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31.
Automating software testing activities can increase the quality and drastically decrease the cost of software development.
Toward this direction, various automated test data generation tools have been developed. The majority of existing tools aim
at structural testing, while a quite limited number aim at a higher level of testing thoroughness such as mutation. In this
paper, an attempt toward automating the generation of mutation-based test cases by utilizing existing automated tools is proposed.
This is achieved by reducing the killing mutants’ problem into a covering branches one. To this extent, this paper is motivated
by the use of state of the art techniques and tools suitable for covering program branches when performing mutation. Tools
and techniques such as symbolic execution, concolic execution, and evolutionary testing can be easily adopted toward automating
the test input generation activity for the weak mutation testing criterion by simply utilizing a special form of the mutant
schemata technique. The propositions made in this paper integrate three automated tools in order to illustrate and examine
the method’s feasibility and effectiveness. The obtained results, based on a set of Java program units, indicate the applicability
and effectiveness of the suggested technique. The results advocate that the proposed approach is able to guide existing automating
tools in producing test cases according to the weak mutation testing criterion. Additionally, experimental results with the
proposed mutation testing regime show that weak mutation is able to speedup the mutant execution time by at least 4.79 times
when compared with strong mutation. 相似文献
32.
Steven Hancock Mathias Disney Jan-Peter Muller Philip Lewis Mike Foster 《Remote sensing of environment》2011,115(12):3286-3297
Lidars have the unique ability to make direct, physical measurements of forest height and vertical structure in much denser canopies than is possible with passive optical or short wavelength radars. However the literature reports a consistent underestimate of tree height when using physically based methods, necessitating empirical corrections. This bias is a result of overestimating the range to the canopy top due to background noise and failing to correctly identify the ground.This paper introduces a method, referred to as “noise tracking”, to avoid biases when determining the range to the canopy top. Simulated waveforms, created with Monte-Carlo ray tracing over geometrically explicit forest models, are used to test noise tracking against simple thresholding over a range of forest and system characteristics. It was found that noise tracking almost completely removed the bias in all situations except for very high noise levels and very low (< 10%) canopy covers. In all cases noise tracking gave lower errors than simple thresholding and had a lower sensitivity to the initial noise threshold.Finite laser pulses spread out the measured signal, potentially overriding the benefit of noise tracking. In the past laser pulse length has been corrected by adding half that length to the signal start range. This investigation suggests that this is not always appropriate for simple thresholding and that the results for noise tracking were more directly related to pulse length than for simple thresholding. That this effect has not been commented on before may be due to the possible confounding impacts of instrument and survey characteristics inherent in field data. This method should help improve the accuracy of waveform lidar measurements of forests, whether using airborne or spaceborne instruments. 相似文献
33.
X-machines were proposed by Holcombe as a possible specification language and since then a number of further investigations
have demonstrated that the model is intuitive and easy to use as well as general enough to cater for a wide range of applications.
In particular (generalised) stream X-machines have been found to be extremely useful as a specification method and most of
the theory developed so far has concentrated on this particular class of X-machines. Furthermore, a method for testing systems
specified by stream X-machines exists and is proved to detect all faults of the implementation provided that the system meets
certain initial requirements. However, this method can only be used to generate test sequences from deterministic X-machine
specifications. In this paper we present the theoretical basis for a method for generating test sets from non-deterministic
generalised stream X-machines.
Received November 1999 / Accepted in revised form September 2000 相似文献
34.
Hussein Abdel-Jaber Mike Woodward Fadi Thabtah Amer Abu-Ali 《Journal of Network and Computer Applications》2008,31(4):750-770
Due to the rapid development in computer networks, congestion becomes a critical issue. Congestion usually occurs when the connection demands on network resources, i.e. buffer spaces, exceed the available ones. We propose in this paper a new discrete-time queueing network analytical model based on dynamic random early drop (DRED) algorithm to control the congestion in early stages. We apply our analytical model on two-queue nodes queueing network. Furthermore, we compare between the proposed analytical model and three known active queue management (AQM) algorithms, including DRED, random early detection (RED) and adaptive RED, in order to figure out which of them offers better quality of service (QoS). We also experimentally compare the queue nodes of the proposed analytical model and the three AQM methods in terms of different performance measures, including, average queue length, average queueing delay, throughput, packet loss probability, etc., aiming to determine the queue node that offers better performance. 相似文献
35.
Visualization of heterogeneous data 总被引:1,自引:0,他引:1
36.
My early research was inspired by the mathematical semantics of Scott and Strachey. Two such topics, recounted in this paper, were the fixed-point analysis of pointer loops and the expressibility of a style of functional programming introduced by Barron and Strachey. 相似文献
37.
Mike Livesey 《International journal of parallel programming》1991,20(1):55-74
We consider two algorithms for the barrier synchronization ofN processes: the Dissemination algorithm(2) and Brooks algorithm.(1,2) Both algorithms comprise a number of binary communications amongst the processes, organized into a sequence of stages. It is shown that Brooks' algorithm(1) requires between LogN(log2
N) and 2 LogN stages, the lower bound being guaranteed only in the case thatN is a power of 2 (cubic) and the upper bound seemingly needed for most otherN. On the other hand, it is shown(2) that the Dissemination algorithm requires only LogN stages regardless ofN, making it apparently superior to the Brooks algorithm. We introduce a network model of local barrier algorithms. Using it we obtain a rigorous correctness proof for local barrier algorithms, and show that the number of stages in the Brooks algorithm is bounded above by LogN+1. The Brooks algorithms is therefore essentially equivalent in time complexity to the Dissemination algorithm. We then address the question of which values ofN admit exactly LogN Brooks stages. We find a sufficient condition, and conjecture that it is also necessary. 相似文献
38.
Christian Bur Peter Reimann Mike Andersson Anita Lloyd Spetz Andreas Schütze 《Microsystem Technologies》2012,18(7-8):1015-1025
A silicon carbide based enhancement type metal insulator field effect transistor with porous gate metallization has been investigated as a total NO x sensor operated in a temperature cycling mode. This operating mode is quite new for gas sensors based on the field effect but promising results have been reported earlier. Based on static investigations we have developed a suitable T-cycle optimized for NO x detection and quantification in a mixture of typical exhaust gases (CO, C2H4, and NH3). Significant features describing the shape of the sensor response have been extracted and evaluated with multivariate statistics (e.g. linear discriminant analysis) allowing quantification of NO x . Additional cleaning-cycles every 30?min improve the stability of the sensor further. With this kind of advanced signal processing the influence of sensor drift and cross sensitivity to ambient gases can be reduced effectively. Measurements have proven that different concentrations of NO x can be detected even in a changing mixture of other typical exhaust gases under dry and humid conditions. In addition to that, unknown concentrations of NO x can be detected based on a small set of training data. It can be concluded that the performance of GasFETs for NO x determination can be enhanced considerably with temperature cycling and appropriate signal processing. 相似文献
39.
Halari Rozmin; Hines Melissa; Kumari Veena; Mehrotra Ravi; Wheeler Mike; Ng Virginia; Sharma Tonmoy 《Canadian Metallurgical Quarterly》2005,119(1):104
Sexually dimorphic cognitive performance in men (n=42) and women (n=42) was related to testosterone, estradiol, progesterone, luteinizing hormone, follicle-stimulating hormone, and sex hormone binding globulin, measured in 10-ml blood samples collected between 0900 and 1030 and, among women, during the follicular phase of the menstrual cycle. Significant sex differences favored men on spatial tasks (Mental Rotation and Judgment of Line Orientation) and on an inhibition task and favored women on a verbal task (category fluency). However, there were no significant relationships between any of the hormones and cognitive performance, suggesting that there are few, if any, consistent, substantial relationships between endogenous, nonfluctuating levels of gonadal hormones or gonadotropins and these cognitive abilities in men or women. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
40.
Lutz Wolfgang; Leach Chris; Barkham Michael; Lucock Mike; Stiles William B.; Evans Chris; Noble Rachael; Iveson Steve 《Canadian Metallurgical Quarterly》2005,73(5):904
This study extended client-focused research by using the nearest neighbor (NN) approach, a client-specific sampling and prediction strategy derived from research on alpine avalanches. Psychotherapy clients (N = 203) seen in routine practice settings in the United Kingdom completed a battery of intake measures and then completed symptom intensity ratings before each session. Forecasts of each client's rate of change and session-by-session variability were computed on the basis of that client's NNs (n = 10-50 in different comparisons). Alternative forecasts used linear or log-linear slopes and were compared with an alternative prediction strategy. Results showed that the NN approach was superior to the alternative model in predicting rate of change, though the advantage was less clear for predicting variability. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献