
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作者 WANG Yuhao XU Jisheng 《Wuhan University Journal of Natural Sciences》 CAS 2007年第3期457-461,共5页
This paper presents a software simulator applicable to multipath fading channels in urban environments of mobile communication networks. The simulator is constructed by a two-state Markov model and several statistical... This paper presents a software simulator applicable to multipath fading channels in urban environments of mobile communication networks. The simulator is constructed by a two-state Markov model and several statistical models for simulating the characterizations of different environments. A core idea of the simulator is to construct a Rice distribution-based multipath fading module produced by a modified Gans Doppler power spectrum, and in combination with a Markov model to predict the time-dependent characteristics of packet in different radio circumstances. It can simply predict the packet performance of the future channel and evaluate the relations between the radio channel and the modulation schemes, error control protocols and channel coding. Simulation results demonstrate that it is a reliable and efficient method. 展开更多
关键词 radio channel multipath fading SIMULATION packet communication performance prediction
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