Shear-rate dependence of first normal stress difference of poly(isoprene-b-styrene) in solution near the order-disorder transition temperature

Viscoelastic properties of poly(isoprene-b-styrene) in dioctylphthalate under steady shear flow were measured near the order—disorder transition temperature. In ordered states, first normal stress difference N₁ is proportional to shear rate at low region, but becomes proportional to at the high region, similar to the N₁ behaviour of polymer blends undergoing shear-induced homogenization. Because the existence of microdomains was confirmed at the high region by the flow birefringence method, it is concluded that the above N₁ behaviour is not caused by shear-induced homogenization, but is probably caused by the shear-induced alignment of the microdomain structure.     

Application of open-pit and underground mining technology for residual coal of end slopes

Given the conditions of residual coal from the boundary of a flat dipping open-pit mine,which uses strip areas mining and inner dumping with slope-covering,we propose an open-pit and underground integrated mining technology for residual coal of end slopes.In the proposal a conveyance road and ventilation conveyance near the slope are built,corresponding to the pit mining area and the surface coal mine dump,as well as an interval haulage tunnel and air-inlet tunnel.The outcome shows that such mining method may reduce the effect to slope stability from underground mining,it does not affect the dumping advance and has a high recovery rate of residual coal resources.The working face is timbered by single hydraulic props,transported by a scraper conveyor and supported by coal walls.This method of mining is one of layered top coal caving,with high resource recovery,low production cost where positive economic benefit can be realized.     

Deformation and failure study of surrounding rocks of dynamic pressure roadways in deep mines

In order to understand the change rules of stress-displacement in surrounding rocks of dynamic pressure roadways in deep mines and to obtain a theoretical basis for analyses of roadway stability and designs of support,we established a coupling equation of adjacent rock strength,mining stress and supporting resistance on the basis of an elastic-plastic theory of mechanics.We obtained an analytical solution for stress and displacement distribution of elastic and plastic regions in surrounding rock of dynamic pressure roadway..Based on this theory,we have analyzed the changes in stress-displacement in elastic and plastic regions of surrounding rocks of dynamic pressure roadways in the Haizi Coal Mine.The results show that:1) radial and tangential stress change violently within the first 4 m from the inner surface of a roadway after excavation;radial stress increases while tangential stress decreases within a range of about 6 m from the inner surface of the roadway as a function of q3;2) radial and tangential stress increase with an increase in the mining pressure coefficient k;the increase in the rate of tangential stress is greater than that of radial stress;3) the radial displacement of the inner surface of roadways decreases with an increase in q3,provided that k remains unchanged.     

Reserve estimation of an open pit mine under price uncertainty by real option approach

Reserve estimation is a key to find the correct NPV in a mining project. The most important factor in reserve estimation is the metal price. Metal price fluctuations in recent years were exaggerated, and imposed a high degree of uncertainty to the re-serve estimation, and in consequence to the whole mine planning procedure. Real option approach is an efficient method of deci-sion making in the uncertain conditions. This approach has been used for evaluation of defined natural resources projects until now. This study considering the metal price uncertainty used real option approach to prepare a methodology for reserve estimation in open pit mines. This study was done on a copper cylindrical deposit, but the achieved methodology can be adjusted for all kinds of deposits. This methodology was comprehensively described through the examples in such a manner that can be used by the mine planners.     

商务智能系统中两种改进的关联规则挖掘算法

根据日常商务数据的特点,提出了商业应用系统中进行数据挖掘的改进的Apriori算法和对点击流数据进行挖掘的改进的多支持度关联规则算法,并结合具体实例进行了分析.分析结果表明,2种改进的算法可以有效地提高系统数据挖掘的效率.     

基于关联分析的数据挖掘在体检CRM中的应用

运用关联分析方法对体检中心数据进行挖掘。首先分析了关联规则的原理和方法,然后对待挖掘数据进行集成、变换等预处理,得到能进行挖掘的原始数据.采用挖掘工具WEKA,选用关联规则中的Apriori算法对处理后数据进行分析,得到了与某一病症相关的各个症状之间的关联关系,以及各个症状与健康之间的关联关系。     

动态挖掘进程内在机制研究

针对动态挖掘进程内在运行机理,通过对动态挖掘进程中不同挖掘任务的优化分析以及动态挖掘进程和生物免疫过程之间的对比分析,提出了动态挖掘进程的eDMP机制;定义健壮型协调器,融合进化计算和免疫算法,设计了eDMP机制的实现方案;在理论分析和方案设计的基础上,给出了eDMP机制的一般流程。实验结果表明,eDMP机制及其实现方案在解决动态挖掘问题上有效、适用。     

基于Web日志挖掘的客户访问兴趣分析

数据预处理是Web日志挖掘中的一项关键技术,如何分析客户访问兴趣是Web挖掘中的一个重要研究课题。概述了Web日志挖掘的概念、方法和步骤,重点分析了数据预处理的主要步骤及其实现技术,考虑客户访问路径和浏览时间长度等因素,给出并计算分析了网站用户的访问兴趣的方法。汽修之家网站日志的实际测试结果表明了该方法的有效性。     

企业网站设计内容第一的原则

企业网站设计内容第一的原则,其根本在于企业网站能否吸引和留住客户或潜在客户,它包含三层意思：网站内容的面向对象要准确清晰;针对目标访客的网站内容要紧扣其兴趣中心,从为其带来价值的角度出发,令其感到有收获;促使目标访客对网站内容建立起充分的信任感、解答其疑问。从网站内容方面保证了企业网站对目标访客的吸引力和访问粘度,从而为企业网站实现其既定目标打下了良好的基础。     

A fast updated algorithm to maintain the discovered high-utility itemsets for transaction modification

High-utility itemsets mining (HUIM) is a critical issue which concerns not only the occurrence frequencies of itemsets in association-rule mining (ARM), but also the factors of quantity and profit in real-life applications. Many algorithms have been developed to efficiently mine high-utility itemsets (HUIs) from a static database. Discovered HUIs may become invalid or new HUIs may arise when transactions are inserted, deleted or modified. Existing approaches are required to re-process the updated database and re-mine HUIs each time, as previously discovered HUIs are not maintained. Previously, a pre-large concept was proposed to efficiently maintain and update the discovered information in ARM, which cannot be directly applied into HUIM. In this paper, a maintenance (PRE-HUI-MOD) algorithm with transaction modification based on a new pre-large strategy is presented to efficiently maintain and update the discovered HUIs. When the transactions are consequentially modified from the original database, the discovered information is divided into three parts with nine cases. A specific procedure is then performed to maintain and update the discovered information for each case. Based on the designed PRE-HUI-MOD algorithm, it is unnecessary to rescan original database until the accumulative total utility of the modified transactions achieves the designed safety bound, which can greatly reduce the computations of multiple database scans when compared to the batch-mode approaches.