1,559 research outputs found

    Time-division-multiplexing using pulse position locking for 100 Gb/s applications

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    Recently, there is a great interest in pushing communication technologies to 100 Gb/s. However, there are still many challenges to perform high speed (> 40 Gb/s) clock and data recovery, and data time-division-multiplexing (TDM). Here, we propose and numerically analyze an asynchronous optical packet retimer using parabolic or sinusoidal phase modulation and linear dispersion. This scheme is named pulse position locking (PPL). Numerical simulation shows that this scheme can effectively resynchronize input signals with arbitrary delays to the local clock, and reduce input jitter. The scheme can also be applied to TDM 10 Gb/s and 40 Gb/s signals to over 100 Gb/s

    1928 Packard sedan and woman with chow-chow dog on leash

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    8x10 black and white Packard Co. file photograph of a 1928 Packard left side view, parked in field, female at wheel, another female with a chow-chow dog on leash standing at rear. Inscribed on photo back: Packard 443, custom eight (produced 7/1/1927-8/1/1928), fourth series eight, 8-cylinder, 106-horsepower, 143-inch wheelbase, 4-person sedan (body type #1504), body by Dietrich, owner Mr. C.W. Bell of Boston, Mass., an equally prized possession is the blue-ribbon winning chow-chow dog, Whang, whose line goes back through Wahhang (A.K.C. 249626) & Chee Toy (A.K.C. 221719)

    Deriving Regression Lines Without Calculus

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    This article, C.W. Puritz of the Royal Grammar School - High Wycombe, describes a method to calculate the least squares line algebraically. First, the author uses a numeric example, which uses calculus, then describes a simpler algebraic method. This is a great lesson plan for those instructors attempting to teach this method with having students with prior knowledge of calculus. The author uses a step by step approach to help best describe both the technique and subsequent ways to best teach this method

    Development and optimisation of a duplex real-time reverse transcription quantitative PCR assay targeting the VP7 and NS2 genes of African horse sickness virus

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    Nucleotide sequences of 52 South African isolates of African horse sickness virus (AHSV) collected during 2004–2005 and including viruses of all nine AHSV serotypes, were used to design and develop a duplex real-time reverse transcription quantitative PCR (RT-PCR) assay targeting the VP7 (S8) and NS2 (S9) genes of AHSV. The assay was optimized for detection of AHSV in fresh and frozen blood of naturally infected horses. Assay performance was enhanced using random hexamers rather than gene-specific primers for RT, and with denaturation of double-stranded RNA in the presence of random hexamers. The assay was efficient with a linear range of at least five orders of magnitude. The analytical sensitivity of the assay was 132 copies of the target genes (4125 copies per ml of blood), and the assay was at least 10-fold more sensitive than virus isolation on BHK-21 cells. The assay was also highly specific because it did not detect related orbiviruses, such as bluetongue and equine encephalosis viruses.ID: S0166093410000893; M3: Article; Accession Number: S0166093410000893; Author: M. Quan (a, b, ⁎); Author: C.W. Lourens (a, b); Author: N.J. MacLachlan (c); Author: I.A. Gardner (d); Author: A.J. Guthrie (a); Affiliation: Equine Research Centre, Faculty of Veterinary Science, University of Pretoria, Private Bag X04, Onderstepoort 0110, South Africa; Affiliation: Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Private Bag X04, Onderstepoort 0110, South Africa; Affiliation: Equine Viral Disease Laboratory, Department of Pathology, Microbiology and Immunology, School of Veterinary Medicine, University of California, Davis, CA 95616, USA; Affiliation: Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis, CA 95616, USA; Keyword: African horse sickness virus; Keyword: Real-time quantitative RT-PCR; Keyword: VP7 gene; Keyword: NS2 gene; Keyword: Duplex; Number of Pages: 8; Language: English

    Nota, betreffende berekeningen omtrent rivierverbeteringen: opgemaakt door den ingenieur van den Rijkswaterstaat C.W. Lely

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    Hydraulische basis voor de normalisatiewerken van de grote rivieren. Berekingen van optimale breedte en diepte

    Onderzoek naar signaalgeneratie met behulp van fasedraaiers ten behoeve van reflectie-compensatie in een F.M.-C.W. radarsysteem

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    Voor onderzoek aan de troposfeer wordt gebruik gemaakt van een F.M.-C.W. radarsysteem. Een aspect van het radarsysteem waarnaar nog onderzoek gewenst is, is de onderdrukking van de overspraak van zender naar ontvanger, en van sterke reflecties aan nabije obstakels: deze signalen houden nl. het gevaar in van oversturing van de ontvanger. Dit aspect is met name van belang voor een mogelijk nog te realiseren F.M. -C.V. radarsysteem met één antenne…Applied SciencesElectrotechniekTelecommunicatie- en Verkeersbegeleidingssysteme
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