Design and evaluation of system-level checks for on-line controlflow error detection

This paper evaluates the concurrent error detection capabilities of system-level checks, using fault and error injection. The checks comprise application and system level mechanisms to detect control flow errors. We propose Enhanced Control-Flow Checking Using Assertions (ECCA). In ECCA, branch-free intervals (BFI) in a given high or intermediate level program are identified and the entry and exit points of the intervals are determined. BFls are then grouped into blocks, the size of which is determined through a performance/overhead analysis. The blocks are then fortified with preinserted assertions. For the high level ECCA, we describe an implementation of ECCA through a preprocessor that will automatically insert the necessary assertions into the program. Then, we describe the intermediate implementation possible through modifications made on gee to make it ECCA capable. The fault detection capabilities of the checks are evaluated both analytically and experimentally. Fault injection experiments are conducted using FERRARI to determine the fault coverage of the proposed techniques     

Improving the reliability of function point measurement: anempirical study

One measure of the size and complexity of information systems that is growing in acceptance and adoption is function points, a user-oriented, nonsource line of code metric of the systems development product. Previous research has documented the degree of reliability of function points as a metric. This research extends that work by (a) identifying the major sources of variation through a survey of current practice, and (b) estimating the magnitude of the effect of these sources of variation using detailed case study data from commercial systems. The results of this research show that a relatively small number of factors has the greatest potential for affecting reliability, and recommendations are made for using these results to improve the reliability of function point counting in organizations     

考虑错误检测两阶依赖性以及错误校正延迟效应的软件可靠性模型

随着科技的进步和全面智能化时代的到来,软件在人类社会扮演着愈发重要的角色,因此软件的可靠性成为了一个重要的研究领域。然而到目前为止,还没有研究综合考虑到软件错误检测两阶依赖性和校正延迟效应的文献。文章提出了一个软件可靠性增长模型。该模型考虑了错误检测的两阶依赖性和错误校正的延迟效应。在文章中,软件错误被分为三种类型:独立错误、一阶依赖错误和二阶依赖错误。后两种错误依次对前一种错误具有依赖性,即只有相应的错误被检测之后,对应的依赖性错误才能被检测到。利用该模型可以计算出不同时刻下错误检测出的数量和校正的数量。这个模型相比于之前的模型更加符合实际情况。该模型对于软件投放时间等重要决策具有很大的参考价值。     

Theoretical analyses of cross-validation error and voting in instance-based learning

Abstract

This paper begins with a general theory of error in cross-validation testing of algorithms for supervised learning from examples. It is assumed that the examples are described by attribute-value pairs, where the values are symbolic. Cross-validation requires a set of training examples and a set of testing examples. The value of the attribute that is to be predicted is known to the learner in the training set, but unknown in the testing set. The theory demonstrates that cross-validation error has two components: error on the training set (inaccuracy) and sensitivity to noise (instability). This general theory is then applied to voting in instance-based learning. Given an example in the testing set, a typical instance-based learning algorithm predicts the designated attribute by voting among the k nearest neighbours (the k most similar examples) to the testing example in the training set. Voting is intended to increase the stability (resistance to noise) of instance-based learning, but a theoretical analysis shows that there are circumstances in which voting can be destabilising. The theory suggests ways to minimize cross-validation error, by insuring that voting is stable and does not adversely affect accuracy.     

Hierarchical error detection in a software implemented faulttolerance (SIFT) environment

Proposes a hierarchical error detection framework for a software-implemented fault tolerance (SIFT) layer of a distributed system. A four-level error detection hierarchy is proposed in the context of Chameleon, a software environment for providing adaptive fault tolerance in an environment of commercial off-the-shelf (COTS) system components and software. The design and implementation of a software-based distributed signature monitoring scheme, which is central to the proposed four-level hierarchy, is described. Both intra-level and inter-level optimizations that minimize the overhead of detection and are capable of adapting to runtime requirements are proposed. The paper presents results from a prototype implementation of two levels of the error detection hierarchy and results of a detailed simulation of the overall environment. The results indicate a substantial increase in availability due to the detection framework and help in understanding the tradeoffs between overhead and coverage for different combinations of techniques     

The basic driver error: late detection

Over the past two or three decades we have been quite successful in reducing injuries of car occupants by the use of energy-absorbing techniques; but we have not been as successful in reducing the risks of having collisions. When drivers are asked why an accident occurred very often they claim that they saw the other road user too late to avoid collision. This paper discusses the basic road user error of failing to see another road user in time, why such errors happen, and how they can be reduced. A detection error is basic, because without detection no processing of information, no decision process including that road user, takes place. Among the many causes of detection error two of the more important are: a lapse of cognitive expectation, illustrated by the failure to scan for a particular class of road user, or to look in the appropriate direction; a difficulty with perceptual thresholds, illustrated by the failure to discern the relevant stimuli in lower levels of ambient illumination or in situations where vehicles approach in the peripheral visual field of road users.     

The basic driver error: late detection

Over the past two or three decades we have been quite successful in reducing injuries of car occupants by the use of energy-absorbing techniques; but we have not been as successful in reducing the risks of having collisions. When drivers are asked why an accident occurred very often they claim that they saw the other road user too late to avoid collision. This paper discusses the basic road user error of failing to see another road user in time, why such errors happen, and how they can be reduced. A detection error is basic, because without detection no processing of information, no decision process including that road user, takes place. Among the many causes of detection error two of the more important are:

?a lapse of cognitive expectation, illustrated by the failure to scan for a particular class of road user, or to look in the appropriate direction;

?a difficulty with perceptual thresholds, illustrated by the failure to discern the relevant stimuli in lower levels of ambient illumination or in situations where vehicles approach in the peripheral visual field of road users.     

选举投票系统中主机软件的设计与实现

为了提高基于OCR技术的选举投票系统效率,提出了系统主机端软件的设计方法.该方法将主机端软件和票箱端软件统一起来考虑,充分考虑选举信息,利用选票中相关对象的位置数据设计选票,将选票格式数据发送到票箱,实现一系列选举投票系统功能,从而开发出一套主机端软件.该方法使得选票版面可以更复杂、基于选票格式数据而设计的票箱端识别软件定位速度更快,有效提高了系统效率,选举投票系统更加完善.     

The use of error detection and compensation techniques for testing the integer class cBigNumber

The use of automatic error detection and compensation techniques for testing the class cBigNumber written in C++ is discussed; this class is designed for performing operations on unbounded integer numbers. It implements the standard operations of C++, square rooting, binary exponentiation, and Miller-Rabin primality test. The class is tested in the automatic mode. The reliability of computations is ensured using the built-in error control and compensation tools.     

On the use of error propagation for statistical validation of computer vision software

Computer vision software is complex, involving many tens of thousands of lines of code. Coding mistakes are not uncommon. When the vision algorithms are run on controlled data which meet all the algorithm assumptions, the results are often statistically predictable. This renders it possible to statistically validate the computer vision software and its associated theoretical derivations. In this paper, we review the general theory for some relevant kinds of statistical testing and then illustrate this experimental methodology to validate our building parameter estimation software. This software estimates the 3D positions of buildings vertices based on the input data obtained from multi-image photogrammetric resection calculations and 3D geometric information relating some of the points, lines and planes of the buildings to each other.     

规范化嵌入式软件自测试方法

根据嵌入式软件特点,提出了集文档审查、含编码规则扫描的静态分析、代码审查、动态单元测试、部件测试和配置项测试的规范化自测试模型,并重点阐述了可定制编码规则的静态分析、基于宿主机的动态单元测试、部分增量的部件测试及基于故障注入的配置项测试等关键技术.该方法测试级别、测试类型全面,统计数据表明其有效减少了冗余测试工作时间,提高了测试效率,并在不同层次上消除了软件缺陷.     

Pager messages as self reminders: A case study of their use in memory impairment

Each year many people suffer an accident or illness which leaves them with a permanent memory impairment. As a result they will fail to remember to do things, making it difficult for them to maintain employment or independent leisure activities. Conventional memory aids offer little assistance because their use depends on relatively normal memory functioning. A system designed specifically for memory-impaired people has been developed recently in the USA, however. NeuroPage uses a combination of computing and telecommunications to store and transmit reminders to a pager worn by the user. The system is designed to place minimal demands on memory. This paper presents a case study evaluation of NeuroPage in use by a young man with a severe memory impairment. The pager messages led to a marked increase in the probability that he would carry out his intended tasks. Issues of usability and acceptability of the system to the user and his family are also reported. A number of possible developments to the system are considered, including the incorporation of artificial intelligence and context-sensitivity. Broader issues in the design of memory aids for people with and without memory impairments are also considered, as well as the potential role of memory-impaired people in the design of technology for their own use.     

The use of mathematics in software quality assurance

The use of mathematics for documenting, inspecting, and testing software is explained and illustrated. Three measures of software quality are described and discussed. Then three distinct complementary approaches to software quality assurance are presented. A case study, the testing and inspection of a safety-critical system, is discussed in detail.     

一种带姿态检测的水域水质检测自组织节点设计

无线自组网系统有着较强的鲁棒性,但对于一个节点来说,节点容易消亡。针对水域特定检测环境,利用ZigBee、GPRS以及姿态检测技术,设计了一种带姿态检测的水域水质检测的自组织节点,利用MEMS陀螺仪增强节点对自身的环境的感知能力,并通过差速电机驱动模块微调能力增强节点的稳定性,实现了带姿态检测的水域水质检测节点。     

Three way branching self consistency checking of hardware and software

A simple technique that improves a system's capability of error detection and correction, and enhances software debugging is described in this note. The technique relies on consistency checking of branching variables during branching decisions and the appropriate selection of codes for the permissible values of variables.     

Error detection and correction in switched linear controllers via periodic and non-concurrent checks

Control systems that utilize switched linear controllers have proven to be useful (and, in some cases, essential) for accomplishing certain control objectives in particular classes of plants. These controllers are often digital in nature and, as such, are subject to internal hardware malfunctions (faults). In this paper, we present a systematic methodology for constructing embeddings to protect switched linear controllers against hardware faults that corrupt their internal state. Our methodology is based on replacing the original controller with a redundant (higher dimensional) controller that preserves the functionality of the original controller while enabling error detection and correction. More importantly, this methodology allows an external mechanism to detect and identify transient state-transition faults through non-concurrent (e.g. periodic) parity checks. The resulting error detection and correction procedures can then be performed periodically, thereby relaxing the reliability requirements and overhead associated with the checking mechanism.     

The links between human error diversity and software diversity: Implications for fault diversity seeking

Software diversity is known to improve fault tolerance in N-version software systems by independent development. As the leading cause of software faults, human error is considered an important factor in diversity seeking. However, there is little scientific research focusing on how to seek software fault diversity based on human error mechanisms. A literature review was conducted to extract factors that may differentiate people with respect to human error-proneness. In addition, we constructed a conceptual model of the links between human error diversity and software diversity. An experiment was designed to validate the hypotheses, in the form of a programming contest, accompanied by a survey of cognitive styles and personality traits. One hundred ninety-two programs were submitted for the identical problem, and 70 surveys were collected. Code inspection revealed 23 faults, of which 10 were coincident faults. The results show that personality traits seems not effective predictors for fault diversity as a whole model, whereas cognitive styles and program measurements moderately account for the variation of fault density. The results also show causal relations between performance levels and coincident faults: coincident faults are unlikely to occur at skill-based performance level; the coincident faults introduced in rule-based performances show a high probability of occurrence, and the coincident faults introduced in knowledge-based performances are shaped by the content and formats of the task itself. Based on these results, we have proposed a model to seek software diversity and prevent coincident faults.     

The association between students' use of an electronic voting system and their learning outcomes

Abstract This paper reports on the use of an electronic voting system (EVS) in a first-year computing science subject. Previous investigations suggest that students' use of an EVS would be positively associated with their learning outcomes. However, no research has established this relationship empirically. This study sought to establish whether there was an association between students' use of an EVS over one semester and their performance in the subject's assessment tasks. The results from two stages of analysis are broadly consistent in showing a positive association between EVS usage and learning outcomes for students who are, relative to their class, more correct in their EVS responses. Potential explanations for this finding are discussed as well as modifications and future directions of this program of research.