Effective construction management involves real-time decisions regarding the progress of specific activities, the location of materials and equipment, and the construction site safety. The decision making process can be improved using real-time positioning technologies such as Radio Frequency Identification Device (RFID) systems, Global Positioning System (GPS), and Ultra Wide Band (UWB) sensors. While the GPS is not applicable to indoor positioning and RFID tags cannot provide a fully automated system for position location, the characteristics of UWB systems make this technology a strong candidate for a fully automated positioning system in an indoor construction environment. This thesis presents a comprehensive study of the performance of UWB systems in a controlled laboratory environment and in an institutional construction site in Waterloo, Canada as well as for a particular safety application. A primary objective of the research was to establish the accuracy of real-time position location under various conditions, including the effect of different construction materials (e.g., wood and metal), and to analyze changes in the accuracy of position location as construction progresses and the indoor environment physically evolves. Different challenges faced in implementing such a system in an active construction environment are addressed. Based on a statistical analysis of laboratory data, and considering the construction site experience, the reliability of the UWB positioning system for the aforementioned environments is discussed. Furthermore, an automated safety system is proposed using the real-time UWB positioning technology. Based on the error modeling of the UWB position location, an optimum alarming algorithm is designed for the proposed safety system and the reliability of such system is evaluated through a statistical analysis.

The main goal of this thesis is to develop real-time computer vision algorithms in order to detect and to track targets in uncertain complex environments purely based on a visual sensor. Two major subjects addressed by this work are: 1. The development of fast and robust image segmentation algorithms that are able to search and automatically detect targets in a given image. 2. The development of sound filtering algorithms to reduce the effects of noise in signals from the image processing. The main constraint of this research is that the algorithms should work in real-time with limited computing power on an onboard computer in an aircraft. In particular, we focus on contour tracking which tracks the outline of the target represented by contours in the image plane. This thesis is concerned with three specific categories, namely image segmentation, shape modeling, and signal filtering. We have designed image segmentation algorithms based on geometric active contours implemented via level set methods. Geometric active contours are deformable contours that automatically track the outlines of objects in images. In this approach, the contour in the image plane is represented as the zero-level set of a higher dimensional function. (One example of the higher dimensional function is a three-dimensional surface for a two-dimensional contour.) This approach handles the topological changes (e.g., merging, splitting) of the contour naturally. Although geometric active contours prevail in many fields of computer vision, they suffer from the high computational costs associated with level set methods. Therefore, simplified versions of level set methods such as fast marching methods are often used in problems of real-time visual tracking. This thesis presents the development of a fast and robust segmentation algorithm based on up-to-date extensions of level set methods and geometric active contours, namely a fast implementation of Chan-Vese's (active contour) model (FICVM). The shape prior is a useful cue in the recognition of the true target. For the contour tracker, the outline of the target can be easily disrupted by noise. In geometric active contours, to cope with deviations from the true outline of the target, a higher dimensional function is constructed based on the shape prior, and the contour tracks the outline of an object by considering the difference between the higher dimensional functions obtained from the shape prior and from a measurement in a given image. The higher dimensional function is often a distance map which requires high computational costs for construction. This thesis focuses on the extraction of shape information from only the zero-level set of the higher dimensional function. This strategy compensates for inaccuracies in the calculation of the shape difference that occur when a simplified higher dimensional function is used. This is named as contour-based shape modeling. Filtering is an essential element in tracking problems because of the presence of noise in system models and measurements. The well-known Kalman filter provides an exact solution only for problems which have linear models and Gaussian distributions (linear/Gaussian problems). For nonlinear/non-Gaussian problems, particle filters have received much attention in recent years. Particle filtering is useful in the approximation of complicated posterior probability distribution functions. However, the computational burden of particle filtering prevents it from performing at full capacity in real-time applications. This thesis concentrates on improving the processing time of particle filtering for real-time applications. In principle, we follow the particle filter in the geometric active contour framework. This thesis proposes an advanced blob tracking scheme in which a blob contains shape prior information of the target. This scheme simplifies the sampling process and quickly suggests the samples which have a high probability of being the target. Only for these samples is the contour tracking algorithm applied to obtain a more detailed state estimate. Curve evolution in the contour tracking is realized by the FICVM. The dissimilarity measure is calculated by the contour based shape modeling method and the shape prior is updated when it satisfies certain conditions. The new particle filter is applied to the problems of low contrast and severe daylight conditions, to cluttered environments, and to the appearing/disappearing target tracking. We have also demonstrated the utility of the filtering algorithm for multiple target tracking in the presence of occlusions. This thesis presents several test results from simulations and flight tests. In these tests, the proposed algorithms demonstrated promising results in varied situations of tracking.

The electrocardiograph (ECG) is a common clinical and biomedical research tool used for both diagnostic and prognostic purposes. In recent years computer aided analysis of the ECG has enabled cardiographic patterns to be found which were hitherto not apparent. Many of these analyses rely upon the segmentation of the ECG into separate time delimited waveforms. The instants delimiting these segments are called the

Thesis (Ph. D.)--Aerospace Engineering, Georgia Institute of Technology, 2008. / Committee Chair: Johnson, Eric; Committee Co-Chair: Calise, Anthony; Committee Member: Prasad, J.V.R.; Committee Member: Tannenbaum, Allen; Committee Member: Tsiotras, Panagiotis.

Thesis (M.S.) -- Mississippi State University. Department of Computer Science and Engineering. / Title from title screen. Includes bibliographical references.

Thesis (Ph. D.)--State University of New York at Binghamton, Thomas J. Watson School of Engineering and Applied Science, Department of Mechanical Engineering, 2008. / Includes bibliographical references.

Thesis (MScIng)--Stellenbosch University, 2004. / ENGLISH ABSTRACT: This dissertation's research aims at studying the viability of using both low cost consumer Commodity Off The Self (COTS) PCs and libn~software in implementing a distributed real-time system modeled on a real-world engineering problem. Debugging and developing a modular satellite system is both time consuming and complex, to this end the SUNSATteam has envisioned the Interactive Test System that would be a dual mode simulator/monitoring system. It is this system that requires a real-time back-end and is used as a real world problem model to implement. The implementation was accomplished by researching the available parallel processing software and real-time extensions to GNU/Linux and choosing the appropriate solutions based on the needs of the model. A monitoring system was also implemented, for system verification, using freely available system monitoring utilities. The model was successfully implemented and verified with a global synchronization of < 10ms. It was shown that GNU/Linux and libn~ software is both mature enough and appropriate in solving a real world distributed real-time problem. / AFRIKAANSE OPSOMMING: Die tesis se navorsing is daarop gemik om die toepaslikheid van beide lae koste verbruikers Komoduteits Van Die Rak (KVDR)persoonlike rekenaars en vemiet sagteware in die implementasie van verspreide intydse stelsels te ondersoek aan die hand van die oplossing van 'n gemodelleerde ingenieurs probleem. Die ontfouting en ontwikkeling van 'n modulere satelliet is beide tyd rowend en kompleks, om hierdie te vergemaklik het die SUNSAT span die Interaktiewe Toets Stelsel gekonseptualiseer, wat in wese'n dubbel modus simulator/moniteerings stelsel sou wees. Dit is hierdie stelsel wat 'n verspreide intydse onderstel benodig en dien as die regte wereld probleem model om op te los. Die implementasie is bereik deur die beskikbare verspreide verwerkings sagteware en intydse uitbreidings vir GNU/Linux te ondersoek en die toepaslike opsies te kies gegrond op die behoeftes van die model. 'n Moniteerings stelsel is ook geimplimenteer, met behulp van libn~sagteware, vir stelsel verifikasie. Die model was suksesvol geimplimenteer en geverifieer met 'n globale sinkronisasie van < 10ms. Daar is getoon dat GNU/Linux en libn~sagteware beide volwaardig en geskik is vir die oplossing van regte wereld verspreide intydse probleme.

Thesis (MPhil)--Stellenbosch University, 2004. / ENGLISH ABSTRACT: The rise of the network economy had a resounding impact on the world economy. Business remains transfixed between choosing between hierarchical organizational structures suited to a control and command mindset or transforming to an organizational structure intent on sensing and responding. Flexible and adaptive enterprises are more suitable to an increasingly volatile business environment. Current business trends worldwide seem to point in this direction. This may be an indication of the way in which organizations strive to avoid running the risk of business insignificance. Driven by business volatility, organizational structures are turning increasingly to naturally occurring ‘organizations’ to construct their own malleable versions. The redesign of an organizational structure is as important as reviewing information flows, optimizing technology and most importantly, finding the right type of employee to set the wheels of a real-time enterprise (RTE) in motion. Any discussion pertaining to real-time will touch on time. A reflection on hierarchical organizations highlights their stability, but also their inflexibility and sufficing information practices. It then becomes clear that the new business direction in an intensely competitive environment will have little tolerance for any measure of organizational rigidity. But how driven and fast can information really be processed and still enhance the value of an enterprise? The RTE is not a fully automated enterprise. Its employees may be less involved in its everyday tasks, but remain part of its decision-making process. To what degree does the RTE business model then facilitate value-adding information processing by both automation and manual interventions? Do limits exist where speed and time wastage in business are concerned? Is speed at all costs the only concern of the RTE? The aim of this paper is to answer these questions conceptually. Cognizance was taken of the impact of the volatile business environment on organizational structures influencing the current understanding. The highlighted business trends are based on recently published global and authoritative industry papers, business analyses and academic interpretations. Some of the best material was sourced from professional journals discussing the infinite angles of real-time information. Castells’s work on the network society proved to be extremely valuable to gain a holistic understanding. The latest developments were obtained from well-established research companies. During the investigative phase of this paper, the author encountered one thesis on real-time information focusing on information technology. It was evident that more research is required to answer the questions posed. The eventual findings were in line with the complexity and scope of the subject. The current demands of a global network economy necessitate agile and adaptive networked enterprises, not hierarchies. Roles are becoming more important than positions in the organizational transition phase to a networked, flat structure. A failure to start with such a transformation programme will result in a failure to survive in a fiercely competitive global business environment. It was clear that the RTE is dependent on the establishment of a balance struck between business entities in their interactions with one another as parts of a whole, replete with conditions and requirements. It is only in this sense that access to real-time information could be seen as a differentiating factor in global business. / AFRIKAANSE OPSOMMING: Die ontstaan van die netwerk-ekonomie het ‘n beduidende invloed op wêreldhandel gehad. Besigheid het nog nie uitsluitsel verkry tussen twee soorte organisatoriese strukture nie, naamlik, ‘n hiërargiese organisasiestruktuur wat pas by ’n beheer-en-regeer denkwyse en die ander, ’n veranderende organiese struktuur wat aanvoeling en reaksie belangriker ag. Buigsame, aanpasbare organisasies is uitstekend aangepas by ’n toenemend onsekere besigheidsomgewing. Dit wil voorkom of organisasies tans in hierdie rigting neig om die risiko van onbeduidenheid in die hedendaagse sakewêreld op dié manier te systap. Onsekerheid in besigheid noop organisatoriese strukture om hul toenemend te wend na organisasiestrukture wat natuurlik voorkom, ten einde ‘n eiesoortige buigsame weergawe daarvan te skep. Organisatoriese herstrukturering is ewe belangrik as die hersiening van inligtingsvloei, die optimisering van tegnologie en bowenal, die soektog na die regte soort werknemer wat dryfkrag aan die ‘real-time enterprise’ of RTE sal verleen. ‘Real-time’ besprekings sluit noodwendig die tydskwessie in, terwyl enige nabetragting oor hiërargiese organisasies sal fokus op stabiliteit, maar ook op onbuigsaamheid en ontoereikende inligtingspraktyke. Die nuwe besigheidsrigting in ’n uiters mededingende omgewing laat min ruimte vir enige mate van organisatoriese onbuigsaamheid. Die vraag ontstaan egter hoe vinnig en gedrewe inligting verwerk kan word ten einde besigheidswaarde te vermeerder? RTE’s is nie volledig geoutomatiseerde organisasies nie. Hoewel werknemers nie ten volle betrek word by alledaagse werk nie, is hulle steeds deel van die besluitnemingsproses. Maar vergemaklik die RTE-besigheidsmodel inderdaad die verwerking van inligting deur gedeeltelike outomatisering? Hoe word spoed en tydsvermorsing in organisasies hanteer? Sou spoed byvoorbeeld ten alle koste die enigste belang wees van die RTE? Die doel van hierdie proefskrif is om hierdie vrae in beginsel te beantwoord. Die invloed van besigheidsonsekerheid op organisatoriese strukture wat die huidige denkwyse beïnvloed, word erken. Die aanduiding oor organisatoriese ontwikkeling is gebaseer op internasionale, gesaghebbende spesialisgeskrifte, besigheidsontledings, sowel as akademiese vertolkings. Voortreflike literatuur is bekom in professionele joernale oor die ontelbare nuanses van ‘real-time’ inligting. Castells se werk oor die netwerkgemeenskap was van onskatbare waarde vir ’n oorsigtelike insig, terwyl die jongste ontwikkelinge verkry is uit artikels afkomstig van gevestigde navorsingsinstansies. Die skrywer het gedurende die navorsingsfase slegs een proefskrif teengekom oor ‘real-time’ inligting met inligtingstegnologie as die hooffokus. Dit is duidelik dat toenemende navorsing steeds ontbreek. Die uiteindelike bevindings het ooreengestem met die ingewikkeldheid en omvang van die onderwerp. Die eise van ’n internasionale netwerk kan slegs beantwoord word deur ratse en aanpasbare netwerk organisasies, allermins deur hiërargieë. ’n Rol, pleks van ’n aanstelling, raak van toenemende belang in die organisatoriese oorgangsfase na ’n plat struktuur wat deel is van ’n netwerk. Versuim om te begin met so ’n oorgangsprogram sal mislukking tot gevolg hê in die geweldig mededingende besigheidsomgewing wat dwarsoor die wêreld heers. Die RTE is afhanklik van die daarstelling van ‘n balans tussen besighede as dele van ’n geheel in hul omgang met mekaar wat die nodige voorwaardes en vereistes insluit. Dis slegs binne hierdie raamwerk dat toegang tot ‘real-time’ inligting beskou kan word as ’n unieke faktor wat aan besigheidsorganisasies wêreldwyd gebied word.

Os sistemas embarcados automotivos são caracterizados por sistemas computacionais que suportam funcionalidades na forma de softwares embarcados para proporcionar aos usuários maior conforto, segurança e desempenho. Entretanto, existe uma grande quantidade de funções integradas que elevam o nível de complexidade de forma que se deve utilizar métodos e ferramentas de projetos adequados para garantir os requisitos funcionais e não funcionais do sistema. Todo o projeto de software embarcado automotivo deve iniciar com a definição de requisitos funcionais e de acordo com a dinâmica do subsistema que uma ECU (Electronic Control Unit) irá controlar e/ou gerenciar, deve-se ainda definir os requisitos temporais. Uma função automotiva pode ter requisitos temporais do tipo, período de ativação, atraso fim-a-fim, deadline entre outras que por sua vez estão estritamente relacionadas com as características da arquitetura de hardware utilizada. Em um sistema automotivo, tem-se uma arquitetura de computação embarcada distribuída em que existem tarefas e mensagens que trocam sinais entre si e podem ter requisitos temporais que devam ser atendidos. A análise temporal para verificação e validação dos requisitos temporais pode ser realizada ao nível de arquitetura distribuída, tarefas e instruções sendo que a utilização adequada de métodos e ferramentas é uma condição necessária para sua verificação. Desta forma, apresenta-se uma descrição do estado da arte de análise temporal em sistemas embarcados automotivos, suas propriedades e a utilização das ferramentas da Gliwa para avaliar se os requisitos temporais são atendidos. Um exemplo ilustrativo foi implementado com o propósito de apresentar como os métodos, processos e ferramentas devem ser aplicados para verificar se os requisitos temporais definidos previamente no início do projeto foram atendidos e para que em um sistema já existente possam suportar funções adicionais com requisitos temporais a serem garantidos. É importante verificar que as ferramentas de análise temporal, tem o propósito ainda de verificar se os recursos computacionais estão sendo utilizados de acordo com o especificado no início do projeto. / Automotive embedded systems are characterized by computer systems that support embedded software functionalities to provide users with greater comfort, security and performance. However, there are a number of integrated functions that raise the level of complexity so that appropriate design methods and tools must be used to guarantee the functional and non-functional requirements of the system. All automotive embedded software design must begin with the definition of functional requirements and according to the dynamics of the subsystem that an ECU (Electronic Control Unit) will control and/or manage, it is necessary to define the time requirements. An automotive function may have time requirements of type, activation period, end-to-end delay and deadline among others which in turn are strictly related to the characteristics of the hardware architecture used. In an automotive system there is a distributed embedded computing architecture in which there are tasks and messages that exchange signals between them and may have timing requirements that must be met. The timing analysis for verification and validation of timing constrains can be carried out at the level of distributed architecture, tasks and instructions, and the proper use of methods and tools is a necessary condition for their verification. In this way, a description of the state of the art of timing analysis in automotive embedded systems, their properties and the use of the tools of Gliwa to evaluate if the timing constrains are met. An illustrative example has been implemented with the purpose of presenting how the methods, processes and tools should be applied to verify that the time requirements defined at the beginning of the project are met and that in an existing system can support additional functions with requirements to be guaranteed. It is important to note that timing analysis tools are still intended to verify that computational resources are being used as specified at the beginning of the project.

CNPq / Sistemas embarcados são sistemas computacionais projetados para aplicações específicas, os quais estão presentes em praticamente todos os dispositivos eletrônicos atuais. A utilização de um sistema operacional (SO) é uma maneira de simplificar o desenvolvimento de software, livrando os programadores do gerenciamento do hardware de baixo nível e fornecendo uma interface de programação simples para tarefas que ocorrem com frequência. A alta complexidade dos computadores pessoais atuais torna a utilização de um SO indispensável. Por outro lado, sistemas embarcados são arquiteturas limitadas, geralmente com muitas restrições de custo e consumo. Devido às demandas adicionais impostas por um SO, os desenvolvedores de sistemas embarcados enfrentam a crítica decisão quanto à adoção ou não de um SO. Nesta dissertação, apresenta-se uma série de critérios a fim de auxiliar os projetistas de sistemas embarcados na decisão quanto ao uso ou não de um SO. Além disso, outros critérios são apresentados com o intuito de guiar a seleção do SO mais adequado às características do projeto. Adicionalmente, escolheu-se 15 sistemas operacionais para serem analisados de acordo com os critérios apresentados, os quais podem ser utilizados como base para o processo de seleção de um SO. Adicionalmente, a fim de avaliar o impacto da adoção de um SO em um projeto embarcado, apresenta-se um estudo de caso no qual uma aplicação modelo (uma estação meteorológica embarcada) foi desenvolvida em três diferentes cenários: sem um SO, usando um SO de tempo real (µC/OS-II), e usando um SO de propósito geral (uClinux). Uma FPGA e um SoPC foram utilizados para obter uma plataforma flexível de hardware apta para acomodar as três configurações. A adoção de um SO proporcionou uma redução de até 48% no tempo de desenvolvimento; em contrapartida, isto aumentou os requisitos de memória de programa em pelo menos 71%. / An embedded system (ES) is a computing system designed for a specific purpose, present essentially in every electronic device. The use of an operating system (OS) is advocated as a means to simplify software development, freeing programmers from managing low-level hardware and providing a simpler programming interface for common tasks. The high complexity of modern desktop computers makes an OS indispensable; embedded systems, on the other hand, are limited architectures, usually severely cost- and power-constrained. Because of the additional demands imposed by an OS, embedded developers are faced with the crucial decision of whether to adopt an OS or not. In this work, we introduce a set of criteria to help determine whether an OS should be adopted in an embedded design. We then go further and establish a series of rules to help decide which OS to pick, if one should be used. In addition, we present a case study in which a sample application (an embedded weather station) was developed under three different scenarios: without any OS, using the µC/OS-II real-time OS, and using the uClinux general-purpose OS. An FPGA and a SoPC were used to provide a flexible hardware platform able to accommodate all three configurations. The adoption of an OS provided a reduction of up to 48% in development time; on the other hand, it increased program memory requirements in at least 71%.