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Pose estimation is a well-studied problem in computer vision. Many solutions which provide high accuracy depend on nonlinear optimization. For real-time applications, linear or closed-form solutions are preferred. Some relatively new methods also fuse inertial sensor data with that from the visual sensor to achieve higher accuracy. We propose a closed-form solution to estimate camera pose using two lines and gravity information. The system is developed so that it could work in unprepared environments which satisfy the Manhattan world assumption. We first test the proposed method on a synthetic data set and compare it to other state-of-the-art point and line based pose estimation methods, comparing their mean rotation and mean translation errors. I.M.U. noise effect on the overall performance of the system is also tested. We then proceed to test our algorithm in real world by rectifying perspective deformed images. The deviation of the calculated pose from the ground-truth pose is calculated for each image to test the real world performance of the proposed algorithm. Also, I.M.U. noise is calculated, which correspond to the 0.5% noise level expected in low cost I.M.U.’s.
The adiabatic manipulation of quantum states is a powerful technique that opened up new directions in quantum engineering-enabling tests of fundamental concepts such as geometrical phases and topological transitions, and holding the promise of alternative models of quantum computation. Here we benchmark the stimulated Raman adiabatic passage for circuit quantum electrodynamics by employing the first three levels of a transmon qubit. In this ladder configuration, we demonstrate a population transfer efficiency >80% between the ground state and the second excited state using two adiabatic Gaussian-shaped control microwave pulses. By doing quantum tomography at successive moments during the Raman pulses, we investigate the transfer of the population in time domain. Furthermore, we show that this protocol can be reversed by applying a third adiabatic pulse, we study a hybrid nondiabatic-adiabatic sequence, and we present experimental results for a quasi-degenerate intermediate level.
Logistics activities have become more uncertain amid current trends like the COVID-19 pandemic and new environmental regulation. The role of technology has become more important in handling these uncertainties. This thesis aims to investigate the current state of logistics activities in North European companies regarding their trade with China and Russia. The research applies a mixed method with a survey strategy to collect the data. The survey was targeted to logistics and manufacturing companies and was divided into two parts: the first survey was targeted to multinational companies from Finland, Norway, Sweden, and Estonia while, the second survey was specifically focused for regional companies from Finland. A web-based questionnaire was sent to all the targeted companies. Both literature and survey results show that the semi-trailer followed by the container is the most important transport unit. For freight, the road is a preferable mode for shorter distances, and sea is the dominant mode over longer distances while, railways are expected to have potential growth throughout the decade in the future for logistics activities between North European companies and eastern markets of China and Russia. Research reveals that COVID-19 has a moderate impact on companies' logistics operations while environmental regulations will increase their transport costs and the vitality of cutting-edge technology is expected to rise. This thesis contributes to theory development for research as additional information. In a nutshell, proper planning and adopting new trends of technologies, strategic changes to prepare for the future encounters of the pandemic, epidemics, and other risks can help to keep the momentum of logistics and supply chain operations in North European companies.
Unbalanced magnetic pull (UMP) reduction is an important aspect of high-speed electrical machines and it can be reduced using a specialized winding scheme called bridge configured winding. A bridge configuration winding has two parallel paths in each phase. The mid points of these two parallel paths can be short-circuited to achieve passive control of the UMP or a power supply can be added in between these points to achieve active control of UMP. Moreover, it is important to understand the behavior of UMP in different eccentricity conditions for its active suppression. A finite-element modeling of a bridge configured induction machine has been developed to study the effects of different eccentricity conditions on UMP and bridge currents. A generalized circuit equation has been coupled with the field equation for the implementation of bridge configuration winding. All of the three kinds of eccentricity conditions have been simulated. In addition, two experimental setups have been developed to study the UMP-induced vibration and to study the effect of eccentricity on bridge currents.
Abstract The energy consumption around the globe is on the rise due to the exponential population growth and urbanization. There is a need for alternative and non-conventional energy sources, which are CO2-neutral, and a need to produce less or no environmental pollutants and to have high energy efficiency. One of the alternative approaches is hydrogen economy with the fuel cell (FC) technology which is forecasted to lead to a sustainable society. Hydrogen (H2) is recognized as a potential fuel and clean energy carrier being at the same time a carbon-free element. Moreover, H2 is utilized in many processes in chemical, food, metallurgical, and pharmaceutical industry and it is also a valuable chemical in many reactions (e.g. refineries). Non-renewable resources have been the major feedstock for H2 production for many years. At present, ~50% of H2 is produced via catalytic steam reforming of natural gas followed by various down-stream purification steps to produce ~99.99% H2, the process being highly energy intensive. Henceforth, bio-fuels like biomass derived alcohols (e.g. bio-ethanol and bio-glycerol), can be viable raw materials for the H2 production. In a membrane based reactor, the reaction and selective separation of H2 occur simultaneously in one unit, thus improving the overall reactor efficiency. The main motivation of this work is to produce H2 more efficiently and in an environmentally friendly way from bio-alcohols with a high H2 selectivity, purity and yield. In this thesis, the work was divided into two research areas, the first being the catalytic studies using metal decorated carbon nanotube (CNT) based catalysts in steam reforming of ethanol (SRE) at low temperatures (<450 °C). The second part was the study of steam reforming (SR) and the water-gas-shift (WGS) reactions in a membrane reactor (MR) using dense and composite Pd-based membranes to produce high purity H2. CNTs were found to be promising support materials for the low temperature reforming compared to conventional catalyst supports, e.g. Al2O3. The metal/metal oxide decorated CNTs presented active particles with narrow size distribution and small size (~2–5 nm). The ZnO promoted Ni/CNT based catalysts showed the highest H2 selectivity of ~76% with very low CO selectivity <1%. Ethanol was shown to be a more suitable and viable source for H2 than glycerol. The dense Pd-Ag membrane had higher selectivity but a lower permeating flux than the composite membrane. The MR performance is also dependent on the active catalyst materials and thus, both the catalyst and membrane play an important role. Overall, the membrane–assisted reformer outperforms the conventional reformer and it is a potential technology in pure H2 production. The high purity of H2 gas with a CO-free reformate for fuel cell applications can be gained using the MR system.
Abstract In ladle metallurgy, gas stirring and the behaviour of the slag layer are very important for alloying and the homogenization of the steel. When gas is injected through a nozzle located at the bottom of the ladle into the metal bath, the gas jet exiting the nozzle breaks up into gas bubbles. The rising bubbles break the slag layer and create an open-eye. The size of the open-eye is very important as the efficiency of the metal-slag reactions depend on the interaction between the slag and steel created during the stirring process, and information about the position and size of the open-eye is important for effective alloying practice. Moreover, the open-eye has an effect on the energy balance since it increases heat losses. In this study, experimental measurements and numerical simulations were performed to study the effect of different operating parameters on the formation of the open-eye and mixing time in a water model and industrial ladle. Experimental measurements were performed to study the effect of the gas flow rate, slag layer thickness, slag layer densities and number of porous plugs in a 1/5 scale water model and in a 150-ton steelmaking ladle. For numerical modelling, a multi-phase volume of fluid (VOF) model was used to simulate the system including the behaviour of the slag layer. The numerical simulation of the open-eye size and mixing time was found to be in good agreement with the experimental data obtained from the water model and data obtained from the industrial measurements.
Abstract Potential lethal diarrhoea caused by enterotoxigenic Escherichia coli strains is one of the most common diseases in young pigs. It can be cured by single-chain antibody fragments (scFv), which can be produced in recombinant microorganisms. Pichia pastoris, a methylotrophic yeast, is generally considered an interesting production system candidate, as it can secrete properly folded proteins. These proteins accumulate in high concentrations during fermentation, reducing the cost for product recovery. Strong inducible AOX1 promoter, widely used in P. pastoris for fast, inexpensive production, is typically induced by methanol. The high oxygen demand of methanol metabolism makes oxygen supply a major parameter in cultivations requiring special process design strategies. In standard fed-batch cultivation, dissolved oxygen concentration inside a bioreactor is kept at a certain level by pumping air and pure oxygen into the reactor. There are safety concerns over the handling of oxygen, especially at a large scale. Therefore, there is a need to develop a production process under oxygen-limited conditions. This dissertation studies the development of a cost-efficient production process of scFv in P. pastoris. Both methanol and oxygen parameters influence the production process and the objective was to find a robust production process. Fed-batch cultivations were performed in a 10 L scale bioreactor. The effects of lower oxygen level, methanol concentration, glycerol feeding duration and specific substrate-uptake rates on product formation were studied. A P. pastoris GS115 his4 strain under an AOX1 promoter system expressing scFv was used in this study. The fed-batch fermentations were carried out in a bioreactor with basal salt media. In this doctoral dissertation, a process was developed for a single-chain antibody fragment (scFv) production in P. pastoris. The product levels of 3.5 g L−1 scFv in culture supernatant were achieved and a production process was designed without additional need of pure oxygen, thus relieving safety requirements and lowering the amount of methanol. The process developed during this research may potentially be utilised by both academia and industry having interests in expressing proteins in P. pastoris. The methanol-uptake control strategy is beneficial for those products that suffer from degradation or modification during limited feeding of methanol.
Abstract Tigers are endangered in the wild and face increasing threats from habitat loss and fragmentation. The majority of their range occurs in the Indian subcontinent, which is therefore a critical area for tiger conservation. Bengal tigers are distributed across many small protected areas in India. Two important Bengal tiger landscapes — Terai Arc Landscape (TAL) and Sundarbans in India were lacking in basic genetic information and needed to address the impact of anthropogenic pressure and climate change on their genetic makeup in order to identify conservation units. Therefore, I employed nuclear and mitochondrial genetic markers on TAL and Sundarbans tiger individuals to respond these demands for the first time. Thirty-nine heterologous microsatellite loci were screened on Bengal tigers and thirteen of these loci were selected to genotype Bengal tiger samples from western TAL (WTAL) and Sundarbans. After I had genotyped seventy-one Bengal tiger individuals from WTAL, I found cryptic population genetic structure, moderate gene flow and asymmetric migration among the subpopulation. Genetic diversity was moderate and there were no signs of population bottlenecks. In order to maintain the connectivity of subpopulations and avoid human—wildlife conflict, relocation of villages is necessary. Preventive measures against habitat encroachment and a ban on sand and boulder mining in the corridor area should also be implemented. Noninvasively-collected tiger samples from Sundarbans were analyzed for mitochondrial and microsatellite markers and compared with mainland (northern and peninsular) Bengal tiger populations in India. Sundarbans tigers were found to be genetically distinct and had lower genetic variation in comparison to other mainland tiger populations. Demographic analysis indicated recent historical isolation (600—2000 years ago) of the Sundarbans tiger from the mainland. Both historical and genetic evidence supported that the Sundarbans tiger was genetically connected to other mainland tigers until recently. Conclusively, genetic isolation from the mainland tiger population and adaptation to the mangrove ecosystem might have jointly shaped the genetic architecture of the Sundarbans tiger. Hence, the Sundarbans tiger needs special conservation attention for the preservation of its unique ability to adapt and for its genetic individuality. It should be managed as an evolutionary significant unit (ESU) under the adaptive evolutionary conservation (AEC) criteria. I also addressed a problem in the previously suggested sex-specific gene flow estimation method and recommended an alternative approach for a more precise estimation.
Abstract We study numerically the onset of higher-level excitations and resonance frequency shifts in the generalized multilevel Rabi model with dispersive coupling under strong driving. The response to a weak probe is calculated using the Floquet method, which allows us to calculate the probe spectrum and extract the resonance frequency. We test our predictions using a superconducting circuit consisting of a transmon coupled capacitively to a coplanar waveguide resonator. This system is monitored by a weak probe field and at the same time driven at various powers by a stronger microwave tone. We show that the transition from the quantum to the classical regime is accompanied by a rapid increase of the transmon occupation and consequently that the qubit approximation is valid only in the extreme quantum limit.