<p>Att ta fram en ny bilmodell är ett tidskrävande och omfattande arbete där många olika kunskapsområden måste samspela. En del i utvecklingsprocessen som får allt större betydelse är designarbetet. Om bilens utförande och design inte tilltalar konsumenterna innebär detta låga försäljningssiffror och därmed förlorade intäkter för företaget.</p><p>Det huvudsakliga syftet med detta arbete är att grundligt undersöka om och hur CAD-programmet Catia V5 med modulen Imagine & Shape (IMA) skulle kunna användas på Volvo Car Corporations designavdelning (PVS). Syftet är också att granska vad en implementering av Catia V5 med IMA-modulen skulle innebära för produktutvecklingsprocessen, samt att undersöka vilka som skulle kunna använda sig av programmet. </p><p>För att undersöka hur Catia V5:s IMA-modul skulle kunna fungera på PVS har vi i samarbete med designstuderande Pontus Ny modellerat en konceptbil, komplett med exteriör, instrumentpanel, mittkonsol, ratt, stolar, baksäte, fälgar och hjul. Vi har även modellerat en växelspak och en backspegel som först har tagits fram i Alias, vilket har möjliggjort en jämförelse mellan Alias och Catia V5:s IMA-modul. Modellerna har sedan utvärderats genom enkäter med uppföljande intervjuer. Urvalsguppen utgörs av ett antal anställda hos PVS som har haft möjlighet att sätta sig in i IMA-modulen. </p><p>Respondenterna uppgav fördelar som anmärkningsvärd snabbhet vid framtagning av 3D-modeller i de fall där ytan inte behöver vara perfekt. Dock krävs stor erfarenhet för att skapa en bra renhet och ytjämnhet vid stora ytor. Samtliga involverade i detta projekt anser också att Catia V5 med IMA-modulen skulle kunna fungera som ett konceptgenereringsverktyg i ett tidigt skede. Att använda IMA-modulen i den första förberedande fasen skulle enligt vår mening innebära tidsbesparingar, eftersom användaren snabbt kan genomföra förändringar på en modell redan på möten. I dagsläget måste en Alias-modellör samla in alla ändringar, genomföra dessa snabbast möjligt och därefter bestämma en tid för ett nytt möte då alla inblandade kan närvara, vilket sällan är enkelt. </p><p>IMA-modulen skulle även kunna vara ett bra hjälpmedel för en designer, som själv kan modellera sina idéer och därigenom lättare åskådliggöra och diskutera sitt koncept vid möten. I många fall är det enklare att förstå en 3D-modell som man kan vrida och vända på, än en ritning på ett papper. Utifrån IMA-modellen skulle det vara möjligt att fräsa ut en lermodell, vilken kan finjusteras och sedan åter scannas in och bearbetas vidare i Alias.</p>

Att ta fram en ny bilmodell är ett tidskrävande och omfattande arbete där många olika kunskapsområden måste samspela. En del i utvecklingsprocessen som får allt större betydelse är designarbetet. Om bilens utförande och design inte tilltalar konsumenterna innebär detta låga försäljningssiffror och därmed förlorade intäkter för företaget. Det huvudsakliga syftet med detta arbete är att grundligt undersöka om och hur CAD-programmet Catia V5 med modulen Imagine & Shape (IMA) skulle kunna användas på Volvo Car Corporations designavdelning (PVS). Syftet är också att granska vad en implementering av Catia V5 med IMA-modulen skulle innebära för produktutvecklingsprocessen, samt att undersöka vilka som skulle kunna använda sig av programmet. För att undersöka hur Catia V5:s IMA-modul skulle kunna fungera på PVS har vi i samarbete med designstuderande Pontus Ny modellerat en konceptbil, komplett med exteriör, instrumentpanel, mittkonsol, ratt, stolar, baksäte, fälgar och hjul. Vi har även modellerat en växelspak och en backspegel som först har tagits fram i Alias, vilket har möjliggjort en jämförelse mellan Alias och Catia V5:s IMA-modul. Modellerna har sedan utvärderats genom enkäter med uppföljande intervjuer. Urvalsguppen utgörs av ett antal anställda hos PVS som har haft möjlighet att sätta sig in i IMA-modulen. Respondenterna uppgav fördelar som anmärkningsvärd snabbhet vid framtagning av 3D-modeller i de fall där ytan inte behöver vara perfekt. Dock krävs stor erfarenhet för att skapa en bra renhet och ytjämnhet vid stora ytor. Samtliga involverade i detta projekt anser också att Catia V5 med IMA-modulen skulle kunna fungera som ett konceptgenereringsverktyg i ett tidigt skede. Att använda IMA-modulen i den första förberedande fasen skulle enligt vår mening innebära tidsbesparingar, eftersom användaren snabbt kan genomföra förändringar på en modell redan på möten. I dagsläget måste en Alias-modellör samla in alla ändringar, genomföra dessa snabbast möjligt och därefter bestämma en tid för ett nytt möte då alla inblandade kan närvara, vilket sällan är enkelt. IMA-modulen skulle även kunna vara ett bra hjälpmedel för en designer, som själv kan modellera sina idéer och därigenom lättare åskådliggöra och diskutera sitt koncept vid möten. I många fall är det enklare att förstå en 3D-modell som man kan vrida och vända på, än en ritning på ett papper. Utifrån IMA-modellen skulle det vara möjligt att fräsa ut en lermodell, vilken kan finjusteras och sedan åter scannas in och bearbetas vidare i Alias.

<p> Mechanized mathematics systems, especially Theorem Provers (TP) and Computer Algebra Systems (CAS), can play a very helpful role in handling relational calculus. Computer Algebra Systems help to automate tedious symbolic computations. However, they lack the ability to make sophisticated derivations of logical formulas. Correspondingly, a Theorem Prover is powerful in deriving the truth-value of a logical formula. Nevertheless, it is not suitable for dealing with symbolic expressions.</p> <p> The main goal for our research is to investigate the automation of relational calculus using existing mechanized mathematics technologies. Particularly, we elaborated a heuristic that enables the assignment of tasks to PVS and Maxima to help perform relational calculus. As well we built a proof-of-concept tool that supports this calculus.</p> <p> To fulfill our objective, we adopted the following steps: 1. Investigated and evaluated the characteristics and capabilities of TPs and CASs. This step led us to select PVS and Maxima as the tools to be used by our system. 2. Explored a strategy that governs setting tasks to PVS and Maxima in order to perform relational calculus. Then, we propose a task assignment heuristic based on this strategy. 3. Designed and built a proof-of-concept tool that makes use of PVS and Maxima to help perform relational calculus. 4. Assessed our tool by using it to handle some illustrative examples of operations on concrete relations.</p> <p> In our work, relations are given by their characteristic predicates. We assume as well that predicates that are provided to our proof-of-concept tool are in a Disjunctive Normal Form. We adopt a linear notation for the representation of propositions, quantifications, and expressions. We fall short of providing a user interface, which makes the use of the tool that we built slightly difficult.</p> / Thesis / Master of Science (MSc)

Le système de types de la logique d'ordre supérieur permet d'exclure certaines expressions indésirables telles que l'application d'un prédicat à lui-même. Cependant, il ne suffit pas pour vérifier des critères plus complexes comme l'absence de divisions par zéro. Cette thèse est consacrée à l’étude d’une extension de la logique d’ordre supérieur appelée sous-typage par prédicats (predicate subtyping), dont l'objet est de rendre l'attribution de types aussi expressive que l'attribution de prédicats. A partir d'un type A et d'un prédicat P(x) de domaine A, le sous-typage par prédicats permet de construire un sous-type de A, noté {x : A | P(x)}, dont les éléments sont les termes t de type A tels que P(t) est démontrable. Le sous-typage par prédicats est au coeur du système PVS.Ce travail présente la formalisation d'un système minimal incluant le sous-typage par prédicats, appelé PVS-Core, ainsi qu'un système de certificats vérifiables pour PVS-Core. Ce deuxième système, appelé PVS-Cert, repose sur l'introduction de termes de preuves et de coercions explicites. PVS-Core et PVS-Cert sont munis d'une notion de conversion correspondant respectivement à l'égalité modulo beta et à l'égalité modulo beta et effacement des coercions, choisi pour établir une correspondance simple entre les deux systèmes.La construction de PVS-Cert est semblable à celle des PTS (Pure Type Systems) avec paires dépendantes et PVS-Cert peut être muni de la notion de beta-sigma-réduction utilisée au coeur de ces systèmes. L'un des principaux théorèmes démontré dans ce travail est la normalisation forte de la réduction sous-jacente à la conversion et de la beta-sigma-réduction. Ce théorème permet d'une part de construire un algorithme de vérification du typage (et des preuves) pour PVS-Cert et d'autre part de démontrer un résultat d'élimination des coupures, utilisé à son tour pour prouver plusieurs propriétés importantes des deux systèmes étudiés. Par ailleurs, il est également démontré que PVS-Cert est une extension conservative du PTS lambda-HOL, et qu'en conséquence PVS-Core est une extension conservative de la logique d'ordre supérieur.Une deuxième partie présente le prototype d'une instrumentation de PVS pour produire des certificats de preuve. Une troisième et dernière partie est consacrée à l'étude de liens entre logique classique et constructive avec la définition d'une traduction par double négation minimale ainsi que la présentation d'un algorithme de constructivisation automatique des preuves. / The type system of higher-order logic allows to exclude some unexpected expressions such as the application of a predicate to itself. However, it is not sufficient to verify more complex criteria such as the absence of divisions by zero. This thesis is dedicated to the study of an extension of higher-order logic, named predicate subtyping, whose purpose is to make the assignment of types as expressive as the assignment of predicates. Starting from a type A and a predicate P(x) of domain A, predicate subtyping allows to build a subtype of A, denoted {x : A | P(x)}, whose elements are the terms t of type A such that P(t) is provable. Predicate subtyping is at the heart of the proof system PVS.This work presents the formalization of a minimal system expressing predicate subtyping, named PVS-Core, as well as a system of verifiable certificates for PVS-Core. This second system, named PVS-Cert, is based on the introduction of proof terms and explicit coercions. PVS-Core and PVS-Cert are equipped with a notion of conversion corresponding respectively to equality modulo beta and to equality modulo beta and the erasure of coercions, chosen to establish a simple correspondence between the two systems.The construction of PVS-Cert is similar to that of PTSs (Pure Type Systems) with dependent pairs and PVS-Cert can be equipped with the notion of beta-sigma-reduction used at the core of these systems. One of the main theorems proved in this work is the strong normalization of both the reduction underlying the conversion and beta-sigma-reduction. This theorem allows, on the one hand, to build a type-checking (and proof-checking) algorithm for PVS-Cert and, on the other hand, to prove a cut elimination result, used in turn to prove important properties of the two studied systems. Furthermore, it is also proved that PVS-Cert is a conservative extension of the PTS lambda-HOL and that, as a consequence, PVS-Core is a conservative extension of higher-order logic.A second part presents the prototype of an instrumentation of PVS to generate proof certificates. A third and final part is dedicated to the study of links between classical and constructive logic, with the definition of a minimal double-negation translation as well as the presentation of an automated proof constructivization algorithm.

We report on a new framework for preparing high-refractive index polymeric materials which combines the selective thiol radical mono-addition to phenyl-acetylene derivatives with hyperbranched architectures. Using this strategy we have synthesized a series of linear and hyperbranched polyvinyl sulfide (PVS) materials, employing different dithiol (A₂ and A'₂) and di- and trialkyne (B and B₃) monomers. The process requires only a simple radical initiator, such as AIBN, in lieu of expensive or toxic catalysts and this chemistry produces polymers in high yield (up to 96%) and high molecular weight (up to 123 000 g mol⁻¹). The polymers are optically transparent, thermally stable (up to 420 °C) and readily form highquality films. The end group composition of the hyperbranched materials can be easily adjusted by changing the A₂/B₃ feed ratio. The sulfur incorporation and conjugation resulting from thiol–yne coupling with selective mono-addition results in materials with high refractive indices in the visible and IR region (nD = 1.68–1.75) and optical dispersions as low as 0.004. Moreover, we demonstrate that the hyperbranched architecture produces materials with better performance in terms of light reflection and chromatic dispersion compared to linear structures.

In current online games, player positions are synchronized by means of continual broadcasts through the server. This solution is expensive, forcing any server to limit its number of clients. With a hybrid networking architecture, player synchronization can be distributed to the clients, bypassing the server bottleneck and decreasing latency as a result. Synchronization in a decentralized fashion is difficult as each player must communicate with every other player. The communication requirements can be reduced by computing and exploiting frontier sets: For a pair of players in an online game, a player's frontier is the region of the game space where the player may move without seeing (and without communicating to) the other player. A pair of frontiers is called a frontier set. This thesis describes the first fast and space-efficient method of computing frontier sets in large terrains. Frontier sets are computed by growing regions in a connected set of quads in a hierarchical decomposition of the terrain. The solution involves the precomputation of a potentially visible set (PVS) for each quad in the decomposition, which stores all the quads potentially visible from any point within the current quad. Since the memory needed to store the PVSs for all the quads is quite large, a compression technique is introduced which controls the size of each PVS. A PVS merging algorithm, with both lossless and lossy variations, is also described which permits adding the PVS of a point or quad to the PVS of a growing region. The new algorithm is compared to a simple region growing approach where frontiers are grown along the individual terrain points. Using similar merging techniques, the new algorithm performs better, producing larger frontier sets with faster execution times. / Thesis (Master, Computing) -- Queen's University, 2010-05-25 14:53:24.375

abstract: Residential air conditioning systems represent a critical load for many electric utilities, especially for those who serve customers in hot climates. In hot and dry climates, in particular, the cooling load is usually relatively low during night hours and early mornings and hits its maximum in the late afternoon. If electric loads could be shifted from peak hours (e.g., late afternoon) to off-peak hours (e.g., late morning), not only would building operation costs decrease, the need to run peaker plants, which typically use more fossil fuels than non-peaker plants, would also decrease. Thus, shifting electricity consumption from peak to off-peak hours promotes economic and environmental savings. Operational and technological strategies can reduce the load during peak hours by shifting cooling operation from on-peak hours to off-peak hours. Although operational peak load shifting strategies such as precooling may require mechanical cooling (e.g., in climates like Phoenix, Arizona), this cooling is less expensive than on-peak cooling due to demand charges or time-based price plans. Precooling is an operational shift, rather than a technological one, and is thus widely accessible to utilities’ customer base. This dissertation compares the effects of different precooling strategies in a Phoenix-based utility’s residential customer market and assesses the impact of technological enhancements (e.g., energy efficiency measures and solar photovoltaic system) on the performance of precooling. This dissertation focuses on the operational and technological peak load shifting strategies that are feasible for residential buildings and discusses the advantages of each in terms of peak energy savings and residential electricity cost savings. / Dissertation/Thesis / Doctoral Dissertation Civil Engineering 2016

Lors de la production du PVC en poudre, après l’étape de polymérisation en suspension, on obtient une bouillie constituée d’un mélange de grains macroporeux de taille comprise entre 100 et 200 μm et d’eau. L’étape de centrifugation permet la séparation de la phase liquide exprimable et la production d’un milieu poreux humide appelé « gâteau ». La teneur en eau du gâteau ainsi formé est de 30 % de la masse du produit anhydre. Le séchage du gâteau de filtration se fait dans un séchoir Flash (séchoir pneumatique) couplé à un séchoir à lit fluidisé. Cette opération, très gourmande en énergie et donc très impactante en termes d’émission de Gaz à Effet de Serre (GES), représente 30% du coût de fabrication et 50% des émissions de CO2. Ce travail, réalisé dans le cadre d’une collaboration avec le groupe INEOS ChlorVinyls, est consacrée à l’étude de l’étape de séchage thermique, et à la réalisation d’outils expérimentaux et théoriques permettant d’optimiser le fonctionnement et de réduire la consommation énergétique de cette étape. Dans ce but, l’étude du séchage du PVC est réalisée à l’échelle d’une particule isolée d’une part, et à l’échelle du procédé industriel d’autre part. La détermination expérimentale de la cinétique de séchage est effectuée en immergeant une quantité de produit humide (gâteau de filtration) dans un lit fluidisé de grosses particules inertes et chaudes (billes de verre), et permet d’étudier l’influence de différents paramètres sur la cinétique d’évaporation. Les résultats ont montré que cette cinétique est limitée par les processus d’évaporation à l’intérieur et à la surface des particules. Du point de vue théorique, un modèle dont le principe repose sur les bilans de matière et de chaleur à l’échelle du grain de PVC, couplés aux bilans sur le séchoir à lit fluidisé, a été élaboré. La comparaison des résultats de ce modèle avec les résultats expérimentaux a permis de vérifier la validité de la loi cinétique ainsi établie. Finalement, cette loi a été intégrée dans un modèle simulant le séchoir pneumatique industriel. Les résultats théoriques sont comparés à des mesures réalisées sur un séchoir pneumatique industriel équipé de capteurs de pression, d’humidité et de température. Les résultats de cette étude ont permis de proposer une nouvelle stratégie de régulation du séchoir pneumatique ainsi que des modifications du procédé, ne nécessitant pas d’investissement. L’ensemble de ces propositions a permis de réduire d’environ 30% la consommation énergétique pour un rendement de séchage équivalent. / In a PVC powder production line, the step of suspension polymerization produces a mixture of macroporous particles and water, called “slurry”. The mean particle size varies between 100 and 200 µm. The centrifugation step eliminates most of water content and produces a wet porous medium called “cake”. The water content of the cake is about 30% of the dry product mass. Drying operations take place in a Flash dryer (pneumatic dryer) coupled with a fluidized bed dryer. These operations, which consume a lot of energy and produce greenhouse gas, represent 30% of the production cost and 50% of the CO2 emissions. This work, realized in collaboration with INEOS ChlorVinyls group, is devoted to the study of the thermal drying step and to the realization of experimental and theoretical tools in order to optimize and reduce the energy consumption of this step. The study of the drying step is realized, on the one hand, at the particle scale and, on the other hand, at the industrial dryer scale. The particle scale drying kinetic is obtained by immersing a sample of wet product in a fluidized bed of warm inert particles (glass beads), and enables to study the influence of different parameters on the evaporation kinetic. The results have shown a limitation of this kinetic by the evaporation process both inside the particles and on their outer surface. In a theoretical way, a model based on mass and heat balances at particle scale coupled with fluidized bed balances, has been developed. The kinetic law developed is validated by the comparison between the results of this model and the experimental results. Finally, this law is integrated in a model simulating the industrial pneumatic dryer. The theoretical results are compared to the measurements realized on an industrial pneumatic dryer, equipped with several pressure, humidity and temperature sensors. The results of this study lead to the proposition of a new regulation strategy for the pneumatic dryer and some zero-investment modifications of the process. All these propositions enable an energy consumption reduction of 30%.

Many industrial control systems use programmable logic controllers (PLCs) since they provide a highly reliable, off-the-shelf hardware platform. On the programming side, function blocks (FBs) are reusable PLC components that can be composed to implement the required system behaviour. A higher quality system may be realized if the FBs are pre-certified to be compliant with an international standard such as IEC 61131-3. Unfortunately, the set of programming notations defined in IEC 61131-3 lack well-defined formal semantics. As a result, tool vendors and users of PLCs may have inconsistent interpretations of the expected system behaviour. To address this issue, we propose an engineering method for formally verifying the conformance of candidate implementations of FBs (and their compositions) to their high-level, input-output requirements. The proposed method is sufficiently general to handle FBs supplied by IEC 61131-3, and industrial FB applications involving real-time requirements. Our method involves several steps. First, we use tabular expressions to ensure the completeness and disjointness of the requirements for the FB. Second, we formalize the candidate implementation(s) of the FB in question. Third, we state and prove theorems regarding the consistency and correctness of the FB. All three steps are performed using the Prototype Verification Systems (PVS) proof assistant. As a first case study, we apply our approach to the IEC 61131-3 standard to examine the entire library of FBs and their supplied implementations described in structured text (ST) and function block diagrams (FBDs). As a second case study, we apply our approach to two realistic sub-systems taken from the nuclear domain. Applying the proposed method, we identified three kinds of issues: ambiguous behavioural descriptions, missing assumptions, and erroneous implementations. Furthermore, we suggest solutions to these issues. / Thesis / Doctor of Philosophy (PhD) / A formal verification approach for the function block based control systems

No description available.