Empirical studies show that similar patterns emerge from a large number of different biological systems. For example, the group size distributions of several fish species and house sparrows all follow power law distributions with an exponential truncation. Networks built by ant colonies, slime mold and those are designed by engineers resemble each other in terms of structure and transportation efficiency. Based on the investigation of experimental data, we propose a variety of simple stochastic models to unravel the underlying mechanisms which lead to the collective phenomena in different systems. All the mechanisms employed in these models are rooted in the concept of selective reinforcement. In some systems the reinforcement can build optimal solutions for biological problem solving. This thesis consists of five papers. In the first three papers, I collaborate with biologists to look into group formation in house sparrows  and the movement decisions of damsel fish.  In the last two articles, I look at how shortest paths and networks are  constructed by slime molds and pheromone laying ants, as well as studying  speed-accuracy tradeoffs in slime molds' decision making. The general goal of the study is to better understand how macro level patterns and behaviors emerges from micro level interactions in both spatial and non-spatial biological systems. With the combination of mathematical modeling and experimentation, we are able to reproduce the macro level patterns in the studied biological systems and predict behaviors of the systems using minimum number of parameters.

The aim of this study is to investigate the similarities/differences in the views on and practices of grammar teaching of a Swedish teacher of English (FL – Foreign Language) and a UK teacher of English (L1 – First Language). Furthermore, the study tries to explain how the differences found in the comparison can be connected to each country’s different steering documents and to the different teaching conditions involved in teaching English to L1 learners compared to FL learners. The two participating teachers were both interviewed and observed. The results of this study show that the teachers’ grammar practices are very similar since they include explicit formal instruction both inductively and deductively, but with a focus on the latter. These are typical ‘Focus on FormS’ related practices even though both teachers want to achieve a ‘Focus on Form’ directed practice. Furthermore, both teachers use metalanguage in their teaching. The main difference between the teachers’ grammar approaches are the aims that they have with their teaching. The UK teacher aims at plain accuracy in her pupils’ written production whereas the Swedish teacher aims at developing all-round communicative abilities among her pupils. This is explained with the different accuracy-focus which each country’s steering documents hold.

A set of algorithms building a program package for the generation of twoandthree-dimensional unstructured/hybrid grids around complex geometrieshas been developed. The unstructured part of the grid generator is based on the advancing frontalgorithm. Tetrahedra of variable size, as well as directionally stretched tetrahedracan be generated by specification of a proper background grid, initiallygenerated by a Delaunay algorithm. A marching layer prismatic grid generation algorithm has been developedfor the generation of grids for viscous flows. The algorithm is able to handleregions of narrow gaps, as well as concave regions. The body surface is describedby a triangular unstructured surface grid. The subsequent grid layers in theprismatic grid are marched away from the body by an algebraic procedurecombined with an optimization procedure, resulting in a semi-structured gridof prismatic cells. Adaptive computations using remeshing have been done with use of a gradientsensor. Several key-variables can be monitored simultaneously. The sensorindicates that only the key-variables with the largest gradients give a substantialcontribution to the sensor. The sensor gives directionally stretched grids. An algorithm for the surface definition of curved surfaces using a biharmonicequation has been developed. This representation of the surface canbe used both for projection of the new surface nodes in h-refinement, and theinitial generation of the surface grid. For unsteady flows an algorithm has been developed for the deformationof hybrid grids, based on the solution of the biharmonic equation for the deformationfield. The main advantage of the grid deformation algorithm is that itcan handle large deformations. It also produces a smooth deformation distributionfor cells which are very skewed or stretched. This is necessary in orderto handle the very thin cells in the prismatic layers. The algorithms have been applied to complex three-dimensional geometries,and the influence of the grid quality on the accuracy for a finite volumeflow solver has been studied for some simpler generic geometries. / QC 20100812

The aim of the present study is to examine how the development of syntactic complexity and accuracy in spoken Spanish L2 is related to two parameters, motivation and aptitude, in which individual differences are often claimed to correlate with successful second language learning (Dörnyei and Skehan 2003). The study shows how an understanding of the relationship between progression in second language proficiency and motivation is gained through the study of longitudinal data and the assessment of motivation in discourse. The development of syntactic complexity and accuracy in oral performance has been chosen as main indicators of proficiency level. Correlations have been computed between proficiency levels, development coefficients, quantitative outcomes of aptitude tests and quantified assessment of motivation. The study is based on longitudinal data consisting of recorded interviews and conversations in Spanish in Swedish upper secondary school. The results from the progression analysis show that the whole group develops syntactic complexity, and that individual learners concentrate on either syntactic complexity or accuracy in their development. Discourse analytical methods have been applied to the in-depth interviews in order to identify motivational types expressed by the learner and the strength of each type. These have been represented in terms of values on a self-determination scale, the extreme points of which are 'intrinsic' vs. 'extrinsic' motivation. An aptitude test (Lat03, Meara 2005) has also been administered to the participants and analysed . Correlations (Spearman) have been further calculated between the relevant parameters. The results indicate that self-determined, intrinsic motivation correlates with progression. Analytic aptitude, however, does not predict progression to the same extent as intrinsic motivation seems to do at this level.

Large area flat displays are nowadays considered being a commodity. After the era of bulky CRT TV technology, LCD and OLED have taken over as the most prevalent technologies for high quality image display devices. An important factor underlying the success of these technologies has been the development of high performance photomask writers in combination with a precise photomask process. Photomask manufacturing can be regarded as an art, highly dependent on qualified and skilled workers in a few companies located in Asia. The manufacturing yield in the photomask process depends to a great extent on several steps of measurements and inspections. Metrology, which is the focus of this thesis, is the science of measurement and is a prerequisite for maintaining high quality in all manufacturing processes. The details and challenges of performing critical measurements over large area photomasks of square meter sizes will be discussed. In particular the development of methods and algorithms related to the metrology system MMS15000, the world standard for large area photomask metrology today, will be presented. The most important quality of a metrology system is repeatability. Achieving good repeatability requires a stable environment, carefully selected materials, sophisticated mechanical solutions, precise optics and capable software. Attributes of the air including humidity, CO2 level, pressure and turbulence are other factors that can impact repeatability and accuracy if not handled properly. Besides the former qualities, there is also the behavior of the photomask itself that needs to be carefully handled in order to achieve a good correspondence to the Cartesian coordinate system. An uncertainty specification below 100 nm (3σ) over an area measured in square meters cannot be fulfilled unless special care is taken to compensate for gravity-induced errors from the photomask itself when it is resting on the metrology tool stage. Calibration is therefore a considerable challenge over these large areas. A novel method for self-calibration will be presented and discussed in the thesis. This is a general method that has proven to be highly robust even in cases when the self-calibration problem is close to being underdetermined. A random sampling method based on massive averaging in the time domain will be presented as the solution for achieving precise spatial measurements of the photomask patterns. This method has been used for detection of the position of chrome or glass edges on the photomask with a repeatability of 1.5 nm (3σ), using a measurement time of 250 ms. The method has also been used for verification of large area measurement repeatability of approximately 10 nm (3σ) when measuring several hundred measurement marks covering an area of 0.8 x 0.8 m2. The measurement of linewidths, referred to in the photomask industry as critical dimension (CD) measurements, is another important task for the MMS15000 system. A threshold-based inverse convolution method will be presented that enhances resolution down to 0.5 µm without requiring a change to the numerical aperture of the system. As already mentioned, metrology is very important for maintaining high quality in a manufacturing environment. In the mask manufacturing industry in particular, the cost of poor quality (CoPQ) is extremely high. Besides the high materials cost, there are also the stringent requirements placed on CD and mask overlay, along with the need for zero defects that make the photomask industry unique. This topic is discussed further, and is shown to be a strong motivation for the development of the ultra-precision metrology built into the MMS15000 system. / <p>QC 20130515</p>

The aim of this thesis is to investigate how the absolute accuracy of an industrial robot can be increased by monitoring the position of the robot. The motive is to automate high precision, low volume production such as aircraft industry. A laser tracker that can measure both position and orientation with very high accuracy isused to monitor the robot tool position. The robot and laser tracker are integrated via a standard computer. The abilities and performance of the robot, with and without feedback from the laser tracker, are investigated. Robotic drilling is performed with supervision and control from the laser tracker. The system is implemented and tested on parts of a demonstrator for new aircraft assembly techniques. The ability to position components with internal friction to (+/-)0.05 mm absolute accuracy is shown.

Bakgrund      Skogsmaskiner har under många år förstört både fornlämningar och gränsmärken. Idén till databasen/tjänsten uppkom av egna erfarenheter vid en förrättning, där flertalet gränsmärken hade blivit överkörda av skogsmaskiner. Syfte              Examensarbetets syfte är att lyfta fram en ny idé för att minska skadorna på fornlämningar och gränsmärken som skogsmaskiner orsakar, samt hur lägesnoggrannheten påverkar den nya tjänstens ändamål. Metod           Examensarbetet består av en litteraturstudie med syfte att besvara och ge en bakgrund till problemställningen. För att undersöka hur vanligt det är att lantmätare/mätingenjörer stöter på att gränsmärken blivit skadade av skogsmaskiner genomfördes en enkätundersökning. För en djupare inblick av lägesnoggrannheten på utrustningen i skogsmaskiner och vilken kvalitet på koordinaterna som krävs för en mer ändamålsenligt tjänst gjordes en intervjustudie. Slutsats         De uppgifter som finns tillängliga idag ska vara användbara när det gäller fornlämningar, för en ändamålsenlig tjänst som ska fungera ute i skogen där lägesnoggrannheten inte alltid är den bästa. Däremot är kvaliteten på gränspunkter i DRK inte helt perfekt för att kunna användas. / Background  Forest machines has for many years destroyed both ancient monuments and boundary marks. The Idea for the database/service grew out of personal experience at a land parceling ceremony, where most boundary markings had been run over by forest machinery. Objective      Purpose of this thesis is to present a new idea to reduce the damage to ancient monuments and boundary marks that forestry machinery causes, and how positional accuracy affects the new service use. Method         The thesis consists of a literature study aimed to answer and give a background to the issue. To investigate how common, surveyors come across that boundary markings are damaged by forest machines a questionnaire survey was made. For a deeper insight of the positional accuracy and quality of coordinates required for a more appropriate service, an interview study was made. Conclusion    The information available today should be useful in the case of ancient monuments, for an efficient service that will work in the woods where positional accuracy is not always the best. However, the quality of the boundary points in the DRK may not be perfect for use.

The accuracy of a quantum chemical calculation inherently depends on the ability to account for the completeness of the one- and n-particle spaces. The size of the basis set used can be systematically increased until it reaches the complete one-particle basis set limit (CBS) while the n-particle space approaches its exact full configuration interaction (FCI) limit by following a hierarchy of electron correlation methods developed over the last seventy years. If extremely high accuracy is desired, properly correcting for very small effects such as those resulting the Born-Oppenheimer approximation and the neglect of relativistic effects becomes indispensable. For a series of chemically interesting and challenging systems, we identify the limits of conventional approaches and use state-of-the-art quantum chemical methods along with large basis sets to get the “right answer for the right reasons.” First, we quantify the importance of small effects that are ignored in conventional quantum chemical calculations and manage to achieve spectroscopic accuracy (agreement of 1 cm−1 or less with experimental harmonic vibrational frequencies) for BH, CH+ and NH. We then definitively resolve the global minimum structure for Li₆ , Li₆⁺ , and Li₆- using high accuracy calculations of the binding energies, ionization potentials, electron affinities and vertical excitation spectra for the competing isomers. The same rigorous approach is used to study a series of hydrogen transfer reactions and validate the necessary parameters for the hydrogen abstraction and donation steps in the mechanosynthesis of diamondoids. Finally, in an effort to overcome the steep computational scaling of most high-level methods, a new hybrid methodology which scales as O(N⁵) but performs comparably to O(N⁶) methods is benchmarked for its performance in the equilibrium and dissociation regimes.

Bandgap reference circuits are used in a host of analog, digital, and mixed-signal systems to establish an accurate voltage standard for the entire IC. The accuracy of the bandgap reference voltage under steady-state (dc) and transient (ac) conditions is critical to obtain high system performance. In this work, the impact of process, power-supply, load, and temperature variations and package stresses on the dc and ac accuracy of bandgap reference circuits has been analyzed. Based on this analysis, the a bandgap reference that 1. has high dc accuracy despite process and temperature variations and package stresses, without resorting to expensive trimming or noisy switching schemes, 2. has high dc and ac accuracy despite power-supply variations, without using large off-chip capacitors that increase bill-of-material costs, 3. has high dc and ac accuracy despite load variations, without resorting to error-inducing buffers, 4. is capable of producing a sub-bandgap reference voltage with a low power-supply, to enable it to operate in modern, battery-operated portable applications, 5. utilizes a standard CMOS process, to lower manufacturing costs, and 6. is integrated, to consume less board space has been proposed. The functionality of critical components of the system has been verified through prototypes after which the performance of the complete system has been evaluated by integrating all the individual components on an IC. The proposed CMOS bandgap reference can withstand 5mA of load variations while generating a reference voltage of 890mV that is accurate with respect to temperature to the first order. It exhibits a trimless, dc 3-sigma accuracy performance of 0.84% over a temperature range of -40°C to 125°C and has a worst case ac power-supply ripple rejection (PSRR) performance of 30dB up to 50MHz using 60pF of on-chip capacitance. All the proposed techniques lead to the development of a CMOS bandgap reference that meets the low-cost, high-accuracy demands of state-of-the-art System-on-Chip environments.

In this paper, we propose a novel similarity measure for document data processing and apply it to text classification and clustering. For two documents, the proposed measure takes three cases into account: (a) The feature considered appears in both documents, (b) the feature considered appears in only one document, and (c) the feature considered appears in none of the documents. For the first case, we give a lower bound and decrease the similarity according to the difference between the feature values of the two documents. For the second case, we give a fixed value disregarding the magnitude of the feature value. For the last case, we ignore its effectiveness. We apply it to the similarity based single-label classifier k-NN and multi-label classifier ML-KNN, and adopt these properties to measure the similarity between a document and a specific set for document clustering, i.e., k-means like algorithm, to compare the effectiveness with other measures. Experimental results show that our proposed method can work more effectively than others.