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21.
Informed by research over the past two years and the work of colleagues in peer institutions, the IFI Irish Film Archive developed a six-year Digital Preservation and Access strategy which launched in 2014. Fundamental to this Strategy was the design and installation of digital archive tools for long term preservation and the redesign of workflow practices to facilitate accession and management of high resolution digital film and broadcast assets and associated metadata. This article outlines the steps taken and standards applied in developing a future proof digital audiovisual archive. 相似文献
22.
Dorothy K. Hall Jason E. Box Kimberly A. Casey Simon J. Hook Christopher A. Shuman Konrad Steffen 《Remote sensing of environment》2008,112(10):3739-3749
The most practical way to get spatially broad and continuous measurements of the surface temperature in the data-sparse cryosphere is by satellite remote sensing. The uncertainties in satellite-derived LSTs must be understood to develop internally-consistent decade-scale land surface temperature (LST) records needed for climate studies. In this work we assess satellite-derived “clear-sky” LST products from the Moderate Resolution Imaging Spectroradiometer (MODIS) and the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), and LSTs derived from the Enhanced Thematic Mapper Plus (ETM+) over snow and ice on Greenland. When possible, we compare satellite-derived LSTs with in-situ air temperature observations from Greenland Climate Network (GC-Net) automatic weather stations (AWS). We find that MODIS, ASTER and ETM+ provide reliable and consistent LSTs under clear-sky conditions and relatively-flat terrain over snow and ice targets over a range of temperatures from ? 40 to 0 °C. The satellite-derived LSTs agree within a relative RMS uncertainty of ~ 0.5 °C. The good agreement among the LSTs derived from the various satellite instruments is especially notable since different spectral channels and different retrieval algorithms are used to calculate LST from the raw satellite data. The AWS record in-situ data at a “point” while the satellite instruments record data over an area varying in size from: 57 × 57 m (ETM+), 90 × 90 m (ASTER), or to 1 × 1 km (MODIS). Surface topography and other factors contribute to variability of LST within a pixel, thus the AWS measurements may not be representative of the LST of the pixel. Without more information on the local spatial patterns of LST, the AWS LST cannot be considered valid ground truth for the satellite measurements, with RMS uncertainty ~ 2 °C. Despite the relatively large AWS-derived uncertainty, we find LST data are characterized by high accuracy but have uncertain absolute precision. 相似文献
23.
Much of what modern digital rights management (DRM) systems attempt to accomplish was actually forcefully implemented on videogame consoles beginning with the Nintendo Entertainment System (NES) and SEGA Genesis system in the early 1980s. Examining the links between modern DRM mechanisms and these early production and copy protection systems can help contextualize the future of media production and access. 相似文献
24.
Leopoldina Fortunati Mauro Sarrica John O'Sullivan Aukse Balcytiene Halliki Harro-Loit Phil Macgregor Nayia Roussou Ramón Salaverría Federico de Luca 《Journal of Computer-Mediated Communication》2009,14(4):928-963
This study investigates how European journalists evaluate the changes that have occurred in their profession since the Internet has been integrated in newsrooms. How do journalists perceive the features and innovations associated with the Internet? What are the principal changes in the profession? Do practitioners believe that the quality of journalism has been raised or lowered? To answer to these research questions, we carried out a survey across 11 European countries–Cyprus, Estonia, Finland, Greece, Ireland, Italy, Lithuania, United Kingdom, Slovenia, Spain, Sweden–of 239 journalists, working for 40 of the most‐read print/online news outlets in these countries. The survey shows that the opportunity to use the Internet to reinforce the social functions of journalism has not been fully recognised. 相似文献
25.
Triangulation is the means by which an alternate perspective is used to validate, challenge or extend existing findings. It
is frequently used when the field of study is difficult, demanding or contentious and presence research meets all of these
criteria. We distinguish between the use of hard and soft triangulation—the former emphasising the challenging of findings,
the latter being more confirmatory in character. Having reviewed a substantial number of presence papers, we conclude that
strong triangulation is not widely used while soft triangulation is routinely employed. We demonstrate the usefulness of hard
triangulation by contrasting an ontological analysis of in-ness with an empirical study of (computer) game playing. We conclude that presence research would be well served by the wider
use of hard triangulation and for the reporting of anomalous and ill-fitting results.
相似文献
Susan TurnerEmail: |
26.
Optimizing rod window width in positron emission tomography 总被引:1,自引:0,他引:1
A technique determines the optimal window width for orbiting rod transmission studies in positron emission tomography (PET). Windowing reduces noise in orbiting rod transmission studies. Lines-of-response (LOR) which intersect the rods generate primarily true coincidence events. LOR which pass far from the rods generate random and scatter events. Since the angular position of the orbiting rods is known in real-time, LOR which produce mostly noise are gated off. When optimally determined, the rod window width maximizes the noise equivalent counts (NEC) collected in the transmission study. Transaxial rod projection profiles of trues, randoms, and scatter produce NEC versus window width plots. For the ECAT EXACT line of PET systems and a 20-cm water cylinder, optimal is five LOR wide. 相似文献
27.
This paper focuses on the adaptive observer design for nonlinear discrete‐time MIMO systems with unknown time‐delay and nonlinear dynamics. The delayed states involved in the system are arguments of a nonlinear function and only the estimated delay is utilized. By constructing an appropriate Lyapunov–Krasovskii function, the delay estimation error is considered in the observer parameter design. The proposed method is then extended to the system with a nonlinear output measurement equation and the delayed dynamics. With the help of a high‐order neural network (HONN), the requirement for a precise system model, the linear‐in‐the‐parameters (LIP) assumption of the delayed states, the Lipschitz or norm‐boundedness assumption of unknown nonlinearities are removed. A novel converse Lyapunov technical lemma is also developed and used to prove the uniform ultimate boundedness of the proposed observer. The effectiveness of the proposed results is verified by simulations. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
28.
Translating between dissimilar languages requires an account of the use of divergent word orders when expressing the same
semantic content. Reordering poses a serious problem for statistical machine translation systems and has generated a considerable
body of research aimed at meeting its challenges. Direct evaluation of reordering requires automatic metrics that explicitly
measure the quality of word order choices in translations. Current metrics, such as BLEU, only evaluate reordering indirectly.
We analyse the ability of current metrics to capture reordering performance. We then introduce permutation distance metrics
as a direct method for measuring word order similarity between translations and reference sentences. By correlating all metrics
with a novel method for eliciting human judgements of reordering quality, we show that current metrics are largely influenced
by lexical choice, and that they are not able to distinguish between different reordering scenarios. Also, we show that permutation
distance metrics correlate very well with human judgements, and are impervious to lexical differences. 相似文献
29.
Abhishek Arun Barry Haddow Philipp Koehn Adam Lopez Chris Dyer Phil Blunsom 《Machine Translation》2010,24(2):103-121
Recent advances in statistical machine translation have used approximate beam search for NP-complete inference within probabilistic
translation models. We present an alternative approach of sampling from the posterior distribution defined by a translation
model. We define a novel Gibbs sampler for sampling translations given a source sentence and show that it effectively explores
this posterior distribution. In doing so we overcome the limitations of heuristic beam search and obtain theoretically sound
solutions to inference problems such as finding the maximum probability translation and minimum risk training and decoding. 相似文献
30.
Guillaume F. Remy Hassan B. Kazemian Phil Picton 《Neural computing & applications》2011,20(6):879-887
This paper is to introduce an application of Computational Intelligence (CI) to Moving Picture Expert Group-4 (MPEG-4) video
compression over IEEE.802.15.1 wireless communication, known as Bluetooth 1.2, in order to improve picture quality. The 2.4 GHz
Industrial, Scientific and Medical frequency band is used for the IEEE.802.15.1 standard. IEEE.802.15.1 can be affected by
noise and interference due to other neighboring wireless devices sharing the same frequency carrier. The noise and interference
create difficulties in ascertaining an accurate real-time transmission rate at the receiving end. Furthermore, the MPEG-4
codec is an object-oriented compression system and demands a high bandwidth. It is therefore difficult to avoid excessive
delay, image quality degradation and/or data loss during MPEG-4 video transmission over standard systems. A new buffer entitled
‘buffer added’ has been introduced at the input of the Bluetooth 1.2 device. This buffer is controlled by a Rule-Based Fuzzy
(RBF) logic controller at the input and a neural-fuzzy controller (NFC) at the output. The two new fuzzy rules manipulate
and supervise the flow of video over the Bluetooth 1.2 standard. The computer simulation results illustrate the comparison
between a non-CI video transmission over Bluetooth 1.2 and the proposed design, confirming that the applications of RBF and
NFC do improve the image quality, reduce data loss and reduce time delay. 相似文献