6,514 research outputs found

    A Framework for Phasor Measurement Placement in Hybrid State Estimation via Gauss-Newton

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    In this paper, we study the placement of Phasor Measurement Units (PMU) for enhancing hybrid state estimation via the traditional Gauss-Newton method, which uses measurements from both PMU devices and Supervisory Control and Data Acquisition (SCADA) systems. To compare the impact of PMU placements, we introduce a useful metric which accounts for three important requirements in power system state estimation: {\it convergence}, {\it observability} and {\it performance} (COP). Our COP metric can be used to evaluate the estimation performance and numerical stability of the state estimator, which is later used to optimize the PMU locations. In particular, we cast the optimal placement problem in a unified formulation as a semi-definite program (SDP) with integer variables and constraints that guarantee observability in case of measurements loss. Last but not least, we propose a relaxation scheme of the original integer-constrained SDP with randomization techniques, which closely approximates the optimum deployment. Simulations of the IEEE-30 and 118 systems corroborate our analysis, showing that the proposed scheme improves the convergence of the state estimator, while maintaining optimal asymptotic performance.Comment: accepted to IEEE Trans. on Power System

    The Challenges of Balancing Careers and Family Life Facing College Women in Jordan

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    The country of Jordan serves as one of the most progressive countries in the Middle East, yet Jordan has the lowest female economic participation rates out of all the countries in the Middle East and North Africa (MENA) region. Quantitatively, women’s higher education attainment equals and, in some cases, even surpasses that of men. However, their economic participation barely begins to compare to that of their male counterparts. The purpose of this study is to investigate the potential causes for this large gap, using qualitative evidence from the interviews of fifteen college women at the University of Jordan and regional and national statistics and indicators. By analyzing women’s plans, or lack thereof, for the future, the study hopes to provide Jordanian college women with a chance to share their ideas on gender equality, ideal family dynamics, and pressures from society. By investigating the research question of, “What are the challenges college women believe they will face when trying to balance pursuing a career and fulfilling the demands of a family?” the findings led to a conclusion in support of the original hypothesis. Women who have yet to attempt to juggle professional goals with family demands underestimate the challenges they will face and thus also fail to address these concerns realistically

    Quality Assurance in Telehealth: Adherence to Evidence-Based Indicators.

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    Background: Value enhancing telehealth (TH) lacks a robust body of formal clinically focused quality assessment studies. Innovations such as telehealth must always demonstrate that it preserves or hopefully advances quality. Introduction: We sought to determine whether adherence to the evidence-based Choosing Wisely (CW) recommendations (antibiotic stewardship) for acute sinusitis differs for encounters through direct-to-consumer (DTC) telemedicine verses in-person care in an emergency department (ED) or an urgent care (UC) center. Materials and Methods: Study design was a retrospective review. Patients with a symptom complex consistent with acute sinusitis treated through DTC were matched with ED and UC patients, based upon time of visit. Charts were reviewed to determine patient characteristics, chief complaint, final diagnosis, presence or absence of criteria within the CW guidelines, and whether or not antibiotics were prescribed. The main outcome was adherence to the CW campaign recommendations. Results: A total of 570 visits were studied: 190 DTC, 190 ED, and 190 UC visits. The predominant chief complaints were upper respiratory infection (36%), sore throat (25%), and sinusitis (18%). Overall, there was a 67% (95% CI 62.3-71.7) adherence rate with the CW guidelines for sinusitis: DTC visits (71%), ED visits (68%), and UC visits (61%). There was a nonsignificant difference (p = 0.29) in adherence to CW guidelines based upon type of visit (DTC, UC, and ED). Discussion: The challenge is to demonstrate whether or not DTC TH compromises quality. Conclusion: In this study, DTC visits were associated with at least as good an adherence to the CW campaign recommendations as emergency medicine (EM) and UC in-person visits. © Daniel Halpren-Ruder et al

    Fooling Vision and Language Models Despite Localization and Attention Mechanism

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    Adversarial attacks are known to succeed on classifiers, but it has been an open question whether more complex vision systems are vulnerable. In this paper, we study adversarial examples for vision and language models, which incorporate natural language understanding and complex structures such as attention, localization, and modular architectures. In particular, we investigate attacks on a dense captioning model and on two visual question answering (VQA) models. Our evaluation shows that we can generate adversarial examples with a high success rate (i.e., > 90%) for these models. Our work sheds new light on understanding adversarial attacks on vision systems which have a language component and shows that attention, bounding box localization, and compositional internal structures are vulnerable to adversarial attacks. These observations will inform future work towards building effective defenses.Comment: CVPR 201

    Associations of Emergency Department Length of Stay With Publicly Reported Quality-of-care Measures.

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    OBJECTIVE: The Institute of Medicine identified emergency department (ED) crowding as a critical threat to patient safety. We assess the association between changes in publicly reported ED length of stay (LOS) and changes in quality-of-care measures in a national cohort of hospitals. METHODS: Longitudinal analysis of 2012 and 2013 data from the American Hospital Association (AHA) Survey, Center for Medicare and Medicaid Services (CMS) Cost Reports, and CMS Hospital Compare. We included hospitals reporting Hospital Compare timeliness measure of LOS for admitted patients. We used AHA and CMS data to incorporate hospital predictors of interest. We used the method of first differences to test for relationships in the change over time between timeliness measures and six hospital-level measures. RESULTS: The cohort consisted of 2,619 hospitals. Each additional hour of ED LOS was associated with a 0.7% decrease in proportion of patients giving a top satisfaction rating, a 0.7% decrease in proportion of patients who would definitely recommend the hospital, and a 6-minute increase in time to pain management for long bone fracture (p \u3c 0.01 for all). A 1-hour increase in ED LOS is associated with a 44% increase in the odds of having an increase in left without being seen (95% confidence interval = 25% to 68%). ED LOS was not associated with hospital readmissions (p = 0.14) or time to percutaneous coronary intervention (p = 0.14). CONCLUSION: In this longitudinal study of hospitals across the United States, improvements in ED timeliness measures are associated with improvements in the patient experience

    Fooling Vision and Language Models Despite Localization and Attention Mechanism

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    Adversarial attacks are known to succeed on classifiers, but it has been an open question whether more complex vision systems are vulnerable. In this paper, we study adversarial examples for vision and language models, which incorporate natural language understanding and complex structures such as attention, localization, and modular architectures. In particular, we investigate attacks on a dense captioning model and on two visual question answering (VQA) models. Our evaluation shows that we can generate adversarial examples with a high success rate (i.e., > 90%) for these models. Our work sheds new light on understanding adversarial attacks on vision systems which have a language component and shows that attention, bounding box localization, and compositional internal structures are vulnerable to adversarial attacks. These observations will inform future work towards building effective defenses.Comment: CVPR 201

    Improving reading rate activities for EFL students: Timed reading and repeated oral reading

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    This study investigates the effect of timed reading (TR) and repeated oral reading (RR) on 35 adult students of English as a foreign language. Students in the TR (n =18) and RR (n =17) groups read 52 and 26 passages respectively over a 13-week period. Reading rates and comprehension levels were measured at three occasions: pre-intervention, post-intervention, and delayed post-intervention. The reading rate results show that the TR group increased 50 (49%) words per minute (wpm) and 23 wpm (27%) for the RR group. The rate gains of both groups were largely retained after six weeks with no further instructional practice. In terms of comprehension levels, the TR group scored 53%, 67%, and 63%, and the RR group 53%, 60%, and 53% at the pretest, posttest and delayed posttest respectively. Overall, increasing the reading amount for the TR group improved reading rates and comprehension ; increasing the reading rate for the RR group did not have a negative impact on reading comprehension. Thus, it is worthwhile including reading ratebuildup activities in L2 reading instruction
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