Pairwise testing for software product lines: comparison of two approaches

Software Product Lines (SPL) are difficult to validate due to combinatorics induced by variability, which in turn leads to combinatorial explosion of the number of derivable products. Exhaustive testing in such a large products space is hardly feasible. Hence, one possible option is to test SPLs by generating test configurations that cover all possible t feature interactions (t-wise). It dramatically reduces the number of test products while ensuring reasonable SPL coverage. In this paper, we report our experience on applying t-wise techniques for SPL with two independent toolsets developed by the authors. One focuses on generality and splits the generation problem according to strategies. The other emphasizes providing efficient generation. To evaluate the respective merits of the approaches, measures such as the number of generated test configurations and the similarity between them are provided. By applying these measures, we were able to derive useful insights for pairwise and t-wise testing of product lines.     

The multiobjective multidimensional knapsack problem: a survey and a new approach

The knapsack problem (KP) and its multidimensional version (MKP) are basic problems in combinatorial optimization. In this paper, we consider their multiobjective extension (MOKP and MOMKP), for which the aim is to obtain or approximate the set of efficient solutions. In the first step, we classify and briefly describe the existing works that are essentially based on the use of metaheuristics. In the second step, we propose the adaptation of the two‐phase Pareto local search (2PPLS) to the resolution of the MOMKP. With this aim, we use a very large scale neighborhood in the second phase of the method, that is the PLS. We compare our results with state‐of‐the‐art results and show that the results we obtained were never reached before by heuristics for biobjective instances. Finally, we consider the extension to three‐objective instances.     

Do personality problems improve during psychodynamic supportive–expressive psychotherapy? Secondary outcome results from a randomized controlled trial for psychiatric outpatients with personality disorders.

Studies involving patients with personality disorders (PDs) have not focused on improvement of core aspects of the PD. The authors examined changes in quality of object relations, interpersonal problems, psychological mindedness, and personality traits in a sample of 156 patients with Diagnostic and Statistical Manual of Mental Disorders (4th ed.) PD diagnoses being randomized to either manualized or nonmanualized dynamic psychotherapy. Effect sizes adjusted for symptomatic change and reliable change indices were calculated. The authors found that both treatments were equally effective at reducing personality pathology. Only in neuroticism did the nonmanualized group do better during the follow-up period. The largest improvement was found in quality of object relations. For the remaining variables, only small and clinically insignificant magnitudes of change were found. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

MINIATURE PULSE TUBE FOR THE COOLING OF ELECTRONIC DEVICES: FUNCTIONING PRINCIPLES AND PRACTICAL MODELING

The miniaturization of refrigerating systems represents a very current scientific and technical challenge to improve the performances of numerous electronic components. This work presents a global approach to the problem and suggests studying the cooling by means of small channels filled with an oscillating gas: the double inlet pulse tube refrigerator (DIPTR). A great level of miniaturization based on the technology of carving silicon is exposed. This study proposes to apply an electric analogy for modeling both hydrodynamic and thermal phenomena. Considering the complexity of the theoretical problem including mechanical, thermal, thermodynamical, and acoustic considerations, the authors take care to summarize the main governing equations in a particular form so any scientific engineer could understand the DIPTR principle.     

Path resolution for nested recursive modules

The ML module system facilitates the modular development of large programs, through decomposition, abstraction and reuse. To increase its flexibility, a lot of work has been devoted to extending it with recursion, which is currently prohibited. The introduction of recursion adds expressivity to the module system. However it also creates problems that a non-recursive module system does not have. In this paper, we address one such problem, namely resolution of path references. Paths are how one refers to nested modules in ML. Without recursion, well-typedness guarantees termination of path resolution, in other words, we can statically determine the module that a path refers to. This does not always hold with recursive module extensions, since the module system then can encode a lambda-calculus with recursion, whose termination is undecidable regardless of well-typedness. We formalize this problem of path resolution by means of a rewrite system on paths and prove that the problem is undecidable even without higher-order functors, via an encoding of the Turing machine into a calculus with just recursive modules, first-order functors, and nesting. Motivated by this result, we introduce a further restriction on first-order functors, limiting polymorphism on functor parameters by requiring signatures for functor parameters to be non-recursive, and show that this restriction is decidable and admits terminating path resolution.     

Role of strain induced crystallization and oxidative crosslinking in fracture properties of rubbers

Tensile properties and crack propagation properties, especially critical strain energy release rate in mode I, G_IC, have been used to investigate fracture properties of elastomers and their relationships with microstructure. These investigations were mainly based on a series of comparisons: first, the behaviour of polychloroprene rubber (CR), undergoing stress hardening due to strain induced crystallization (SIC) and oxidative crosslinking (OCL) was compared with that of chlorinated polyethylene (CPE), which undergoes SIC but not OCL, and with a polyurethane based on hydroxyl terminated polybutadiene (PU) which undergoes OCL but not SIC. Comparisons were also made on CR between fracture behaviour at ambient temperature, where SIC occurs and at 100 °C where there is no SIC. Finally, oxidative crosslinking was used to vary in a continuous way the crosslink density in CR and PU, in order to evaluate the role of crosslinking in fracture behaviour.     

Determination of Amylose in Cereal and Non-Cereal Starches by a Colorimetric Assay: Collaborative Study

An improved colorimetric method, based on the well-known reaction between amylose and iodine, is described. Native starch is dissolved in ureadimethylsulfoxide and the resulting solution defatted with ethanol. An aliquot of the lipid-free solution is then reacted with iodine and the absorbance of the blue-coloured amylose-iodine complex measured, thus determining the iodine-binding capacity of starch (Blue Value). A collaborative study was conducted, according to official guidelines, to determine the method's repeatability and reproducibility: 8 participants were each sent 8 starch samples from different botanic origin for duplicate analysis. Statistical evaluation of the results gave good precision results, with an average repeatability relative standard deviation of 2.1% and an average reproducibility relative standard deviation of 5.6%. The method is, therefore, suitable to determine precisely the amylose content of native starch.     

Sequestration and metabolism of protoxic pyrrolizidine alkaloids by larvae of the leaf beetle Platyphora boucardi and their transfer via pupae into defensive secretions of adults

Several neotropical leaf-beetles of the genus Platyphora ingest and specifically metabolize plant acquired pyrrolizidine alkaloids (PAs) of the lycopsamine type (e.g., rinderine or intermedine) and enrich the processed alkaloids in their exocrine defensive secretions. In contrast to the related palaearctic leaf beetles of the genus Oreina, which absorb and store only the non-toxic alkaloid N-oxides, Platyphora sequesters PAs exclusively as protoxic tertiary amines. In this study, the ability of P. boucardi larvae to accumulate PAs was investigated. Tracer studies with [¹⁴C]rinderine and its N-oxide revealed that P. boucardi larvae, like adult beetles, utilize the two alkaloidal forms with the same efficiency, but accumulate the alkaloid as a tertiary amine exclusively. Ingested rinderine is rapidly epimerized to intermedine, which is localized in the hemolymph and all other tissues; it is also detected on the larval surface. Like adults, larvae are able to synthesize their own alkaloid esters (beetle PAs) from orally administered [¹⁴C]retronecine and endogenous aliphatic 2-hydroxy acids. These retronecine esters show the same tissue distribution as intermedine. A long-term feeding experiment lasting for almost four months revealed that retronecine esters synthesized from [¹⁴C]retronecine in the larvae are transferred from larvae via pupae into the exocrine glands of adult beetles. Pupae contain ca. 45% of the labeled retronecine originally ingested, metabolized, and stored by larvae; ca. 12% of larval radioactivity could be recovered from the defensive secretions of adults sampled successively over two and a half months. Almost all of this radioactivity is found in the insect-made retronecine esters that are highly enriched in the defensive secretions, i.e., more than 200-fold higher concentration compared to pupae.