Verifying Web Applications: From Business Level Specifications to Automated Model-Based Testing

One of reasons preventing a wider uptake of model-based testing in the industry is the difficulty which is encountered by developers when trying to think in terms of properties rather than linear specifications. A disparity has traditionally been perceived between the language spoken by customers who specify the system and the language required to construct models of that system. The dynamic nature of the specifications for commercial systems further aggravates this problem in that models would need to be rechecked after every specification change. In this paper, we propose an approach for converting specifications written in the commonly-used quasi-natural language Gherkin into models for use with a model-based testing tool. We have instantiated this approach using QuickCheck and demonstrate its applicability via a case study on the eHealth system, the national health portal for Maltese residents.Comment: In Proceedings MBT 2014, arXiv:1403.704

Beyond multiregional and simple out-of-Africa models of human evolution

info:eu-repo/semantics/publishedVersio

Primary fallopian tube carcinoma presenting with a solitary metastasis in a Spigelian hernia

Primary fallopian tube carcinoma (PFTC) is a rare gynaecological tumour. Histologically, this type of tumour resembles other tumours of the female reproductive tract, predominantly serous tumours. These cancers are often difficult to distinguish from ovarian cancers and are generally treated with the same standards of surgery and chemotherapy. Diagnosis of PFTC is rarely made preoperatively. Very often, the diagnosis is made either at the operating table or by the pathologist. In this report we present a rare case of PFTC with a solitary metastatic deposit in a right Spigelian hernia, the latter being the initial presenting complaint.peer-reviewe

The use of Positive Matrix Factorization (PMF) in source apportionment of ambient aerosol in the Central Mediterranean

Positive Matrix Factorization (PMF) is a widely used receptor modelling technique in order to determine the nature and contribution of the different aerosol sources modulating ambient levels of particulate matter at a receptor. This cumulative thesis together with the papers included within, reports the results of three source apportionment exercises: a) the isolation of the natural contribution to PM10 levels at a rural background site in Malta; b) the estimation of the contributions of the sources driving PM2.5 levels at a traffic hotspot in Malta and c) a methodological investigation of how PMF can be used on a smaller dataset using samples taken from an agricultural area in Apulia, South eastern Italy. The study on the magnitude of the natural contribution to PM10 involved a sampling campaign at a rural background station in Għarb, Gozo (one of the islands in the Maltese archipelago). This sampling campaign resulted in the collection 224 samples, which were subsequently characterised by inductively coupled plasma mass spectrometry (ICP – MS) and ion chromatography (IC) respectively for, their metallic and ionic content. The use of data resulting from this analysis with PMF resulted in the isolation of the two natural sources expected to be of relevance to Malta (marine aerosol and Saharan dust) as well as in the estimation of their apportionment. PMF also resolved three additional sources: a local crustal source, and two secondary inorganic aerosol components (one rich in nitrate and the other rich in sulfate). The natural sources jointly accounted for approximately 39% of the measured PM10, which is at the upper end of the 0.5 – 58% range determined by previous studies for natural contributions in Europe. A total of 180 membranes sampled throughout 2016 were used in the study on the sources of PM2.5 at a traffic site. These membranes were analysed for: elemental concentrations (using X-ray fluorescence spectroscopy, XRF); ionic content (using IC) and for black carbon – BC (using an optical method). The use of this chemical database with PMF resulted in the isolation of 7 aerosol sources, 4 of which were common to the exercise carried out on PM10 at the rural background site (all the sources except for the local crustal source). The additional three sources isolated at this site were traffic, shipping and fireworks. The isolation of the latter component is itself an interesting result, because it shows that a seasonal activity such as the letting of fireworks during the summer village feasts affects the annual levels of PM2.5. Additionally, this component probably has an effect on human health due to its chemical composition. This work will also provide evidence-based information to the policy makers on the emission reductions required in order for the PM2.5 levels to be compliant with the annual air quality guideline issued by the World Health Organization. Finally, a fundamental methodological investigation on how PMF can be used on a small dataset was carried out. This study is based on 29 PM10 and 33 PM2.5 samples collected from a rural area in Apulia, Italy. PMF did not work correctly when the datasets for the two different fractions were used separately. The datasets were therefore aggregated into a single chemical database of 62 samples and this was then used with PMF. A 5-factor model, which exhibited a fairly good rotational stability was the result of this modelling exercise. This was subsequently further improved through the imposition of constraints based on the chemical constitution of the aerosol sources affecting this receptor, which is made possible by the new features included in the United States Environment Protection Agency PMF version 5. Given the size of the dataset the, the uncertainties in the solution returned by PMF were fully characterised using all the error estimation methodologies included in this version of PMF. Additionally, the results of the PMF modelling were validated against those returned by two other models, Constrained Weighted Non-negative Matrix Factorization (CW – NMF) and Chemical Mass Balance (CMB) as well as through the use of other statistical parameters. These results essentially confirm the validity of the model returned by PMF and indicate that the latter model extracted all the information about the aerosol sources affecting the receptor from the speciation data

Verifying web applications : from business level specifications to automated model-based testing

One of reasons preventing a wider uptake of model-based testing in the industry is the difficulty which is encountered by developers when trying to think in terms of properties rather than linear specifications. A disparity has traditionally been perceived between the language spoken by customers who specify the system and the language required to construct models of that system. The dynamic nature of the specifications for commercial systems further aggravates this problem in that models would need to be rechecked after every specification change. In this paper, we propose an approach for converting specifications written in the commonly-used quasi-natural language Gherkin into models for use with a model-based testing tool. We have instantiated this approach using QuickCheck and demonstrate its applicability via a case study on the eHealth system, the national health portal for Maltese residents.peer-reviewe

Spatio-temporal analysis of air pollution data in Malta

Air pollution measurements display patterns over space and time allowing for spatio-temporal modelling, through which pollution concentrations and trends can be analysed. In Malta, the MEPA (Malta Environment and Planning Authority) collects monthly averaged data for various pollutants from a network of 123 diffusion tubes located around the Islands (Figure 1). This preliminary study uses data associated with traffic, that is nitrogen dioxide (NO2) and benzene, collected monthly between the period 2004 and 2010 with the objectives to i) develop a computationally efficient method that best describes the data; ii) determine the level of dependency of each site on neighbouring ones and iii) identify any factors that affect the behaviour and patterns of pollution. Results will show that generally there is a low spatial dependency between close sites, thus implying that local sources, rather than diffusion, have a predominant effect on the measurements. This analysis will prove valuable in MEPA’s redistribution exercise of the diffusion tube network to determine which sites are necessary to retain and which sites can be removed without significantly affecting the information gathered.peer-reviewe

Maximizing negative thermal expansion via rigid unit modes : a geometry-based approach

Existent rigid unit mode (RUM) models based on rotating squares, which may explain the phenomenon of negative thermal expansion (NTE), are generalized so as to assess the NTE potential for novel systems made from rectangular or rhombic rigid units. Analytical models for the area coefficients of thermal expansion (CTE) of these innovative networks are derived in an attempt to determine the optimal geometrical parameters and connectivity for maximum NTE. It was found that all systems exhibit NTE, the extent of which is determined by the shape and connectivity of the elemental rigid units (side lengths ratio or internal angle). It was also found that some of the networks proposed here should exhibit significantly superior NTE properties when compared with the well-known network of squares, and that for optimal NTE characteristics, pencil-like rigid units should be used rather than square-shaped ones, as these permit larger pore sizes that are more conducive to NTE. All this compliments earlier work on the negative Poisson's ratio (auxetic) potential of such systems and may provide a route for the design of new materials exhibiting superior thermo-mechanical characteristics including specifically tailored CTEs or giant NTE characteristics.peer-reviewe

Taking social networks to the next level

Since the boom of social networking lead to people using multiple account on many platforms in order to keep in touch with hundreds of contacts, managing one's contacts risks becoming a burden for many users. Following and finding information about friends and family has become an issue too. Guided by these observations and by careful research of existing adaptive web technologies, our team worked on the development of SNAP - an adaptive social network integrator which aimed to amalgamate various social networks (Facebook, Twitter and Flickr) in one adaptive environment, which unobtrusively sorts the users' feed according to his/her preference. To achieve data transfer and authorisation, SNAP uses the newest version of the OAuth protocol. Adaptivity was achieved through statistical filtering. The initial field tests show that the system works, however there is definitely room for improvement in terms of Social Network Integration, and testers generally expressed an interest in the idea of using an adaptive social integrator such as SNAP. On top of this, we will be suggesting a number of improvements which will change the way we use social networks forever.peer-reviewe

SNAP : the social network adaptive portal

Since the boom of social networking lead to people using multiple account on many platforms in order to keep in touch with hundreds of contacts, managing one's contacts risks becoming a burden for many users. Following and finding information about friends and family has become an issue too. Guided by these observations and by careful research of existing adaptive web technologies, our team worked on the development of SNAP - an adaptive social network integrator which aimed to amalgamate four social networks (Facebook, Twitter, Flickr and Buzz) in one adaptive environment, which to unobtrusively sort the users' feed according to his/her preference. To achieve data transfer and authorisation, SNAP used APIs and the newest version of the OAuth protocol. Adaptivity was achieved through statistical filtering. Despite efforts, the initial field tests show that the system is not as yet ready to be launched for wider use. However, there is room for improvement in terms of Social Network Integration, and tester users expressed an interest in the idea of using an adaptive social integrator such as SNAP.peer-reviewe