The scaling of CMOS technologies has increased the performance of general purpose processors and DSPs. However, analog circuits designed in the same process have not been able to utilize the scaling to the same extent, suffering from reduced voltage headroom and reduced analog gain. Integration of the system components on the same die means that the analog-to-digital converters (ADCs) needs to be implemented in the newest technologies in order to utilize the digital capabilities at these process nodes. To design efficient ADCs in nanoscale CMOS technologies, there is a need to both understand the physical limitations as well as to develop new architectures and circuits that take full advantage of the potential that process has to offer. As the technology scales to smaller feature sizes, the possible sample-rate of ADCs can be increased. This thesis explores the design of high-speed ADCs and investigates architectural and circuit concepts that address the problems associated with lower supply voltage and analog gain. The power dissipation of Nyquist rate ADCs is investigated and lower bounds, as set by both thermal noise and minimum feature sizes are formulated. Utilizing the increasing digital performance, low-accuracy analog components can be used, assisted by digital correction or calibration, which leads to a reduction in power dissipation. Through the aid of new techniques and concepts, the power dissipation of low-to-medium resolution ADCs benefit from going to more modern CMOS processes, which is supported by both theory and published results. New architectures and circuits of high-speed ADCs are explored in test-chips based on the flash and pipeline ADC architectures. Two flash ADCs were developed, both based on a new comparator that suppresses common-mode kick-back by a factor of 6x compared to conventional topologies. The first flash ADC is based on redundancy in the comparator array, allowing the use of low-accuracy, small-sized and low-power comparators to achieve an overall low-power solution. The flash ADC achieves 4.0 effective bits at 2.5 GS/s while dissipating 30 mW of power. The second Flash ADC further explores the use of low-accuracy components, relying on the process variations to generate the reference levels based on the mismatch induced comparator offsets. The reference-free ADC achieves a resolution of 3.7 bits at 1.5 GS/s and dissipates 23 mW of power, showing that process variations does not necessarily has to be seen as detrimental to circuit performance, but rather can be seen as a source of diversity. In two implemented pipeline ADCs, the potential of very high sample-rates and energy efficiency is explored. The first pipeline ADC utilizes a new high-speed currentmode amplifier in open-loop configuration in order to reach a sample-rate of 2.4 GS/s in a single-channel pipeline ADC, a speed which is significantly faster than previous stateof-the-art The ADC achieved above 4.7 bits throughout the Nyquist range while dissipating 318 mW. The second pipeline ADC relies on an inverter-based amplifier, used in switched-capacitor feedback in order to keep the amplifier biased at a poweroptimal point. The amplifier uses asymmetrically biased transistors in order to better match the p- and n-type transistors, which increases linearity and allows for fully symmetrical layout. Operating at 1.0 GS/s, the effective resolution of the ADC was 7.5 bits and the power dissipation was 73 mW. This shows that it is possible to achieve low power dissipation while maintaining both high sample-rates and medium resolution.

The use of new information technologies has drastically changed the way that we lead our lives. Communication technologies in particular have had a great impact on our day-to-day behavior. For example, it is now common to hear the voice and see the face of our loved-ones on another continents, or work with colleagues across the globe on a daily basis. With this change in behavior and the fast adoption of emerging technologies, new challenges in the telecommunications area are arising. This thesis is concerned with two such challenges: real-time video communication and video distribution. The latency constraint in real-time video communication is in essence incompatible with the uncertainty of best-effort networks, such as the Internet. The recent arrival of smart-phones has added another requirement to the application, in terms of the limited computational and battery power. The research community has invested a large amount of effort in developing techniques that allow a mobile sender to outsource video encoding complexity to an unconstrained receiver by means of a feedback channel. We question that approach with respect to real-time applications, arguing that long round-trip-times may render any feedback unusable at best, and costly in practice. We investigate the effect of channel round-trip-times on the popular distributed video coding setup, as well as on the traditional hybrid video coding architecture. Using a simple analytical framework, we propose the use of systems that adapt to the video content and the network in real- time. Our results show that substantial improvements in video quality can be achieved when the feedback channel is used correctly. The use of mobile devices has also a significant impact on the application of video distribution. In general, the multitude of devices that can be used to download and view video places new requirements on video distribution systems. The system must not only be able to scale to a large number of receivers in a bandwidth efficient manner, it must also support a wide range of network capacities and display capabilities. We address this problem by optimizing the set of rates that is used to provide video to receivers with heterogeneous requirements. Our approach is based on a favorable interpretation of the underlying mathematical problem, allowing the use of well-known quantization theoretic concepts. The resulting solution provides the possibility to design video distribution systems that adapt to changes in receiver characteristics online, with minimal delay. / QC 20110411

This thesis concerns structural optimization of product families and robustness. The overall objective is to find a method for performing structural optimization of product families subjected to multiple crash load cases and to ensure a robust behavior. A product family is a family of products where every product variant, or family member, shares at least one component with at least one other product in the family. Structural optimization of such a family is complex and for expensive function evaluations, e.g. crash simulations, the computing time to solve the problem with traditional methods gets unrealistically long. Therefore, a new optimization algorithm for product families is presented, called the critical constraint method (CCM), that reduces the number of required evaluations by only considering the active constraints in the optimal solution. Traditionally optimized structures have a tendency of being sensitive to small variations in the design or loading conditions. As these kind of variations are inevitable, it is important to account for this sensitivity in the design process to ensure the robustness of the optimized design. The thesis is divided in two parts. The first part serves as a theoretical background to the second part, the two appended articles. This first part includes introductions to the concepts of product families, optimization, meta modeling and robust design. The first appended paper presents a new optimization algorithm for product families subjected to multiple crash loads. The method is compared to traditional methods and tested on two smaller product family examples. The second paper is an application of an existing sensitivity analysis method on a large industrial application example. A sensitivity analysis is performed on a Scania truck cab subjected to an impact load in order to identify the most  influencing variables on the crash responses.

Due to man made events and natural causes many regions are currently undergoing rapid and wide ranging changes in land cover globally including developing and developed countries. India is one of them where land use and land cover change are taking place at a rapid pace. Forests are the most valuable natural resources available to the mankind on planet earth. On the one hand, they are the essential source of livelihood for the poor and marginalized sections of the society; on the other hand they provide furniture and other items of desire for the rich. Forest land cover change is an important input for modeling ecological and environmental processes at various scales. Rapid delineation in naturally forested regions is one of the major environmental issues facing the world today. It has been estimated that vegetation change threatens about one sixth of the world's population and one quarter of global terrestrial land. Vegetation cover plays a key role in terrestrial biophysical process and is related to a number of ways to the dynamics of global climate. Monitoring seasonal changes in vegetation activity and crop phenology over wide areas is essential for many applications, such as estimation of net primary production, deciding time boundary conditions for crop yield modeling and supporting decisions about water supply. Vegetations are the major part of land cover and their changes have an important influence on the energy and mass biochemical cycles and are also a key indicator of regional ecological environment change. Urbanization, demand of land for agriculture and demand of timbers for industrial purposes are the main reasons of manmade natural forest destruction. Though we are planting trees through reforestation and afforestation programs but these new forests never can be the representative of natural forest. In order to understand and manage environment at large variety of temporal and spatial scales, up-to-date and reliable information is required all the time. Remote Sensing is a valuable data source which can provide us land-use/land-cover change information on a continuous basis with very high accuracy. Remotely sensed data like aerial photographs and satellite images are the only option that allows detecting land cover changes on a large scale. Satellite images have the potential of offering the most accurate and latest information compared to statistical, topographic or land use maps. In this study an attempt has been made in analyzing vegetation change detection that took place between 2000 and 2005 using Terra MODIS 32 day 500m time series data on a monthly basis. With the launch of National Aeronautics and Space Administration (NASA) onboard aqua and terra platform, a new generation of satellite sensor data is now available. Normalized Difference Vegetation Index method has been employed for accurate classification of images and has proved to be successful.

This thesis concerns command and control (C2) work at the tactical level in emergency and crisis response operations. The presented research addresses two main research questions. The first question is whether it is feasible to simulate and study C2 work in the initial stages of response operations by means of role-playing simulations. If so, the second question is how to develop and execute role-playing simulations in order to explore this type of C2 work in a methodologically sound way. The presented research is based on simulations as methodological means for qualitative research. The utilized simulation approach is scenario-based real-time role-playing simulations grounded in models of C2 work and response operations. Three simulations have been conducted based on this methodology and are reported in this thesis. Simulation I focused on the work practice of cooperating commanders whose activities may be enhanced by the use of artifacts. Simulation II concerned the issues of operationalizing advanced technological artifacts in rapid response expert teams. Simulation III gave attention to the role improvisation in C2 teams designated for international operations. The results from the simulations and from the work conducted and presented in this thesis contribute with knowledge and experience from using role-playing simulations to study C2 work. This includes the methodological aspects of designing and conducting role-playing simulations such as scenarios, realism, evaluation and simulation format and control. It also includes the identification of the main application and problem areas for which the methodology is suitable, that is explorative qualitative inquiries and evaluation studies. The thesis provides new insights in C2 work with respect to adaptive behavior and improvisation. The thesis also identifies areas that need to be considered in order to further develop the role-playing simulation approach and its applicability.

The energy demand of today, with increasing population and the price of fossil fuels in one hand and consequent environmental issues such as climate change and global warming on the other hand, has resulted in global consideration concerning increasing energy efficiency in distribution network. Integrated product/service engineering (IPSE) has been frequently applied to propose integrated product/service offering at different physical product manufacturing companies. However, it has not been utilized at utility providers. Therefore, this project applies IPSE, at a Swedish utility provider to introduce new ideas of business models with the aims of increasing energy efficiency in the distribution network with means of new technologies and energy policy instruments. Literature survey on IPSE methods to choose the most appropriate method was followed by literature review on smart grid and new technologies as means for utility provider to increase energy efficiency in distribution network. Different IPSE methods has been discussed and investigated recently. For this thesis, however, PSS Layer method was applied to answer the research questions such as customer needs, new technologies, involved actors, the flow of information and service between actors, life cycle activities, associated services, contracts and finances. Then, interviews with experts at Göteborg Energi AB were implemented to investigate customer demands, available new technologies, economic and technical opportunities and barriers. Five different integrated product/service proposals by providing the nine dimension of PSS Layer method were designed. In each model, new actors and technologies were introduced to increase value for both customer and utility provider. As discussion, first, it was shown that the findings in designing new business models at GBE could be generalized to the most of Swedish utility providers. Second, the five proposals with their impacts on GBE were presented and the main aspects of each integrated product/service proposals were discussed. Then, the keys to tackle the problem by designers were described. Finally, the feasibility of the results by PSS layer method was assessed by comparing the method with theory. Organizing workshops with the attendance of involved actors was recommended to add more details to the proposed business models. For further research, cost-benefit analysis and life cycle assessment were important to analyze the feasibility of proposals.

To find a shape in an image, a technique called snakes or active contours can be used. An active contour is a curve that moves towards the sought-for shape in a way controlled by internal forces - such as rigidity and elasticity - and an image force. The image force should attract the contour to certain features, such as edges, in the image. This is done by creating an attractor image, which defines how strongly each point in the image should attract the contour. In this thesis the extension to contours (surfaces) in three dimensional images is studied. Methods of representation of the contour and computation of the internal forces are treated. Also, a new way of creating the attractor image, using the orientation tensor to detect planar structure in 3D images, is studied. The new method is not generally superior to those already existing, but still has its uses in specific applications. During the project, it turned out that the main problem of active contours in 3D images was instability due to strong internal forces overriding the influence of the attractor image. The problem was solved satisfactory by projecting the elasticity force on the contour’s tangent plane, which was approximated efficiently using sphere-fitting.

This thesis concerns the robustness of structures considering various uncertainties. The overall objective is to evaluate and develop simulation based design methods in order to find solutions that are optimal both in the sense of handling typical load cases and minimising the variability of the response, i.e. robust optimal designs. Conventionally optimised structures may show a tendency of being sensitive to small perturbations in the design or loading conditions. These variations are of course inevitable. To create robust designs, it is necessary to account for all conceivable variations (or at least the influencing ones) in the design process. The thesis is divided into two parts. The first part serves as a theoretical background for this work. It includes introductions to the concept of robust design, basic statistics, optimisation theory and metamodelling. The second part consists of five appended papers on the topic. The first and third papers focuse on the evaluation of robustness, given some dispersions in the input data. Established existing methods are applied, and for paper three, comparisons with experimentally evaluated dispersions on a larger system are made. The second and fourth paper introduce two new approaches to perform robust optimisation, i.e. optimisations where the mean performance and the robustness in the objectives are simultaneously optimised. These methods are demonstrated both on an analytical example and on a Finite Element model design example. The fifth paper studies the variations in mechanical properties between several different batches of the same steel grade. A material model is fitted to each batch of material, whereby dispersions seen in test specimens are transferred to material model parameter variations. The correlations between both test and material model parameters are studied.

This thesis concerns structural optimization and robustness evaluations, and new methods are presented that considerably reduce the computational cost of these evaluations. Optimization is an effective tool in the design process and the interest from industry of its usage is quickly increasing. However, the usage would probably have grown faster if the required number of computationally costly finite element analyses could be reduced. Especially in the case of product family optimization, the problem size can easily get too large to be solved within a reasonable time. This is sometimes also true for robustness evaluations. To enable the usage of optimization and robustness evaluations also for large scale industrial problems, two new methods are here presented, which require a considerably smaller number of finite element analyses. The first method concerns structural optimization of product families subjected to multiple crash load cases. Here, the number of required finite element analyses are considerably reduced by only considering the critical constraint in each iteration step. The second method is an approach to approximate the variable sensibility based on the distribution of internal energy in a structure. The method can be used to evaluate the relative robustness of different design proposals or for structural optimization. Since the method is independent of the number of parameters and design variables the computational cost of such evaluations is drastically reduced for computationally large problems.

Energy conservation, energy efficiency measures, and energy carrier conversion within the industry are extremely important issues in order to deal with energy resource depletion and the threats from global warming. In Swedish industry there is potential for reductions of carbon dioxide emissions and resource use through utilization of excess heat and conversion of compression cooling to other cooling technologies using less electricity. Co-operation between industries and utilities can be obtained concerning both heating and cooling, but the choice of technologies and the profitability of co-operation are influenced by a number of factors such as the type of industry, policy instruments, the size and design of the district heating and cooling systems, and energy market prices. In this thesis, energy co-operation has been studied on two levels: a techno-economic level and a socio-technical level. On the techno-economic level the possibilities for co-operation in two industrial cases have been studied, Scandinavian kraft pulp mills and manufacturing industry in the municipality of Södertälje: The pulp and paper industry is one of the major energy users in Sweden, and 2.2 TWh of heat was delivered from pulp mills in 2007, mainly to district heating systems. At kraft pulp mills the excess heat can be used either internally or externally. Internally, excess heat can be used in the production process and/or to replace steam and thereby increase the production of electricity, depending on the quality of the excess heat. Externally, excess heat can be used as district heating. The trade-off between internal and external use of excess heat depends on numerous factors. The economic profitability of possible investments is influenced not only by investment costs and fuel costs; several policy instruments, including the electricity certificate system and the carbon dioxide trading scheme, also influence the choice of technology as well as the willingness to co-operate. In the municipality of Södertälje two large industries use large amounts of electricity, district heating and cooling. The cooling demand in Södertälje is currently covered by free cooling from lake water and compression chillers; but in order to reduce the use of electricity, conversion to heat-driven cooling or increased lake water cooling can be considered. The large CHP plant in Södertälje is today not used to its full potential, but investment in heat-driven cooling and/or a cold condenser unit integrated with the CHP plant could increase the plant’s operation hours. New investments in district cooling could increase the level of co-operation between the two industries and the local utility, but depending on policy instruments, energy market prices and the possible exchange of heat between Södertälje and Stockholm, the profitability of such investments will vary. On the socio-technical level, co-operation between utilities and industries has been studied through interviews and surveys to further analyze factors concerning co-operation beyond the techno-economic level. Results from the studies show that communication between the parties, the willingness to take risks, and trust between the co-operating parties are key factors that are as vitally important for a co-operation to take place as technical and economic factors. / Energibesparingar, energieffektivitet och konvertering av energibärare i industrin är oerhört viktiga frågor att hantera med tanke på det hot vi står inför med uttömning av resurser och global uppvärmning. I svensk industri finns det potential för reducering av koldioxidemissioner och resursanvändning genom utnyttjande av industriell överskottsvärme och konvertering av kompressionskyla till andra kyltekniker som använder mindre el. Samarbete mellan industrier och energibolag kan uppnås både för värme och kyla, men valet av teknik och lönsamheten i samarbete påverkas av ett flertal faktorer som typen av industri, styrmedel, storleken och produktionsmixen i fjärrvärme- och fjärrkylanäten samt energimarknadspriser. I den här avhandlingen har energisamarbeten studerats på två olika nivåer: en tekno-ekonomisk nivå och en socio-teknisk nivå. På den tekno-ekonomiska nivån har möjligheter till samarbete undersökts i två industriella fall, skandinaviska kemiska massabruk och tillverkningsindustri i Södertälje. Massa- och pappersindustrin är en av de största energianvändarna i Sverige och 2,2 TWh värme levererades 2007 från olika bruk till fjärrvärmenäten. I ett kemiskt massabruk kan överskottsvärme användas antingen internt eller externt. Intern kan värmen användas i produktionsprocesserna och/eller för att ersätta ånga och därmed öka elproduktionen, beroende på överskottsvärmens kvalitet. Externt kan värmen användas till fjärrvärme. Avvägningen mellan intern och extern användning beror på flera faktorer. Den ekonomiska lönsamheten för möjliga investeringar påverkas inte bara av investeringskostnader och bränslekostnader, ett flertal styrmedel, inklusive elcertifikatsystemet och handeln med utsläppsrätter, påverkar valet av teknik och viljan att samarbeta. I Södertälje finns två stora industrier som använder stora mängder el, fjärrvärme och kyla. Kylbehovet i Södertälje täcks för närvarande av frikyla från sjövatten och kompressionskylmaskiner, men för att minska elanvändningen kan konvertering till värmedriven kyla eller en ökning av mängden frikyla vara aktuellt. Den stora kraftvärmeanläggning som finns i Södertälje utnyttjas idag inte till sin fulla potential, men investering in värmedriven kyla kan öka drifttiden i anläggningen. Nya investeringar i fjärrkyla kan ge ett ökat samarbete mellan industrierna och energibolaget i Södertälje, men beroende på styrmedel, energimarknadspriser och det fjärrvärmeutbytet mellan Södertälje och Stockholm, kommer lönsamheten i dessa investeringar att variera. På den socio-tekniska nivån har samarbeten mellan industrier och energibolag undersökts genom intervjuer och enkäter för att ytterligare analysera de faktorer som påverkar samarbeten utöver de tekno-ekonomiska möjligheterna. Resultaten från studierna visar att kommunikation mellan parterna, vilja att ta risker och förtroende mellan parterna är faktorer som är lika viktiga för att uppnå ett samarbete som tekniska möjligheter och ekonomisk lönsamhet.