International Telemetering Conference Proceedings / October 17-20, 1994 / Town & Country Hotel and Conference Center, San Diego, California / The Distributed Interactive Simulation (DIS) concept, since its inception, has been defined into three separate but distinct areas of service. • Viewing of data in the real-time environment. • Multiple range viewing and usage of"real-time data." • Problems with the sharing of information through DIS. This paper will discuss the DIS concept and some of the various methods available to display this data to users of the system.

While memory is the faculty that affords us learning, adaptation and development, it is our executive function that oversees, manages and organizes these abilities. Still, there is limited research on the interaction between memory and executive function. The present study investigated this relationship through Principal Components Analysis. Performances on accepted measures of memory and executive function were evaluated in an adult clinical sample. Components were retained using three criteria: a predetermined four-component structure, eigenvalues exceeding a value of one, and parallel analysis. Results demonstrated that a four-component model most accurately represented the data. Analyses also revealed that measures of immediate and delayed memory did not uniquely assess memory but instead loaded onto components associated with visual and verbal processing. The findings were shown to be in support of the brain working in an integrated, systematic manner in which abilities hierarchically ascend from arousal to tertiary function. Consequently, several accepted measures of memory and executive function failed to measure cognitive capacity unique from visual and verbal processing, placing their construct validity and efficacy in question.

published_or_final_version / abstract / Electrical and Electronic Engineering / Master / Master of Philosophy

Increased access to energy is a key factor to reduce poverty and to gain increased development and prosperity. Access to energy is not equally distributed globally. On average a Swedish person consumes more energy than 12 individuals in Tanzania. The Msambara village arose in the 1930s. 80% of the inhabitants are children and the families are large. Life expectancy is 52 years for women and 54 for men. The entire region is very poor and the standard of living in Msambara is low, even compared to other parts of the country. In rural Msambara in Tanzania the cooking method is very primitive and is usually carried out indoors on three stones. Indoor pollution is contributing to eye infections. Incomplete combustion not only emits greenhouse gases increasing global warming, but also more directly emits particles effecting human health. Women and girls are particularly vulnerable to burning caused by air pollution, especially since they are responsible for cooking. The women pull a heavy load in the household work. They are responsible for raising and caring for children, managing farms, collecting firewood, fetching water, visiting the market and cooking for the family. The adoption of biogas technology reduces the need for traditional energy and thereby reduces environmental degradation. In addition, the residue is an improved agricultural fertiliser. Biogas technology has social considerations; burning of biomass for cooking reduces indoor air pollution and reduces workload to collect firewood, often performed by women. Moreover, biogas is desirable from an economic point of view. The method in this work can conveniently be divided into three different parts. These are the designing and construction process as well as the socio-economic study. The socio-economic component is split into two different sections, which are field study and data modelling. The study shows that the social negative impact may or may not be reduced by the introduction of the biogas facility, but the biogas facility in the way it is made will potentially contribute to sustainable economic growth for the household. It also shows that the household’s organic waste produced from human, animal, kitchen and garden waste is enough to provide the necessary gas needed for cooking and no additional firewood will be needed. Two diary cows, in addition to the household’s waste, will provide enough gas needed to introduce cooling capacity for food storage. By adding cooling capacity in the household, time will be saved from the food preparation process but the introduction of biogas itself will not reduce the individual work burden when no cooling capacity is installed. The study also shows that placing the digester in the ground makes a stable environment for the mesophilic and methanogenic microbes. The Socio-economic study indicates that by introducing an alternative method to cooking, positive health effects will arise and the household benefits economically. It is not possible from this thesis to conclude that by adding and treating human toilets as a substrate that possible health benefits will take place. / Sammanfattning Ökad tillgång till energi är en nyckelfaktor för att minska fattigdom och för att få ökad utveckling och välstånd. Tillgången till energi är inte jämnt fördelad globalt. En svensk person konsumerar i genomsnitt mer energi än 12 individer i Tanzania. Byn Msambara uppstod på 1930-talet, 80 % av invånarna utgörs av barn, familjerna är stora. Medellivslängden är 52 år för kvinnor och 54 år för män. Hela regionen präglas av fattigdom och levnadsstandarden i Msambara är låg, även jämfört med andra delar av landet. I Msambara som ligger på Tanzanias landsbygd är tillagningsmetoden mycket primitiv och utförs vanligen inomhus på tre stenar. Den rökiga inomhusmiljön leder ofta till ögoninfektioner. Den ofullständiga förbränningen frigör inte bara växthusgaser och bidrar till den globala uppvärmningen, utan mer direkt avges partiklar som påverkar människors hälsa. Kvinnor och flickor är särskilt utsatta för luftföroreningar eftersom de är ansvariga för matlagning. Kvinnorna drar ett tungt lass i hushållsarbetet. De är ansvarig för uppfostran och vårdnaden utav barnen, hushållsarbetet, sköta jordbruket, samla ved, hämta vatten, besöka marknaden och att laga familjens mat. Introduktion av biogasteknik minskar behovet av traditionell energi och miljöbelastningen. Rötresten är dessutom ett förädlat gödningsmedel. Biogas introduktionen ger positiva sociala konsekvenser då det leder till reducerade luftföroreningar inomhus och minskar behovet av att införskaffa ved, vilket nästan undantagslöst utförs av kvinnor. Dessutom är biogas positivt ur ekonomisk synvinkel. Arbetsmetoden är tydlighetens uppdelat i tre delar. Nämligen dimensionering av rötkammaren, uppförandet av densamma och en okonstlad socioekonomisk studie som i sin tur är uppdelad i en fältstudie och simulering. Studien kan inte visa på att summan av de sociala negativa effekterna minskar med införandet av biogasanläggningen men däremot att den potentiellt bidrar till stärkt ekonomi för hushållet. Den visar också att hushållens organiska avfall som produceras i form av avfall från människor, djur, kök och trädgård är fullt tillräckligt för att producera den nödvändiga gasen som behövs för matlagning. Ingen ytterligare ved kommer att behövas. Två kor förutom hushållets avfall ger den biogas som krävs för att driva ett kylskåp vilket ökar hållbarheten vid matförvaring. Genom tillförandet av kyleffekt till hushållet frigörs tid vilket innebär en tidsbesparing. Införandet av biogas i sig minskar inte den individuella arbetetsbördan. Studien visar också att placeringen av rötkammaren i marken utgör en stabil miljö för de mesofila metanogena. Den socioekonomiska studien visar att införandet av den alternativ matlagningsmetoden medför positiva hälsoeffekter och är ekonomiskt gynnsamt för hushållet. Från denna studie är det inte möjligt att dra slutsatsen att tillförandet och behandlingen av den mänskliga toaletten i rötprocessen ger hälsofördelar.

Accurate predictions of macroscopic multiphase flow properties, such as relative permeability and capillary pressure, are necessary for making key decisions in reservoir engineering. These properties are usually measured experimentally, but pore-scale network modeling has become an efficient alternative for understanding fundamental flow behavior and prediction of macroscopic properties. In many cases network modeling gives excellent agreement with experiment by using models physically representative of real media. Void space within a rock sample can be extracted from high resolution images and converted to a topologically equivalent network of pores and throats. Multiphase fluid transport is then modeled by imposing mass conservation at each pore and implementing the Young-Laplace equation in pore throats; the resulting pressure field and phase distributions are used to extract macroscopic properties. Advancements continue to be made in making network modeling predictive, but one limitation is that artificial (e.g. constant pressure gradient) boundary conditions are usually assumed; they do not reflect the local saturations and pressure distributions that are affected by flow and transport in the surrounding media. In this work we demonstrate that flow behavior at the pore scale, and therefore macroscopic properties, is directly affected by the boundary conditions. Pore-scale drainage is modeled here by direct coupling to other pore-scale models so that the boundary conditions reflect flow behavior in the surrounding media. Saturation couples are used as the mathematical tool to ensure continuity of saturations between adjacent models. Network simulations obtained using the accurate, coupled boundary conditions are compared to traditional approach and the resulting macroscopic petrophysical properties are shown to be largely dependent upon the specified boundary conditions. The predictive ability of network simulations is improved using the novel network coupling scheme. Our results give important insight into upscaling as well as approaches for including pore-scale models directly into reservoir simulators. / text

<p align="justify">The conservation of structures of the historical heritage is an increasing concern nowadays for public authorities. The technical design phase of repair operations for these structures is of prime importance. Such operations usually require an estimation of the residual strength and of the potential structural failure modes of structures to optimize the choice of the repairing techniques.</p> <p align="justify">Although rules of thumb and codes are widely used, numerical simulations now start to emerge as valuable tools. Such alternative methods may be useful in this respect only if they are able to account realistically for the possibly complex failure modes of masonry in structural applications.</p> <p align="justify">The mechanical behaviour of masonry is characterized by the properties of its constituents (bricks and mortar joints) and their stacking mode. Structural failure mechanisms are strongly connected to the mesostructure of the material, with strong localization and damage-induced anisotropy.</p> <p align="justify">The currently available numerical tools for this material are mostly based on approaches incorporating only one scale of representation. Mesoscopic models are used in order to study structural details with an explicit representation of the constituents and of their behaviour. The range of applicability of these descriptions is however restricted by computational costs. At the other end of the spectrum, macroscopic descriptions used in structural computations rely on phenomenological constitutive laws representing the collective behaviour of the constituents. As a result, these macroscopic models are difficult to identify and sometimes lead to wrong failure mode predictions.</p> <p align="justify">The purpose of this study is to bridge the gap between mesoscopic and macroscopic representations and to propose a computational methodology for the analysis of plane masonry walls. To overcome the drawbacks of existing approaches, a multi-scale framework is used which allows to include mesoscopic behaviour features in macroscopic descriptions, without the need for an a priori postulated macroscopic constitutive law. First, a mesoscopic constitutive description is defined for the quasi-brittle constituents of the masonry material, the failure of which mainly occurs through stiffness degradation. The mesoscopic description is therefore based on a scalar damage model. Plane stress and generalized plane state assumptions are used at the mesoscopic scale, leading to two-dimensional macroscopic continuum descriptions. Based on periodic homogenization techniques and unit cell computations, it is shown that the identified mesoscopic constitutive setting allows to reproduce the characteristic shape of (anisotropic) failure envelopes observed experimentally. The failure modes corresponding to various macroscopic loading directions are also shown to be correctly captured. The in-plane failure mechanisms are correctly represented by a plane stress description, while the generalized plane state assumption, introducing simplified three-dimensional effects, is shown to be needed to represent out-of-plane failure under biaxial compressive loading. Macroscopic damage-induced anisotropy resulting from the constituents' stacking mode in the material, which is complex to represent properly using macroscopic phenomenological constitutive equations, is here obtained in a natural fashion. The identified mesoscopic description is introduced in a scale transition procedure to infer the macroscopic response of the material. The first-order computational homogenization technique is used for this purpose to extract this response from unit cells. Damage localization eventually appears as a natural outcome of the quasi-brittle nature of the constituents. The onset of macroscopic localization is treated as a material bifurcation phenomenon and is detected from an eigenvalue analysis of the homogenized acoustic tensor obtained from the scale transition procedure together with a limit point criterion. The macroscopic localization orientations obtained with this type of detection are shown to be strongly related to the underlying mesostructural failure modes in the unit cells.</p> <p align="justify">A well-posed macroscopic description is preserved by embedding localization bands at the macroscopic localization onset, with a width directly deduced from the initial periodicity of the mesostructure of the material. This allows to take into account the finite size of the fracturing zone in the macroscopic description. As a result of mesoscopic damage localization in narrow zones of the order of a mortar joint, the material response computationally deduced from unit cells may exhibit a snap-back behaviour. This precludes the use of such a response in the standard strain-driven multi-scale scheme.</p> <p align="justify">Adaptations of the multi-scale framework required to treat the mesostructural response snap-back are proposed. This multi-scale framework is finally applied for a typical confined shear wall problem, which allows to verify its ability to represent complex structural failure modes.</p>

New Zealand wood availability forecasts indicate that increases in the future wood availability significantly relies on small-scale forest owners' resources. This "small-scale" resource is poorly understood and comprises a large number of owners. It is questionable how many of these forests are established with consideration of the cost and practicality of harvesting. An improved understanding of the likelihood of this resource ever being harvested is important for understanding future wood supply. The main objective of this study is to answer a fundamental question on how much small scale forest area is economic to harvest. The study aims to estimate the basic stumpage value of the forests at modelled costs and different log price levels, and to analyse the profitability of the small scale forests by looking at the historic rate of return, as well as the net present value (NPV) and internal rate of return on existing and future forest land. The emission trading scheme (ETS) was also taken into account during the analyses and the effects of the ETS on the profitability, optimum age and future wood availability were investigated. The methodology developed for this study uses a forest growth model (Radiata Pine Calculator), Geographic Information Systems, the Visser harvest cost model, and Microsoft Excel. The growth model enables the analysis to be customised to a specific region of interest, while spatial characteristics such as slope and transportation distance of individual forests were taken into account by using GIS. The cost model allows the analysis to be customised to individual forests to some extent although a number of assumptions are made generalising the forests as whole. Developing the overall framework within Excel allows easy analysis of the results and changes to the underlying assumptions. Harvesting and transportation costs are the main drivers in determining the profitability of small scale forests. A significant increase in log prices is required for the existing forests to obtain substantial profit from log production. At current log prices 90% of small-scale forests in the Wanganui District are economically available. The other 10% small blocks on steep sites, have negative stumpage revenues because of high harvesting costs. Additional cashflows from entering the ETS have the potential to generate significant revenue for post-89 forests. However the substantial increases in optimal rotation age are likely to delay the increase in harvest volumes forecast from the small-scale estate.

Protein nanofibres, commonly known as amyloid fibrils, are emerging as potential biological nanomaterials in a number of applications. Protein nanofibres are a highly ordered insoluble form of protein, which results when a normally soluble protein aggregates via a self-association process. However, researchers are currently faced with several challenges such as finding a cheap source of proteins that can be obtained without expensive purification and optimizing a scalable method of the manufacturing of protein nanofibres. This thesis has identified crude mixtures of fish lens crystallins as a cheap protein source and has optimized methods for large scale production of protein nanofibres of varying morphologies. Results show that by varying the conditions of fibre formation, individual protein fibres can be used as building blocks to form higher order structures. This ability to control the morphology and form higher ordered structures is a crucial step in bottom up assembly of bionanomaterials and opens possibilities for applications of protein nanofibres. The method of formation of protein nanofibres was optimized on a bench scale (1.5 mL Eppendorf tubes) and successfully scaled-up to 1 L volume. For larger scale-up volume (i.e. greater than 10 ml), internal surface area was important for the formation of protein nanofibres. The crude crystallin mixture prepared at 10 mg/mL was heated at 80oC in the presence of 10% v/v TFE at pH 3.8 for 24 hours and stored for an additional of 24 hours at room temperature for storage process. Aggregation and precipitation of proteins were observed as the protein solution was added to the pre-heated TFE. The resulting protein nanofibres were characterised using ThT dye binding, TEM and SEM. The TEM images show a network of long and criss-crossing protein nanofibres with individual fibres of approximately 10 to 20 nm in diameter and 0.5 to 1 μm long. These protein nanofibres were prepared in 1 mL centrifuge tubes and were left on the laboratory bench at room temperature. After 5 months, fresh TEM grids of the sample were prepared and visualized using TEM. Interestingly, TEM images show that a number of individual fibres had self-assembled in an intertwining fashion to form large bundles and higher order structures containing bundles of nanofibres up to 200 nm thick.

This dissertation describes an innovative approach to the state justification portion of the sequential circuit automatic test pattern generation (ATPG) process. Given the absence of a stored fault an ATPG controller invokes some combinational circuit test generation procedure, such as the D-algorithm, to identify a circuit state (goal state) and input vectors that will sensitize a selected fault. The state justification phase then finds a transfer sequence to the goal from the present state. A forward fault propogation search can be successfully guided through state space from the present state but the forward justification search is less efficient and the failure rate is high. The backward function level search invokes inverse RTL level primitives and exploits easy movement of data vectors in structured VLSI circuits. Examples illustrated are in AHPL. This search is equally applicable to an RTL level subset of VHDL. Combinational logic units are treated as functions and the circuit states are partitioned into control states and data states. The search proceeds backwards over the control state space starting from the goal state node and data states are transformed according to the control flow. Vectorized data paths in VLSI circuits and search guiding heuristics which favor convenient inverse functions keep the number of search nodes low. Partial covers, conceptually similar to singular covers in D-algorithm, model the inverse functions of combinational logic units. The search successfully terminates when a child state node logically matches the present state and the present state values can satisfy all the constraints encountered along the search path.

We present techniques for obtaining precision distance measurements using the baryon acoustic oscillations (BAO) through controlling systematics and reducing statistical uncertainties. Using the resulting distance-redshift relation, we can infer cosmological parameters such as w, the equation of state of dark energy. We introduce a new statistic, ɷ(l)(r(s)), for BAO analysis that affords better control over systematics. It is computed by band-filtering the power spectrum P(k) or the correlation function ξ(r) to extract the BAO signal. This is conducive to several favourable outcomes. We compute ɷ(l)(r(s)) from 44 simulations and compare the results to P(k) and ξ(r). We find that the acoustic scales and theoretical errors we measure are consistent between all three statistics. We demonstrate the first application of reconstruction to a galaxy redshift survey. Reconstruction is designed to partially undo the effects of non-linear structure growth on the BAO, allowing more precise measurements of the acoustic scale. We also present a new method for deriving a smooth covariance matrix based on a Gaussian model. In addition, we develop and perform detailed robustness tests on the ξ(r) model we employ to extract the BAO scale from the data. Using these methods, we obtain spherically-averaged distances to z = 0.35 and z = 0.57 from SDSS DR7 and DR9 with 1.9% and 1.7% precision respectively. Combined with WMAP7 CMB observations, SNLS3 data and BAO measurements from 6dF, we measure w = -1.08 ± 0.08 assuming a wCDM cosmology. This represents a ~8% measurement of w and is consistent with a cosmological constant.The preceding does not capture the expansion history of the universe, H(z), encoded in the line-of-sight distance scale. To disentangle H(z), we exploit the anisotropic BAO signal that arises if we assume the wrong cosmology when calculating the clustering distribution. Since we expect the BAO signal to be isotropic, we can use the magnitude of the anisotropy to separately measure H(z) and D(A)(z). We apply our simple models to SDSS DR7 data and obtain a ~3.6% measurement of D(A)(z=0.35) and a ~8.4% measurement of H(z = 0.35).