Cameo: an alternative model of concurrency for Eiffel

We present a new concurrency model for the Eiffel programming language. The model is motivated by describing a number of semantic problems with the leading concurrency model for Eiffel, namely SCOOP. Our alternative model aims to preserve the existing behaviour of sequential programs and libraries wherever possible. Comparison with the SCOOP model is made. The concurrency aspects of the alternative model are presented in CSP along with a model of exceptions. The results show that while the new model provides increased parallelism, this comes with the price of increased overhead due to lock management.     

Exploring the Interaction between Java's Implicitly Thrown Exceptions and Instruction Scheduling

The frequent occurrence of implicitly thrown exceptions poses one of the challenges present in a Java compiler. Not only do these implicitly thrown exceptions directly affect the performance by requiring explicit checks, they also indirectly impact the performance by restricting code movement in order to satisfy the precise exception model in Java. In particular, instruction scheduling is one transformation that is restricted by implicitly thrown exceptions due to the heavy reliance on reordering instructions to exploit maximum hardware performance. The goal of this study is two-fold: first, investigate the degree to which implicitly thrown exceptions in Java hinder instruction scheduling, and second, find new techniques for allowing more efficient execution of Java programs containing implicitly thrown exceptions. Experimental results show that with aggressive scheduling techniques, such as superblock scheduling, the negative performance impact can be greatly reduced.     

面向意外处理的工作流系统建模与执行

产生于工作流系统的执行阶段、未在系统建模阶段进行描述和定义的突发事件，称为工作流意外事件，对应意外事件的处理过程，称为意外处理。该文针对意外事件，从系统建模与模型执行两个方面对工作流意外处理进行了探讨，在系统建模阶段，通过拓展Petri网中的基本概念，提出并构造了组成工作流的过程单元，在将工作流内在的逻辑关系分解为控制流与数据流的基础上，讨论了一个面向意外处理的工作流系统复合建模方法，对应工作流的模型执行，定义了两类意外处理，用矩阵形式分别表示或标识控制流、数据流和意外事件，经过矩阵分析与变换，对意外事件的影响区域进行范围界定。最后，探讨了这种意外处理方法在数据流意外处理中的实例应用。     

Death and resurrection of copyright between law and technology

The paper reviews copyright philosophical, economic and social justification confronted by the dematerialization of creative outputs. Digital Rights Management (DRM) is the tool implemented by copyright owners to adjust to the advent of the Digital Era. The claim is that DRM effectively addresses digital threats and market failures. If this is true, what is left of the role of copyright law in the digital environment? This review suggests an argument for traditional copyright justifications to resist in the digital environment. As a consequence, digital tools such as DRM need to be engineered according to these justifications, in order to preserve the balance between law and technology.     

Defeasible inheritance with doubt index and its axiomatic characterization

This article introduces and uses a representation of defeasible inheritance networks where links in the network are viewed as propositions, and where defeasible links are tagged with a quantitative indication of the proportion of exceptions, called the doubt index. This doubt index is used for restricting the length of the chains of inference.The representation also introduces the use of defeater literals that disable the chaining of subsumption links. The use of defeater literals replaces the use of negative defeasible inheritance links, expressing “most A are not B”. The new representation improves the expressivity significantly.Inference in inheritance networks is defined by a combination of axioms that constrain the contents of network extensions, a heuristic restriction that also has that effect, and a nonmonotonic operation of minimizing the set of defeater literals while retaining consistency.We introduce an underlying semantics that defines the meaning of literals in a network, and prove that the axioms are sound with respect to this semantics. We also discuss the conditions for obtaining completeness.Traditional concepts, assumptions and issues in research on nonmonotonic or defeasible inheritance are reviewed in the perspective of this approach.     

Informed consent and dual purpose research.

The ethical treatment of human participants in psychological research is regulated by both federal guidelines and the ethical standards of the American Psychological Association (APA). Under certain circumstances, however, both APA standards and federal regulations allow for exceptions for informed consent. In spite of the possibility of exception, a number of factors have made it difficult to conduct and publish research that does not incorporate informed consent. The authors consider these factors and propose 2 approaches that may reduce reluctance to consider exceptions to informed consent under appropriate circumstances. First, journals should not rely on informed consent as the only method of screening research for the ethical treatment of human participants. Second, efforts must be made to work with institutional review boards and other units that review psychological research to ensure that their members are aware of the conditions under which informed consent is considered reasonable. Failure to consider ethical research without informed consent may have serious ethical consequences for research. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Induction of ripple-down rules applied to modeling large databases

A methodology forthe modeling of large data sets is described which results in rule sets having minimal inter-rule interactions, and being simply maintained. An algorithm for developing such rule sets automatically is described and its efficacy shown with standard test data sets. Comparative studies of manual and automatic modeling of a data set of some nine thousand five hundred cases are reported. A study is reported in which ten years of patient data have been modeled on a month by month basis to determine how well a diagnostic system developed by automated induction would have performed had it been in use throughout the project.     

Modifying YCN key assignment scheme to resist the attack from Hwang

This paper presents a modified YCN cryptographic key assignment scheme in a hierarchy with exceptions which is secure against Hwang's attack.     

A Nearest Hyperrectangle Learning Method

This paper presents a theory of learning called nested generalized exemplar (NGE) theory, in which learning is accomplished by storing objects in Euclidean n-space, En, as hyperrectangles. The hyperrectangles may be nested inside one another to arbitrary depth. In contrast to generalization processes that replace symbolic formulae by more general formulae, the NGE algorithm modifies hyperrectangles by growing and reshaping them in a well-defined fashion. The axes of these hyperrectangles are defined by the variables measured for each example. Each variable can have any range on the real line; thus the theory is not restricted to symbolic or binary values.This paper describes some advantages and disadvantages of NGE theory, positions it as a form of exemplarbased learning, and compares it to other inductive learning theories. An implementation has been tested in three different domains, for which results are presented below: prediction of breast cancer, classification of iris flowers, and prediction of survival times for heart attack patients. The results in these domains support the claim that NGE theory can be used to create compact representations with excellent predictive accuracy.     

基于ARM7TDMI内核的S3C4480异常处理分析

介绍了ARM7TDMI的7种工作模式及各种工作模式下处理器的基本功能、适用的条件以及在嵌入式系统设计中的重要性。详细分析了复位、快速中断和普通中断的编程要点以及在嵌入程序设计中的作用，并结合S3C44BO示例程序分析了CPU对异常处理的方法。