Search

In this paper we introduce a new technique to synthesize functions matching a given set of input-output pairs. Using techniques similar to defunctionalisation the abstract syntax tree of the candidate functions is specified at a high level of abstraction. We use a recursive data type to represent the syntax tree of the candidate functions. The test system G∀ST is used for the systematic synthesis of candidate functions and the selection of functions matching the given condition. The representation of candidate functions as data structures gives us full control over them and the transformation of the syntax tree to the actual function is straight forward. Instances of the syntax tree are generated by a generic algorithm that can be tailored easily to specific needs. This yields a very flexible system to synthesize clear (recursive) function definitions efficiently. [ABSTRACT FROM AUTHOR]

In this paper, effect of dynamic compensators on power quality problems and especially flicker is discussed. The dynamic compensators are used in networks including wind turbines. An accurate model for flickermeter is presented and short term and instantaneous indices of flicker are analyzed to examine the effect of dynamic compensators. Finally, a test system is used for producing flicker with flickermeter model in Matlab-Simulink software and effect of dynamic compensators on flicker reduction is analyzed. [ABSTRACT FROM AUTHOR]

In this paper, the traditional II equivalent circuit used to model the transformer is replaced by an ideal model in discrete optimal power flow (DOPF) formulation, which introduces a fictitious bus to express the power and voltage converting relations of the tap-changing transformer, so the admittance matrix is fixed during iterations to reduce computational efforts. Furthermore, this representation of transformer helps DOPF problem to be decoupled into two subproblems, which can improve computational efficiency greatly. Interior point method is used to solve continuous active power subproblem, and interior point cutting plane method (IPCPM) is adopted to solve discrete reactive power subproblem. Unfortunately, we find that the convex combination solution appears with great probability when solving DOPF problem, so in this paper IPCPM is improved to repair this shortcoming. Numerical simulations on IEEE14~300 test systems show that the improvement of IPCPM is efficient, and the proposed method is suitable for solving DOPF problems for large-scale systems. [ABSTRACT FROM AUTHOR]

An automatic test system for logical properties represents universal quantified properties by Boolean functions. Such a function is evaluated for a large number of values: the test suite. Automatic test systems generate a test suite of the desired size, evaluate the predicate for the values in this test suite, and generate a verdict based on the test results. The automatic test system Gast uses a generic algorithm that generates test suites for arbitrary data types in a systematic way. Such a generic algorithm has as advantages that the generation of values of a new type can be derived automatically, instead of being hand coded. The systematic generation has as advantages that it allows proofs by exhaustive testing, and it is more efficient since test values are not duplicated. In this paper we present a new generic algorithm for the systematic generation of elements of data types that is much more elegant, efficient and flexible than the existing algorithm. We also show a variant that yields the elements in pseudorandom order. Both algorithms are very efficient and lazy; only the elements actually needed are generated. [ABSTRACT FROM AUTHOR]

G∀ST is a fully automatic test system. Given a logical property, stated as a function, it is able to generate appropriate test values, to execute tests with these values, and to evaluate the results of these tests. Many reactive systems, like automata and protocols, however, are specified by a model rather than in logic. There exist tools that are able to test software described by such a model-based specification, but these tools have limited capabilities to generate test data involving data types. Moreover, in these tools it is hard or even impossible to state properties of these values in logic. In this paper we introduce some extensions of G∀ST to combine the best of logic and model based testing. The integration of model based testing and testing based on logical properties in a single automated system is the contribution of this paper. The system consists only of a small library rather than a huge stand-alone system. [ABSTRACT FROM AUTHOR]

The article presents information on manufacturers and users of integrated circuits (ICs) who have derived the electrostatic discharge (ESD) test methods from the basic ESD stress models: the Human Body Model (HBM) and the Charged Device Model (CDM). The ESD test should reproduce the different failure signatures and quantify the sensitivities attributable to the various types of ESD in an IC environment. A key issue of the ESD test and its standardization is the reproducibility of test results on the same test system and the correlation between different test systems.