Au cours de ces dernières années, les chercheurs ont démontré l’importance de l’accordabilité dans les systèmes de télécommunications fonctionnant pour des multiples bandes de fréquences, afin de réduire leur complexité et leur coût. Ce travail se focalise sur des filtres innovants accordables optiquement et propose ainsi une solution alternative aux méthodes plus classiques comme les MEMS ou les diodes. Cette thèse retrace la conception de trois résonateurs pouvant être de bons candidats à intégrer dans le système accordable optiquement développé au travers du manuscrit. Ces éléments sont conçus par le biais de différentes technologies comme : la technologie « Substrate Integrated Waveguide » combinée avec un effet dit métamatériau et la méthode de cavité chargée par un plot capacitif. Tous ces résonateurs ont été créés dans le but d’avoir des performances intéressantes pour trois critères : le facteur de qualité à vide (Q0), la plage d’accord (TR) et la taille. La dernière partie, quant à elle, se consacre au système d’accordabilité basé sur l’utilisation de capacité CMS et de switches RF contrôlés optiquement et fabriqués à l’aide de la technologie silicium CMOS. Plusieurs méthodes ont été utilisées afin d’améliorer les pertes d’insertion des switches RF et par conséquent les performances du système global, démontrant la faisabilité de ce concept innovant accordable optiquement. / Researchers have demonstrated over the last decade the importance of tunability to reduce the complexity and the cost of telecommunication systems operating at multiple frequency bands and standards. This work focuses on novel optically tunable filters for microwave applications and therefore proposes alternative solution to commonly used tuning methods such as MEMS or diodes. The thesis has investigated different resonators for having good candidates for the novel optically tunable system developed throughout this manuscript. Different technologies are used to design such components, namely: Substrate Integrated Waveguide (SIW) technology combined with metamaterial effect and cavity loading. All manufactured resonators are designed to be balanced between three features: the unloaded quality factor (Q0), the tuning range (TR) and the size. The last part deals with the tuning system based on SMT capacitance and optically controlled RF switches based on Si CMOS technology. Several methods have been used to improve the insertion loss of manufactured switches and therefore the performance of the whole system, demonstrating the feasibility of this novel optically based tunable concept.

Bridges often use pile foundations behind MSE walls to help resist lateral loading from seismic and thermal expansion and contraction loads. Overdesign of pile spacing and sizes occur owing to a lack of design code guidance for piles behind an MSE wall. However, space constraints necessitate the installation of piles near the wall. Full scale lateral load tests were conducted on piles behind an MSE wall. This study involves the testing of four HP12X74 H-piles and four HSS12X12X5/16 square piles. The H-piles were tested with ribbed strip soil reinforcement at a wall height of 15 feet, and the square piles were tested with welded wire reinforcement at a wall height of 20 feet. The H-piles were spaced from the back face of the MSE wall at pile diameters 4.5, 3.2, 2.5, and 2.2. The square piles were spaced at pile diameters 5.7, 4.2, 3.1, and 2.1. Testing was based on a displacement control method where load increments were applied every 0.25 inches up to three inches of pile deflection. It was concluded that piles placed closer than 3.9 pile diameters have a reduction in their lateral resistance. P-multipliers were back-calculated in LPILE from the load-deflection curves obtained from the tests. The p-multipliers were found to be 1.0, 0.85, 0.60, and 0.73 for the H-piles spaced at 4.5, 3.2, 2.5, and 2.2 pile diameters, respectively. The p-multipliers for the square piles were found to be 1.0, 0.77, 0.63, and 0.57 for piles spaced at 5.7, 4.2, 3.1, and 2.1 pile diameters, respectively. An equation was developed to estimate p-multipliers versus pile distance behind the wall. These p-multipliers account for reduced soil resistance, and decrease linearly with distance for piles placed closer than 3.9 pile diameters. Measurements were also taken of the force induced in the soil reinforcement. A statistical analysis was performed to develop an equation that could predict the maximum induced reinforcement load. The main parameters that went into this equation were the lateral pile load, transverse distance from the reinforcement to the pile center normalized by the pile diameter, spacing from the pile center to the wall normalized by the pile diameter, vertical stress, and reinforcement length to height ratio where the height included the equivalent height of the surcharge. The multiple regression equations account for 76% of the variation in observed tensile force for the ribbed strip reinforcement, and 77% of the variation for the welded wire reinforcement. The tensile force was found to increase in the reinforcement as the pile spacing decreased, transverse spacing from the pile decreased, and as the lateral load increased.

The lateral resistance of pile foundations is typically based on the performance of round piles even though other pile types are used. Due to lack of data there is a certain level of uncertainty when designing pile foundations other than round piles for lateral loading. Theoretical analyses have suggested that square sections will have more lateral resistance due to the increased side shear resistance, no test results have been available to substantiate the contention. Full-scale lateral load tests involving pile shapes such as circular, circular wrapped with high density polyethylene sheeting, square, H, and circular with a corrugated metal sleeve have been performed considering the influence of soil-pile interaction on lateral load resistance. The load test results, which can be summarized as a p-y curve, show higher soil resistance from the H and square sections after accounting for differences in the moment of inertia for the different pile sections. The increased soil resistance can generally be accounted for using a p-multiplier approach with a value of approximately 1.25 for square or 1.2 for H piles relative to circular piles. It has been determined that high density polyethylene sheeting provides little if any reduction in the lateral resistance when wrapped around a circular pile. Circular piles with a corrugated metal sleeve respond to lateral loading with higher values of lateral resistance than independent circular piles in the same soil.

Comprehensive knowledge and information about the static and dynamic behaviour of machine tools, cutting processes and their interaction is essential for machining system design, simulation, control and robust operation in safe conditions. The very complex system of a machine tool, fixture and cutting tools during the machining of a part is almost impossible to model analytically with sufficient accuracy. In combination with increasing demands for precision and efficiency in machining call for new control strategies for machining systems. These strategies need to be based on the identification of the static and dynamic stability under both the operational and off-operational conditions. To achieve this it is necessary to monitor and analyze the real system at the factory floor in full production. Design information and operational data can then be linked together to make a realistic digital model of a given machining system. Information from such a model can then be used as input in machining simulation software to find the root causes of instability. The work presented in this thesis deals with the static and dynamic capability of machining systems. The main focus is on the operational stability of the machining system and structural behaviour of only the machine tool, as well. When the accuracy of a machining system is measured by traditional techniques, effects from neither the static stiffness nor the cutting process are taken into account. This limits the applicability of these techniques for realistic evaluation of a machining system’s accuracy. The research presented in this thesis takes a different approach by introducing the concept of operational dynamic parameters. The concept of operational dynamic parameters entails an interaction between the structural elements of the machining systems and the process parameters. According to this concept, the absolute criterion of damping is used to evaluate the dynamic behaviour of a machining system. In contrast to the traditional theory, this methodology allows to determine the machining system's dynamic stability, in real time under operating conditions. This framework also includes an evaluation of the static deformations of a machine tool.  In this context, a novel concept of elastically linked system is introduced to account for the representation of the cutting force trough an elastic link that closes the force loop. In addition to the elastic link which behaves as a static element, a dynamic non-contact link has been introduced. The purpose is to study the non-linear effects introduced by variations of contact conditions in joints due to rotational speed. / QC 20111123

Pronking is a legged locomotory gait in which all legs are used in synchrony, usually resulting in slow speeds but long flight phases and large jumping heights that may potentially be useful for mobile robots locomoting in cluttered natural environments. Instantiations of this gait for robotic systems suffer from severe pitch instability either due to underactuated leg designs, or the open-loop nature of proposed controllers. Nevertheless, both the kinematic simplicity of this gait and its dynamic nature suggest that the Spring-Loaded Inverted Pendulum Model (SLIP), a very successful predictive model for both natural and robotic runners, would be a good basis for more robust and maneuverable robotic pronking. In the scope of thesis, we describe a novel controller to achieve stable and controllable pronking for a planar, underactuated hexapod model, based on the idea of &ldquo / template-based control&rdquo / , a controller structure based on the embedding of a simple dynamical template within a more complex anchor system. In this context, high-level control of the gait is regulated through speed and height commands to the SLIP template, while the embedding controller based on approximate inverse-dynamics and carefully designed passive robot morphology ensures the stability of the remaining degrees of freedom. We show through extensive simulation experiments that unlike existing open-loop alternatives, the resulting control structure provides stability, explicit maneuverability and significant robustness against sensor noise.

In several mathematical models of physical or technical processes there are non-local boundary-value problems in terms of partial differential equations with integral conditions. In this article we consider hyperbolic differential equations of second order in the rectangle with some integral conditions and their relationship to boundary-value problems for some certain type of loaded equations. / Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.

The need for miniaturized, and high performance microwave devices has focused significant attention onto new fabrication technologies that can simultaneously achieve high performance and low manufacturing complexity. Additive manufacturing (AM) has proven its capability in fabricating high performance, compact and light weight microwave circuits and antennas, as well as the ability to achieve designs that are complicated to fabricate using other manufacturing approaches. Direct print additive manufacturing (DPAM) is an emerging AM process that combines the fused deposition modeling (FDM) of thermoplastics with micro-dispensing of conductive and insulating pastes. DPAM has the potential to jointly combine high performance and low manufacturing complexity, along with the possibility of real-time tuning. This dissertation aims to leverage the powerful capabilities of DPAM to come-up with new designs and solutions that meet the requirements of rapidly evolving wireless systems and applications. Furthermore, the work in this dissertation provides new techniques and approaches to alleviate the drawbacks and limitations of DPAM fabrication technology. Firstly, the development of 3D packaged antenna, and antenna array are presented along with an analysis of the inherent roughness of 3D printed structures to provide a deeper understanding of the antenna RF performance. The single element presents a new volumetric approach to realizing a 3D half-wave dipole in a packaged format, where it provides the ability to keep a signal distribution network in close proximity to the ground plane, facilitating the implementation of ground connections (e.g. for an active device), mitigating potential surface wave losses, as well as achieving a modest (10.6%) length reduction. In addition, a new approach of implementing conformal antennas using DPAM is presented by printing thin and flexible substrate that can be adhered to 3D structures to facilitate the fabrication and reduce the surface roughness. The array design leverages direct digital manufacturing (DDM) technology to realize a shaped substrate structure that is used to control the array beamwidth. The non-planar substrate allows the element spacing to be changed without affecting the length of the feed network or the distance to the underlying ground plane. The second part describes the first high-Q capacitively-loaded cavity resonator and filter that is compatible with direct print additive manufacturing. The presented design is a compromise between quality factor, cost and manufacturing complexity and to the best of our knowledge is the highest Q-factor resonator demonstrated to date using DPAM compatible materials and processes. The final version of the single resonator achieves a measured unloaded quality factor of 200-325 over the frequency range from 2.0 to 6.5 GHz. The two pole filter is designed using a coupled-resonator approach to operate at 2.44 GHz with 1.9% fractional bandwidth. The presented design approach simplifies evanescent-mode filter fabrication, eliminating the need for micromachining and vias, and achieving a total weight of 1.97 g. The design is fabricated to provide a proof-of-principle for the high-Q resonator and filter that compromises between performance, cost, size, and complexity. A stacked version of the two-pole filter is presented to provide a novel design for multi-layer embedded applications. The fabrication is performed using an nScrypt Tabletop 3Dn printer. Acrylonitrile Butadiene Styrene (ABS) (relative permittivity of 2.7 and loss tangent of 0.008) is deposited using fused deposition modeling to form the antenna, array, resonator, and filter structures, and Dupont CB028 silver paste is used to form the conductive traces conductive regions (the paste is dried at 90 °C for 60 minutes, achieving a bulk DC conductivity of 1.5×106 S/m.). A 1064 nm pulsed picosecond Nd:YAG laser is used to laser machine the resonator and filter input and output feedlines.

El objetivo del presente trabajo de investigación consiste en evaluar la calidad de la carpeta asfáltica mediante el análisis de la rueda cargada de Hamburgo, usando el Método Marshall en la rehabilitación de la carretera de Imperial Pampas. El método de la investigación es de tipo cualitativo-cuantitativo. El problema consistió en determinar de qué manera el análisis de la rueda cargada de Hamburgo permite comprobar si la carpeta asfáltica usada en la rehabilitación de la carretera Imperial Pampas cumple con los estándares de calidad de acuerdo al método de Marshall. La hipótesis planteada es que la Rueda de Hamburgo permite comprobar que la carpeta asfáltica usada en la rehabilitación de la carretera Imperial pampas cumple con los estándares de calidad de acuerdo al método Marshall. Llegando a la conclusión que el método Marshall mostró buen performance en condiciones extremas, por cuanto se obtuvo en el umbral de aprobación. The research objective of this study is to assess the quality of the asphalt by analyzing the wheel loaded Hamburg using the Marshall method in the rehabilitation of the road from Imperial Pampas. The research method is qualitative - quantitative The problem was to determine how the analysis of Hamburg loaded wheel lets you check whether the asphalt used in road rehabilitation Imperial Pampas meets quality standards according to the Marshall method. The hypothesis is that the Hamburg Wheel lets you check that the asphalt used in road rehabilitation Imperial pampas meet the quality standards according to the Marshall method. I came to the conclusion that the Marshall method showed good performance in extreme conditions was obtained because the threshold of approval.

Contraception through a vaccine has been a very attractive proposition and several attempts were made in the past. To achieve contraception through immunological means, several points need to be considered. First, the targeted antigen should be an important component of reproduction and interference in its actions should lead to infertility. Second, the antigen must be highly immunogenic and the antibodies elicited should be able to block the functions of the antigen. Third, the antibody titres should be effective and must sustain for longer periods. Gonadotropins fulfill all the above criteria and therefore, have been attractive targets for developing human contraceptive vaccines. The pituitary gonadotropins- Luteinizing hormone (LH) and the Follicle stimulating hormone (FSH) are the principal regulators of the reproduction process in all the mammalian species (McLachlan et al., 1995c; Moudgal et al., 1992b; Murty et al., 1979a; Selvaraj and Moudgal, 1994a; Weinbauer et al., 1991). In males, LH binds to its specific receptor-LHR, expressed on the Leydig cells and regulates the production of testosterone. This testosterone binds to the androgen receptors expressed in the Sertoli cells and along with FSH, which binds to the specific receptors present on the Sertoli cell membranes, regulate the testicular functions and the spermatogenesis (Simoni et al., 1997; Themmen and Huhtaniemi, 2000; Ulloa-Aguirre and Timossi, 1998). The well documented studies have unequivocally established that the specific immunoneutralization of either hormone by active or passive immunization, leads to disruption of the gonadal functions (Fraser et al., 1986a; Marathe et al., 1995; Moudgal et al., 1992b; Murty et al., 1979b; Shetty et al., 1996; Srinath et al., 1983b) and consequent infertility and this observation formed the basis of the human contraceptive vaccines (Moudgal et al., 1997b; Talwar et al., 2011a; Talwar et al., 2009a). Several studies using testosterone as the main male hormonal contraception method (Matsumoto et al., 1986; Matsumoto et al., 1983a) and anti-hCG vaccine as the female hormonal contraceptive vaccine reached Phase I and II clinical trials (Talwar, 1997; Talwar et al., 1994; Talwar et al., 1997) . However, these human contraceptive vaccines faced several limitations. There was a need to inhibit only particular segments of the entire reproduction process whereas others needed to remain completely unaffected. For example, in males, the FSH regulated functions, the sperm production and spermatogenesis needed to be inhibited whereas the LH/testosterone associated functions should be unaffected. Similarly in females, the functions of hCG alone, elaborated by the conceptus should be blocked without affecting either LH or FSH regulated functions, thus, maintaining the normal reproductive cycle. This however is a difficult task especially when the antigens share a large degree of homology and common subunits (Pierce and Parsons, 1981). Moreover, the issues relating to the development and sustenance of high titres of the bioneutralizing antibodies were major limitations of these human contraceptive vaccines. Therefore, despite reaching Phase I and II clinical trials, these studies did not progress further. However, the same concept of an immunocontraceptive vaccine involving the neutralization of the functions of the gonadotropins is an extremely attractive strategy for controlling the animal populations where the reproduction process could be inhibited in its entirety. The overgrowing populations of the stray animals such as dogs and cats pose problems unlike those experienced with the human overpopulation. Thus, there is an immediate need to develop the methods of controlling the populations of these animals both in the developed and the developing countries. Whereas, in countries like the US, the major emphasis is on the domestic animals, in countries like India, the populations of the stray animals need to be controlled. The current methods employed for reducing the numbers of these animals include either castration or culling of the animals. These methods are however, traumatic, unsafe and not widely accepted by the society. The animal contraceptive vaccines currently available are mostly GnRH vaccines which have high cost of production, are not safe for animal use and elicit unwanted side effects. Apart from these, the animals need multiple administrations of these vaccines to elicit high and effective antibody titres, mostly with the use of conventional but non-approved adjuvants (Boedeker et al., 2009; McCoy, 1994). As mentioned above, the gonadotropins, by virtue of their ability to control the mammalian reproduction process, are attractive targets for achieving contraception. Moreover, the ease of administration of this vaccine to neutralize the functions of the endogenous circulating hormones makes them ideal targets for developing animal immunocontraceptive vaccines. This method of neutralizing the functions of the gonadotropins is also humane and safe for the animals as opposed to the current methods which are employed to reduce their numbers. However, in case of animal contraception, particularly for strays such as dogs, where large numbers of animals need to be treated, the challenge is to develop a method to sustain the high levels of the bioneutralizing antibodies for prolonged periods preferably with a single administration of the immunogen and without the use of conventional adjuvants such as the Freund’s adjuvant. In the present study, an attempt has been made develop a strategy to achieve a sustained immune response to small quantities of the hormonal antigens, preferably with a single administration of the immunogen resulting in complete disruption of the gonadal function for prolonged periods. To achieve this goal, recent developments in the field of immunology and vaccinology have been employed. This involves targeting of the hormonal antigens to the dendritic cells. Targeting the antigens to the dendritic cells for vaccination is becoming an extremely fascinating strategy and is being used extensively to target the antigens involved in several diseases (Escudier et al., 2005; Frankel et al., 1998; Garcia et al., 2005; Nouri-Shirazi et al., 2000a; Nouri-Shirazi et al., 2000b; Steinman and Germain, 1998). Most antigens are targeted to the dendritic cells by coupling them to the antibodies specific for the receptors expressed on the dendritic cell surface. One such receptor is the DEC205, which is expressed on most of the dendritic cells (Jiang et al., 1995) and is being widely used to develop vaccines and vaccination strategies. Targeting the antigens to the dendritic cells provides advantages such as ability to induce hundred fold higher immune response to very low doses of antigen without the use of any conventional adjuvant (Bonifaz et al., 2004a). Therefore, in the present study, these features of the dendritic cells have been harnessed to target the hormonal antigens (hCG and hFSH) to the canine DEC205 receptor to induce a long-term immune response capable of disrupting the gonadal functions. Towards this goal of delivering hormonal antigens to the dendritic cells, a fragment of the canine DEC205 corresponding to the Cysteine Rich Fibronectin II domain (CR/FNII) was expressed and used to isolate several canine DEC205 specific recombinant antibodies in the form of single chain fragment variable (ScFvs) from the Tomlinson’s and the yeast human ScFv display libraries. From a pool of eight unique ScFvs screened from the Tomlinson’s libraries, three ScFvs namely B3, G10 and H4 were characterized. All these ScFvs could bind to the human DEC205 receptor but not to the mouse DEC205. Their inability to recognise the mouse DEC205 suggested that mouse could not be used as the model system for these studies and therefore, a surrogate model system was needed. As the canine CR/FNII shared a high degree of homology with the rabbit counterpart, adult rabbits have been used as the surrogate model for immunization studies after confirming the binding of the ScFvs to the rabbit dendritic cells. Since the goal of the study was to deliver the hormonal antigens to the dendritic cells, each ScFv was translationally fused to a core streptavidin fragment, thus creating bi-functional agents (ScFv-CS) capable of binding to the dendritic cells and also to any biotin-tagged antigen, thus delivering the antigen to the dendritic cells. Of the three ScFvs, the ScFv-CS-H4 which could bind to the canine CR/FNII with the KD of 25nM was used for demonstrating the ability of the ScFv-hormone complex to elicit the bioneutralizing antibody response. The ScFv-CS-H4-biotin-hCG or hFSH or both were administered to adult male rabbits along with poly IC: LC, a Toll-like receptor agonist and the antibody titres were monitored. It was possible to maintain high titres of the bioneutralizing antibodies for more than one year with a single administration of the immunogen. Testicular histology of the immunized animals showed extensive disruption of spermatogenesis with most of the germ cells being TUNEL positive undergoing apoptosis. There was complete absence of elongated spermatids and sperms in the testis indicating infertility caused by immunization with the gonadotropins. These data show that targeting the hormonal antigens to the dendritic cells leads to long-term infertility with minimal immunization. Although the ScFvs from the Tomlinson’s libraries were able to deliver the hormonal antigens to the dendritic cells and produce robust and sustained antibody response capable of disrupting the gonadal functions, the affinities of these ScFvs to DEC205 were moderate. It was felt that increasing the affinities of the ScFvs could enhance the effect with respect to the dose of the antigen that needs to be administered and the duration until which the high antibody titres could be maintained. Therefore, the yeast human ScFv display library offering higher diversity of the human ScFvs displayed, was screened for high affinity DEC205 specific binders. From a pool of several ScFvs, six unique ScFvs were characterized. The amino acid sequences of all ScFvs followed the Kabat's rules for identifying the complimentarity determining regions of the heavy and the light chains of the antibodies. All these ScFvs were unique in their amino acid sequences. The dissociation constants of all these antibodies for the canine CR/ FNII ranged from 10-9 to 10-11 M which was 20-300 fold higher than the ScFvs obtained from the Tomlinson’s libraries. The best ScFv obtained from this library was ScFv-92 with a KD value of 8 x10-11 M. All these ScFvs were able to deliver the payload antigen to both, the mouse DEC205 over-expressing cells and the bone marrow derived dendritic cells. Mice immunized with yeast display ScFvs also yielded antibody response to very small quantities of the immunogen with the highest antibody titres obtained with the ScFv-92. It was further demonstrated that all ScFvs also activated the cell-mediated immunity with significant increase in the antigen stimulated T cell proliferation. These ScFvs could also deliver the antigen to the human dendritic cells differentiated from the human monocytes in vitro, thus emphasising their utility in human vaccine development. An attempt was also made to develop nanoparticle (NP) based strategies of delivering the antigen to the dendritic cells. The PLGA-NPs, encapsulating hCG and coated with the DEC205 ScFv-92 was able to elicit high antibody response to very low doses of the antigen. This response could be sustained for 120 days and was higher than the response obtained with similar doses of hCG encapsulated NPs or hCG complexed to ScFv-92 alone. Targeting of the NPs also elicited antigen specific T cell response thus, potentiating their use in cell mediated immunity along with humoral immune responses. In conclusion, this approach of delivering the gonadotropins to the dendritic cells resulted in the production of bioneutralizing antibodies that could disrupt the gonadal functions for a prolonged period and can be effectively used in the fields for controlling the animal populations. This method fulfils all the criteria for any animal contraception. This strategy also elicits both T cell mediated and humoral immunity and can thus be used for producing vaccine against viral and parasitic infections. It can also be used for cancer immunotherapy. Another exciting feature of the strategy used in this study is the usage of ScFv-CS which allows the delivery of any biotin tagged antigen to the rodent and human dendritic cells. As discussed above, the methods for controlling the animal populations are expected to be effective, humane, safe, simple, non-surgical, single shot with long lasting effects, cheap, applicable in the fields and widely accepted by different societies. The methods presented in this study fulfill all these criteria and should be effective in controlling populations of different animal species.

Electric and hybrid vehicles are particularly suited for use in urban areas since city transportation is mainly characterized by relatively short driving distances, low continuous power requirements, long idling times and high availability of regenerative braking energy. These characteristics, when carefully incorporated into the design process, create valuable opportunities for developing clean, efficient and cost effective urban vehicle propulsion systems. In the first part of the thesis, we present data collected in the city of Bangalore, India from a very commonly seen mode of transportation for hire in India and other emerging economies, namely a three-wheeled vehicle known as the “auto-rickshaw”. From a statistical analysis, it is shown that the typical range is 72.5 km with a mean speed of 12.5 km/h. More than 60% of the time the auto-rickshaw is stationary or has a speed of less than 5 km/h. From a model of the auto-rickshaw, it is shown from simulations that 4 kW DC motor and about 10 kWh of electrical energy is enough to meet 80% of typical requirement. Based on this finding, in this thesis, a novel parallel hybrid architecture is proposed where two 2 kW DC hub motors are directly mounted on the wheels and an internal combustion (IC) engine output is connected to the stator of the DC hub motors to provide additional power when required. To match load and speed, a continuously variable transmission (CVT) is placed in-between the IC engine and the DC hub motor. The proposed hybrid configuration adds speed to the wheel output unlike the normal power split configuration which adds torque. One of the main objective of this work is to study and compare the performance of the above novel speed-addition and compare with the typical torque-addition configuration. A MATLAB/Simulink model for both the configurations, with DC hub motor and a small IC engine, has been created and the fuel consumption has been calculated. It is shown that the proposed speed-addition concept gives better fuel efficiency for the standard modified Indian Driving Cycle. The models have also been compared for actual driving data and an optimal control strategy has been developed using dynamic programming. It is again shown that the proposed speed-addition concept results in better fuel economy. In the last part of the thesis, a low cost experimental test-bed consisting of an auto-rickshaw IC engine, a CVT and a 2 kW DC hub motor has been developed to validate the speed-addition concept and compare with the torque-addition configuration. The torque-speed curves of the IC engine, the DC motor and both of them together, in the speed and torque-addition configuration, have been obtained. It is shown that the speed-addition concept does indeed work and the obtained results are significantly different from the torque-addition configuration.