Submitted by Emanuel Varela Cardoso (emanuel.varela@ufcg.edu.br) on 2018-05-04T17:30:47Z No. of bitstreams: 1 ALDENOR FALCÃO MARTINS – DISSERTAÇÃO (PPGEE) 2015.pdf: 15602466 bytes, checksum: 608173ca67ff68da8ae45b321aa82204 (MD5) / Made available in DSpace on 2018-05-04T17:30:47Z (GMT). No. of bitstreams: 1 ALDENOR FALCÃO MARTINS – DISSERTAÇÃO (PPGEE) 2015.pdf: 15602466 bytes, checksum: 608173ca67ff68da8ae45b321aa82204 (MD5) Previous issue date: 2015-04-24 / Segundo o IBGE em 2013, o Brasil apresentava 13% de sua população composta por pessoas acima de 65 anos, somado a isto, o estilo de vida das sociedades ocidentais tem facilitado o aparecimento de doenças crônicas cada vez mais cedo. A premissa é que tornemos mais eficiente a utilização do nosso sistema de saúde, pois este é um recurso escasso. Uma forma de melhorar esta eficiência é assegurar que os tratamentos prescritos serão devidamente seguidos. Quando o paciente se encontra no hospital uma gama de recursos monitora a saúde do paciente oferecendo acompanhamento seguro na eventualidade de um desvio, alertando e armazenando as informações do paciente no decorrer de suas atividades. Um recurso que ajuda no acompanhamento deste paciente é a monitoração remota do paciente, que possibilita que sensores enviem a informação da condição de saúde do paciente e permitam o acompanhamento do mesmo. Sistemas Físicos Cibernéticos (SFC) são entidades computacionais ligadas em rede que operam entidades no mundo físico de maneira cooperativa. Tais sistemas podem ser utilizados em redes de monitoramento remoto de pacientes com o fim de apresentar e ajustar o tratamento de acordo com as recomendações do médico. Este trabalho propõe um passo na direção da autonomia, que permita uma melhor qualidade de vida ao paciente crônico, permitindo que situações conhecidas e dentro de um regime de segurança previamente determinado pelo médico sejam ajustadas. Este trabalho apresenta uma proposta de um Sistema Físico Cibernético (SFC), que permite que adequações ao tratamento previamente elaboradas sejam colocadas em planos de tratamento por meio de agentes inteligentes e de planejadores SAT e sejam disponibilizadas de acordo com a mudança da condição do paciente, através de uma rede monitoramento do paciente, seguindo padrões estabelecidos para dispositivos médicos utilizados em casa que disponibiliza o tratamento ao paciente. O modelo proposto é indicado para o acompanhamento em casa de doenças crônicas através de um coletor central responsável pela coordenação do acompanhamento do paciente. / According to IBGE in 2013 13% of the population had 60 or more years old. As the national population ages, we have to move towards more efficient use of SUS. A way to improve is the closer followup of patient’s evolution by the healthcare professional. At the hospital the patient has access to a set of equipments and expert knowledge capable to correct the treatment path. From this scenario it is easy to imply the need for a change, the current status quo is unbearable financially and cumbersome for patient and doctor routines. A resource that helps is the remote patient monitoring (RPM) , where sensors provide the latest information about patient’s health status and are able to suggest a course correction on the treatment path. A Cyber-Physical System (CPS) is a network of interacting computational entities with physical inputs and outputs that work together towards a goal. A CPS can be part of a RPM in order to present and adjust the treatment according to the healthcare professional recommendations. This work offers a framework for situations where the medical expert knowledge is complete allowing changes on the treatment path be adjusted with minimum risk. Our proposal to deal with the problem is a CPS based remote patient monitoring network where a model for the system is developed based on Multiagent Agent System (MAS) and automatic planning system based on SAT, allowing safe and minimal course correction on treatment paths already set for a patient. This proposal operates through a central hub element responsible to coordinate the followup of the patient.

The power grid has changed a great deal from what has been generally viewed as a traditional power grid. The modernization of the power grid has seen an increase in the integration and incorporation of computing and communication elements, creating an interdependence of both physical and cyber assets of the power grid. The fast-increasing connectivity has transformed the grid from what used to be primarily a physical system into a Cyber- Physical System (CPS). The physical elements within a power grid are well understood by power engineers; however, the newly deployed cyber aspects are new to most researchers and operators in this field. The new computing and communications structure brings new vulnerabilities along with all the benefits it provides. Cyber security of the power grid is critical due to the potential impact it can make on the community or society that relies on the critical infrastructure. These vulnerabilities have already been exploited in the attack on the Ukrainian power grid, a highly sophisticated, multi-layered attack which caused large power outages for numerous customers. There is an urgent need to understand the cyber aspects of the modernized power grid and take the necessary precautions such that the security of the CPS can be better achieved. The power grid is dependent on two main cyber infrastructures, i.e., Supervisory Control And Data Acquisition (SCADA) and Advanced Metering Infrastructure (AMI). This thesis investigates the AMI in power grids by developing a testbed environment that can be created and used to better understand and develop security strategies to remove the vulnerabilities that exist within it. The testbed is to be used to conduct and implement security strategies, i.e., an Intrusion Detections Systems (IDS), creating an emulated environment to best resemble the environment of the AMI system. A DoS flooding attack and an IDS are implemented on the emulated testbed to show the effectiveness and validate the performance of the emulated testbed. / M.S. / The power grid is becoming more digitized and is utilizing information and communication technologies more, hence the smart grid. New systems are developed and utilized in the modernized power grid that directly relies on new communication networks. The power grid is becoming more efficient and more effective due to these developments, however, there are some considerations to be made as for the security of the power grid. An important expectation of the power grid is the reliability of power delivery to its customers. New information and communication technology integration brings rise to new cyber vulnerabilities that can inhibit the functionality of the power grid. A coordinated cyber-attack was conducted against the Ukrainian power grid in 2015 that targeted the cyber vulnerabilities of the system. The attackers made sure that the grid operators were unable to observe their system being attacked via Denial of Service attacks. Smart meters are the digitized equivalent of a traditional energy meter, it wirelessly communicates with the grid operators. An increase in deployment of these smart meters makes it such that we are more dependent on them and hence creating a new vulnerability for an attack. The smart meter integration into the power grid needs to be studied and carefully considered for the prevention of attacks. A testbed is created using devices that emulate the smart meters and a network is established between the devices. The network was attacked with a Denial of Service attack to validate the testbed performance, and an Intrusion detection method was developed and applied onto the testbed to prove that the testbed created can be used to study and develop methods to cover the vulnerabilities present.

<p dir="ltr">In the context of a Human-in-the-Loop (HITL) system, the accuracy of reachability analysis plays a significant role in ensuring the safety and reliability of HITL systems. In addition, one can avoid unnecessary conservativeness by explicitly considering human control behavior compared to those methods that rely on the system dynamics alone. One possible approach is to use a Gaussian Mixture Model (GMM) to encode human control behavior using the Expectation-Maximization (EM) algorithm. However, relatively few works consider the admissible control input ranges due to physical limitations when modeling human control behavior. This could make the following reachability analysis overestimate the system's capability, thereby affecting the performance of the HITL system. To address this issue, this work presents a constrained stochastic reachability analysis algorithm that can explicitly account for the admissible control input ranges. By confining the ellipsoidal confidence region of each Gaussian component using Sequential Quadratic Programming (SQP), we probabilistically constrain the GMM as well as the corresponding stochastic reachable sets. A comprehensive mathematical analysis of how the constrained GMM can affect the stochastic reachable sets is provided in this work. Finally, the proposed stochastic reachability analysis algorithm is validated via an illustrative numerical example.</p>

Indoor localization remains an open problem in geolocation research, and once this is solved the localization enables counting and tracking of building occupants. This information is vital in an emergency, enables occupancy-optimized heating or cooling, and assists smart buildings in tailoring services for occupants. Unfortunately, two prevalent technologies---GPS and cellular-based positioning---perform poorly indoors due to attenuation and multipath from the building. To address this issue, the research community devised many alternatives for indoor localization (e.g., beacons, RFID tags, Wi-Fi fingerprinting, and UWB to cite just a few examples). A drawback with most is the requirement for those being located to carry a properly-configured device at all times. An alternative based on computer vision techniques poses significant privacy concerns due to cameras recording building occupants. By contrast, ILoViT research makes novel use of accelerometers already present in some buildings. These sensors were originally intended to monitor structural health or to study structural dynamics. The key idea is that when a person's footstep-generated floor vibrations can be detected and located then it becomes possible to locate persons moving within a building. Vibration propagation in buildings has complexities not encountered by acoustic or radio wave propagation in air; thus, conventional localization algorithms are inadequate. ILoVIT algorithms account for these conditions and have been demonstrated in a public building to provide sub-meter accuracy. Localization provides the foundation for counting and tracking, but providing these additional capabilities confronts new challenges. In particular, how does one determine the correct association of footsteps to the person making them? The ILoViT research created two methods for solving the data association problem. One method only provides occupancy counting but has modest, polynomial time complexity. The other method draws inspiration from prior work in the radar community on the multi-target tracking problem, specifically drawing from the multiple hypothesis tracking strategy. This dissertation research makes new enhancements to this tracking strategy to account for human gait and characteristics of footstep-derived multilateration. The Virginia Polytechnic Institute and State University's College of Engineering recognized this dissertation research with the Paul E. Torgersen Graduate Student Research Excellence Award. / Ph. D. / Indoor localization remains an open problem in geolocation research, and once this is solved the localization enables counting and tracking of building occupants. This information is vital in an emergency, enables occupancy-optimized heating or cooling and assists smart buildings in tailoring services for occupants. Unfortunately, two prevalent technologies—GPS and cellular-based positioning—are ill-suited here due to the way a building’s weakens and distorts wireless signals. To address this issue the research community devised many alternatives for indoor localization. A drawback with most is the requirement for those being located to carry a properly-configured device at all times. An alternative based on computer vision techniques poses significant privacy concerns due to cameras recording building occupants. By contrast, ILoViT research makes novel use of a mature sensor technology already present in some buildings. These sensors were originally intended to monitor structural health or to study structural dynamics. The key idea behind this unconventional role for building sensors is that when a person’s footstep-generated floor vibrations can be detected and located then it is possible to locate persons moving within a building. Vibration propagation in buildings has complexities not encountered by acoustic or radio wave propagation in air; thus, conventional localization algorithms designed for those applications are inadequate. ILoVIT algorithms account for these conditions and have been demonstrated in a public building to provide sub-meter accuracy. Localization provides the foundation for counting and tracking, but providing these additional capabilities confronts new challenges. In particular, how does one determine the correct association of footsteps to the person making them? The ILoViT research created two methods for solving the data association problem. One method only provides area occupancy counting but has modest complexity. The other method draws inspiration from prior work in the radar community on the multi-target tracking problem, and the dissertation research makes new enhancements to account for human gait and footstep-based localization. The Virginia Polytechnic Institute and State University’s College of Engineering recognized this dissertation research with the Paul E. Torgersen Graduate Student Research Excellence Award.

A Cyber-physical System (CPS) can be described as a network of interlinked, concurrent computational components that interact with the physical world. Such a system is usually of reactive nature and must satisfy strict timing requirements to guarantee a correct behaviour. The components can be of mixed-criticality which implies different progress models and communication models, depending whether the focus of a component lies on predictability or resource efficiency. In this dissertation I present a novel approach that bridges the gap between stream processing models and Labelled Transition Systems (LTSs). The former offer powerful tools to describe concurrent systems of, usually simple, components while the latter allow to describe complex, reactive, components and their mutual interaction. In order to achieve the bridge between the two domains I introduce the novel LTS Synchronous Interface Automaton (SIA) that allows to model the interaction protocol of a process via its interface and to incrementally compose simple processes into more complex ones while preserving the system properties. Exploiting these properties I introduce an analysis to identify permanent blocking situations in a network of composed processes. SIAs are wrapped by the novel component-based coordination model Process Network with Synchronous Communication (PNSC) that allows to describe a network of concurrent processes where multiple communication models and the co-existence and interaction of heterogeneous processes is supported due to well defined interfaces. The work presented in this dissertation follows a holistic approach which spans from the theory of the underlying model to an instantiation of the model as a novel coordination language, called Streamix. The language uses network operators to compose networks of concurrent processes in a structured and hierarchical way. The work is validated by a prototype implementation of a compiler and a Run-time System (RTS) that allows to compile a Streamix program and execute it on a platform with support for ISO C, POSIX threads, and a Linux operating system.

Submitted by Johnny Rodrigues (johnnyrodrigues@ufcg.edu.br) on 2018-05-09T17:24:59Z No. of bitstreams: 1 LENARDO CHAVES E SILVA - TESE PPGCC 2015..pdf: 9863003 bytes, checksum: b4ff7a7517f3ec159596b4b3c8730219 (MD5) / Made available in DSpace on 2018-05-09T17:24:59Z (GMT). No. of bitstreams: 1 LENARDO CHAVES E SILVA - TESE PPGCC 2015..pdf: 9863003 bytes, checksum: b4ff7a7517f3ec159596b4b3c8730219 (MD5) Previous issue date: 2015-11-12 / Capes / Sistemas Médicos Físico-Cibernéticos (SMFC) são sistemas críticos cientes de contexto que têm a segurança do paciente como principal requisito, demandando processos rigorosos de validação para garantir a conformidade com os requisitos do usuário e a corretude orientada à especificação. Neste trabalho é proposta uma arquitetura baseada em modelos para validação de SMFC, focando em promover a reúso e a produtividade. Tal abordagem permite que desenvolvedores de sistemas construam modelos formais de SMFC baseados em uma biblioteca de modelos de pacientes e dispositivos médicos, bem como simular o SMFC para identificar comportamentos indesejados em tempo de projeto. A abordagem proposta foi aplicada a três diferentes cenários clínicos para avaliar seu potencial de reúso para diferentes contextos. A abordagem foi também validada por meio de uma avaliação empírica com desenvolvedores para avaliar o reúso e a produtividade. Finalmente, os modelos foram formalmente verificados considerando os requisitos funcionais e de segurança, além da cobertura dos modelos. / Medical Cyber-Physical Systems (MCPS) are context-aware, life-critical systems with patient safety as the main concern, demanding rigorous processes for validation to guarantee user requirement compliance and specification-oriented correctness. In this article, we propose a model-based approach for early validation of MCPS, focusing on promoting reusability and productivity. It enables system developers to build MCPS formal models based on a library of patient and medical device models, and simulate the MCPS to identify undesirable behaviors at design time. Our approach has been applied to three different clinical scenarios to evaluate its reusability potential for different context. We have also validated our approach through an empirical evaluation with developers to assess productivity and reusability. Finally, our models have been formally verified considering functional and safety requirements and model coverage.

The manufacturing industry is competitive and is constantly striving to improve OEE. In the transition to smart production, digital technologies such as IIoT are highlighted as important. IIoT platforms enable real-time monitoring. In this sense, digital technologies such as IIoT are expected to improve OEE by enabling the analysis of real-time data and production availability.  A qualitative study with an abductive approach has been conducted. The empirical material has been collected through a case study of a heavy-duty vehicle industry and the theoretical framework is based on a literature study. Lastly, a thematic analysis has been used for the derivation of appropriate themes for analysis. The study concluded that challenges and enablers related to the implementation of IIoT to improve OEE can be divided into technical and cultural factors. Technical challenges and enablers mainly consider the achievement of interoperability, compatibility, and cyber security, while cultural factors revolve around digital acceptance, competence, encouragement of digital curiosity, and creating knowledge and understanding towards OEE. Lastly, conclusions can be drawn that implementation of IIoT has a positive effect on OEE since it ensures consistent and accurate data, which lies a solid foundation for production decisions. Also, digitalization of production enhances lean practices which are considered a key element for improving OEE.