Web-Based Networked Music Performances via WebRTC: A Low-Latency PCM Audio Solution

Nowadays, widely used videoconferencing software has been diffused even further by the social distancing measures adopted during the SARS-CoV-2 pandemic. However, none of the Web-based solutions currently available support high-fidelity stereo audio streaming, which is a fundamental prerequisite for networked music applications. This is mainly because of the fact that the WebRTC RTCPeerConnection standard or Web-based audio streaming do not handle uncompressed audio formats. To overcome that limitation, an implementation of 16-bit pulse code modulation (PCM) stereo audio transmission on top of the WebRTC RTCDataChannel, leveraging Web Audio and AudioWorklets, is discussed. Results obtained with multiple configurations, browsers, and operating systems showthat the proposed approach outperforms theWebRTC RTCPeerConnection standard in terms of audio quality and latency, which in the authors' best case to date has been reduced to only 40 ms between twoMacBooks on a local area network

An intelligent home automation control system based on A novel heat pump and wireless sensor networks

One of technology's main goals is to providing comfort to humans. However, in order to be an aid, it has to be easy to install, use and maintain. The ever growing complexity of technological systems can only be achieved by converging different technologies. This is usually expressed as Cyber-Physical Systems (CPS), previews the symbiosis of several technologies in order to make them more accessible. This paper attempts to demonstrate the integration between two technologies such as: Heat-pump System and Wireless Sensor Network (WSN) to provide a new control mechanism for new building generations so-called smart houses. The proposed control architecture benefits from our developed WSN hardware platform. It enables the user to control and monitor the ventilation system using our developed mobile application and/or a personal computer. Also, the performance of the proposed hardware platform is measured in three different environments in order to observer the coverage area of the WSN.Tiago Gomes is supported by FCT, the Portuguese Foundation for Science and Technology (grant SFRH/BD/90162/2012). This work is supported by FEDER through COMPETE and national funds through FCT - Foundation for Science and Technology in the framework of the project FCOMP-OI-0124-FEDER-022674

Actor-network procedures: Modeling multi-factor authentication, device pairing, social interactions

As computation spreads from computers to networks of computers, and migrates into cyberspace, it ceases to be globally programmable, but it remains programmable indirectly: network computations cannot be controlled, but they can be steered by local constraints on network nodes. The tasks of "programming" global behaviors through local constraints belong to the area of security. The "program particles" that assure that a system of local interactions leads towards some desired global goals are called security protocols. As computation spreads beyond cyberspace, into physical and social spaces, new security tasks and problems arise. As networks are extended by physical sensors and controllers, including the humans, and interlaced with social networks, the engineering concepts and techniques of computer security blend with the social processes of security. These new connectors for computational and social software require a new "discipline of programming" of global behaviors through local constraints. Since the new discipline seems to be emerging from a combination of established models of security protocols with older methods of procedural programming, we use the name procedures for these new connectors, that generalize protocols. In the present paper we propose actor-networks as a formal model of computation in heterogenous networks of computers, humans and their devices; and we introduce Procedure Derivation Logic (PDL) as a framework for reasoning about security in actor-networks. On the way, we survey the guiding ideas of Protocol Derivation Logic (also PDL) that evolved through our work in security in last 10 years. Both formalisms are geared towards graphic reasoning and tool support. We illustrate their workings by analysing a popular form of two-factor authentication, and a multi-channel device pairing procedure, devised for this occasion.Comment: 32 pages, 12 figures, 3 tables; journal submission; extended references, added discussio

A Process-Oriented Software Architecture Reconstruction Taxonomy

International audienceTo maintain and understand large applications, it is cru- cial to know their architecture. The first problem is that architectures are not explicitly represented in the code as classes and packages are. The second problem is that suc- cessful applications evolve over time so their architecture inevitably drifts. Reconstructing and checking whether the architecture is still valid is thus an important aid. While there is a plethora of approaches and techniques supporting architecture reconstruction, there is no comprehensive state of the art and it is often difficult to compare the ap- proaches. This article presents a first state of the art in soft- ware architecture reconstruction, with the desire to support the understanding of the field

Processamento de fala e linguagem para auxiliar na coordenação de reuniões

Meetings are an important part of our daily lives. Formal or informal, in-person or remote, they are something unavoidable in our society. In companies they assume even greater importance, being decisive for the definition of their present and future. Despite being an extremely important area, not enough research has been carried out to understand and improve the quality of meetings. Current technologies can enhance understanding of the meeting, by providing data with greater precision and/or that was simply not possible before. This dissertation proposes a platform that can help coordinate a meeting in real-time, providing relevant information for the coordinator and all participants. To develop a proof-of-concept system, a user-centered Design approach was adopted, starting with the identification of target users and the set of main requirements derived from usage scenarios. The developed system adopted a decoupled architecture and a semantic knowledge base to provide flexibility for future evolutions. The proof-of-concept integrates several processing modules capable of converting speech to text and doing voice analysis. A set of existing pre-recorded meetings was used to test it. The presented system showed to be already capable of providing meeting managers with useful and interesting information. It can extract a set of statistics and present them in the form of charts or text. These are available through a dashboard or an alert module. The presented work is both a first step and an initial proof-of-concept, the future work is rich and covers distinct lines of research.As reuniões são uma parte importante do nosso dia a dia. Formais ou informais, presenciais ou remotas, são algo inevitável na nossa sociedade. Nas empresas assumem uma importância ainda maior, sendo decisivas para a definição do seu presente e futuro. Apesar de ser uma área de extrema importância, não foi ainda realizada investigação suficiente para compreender e melhorar a qualidade das reuniões. As tecnologias atuais podem melhorar a nossa compreensão das reuniões, fornecendo dados com maior precisão e/ou que simplesmente não eram possíveis antes. Esta dissertação propõe uma plataforma que pode ajudar a coordenar uma reunião em tempo real, fornecendo informações relevantes para o coordenador e todos os participantes. Para desenvolver o sistema, uma abordagem centrada no utilizador foi adotada, começando com a identificação dos utilizadores-alvo e o conjunto de requisitos derivados dos cenários de uso. O sistema desenvolvido adotou ainda uma arquitetura desacoplada e uma semantic knowledge base para fornecer flexibilidade para futuras evoluções. A prova de conceito integra vários módulos de processamento capazes de converter fala em texto e realizar análise da voz. Um conjunto de reuniões pré-gravadas foi usado para testar o sistema. O sistema apresentado mostrou já ser capaz de fornecer aos coordenadores de reuniões informações úteis e interessantes. Pode extrair um conjunto de estatísticas e apresentá-las na forma de gráficos ou texto. Estes estão disponíveis numa dashboard ou através de alertas. O trabalho apresentado é um primeiro passo e uma primeira prova de conceito. O trabalho futuro é rico e cobre distintas linhas de investigação.Mestrado em Engenharia de Computadores e Telemátic

BioModels Database: An enhanced, curated and annotated resource for published quantitative kinetic models

Background: Quantitative models of biochemical and cellular systems are used to answer a variety of questions in the biological sciences. The number of published quantitative models is growing steadily thanks to increasing interest in the use of models as well as the development of improved software systems and the availability of better, cheaper computer hardware. To maximise the benefits of this growing body of models, the field needs centralised model repositories that will encourage, facilitate and promote model dissemination and reuse. Ideally, the models stored in these repositories should be extensively tested and encoded in community-supported and standardised formats. In addition, the models and their components should be cross-referenced with other resources in order to allow their unambiguous identification. Description: BioModels Database http://www.ebi.ac.uk/biomodels/ is aimed at addressing exactly these needs. It is a freely-accessible online resource for storing, viewing, retrieving, and analysing published, peer-reviewed quantitative models of biochemical and cellular systems. The structure and behaviour of each simulation model distributed by BioModels Database are thoroughly checked; in addition, model elements are annotated with terms from controlled vocabularies as well as linked to relevant data resources. Models can be examined online or downloaded in various formats. Reaction network diagrams generated from the models are also available in several formats. BioModels Database also provides features such as online simulation and the extraction of components from large scale models into smaller submodels. Finally, the system provides a range of web services that external software systems can use to access up-to-date data from the database. Conclusions: BioModels Database has become a recognised reference resource for systems biology. It is being used by the community in a variety of ways; for example, it is used to benchmark different simulation systems, and to study the clustering of models based upon their annotations. Model deposition to the database today is advised by several publishers of scientific journals. The models in BioModels Database are freely distributed and reusable; the underlying software infrastructure is also available from SourceForge https://sourceforge.net/projects/biomodels/ under the GNU General Public License