Detecting Web requirements conflicts and inconsistencies under a model-based perspective

Web requirements engineering is an essential phase in the software project life cycle for the project results. This phase covers different activities and tasks that in many situations, depending on the analyst's experience or intuition, help getting accurate specifications. One of these tasks is the conciliation of requirements in projects with different groups of users. This article presents an approach for the systematic conciliation of requirements in big projects dealing with a model-based approach. The article presents a possible implementation of the approach in the context of the NDT (Navigational Development Techniques) Methodology and shows the empirical evaluation in a real project by analysing the improvements obtained with our approach. The paper presents interesting results that demonstrate that we can get a reduction in the time required to find conflicts between requirements, which implies a reduction in the global development costs.     

Strengthening Brady’s Paraconsistent 4-Valued Logic BN4 with Truth-Functional Modal Operators

?ukasiewicz presented two different analyses of modal notions by means of many-valued logics: (1) the linearly ordered systems ?3,..., Open image in new window ,..., \(\hbox {L}_{\omega }\); (2) the 4-valued logic ? he defined in the last years of his career. Unfortunately, all these systems contain “?ukasiewicz type (modal) paradoxes”. On the other hand, Brady’s 4-valued logic BN4 is the basic 4-valued bilattice logic. The aim of this paper is to show that BN4 can be strengthened with modal operators following ?ukasiewicz’s strategy for defining truth-functional modal logics. The systems we define lack “?ukasiewicz type paradoxes”. Following Brady, we endow them with Belnap–Dunn type bivalent semantics.     

MQDM: An Iterative Fuzzy Method for Group Decision Making in Structured Social Networks

Modern human societies have evolved into an almost entirely connected world, giving place to a remarkable increase in social interactions. In this new context and because of the globalization of all human activities, the collective participation in decision‐making processes takes an increasingly prominent role. In this paper, a method for group decision making from a set of imprecise opinions called “moviQuest Decision Making” (MQDM), is presented. This method allows to integrate the opinions of heterogeneous groups of agents in a structured social network along a sequence of voting rounds for collective decision making.     

Electro-thermal modeling of multifinger AlGaN/GaN HEMT device operation including thermal substrate effects

AlGaN/GaN high electron mobility transistor (HEMT) device operation was modeled from the sub-micrometer scale to the substrate using a combination of an electro-thermal device model for the active device with realistic power dissipation within the device and a coupled three dimensional thermal model to account for the substrate. Temperatures for various points within a device were determined as a function of biasing conditions, substrate thickness and temperature, number of fingers, and gate length and pitch. As an example, we have used our model to show that life test results of industry-relevant devices can be significantly affected by the exact testing technique used.     

The thermocapillary migration of gas bubbles in a viscoelastic fluid

The steady thermocapillary flow of a spherical bubble in a linear temperature field is analyzed by considering that the continuous phase is a weak viscoelastic fluid. Convective heat and momentum transfers are neglected but the action of gravity is taken into account. The problem is formulated for non shear thinning elastic fluids which may be described by the Olroyd-B constitutive equation. The analysis is restricted to weak elastic fluids, an assumption that in dimensionless terms is equivalent to assuming that the Weissenberg number Wi=λ/t_c where λ is the relaxation time of the fluid and t_c the scale time of the flow, is small compared to unity. Thus, the corresponding boundary value problem is solved following a perturbation procedure by regular expansions of the kinematic and stress variables in powers of Wi (retarded motion expansion). Velocity fields as well as the force exerted by the fluid upon the bubble are determined at second order in Wi. It is shown that when the motion is driven by buoyancy in the presence of surface tension forces of a comparable order of magnitude, the velocity fields are strongly affected. Unlike the newtonian case where the recirculation region generated is symmetrical, in a non-newtonian fluid elastic effects produce a breaking of symmetry, so that this region is enhanced and shifted in the downstream direction. The analysis also provides the second order correction to both the terminal velocity and the temperature gradient needed to hold the bubble at rest.     

Theoretical study of the gap evolution of In2X3 (X=O, S, Se, Te) with lattice compression

We report a systematic study of the electronic structure of In₂X₃ (X=O, S, Se, Te) semi-conductors using the ab initio tight-binding linear muffin-tin orbital (TB-LMTO) method. Taking into account the experimental structure of each compound we have determined the gap evolution under lattice compression in the whole series. We have found that the compression of the lattice produces an enhancement of the energy gap. This could be driven in some cases by doping with shallow impurities.     

Familial aggregation of arterial pressure figures and weight indices: study in Cuenca

BACKGROUND: The aim of this study was to assess the familial aggregation of blood pressure and body mass index levels in schoolchildren of Cuenca city, Spain. SUBJECTS AND METHODS: A cross sectional study was made including 307 both sexes schoolchildren 9-12 years old recruited in three schools of Cuenca city, and 346 of their parents. There were determined sociodemographics variables, weight, height, body mass index, SBP, DBP and fasting plasma total cholesterol, cLDL, cHDL and triglyceride concentrations. RESULTS: Parents-children correlation coefficients in blood pressure levels ranged between -0.1 and 0.2. Parents-daughters correlations were stronger than parents-sons in ponderal indexes. The relationship of ponderal indexes and blood pressure between spouses was weak, with correlation coefficients between 0.08 y 0.1. By stepwise multiple regression analysis it was found that the only variable that explained a significant percentage of blood pressure variability (both systolic and diastolic) was the weight of the schoolchildren in both sexes. Parents body mass index explained more than 32% of body mass index daughter's variability. In sons any variable explained a significant percentage of variability. CONCLUSIONS: The parents-children aggregation of blood pressure is weak. Parents-children aggregation of ponderal indexes is stronger, though there are considerable sex-differences. Spouses relationship, though positive, is weak in all variables.     

Nitrogen solubility in CaO-CaF2-SiO2 melts

The preceding paper^[5] demonstrated that nitrogen dissolves in silicate melts either as a free ion or complex anion, being incorporated into silicate networks. In the present study, the influence of CaF₂ addition to CaO-SiO₂ melts on the nitrogen solubility was investigated along the liquidus at 1573 K and within the liquidus at 1723 K at constant CaF₂ levels. In the latter case, as the SiO₂ content increases from CaO saturation, the total nitrogen content decreases to reach the minimum and then starts to increase up to the SiO₂ saturation. This is in accord with the abovementioned mechanism of nitrogen dissolution, which is supported by the changing behavior of free and incorporated nitrogen contents with the slag composition. The role of CaF₂ is complicated through the formation of fluorosilicates. The CaF₂ seems not to function simply as a diluent but to enhance the dissolution of nitrogen by releasing oxygen from silicate networks, promoting the formation of free nitride ions. Formerly Graduate Student, Department of Metallurgy, The University of Tokyo.