A decision support tool for the diagnosis of breast cancer based upon Fuzzy ARTMAP

This paper presents research into the application of the fuzzy ARTMAP neural network model to the diagnosis of cancer from fine-needle aspirates of the breast. Trained fuzzy ARTMAP networks are differently pruned so as to maximise accuracy, sensitivity and specificity. The differently pruned networks are then employed in a cascade of networks intended to separate cases into certain and suspicious classes. This mimics the predictive behaviour of a human pathologist. The fuzzy ARTMAP model also provides symbolic rule extraction facilities and the validity of the derived rules for this domain is discussed. Additionally, results are provided showing the effects upon network performance of different input features and different observers. The implications of the findings are discussed.     

一类复杂生产调度问题的基于符号演绎的调度方法

针对带有时问不确定件的复杂生产过程调度问题,提出一种基于符号演绎的调度方法.首先将时间的不确定性信息看作符号型数据,并提出一种用于处理这些符号型数据的基于不确定区间的符号演绎方法;然后将此符号演绎方法与遗传算法相结合,提出一种预排调度计划与实时调度规则相结合的调度方法来求解上述复杂生产调度问题.实验表明,将基于符号演绎的调度方法用于求解带有时间不确定性的复杂生产过程调度问题,能够取得较好的调度效果.     

模型转换过程中的映射发现方法

基于本体的计算无关模型到平台无关模型的转换过程,分为元本体映射规则的发现以及基于元本体映射规则的转换执行这2个部分,其中,映射发现是转换实现的基础。为此,提出一种映射发现方法以进行模型转换。该方法在已知计算无关模型和平台无关模型的元模型基础上,抽取各自的元本体,结合基于相似度的本体映射技术建立2种模型的元本体映射关系,并作为模型转换语义匹配推理的基础。通过实例验证该方法的可行性和实用性。     

A local construction of the Smith normal form of a matrix polynomial

We present an algorithm for computing a Smith form with multipliers of a regular matrix polynomial over a field. This algorithm differs from previous ones in that it computes a local Smith form for each irreducible factor in the determinant separately and then combines them into a global Smith form, whereas other algorithms apply a sequence of unimodular row and column operations to the original matrix. The performance of the algorithm in exact arithmetic is reported for several test cases.     

fKenzo: A user interface for computations in Algebraic Topology

fKenzo (=friendly Kenzo) is a graphical user interface providing a user-friendly front-end for the Kenzo system, a Common Lisp program devoted to Algebraic Topology. The fKenzo system provides the user interface itself, an XML intermediary generator-translator and, finally the Kenzo kernel. We describe in this paper the main points of fKenzo, and we explain also the advantages and limitations of fKenzo with respect to Kenzo itself. The text is separated into two parts, trying to cover both the user and the developer perspectives.     

Fast Isosurface Rendering on a GPU by Cell Rasterization

This paper presents a fast, high‐quality, GPU‐based isosurface rendering pipeline for implicit surfaces defined by a regular volumetric grid. GPUs are designed primarily for use with polygonal primitives, rather than volume primitives, but here we directly treat each volume cell as a single rendering primitive by designing a vertex program and fragment program on a commodity GPU. Compared with previous raycasting methods, ours has a more effective memory footprint (cache locality) and better coherence between multiple parallel SIMD processors. Furthermore, we extend and speed up our approach by introducing a new view‐dependent sorting algorithm to take advantage of the early‐z‐culling feature of the GPU to gain significant performance speed‐up. As another advantage, this sorting algorithm makes multiple transparent isosurfaces rendering available almost for free. Finally, we demonstrate the effectiveness and quality of our techniques in several real‐time rendering scenarios and include analysis and comparisons with previous work.     

Symbolic hierarchical analysis in currency markets: An application to contagion in currency crises

In this paper we introduce a new method to describe dynamical patterns of the real exchange rate co-movements time series and to analyze contagion in currency crisis. The method combines the tools of symbolic time series analysis with the nearest neighbor single linkage clustering algorithm. Data symbolization allows us obtaining a metric distance between two different time series that is used to construct an ultrametric distance. By analyzing the data of various countries, we derive a hierarchical organization, constructing minimal-spanning and hierarchical trees. From these trees we detect different clusters of countries according to their proximity. We show that this methodology permits us to construct a structural and dynamic topology that is useful to study interdependence and contagion effects among financial time series.     

一种自动机学习和符号化执行的软件自动测试方法

针对高可信软件提出一种软件脆弱性自动测试方法。与传统测试方法不同,该方法对待测试程序进行预处理,使用自动机学习算法构造软件与环境交互的抽象机模型,在符号化执行迭代过程中利用抽象机模型指导符号化执行,并动态生成测试数据,同时精化交互抽象机用于后继的符号化迭代测试。解决了传统符号化执行测试技术中缺乏指引、具有较高盲目性的问题,同时也提高了符号化执行测试的效率和代码覆盖率。     

自动并行化中不规则循环的代码生成

许多大规模计算程序包含了不规则循环,但在面向分布存储的自动并行化中,以往的研究难以在编译时为不规则循环生成并行代码。针对一类常见的不规则循环提出了一种代码生成方法, 该方法 能在编译时将串行代码转换成等价的并行计算和通信代码,通过计算分解和数组引用的访问表达式来求解不规则循环在各处理器的本地定义集,并通过部分冗余的通信来满足不规则数组引用的生产者-消费者关系。实验结果表明,该方法是有效的,并对测试用例取得了预期的加速比。     

Constant round group key agreement protocols: A comparative study

The scope of this paper is to review and evaluate all constant round Group Key Agreement (GKA) protocols proposed so far in the literature. We have gathered all GKA protocols that require 1,2,3,4 and 5 rounds and examined their efficiency. In particular, we calculated each protocol’s computation and communication complexity and using proper assessments we compared their total energy cost. The evaluation of all protocols, interesting on its own, can also serve as a reference point for future works and contribute to the establishment of new, more efficient constant round protocols.