<p>In this thesis we study hybrid numerical methods to be usedin computational electromagnetics. We restrict the methods tospectral domain and scattering problems. The hybrids consist ofcombinations of Boundary Element Methods and Geometrical Theoryof Diffraction.</p><p>In the thesis three hybrid methods will be presented. Onemethod has been developped from a theoretical idea to anindustrial code. The two other methods will be presented mainlyfrom a theoretical perspective. We will also give shortintroductions to the Boundary Element Method and theGeometrical Theory of Diffraction from a theoretical andimplementational point of view.</p><p><b>Keywords:</b>Maxwell’s equations, Geometrical Theoryof Diffraction, Boundary Element Method, Hybrid methods,Electromagnetic Scattering</p>

<p>In this thesis a hybrid electrical powertrain called the Four Quadrant Transducer (4QT) has been evaluated through different driving simulations, which later resulted in the manufacture of a prototype.</p><p>The simulation of a 12 metric ton distribution truck showed that the 4QT system can reduce the fuel consumption by approximately 30 % during the FTP75 drive cycle. The reduction in fuel consumption is due to a more optimal control of the combustion engine and regenerative braking of the vehicle.</p><p>The prototype 4QT has been down scaled from the distribution truck size used in the simulations to a size suitable for a medium sized passenger car. This was done to fit the test rig in the electric machine laboratory.</p><p>The prototype was tested in the test bench to analyse performances such as efficiency, losses and thermal behaviour. These factors were investigated using both analytical models and the finite element method and later by measurements. The measured results were according to expectations.</p> / <p>I denna doktorsavhandling presenteras ett nytt elhybridsystem för vägfordon benämnt fyrkvadrant omvandlare, "Four Quadrant Transducer (4QT)". Detta system har simulerats under körcykler som t ex FTP75 för att kunna bilda sig en uppfattning om bränsleförbrukningen för hybridsystemet och för att kunna dimensionera elmaskinerna till systemet. En elmaskinprototyp för hybridsystemet har konstruerats och provats i momentvåg.</p><p>Enligt utförda simuleringar blir besparingen i bränsleförbrukning ca 30% för en tolv tons distributionslastbil utrustad med en 100kW dieselmotor under körcykeln FTP75. Denna minskning av bränsleförbrukning kommer främst från en mera optimal kontroll av förbränningsmotorn samt regenerativ bromsning av fordonet.</p><p>Den konstruerade prototypen är avsedd för en medelstor bil. Anledningen till att prototypen inte byggdes i en storlek passande för distributionslastbilen var att prototypen skulle passa i testutrustningen i elmaskinlaboratoriet.</p><p>Prototypen provades i momentvåg för att undersöka verkningsgrad, förluster och termiska prestanda. Resultaten är enligt förväntningarna.</p>

This study explores the relation between Scandinavian donor private sector development and collaboration (PSD/PSC) policies and recipients of the support in Mozambique. It seeks to understand how such relations function in the complex local political and business environment. The study departs in theory regarding hybrid regimes and private sector development, and an analytical framework is designed as a model for relations based on theories on state-business relations and aid effectiveness. The material was gathered during a two-months field study where interviews were carried out with key actors of development cooperation such as embassy staff, fund managers and local entrepreneurs. The study finds that several PSC tools are shaped according to a western point of view and not always well adjusted to the local Mozambican context. It also finds that the design of the policies in many cases produces a high entrance barrier to Mozambican entrepreneurs, why most recipients are essentially foreign business people.

Determining the genetic basis of reproductive isolation is a fundamental goal in evolutionary biology. Intrinsic reproductive isolation often arises due to epistasis between divergent interacting genes. The rapid evolution of hybrid male sterility is known to have several causes, including the exposure of recessive X-linked incompatibilities in males and the rapid evolution of male reproductive traits. Despite these insights, little is known about the genetics of reproductive isolation during the early stages of speciation. This deficiency inspired parallel studies on the molecular evolution of male reproduction in house mice and the genetic basis of hybrid male sterility between two mouse species, Mus domesticus and M. musculus. Evolutionary analysis of 946 genes showed that the intensity of positive selection varies across sperm development and acts primarily on phenotypes that develop late in spermatogenesis (Appendix A). Several reciprocal crosses between wild-derived strains of M. musculus and M. domesticus were used to examine F1 hybrid male sterility (Appendix B). These crosses revealed hybrid male sterility linked to the M. musculus X chromosome and a novel sterility polymorphism within M. musculus. A large introgression experiment was used to further dissect the genetic basis of X-linked incompatibilities between M. musculus and M. domesticus (Appendix C). Introgression of the M. musculus X chromosome into a M. domesticus genetic background produced male sterility and involved a minimum of four factors. No sterility factors were uncovered on the M. domesticus X chromosome. These data demonstrate the complex genetic basis of hybrid sterility in mice and provide numerous X-linked candidate sterility genes. The molecular evolution of five rapidly evolving candidate genes was examined using population and phylogenetic sampling in Mus (Appendix D). Four of these loci showed evidence of positive natural selection. One locus, 4933436I01Rik, showed divergent protein evolution between M. domesticus and M. musculus and was one of a handful of testis-expressed genes within a narrow interval involved in hybrid male sterility. In summary, these data demonstrate that hybrid male sterility has a complex genetic basis between two closely related species of house mice and provide a foundation for the identification of specific mutations that isolate these species.

Eukaryotic protein kinases are one of the most important classes of human proteins, and a great deal of research has focused on the development of small molecule inhibitors as biological probes for the determination of their cellular function or as therapeutics for the treatment of disease, such as cancer. The need for new selective inhibitors and a better understanding of the selectivities of existing small molecules is readily apparent. Towards the goal of better understanding protein kinases and the molecules that inhibit them, I have developed a split-protein-based approach for the investigation of these kinase-small molecule interactions. Employing split-firefly luciferase as a reporter domain, we engineered a three-hybrid system capable of determining kinase inhibition through competitive interactions between an active site-directed ligand and a small molecule of interest. This method measures luciferase activity as a function of ligand binding, as opposed to the more traditional assays which quantify kinase activity directly, and alleviates the laborious process of protein purification. The model kinase PKA and the promiscuous ligand staurosporine were used in an initial test case to successfully validate the general design principles of our assay. The modular nature inherent to the assay's design enabled us to adapt it to roughly 300 additional protein kinases and two different ligands. We were able to establish a protocol for rapidly ascertaining the inhibition of a kinase by a library of 80 commercially available kinase inhibitors in a 96-well, high-throughput format. This protocol was then systematically applied to the AGC group of kinases to observe patterns of inhibition across similarly related kinases. We have further shown how these results might be correlated with the sequence identity between kinases to better anticipate inhibitor promiscuity. Finally, we were able to illustrate how a kinase-centric approach could be applied to correlate alterations to the kinase domain with changes in luminescence. This has use for the interrogation of different modes of inhibition as well as in identifying the specific determinants of inhibitor binding. In total, these efforts represent the optimization of a new, general platform for determining kinase inhibitor selectivity across the kinome, and it could potentially be applied universally to the interrogation of protein-ligand interactions.

The study and applications of surface plasmon polaritons (SP) – also known as plasmonics – has attracted the interest of a wide range of researchers in various fields such as biology, physics, and engineering. Unfortunately, the large propagation losses of the SP severely limit the usefulness of plasmonics for many practical applications. In this dissertation a new wave guiding mechanism is proposed in order to address the large propagation losses of the plasmonic guides. Possible applications of this guiding scheme are also investigated. The proposed hybrid plasmonic waveguide (HPWG) consists of a metal layer separated from a high index slab by a low index spacer. A detailed analysis is carried out to clarify the wave guiding mechanism and it is established that the mode guided by the HPWG results from the coupling of a SP mode and a dielectric waveguide mode. A two dimensional HPWG is proposed and the effects of various parameters on the HPWG performance are analyzed in detail. This structure offers the possibility of integrating plasmonic devices on a silicon platform. The proposed waveguide supports two different modes: a hybrid TM mode and a conventional TE mode. The hybrid TM mode is concentrated in the low index layer, whereas the conventional TE mode is concentrated in the high index region. This polarization diversity is used to design a TM- and a TE-pass polarizer and a polarization independent coupler on a silicon-on-insulator (SOI) platform. Moreover, the performance of a HPWG bend is investigated and is compared with plasmonic waveguide bends. The proposed devices are very compact and outperform previously reported designs. The application of HPWG for biosensing is also explored. By utilizing the polarization diversity, the HPWG biosensor can overcome some of the limitations of plasmonic sensors. For example, unlike plasmonic sensors, the HPWG biosensor can remove the interfering bulk and surface effects.

A polygon mesh, or a 3D mesh, consisting of a collection of vertices, edges, and polygons in three-dimensional space, is the standard way of representing 3D objects. In practice, polygon meshes acquired from the 3D scanning process fail to meet the quality requirements for most practical applications. Mesh defects like holes, duplicate elements, non-manifold elements are introduced during the scanning process, which lowers the quality of the output meshes. In this thesis, we describe a complete mesh-repairing process that fixes all defects within a polygon mesh. This process is divided into two parts: the mesh-cleaning part and the hole-filling part. In the mesh-cleaning part, we describe the ways of repairing different types of mesh defects. In the hole-filling part, we discuss two main hole-filling approaches: the surface-based method and the volumetric. In addition, we present a hybrid algorithm by combining the surface-based approach and the volumetric approach. We compare the meshes created by different hole-filing algorithms and show that the new algorithm is a good alternative to the existing ones. / Thesis (Master, Computing) -- Queen's University, 2013-09-11 23:45:08.591

The energy sector is currently in a state of change as conventional energy sources are questioned by the need of new clean and sustainable energy sources to satisfy the global energy demand in the long term. Renewable energies respond to this increasing demand and solar energy is an advanced example of them. Photovoltaic modules are experiencing a steady reduction in their production costs. It is needed that this trend continues and, along with it, their propagation and expansion in the market continues. One way of reducing production costs is by using inexpensive light concentrators to increase the output of the costly photovoltaic cell. In this respect, the Solarus AB hybrid PV/T collector has been designed based on this principle. This collector is a CPC (Compound Parabolic Collector) and belongs to the MaReCo (Maximum Reflector Collector) family. The aim of this thesis is to deeply investigate this technology in two main areas. Firstly, the collector will be tested both electrically and thermally in order to evaluate its performance. To do so, a solar test rig has been built and connected at the building Hall 45 of Högskolan i Gävle, Gävle, Sweden. The second main area of investigation of this thesis is to determine the optimal price for the Solarus AB hybrid PV/T collector in order to be competitive in the solar energy market. This study will be based in the current market prices of photovoltaic and thermal collectors. Regarding the electrical performance of the collector, the results obtained show that the front side of the receiver produces more electricity throughout the day than the reflector side. This has guided Solarus AB to decide to change the design of its receiver to improve its performance. With the current design, it has been obtained a peak power at STC of 220W. In relation with the thermal part, the heat losses of the collector have been estimated obtaining a U value of 6,8W/(m2*K), a thermal optical beam efficiency of 63,5% and a total optical beam efficiency of 74,5%. The price market study of photovoltaic and thermal collector has shown that 2m2 of the Solarus AB hybrid PV/T collector produces approximately the same annual electricity and heat as 1,1m2 of a photovoltaic module with an efficiency of 15,5% and a flat plate collector of 0,85m2 of aperture area. According to the market study, its cost is equivalent to 190€ for the PV module and 220€ for the flat plate collector. This means that the price of the Solarus AB hybrid PV/T collector should be lower than 410€.

The availability of cost-effective high throughput screening assays combined with an enhanced understanding of oncogenesis has driven the development of more potent, specific, and less toxic anti-cancer agents. At the forefront of these advances are immunoglobulin molecules and their fragments. However, difficulties in producing antibodies in sufficient quantity and quality for commercial application have driven the development of alternative systems that can produce antibodies efficiently and cost-effectively. This thesis focuses on the engineering of an antibody fragment referred to as a single chain variable fragment (scFv), which consists of antibody light and heavy chain variable domains fused together by a peptide linker. Although the use of scFvs circumvents many of the issue of full-length antibody production, they still possess their own unique set of difficulties, including stability. In this thesis, we explored the following strategies to increase scFv stability. First, we increased the number of linkers used to join the variable light and heavy domains. We constructed two linear and two cyclic permutated scFvs that contained additional peptide linkers. Two linear permutated scFvs, named Model 1 and Model 3, showed increased stability with calculated melting temperatures (Tms) exceeding that of the unpermutated scFv. The two cyclic scFvs were less stable with Tms less than that of the unpermutated scFv. Second, we mutated light and heavy variable domains by introducing prolines or mutating glycine to alanine in the variable domain framework regions. Sites for proline mutations and glycine to alanine mutations were identified and scFvs containing the mutations were purified and their thermal stability tested. Unfortunately, there were no discernible differences between purified scFv mutants and the control scFv. Third, we designed a new selection/screening strategy using phage display and yeast two-hybrid assays to identify complementarity determining regions on scFvs that increased intracellular stability. We used this strategy to isolate anti-Abl-SH3 scFvs. Transient expression of scFvs in K562 cells indicated that two anti-Abl-SH3 scFv decreased viability.

Due to the attractive advantages of wireless communication technologies, wireless networking and mobile computing has developed expeditiously and gained ample prevalence. Thereby, many practical applications are being designed for the use of wireless ad hoc networks in both military and civilian scenarios. However, some security concerns have arisen from such networks, especially in that misbehaving nodes pose a major threat during the construction of a trusted network. Therefore, security is one of the key challenges in wireless ad hoc networks, requiring significant attention due to their own features and concerns. This thesis presents several computational models and security strategies for the design of secure, trustworthy networks, which are able to make rational decisions when encountering potential threats. In this thesis, we first propose a distributed network management model for secure group communication. Our approach simplifies the complexity of traditional group management and supports the inclusion of other security mechanisms for the purpose of secure communications. As a decentralized management method, trust can perform well in a dynamic and agile environment. Our proposed trust system defines the concept of trust, establishes the trust relationship between distributed nodes, involves the novel and effective computational model, and specifies a set of trust-based rules in this system for wireless nodes. We also propose a hybrid cryptosystem through the application of both symmetric and asymmetric key algorithms to provide reliable and secure protection of data confidentiality. With the design of selective encryption, uncertainty is incorporated into data encryption and the overhead spent on the data protection is significantly reduced. Thus, the communicating parties not only obtain reliable security protection, but also improve the efficiency of data communication. Through security analysis and simulation experiments, we have shown how decentralized management is useful in wireless and ad hoc scenarios, how trust provides feasible solutions for misbehavior detection, and how our proposed strategies offer security properties.