68 research outputs found
Spontaneous Ultra-Weak Photon Emission from Human Hands Is Time Dependent
Ultra-weak photon emission in the visible range was measured on palm and dorsal side of left and right hand by means of a low noise photomultiplier system. To study the dynamics of this photon emission in a 24 h period photon emission was recorded in 2 h intervals in 5 experiments, utilizing strict protocols for dark adaptation and recording of subjects. Fluctuations in photon emission in the course of 24 h period were demonstrated for each anatomic location. Mean photon emission over the 24 h period differed both between subjects and hand locations. To detect a pattern in the fluctuations the mean value for each location of each subject in each experiment was utilized to calculate fluctuations during the course of 24 h for each anatomical location. The fluctuations in photon emission in the course of 24 h were more at dorsal sides than palm sides. The correlation between fluctuations in palm and dorsal side was not apparent. During the 24 h period a change in left-right symmetry occurred for the dorsal side but not for the palm of the hands. Photon emission at the left dorsal location was high at night, while the right dorsal side emitted most during the day. It is concluded that a daily rhythm in photon emission can be recorded from both the dorsal and palm sides of the hands
Applying SMT Solvers to the Test Template Framework
The Test Template Framework (TTF) is a model-based testing method for the Z
notation. In the TTF, test cases are generated from test specifications, which
are predicates written in Z. In turn, the Z notation is based on first-order
logic with equality and Zermelo-Fraenkel set theory. In this way, a test case
is a witness satisfying a formula in that theory. Satisfiability Modulo Theory
(SMT) solvers are software tools that decide the satisfiability of arbitrary
formulas in a large number of built-in logical theories and their combination.
In this paper, we present the first results of applying two SMT solvers, Yices
and CVC3, as the engines to find test cases from TTF's test specifications. In
doing so, shallow embeddings of a significant portion of the Z notation into
the input languages of Yices and CVC3 are provided, given that they do not
directly support Zermelo-Fraenkel set theory as defined in Z. Finally, the
results of applying these embeddings to a number of test specifications of
eight cases studies are analysed.Comment: In Proceedings MBT 2012, arXiv:1202.582
Recommended from our members
Software integration testing based on communication coverage criteria and partial model generation
This paper considers the problem of integration testing the components of a timed distributed software system. We assume that communication between the components is specified using timed interface automata and use computational tree logic (CTL) to define communication-based coverage criteria that refer to send- and receive-statements and communication paths. The proposed method enables testers to focus during component integration on such parts of the specification, e.g. behaviour specifications or Markovian usage models, that are involved in the communication between components to be integrated. A more specific application area of this approach is the integration of test-models, e.g. a transmission gear can be tested based on separated models for the driver behaviour, the engine condition, and the mechanical and hydraulical transmission states. Given such a state-based specification of a distributed system and a concrete coverage goal, a model checker is used in order to determine the coverage or generate test sequences that achieve the goal. Given the generated test sequences we derive a partial test-model of the components from which the test sequences are derived. The partial model can be used to drive further testing and can also be used as the basis for producing additional partial models in incremental integration testing. While the process of deriving the test sequences could suffer from a combinatorial explosion, the effort required to generate the partial model is polynomial in the number of test sequences and their length. Thus, where it is not feasible to produce test sequences that achieve a given type of coverage it is still possible to produce a partial model on the basis of test sequences generated to achieve some other criterion. As a result, the process of generating a partial model has the potential to scale to large industrial software systems. While a particular model checker, UPPAAL, was used, it should be relatively straightforward to adapt the approach for use with other CTL based model checkers. A potential additional benefit of the approach is that it provides a visual description of the state-based testing of distributed systems, which may be beneficial in other contexts such as education and comprehension
Recommended from our members
Distinguishing Sequences for Distributed Testing: Adaptive Distinguishing Sequences
This paper concerns the problem of testing from a finite state machine (FSM) M modelling a system that interacts with its environment at multiple physically distributed interfaces, called ports. We assume that the distributed test architecture is used: there is a local tester at each port, the tester at port p only observes events at p, and the testers do not interact during testing. This paper formalises the notion of an adaptive test strategy and what it means for an adaptive test strategy to be controllable. We provide algorithms to check whether a global strategy is controllable and to generate a controllable adaptive distinguishing sequence (ADS). We prove that controllable ADS existence is PSPACE-hard and that the problem of deciding whether M has a controllable ADS with length l is NP-hard. In practice, there is likely to be a polynomial upper bound on the length of ADS in which we are interested and for this case the decision problem is NP-complete
Synthesis of Distributed Testers from True-concurrency Models of Reactive Systems
Automatic synthesis of test cases for conformance testing has been principall- y developed with the objective of generating sequential test cases. In the distributed system context, it is worth extending the synthesis techniques to the generation of multiple testers. We base our work on our experience in using model-checking techniques, as successfully implemented in the TGV tool. Continuing the works of A. Ulrich and H. König, we propose to use a true-concurrency model based on graph unfolding. The article presents the principles of a complete chain of synthesis, starting from the definition of test purposes and ending with a projection onto a set of testers
Synthesis of Distributed Testers from True-concurrency Models of Reactive Systems
Automatic synthesis of test cases for conformance testing has been principall- y developed with the objective of generating sequential test cases. In the distributed system context, it is worth extending the synthesis techniques to the generation of multiple testers. We base our work on our experience in using model-checking techniques, as successfully implemented in the TGV tool. Continuing the works of A. Ulrich and H. König, we propose to use a true-concurrency model based on graph unfolding. The article presents the principles of a complete chain of synthesis, starting from the definition of test purposes and ending with a projection onto a set of testers
MDM: A Mode Diagram Modeling Framework
Periodic control systems used in spacecrafts and automotives are usually
period-driven and can be decomposed into different modes with each mode
representing a system state observed from outside. Such systems may also
involve intensive computing in their modes. Despite the fact that such control
systems are widely used in the above-mentioned safety-critical embedded
domains, there is lack of domain-specific formal modelling languages for such
systems in the relevant industry. To address this problem, we propose a formal
visual modeling framework called mode diagram as a concise and precise way to
specify and analyze such systems. To capture the temporal properties of
periodic control systems, we provide, along with mode diagram, a property
specification language based on interval logic for the description of concrete
temporal requirements the engineers are concerned with. The statistical model
checking technique can then be used to verify the mode diagram models against
desired properties. To demonstrate the viability of our approach, we have
applied our modelling framework to some real life case studies from industry
and helped detect two design defects for some spacecraft control systems.Comment: In Proceedings FTSCS 2012, arXiv:1212.657
Recommended from our members
Parallel algorithms for generating distinguishing sequences for observable non-deterministic FSMs
A distinguishing sequence (DS) for a finite state machine (FSM) is an input sequence that distinguishes
every pair of states of the FSM. There are techniques that generate a test sequence with guaranteed fault
detection power and it has been found that shorter test sequence can be produced if DSs are used. Despite
these benefits, however, until recently the only published DS generation algorithms have been for deterministic
FSMs. This paper develops a massively parallel algorithm, which can be used in GPU Computing, to
generate DSs from partial observable non-deterministic FSMs. We also present the results of experiments
using randomly generated FSMs and some benchmark FSMs. The results are promising and indicate that
the proposed algorithm can derive DSs from partial observable non-deterministic FSMs with 32,000 states
in an acceptable amount of time.This work is supported by the Scientific and Technological Research Council of Turkey (TUBITAK) under Grant #1059B191400424 and by the NVIDIA corporation
- …