Model-driven development of sensor network applications with optimization of non-functional constraints

Wireless sensor networks (WSNs) differ from conventional distributed systems in many aspects. The resource limitation of sensor nodes, the ad-hoc communication and topology of the network, coupled with an unpredictable deployment environment are difficult non-functional constraints that must be carefully taken into account when developing software systems for a WSN. Thus, more research needs to be done on designing, implementing and maintaining software for WSNs. This thesis aims to contribute to research being done in this area by presenting an approach to WSN application development that will improve the reusability, flexibility, and maintainability of the software. Firstly, we present a programming model and software architecture aimed at describing WSN applications, independently of the underlying operating system and hardware. The proposed architecture is described and realized using the Model-Driven Architecture (MDA) standard in order to achieve satisfactory levels of encapsulation and abstraction when programming sensor nodes. Besides, we study different non-functional constrains of WSN application and propose two approaches to optimize the application to satisfy these constrains. A real prototype framework was built to demonstrate the developed solutions in the thesis. The framework implemented the programming model and the multi-layered software architecture as components. A graphical interface, code generation components and supporting tools were also included to help developers design, implement, optimize, and test the WSN software. Finally, we evaluate and critically assess the proposed concepts. Two case studies are provided to support the evaluation. The first case study, a framework evaluation, is designed to assess the ease at which novice and intermediate users can develop correct and power efficient WSN applications, the portability level achieved by developing applications at a high-level of abstraction, and the estimated overhead due to usage of the framework in terms of the footprint and executable code size of the application. In the second case study, we discuss the design, implementation and optimization of a real-world application named TempSense, where a sensor network is used to monitor the temperature within an area.

Decision Making for Teams of Mobile Robots

In the past years, we could observe a significant amount of new robotic systems in science, industry, and everyday life. To reduce the complexity of these systems, the industry constructs robots that are designated for the execution of a specific task such as vacuum cleaning, autonomous driving, observation, or transportation operations. As a result, such robotic systems need to combine their capabilities to accomplish complex tasks that exceed the abilities of individual robots. However, to achieve emergent cooperative behavior, multi-robot systems require a decision process that copes with the communication challenges of the application domain. This work investigates a distributed multi-robot decision process, which addresses unreliable and transient communication. This process composed by five steps, which we embedded into the ALICA multi-agent coordination language guided by the PROViDE negotiation middleware. The first step encompasses the specification of the decision problem, which is an integral part of the ALICA implementation. In our decision process, we describe multi-robot problems by continuous nonlinear constraint satisfaction problems. The second step addresses the calculation of solution proposals for this problem specification. Here, we propose an efficient solution algorithm that integrates incomplete local search and interval propagation techniques into a satisfiability solver, which forms a satisfiability modulo theories (SMT) solver. In the third decision step, the PROViDE middleware replicates the solution proposals among the robots. This replication process is parameterized with a distribution method, which determines the consistency properties of the proposals. In a fourth step, we investigate the conflict resolution. Therefore, an acceptance method ensures that each robot supports one of the replicated proposals. As we integrated the conflict resolution into the replication process, a sound selection of the distribution and acceptance methods leads to an eventual convergence of the robot proposals. In order to avoid the execution of conflicting proposals, the last step comprises a decision method, which selects a proposal for implementation in case the conflict resolution fails. The evaluation of our work shows that the usage of incomplete solution techniques of the constraint satisfaction solver outperforms the runtime of other state-of-the-art approaches for many typical robotic problems. We further show by experimental setups and practical application in the RoboCup environment that our decision process is suitable for making quick decisions in the presence of packet loss and delay. Moreover, PROViDE requires less memory and bandwidth compared to other state-of-the-art middleware approaches.

Efficient Security and Privacy Enhancing Solutions in Untrusted Environments

Thesis (Ph.D.)--University of Washington, 2016-08

Context-awareness privacy in data communications

Internet users consume online targeted advertising based on information collected about them and voluntarily share personal information in social networks. Sensor information and data from smart-phones is collected and used by applications, sometimes in unclear ways. As it happens today with smartphones, in the near future sensors will be shipped in all types of connected devices, enabling ubiquitous information gathering from the physical environment, enabling the vision of Ambient Intelligence. The value of gathered data, if not obvious, can be harnessed through data mining techniques and put to use by enabling personalized and tailored services as well as business intelligence practices, fueling the digital economy. However, the ever-expanding information gathering and use undermines the privacy conceptions of the past. Natural social practices of managing privacy in daily relations are overridden by socially-awkward communication tools, service providers struggle with security issues resulting in harmful data leaks, governments use mass surveillance techniques, the incentives of the digital economy threaten consumer privacy, and the advancement of consumergrade data-gathering technology enables new inter-personal abuses. A wide range of fields attempts to address technology-related privacy problems, however they vary immensely in terms of assumptions, scope and approach. Privacy of future use cases is typically handled vertically, instead of building upon previous work that can be re-contextualized, while current privacy problems are typically addressed per type in a more focused way. Because significant effort was required to make sense of the relations and structure of privacy-related work, this thesis attempts to transmit a structured view of it. It is multi-disciplinary - from cryptography to economics, including distributed systems and information theory - and addresses privacy issues of different natures. As existing work is framed and discussed, the contributions to the state-of-theart done in the scope of this thesis are presented. The contributions add to five distinct areas: 1) identity in distributed systems; 2) future context-aware services; 3) event-based context management; 4) low-latency information flow control; 5) high-dimensional dataset anonymity. Finally, having laid out such landscape of the privacy-preserving work, the current and future privacy challenges are discussed, considering not only technical but also socio-economic perspectives.

Application of an online-biomass sensor in an optical multisensory platform prototype for growth monitoring of biotechnical relevant microorganism and cell lines in single-use shake flasks

In the context of this work we evaluated a multisensory, noninvasive prototype platform for shake flask cultivations by monitoring three basic parameters (pH, pO2 and biomass). The focus lies on the evaluation of the biomass sensor based on backward light scattering. The application spectrum was expanded to four new organisms in addition to E. coli K12 and S. cerevisiae [1]. It could be shown that the sensor is appropriate for a wide range of standard microorganisms, e.g., L. zeae, K. pastoris, A. niger and CHO-K1. The biomass sensor signal could successfully be correlated and calibrated with well-known measurement methods like OD600, cell dry weight (CDW) and cell concentration. Logarithmic and Bleasdale-Nelder derived functions were adequate for data fitting. Measurements at low cell concentrations proved to be critical in terms of a high signal to noise ratio, but the integration of a custom made light shade in the shake flask improved these measurements significantly. This sensor based measurement method has a high potential to initiate a new generation of online bioprocess monitoring. Metabolic studies will particularly benefit from the multisensory data acquisition. The sensor is already used in labscale experiments for shake flask cultivations.

Knowledge of pre-eclampsia in women living in Makole Ward, Dodoma, Tanzania.

Background: Pre-eclampsia is a hypertensive disorder specific to pregnancy responsible for significant maternal morbidity and mortality in Africa. The majority of deaths related to pre-eclampsia could be avoided with timely and effective care. “Phase one delays” arise because of lack of knowledge. Objectives: This study aimed to assess the knowledge levels of women living in Makole ward, comparing respondent subgroups with different demographic characteristics. It also aimed to compare knowledge levels in respect to six subtopics of pre-eclampsia. This was to allow for planning of appropriate activities to reduce delays in seeking health care. Methods: This study surveyed 200 adult women randomly identified in the community. They were asked 36 questions on preeclampsia requiring yes / no answers. The data was analysed quantitatively. Results: Overall knowledge levels were low with an average of 41% of correct answers. Minor differences in the knowledge levels of demographic subgroups were found. Statistically significant differences were identified between sub-topics of preeclampsia; signs and symptoms were the least well known. Conclusion: Educational systems (formal and informal) are failing to provide communities with potentially life-saving information. Health centre, community and school based education programmes are recommended.

TcT: Tyrolean Complexity Tool

International audience

GIS-integrated mathematical modeling of social phenomena at macro- and micro- levels—a multivariate geographically-weighted regression model for identifying locations vulnerable to hosting terrorist safe-houses: France as case study

Adaptability and invisibility are hallmarks of modern terrorism, and keeping pace with its dynamic nature presents a serious challenge for societies throughout the world. Innovations in computer science have incorporated applied mathematics to develop a wide array of predictive models to support the variety of approaches to counterterrorism. Predictive models are usually designed to forecast the location of attacks. Although this may protect individual structures or locations, it does not reduce the threat—it merely changes the target. While predictive models dedicated to events or social relationships receive much attention where the mathematical and social science communities intersect, models dedicated to terrorist locations such as safe-houses (rather than their targets or training sites) are rare and possibly nonexistent. At the time of this research, there were no publically available models designed to predict locations where violent extremists are likely to reside. This research uses France as a case study to present a complex systems model that incorporates multiple quantitative, qualitative and geospatial variables that differ in terms of scale, weight, and type. Though many of these variables are recognized by specialists in security studies, there remains controversy with respect to their relative importance, degree of interaction, and interdependence. Additionally, some of the variables proposed in this research are not generally recognized as drivers, yet they warrant examination based on their potential role within a complex system. This research tested multiple regression models and determined that geographically-weighted regression analysis produced the most accurate result to accommodate non-stationary coefficient behavior, demonstrating that geographic variables are critical to understanding and predicting the phenomenon of terrorism. This dissertation presents a flexible prototypical model that can be refined and applied to other regions to inform stakeholders such as policy-makers and law enforcement in their efforts to improve national security and enhance quality-of-life.

Spectral asymptotic properties of semi-regular non-commutative harmonic oscillators

The study carried out in this thesis is devoted to spectral analysis of systems of PDEs related also with quantum physics models. Namely, the research deals with classes of systems that contain certain quantum optics models such as Jaynes-Cummings, Rabi and their generalizations that describe light-matter interaction. First we investigate the spectral Weyl asymptotics for a class of semiregular systems, extending to the vector-valued case results of Helffer and Robert, and more recently of Doll, Gannot and Wunsch. Actually, the asymptotics by Doll, Gannot and Wunsch is more precise (that is why we call it refined) than the classical result by Helffer and Robert, but deals with a less general class of systems, since the authors make an hypothesis on the measure of the subset of the unit sphere on which the tangential derivatives of the X-Ray transform of the semiprincipal symbol vanish to infinity order. Abstract Next, we give a meromorphic continuation of the spectral zeta function for semiregular differential systems with polynomial coefficients, generalizing the results by Ichinose and Wakayama and Parmeggiani. Finally, we state and prove a quasi-clustering result for a class of systems including the aforementioned quantum optics models and we conclude the thesis by showing a Weyl law result for the Rabi model and its generalizations.

Refining specifications to logic programs

The refinement calculus provides a framework for the stepwise development of imperative programs from specifications. In this paper we study a refinement calculus for deriving logic programs. Dealing with logic programs rather than imperative programs has the dual advantages that, due to the expressive power of logic programs, the final program is closer to the original specification, and each refinement step can achieve more. Together these reduce the overall number of derivation steps. We present a logic programming language extended with specification constructs (including general predicates, assertions, and types and invariants) to form a wide-spectrum language. General predicates allow non-executable properties to be included in specifications. Assertions, types and invariants make assumptions about the intended inputs of a procedure explicit, and can be used during refinement to optimize the constructed logic program. We provide a semantics for the extended logic programming language and derive a set of refinement laws. Finally we apply these to an example derivation.

Induction in the timed interval calculus

The Timed Interval Calculus, a timed-trace formalism based on set theory, is introduced. It is extended with an induction law and a unit for concatenation, which facilitates the proof of properties over trace histories. The effectiveness of the extended Timed Interval Calculus is demonstrated via a benchmark case study, the mine pump. Specifically, a safety property relating to the operation of a mine shaft is proved, based on an implementation of the mine pump and assumptions about the environment of the mine. (C) 2002 Elsevier Science B.V. All rights reserved.

Ensino primário e matemática dos imigrantes e descendentes germânicos em Santa Leopoldina (1857-1907)

O objetivo da pesquisa é descrever o cenário da imigração germânica no século XIX, tratando também, de trilhar o caminho da educação por meio de educadores e das comunidades na Colônia de Santa Leopoldina, criada em 1857, na Província do Espírito Santo, considerando 50 anos a partir do início da imigração (1857-1907). A pesquisa histórica ancorou-se em consultas a documentos oficiais do Império, documentos e relatórios oficiais dos Presidentes da Província do Espírito Santo, jornais de circulação da época, fotografias, mapas geográficos, mapas estatísticos, livros didáticos antigos e livros de autores que abordaram o processo imigratório do Espírito Santo. O diálogo com Marc Bloch ajudou a entender essa multiplicidade de documentos, na complexa relação entre o passado e o presente da educação do Espírito Santo. O trabalho apresenta uma trajetória do imigrante germânico vindo da Europa até a ex-colônia e como a administração da província tratou a imigração e a educação. O ensino primário iniciou-se a partir de iniciativas públicas e particulares. Foram identificados as primeiras escolas e os nomes de muitos professores que atuaram no período estudado. Os livros utilizados nas escolas das comunidades teuto-brasileiras eram oriundos da Alemanha e posteriormente foram produzidos no sul do Brasil. Entre os livros escritos em alemão encontrados destacam-se o livro texto de alfabetização „Lese – Schule I für Deutsche Kinder in Brasilien‟, editado na Alemanha no final do século XIX, de autoria do diretor de uma escola particular em Santa Leopoldina, Albert Richard Dietze, e o primeiro volume do livro de matemática „Rechenbuch für Deutsch-Brasilianische Volksschulen‟, de Ferdinand Hackbart, Konrad Glaus e Hermann Lange. Foi feita uma análise sob os aspectos físicos e formais, o processo de ensino e os conteúdos do livro de matemática. A análise evidenciou que a proposta de ensino apoia-se no “cálculo mental” e o escrito, com a repetição dos conteúdos, envolvendo o treino intensivo. Os conceitos de matemática são apresentados partindo de problemas com situações concretas do aluno para a aquisição de competências necessárias para inserir o aluno em sua comunidade. Levando-se em conta que o livro foi editado em 1906, conclui-se que se trata de uma obra relevante com uma proposta de ensino que se manteve presente nos livros didáticos de matemática até os dias atuais.

Representing organizational structures in enterprise architecture : an ontology-based approach

Arquitetura Corporativa promove o estabelecimento de uma visão holística da estrutura e forma de trabalho de uma organização. Um dos aspectos abordados em Arquitetura Corporativa está associada a "estrutura ativa" da organização, que diz respeito a “quem" realiza as atividades organizacionais. Várias abordagens têm sido propostas a fim de proporcionar um meio para a representação de Arquitetura Corporativa, entre as quais ARIS, RM-ODP, UPDM e ArchiMate. Apesar da aceitação por parte da comunidade, as abordagens existentes se concentram em propósitos diferentes, têm limitações de escopo e algumas não têm semântica de mundo real bem definida. Além das abordagens de modelagem, muitas abordagens de ontologias têm sido propostas, a fim de descrever o domínio de estrutura ativa, incluindo as ontologias de SUPER Project, TOVE, Enterprise Ontology e W3C Org Ontology. Embora especificadas para fundamentação semântica e negociação de significado, algumas das abordagens propostas têm fins específicos e cobertura limitada. Além disso, algumas das abordagens não são definidas usando linguagens formais e outras são especificadas usando linguagens sem semântica bem definida. Este trabalho apresenta uma ontologia de referência bem fundamentada para o domínio organizacional. A ontologia organizacional de referência apresentada abrange os aspectos básicos discutidos na literatura organizacional, tais como divisão do trabalho, relações sociais e classificação das unidades estruturais. Além disso, também abrange os aspectos organizacionais definidos em abordagens existentes, levando em consideração tanto abordagens de modelagem quanto abordagens ontológicas. A ontologia resultante é especificada em OntoUML e estende os conceitos sociais de UFO-C.