The automation of airfoil design process is an ongoing effort within the field of turbo-machinery design, with significant focus on developing new reliable and consistent methods that can meet the needs of the engineers. A wide variety of approaches has been in use for inverse airfoil design process which benefit from theoretical inverse design, statistical methods, empirical discoveries and many other ways to solve the design problem. This thesis work also develops a tool in Python to be used in airfoil aerodynamic design process that is simple, fast and accurate enough for initial design of turbo-machinery blades with focus on turbine airfoils used for operation in aircraft engines. To convey the decision-making process during development a simplified case is presented. The underlying considerations are discussed. Other available methods in the literature used for similar problems, are also evaluated and compared to demonstrate the advantages and limitations of the methods used within the tool. The inverse design problem is formulated as a multi-objective optimization problem to handle various different objectives that are relevant for aerodynamic design of turbo-machinery airfoils. Test runs are made and the results are discussed to assess how robust the tool is and how the current capabilities can be modified or extended. After the development process, the tool is verified to be a suitable option for real-life design optimization tasks and can be used as a building block for a much more comprehensive tool that may be developed in the future. / Automatisering av processen för design av vingprofiler kräver fortlöpande insatser inom området turbomaskindesign, med stort fokus på att utveckla nya tillförlitliga och konsekventa metoder som kan tillgodose ingenjörernas behov. Ett stort antal olika tillvägagångssätt har provats för omvänd design av vingprofiler såsom teoretisk invers design, statistiska metoder, empiriska upptäckter och många andra sätt att lösa designproblemet. Detta avhandlingsarbete är också ett lyckat försök att utveckla ett verktyg i Python som ska användas i den aerodynamiska designprocessen; det är enkelt, snabbt och noggrant för den initiala designen av turbomaskinblad med fokus på turbinblad som för användning i flygmotorer. För att förmedla beslutsprocessen under utvecklingen presenteras ett förenklat fall. De underliggande övervägandena diskuteras. Andra tillgängliga metoder i litteraturen som används för liknande problem utvärderas och jämförs för att visa fördelarna och begränsningarna med de metoder som används i verktyget. Det omvända designproblemet formuleras som ett multi-objektivt optimeringsproblem för att hantera olika mål som är relevanta för aerodynamisk design av turbomaskiner. Testkörningar görs och resultaten diskuteras för att bedöma hur robust verktyget är och hur de nuvarande funktionerna kan modifieras eller utökas. Efter utvecklingsprocessen verifieras verktyget som ett lämpligt alternativ för verkliga designoptimeringsuppgifter och kan användas som en byggsten för ett mycket mer omfattande verktyg som kan utvecklas i framtiden.

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Long wait times constitute a bottleneck limiting the number of compilation runs performed in a day, thus risking to restrict Field-Programmable Gate Array (FPGA) adaptation in modern computing platforms. This work presents an FPGA development paradigm that exploits logic variance and hierarchy as a means to increase FPGA productivity. The practical tasks of logic partitioning, placement and routing are examined and a resulting assembly framework, Quick Flow (qFlow), is implemented. Experiments show up to 10x speed-ups using the proposed paradigm compared to vendor tool flows. / Ph. D.

Today's Field Programmable Gate Array (FPGA) research community could use an extensible tool flow enabling designers to examine new algorithms and new methods of interacting with FPGA configurations. One such flow is JHDLBits, which integrates two prominent FPGA design environments: JHDL and JBits. JHDLBits offers the low-level access and control provided by JBits with the high-level structural circuit design of JHDL. Furthermore, the JHDLBits flow provides greater control of resource manipulation, placement, and routing, and gives researchers a sandbox to explore advanced interactions with FPGA configurations. This thesis presents the overall architecture of the open-source JHDLBits project. Details are provided on how the core components -- JHDL, JBits3 for Virtex-II, the ADB connectivity database, and VTsim, a Virtex-II device simulator -- are linked together to provide an integrated design environment. Strategies and philosophies of the open source movement are also examined to successfully establish the support for and involvement of the FPGA research community throughout the JHDLBits open source endeavor. / Master of Science

As complementary metal-oxide semiconductor (CMOS) technology faces more and more severe physical barriers down the path of continuously feature size scaling, innovative nano-scale devices and other post-CMOS technologies have been developed to enhance future circuit design and computation. These nanotechnologies have shown promising potentials to achieve magnitude improvement in performance and integration density. The substitution of CMOS transistors with nano-devices is expected to not only continue along the exponential projection of Moore's Law, but also raise significant challenges and opportunities, especially in the field of electronic design automation. The major obstacles that the designers are experiencing with emerging nanotechnology design include: i) the existing computer-aided design (CAD) approaches in the context of conventional CMOS Boolean design cannot be directly employed in the nanoelectronic design process, because the intrinsic electrical characteristics of many nano-devices are not best suited for Boolean implementations but demonstrate strong capability for implementing non-conventional logic such as threshold logic and reversible logic; ii) due to the density and size factors of nano-devices, the defect rate of nanoelectronic system is much higher than conventional CMOS systems, therefore existing design paradigms cannot guarantee design quality and lead to even worse result in high failure ratio. Motivated by the compelling potentials and design challenges of emerging post-CMOS technologies, this dissertation work focuses on fundamental design methodologies to effectively and efficiently achieve high quality nanoscale design. A novel programmable logic element (PLE) is first proposed to explore the versatile functionalities of threshold gates (TGs) and multi-threshold threshold gates (MTTGs). This PLE structure can realize all three- or four-variable logic functions through configuring binary control bits. This is the first single threshold logic structure that provides complete Boolean logic implementation. Based on the PLEs, a reconfigurable architecture is constructed to offer dynamic reconfigurability with little or no reconfiguration overhead, due to the intrinsic self-latching property of nanopipelining. Our reconfiguration data generation algorithm can further reduce the reconfiguration cost. To fully take advantage of such threshold logic design using emerging nanotechnologies, we also developed a combinational equivalence checking (CEC) framework for threshold logic design. Based on the features of threshold logic gates and circuits, different techniques of formulating a given threshold logic in conjunctive normal form (CNF) are introduced to facilitate efficient SAT-based verification. Evaluated with mainstream benchmarks, our hybrid algorithm, which takes into account both input symmetry and input weight order of threshold gates, can efficiently generate CNF formulas in terms of both SAT solving time and CNF generating time. Then the reversible logic synthesis problem is considered as we focus on efficient synthesis heuristics which can provide high quality synthesis results within a reasonable computation time. We have developed a weighted directed graph model for function representation and complexity measurement. An atomic transformation is constructed to associate the function complexity variation with reversible gates. The efficiency of our heuristic lies in maximally decreasing the function complexity during synthesis steps as well as the capability to climb out of local optimums. Thereafter, swarm intelligence, one of the machine learning techniques is employed in the space searching for reversible logic synthesis, which achieves further performance improvement. To tackle the high defect-rate during the emerging nanotechnology manufacturing process, we have developed a novel defect-aware logic mapping framework for nanowire-based PLA architecture via Boolean satisfiability (SAT). The PLA defects of various types are formulated as covering and closure constraints. The defect-aware logic mapping is then solved efficiently by using available SAT solvers. This approach can generate valid logic mapping with a defect rate as high as 20%. The proposed method is universally suitable for various nanoscale PLAs, including AND/OR, NOR/NOR structures, etc. In summary, this work provides some initial attempts to address two major problems confronting future nanoelectronic system designs: the development of electronic design automation tools and the reliability issues. However, there are still a lot of challenging open questions remain in this emerging and promising area. We hope our work can lay down stepstones on nano-scale circuit design optimization through exploiting the distinctive characteristics of emerging nanotechnologies. / Ph. D.

The purpose of this thesis is to provide a complete package for the synthesis and design of the RSSR spatial function generating mechanism. In addition to the introductory material this thesis is divided into three sections. The section on background kinematic theory includes synthesis, analysis, link rotatability, transmission quality, and branching analysis. The second division details the computer application of the kinematic theory. The program RSSRSD has been developed to incorporate the RSSR synthesis and design theory. An example is included to demonstrate the computer-implemented theory. The third part of this thesis includes miscellaneous mechanism considerations and recommendations for further research. The theoretical work in this project is a combination of original derivations and applications of the theory in the mechanism literature. / Master of Science

Övergången från CATIA V4 till CATIA V5 innebär nya möjligheter för konstruktörerna på Scania att arbeta med Knowledge Based Engineering, KBE, för att effektivisera och kvalitets-säkra sitt arbete. Då CATIA V5 är en ny plattform som innehåller verktyg med samlingsnamnet knowledgware, för att bygga in kunskap i modeller ville Scania undersöka potentialen i att arbeta med KBE, och hur detta skulle kunna ske på Scania. Vid traditionell produktutveckling tas en helt ny artikel fram vid behov och ofta innebär detta att arbete som tidigare utförts, görs om igen. Syftet med arbetet är därför att undersöka huruvida KBE i CATIA V5 kan erbjuda möjligheter att återanvända kunskap från tidigare arbete och samtidigt kvalitetssäkra denna, samt utreda vilka knowledgewarelicenser som i så fall kan vara lämpliga för Scania. För att göra detta har en litteraturstudie genomförts för att undersöka vad som har gjorts inom området, och även en intervjustudie har utförts inom R&D på Scania. Vidare har sakkunniga på Linköpings Universitet och Tekniska Högskolan i Jönköping intervjuats. Detta material har sedan sammanställts och analyserats för att sedan resultera i slutsats och rekommendationer. Arbetet har resulterat i en demonstrationsmodell för Scania internt, som baserar sig på den information som framkommit under litteraturstudier och intervjuer. Att arbeta med KBE har både fördelar och nackdelar där den största svårigheten ligger i att bedöma om en artikel lämpar sig för KBE-modellering. Vinsterna med KBE är att stora tidsvinster kan göras och kvalitet kan säkerställas. De mest användbara licenserna för Scanias vidkommande är KWA och PKT, med vilka exempelvis kontroller av standarder och återanvändning av geometrier kan göras. Den slutliga rekommendationen baserat på teori och resultat är att Scania bör överväga att införa KBE som arbetssätt, och därför tillsätta en grupp som fungerar som expertis inom KBE. Denna bör då fungera som support och en resurs vid skapande av KBE-modeller och ansvara för att dessa är korrekta och underhålls. Vidare bör arbete med att definiera fysiska gränssnitt mellan artiklar startas och lämpligtvis då av GEO- eller Layoutgrupperna. / The transition from CATIA V4 to CATIA V5 opens up new possibilities for designers at Scania to work with Knowledge Based Engineering, KBE, in order to increase efficiency and assure quality. As CATIA V5 is a new platform complete with tools, referred to as knowledgeware, for infusing knowledge into models, Scania wanted to investigate the potential of working with KBE, and how this could be used at Scania. In traditional product development a completely new model is produced when needed, and this often entails performing tasks already undertaken and completed. Therefore, the purpose of this thesis is to ascertain whether or not KBE in CATIA V5 can offer the possibility to reuse knowledge from previous work and assuring the quality of this, and if so, determine which knowledgeware licenses would be appropriate for Scania. In order to do this, a literature study was conducted in order to look into what had been done in this field. Also, an interview study was carried out within Scanias R&D department. In addition to this, interviews were held with expertise at Linköping University and Jönköping University. The material was then compiled and analyzed, resulting in conclusions and recommendations. The thesis resulted in a demonstration model for Scania internally, based on the information gathered from literature and interviews. Working with KBE has its pros and cons, the biggest difficulty being to determine whether or not an article is suitable for KBE-modelling. The profits of KBE include quality assurance and sizeable reductions in design time. The most useful knowledgeware licenses for Scania are KWA and PKT, which for example enables users to implement checks for standards and to easily reuse geometry. The final recommendations of this thesis, based on theory and results, is that Scania should consider introducing KBE, and should therefore appoint a group to function as an authority on KBE. This group would provide support and act as a resource in the creation of KBE-models, and also be responsible for the validity and maintenance on these. Furthermore work should begin with defining physical interfaces between articles, preferably by GEO- and Layout groups.

Intensive competition on the global market puts great pressure on manufacturing companies to develop and produce products that meet requirements from customers and investors. One key factor in meeting these requirements is the efficiency of the product development and the production preparation process. Design automation is a powerful tool to increase efficiency in these two processes. The benefits of automating the production preparation process are shortened led-time, improved product performance, and ultimately decreased cost. Further, automation is beneficial as it increases the ability to adapt products to new product specifications with production preparations done in few or in a single step. During the automation process, knowledge about the production preparation process is collected and stored in central systems, thus allowing full control over the design of production equipments. Three main topics are addressed in this thesis: the flexibility of design automation systems, knowledge bases containing conflicting rules, and the automation of the finite element analysis process. These three topics are discussed in connection with the production preparation process of rotary draw bending. One conclusion drawn from the research is that it is possible to apply the concept of design automation to the production preparation process at different levels of automation depending on characteristics of the implemented knowledge. In order to make design automation systems as flexible as possible, the concept of object orientation should be adapted when building the knowledge base and when building the products geometrical representations. It is possible to automate the process of setting up, running, and interpreting finite element analyses to a great extent and making the automated finite element analysis process a part of the global design automation system.

There are different phases in any design activity, one of them being concept generation. Research in automating the conceptual design process in planar mechanisms is always challenging due to the existence of many different elements and their endless combinations. There may be instances where designers arrive at a concept without considering all the alternatives. Computational synthesis aims to arrive at a design by considering the entire space of valid designs. Different researchers have adopted various methods to automate the design process that includes existence of similar graph grammar approaches. But few methods replicate the way humans’ design. An attempt is being made in the thesis in this direction and as a first step, we focus on representing and evaluating planar mechanisms designed using graph grammars. Graph grammars have been used to represent planar mechanisms but there are disadvantages in the methods currently available. This is due to the lack of information in understanding the details of a mechanism represented by the graph since the graphs do not include information about the type of joints and components such as revolute links, prismatic blocks, gears and cams. In order to overcome drawbacks in the existing methods, a novel representation scheme has been developed. In this method, labels and x, y position information in the nodes are used to represent the different mechanism types. A set of sixteen grammar rules that construct different mechanisms from the basic seed is developed, which implicitly represents a tree of candidate solutions. The scheme is tested to determine its capability in capturing the entire set of feasible planar mechanisms of one degree of freedom including Stephenson and double butterfly linkages. In addition to the representation, another important consideration is the need for an accurate and generalized evaluator for kinematic analysis of mechanisms which, given the lack of information, may not be possible with current design automation schemes. The approach employed for analysis is purely kinematic and hence the instantaneous center of rotation method is employed in this research. The velocities of pivots and links are obtained using the instant center method. Once velocities are determined, the vector polygon approach is used to obtain accelerations and geometrical intersection to determine positions of pivots. The graph grammar based analysis module is implemented in an existing object-oriented grammar framework and the results have found this to be superior to or equivalent to existing commercial packages such as Working Model and SAM for topologies consisting of four-bar loop chain with single degree of freedom. / text

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