In order to be competitive with emerging mobile systems and to satisfy the ever growing request for higher data rates, the 3G consortium, 3rd Generation Partnership Project (3GPP), is currently developing concepts for a long term evolution (LTE) of the 3G standard. The LTE-concept at Ericsson is based on Orthogonal Frequency Division Multiplexing (OFDM) as downlink air interface. OFDM enables the use of frequency domain link adaptation to select the most appropriate transmission parameters according to current channel conditions, in order to maximize the throughput and maintain the delay at a desired level. The purpose of this thesis work is to study, implement and evaluate different link adaptation algorithms. The main focus is on modulation adaptation, where the differences in performance between time domain and frequency domain adaptation are investigated. The simulations made in this thesis are made with a simulator developed at Ericsson. Simulations show in general that the cell throughput is enhanced by an average of 3% when using frequency domain modulation adaptation. When using the implemented frequency domain power allocation algorithm, a gain of 23-36% in average is seen in the users 5th percentile throughput. It should be noted that the simulations use a realistic web traffic model, which makes the channel quality estimation (CQE) difficult. The CQE has great impact on the performance of frequency domain adaptation. Throughput improvements are expected when using an improved CQE or interference avoidance schemes. The gains with frequency domain adaptation shown in this thesis work may be too small to motivate the extra signalling overhead required. The complexity of the implemented frequency domain power allocation algorithm is also very high compared to the performance enhancement seen.

Abstract PURPOSE: The aim of this study was to describe and compare possible differences regarding selected prognostic factors for disability between patients with non-specific chronic pain who were about to start a multidisciplinary treatment program (MMR), either within primary care (MMR1) or hospital care (MMR2). METHODS: The study had a descriptive and comparative cross sectional design. Eighty-nine patients were recruited consecutively when they were about to start their team treatment (50 in MMR1,39 in MMR2). The measurements were; Evaluation of self-reported self-efficacy for eight daily activities (STIVA-8), The Pain Belief Screening Instrument (PBSI) and Hospital Anxiety and Depression Scale (HADS). RESULTS: The study found some significant differences between the answers from patients in MMR1 and those from patients in MMR2. For instance, patients in MMR2 estimated lower self-efficacy according to STIVA-8 than patients in MMR1. Also, there were fewer low risk patients and more high risk patients in MMR2 than in MMR1 regarding pain intensity according to PBSI. In addition to this, there were fewer patients without depression and more with moderate depression in MMR2 than in MMR1 according to HADS. No significant differences could be shown for either anxiety according to HADS or for low- and high risk regarding activity disability according to PBSI. No significant differences could be found when pain intensity was measured with mean values on a scale from 0-10. CONCLUSIONS: Patients in MMR2 experienced more negative consequences from their pain disease than patients in MMR1. Systematic use of standardized self-reported instruments for selected prognostic factors could be helpful when screening for complexity and make it easier to decide whether the rehabilitation should be within MMR1 or MMR2 for patients in need of MMR. / Sammanfattning SYFTE: Syftet med denna studie var att beskriva och jämföra om patienter med långvarig smärtproblematik inom primärvård (MMR1) respektive specialiserad sjukhusvård (MMR2), som stod i begrepp att påbörja multimodal smärtrehabilitering (MMR), skattade olika avseende ett antal prognostiska faktorer för funktionsförmåga. METOD: Studien hade en deskriptiv och komparativ tvärsnittsdesign. Åttionio konsekutivt tillfrågade patienter deltog (50 i MMR1, 39 i MMR2). Datainsamlingen gjordes vid start av MMR med tre självskattningsformulär; Skattning av tilltro till sin förmåga att utföra åtta specificerade vardagsaktiviteter (STIVA-8), The Pain Belief Screening Instrument (PBSI) och Hospital Anxiety and Depression Scale (HADS). RESULTAT: Studien visade statistiskt signifikanta skillnader avseende att patienterna i MMR2 skattade lägre tilltro till sin förmåga enligt STIVA-8, det var färre andel lågriskpatienter och större andel högriskpatienter i MMR2 avseende smärtintensitet enligt PBSI samt färre andel patienter utan depression i MMR2 och fler med måttliga depressionsbesvär i MMR2 enligt HADS. Inga signifikanta skillnader kunde visas avseende låg- och högrisk för aktivitetsbegränsning enligt PBSI och inte heller för ångest enligt HADS. När smärtintensitet beräknades med medelvärde på skalan 0-10 fanns inga signifikanta skillnader. KONKLUSION: Patienterna i MMR2 skattade mer negativa konsekvenser av sin smärtsjukdom än i MMR1. Systematisk användning av skattningsformulär som ringar in olika prognostiska faktorer bör kunna underlätta selektion och sortering vid val av vårdnivå för patienter i behov av MMR.

Multi-processor computers are becoming increasingly popular and are important for improving application performance. Providing high-performance memory-management is important for multi-threaded programs. This thesis looks at memory allocation of dynamic-allocation memory in concurrent C and C++ programs. The challenges facing the design of any memory allocator include minimizing fragmentation, and promoting good locality. A multi-threaded memory-allocator is also concerned with minimizing contention, providing mutual exclusion, avoiding false-sharing, and preventing heap-blowup (a form of fragmentation). Several potential features are identified in existing multi-threaded memory-allocators. These features include per-thread heaps with a global heap, object ownership, object containers, thread-local free-list buffers, remote free-lists, allocation buffers, and lock-free operations. When used in different combinations, these features can solve most of the challenges facing a multi-threaded memory-allocator. Through the use of a test suite composed of both single and multi-threaded benchmark programs, several existing memory allocators and a set of new allocators are compared. It is determined that different features address different multi-threaded issues in the memory allocator with respect to performance, scaling, and fragmentation. Finally, recommendations are made for the design of a general-purpose memory-allocator.

Modern processors have multiple pipelined functional units and can issue more than one instruction per clock cycle. This puts great pressure on the instruction scheduling phase in a compiler to expose maximum instruction level parallelism. Basic blocks and superblocks are commonly used regions of code in a program for instruction scheduling. Instruction scheduling coupled with register allocation is also a well studied problem to produce better machine code. Scheduling basic blocks and superblocks optimally with or with out register allocation is NP-complete, and is done sub-optimally in production compilers using heuristic approaches. In this thesis, I present a constraint programming approach to the superblock and basic block instruction scheduling problems for both idealized and realistic architectures. Basic block scheduling with register allocation with no spilling allowed is also considered. My models for both basic block and superblock scheduling are optimal and fast enough to be incorporated into production compilers. I experimentally evaluated my optimal schedulers on the SPEC 2000 integer and floating point benchmarks. On this benchmark suite, the optimal schedulers were very robust and scaled to the largest basic blocks and superblocks. Depending on the architectural model, between 99.991\% to 99.999\% of all basic blocks and superblocks were solved to optimality. The schedulers were able to routinely solve the largest blocks, including blocks with up to 2600 instructions. My results compare favorably to the best previous optimal approaches, which are based on integer programming and enumeration. My approach for basic block scheduling without allowing spilling was good enough to solve 97.496\% of all basic blocks in the SPEC 2000 benchmark. The approach was able to solve basic blocks as large as 50 instructions for both idealized and realistic architectures within reasonable time limits. Again, my results compare favorably to recent work on optimal integrated code generation, which is based on integer programming.

This research is concerned with bioenergy systems planning and optimization modelling in the context of locating biomass power plants and allocating available biomass feedstock to the active plants. Bioenergy, a promising renewable energy resource, has potentially significant benefits to climate change, global warming, and alternative energy supplies. As modern bioenergy applications in power production have the ability to generate cleaner electricity and reduce Green House Gas (GHG) emissions compared with traditional fossil fuels, many researchers have proposed various approaches to obtain competitive power generation prices from biomass in different ways. However, the highly dispersed geographical distribution of biomass is a big challenge for regional bioenergy systems planning. This thesis introduces an integrated methodology combining Geographic Information Systems (GIS) and discrete location theories for biomass availability assessment, biomass power plant candidate selection, and location-allocation of power plants and biomass supplies. Firstly, a well known discrete location model – the p-Median Problem (PMP) model is employed to minimize the weighted transportation costs of delivering all collectable biomass to active power plants. Then, a p-Uncapacitated Facility Location Problem (p-UFLP) model for minimizing the Levelized Unit Costs of Energy (LUCE) is proposed and genetic algorithms (GAs) for solving these optimization problems are investigated. To find the most suitable sites for constructing biomass power plants, the Analytic Hierarchy Process (AHP) and GIS based suitability analysis are employed subject to economical, societal, public health, and environmental constraints and factors. These methods and models are aimed at evaluating available biomass, optimally locating biomass power plants and distributing all agricultural biomass to the active power plants. The significance of this dissertation is that a fully comprehensive approach mixed with the applications of GIS, spatial analysis techniques, an AHP method and discrete location theories has been developed to address regional bioenergy systems planning, involving agricultural biomass potential estimation, power plants siting, and facility locations and supplies allocation scenarios. With the availability of the spatial and statistical data, these models are capable of evaluating and identifying electric power generation from renewable bioenergy on the regional scale optimally. It thus provides the essential information to decision makers in bioenergy planning and renewable bioenergy management. An application sited in the Region of Waterloo, Ontario Canada is presented to demonstrate the analysis and modelling process.

Cooperative communication is a new class of wireless communication techniques in which wireless nodes help each other relay information and realize spatial diversity advantages in a distributed manner. This new transmission technique promises significant performance gains in terms of link reliability, spectral efficiency, system capacity, and transmission range. Analysis and design of cooperative communication wireless systems have been extensively studied over the last few years. The introduction and integration of cooperative communication in next generation wireless standards will lead to the design of an efficient and reliable fully-distributed wireless network. However, there are various technical challenges and open issues to be resolved before this promising concept becomes an integral part of the modern wireless communication devices. A common assumption in the literature on cooperative communications is the equal distribution of power among the cooperating nodes. Optimum power allocation is a key technique to realize the full potentials of relay-assisted transmission promised by the recent information-theoretic results. In this dissertation, we present a comprehensive framework for power allocation problem. We investigate the error rate performance of cooperative communication systems and further devise open-loop optimum power allocation schemes to optimize the performance. By exploiting the information about the location of cooperating nodes, we are able to demonstrate significant improvements in the system performance. In the first part of this dissertation, we consider single-relay systems with amplify-and-forward relaying. We derive upper bounds for bit error rate performance assuming various cooperation protocols and minimize them under total power constraint. In the second part, we consider a multi-relay network with decode-and-forward relaying. We propose a simple relay selection scheme for this multi-relay system to improve the throughput of the system, further optimize its performance through power allocation. Finally, we consider a multi-source multi-relay broadband cooperative network. We derive and optimize approximate symbol error rate of this OFDMA (orthogonal frequency division multiple access) system.

The introduction of deregulation and subsequent open access policy in electricity sector has brought competition in energy market. Allocation of transmission loss has become a contentious issue among the electricity producers and consumers. A closed form solution for transmission loss allocation does not exist due to the fact that transmission loss is a highly non-linear function of system states and it is a non-separable quantity. In absence of a closed form solution different utilities use different methods for transmission loss allocation. Most of these techniques involve complex mathematical operations and time consuming computations. A new transmission loss allocation tool based on artificial neural network has been developed and presented in this thesis. The proposed artificial neural network computes loss allocation much faster than other methods. A relatively short execution time of the proposed method makes it a suitable candidate for being a part of a real time decision making process. Most independent system variables can be used as inputs to this neural network which in turn makes the loss allocation procedure responsive to practical situations. Moreover, transmission line status (available or failed) was included in neural network inputs to make the proposed network capable of allocating loss even during the failure of a transmission line. The proposed neural networks were utilized to allocate losses in two types of energy transactions: bilateral contracts and power pool operation. Two loss allocation methods were utilized to develop training and testing patterns; the Incremental Load Flow Approach was utilized for loss allocation in the context of bilateral transaction and the Z-bus allocation was utilized in the context of pool operation. The IEEE 24-bus reliability network was utilized to conduct studies and illustrate numerical examples for bilateral transactions and the IEEE 14-bus network was utilized for pool operation. Techniques were developed to expedite the training of the neural networks and to improve the accuracy of results.

The <i>Hukou</i> system has been a basic institution in Chinese society for several decades. My thesis explores whether, after nearly 30 years of reform and opening up in China, this system still plays a role in individuals lives and if so, what is this role? This study uses qualitative data from policy documents and quantitative data from the China General Social Survey 2003 to examine differences in income and access to welfare services among rural and urban <i>Hukou</i> holders and in <i>Hukou</i> status conversion both before and since the reform era and point out that the <i>Hukou</i> system contributes to inequality in individuals life chances in two dimensions: resource allocation and <i>Hukou</i> status conversion. The findings show that urban residents are advantaged in resource allocation before and in the reform era; the control mechanism of quota and policy for <i>Hukou</i> status conversion from rural to urban in the pre-reform era was replaced by the locally defined but nationally enforced entry conditions or requirements in reform era. The talented people, the CCP members, the people who have permanent jobs in urban areas, and the people whose family members hold urban Hukou are more likely now to overcome the <i>Hukou</i>-based control. The <i>Hukou</i>-based migration control continues on a localized basis and excludes the majority of rural residents from access to the rights enjoyed by urban residents. The findings of this thesis indicate that the consequences of the Hukou system continue today and additional reform still needs to be introduced.

Abstract Title: Taxation - A critical discussion of the present tax system in Kosovo Institution: School of Business and Economics University: Linnaeus University Aim: The aim of this thesis is to characterize and critically discuss thepresent tax system in Kosovo, keeping in mind the fundamentalproblems presented in weak tax bases, informal economies, ethniccontroversy and limited inflow of FDI in the country. Further,contributing with alternative designs of the tax system and argueadvantages and disadvantages of these designs Method: The thesis will attempt to relate the descriptions and analysis of the taxsystem in existing and essentially established theory. Further a casestudy is performed using of quantitative, secondary data available ontaxes in transition, with the purpose to enhance the understanding oftax systems in transition, and apply the knowledge on the case ofKosovo. Conclusion: The corporate taxation should not be much lowered in the present,however, in the future a lowering of the corporate taxation could helpbring up the employment level. The government should furtherconsider inferring contribution and payroll taxes to broaden the taxbase. The indirect taxation rate should not be increased in the longterm, but the country has the opportunity to increase the VAT rate to17 percent in shorter terms. A progressive, territorial tax system, with adeduction of taxation of roughly 80 Euros per month in income taxshould be kept.

Life-history theory proposes that different activities, such as growth, maintenance and reproduction compete for limited resources and therefore, life-history traits are bound together by physiological trade-offs. In dioecious species, females are assumed to invest a higher amount of resources in reproduction in comparison with males and this higher investment in reproduction is then assumed to have numerous consequences for the expression of other life-history traits. Some recent papers have, however, suggested that although common, this investment pattern may not be the case in all dioecious plant species. One notable exception is Silene latifolia. Therefore, I examined whether the male sex could be investing more in reproduction than females in a closely related Silene species, Silene dioica. This study was carried out on three islands in the Skeppsvik Archipelago, Umeå, where I examined possible differences between the sexes in different life history traits. On each island, 20 patches were laid out in two different successional zones. In each patch, flowering date was recorded and stem diameter, length and width of cauline leaves, flower diameter, and number of open flowers on male and female plants was measured. At the end of the study, flowering stems were collected and thereafter dried so they could be weighed to estimate biomass allocated to male and female vegetative and reproductive structures. The hypothesis that males of S. dioica should have a higher reproductive cost seemed to be confirmed since males started flowering earlier, produced more and larger flowers, produced smaller and fewer leaves and thinner stems. The males also allocated a greater proportion of their total biomass to reproductive parts and as a consequence, had a higher sink to source ratio. This study has shown that there are exceptions to the "rule" of females having a higher cost of reproduction and when doing research on dioecious species, it is important not to assume that only one and the same sex has the higher investment in reproduction in all species. This higher cost may have consequences for survival and reproductive fitness and can select for differences in other ecological traits, such as phenology, growth, chemical composition and morphology, which could in turn affect the competitive ability and the susceptibility to herbivores and pathogens.