Design of a FLAP antenna for in-flight satellite communication

Modern satellite demands wide band communication channels for static and dynamic mobile terminals. For mobile terminal like airplane to satellite communications, conformal electronically scanned phased array FLAPS will be preferred over parabolic reflector antenna for efficient satellite tracking and to minimize life cycle cost, size, weight, aerodynamic drag and limited wind resistance. Flat parabolic surface (FLAPS) has a good geometrically flat surface and behaves electromagnetically as tough as it were a parabolic reflector. Although flat, it converts a quasi-spherical wave from the feed into a focused beam, similar to that of a parabolic dish. The FLAPS consists of an array of dipole scatterers. FLAP antenna has significant power transfer efficiency and can be able to beam a large amount of energy. In this work a FLAP antenna has been designed to operate in X-band and the various parameters are studied showing the antenna ability for in-flight communication system

Comparative study of DR Nanoantenna Array For Optical Frequencies

The frequency dependent complex permittivity of plasmonic materials is one of the most decisive parameters in their resonant characteristics. This work shows how the optical responses of gold (Au),and silver(Ag) optical nanoantennas are affected by their size, shape and their frequency dependent optical functions. The optical functions of these metals are described by the Drude-Lorentz model in which both the free electrons contributions and harmonic oscillator (SPRs) acivities are considered. The change of material in the nanostrip and the ground plane results in the change in different parameters like return loss, VSWR , etc

MAP's not dead yet: Uncovering true language model modes by conditioning away degeneracy

It has been widely observed that exact or approximate MAP (mode-seeking) decoding from natural language generation (NLG) models consistently leads to degenerate outputs (Stahlberg and Byrne, 2019, Holtzman et al., 2019). This has generally been attributed to either a fundamental inadequacy of modes in models or weaknesses in language modeling. Contrastingly in this work, we emphasize that degenerate modes can even occur in the absence of any model error, due to contamination of the training data. Specifically, we show that mixing even a tiny amount of low-entropy noise with a population text distribution can cause the data distribution's mode to become degenerate, implying that any models trained on it will be as well. As the unconditional mode of NLG models will often be degenerate, we therefore propose to apply MAP decoding to the model's distribution conditional on avoiding specific degeneracies. Using exact-search, we empirically verify that the length-conditional modes of machine translation models and language models are indeed more fluent and topical than their unconditional modes. For the first time, we also share many examples of exact modal sequences from these models, and from several variants of the LLaMA-7B model. Notably, the modes of the LLaMA models are still degenerate, showing that improvements in modeling have not fixed this issue. Because of the cost of exact mode finding algorithms, we develop an approximate mode finding approach, ACBS, which finds sequences that are both high-likelihood and high-quality. We apply this approach to LLaMA-7B, a model which was not trained for instruction following, and find that we are able to elicit reasonable outputs without any finetuning.Comment: 49 pages, 3 figure

Intra-atrial right coronary artery on dual-source CT: prevalence and characteristics

PURPOSEWe aimed to determine the prevalence rate and radiological characteristics of intra-atrial right coronary artery (IARCA) in an adult population undergoing computed tomography coronary angiography (CTCA) on a dual-source CT scanner. METHODSOverall, 7114 consecutive CTCAs acquired using a dual-source CT scanner in a high-volume, specialized cardiac care facility were retrospectively analyzed for the presence of IARCA. We scrutinized the CTCA datasets to determine the prevalence rate of IARCA and also to characterize its various imaging features including its length, depth from right atrial wall, segment involved, and presence and absence of atherosclerosis within the involved segment and in the rest of the right coronary artery (RCA).RESULTSThe prevalence of IARCA was 0.29% (21/7114) in our study population. The mean length and depth of the intra-atrial segment was 14.85 mm and 2.57 mm, respectively. The mid-RCA was the most common segment to be involved, and no significant atherosclerosis was noted either in the intra-atrial segment or the rest of the RCA.CONCLUSIONThe prevalence rate of the incidental IARCA in the adult subjects undergoing CTCA is higher than previously reported for anatomical series, as seen in our study using a dual-source scanner. This under-reported anomaly must be explicitly assessed in patients undergoing ablative and other electrophysiological procedures, where it can have important implications

Who Rpinted Shakespeare’s Fourth Folio?

According to Fredson Bowers, writing in Shakespeare Quarterly in 1951, we will never know the printer of that section "until we know everything there is to be learned about seventeenth-century types." 2 Bowers doubted we could ever list the full set of F4's printers because F4 was printed anonymously, and the volume left few clues about its printers. While George Watson Cole's 1909 "examination of the letterpress show[ed] that a copy of the Third Folio was apparently broken into three portions and sent to three different printers," Bowers himself only got as far as attributing the first of F4's three separately paginated parts. 3 The purpose of this note is to identify the other two printers involved in F4, one of whom, John Macock, was the printer whose shop was responsible for F4's Hamlet. Regrettably, this short note does not include everything there is to be learned about seventeenth-century types.