Compact Structural Test Generation for Analog Macros

A structural, fault-model based methodology for the generation of compact high-quality test sets for analog macros is presented. Results are shown for an IV-converter macro design. Parameters of so-called test configurations are optimized for detection of faults in a fault-list and an optimal selection algorithm results in determining the best test set. The distribution of the results along the parameter-axes of the test configurations is investigated to identify a collapsed high-quality test se

An Automated Framework for Structural Test-data Generation

Structural testing criteria are mandated in many software development standards and guidelines. The process of generating test data to achieve 100% coverage of a given structural coverage metric is labour-intensive and expensive. This paper presents an approach to automate the generation of such test data. The test-data generation is based on the application of a dynamic optimisation-based search for the required test data. The same approach can be generalised to solve other test-data generation problems. Three such applications are discussed-boundary value analysis, assertion/run-time exception testing, and component re-use testing. A prototype tool-set has been developed to facilitate the automatic generation of test data for these structural testing problems. The results of preliminary experiments using this technique and the prototype tool-set are presented and show the efficiency and effectiveness of this approac

The KPSS Test with Two Structural Breaks

In this paper we generalize the KPSS-type test to allow for two structural breaks. Seven models have been de?ned depending on the way that the structural breaks a¤ect the time series behaviour. The paper derives the limit distribution of the test both under the null and the alternative hypotheses and conducts a set of simulation experiments to analyse the performance in finite samples.Stationary tests, structural breaks, unit root.

Analyzing the test process using structural coverage

A large, commercially developed FORTRAN program was modified to produce structural coverage metrics. The modified program was executed on a set of functionally generated acceptance tests and a large sample of operational usage cases. The resulting structural coverage metrics are combined with fault and error data to evaluate structural coverage. It was shown that in the software environment the functionally generated tests seem to be a good approximation of operational use. The relative proportions of the exercised statement subclasses change as the structural coverage of the program increases. A method was also proposed for evaluating if two sets of input data exercise a program in a similar manner. Evidence was provided that implies that in this environment, faults revealed in a procedure are independent of the number of times the procedure is executed and that it may be reasonable to use procedure coverage in software models that use statement coverage. Finally, the evidence suggests that it may be possible to use structural coverage to aid in the management of the acceptance test processed

Rocket nozzle thermal shock tests in an arc heater facility

A rocket motor nozzle thermal structural test technique that utilizes arc heated nitrogen to simulate a motor burn was developed. The technique was used to test four heavily instrumented full-scale Star 48 rocket motor 2D carbon/carbon segments at conditions simulating the predicted thermal-structural environment. All four nozzles survived the tests without catastrophic or other structural failures. The test technique demonstrated promise as a low cost, controllable alternative to rocket motor firing. The technique includes the capability of rapid termination in the event of failure, allowing post-test analysis

Development of structural test articles from magnesium-lithium and beryllium

Study on the fabrication and testing of a magnesium-lithium box beam shows the formability and machinability characteristics of that alloy to be excellent. Results of forming tests for shrink and stretch flanges show values for both flange heights that may be used in future beryllium design

A simple encompassing test for the deterministic and bilinear unit root models

A new parameters’ encompassing test is proposed for deciding between the deterministic unit root processes with a structural break and the bilinear unit root model without such break. The test consists in testing three sets of hypotheses regarding parameters in a simple regression model. The test uses the t-ratio and F-statistics, of non-trivial distributions under the null hypothesis. The finite sample distributions for the relevant statistics are tabulated and the asymptotic distribution of the F-test is derived. The test has been applied for the daily stock price indices for 66 countries, for the period 1992-2001. The results support the conjecture that the bilinear model dominates the structural break model more often than the other way around. Also, it is likely that in practical applications the bilinear unit root process might be mistaken for the deterministic unit root process with a structural break

Using the simple peel test to measure the adhesive fracture energy, Ga

The adhesive fracture energy of structural adhesive joints may be readily ascertained from linear-elastic fracture-mechanics (LEFM) methods, and indeed an ISO Test Method (ISO 25217: 2009) now exists for the LEFM Mode I value, Gc, as a result of the efforts of the European Structural Integrity Society (ESIS) ‘TC4 Committee’ [1,2]. These LEFM test methods involve the preparation and testing of adhesively-bonded double-cantilever beam (DCB) and tapered double-cantilever beam (TDCB) specimens [3,4]. Notwithstanding the sound and reproducible results that may be obtained from such methods, the LEFM test specimens are relatively complex and expensive to make and test, and many industries would far prefer to deduce the value of the adhesive fracture energy from the very common and widely-used ‘peel test’. (In the present paper, for clarity, the adhesive fracture energy is termed GA when deduced from a peel test.) Indeed, the peel test is an attractive test method to assess the fracture performance of a wide range of structural adhesive joints and flexible laminates. However, although it is a relatively simple test to undertake, it is often a complex test to analyse and thus obtain a characteristic measure of the toughness of the adhesive joint, or laminate