Search results for: Spearman correlation
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 3833

Search results for: Spearman correlation

3803 Correlation between the Larvae Density (Diptera: Culicidae) and Physicochemical Characteristics of Habitats in Mazandaran Province, Northern Iran

Authors: Seyed Hassan Nikookar, Mahmoud Fazeli-Dinan, Seyyed Payman Ziapour, Ahmad-Ali Enayati

Abstract:

Background: Mosquitoes look for all kinds of aquatic habitats for laying eggs. Characteristics of water habitats are important factors in determining whether a mosquito can survive and successfully completed their developmental stages. Physicochemical factors can display an important role in vector control programs. This investigate determined whether physicochemical factors differ between habitats can be effective in the larvae density in Mazandaran province. Methods: Larvae were collected by the standard dipper up to 350 ml for 15-20 minutes from fixed habitats in 16 villages of 30 townships, the specimens identified by morphological key. Water samples were collected during larval collection and were evaluated for temperature (°C), acidity (pH), turbidity (NTU), electrical conductivity (μS/cm), alkalinity (mg/l), total hardness (mg/l), nitrate (mg/l), chloride (mg/l), phosphate (mg/l), sulfate (mg/l) in selected habitats using standard methods. Spearman Correlation coefficient was used for analyze data. Results: Totally 7566 mosquito larvae of three genera and 15 species were collected of fixed habitats. Cx. pipiens was the dominant species except in villages of Tileno, Zavat, Asad Abad, Shah Mansur Mahale which An. maculipennis, Cx. torrentium were as the predominant species. Turbidity in Karat Koti, Chloride in Al Tappeh, nitrate, phosphate and sulfate in Chalmardi, electrical conductivity, alkalinity, total hardness in Komishan villages were significantly higher than other villages (P < 0.05). There were a significant positive correlation between Cx. pipiens and Electrical conductivity, Alkalinity, Total hardness, Chloride, Cx. tritaeniorhynchus and Chloride, whereas a significant negative correlation observed between Sulfate and Cx. perexiguss. Conclusion: The correlations observed between physicochemical factor and larval density, possibly can confirm the effect of these parameters on the breeding activities of mosquitoes, and could probability facilitate larval control programs by the handwork of such factors.

Keywords: anopheles, culex, culiseta, physicochemical, habitats, larvae density, correlation

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3802 Organizational Commitment and Job Satisfaction of Job Order Personnel in the Overseas Workers Welfare Administration Regional Welfare Office Caraga

Authors: Anne Jane M. Hallasgo

Abstract:

This study assessed the level of job satisfaction and organizational commitment among job order personnel at the Overseas Workers Welfare Administration (OWWA) Regional Welfare Office Caraga. The primary objective of the study was to determine a correlation between the employees’ level of organizational commitment, job satisfaction, and their work performance. A carefully selected sample of twenty-five job orders from the OWWA Regional Welfare Office Caraga participated in the study. These individuals were chosen to represent the organization’s job order workforce. For accuracy and dependability, various types of statistical methods and instruments were employed, including advanced statistical tests like the independent sample T-test, one-way analysis of variance (ANOVA), and Spearman's rank correlation coefficient, as well as descriptive statistics like mean, frequency, and percentage. The study found an acceptable level of job satisfaction regarding work performance. It revealed a significant relationship between affective commitment and job satisfaction concerning leadership and coworkers. A correlation was observed between normative commitment and work performance. The findings suggest that organizations emphasizing positive leadership, fostering supportive coworker relationships, aligning with employee values, and promoting a culture of commitment are likely to enhance both affective and normative commitment, thereby improving overall employee satisfaction. The study recommends designing and implementing a holistic employee well-being program that addresses physical, mental, and emotional health contributing to increased job satisfaction and organizational commitment, creating a healthier and engaged workforce. This research contributes to the understanding of the dynamics of organizational commitment and job satisfaction among job order employees in the public sector.

Keywords: affective commitment, continuous commitment, normative commitment, job satisfaction

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3801 Relationship between the Level of Perceived Self-Efficacy of Children with Learning Disability and Their Mother’s Perception about the Efficacy of Their Child, and Children’s Academic Achievement

Authors: Payal Maheshwari, Maheaswari Brindavan

Abstract:

The present study aimed at studying the level of perceived self-efficacy of children with learning disability and their mother’s perception about the efficacy of the child and the relationship between the two. The study further aimed at finding out the relationship between the level of perceived self-efficacy of children with learning disability and their academic achievement and their mother’s perception about the Efficacy of the child and child’s Academic Achievement. The sample comprised of 80 respondents (40 children with learning disability and their mothers). Children with learning disability as their primary condition, belonging to middle or upper middle class, living with both the parents, residing in Mumbai and their mothers were selected. Purposive or judgmental and snowball sampling technique was used to select the sample for the present study. Proformas in the form of questionnaires were used to obtain the background information of the children with learning disability and their mother’s. A self-constructed Mother’s Perceived Efficacy of their Child Assessment Scale was used to measure mothers perceived level of efficacy of their child with learning disability. Self-constructed Child’s Perceived Self-Efficacy Assessment Scale was used to measure the level of child’s perceived self-efficacy. Academic scores of the child were collected from the child’s parents or teachers and were converted into percentage. The data were analyzed quantitatively using frequencies, mean and standard deviation. Correlations were computed to ascertain the relationships between the different variables. The findings revealed that majority of the mother’s perceived efficacy about their child with learning disability was above average as well as majority of the children with learning disability also perceived themselves as having above average level of self-efficacy. Further in the domains of self-regulated learning and emotional self-efficacy majority of the mothers perceived their child as having average or below average efficacy, 50% of the children also perceived their self-efficacy in the two domains at average or below average level. A significant (r=.322, p < .05) weak correlation (Spearman’s rho) was found between mother’s perceived efficacy about their child, and child’s perceived self-efficacy and a significant (r=.377, p < .01) weak correlation (Pearson Correlation) was also found between mother’s perceived efficacy about their child and child’s academic achievement. Significant weak positive correlation was found between child’s perceived self-efficacy and academic achievement (r=.332, p < .05). Based on the findings, the study discussed the need for intervention program for children in non-academic skills like self-regulation and emotional competence.

Keywords: learning disability, perceived self efficacy, academic achievement, mothers, children

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3800 Recommendations Using Online Water Quality Sensors for Chlorinated Drinking Water Monitoring at Drinking Water Distribution Systems Exposed to Glyphosate

Authors: Angela Maria Fasnacht

Abstract:

Detection of anomalies due to contaminants’ presence, also known as early detection systems in water treatment plants, has become a critical point that deserves an in-depth study for their improvement and adaptation to current requirements. The design of these systems requires a detailed analysis and processing of the data in real-time, so it is necessary to apply various statistical methods appropriate to the data generated, such as Spearman’s Correlation, Factor Analysis, Cross-Correlation, and k-fold Cross-validation. Statistical analysis and methods allow the evaluation of large data sets to model the behavior of variables; in this sense, statistical treatment or analysis could be considered a vital step to be able to develop advanced models focused on machine learning that allows optimized data management in real-time, applied to early detection systems in water treatment processes. These techniques facilitate the development of new technologies used in advanced sensors. In this work, these methods were applied to identify the possible correlations between the measured parameters and the presence of the glyphosate contaminant in the single-pass system. The interaction between the initial concentration of glyphosate and the location of the sensors on the reading of the reported parameters was studied.

Keywords: glyphosate, emergent contaminants, machine learning, probes, sensors, predictive

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3799 Comparing Groundwater Fluoride Level with WHO Guidelines and Classifying At-Risk Age Groups; Based on Health Risk Assessment

Authors: Samaneh Abolli, Kamyar Yaghmaeian, Ali Arab Aradani, Mahmood Alimohammadi

Abstract:

The main route of fluoride uptake is drinking water. Fluoride absorption in the acceptable range (0.5-1.5 mg L-¹) is suitable for the body, but it's too much consumption can have irreversible health effects. To compare fluoride concentration with the WHO guidelines, 112 water samples were taken from groundwater aquifers in 22 villages of Garmsar County, the central part of Iran, during 2018 to 2019.Fluoride concentration was measured by the SPANDS method, and its non-carcinogenic impacts were calculated using EDI and HQ. The statistical population was divided into four categories of infant, children, teenagers, and adults. Linear regression and Spearman rank correlation coefficient tests were used to investigate the relationships between the well's depth and fluoride concentration in the water samples. The annual mean concentrations of fluoride in 2018 and2019 were 0.75 and 0.64 mg -¹ and, the fluoride mean concentration in the samples classifying the cold and hot seasons of the studied years was 0.709 and 0.689 mg L-¹, respectively. The amount of fluoride in 27% of the samples in both years was less than the acceptable minimum (0.5 mg L-¹). Also, 11% of the samples in2018 (6 samples) had fluoride levels higher than 1.5 mg L-¹. The HQ showed that the children were vulnerable; teenagers and adults were in the next ranks, respectively. Statistical tests showed a reverse and significant correlation (R2 = 0.02, < 0.0001) between well depth and fluoride content. The border between the usefulness/harmfulness of fluoride is very narrow and requires extensive studies.

Keywords: fluoride, groundwater, health risk assessment, hazard quotient, Garmsar

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3798 Farmers’ Awareness of Pillars of Planting for Food and Jobs Programme in Ghana

Authors: Franklin Nantui Mabe, Gideon Danso-Abbeam, Dennis Sedem Ehiakpor

Abstract:

In order for the government of Ghana through the Ministry of Food and Agriculture to motivate farmers to adopt improved agricultural technologies, expand their farms and encourage youth to enter into agricultural production so as to increase crop productivity, “Planting for Food and Jobs” (PFJ) programme was launched in April 2017. The PFJ programme covers five pillars, namely, provision of subsidized and improved seeds; subsidized fertilizer; agricultural extension services; establishment of markets; and e-agriculture. This study assesses the awareness of farmers about the packages of these pillars using the Likert scale, paired t-test and Spearman’s rank correlation coefficient. The study adopted a mixed research design. A semi-structured questionnaire and checklist were used to collect data. The data collection was done using interviews and focus group discussions. The PFJ pillar farmers are much aware is a subsidy on fertilizer followed by a subsidy on improved seeds. Electronic agriculture is a pillar with the lowest level of awareness. There is a strong positive correlation between awareness of fertilizer and seed packages suggestion their complementarities. Lack of information/awareness of the packages of the programme can affect farmers’ participation in all the pillars. Farmers, in particular, should be educated for them to know what they are entitled to in each of the pillars. The programme implementation plan should also be made available to farmers as a guide.

Keywords: awareness, planting for food and jobs, programme, farmers, likert scale

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3797 The Relationship between EFL Learners' Self-Regulation and Willingness to Communicate

Authors: Mania Nosratinia, Zahra Deris

Abstract:

The purpose of the present study was to investigate the relationship between EFL learners' self-regulation (SR) and willingness to communicate (WTC). To this end, 520 male and female EFL learners, ranging between 19 and 34 years old (Mage = 26), majoring in English Translation, English Language Teaching and English Literature at Islamic Azad University, Fars Province, were randomly selected. They were given two questionnaires: Self-Regulation Questionnaire devised by Brown, Miller, and Lawendowski (1999) and Willingness to Communicate Scale devised by McCroskey and Baer (1985). Preliminarily, pertinent analyses were performed on the data to check the assumptions of normality, linearity, and homoscedasticity. Since the assumption of normality was violated, Spearman's rank-order correlation was employed to probe the relationships between SR and WTC. The results indicated a significant and positive correlation between the two variables, ρ = .56, n = 520, p < .05, which signified a large effect size supplemented by a very small confidence interval (0.503 – 0.619). The results of the Kruskal-Wallis tests indicated that there is a statistically significant difference in WTC score between the different levels of SR, χ2(2) = 157.843, p = 0.000 with a mean rank SR score of 128.13 for low-SR level, 286.64 for mid-SR level, and 341.12 for high-SR level. Also, a post-hoc comparison through running a Dwass-Steel-Critchlow-Fligner indicated significant differences among the SR level groups on WTC scores. Given the findings of the study, the obtained results may help EFL teachers, teacher trainers, and material developers to possess a broader perspective towards the TEFL practice and to take practical steps towards the attainments of the desired objectives and effective instruction.

Keywords: EFL learner, self-regulation, willingness to communicate, relationship

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3796 The Influence of Interest, Beliefs, and Identity with Mathematics on Achievement

Authors: Asma Alzahrani, Elizabeth Stojanovski

Abstract:

This study investigated factors that influence mathematics achievement based on a sample of ninth-grade students (N  =  21,444) from the High School Longitudinal Study of 2009 (HSLS09). Key aspects studied included efficacy in mathematics, interest and enjoyment of mathematics, identity with mathematics and future utility beliefs and how these influence mathematics achievement. The predictability of mathematics achievement based on these factors was assessed using correlation coefficients and multiple linear regression. Spearman rank correlations and multiple regression analyses indicated positive and statistically significant relationships between the explanatory variables: mathematics efficacy, identity with mathematics, interest in and future utility beliefs with the response variable, achievement in mathematics.

Keywords: Mathematics achievement, math efficacy, mathematics interest, factors influence

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3795 Hematological Profiles of Visceral Leishmaniasis Patients before and after Treatment of Anti-Leishmanial Drugs at University of Gondar Leishmania Research and Treatment Center Northwest, Ethiopia

Authors: Fitsumbrhan Tajebe, Fadil Murad, Mitikie Tigabie, Mareye Abebaw, Tadele Alemu, Sefanit Abate, Rezika Mohammedw, Arega Yeshanew, Elias Shiferaw

Abstract:

Background: Visceral leshimaniasis is a parasitic disease characterized by a systemic infection of phagocytic cells. Hematological parameters of these patients may be affected by the progress of the disease or treatment. Thus, the current study aimed to assess the hematological profiles of visceral leishmaniasis patients before and after treatment. Method: An institutional based retrospective cohort study was conducted among visceral leishmaniasis patients at University of Gondar Comprehensive Specialized Referral Hospital Leishmaniasis Research and Treatment Center from 2013 to 2018. Hematological profiles before initiation and after completion of treatment were extracted from registration book. Descriptive statics was presented using frequency and percentage. Paired t-test and Wilcoxon Signed rank test were used for comparing mean difference for normally and non- normally distributed data, respectively. Spearman and Pearson correlation analysis was used to describe the correlation of hematological parameters with different variables. P value < 0.05 was considered as statistically significant. Result: Except absolute nerutrophil count, post treatment hematological parameters show a significant increment compared to pretreatment one. The prevalence of anemia, leucopenia and thrombocytopenia was 85.5%, 83.4% and 75.8% prior to treatment and it was 58.3%, 38.2% and 19.2% after treatment, respectively. Moreover, parasite load of the disease showed statistically significant negative correlation with hematological profiles mainly with white blood cell and red blood cell. Conclusion: Majority of hematological profiles of patients with active VL have been restored after treatment, which might be associated with treatment effect on parasite proliferation and concentration of parasite in visceral organ, which directly affect hematological profiles.

Keywords: visceral leshimaniasis, hematological profile, anti-leshimanial drug, Gondar

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3794 Investigating the Effective Factors on Product Performance and Prioritizing Them: Case Study of Pars-Khazar Company

Authors: Ebrahim Sabermaash Eshghi, Donna Sandsmark

Abstract:

Nowadays, successful companies try to create a reliable and unique competitive position in the market. It is important to consider that only choosing and codifying a competitive strategy appropriate with the market conditions does not have any influence on the final performance of the company by itself, but it is the connection and interaction between upstream level strategies and functional level strategies which leads to development of company performance in its operating environment. Given the importance of the subject, this study tries to investigate effective factors on product performance and prioritize them. This study was done with quantitative-qualitative approach (interview and questionnaire). In sum, 103 informed managers and experts of Pars-Khazar Company were investigated in a census. Validity of measure tools was approved through experts’ judgments. Reliability of the tools was also gained through Cronbach's Alpha Coefficient as 0.930 and in sum, validity and reliability of the tools was approved generally. Analysis of collected data was done through Spearman Correlation Test and Friedman Test using SPSS software. The results showed that management of distribution and demand process (0.675), management of Product Pre-test (0.636) and Manufacturing and inventory management(0.628) had the highest correlation with product performance. Prioritization of factors of structure of launching new products based on the average showed that management of volume of launched products and Manufacturing and inventory management had the most importance.

Keywords: product performance, home appliances, market, case study

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3793 Analysis of Basic Science Curriculum as Correlates of Secondary School Students' Achievement in Science Test in Oyo State

Authors: Olubiyi Johnson Ezekiel

Abstract:

Basic science curriculum is an on-going effort towards developing the potential of manner to produce individuals in a holistic and integrated person, who are intellectually, spiritually, emotionally and physically balanced and harmonious. The main focus of this study is to determine the relationship between students’ achievement in junior school certificate examination (JSCE) and senior school basic science achievement test (SSBSAT) on the basis of all the components of basic science. The study employed the descriptive research of the survey type and utilized junior school certificate examination and senior school basic science achievement test(r = .87) scores as instruments. The data collected were subjected to Pearson product moment correlation, Spearman rank correlation, regression analysis and analysis of variance. The result of the finding revealed that the mean effects of the achievement in all the components of basic science on SSBSAT are significantly different from zero. Based on the results of the findings, it was concluded that the relationship between students’ achievement in JSCE and SSBSAT was weak and to achieve a unit increase in the students’ achievement in the SSBSAT when other subjects are held constant, we have to increase the learning of: -physics by 0.081 units; -chemistry by 0.072 units; -biology by 0.025 units and general knowledge by 0.097 units. It was recommended among others, that general knowledge aspect of basic science should be included in either physics or chemistry aspect of basic science.

Keywords: basic science curriculum, students’ achievement, science test, secondary school students

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3792 Clinical Correlates of Suicide Attempts in Trauma-Exposed Youth

Authors: Sandra Landy

Abstract:

Traumatic experiences in youth are a major risk factor for future suicidality. With suicide steadily increasing over the last 20 years as one of the top three leading causes of death in children and adolescents, it is essential to examine the aspects of trauma that contribute to suicidality. A quantitative secondary data analysis of a prospective, multicenter 24-month observational study of youth who have experienced traumatic experiences was utilized to determine the relationship between bullying and suicide attempts, cyberbullying and suicide attempts, and number of traumas and suicide attempts. Data was analyzed with the Spearman-rank correlation test to determine the relationships. Findings supported past research establishing a relationship between bulling, including cyberbullying, and suicide attempts, as well as increasing number of traumatic experiences and suicide attempts. Further large scale studies may be beneficial to support these findings.

Keywords: adolescent(s), suicide, trauma, bullying, cyberbullying

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3791 A Cross-Sectional Study of Parents’ Knowledge, Attitude, and Health-Seeking Behaviour Towards Childhood Tuberculosis during COVID-19 Pandemic: Lessons Learned from Indonesia

Authors: Windy Rakhmawati, Suryani Suryani, Sri Hendrawati, Nenden Nur Asriyani Maryam

Abstract:

Tuberculosis (TB) is one of the leading causes of death in the world. Fear of COVID-19 has made people reluctant to visit health facilities, leading to disruptions to childhood TB control programs, which may increase household transmission and delay diagnosis and treatment. This study aimed to describe parents' knowledge, attitudes, and health-seeking behaviour towards childhood TB during the COVID-19 pandemic. This cross-sectional study was performed on 392 parents with TB children in three provinces with the highest proportion of TB cases in Indonesia. This study was conducted from February to December 2022. The inclusion criteria of respondents were parents with a child aged 0-14 years old with TB diagnosis who live with their parents. Data were collected using the Knowledge, Attitude, and Practice (KAP) survey guidelines from the World Health Organization and analyzed descriptively, as well as Spearman’s correlation. Overall, 392 parents of children with TB had poor knowledge (51.8%) including about causes, risk factors, transmission, symptoms, treatment, and prevention, which about 52.3%, 55.1%, 61.2%, 69.6%, 100%, 59.2%, respectively. Parents' health service-seeking behaviour towards Child TB was not normally distributed (P < 0.05) with knowledge test results (.000) and Seeking Health Services (.000). Health-seeking behaviour of parents in pediatric TB care was self-medication or self-treatment (86.2%), Traditional health seeking behaviour (4.8%), and modern health seeking behaviour (8.9%). The correlation between knowledge and seeking health services (Sig= .609) means there is no correlation between knowledge about TB and parents' health-seeking behaviour. Furthermore, 60.2% of the respondents would be shocked if their child had TB. More than half of the families in this study have poor knowledge and did self-medication or self-treatment regarding health-seeking behaviour for TB disease. Therefore, health workers, especially nurses, must provide TB-related education and health promotion and emphasize the importance of early detection. Health workers can also optimize their role in caring for and providing care to patients by increasing their trust in health workers, which will impact health-seeking behaviour in the future.

Keywords: attitude, child, health seeking behaviour, knowledge, tuberculosis

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3790 Serum Levels of Carnitine in Multiple Sclerosis Patients in Comparison with Healthy People and its Association with Fatigue Severity

Authors: Mohammad Hossein Harirchian, Siavash Babaie, Nika keshtkaran, Sama Bitarafan

Abstract:

Background: Fatigue is a common complaint of multiple sclerosis (MS) patients, adversely affecting their quality of life. There is a lot of evidence showing that Carnitine deficiency is linked to fatigue development and severity in some conditions. This study aimed to compare the levels of Free L-Carnitine (FLC) between MS patients and healthy people and evaluate its association with the severity of fatigue. Methods: This case-control study included 30 patients with relapsing-remitting MS (RRMS) in 2 sex-matched equal-number groups according to the presence or absence of fatigue and 30 sex-matched healthy people in the control group. In addition, between two patient groups, we compared Serum level of FLC between the patient and healthy group. Fatigue was scored using two valid questionnaires of fatigue Severity Scale (FSS) and Modified Fatigue Impact Scale (MFIS). In addition, association between Serum level of FLC and fatigue severity was evaluated in MS patients. Results: There was no significant difference in serum levels of FLC between MS patients and healthy people. The patients with fatigue had a significantly lower FLC (mg/dl) value than patients without fatigue (22.53 ± 15.84 vs. 75.36 ± 51.98, P < 0.001). The mean value of FSS and MFIS in patients with fatigue were 48.80±8.55 and 62.87 ± 13.63, respectively, which was nearly two-fold higher than group without fatigue (P < 0.001). There was a negative correlation between the serum level of FLC and fatigue severity scales (Spearman rank correlation= 0.76, P < 0.001). Conclusion: We showed healthy people and MS patients were not different in levels of FLC. In addition, patients with lower serum levels of FLC might experience more severe fatigue. Therefore, this could clarify that supplementation with L-Carnitine might be considered as a complementary treatment for MS-related fatigue.

Keywords: fatigue, multiple sclerosis, L-carnitine, modified fatigue impact scale

Procedia PDF Downloads 107
3789 Correlation between Pinch and Grip Strength with Dexterity in Adult Hemiplegic

Authors: S. Abbsi, M. R. Hadian, M. Abdolvahab, M. Jalili, S. Khafri

Abstract:

Background: According to physical effects of cardiovascular accident (CVA) which is the most common disabilities in adulthood. It seems attention to treatment and rehabilitation of this patient has importance. Hemiplegic patients have been experienced of wild functional disabilities. Numerous patients have been suffered from upper limb disabilities. Aim of this study correlation of pinch and grip strength with dexterity in adult hemiplegic. Methods: 34 adult hemiplegic in range of 50-70 years participate in this study. After introduce and take a satisfaction patient, pinch and grip strength have evaluated by dynamometer and dexterity have evaluated by Minnesota manual dexterity test and correlation effects of them have studied. Result: According to result of present investigation, patients with hemiplegia have shown significant correlation between dexterity with pinch and grip strength. Conclusion: Dexterity has correlation with pinch and grip strength, but it seems, not have correlation with age and duration of CVA.

Keywords: pinch strength, grip strength, dexterity, hemiplegia

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3788 Modeling and Statistical Analysis of a Soap Production Mix in Bejoy Manufacturing Industry, Anambra State, Nigeria

Authors: Okolie Chukwulozie Paul, Iwenofu Chinwe Onyedika, Sinebe Jude Ebieladoh, M. C. Nwosu

Abstract:

The research work is based on the statistical analysis of the processing data. The essence is to analyze the data statistically and to generate a design model for the production mix of soap manufacturing products in Bejoy manufacturing company Nkpologwu, Aguata Local Government Area, Anambra state, Nigeria. The statistical analysis shows the statistical analysis and the correlation of the data. T test, Partial correlation and bi-variate correlation were used to understand what the data portrays. The design model developed was used to model the data production yield and the correlation of the variables show that the R2 is 98.7%. However, the results confirm that the data is fit for further analysis and modeling. This was proved by the correlation and the R-squared.

Keywords: General Linear Model, correlation, variables, pearson, significance, T-test, soap, production mix and statistic

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3787 Correlation of the Biometric Parameters of Eggs

Authors: S. Zenia, A. Menasseria, A. E. Kheidous, F. Lariouna, A. Smai, H. Saadi, F. Haddadj, A. Milla, F. Marniche

Abstract:

The objective of this study was to estimate the correlation ship between different pheasant external egg quality traits. A total of 938 eggs were collected. Egg weight (g), egg length (mm), egg width (mm), volume (cm3), shape index egg, surface area and water loss were measured. The overall mean values obtained for the different variables are respectively 29.2 ± 2,24, 43.01 ± 1,84, 34.05 ± 1,44, 25.63 ± 2.88 cm3, 79.00 ± 3%, 68% and 13%. Concerning studied regressions, it was considered only the most important regressions. Those that show significant links between the different parameters studied. The ANOVA procedure was applied to estimate correlations for the examined traits. The weights of the eggs being observed before incubation and before hatching are linearly correlated with a positive correlation coefficient of order 0.75. Egg length and the weight before incubation had a good and positive correlation with a coefficient r = 0.6. However, density had high and negative correlations with egg height r = -0.78. Shape index had a good linear and negative r= - 0.71 correlation with water loss.

Keywords: correlation, egg, morphometry of eggs, analysis of variance

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3786 Hounsfield-Based Automatic Evaluation of Volumetric Breast Density on Radiotherapy CT-Scans

Authors: E. M. D. Akuoko, Eliana Vasquez Osorio, Marcel Van Herk, Marianne Aznar

Abstract:

Radiotherapy is an integral part of treatment for many patients with breast cancer. However, side effects can occur, e.g., fibrosis or erythema. If patients at higher risks of radiation-induced side effects could be identified before treatment, they could be given more individual information about the risks and benefits of radiotherapy. We hypothesize that breast density is correlated with the risk of side effects and present a novel method for automatic evaluation based on radiotherapy planning CT scans. Methods: 799 supine CT scans of breast radiotherapy patients were available from the REQUITE dataset. The methodology was first established in a subset of 114 patients (cohort 1) before being applied to the whole dataset (cohort 2). All patients were scanned in the supine position, with arms up, and the treated breast (ipsilateral) was identified. Manual experts contour available in 96 patients for both the ipsilateral and contralateral breast in cohort 1. Breast tissue was segmented using atlas-based automatic contouring software, ADMIRE® v3.4 (Elekta AB, Sweden). Once validated, the automatic segmentation method was applied to cohort 2. Breast density was then investigated by thresholding voxels within the contours, using Otsu threshold and pixel intensity ranges based on Hounsfield units (-200 to -100 for fatty tissue, and -99 to +100 for fibro-glandular tissue). Volumetric breast density (VBD) was defined as the volume of fibro-glandular tissue / (volume of fibro-glandular tissue + volume of fatty tissue). A sensitivity analysis was performed to verify whether calculated VBD was affected by the choice of breast contour. In addition, we investigated the correlation between volumetric breast density (VBD) and patient age and breast size. VBD values were compared between ipsilateral and contralateral breast contours. Results: Estimated VBD values were 0.40 (range 0.17-0.91) in cohort 1, and 0.43 (0.096-0.99) in cohort 2. We observed ipsilateral breasts to be denser than contralateral breasts. Breast density was negatively associated with breast volume (Spearman: R=-0.5, p-value < 2.2e-16) and age (Spearman: R=-0.24, p-value = 4.6e-10). Conclusion: VBD estimates could be obtained automatically on a large CT dataset. Patients’ age or breast volume may not be the only variables that explain breast density. Future work will focus on assessing the usefulness of VBD as a predictive variable for radiation-induced side effects.

Keywords: breast cancer, automatic image segmentation, radiotherapy, big data, breast density, medical imaging

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3785 Development of Generalized Correlation for Liquid Thermal Conductivity of N-Alkane and Olefin

Authors: A. Ishag Mohamed, A. A. Rabah

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The objective of this research is to develop a generalized correlation for the prediction of thermal conductivity of n-Alkanes and Alkenes. There is a minority of research and lack of correlation for thermal conductivity of liquids in the open literature. The available experimental data are collected covering the groups of n-Alkanes and Alkenes.The data were assumed to correlate to temperature using Filippov correlation. Nonparametric regression of Grace Algorithm was used to develop the generalized correlation model. A spread sheet program based on Microsoft Excel was used to plot and calculate the value of the coefficients. The results obtained were compared with the data that found in Perry's Chemical Engineering Hand Book. The experimental data correlated to the temperature ranged "between" 273.15 to 673.15 K, with R2 = 0.99.The developed correlation reproduced experimental data that which were not included in regression with absolute average percent deviation (AAPD) of less than 7 %. Thus the spread sheet was quite accurate which produces reliable data.

Keywords: N-Alkanes, N-Alkenes, nonparametric, regression

Procedia PDF Downloads 627
3784 Spirituality and Happiness among Youth: A Correlative Study

Authors: Harsh Shah

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Spirituality and happiness are two very important aspects of human life. After defining happiness, an attempt has been made in this paper to review research on the relationship between happiness and spirituality, and then to experimentally study their correlation among students aged between 18-24 years. The relation was assessed in 200 students from IIT Kharagpur, who rated their own spirituality, and happiness using the Daily Spiritual Experience Scale (DSES) developed by Underwood, and the Subjective Happiness Scale (SHS) developed by Lyubomirsky and Lepper, respectively. Students who were more spiritual in general, were happier as well, and the Pearson Correlation Coefficient method gave a high positive correlation between happiness and spirituality.

Keywords: happiness, spirituality, youth, correlation, depression, religion

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3783 Preoperative Anxiety Evaluation: Comparing the Visual Facial Anxiety Scale/Yumul Faces Anxiety Scale, Numerical Verbal Rating Scale, Categorization Scale, and the State-Trait Anxiety Inventory

Authors: Roya Yumul, Chse, Ofelia Loani Elvir Lazo, David Chernobylsky, Omar Durra

Abstract:

Background: Preoperative anxiety has been shown to be caused by the fear associated with surgical and anesthetic complications; however, the current gold standard for assessing patient anxiety, the STAI, is problematic to use in the preoperative setting given the duration and concentration required to complete the 40-item extensive questionnaire. Our primary aim in the study is to investigate the correlation of the Visual Facial Anxiety Scale (VFAS) and Numerical Verbal Rating Scale (NVRS) to State-Trait Anxiety Inventory (STAI) to determine the optimal anxiety scale to use in the perioperative setting. Methods: A clinical study of patients undergoing various surgeries was conducted utilizing each of the preoperative anxiety scales. Inclusion criteria included patients undergoing elective surgeries, while exclusion criteria included patients with anesthesia contraindications, inability to comprehend instructions, impaired judgement, substance abuse history, and those pregnant or lactating. 293 patients were analyzed in terms of demographics, anxiety scale survey results, and anesthesia data via Spearman Coefficients, Chi-Squared Analysis, and Fischer’s exact test utilized for comparison analysis. Results: Statistical analysis showed that VFAS had a higher correlation to STAI than NVRS (rs=0.66, p<0.0001 vs. rs=0.64, p<0.0001). The combined VFAS-Categorization Scores showed the highest correlation with the gold standard (rs=0.72, p<0.0001). Subgroup analysis showed similar results. STAI evaluation time (247.7 ± 54.81 sec) far exceeds VFAS (7.29 ± 1.61 sec), NVRS (7.23 ± 1.60 sec), and Categorization scales (7.29 ± 1.99 sec). Patients preferred VFAS (54.4%), Categorization (11.6%), and NVRS (8.8%). Anesthesiologists preferred VFAS (63.9%), NVRS (22.1%), and Categorization Scales (14.0%). Of note, the top five causes of preoperative anxiety were determined to be waiting (56.5%), pain (42.5%), family concerns (40.5%), no information about surgery (40.1%), or anesthesia (31.6%). Conclusions: Combined VFAS-Categorization Score (VCS) demonstrates the highest correlation to the gold standard, STAI. Both VFAS and Categorization tests also take significantly less time than STAI, which is critical in the preoperative setting. Among both patients and anesthesiologists, VFAS was the most preferred scale. This forms the basis of the Yumul FACES Anxiety Scale, designed for quick quantization and assessment in the preoperative setting while maintaining a high correlation to the golden standard. Additional studies using the formulated Yumul FACES Anxiety Scale are merited.

Keywords: numerical verbal anxiety scale, preoperative anxiety, state-trait anxiety inventory, visual facial anxiety scale

Procedia PDF Downloads 106
3782 Quality of Life and Renal Biomarkers in Feline Chronic Kidney Disease

Authors: Bárbara Durão, Pedro Almeida, David Ramilo, André Meneses, Rute Canejo-Teixeira

Abstract:

The importance of quality of life (QoL) assessment in veterinary medicine is an integral part of patient care. This is especially true in cases of chronic diseases, such as chronic kidney disease (CKD), where the ever more advanced treatment options prolong the patient’s life. Whether this prolongment of life comes with an acceptable quality of life remains has been called into question. The aim of this study was to evaluate the relationship between CKD disease biomarkers and QoL in cats. Thirty-seven cats diagnosed with CKD and with no known concurrent illness were enrolled in an observational study. Through the course of several evaluations, renal biomarkers were assessed in blood and urine samples, and owners retrospectively described their cat’s quality of life using a validated instrument for this disease. Correlations between QoL scores (AWIS) and the biomarkers were assessed using Spearman’s rank test. Statistical significance was set at p-value < 0.05, and every serial sample was considered independent. Thirty-seven cats met the inclusion criteria, and all owners completed the questionnaire every time their pet was evaluated, giving a total of eighty-four questionnaires, and the average-weighted-impact-score was –0.5. Results showed there was a statistically significant correlation between the quality of life and most of 17 the studied biomarkers and confirmed that CKD has a negative impact on QoL in cats especially due to the management of the disease and secondary appetite disorders. To our knowledge, this is the attempt to assess the correlation between renal biomarkers and QoL in cats. Our results reveal a strong potential of this type of approach in clinical management, mainly in situations where it is not possible to measure biomarkers. Whilst health-related QoL is a reliable predictor of mortality and morbidity in humans; our findings can help improve the clinical practice in cats with CKD.

Keywords: chronic kidney disease, biomarkers, quality of life, feline

Procedia PDF Downloads 149
3781 Comparison of the Yumul Faces Anxiety Scale to the Categorization Scale, the Numerical Verbal Rating Scale, and the State-Trait Anxiety Inventory for Preoperative Anxiety Evaluation

Authors: Ofelia Loani Elvir Lazo, Roya Yumul, David Chernobylsky, Omar Durra

Abstract:

Background: It is crucial to detect the patient’s existing anxiety to assist patients in a perioperative setting which is to be caused by the fear associated with surgical and anesthetic complications. However, the current gold standard for assessing patient anxiety, the STAI, is problematic to use in the preoperative setting, given the duration and concentration required to complete the 40-item questionnaire. Our primary aim in the study is to investigate the correlation of the Yumul Visual Facial Anxiety Scale (VFAS) and Numerical Verbal Rating Scale (NVRS) to State-Trait Anxiety Inventory (STAI) to determine the optimal anxiety scale to use in the perioperative setting. Methods: A clinical study of patients undergoing various surgeries was conducted utilizing each of the preoperative anxiety scales. Inclusion criteria included patients undergoing elective surgeries, while exclusion criteria included patients with anesthesia contraindications, inability to comprehend instructions, impaired judgement, substance abuse history, and those pregnant or lactating. 293 patients were analyzed in terms of demographics, anxiety scale survey results, and anesthesia data via Spearman Coefficients, Chi-Squared Analysis, and Fischer’s exact test utilized for comparative analysis. Results: Statistical analysis showed that VFAS had a higher correlation to STAI than NVRS (rs=0.66, p<0.0001 vs. rs=0.64, p<0.0001). The combined VFAS-Categorization Scores showed the highest correlation with the gold standard (rs=0.72, p<0.0001). Subgroup analysis showed similar results. STAI evaluation time (247.7 ± 54.81 sec) far exceeds VFAS (7.29 ± 1.61 sec), NVRS (7.23 ± 1.60 sec), and Categorization scales (7.29 ± 1.99 sec). Patients preferred VFAS (54.4%), Categorization (11.6%), and NVRS (8.8%). Anesthesiologists preferred VFAS (63.9%), NVRS (22.1%), and Categorization Scales (14.0%). Of note, the top five causes of preoperative anxiety were determined to be waiting (56.5%), pain (42.5%), family concerns (40.5%), no information about surgery (40.1%), or anesthesia (31.6%). Conclusıons: Both VFAS and Categorization tests also take significantly less time than STAI, which is critical in the preoperative setting. Combined VFAS-Categorization Score (VCS) demonstrates the highest correlation to the gold standard, STAI. Among both patients and anesthesiologists, VFAS was the most preferred scale. This forms the basis of the Yumul Faces Anxiety Scale, designed for quick quantization and assessment in the preoperative setting while maintaining a high correlation to the golden standard. Additional studies using the formulated Yumul Faces Anxiety Scale are merited.

Keywords: numerical verbal anxiety scale, preoperative anxiety, state-trait anxiety inventory, visual facial anxiety scale

Procedia PDF Downloads 90
3780 Use of Selected Cytokines in the Early SIRS/MODS Diagnostic Testing at Patients after Trauma

Authors: Aneta Binkowska, Grzegorz Michalak, Slawomir Pilip, Lukasz Bondaruk, Daniel Celinski, Robert Slotwinski

Abstract:

Post-traumatic mortality rates are still very high and show an increasing tendency. Early identification of patients at high risk of severe complications has a significant impact on treatment outcomes. The aim of the study was to better understand the early pathological inflammatory response to injury and infection and to determine the usefulness of the assessment of TNF-α and sTNFR1 concentrations in the peripheral blood as early indicators of severe post-traumatic complications. The study was carried out in a group of 51 patients after trauma treated in the ED, including 32 patients that met inclusion criteria for immunological analysis. Patients were divided into two groups using the ISS scale (group A with ISS ≥20, group B with ISS <20). Serum levels of TNF-α and sTNFR1 were determined after admission to the ED and after 3, 6, 12 and 24 hours. The highest TNF-α and sTNFR1 concentrations in both groups were recorded at admission and were significantly higher in group A compared to group B (A vs B TNF-α 2.46 pg/ml vs 1.78 pg/ml; sTNFR1 1667.5 pg/ml vs 875.2 p<0.005). The concentration of sTNFR1 in patients with severe complications was significantly higher compared to patients without complications and preceded clinical symptoms of complications ( C+ vs C- 1561.5 pg/ml vs 930.6 pg/ml). Spearman's correlation showed a statistically significant positive correlation between the baseline concentrations of IL-6 (r=0.38, p<0.043) and sTNFR1 (r=0.59, p=0.001) and the ISS scores. The high diagnostic sensitivity calculated from the ROC (receiver operating characteristic) curves was found for the concentrations of both cytokines: TNF α (AUC=0.91, p=0.004) and sTNFR1 (AUC=0.86, p=0.011). Elevated levels of sTNFR1, determined in the peripheral blood shortly after injury, is significantly associated with the occurrence of later complications, which in some patients lead to death. In contrast, high levels of TNF-α shortly after injury are associated with high mortality.

Keywords: cytokine, SIRS, MODS, trauma

Procedia PDF Downloads 140
3779 The Use of Five Times Sit-To-Stand Test in Ambulatory People with Spinal Cord Injury When Tested with or without Hands

Authors: Lalita Khuna, Sugalya Amatachaya, Pipatana Amatachaya, Thiwabhorn Thaweewannakij, Pattra Wattanapan

Abstract:

The five times sit-to-stand test (FTSST) has been widely used to quantify lower extremity motor strength (LEMS), dynamic balance ability, and risk of falls in many individuals. Recently, it has been used in ambulatory patients with spinal cord injury (SCI) but variously using with or without hands according to patients’ ability. This difference might affect the validity of the test in these individuals. Thus, this study assessed the concurrent validity of the FTSST in ambulatory individuals with SCI, separately for those who could complete the test with or without hands using LEMS and standard functional measures as gold standards. Moreover, the data of the tests from those who completed the FTSST with and without hands were compared. A total of 56 ambulatory participants with SCI who could complete sit-to-stand with or without hands were assessed for the time to complete the FTSST according to their ability. Then they were assessed for their LEMS scores and functional abilities, including the 10-meter walk test (10MWT), the walking index for spinal cord injury II (WISCI II), the timed up and go test (TUGT), and the 6-minute walk test (6MWT). The Mann-Whitney U test was used to compare the different findings between the participants who performed the FTSST with and without hands. The Spearman rank correlation coefficient (ρ) was applied to analyze the levels of correlation between the FTSST and standard tests (LEMS scores and functional measures). There were significant differences in the data between the participants who performed the test with and without hands (p < 0.01). The time to complete the FTSST of the participants who performed the test without hands showed moderate to strong correlation with total LEMS scores and all functional measures (ρ = -0.71 to 0.69, p < 0.001). On the contrary, the FTSST data of those who performed the test with hands were significantly correlated only with the 10MWT, TUGT, and 6MWT (ρ = -0.47 to 0.57, p < 0.01). The present findings confirm the concurrent validity of the FTSST when performed without hands for LEMS and functional mobility necessary for the ability of independence and safety of ambulatory individuals with SCI. However, the test using hands distort the ability of the outcomes to reflect LEMS and WISCI II that reflect lower limb functions. By contrast, the 10MWT, TUGT, and 6MWT allowed upper limb contribution in the tests. Therefore, outcomes of these tests showed a significant correlation to the outcomes of FTSST when assessed using hands. Consequently, the use of FTSST with or without hands needs to consider the clinical application of the outcomes, i.e., to reflect lower limb functions or mobility of the patients.

Keywords: mobility, lower limb muscle strength, clinical test, rehabilitation

Procedia PDF Downloads 114
3778 Effect of Correlation of Random Variables on Structural Reliability Index

Authors: Agnieszka Dudzik

Abstract:

The problem of correlation between random variables in the structural reliability analysis has been extensively discussed in literature on the subject. The cases taken under consideration were usually related to correlation between random variables from one side of ultimate limit state: correlation between particular loads applied on structure or correlation between resistance of particular members of a structure as a system. It has been proved that positive correlation between these random variables reduces the reliability of structure and increases the probability of failure. In the paper, the problem of correlation between random variables from both side of the limit state equation will be taken under consideration. The simplest case where these random variables are of the normal distributions will be concerned. The case when a degree of that correlation is described by the covariance or the coefficient of correlation will be used. Special attention will be paid on questions: how much that correlation changes the reliability level and can it be ignored. In reliability analysis will be used well-known methods for assessment of the failure probability: based on the Hasofer-Lind reliability index and Monte Carlo method adapted to the problem of correlation. The main purpose of this work will be a presentation how correlation of random variables influence on reliability index of steel bar structures. Structural design parameters will be defined as deterministic values and random variables. The latter will be correlated. The criterion of structural failure will be expressed by limit functions related to the ultimate and serviceability limit state. In the description of random variables will be used only for the normal distribution. Sensitivity of reliability index to the random variables will be defined. If the reliability index sensitivity due to the random variable X will be low when compared with other variables, it can be stated that the impact of this variable on failure probability is small. Therefore, in successive computations, it can be treated as a deterministic parameter. Sensitivity analysis leads to simplify the description of the mathematical model, determine the new limit functions and values of the Hasofer-Lind reliability index. In the examples, the NUMPRESS software will be used in the reliability analysis.

Keywords: correlation of random variables, reliability index, sensitivity of reliability index, steel structure

Procedia PDF Downloads 205
3777 The Association of Anthropometric Measurements, Blood Pressure Measurements, and Lipid Profiles with Mental Health Symptoms in University Students

Authors: Ammaarah Gamieldien

Abstract:

Depression is a very common and serious mental illness that has a significant impact on both the social and economic aspects of sufferers worldwide. This study aimed to investigate the association between body mass index (BMI), blood pressure, and lipid profiles with mental health symptoms in university students. Secondary objectives included the associations between the variables (BMI, blood pressure, and lipids) with themselves, as they are key factors in cardiometabolic disease. Sixty-three (63) students participated in the study. Thirty-two (32) were assigned to the control group (minimal-mild depressive symptoms), while 31 were assigned to the depressive group (moderate to severe depressive symptoms). Montgomery-Asberg Depression Rating Scale (MADRS) and Beck Depression Inventory (BDI) were used to assess depressive scores. Anthropometric measurements such as weight (kg), height (m), waist circumference (WC), and hip circumference were measured. Body mass index (BMI) and ratios such as waist-to-hip ratio (WHR) and waist-to-height ratio (WtHR) were also calculated. Blood pressure was measured using an automated AfriMedics blood pressure machine, while lipids were measured using a CardioChek plus analyzer machine. Statistics were analyzed via the SPSS statistics program. There were no significant associations between anthropometric measurements and depressive scores (p > 0.05). There were no significant correlations between lipid profiles and depression when running a Spearman’s rho correlation (P > 0.05). However, total cholesterol and LDL-C were negatively associated with depression, and triglycerides were positively associated with depression after running a point-biserial correlation (P < 0.05). Overall, there were no significant associations between blood pressure measurements and depression (P > 0.05). However, there was a significant moderate positive correlation between systolic blood pressure and MADRS scores in males (P < 0.05). Depressive scores positively and strongly correlated to how long it takes participants to fall asleep. There were also significant associations with regard to the secondary objectives. This study indicates the importance of determining the prevalence of depression among university students in South Africa. If the prevalence and factors associated with depression are addressed, depressive symptoms in university students may be improved.

Keywords: depression, blood pressure, body mass index, lipid profiles, mental health symptoms

Procedia PDF Downloads 36
3776 Trends in Extreme Rainfall Events in Tasmania, Australia

Authors: Orpita U. Laz, Ataur Rahman

Abstract:

Climate change will affect various aspects of hydrological cycle such as rainfall. A change in rainfall will affect flood magnitude and frequency in future which will affect the design and operation of hydraulic structures. In this paper, trends in sub-hourly, sub-daily, and daily extreme rainfall events from 18 rainfall stations located in Tasmania, Australia are examined. Two non-parametric tests (Mann-Kendall and Spearman’s Rho) are applied to detect trends at 10%, 5%, and 1% significance levels. Sub-hourly (6, 12, 18, and 30 minutes) annual maximum rainfall events have been found to experience statistically significant upward trends at 10 % level of significance. However, sub-daily durations (1 hour, 3 and 12 hours) exhibit decreasing trends and no trends exists for longer duration rainfall events (e.g. 24 and 72 hours). Some of the durations (e.g. 6 minutes and 6 hours) show similar results (with upward trends) for both the tests. For 12, 18, 60 minutes and 3 hours durations both the tests show similar downward trends. This finding has important implication for Tasmania in the design of urban infrastructure where shorter duration rainfall events are more relevant for smaller urban catchments such as parking lots, roof catchments and smaller sub-divisions.

Keywords: climate change, design rainfall, Mann-Kendall test, trends, Spearman’s Rho, Tasmania

Procedia PDF Downloads 182
3775 Statistical Correlation between Ply Mechanical Properties of Composite and Its Effect on Structure Reliability

Authors: S. Zhang, L. Zhang, X. Chen

Abstract:

Due to the large uncertainty on the mechanical properties of FRP (fibre reinforced plastic), the reliability evaluation of FRP structures are currently receiving much attention in industry. However, possible statistical correlation between ply mechanical properties has been so far overlooked, and they are mostly assumed to be independent random variables. In this study, the statistical correlation between ply mechanical properties of uni-directional and plain weave composite is firstly analyzed by a combination of Monte-Carlo simulation and finite element modeling of the FRP unit cell. Large linear correlation coefficients between the in-plane mechanical properties are observed, and the correlation coefficients are heavily dependent on the uncertainty of the fibre volume ratio. It is also observed that the correlation coefficients related to Poisson’s ratio are negative while others are positive. To experimentally achieve the statistical correlation coefficients between in-plane mechanical properties of FRP, all concerned in-plane mechanical properties of the same specimen needs to be known. In-plane shear modulus of FRP is experimentally derived by the approach suggested in the ASTM standard D5379M. Tensile tests are conducted using the same specimens used for the shear test, and due to non-uniform tensile deformation a modification factor is derived by a finite element modeling. Digital image correlation is adopted to characterize the specimen non-uniform deformation. The preliminary experimental results show a good agreement with the numerical analysis on the statistical correlation. Then, failure probability of laminate plates is calculated in cases considering and not considering the statistical correlation, using the Monte-Carlo and Markov Chain Monte-Carlo methods, respectively. The results highlight the importance of accounting for the statistical correlation between ply mechanical properties to achieve accurate failure probability of laminate plates. Furthermore, it is found that for the multi-layer laminate plate, the statistical correlation between the ply elastic properties significantly affects the laminate reliability while the effect of statistical correlation between the ply strength is minimal.

Keywords: failure probability, FRP, reliability, statistical correlation

Procedia PDF Downloads 127
3774 Combining the Dynamic Conditional Correlation and Range-GARCH Models to Improve Covariance Forecasts

Authors: Piotr Fiszeder, Marcin Fałdziński, Peter Molnár

Abstract:

The dynamic conditional correlation model of Engle (2002) is one of the most popular multivariate volatility models. However, this model is based solely on closing prices. It has been documented in the literature that the high and low price of the day can be used in an efficient volatility estimation. We, therefore, suggest a model which incorporates high and low prices into the dynamic conditional correlation framework. Empirical evaluation of this model is conducted on three datasets: currencies, stocks, and commodity exchange-traded funds. The utilisation of realized variances and covariances as proxies for true variances and covariances allows us to reach a strong conclusion that our model outperforms not only the standard dynamic conditional correlation model but also a competing range-based dynamic conditional correlation model.

Keywords: volatility, DCC model, high and low prices, range-based models, covariance forecasting

Procedia PDF Downloads 149