129 research outputs found

    Inequalities For Numerical Radius And The Spectral Norm Of Hilbert Space Operators

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    Let (H,< .,. >) be a complex Hilbert space and B(H) denote the C-algebra of all bounded linear operators on H. In this paper we establishinequalities for numerical radius and the spectral norm of Hilbert spaceoperators , from the previous inequalitiesMathematics Subject Classi?cation: 47A12,47A63; 47A99.Keywords: Numerical Radius, Complex Hilbert Space, Operator Norm,Boundedlinear operators, Inequalities for norms and numerical radius

    Special Cases for Numerical Radius and Spectral Radius Inequalities

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    In  this paper, the aim of this study  is to find special cases  of  some inequalities for numerical radius and spectral radius of a bounded linear operator on a Hilbert space, Finally, some new results about this subject are obtained. Keywords: Spectral norm, Numerical radius, Spectral radius

    RANCANGAN MEDIA PEMBELAJARAN BERUPA APLIKASI AUGMENTED REALITY BERBASIS ANDROID

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    Abstract-Augmented Reality (AR) is a technology that combines objects from the real world and virtual objects in real-time conditions. The merging of real and virtual objects occurs with the support of the right technology while the interactions that are carried out can occur using certain devices. AR is a breakthrough in the field of very sophisticated technology. Because with this technology we can make all abstract or virtual things look real or real. So that researchers apply the Waterfall Media AR Mobile Learning Method to be able to display 3D images and animations in class VIII math subjects, specifically geometric shapes including: blocks, balls, cones, cubes, pyramids, prisms, and tubes, Provides convenience for teachers to add insight into the use of AR learning media in increasing student motivation and interest in learning at SMP NEGERI 1 Bengkulu City. Provides convenience for teachers to add insight into the use of AR learning media in increasing student motivation and interest in learning at SMP NEGERI 1 Bengkulu City. Based on the results of testing the learning media application in the form of Android-based Augmented Reality application as expected based on the menu being tested. &nbsp

    Exact Solutions for Chebyshev Equations by using the Asymptotic Iteration Method

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    The asymptotic iteration method is used in order to solve the Chebyshev differential equations, and to reproduce the Chebyshev polynomials T n ( x ), U n ( x ) of the first and second kinds respectively. It is shown that the asymptotic iteration method is valid for any degree \u3b

    Project X: Physics Opportunities

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    Part 2 of "Project X: Accelerator Reference Design, Physics Opportunities, Broader Impacts". In this Part, we outline the particle-physics program that can be achieved with Project X, a staged superconducting linac for intensity-frontier particle physics. Topics include neutrino physics, kaon physics, muon physics, electric dipole moments, neutron-antineutron oscillations, new light particles, hadron structure, hadron spectroscopy, and lattice-QCD calculations. Part 1 is available as arXiv:1306.5022 [physics.acc-ph] and Part 3 is available as arXiv:1306.5024 [physics.acc-ph]

    Mortality and pulmonary complications in patients undergoing surgery with perioperative sars-cov-2 infection: An international cohort study

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    Background The impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on postoperative recovery needs to be understood to inform clinical decision making during and after the COVID-19 pandemic. This study reports 30-day mortality and pulmonary complication rates in patients with perioperative SARS-CoV-2 infection. Methods This international, multicentre, cohort study at 235 hospitals in 24 countries included all patients undergoing surgery who had SARS-CoV-2 infection confirmed within 7 days before or 30 days after surgery. The primary outcome measure was 30-day postoperative mortality and was assessed in all enrolled patients. The main secondary outcome measure was pulmonary complications, defined as pneumonia, acute respiratory distress syndrome, or unexpected postoperative ventilation. Findings This analysis includes 1128 patients who had surgery between Jan 1 and March 31, 2020, of whom 835 (740%) had emergency surgery and 280 (248%) had elective surgery. SARS-CoV-2 infection was confirmed preoperatively in 294 (261%) patients. 30-day mortality was 238% (268 of 1128). Pulmonary complications occurred in 577 (512%) of 1128 patients; 30-day mortality in these patients was 380% (219 of 577), accounting for 817% (219 of 268) of all deaths. In adjusted analyses, 30-day mortality was associated with male sex (odds ratio 175 [95% CI 128-240], p<00001), age 70 years or older versus younger than 70 years (230 [165-322], p<00001), American Society of Anesthesiologists grades 3-5 versus grades 1-2 (235 [157-353], p<00001), malignant versus benign or obstetric diagnosis (155 [101-239], p=0046), emergency versus elective surgery (167 [106-263], p=0026), and major versus minor surgery (152 [101-231], p=0047). Interpretation Postoperative pulmonary complications occur in half of patients with perioperative SARS-CoV-2 infection and are associated with high mortality. Thresholds for surgery during the COVID-19 pandemic should be higher than during normal practice, particularly in men aged 70 years and older. Consideration should be given for postponing non-urgent procedures and promoting non-operative treatment to delay or avoid the need for surgery. Funding National Institute for Health Research (NIHR), Association of Coloproctology of Great Britain and Ireland, Bowel and Cancer Research, Bowel Disease Research Foundation, Association of Upper Gastrointestinal Surgeons, British Association of Surgical Oncology, British Gynaecological Cancer Society, European Society of Coloproctology, NIHR Academy, Sarcoma UK, Vascular Society for Great Britain and Ireland, and Yorkshire Cancer Research

    Elective Cancer Surgery in COVID-19-Free Surgical Pathways During the SARS-CoV-2 Pandemic: An International, Multicenter, Comparative Cohort Study.

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    PURPOSE: As cancer surgery restarts after the first COVID-19 wave, health care providers urgently require data to determine where elective surgery is best performed. This study aimed to determine whether COVID-19-free surgical pathways were associated with lower postoperative pulmonary complication rates compared with hospitals with no defined pathway. PATIENTS AND METHODS: This international, multicenter cohort study included patients who underwent elective surgery for 10 solid cancer types without preoperative suspicion of SARS-CoV-2. Participating hospitals included patients from local emergence of SARS-CoV-2 until April 19, 2020. At the time of surgery, hospitals were defined as having a COVID-19-free surgical pathway (complete segregation of the operating theater, critical care, and inpatient ward areas) or no defined pathway (incomplete or no segregation, areas shared with patients with COVID-19). The primary outcome was 30-day postoperative pulmonary complications (pneumonia, acute respiratory distress syndrome, unexpected ventilation). RESULTS: Of 9,171 patients from 447 hospitals in 55 countries, 2,481 were operated on in COVID-19-free surgical pathways. Patients who underwent surgery within COVID-19-free surgical pathways were younger with fewer comorbidities than those in hospitals with no defined pathway but with similar proportions of major surgery. After adjustment, pulmonary complication rates were lower with COVID-19-free surgical pathways (2.2% v 4.9%; adjusted odds ratio [aOR], 0.62; 95% CI, 0.44 to 0.86). This was consistent in sensitivity analyses for low-risk patients (American Society of Anesthesiologists grade 1/2), propensity score-matched models, and patients with negative SARS-CoV-2 preoperative tests. The postoperative SARS-CoV-2 infection rate was also lower in COVID-19-free surgical pathways (2.1% v 3.6%; aOR, 0.53; 95% CI, 0.36 to 0.76). CONCLUSION: Within available resources, dedicated COVID-19-free surgical pathways should be established to provide safe elective cancer surgery during current and before future SARS-CoV-2 outbreaks
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