Classification of model transformation techniques used in UML-based Web engineering

Software development techniques are continuously evolving with the goal of solving the main problems that still affect the building and maintenance of software systems: time, costs and error-proneness. Model-driven engineering (MDE) approaches aim to reduce at least some of these problems providing techniques for the construction of models and the specification of transformation rules, tool support and automatic generation of code and documentation. The method of resolution of MDE is to first build models, which are independent of the platform, transforming them in later stages to technological-dependent models, and to achieve automatic model and code generation based on transformation rules. Web engineering is a domain where model-driven approaches can be used to address evolution and adaptation of Web software to continuously emerging new platforms and changes in technologies. We present an overview of the development process of the Unified Modelling Language (UML)-based Web engineering (UWE) defined as an MDE approach. The main characteristic of UWE is the use of standards including the UML, XML metadata interchange as model exchange, meta-object facility for metamodelling, model-driven architecture and the transformation language query-view-transformation. We focus on the model transformation aspects of the UWE process.     

Hybrid finite-element method for discretising cylindrically symmetric parts in electrotechnical models

In many technical devices such as transformers and electrical machines, large differences in geometric dimensions are observed. As a consequence, the generation of a 3D computational grid for the whole device leads to unacceptably large numbers of elements or can even fail. In addition to the commonly applied cartesian or cylindrical symmetries of the overall geometry, the model can be subdivided into parts featuring translational or cylindrical symmetries. Such parts are discretised separately, accounting for the local symmetry, and are then combined with the surrounding 3D model. Excitations and boundary conditions of the submodels are not necessarily symmetric but are expected to be smooth in the direction of the symmetry. Then, the field distribution at the interface is well approximated by a set of spectral elements along the dimension of symmetry. Coupling between the model parts is carried out by means of Lagrange multipliers. A single-phase transformer with thin insulation sheets is taken as an example to illustrate the proposed hybrid discretisation. The cross-section of the cylindrically symmetric part containing thin sheets, is represented by a fine 2D finite-element mesh so that all the geometrical details can be resolved, and the rest of the structure is discretised by a 3D mesh. Nevertheless, a fully 3D field distribution is calculated in all model parts. Only a small number of harmonic functions is needed to account for the azimuthal field variation at the cylindrical interface. Hence, the number of unknowns in the numerical model is reduced significantly, while a high level of accuracy is maintained     

Linewidth and alpha-factor of detuned-loaded DBR lasers

The authors report measurements of the α-factor and linewidth of DBR (distributed Bragg reflector) lasers fabricated with weak grating constants. Such devices exhibit detuned-loading effects, and the measured values depend strongly on the tuning current of the Bragg section. α-factor behavior is found to agree with earlier theoretical predictions. Linewidth behavior is shown to be dominated by carrier shot noise in the tuning section. A theoretical analysis of the DBR laser is outlined including detuned loading and carrier shot noise effect     

Distribution of diethylstilboestrol in pigs

The synthetic growth promoter diethylstilboestrol (DES) administered orally to pigs can be detected by radioimmunoassay (RIA) analysis of kidney, liver, faeces, bile and urine from animals fed continuously to slaughter, but not in muscle, fat or plasma. If treated animals are fed on material not containing DES for 72 h prior to slaughter, then the levels of parent compound and metabolite in all products decrease to become not significantly greater than those in control animals. The gross metabolism of DES in pigs and bovines appears to be similar.     

Pilot experiments with electrodialysis and ozonation for the production of a fertiliser from urine.

Pilot tests were performed with a process combination of electrodialysis and ozonation for the removal of micropollutants and the concentration of nutrients in urine. In continuous and batch experiments, maximum concentration factors up to 3.5 and 4.1 were obtained, respectively. The desalination capacity did not decrease significantly during continuous operation periods of several weeks. Membrane cleaning after 195 days resulted in approximately 35% increase in desalination rate. The Yeast Estrogen Screen (YES), a bioassay that selectively detects oestrogenic compounds, confirmed that about 90% of the oestrogenic activity was removed by electrodialysis. HPLC analysis showed that ibuprofen was removed to a high extent, while other micropollutants were below the detection limit. In view of the fact that ibuprofen is among the most rapidly transported micropollutants in electrodialysis processes, this result indicates that electrodialysis provides an effective barrier for micropollutants. Standardised plant growth tests were performed in the field with the salt solution resulting from the treatment by electrodialysis and subsequent ozonation. The results show that the plant height is comparable to synthetic fertilisers, but the crop yield is slightly lower. The latter is probably caused by volatilisation losses during field application, which can be prevented by improved application technologies.     

Correction to: Where do university graduates live? – a computer vision approach using satellite images

Applied Intelligence - A Correction to this paper has been published: https://doi.org/10.1007/s10489-021-02433-z     

Fast full‐color reflective display via photoluminescent enhancement

Reflective displays are advantageous in applications requiring low power or daylight readability. However, there are no low‐cost reflective technologies capable of displaying bright colors. By employing photoluminescence to more efficiently use ambient light, we created a prototype display that provides bright, full color in a simple, low‐cost architecture. This prototype includes a novel electrokinetic shutter, a layer that incorporates patterned luminescent red, green, and blue sub‐pixel elements, and a novel optical out‐coupling scheme. The luminescent elements convert otherwise‐wasted portions of the incident spectrum to light in the desired color band, resulting in improved color saturation and lightness. This prototype provides a color gamut that is superior to competing reflective display technologies that utilize color filters in single‐layer side‐by‐side sub‐pixel architectures. The current prototype is capable of switching in <0.5 s; future displays based on an alternative electro‐optic shutter technology should achieve video rate operation. A transflective version of this technology has also been prototyped. The transflective version utilizes its backlight with a power efficiency that is at least three times that of a conventional liquid crystal display. These photoluminescence‐based technologies enable a host of applications ranging from low‐power mobile products and retail pricing signage to daylight readable signage for outdoor advertising segments.     

Formation of amorphous Ni-Zr alloy powder by mechanical alloying of intermetallic powder mixtures and mixtures of nickel or zirconium with intermetallics

Mechanical alloying was used to synthesize Ni_xZr_1–x alloys from mixtures of intermetallic compound powders, and also from mixtures of intermetallic compound powders and pure elemental powders. The mechanically alloyed powders were amorphous in the range 0.24 x 0.85. This range is larger than amorphous alloys produced by the melt-spinning technique and mechanical alloying of elemental crystalline powders. Two-phase mixtures of the amorphous phase and the corresponding crystalline terminal solid solution were formed in the range 0.10 x 0.22, and x=0.90. It is found that the morphological development during mechanical alloying of these powders is different from mechanical alloying using only pure ductile crystalline elemental powders. The thermal stability has been investigated. The enthalpy and activation energy of crystallization for Ni-Zr amorphous powders prepared by mechanical alloying are lower than those for melt-spun samples of the same composition. The crystallization temperature of the mechanically alloyed Ni-Zr amorphous powders is higher than that of meltspun samples in the composition range Ni₂₀Zr₈₀ to Ni₃₃Zr₆₇ and Ni₄₀Zr₆₀ to Ni₆₀Zr₄₀. The presence of tiny crystallites as nucleation centres and high oxygen levels in the mechanically alloyed amorphous alloys might be responsible for the differences in crystallization behaviour. A new crystalline metastable phase was observed during crystallization studies of Ni₂₄Zr₇₆ amorphous powder.     

Luminescent Amphiphilic Aminoglycoside Probes to Study Transfection

We report the characterization of amphiphilic aminoglycoside conjugates containing luminophores with aggregation-induced emission properties as transfection reagents. These inherently luminescent transfection vectors are capable of binding plasmid DNA through electrostatic interactions; this binding results in an emission “on” signal due to restriction of intramolecular motion of the luminophore core. The luminescent cationic amphiphiles effectively transferred plasmid DNA into mammalian cells (HeLa, HEK 293T), as proven by expression of a red fluorescent protein marker. The morphologies of the aggregates were investigated by microscopy as well as ζ-potential and dynamic light-scattering measurements. The transfection efficiencies using luminescent cationic amphiphiles were similar to that of the gold-standard transfection reagent Lipofectamine® 2000.