2,012 research outputs found
Design of an all-attitude flight control system to execute commanded bank angles and angles of attack
A flight control system for use in air-to-air combat simulation was designed. The input to the flight control system are commanded bank angle and angle of attack, the output are commands to the control surface actuators such that the commanded values will be achieved in near minimum time and sideslip is controlled to remain small. For the longitudinal direction, a conventional linear control system with gains scheduled as a function of dynamic pressure is employed. For the lateral direction, a novel control system, consisting of a linear portion for small bank angle errors and a bang-bang control system for large errors and error rates is employed
Evaluating observed versus predicted forest biomass: R-squared, index of agreement or maximal information coefficient?
The accurate prediction of forest above-ground biomass is nowadays key to implementing climate change mitigation policies, such as reducing emissions from deforestation and forest degradation. In this context, the coefficient of determination () is widely used as a means of evaluating the proportion of variance in the dependent variable explained by a model. However, the validity of for comparing observed versus predicted values has been challenged in the presence of bias, for instance in remote sensing predictions of forest biomass. We tested suitable alternatives, e.g. the index of agreement () and the maximal information coefficient (). Our results show that renders systematically higher values than , and may easily lead to regarding as reliable models which included an unrealistic amount of predictors. Results seemed better for , although favoured local clustering of predictions, whether or not they corresponded to the observations. Moreover, was more sensitive to the use of cross-validation than or , and more robust against overfitted models. Therefore, we discourage the use of statistical measures alternative to for evaluating model predictions versus observed values, at least in the context of assessing the reliability of modelled biomass predictions using remote sensing. For those who consider to be conceptually superior to , we suggest using its square , in order to be more analogous to and hence facilitate comparison across studies
Slow relaxation in the two dimensional electron plasma under the strong magnetic field
We study slow relaxation processes in the point vortex model for the
two-dimensional pure electron plasma under the strong magnetic field. By
numerical simulations, it is shown that, from an initial state, the system
undergoes the fast relaxation to a quasi-stationary state, and then goes
through the slow relaxation to reach a final state. From analysis of simulation
data, we find (i) the time scale of the slow relaxation increases linearly to
the number of electrons if it is measured by the unit of the bulk rotation
time, (ii) during the slow relaxation process, each electron undergoes an
superdiffusive motion, and (iii) the superdiffusive motion can be regarded as
the Levy flight, whose step size distribution is of the power law. The time
scale that each electron diffuses over the system size turns out to be much
shorter than that of the slow relaxation, which suggests that the correlation
among the superdiffusive trajectories is important in the slow relaxation
process.Comment: 11pages, 19 figures. Submitted to J. Phys. Soc. Jp
Reviews
The following publications have been reviewed by the mentioned authors;Windsor Chairmaking by Thos Moser, reviewed by Bernard AylwardRelief Woodcarving by E. J. Tangerman, reviewed by Bernard AylwardWorking Green Wood with PEG by Patrick Spielman, reviewed by J. W. ThompsonWork Experience in Secondary Schools edited by John Eggleston, reviewed by Charles PeaceScale Model Cannon by Richard Stewart and Donald Heyes, reviewed by John EgglestonHow to Make Your Own Picture Frames by Hal Rogers and Ed Reinhardt, reviewed by John EgglestonThe Story of Craft by Edward Lucie Smith, reviewed by John EgglestonThe Landsdowne Book of Handcrafts reviewed by Roger BensonUnderstanding Design in the Home by Margaret Picton, reviewed by John EgglestonWoodturning Projects for Dining by John Sainsbury, reviewed by M. P. BourneCrafts Conference for Teachers - April 1982 published by Crafts Council, reviewed by Bernard L. MyersCraft Design Technology reviewed by M. JohnArt and Imaginations: A Study in the Philosophy of Mind by Roger Scruton, reviewed by G. H. Bantock'Forget all the rules you ever learned about Graphic Design including the ones in this Book by Bob Gill, reviewed by Cal SwannProfessional Smithing by Donald Streeter, reviewed by J. N. AtkinsGraphic Communication by John Twyford, reviewed by Cal Swan
Presence of Amorphous Carbon Nanoparticles in Food Caramels
We report the finding of the presence of carbon nanoparticles (CNPs) in different carbohydrate based food caramels, viz. bread, jaggery, sugar caramel, corn flakes and biscuits, where the preparation involves heating of the starting material. The CNPs were amorphous in nature; the particles were spherical having sizes in the range of 4–30 nm, depending upon the source of extraction. The results also indicated that particles formed at higher temperature were smaller than those formed at lower temperature. Excitation tuneable photoluminescence was observed for all the samples with quantum yield (QY) 1.2, 0.55 and 0.63%, for CNPs from bread, jaggery and sugar caramels respectively. The present discovery suggests potential usefulness of CNPs for various biological applications, as the sources of extraction are regular food items, some of which have been consumed by humans for centuries, and thus they can be considered as safe
Prolate spheroidal hematite particles equatorially belt with drug-carrying layered double hydroxide disks: Ring Nebula-like nanocomposites
A new nanocomposite architecture is reported which combines prolate spheroidal hematite nanoparticles with drug-carrying layered double hydroxide [LDH] disks in a single structure. Spindle-shaped hematite nanoparticles with average length of 225 nm and width of 75 nm were obtained by thermal decomposition of hydrothermally synthesized hematite. The particles were first coated with Mg-Al-NO3-LDH shell and then subjected to anion exchange with salicylate ions. The resulting bio-nanohybrid displayed a close structural resemblance to that of the Ring Nebula. Scanning electron microscope and transmission electron microscopy images showed that the LDH disks are stacked around the equatorial part of the ellipsoid extending along the main axis. This geometry possesses great structural tunability as the composition of the LDH and the nature of the interlayer region can be tailored and lead to novel applications in areas ranging from functional materials to medicine by encapsulating various guest molecules
Search for chargino-neutralino production with mass splittings near the electroweak scale in three-lepton final states in √s=13 TeV pp collisions with the ATLAS detector
A search for supersymmetry through the pair production of electroweakinos with mass splittings near the electroweak scale and decaying via on-shell W and Z bosons is presented for a three-lepton final state. The analyzed proton-proton collision data taken at a center-of-mass energy of √s=13  TeV were collected between 2015 and 2018 by the ATLAS experiment at the Large Hadron Collider, corresponding to an integrated luminosity of 139  fb−1. A search, emulating the recursive jigsaw reconstruction technique with easily reproducible laboratory-frame variables, is performed. The two excesses observed in the 2015–2016 data recursive jigsaw analysis in the low-mass three-lepton phase space are reproduced. Results with the full data set are in agreement with the Standard Model expectations. They are interpreted to set exclusion limits at the 95% confidence level on simplified models of chargino-neutralino pair production for masses up to 345 GeV
Looking for the women in Baron and Taylor's (1969) Educational administration and the social sciences
A search for women in Baron and Taylor's (1969) Educational administration and the social sciences [London: The Athlone Press] using feminist poststructural discourse analysis (FPDA) has revealed a changing discourse about gendered educational administration over the course of 50 years. Whilst few women are featured in the text itself, citations of women's writing surface the historical contributions of women as headmistresses and public servants. Women who have cited the text since its publication have challenged gendered theory and academic writing conventions. FPDA is used to explore the gendered educational administration discourse through the intertextuality of academic writing. Fluctuations between powerfulness and powerlessness are revealed depending on the socio-political context and women's circumstances
Oral carcinoma after hematopoietic stem cell transplantation – a new classification based on a literature review over 30 years
BACKGROUND: Patients undergoing hematopoietic stem cell transplantation (HSCT) have a higher risk of developing secondary solid tumors, in particular squamous cell carcinoma, because of several risk factors, including full-body irradiation (TBI), chemotherapy, and chronic graft versus host disease (GVHD). Based on the review presented here, a classification of oral changes is suggested in order to provide a tool to detect high-risk patients. Methods and Results The literature over the last 30 years was reviewed for development of malignoma of the oral cavity after HSCT. Overall, 64 cases were found. In 16 out of 30 cases, the tongue was the primary location, followed by the salivary gland (10 out of 30); 56.4% appeared in a latency time of 5 to 9 years after HSCT. In 76.6%, GVHD was noticed before the occurrence of oral malignancy. Premalignant changes of the oral mucosa were mucositis, xerostomia, and lichenoid changes, developing into erosive form. CONCLUSION: All physicians involved in the treatment of post-HSCT patients should be aware of the increased risk, even after 5 years from the development of oral malignancy, in particular when oral graft versus host changes are visible. In order to develop evidence management and to detect and offer adequate therapy as early as possible in this patient group, multicenter studies, involving oncologists and head and neck surgeons, should be established
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