6665 research outputs found
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Pandemi süreci ve açık bilim
No full text15-16 Ocak 2021 tarihlerinde çevrimiçi olarak gerçekleştirilen ve ana temasını "Pandemi ile Değişen Tıp Eğitimi ile Klinik ve Temel Araştırmalar" olarak belirlenen COVID-19 Pandemisinde Araştırma-Yayın ve Eğitim Süreçlerine Bakış Kongresi'nde yapılan sunumdur
Rüzgar atlaslarında, atlas noktalarının interpolasyon katsayılarının hesabı
No full textBuluş özellikle, seçilen en yakın atlas noktalarının (n) hesaplanması istenilen rüzgar tribünü kurulacak noktaya (p) benzerliklerinin bilimsel olarak hesaplanıp sayısallaştırılması sonucunda, mühendislerin bilimsel metotlara göre etki faktörlerinin hesaplamasını ve dolayısıyla interpolasyonlarda daha sağlıklı sonuçlar elde etmesini sağlayan bir atlas elde etme sistemi ile ilgilidir
Koronavirüs sürecinde İYTE Kütüphanesi hizmetleri ve kullanıcı memnuniyeti
Full text linkKoronavirüs (Covid 19) salgınının Dünya Sağlık Örgütü tarafından pandemi olarak ilan edilmesi üzerine YÖK tarafından üniversitelerde eğitime uzaktan devam edileceği açıklanmıştır. Verilmiş olan bu karar karşısında fiziksel olarak kütüphaneye erişim kısıtlı olsa da İYTE kütüphanesi olarak kullanıcılarımızın yanında olmamız ve uzaktan eğitime destek vermemiz zorunlu hale gelmiştir.
Kullanıcılarımızın bu süreçte kütüphane e-kaynaklarına erişim ile ilgili sorun yaşamamaları adına kampüs dışı erişimde izlenecek yollar, e-kitap veri tabanlarının kullanımı, aboneliğimiz olan veri tabanları, Koronavirüs hakkındaki bilimsel ve yararlı bilgiler, açık dersler, ücretsiz sertifikalı kurslar, bu süreçte yayınevlerinin erişime açtığı kaynaklar ve ilgili veri tabanlarına erişim, yayınevlerinin ve firmaların bu süreçte tüm araştırmacılara destek olmak için düzenledikleri webinarlar ve ürünlerine yönelik olarak düzenledikleri online eğitim seminerlerinin duyuruları, sanal müzeler ile online etkinlik ve konser bilgilerinin kullanıcılarımızla paylaşılması amaçlanmıştır.
Yaşanan bu süreçte İYTE Kütüphanesi’nce verilen hizmetlerin faydasının kullanıcılarımıza ne ölçüde olduğunun değerlendirilebilmesi amacıyla bir anket hazırlanarak online ortamda kullanıcılarımızın bu ankete katılımı sağlanarak yapılmıştır. Bu anketin sonuçları değerlendirilip Koronavirüs sürecine özel verilen hizmetlerin faydası ölçülmüş ve sonuçlar değerlendirilmiştir
Time efficient stiffness model computation for a parallel haptic mechanism via the virtual joint method
No full textHaptic devices are used for displaying a range of mechanical impedance values to the user. This impedance is regulated by a real-time control loop depending on the position information of the end-effector, which is usually acquired indirectly by using forward kinematics equations. Nevertheless, the kinematic model is insufficient to obtain accurate values if there are non-negligible compliant displacements. This gives a strong motivation for implementing a real-time stiffness model in the haptic control loop for improving its accuracy. Additionally, stiffness performance indices can be used at the design stage for enhancing the haptic devices impedance range within optimal design procedures. Fast solutions of a stiffness model are required for a real-time control as well as for decreasing the optimization time during a design process with a trade-off between accuracy and computational costs. In this study, we propose a computation time-efficient stiffness analysis of a parallel haptic device mechanism. The accuracy and computational costs of the proposed model are calculated and compared with a model that is obtained via a finite element method to demonstrate the effectiveness of the proposed approach with the desired real-time and accuracy performance. (C) 2019 Elsevier Ltd. All rights reserved
Cold sintering of ceramics and glasses: A review
No full textTraditionally ceramic artifacts are processed at high temperatures (> 1000 degrees C) by classical sintering techniques such as solid state, liquid phase and pressure-assisted sintering. Recently, inspired from the geology, novel sintering approaches that allow the densification of ceramic components at relatively low temperatures <= 400 degrees C have been proposed. While initial efforts for such low temperature densification concept were developed in the mid-70s, the topic has become increasingly prominent in the last decade. Currently, these low temperature methods can be classified into four main groups: (i) hydrothermal reaction sintering (HRS), (ii) hydrothermal hot pressing (HHP), (iii) pressure-assisted densification techniques: room-temperature densification (RTD), cold sintering (CS), warm press (WP), and finally no-pressure assisted method called (iv) reactive hydrothermal liquid phase densification (rHLPD). Above named techniques are commonly assisted by an aqueous solution used as either reactant or transient liquid phase to assist densification. Starting from the background in traditional sintering processes, this review aims to explore in depth the existing literature about low temperature densification approaches along with their advantages & disadvantages, and probable application areas
Search for supersymmetry in pp collisions at √s=13 TeV with 137 fb(-1) in final states with a single lepton using the sum of masses of large-radius jets
No full textResults are reported from a search for new physics beyond the standard model in proton-proton collisions in final states with a single lepton; multiple jets, including at least one jet tagged as originating from the hadronization of a bottom quark; and large missing transverse momentum. The search uses a sample of proton-proton collision data at root s =13 TeV, corresponding to 137 fb(-1), recorded by the CMS experiment at the LHC. The signal region is divided into categories characterized by the total number of jets, the number of bottom quark jets, the missing transverse momentum, and the sum of masses of large-radius jets. The observed event yields in the signal regions are consistent with estimates of standard model backgrounds based on event yields in the control regions. The results are interpreted in the context of simplified models of supersymmetry involving gluino pair production in which each gluino decays into a top quark-antiquark pair and a stable, unobserved neutralino, which generates missing transverse momentum in the event. Scenarios with gluino masses up to about 2150 GeV are excluded at 95% confidence level (or more) for neutralino masses up to 700 GeV. The highest excluded neutralino mass is about 1250 GeV, which holds for gluino masses around 1850 GeV
Modelling impulsive noise in indoor powerline communication systems
No full textPowerline communication (PLC) is an emerging technology that has an important role in smart grid systems. Due to making use of existing transmission lines for communication purposes, PLC systems are subject to various noise effects. Among those, the most challenging one is the impulsive noise compared to the background and narrowband noise. In this paper, we present a comparative study on modelling the impulsive noise amplitude in indoor PLC systems by utilising several impulsive distributions. In particular, as candidate distributions, we use the symmetric alpha-Stable (S alpha S), generalised Gaussian, Bernoulli Gaussian and Student's t distribution families as well as the Middleton Class A distribution, which dominates the literature as the impulsive noise model for PLC systems. Real indoor PLC system noise measurements are investigated for the simulation studies, which show that the S alpha S distribution achieves the best modelling success when compared to the other families in terms of the statistical error criteria, especially for the tail characteristics of the measured data sets
Measurement of properties of Bs0 → μ+μ− decays and search for B0 → μ+μ− with the CMS experiment
No full textResults are reported for the B 0s ! + branching fraction and effective lifetime and from a search for the decay B0 ! + . The analysis uses a data sample of proton-proton collisions accumulated by the CMS experiment in 2011, 2012, and 2016, with center-of-mass energies (integrated luminosities) of 7TeV (5 fb), 8TeV (20 fb), and 13TeV (36 fb). The branching fractions are determined by measuring event yields relative to B+ ! J= K+ decays (with J= ! + ), which results in the reduction of many of the systematic uncertainties. The decay B 0s ! + is observed with a significance of 5.6 standard deviations. The branching fraction is measured to be B (B 0s ! + ) = [2:9 0:7(exp) 0:2(frag)] 10, where the first uncertainty combines the experimental statistical and systematic contributions, and the second is due to the uncertainty in the ratio of the B 0s and the B+ fragmentation functions. No significant excess is observed for the decay B0 ! + , and an upper limit of B(B0 ! + ) < 3:6 10 is obtained at 95% confidence level. The B 0s ! + effective lifetime is measured to be + = 1:70 +0:61 ps. These results are consistent with standard model predictions
Measurement of the top quark pair production cross section in dilepton final states containing one τ lepton in pp collisions at √s = 13 TeV
No full textThe cross section of top quark pair production is measured in the t (t) over bar -> (lv(l))(tau(h)v(tau))b (b) over bar final state, where tau(h) refers to the hadronic decays of the tau lepton, and l is either an electron or a muon. The data sample corresponds to an integrated luminosity of 35.9 fb(-1) collected in proton-proton collisions at root s = 13TeV with the CMS detector. The measured cross section is sigma(t (t) over bar) = 781 +/- 7 (stat) +/- 62 (syst) +/- 20 (lumi) pb, and the ratio of the partial width Gamma(t -> tau v(tau)b) to the total decay width of the top quark is measured to be 0.1050 +/- 0.0009 (stat) +/- 0.0071 (syst). This is the first measurement of the t (t) over bar production cross section in proton-proton collisions at root s = 13TeV that explicitly includes t leptons. The ratio of the cross sections in the l tau(h) and ll final states yields a value R-l tau h/ll = 0.973 +/- 0.009 (stat) +/- 0.066 (syst), consistent with lepton universality
Measurement of the tt‾bb‾ production cross section in the all-jet final state in pp collisions at √s=13 TeV
No full textA measurement of the production cross section of top quark pairs in association with two b jets (t (t) over barb (b) over bar) is presented using data collected in proton-proton collisions at root s=13 TeV by the CMS detector at the LHC corresponding to an integrated luminosity of 35.9 fb(-1). The cross section is measured in the all-jet decay channel of the top quark pair by selecting events containing at least eight jets, of which at least two are identified as originating from the hadronization of b quarks. A combination of multivariate analysis techniques is used to reduce the large background from multijet events not containing a top quark pair, and to help discriminate between jets originating from top quark decays and other additional jets. The cross section is determined for the total phase space to be 5.5 +/- 0.3 (stat)(-1.3)(+)(1.6) (syst)pb and also measured for two fiducial t (t) over barb (b) over bar, definitions. The measured cross sections are found to be larger than theoretical predictions by a factor of 1.5-2.4, corresponding to 1-2 standard deviations. (C) 2020 The Author. Published by Elsevier B.V