10,696,125 research outputs found
TestEra: Specification-based Testing of Java Programs Using SAT
No full textTestEra is a framework for automated specification-based testing of Java programs. TestEra requires as input a Java method (in sourcecode or bytecode) , a formal specification of the pre- and post-conditions of that method, and a bound that limits the size of the test cases to be generated. Using the method's pre-condition, TestEra automatically generates all nonisomorphic test inputs up to the given bound. It executes the method on each test input, and uses the method postcondition as an oracle to check the correctness of each output. Specifications are first-order logic formulae. As an enabling technology, TestEra uses the Alloy toolset, which provides an automatic SAT-based tool for analyzing first-order logic formulae. We have used TestEra to check several Java programs including an architecture for dynamic networks, the Alloy-alpha analyzer, a fault-tree analyzer, and methods from the Java Collection Framework
Checking Java Implementation of a Naming Architecture Using Testera
No full textAbstractTestEra is a novel framework for automated testing of Java programs. We have built TestEra upon Alloy, a lightweight first-order relational language, and the Alloy Analyzer, a fully automatic simulation and checking tool. Checking a Java program with TestEra involves modeling the correctness criteria for the program in Alloy and specifying abstraction and concretization translations between instances of Alloy models and Java data structures. TestEra automatically generates all non-isomorphic test cases within a given input size and verifies the correctness.We present our initial evaluation of TestEra performed by checking the Java implementation of a naming architecture for resource discovery in dynamic networked environments. Our study delineates the use of TestEra in testing methods for manipulating complex data structures
LAUNCHING OF ANTIPROTONS FROM THE CATCHING PENNING TRAP BY EVAPORATION METHOD
No full textIn this paper the launching of antiprotons from the catching Penning trap by evaporation method has been studied. The distributions of velocity and time-of-flight spectrum of launching antiprotons depend on the methods of reducing the trapping electric potential
Erratum: Comparison of classical and quantum models of anti-hydrogen formation through charge exchange (Journal of Physics B: Atomic, Molecular and Optical Physics (2019) 52 (115202) DOI: 10.1088/1361-6455/ab1151)
No full textA typographical error introduced during production is present in appendix B of this article. The word 'Schrödinger' is corrected to 'Schrödinger'. Additionally, figure 1 appears in lower quality in the published article than what was provided by the authors. This lower figure quality was introduced during production. A higher quality version is provided below, to improve the clarity of the authors' work. These changes do not affect the results of the article. (Figure Presented)
Comparison of classical and quantum models of anti-hydrogen formation through charge exchange
No full textWe compare classical and quantum predictions of the cross section for anti-hydrogen formation by charge exchange between Rydberg positronium and antiprotons as a function of the positronium energy. We show that these two highly different approaches furnish the same scaling law with the principal quantum number of positronium n Ps and numerical values in agreement within some tens of percent for and down to very low collision energy of tens of μeV. We discuss these results in the context of a recently claimed hypothesis of quantum suppression of the reaction driven by supposedly different scaling law of classical and quantum predictions. Finally we underline how the basic agreement between classical and quantum results enforces the reliability of the classical calculations that, presently, are the only ones able to obtain the cross section for positronium initially in high Rydberg states and in the presence of external electric and magnetic fields
Media testera del caballo del Duque de Feria
No full textProcede del legado testamentario de la Colección de la Armería Ducal de la Casa de Medinaceli.Descripción: Media testera de metal con orejeras y dorada al fuego. Tiene grabadas cuatro "F"Inscripciones - Transcripción: F (cuatro
ANTIHYDROGEN PRODUCTION IN A COMBINED TRAP
No full textIn this paper we study the properties of a Paul trap with a superimposed magnetic field (combined trap) and discuss the possibility of using this trap to simultaneously store positrons and antiprotons to form antihydrogen
ADIABATIC COOLING OF IONS IN THE PENNING TRAP
No full textAn ion cloud in a Penning trap can be cooled by adiabatic expansion by reducing the trap's magnetic and electric fields. We treat the ion cloud as a classical gas and obtain the relations between the temperature and the trapping fields. This cooling method may be useful in trapping and cooling of antiprotons with the aim of measuring the gravitational acceleration of antiprotons and other experiments on heavy ions
ADIABATIC COOLING OF ANTIPROTONS IN A PENNING TRAP
No full textAn antiproton cloud cooled at 4.2 K in a Penning trap can be further cooled by adiabatic reduction of the trap magnetic and electric fields. It will be shown that the temperature can be reduced by two orders of magnitude. This cooling method may be useful to obtain ultra-low energy antiprotons for the measurement of their gravitational properties and the production of ultra-low energy antihydrogen atoms
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