scholarly journals Growth Estimators and Confidence Intervals for the Mean of Negative Binomial Random Variables with Unknown Dispersion

2013 ◽  
Vol 2013 ◽  
pp. 1-9
Author(s):  
David Shilane ◽  
Derek Bean
Keyword(s):  
Confidence Intervals ◽  
Negative Binomial ◽  
Normal Approximation ◽  
Tail Probability ◽  
Expected Value ◽  
Alternative Methods ◽  
High Dispersion ◽  
Chi Square ◽  
Sample Mean ◽  
Wide Range

The negative binomial distribution becomes highly skewed under extreme dispersion. Even at moderately large sample sizes, the sample mean exhibits a heavy right tail. The standard normal approximation often does not provide adequate inferences about the data's expected value in this setting. In previous work, we have examined alternative methods of generating confidence intervals for the expected value. These methods were based upon Gamma and Chi Square approximations or tail probability bounds such as Bernstein's inequality. We now propose growth estimators of the negative binomial mean. Under high dispersion, zero values are likely to be overrepresented in the data. A growth estimator constructs a normal-style confidence interval by effectively removing a small, predetermined number of zeros from the data. We propose growth estimators based upon multiplicative adjustments of the sample mean and direct removal of zeros from the sample. These methods do not require estimating the nuisance dispersion parameter. We will demonstrate that the growth estimators' confidence intervals provide improved coverage over a wide range of parameter values and asymptotically converge to the sample mean. Interestingly, the proposed methods succeed despite adding both bias and variance to the normal approximation.

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.

Classical and modern drug extraction techniques: facts and figures

2017 ◽  
Vol 2 (4) ◽  
Author(s):  
Bharti Umrethia ◽  
Bharat Kalsariya ◽  
Prof. P. U. Vaishnav
Keyword(s):  
Solvent Extraction ◽  
Dosage Forms ◽  
Herbal Extract ◽  
Alternative Methods ◽  
Extraction Techniques ◽  
Modern Drug ◽  
Novel Drugs ◽  
Wide Range ◽  
In The Mists ◽  
Heating Pattern

In present era, herbal extract succeeds inimitable place in pharmaceutical science. In view back the earliest extraction techniques are lost in the mists of history. As time went the plants have been processed by grinding, boiling or immersing. The systemic presentation of Ayurvedic extraction system has been first time familiarized by Acharya Charaka as Panchavidha Kashaya Kalpana (five basic primary dosage forms) and based upon these primary dosage forms, secondary dosage forms are developed by using different heating pattern for extraction of pharmacological active ingredients. The administration of these dosage forms is mainly dependent on the Bala (strength) of Vyadhi (disease) and Atura (patient). Due to increased demand of Ayurvedic medicines and industrialization, the transformation of classical dosage forms takes place by implanting a wide range of technologies with different methods of extraction include conventional techniques such as maceration, percolation, infusion, decoction, hot continuous extraction etc. and recently, alternative methods like ultrasound assisted solvent extraction (UASE), microwave assisted solvent extraction (MASE) and supercritical fluid extractions (SFE). The extract obtained by these procedure uses as a large source of therapeutic phyto-chemicals that may lead to the development of novel drugs. Essentially, the purpose behind this changing face in both the extraction systems are different but can say that it is a new insight from ancient essence.

scholarly journals 264 Effects of Water Quality on Nursery Pig Performance and Health

2020 ◽  
Vol 98 (Supplement_3) ◽  
pp. 89-89
Author(s):  
Brigit Lozinski ◽  
Brent Frederick ◽  
Adrienne Hilbrands ◽  
Yuzhi Li ◽  
Milena Saqui-Salces ◽  
...  
Keyword(s):  
Water Quality ◽  
Experimental Unit ◽  
Respiratory Syndrome Virus ◽  
Chi Square ◽  
Wide Range ◽  
Mycoplasma Pneumonia ◽  
Quality Water ◽  
Pig Performance ◽  
Chi Square Analysis ◽  
Water Treatments

Abstract Newly-weaned pigs (n = 450; age = 20 d) were used in a 40-d experiment to determine the effects of water quality on pig performance and health. Pigs were sourced from a single commercial sow farm that was negative for both Porcine Reproductive and Respiratory Syndrome virus and Mycoplasma Pneumonia. Pigs were allotted randomly to 45 pens (10 pigs/pen) and pens were assigned to 1 of 3 water treatments that provided water of differing quality. Waters were selected to represent a wide range of perceived water quality. Water quality was determined based on concentration of analytes including sulfates (1,120; 617; 2 ppm), iron (5.4; 5.2; 1.3 ppm), Total Dissolved Solids (TDS; 1,500; 1,050; 348 ppm), hardness (1,410; 909; 235 mg Eq CaCO3/L), magnesium (171; 91; 21 ppm) and sodium (64; 37; 29 ppm) for waters A, B, and C, respectively. Pigs were housed in an environmentally controlled, power ventilated, confinement nursery barn and were allowed ad libitum access to a common three-phase diet and water across all water treatments. Weekly ADG, ADFI, and G:F were measured and subjective scour score (1=solid feces to 4=liquid feces) was recorded daily through day 7. Data for pig growth performance were analyzed using PROC GLIMMIX with water quality as a fixed effect and pen served as the experimental unit. There were no differences among treatments in ADG, ADFI, and G:F (Table 1). Number of pigs treated with antibiotics throughout the experiment did not differ among treatments as determined by Chi-Square analysis. Average subjective scour score on day 7 of the experiment also did not differ among treatments. In conclusion, performance and health of nursery pigs as measured in this experiment were not influenced by the differing water qualities studied.

scholarly journals Results of the Behavioral Health Readiness Evaluation and Decision-Making Instrument Study

2021 ◽  
Vol 186 (Supplement_1) ◽  
pp. 142-152
Author(s):  
Justin M Curley ◽  
Katie L Nugent ◽  
Kristina M Clarke-Walper ◽  
Elizabeth A Penix ◽  
James B Macdonald ◽  
...  
Keyword(s):  
Decision Making ◽  
Behavioral Health ◽  
User Satisfaction ◽  
Safety Issue ◽  
Walter Reed Army Institute ◽  
End User ◽  
Chi Square ◽  
Proficiency Level ◽  
Wide Range ◽  
Decision Making Support

ABSTRACT Introduction Recent reports have demonstrated behavioral health (BH) system and individual provider challenges to BH readiness success. These pose a risk to winning on the battlefield and present a significant safety issue for the Army. One of the most promising areas for achieving better BH readiness results lies in improving readiness decision-making support for BH providers. The Walter Reed Army Institute of Research (WRAIR) has taken the lead in addressing this challenge by developing and empirically testing such tools. The results of the Behavioral Health Readiness Evaluation and Decision-Making Instrument (B-REDI) field study are herein described. Methods The B-REDI study received WRAIR Institutional Review Board approval, and BH providers across five U.S. Army Forces Command installations completed surveys from September 2018 to March 2019. The B-REDI tools/training were disseminated to 307 providers through random clinic assignments. Of these, 250 (81%) providers consented to participate and 149 (60%) completed both initial and 3-month follow-up surveys. Survey items included a wide range of satisfaction, utilization, and proficiency-level outcome measures. Analyses included examinations of descriptive statistics, McNemar’s tests pre-/post-B-REDI exposure, Z-tests with subgroup populations, and chi-square tests with demographic comparisons. Results The B-REDI resulted in broad, statistically significant improvements across the measured range of provider proficiency-level outcomes. Net gains in each domain ranged from 16.5% to 22.9% for knowledge/awareness (P = .000), from 11.1% to 15.8% for personal confidence (P = .001-.000), and from 6.2% to 15.1% for decision-making/documentation (P = .035-.002) 3 months following B-REDI initiation, and only one (knowledge) failed to maintain a statistically significant improvement in all of its subcategories. The B-REDI also received high favorability ratings (79%-97% positive) across a wide array of end-user satisfaction measures. Conclusions The B-REDI directly addresses several critical Army BH readiness challenges by providing tangible decision-making support solutions for BH providers. Providers reported high degrees of end-user B-REDI satisfaction and significant improvements in all measured provider proficiency-level domains. By effectively addressing the readiness decision-making challenges Army BH providers encounter, B-REDI provides the Army BH health care system with a successful blueprint to set the conditions necessary for providers to make more accurate and timely readiness determinations. This may ultimately reduce safety and mission failure risks enterprise-wide, and policymakers should consider formalizing and integrating the B-REDI model into current Army BH practice.

scholarly journals A coma-free super-high resolution optical spectrometer using 44 high dispersion sub-gratings

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hua-Tian Tu ◽  
An-Qing Jiang ◽  
Jian-Ke Chen ◽  
Wei-Jie Lu ◽  
Kai-Yan Zang ◽  
...  
Keyword(s):  
High Resolution ◽  
Spectral Resolution ◽  
Wavelength Region ◽  
Ultra Violet ◽  
High Spectral Resolution ◽  
Visible Range ◽  
High Dispersion ◽  
Charge Coupled Device ◽  
Wide Range ◽  
High Resolution Spectrometer

AbstractUnlike the single grating Czerny–Turner configuration spectrometers, a super-high spectral resolution optical spectrometer with zero coma aberration is first experimentally demonstrated by using a compound integrated diffraction grating module consisting of 44 high dispersion sub-gratings and a two-dimensional backside-illuminated charge-coupled device array photodetector. The demonstrated super-high resolution spectrometer gives 0.005 nm (5 pm) spectral resolution in ultra-violet range and 0.01 nm spectral resolution in the visible range, as well as a uniform efficiency of diffraction in a broad 200 nm to 1000 nm wavelength region. Our new zero-off-axis spectrometer configuration has the unique merit that enables it to be used for a wide range of spectral sensing and measurement applications.

scholarly journals Modelling the atmosphere of lava planet K2-141b: implications for low- and high-resolution spectroscopy

2020 ◽  
Vol 499 (4) ◽  
pp. 4605-4612
Author(s):  
T Giang Nguyen ◽  
Nicolas B Cowan ◽  
Agnibha Banerjee ◽  
John E Moores
Keyword(s):  
Steady State ◽  
Ocean Circulation ◽  
Scale Height ◽  
High Resolution Spectroscopy ◽  
Return Flow ◽  
High Dispersion ◽  
Magma Ocean ◽  
Steady State Flow ◽  
Wide Range ◽  
Very High

ABSTRACT Transit searches have uncovered Earth-size planets orbiting so close to their host star that their surface should be molten, so-called lava planets. We present idealized simulations of the atmosphere of lava planet K2-141b and calculate the return flow of material via circulation in the magma ocean. We then compare how pure Na, SiO, or SiO2 atmospheres would impact future observations. The more volatile Na atmosphere is thickest followed by SiO and SiO2, as expected. Despite its low vapour pressure, we find that a SiO2 atmosphere is easier to observe via transit spectroscopy due to its greater scale height near the day–night terminator and the planetary radial velocity and acceleration are very high, facilitating high dispersion spectroscopy. The special geometry that arises from very small orbits allows for a wide range of limb observations for K2-141b. After determining the magma ocean depth, we infer that the ocean circulation required for SiO steady-state flow is only 10−4 m s−1, while the equivalent return flow for Na is several orders of magnitude greater. This suggests that a steady-state Na atmosphere cannot be sustained and that the surface will evolve over time.

scholarly journals Prevalence and risk factors of apical periodontitis in endodontically treated teeth in a selected population of Brazilian adults

2008 ◽  
Vol 19 (1) ◽  
pp. 34-39 ◽  
Author(s):  
Carlos Estrela ◽  
Cláudio Rodrigues Leles ◽  
Augusto César Braz Hollanda ◽  
Marcelo Sampaio Moura ◽  
Jesus Djalma Pécora
Keyword(s):  
Risk Factors ◽  
Confidence Intervals ◽  
Odds Ratio ◽  
Apical Periodontitis ◽  
Endodontic Treatment ◽  
Technical Quality ◽  
Endodontically Treated Teeth ◽  
Chi Square ◽  
Chi Square Test

The aim of this study was to assess the prevalence and risk factors of apical periodontitis in endodontically treated teeth in a selected population of Brazilian adults. A total of 1,372 periapical radiographs of endodontically treated teeth were analyzed based on the quality of root filling, status of coronal restoration and presence of posts associated with apical periodontitis (AP). Data were analyzed statistically using odds ratio, confidence intervals and chi-square test. The prevalence of AP with adequate endodontic treatment was low (16.5%). This percentage dropped to 12.1% in cases with adequate root filling and adequate coronal restoration. Teeth with adequate endodontic treatment and poor coronal restoration had an AP prevalence of 27.9%. AP increased to 71.7% in teeth with poor endodontic treatment associated with poor coronal restoration. When poor endodontic treatment was combined with adequate coronal restoration, AP prevalence was 61.8%. The prevalence of AP was low when associated with high technical quality of root canal treatment. Poor coronal restoration increased the risk of AP even when endodontic treatment was adequate (OR=2.80; 95%CI=1.87-4.22). The presence of intracanal posts had no influence on AP prevalence.

SPATIAL PATTERN OF THE IMMATURE STAGES OF HYLEMYA BRASSICAE ON CABBAGE

1970 ◽  
Vol 102 (10) ◽  
pp. 1216-1222 ◽  
Author(s):  
M. K. Mukerji ◽  
D. G. Harcourt
Keyword(s):  
Spatial Pattern ◽  
Poisson Distribution ◽  
Negative Binomial ◽  
Immature Stages ◽  
Expected Number ◽  
Chi Square ◽  
Binomial Series ◽  
Binomial Parameter ◽  
Hylemya Brassicae ◽  
Cabbage Maggot

AbstractCounts of the cabbage maggot, Hylemya brassicae (Bouché), on cabbage did not conform to the Poisson distribution, there being an excess of uninfested and highly infested plants over the expected number. But when the negative binomial series was fitted to the observed distribution, the discrepancies were not significant when tested by chi-square. The negative binomial parameter k tended to increase with density. Using a common k, the distribution of the various stages may be described by expansion of (q − p)−k, when values of k are as follows: egg 0.78, larva 0.71, pupa 0.84. Three different transformations are offered for stabilizing the variance of field counts.

Sign in / Sign up

Export Citation Format

Share Document