752 publications from this institution
Test effort estimation is the process of predicting effort for testing the software. It has always been a fascinating area for software engineering researchers. "How long will it take to test the system?" is the most promising question in minds of testers before the testing process actually starts. Many factors such as the productivity of the test team, strategy chosen for testing, the size and complexity of the system, technical factors, and expected quality can affect test effort estimation. Testing requires a good amount of time and effort in the entire software development life cycle. Several researches have attempted to develop test effort estimation models but still it is not possible to achieve accurate forecasting. A new model based on a metaheuristic technique called, cuckoo search, for estimating the test effort is proposed in this paper. The proposed model is used to assign weights to the various factors involved based on past results, and, is then used for predicting the test effort for new projects of similar kind.
A model of the interaction of pressure changes with strained premixed flames is formulated by extending previous work on interactions with nonstrained flames. By making the assumption of no divergence in the velocity field (∇ · u = 0) and writing the full equations in terms of mass-weighted coordinates (with explicit strain terms) following the flame sheet, we study the time-varying response of the mass burning rate to an imposed pressure disturbance. Numerical solution of the full nonlinear equations shows that strain has a strong effect on the flame response. It is found that, for large amplitude step pressure drops, the flame does not recover for moderate and small strain rates. As expected, for larger positive strain rates the flame recovers, because it is known that positive strain stabilizes premixed flames. The reverse happens for flames experiencing pressure drops in a convergent flow (negative strain). In this case, extinction of the flame by pressure drops becomes more likely as the convergence of the flow increases. Of particular interest for the negative strain case is the onset of the pulsating instability for a finite range of small values of pressure drop, which then gives way to a region of recovery if the pressure drop is larger, before finally for larger drops the extinction pressure drop is reached.
