121,811 research outputs found
Coverage and interference in co-channel spectrum sharing between terrestrial and satellite networks
The satellite access to 6G services has the ambition to literally extend the coverage of the terrestrial networks to everywhere on Earth. 3GPP communication technologies are extended from Terrestrial Networks (TNs) to Non-Terrestrial Networks (NTNs), but so far the focus has been on systems where TNs and NTNs operate in their dedicated frequency bands. Providing the services in the same frequency band in satellite and terrestrial networks increases spectrum utilization efficiency, simplifies the user equipment, and shortens the delay of spectrum availability for satellite 6G services. However, the lack of capability to adapt to the expansion of TNs and the rigid sharing arrangements have not encouraged cooperative business cases between satellite and terrestrial networks. We show how cognitive, database-driven control of earth-fixed satellite beams enables co-channel DSA of NTN and TN, in the way that NTN downlink does not decrease the TN downlink capacity. We focus on the case where TN has a priority over the satellite network. The performance of the designed system is evaluated in terms of interference, capacity, coverage and spectrum utilization efficiency for cooperative and non-cooperative sharing. In the simulated study cases, the median coverage improvement with maximum -6 dB I/N at TN user equipment is 400% compared to no sharing cases. The results confirm that the maximum I/N level can be controlled by the database system to the specified level and that the separation distance between the TN and NTN coverage areas is highly dependent on the direction of the NTN beams
Coverage and interference in co-channel spectrum sharing between terrestrial and satellite networks
The satellite access to 6G services has the ambition to literally extend the coverage of the terrestrial networks to everywhere on Earth. 3GPP communication technologies are extended from Terrestrial Networks (TNs) to Non-Terrestrial Networks (NTNs), but so far the focus has been on systems where TNs and NTNs operate in their dedicated frequency bands. Providing the services in the same frequency band in satellite and terrestrial networks increases spectrum utilization efficiency, simplifies the user equipment, and shortens the delay of spectrum availability for satellite 6G services. However, the lack of capability to adapt to the expansion of TNs and the rigid sharing arrangements have not encouraged cooperative business cases between satellite and terrestrial networks. We show how cognitive, database-driven control of earth-fixed satellite beams enables co-channel DSA of NTN and TN, in the way that NTN downlink does not decrease the TN downlink capacity. We focus on the case where TN has a priority over the satellite network. The performance of the designed system is evaluated in terms of interference, capacity, coverage and spectrum utilization efficiency for cooperative and non-cooperative sharing. In the simulated study cases, the median coverage improvement with maximum-6 dB I/N at TN user equipment is 400% compared to no sharing cases. The results confirm that the maximum I/N level can be controlled by the database system to the specified level and that the separation distance between the TN and NTN coverage areas is highly dependent on the direction of the NTN beams
Proof of Concept for Spectrum Sharing between Terrestrial and Satellite Networks
Satellite communication systems are fundamental components to deploy the future smart and sustainable networks and to achieve the ambitious goal of bringing wireless connectivity anywhere, anytime, at any device. In this new role, one of the main challenges that satellite communication component has to face is the maximization of the spectrum usage. 3GPP communication technologies are extended from Terrestrial Networks (TNs) to Non-Terrestrial Networks (NTNs), but so far the standardisation efforts have been focused on systems where TNs and NTNs operate in their dedicated frequency bands. In this paper, a dynamic spectrum sharing model between NTN elements, in a Non Geostationary orbit, and TN is proposed. A Proof of Concept (PoC) is developed, in order to carry out the interference protection computation. We show that the developed spectrum sharing model can enable spectrum sharing between NTN and TN when their coverage areas do not have to overlap, that the sharing arrangement increases significantly the service coverage in the frequency band and slightly improves the spectrum utilization efficiency. It is also shown that the spectrum management system is able to manage the interference level and to keep the interference-to-noise ratio at the TN user equipment below the specified limit. In fact, the aggregate interference caused by the sharing arrangement does not decrease the capacity of the TN downlink
A Multi-Language Comparison of Influences on Author Verification using Character N-Grams
We create a new multi-language corpus for author verification based on Wikipedia talkpages, and evaluate the influence that differences in topic and time have on character n-gram author profiles. Topic alignment between two texts is found to increase author verification precision, and an authors writing style is found to change over time, but not more significantly after 3 years than after 1 year.Information ArchitectureWISElectrical Engineering, Mathematics and Computer Scienc
Appropriate Similarity Measures for Author Cocitation Analysis
We provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
The vanishing author in computer-generated works: a critical analysis of recent Australian case law
Abstract
The use of software is ubiquitous in the creation of many copyright works, yet the requirement in copyright law that every work have a human author who engages in independent intellectual effort means that its use may prevent copyright subsistence. Several recent Australian cases have refocused attention on authorship as an essential criterion of copyright subsistence, and these cases suggest that much computer-produced output may be authorless and thus lack copyright protection. This article, the first in a two-part series, analyses how each case deals with the question of authorship of computer-produced works and why the use of software diminishes copyright protection for a significant number of computer-generated works. The article critiques the application of conventional notions of human authorship developed in the pre-computer age to modern productions and suggests alternative approaches to authorship that satisfy both the major objectives of copyright policy and the need to adapt to the computer age. The article argues that, without a broader judicial approach to authorship of computer-generated works, Parliament must remedy the lacuna in protection for these ‘authorless’ works. Possible solutions for reform are suggested. In a forthcoming article, the author comprehensively examines those reform proposals
Diffusive author(s), cohesive author: Analysis of S/N (1994)
This study indicates the ways in which various aspects of the author(s) are brought forth in Dumb type’s performance art, the S/N production. Previous research has suggested a non-hierarchical organization of Dumb type and the absence of a “privileged author” in Dumb type’s collaborative work, S/N. However, the results that I have investigated from member’s interviews on the creative process of S/N along with my analysis of the recorded images of S/N, indicate a different aspect of the author(s). First, S/N was created through, so to speak, the collective ideas of the members of Dumb type. Further, S/N has at least nine quotations from previous performances, installations, and printed writings, besides the work-in-progress technique. Explicating one of the “author functions” as given by Michel Foucault, each text has plural subjects of the author. However, it has been revealed from members’ interviews that Teiji Furuhashi had a decision-making role in selecting the members’ ideas within the performance. Since then, S/N has had plural subjects of creation; however, Furuhashi is one of the subjects of creation along with the “privileged author.” S/N has plural authors (diffusive authors) yet at the same time, it has a “privileged author,” Teiji Furuhashi (cohesive author)
Dissipative Range Scaling of Higher Order Structure Functions for Velocity and Passive Scalars
Differently to Kolmogorov's second similarity hypothesis, we find that the 2n-th order velocity and scalar structure functions scale with n-th order moment of the energy dissipation and the scalar dissipation, respectively. The origins of this scaling are analyzed by the transport equations of the fourth order velocity and scalar increment moments and by direct numerical simulations
Fast implementation of iterative adaptive approach for wideband unambiguous radar detection
Accepted author manuscriptMicrowave Sensing, Signals & System
Ratio of n-6/n-3 in the diets of beef cattle
Effects of feeding heat-treated canola (C), soybean (S) and flax (F) or mixtures on growth and slaughter characteristics, taste and fatty acid (FA) composition of beef tissue were investigated using 128 crossbred steers to determine the potential of improving the nutritional quality of beef for humans. For Trial 1 (48 steers), dietary treatments were: roasted C, extruded C, roasted S, extruded S, roasted F and extruded F. For Trial 2 (80 steers), the dietary treatments were: S:F (1:1), S:C (1:1), C:F (1:1) and S:F:C (1:1:1), and the oilseeds were processed either by roasting or extruding before mixing. Soybean meal and soybean oil were used to give equivalent lipid and protein contents to each experimental diet. The basal diet consisted of grass silage, barley grain, vitamins and minerals. Steers were fed for a minimum of 100d then slaughtered at a uniform degree of finish. Growth and slaughter characteristics of the steers were only slightly affected by dietary treatment in that the soybean-fed steers consumed more feed and had a higher average daily gain than the canola or flax-fed animals in Trial 1. There was no difference in taste panel parameters for any of the treatments. Inclusion of flax in the diet increased the total n-3 content of meat. Similar results were found for canola and C18:1n-9 although this was not the case for soybean and the n-6 FA. For the n-6 FA in the PL and neutral lipid fractions of the meat samples, levels were correlated with high dietary levels of n-6 or n-9 with low levels of n-3 while for the n-3 FA, levels were correlated with high dietary n-3 levels and low n-6 levels. Oilseed processing method did not have an effect on any fatty acid levels. It is possible to modify the FA composition of beef meat toward a healthier profile by including heat-treated oilseeds in the diet to influence the degree of lipid metabolism in the rumen.ID: S0377840111004007; M3: Article; Accession Number: S0377840111004007; Author: M.A. McNiven (a, ⁎); Author: J.L. Duynisveld (b); Author: T. Turner (a); Author: A.W. Mitchell (a); Affiliation: Department of Health Management, Atlantic Veterinary College, University of PEI, Charlottetown, PEI, Canada C1A 4P3; Affiliation: Agriculture and Agri-Food Canada, Nappan, NS, Canada B0L 1C0; Keyword: Oilseeds; Keyword: Roasted; Keyword: Extruded; Keyword: Fatty acids; Keyword: Healthy fat; Number of Pages: 11; Language: English
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