251 research outputs found

    Implementing a streaming application on a processor array

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    A modern way of processing information is to do it in parallel. This Master Thesis conducts a case study of how to parallelize a streaming application on a highly parallel platform. This involves porting a real-world application, written in a stream processing language and compiled by tools, developed by the Embedded System Design research group at Lund University, onto a platform including an embedded processor array (the Adapteva’s Epiphany), an ARM processor, and programmable logic. The driver application that we used was a video decoder. The host platform was a Parallella board, with a 16-core Epiphany co-processor and a Zynq host processor that had dual ARM cores. Our Master Thesis covers the creation of some library elements to support complex applications on that platform, such as FIFOs between Epiphany cores and the ARM host, some components that handle access to external RAM and a component that draws pixels onto a screen.A modern way of processing information is to do it in parallel. This master’s thesis conducts a case study of how to parallelize an application on a highly parallel platform

    Detection of metal objects in trees during processing in harvesting heads

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    Fortifikationsverket which is the landlord for the Swedish national defence has a great problem in their forestry due to the relatively large amount of metal objects in their timber. These metal objects cause different types of economical losses in the timber refinement chain. To enable out sorting of logs containing metal objects already in the harvesting phase, Fortifikationsverket is interested of the possibility to utilize some type of metal detector in a harvesting head for that purpose. The goal of this study was to, with help of a case study, enlighten the problem that metal objects in timber cause for Fortifikationsverket and their customers of timber and to investigate conditions of to mount and utilize some kind of metal detector in a harvesting head at present. The saw timber deliveries by Fortifikationsverket during the time period 2003-2005 was used as a reference volume for calculations of economical losses. In this case study was included two sawmills where timber from Fortifikationsverket were delivered to for further refinement. Factors investigated were the type of damage metal objects caused in these two sawmills and the economical signification of these damages. Even the harvesting and managing of Fortifikationsverket´s timber in areas where trees contained relatively much metal objects and the harvesting procedure was investigated by interviewing entrepreneurs. Further, the possibilities to use some type of metal detector on a harvesting head for out sorting logs containing metal objects were investigated by interviewing scientists and specialists and by literature searches. The interval of damage costs for the sawmills included in this case study was approximately 14 000 – 433 000 SEK. The economical scope for a metal detector amounted to approximately 130 000 SEK for the reference volume when only economical losses due to metal objects in connection with harvesting and transport where taken into consideration. Electromagnetics, X-rays, microwaves and ultrasound are methods which could be used to detect metal objects in timber. The tough environment provided by the harvesting head and the harvesting technique it self precludes a practical usage of these methods at present, but it could be theoretically possible with the aid of microwave technique

    Вплив попиту на процес ціноутворення

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    The creep behavior of nanocellulose films and aerogels are studied in a dynamic moisture environment, which is crucial to their performance in packaging applications. For these materials, the creep rate under cyclic humidity conditions exceeds any constant humidity creep rate within the cycling range, a phenomenon known as mechanosorptive creep. By varying the sample thickness and relative humidity ramp rate, it is shown that mechanosorptive creep is not significantly affected by the through-thickness moisture gradient. It is also shown that cellulose nanofibril aerogels with high porosity display the same accelerated creep as films. Microstructures larger than the fibril diameter thus appear to be of secondary importance to mechanosorptive creep in nanocellulose materials, suggesting that the governing mechanism is found between molecular scales and the length-scales of the fibril diameter.funding agencies|BiMaC Innovation|

    A study of a flexible fiber model and its behavior in DNS of turbulent channel flow

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    The dynamics of individual flexible fibers in a turbulent flow field have been analyzed, varying their initial position, density and length. A particlelevel fiber model has been integrated into a general-purpose, open source Computational Fluid Dynamics (CFD) code. The fibers are modeled as chains of cylindrical segments connected by ball and socket joints. The equations of motion of the fibers contain the inertia of the segments, the contributions from hydrodynamic forces and torques, and the connectivity forces at the joints. Direct Numerical Simulation (DNS) of the incompressible Navier–Stokes equations is used to describe the fluid flow in a plane channel and a one-way coupling is considered between the fibers and the fluid phase. We investigate the translational motion of fibers by considering the mean square displacement of their trajectories. We find that the fiber motion is primarily governed by velocity correlations of the flow fluctuations. In addition, we show that there is a clear tendency of the thread-like fibers to evolve into complex geometrical configurations in a turbulent flow field, in fashion similar to random conformations of polymer strands subjected to thermal fluctuations in a suspension. Finally, we show that fiber inertia has a significant impact on reorientation time-scales of fibers suspended in a turbulent flow field

    Realistic assumptions about spatial locations and clustering of premises matter for models of foot-and-mouth disease spread in the United States

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    Spatially explicit livestock disease models require demographic data for individual farms or premises. In the U.S., demographic data are only available aggregated at county or coarser scales, so disease models must rely on assumptions about how individual premises are distributed within counties. Here, we addressed the importance of realistic assumptions for this purpose. We compared modeling of foot and mouth disease (FMD) outbreaks using simple randomization of locations to premises configurations predicted by the Farm Location and Agricultural Production Simulator (FLAPS), which infers location based on features such as topography, land-cover, climate, and roads. We focused on three premises-level Susceptible-Exposed-Infectious-Removed models available from the literature, all using the same kernel approach but with different parameterizations and functional forms. By computing the basic reproductive number of the infection (R0) for both FLAPS and randomized configurations, we investigated how spatial locations and clustering of premises affects outbreak predictions. Further, we performed stochastic simulations to evaluate if identified differences were consistent for later stages of an outbreak. Using Ripley's K to quantify clustering, we found that FLAPS configurations were substantially more clustered at the scales relevant for the implemented models, leading to a higher frequency of nearby premises compared to randomized configurations. As a result, R0 was typically higher in FLAPS configurations, and the simulation study corroborated the pattern for later stages of outbreaks. Further, both R0 and simulations exhibited substantial spatial heterogeneity in terms of differences between configurations. Thus, using realistic assumptions when de-aggregating locations based on available data can have a pronounced effect on epidemiological predictions, affecting if, where, and to what extent FMD may invade the population. We conclude that methods such as FLAPS should be preferred over randomization approaches

    Effects of regional differences and demography in modelling foot-and-mouth disease in cattle at the national scale

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    Foot-and-mouth disease (FMD) is a fast-spreading viral infection that can produce large and costly outbreaks in livestock populations. Transmission occurs at multiple spatial scales, as can the actions used to control outbreaks. The US cattle industry is spatially expansive, with heterogeneous distributions of animals and infrastructure. We have developed a model that incorporates the effects of scale for both disease transmission and control actions, applied here in simulating FMD outbreaks in US cattle. We simulated infection initiating in each of the 3049 counties in the contiguous US, 100 times per county. When initial infection was located in specific regions, large outbreaks were more likely to occur, driven by infrastructure and other demographic attributes such as premises clustering and number of cattle on premises. Sensitivity analyses suggest these attributes had more impact on outbreak metrics than the ranges of estimated disease parameter values. Additionally, although shipping accounted for a small percentage of overall transmission, areas receiving the most animal shipments tended to have other attributes that increase the probability of large outbreaks. The importance of including spatial and demographic heterogeneity in modelling outbreak trajectories and control actions is illustrated by specific regions consistently producing larger outbreaks than others

    Tacht-i Sangin, Tadschikistan. Griechische Musikinstrumente (auloí) aus dem Oxos-Tempel. Die Arbeiten des Jahres 2022

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    In the 1980s, 44 fragments of musical instruments from the 3rd/2nd century BCE were excavated in the Oxus Temple at Takht-i Sangin, Tajikistan. Correctly identified as remnants of doublepipes (Greek: auloí) and provisionally published, this unique cache from the Hellenistic period had never been evaluated in terms of its music-archaeological potential. We endeavor to fill this gap using a combination of physical modelling and 3D printing, interpreting the fragments in the context of other finds. Study sessions with the originals in Dushanbe thus enabled us to join fragments to longer pipe sections, revealing an instrument design that appears closely tied to the technical advancements of Hellenistic music

    Greetings as social action in Finland Swedish and Sweden Swedish service encounters – a pluricentric perspective

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    While greetings are performed in all cultures and open most conversations, previous studies suggest that there are cross-cultural differences between different languages in greeting behavior. But do speakers of different national varieties of the same language organize and perform their greeting behavior in similar ways? In this study, we investigate the sequential organization of greetings in relation to gaze behavior in the two national varieties of wedish: Sweden Swedish spoken in Sweden and Finland Swedish spoken in Finland. In recent years, the importance of studying pluricentric languages from a pragmatic perspective has been foregrounded, not least within the framework of variational pragmatics. To date, most studies have focused on structural differences between national varieties of pluricentric languages. With this study, we extend the scope of variational pragmatics through adding an interactional, micro perspective to the broader macro analysis typical of this field. For this study, we have analyzed patterns for greetings in 297 videorecorded service encounters, where staff and customers interact at theatre box offices and event booking venues in Sweden and Finland. The study shows that there are similarities and differences in greeting behavior between varieties. There is a strong preference for exchanging reciprocal verbal greetings, one at a time, in both. There is also a similar organization of the greeting sequence, where customer and staff establish mutual gaze prior to the verbal greetings, thus signaling availability for interaction. The duration of mutual gaze and the timing of the greeting, however, differ between the two varieties. We have also conducted a multi modal analysis of gaze behavior in correlation to the greeting. We found that the customers and staff in the Finland Swedish data share mutual gaze before and during the verbal greeting, and often avert gaze after the verbal greetings. However, in the Sweden Swedish data, the participants often avert gaze before the verbal greetings. Our results thus indicate that both similarities and differences in pragmatic routines and bodily behavior exist between the two national varieties of Swedish. The present study on greeting practices in Finland Swedish and Sweden Swedish should contribute to the field of variational pragmatics and to the development of pluricentric theory.</p

    Disruption of the 5S RNP-Mdm2 interaction significantly improves the erythroid defect in a mouse model for Diamond-Blackfan anemia.

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    Diamond-Blackfan anemia (DBA) is a congenital erythroid hypoplasia caused by haploinsufficiency of genes encoding ribosomal proteins (RPs). Perturbed ribosome biogenesis in DBA has been shown to induce a p53-mediated ribosomal stress response. However, the mechanisms of p53 activation and its relevance for the erythroid defect remain elusive. Previous studies have indicated that activation of p53 is caused by the inhibition of Mdm2, the main negative regulator of p53, by the 5S ribonucleoprotein particle (RNP). Meanwhile, it is not clear whether this mechanism solely mediates the p53-dependent component found in DBA. To approach this question, we crossed our mouse model for RPS19-deficient DBA with Mdm2(C305F) knock-in mice that have a disrupted 5S RNP-Mdm2 interaction. Upon induction of the Rps19 deficiency, Mdm2(C305F) reversed the p53 response and improved expansion of hematopoietic progenitors in vitro, and ameliorated the anemia in vivo. Unexpectedly, disruption of the 5S RNP-Mdm2 interaction also led to selective defect in erythropoiesis. Our findings highlight the sensitivity of erythroid progenitor cells to aberrations in p53 homeostasis mediated by the 5S RNP-Mdm2 interaction. Finally, we provide evidence indicating that physiological activation of the 5S RNP-Mdm2-p53 pathway may contribute to functional decline of the hematopoietic system in a cell-autonomous manner over time.Leukemia accepted article preview online, 19 May 2015. doi:10.1038/leu.2015.128

    Підвищення енергоефективності комплекту розрядна лампа-ЕПРА

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    The network geometries of rigidly cross-linked fibrin and collagen type I networks are imaged using confocal microscopy and characterized statistically. This statistical representation allows for the regeneration of large, three-dimensional biopolymer networks using an inverse method. Finite element analyses with beam networks are then used to investigate the large deformation, nonlinear elastic response of these artificial networks in isotropic stretching and simple shear. For simple shear, we investigate the differential bulk modulus, which displays three regimes: a linear elastic regime dominated by filament bending, a regime of strain-stiffening associated with a transition from filament bending to stretching, and a regime of weaker strain-stiffening at large deformations, governed by filament stretching convolved with the geometrical nonlinearity of the simple shear strain tensor. The differential bulk modulus exhibits a corresponding strain-stiffening, but reaches a distinct plateau at about 5% strain under isotropic stretch conditions. The small-strain moduli, the bulk modulus in particular, show a significant size-dependence up to a network size of about 100 mesh sizes. The large-strain differential shear modulus and bulk modulus show very little size-dependence.Funding Agencies|BiMaC Innovation||Alf de Ruvo Memorial Foundation of SCA AB||WoodWisdom-net research program||Harvard MRSEC|DMR-0820484|NSF|DMR-1006546|</p
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