Are test cases needed? Replicated comparison between exploratory and test-case-based software testing

Manual software testing is a widely practiced verification and validation method that is unlikely to fade away despite the advances in test automation. In the domain of manual testing, many practitioners advocate exploratory testing (ET), i.e., creative, experience-based testing without predesigned test cases, and they claim that it is more efficient than testing with detailed test cases. This paper reports a replicated experiment comparing effectiveness, efficiency, and perceived differences between ET and test-case-based testing (TCT) using 51 students as subjects, who performed manual functional testing on the jEdit text editor. Our results confirm the findings of the original study: 1) there is no difference in the defect detection effectiveness between ET and TCT, 2) ET is more efficient by requiring less design effort, and 3) TCT produces more false-positive defect reports than ET. Based on the small differences in the experimental design, we also put forward a hypothesis that the effectiveness of the TCT approach would suffer more than ET from time pressure. We also found that both approaches had distinctive issues: in TCT, the problems were related to correct abstraction levels of test cases, and the problems in ET were related to test design and logging of the test execution and results. Finally, we recognize that TCT has other benefits over ET in managing and controlling testing in large organizations.     

A method for predicting the probability of business network profitability

In the design phase of business collaboration, it is desirable to be able to predict the profitability of the business-to-be. Therefore, techniques to assess qualities such as costs, revenues, risks, and profitability have been previously proposed. However, they do not allow the modeler to properly manage uncertainty with respect to the design of the considered business collaboration. In many real collaboration projects today, uncertainty regarding the business’ present or future characteristics is so significant that ignoring it becomes problematic. In this paper, we propose an approach based on the predictive, probabilistic architecture modeling framework (P²AMF), capable of advanced and probabilistically sound reasoning about profitability risks. The P²AMF-based approach for profitability risk prediction is also based on the e³-value modeling language and on the object constraint language. The paper introduces the prediction and modeling approach, and a supporting software tool. The use of the approach is illustrated by means of a case study originated from the Stockholm Royal Seaport smart city project.     

Determination of positional distribution of butyryl groups in milkfat triacylglycerols,triacylglycerol mixtures,and isolated positional isomers of triacylglycerols by gas chromatography and1H nuclear magnetic resonance spectroscopy

Positional isomers (1-butyryl-2X-3Y-rac-glycerol and 2-butyryl-1X-3Y-rac-glycerol;X,Y=long-chain acyls) of saturated triacylglycerols (TAG) with 34 and 40 acyl carbons were shown to separate in two chromatographic peaks on immobilized phenyl(65%) methylsilicone column by gas-liquid chromatography, and on reversed-phase ODS-1 column by high-performance liquid chromatography. The analysis of 500-MHz¹H nuclear magnetic resonance (NMR) spectra showed distinct differences between 2-butyryl-1X-3Y-rac-glycerol and 1-butyryl-2X-3Y-rac-glycerol isomers in the resonance signals of methylene and methine protons of glycerol backbone, and carbon-2 methylene of acyl groups, and methyl protons of butyryl group. The¹H NMR spectra of three interesterified mixtures of three monoacid TAG containing saturated butyrate and caproate TAG and unsaturated butyrate TAG showed that triplets of methyl protons of butyryl groups atsn-1(3)- andsn-2-positions in saturated and unsaturated TAG had similar chemical shifts and that the chemical shift of caproyl methyl protons was different from those of butyryl methyl protons. The positional distribution of butyryl groups in isolated positional isomers of butyrate TAG, interesterified TAG mixtures, and natural and interesterified butteroil can be determined by integration of these signals.     

Ribosome display of mammalian receptor domains

Many mammalian receptor domains, among them a large number of potential therapeutic target proteins, are highly aggregation-prone upon heterologous expression in bacteria. This severely limits functional studies of such receptor domains and also their engineering towards improved properties. One of these proteins is the Nogoreceptor, which plays a central role in mediating the inhibition of axon growth and functional recovery after injury of the adult mammalian central nervous system. We show here that the ligand binding domain of the Nogoreceptor folds to an active conformation in ternary ribosomal complexes, as formed in ribosome display. In these complexes the receptor is still connected, via a C-terminal tether, to the peptidyl tRNA in the ribosome and the mRNA also stays connected. The ribosome prevents aggregation of the protein, which aggregates as soon as the release from the ribosome is triggered. In contrast, no active receptor was observed in phage display, where aggregation appears to prevent incorporation of the protein into the phage coat. This strategy sets the stage for rapidly studying defined mutations of such aggregation-prone receptors in vitro and to improve their properties by in vitro evolution using the ribosome display technology.     

A new method for measuring the transfer of oxygen in liquids. MeasurementS of oxygen transfer from bubbles in water and in water + 1-butanol

At the base of a column of liquid 20 cm in diameter and well over 1 m in height, oxygen bubbles of constant volume were formed and released with a frequency of approximately one bubble per second. Measurements were carried out on bubbles with volumes ranging from 0·2 to 2 cm³. The mass transfer per bubble was determined by measuring the increase in oxygen concentration of the liquid phase with an oxygen electrode and counting the number of bubbles. The results were reproducible within 3 per cent, and it is probable that still better results are attainable with this method.The measurements were initially performed in distilled water to test the apparatus. Later, water—butanol mixtures were employed in order to determine the influence of butanol on the mass transfer. The results of the latter experiments have been checked with a theory published previously [23, 24]. Theory and results appear to be in satisfactory agreement.     

An enterprise architecture framework for multi-attribute information systems analysis

Enterprise architecture is a model-based IT and business management discipline. Enterprise architecture analysis concerns using enterprise architecture models for analysis of selected properties to provide decision support. This paper presents a framework based on the ArchiMate metamodel for the assessment of four properties, viz., application usage, system availability, service response time and data accuracy. The framework integrates four existing metamodels into one and implements these in a tool for enterprise architecture analysis. The paper presents the overall metamodel and four viewpoints, one for each property. The underlying theory and formalization of the four viewpoints is presented. In addition to the tool implementation, a running example as well as guidelines for usage makes the viewpoints easily applicable.     

Oligomerization of phenyl glycidyl ether in the presence of ZnCl2

Summary In the presence of ZnCl₂ phenyl glycidyl ether reacts to different products owing to the ring-opening reaction of the oxirane and the cleavage of the ether bond. Using HPLC and offline mass spectrometry most of the reaction products could be identified.A reaction scheme and the supposed reaction mechanism were described involving the formation of chlorine — containing oligomers and low molecular weight by — products resulting from the cleavage of the ether bond of the monomer. Conclusions were drawn for original polyfunctional epoxy resin systems.     

Furfural Oxidation with Hydrogen Peroxide Over ZSM-5 Based Micro-Mesoporous Aluminosilicates

Micro-mesoporous aluminosilicates based on ZSM-5 zeolite, obtained by a dual template method, as well as in the presence of a dual-functional template (i.e. a Gemini-type surfactant), were tested in the oxidation of furfural with hydrogen peroxide. Even substantial changes in acidity and porosity of the catalysts result in minor variations of selectivity towards the desired products. Application of the synthesized zeolite-based materials in the oxidation of furfural with hydrogen peroxide leads to formation of 2(5H)-furanone (yield up to 28.5%) and succinic acid (up to 19.5%) as the main C4 reaction products. The kinetic model developed previously to treat the results for oxidation of furfural over sulfated zirconia was able to describe the data also for micro-mesoporous aluminosilicates.

Graphical Abstract

     

Analysis of triacylglycerols by silver-ion high-performance liquid chromatography-atmospheric pressure chemical ionization mass spectrometry

Triacylglycerols of the seed oils rich in α- and/or γ-linolenic acid moieties were separated by silver-ion high-performance liquid chromatography (HPLC) followed by on-line atmospheric pressure chemical ionization-mass spectrometric (APCI-MS) detection. Mass spectra of most triacylglycerols exhibited abundant [M + H]⁺ and [M − RCO₂]⁺ ions, which defined the molecular weight and the molecular association of fatty acyl residues of a triacylglycerol, respectively. Silver ions formed weaker complexes with triacylglycerols containing γ-linolenic acid than with those containing α-linolenic acid, i.e., the elution order of molecules wasXYT _γ>XYT _α’,XT _γ T _α>XT _α T _α>, andT _γ T _γ T _γ>T _γ T _γ T _α>T _γ T _α T _α>T _α T _α T _α, whereT _α=α-linolenic acid,T _γ=γ-linolenic acid, andX, Y=fatty acids different from linolenic acid. Furthermore, silver-ion HPLC resulted in partial separation within equally unsaturated triacylglycerols according to differences in the combined number of acyl carbons. Regioisomeric forms of triacylglycerols were not determined from the seed oil samples, although differences were measured with reference compounds in the relative abundances of [M − RCO₂]⁺ ions formed by a loss of a fatty acyl residue from thesn-2 position and thesn-1/3 positions. Silverion HPLC/APCI-MS provided valuable information for structure elucidation of seed oil triacylglycerols: 43 molecular species were identified from cloudberry seed oil, 39 from evening primrose oil, 79 from borage oil, 44 from alpine currant, and 56 from black currant seed oils. The quantitation requires to be studied further, especially in those cases where several molecular weight species of triacylglycerols eluted in a single chromatographic peak.