利用BP神经网络进行测井资料外推

针对在地震资料约束下资料外推的具体问题，修改了ＢＰ网络的能量函数，增加一项反演目标函数，使之作为一项新的能量约束，从而实现用ＢＰ网络自适应地外推测井资料，有机地将ＢＰ网络与地震反演结合起来，本文论述了其理论与算法，并给出了资料处理应用实例，对实际资料的测井速度外推结果表明，此方法处理速度快，稳定性好，可信度高，具有较好的应用前景。     

Appropriate lemmae discovery

An inductive proof attempt may fail as the available induction hypotheses cannot be applied to simplify the conclusion. One of the major problems which arise when performing inductive proofs is to transform the conclusion of an induction step in order to make the hypothesis applicable. Often, to overcome this problem, several additional lemmae are needed. However, most inductive theorem provers rely upon user intervention in supplying the required lemmae. In contrast, we present a method for generating automatically lemmae. Generation of lemmae is motivated by attempts to find appropriate instantiations for non-induction variables in the inductive step. We consider implicative formulae of the form , where ΓandΔ are conjunction of atoms and x? and ? are vectors of universal and of existential variables respectively.     

Classification Using Φ-Machines and Constructive Function Approximation

This article presents a new classification algorithm, called CLEF, which induces a -machine by constructing its own features based on the training data. The features can be viewed as defining subsets of the instance space, and they allow CLEF to create useful non-linear functions over the input variables. The algorithm is guaranteed to find a classifier that separates the training instances, if such a separation is possible. We compare CLEF empirically to several other classification algorithms, including a well-known decision tree inducer, an artificial neural network inducer, and a support vector machine inducer. Our results show that the CLEF-induced -machines and support vector machines have similar accuracy on the suite tested, and that both are significantly more accurate than the other classifiers produced. We argue that the classifiers produced by CLEF are easy to interpret, and hence may be preferred over support vector machines in certain circumstances.     

侧向测井曲线分辨率匹配方法及其在松辽盆地的应用

对于松辽盆地中的一些较薄的致密砂岩储层,常规测井曲线,尤其是电阻率测井曲线,因为它们的纵向分辨率较低,往往会降低薄储层含油饱和度的计算精度。为此,探讨了应用“分辨率匹配”方法,将低分辨率的曲线提高为具有较高分辨率的曲线。并利用地层界面处的测井曲线变化率来提取实际的综合响应函数,而不是直接使用测井仪器的响应函数,因此使提高分辨率的处理更符合实际。最后给出了将深浅侧向电阻率测井曲线的分辨率提高到微球形聚焦测井分辨率的应用实例。     

石油测井仪器筒体内孔加工技术

石油测井仪器筒体内孔的加工属于难加工材料的超细长深孔加工 ,加工精度要求较高 ,难度很大 ,效率很低。针对筒体的加工特点 ,进行了深孔加工方法的研究 ,设计了深孔钻削、深孔镗削和深孔珩磨加工工艺 ,对现有深孔钻和深孔珩磨工具的结构做了改进 ,优化切削参数。对传统的深孔加工方法改进后 ,可以明显地减小切削力 ,减小钻削过程中的振动 ,提高钻头耐用度、钻孔效率和钻孔精度 ,可以较准确地控制油石压力 ,防止珩磨头“抱死” ,使该筒体的加工质量和加工效率大大提高     

基于随机算法的三相异步电动机全局优化

以效率为目标函数的铸铝转子异步电机全局优化是一种个复杂的非凸、非线性规划问题。首先使用ＴＡＢＵ算法将这一高维问题降维分解并缩步搜索域,一局寻优。验证结果表明,该方法充分了长期积累的经验知识,与单独使用ＴＡＢＵ算法或遗传算法相比,计算量较为合理,结果满意度较高,基本满足了高效电机设计的要求。     

Predicting adequacy of vancomycin regimens: A learning-based classification approach to improving clinical decision making

Clinicians' drug regimen decision making is critical, particularly when involving high-alert medications. In this study, we use decision-tree induction C4.5 and a backpropagation neural network to construct decision support systems for predicting the regimen adequacy of vancomycin, a glycopeptide antimicrobial antibiotic effective for Gram-positive bacterial infections. We comparatively evaluate the respective systems using a total of 987 clinical vancomycin cases collected from a major tertiary medical center in southern Taiwan. We supplement each system using Bagging and then examine the predictive power of the extended system. Overall, our evaluation results show the overall accuracy of the decision support system based on C4.5 or the neural network to be significantly higher than that of the benchmark one-compartment pharmacokinetic model. Use of Bagging can considerably improve the effectiveness of each system across different performance measures, particularly for cases of decision classes in which the base systems (i.e., without Bagging) perform modestly. Taken together, our evaluation results seem to favor the use of Bagging to enhance the performance of decision support systems constructed using decision-tree induction C4.5.     

测井刻度软件结构设计中关于系统功能扩展的探讨与实现

针对测井仪器刻度软件系统功能扩展性能的需求,提出了设计测井仪器刻度软件系统结构时两种不同的思想,探讨了这两种设计思想对系统功能扩展性能的影响;给出了设计思想具体实现时动态加载功能模块的方法,证明了软件开发中所采纳的设计思想实现的可行性,有效地解决了系统功能的扩展需求。     

归纳学习XPATH Web信息提取规则

XPATH在Web信息提取中起重要作用,但是这些XPATH规则通常要人工生成。文中讨论了在XPATH与基于文本上下文规则的信息提取方法结合的系统中如何归纳学习XPATH规则。生成的XPATH规则结构简单,可以为基于文本上下文的信息提取系统提供较为准确的信息定位。     

以低纯度钆研究Gd5Si2Ge2的磁热效应及制备工艺

以99%级的低纯度金属Gd为原料, 采用真空感应炉制备工艺, 辅以1470 K热处理工艺, 获得了与99.99%级高纯度Gd为原料制备的Gd5Si2Ge2合金相近的磁热效应, 5 T外场下最大磁熵变达17.5 J·kg^-1·K^-1, 对比电弧熔炼与感应熔炼两种制备方法, 感应熔炼条件下C, N, O杂质含量明显降低, 发现了Gd5Si2Ge2合金巨磁熵变与相结构的本质联系.