Reviewing technical approaches for sharing and preservation of experimental data

Empirical Software Engineering (ESE) replication researchers need to store and manipulate experimental data for several purposes, in particular analysis and reporting. Current research needs call for sharing and preservation of experimental data as well. In a previous work, we analyzed Replication Data Management (RDM) needs. A novel concept, called Experimental Ecosystem, was proposed to solve current deficiencies in RDMapproaches. The empirical ecosystem provides replication researchers with a common framework that integrates transparently local heterogeneous data sources. A typical situation where the Empirical Ecosystem is applicable, is when several members of a research group, or several research groups collaborating together, need to share and access each other experimental results. However, to be able to apply the Empirical Ecosystem concept and deliver all promised benefits, it is necessary to analyze the software architectures and tools that can properly support it.

Replication types: towards a shared taxonomy

Context: The software engineering community is becoming more aware of the need for experimental replications. In spite of the importance of this topic, there is still much inconsistency in the terminology used to describe replications. Objective: Understand the perspectives of empirical researchers about various terms used to characterize replications and propose a consistent taxonomy of terms. Method: A survey followed by plenary discussion during the 2013 International Software Engineering Research Network meeting. Results: We propose a taxonomy which consolidates the disparate terminology. This taxonomy had a high level of agreement among workshop attendees. Conclusion: Consistent terminology is important for any field to progress. This work is the first step in that direction. Additional study and discussion is still necessary.

Basics on design and analysis of SE experiments: widespread shortcomings

Keynote speech about experimental design

Identification and correction of besouro's faults: impact on test‐driven development experiments

Context. This thesis is framed in experimental software engineering. More concretely, it addresses the problems arisen when assessing process conformance in test-driven development experiments conducted by UPM's Experimental Software Engineering group. Process conformance was studied using the Eclipse's plug-in tool Besouro. It has been observed that Besouro does not work correctly in some circumstances. It creates doubts about the correction of the existing experimental data which render it useless. Aim. The main objective of this work is the identification and correction of Besouro's faults. A secondary goal is fixing the datasets already obtained in past experiments to the maximum possible extent. This way, existing experimental results could be used with confidence. Method. (1) Testing Besouro using different sequences of events (creation methods, assertions etc..) to identify the underlying faults. (2) Fix the code and (3) fix the datasets using code specially created for this purpose. Results. (1) We confirmed the existence of several fault in Besouro's code that affected to Test-First and Test-Last episode identification. These faults caused the incorrect identification of 20% of episodes. (2) We were able to fix Besouro's code. (3) The correction of existing datasets was possible, subjected to some restrictions (such us the impossibility of tracing code size increase to programming time. Conclusion. The results of past experiments dependent upon Besouro's data could no be trustable. We have the suspicion that more faults remain in Besouro's code, whose identification requires further analysis.

Evidence of the presence of bias in subjective metrics: analysis within a family of experiments

Context: Measurement is crucial and important to empirical software engineering. Although reliability and validity are two important properties warranting consideration in measurement processes, they may be influenced by random or systematic error (bias) depending on which metric is used. Aim: Check whether, the simple subjective metrics used in empirical software engineering studies are prone to bias. Method: Comparison of the reliability of a family of empirical studies on requirements elicitation that explore the same phenomenon using different design types and objective and subjective metrics. Results: The objectively measured variables (experience and knowledge) tend to achieve more reliable results, whereas subjective metrics using Likert scales (expertise and familiarity) tend to be influenced by systematic error or bias. Conclusions: Studies that predominantly use variables measured subjectively, like opinion polls or expert opinion acquisition.

A systematic mapping study on testing technique experiments: has the situation changed since 2000?

Context: Empirical Software Engineering (ESE) replication researchers need to store and manipulate experimental data for several purposes, in particular analysis and reporting. Current research needs call for sharing and preservation of experimental data as well. In a previous work, we analyzed Replication Data Management (RDM) needs. A novel concept, called Experimental Ecosystem, was proposed to solve current deficiencies in RDM approaches. The empirical ecosystem provides replication researchers with a common framework that integrates transparently local heterogeneous data sources. A typical situation where the Empirical Ecosystem is applicable, is when several members of a research group, or several research groups collaborating together, need to share and access each other experimental results. However, to be able to apply the Empirical Ecosystem concept and deliver all promised benefits, it is necessary to analyze the software architectures and tools that can properly support it.

Topic selection in industry experiments

This paper shares our experience with initial negotiation and topic elicitation process for conducting industry experiments in six software development organizations in Finland. The process involved interaction with company representatives in the form of both multiple group discussions and separate face-to-face meetings. Fitness criteria developed by researchers were applied to the list of generated topics to decide on a common topic. The challenges we faced include diversity of proposed topics, communication gaps, skepticism about research methods, initial disconnect between research and industry needs, and lack of prior work relationship. Lessons learned include having enough time to establish trust with partners, importance of leveraging the benefits of training and skill development that are inherent in the experimental approach, uniquely positioning the experimental approach within the landscape of other validation approaches more familiar to industrial partners, and introducing the fitness criteria early in the process.

Supervisión de un sistema de tiempo real distribuido

En el presente proyecto se propone la definición e implementación de un subsistema de monitorización para un sistema de tiempo real distribuido. Este monitor supervisará el estado de todos los componentes software y hardware del sistema original, y permitirá el arranque y parada de cada componente individualmente o del subsistema completo. Constará de dos componentes básicos: un supervisor local para cada subsistema, y un supervisor central con interfaz gráfica. El supervisor local es un componente software asociado a cada subsistema que realizará las funciones de monitorización, arranque/parada de los componentes y envío de informes al supervisor central. Atenderá además a los comandos de arranque y parada provenientes del supervisor central. El supervisor central recibirá los informes de estado de cada uno de los supervisores locales y permitirá el arranque y parada de los subsistemas. Contará con un interfaz gráfico a modo de posición de control. El sistema será desarrollado íntegramente (salvo la posición gráfica) en ADA95, y podrá ejecutarse en cualquiera de las distribuciones Linux más extendidas. En el contexto de Ingeniería de Software, se seguirá un desarrollo en cascada, aportándose los requisitos, el diseño, la codificación y un plan de pruebas. Abstract In this project, the definition and implementation of a monitoring system is proposed for a previously defined real-time distributed system. This supervisory system will monitor the status of each subsystem and its software and hardware components. This new system will also be able to start and stop each individual component and start or stop the entire system. It will consist of two basic components: a local supervisor for each subsystem, and a central supervisor with a graphical unit interface (GUI). The local supervisor will be a software component attached to each original subsystem, which will perform functions such as components monitoring, start and stop the associated subsystem, and sending reports to the central supervisor. It also will attend the start and stop commands from the central supervisor. The central supervisor will receive status reports from each of the local supervisors and will allow starting and stopping the subsystems. It will offer a graphical interface to be used as a main control panel. The system will be developed in ADA 95 (except the graphical position), and should work on any of the most common Linux distributions. In the context of Software Engineering, the project will be developed following a waterfall life cycle. Reports on the stages of requirements, design, coding and testing plan shall be provided.

Geografía del carbono en alta resolución en bosque tropical amazónico del Ecuador mediante sensores aerotransportados

La estimación de la biomasa de la vegetación terrestre en bosque tropical no sólo es un área de investigación en rápida expansión, sino también es un tema de gran interés para reducir las emisiones de carbono asociadas a la deforestación y la degradación forestal (REDD+). Las estimaciones de densidad de carbono sobre el suelo (ACD) en base a inventarios de campo y datos provenientes de sensores aerotransportados, en especial con sensores LiDAR, han conducido a un progreso sustancial en el cartografiado a gran escala de las reservas de carbono forestal. Sin embargo, estos mapas de carbono tienen incertidumbres considerables, asociadas generalmente al proceso de calibración del modelo de regresión utilizado para producir los mapas. En esta tesis se establece una metodología para la calibración y validación de un modelo general de estimación de ACD usando LiDAR en un sector del Parque Nacional Yasuní en Ecuador. En el proceso de calibración del modelo se considera el tamaño y la ubicación de las parcelas, la influencia de la topografía y la distribución espacial de la biomasa. Para el análisis de los datos se utilizan técnicas geoestadísticas en combinación con variables geomorfométricas derivadas de datos LiDAR, y se propone un esquema de muestreo estratificado por posiciones topográficas (valle, ladera y cima). La validación del modelo general para toda la zona de estudio presentó valores de RMSE = 5.81 Mg C ha-1, R2 = 0.94 y sesgo = 0.59, mientras que, al considerar las posiciones topográficas, el modelo presentó valores de RMSE = 1.67 Mg C ha-1, R2 = 0.98 y sesgo = 0.23 para el valle; RMSE = 3.13 Mg C ha-1, R2 = 0.98 y sesgo = - 0.34 para la ladera; y RMSE = 2.33 Mg C ha-1, R2 = 0.97 y sesgo = 0.74 para la cima. Los resultados obtenidos demuestran que la metodología de muestreo estratificado por posiciones topográficas propuesto, permite calibrar de manera efectiva el modelo general con las estimaciones de ACD en campo, logrando reducir el RMSE y el sesgo. Los resultados muestran el potencial de los datos LiDAR para caracterizar la estructura vertical de la vegetación en un bosque altamente diverso, permitiendo realizar estimaciones precisas de ACD, y conocer patrones espaciales continuos de la distribución de la biomasa aérea y del contenido de carbono en la zona de estudio. ABSTRACT Estimating biomass of terrestrial vegetation in tropical forest is not only a rapidly expanding research area, but also a subject of tremendous interest for reducing carbon emissions associated with deforestation and forest degradation (REDD+). The aboveground carbon density estimates (ACD) based on field inventories and airborne sensors, especially LiDAR sensors have led to a substantial progress in large-scale mapping of forest carbon stocks. However, these carbon maps have considerable uncertainties generally associated with the calibration of the regression model used to produce these maps. This thesis establishes a methodology for calibrating and validating a general ACD estimation model using LiDAR in Ecuador´s Yasuní National Park. The size and location of the plots are considered in the model calibration phase as well as the influence of topography and spatial distribution of biomass. Geostatistical analysis techniques are used in combination with geomorphometrics variables derived from LiDAR data, and then a stratified sampling scheme considering topographic positions (valley, slope and ridge) is proposed. The validation of the general model for the study area showed values of RMSE = 5.81 Mg C ha-1, R2 = 0.94 and bias = 0.59, while considering the topographical positions, the model showed values of RMSE = 1.67 Mg C ha-1, R2 = 0.98 and bias = 0.23 for the valley; RMSE = 3.13 Mg C ha-1, R2 = 0.98 and bias = - 0.34 for the slope; and RMSE = 2.33 Mg C ha-1, R2 = 0.97 and bias = 0.74 for the ridge. The results show that the stratified sampling methodology taking into account topographic positions, effectively calibrates the general model with field estimates of ACD, reducing RMSE and bias. The results show the potential of LiDAR data to characterize the vertical structure of vegetation in a highly diverse forest, allowing accurate estimates of ACD, and knowing continuous spatial patterns of biomass distribution and carbon stocks in the study area.

Estimación del consumo de potencia en un terminal portátil multimedia basada en la PMU del procesador

Este proyecto se incluye en una línea de trabajo que tiene como objetivo final la optimización de la energía consumida por un dispositivo portátil multimedia mediante la aplicación de técnicas de control realimentado, a partir de una modificación dinámica de la frecuencia de trabajo del procesador y de su tensión de alimentación. La modificación de frecuencia y tensión se realiza a partir de la información de realimentación acerca de la potencia consumida por el dispositivo, lo que supone un problema ya que no suele ser posible la monitorización del consumo de potencia en dispositivos de estas características. Este es el motivo por el que se recurre a la estimación del consumo de potencia, utilizando para ello un modelo de predicción. A partir del número de veces que se producen ciertos eventos en el procesador del dispositivo, el modelo de predicción es capaz de obtener una estimación de la potencia consumida por dicho dispositivo. El trabajo llevado a cabo en este proyecto se centra en la implementación de un modelo de estimación de potencia en el kernel de Linux. La razón por la que la estimación se implementa en el sistema operativo es, en primer lugar para lograr un acceso directo a los contadores del procesador. En segundo lugar, para facilitar la modificación de frecuencia y tensión, una vez obtenida la estimación de potencia, ya que esta también se realiza desde el sistema operativo. Otro motivo para implementar la estimación en el sistema operativo, es que la estimación debe ser independiente de las aplicaciones de usuario. Además, el proceso de estimación se realiza de forma periódica, lo que sería difícil de lograr si no se trabajase desde el sistema operativo. Es imprescindible que la estimación se haga de forma periódica ya que al ser dinámica la modificación de frecuencia y tensión que se pretende implementar, se necesita conocer el consumo de potencia del dispositivo en todo momento. Cabe destacar también, que los algoritmos de control se tienen que diseñar sobre un patrón periódico de actuación. El modelo de estimación de potencia funciona de manera específica para el perfil de consumo generado por una única aplicación determinada, que en este caso es un decodificador de vídeo. Sin embargo, es necesario que funcione de la forma más precisa posible para cada una de las frecuencias de trabajo del procesador, y para el mayor número posible de secuencias de vídeo. Esto es debido a que las sucesivas estimaciones de potencia se pretenden utilizar para llevar a cabo la modificación dinámica de frecuencia, por lo que el modelo debe ser capaz de continuar realizando las estimaciones independientemente de la frecuencia con la que esté trabajando el dispositivo. Para valorar la precisión del modelo de estimación se toman medidas de la potencia consumida por el dispositivo a las distintas frecuencias de trabajo durante la ejecución del decodificador de vídeo. Estas medidas se comparan con las estimaciones de potencia obtenidas durante esas mismas ejecuciones, obteniendo de esta forma el error de predicción cometido por el modelo y realizando las modificaciones y ajustes oportunos en el mismo. ABSTRACT. This project is included in a work line which tries to optimize consumption of handheld multimedia devices by the application of feedback control techniques, from a dynamic modification of the processor work frequency and its voltage. The frequency and voltage modification is performed depending on the feedback information about the device power consumption. This is a problem because normally it is not possible to monitor the power consumption on this kind of devices. This is the reason why a power consumption estimation is used instead, which is obtained from a prediction model. Using the number of times some events occur on the device processor, the prediction model is able to obtain a power consumption estimation of this device. The work done in this project focuses on the implementation of a power estimation model in the Linux kernel. The main reason to implement the estimation in the operating system is to achieve a direct access to the processor counters. The second reason is to facilitate the frequency and voltage modification, because this modification is also done from the operating system. Another reason to implement the estimation in the operating system is because the estimation must be done apart of the user applications. Moreover, the estimation process is done periodically, what is difficult to obtain outside the operating system. It is necessary to make the estimation in a periodic way because the frequency and voltage modification is going to be dynamic, so it needs to know the device power consumption at every time. Also, it is important to say that the control algorithms have to be designed over a periodic pattern of action. The power estimation model works specifically for the consumption profile generated by a single application, which in this case is a video decoder. Nevertheless, it is necessary that the model works as accurate as possible for each frequency available on the processor, and for the greatest number of video sequences. This is because the power estimations are going to be used to modify dynamically the frequency, so the model must be able to work independently of the device frequency. To value the estimation model precision, some measurements of the device power consumption are taken at different frequencies during the video decoder execution. These measurements are compared with the power estimations obtained during that execution, getting the prediction error committed by the model, and if it is necessary, making modifications and settings on this model.

Desarrollo de una aplicación para la escalada y oferta de servicios web

El autor de este proyecto es miembro reciente de la asociación SoloBoulder, dedicada a la modalidad de escalada boulder, noticias y actualidad, contenido multimedia, promoción de un equipo de escaladores y defensa de valores medioambientales en la montaña. El principal canal de distribución de contenidos es una página web existente previa a este proyecto. La asociación ha detectado una escasez y mala calidad de recursos en internet en cuanto a guías de zonas donde poder practicar el boulder. Tal circunstancia impulsa la iniciativa de este proyecto fin de carrera. El objetivo general es el desarrollo de una nueva aplicación que proporcione a los usuarios a nivel mundial una guía interactiva de boulder y otros puntos de interés, una red social que permita la creación cooperativa y orgánica de contenido, y servicios web para el consumo de la información desde otras plataformas u organizaciones. El nuevo software desarrollado es independiente de la página web de SoloBoulder previa. No obstante, ambas partes se integran bajo el mismo domino web y aspecto. La nueva aplicación ofrece a escaladores y turistas un servicio informativo e interactivo de calidad, con el que se espera aumentar el número de visitas en todo el sitio web y poder ampliar la difusión de valores medioambientales, diversificar las zonas de boulder y regular las masificadas, favorecer el deporte y brindar al escalador una oportunidad de autopromoción personal. Una gran motivación para el autor también es el proceso de investigación y formación en tecnologías, patrones arquitecturales de diseño y metodologías de trabajo adaptadas a las tendencias actuales en la ingeniería de software, con especial curiosidad hacia el mundo web. A este respecto podemos destacar: metodología de trabajo en proyectos, análisis de proyectos, arquitecturas de software, diseño de software, bases de datos, programación y buenas prácticas, seguridad, interfaz gráfica web, diseño gráfico, Web Performance Optimization, Search Engine Optimization, etc. En resumen, este proyecto constituye un aprendizaje y puesta en práctica de diversos conocimientos adquiridos durante la ejecución del mismo, así como afianzamiento de materias estudiadas en la carrera. Además, el producto desarrollado ofrece un servicio de calidad a los usuarios y favorece el deporte y la autopromoción del escalador. ABSTRACT. The author of this Project is recent member of the association SoloBoulder, dedicated to a rock climbing discipline called bouldering, news, multimedia content, promotion of a team of climbers and defense of environmental values in the mountain. The main content distribution channel is a web page existing previous to this project. The association has detected scarcity and bad quality of resources on the internet about guides of bouldering areas. This circumstance motivates the initiative of this project. The general objective is the development of a new application which provides a worldwide, interactive bouldering guide, including other points of interest, a social network which allows the cooperative and organic creation of content, and web services for consumption of information from other platforms or organizations. The new software developed is independent of the previous SoloBoulder web page. However, both parts are integrated under the same domain and appearance. The new application offers to climbers and tourists a quality informative and interactive service, with which we hope to increase the number of visits in the whole web site and be able to expand the dissemination of environmental values, diversify boulder areas and regulate the overcrowded ones, encourage sport and offer to the climber an opportunity of self-promotion. A strong motivation for the author is also the process of investigation and education in technologies, architectural design patterns and working methodologies adapted to the actual trends in software engineering, with special curiosity about the web world. In this regard we could highlight: project working methodologies, project analysis, software architectures, software design, data bases, programming and good practices, security, graphic web interface, graphic design, Web Performance Optimization, Search Engine Optimization, etc. To sum up, this project constitutes learning and practice of diverse knowledge acquired during its execution, as well as consolidation of subjects studied in the degree. In addition, the product developed offers a quality service to the users and favors the sport and the selfpromotion of the climber.

Development of a tool for designing tests based on statistics and metadata

Background: This project’s idea arose derived of the need of the professors of the department “Computer Languages and Systems and Software Engineering (DLSIIS)” to develop exams with multiple choice questions in a more productive and comfortable way than the one they are currently using. The goal of this project is to develop an application that can be easily used by the professors of the DLSIIS when they need to create a new exam. The main problems of the previous creation process were the difficulty in searching for a question that meets some specific conditions in the previous exam files; and the difficulty for editing exams because of the format of the employed text files. Result: The results shown in this document allow the reader to understand how the final application works and how it addresses successfully every customer need. The elements that will help the reader to understand the application are the structure of the application, the design of the different components, diagrams that show the workflow of the application and some selected fragments of code. Conclusions: The goals stated in the application requirements are finally met. In addition, there are some thoughts about the work performed during the development of the application and how it improved the author skills in web development.

Desenvolvimento de sistema automatizado de monitoramento de ambientes de produção animal, utilizando uma rede de sensores sem fio

As redes de sensores sem fio, aplicadas à automação do controle de ambientes representam um paradigma emergente da computação, onde múltiplos nós providos de sensores, sistemas computacionais autônomos e capacidade de comunicação sem fio, conformam uma rede cuja topologia altamente dinâmica permite adquirir informações sobre sistemas complexos sendo monitorados. Um dos fatores essenciais para obter um ganho na produtividade avícola é o controle da ambiência animal. Atualmente os métodos utilizados para o monitoramento e controle ambiental não podem considerar a grande quantidade de microambientes internos nos ambientes de produção animal e também requerem infraestruturas cabeadas complexas. Dentro desse contexto o objetivo deste trabalho foi desenvolver e testar um sistema automatizado de controle ambiental, através da utilização de sensores sem fio, que auxilie e proporcione maior segurança no controle de ambientes automatizados. O sistema monitora variáveis que influenciam na produtividade de aves, tais como temperatura e umidade e outras variáveis físico-químicas do aviário. A infraestrutura desenvolvida foi testada em um aviário experimental e resultou em um sistema seguro e com grande escalabilidade, que é capaz de controlar e monitorar o ambiente e ainda coletar e gravar dados. Foi utilizado o protocolo ZigBee® para gerenciar o fluxo de dados do sistema. Foram feitas análises da eficiência de comunicação do sistema no aviário, monitorando os pacotes de dados perdidos. Os testes demonstraram uma perda de dados de aproximadamente 2% dos pacotes enviados, demonstrando a eficiência das redes ZigBee® para gerenciar o fluxo de dados no interior do aviário. Desta forma, pode-se concluir que é possível e viável a implantação de uma rede ZigBee®, para automatizar ambientes de produção animal com coleta de dados em tempo real, utilizando um sistema integrado via internet, que compreende: instrumentação eletrônica, comunicação sem fio e engenharia de software\".

Data normalization and integration in robotic systems using web services technologies

The robotics is one of the most active areas. We also need to join a large number of disciplines to create robots. With these premises, one problem is the management of information from multiple heterogeneous sources. Each component, hardware or software, produces data with different nature: temporal frequencies, processing needs, size, type, etc. Nowadays, technologies and software engineering paradigms such as service-oriented architectures are applied to solve this problem in other areas. This paper proposes the use of these technologies to implement a robotic control system based on services. This type of system will allow integration and collaborative work of different elements that make up a robotic system.

Airport Security: Passenger's Perception and Design Issues

The main goal of this thesis is to report patterns of perceived safety in the context of airport infrastructure, taking the airport of Bologna as reference. Many personal and environmental attributes are investigated to paint the profile of the sensitive passenger and to understand why precise factors of the transit environment are so impactful on the individual. The main analyses are based on a 2014-2015 passengers’ survey, involving almost six thousand of incoming and outgoing passengers. Other reports are used to implement and support the resource. The analysis is carried out by using a combination of Chi-square tests and binary logistic regressions. Findings shows that passengers result to be particularly affected by the perception of airport’s environment (e.g., state and maintenance of facilities, clarity and efficacy of information system, functionality of elevators and escalators), but also by the way how the passenger reaches the airport and the quality of security checks. In relation to such results, several suggestions are provided for the improvement of passenger satisfaction with safety. The attention is then focused on security checkpoints and related operations, described on a theoretical and technical ground. We present an example of how to realize a proper model of the security checks area of Bologna’s airport, with the aim to assess present performances of the system and consequences of potential variations. After a brief introduction to Arena, a widespread simulation software, the existing model is described, pointing out flaws and limitations. Such model is finally updated and changed in order to make it more reliable and more representative of the reality. Different scenarios are tested and results are compared using graphs and tables.