一种扩展的关联规则挖掘算法

提出一种扩展的关联规则挖掘算法, 该算法扩展了传统 算法都是针对二元数据矩阵的缺点, 引入了挖掘量化的关联规则, 通过试验发现, 该算法同样适用于传统的布尔矩阵. 该算法主要是基于主成分分析法发现数据中特征向量的思想来挖掘数据中的量化关联, 同时定义了比例项目集. 该算法在时空复杂性上也取得了较好的效果     

裂缝性油藏注气提高采收率技术进展

注气可以维持裂缝性储层的地层压力,并提高驱油效率。阐述了世界裂缝性油藏注气提高原油采收率（EOR）技术的发展概况,分析和讨论了裂缝性储层注气开采特征、室内实验研究及理论研究技术现状。指出,储层中裂缝发育方向和程度严重影响注气驱替效果;气驱突破速度未必比水驱突破快;气驱波及范围有可能比水驱波及范围广。多孔介质将影响流体相态、油气混相性及气驱油机理,建议加强考虑双重介质特性的注气驱相关室内实验研究和混相理论研究。     

论公路施工项目的成本控制

公路施工企业承揽工程的目的是为了最大化争取利润,同时也是衡量企业的管理水平标准, 文章从公路施工项目管理的控制办法及项目管理优缺点、管理规划与施工组织的关系进行了论述.     

基于改进的伪并行遗传算法的智能组卷的研究

传统的组卷方式存在组卷时间长、成功率低等缺点,本文提出了一种基于改进的伪并行遗传算法的智能组卷策略,其组卷时间短、成功率高,具有很好的性能和实用性。同时可以提高试卷质量,增加了考试的科学性和客观性,对考试工作的顺利实施具有重要的实际意义。     

Effect of Processing Parameters on Thermal Phenomena in Direct Laser Metallic Powder Deposition

Direct laser metallic powder deposition technique is widely used in manufacturing, part repairing, and metallic rapid prototyping. The ability to predict geometrical accuracy and residual stress requires an understanding of temperature distribution during the deposition process. This study presents a numerical model of three-dimensional transient heat transfer in a finite model heated by a moving laser beam. Thermal phenomena in the process were investigated. The complex solid-liquid problem and latent heat of fusion were treated by means of equivalent thermal conductivity and modified specific heat, respectively. Using method of birth and death of elements, the growth of additive layers and the shape of melt pool were obtained. The effect of processing parameters such as absorbed power, travel speed, and preheated temperature on melt pool sizes and cross-section of deposited layer profile was studied. The results show that the melt pool sizes increase with absorbed power and decrease with travel velocity. In addition, the preheated temperature contributes less to the melt pool size. The results are generally in a good agreement with experiments in published literature.     

大型游泳池水温的预测模糊控制

分析了容积为 2 50 0m3大型游泳池的池水温度特性 ,提出了预测模糊控制算法 .采用该算法对具有大惯性、纯滞后等特性的池水温度进行控制 ,取得了良好的效果 ,而且调节过程平稳 ,实际控制精度达± 0 .0 2℃ .由此可得 ,这种算法也可以应用到具有类似特性参数的工业过程控制之中 ,并能取得有效的控制精确度和稳定性 .     

铸造工艺参数对7075/6009铸锭外层合金厚度的影响

采用双流浇注半连续铸造技术制备了7075/6009梯度复合铝合金铸锭,分析了内、外熔体温度、铸造速度、节流片孔径大小、内导管插入深度等工艺参数对铸锭外层厚度的影响,结果表明：内熔体温度的升高、内导管插入深度的增加及节流片孔径的增大都将显著减小铸锭外层厚度,当内熔体温度从680 ℃升高到780 ℃,内导管插入深度从0 mm增大到15 mm,节流孔径从1.6 mm增大到1.8 mm时,7075/6009复合铸锭的外层合金厚度分别可减小38.8 %、30 %和42.2 %;而外熔体温度的升高及铸造速度的增大对减薄铸锭外层厚度不明显;同时探讨了铸造工艺参数对凝固液穴形成和铸锭外层厚度的影响机制。     

Orientation to learning context modulates retrieval processing for unrecognized words

Explicit memory errors may occur when individuals fail to retrieve information about items previously studied (item memory) or about the learning context (source memory). We examined electrophysiological measures during recognition failure in order to determine the influence of retrieval orientation for item versus source information. Recognition failure was associated with brain potentials distinct from those associated with success. Furthermore, source-memory failures were associated with earlier-onset brain potentials with a more anterior distribution compared to item-memory failures. Neurocognitive processing was thus modulated by retrieval orientation so as to differentially influence neural correlates of successful versus unsuccessful retrieval.     

Experimental study on burning rate of small scale heptane pool fires

Burning characteristics of small scale thin-layer n-heptane pool fires were experimentally studied.Flame height,burning rate and fuel temperature distribution of pool fires with different diameters were measured.Fuel surface temperature and wall heat flux were analyzed.Four typical burning phases,which include pre-burning,quasi-steady state burning,boiling burning and decaying phases,are revealed based on the experimental data and phenomenological analysis.It is shown that flame height and burning rate of b...     

基于驱使项惩罚的曲线演化模型改进

针对变分水平集方法在IMV图像处理软件设计上的应用,提出了基于驱使项惩罚的思想,并应用曲线演化驱动算法,对迭代格式中的驱使项进行改进,增加了惩罚项,有效地降低了时间消耗。通过验证,曲线的演化效率大幅增加,极大地提高了曲线演化的实时性。