Kirby P.,Vector Software
Computer Physics Communications | Year: 2010
Spheroidal wave functions are important for boundary-value calculations in electromagnetics, acoustics and quantum mechanics. This paper discusses the calculation of radial prolate spheroidal wave functions of the second kind for integral mode numbers and real spheroidal parameter. The calculation of these functions is difficult. The existing methods are variously limited by numerical cancellation, slow convergence, algebraic complexity and restricted scope. The paper proposes a hybrid scheme. It uses an analytical solution to give the initial conditions for a numerical solution of the defining differential equation using the Bulirsch-Stoer method. Multiple-precision arithmetic is used to overcome the problem of numerical cancellation. The Wronskian is used to assess the accuracy of the solution. The results are highly accurate. The scheme should provide a practical approach for many applications. Reference results are presented for validation purposes. © 2009 Elsevier B.V. All rights reserved.
Jones A.V.,Vector Software
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2016
The regression test selection problem—selecting a subset of a test suite given a change—has been studied widely over the past two decades. However, the problem has seen little attention when constrained to high-criticality developments and where a “safe” selection of tests need to be chosen. Further, no practical approaches have been presented for the programming language Ada. In this paper, we introduce an approach to solving the selection problem given a combination of both static and dynamic data for a program and a change-set. We present a change impact analysis for Ada that selects the safe set of tests that need to be re-executed to ensure no regressions. We have implemented the approach in the commercial, unit-testing tool VectorCAST, and validated it on a number of open-source examples. On an example of a fully-functioning Ada implementation of a DNS server (IRONSIDES), the experimental results show a 97% reduction in test-case execution. © Springer International Publishing Switzerland 2016.
Paliotta J.,Vector Software
AUTOTESTCON (Proceedings) | Year: 2015
Competition in the automotive industry is intense, and successful companies must constantly innovate by introducing new technology to differentiate and improve their brands. As a result, today's vehicles have evolved from a mechanical device into an integrated machine with embedded software powering performance in all major systems including: engine control, power train, suspension, braking, and entertainment. Consider a few of these incredible statistics: today's vehicles have more computer processing power than NASA's early spacecraft. An "average modern high end car" has more lines of code than an F-35 Joint Strike Fighter. And finally, many automobiles actually have an addressable IP address. These technological improvements are driving brand success stories, as modern consumers' experiences are shaped more by the software than the hardware. A strong brand can create significant value in the automotive industry as a focus on integrated technology helps to drive brand loyalty and value. According to Interbrand's 15th annual Best Global Brands Report, the collective value of the automotive brands appearing on the Global Brands ranking increased 14.6 percent. Three out of the five "Top Risers" listed were from the automotive sector, making the 15th annual report a record-breaking one for the auto industry. However, statistics also show that more than 50 percent of auto recalls are now due to software bugs, not mechanical issues. With an industry average of 5-10 bugs per thousand lines of code, the errors can pile up fast. As automobiles evolve from mechanical to software devices, automakers must rethink fundamental product development principles, including moving from a sequential, compartmentalized design process to a more agile approach, with higher degrees of collaboration between self-directed, cross-functional teams. This paper will outline why software quality needs to be at the top of the list for automotive OEMs looking to preserve - and elevate - their brand status. For quality to improve, continuous integration and continuous software testing are a necessity. While software testing has traditionally been viewed as a development expense, we will explain that when developed properly, software tests are an asset similar to source code that should provide value over the entire product life cycle. Well-designed tests allow regressions to be caught prior to product release, and lead to a reduction in branch damage and costs associated with product recalls. © 2015 IEEE.
Riley C.P.,Vector Software
Sensor Letters | Year: 2013
Magnetic hysteresis can significantly modify the operation of electromechanical devices. A simulation of a dual solenoid, electromagnetic valve during cyclical operation using a finite element method that includes a recently developed model for hysteresis is presented, and compared to a simulation when hysteresis is neglected. The increased time for each stroke is observed and the latching force resulting from magnetic remanence is discussed. The distribution of magnetic energy throughout the finite element model is used to determine the energy lost due to hysteresis in each mechanical cycle. Including hysteresis results in the simulation CPU time increasing by more than a factor of three compared to when it is neglected, but is still sufficiently fast that it can be used as part of the design process. Copyright © 2013 American Scientific Publishers All rights reserved.
Riley C.P.,Vector Software
Sensor Letters | Year: 2013
The most important criterion for an electromagnetic sensing coil is that the response it receives is unique for a particular type of object. This paper demonstrates that the Pareto optimization method, which can be used to ensure the maximum sensitivity of the sensing coil, can also be used to establish the uniqueness of the response. The technique is initially applied to the design of a simple coil system where the response is the change in coil impedance due to a buried pipeline. A coil design that achieves close to maximum response in both the resistive and inductive components is selected and the Pareto optimization is then also applied to the inverse problem. A parametric model of the pipeline is used and it is established that with frequencies of 5 and 50 Hz applied to the coil it is possible to obtain a unique response for the depth, radius and displacement, but not wall thickness, of the pipeline. In a second example, Pareto optimization can determine that a unique response from a buried copper sphere will be obtained with supply of 20 and 50 Hz current to the coil. Copyright © 2013 American Scientific Publishers All rights reserved.