XGBoost Gradient-Boosted Tree Predictions Using Limited Data for Coaxial Rotor Helicopters

2021 ◽  
pp. 1-9
Author(s):  
Cory A. Seidel ◽  
Ethan Genter ◽  
David A. Peters
Keyword(s):  
Limited Data ◽  
Coaxial Rotor ◽  
Boosted Tree

Analysis of power law assumptions for short-period comets and Kuiper bodies

1999 ◽  
Vol 173 ◽  
pp. 289-293 ◽  
Author(s):  
J.R. Donnison ◽  
L.I. Pettit
Keyword(s):  
Power Law ◽  
Pareto Distribution ◽  
Limited Data ◽  
Short Period ◽  
Probability Plots ◽  
Exponential Probability

AbstractA Pareto distribution was used to model the magnitude data for short-period comets up to 1988. It was found using exponential probability plots that the brightness did not vary with period and that the cut-off point previously adopted can be supported statistically. Examination of the diameters of Trans-Neptunian bodies showed that a power law does not adequately fit the limited data available.

Predictive value of the ankle brachial index in patients with acute ischemic stroke

VASA ◽  
2014 ◽  
Vol 43 (1) ◽  
pp. 55-61 ◽  
Author(s):  
Konstantinos Tziomalos ◽  
Vasilios Giampatzis ◽  
Stella Bouziana ◽  
Athinodoros Pavlidis ◽  
Marianna Spanou ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Hospital Mortality ◽  
Acute Ischemic Stroke ◽  
Ankle Brachial Index ◽  
Arterial Disease ◽  
National Institutes Of Health ◽  
Limited Data ◽  
Severe Stroke ◽  
Hospital Outcome ◽  
Peripheral Arterial

Background: Peripheral arterial disease (PAD) is frequently present in patients with acute ischemic stroke. However, there are limited data regarding the association between ankle brachial index (ABI) ≤ 0.90 (which is diagnostic of PAD) or > 1.40 (suggesting calcified arteries) and the severity of stroke and in-hospital outcome in this population. We aimed to evaluate these associations in patients with acute ischemic stroke. Patients and methods: We prospectively studied 342 consecutive patients admitted for acute ischemic stroke (37.4 % males, mean age 78.8 ± 6.4 years). The severity of stroke was assessed with the National Institutes of Health Stroke Scale (NIHSS)and the modified Rankin scale (mRS) at admission. The outcome was assessed with the mRS and dependency (mRS 2 - 5) at discharge and in-hospital mortality. Results: An ABI ≤ 0.90 was present in 24.6 % of the patients whereas 68.1 % had ABI 0.91 - 1.40 and 7.3 % had ABI > 1.40. At admission, the NIHSS score did not differ between the 3 groups (10.4 ± 10.6, 8.3 ± 9.3 and 9.3 ± 9.4, respectively). The mRS score was also comparable in the 3 groups (3.6 ± 1.7, 3.1 ± 1.8 and 3.5 ± 2.3, respectively). At discharge, the mRS score did not differ between the 3 groups (2.9 ± 2.2, 2.3 ± 2.1 and 2.7 ± 2.5, respectively) and dependency rates were also comparable (59.5, 47.6 and 53.3 %, respectively). In-hospital mortality was almost two-times higher in patients with ABI ≤ 0.90 than in patients with ABI 0.91 - 1.40 or > 1.40 but this difference was not significant (10.9, 6.6 and 6.3 %, respectively). Conclusions: An ABI ≤ 0.90 or > 1.40 does not appear to be associated with more severe stroke or worse in-hospital outcome in patients with acute ischemic stroke.

Von Willebrand disease and Weibel-Palade bodies

2010 ◽  
Vol 30 (03) ◽  
pp. 150-155 ◽  
Author(s):  
J. W. Wang ◽  
J. Eikenboom
Keyword(s):  
Platelet Adhesion ◽  
Coagulation Factor ◽  
Von Willebrand Disease ◽  
Inflammatory Factors ◽  
Limited Data ◽  
Storage Organelle ◽  
And Function ◽  
Von Willebrand ◽  
Willebrand Factor

SummaryVon Willebrand factor (VWF) is a pivotal haemostatic protein mediating platelet adhesion to injured endothelium and carrying coagulation factor VIII (FVIII) in the circulation to protect it from premature clearance. Apart from the roles in haemostasis, VWF drives the formation of the endothelial cell specific Weibel-Palade bodies (WPBs), which serve as a regulated storage of VWF and other thrombotic and inflammatory factors. Defects in VWF could lead to the bleeding disorder von Willebrand disease (VWD).Extensive studies have shown that several mutations identified in VWD patients cause an intracellular retention of VWF. However, the effects of such mutations on the formation and function of its storage organelle are largely unknown. This review gives an overview on the role of VWF in WPB biogenesis and summarizes the limited data on the WPBs formed by VWD-causing mutant VWF.

TBE in Croatia

2020 ◽  
Keyword(s):  
Tick Species ◽  
Limited Data ◽  
Notifiable Disease ◽  
Genetic Characteristics ◽  
Central European ◽  
Tick Borne Encephalitis ◽  
Tbe Virus ◽  
Endemic Areas ◽  
European Subtype

Even though tick-borne encephalitis (TBE) has been a notifiable disease in Croatia since 2007, there are no or only limited data available on the occurring tick species in the endemic areas, on the prevalence of TBE virus (TBEV) in ticks, its distribution in Croatia, and its genetic characteristics. Reporting of human cases also is very scarce. The Central European subtype of virus (TBEV-EU) appears to be present in Croatia

Comparative Responses to Squats Completed with Free Weights and an Exoskeleton

2020 ◽  
Vol 4 (1) ◽  
pp. 51-63
Author(s):  
Peter Neuhaus ◽  
Chris Jumonville ◽  
Rachel A. Perry ◽  
Roman Edwards ◽  
Jake L. Martin ◽  
...  
Keyword(s):  
Data Collection ◽  
Female Athletes ◽  
Pearson Correlation ◽  
Correlation Coefficients ◽  
Actual Data ◽  
Limited Data ◽  
Comparative Similarity ◽  
Insufficient Amount ◽  
Force Data ◽  
Familiarization Session

AbstractTo assess the comparative similarity of squat data collected as they wore a robotic exoskeleton, female athletes (n=14) did two exercise bouts spaced 14 days apart. Data from their exoskeleton workout was compared to a session they did with free weights. Each squat workout entailed a four-set, four-repetition paradigm with 60-second rest periods. Sets for each workout involved progressively heavier (22.5, 34, 45.5, 57 kg) loads. The same physiological, perceptual, and exercise performance dependent variables were measured and collected from both workouts. Per dependent variable, Pearson correlation coefficients, t-tests, and Cohen's d effect size compared the degree of similarity between values obtained from the exoskeleton and free weight workouts. Results show peak O2, heart rate, and peak force data produced the least variability. In contrast, far more inter-workout variability was noted for peak velocity, peak power, and electromyography (EMG) values. Overall, an insufficient amount of comparative similarity exists for data collected from both workouts. Due to the limited data similarity, the exoskeleton does not exhibit an acceptable degree of validity. Likely the cause for the limited similarity was due to the brief amount of familiarization subjects had to the exoskeleton prior to actual data collection. A familiarization session that accustomed subjects to squats done with the exoskeleton prior to actual data collection may have considerably improved the validity of data obtained from that device.

Effects of Cyclic Pitch on Time Delayed Dynamics in Coaxial Rotor Systems

2021 ◽  
Author(s):  
Ethan S. Genter ◽  
Cory A. Seidel ◽  
David A. Peters
Keyword(s):  
Rotor Systems ◽  
Coaxial Rotor

ANALISIS RISIKO OPERASIONAL MENGGUNAKAN PENDEKATAN DISTRIBUSI KERUGIAN DENGAN METODE AGREGAT

2011 ◽  
Vol 10 (2) ◽  
pp. 1
Author(s):  
Y. ARBI ◽  
R. BUDIARTI ◽  
I G. P. PURNABA
Keyword(s):  
Negative Binomial Distribution ◽  
Binomial Distribution ◽  
Negative Binomial ◽  
Financial Institution ◽  
Expected Value ◽  
Insurance Companies ◽  
Limited Data ◽  
Loss Distribution Approach ◽  
Potential Loss ◽  
The Impact

Operational risk is defined as the risk of loss resulting from inadequate or failed internal processes or external problems. Insurance companies as financial institution that also faced at risk. Recording of operating losses in insurance companies, were not properly conducted so that the impact on the limited data for operational losses. In this work, the data of operational loss observed from the payment of the claim. In general, the number of insurance claims can be modelled using the Poisson distribution, where the expected value of the claims is similar with variance, while the negative binomial distribution, the expected value was bound to be less than the variance.Analysis tools are used in the measurement of the potential loss is the loss distribution approach with the aggregate method. In the aggregate method, loss data grouped in a frequency distribution and severity distribution. After doing 10.000 times simulation are resulted total loss of claim value, which is total from individual claim every simulation. Then from the result was set the value of potential loss (OpVar) at a certain level confidence.

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