Supporting On-Line Distributed Monitoring and Debugging

Monitoring systems have traditionally been developed with rigid objectives and functionalities, and tied to specific languages, libraries and run-time environments. There is a need for more flexible monitoring systems which can be easily adapted to distinct requirements. On-line monitoring has been considered as increasingly important for observation and control of a distributed application. In this paper we discuss monitoring interfaces and architectures which support more extensible monitoring and control services. We describe our work on the development of a distributed monitoring infrastructure, and illustrate how it eases the implementation of a complex distributed debugging architecture. We also discuss several issues concerning support for tool interoperability and illustrate how the cooperation among multiple concurrent tools can ease the task of distributed debugging

Generalised verification of the observer property in discrete event systems

The observer property is an important condition to be satisfied by abstractions of Discrete Event Systems (DES) models. This paper presents a generalised version of a previous algorithm which tests if an abstraction of a DES obtained through natural projection has the observer property. The procedure called OP-verifier II overcomes the limitations of the previously proposed verifier while keeping its computational complexity. Results are illustrated by a case study of a transfer line system

Generalised verification of the observer property in discrete event systems

The observer property is an important condition to be satisfied by abstractions of Discrete Event Systems (DES) models. This paper presents a generalised version of a previous algorithm which tests if an abstraction of a DES obtained through natural projection has the observer property. The procedure called OP-verifier II overcomes the limitations of the previously proposed verifier while keeping its computational complexity. Results are illustrated by a case study of a transfer line system

Verification of the observer property in discrete event systems

The observer property is an important condition to be satisfied by abstractions of Discrete Event System (DES) models. This technical note presents a new algorithm that tests if an abstraction of a DES obtained through natural projection has the observer property. The procedure, called OP-Verifier, can be applied to (potentially nondeterministic) automata, with no restriction on the existence of cycles of 'non-relevant' events. This procedure has quadratic complexity in the number of states. The performance of the algorithm is illustrated by a set of experiments

Assessing the quality of the relation between scalarizing function parameters and solutions in multiobjective optimization

Different Multi-Objective Optimization Methods (MOOM) for solving Multi-Objective Optimization Problems (MOOP) have been suggested in the literature. These methods often comprise two stages (not necessarily sequential): i) the search for the Pareto-optimal set and ii) the selection of a single solution from this non-dominated set. Various studies comparing performance of particular aspects of these methods have been carried out. However, a theoretical support that changes on the preferences of a Decision Maker (DM) will be reflected in the same way on the solution of the MOOP given by the MOOM has not been presented. In this work a consistency measure to assess MOOM is proposed. It will used to compare the performance of different methods available in the literature. This study was performed using some benchmark test problems, with two criteria.This work was supported in part by the Portuguese Fundacao para a Ciencia e Tecnologia under grants: PTDC/GES/70168/2006 and SFRH/BD/22808/2005

On the viability of dc homes: an economic perspective from domestic electrical appliances

The past few years witnessed a growing acclaim for dc power systems, which is mainly justified by the increasing use of energy storage systems and renewable energy sources based mainly on solar photovoltaic technologies. However, there is also a motivation from the point of view of domestic electrical appliances. Since the vast majority of these appliances is comprised by an ac-dc converter, it can be convenient to shift the domestic power supply from ac to dc. In this context, this paper presents an economic assessment of dc homes from the energy consumption perspective and its comparison with traditional homes supplied by ac electrical power grids. In order to perform such assessment, the main type of electronic loads is powered both by ac voltage and by dc voltage, comparing the efficiency and estimated energy cost for each case. The removal of the ac-dc converter present in these loads is also analyzed and compared with the two previously referred cases, supporting the supply of dc power to this type of loads. The analysis is performed by means of experimental results obtained with a laboratorial setup, aiming to validate the feasibility of dc homes under realistic operating conditions of the loads.This work has been supported by FCT - Fundacao para a Ciencia e Tecnologia within the Project Scope: UID/CEC/00319/2019. This work has been supported by FCT within the Project Scope DAIPESEV -Development of Advanced Integrated Power Electronic Systems for Electric Vehicles: PTDC/EEI-EEE/30382/2017. This work is part of the FCT project 0302836 NORTE-01-0145-FEDER-030283. Mr. Tiago Sousa is supported by the doctoral scholarship SFRH/BD/134353/2017 granted by the Portuguese FCT agency

Validity and reliability of the Parental Homework Management Scale

Background: Prior research has shown that parents help their children manage homework (i.e. environment, time, motivation and emotion management), especially in elementary school. However, researchers have not developed and validated a scale focused on those dimensions. Method: The purpose of the present study is to validate the Parental Homework Management Scale (PHMS) for parents of elementary school children in the domain of mathematics. A sample of 2,118 parent-child dyads was split randomly into two groups to conduct the analysis in two stages: (i) exploratory factor analysis on Group 1 and (ii) confi rmatory factor analysis on Group 2. Results: PHMS is comprised of two distinct but related factors (i.e. environment-time and motivation-emotion management). Results further indicated that the PHMS was positively related to homework self-regulation and positive emotions, and negatively related to math achievement. Contrary to expectations, no relationship was found between PHMS and amount of student homework completed. Conclusions: The scale revealed good psychometric quality.Validación y fi abilidad de la escala de gestión de tareas para casa para padres. Antecedentes: investigaciones previas revelaron que los padres ayudan a sus hijos a gestionar las tareas para casa (i.e., el ambiente, el tiempo, la motivación y las emociones), especialmente en la escuela primaria. Sin embargo, la investigación no ha construido y validado una escala enfocada en esas dimensiones. Método: el presente estudio valida el Parental Homework Management Scale (PHMS) para padres de niños de escuela primaria en el dominio de las matemáticas. Una muestra de 2,118 díadas padres-hijos se dividió aleatoriamente en dos grupos para realizar el análisis en dos etapas: (i) análisis factorial exploratorio en el Grupo 1 y (ii) análisis factorial confi rmatorio en el Grupo 2. Resultados: PHMS está compuesto por dos factores distintos pero relacionados (i.e., gestión del ambiente-tiempo y de la motivación-emoción). Los resultados indicaron además que el PHMS se relacionó positivamente con la autorregulación y las emociones positivas en las tareas para casa, y se relacionó negativamente con el rendimiento en matemáticas. Contrario a las expectativas, no se encontró relación entre PHMS y la cantidad de tareas completadas por los estudiantes. Conclusiones: la escala ha revelado una buena calidad psicométrica.This work was supported by Portuguese Foundation for Science and Technology (FCT) and the Portuguese Ministry of Science (UID/PSI/01662/2013). JC was supported by a PhD fellowship from the Portuguese FCT (SFRH/BD/95341/2013)

Improving the visualization of alloy instances

Alloy is a lightweight formal specification language, supported by an IDE, which has proven well-suited for reasoning about software design in early development stages. The IDE provides a visualizer that produces graphical representations of analysis results, which is essential for the proper validation of the model. Alloy is a rich language but inherently static, so behavior needs to be explicitly encoded and reasoned about. Even though this is a common scenario, the visualizer presents limitations when dealing with such models. The main contribution of this paper is a principled approach to generate instance visualizations, which improves the current Alloy Visualizer, focusing on the representation of behavior.This work is financed by the ERDF - European Regional Development Fund through the Operational Programme for Competitiveness and Internationalisation - COMPETE 2020 Programme and by National Funds through the Portuguese funding agency, FCT - Fundacao para a Ciencia e a Tecnologia, within project POCI-01-0145-FEDER-016826

Data analytics in the cloud with flexible MapReduced workflows

Data analytic applications are characterized by large data sets that are subject to a series of processing phases. Some of these phases are executed sequentially but others can be executed concurrently or in parallel on clusters, grids or clouds. The MapReduce programming model has been applied to process large data sets in cluster and cloud environments. For developing an application using MapReduce there is a need to install/configure/access specific frameworks such as Apache Hadoop or Elastic MapReduce in Amazon Cloud. It would be desirable to provide more flexibility in adjusting such configurations according to the application characteristics. Furthermore the composition of the multiple phases of a data analytic application requires the specification of all the phases and their orchestration. The original MapReduce model and environment lacks flexible support for such configuration and composition. Recognizing that scientific workflows have been successfully applied to modeling complex applications, this paper describes our experiments on implementing MapReduce as subworkflows in the AWARD framework (Autonomic Workflow Activities Reconfigurable and Dynamic). A text mining data analytic application is modeled as a complex workflow with multiple phases, where individual workflow nodes support MapReduce computations. As in typical MapReduce environments, the end user only needs to define the application algorithms for input data processing and for the map and reduce functions. In the paper we present experimental results when using the AWARD framework to execute MapReduce workflows deployed over multiple Amazon EC2 (Elastic Compute Cloud) instances

Optimized exploitation of aquifers: application to the Querenca-Silves aquifer system

A great deal of optimization models have been developed to support aquifer planning and management with the goal of arriving at the best decisions in relation to the number and siting of infrastructures to be built and how to operate them. A mixed-integer multi-objective linear model has been taken from the literature to define the best decision for the development of the aquifer of Querenca-Silves (Portugal). It identifies efficient solutions for the location and design of pumping stations and their catchment area to supply a given number of demand centers, without disregarding the effect of groundwater management on the piezometric surface of aquifers and the many facets of groundwater management. The multi-objective model includes two objectives: (1) the minimization of aggregate water elevation height, and (2) the minimization of aggregate water transport length, weighted by the flows conveyed from the facilities to the centers. The effect of groundwater extraction on the piezometric surface of the aquifer is modelled with a response matrix method, with the establishment of maximum drawdown to prevent over-exploitation