Using differential evolution for fine tuning naïve Bayesian classifiers and its application for text classification

The Naive Bayes (NB) learning algorithm is simple and effective in many domains including text classification. However, its performance depends on the accuracy of the estimated conditional probability terms. Sometimes these terms are hard to be accurately estimated especially when the training data is scarce. This work transforms the probability estimation problem into an optimization problem, and exploits three metaheuristic approaches to solve it. These approaches are Genetic Algorithms (GA), Simulated Annealing (SA), and Differential Evolution (DE). We also propose a novel DE algorithm that uses multi-parent mutation and crossover operations (MPDE) and three different methods to select the final solution. We create an initial population by manipulating the solution generated by a method used for fine tuning the NB. We evaluate the proposed methods by using their resulted solutions to build NB classifiers and compare their results with the results of obtained from classical NB and Fine-Tuning Naïve Bayesian (FTNB) algorithm, using 53 UCI benchmark data sets. We name these obtained classifiers NBGA, NBSA, NBDE, and NB-MPDE respectively. We also evaluate the performance NB-MPDE for text-classification using 18 text-classification data sets, and compare its results with the results of obtained from FTNB, BNB, and MNB. The experimental results show that using DE in general and the proposed MPDE algorithm in particular are more convenient for fine-tuning NB than all other methods, including the other two metaheuristic methods (GA, and SA). They also indicate that NB-MPDE achieves superiority over classical NB, FTNB, NBDE, NBGA, NBSA, MNB, and BNB.     

细粒锡石浮选组合药剂研究与应用进展

采用浮选工艺回收细粒锡石,药剂是关键。大量的研究与生产实践表明,浮选药剂的组合能提升锡石的综合回收指标。为了系统、全面地了解细粒锡石浮选组合药剂的研究与应用进展,综述了细粒锡石浮选的组合捕收剂、组合调整剂以及捕收剂+调整剂组合的优点、作用机理及应用现状,指出使用组合药剂能取得较理想的浮选指标与药剂间的协同作用密不可分。     

细粒尾矿综合利用技术研究

姑山矿业公司为提高细粒尾矿的综合利用率,研究分析了细粒尾矿的性质,系统研究了尾矿含量、煅烧工艺制度对不同成分体系尾矿陶粒堆积密度、表观密度、空隙率、吸水率、筒压强度及软化系数的影响。研究得出了全尾矿陶粒、细粒尾矿+污泥陶粒、细粒尾矿+污泥+粉煤灰陶粒3种成分体系的尾矿陶粒较优的尾矿含量及煅烧工艺制度,且3种尾矿陶粒均可代替石头用作粗集料。     

基于TOD模式的高铁站区景观设计初探——以济南西客站为调研解析案例

在我国快速城市化进程中,近年来高铁站区的建设方兴未艾,城市与站区各方面的发展需求日益迫切。TOD模式作为协调城市交通与土地利用的有效途径,是一种较为理想的高铁站区发展模式。通过典型高铁站区的实地调研与问卷访谈,分析总结经验并结合TOD发展理念,建设性地提出TOD模式下的高铁站区景观设计策略,阐述相关设计内容,希望对现阶段我国高铁站区景观设计与站区TOD健康发展思路具有良好的启示。     

高速机床导轨防护罩的结构分析

介绍了两种高速机床导轨防护罩,即高速同动机构防护罩和高速同动平行机构防护罩.分析其结构原理、特点及选择的原则.     

Indoor inhalation intake fractions of fine particulate matter: review of influencing factors

Exposure to fine particulate matter (PM_2.5) is a major contributor to the global human disease burden. The indoor environment is of particular importance when considering the health effects associated with PM_2.5 exposures because people spend the majority of their time indoors and PM_2.5 exposures per unit mass emitted indoors are two to three orders of magnitude larger than exposures to outdoor emissions. Variability in indoor PM_2.5 intake fraction (iF_in,total), which is defined as the integrated cumulative intake of PM_2.5 per unit of emission, is driven by a combination of building‐specific, human‐specific, and pollutant‐specific factors. Due to a limited availability of data characterizing these factors, however, indoor emissions and intake of PM_2.5 are not commonly considered when evaluating the environmental performance of product life cycles. With the aim of addressing this barrier, a literature review was conducted and data characterizing factors influencing iF_in,total were compiled. In addition to providing data for the calculation of iF_in,total in various indoor environments and for a range of geographic regions, this paper discusses remaining limitations to the incorporation of PM_2.5‐derived health impacts into life cycle assessments and makes recommendations regarding future research.     

Particle filtration and distribution during the liquid composite molding process for manufacturing particles containing composite materials

The effects of major process parameters on particle filtration and distribution were investigated by using newly developed microscopic methodology using an electron probe micro-analyzer and numerical simulation. The mapping results indicated that well-dispersed particles were distributed uniformly in the inter-tow and intra-tow regions. Agglomerates were likely to be filtered at the boundary or inside of the fiber bundle. The results of quantitative analyses showed particle concentrations in the inter-tow region to be uniform throughout the composite part, whereas the intra-tow concentrations varied according to particle size and fiber orientation. The poor dispersion state of the CNT-Ag particles resulted in quite irregular distributions. A high volume fraction of the fiber preform resulted in a lower particle concentration inside the fiber tow. Numerical analysis of the filtration of large clusters of particles indicated that filtration occurred in the initial stage of the injection process at the tow boundaries.     

Simulation of granular packing of particles with different size distributions

The study of granular matter composed of spherical particles is of interest in manufacturing, material, and metallurgy. The viscoelastic and frictional contacts between the particles are the cause of forming the agglomeration. We present a numerical simulation for particles packing with three different kinds of size distributions: monosize, bimodal, and Gaussian, using distinct element method (DEM). The particles are initially put randomly but without any overlap, and then fall down due to the gravity force and collide with neighbor particles. Because of the dissipative factors of viscoelastic collision and frictional force, all the particles finally come together to form an agglomeration. Coordination number, porosity, radial distribution function, and force distribution are calculated for different size distributions. It is demonstrated that particle size distribution does affect the granular packing structure.     

Colloid Transport through Natural Filter Media

In this project the use of natural media filtration (NMF) was evaluated for its ability to remove colloidal particles from the aqueous phase as a function of ionic strength and filter media type by determining first-order kinetic deposition rate coefficients. Mushroom compost (MC) and leaf compost (LC) were tested as natural filter media and the results were compared to those obtained using sand and granular activated carbon (GAC). The highest deposition rate coefficients were observed for GAC, followed by LC and MC, and the lowest deposition rate coefficients were found for sand. As predicted by the Derjaguin–Landau–Verwey–Overbeek theory, higher deposition rates were obtained at higher solution ionic strengths. Overall the experiments suggest that the NMF process can efficiently remove colloidal particles from surface waters.     

Heavy Metals In Water,Suspended Particles,Sediments And Aquatic Plants Of Habbaniya Lake,Iraq

Seasonal samples were taken from four selected stations on the Habbaniya lake, middle of Iraq during 1997, to study six heavy metals (Cu, Cd, Pb, Ni, Mn, and Zn), in water suspended particles, sediments and aquatic plants. Five plant species were collected, represented the most dominant in the lake, namely Myriophyllum verticillatum, Potamogeton crispus, P. pectinatus, Ceratophyllum demersum and Vallisnaria spiralis . Zn had the highest concentration among the studied metals in filtered water and suspended particles with an average of 4.08 w g/l and 26088 w g/g, respectively. Whereas, Mn had the highest in the sediments and all studied aquatic plants, which ranged between 213.3- 2027 w g/g and 100-1725 w g/g, respectively, Meanwhile, Cd had the lowest concentration in all studied samples.