CIIC - Publicações em Atas de Conferências com Peer Review
URI permanente para esta coleção:
Navegar
Entradas recentes
- Some results on Gaussian mixturesPublication . Felgueiras, Miguel; Santos, Rui; Martins, João PauloWe investigate Gaussian mixtures with independent components, whose parameters are numerically estimated. A decomposition of a Gaussian mixture is presented when the components have a common variance. We introduce a shifted and scaled t-Student distribution as an approximation for the distribution of Gaussian mixtures when their components have a common mean and develop a hypothesis test for testing the equality of the components means. Finally, we analyse the fitness of the approximate model to the logarithmic daily returns of the Portuguese stock index PSI-20.
- Maximum likelihood estimation in pooled sample testsPublication . Martins, João Paulo; Felgueiras, Miguel; Santos, RuiPooled sample tests, firstly used on the classification problem (identifying all individuals with some characteristic), may also be applied to estimate the prevalence rate. Moreover, the pooled sample methods may attain greater efficiency when applied to estimate some prevalence rate, since it is no longer necessary to perform any individual test.We develop a maximum likelihood computational algorithm for the prevalence rate estimation, and we analyze its performance.
- Collecting Data from Continuous Practices: an Infrastructure to Support Team DevelopmentPublication . Nogueira, Ana Filipa; Sergeant, Emilien; Craske, Antoine; Ribeiro, José Carlos Bregieiro; Zenha-Rela, MárioThrough software analytics, raw data with low value originates information that is valuable and able to provide insights, enabling the support of claims that would otherwise not be possible to verify. The software development ecosystem has plenty of sources that can help understanding the quality of processes and products but, to reach that goal, it is necessary to collect and store the data. This paper describes an infrastructure to allow the collection, storage and analysis of data from software repositories. The scope of the research is an industrial case study, which encompasses several specificities: tools and work methodology. The current solution is able to collect information from the continuous delivery & deployment pipeline, which includes data sources such as the source code repository (SVN), the static analysis tool (SonarQube), the continuous integration server (from Jenkins jobs) and the continuous testing tool (an in-house tool called Cerberus). Future work also includes the implementation of components that will allow the collection of unstructured data from the bug-tracking system and incident management tool. As stated in the literature, correlating the history of issues and incidents will allow the team to address, or at least identify, areas of improvement.
- Secure Low-cost Solution for Elder's eCardio SurveillancePublication . Mendes, Jorge; Simões, Heitor; Rosa, Patrício; Costa, Nuno; Rabadão, Carlos; Pereira, AntónioIn recent years we have assisted to the growth in two major areas related to eHealth: one dedicated to the conception, creation and implementation of biosensors and another dedicated to the monitoring of vital parameters provided by these sensors. Furthermore, the exponential growth of mobile technologies and the widespread use of mobile devices embedding standards of next-generation Personal Area Networks (PAN), such as the Bluetooth Low Energy, come to revolutionize the way the monitoring of vital parameters is done, now following the anytime and anywhere approach with further energy efficiency. The work presented in this paper brings together the technologies addressed above in order to create a ready-to-use, simple, efficient, safe, low-cost and compatible solution capable of monitoring vital parameters and generate alerts in the presence of abnormal values. The tests showed the simplicity of the system setup, which is an important feature for elderly, demonstrated the reliability of measuring values and alarm rising, and also the warranty of data confidentiality.
- State of the art of accessible development for smart devices: From a disable and not impaired point of viewPublication . Silva, João de Sousa e; Pereira, António; Gonçalves, Ramiro; Gomes, SílviaThe need and benefits of digital accessibility are evident and, with the current ubiquitous trends, the profits are hugely potentiated. However, the fast evolution is instigating some issues in this area's accessibility. To understand the conceivable impact of these issues' tenacity in society, general accessibility features are explained as a reasonable application for all parties. Nevertheless, the potential of ubiquitous computation in order to promote social integration of citizens with impairments is focused and elucidated. The benefits of applying so much effort on accessibility as well as on usability is asserted and related to universal design. Hence, in order to promote a more universal applications development, the mobile operating systems available in the market, which are more plausible to be chosen and used by people with impairments, are scrutinized and shown from a standpoint of a developer that has accessibility and usability concerns. The paper leads to the conclusions that ubiquitous computation may have power to nullify impairments but, to be assistive, several issues regarding the devices and the operating system that runs on them have to be taken in mind and considered.
- Integrating a Head-mounted Display with a Mobile Device for Real-time Augmented Reality PurposesPublication . Madeira, Bruno; Alves, Pedro; Marto, Anabela; Rodrigues, Nuno; Gonçalves, AlexandrinoFollowing the current technological growth and subsequent needs felt by industries, new processes should be adopted to make tasks simpler. Using Augmented Reality in conjunction with other technologies, it is possible to develop innovative solutions that aim to alleviate the difficulty of certain processes in the industry, or to reduce the time of their execution. This article addresses one of the possible applications of new technologies in the industry, using devices that allow the use of Augmented Reality without requiring much or no physical interaction by workers or causing many distractions, thus giving relevant information to the work to be performed without interfering with the quality of it. It will focus, more precisely, on integrating the Head-Mounted Display Moverio BT-35E with a mobile device and in describing the needed configurations for preparing this device to show information to warehouse operators, using Augmented Reality, provided by a software that runs on a capable device, discussing also what are the main mishaps discovered with the use of this device.
- The regression analysis of the data to determine the buffer size when serving a self-similar packets flowPublication . Linets, Gennadiy; Voronkin, Roman; Govorova, Svetlana; Palkanov, Ilya; Grilo, CarlosUsing the methods of regression analysis on the basis of simulation data, a model for predicting the queue size of the input self-similar packet flow, distributed according to the Pareto law when it is transformed into a flow having an exponential distribution, is constructed. Since the amount of losses in the general case does not give any information about the efficiency of using the buffer memory space in the process of transforming a self-similar packet flow, a quality metric (penalty) was introduced to get the quality of the models after training, which is a complex score. This criterion considers both packet loss during functional transformations and ineffective use of the buffer space in switching nodes. The choice of the best model for predicting the queue size when servicing a self-similar packet flow was carried out using the following characteristics: the coefficient of determination; root-mean-square regression error; mean absolute error; the penalty score. The best in terms of the investigated characteristics are the models using the isotonic regression and the support vector regression.
- EasyBDI: Near Real-Time Data Analytics over Heterogeneous Data SourcesPublication . Silva, Bruno; Moreira, José; Costa, Rogério Luís de C.The large volume of currently available data creates several opportunities for sciences and industry, especially with the application of data analytics. But also raises challenges that make unfeasible the use of batch-based ETL processes. Indeed, near real-time data analytics is a requirement in several domains as an alternative to traditional data warehouses. In the last years, big data platforms have been developed to enable query execution over distributed data sources. However, they do not deal with subject-oriented analysis, do not provide data distribution transparency, or do not assist with schema mapping and integration. In this demonstration, we present EasyBDI. It's a near real-time big data analytics prototype that enables users to run queries over heterogeneous data sources based on global logical abstractions created by the system and provides some usual concepts of data warehouse systems, like facts and dimensions. We use two motivating scenarios, one based on three years of real data on photovoltaic energy production and consumption, and the other based on the SSB+ benchmark. We will also present implementation challenges, issues, solutions, and insights.
- Reconstructing Conimbriga - Digital CantaberPublication . Ferreira, César; Rodrigues, Nuno; Gonçalves, Alexandrino; Hipólito-Correia, VirgílioBeing the ancient cultural heritage structures and artefacts so full of detail and relevance to studies related to our past, it would be desirable to have precise virtual replicas that could be freely explored without endangering important pieces of history. However, the costs to produce three-dimensional environments are sometimes discouraging, due to the significant cost of some 3D authoring tools, and to the time necessary to manually produce the models. This paper presents a low-cost alternative to the classic manual modelling process, towards the production of highly detailed virtual models, by using open source software and a lowcost moving depth camera. The ambition is the dissemination of our cultural heritage legacy, making it accessible, not only to experts, but also to the general public, without requiring any high-performance hardware, authoring software or professional 3D skills. For the visualization, our virtual reconstructions will be available through a three-dimensional live model viewer, based on recent technologies such as HTML5 and WebGL. Those may be triggered from a wide variety of device, contributing in this way to a true democratization of history knowledge. The proposed approach was applied to create a virtual model of the so-called "House of Cantaber".
- A Customizable Web Platform to Manage Standards Compliance of Information Security and Cybersecurity AuditingPublication . Antunes, Mário; Maximiano, Marisa; Gomes, RicardoInformation security and cybersecurity are key subjects in modern enterprises' management, being ISO-27001:2013, NIST Cybersecurity Framework and ISO-27009 some of the most implemented international frameworks and standards. Their main goal is to globally reduce the risk, by leveraging enterprises' competitiveness in global markets and enhancing business processes and collaborators' cyber awareness. Auditing processes examine and assess a list of predefined controls. For each control, a set of corrective measures could be proposed, to increase its compliance with the standard being used. These processes are time-consuming, involve on-site intervention by specialized consulting teams on the intervened enterprises, and a set of status reports of all the interventions should be elaborated and delivered. The existing auditing information systems are not developed to meet Small and Medium-sized Enterprises (SME) requirements, as they are mostly proprietary and expensive, ground usually on off-the-shelf applications, and are not generic to be used by several standards with different checklists and auditing methodologies. In this paper, a generic and web-integrated cybersecurity auditing information system is described. Its architecture, design, and data model enable it to be used in a wide set of auditing processes, by loading a predefined controls checklist assessment and their corresponding mitigation tasks list. It was designed to meet both SMEs and large enterprises' requirements, and stores auditing and intervention-related data in a relational database. The information system was tested on an ISO-27001:2013 information security auditing project, which has integrated fifty SMEs. The results obtained during the project are promising and reveal the appropriateness of using this information system in further similar auditing processes.