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1.
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
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This paper presents the existing techniques for P system testing and performs an empirical evaluation of their fault-detection
efficiency. The comparison is performed using mutation testing and, based on the results obtained, some improved testing methodologies
are proposed. 相似文献
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Although testing is a major part of software development, it rarely gets the attention it deserves from researchers, partly because its foundations are weak and ill-understood. The principal purpose of testing is to detect (and then remove) faults in a software system. However, very few of the existing methods allow the tester to make any precise statement about the type or number of faults that remain undetected after testing is completed. In particular, none of the main techniques used by the software industry can give serious guarantees that a system is fault-free after testing has been completed. This paper advocates the use of a formal method both as a specification language and as the basis of a test data selection strategy. It presents a new method for generating test cases from this type of formal specification that provides a more convincing answer to the problem of detecting all faults in a software system. The method is reductionist in the sense that it guarantees that a system is fault-free provided that its components are fault-free; in turn, the same method could be used to test the resulting sub-systems, so the reduction will continue until the components considered are either known to be correct or are fairly simple pieces of code that can be successfully tested using traditional methods. The formal method used, X-machines, is a blend of finite state machines, data structures and processing functions and provides a simple and intuitive way of specifying computer systems. The use of X-machines as a specification tool and the testing method are illustrated with a case study. © 1998 John Wiley & Sons, Ltd. 相似文献
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Testing a deterministic implementation against a non-controllable non-deterministic stream X-machine
A stream X-machine (SXM) is a type of extended finite state machine with an associated development approach that consists
of building a system from a set of trusted components. One of the great benefits of using SXMs for the purpose of specification
is the existence of test generation techniques that produce test suites that are guaranteed to determine correctness as long
as certain well-defined conditions hold. One of the conditions that is traditionally assumed to hold is controllability: this
insists that all paths through the SXM are feasible. This restrictive condition has recently been weakened for testing from
a deterministic SXM. This paper shows how controllability can be replaced by a weaker condition when testing a deterministic
system against a non-deterministic SXM. This paper therefore develops a new, more general, test generation algorithm for testing
from a non-deterministic SXM. 相似文献
7.
Florentin Ipate Mike Holcombe 《Applicable Algebra in Engineering, Communication and Computing》2002,13(2):67-91
Over the last decade, stream X-machines have been used in order to specify a range of systems. One of the strengths of this approach is that, under certain well
defined conditions, it is possible to produce a test set that is guaranteed to determine the correctness of the implementation
under test. However, if X-machines are to be used in practice as a tool for specification and test generation, there needs
to be ways of developing existing specifications into more complex and more detailed versions through a process of refinement. Associated with the refinement of the specification, there needs to be methods of refining the corresponding test sets, that is to construct the test set in parallel with the specification and to distribute the testing into smaller chunks,
with major cost and time savings. A few such specification and testing refinements of X-machine have already been investigated.
This paper introduces a new type of X-machine refinement, called simple covering, which expands the input-output behaviour of an existing X-machine. Associated with this process, the corresponding refinement
of the test set is described and a method of testing X-machines constructed as simple coverings is developed.
Received: March 29, 2000; revised version: December 2, 2001 相似文献
8.
Corneliu Hamciuc Elena Hamciuc Alina Mirela Ipate Mariana Cristea Lidia Okrasa 《应用聚合物科学杂志》2009,113(1):383-391
A series of aromatic copolyethers containing 1,3,4‐oxadiazole rings and fluorene groups was prepared by nucleophilic substitution polymerization technique of 9,9‐bis(4‐hydroxyphenyl)fluorene, 1 , or of different amounts of 1 and an aromatic bisphenol, such as 4,4′‐isopropylidenediphenol or phenolphthalein, with 2,5‐bis(p‐fluorophenyl)‐1,3,4‐oxadiazole. The polymers were easily soluble in polar solvents like N‐methylpyrrolidone, N,N‐dimethylacetamide, N,N‐dimethylformamide, and chloroform and can be cast from solutions into thin flexible films. They showed high thermal stability, with decomposition temperature being above 425°C. The polymers exhibited a glass‐transition temperature in the range of 195–295°C, with a reasonable interval between glass‐transition and decomposition temperature. Electrical insulating properties of some polymer films were evaluated on the basis of dielectric constant and dielectric loss and their variation with frequency and temperature. The values of the dielectric constant at 10 kHz and 20°C were in the range of 3.16–3.25. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009 相似文献
9.
Ipate Florentin Gheorghe Marian Holcombe Mike 《Applicable Algebra in Engineering, Communication and Computing》2003,14(3):217-237
In 1988 X-machines were proposed as a basis for a specification language and, since then, a number of further investigations have demonstrated the value of this idea. A number of classes of X-machines have been identified and studied, most importantly the class of stream X-machines. A theory of testing based on stream X-machines has also been developed. This allows the generation of test sets which, if satisfied, guarantee, under certain constraints, the correctness of implementation with respect to specification. This paper extends this theory in two ways. Firstly, it considers the general X-machine model rather than the particular stream X-machine class. Secondly, the theoretical results proved give rise to at least two different testing strategies. These results are then particularised to the stream X-machine class.
Key words:Testing, Finite state machine, (stream) X-machine, Formal specification. 相似文献
10.
In this paper, we propose an approach to P system testing based on finite state machine conformance techniques. Of the many
variants of P systems that have been defined, we consider cell-like P systems which use non-cooperative transformation and
communication rules. We show that a (minimal) deterministic finite cover automaton (DFCA) (a finite automaton that accepts all words in a given finite language, but can also accept words that are longer than any
word in the language) provides the right approximation for the computation of a P system. Furthermore, we provide a procedure
for generating test sets directly from the P system specification (without explicitly constructing the minimal DFCA model). 相似文献