Multidimensional catalogs for systematic exploration of component-based design spaces

Most component-based approaches to elaborate software require complete and consistent descriptions of components, but in practical settings components information is incomplete, imprecise and changing, and requirements may be likewise. More realistically deployable are approaches that combine exploration of candidate architectures with their evaluation vis-a-vis requirements, and deal with the fuzzyness of available component information. This article presents an approach to systematic generation, evaluation and re-generation of component assemblies, using potentially incomplete, imprecise, unreliable and changing descriptions of requirements and components. The key ideas are representation of NFRs using architectural policies, systematic reification of policies into mechanisms and components that implement them, multi-dimensional characterizations of these three levels, and catalogs of them. The Azimut framework embodies these ideas and enables traceability of architecture by supporting architecture-level reasoning, and allows architects to engage into systematic exploration of design spaces. A detailed illustrative example illustrates the approach.1st International Workshop on Advanced Software Engineering: Expanding the Frontiers of Software Technology - Session 1: Software ArchitectureRed de Universidades con Carreras en Informática (RedUNCI

An architecture based on computing with words to support runtime reconfiguration decisions of service-based systems

Service-based systems (SBSs) need to be reconfigured when there is evidence that the selected Web services configurations no further satisfy the specifications models and, thus the decision-related models will need to be updated accordingly. However, such updates need to be performed at the right pace. On the one hand, if the updates are not quickly enough, the reconfigurations that are required may not be detected due to the obsolescence of the specification models used at runtime, which were specified at design-time. On the other hand, the other extreme is to promote premature reconfiguration decisions that are based on models that may be highly sensitive to environmental fluctuations and which may affect the stability of these systems. To deal with the required trade-offs of this situation, this paper proposes the use of linguistic decision-making (LDM) models to represent specification models of SBSs and a dynamic computing-with-words (CWW) architecture to dynamically assess the models by using a multi-period multi-attribute decision making (MP-MADM) approach. The proposed solution allows systems under dynamic environments to offer improved system stability by better managing the trade-off between the potential obsolescence of the specification models, and the required dynamic sensitivity and update of these model

Multidimensional catalogs for systematic exploration of component-based design spaces

Most component-based approaches to elaborate software require complete and consistent descriptions of components, but in practical settings components information is incomplete, imprecise and changing, and requirements may be likewise. More realistically deployable are approaches that combine exploration of candidate architectures with their evaluation vis-a-vis requirements, and deal with the fuzzyness of available component information. This article presents an approach to systematic generation, evaluation and re-generation of component assemblies, using potentially incomplete, imprecise, unreliable and changing descriptions of requirements and components. The key ideas are representation of NFRs using architectural policies, systematic reification of policies into mechanisms and components that implement them, multi-dimensional characterizations of these three levels, and catalogs of them. The Azimut framework embodies these ideas and enables traceability of architecture by supporting architecture-level reasoning, and allows architects to engage into systematic exploration of design spaces. A detailed illustrative example illustrates the approach.1st International Workshop on Advanced Software Engineering: Expanding the Frontiers of Software Technology - Session 1: Software ArchitectureRed de Universidades con Carreras en Informática (RedUNCI

Theoretical and Numerical Analysis of Laminar Spray Flames for Use in Turbulent Spray Combustion Modeling

Spray combustion under turbulent conditions occurs in many technical devices. Therefore, the proper prediction of the characteristics of turbulent spray flames is of vital importance for the design of new combustion technologies in view of efficiency and pollutant reduction, where the latter requires consideration of detailed chemical reaction mechanisms. Unfortunately, a direct inclusion of detailed chemical reactions dramatically increases the computational cost of the numerical simulations of technical combustion processes, and it is prohibitive in practical situations. Models based on the assumption that turbulent ames can be seen as an ensemble of laminar stretched flame structures, the so-called flamelet models, represent a very promising approach for the cost effective inclusion of detailed chemical reaction mechanisms in the simulation of turbulent spray flames. Several flamelet models are currently available in the literature for the simulation of pure non-premixed and pure premixed gas flames. Additionally, some two-regime flamelet formulations have been proposed in the last years for situations where nonpremixed and premixed gas combustion coexist and interact. These models, however, are not adequate for the simulation of turbulent spray combustion, since they do not take into account spray evaporation, which strongly affects the flame structure. Although a spray flamelet model has been proposed for the simulation of flames where non-premixed and evaporation-dominated combustion regimes coexist, most studies of turbulent spray flames use gas flamelet models, neglecting the effects of evaporation on the flame structure. In the present thesis, a common framework is developed in which the several single and two-regime flamelet models existing in the literature can be described and combined in order to advance the development of a comprehensive multi-regime spray flamelet model for turbulent spray flames. For this purpose, a set of multi-regime spray flamelet equations in terms of the mixture fraction and a reaction progress variable is derived, which describes all combustion regimes appearing in spray flames. The flamelet equations available in the literature for single and two-regime flames are retrieved from these multi-regime spray flamelet equations as special cases. Additionally, exact transport equations of the mixture fraction and its scalar dissipation rate are derived, which are then used to evaluate the validity of several assumptions commonly made in the literature during their derivation, such as the use of unity Lewis number and the negligence of spatial variations of the mean molecular weight of the mixture. These assumptions had not yet been tested for the calculation of the scalar dissipation rate of the mixture fraction in spray flames, and their validation is of vital importance for the formulation of any spray flamelet model. Numerical simulations of axi-symmetric laminar mono-disperse ethanol/air counterflow spray flames are carried out to analyze the influence of spray evaporation on the flame structure. Parametric studies of the influence of the initial droplet radius and strain rate are presented, which clearly illustrate the major importance of evaporation in the determination of the flame structure. Additionally, the relative importance of non-premixed and premixed combustion regimes in the previously analyzed counterflow spray flames is studied by means of the derived multi-regime spray flamelet equations. The results show that premixed effects can be neglected in this kind of flame with all fuel injected in liquid phase. Moreover, the derived transport equations of mixture fraction and its scalar dissipation rate are solved for the counterflow spray flames considered in this work considering and without considering the assumptions of unity Lewis number and spatially uniform mean molecular weight of the mixture. The results are compared, and it is found that the assumption of unity Lewis number may lead to non-physical values of the scalar dissipation rate of the mixture fraction, whereas the use of a mass-averaged diffusion coefficient of the mixture is an acceptable approximation. Effects associated with the spatial variation of the mean molecular weight of the mixture are found to be small at low strain rate and negligible at high strain rates. These results confirm the validity of the use of Fick's diffusion law in highly strained flames. Finally, a set of non-premixed spray amelet equation is obtained by neglecting premixed effects in the previously derived multi-regime spray flamelet equations. This set of equations, which is valid in situations where non-premixed and evaporation-dominated combustion regime coexist, is similar to the classical non-premixed gas flamelet equations, but it contains two additional terms for the description of evaporation effects. These equations are then used to evaluate the relative importance of the effects attributable to evaporation. The results show that they are always relevant and they should be always considered

From i* models to service oriented architecture models

Requirements engineering and architectural design are key activities for successful development of software systems. Specifically in the service-oriented development systems there is a gap between the requirements description and architecture design and assessment. This article presents a systematic process for systematically deriving service-oriented architecture from goal-oriented models. This process allows generate candidate architectures based on i* models and helps architects to select a solution using services oriented patterns for both services and components levels. The process is exemplified by applying it in a synthesis metadata and assembly learning objects system.Peer ReviewedPostprint (author’s final draft

Introduction to the digital government and Business Process Management (BPM) minitrack HICSS'54

Digital Government (traditionally known as e- Government) focuses on value delivery to citizens through information and communication technology (ICT) support for processes, activities and resources. Digital government’s collaborative processes involve organizations (employees, technologies), partners (providers, consumers), and users (citizens, foreigners), leading to complex interactions within different e- Government models and available technologies. Business Process Management (BPM) constitutes a real asset for enhancing the services of an organization and their coordination, as well as the products that each actor of a virtual network delivers to meet clients’ expectations (citizens, patients, etc.). Successful interorganizational process management within e- Government collaborative organizations will lead to better conceptual and technological integration, not only with each other but also with citizens and users in general. To this end, it is necessary to devise new ways to deal with the complexity of e-Government collaborative process definition, modeling, analysis, enactment and monitoring from various dimensions and points of view including theory, engineering, interoperability, agility, social aspects, etc

OTA updates mechanisms: a taxonomy and techniques catalog

The use of the Internet of Things (IoT) and Cyber-Physical Systems (CPS) in industry and daily life has increased. The embedded software of IoT systems requires updates over time for long-term maintainability, bug xes, and improvements. Developers and manufacturers design and implement OTA update systems in ad-hoc manners because there are no speci c standards and little empirical information about mechanisms. This article describes a systematic literature review to identify proposed OTA update mechanisms, and a taxonomy to orga- nize them for system designers. Academic and professional (grey) litera- ture was gathered from four information sources; 109 studies were found, of which 29 remained after applying inclusion and exclusion criteria; and they were recognized as belonging to six mechanisms (categories). Each technique was associated to a mechanism, yielding an (initial) catalog of OTA update techniques. This taxonomy and catalog can be used to design IoT and CPS applications that must include OTA update functionality.Sociedad Argentina de Informática e Investigación Operativ

Acumulacion de nitratos en 4 tipos de lechuga cultivados al aire libre y en invernadero en otono-invierno

Resumen (Spanish, English)72 p.La lechuga es la principal hortaliza de hoja consumida en Chile. Esta se encuentra en el grupo de plantas que acumulan una mayor cantidad de NO3-. Se ha visto a través de numerosas investigaciones que la ingestión de altas cantidades de NO3- puede ser nociva para la salud humana, debido a que al ser reducido a NO2- y convinarse con aminas secundarias y terciarias y formar derivados N-nitrosos, compuestos que pueden ser causantes de cáncer gástrico o al esófago. En nuestro país no existen antecedentes concretos que permitan tener una información completa sobre los contenidos de NO3- en la lechuga. Considerando éstos antecedentes se determinaron los contenidos de NO3- a cosecha para los cuatro cultivares de lechuga más consumidos en Chile: Great Lakes, Costina lo Abarca, Parker y Floresta producidos en la época de otoño-invierno bajo invernadero de polietileno y al aire libre en la Estación Experimental Panguilemo de la Universidad de Talca ubicada en la comuna de Talca, VII región. Para la determinación de los niveles de NO3- se utilizó el método colorimétrico con la utilización de una columna de cadmio. Se determinó el contenido de NO3- total y foliar, contenido de N total y se estimó la ingesta humana diaria de NO3-. En las cosechas realizadas bajo invernadero los cvs. Costina lo Abarca, Parker y Floresta presentaron contenidos de NO3- de 3.027, 3.466, 3.038 mg/kg MF respectivamente, a diferencia del cv. Great Lakes el cual presentó contenidos de NO3- no superiores a 2.500 mg/kg MF. En el ensayo realizado al aire libre los cvs. Great Lakes, Costina lo Abarca y Floresta presentaron contenidos de NO3- de 2.669, 2765, 2637 mg/kg MF respectivamente, a diferencia del cv. Parker el cual presentó contenidos de NO3- de 3.118 mg/kg MF, todos de rendimientos aceptables. Para ambos ensayos al aire libre y bajo invernadero los contenidos de NO3- encontrados el los cvs. no superaron los limites permitidos por países desarrollados de Europa

Primeros reportes de Myotis riparius (Chiroptera: Vespertilionidae) en los altos Andes del sur del Ecuador

The Vespertilionidae family is widely distributed in South America. In Ecuador, there are 20 species including Myotis riparius. The species has been recorded between 10 to 1240 m a.s.l. on the both eastern and western sides of the Andes cordillera. In this work we reported two new localities for southern Ecuador which include the highest records for the species and increasing in 1077 m the limit elevation previously known in Ecuador.La familia Vespertilionidae está ampliamente distribuida en América del Sur. En Ecuador habitan 20 especies incluyendo a Myotis riparius. Esta especie ha sido registrada entre 10 y 1240 metros de elevación en las estribaciones de la cordillera de los Andes. En este trabajo reportamos dos nuevas localidades para el sur del Ecuador las cuales incluyen los registros de mayor elevación para la especie e incrementan 1077 metros el límite altitudinal conocido en Ecuador