Analysis and representation of test cases generated from LOTOS

Cataloged from PDF version of article.This paper presents a method to generate, analyse and represent test cases from protocol specification. The language of temporal ordering specification (LOTOS) is mapped into an extended finite state machine (EFSM). Test cases are generated from EFSM. The generated test cases are modelled as a dependence graph. Predicate slices are used to identify infeasible test cases that must be eliminated. Redundant assignments and predicates in all the feasible test cases are removed by reducing the test case dependence graph. The reduced test case dependence graph is adapted for a local single-layer (LS) architecture. The reduced test cases for the LS architecture are enhanced to represent the tester's behaviour. The dynamic behaviour of the test cases is represented in the form of control graphs by inverting the events, assigning verdicts to the events in the enhanced dependence graph. © 1995

Contextualizing Kurdish gender studies decolonial feminist knowledge production and the genesis of the Kurdish Gender Studies Network

Established in 2020, the Kurdish Gender Studies Network (KGSN) is an online epistemic community that brings together activists and scholars dedicated to advancing knowledge in Kurdish gender and sexuality studies. This paper aims to introduce the network to a larger public while situating the formation of the KGSN in relation to the growth of Kurdish gender studies (KGS), and the increasing influence of women and queer scholars in Kurdish studies (KS) since 2010. It highlights that both KGSN and KS have been greatly influenced by the conditions shaped by the colonial legacy surrounding Kurdistan and the Kurdish issue while discussing the ways in which Kurdish women’s and gender studies were often marginalized in KS. As Kurdish women scholars and members of the network’s steering committee, we position the trajectory of the network and the evolution of KGS within the broader framework of knowledge production in colonial contexts and address the ongoing struggle to decolonize feminist knowledge production, which, historically, has been dominated by Western-centric epistemologies and methodologies

Test case verification by model checking

Verification of a test case for testing the conformance of protocol implementations against the formal description of the protocol involves verifying three aspects of the test case: expected input/output test behavior, test verdicts, and the test purpose. We model the safety and liveness properties of a test case using branching time temporal logic. There are four types of safety properties: transmission safety, reception safety, synchronization safety, and verdict safety. We model a test purpose as a liveness property and give a set of notations to formally specify a test purpose. All these properties expressed as temporal formulas are verified using model checking on an extended state machine graph representing the composed behavior of a test case and protocol specification. This methodology is shown to be effective in finding errors in manually developed conformance test suites. © 1993 Kluwer Academic Publishers

Verification of protocol conformance test cases using reachability analysis

A methodology is presented to verify manually written test cases against the formal specification of a protocol. Initially, a protocol and a test case are modeled as nondeterministic finite state machines and test case verification is viewed as a reachability analysis problem. An existing reachability analysis algorithm, based on the well-known perturbation technique, is modified to take nondeterminism in protocols and special test case features (timeouts and OTHERWISE events) into account. Correctness aspects of the reachability algorithm are proved. The notion of a synchronization error manifesting in a test case due to the nondeterministic nature of a protocol specification is studied. To verify data flow aspects of test cases, we extend our technique by modeling the test case and protocol specification as extended finite state machines. A test case from a proprietary test suite for the transport protocol Class 2 is taken as an example and is shown to contain several design errors. © 1992

Performance comparison of ASN.1 encoder/decoders using FTAM

Abstract Syntax Notation-One (ASN.1) is a standard external data representation language used to define messages of application layer protocols. Its encoding rules, the Basic Encoding Rules (BER), are also international standards that define the encoding/decoding of data values into/from a transfer syntax. Various approaches to automating BER encoding/decoding are examined; in particular, two widely used software packages (ISODE and CASN 1) are studied. A hardware BER encoder/decoder called VASN 1 is presented. Performance of software and hardware approaches are evaluated on real instances of file transfer using a standard FTAM protocol. Benchmarks obtained from running CASN 1 on one of the fastest workstations and from running VHDL simulations of VASN 1 indicate the superiority of the hardware approach. © 1993

Conformance relations for distributed testing based on CSP

Copyright @ 2011 Springer Berlin HeidelbergCSP is a well established process algebra that provides comprehensive theoretical and practical support for refinement-based design and verification of systems. Recently, a testing theory for CSP has also been presented. In this paper, we explore the problem of testing from a CSP specification when observations are made by a set of distributed testers. We build on previous work on input-output transition systems, but the use of CSP leads to significant differences, since some of its conformance (refinement) relations consider failures as well as traces. In addition, we allow events to be observed by more than one tester. We show how the CSP notions of refinement can be adapted to distributed testing. We consider two contexts: when the testers are entirely independent and when they can cooperate. Finally, we give some preliminary results on test-case generation and the use of coordination messages. © 2011 IFIP International Federation for Information Processing

Estelle-based test generation tool

A test design tool for functional analysis and test derivation of protocols formally specified using an extended finitestate machine model is presented. The formal description language supported is Estelle. The tool's main components include a compiler, a normalizer, a multiple module transition tour generator and several interactive programs. The tool is based on a static analysis of Estelle called normalization, which is explained in detail with various examples. The normalized specification facilitates graphical displays of the control and data flow in the specification by the interactive tools. Next discussed is test generation, which is based on verifying the control and data flow. First the data flow graph must be decomposed into blocks where each block represents the data flow in a protocol function. From the control graph the tool generates transition tours, and then test sequences are derived from the transition tour to test each function. The performance of the tool on various applications is also included. © 1991

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

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

Correlation between carotid bifurcation calcium burden on non-enhanced CT and percentage stenosis, as confirmed by digital subtraction angiography

Objectives: Previous evidence supports a direct relationship between the calcium burden (volume) on post-contrast CT with the percent internal carotid artery (ICA) stenosis at the carotid bifurcation. We sought to further investigate this relationship by comparing non-enhanced CT (NECT) and digital subtraction angiography (DSA). Methods: 50 patients (aged 41-82 years) were retrospectively identified who had undergone cervical NECT and DSA. A 64-multidetector array CT (MDCT) scanner was utilised and the images reviewed using preset window widths/levels (30/300) optimised to calcium, with the volumes measured via three-dimensional reconstructive software. Stenosis measurements were performed on DSA and luminal diameter stenoses >40% were considered "significant". Volume thresholds of 0.01, 0.03, 0.06, 0.09 and 0.12 cm(3) were utilised and Pearson's correlation coefficient (r) was calculated to correlate the calcium volume with percent stenosis. Results: Of 100 carotid bifurcations, 88 were available and of these 7 were significantly stenotic. The NECT calcium volume moderately correlated with percent stenosis on DSA r=0.53 (p<0.01). A moderate-strong correlation was found between the square root of calcium volume on NECT with percent stenosis on DSA (r=0.60, p<0.01). Via a receiver operating characteristic curve, 0.06 cm(3) was determined to be the best threshold (sensitivity 100%, specificity 90.1%, negative predictive value 100% and positive predictive value 46.7%) for detecting significant stenoses. Conclusion: This preliminary investigation confirms a correlation between carotid bifurcation calcium volume and percent ICA stenosis and is promising for the optimal threshold for stenosis detection. Future studies could utilise calcium volumes to create a "score" that could predict high grade stenosis

Using schedulers to test probabilistic distributed systems

This is the author's accepted manuscript. The final publication is available at Springer via http://dx.doi.org/10.1007/s00165-012-0244-5. Copyright © 2012, British Computer Society.Formal methods are one of the most important approaches to increasing the confidence in the correctness of software systems. A formal specification can be used as an oracle in testing since one can determine whether an observed behaviour is allowed by the specification. This is an important feature of formal testing: behaviours of the system observed in testing are compared with the specification and ideally this comparison is automated. In this paper we study a formal testing framework to deal with systems that interact with their environment at physically distributed interfaces, called ports, and where choices between different possibilities are probabilistically quantified. Building on previous work, we introduce two families of schedulers to resolve nondeterministic choices among different actions of the system. The first type of schedulers, which we call global schedulers, resolves nondeterministic choices by representing the environment as a single global scheduler. The second type, which we call localised schedulers, models the environment as a set of schedulers with there being one scheduler for each port. We formally define the application of schedulers to systems and provide and study different implementation relations in this setting