scholarly journals A Novel Adaptive Probabilistic Nonlinear Denoising Approach for Enhancing PET Data Sinogram

2013 ◽  
Vol 2013 ◽  
pp. 1-14 ◽  
Author(s):  
Musa Alrefaya ◽  
Hichem Sahli
Keyword(s):  
Poisson Distribution ◽  
Expectation Maximization ◽  
Poisson Noise ◽  
Chi Square ◽  
Statistical Measures ◽  
Curvature Motion ◽  
Edge Probability ◽  
Nonlinear Denoising ◽  
Diffusivity Function

We propose filtering the PET sinograms with a constraint curvature motion diffusion. The edge-stopping function is computed in terms of edge probability under the assumption of contamination by Poisson noise. We show that the Chi-square is the appropriate prior for finding the edge probability in the sinogram noise-free gradient. Since the sinogram noise is uncorrelated and follows a Poisson distribution, we then propose an adaptive probabilistic diffusivity function where the edge probability is computed at each pixel. The filter is applied on the 2D sinogram prereconstruction. The PET images are reconstructed using the Ordered Subset Expectation Maximization (OSEM). We demonstrate through simulations with images contaminated by Poisson noise that the performance of the proposed method substantially surpasses that of recently published methods, both visually and in terms of statistical measures.

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.

Phenotypes of Enamel Hypomineralization and Molar Incisor Hypomineralization in Permanent Dentition: Identification, Quantification and Proposal for Classification

2016 ◽  
Vol 40 (5) ◽  
pp. 367-374 ◽  
Author(s):  
Neeti Mittal
Keyword(s):  
Observational Study ◽  
Random Sample ◽  
Comparative Evaluation ◽  
Clinical Presentation ◽  
Permanent Dentition ◽  
Chi Square ◽  
Cross Sectional ◽  
Statistical Measures ◽  
Molar Incisor Hypomineralization ◽  
Phenotypic Variations

Objectives: To report the extent, pattern, clinical presentation and phenotypes of enamel hypomineralization in permanent dentition Study Design: This cross sectional observational study recruited a random sample of 1726, 12–16 year olds. Enamel hypomineralization was scored on all teeth by a calibrated examiner using the EAPD 2003 criteria. Proportions of affected subjects (prevalence) with a minimum of one hypomineralization and Molar Incisor Hypomineralization (MIH) were calculated. Proportions of following phenotypes were quantified i.e. MH (only FPM hypomineralization), M+IH (concomitantly affected FPMs and permanent incisors without affecting any other tooth in the arch), MIHO (hypomineralization affecting at least one of the canines, premolars or 2nd molars and simultaneously including at least one FPM), IH (only permanent incisor's hypomineralization) and NoFPM (hypomineralization affecting at least one of the canines, premolars and 2nd molars but not FPM; incisors can be affected concomitantly). A comparative evaluation of extent and severity of enamel hypomineralization was performed amongst various phenotypes. Statistical measures employed t-test, chi square tests and ANOVA. Results: Overall prevalence of affected subjects was 13.21% (228/1726) and 9.79% (169/1726) for enamel hypomineralization and MIH respectively. A total of 4.36±3.45 teeth/subject and 6.01±5.20 surfaces/subject were found to be affected with enamel hypomineralization. Most prevalent phenotype was M+IH while the least prevalent was IH. Maximum severity i.e. number of affected surfaces and surfaces with PEB were reported for MIHO (p<0.001). Conclusion: Enamel hypomineralization can manifest in any tooth in five phenotypic variations in permanent dentition with varying extent and severity.

scholarly journals Exploring the Spatiotemporal Characteristics of COVID-19 Infections among Healthcare Workers: A Multi-Scale Perspective

2021 ◽  
Vol 10 (10) ◽  
pp. 691
Author(s):  
Hui Ren ◽  
Peixiao Wang ◽  
Wei Guo ◽  
Xinyan Zhu
Keyword(s):  
High Risk ◽  
Poisson Distribution ◽  
Infection Rate ◽  
Healthcare Workers ◽  
Chi Square ◽  
Multi Scale ◽  
Spatiotemporal Characteristics ◽  
Care Workers ◽  
Different Types ◽  
Chi Square Test

The outbreak of COVID-19 has constantly exposed health care workers (HCWs) around the world to a high risk of infection. To more accurately discover the infection differences among high-risk occupations and institutions, Hubei Province was taken as an example to explore the spatiotemporal characteristics of HCWs at different scales by employing the chi-square test and fitting distribution. The results indicate (1) the units around the epicenter of the epidemic present lognormal distribution, and the periphery is Poisson distribution. There is a clear dividing line between lognormal and Poisson distribution in terms of the number of HCWs infections. (2) The infection rates of different types of HCWs at multiple geospatial scales are significantly different, caused by the spatial heterogeneity of the number of HCWs. (3) With the increase of HCWs infection rate, the infection difference among various HCWs also gradually increases and the infection difference becomes more evident on a larger scale. The analysis of the multi-scale infection rate and statistical distribution characteristics of HCWs can help government departments rationally allocate the number of HCWs and personal protective equipment to achieve distribution on demand, thereby reducing the mental and physical pressure and infection rate of HCWs.

scholarly journals Prediabetic state and dyslipidemia in freshmen in Health Sciences campus of a Mexican University

2018 ◽  
Vol 18 (2) ◽  
pp. 270-278
Author(s):  
Ana Patricia González Ascencio ◽  
Juan Antonio Córdova Hernández ◽  
Crystell Guadalupe Guzmán Priego ◽  
Juan Manuel Muñoz Cano
Keyword(s):  
Central Tendency ◽  
Chi Square ◽  
Prediabetic State ◽  
Cross Sectional ◽  
School Of Medicine ◽  
Statistical Measures ◽  
Support Strategies ◽  
Probabilistic Study ◽  
University Population

Objective: given the dramatic increase of diabetes in the world, the objective of this research was to analyze the values of blood glucose in a university population again income to support strategies for detection and preventive management of pre-diabetes and diabetes. Materials and methods: this is an observational, analytical, cross-sectional, non-probabilistic study to analyze biochemical markers in two freshman populations in a School of Medicine, 367 students enrolled in 2011 and 430 enrolled in 2016. The study variables were glycemia, triglyceridemia, and cholesterolemia. Statistical measures of central tendency, dispersions, and correlations for the groups, and applied Chi-square to clinical categories was analiced. Results: It was found significant increases in women in glycemia between 2011 and 2016: t = -4.582 (p = 0.0001) and cholesterolemia t = -9.124 (p = 0.0001). Men had significant increases in glycemia with t = -6.428 (p = 0.0001) and cholesterolemia with t = -9.499 (p = 0.0001). There was a higher prevalence of prediabetes and total cholesterol in borderline levels and risks in the 2016-population. We found correlation in men and women regarding glucose-triglycerides, glucose-cholesterol, and cholesterol-triglycerides in both populations. Conclusions: in the sample of 2016 there was increase in young adults at risk of developing type 2 diabetes mellitus and atherosclerosis by what is needed to develop strategies to improve lifestyle.

scholarly journals Mining Statistically Significant Substrings Based on the Chi-Square Measure

2012 ◽  
pp. 73-82 ◽  
Author(s):  
Sourav Dutta ◽  
Arnab Bhattacharya
Keyword(s):  
Intrusion Detection ◽  
Sequence Data ◽  
Long Strings ◽  
Intrusion Detection Systems ◽  
Chi Square ◽  
Detection Systems ◽  
Statistical Measures ◽  
Normal Behavior ◽  
Practical Challenge ◽  
String Databases

With the tremendous expansion of reservoirs of sequence data stored worldwide, efficient mining of large string databases in various domains including intrusion detection systems, player statistics, texts, and proteins, has emerged as a practical challenge. Searching for an unusual pattern within long strings of data is one of the foremost requirements for many diverse applications. Given a string, the problem is to identify the substrings that differ the most from the expected or normal behavior, i.e., the substrings that are statistically significant (or, in other words, less likely to occur due to chance alone). We first survey and analyze the different statistical measures available to meet this end. Next, we argue that the most appropriate metric is the chi-square measure. Finally, we discuss different approaches and algorithms proposed for retrieving the top-k substrings with the largest chi-square measure.

Effects of detections and cure in prodromal stadium in schizophrenia relapses on hospital treatment duration

2011 ◽  
Vol 26 (S2) ◽  
pp. 1341-1341
Author(s):  
S. Anakiev ◽  
A. Stanojevic ◽  
D. Milosevic ◽  
G. Tasic ◽  
M. Cvetanovic
Keyword(s):  
Social Withdrawal ◽  
Length Of Hospital Stay ◽  
Economic Effects ◽  
Psychotic Symptoms ◽  
Hospital Treatment ◽  
Chi Square ◽  
Prodromal Symptoms ◽  
Statistical Measures ◽  
Chi Square Test ◽  
The Comparative Study

IntroductionSchizophrenia is a chronic disease with devastating consequences for individuals, families and society. Illness is characterized by alternately periods of relapses and remission. It is therefore of particular importance recognition of prodromal symptoms, which announced a new worsening of the disease and act with treatment timely. This is to prevent early deterioration of personality, shorter stays in hospital, better socialization and significant economic effects.Objectives126 female patients who were admitted on Female Admission Department of Special Hospital for Psychiatrics disease during 2009. with already verified schizophrenia. Patients with somatic disease, social and administrative reasons for prolonged hospitalization were excluded from study.AimAim of the study was to investigate effects on admission in prodromal stadium in schizophrenia relapses on hospital treatment length.MethodPatients were divided in to two groups. First group were patients with prodromal symptoms (anxiety, hostility, irritability, insomnia, inapetitio, aggressive behavior, social withdrawal), and second one were patients with manifest psychotic symptoms (delusions and hallucinations). All data about symptoms were given by heteroanmnesis. In research are used descriptive statistical measures (frequencies, percents and arithmetical mean) and CHI- square test for confirmation statistically significant differences.ResultsResults of study revealed very highly significant differences between two groups (p = .000, p < 0,005).ConclusionsRecognizing the importance of prodrome and early intervention affect the length of hospital stay showed that the comparative study was made.

Image Restoration Using Adaptive Region-Wise p-Norm Filter with Local Constraints

2016 ◽  
Vol 16 (02) ◽  
pp. 1650008
Author(s):  
A. A. Bini ◽  
P. Jidesh
Keyword(s):  
Image Restoration ◽  
Regularization Parameter ◽  
Image Features ◽  
Local Constraints ◽  
Mean Curvature Motion ◽  
Statistical Measures ◽  
Image Characteristics ◽  
Curvature Motion ◽  
Laplacian Filter ◽  
Texture Preservation

In this work, we introduce a feature adaptive second-order p-norm filter with local constraints for image restoration and texture preservation. The p-norm value of the filter is chosen adaptively between 1 and 2 in a local region based on the regional image characteristics. The filter behaves like a mean curvature motion (MCM) [A. Marquina and S. Osher, SIAM Journal of Scientific Computing 22, 387–405 (2000)] in the regions where the p-norm value is 1 and switches to a Laplacian filter in the rest of the regions (where the p-norm value is 2). The proposed study considerably reduces stair-case effect and effectively removes noise from images while deblurring them. The noise is assumed as Gaussian distributed (with zero mean and variance [Formula: see text]) and blur is linearly shift invariant (out-of-focus). The filter converges at a faster rate with semi-implicit Crank–Nicholson scheme. The regularization parameter is initialized and updated based on the local image features and therefore this filter preserves edges, structures, textures and fine details present in images very well. The method is applied on different kinds of images with different image characteristics. We show the response of the filter to various kinds of images and numerically quantify the performance in terms of standard statistical measures.

scholarly journals Sharing, Adaptation and Organization of Open Educational Resources: Exploring the Teachers’ Attitude of Sukhothai Thamathirat Open University, Thailand

2019 ◽  
Vol 9 (1) ◽  
pp. 31-36
Keyword(s):  
Knowledge Society ◽  
Analysis Data ◽  
Open Educational Resources ◽  
Open Educational Resource ◽  
Open University ◽  
Point Scale ◽  
Chi Square ◽  
Statistical Measures ◽  
Chi Square Test ◽  
Strongly Agree

The Open Educational Resource(OER) is based on culture of sharing and learning, encouraging the teachers to adopt existing OER, adapt and share with others to keep up the cycle of collaboration and continuous improvement. Understanding teachers’ attitude towards the use of OER and comparing data across institutions may help to recognize the issues that impact OER take-up. The major objectives of the paper is to study the teacher’s attitude towards OER at Sukhothai Thamathirat Open University(STOU), Thailand. The teachers’ attitude towards OER scale with a five-point scale from strongly disagree to strongly agree was used in this study. Based on the scale, adaptation & use of OER and sharing of OER can be identified. The questionnaire was distributed to the faculty of STOU. There were 32 respondents of STOU considered for analysis. Data captured through online form.The data have been analyzed quantitatively by implying statistical measures. The frequency measures were used to present the demographic as well as other data along with chi-square test. The analysis was done in SPSS.Teachers of Thailand are encouraged to share OER for their professional enhancement and personal satisfaction. It is interesting to find that majority of them are motivated to share and contribute to OER for dissemination of ideas in a knowledge society.

scholarly journals ASSESSMENT OF URBAN GENERATED CLIMATE ANOMALY IN OKENE TOWN, OKENE LOCAL GOVERNMENT AREA OF KOGI STATE, NIGERIA

2020 ◽  
Vol 4 (2) ◽  
pp. 101-110
Author(s):  
Ishaya Sunday
Keyword(s):  
Relative Humidity ◽  
Solar Radiation ◽  
Satellite Image ◽  
Assessment Tools ◽  
Mitigation Measures ◽  
Climate Data ◽  
Chi Square ◽  
Average Deviation ◽  
Statistical Measures ◽  
Deviation Coefficient

Abstract This study assessed urban generate climate change in Okene town of Kogi State, Nigeria. The objectives of this study include acquiring temperature, relative humidity and solar radiation data from SWAT satellite image from 1986 to 2016; determine the trend, normality, changes in temperature, relative humidity and solar radiation in the study area from 1986 to 2016.  Climate data was collected from the Soil and Water Assessment Tools (SWAT) from 1986 to 2016 of Okene Town. Simple Statistical Measures of mean, maximum, minimum, standard deviation, Average deviation, coefficient of variation, skewness and kurtosis were used for discerning the trends and normality of temperature, relative humidity and solar radiation. The chi square statistical test was use to test the study hypothesis. The trend line equation shows positive for temperature (0.0567x +26.27), Solar radiation (0.036x + 18.1) and negative trend in relative humidity (y = -0.001x + 0.733). Chi square statistical result shows that there are significant changes in temperature, relative humidity and solar radiation over the past three decades in Okene town of Kogi State. In tackling this anomaly, there is need for greening the town by embanking on radical planting of trees and creation of cool pavement technologies towards cooler surfaces by convection or higher reflectance as adaptive/mitigation measures against Urban Heat Island in Okene town.

scholarly journals Health insurance coverage and its awareness among population in the rural field practice area of Adichunchanagiri Institute of Medical Sciences, B G Nagara, Karnataka

2019 ◽  
Vol 6 (3) ◽  
pp. 1065
Author(s):  
L. M. Manuja ◽  
P. G. Viswanatha ◽  
Kanchana Nagendra
Keyword(s):  
Health Insurance ◽  
Insurance Coverage ◽  
Health Insurance Coverage ◽  
Cross Sectional Study ◽  
Medical Sciences ◽  
Chi Square ◽  
Cross Sectional ◽  
Statistical Measures ◽  
Field Practice ◽  
Chi Square Test

Background: In India, there is marked lack of awareness of health insurance in the rural and low socioeconomic sector due to reasons like the existing burden on the poor making them reluctant to think of the credit policies that are actually issued in their interest, illiteracy, lack of exposure and the growth of the private sectors has an upper hand over public sectors. Hence this study was done with the objective to determine the health insurance coverage and its awareness including perception among the rural population around Adichunchanagiri Institute of Medical Sciences, BG Nagara, Mandya.Methods: This cross sectional study was carried out among 295 households in the rural field practice area of Adichunchanagiri Institute of Medical Sciences, B G Nagara for a period of 3 months. Personal interview of the households was done using pretested semi structured questionnaire after obtaining the consent. Data was entered in MS excel and descriptive statistical measures like percentage, mean, and standard deviations were calculated. An inferential statistical measure like Chi square test was applied.Results: Among 295 households, Male constituted 49.5% and Hindus were 94.9%. 44.7% of the families were enrolled to health insurance schemes and 75.0% of them use to renew their health insurance scheme regularly. The factors which were significantly associated with health insurance enrollment and awareness were gender, education, occupation, hospitalization during last year and socioeconomic status. Only 173 (58.6%) of the respondents were aware of health insurance.Conclusions:More than half of the study population was covered by health insurance policies and majority of them were unaware of the available insurance schemes, risks and benefits of the same.  

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