122,075 research outputs found
Multimode collective scattering of light in free space by a cold atomic gas
No full textWe have studied collective recoil lasing by a cold atomic gas, scattering photons from an incident laser into many radiation modes in free space. The model consists of a system of classical equations for the atomic motion of N atoms where the radiation field has been adiabatically eliminated. We performed numerical simulations using a molecular dynamics code pepc (Pretty Efficient Parallel Coulomb Solver) to track the trajectories of the atoms. These simulations show the formation of an atomic density grating and collective enhancement of scattered light, both of which are sensitive to the shape and orientation of the atomic cloud. In the case of an initially circular cloud, the dynamical evolution of the cloud shape plays an important role in the development of the density grating and collective scattering. The ability to use efficient molecular dynamics codes will be a useful tool for the study of the multimode interaction between light and cold gases
Characterization of 0.25 um and 0.5 um AlGaN/GaN HEMT Devices forHigh Power Switching Applications
No full textA Multi-Language Comparison of Influences on Author Verification using Character N-Grams
No full textWe 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
No full textWe 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
No full textAbstract
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
Incremental Word Learning Using Large-Margin Discriminative Training and Variance Floor Estimation
No full textAyllon Clemente I, Heckmann M, Denecke A, Wrede B, Görick C. Incremental Word Learning Using Large-Margin Discriminative Training and Variance Floor Estimation. In: Proceedings INTERSPEECH. 2010
Diffusive author(s), cohesive author: Analysis of S/N (1994)
No full textThis 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)
Characterization of a high power GaN device for class E PA design with non-sinusoidal stimulus
No full textThis paper presents the campaign for the characterization of a GaN packaged power transistor, with the aim to test the foundry model accuracy in a non-conventional mode of operation. In particular, the device is adopted for the design of a 30 W, 435 MHz class E power amplifier to be inserted in a radio-frequency pulse-width-modulator for space application. Due to the biasing class of operation (class C), the conditions normally used for modelling are very different to the current design in terms of driving waveform (non-sinusoidal) and high order harmonics' terminations (in open circuit). In this framework, this campaign allowed for verification of the model accuracy, hence increasing the probability of success of the final design. The adopted measurement set-up and the characterization results are discussed in details
Development of a PWM based transmitter for P-band SAR applications
No full textIn this paper, authors present the preliminary measurements of a PWM-based transmitter. It is realised by cascading a pulse width modulator and a driver stage (PWCD), with a high efficiency Class E switched mode power amplifier (SMPA). The PWCD was realized by using 250nm BiCMOS process from IHP (SGB25V GD), while the SMPA was realized by using a packaged GaN device from UMS (CHK040A-SOA). The preliminary results showed output power levels higher than 40W with efficiency close to 70 %
Prevalence, Distribution, and Antimicrobial Susceptibility of Enterobacteriaceae and Non-Fermenting Gram-Negative Bacilli Isolated from Environmental Samples in a Veterinary Clinical Hospital in Madrid, Spain.
No full textManaging infections caused by multidrug-resistant Gram-negative bacilli is a major public health concern, particularly in hos-pitals where surfaces can act as reservoirs for resistant microorganisms. Identifying these bacteria in hospital environmentsis crucial for improving healthcare safety. This study aimed to analyse environmental samples from a veterinary hospital toidentify prevalent microorganisms and detect antimicrobial resistance patterns. A total of 183 surface samples were collectedfrom 26 areas at the Veterinary Clinical Hospital of Alfonso X el Sabio University in Madrid. The isolated strains were identified,and susceptibility profiles were determined via the disk diffusion method. Clonality analysis was performed using pulsed-fieldgel electrophoresis. In total, 109 strains were isolated: 76.15% from the Enterobacteriaceae family and 23.85% non-fermentingGram-negative bacilli. The isolates included Klebsiella, Enterobacter, Escherichia and Pseudomonas species, which could includehigh-risk clones, given their ability to carry several antimicrobial resistance genes. The equine area had the highest number ofisolates (n = 71), accounting for 65% of the total. High resistance indices were observed against at least five of the 16 antibioticstested, indicating significant multidrug resistance. Clonality analysis suggested potential cross-transmission within the facility.This study sampled hospital surfaces but not personnel or animals, making contamination sources unclear. Without resampling,the effectiveness of cleaning protocols remains uncertain. Results suggest that hospital staff play a key role in bacterial transmis-sion. The lack of specialised preventive measures in veterinary hospitals highlights a need for further research and improvement
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