146 research outputs found

    Simulating Memristive Networks in SystemC-AMS

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    This chapter presents a solution for the simulation of large memristive networks with SystemC-AMS. SystemC-AMS allows simulating memristors both on analogue level and on digital level to link analogue memristive devices to digital circuits and system level specifications. We investigate the benefits and drawbacks of a SystemC-AMS simulation compared to a simulation in SPICE. We show for the example of a two-layer memristive network emulating an optical flow algorithm by the detection of moving edges that large memristive networks can be simulated with a free available SystemC-AMS simulation environment, whereas free available SPICE simulation environment fails. However, it is also shown that commercial SPICE simulators are superior against current SystemC-AMS implementations concerning the size of simulated memristive networks. However, SystemC-AMS simulations of memristive networks offer both still more flexibility and similar run times compared to commercial SPICE simulators for small-sized memristive networks. The flexibility and the powerfulness of a SystemC-AMS solution is demonstrated for a complex network that solves edge detection, filtering and detecting of moving objects. The possible run times of the memristive network are determined in the SystemC-AMS simulation environment and are compared with an optical flow algorithm on classical hardware like a CPU and a GPU

    Consonant and syllable complexity of toddlers with Down syndrome and mixed-aetiology developmental delays

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    This study examines whether speech sound production of toddlers with Down syndrome (DS) is on par with or more severely impaired than that of mental age (MA) peers with developmental delay due to aetiologies other than Down syndrome at two points within an 18-month period near the onset of spoken word production. The utterances of 26 children with DS, aged 24–33 months, with a mean MA of 14.3 months, originally studied by Fey et al. (2006) and Warren et al. (2008) were compared to those of a group of 22 children with similar intellectual and communication delay but no DS (NDS). Phonological measures included the size of the consonant inventory, syllable shape complexity, and number of communication acts with canonical vocalizations. At Time 1, the DS group performed as well as or better than the NDS group on these measures of speech production. At Time 2, 18 months later, the DS group was behind the NDS group on the same measures. Results extended the pattern of more severe impairment in children with DS than NDS peers commonly noted in expressive language to measures of phonological development

    Parallel Embedded Computing Architectures

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    It was around the years 2003 to 2005 that a dramatic change seized the semiconductor industry and the manufactures of processors. The increasing of computing performance in processors, based on simply screwing up the clock frequency, could not longer be holded. All the years before the clock frequency could be steadily increased by improvements achieved both on technology and on architectural side. Scaling of the technology processes, leading to smaller channel lengths and shorter switching times in the devices, and measures like instruction-level-parallelism and out-of-order processing, leading to high fill rates in the processor pipelines, were the guarantors to meet MooreĂąs law

    Non-Contact Inline Monitoring of Thermoplastic CFRP Tape Quality Using Air-Coupled Ultrasound

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    Besides the aerospace industry, fibre reinforced plastics have also spread towards many further applications such as automotive, civil engineering as well as sports and leisure articles. Their superior strength and stiffness to mass ratio made them the number one material for achieving high performance. Especially continuous fibre reinforced plastics allow for the construction of structures which are custom tailored to their mechanical loads by adjusting the paths of the fibres to the loading direction. The two main constituents of CFRP are carbon fibres and matrix. Two possibilities for matrix material exist: thermosetting and thermoplastic matrix. While thermosetting matrix may yield better properties with respect to thermal loads, thermoplasticity opens a wide range of applications due to weldability, shapabilty, and compatibility to e.g. injection moulded thermoplastic materials. Thin (0.18 mm) thermoplastic continuous fibre CFRP tapes with a width of 100 mm were examined using air-coupled ultrasound. Transducers were arranged in reflection as well as transmission setup. By slanted incidence of the ultrasound on the tape surface, guided waves were excited in the material in fibre direction and perpendicular to the fibre direction. Artificial defects – fibre cuts, matrix cuts, circular holes, low velocity impacts from tool drop, and sharp bends – were produced. Experiments on a stationary tape showed good detectability of all artificial defects by guided waves. Also the effects of variation in material properties, fibre volume content and fibre matrix adhesion being the most relevant, on guided wave propagation were examined, to allow for quality assessment. Guided wave measurements were supported by destructive analysis. Also an apparatus containing one endless loop of CFRP tape was constructed and built to simulate inline testing of CFRP tapes, as it would be employed in a CFRP tape production environment or at a CFRP tape processing facility. The influences of tape conveying speed on detectability of artificial defects as well as material properties were elaborated and recommendations for implementation in production scale inline monitoring are given

    Hatchery-produced sandfish (Holothuria scabra) show altered genetic diversity in New Caledonia

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    Facing an alarming continuing decline of wild sea cucumber resources, management strategies were developed over the past three decades to sustainably promote development, maintenance, or regeneration of wild sea cucumber fisheries. In New Caledonia (South Pacific), dedicated management efforts via restocking and sea ranching programs were implemented to cope with the overharvesting of the sandfish Holothuria scabra and the recent loss of known populations. In order to investigate genetic implications of a major H. scabra restocking program, we assessed the genetic diversity and structure of wild stocks and hatchery-produced sandfish and compared the genetic outcomes of consecutive spawning and juvenile production events. For this, 1358 sandfish collected at four sites along the northwestern coasts of New Caledonia, as well as during five different restocking events in the Tiabet Bay, were genotyped using nine polymorphic microsatellite markers. We found that wild H. scabra populations from the northwestern coast of New Caledonia likely belonged to one panmictic population with high level of gene flow observed along the study scale. Further, this panmictic population displayed an effective size of breeders large enough to ensure the feasibility of appropriate breeding programs for restocking. In contrast, hatchery-produced samples did suffer from an important reduction in the effective population size: the effective population size were so small that genetic drift was detectable over one generation, with the presence of inbred individuals, as well as more related dyads than in wild populations. All these results suggest that dedicated efforts in hatcheries are further needed to maintain genetic diversity of hatchery-produced individuals in order to unbalance any negative impact during this artificial selection

    Practice in Child Phonological Disorders: Tackling some Common Clinical Problems

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    Goal of presentation is to identify areas of child phonology that clinicans have difficulty with

    Evaluation of a Deductive Procedure to Teach Grammatical Inflections to Children With Language Impairment

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    Purpose: To evaluate the learning effects of a deductive language-teaching procedure when teaching a novel gender agreement verb inflection to children with language impairment. Method: Thirty-two 6-8-year-old children with language impairment were randomly assigned to either a deductive (N = 16) or an inductive (N = 16) treatment group. In the deductive treatment, the examiner presented a rule guiding the novel inflection to be learned as well as models of the inflection. In the inductive treatment, only models of the verb inflection were presented. Learning was assessed in 3 different production contexts during each of 4 treatment sessions. Results: Significantly more participants in the deductive group than the inductive group acquired the novel morpheme based on a teaching probe (10 vs. 3), generalization probe (10 vs. 3), and maintenance probe (7 vs. 2). Task performance was not significantly influenced by language ability or nonverbal intelligence. Conclusions: The deductive teaching procedure was found to be efficacious when teaching a novel grammatical inflection. However, this effect was limited because treatment gains varied across participants, testing contexts, and sessions. Future studies should continue to examine the efficacy of deductive procedures when integrated into traditional implicit approaches for children with language impairment

    Why Dose Frequency Affects Spoken Vocabulary in Preschoolers With Down Syndrome

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    In an earlier randomized clinical trial, daily communication and language therapy resulted in more favorable spoken vocabulary outcomes than weekly therapy sessions in a subgroup of initially nonverbal preschoolers with intellectual disabilities that included only children with Down syndrome (DS). In this reanalysis of the dataset involving only the participants with DS, we found that more therapy led to larger spoken vocabularies at posttreatment because it increased children’s canonical syllabic communication and receptive vocabulary growth early in the treatment phase
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