15,732 research outputs found
The optimal synapse for sparse, binary signals in the rod pathway:Neural Computation
No full textThe sparsity of photons at very low light levels necessitates a nonlinear synaptic transfer function between the rod photoreceptors and the rod-bipolar cells. We examine different ways to characterize the performance of the pathway: the error rate, two variants of the mutual information, and the signal-to-noise ratio. Simulation of the pathway shows that these approaches yield substantially different performance at very low light levels and that maximizing the signal-to-noise ratio yields the best performance when judged from simulated images. The results are compared to recent data.</p
Engineer's Level Rod
No full textReissued patent for an improvement in engineer's level which introduces a novel manner of marking the scale upon the face of the rod
From line to dots: an improved computerised rod and frame system for testing subjective visual vertical and horizontal
No full textBackground Perception of subjective visual vertical (SVV) and horizontal (SVH) has traditionally been measured by rotating a mechanical rod either with or without a frame present. The computerised rod and frame (CRAF) system has previously only been used to measure SVV. We have expanded the use of this system by testing its feasibility to measure SVH. This was done by comparing two groups of subjects (n = 103) randomly assigned to be tested for SVV or SVH. Findings Preliminary results showed a higher than expected percentage of individuals with SVH errors < 0.5°. This was attributed to additional visual cues provided by the changing appearance of the rod as it approached the horizontal. A solution to this problem was sought by replacing the rod by two dots to mark its ends. In a second investigation 30 subjects were tested using both the "rod as line" and "rod as dots" presentation. Bland and Altman analysis showed no difference between the rod and dots presentations in the measurement of SVV, but confirmed a fixed error of -0.93° between rods and dots for SVH. Changing the rod from a line to dots in the computer system resulted in errors for both SVV and SVH that were comparable to previous studies using manual systems. Conclusions The computerized rod and frame system may be improved by replacement of the line with two dots. This reduces clues provided to the subject by the appearance of the rod on the screen
Modelling Rod-like Flexible Biological Tissues for Medical Training
No full textThis paper outlines a framework for the modelling of slender rod-like biological tissue structures in both global and local scales. Volumetric discretization of a rod-like structure is expensive in computation and therefore
is not ideal for applications where real-time performance is essential. In our approach, the Cosserat rod model is introduced to capture the global shape changes, which models the structure as a one-dimensional entity, while the
local deformation is handled separately. In this way a good balance in accuracy and efficiency is achieved. These advantages make our method appropriate for
the modelling of soft tissues for medical training applications
mm-Wave DRW Antenna Phase Centre Determination
No full textThis document presents an approach to the phase centre determination of a dielectric rod waveguide (DRW) antenna by means of measurements obtained with a planar measuring system at millimeter wave lengths. Phase centre determination by the least squares fit technique is described in this document for different DRW antennas (silicon and sapphire). Results at different operating frequencies are offered
Współczesne trendy w miejskim ogrodnictwie działkowym na przykładzie wybranych rodzinnych ogrodów działkowych (ROD) w Warszawie
No full textThe study aims to gain an insight into current trends in the use of four selected allotment gardens (rodzinne ogrody działkowe – RODs) in Warsaw (Poland): ROD ‘Pratulińska’, ROD ‘Obrońców Pokoju’, ROD ‘Kolejarz’ and ROD ‘Zelmot’. The main method used in the research was a survey of plot holders (structured interviews, n = 210). The findings suggest that holders are mainly older, retired people, but the number of younger plot holders has been increasing in recent years. Most live on huge estates in close proximity to the allotment gardens. The main motivations for having a plot are relaxation, gardening as a hobby and connection with the natural environment. Food production itself was not mentioned as a prior motivation. The meaning of having a plot corresponds with motivations. Some plot holders emphasize having their own, private place (a kind of second home, refuge, respite from city life). Most of the respondents have positive opinions regarding opening allotment gardens to local communities, although they are not very eager to participate in integrational events and activities organized by the Polish Association of Allotment Gardens (PZD) or others. The findings are in line with global trends presented in research exploring allotment garden recreational space in Poland and abroad.Artykuł ma na celu charakterystykę aktualnych tendencji w użytkowaniu czterech wybranych ogrodów działkowych w Warszawie: ROD „Pratulińska”, ROD „Obrońców Pokoju”, ROD „Kolejarz” i ROD „Zelmot”. Podstawową metodą badawczą był sondaż ankietowy przeprowadzony wśród działkowiczów (wywiad strukturyzowany, n = 210). Rezultaty analizy pokazują, że są nimi głównie osoby starsze, w tym emeryci, jednakże w ostatnich latach liczba młodszych użytkowników działek stopniowo wzrasta. Większość działkowców mieszka na osiedlach zlokalizowanych w bezpośrednim sąsiedztwie ogrodów. Główne motywacje posiadania działki to: wypoczynek, hobby ogrodnicze oraz kontakt z przyrodą. Popularna do niedawna produkcja własnych płodów rolnych nie została wymieniona jako istotna motywacja. Rola, jaką odgrywa użytkowanie działki, koresponduje z motywacjami. Niektórzy działkowicze podkreślają, że oznacza to posiadanie własnego miejsca (rodzaj drugiego domu, schronienia, wytchnienia od miejskiego życia). Większość respondentów pozytywnie ocenia proces otwierania ogrodów działkowych dla społeczności lokalnych, choć niezbyt chętnie uczestniczy w wydarzeniach integracyjnych organizowanych przez Polski Związek Działkowców (PZD) lub inne instytucje. Uzyskane wyniki są zgodne ze światowymi trendami, prezentowanymi w badaniach nad przestrzenią rekreacyjną ogrodów działkowych w Polsce i za granicą
An Elastic Membrane With an Attached Non-Linear Thermoelastic Rod
No full textWe study a thermo-mechanical system consisting of an elastic membrane to which a shape-memory rod is glued. The slow movements of the membrane are controlled by the motions of the attached rods. A quasi-static model is used. We include the elastic feedback of the membrane on the rods. This results in investigating an elliptic boundary value problem in a domain W is subset R2 with a cut, coupled with non-linear equations for the vertical motions of the rod and the temperature on the rod. We prove the existence of a unique global weak solution to this problem using a fixed point argument
Microspaces. ROD Secret Gardens
No full textArtykuł jest formą krótkiego spaceru po działkach ROD. Opisuje fenomen funkcjonowania ogrodu działkowego, traktuje go jako specyficzną odmianę przestrzeni intymnej, jednej z bliższych człowiekowi, miejsce zaspokajania jego różnych potrzeb. Za jedną z tych potrzeb artykuł przyjmuje ludzką chęć tworzenia, budowania, anektowania przestrzeni według własnych reguł i zasad. Ogród działkowy jako miejsce znajdujące się poza oficjalną strefą miasta, z dala od normalnego codziennego życia, stwarza możliwość kreowania przez jego użytkownika nowej własnej rzeczywistości przestrzennej, nieograniczonej żadnymi barierami. Brama ROD staje się miejscem „przejścia” do innej rzeczywistości, pozwala zapomnieć o codziennych problemach i przenieść się w inny, oswojony wymiar.The article is a form of a short walk through the ROD allotment gardens. Drawing on examples of such allotments not only in Poland, but also in various parts of Europe, it describes the phenomenon of the functioning of the allotment garden, treating it as a specific kind of intimate space, very close to human, a place for satisfying their various needs. The article considers as one of these needs the human desire to create, to build, to annex space according to their own rules and principles. The allotment garden, as a place outside the official zone of the city, away from normal everyday life, offers its user the possibility to create a new spatial reality of their own, unhindered by any barriers. The gate to the ROD allotment gardens becomes a place of ‘transition’ to another reality, allowing you to forget your everyday problems and move into another, tame dimension
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