DEPROVAL: herramienta para la definición del proceso de validación en pequeñas organizaciones de software

En el presesente artículo se presenta una herramienta para la definnición de los procesos de validación de software. La herramienta está implementada en base a un metamodelo de validación de software basado en el modelo CMMI. La herramienta facilita que las pequeñas organizaciones de software que presentan diferentes dificultades como es aplicar los modelos de mejora a su organización y falta de personal con conocimiento en pruebas, puedan establecer los procesos de validacion de sus productos a través de la herramienta

Una aproximación basada en metamodelado del área de proceso de Validación del CMMI: un caso de estudio

En el presente artículo se establece una aproximación para la mejora de procesos a través del área de proceso de validación del CMMI, mediante un enfoque basado en metamodelado. Se consideró el área de proceso de Validación, específicamente la meta SG1 preparar la validación. Mediante el metamodelo, se definen una taxonomía de proyectos, la caracterización de pruebas, plantillas de pruebas para el producto a validar, para el entorno de validación, para los procedimientos y criterios de prueba, y un plan de pruebas. La aproximación fue sometida a evaluación, por medio de un caso de estudio. El caso de estudio se llevó a cabo en la Dirección de Informática, de una institución de educación superior pública. La aproximación demostró su validez, ya que, los probadores consideran que les aporta las pruebas específicas para el desarrollo del proceso de validación y es permite preparar la validación para un proyecto determinado

Justified test foci definition an empirical approach

Since complete testing is not possible, testers have to focus their effort on those parts of the software which they expect to have defects, the test foci. Despite the crucial importance of a systematic and justified definition of the test foci, this task is not well established in practice. Usually, testing resources are uniformly distributed among all parts of the software. A risk of this approach is that parts which contain defects are not sufficiently tested, whereas areas that do not contain defects attain too much consideration. In this thesis, a systematic approach is introduced that allows testers to make justified decisions on the test foci. For this purpose, structural as well as historical characteristics of the software’s past releases are analysed visually and statistically in order to find indicators for the software’s defects. Structural characteristics refer to the internal structure of the software. This thesis concentrates on the analysis of bad software characteristics, also known as “bad smells”. Historical characteristics considered in this thesis are the software’s change history and the software’s age. Simple and combined analyses of defect variance are introduced in order to determine indicators for defects in software. For this purpose, the defect variance analysis diagram is used to explore the relationship between the software’s characteristics and its faultiness visually. Then, statistical procedures are applied in order to determine whether the results obtained visually are statistically significant. The approach is validated in the context of open source development as well as in an industrial setting. For this purpose, seven open source programs as well as several releases of a commercial program are analysed. Thus, the thesis increases the empirical body of knowledge concerning the empirical validation of indicators for defects in software. The results show that there is a subset of bad smells that are well suited as indicators for defects in software. A good indicator in most of all analysed programs is the “God Class” bad smell. Among the historical characteristics analysed in the industrial context, the number of distinct authors as well as the number of changes performed to a file proved to be useful indicators for defects in software

Bioaerosol detection through simultaneous measurement of particle intrinsic fluorescence and spatial light scattering

Interest in the role and detection of airborne biological micro-organisms has increased dramatically in recent years, in part through heightened fears of bioterrorism. Traditional bio-detection methods have generally slow response times and require the use of reagents. Conversely, techniques based on light scattering phenomena are reagent-free and are able to operate in real-time. Previous research has established that classification of certain types of airborne particles on the basis of shape and size may be achieved through the analysis of the spatial light scattering patterns produced by individual particles. Similarly, other research has shown that the intrinsic fluorescence of particles excited by radiation of an appropriate wavelength can be used to establish the presence of biological particles, provided background particles with similar fluorescence properties are not present. This is often not the case. This thesis, therefore, describes the design, development, and testing of a new type of bioaerosol detection instrument in which the advantages of both particle spatial light scattering analysis and intrinsic fluorescence are exploited. The instrument, referred to as the Mult- Parameter Aerosol Monitor (MPAM), is unique in simultaneously recording data relating to the size, shape, and fluorescence properties of individual airborne particles at rates up to several thousand particles per second. The MPAM uses a continuous-wave frequency quadrupled Nd: YVO4 laser to produce both spatial scattering and fluorescence data from particles carried in single-file through the laser beam. This use of a CW laser leads to opto-mechanical simplicity and reduces fluorescence bleaching effects. A custom-designed multi-pixel Hybrid Photodiode (HPD) detector is used to record the spatial scattering data in forward scattering plane whilst particle fluorescence is recorded via a large solid-angle ellipsoidal reflector and single photomultiplier detector. Calibration tests and experimental trials involving a range of both biological and nonbiological aerosols have shown that the MPAM, when supported by appropriate data analysis algorithms, is capable of achieving enhanced levels of discrimination between biological and non-biological particles down to the submicrometre sizes and, in some cases, enhanced discrimination between classes of biological particle

Mechanisms and modelling of stringer debonding in post-buckled carbon-fibre composite stiffened panels

Imperial Users onl

Physicochemical studies of a novel adjuvant and conjugate vaccines

Includes abstract.Includes bibliographical references.South African children currently receive vaccines against Diphtheria, Tetanus, Pertussis (administered as DTP), Hepatitis B (HBV) and Haemophilus influenzae type b (Hib) at 6, 10 and 14 weeks. The use of combination vaccines provides a means of avoiding the logistical problems and costs associated with multiple injections of these different vaccines. A local vaccine manufacturer is in the process of developing a combined tetravalent DTP-HBV as well as a liquid pentavalent DTP-HBV-Hib vaccine. The Hib vaccine is a glycoconjugate in which Haemophilus influenzae type b capsular polysaccharide (polyribosylribitolphosphate or PRP) is conjugated to a carrier protein. The conjugate is immunogenic in infants who have a higher risk of infection while the polysaccharide vaccine is not. The compatibility of the Hib antigenic component in the presence of the other antigens and adjuvant presents a challenge. Aluminium containing adjuvants have been the most widely used adjuvants in human vaccines. Aluminium hydroxide has been found to catalyse the hydrolysis of PRP when added to Hib conjugate vaccines. Although this can be circumvented by the use of aluminium phosphate, there is a need for new adjuvants that elicit broader immune responses. This thesis presents a study of the size, structure and composition of a locally developed experimental adjuvant called Pheroid™ by use of NMR spectroscopy and Coulter Counter. NMR analysis of Pheroid™ formulations provided a structural fingerprint for the formulations and indicated the relative proportions of the major components present, whereas their particle size distribution was profiled using a Coulter Counter. The average size distribution was similar in the formulations tested including those that had been activated using nitrous oxide. The primary focus of this thesis was the application of appropriate physicochemical procedures for evaluation of the locally manufactured Hib vaccine alone and when in combination with DTP-HBV-Hib. Investigating the stability and integrity of Hib conjugate vaccines requires determination of the total saccharide and unbound or free saccharide which is expressed as the percentage of free saccharide present. In the absence of a suitable Hib conjugate, model compounds such as human serum albumin (HSA) , meningococcal group A polysaccharide (PsA) and the derived conjugate (Mn A-IT) were used to investigate three methods of free saccharide separation: solid phase extraction (SPE), acid precipitation using deoxycholate (DOC/HCI) and ultrafiltration (UF). At physiological pH, the binding capacity was low and so the SPE method was not investigated further. For Mn A-IT the DOC/HCI method generally gave lower free saccharide values than the UF method; this was attributed to entrapment and coprecipitation of free saccharide by DOC/HCI. In contrast, washing steps in the UF method ensured good free saccharide recovery. A colorimetric assay for phosphorus and high performance anion exchange chromatography with pulsed amperometric detection (HPAEC-PAD) were investigated for saccharide quantification in Mn A-TT vaccines. The HPAEC-PAD method for the monomer (mannosamine-6-phosphate from acid hydrolysis) permitted higher specificity and sensitivity for the free saccharide analysis compared to the phosphate assay. The DOC/HCI and UF methods were compared by their application to Mn A-TT samples subjected to an accelerated stability study