Non-functional requirements: size measurement and testing with COSMIC-FFP

The non-functional requirements (NFRs) of software systems are well known to add a degree of uncertainty to process of estimating the cost of any project. This paper contributes to the achievement of more precise project size measurement through incorporating NFRs into the functional size quantification process. We report on an initial solution proposed to deal with the problem of quantitatively assessing the NFR modeling process early in the project, and of generating test cases for NFR verification purposes. The NFR framework has been chosen for the integration of NFRs into the requirements modeling process and for their quantitative assessment. Our proposal is based on the functional size measurement method, COSMIC-FFP, adopted in 2003 as the ISO/IEC 19761 standard. Also in this paper, we extend the use of COSMIC-FFP for NFR testing purposes. This is an essential step for improving NFR development and testing effort estimates, and consequently for managing the scope of NFRs. We discuss the merits of the proposed approach and the open questions related to its design

Anaerobic membrane bioreactors: Are membranes really necessary?

Membranes themselves represent a significant cost for the full scale application of anaerobic membrane bioreactors (AnMBR). The possibility of operating an AnMBR with a self-forming dynamic membrane generated by the substances present in the reactor liquor would translate into an important saving. A self-forming dynamic membrane only requires a support material over which a cake layer is formed, which determines the rejection properties of the system. The present research studies the application of self-forming dynamic membranes in AnMBRs. An AnMBR was operated under thermophilic and mesophilic conditions, using woven and non woven materials as support for the dynamic membranes. Results showed that the formation of a cake layer over the support materials enables the retention of more than 99% of the solids present in the reactor. However, only low levels of flux were achieved, up to 3 L/m2 x h, and reactor operation was unstable, with sudden increases in filtration resistance, due to excessive cake layer formation. Further fine-tuning of the proposed technology involves looking for conditions that can control effectively cake layer formatio

Anisotropy of permeability, P-wave velocity and electrical resistivity of Upper Cretaceous carbonate samples from Tushka Area, Western Desert, Egypt

Petrophysical properties (such as porosity, permeability, grain density, bulk density, electrical resistivity, and P-wave velocity), as well as the anisotropy of the permeability, seismic velocity (P-wave velocity) and electrical resistivity were characterized in 42 carbonates (limestone) rock samples, collected from shallow wells (seven wells encountered the Upper Cretaceous carbonate rocks with variation in thickness, where well 1 encountered 50 ft thick Nubian sandstone, which decreased to about 30 ft thickness in well 7) from Tushka area, Egypt. The petrographic investigation of the studied carbonate rock samples shows three microfacies associations: Facies1 (MFA-1) is mainly an oolitic, low dolomitic and low glauconitic, fossil-rich packstone with a tendency towards floatstone or rudstone, Facies 2 (MFA-2) is mainly a glauconite rich, low dolomitic floatstone with some tendencies towards rudstone and Facies3 (MFA-3) is mainly a sparry calcite-cemented, low dolomitic rudstone rich in glauconite and iron minerals. The MFA-2 with the lowest average density and highest average porosity is characterized by a strong anisotropy of both permeability and electrical resistivity. The values of the anisotropy ratio of seismic velocity (P-wave velocity) are close to one for all facies, this means that no anisotropy can be detected in the seismic velocity. A comparison between the coefficients of anisotropy reveals that the anisotropy of electrical resistivity and permeability are related to each other

Young LMC clusters: the role of red supergiants and multiple stellar populations in their integrated light and CMDs

The optical integrated spectra of three LMC young stellar clusters (NGC 1984, NGC 1994 and NGC 2011) exhibit concave continua and prominent molecular bands which deviate significantly from the predictions of single stellar population (SSP) models. In order to understand the appearance of these spectra, we create a set of young stellar population (MILES) models, which we make available to the community. We use archival International Ultraviolet Explorer integrated UV spectra to independently constrain the cluster masses and extinction, and rule out strong stochastic effects in the optical spectra. In addition, we also analyze deep colour-magnitude diagrams of the clusters to provide independent age determinations based on isochrone fitting. We explore hypotheses including age-spreads in the clusters, a top-heavy initial mass function, different SSP models and the role of red supergiant stars (RSG). We find that the strong molecular features in the optical spectra can only be reproduced by modeling an increased fraction of about 20 per cent by luminosity of RSG above what is predicted by canonical stellar evolution models. Given the uncertainties in stellar evolution at Myr ages, we cannot presently rule-out the presence of Myr age-spreads in these clusters. Our work combines different wavelengths as well as different approaches (resolved data as well as integrated spectra for the same sample) in order to reveal the complete picture. We show that each approach provides important information but in combination can we better understand the cluster stellar populations.Comment: Accepted for publication in MNRA

Multi-Scale Cardiovascular Flow Analysis by an Integrated Meshless-Lumped Parameter Model

A computational tool that integrates a Radial basis function (RBF)-based Meshless solver with a Lumped Parameter model (LPM) is developed to analyze the multi-scale and multi-physics interaction between the cardiovascular flow hemodynamics, the cardiac function, and the peripheral circulation. The Meshless solver is based on localized RBF collocations at scattered data points which allows for automation of the model generation via CAD integration. The time-accurate incompressible flow hemodynamics are addressed via a pressure-velocity correction scheme where the ensuing Poisson equations are accurately and efficiently solved at each time step by a Dual-Reciprocity Boundary Element method (DRBEM) formulation that takes advantage of the integrated surface discretization and automated point distribution used for the Meshless collocation. The local hemodynamics are integrated with the peripheral circulation via compartments that account for branch viscous resistance (R), flow inertia (L), and vessel compliance (C), namely RLC electric circuit analogies. The cardiac function is modeled via time-varying capacitors simulating the ventricles and constant capacitors simulating the atria, connected by diodes and resistors simulating the atrioventricular and ventricular-arterial valves. This multi-scale integration in an in-house developed computational tool opens the possibility for model automation of patient-specific anatomies from medical imaging, elastodynamics analysis of vessel wall deformation for fluid-structure interaction, automated model refinement, and inverse analysis for parameter estimation

Meshless 2D direct numerical simulation and heat transfer in a backward-facing step with heat conduction in the step

A meshless direct pressure-velocity coupling procedure is presented to perform Direct Numerical Simulations (DNS) and Large Eddy Simulations (LES) of turbulent incompressible flows in regular and irregular geometries. The proposed method is a combination of several efficient techniques found in different Computational Fluid Dynamic (CFD) procedures. With this new procedure, preliminary calculations with 2D steady state flows show that viscous effects become negligible faster that ever predicted numerically. The fundamental idea of this method lays on several important inconsistencies found in three of the most popular techniques used in CFD, segregated procedures, as well as in other formulations. The inconsistencies found become important in elliptic flows and they might lead to some wrong solutions. Preliminary calculations done in 2D laminar flows, suggest that the numerical diffusion and interpolation error are much important at low speeds, mainly when both, viscous and inertia forces are present. With this competitive and efficient procedure, the solution of the 2D Direct Numerical Simulation of turbulent flow with heat transfer on a backward-facing step is presented. The thermal energy is going to be transferred to the fluid through conduction on the step, with both constant temperature and heat flux conditions in the back wall of the step. The variation of the local Nusselt Number through the wall will be studied and its corresponding effect in the energy transfer to the fluid

Some Comparative Anatomical and Histological Studies on the Laryngeal Cartilages of Buffaloes, Camels and Donkeys

Comparative studies concerned the upper air ways of domestic animals are few. So this study was carried out to compare between the larynx of buffaloes, camels and donkeys. The present investigation was carried out on 39 larynxes, 13 larynxes (7 males, 6 females) of each species. Ten heads from each species were used for gross anatomical study; the remained three heads were used for the histological study. Results revealed that, the laryngeal cartilages of the three species were consisted of three single cartilages; the thyroid, the cricoid and the epiglottis, and two paired cartilages; the arytenoid and the corniculate. The cuneiform cartilages were paired cartilages present only in the larynx of the donkey. Thyroid, arytenoid and cricoid cartilages were of hyaline type, while the epiglottis, cuniform and corniculate cartilages and the vocal process of the arytenoid cartilage were of elastic type. The laryngeal epithelium of aditus laryngis, greater part of epiglottis and vocal folds was lined by non-keratinized stratified squamous epithelium. The remained parts of laryngeal epithelium from base of epiglottis and entire parts caudal to vocal folds were lined by pseudostratified columnar ciliated epithelium with goblet cells. The laryngeal glands of lamina propria were of mixed types in buffaloes and donkeys but in camels it was pure mucous glands. This study will fill a gap in the field of comparative anatomy and help other clinical investigation applied on these animals

Some Comparative Anatomical Studies on the Laryngeal Muscles and Cavity of Buffaloes, Camels and Donkeys

The aim of this study was to compare between the laryngeal muscles and cavity in buffaloes, camels and donkeys. A total of 30 larynxes (10 larynxes from each species) were subjected to study. In the three species, the laryngeal muscles were similar to those of other domestic animals, but the hyoepiglotticus muscle of camel was remarkably longer. Although the thyroarytenoideus muscle was undivided in the buffalo and camel, the slightly deeper lateral ventricle in camel, allowed the muscle anterior part to be covered with mucous membrane forming the vestibular fold. The laryngeal cavity of donkey was characterized by the presence of lateral laryngeal saccule that located between the two separate parts of thyroarytenoideus muscle, the vestibular and vocal muscles; the presence of two small pouches on both sides of median laryngeal recess, and the cuneiform tubercle, which was a mucosal elevation that covered the cuneiform process. This study will fill a gap in the field of comparative anatomy and help other clinical investigation applied on these animals

Comparative Anatomy of the Nasal Cavity in Buffaloes, Camels and Donkeys.

The aim of this study was to reveal the comparative anatomy of the nasal cavity in buffaloes, donkeys and camels. It was carried out on 30 heads of apparently healthy adult animals, 10of each species. Heads were fixed and used for gross and cross sectional anatomy. The study provided information about the peculiarities of nasal anatomy in each species. The conchal arrangement was greatly different in camels, while that of buffaloes and donkeys were similar to other ruminants and equine. In camels, the nasal conchae were condensed in the caudal two thirds, the ventral nasal concha was shorter and twisted and the alar and basal folds were raised from a common extension. Camels have a vestibular pouch known as lateral nasal diverticulum. It was a cylindrical tube anatomically different from the nasal diverticulum of donkeys and other equine. The cartilaginous skeleton of narial aperture was reduced in donkeys and camels. Moreover, the rostral portion of nasal septum in camels was formed of muscles instead of cartilage. In the three species, vomeronasal organ and dorsal and ventral swelling bodies were present on both sides of the nasal septum. However, in camels the vomeronasal organ was notably longer and wider. In conclusion, the anatomy of camel nasal cavity in contrast to other domestic animals was presented interesting anatomical features similar to those of proboscis-bearing mammals

An Inverse POD-RBF Network Approach to Parameter Estimation in Mechanics

An inverse approach is formulated using proper orthogonal decomposition (POD) integrated with a trained radial basis function (RBF) network to estimate various physical parameters of a specimen with little prior knowledge of the system. To generate the truncated POD-RBF network utilized in the inverse problem, a series of direct solutions based on FEM, BEM or exact analytical solutions are used to generate a data set of temperatures or deformations within the system or body, each produced for a unique set of physical parameters. The data set is then transformed via POD to generate an orthonormal basis to accurately solve for the desired material characteristics using the Levenberg-Marquardt (LM) algorithm to minimize the objective least squares functional. While the POD-RBF inverse approach outlined in this paper focuses primarily in application to conduction heat transfer, elasticity, and fracture mechanics, this technique is designed to be directly applicable to other realistic conditions and/or relevant industrial problems