4,910 research outputs found
Industrial GaInP/GaAs Power HBT MMIC Process
UMS has developed an industrial power HBT process especially dedicated to power MMICs in the 10GHz frequency range. The process has been qualified and meets the very demanding specifications required for X-Band high power amplifiers. Aside from the obvious RF performances, this includes the demonstration of the necessary stability and reproducibility of the process, associated with state-of-art reliability. It is important to note that the later has been achieved without affecting the high frequency capability of the devices, and demonstrated directly on high power transistors. Thanks to its intrinsic qualities this process can naturally also be used for other applications, like low phase noise voltage controlled oscillators, and power amplifiers at lower frequencies (for mobile phones for instance)
Twitter Activity Of Urban And Rural Colleges: A Sentiment Analysis Using The Dialogic Loop
The purpose of the present study is to ascertain if colleges are achieving their ultimate communication goals of maintaining and attracting students through their microblogging activity, which according to Dialogic Loop Theory, is directly correlated to the use of positive and negative sentiment. The study focused on a cross-section of urban and rural community colleges within the United States to identify the sentiment score of their microblogging activity. The study included a content analysis on the Twitter activity of these colleges. A data-mining process was employed to collect a census of the tweets associated with these colleges. Further processing was then applied using data linguistic software that removed all irrelevant text, word abbreviations, emoticons, and other Twitter specific classifiers. The resulting data set was then processed through a Multinomial Naive Bayes Classifier, which refers to a probability of word counts in a text. The classifier was trained using a data source of 1.5 million tweets, called Sentiment140, that qualitatively analyzed the corpus of these tweets, labeling them as positive and negative sentiment. The Multinomial Naive Bayes Classifier distinguished specific wording and phrases from the corpus, comparing the data to a specific database of sentiment word identifiers. The sentiment analysis process categorized the text as being positive or negative. Finally, statistical analysis was conducted on the outcome of the sentiment analysis.
A significant contribution of the current work was extending Kent and Taylor\u27s (1998) Dialogic Loop Theory, which was designed specifically for identifying the relationship building capabilities of a Web site, to encompass the microblogging concept used in Twitter. Specifically, Dialogic Loop Theory is applied and enhanced to develop a model for social media communication to augment relationship building capabilities, which the current study established as a new form for evaluating Twitter tweets, labeled in the current body of work as Microblog Dialogic Communication. The implication is that by using Microblog Dialogic Communication, a college can address and correct their microblogging sentiment.
The results of the data collected found that rural colleges tweeted more positive sentiment tweets and less negative sentiment tweets when compared to the urban colleges tweets
Ag-coverage-dependent symmetry of the electronic states of the Pt(111)-Ag-Bi interface: The ARPES view of a structural transition
We studied by angle-resolved photoelectron spectroscopy the strain-related
structural transition from a pseudomorphic monolayer (ML) to a striped
incommensurate phase in an Ag thin film grown on Pt(111). We exploited the
surfactant properties of Bi to grow ordered Pt(111)-xMLAg-Bi trilayers with 0 <
x < 5 ML, and monitored the dispersion of the Bi-derived interface states to
probe the structure of the underlying Ag film. We find that their symmetry
changes from threefold to sixfold and back to threefold in the Ag coverage
range studied. Together with previous scanning tunneling microscopy and
photoelectron diffraction data, these results provide a consistent microscopic
description of the coverage-dependent structural transition.Comment: 10 pages, 9 figure
Magma–host interactions during differentiation and emplacement of a shallow-level, zoned granitic pluton (Tarçouate pluton, Morocco): implications for magma emplacement
The Tarçouate pluton (Anti-Atlas, Morocco) is an inversely zoned laccolith emplaced 583 Ma ago into low-grade metasediments, with the following succession: leucocratic granites, biotite–granodiorites (±monzodiorites), hornblende–granodiorites (±monzodiorites) and monzodiorites syn-plutonic dykes. These rocks form two distinct, chemically coherent, units: (1) A main unit consists of layered (5
Tables of Hyperonic Matter Equation of State for Core-Collapse Supernovae
We present sets of equation of state (EOS) of nuclear matter including
hyperons using an SU_f(3) extended relativistic mean field (RMF) model with a
wide coverage of density, temperature, and charge fraction for numerical
simulations of core collapse supernovae. Coupling constants of Sigma and Xi
hyperons with the sigma meson are determined to fit the hyperon potential
depths in nuclear matter, U_Sigma(rho_0) ~ +30 MeV and U_Xi(rho_0) ~ -15 MeV,
which are suggested from recent analyses of hyperon production reactions. At
low densities, the EOS of uniform matter is connected with the EOS by Shen et
al., in which formation of finite nuclei is included in the Thomas-Fermi
approximation. In the present EOS, the maximum mass of neutron stars decreases
from 2.17 M_sun (Ne mu) to 1.63 M_sun (NYe mu) when hyperons are included. In a
spherical, adiabatic collapse of a 15 star by the hydrodynamics
without neutrino transfer, hyperon effects are found to be small, since the
temperature and density do not reach the region of hyperon mixture, where the
hyperon fraction is above 1 % (T > 40 MeV or rho_B > 0.4 fm^{-3}).Comment: 23 pages, 6 figures (Fig.3 and related comments on pion potential are
corrected in v3.
XNect: Real-time Multi-person 3D Human Pose Estimation with a Single RGB Camera
We present a real-time approach for multi-person 3D motion capture at over 30 fps using a single RGB camera. It operates in generic scenes and is robust to difficult occlusions both by other people and objects. Our method operates in subsequent stages. The first stage is a convolutional neural network (CNN) that estimates 2D and 3D pose features along with identity assignments for all visible joints of all individuals. We contribute a new architecture for this CNN, called SelecSLS Net, that uses novel selective long and short range skip connections to improve the information flow allowing for a drastically faster network without compromising accuracy. In the second stage, a fully-connected neural network turns the possibly partial (on account of occlusion) 2D pose and 3D pose features for each subject into a complete 3D pose estimate per individual. The third stage applies space-time skeletal model fitting to the predicted 2D and 3D pose per subject to further reconcile the 2D and 3D pose, and enforce temporal coherence. Our method returns the full skeletal pose in joint angles for each subject. This is a further key distinction from previous work that neither extracted global body positions nor joint angle results of a coherent skeleton in real time for multi-person scenes. The proposed system runs on consumer hardware at a previously unseen speed of more than 30 fps given 512x320 images as input while achieving state-of-the-art accuracy, which we will demonstrate on a range of challenging real-world scenes
Helenistic moldmade relief bowls from the Calescoves sanctuary (Minorca)
Un proyecto de investigación recientemente desarrollado en Calescoves (Alaior, Menorca), y en concreto las excavaciones llevadas a cabo en la Cova dels Jurats, han supuesto la documentación de un interesante conjunto de materiales cerámicos, en el que conviven elementos de producción local e importaciones. De estos últimos analizamos aquà un conjunto muy significativo, el perteneciente a los boles helenÃsticos procedentes de la zona jonia. Vinculados en su zona de origen al consumo de vino, la presencia de estos vasos en el santuario menorquÃn debe vincularse a los rituales y libaciones que se debieron llevar a cabo en la cueva.The research project recently carried out in Calescoves (Alaior, Menorca), and in particular the excavation in the Cova dels Jurats, has allowed us to study an interesting collection of ceramics, including both local and imported items. We will analyse here the Hellenistic bowls from the Ionian area. Linked in their original area to the consumption of wine, the presence of these vessels in this sanctuary must be linked to the rituals and libations that were due to perform in the cave
Near-threshold high-order harmonic spectroscopy with aligned molecules
We study high-order harmonic generation in aligned molecules close to the
ionization threshold. Two distinct contributions to the harmonic signal are
observed, which show very different responses to molecular alignment and
ellipticity of the driving field. We perform a classical electron trajectory
analysis, taking into account the significant influence of the Coulomb
potential on the strong-field-driven electron dynamics. The two contributions
are related to primary ionization and excitation processes, offering a deeper
understanding of the origin of high harmonics near the ionization threshold.
This work shows that high harmonic spectroscopy can be extended to the
near-threshold spectral range, which is in general spectroscopically rich.Comment: 4 pages, 4 figure
- …