226,245 research outputs found
The results of the Delft Systematic Deadrise Series
No full textIn the present paper the development of the Delft Systematic Deadrise Series (DSDS) is described. The DSDS has been under development for decades by now and consists of a large family of systematically varied hard chine planing monohulls, based on the original research by Clement and Blount, which have all been tested in the same speed range, changing the same parameters and using the same experimental set up. The rationale behind the DSDS is highlighted. The DSDS contains up to now some 24 different models in 350 different conditions all tested in the same speed range between Fn∇ = 0.75 and Fn∇ = 3.0. Recently there has been a new extension to the DSDS with the inclusion of more measurements on hulls with twisted bottom and rocker in the aft ship. These results are presented in this paper.In addition detailed access is facilitated to all the hull geometries used into the DSDS and to all the raw measurement data obtained during the tests by means of free access to a dedicated website.Ship Hydromechanics and Structure
Multi-Stage Multi-User Detection Assisted Asynchronous Fast-FH/MFSK
No full textA multi-stage Multi-User Detection (MUD) scheme designed for asynchronous fast Frequency-Hopping/Multilevel Frequency-Shift-Keying (fast-FH/MFSK) systems is proposed, in which each signal detection interval is divided into sub-intervals and the MUD is applied to each sub-interval. In our scheme the MUD exploits the explicit knowledge of the hopping addresses assigned to users. The received signal level is attenuated by a constant scaling factor, when it is deemed to be overwhelmed by multi-user interference. For the sake of preventing erroneous detection events, when communicating over frequency-selective fading channels, the scheme advocated also invokes a space diversity technique. In the investigated scenario the achievable Bit Error Rate (BER) of the proposed scheme was reduced by as much as an order of magnitude in comparison to that of a conventional MUD scheme, when transmitting over an AWGN channel. For transmission over a channel exhibiting uncorrelated frequency-domain fading, selection diversity was used for the sake of achieving a reduced BER
Effects of Moritella viscosa antigens on pro-inflammatory gene expression in an Atlantic salmon (Salmo salar Linnaeus) cell line (SHK-1)
No full textMoritella viscosa is the causative agent of winter ulcer disease in salmonids reared in North-Atlantic countries. In this study the effects of selected M. viscosa antigens on cytotoxicity and pro-inflammatory gene expression in an Atlantic salmon (Salmo salar Linnaeus) macrophage-like cell line (SHK-1) were examined. SHK-1 cells were stimulated with live and heat-killed bacterial cells, extracellular products (ECP) and an extracellular vibriolysin, termed MvP1. Following incubation, cytotoxicity and expression levels of interleukin-1β (IL-1β) and interleukin-8 (IL-8) were examined at different time points. Both live M. viscosa cells and ECP were cytotoxic, but neither heat-killed cells, nor the MvP1 peptidase caused cell death. Expression levels of both IL-1β and IL-8 increased significantly after stimulation with live cells, but heat-killed cells only caused increased IL-8 expression. ECP did not affect IL-1β expression, but did stimulate IL-8 expression. The isolated MvP1 peptidase stimulated both IL-1β and IL-8 expression at the highest concentration tested. This study reveals a difference in the induction of pro-inflammatory gene expression in salmon SHK-1 cells between live and heat-killed M. viscosa cells, and also that an unknown secreted factor is the main stimulant of IL-β and IL-8 expression.ID: S1050464809000990; M3: Article; Accession Number: S1050464809000990; Author: Bryndis Bjornsdottir (a, b); Author: Mark D. Fast (b, 1); Author: Sandra A. Sperker (b); Author: Laura L. Brown (b, 2); Author: Bjarnheidur K. Gudmundsdottir (a, ∗); Affiliation: Institute for Experimental Pathology, University of Iceland, Keldur v/Vesturlandsveg, 112 Reykjavík, Iceland; Affiliation: National Research Council Canada, Institute for Marine Biosciences, 1411 Oxford Street, Halifax, Nova Scotia B3H 2Z1, Canada; Keyword: Moritella viscosa; Keyword: Extracellular products; Keyword: MvP1 vibriolysin; Keyword: Atlantic salmon; Keyword: SHK-1; Keyword: Gene expression; Keyword: Immune response; Keyword: Pro-inflammatory cytokine; Keyword: Interleukin-1β (IL-1β); Keyword: Interleukin-8 (IL-8); Number of Pages: 6; Language: English;Source type: Electronic(1
Soft Decoding Assisted Interference Cancellation in a Non-Binary LDPC Coded Fast Frequency Hopping Multiuser System Using Product Combining
No full textIn this contribution, soft-input-soft-output (SISO) decoding aided successive interference cancellation (SIC) is considered in fast frequency hopping (FFH), M-ary frequency shift keying (MFSK) using product combining (PC), when operating in multiple access (MA) Nakagami-m channels. All users’ Mary source symbols are encoded using non-binary LDPC codes and the encoded symbols are transmitted using FFH-MFSK modulation. A sub-optimum soft metric is proposed which is based on self-normalization of the diversity combiner outputs. In the context of the proposed SIC scheme, the receiver exploits the soft information fed back by the LDPC decoder to the demodulator in order to cancel the interference imposed by the reliably detected symbols. Our simulation results show that the proposed scheme is capable of combatting the effects of multiuser interference and outperforms conventional iterative decoding by about 1dB
Fast Food: Slow Poison
No full textThe word Fast food which is also called junk food has been primarily resonating in a diet from last decade. The most common ingredients used for making fast foods are maida, corn flour, saturated fats, preserved raw materials, milk products and preservatives which are harmful to maintain a better health. Diet is a route cause of all diseases. Occasional intake of fast food doesn’t cause any diseases. Frequent intake of fast food in a diet has negative impact on health. Though the fast food is tasty, it significantly affects almost all systems of our body like a slow poison which assist in the manifestion of diseases. Pizza, burger, sandwich and bakery products are most often choosen by population. This article is published in order to create awareness among the public to restrict the frequent use of poor nutritious as well as substandard food in routine life for better health
Fast methods for training Gaussian processes
No full textThis submission includes a simplified version of some code we have been developing for fast training of Gaussian processes. We also include a sample data set, which is NOAA tidal data from Woods Hole in the US, downloaded from http://tidesandcurrents.noaa.gov/ .
The code and data included here were used to produce the numerical results in the following paper:
[1] Fast methods for training Gaussian processes, C. J. Moore, A. J. K. Chua, C. P. L. Berry, and J. R. Gair (2016), submitted to RSOS
Fast-acting effects of l-tetrahydropalmatine on depression and anxiety in mice
No full textAbstract: The racemate dl-tetrahydropalmatine (dl-THP) is known for its analgesic and sedative effects, and has been shown by us to be a potential agent for the treatment of anxiety.Herein, to delineate the therapeutic potentials of its different isomeric forms, the behavioral effects of l-THP, dl-THP and d-THP were compared regarding their anxiolytic and antidepressant properties in mouse behavioral models using the elevated plus-maze test and tail suspension test respectively. The anxiolytic and antidepressant effects of both l-THP and dl-THP were evident in forty-five minutes following oral administration. Moreover, l-THP exhibited much greater anxiolytic potency in the elevated plus-maze (0.1-2.5 mg/kg) and antidepressant potency in the tail suspension test (0.5-5.0 mg/kg) than dl-THP, whereas d-THP was inactive in either of these tests. As well, l-THP enhanced sociability and preference for social novelty at 0.1-0.5 mg/kg in Crawley’s three-chamber behavioral tests, and inhibited the amphetamine-induced manic-like hyperactivity of amphetamine-sensitized mice at 0.05-0.2 mg/kg. These pharmacological actions of l-THP were unaccompanied by any significant locomotor or myorelaxant side-effects. Co-administration of flumazenil, a GABAA receptor antagonist, inhibited the anxiolytic and antidepressant effects of l-THP, even though the binding affinity of l-THP was higher for dopamine D2-like receptors than for GABAA receptors. On this basis, l-THP displayed potential as a fast-acting drug for the treatment of anxiety, depression and bipolar disorder
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Diversity Combining for Fast Frequency Hopping Multiple Access Systems Subjected to Nakagami-m Fading
No full textThe achievable performance of various diversity combining schemes used in fast frequency hopping (FFH) aided M-ary frequency shift keying (MFSK) systems operating in a multiple access scenario subjected to Nakagami-m fading is investigated. Specifically, linear, self-normalization, hard limiting majority vote, soft limiting, product combining and order statistics-normalized envelope detection based diversity combining schemes are considered. The comparison of various diversity combining schemes is based on the achievable bit error rate versus the number of simultaneous users supported. It is shown using simulation results that although some of the combining schemes considered result in an inferior performance compared to the optimum soft limiting combiner, they offer the advantage of achieving an acceptable interference suppression performance without requiring side information
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