1,376 research outputs found

    Distinguishing sequences for partially specified FSMs

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    Distinguishing Sequences (DSs) are used inmany Finite State Machine (FSM) based test techniques. Although Partially Specified FSMs (PSFSMs) generalise FSMs, the computational complexity of constructing Adaptive and Preset DSs (ADSs/PDSs) for PSFSMs has not been addressed. This paper shows that it is possible to check the existence of an ADS in polynomial time but the corresponding problem for PDSs is PSPACE-complete. We also report on the results of experiments with benchmarks and over 8 * 106 PSFSMs. © 2014 Springer International Publishing

    Overcoming controllability problems in distributed testing from an input output transition system

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    This is the Pre-print version of the Article. The official published version can be accessed from the link below - Copyright @ 2012 Springer VerlagThis paper concerns the testing of a system with physically distributed interfaces, called ports, at which it interacts with its environment. We place a tester at each port and the tester at port p observes events at p only. This can lead to controllability problems, where the observations made by the tester at a port p are not sufficient for it to be able to know when to send an input. It is known that there are test objectives, such as executing a particular transition, that cannot be achieved if we restrict attention to test cases that have no controllability problems. This has led to interest in schemes where the testers at the individual ports send coordination messages to one another through an external communications network in order to overcome controllability problems. However, such approaches have largely been studied in the context of testing from a deterministic finite state machine. This paper investigates the use of coordination messages to overcome controllability problems when testing from an input output transition system and gives an algorithm for introducing sufficient messages. It also proves that the problem of minimising the number of coordination messages used is NP-hard

    Hacia un nuevo socialismo

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    Nos encontramos ante el testamento político de uno de los líderes norteamericanos del socialismo democrático. M. Harrington murió en agosto de 1989 poco después de haber aparecido este libro. Intuyendo su próximo final hace Un balance histórico del movimiento socialista y apunta hacia su potencial futuro. Es el testamento de un militante y un intelectual que reflexiona sobre lo que es el socialismo desde Estados Unidos, la sociedad occidental del capitalismo más desarrollada y más refractaria a la tradición socialista.Peer reviewe

    Lifestyle and health determinants of cardiovascular disease among Greek older adults living in Eastern Aegean Islands: An adventure within the MEDIS study.

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    OBJECTIVE: The aim of the present study was to evaluate lifestyle and health determinants of cardiovascular disease (CVD) risk among Greek elderly residents living in Eastern Aegean islands, in both Greece and Turkey. METHODS: Under the context of the MEDIS study, 724 older adults (aged 65 to 100 years) from 8 Eastern Aegean Sea Greek islands (n=100 living in Samothrace, 142 in Lesvos, 150 in Limnos, 76 in Ikaria, 52 in Kassos, 149 in Rhodes and Karpathos) and from Turkey (n=55older adults of Greek origin living on Gökçeada Island) were voluntarily recruited. Overall cardiometabolic risk was measured as the sum (range 0-4) of four common CVD risk factors (hypertension, diabetes, dyslipidemia and obesity). RESULTS: Greek islanders had higher CVD scores compared to Greeks of Gökçeada (1.9±1.1 vs 1.4±1.0 risk factors / participant, p<0.001). Further analysis revealed that the diet of Greek islanders was similar to the traditional Mediterranean diet; however, these individuals demonstrated 2-times higher odds (95% CI, 1.04-3.87) for having hypertension, 1.53-times higher odds (95% CI, 0.66-3.54) for having diabetes, 3.29-times higher odds (95% CI, 1.58-6.81) for having hypercholesterolemia; whereas they had 0.78-times lower odds (95% CI, 0.40-1.52) for being obese, compared to elderly Greek adults living on Gökçeada. CONCLUSIONS: Overall, CVD risk seems to be low among Eastern Aegean Islanders; certain differences in CVD risk factors exist between Greek islanders and their counterparts living in Gökçeada, and those differences may be attributed to various environmental, cultural and lifestyle factors

    Generating a checking sequence with a minimum number of reset transitions

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    Given a finite state machine M, a checking sequence is an input sequence that is guaranteed to lead to a failure if the implementation under test is faulty and has no more states than M. There has been much interest in the automated generation of a short checking sequence from a finite state machine. However, such sequences can contain reset transitions whose use can adversely affect both the cost of applying the checking sequence and the effectiveness of the checking sequence. Thus, we sometimes want a checking sequence with a minimum number of reset transitions rather than a shortest checking sequence. This paper describes a new algorithm for generating a checking sequence, based on a distinguishing sequence, that minimises the number of reset transitions used.This work was supported in part by Leverhulme Trust grant number F/00275/D, Testing State Based Systems, Natural Sciences and Engineering Research Council (NSERC) of Canada grant number RGPIN 976, and Engineering and Physical Sciences Research Council grant number GR/R43150, Formal Methods and Testing (FORTEST)

    JWalk: a tool for lazy, systematic testing of java classes by design introspection and user interaction

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    Popular software testing tools, such as JUnit, allow frequent retesting of modified code; yet the manually created test scripts are often seriously incomplete. A unit-testing tool called JWalk has therefore been developed to address the need for systematic unit testing within the context of agile methods. The tool operates directly on the compiled code for Java classes and uses a new lazy method for inducing the changing design of a class on the fly. This is achieved partly through introspection, using Java’s reflection capability, and partly through interaction with the user, constructing and saving test oracles on the fly. Predictive rules reduce the number of oracle values that must be confirmed by the tester. Without human intervention, JWalk performs bounded exhaustive exploration of the class’s method protocols and may be directed to explore the space of algebraic constructions, or the intended design state-space of the tested class. With some human interaction, JWalk performs up to the equivalent of fully automated state-based testing, from a specification that was acquired incrementally

    A photometric and spectroscopic study of the new dwarf spheroidal galaxy in Hercules

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    Our aim is to provide as clean and as complete a sample as possible of red giant branch stars that are members of the Hercules dSph galaxy. With this sample we explore the velocity dispersion and the metallicity of the system. Stromgren photometry and multi-fibre spectroscopy are combined to provide information about the evolutionary state of the stars (via the Stromgren c_1 index) and their radial velocities. Based on this information we have selected a clean sample of red giant branch stars, and show that foreground contamination by Milky Way dwarf stars can greatly distort the results. Our final sample consists of 28 red giant branch stars in the Hercules dSph galaxy. Based on these stars we find a mean photometric metallicity of -2.35 dex which is consistent with previous studies. We find evidence for an abundance spread. Using those stars for which we have determined radial velocities we find a systemic velocity of 45.2 km/s with a dispersion of 3.72 km/s, this is lower than values found in the literature. Furthermore we identify the horizontal branch and estimate the mean magnitude of the horizontal branch of the Hercules dSph galaxy to be V_0=21.17, which corresponds to a distance of 147 kpc. We have shown that a proper cleaning of the sample results in a smaller value for the velocity dispersion of the system. This has implications for galaxy properties derived from such velocity dispersions.Comment: 24 pages, 28 figure

    Pooling time series and cross-sectional data: An Application to Turkish export demand analysis

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    Ankara : The Department of Management and Graduate School of Business Administration of Bilkent University, 1989.Thesis (Master's) -- Bilkent University, 1989.Includes bibliographical references leaves 46.In this study. Pooling of time series and cross sectional data is used for constructing a demand model for the Turkish Exports. Two regression models are employed and compared by their fitness to the proposed pooling arrangements and demand relations. 25 Year time series (1963-1985) and cross sectional data covering top 10 exporters from Turkey are used for this purpose. Multiple regression analysis is conducted over different pooling arrangements and properness of pooling and fitness of model is tested by means of a series of F tests.Ural, A SüreyyaM.S
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