Greedy Heuristic Algorithms to Generate Variable Strength Combinatorial Test Suite

The Target Speed Monitor (TSM), which performs the safety critical function of the Chinese Train Control System Level 3 (CTCS-3), is characterized by large parameter input field and fault modes triggered by complicated combinations of parameters. Although combinatorial testing has been successfully applying in testing TSM, redundant test cases are generated because of covering the parameter combinations without interaction, which leads to the problem of high test execution costs. In this paper, an automatic reduction methodology based on decision tree equivalence and test suite output labels is presented. With previous combinatorial test suite generation experiment results of CTCS-3 TSM function, after data preprocessing, some data set have been constructed by test suites and corresponding output labels and they can be used to infer decision trees. After that, the reduction algorithm was used to reduce the data set to realize the test suite reduction. Related experimental results show that this method can achieve a reduction rate of up to 90%, and at the same time, the low-level combination coverage and the fault detection capability of reduced test suites are almost the same as that before the reduction.

Combinatorial testing (CT) is an important black-box testing method. In CT, the behavior of the system under test (SUT) is affected by several parameters/components. Then CT generates a combinatorial test suite. After the user executes a test suite and starts debugging, some test cases fail and some pass. From the perspective of a black box, the failures are caused by interaction of several parameters. It will be helpful if we can identify a small set of interacting parameters that caused the failures. This paper proposes a new automatic approach to identifying faulty interactions. It uses (pseudo-Boolean) constraint solving and optimization techniques to analyze the execution results of the combinatorial test suite. Experimental results show that the method is quite efficient and it can find faulty combinatorial interactions quickly. They also shed some light on the relation between the size of test suite and the ability of fault localization.

Cutting edge frameworks are turning out to be exceedingly configurable to fulfil the shifting requirements of clients and clients. Programming invention offerings are consequently turning into a typical pattern in programming improvement to decrease cost by empowering deliberate, expansive scale reuse. A few shortcomings may be uncovered just if a specific mix of components is chosen in the conveyed items. Yet, testing all mixes is typically not possible by and by, because of their to a great degree extensive numeral. Combinatorial testing is a method to produce littler test suites for which all mixes of t elements are ensured to be tried. In this research work, we display a few hypotheses depicting the likelihood of irregular testing to recognise connection blames and contrast the outcomes with combinatorial testing. For instance, an irregular testing turns out to be considerably more viable as the quantity of elements increments and focalises toward equivalent adequacy with combinatorial testing. Be that as it may, when imperatives are available among elements, then irregular testing can passage subjectively more awful than combinatorial testing. Subsequently, with a specific end goal to have a reasonable effect, future research ought to concentrate on combinatorial testing.

Usage of combinatorial testing is wide spreading as an effective technique to reveal unintended feature interaction inside a given system. To this aim, test cases are constructed by combining tuples of assignments of the different input parameters, based on some effective combinatorial strategy. The most commonly used strategy is two-way (pairwise) coverage, requiring all combinations of valid assignments for all possible pairs of input parameters to be covered by at least one test case. In this paper a new heuristic strategy developed for the construction of pairwise covering test suites is presented, featuring a new approach to support expressive constraining over the input domain. Moreover, it allows the inclusion or exclusion of ad-hoc combinations of parameter bindings to let the user customize the test suite outcome. Our approach is tightly integrated with formal logic, since it uses test predicates to formalize combinatorial testing as a logic problem, and applies an external model checker tool to solve it. The proposed approach is supported by a prototype tool implementation, and early results of experimental assessment are also presented.

Search based algorithms for test sequence generation in functional testing

Combinatorial testing has been widely utilized in testing softwares, e.g. Siemens Suite. This paper aims to investigate the reason why combinatorial testing works in Siemens Suite. Experiments are designed to get the MFS(minimal failure-causing schema) for Siemens Suite, which has been used as a benchmark to evaluate the effectiveness of many testing techniques. The lowerbound of fault-detecting probability of T-way combinatorial test suite for each program is calculated by analyzing the strengths and the number of MFS for each faulty version. Computational results could explain the effectiveness of combinatorial testing in Siemens Suite.

Testing is considered as indispensable part in the development process life cycle of any software. Testing is performed to improve the performance, quality and reliability of the software. Designing of relevant test cases plays a major role in deciding the quality of testing. Hence test case designing activity is crucial for the success of testing. Combinatorial strategies are one of those most extensively used methods for generating test cases. These strategies detect failures which are caused by interactions of parameters in the Software under Test(SUT) and by using some sampling mechanisms a covering array test suite is generated. With increase in the number of parameter coverage, the t-way test size sets also increase exponentially which would result in explosion problem. This paper presents a technique to generate minimal test suites in Combinatorial testing(CT). Optimization technique used is Greedy computation strategy for mutation and selection of test cases, used in selecting the locally worst test case for elimination. That is the test case that does not cover maximum number of uncovered interactions from a pool of candidate test cases. Additionally, Branch and bound technique is used for cross over. It is used to branch for the possibilities of number of test cases as cross over inputs. If a particular test case is not possible the bounding happens, else branched for further selection of test cases as input. Experimental results show that Recast Ipog-D generates better/comparable results as compared to the existing algorithm. Additionally, Recast IPOG-D has also contributed to enhance many known Variable Strength Covering array(VSCA) that exist in literature.

1. An ionic equivalent circuit model is developed for the purpose of quantifying the strengths of electrical coupling existing between certain receptor cells in the compound eye ofCataglyphis bicolor which show wavelength dependence in the slopes of their ‘V logI’ relations and orientations of maximum PS (Mote and Wehner, 1980). It combines the pure electrical equivalent of the plasma membrane, as proposed by Finkelstein and Mauro (1963), and a closed series circuit such that Kirchhoff's laws are applicable. 2. The model is applied to hypothetical pairs of cells with different sensitivities and different strengths of interaction. It predicts that cells are most strongly coupled when at rest and most weakly coupled when most active. When one is active and the second is not then “apparent rectification” can occur since the coupling strength is not symmetrical. This means that both “resting” and “dynamic” coupling coefficients must be considered. Transition between these modes causes irregularities in the ‘V logI’ relation of a weakly excited cell which is coupled to a strongly excited cell. 3. The model is then applied to data obtained from photoreceptors in the compound eye ofCataglyphis. It adequately simulates the wavelength dependence of both the ‘V logI’ relation (Fig. 6) and the orientation of maximum PS (Fig. 7) measured in these cells. In its simplest form the model permits an estimate of the coupling coefficients which are greater than 0.6 for strongly coupled cells and less than 0.4 for weakly coupled cells. 4. A hypothetical treatment of pairs of coupled cells under conditions approaching the natural situation in the animal's environment suggests that super-numerary analyzers of polarized light in the u.v. could arise through receptor coupling in certain ommatidial types found in the eye ofCataglyphis.

The experimental and theoretical concept concerning the magnetic properties of 2-dimensional arrangements of small particles with different strengths of interaction is discussed. Taking into account recent results on isolated small single-domain particles, a representation for a whole scale of possible structures from these to closely packed ferromagnetic films is given, using a molecular field formalism. The interaction considered may be much weaker than the full ferromagnetic exchange coupling. The resultant collective magnetization <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">M</tex> of such aggregates of small particles may be considerably lower than their spontaneous magnetization M <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">s</inf> . A transition temperature T <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">A</inf> towards occurrence of superparamag-netism may appear that is well below the Curie temperature Θ of the individual particles. These effects seem to be consistent with experimental data obtained by a number of authors using various methods of measurement. Observations of time effects at magnetization reversals in very thin films also support the aforementioned model.

Interaction of poly( l-lysine) and copolymers of lysine with immobilized DNA

This paper firstly takes fully account of the features of Intel multi-core architecture: shared cache architecture and bus interconnection architecture, and then researches on thread scheduling problem in automatic parallelization, finally proposes a greedy heuristic algorithm for thread scheduling. The greedy heuristic algorithm firstly establishes a TIG (thread interaction graph) based on data dependence and communication overhead between each thread. On this basis the algorithm carries out two rounds of operation for TIG, in which the threads are assigned to processors in the first round and the threads are assigned to groups of shared cache cores within a processor in the second round respectively. The experiment results show that greedy heuristic algorithm can find near-optimum solutions in reasonable time and behaves better than random algorithm which widely applied in the current OS and compiler when the number of threads increases, since it can find solutions in much less than random algorithm.

OpenDaylight is an open-source Software-Defined Network controller that has made programmable networks possible. It has got together both industry and the OpenDaylight community in delivering programmable and interoperable networks to service providers, enterprises, universities and organizations. It is a continuously evolving project with many different releases, where every new release requires extensive testing, to ensure quality software. Effective regression testing is required to ensure the existing features are not affected. Also a project of this scale will have many test cases, hence an effective selection method is required to ensure a reduced set of test cases for regression testing. The current paper proposes to adopt Combinatorial testing for generating test suite which has reduced number of test cases and better test coverage. Upon successful execution of the combinatorial test suite, the faults identified needs to be localized to help debug them effectively and in less time. This can be achieved through an efficient fault localization technique.KeywordsCombinatorial testingFault localizationOpenDaylightSoftware Defined Networks

Testing is an important activity to detect faults before software deployment. We focus on black-box combinatorial testing, where fault detection is one of the main objectives. In this paper, we argue that input model abstraction notably impacts the fault detection capability of a combinatorial test suite. First, we present experiments from previous work that support this argument. We then perform new experiments on a more diverse set of programs. These experiments use mutation testing to estimate fault detection capability, but we also include structural coverage measures in the new experiments. Finally, we elaborate on two possible improvements to obtain an optimal input abstraction strategy for not just continuous but all input domains. Both experiments suggest that input abstraction affects the fault detection capability. We claim that the improvements will produce a better input abstraction with which we can achieve better fault detection capability without increasing the test suite size.

In this paper we describe how the test design can be done by using the Combinatorial Testing approach for internet of things operating systems. Contiki operating system is taken as a case study but we discuss what can be the approach for RIOT and Tiny OS operating systems. We discuss how the combinatorial coverage measurement can be gathered in addition to the traditional metrics code coverage. The test design generated by using Advanced Combinatorial Testing for Software is analyzed for Contiki operating system. We elaborate the code coverage gathering technique for Contiki simulator which happens to be in Java. We explain the usage of Combinatorial Coverage Measurement tool. Although we have explained the test design methodology for internet of things operating systems, the approach explained can be followed for other open source software.

With the rapid expansion of optical networks, the number of network cutover tasks has increased significantly. Manual scheduling of cutover tasks typically takes several days, leading to inefficient resource utilization. To address this issue, we propose systematic intelligent task scheduling methods of cutover tasks in optical networks for what we believe to be the first time. The rules and attributes of cutover tasks are abstracted into graphical representations or mathematical expressions. Then, the scheduling process employs layered topological scheduling methods based on greedy heuristic algorithm, maximal cliques and particle swarm optimization. The scheduling results are verified in the real-time resource library by the conflict verification method. When conflicts arise, the scheduling process is iterated to find a conflict-free schedule, and prior rules are updated. The field trial results of national optical networks demonstrated that our proposed intelligent schedule method realizes second-level scheduling without conflicts. Compared with the layered topological scheduling method based on greedy algorithm, the scheduling methods based on maximal clique and particle swarm optimization can reduce the conflict rate by 20% and 30%, enhance the ability of conflict adjustment by 12% and 43%, and improve scheduling efficiency by 12% and 9%, respectively. The proposed intelligent scheduling methods can also autonomously generate multi-period conflict-free schedules.