7,161 research outputs found
Robust Dynamic Selection of Tested Modules in Software Testing for Maximizing Delivered Reliability
Software testing is aimed to improve the delivered reliability of the users.
Delivered reliability is the reliability of using the software after it is
delivered to the users. Usually the software consists of many modules. Thus,
the delivered reliability is dependent on the operational profile which
specifies how the users will use these modules as well as the defect number
remaining in each module. Therefore, a good testing policy should take the
operational profile into account and dynamically select tested modules
according to the current state of the software during the testing process. This
paper discusses how to dynamically select tested modules in order to maximize
delivered reliability by formulating the selection problem as a dynamic
programming problem. As the testing process is performed only once, risk must
be considered during the testing process, which is described by the tester's
utility function in this paper. Besides, since usually the tester has no
accurate estimate of the operational profile, by employing robust optimization
technique, we analysis the selection problem in the worst case, given the
uncertainty set of operational profile. By numerical examples, we show the
necessity of maximizing delivered reliability directly and using robust
optimization technique when the tester has no clear idea of the operational
profile. Moreover, it is shown that the risk averse behavior of the tester has
a major influence on the delivered reliability.Comment: 19 pages, 4 figure
Tetraaquadiimidazolenickel(II) naphthalene-1,5-disulfonate
The triclinic unit cell of the title compound, [Ni(C3H4N2)2(H2O)4](C10H6O6S2), contains one centrosymmetric cation and one centrosymmetric anion. In the cation, the NiII ion is six-coordinated by two imidazole ligands [Ni—N = 2.0568 (14) Å] and four water molecules [both independent Ni—O distances are 2.098 (1) Å] in a distorted octahedral geometry. Intermolecular O—H⋯O and N—H⋯O hydrogen bonds form an extensive three-dimensional network, which consolidates the crystal packing
- …