548 research outputs found

    Implications of surface noise for the motional coherence of trapped ions

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    Electric noise from metallic surfaces is a major obstacle towards quantum applications with trapped ions due to motional heating of the ions. Here, we discuss how the same noise source can also lead to pure dephasing of motional quantum states. The mechanism is particularly relevant at small ion-surface distances, thus imposing a new constraint on trap miniaturization. By means of a free induction decay experiment, we measure the dephasing time of the motion of a single ion trapped 50~μ\mum above a Cu-Al surface. From the dephasing times we extract the integrated noise below the secular frequency of the ion. We find that none of the most commonly discussed surface noise models for ion traps describes both, the observed heating as well as the measured dephasing, satisfactorily. Thus, our measurements provide a benchmark for future models for the electric noise emitted by metallic surfaces.Comment: (5 pages, 4 figures

    Study of chemical and physical behavior cotton fabrics treated by corona discharge after several laundering

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    Cotton fabric because of finishing process has shrinkage behavior after laundering and for improving this problem, chemical agents utilize for anti-shrinkage. This temporary finishing can reduce shrinkagebut has many environmental problems. Corona discharge treatment has been used for cotton fabric, other fibers and polymers. This treatment can reduce costs and environmental impacts. In this study, cotton fabric was treated by corona discharge instrument at 2 - 40 passages and fabrics were washed with laundering method. After four times laundering, shrinkage behavior of corona discharge treated fabric as compared with un-treated fabric decrease. After 10 passages of corona discharge treatment,water, dye absorption and shrinkage are modified but after 14 passages, despite of shrinkage improvement, dyeing properties decrease

    Effect of foot reflexology on anxiety and agitation in patients under mechanical ventilation after open heart surgery: A randomized clinical trial study

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    زمینه و هدف: رویکردهای غیر دارویی از جمله ماساژ بازتابی پا به علت کاهش عوارض و هزینه ها در کانون توجه محققین در جامعه بیماران مختلف قرار گرفته است. این مطالعه با هدف بررسی تأثیر ماساژ بازتابی پا بر اضطراب و بیقراری بیماران تحت تهویه مکانیکی پس از جراحی قلب باز انجام شد. روش بررسی: این مطالعه کارآزمایی بالینی کنترل شده، سه گروهی و دو سو کور با طراحی اندازه گیری مکرر در دو بیمارستان وابسته به دانشگاه علوم پزشکی بقیه الله (عج) تهران، از بهمن1392 تا اردیبهشت 1393 انجام شد. 96 بیمار کاندید جراحی قلب باز به روش نمونه گیری در دسترس انتخاب و به صورت تخصیص تصادفی در سه گروه آزمون (ماساژ بازتابی پا 34 نفر)، درمان نما (تماس سطحی پاشنه پا 30 نفر) و کنترل (مراقبت های معمول 32 نفر) قرار گرفتند. در گروه آزمون، ماساژ بازتابی پا به مدت20 دقیقه بر روی نقاط بازتاب قلب و ریه، انجام شد. میزان اضطراب و بیقراری بر اساس مقیاس سنجش اضطراب (FAS) و مقیاس سنجش بیقراری ریچموند (RSAS) در 6 مرحله زمانی ثبت شد. یافته ها: داده های آماری 92 بیمار (31 نفر گروه آزمون، 30 نفر گروه درمان نما و 31 نفر گروه کنترل) جمع آوری گردید. در مقایسه روند تغییرات سطح اضطراب و بیقراری، آزمون درون گروهی فریدمن نشان داد، بین میانگین سطح اضطراب و بیقراری در گروه ها در مراحل زمانی مختلف تفاوت معنی دار آماری وجود دارد. همچنین آزمون کروسکال والیس نشان داد میزان اضطراب و بیقراری بین سه گروه در مراحل مختلف زمانی تفاوت معنی دار آماری با یکدیگر ندارند. نتیجه گیری: ماساژ بازتابی پا در نقاط بازتابی مربوط به قلب و ریه تغییر معنی داری در کاهش اضطراب و بیقراری بیماران پس از جراحی ایجاد نکرد

    Identifying Incident Casual Factors to Improve Aviation Transportation Safety: Proposing a Deep Learning Approach

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    Aviation is a complicated transportation system, and safety is of paramount importance because aircraft failure often involves casualties. Prevention is clearly the best strategy for aviation transportation safety. Learning from past incident data to prevent potential accidents from happening has proved to be a successful approach. To prevent potential safety hazards and make effective prevention plans, aviation safety experts identify primary and contributing factors from incident reports. However, safety experts’ review processes have become prohibitively expensive nowadays. The number of incident reports is increasing rapidly due to the acceleration of advances in information technologies and the growth of the commercial and private aviation transportation industries. Consequently, advanced text mining algorithms should be applied to help aviation safety experts facilitate the process of incident data extraction. This paper focuses on constructing deep-learning-based models to identify causal factors from incident reports. First, we prepare the data sets used for training, validation, and testing with approximately 200,000 qualified incident reports from the Aviation Safety Reporting System (ASRS). Then, we take an open-source natural language model, which is well trained with a large corpus of Wikipedia texts, as the baseline and fine-tune it with the texts in incident reports to make it more suited to our specific research task. Finally, we build and train an attention-based long short-term memory (LSTM) model to identify primary and contributing factors in each incident report. The solution we propose has multilabel capability and is automated and customizable, and it is more accurate and adaptable than traditional machine learning methods in extant research. This novel application of deep learning algorithms to the incident reporting system can efficiently improve aviation safety

    Computing Local Sensitivities of Counting Queries with Joins

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    Local sensitivity of a query Q given a database instance D, i.e. how much the output Q(D) changes when a tuple is added to D or deleted from D, has many applications including query analysis, outlier detection, and in differential privacy. However, it is NP-hard to find local sensitivity of a conjunctive query in terms of the size of the query, even for the class of acyclic queries. Although the complexity is polynomial when the query size is fixed, the naive algorithms are not efficient for large databases and queries involving multiple joins. In this paper, we present a novel approach to compute local sensitivity of counting queries involving join operations by tracking and summarizing tuple sensitivities -- the maximum change a tuple can cause in the query result when it is added or removed. We give algorithms for the sensitivity problem for full acyclic join queries using join trees, that run in polynomial time in both the size of the database and query for an interesting sub-class of queries, which we call 'doubly acyclic queries' that include path queries, and in polynomial time in combined complexity when the maximum degree in the join tree is bounded. Our algorithms can be extended to certain non-acyclic queries using generalized hypertree decompositions. We evaluate our approach experimentally, and show applications of our algorithms to obtain better results for differential privacy by orders of magnitude.Comment: To be published in Proceedings of the 2020 ACM SIGMOD International Conference on Management of Dat

    The productivity and its barriers in public hospitals: Case study of Iran

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    Background: Due to the increasing health care costs, the issue of productivity in hospitals must be taken into great consideration in order to provide, preserve and promote public health services. Thus, increasing the level of productivity must become the main aim of any hospital. Objective of this study is to determine the total factor productivity and its components over the period under the study. Methods: In this cross sectional study, total factor productivity changes of hospitals affiliated to Tehran University of Medical Sciences were measured according to Malmquist index over the period 2009-2014. To estimate total productivity changes using Data Envelopment Analysis method, inputoriented and variable return to scale assumptions were applied and Deap2.1 software was used. Results: The mean value of total productivity changes was 1.013. It means that during the study period the productivity experienced a 1.3 decrease. Technological efficiency changes have the greatest influence on productivity decrease than the other factors. Scale efficiency, managerial efficiency and technical efficiency changes were ranked. Conclusion: Lack of knowledge of hospital personnel on proper application of technology in patient treatment is the main factor leading to productivity decrease resulting from technological changes in the studied hospitals. Therefore, holding courses for personnel in order to teach them the proper use of technology in diagnosis and patient care can be helpful

    Quantum teleportation with nonclassical correlated states in noninertial frames

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    Quantum teleportation is studied in noninertial frame, for fermionic case, when Alice and Bob share a general nonclassical correlated state. In noninertial frames two fidelities of teleportation are given. It is found that the average fidelity of teleportation from a separable and nonclassical correlated state is increasing with the amount of nonclassical correlation of the state. However, for any particular nonclassical correlated state, the fidelity of teleportation decreases by increasing the acceleration.Comment: 10 pages, 3 figures, expanded version to appear in Quantum Inf. Proces

    Chapter VI: Follow-up after Revascularisation

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    AbstractStructured follow-up after revascularisation for chronic critical limb ischaemia (CLI) aims at sustained treatment success and continued best patient care. Thereby, efforts need to address three fundamental domains: (A) best medical therapy, both to protect the arterial reconstruction locally and to reduce atherosclerotic burden systemically; (B) surveillance of the arterial reconstruction; and (C) timely initiation of repeat interventions. As most CLI patients are elderly and frail, sustained resolution of CLI and preserved ambulatory capacity may decide over independent living and overall prognosis. Despite this importance, previous guidelines have largely ignored follow-up after CLI; arguably because of a striking lack of evidence and because of a widespread assumption that, in the context of CLI, efficacy of initial revascularisation will determine prognosis during the short remaining life expectancy. This chapter of the current CLI guidelines aims to challenge this disposition and to recommend evidentially best clinical practice by critically appraising available evidence in all of the above domains, including antiplatelet and antithrombotic therapy, clinical surveillance, use of duplex ultrasound, and indications for and preferred type of repeat interventions for failing and failed reconstructions. However, as corresponding studies are rarely performed among CLI patients specifically, evidence has to be consulted that derives from expanded patient populations. Therefore, most recommendations are based on extrapolations or subgroup analyses, which leads to an almost systematic degradation of their strength. Endovascular reconstruction and surgical bypass are considered separately, as are specific contexts such as diabetes or renal failure; and critical issues are highlighted throughout to inform future studies

    Ultrasonographic Assessment of Carpal Tunnel Syndrome Severity: A Systematic Review and Meta-Analysis

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    Objective: The aim of the study was to investigate the overall estimates of cross-sectional areas of the median nerve measured by ultrasonography in accordance with the electrodiagnostic classification of carpal tunnel syndrome severity. Design: MEDLINE (PubMed), Embase (Ovid), and Web of Science were searched for studies reporting the median nerve cross-sectional area measured by ultrasonography for mild, moderate, and severe carpal tunnel syndrome based on electrodiagnostic study. Cross-sectional area values measured at the carpal tunnel inlet were included in the analyses. Results: Overall, 866 citations were retrieved and checked for eligibility. Finally, 16 articles were included for meta-analysis. These studies included a total sample of 2292 wrists including 776 mild, 823 moderate, and 693 severe carpal tunnel syndrome. The pooled analysis revealed a mean cross-sectional area of 11.64 mm 2 (95 confidence interval = 11.23-12.05 mm 2 , P < 0.001) for mild carpal tunnel syndrome, a mean cross-sectional area of 13.74 mm 2 (95 confidence interval = 12.59-14.89 mm 2 , P < 0.001) for moderate carpal tunnel syndrome, and a mean cross-sectional area of 16.80 mm 2 (95 confidence interval = 14.50-19.1 mm 2 , P < 0.001) for severe carpal tunnel syndrome. Conclusions: This is the first meta-analysis that provides the pooled median nerve cross-sectional area values in accordance with the electrodiagnostic classification of carpal tunnel syndrome severity. The values obtained in this study have clinical utility in ultrasonographic assessment of patients with carpal tunnel syndrome. © 2019 Wolters Kluwer Health, Inc. All rights reserved

    Examining the role of transfer coupling in sub-barrier fusion of ⁴⁶,⁵⁰Ti+¹²⁴Sn

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    Background: The presence of neutron transfer channels with positive Q values can enhance sub-barrier fusion cross sections. Recent measurements of the fusion excitation functions for 58Ni +132,124Sn found that the fusion enhancement due to the influence of neutron transfer is smaller than that in 40Ca +132,124Sn although the Q values for multineutron transfer are comparable. Purpose: To investigate the differences observed between the fusion of Sn + Ni and Sn + Ca. Methods: Fusion excitation functions for 46,50Ti +124Sn have been measured at energies near the Coulomb barrier. Results: A comparison of the barrier distributions for 46Ti +124Sn and 40Ca +124Sn shows that the 40Ca +124Sn system has a barrier strength resulting from the coupling to the very collective octupole state in 40Ca at an energy significantly lower than the uncoupled barrier. Conclusions: The large sub-barrier fusion enhancement in 40Ca induced reactions is attributed to both couplings to neutron transfer and inelastic excitation, with the octupole vibration of 40Ca playing a major role.Research at ANU was supported by the Australian Research Council Grants DP130101569, FT120100760, DP140101337, FL110100098, DE140100784 and by National Collaborative Research Infrastructure Strategy (NCRIS) for the operation of the Heavy Ion Accelerator Facility
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