Rozprawy doktorskie na temat „Embedded visualization”

This thesis deals with analysis and visualization of data dependencies in embedded system software. The goal was to create a comprehensive, practical analysis tool that fits the needs at Scania well, while being as general and reusable as possible. Given the complexity of problem area, the goal was to position the outcome of this project as the basis for further development, making future extensibility an important consideration. This type of analysis has previously been performed either manually, or with help of problem-specific and system-specific tools developed by specific users for their own needs. Here, a wider user spectrum was interviewed to collect and analyze their needs in order to delimit the scope of the project and provide fundamentals of a solution that would benefit most users to the largest degree.  Application developed throughout this thesis is of a strongly layered structure, to provide most opportunity for future reuse and extension. In the first layer, XML representation of abstract syntax trees is obtained through source code analysis. This part relies on the work performed as a part of the thesis by Martin Pruscha [23], modifying and extending the tools developed for C code parsing and analysis there.  Intermediate part of the toolchain transforms this into a generalized XML representation of desired data relationships, based on detection of patterns in abstract syntax tree that correspond to code structures that signify global variables and functions within C modules, as well as their mutual dependencies, such as function calls or reading or writing to variables. While actual implementation deals only with inter-functional analysis, issues pertaining to problems necessitating intra-functional analysis of data flow (deeper pointer variable analysis, function pointers, flow of data through non-global variables) are discussed. In the final stage, based on user preferences selected via a GUI, this format is converted to GraphML format which can be graphically represented in yEd application. Finally, results and performance were analyzed to provide guidelines to future work

Several decades ago, computer control systems known as Electric Control Units (ECUs) were introduced to the automotive industry. Mechanical hardware units have since then increasingly been replaced by computer controlled systems to manage complex tasks such as airbag, ABS, cruise control and so forth. This has lead to a massive increase of software functions and data which all needs to be managed. There are several tools and techniques for this, however, current tools and techniques for developing real-time embedded system are mostly focusing on software functions, not data. Those tools do not fully support developers to manage run-time data at design time. Furthermore, current tools do not focus on visualization of relationship among data items in the system. This thesis is a part of previous work named the Data Entity approach which prioritizes data management at the top level of development life cycle. Our main contribution is a tool that introduces a new way to intuitively explore run-time data items, which are produced and consumed by software components, utilized in the entire system. As a consequence, developers will achieve a better understanding of utilization of data items in the software system. This approach enables developers and system architects to avoid redundant data as well as finding and removing stale data from the system. The tool also allows us to analyze conflicts regarding run-time data items that might occur between software components at design time.
A Data-Entity Approach for Component-Based Real-Time Embedded Systems Development

Dans ma thèse, je définis ce qu'est la visualisation en mouvement et j'apporte plusieurs contributions sur la manière de visualiser et de concevoir des visualisations localisées en mouvement. Dans la visualisation localisée de données, les données sont directement visualisées à proximité de l'espace physique, de l'objet ou de la personne auxquels elles se réfèrent. Les visualisations localisées sont souvent utiles dans des contextes où le référent des données et l'observateur sont en mouvement relatif. Imaginez, par exemple, un coureur regardant une visualisation sur un bracelet de fitness qu'il porte ou sur un écran public alors qu'il passe devant. De tels scénarios d'utilisation mobile et dynamique peuvent affecter la lecture de visualisations localisées. Il est donc important de comprendre comment optimiser la conception des visualisations pour ces contextes. En d'autres termes, il est d'abord nécessaire de définir des encodages de données localisées efficaces et visuellement stables; puis de les étudier lorsque des facteurs de mouvement sont impliqués. A ce titre, je définis d'abord la visualisation en mouvement comme des représentations de données visuelles utilisées dans des contextes qui présentent un mouvement relatif entre un observateur et une visualisation entière. Je classe la visualisation en mouvement en trois catégories : (a) observateur en mouvement et visualisation stationnaire, (b) visualisation en mouvement et observateur stationnaire, et (c) observateur et visualisation tous deux en mouvement. Pour analyser les opportunités et les défis de la conception de visualisations en mouvement, je propose un agenda de recherche. Pour commencer, j'explore avec quelle précision les observateurs peuvent lire une visualisation en mouvement. A cette fin, je mène une série d'études empiriques sur la perception de l'estimation de la proportion de la magnitude. Mes résultats montrent que les participants peuvent obtenir des informations fiables à partir de visualisations en mouvement, même s'ils se déplacent à grande vitesse et selon des trajectoires irrégulières. Sur la base de mes résultats de perception, je cherche à répondre à la question de savoir comment concevoir et intégrer la visualisation en mouvement dans des contextes réels. J'utilise la natation comme scénario d'application, car la natation possède des données riches et dynamiques. J'implémente un outil de prospection technologique qui permet à des concepteurs d'intégrer les visualisations en mouvement à une vidéo de natation. Les concepteurs peuvent modifier en direct les encodages visuels, l'état de mouvement ainsi que l'emplacement des visualisations. Les visualisations utilisent des données réelles liées à la course. Mon évaluation montre que la conception de visualisations en mouvement nécessite plus que ce que proposent les outils de conception de visualisations traditionnelles : la visualisation doit être placée dans son contexte (par exemple, son référent de données, son arrière-plan) mais doit également pouvoir être prévisualisée avec son déplacement réel. Le contexte complet avec les effets de mouvement peut affecter les décisions de conception. Ensuite, je continue à travailler pour comprendre l'impact du contexte sur la conception de visualisations en mouvement et son expérience utilisateur. J'utilise les jeux vidéo comme plateforme de test, dans lesquels les visualisations en mouvement sont placées dans un arrière-plan chargé et dynamique mais doivent aider les joueurs à prendre des décisions rapides pour gagner. Mon étude montre qu'il existe des compromis entre la lisibilité de la visualisation en mouvement et son esthétique. Les participants recherchent un équilibre entre la lisibilité de la visualisation, l'adéquation esthétique au contexte, l'expérience d'immersion qu'apporte la visualisation, le support que la visualisation peut fournir pour gagner, et l'harmonie entre la conception des visualisations et leur contexte
In my thesis, I define visualization in motion and make several contributions to how to visualize and design situated visualizations in motion. In situated data visualization, the data is directly visualized near their data referent, i.e., the physical space, object, or person it refers to. Situated visualizations are often useful in contexts where the data referent or the viewer does not remain stationary but is in relative motion. For example, a runner is looking at visualizations from their fitness band while running or from a public display as they are passing it by. Reading visualizations in such scenarios might be impacted by motion factors. As such, understanding how to best design visualizations for dynamic contexts is important. That is, effective and visually stable situated data encodings need to be defined and studied when motion factors are involved. As such, I first define visualization in motion as visual data representations used in contexts that exhibit relative motion between a viewer and an entire visualization. I classify visualization in motion into 3 categories: (a) moving viewer & stationary visualization, (b) moving visualization & stationary viewer, and (c) moving viewer & moving visualization. To analyze the opportunities and challenges of designing visualization in motion, I propose a research agenda. To explore to what extent viewers can accurately read visualization in motion, I conduct a series of empirical perception studies on magnitude proportion estimation. My results show that people can get reliable information from visualization in motion, even if at high speed and under irregular trajectories. Based on my perception results, I move toward answering the question of how to design and embed visualization in motion in real contexts. I pick up swimming as an application scenario because swimming has rich, dynamic data. I implement a technology probe that allows users to embed visualizations in motion in a live swimming video. Users can adjust in real-time visual encoding parameters, the movement status, and the situatedness of visualization. The visualizations encode real swimming race-related data. My evaluation with designers confirms that designing visualizations in motion requires more than what traditional visualization toolkits provide: the visualization needs to be placed in-context (e.g., its data referent, its background) but also needs to be previewed under its real movement. The full context with motion effects can affect design decisions. After that, I continue my work to understand the impact of the context on the design of visualizations in motion and its user experience. I select video games as my test platform, in which visualizations in motion are placed in a busy, dynamic background but need to help players make quick decisions to win. My study shows there are trade-offs between visualization's readability under motion and aesthetics. Participants seek a balance between the readability of visualization, the aesthetic fitting to the context, the immersion experience the visualization brings, the support the visualization can provide for a win, and the harmony between the visualization and its context

This thesis concerns automation of software and hardware testing using the robotic testing system called RQA. It aims to design an interface to produce test scenarios using the robotic testing system. Next it elaborates metrics measured during testing used for quality assurance of the system uder test. One of the topics covered is a visualization of test data and measurements for an easy overview of quality.

This thesis presents Pixgis; a novel application for map-centric management of photographs. In short Pixgis is an interactive environment in which photographs may be discovered, viewed and managed through maps. With Pixgis finding photographs from a specific location or of a particular structure is as easy as finding the location or structure on a map. As Pixgis simultaneously displays maps, photographs and spatial metadata it also enables users to analyze photographs in new manners. This thesis work illustrates the benefits of applications for map-centric management of photographs, exposes the problems one faces when implementing such applications and presents novel solutions to many of these problems. The thesis also elaborates on spatial metadata and methods for acquisition of photographs with embedded spatial metadata.

La simulation numérique de phénomènes physiques complexes requiert généralement l’utilisation d’un maillage. En mécanique des fluides numérique, cela consisteà représenter un objet dans un gros volume de contrôle. Cet objet étant celui dont l’on souhaite simuler le comportement. Usuellement, l’objet et la boîte englobante sont représentés par des maillage de surface linéaires et la zone intermédiaire est remplie par un maillage volumique. L’objectif de cette thèse est de s’intéresser à deux manières différentes de représenter cet objet. La première approche dite immergée consiste à mailler intégralement le volume de contrôle et ensuite à simuler le comportement autour de l’objet sans avoir à mailler explicitement dans le volume ladite géometrie. L’objet étant implicitement pris en compte par le schéma numérique. Le couplage de cette méthode avec de l’adaptation de maillage linéaire est notamment étudié. La deuxième approche dite d’ordre élevé consiste quant à elle consiste à augmenter le degré polynomial du maillage de surface de l’objet. La première étape consiste donc à générer le maillage de surface de degré élevé et ensuite àpropager l’information de degré élevé dans les éléments volumiques environnants si nécessaire. Dans ce cadre-là, il s’agit de s’assurer de la validité de telles modifications et à considérer l’extension des méthodes classiques de modification de maillages linéaires
The numerical simulation of complex physical phenomenons usually requires a mesh. In Computational Fluid Dynamics, it consists in representing an object inside a huge control volume. This object is then the subject of some physical study. In general, this object and its bounding box are represented by linear surface meshes and the intermediary zone is filled by a volume mesh. The aim of this thesis is to have a look on two different approaches for representing the object. The first approach called embedded method consist in integrally meshing the bounding box volume without explicitly meshing the object in it. In this case, the presence of the object is implicitly simulated by the CFD solver. The coupling of this method with linear mesh adaptation is in particular discussed.The second approach called high-order method consist on the contrary by increasing the polynomial order of the surface mesh of the object. The first step is therefore to generate a suitable high-order mesh and then to propagate the high-order information in the neighboring volume if necessary. In this context, it is mandatory to make sure that such modifications are valid and then the extension of classic mesh modification techniques has to be considered

This diploma thesis deals with the modification of an existing device for controlling the heating system of the house. The original proposal builds on my bachelor thesis Terminal for visualization and control conditions in a house. Adjustments are based on the findings of the test operation and the deficiencies found in everyday operations. Here, the emphasis is on simple design, low acquisition cost and durability of the resulting device. Newly designed wireless units will replace the original wired sensors, as well as the control unit of the existing device based on the prototype system will be replaced with a new wireless central unit. The alphanumeric display with control buttons will remain as the control panel of this unit. The wireless central unit is connected via a serial communication interface to the visualization and control unit, which extends the offered options of the heating control system.

Les techniques de visualisation de traces sont fréquemment employées par les développeurs pour comprendre, déboguer, et optimiser leurs applications.La plupart des outils d'analyse font appel à des représentations spatiotemporelles, qui impliquent un axe du temps et une représentation des ressources, et lient la dynamique de l'application avec sa structure ou sa topologie.Toutefois, ces dernières ne répondent pas au problème de passage à l'échelle de manière satisfaisante. Face à un volume de trace de l'ordre du Gigaoctet et une quantité d'évènements supérieure au million, elles s'avèrent incapables de représenter une vue d'ensemble de la trace, à cause des limitations imposées par la taille de l'écran, des performances nécessaires pour une bonne interaction, mais aussi des limites cognitives et perceptives de l'analyste qui ne peut pas faire face à une représentation trop complexe. Cette vue d'ensemble est nécessaire puisqu'elle constitue un point d'entrée à l'analyse~; elle constitue la première étape du mantra de Shneiderman - Overview first, zoom and filter, then details-on-demand -, un principe aidant à concevoir une méthode d'analyse visuelle.Face à ce constat, nous élaborons dans cette thèse deux méthodes d'analyse, l'une temporelle, l'autre spatiotemporelle, fondées sur la visualisation. Elles intègrent chacune des étapes du mantra de Shneiderman - dont la vue d'ensemble -, tout en assurant le passage à l'échelle.Ces méthodes sont fondées sur une méthode d'agrégation qui s'attache à réduire la complexité de la représentation tout en préservant le maximum d'information. Pour ce faire, nous associons à ces deux concepts des mesures issues de la théorie de l'information. Les parties du système sont agrégées de manière à satisfaire un compromis entre ces deux mesures, dont le poids de chacune est ajusté par l'analyste afin de choisir un niveau de détail. L'effet de la résolution de ce compromis est la discrimination de l'hétérogénéité du comportement des entités composant le système à analyser. Cela nous permet de détecter des anomalies dans des traces d'applications multimédia embarquées, ou d'applications de calcul parallèle s'exécutant sur une grille.Nous avons implémenté ces techniques au sein d'un logiciel, Ocelotl, dont les choix de conception assurent le passage à l'échelle pour des traces de plusieurs milliards d'évènements. Nous proposons également une interaction efficace, notamment en synchronisant notre méthode de visualisation avec des représentations plus détaillées, afin de permettre une analyse descendante jusqu'à la source des anomalies
Trace visualization techniques are commonly used by developers to understand, debug, and optimize their applications.Most of the analysis tools contain spatiotemporal representations, which is composed of a time line and the resources involved in the application execution. These techniques enable to link the dynamic of the application to its structure or its topology.However, they suffer from scalability issues and are incapable of providing overviews for the analysis of huge traces that have at least several Gigabytes and contain over a million of events. This is caused by screen size constraints, performance that is required for a efficient interaction, and analyst perceptive and cognitive limitations. Indeed, overviews are necessary to provide an entry point to the analysis, as recommended by Shneiderman's emph{mantra} - Overview first, zoom and filter, then details-on-demand -, a guideline that helps to design a visual analysis method.To face this situation, we elaborate in this thesis several scalable analysis methods based on visualization. They represent the application behavior both over the temporal and spatiotemporal dimensions, and integrate all the steps of Shneiderman's mantra, in particular by providing the analyst with a synthetic view of the trace.These methods are based on an aggregation method that reduces the representation complexity while keeping the maximum amount of information. Both measures are expressed using information theory measures. We determine which parts of the system to aggregate by satisfying a trade-off between these measures; their respective weights are adjusted by the user in order to choose a level of details. Solving this trade off enables to show the behavioral heterogeneity of the entities that compose the analyzed system. This helps to find anomalies in embedded multimedia applications and in parallel applications running on a computing grid.We have implemented these techniques into Ocelotl, an analysis tool developed during this thesis. We designed it to be capable to analyze traces containing up to several billions of events. Ocelotl also proposes effective interactions to fit with a top-down analysis strategy, like synchronizing our aggregated view with more detailed representations, in order to find the sources of the anomalies

Born into a visual culture, today’s generation of learners generally prefer a visually-rich multimodal learning environment. Tapping into the potential of visuals in language pedagogy, this study was aimed at discovering the impact of a visual presentation of grammatical concepts related to sentence structure on student writing. The study used a mixed methods design to analyse the impact of the visual approach first by statistically measuring sentence variety and syntactic complexity of student pre and post intervention texts and then using interviews to explain the nature of the impact of visuals on student conceptual understanding and its effect on their writing development. Statistical findings reveal that the experimental groups of Chinese students who were taught grammatical concepts in the context of writing instruction using a visual approach outperformed the students in the control groups who were given similar lessons in the context of writing instruction but using traditional printed hand-outs. Qualitative findings suggest that the visuals seems to have increased these students’ conceptual understanding of grammatical items that were taught, and this resulted in more sophisticated and syntactically complex texts after the intervention. The study supports the theory of contextualized teaching of grammar and proposes the use of external visuals that lead to internal visualization based on the cognitive theory of multimodal learning. In so doing, it extends the use of visual learning to grammar pedagogy. However, the findings also suggest that the visual approach would not work effectively in cultures that promote rote learning and decontextualized exercises in grammar with the sole aim of passing the exams. A shift in attitude towards grammar pedagogy in China is deemed necessary.

A human brain has billions of processing elements operating simultaneously; the only practical way to model this computationally is with a massively-parallel computer. A computer on such a significant scale requires hundreds of thousands of interconnected processing elements, a complex environment which requires many levels of monitoring, management and control. Management begins from the moment power is applied and continues whilst the application software loads, executes, and the results are downloaded. This is the story of the research and development of a framework of scalable management tools that support SpiNNaker, a novel computing architecture designed to model spiking neural networks of biologically-significant sizes. This management framework provides solutions from the most fundamental set of power-on self-tests, through to complex, real-time monitoring of the health of the hardware and the software during simulation. The framework devised uses standard tools where appropriate, covering hardware up / down events and capacity information, through to bespoke software developed to provide real-time insight to neural network software operation across multiple levels of abstraction. With this layered management approach, users (or automated agents) have access to results dynamically and are able to make informed decisions on required actions in real-time.

To ease development and lower the entry barrier for new adopters many development environments offer visual means to edit complex data. Cyber-physical systems are a perfect candidate for such manipulations since they are usually described in the form of isolated, well defined components that can be manipulated individually. The physical parts of such systems often can be directly translated into real world objects and allowing the developer to interact with those in a familiar manner can greatly increase the usability and agility of the development process. In this thesis we focus on the exploration of interactive manipulation of hybrid system models. Our research examines a solution based on the Acumen simulation environment. We describe the tight integration between the textual model and 3D visualisation, go into detailed analysis of the implementation and use case-studies to illustrate concrete applications

Mestrado em Engenharia de Computadores e Telemática
A Internet permitiu revolucionar várias áreas económicas graças à facilidade com que é possível distribuir informação e comunicar entre entidades. Existem ainda áreas onde a Internet não só revolucionou os mercados financeiros, como levou à criação de novos mercados, permitindo o acesso desses mercados a novas entidades. Neste contexto, o aparecimento de mercados de negociação de bens e serviços em tempo-real é paradigmático. As bolsas de valores, mercados primários, correctores de apostas, entre outros, viram o seu modelo de funcionamento alterado pela Internet. Estes mercados passaram a negociar em permanência, pelo que, o número de ordens financeiras subiu tão exponencialmente que é actualmente necessário recorrer a complexas plataformas de transações. Hoje em dia existem inúmeras aplicações de negociação em tempo-real para os diversos mercados, umas nativas (domínio de plataformas Microsoft) e outras Web (limitações ao nível de tempo de resposta e das capacidades gráficas). Um aspecto comum a todas elas é o facto de se centrarem na negociação electrónica de ordens emitidas de forma explícita por humanos e ter apenas automatismos para situações de controlo de prejuízo (via triggers). Esta dissertação pretende, por isso, estudar o desenvolvimento de uma nova geração de aplicações de trading que incluam um ambiente de programação embutido na própria aplicação, automação de negociação e backtesting. De forma a colmatar a inexistência deste tipo de aplicações em ambientes não Windows, pretende-se que a mesma seja desenvolvida para ambientes Linux, OSX e Windows.
The Internet brought a revolution to several economic areas because it facilitated the distribution of information and communication between entities. In this context, the emergence of online trading markets of goods and services is paradigmatic. Markets started to negotiate continuously and the number of financial orders rose exponentially as it is currently necessary to employ complex transactions platforms. Today, there are numerous applications of online trading, some are native (limited to platforms such as Microsoft OS), others are Web-based (latency issues). This dissertation presents the development of a new generation of trading applications that includes an embedded programming environment in the application itself, trading automation and backtesting. It was developed as a multi platform application for Linux, OSX and Windows platforms.

This thesis focuses on the creation of a systems architecture to help inform development of next generation knowledge-building environments. The architectural model consists of three components: an infrastructure layer, a discourse layer, and a visualization layer. The Knowledge Space Visualizer (KSV), which defines the top visualization layer, is a prototypic system for showing reconstructed representations of discourse-based artifacts and facilitating assessment in light of patterns of interactivity of participants and their ideas. The KSV uses Latent Semantic Analysis to extend techniques from Social Network Analysis, making it possible to infer relationships among note contents. Thus idea networks can be studied in conjunction with social networks in online discourse. Further, benchmark corpora can be used to determine knowledge advances, and systems of interactivity leading to them. Results can then provide feedback to students and teachers to support them in obtaining continually higher level achievements. In addition to visual representations, the KSV provides quantitative network metrics such as degree and density. Data drawn from 9- and 10-year-old students working on a six-week unit on optics were used to illustrate some of the functionality of the KSV. Three studies show ways in which new visualizations can be used: (a) to highlight relationships among notes, (b) as a way of tracking the development of discourse over time, and (c) as an assessment tool. Implications for the design of knowledge building environments, assessment tools, and design-based research are discussed.

Volvo Group Trucks Technology has found a need for a new way to present the battery status and electricity consumption of their on-board batteries in combustion engine trucks. Many battery related issues the drivers are facing could be prevented if a tool was developed that could assist with energy planning in an intuitive way. In many cases, the climate control system will constitute the bulk of the energy supplied by the battery. In addition, the climate system energy demand is dependent on both user settings and factors beyond the driver’s control. This work describes the process of developing a grey-box Simulink model able to predict the battery charge depletion rate based on signals already sampled by many Volvo truck versions. The resulting model is able to estimate the time remaining until the battery state of charge (SOC) is getting close to the crankability (starting engine) limit or risks causing battery damage. The settings of the climate system are shown to have great impact on the battery charge depletion rate. Predicting the time until the battery will reach a critical limit, and adjusting the climate system settings accordingly, can make the difference between the battery charge lasting overnight or not. A way to implement additional influences, such as sunlight, are discussed and recommendations are given.

碩士
國立交通大學
機械工程系
90
An experiment combining flow visualization and temperature measurement is conducted here to investigate the buoyancy induced return flow in mixed convection of air over a heated circular plate embedded in the bottom of a horizontal heat duct. Both the spatial and temporal structures of the return flow are examined in detail. Besides, how the return flow induced in the upstream portion of the duct is related to the vortex flow in the downstream is delineated. Moreover, the formation processes leading to the return flow from the unidirectional forced main flow are explored. In the experiment the Reynolds number of the flow is varied from 5 to 50 and the Rayleigh number from 4, 000 to 16, 000 and the effects of the Reynolds and Rayleigh numbers on the return flow are examined in detail. The results show that at a low buoyancy-to-inertia ratio only steady longitudinal vortex rolls (L-rolls) are induced in the exit half of the duct and no return flow appears in the duct. At a intermediate buoyancy-to-inertia ratio a small flow recirculation exists around the duct inlet near the top wall and the L-rolls become unsteady. When the buoyancy-to-inertia ratio is high and the Reynolds number is small with Re＜10, the upstream return flow is strong and occupies a large region. There is another return flow zone around the exit end of the duct. Over the heated circular plate the flow is dominated by the moving transverse rolls. It is of interest to note that the return flow around the duct inlet at steady or statistically stable state is in the form of a semicircular roll around the upstream edge of the circular plate. We further note that during the transient stage the return flow first appears in the side wall region of the duct. Flow visualization also reveals that the splitting of the downstream tip of the return flow zone in the upstream near the duct inlet and the buoyancy driven, spanwisely extended thermal under the tip generate a pair of counter-rotating transverse rolls in the entry portion of the duct. The rolls are then pushed by the main flow to move slowly downstream and grow slightly in size. In addition, the criterion for the onset of the return flow near the duct inlet, the size and the center position of the return flow, based on the present experimental data, are correlated empirically.