5,658 research outputs found

    Delay-Tolerant, Low-Power Protocols for Large Security-Critical Wireless Sensor Networks

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    This paper reports the analysis, implementation, and experimental testing of a delay-tolerant and energy-aware protocol for a wireless sensor node, oriented to security applications. The solution proposed takes advantages from different domains considering as a guideline the low power consumption and facing the problems of seamless and lossy connectivity offered by the wireless medium along with very limited resources offered by a wireless network node. The paper is organized as follows: first we give an overview on delay-tolerant wireless sensor networking (DTN); then we perform a simulation-based comparative analysis of state-of-the-art DTN approaches and illustrate the improvement offered by the proposed protocol; finally we present experimental data gathered from the implementation of the proposed protocol on a proprietary hardware node

    Quality aware selective ECC for approximate DRAM

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    Approximate DRAMs are DRAM memories where energy saving techniques have been implemented by trading off bit-cell error rate with power consumption. They are considered part of the building blocks in the larger area of approximate computing. Relaxing refresh rate has been proposed as an interesting solution to achieve better efficiency at the expense of rising error rate. However, some works have demonstrated that much better results are achieved if at word-level some bits are retained without errors (i.e. their cells are refreshed at nominal rate), resulting in architectures using multiple refresh rates. In this paper we present a technique that can be applied to approximate DRAMs under reduced refresh rate. It allows to trim error rate at word-level, while still performing the refresh operation at the same rate for all cells. The number of bits that are protected is configurable and depends on output quality degradation that can be accepted by the application

    Customizable vector acceleration in extreme-edge computing. A risc-v software/hardware architecture study on VGG-16 implementation

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    Computing in the cloud-edge continuum, as opposed to cloud computing, relies on high performance processing on the extreme edge of the Internet of Things (IoT) hierarchy. Hardware acceleration is a mandatory solution to achieve the performance requirements, yet it can be tightly tied to particular computation kernels, even within the same application. Vector-oriented hardware acceleration has gained renewed interest to support artificial intelligence (AI) applications like convolutional networks or classification algorithms. We present a comprehensive investigation of the performance and power efficiency achievable by configurable vector acceleration subsystems, obtaining evidence of both the high potential of the proposed microarchitecture and the advantage of hardware customization in total transparency to the software program

    Griscelli syndrome type 2: long-term follow-up after unrelated donor bone marrow transplantation

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    Griscelli syndrome (GS) is a rare autosomal recessive disease characterized by silvery hair ('partial albinism'). Three forms exist; GS type 2 (GS2), the most common one, is characterized by severe primary immunodeficiency with acute episodes of hemophagocytic lymphohistiocytosis (HLH) which may be fatal in the absence of hematopoietic stem cell transplantation. A 5-year-old boy with HLH was referred to us because of silvery-gray hair present since birth. Abnormal pigment clumps were observed in the medulla of hair shafts on light microscopy. Electron microscopy of a skin biopsy revealed melanosomes in melanocytes, but not in keratinocytes. Leukocytes were devoid of intracytoplasmic granules on blood smear. Neurological signs were absent. Genotyping revealed a homozygous haplotype for polymorphic markers linked to the RAB27A locus, but no RAB27A mutation. A diagnosis of GS2 was established. The patient received bone marrow transplantation (BMT) from an unrelated donor, and after 72 months he did not show relapse of HLH. The long, uneventful follow-up supports the use of BMT from an unrelated donor if transplantation from a relative is not possible

    A calorimeter coupled with a magnetic spectrometer for the detection of primary cosmic antiprotons

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    A tracking calorimeter made of 3200 brass streamer tubes together with 3200 pick-up strips has been built to complement a magnetic spectrometer in order to detect cosmic antiprotons in space. The characteristics of such a calorimeter, the results of a preliminary test of a prototype as well as the properties of the whole apparatus are presented. The apparatus, designed to operate on a balloon at an altitude of about 40 km, can be considered as a second generation detector, capable in principle to solve the problem of the presence of low energy (≤1 Ge V/c) antiprotons in the cosmic rays which is still open because of the disagreement between the existent experimental data

    Site-specific genetic engineering of the Anopheles gambiae Y chromosome.

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    Despite its function in sex determination and its role in driving genome evolution, the Y chromosome remains poorly understood in most species. Y chromosomes are gene-poor, repeat-rich and largely heterochromatic and therefore represent a difficult target for genetic engineering. The Y chromosome of the human malaria vector Anopheles gambiae appears to be involved in sex determination although very little is known about both its structure and function. Here, we characterize a transgenic strain of this mosquito species, obtained by transposon-mediated integration of a transgene construct onto the Y chromosome. Using meganuclease-induced homologous repair we introduce a site-specific recombination signal onto the Y chromosome and show that the resulting docking line can be used for secondary integration. To demonstrate its utility, we study the activity of a germ-line-specific promoter when located on the Y chromosome. We also show that Y-linked fluorescent transgenes allow automated sex separation of this important vector species, providing the means to generate large single-sex populations. Our findings will aid studies of sex chromosome function and enable the development of male-exclusive genetic traits for vector control

    A synthetic sex ratio distortion system for the control of the human malaria mosquito.

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    It has been theorized that inducing extreme reproductive sex ratios could be a method to suppress or eliminate pest populations. Limited knowledge about the genetic makeup and mode of action of naturally occurring sex distorters and the prevalence of co-evolving suppressors has hampered their use for control. Here we generate a synthetic sex distortion system by exploiting the specificity of the homing endonuclease I-PpoI, which is able to selectively cleave ribosomal gene sequences of the malaria vector Anopheles gambiae that are located exclusively on the mosquito's X chromosome. We combine structure-based protein engineering and molecular genetics to restrict the activity of the potentially toxic endonuclease to spermatogenesis. Shredding of the paternal X chromosome prevents it from being transmitted to the next generation, resulting in fully fertile mosquito strains that produce >95% male offspring. We demonstrate that distorter male mosquitoes can efficiently suppress caged wild-type mosquito populations, providing the foundation for a new class of genetic vector control strategies

    A Study of Marketing Strategy of Sony Electron in China

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    本文首先对索尼的企业创建、品牌成长、在华历程进行简要回顾。然后运用PEST、波特五力模型、SWOT分析法分析索尼电子在中国市场面临的宏观环境及所处的行业结构,揭示环境和行业结构对索尼电子带来的机会和挑战,分析索尼电子在中国营销的优势、劣势。在此基础上,以4P理论为视角,从产品、价格、渠道、促销四个方面对索尼在华营销策略进行了研究。研究发现,在产品策略方面,索尼注重以消费者需求为导向提供产品,在塑造品牌形象的同时不断加强售后服务网络的建设,以切实的行动维护消费者的利益,赢得了消费者的青睐;在价格策略方面,索尼主要采用了高价位的策略来提升产品定位,采用波浪式的降价来促销中等价位产品,结合中国市场的...The paper first makes a concise review of Sony’s history and its development in China. The paper then analyzes the macro environments and the industrial structure of Sony Electric in China by methods of PEST, Porter’s Five Forces Model and SWOT, to reveal opportunities and threats coming from the environments and the industrial structure, and analyzes Sony’s advantages and disadvantages in China’s...学位:文学硕士院系专业:新闻传播学院广告学系_传播学学号:3062007115249

    Full Geant4 and FLUKA Simulations of an e-LINAC for its Use in Particle Detectors Performance Tests

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    In this work we present the results of full Geant4 and FLUKA simulations and comparison with dosimetry data of an electron LINAC of St. Maria Hospital located in Terni, Italy. The facility is being used primarily for radiotherapy and the goal of present study is the detailed investigation of electron beam parameters to evaluate the possibility to use the e-LINAC (during time slots when it is not used for radiotherapy) to test the performance of detector systems in particular those designed to operate in space. The critical beam parameters are electron energy, profile and flux available at the surface of device to be tested. The present work aims to extract these parameters from dosimetry calibration data available at the e-LINAC. The electron energy ranges is from 4 MeV to 20 MeV. The dose measurements have been performed by using an Advanced Markus Chamber which has a small sensitive volume.Comment: 10 pages, 10 figures, 2 table

    Atrial fibrillation pattern, left atrial diameter and risk of cardiovascular events and mortality. A prospective multicenter cohort study.

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    BACKGROUND There are conflicting evidence on the association between atrial fibrillation (AF) pattern, such as persistent/permanent (Pers/Perm) and paroxysmal (PAF) AF and risk of ischemic events. We investigated if left atrial diameter (LAd) may affect the risk of cardiovascular outcomes according to AF pattern. METHODS Prospective multicenter observational including 1,252 non-valvular AF patients (533 PAF and 719 Pers/Perm AF). Study endpoints were cardiovascular events (CVEs), major adverse cardiac events (MACE) and CV death. LA anteroposterior diameter (LAd) was obtained by transthoracic echocardiography. RESULTS Pers/Perm AF patients had a higher proportion of LAd above median than PAF (≥44 mm, 59.5% vs 37.5% respectively, P < .001). In a mean follow-up of 42.2 ± 31.0 months (4,315 patients/year) 179 CVEs (incidence rate [IR] 4.2%/year), 133 MACE (IR 3.1%/year), and 97 CV deaths (IR 2.2%/year) occurred. Compared to patients with LAd below median, those with LAd above the median had a higher rate of CVEs (log-rank test, P < .001), MACE (log-rank test P < .001), and CV death (log-rank test P < .001). Multivariable Cox regression analysis showed that LAd above the median was associated with CVEs, (HR 1.569, 95% CI 1.129-2.180, P = .007) MACE (HR 1.858, 95% CI 1.257-2.745, P = .002) and CV death (HR 2.106, 95% CI 1.308-3.390, P = .002). The association between LAd and outcomes was evident both in PAF and Pers/Perm AF patients. No association between AF pattern and outcomes was found. CONCLUSION LAd is a simple parameter that can be obtained in virtually all AF patients and can provide prognostic information on the risk of CVEs, MACE and CV death regardless of AF pattern
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