Automatic string test data generation for detecting domain errors

Domain testing is designed to detect domain errors that result from a small boundary shift in a path domain. Although many researchers have studied domain testing, automatic domain test data generation for string predicates has seldom been explored. This paper presents a novel approach for the automatic generation of ON–OFF test points for string predicate borders, and describes a corresponding test data generator. Our empirical work is conducted on a set of programs with string predicates, where extensive trials have been done for each string predicate, and the results are analysed using the SPSS tool. Conclusions are drawn that: (i) the approach is promising and effective; (ii) there is a strong linear relationship between the performance of the test generator and the length of target string in the predicate tested; and (iii) initial inputs, no shorter than the target string and with characters generated randomly, may enhance the performance in the test data generation for string predicates. Copyright © 2009 John Wiley & Sons, Ltd.     

非法计算故障的一种静态测试方法

非法计算是C／C＋＋程序中的常见故障,该类故障极易导致系统崩溃。针对C／C＋＋语言中常见非法计算故障进行了分析,并从面向具体故障的测试思想出发,建立了C／C＋＋语言中非法计算的故障模型,结合静态测试的特点,给出了一种静态查找此类故障的方法。此方法已实现,并已应用于面向故障的软件测试系统中。     

一种内存错误的动态检测方法*

提出了一种内存错误的动态检测方法,通过统一的内存错误检测模型和接口,使内存错误检测处理过程规范化,便于扩展。实验表明,该方法可以方便地进行扩展,以增加内存错误的检测能力。     

An efficient method for detecting concurrency errors in object-oriented programs

Multicore and multi-threaded processors have become the norm for modern processors.Accordingly,concurrent programs have become more and more prevalent despite being difficult to write and understand.Although errors are highly likely to appear in concurrent code,conventional error detection methods such as model checking,theorem proving,and code analysis do not scale smoothly to concurrent programs.Testing is an indispensable technique for detecting concurrency errors,but it involves a great deal of manual work and is inefficient.This paper presents an automatic method for detecting concurrency errors in classes in object-oriented languages.The method uses a heuristic algorithm to automatically generate test cases that can effectively trigger errors.Then,each test case is executed automatically and a fast method is adopted to identify the actual concurrency error from anomalous run results.We have implemented a prototype of the method and applied it to some typical Java classes.Evaluation shows that our method is more effective and faster than previous work.     

Methods for detecting errors in numerically controlled machining ofsculptured surfaces

The numerically controlled (NC) machining of sculptured surfaces is an error-prone process often requiring several attempts before an error-free NC program is produced. A technique designed to move the NC proof process into software is described. The system outputs a color-coded graphics display of the machined surface that shows out-of-tolerance areas. To gain efficiency, surface curvature and cutting-tool size are used as inputs to a surface discretization algorithm, which guarantees that a user-defined level of simulation accuracy is achieved. The simulation time grows linearly in both desired accuracy and in the number of tool movements. In typical test cases, NC programs for complex automotive body panels were simulated and verified in CPU times that ranged between 5 and 30 minutes     

String techniques for detecting duplicates in document databases

Detecting duplicates in document image databases is a problem of growing importance. The task is made difficult by the various degradations suffered by printed documents, and by conflicting notions of what it means to be a "duplicate". To address these issues, this paper introduces a framework for clarifying and formalizing the duplicate detection problem. Four distinct models are presented, each with a corresponding algorithm for its solution adapted from the realm of approximate string matching. The robustness of these techniques is demonstrated through a set of experiments using data derived from real-world noise sources. Also described are several heuristics that have the potential to speed up the computation by several orders of magnitude.     

A frequency domain test for detecting nonstationary time series

We propose a frequency domain generalized likelihood ratio test for testing nonstationarity in time series. The test is constructed in the frequency domain by comparing the goodness of fit in the log-periodogram regression under the varying coefficient fractionally exponential models. Under such a locally stationary specification, the proposed test is capable of detecting dynamic changes of short-range and long-range dependences in a regression framework. The asymptotic distribution of the proposed test statistic is known under the null stationarity hypothesis, and its finite sample distribution can be approximated by bootstrap. Numerical results show that the proposed test has good power against a wide range of locally stationary alternatives.     

A survey of systems for detecting serial run‐time errors

This paper evaluates the ability of a variety of commercial and non‐commercial software products to detect serial run‐time errors in C and C++ programs, to issue meaningful messages, and to give the line in the source code where the error occurred. The commercial products Insure++ and Purify performed the best of all the software products we evaluated. Error messages were usually better and clearer when using Insure++ than when using Purify. Our evaluation shows that the overall capability of detecting run‐time errors of non‐commercial products is significantly lower than the quality of both Purify and Insure++. Of all non‐commercial products evaluated, Mpatrol provided the best overall capability to detect run‐time errors in C and C++ programs. Copyright © 2006 John Wiley & Sons, Ltd.     

Hierarchical matrix techniques for a domain decomposition algorithm

Summary In this paper, we investigate the effectiveness of hierarchical matrix techniques when used as the linear solver in a certain domain decomposition algorithm. In particular, we provide a direct performance comparison between an algebraic multigrid solver and a hierarchical matrix solver which is based on nested dissection clustering within the software package PLTMG.      

Spectral domain decomposition techniques for viscous incompressible flows

Spectral domain decomposition methods are described for solving the equations governing the flow of viscous incompressible fluids in rectangularly decomposable domains. The domain of interest is divided into a number of rectangular subdomains on each of which a spectral approximation of the flow variables is sought. For Newtonian flows a stream function formulation is used whereas for nonNewtonian flows the components of the extra-stress tensor are also used. Efficient direct methods for the solution of the algebraic systems are discussed. Numerical results are presented for laminar flow through a channel contraction and for the stick-slip problem.     

Parallel pseudospectral domain decomposition techniques

The influence of interface boundary conditions on the ability to parallelize pseudospectral multidomain algorithms is investigated. Using the properties of spectral expansions, a novel parallel two-domain procedure is generalized to an arbitrary number of domains each of which can be solved on a separate processor. This interface boundary condition considerably simplifies influence matrix techniques.     

Optimization techniques for parallel molecular dynamics using domain decomposition

In this paper we describe the implementation of a new parallelized Molecular Dynamics code for many-particle problems with short-ranged interactions. While the basic algorithms have their foundation in the fairly standard methods of domain decomposition, linked-cell pair search and Verlet pair list, we have developed some refined techniques for optimizing them. The rewards of these optimizations are a up to 45% overall improvement in the scalar performance and very good scaling behavior in the number of processors even down to a few hundred particles per processor on a CRAY T3E.The best speedup can be obtained for systems with pair forces only since then the data structures can be organized in a very simple manner. To deal with more complex situations as well, we have developed a partial replicated data scheme which is suitable to simulate many molecules consisting of many simple particles (e.g. polymer chains) for many types of short-range interactions.     

基于神经网络的多过失误差侦破方法的研究

基于神经网络的过失误差侦破方法具有简单、计算量小和适于在线应用的优点,并且相对于传统方法具有处理非线性问题能力较强的特点。但是在侦破多过失误差时,现有的直接侦破法和序列侦破法的侦破率较低。针对这一情况,本文提出了将神经网络和测量数据检验法相结合的侦破多过失误差的新方法,该方法首先利用神经网络较强的鲁棒性和容错能力对数据进行处理,然后再进行过失误差侦破。实例研究表明,这种方法能够有效地提高多过失误差共存时的侦破能力。     

Controller performance assessment by frequency domain techniques

A system identification based method for assessing the performance of closed-loop systems is proposed, utilizing measures which coincide naturally with classical and modern frequency domain design specifications. Standard robust control system design methodologies seek to maximize closed-loop performance, subject to strict robustness requirements and include specifications for bandwidth and peak magnitude of the sensitivity and complementary sensitivity functions. Estimates of these transfer functions can be obtained by exciting the reference input with a zero mean, pseudo random binary sequence, observing the process output and error response, and developing a closed-loop model. Performance assessment is based on the comparison between the observed frequency response characteristics and the design specifications. Selection of appropriate model structures, experiment design, and model validation which will ensure reasonable estimates of the closed-loop transfer functions are considered in this paper. A case study involving the performance assessment of a packed bed tubular reactor control system is presented.     

基于多协议标签交换的IP组播技术

多协议标签交换（MPLS）和组播技术的结合可以获得MPLS的高速率、QoS、流量工程、VPN和组播的带宽节省两方面的益处,MPLS和组播是两种互补的技术,这对于带QoS参数的实时的多媒体应用是必须和紧迫的。文章综述了MPLS组播技术在实现机制、组播树的构建等方面的基本原理和研究进展,分析了存在的问题和发展方向。     

Efficient techniques and tools for intra‐domain traffic engineering

Intra‐domain routing protocols are based on Shortest Path First (SPF) routing, where shortest paths are calculated between each pair of nodes (routers) using pre‐assigned link weights, also referred to as link metric. These link weights can be modified by network administrators in accordance with the routing policies of the network operator. The operator's objective is usually to minimize traffic congestion or minimize total routing costs subject to the traffic demands and the protocol constraints. However, determining a link weight combination that meets a network operator's objectives is a difficult task. In this paper, we study the link weight optimization problem in intra‐domain networks. This problem is proved to be NP‐hard with hard protocol constraints, e.g., a flow is evenly distributed along the shortest paths between its origin and destination nodes. We present two fast heuristic approaches to generate efficient link metrics for intra‐domain routing. Some promising experimental results are reported.     

DCT域彩色图像增强技术研究

为了减少图像的存储量,提高图像的传输效率,大量的图像被压缩,因此基于压缩域图像的增强技术越来越引起人们的重视。介绍了DCT域彩色图像增强技术的各种算法,其问题是会在图像块的交界处产生块状效应。着重分析了CES算法产生块状效应的原因,提出了两种改进方法来抑制块状效应。仿真结果表明,改进的算法不仅能够很好地抑制块状效应,而且降低了计算的复杂度。     

A survey on compressed domain video analysis techniques

Image and video analysis requires rich features that can characterize various aspects of visual information. These rich features are typically extracted from the pixel values of the images and videos, which require huge amount of computation and seldom useful for real-time analysis. On the contrary, the compressed domain analysis offers relevant information pertaining to the visual content in the form of transform coefficients, motion vectors, quantization steps, coded block patterns with minimal computational burden. The quantum of work done in compressed domain is relatively much less compared to pixel domain. This paper aims to survey various video analysis efforts published during the last decade across the spectrum of video compression standards. In this survey, we have included only the analysis part, excluding the processing aspect of compressed domain. This analysis spans through various computer vision applications such as moving object segmentation, human action recognition, indexing, retrieval, face detection, video classification and object tracking in compressed videos.     

Analyzing CT images for detecting lung cancer by applying the computational intelligence-based optimization techniques

Lung cancer is the most critical disease because it affects both men and women. Most of the time, lung cancer leads to death due to less health care and medical attention. In addition, lung cancer is difficult to identify in earlier stages due to the low-level symptoms and risk factors. To overcome the complexity, effective techniques must predict lung cancer earlier. To attain the problem statement, an lung cancer identification system is developed with the help of a meta-heuristic algorithm. The CT imageries obtained from the CIA database are analyzed step by step. The gathered image noise is removed by applying the mean filter, and the affected regions are segmented with the help of the Butterfly Optimization Algorithm-based K-Means Clustering (BOAKMC) algorithm. Afterward, various statistical features are derived, and the Supervised Jaya Optimized Rough Set related Feature Selection (SJORSFS) process is used to select the lung features. Finally, the lung cancer is identified using Autoencoder based Recurrent Neural Network (ARNN) classification algorithm, successfully recognizing the lung cancer features. Then the system's efficiency is evaluated using a MATLAB setup; here, 3000 are treated as training images and 2043 for testing images. The effective training enhances overall lung cancer prediction accuracy by up to 99.15%.