Gloria I. Giraldo

An Ontological Rule-Based Approach for Analyzing Dead and False Optional Features in Feature Models

Feature models are a common way to represent variability requirements of software product lines by expressing the set of feature combinations that software products can have. Assuring quality of feature models is thus of paramount importance for assuring quality in software product line engineering. However, feature models can have several types of defects that disminish benefits of software product line engineering.Two of such defects are dead features and false optional features. Several state-of-the-art techniques identify these defects, but only few of them tackle the problem of identifying their causes. Besides, the explanations they provide are cumbersome and hard to understand by humans. In this paper, we propose an ontological rule-based approach to: (a) identify dead and false optional features; (b)identify certain causes of these defects; and (c) explain these causes in natural language helping modelers to correct found defects. We represent our approach with a feature model taken from literature. A preliminary empirical evaluation of our approach over 31 FMs shows that our proposal is effective, accurate and scalable to 150 features.

Effect of temperature on partial molar volumes and viscosities of dilute aqueous solutions of 1-butanol, 1,2-butanediol, 1,4-butanediol, 1,2,4-butanetriol, and butanetetrol

Experimental densities and viscosities of dilute aqueous binary mixtures of 1-butanol, 1,2-butanediol, 1,4-butanediol, 1,2,4-butanetriol, and 1,2,3,4-butanetetrol (erythritol) were measured in the temperature range from 283.15 to 323.15 K. Apparent molar volumes were determined as a function of composition from density measurements. The limiting partial molar volumes of alcohols in aqueous solution were evaluated through extrapolation. The relative viscosity values were adjusted by least-squares to a second order equation to obtain the viscosity B coefficient which has been related to the size and shape of the solute molecule. The temperature dependence of the partial molar volume at infinite dilution and the viscosity B coefficient are discussed in terms of the relationship among polar and non polar groups on water structure and the effect of the position of hydroxyl groups in the molecule.

Propiedades Físicas del Jugo de Uchuva (Physalis peruviana) Clarificado en Función de la Concentración y la Temperatura

espanolSe estudio el efecto de la concentracion (20 a 50 °Brix) y la temperatura (20 a 50 °C) sobre la densidad y viscosidad del jugo de uchuva (Physalis peruviana) clarificado, empleando un diseno aleatorio con arreglo de dos factores: temperatura con cinco niveles, concentracion con siete niveles y tres repeticiones. Tambien se determino el punto de congelacion del jugo de uchuva en funcion de la concentracion. Los valores de densidad y viscosidad del jugo disminuyeron al aumentar temperatura y se incrementaron al aumentar la concentracion de solidos solubles. El efecto de la temperatura sobre la viscosidad del jugo a diferentes concentraciones fue descrito por una relacion tipo Arrhenius, encontrandose una energia de activacion de flujo en el rango de 7.02 a 17.62 kJ/mol. Los puntos de congelacion del jugo se calcularon a partir de las curvas de enfriamiento y los resultados se compararon con los estimados a partir de un modelo aplicable a jugos de frutas, con un error relativo promedio del 6.6%. EnglishThe effect of concentration (20 to 50 °Brix) and temperature (20 to 50 °C) on density and viscosity of clarified cape gooseberry (Physalis peruviana) juice was studied, using a randomized arrangement of two factors: temperature with five levels, concentration with seven levels and three repetitions. In addition, the freezing point of cape gooseberry juice at various concentrations was determined. Density and viscosity values of juice decreased with increasing temperature and increased with increasing concentration of soluble solids. The effect of temperature on viscosity at different concentrations of juice was described by an Arrhenius type relationship while the activation energy of flow was found to be in the range of 7.02 to 17.62 kJ/mol. The freezing points of juice at various concentrations were determined based on the cooling curves. The results were compared with those estimated from a model applicable to fruit juices, with an average relative error of 6.6%.

Encapsulación de Alimentos Probióticos mediante Liofilización en Presencia de Prebióticos

espanolSe evaluo Curante liofilizacion y almacenamiento, el efecto Ce los prebioticos inulina y fructo-oligosacariCo-FOS (25% p/v) sobre las propieCaCes fisicoquimicas Ce los polvos y la viabilidad Ce las cepas L. casei ATCC-393 y Lactobacillus rhamnosus ATCC-9469. La humeCaC, la activiCaC Ce agua y los recuentos Ce celulas viables no menores a 106 UFCg-1 fueron los criterios Ce estabiliCaC. Se evaluaron las propieCaCes Ce rehiCratacion (higroscopiciCaC, humectabiliCaC, solubiliCaC) y estructurales (tamano Ce poro, area superficial). En el almacenamiento (20±2°C) se Ceterminaron Ciferencias significativas en la supervivencia; para L casei fue Ce 70.49% a los 63 Cias y para L. rhamnosus fue 73.58% a los 98 Cias. Para ambos microorganismos la humeCaC y la activiCaC Ce agua se incrementaron por encima Cel 50%; el tamano Ce poro se incremento por la aCicion Ce los prebioticos y el area superficial (BET) reporto valores bajos. Se Cemostro que la inulina genera una mayor estabiliCaC al L. rhamnosus permitienCo su aplicacion en alimentos funcionales con potencial simbiotico. EnglishDuring lyophilization and storage the effects of the prebiotics inulin and fructo-oligosaccharide-FOS (25% w/v) on the physicochemical properties of powders and the viability of the strains L. casei ATCC-393 y Lactobacillus rhamnosus ATCC-9469 were evaluated. Humidity, water activity and the viable cell counts not less than 106 CFUg-1 were the stability criteria. Properties of rehydration (hygroscopicity, wettability, solubility) and structural properties (pore size, surface area) were evaluated. Significant differences in survival during storage (20 ± 2 ° C) were determined. For L casei was 70.49% after 63 days and for L. rhamnosus was 73.58% after 98 days. For both microorganisms, the moisture and the water activity, increased above 50%; the pore size was increased by addition of prebiotics and the surface area (BET) reported low values. It is shown that inulin generates greater stability for L. rhamnosus, allowing its application in functional foods with symbiotic potential.

Evaluación de la Incorporación de Fibra Prebiótica sobre la Viabilidad de LactobaciHus casei Impregnado en Matrices de Mora (Rubus glaucus)

espanolEn este trabajo se evaluo el efecto de la fibra prebiotica en la supervivencia de la cepa Lactobacillus casei ATCC 393, incorporado en matrices de mora mediante un proceso de impregnacion a vacio y posterior liofilizacion. Laminas de mora fueron impregnadas con soluciones isotonicas de inulina, fruto-oligosacarido (FOS), inulina-FOS y control sin prebiotico, inoculadas con 109 UCF/ml del microorganismo. Las muestras impregnadas fueron liofilizadas y almacenadas a condiciones ambientales para su seguimiento. Se observo efecto favorable de la presencia de prebioticos sobre la viabilidad del microorganismo al permitir la supervivencia por mas de 40 dias, con recuentos superiores a 106 UCF/g mientras en la muestra control fue inferior luego de 25 dias. El analisis sensorial arrojo un puntaje de aceptacion superior a 5 en una escala de 1 a 7. La presencia de los microorganismos incorporados en la fruta fue evidenciada mediante las observaciones con microscopia electronica de barrido. EnglishThis study showed the favorable effect of prebiotic fiber in the survival of Lactobacillus casei of ATCC 393, incorporated in matrices of Andean blackberry by a process of vacuum impregnation and subsequent lyophilization. Blackberry slices were impregnated with isotonic solutions of inulin, fruit - oligosaccharide (FOS) and inulin-FOS control without prebiotic inoculated with 109 UCF / ml of the microorganism. The impregnated samples were lyophilized and stored at ambient conditions for monitoring. Favorable effects were observed for the presence of prebiotics to the viability of the microorganism, allowing its survival for more than 40 days, with higher counts to 106 UCF / g while in the control sample was lower after 25 days. Sensory analysis showed a higher acceptance score greater than 5 on a scale from 1 to 7. The presence of microorganisms embedded in the fruit was evidenced by the observation with scanning electronic microscopy.