Compact, electric drives for automotive traction applications represent animportant enabler towards realizing tomorrow’s fossil free transport solutions.One attractive solution is to integrate the power electronic converter withits associated electric machinery into a single unit. This thesis, along withits appended papers, considers design and analysis of electric machinery forintegrated electric drives intended for automotive applications. Particular focusis put on permanent-magnet synchronous machines (PMSMs) with interiormountedpermanent magnets combined with modular converter topologies.In the first part of the thesis, different converter concepts and windingarrangements suitable for an integrated drive are reviewed. Compared to theconventional solution utilizing a three-phase two-level converter, a compactintegration can be implemented by physically splitting the converter and itsassociated dc-link capacitor into a number of converter submodules. Moreover,a modular concept also enables a certain level of fault tolerance.In the second part of the thesis, fractional-slot concentrated windings(FSCWs) are analyzed. First, a review for how to determine suitable slot, pole,and phase combinations is identified considering mainly the winding factor forthe main harmonic and the associated rotor losses. Then, integrated modularconverter concepts and associated winding configurations are considered andslot, pole and phase combinations that also comply with the consideredmodular converters are proposed. Further, two possible winding arrangementssuitable for the stacked polyphase bridges (SPB) and the parallel polyphasebridges (PPB) type converter are compared with respect to torque duringpost-fault operation in the event of failure of a single converter submodule.In the third part, an iterative process adopting both finite element analysisand analytical techniques is proposed for the design of PMSMs with interiormountedpermanent magnets and FSCWs. The resulting machine designsillustrate tradeoffs in terms of fault tolerance, power factor, torque density,and potential for field-weakening operation. From a given set of specifications,an experimental prototype is also designed and built.Finally, since a FSCW generally results in a large harmonic content ofthe resulting flux-density waveform, models for predicting eddy-current lossesin the permanent magnets are analyzed and compared. Particularly, modelsadopting different formulations to the Helmholtz equation to solve for the eddycurrents are compared to a simpler model relying on an assumed eddy-currentdistribution. Boundaries in terms of magnet dimensions and angular frequencyare also identified in order to aid the machine designer whether the mostsimple loss model is applicable or not. With a prediction of the eddy-currentlosses in the permanent magnets together with a corresponding thermal model,predicted volumetric loss densities exemplified for combinations of slot andpole numbers common in automotive applications are presented along withthe associated thermal impact. / <p>QC 20170530</p>

For a mobile robot to engage in exploration of a-priori unknown environments it must be able to identify locations which will yield new information when visited. This thesis presents two novel algorithms which attempt to answer the question of choosing where a robot should go next in a partially explored workspace. To begin we describe the process of acquiring highly accurate dense 3D data from a stereo camera. This approach combines techniques from a number of existing implementations and is demonstrated to be more accurate than a range of commercial offerings. Combined with state of the art visual odometry based pose estimation we can use these point clouds to drive exploration. The first exploration algorithm we present is an attempt to represent the three dimensional world as a continuous two dimensional surface. The surface is maintained as a planar graph structure in which vertices correspond to points in space as seen by the stereo camera. Edges connect vertices which have been seen as adjacent pixels in a stereo image pair, and have a weight equal to the Euclidean distance between the end points. Discontinuities in the input stereo data manifest as areas of the graph with high average edge weight, and by moving the camera to view such areas and merging the new scan with the existing graph, we push back the boundary of the explored workspace. Motivated by scaling and precision problems with the graph-based method, we present a second exploration algorithm based on continuum methods. We show that by solving Laplace’s equation over the freespace of the partially explored environment, we can guide exploration by following streamlines in the resulting vector field. Choosing appropriate boundary conditions ensures that these streamlines run parallel to obstacles and are guaranteed to lead to a frontier – a boundary between explored and unexplored space. Results are shown which demonstrate this method fully exploring three dimensional environments and outperforming oft-used information gain based approaches. We show how analysis of the potential field solution can be used to identify volumes of the workspace which have been fully explored, thus reducing future computation.

Scalable autonomy requires a robot to be able to recognize and contend with the uncertainty in its knowledge of the world stemming from its noisy sensors and actu- ators. The regions it chooses to explore, and the paths it takes to get there, must take this uncertainty into account. In this thesis we outline probabilistic approaches to represent that world; to construct plans over it; and to determine which part of it to explore next. We present a new technique to create probabilistic cost maps from overhead im- agery, taking into account the uncertainty in terrain classification and allowing for spatial variation in terrain cost. A probabilistic cost function combines the output of a multi-class classifier and a spatial probabilistic regressor to produce a probability density function over terrain for each grid cell in the map. The resultant cost map facilitates the discovery of not only the shortest path between points on the map, but also a distribution of likely paths between the points. These cost maps are used in a path planning technique which allows the user to trade-off the risk of returning a suboptimal path for substantial increases in search speed. We precompute a probability distribution which precisely approximates the true distance between any grid cell in the map and goal cell. This distribution under- pins a number of A* search heuristics we present, which can characterize and bound the risk we are prepared to take in gaining search efficiency while sacrificing optimal path length. Empirically, we report efficiency increases in excess of 70% over standard heuristic search methods. Finally, we present a global approach to the problem of robotic exploration, uti- lizing a hybrid of a topological data structure and an underlying metric mapping process. A ‘Gap Navigation Tree’ is used to motivate global target selection and occluded regions of the environment (‘gaps’) are tracked probabilistically using the metric map. In pursuing these gaps we are provided with goals to feed to the path planning process en route to a complete exploration of the environment. The combination of these three techniques represents a framework to facilitate robust exploration in a-priori unknown environments.

This thesis presents a novel system-level synthesis framework called System-Level Architectural Synthesis Framework (SYLVA), which synthesizes DigitalSignal Processing (DSP) sub-systems modeled by synchronous data ?ow intohardware implementations in Application-Specific Integrated Circuit (ASIC),Field-Programmable Gate Array (FPGA) or Coarse-Grained ReconfigurableArchitecture (CGRA) style. SYLVA synthesizes in terms of pre-characterizedFunction Implementations (FIMPs). It explores the design space in threedimensions, number of FIMPs, type of FIMPs, and pipeline parallelism be-tween the producing and consuming FIMPs. SYLVA also introduces timingand interface model of FIMPs to enable reuse and automatic generation ofGlobal Interconnect and Control (GLIC) to glue the FIMPs together into aworking system. SYLVA has been evaluated by applying it to several realand synthetic DSP applications and the experimental results are analyzedfor the design space exploration, the GLIC synthesis, the code generation,and the CGRA floorplanning features. The conclusion from the experimentalresults is that by exploring the multi-dimensional design space in terms ofpre-characterized FIMPs, SYLVA explores a richer design space and does itmore effectively compared to the existing High-Level Synthesis (HLS) toolsto improve both engineering and computational efficiency. / <p>QC 20160125</p>

Several factors affect the perceived quality of a video streamed over a network. Technical aspects related to the codec and the video play an important role besides the delivery of the video content in a timely and error-free manner. If the streamed video frames do not arrive in time, temporal artifacts may become observable during the video playback. This has potentially an adverse effect on the user experience. The study of temporal artifacts during the video playback is the area of concern for Quality of Delivery. The licentiate work investigates the Quality of Delivery for Variable Bit Rate video sent over wireless technologies. The ability of the network to deliver data to the video’s jitter buffer before its playout deadline is studied. Jitter buffer exhaustions are of particular interest as they tell something about the Quality of Delivery. A number of experiments are conducted where a set of videos with different bit-rates are streamed to a mobile device over a wireless LAN and a W-CDMA network. The video streams are recorded and analyzed based on specific Quality of Service parameters and are related to the states of the jitter buffer. The statistical tools Support Vector Machines and the Mahalanobis distance are applied to the parameters to obtain a model that can classify the jitter buffer states. The performance evaluation indicates that the Mahalanobis distance can classify the jitter buffer state marginally better than the Support Vector Machines. However, the Support Vector Machines can produce more reliable predictions compared to the Mahalanobis distance. It is also observed that the perceived Quality of Delivery is not only affected by the behavior of the wireless networks but also by the behavior of the streaming server. Finally, the ability of the Quality of Service parameters to describe the Quality of Delivery is studied. The results indicate that metrics based on the packet arrival-rate and packet inter-arrival time are most suitable in this particular case.

This project deals with E-health web application framework, cloud platform and responsive web design which aim to adjust the presentation on mobile devices. This work presents the whole development process of the self-care management web-app framework which provides instructive supports for future other E-health field application. The report consists of the following main parts: analysis, design and implementation, and evaluation. Literature review and internet search are main methods for making an investigation on existing systems and related works. A prototype is developed by using .Net, CSS3, Java script and HTML5 technologies. The system test and evaluation is made to show the system’s usability.

A theoretical investigation of existing sensor techniques, bothcommercial sensors and scientific studies, has been performed inorder to find a cost efficient fluid sensor with the ability todetect small amounts of non-conducting fluids. From these studies,six different techniques could be distinguished. The techniques weretested and compared, both in theory and practically, against certaincriteria’s such as temperature and movement sensibility. Three of thetechniques have been proved to work and two of them were built,installed and tested on an industrial robot manufactured by ABBRobotics. The two most promising techniques distinguished were a photointerrupter and a Quartz Crystal Microbalance sensor. After tests itcould be concluded that both sensors fulfilled all preferences. However out of the two, the Quartz Crystal Microbalance sensorperformed best and could detect smaller amounts of fluid more quicklyand reliably than the photo interrupter. This work has resulted in a patent application.

Modern technologies have resulted in the production of numerous high-throughput biological datasets. However, the pace of development of capable computational methods does not cope with the pace of generation of new high-throughput datasets. Amongst the most popular biological high-throughput datasets are gene expression datasets (e.g. microarray datasets). This work targets this aspect by proposing a suite of computational methods which can analyse multiple gene expression datasets collectively. The focal method in this suite is the unification of clustering results from multiple datasets using external specifications (UNCLES). This method applies clustering to multiple heterogeneous datasets which measure the expression of the same set of genes separately and then combines the resulting partitions in accordance to one of two types of external specifications; type A identifies the subsets of genes that are consistently co-expressed in all of the given datasets while type B identifies the subsets of genes that are consistently co-expressed in a subset of datasets while being poorly co-expressed in another subset of datasets. This contributes to the types of questions which can addressed by computational methods because existing clustering, consensus clustering, and biclustering methods are inapplicable to address the aforementioned objectives. Moreover, in order to assist in setting some of the parameters required by UNCLES, the M-N scatter plots technique is proposed. These methods, and less mature versions of them, have been validated and applied to numerous real datasets from the biological contexts of budding yeast, bacteria, human red blood cells, and malaria. While collaborating with biologists, these applications have led to various biological insights. In yeast, the role of the poorly-understood gene CMR1 in the yeast cell-cycle has been further elucidated. Also, a novel subset of poorly understood yeast genes has been discovered with an expression profile consistently negatively correlated with the well-known ribosome biogenesis genes. Bacterial data analysis has identified two clusters of negatively correlated genes. Analysis of data from human red blood cells has produced some hypotheses regarding the regulation of the pathways producing such cells. On the other hand, malarial data analysis is still at a preliminary stage. Taken together, this thesis provides an original integrative suite of computational methods which scrutinise multiple gene expression datasets collectively to address previously unresolved questions, and provides the results and findings of many applications of these methods to real biological datasets from multiple contexts.

The current demands for extremely high data rate wireless services and the spectrum scarcity at the sub-6 GHz bands are forcefully motivating the use of the millimeter-wave (mmWave) frequencies. The main characteristics of mmWave communications are severe attenuation, sparse-scattering environment, huge bandwidth, vulnerability to obstacles and antenna misalignment, massive beamforming, and possible noise-limited operation. These characteristics constitute a major difference with respect to legacy communication technologies, primarily designed for the sub-6 GHz bands, and are posing major theoretical design challenges that have not been sufficiently addressed so far. Motivated by these challenges, this doctoral thesis considers mmWave communications and investigates medium access control (MAC) layer design principles and performance analysis. Specifically, we focus on fundamental performance metrics, including coverage, fairness, robustness, throughput, and delay, which we address by three main research threads of increasing complexity. The first thread of the thesis analyzes the interference behavior in mmWave networks.We first propose a new index for assessing the accuracy of any interference model under any network scenario, which helps us develop a simple interference model of adequate accuracy. We then derive closed-form expressions for the throughput of mmWave ad hoc networks. The new analysis reveals that mmWave networks may exhibit a non-negligible transitional behavior from a noise-limited to an interference-limited behavior, depending on the system parameters such as density of transmitters, transmission power, and operating beamwidth. The second thread of this thesis builds on the previous one and addresses resource allocation in mmWave networks. For the short-term resource allocation, we establish a mathematical framework to investigate the impact of beam training (alignment) overhead on the network throughput. For the long-term resource allocation, we formulate a series of optimization problems that address relaying capability, frequent handovers, small multiuser interference, and load balancing. The third thread of this thesis extends the second one toward spectrum sharing in mmWave networks and characterizes the gains of beamforming and coordination in spectrum sharing via several optimization problems. We analyze these problems in the asymptotic regimes when the number of antennas becomes large and conclude that spectrum sharing with light on-demand coordination is feasible, especially at higher mmWave frequencies (for example, 73 GHz). The original analysis proposed in this thesis gives novel insights into many MAC layer issues such as resource allocation, interference management, random access, mobility management, and synchronization in future mmWave networks. The thesis also highlights that the design of mmWave networks poses open problems at the intersection of optimization and learning theories. Given the recent interest in the standardization of mmWave cellular networks and the highly sub-optimal nature of the existing standards for mmWave short-range networks, the results of this thesis may have the potential to substantially steer future standardizations. / <p>QC 20170523</p>

The aim of this thesis has been to investigate if it’s possible to build a system that can be used to automate the process of measuring environmental parameters, and to examine the performance of the system. This thesis describes the development of a mobile activity logger and presents the achieved performance of the system. It consists of three subsystems: The mobile unit, the base station and the NAS (Network Attached Storage). The mobile unit measures environmental parameters such as temperature and acceleration, and connects them to a measured GPS position and time. This data is sent to the base station using LoRa which transmits the data to the NAS using GSM where it is stored on an FTP-server. A client application has been developed for accessing the data and visualizing it on the screen. Amaximum range of 1.84 km during line of sight has been achieved between the mobile unit and the base station, with a theoretical battery life span of roughly 50 days. The system has a measured accuracy of 1-2 m in open areas.