Browsing by Author "Ali, Md. Ayub"

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A Study on Finitely Generated N-Ideals of a Lattice
(University of Rajshahi, 1998) Ali, Md. Ayub; Noor, A. S. A.
This thesis studies extensively the finitely generated n-ideals of a lattice. The idea of n-ideals in a lattice was first introduced by Cornish and Noor in studying the kernels around a particular element n, of a skeletal congruence on a distributive lattice. Then Latif in his thesis "n-ideals of a lattice" studied thoroughly on the n-ideals and established many valuable results. For a fixed element n of a lattice L, a convex sub lattice of L containing n is called an n-ideal. If L has a "O", then replacing n by 0, an n-ideal becomes an ideal and if L has a "1" then it becomes a filter by replacing n by 1. Thus, the idea of n-ideals is a kind of generalization of both ideals and filters of lattices. The n-ideal generated by a finite number of elements of a lattice is called a finitely generated n-ideal, while the n-ideal generated by a single. element is known as a principal n-ideal. Latif in his thesis has given a neat description on finitely generated n-ideals of a lattice a'nd has provided a number of important results on them.
Allometric Model Study of Inter Limb Growth: A Case Study of Children From Jessore District
(University of Rajshahi, 2010) Nawaz, Md. Shahjada Ali; Ali, Md. Ayub
The aim of this study was to investigate the allometric growth of inter-limbs of males and females. All the subjects were student of primary school of urban and rural area at Jessore district in Bangladesh. The age ranges of the subjects were between 6 to 12 years for males, 6-11 years for females. Longitudinal data on body and head dimensions (stature, weight, sitting height, leg length, chest circumference, left and right upper arm length, elbow-wrist length, left and right tibia length, left and right upper arm circumference, head length, head breadth and head circumference) were measured from 2006 to 2009. The study started with 117 children. There was about 24% loss of the sample size. Finally we were 89 subjects. Descriptive statistics, growth chart and allometric growth model were used. Allometric relationships between body and head dimensions were obtained through log-linear regression analysis. Growth of head dimensions (head length, head breadth and head circumference) was negatively allometric with respect to stature for males and females, i.e., growth rate of head dimensions were smaller than growth rate of stature. Growth of body dimensions (leg length, tibia length, arm length etc.) were positive allometry with respect to stature implying growth of these body dimensions were greater than that of stature but the growth of sitting height with respect to stature were negative allometry. Growth of leg length and upper arm length with respect to stature were isometry for urban females. Growth of urban males and females were greater than rural males and females in stature, weight, sitting height, leg length, chest circumference, head length, head breadth and head circumference. Average stature differs more than 5 cm between urban and rural females, 4 cm for urban males and females. Average weight differs more than 4 kg between urban and rural males, 6 kg for urban and rural females. An in-depth further study should be taken into accounts for searching the reason of this regional difference.
Anthropometric Study of the Shantal Community in Rajshahi District
(University of Rajshahi, 2006) Karim, Md. Rezaul; Islam, Md. Nurul; Ali, Md. Ayub
The aim of the thesis was to study Anthropometric variables sta􀀊ure, body weight, body mass index (BMI), sitting height and chest circumference, to find their relationships with some of the demographic and Socio-economic variables of Shantal community in Rajshshi District, Bangladesh. The_demographic and socioeconomic variables were collected through a questionnaire (in Appendix-I). Anthropometric measurements were taken by the· author himself. The cluster sampling technique was applied. The sample size were 396 for male and 438 for female. The present study demonstrated that the average stature, body weight, sitting height and chest circumference of young Shantals were increasing comparatively with those of oldest Shantals. Almost every Shantals were very lean and thin and stature, body weight, sitting height, and chest circumference of Shantals were positively and significantly related to each other. The present study indicated that the female onset of menarche of Shantals community reached earlier who were heavier and became late menarche who were both taller and thinner. Also lower BMI of female Shantals were reached age at menarche earlier than those of larger BMI. Also, age at menarche was earlier for those whose family income were higher and was late for those whose family income were lower and the onset of menarche reached earlier than those who have fewer number of sibling. Through the logistic regression, the present study suggest that the stature of literate male Shantals were shorter than the stature of illiterate Shantals and their differences were signHicant (p<0.05). The body weight and occupation were negatively associated but their differences were insignificant. The stature of literate female Shantals were higher than the stature of illiterate female Shantals and the body weight of female labors were lower than the body weight of non-labor female Shantals with significant differences. Sexual differences among stature, body weight and BMI of Shantals were found and the male Shantals were taller in stature and heavier in body weight than female Shantals and female Shantals were lean and thin. Government should take favorable view and necessary co-operations for their better health, social and economic management.
Determinants of Hypertension in Bangladesh: A Case Study of Rajshahi District
(University of Rajshahi, 2013) Ali, Md. Ayub; Mondal, Md. Nazrul Islam; Ali, Md. Ayub
Hypertension is a silent killer of human life and the numbers of hypertensive patients are increasing globally and nationally. Therefore, the purpose of the study was to investigate age-specific hypertension patterns, alarming age for hypertension, and many determinants of hypertension in Bangladesh, e.g., feminine and nuptial determinants, socio-demographic determinants, health complication determinants, and body composition determinants. The data were collected from Rajshahi district using stratified multistage sampling with technique based on the scheduled questionnaire for this study. To identify the most important determinants, sophisticated statistical tools have been used such as percentage distribution, point bi-serial correlation, phi correlation, Pearson product-moment correlation, path analysis, boot strapping technique, binary backward logistic regression method including Likelihood ratio test, Hosmer-lemeshow test, Nagelkerke R2, Sensitivity and specificity, receiver operating characteristics (ROC) curve etc. It was found that the number of systolic hypertensive patients (60.40%) were greater than diastolic hypertensive patients (47.90%) in old age group (≥61 years) where diastolic hypertensive patients (7.40%) were greater than systolic hypertensive patients (3.80%) in young age group (≤39 years) and in middle age group (40-60 years) both are same. Hence, young age (≤39 years) was risk period for occurring diastolic hypertension than systolic and old age (≥61years) was risk period for occurring systolic hypertension than diastolic when middle age (40-60 years) was also risk period for occurring both type of hypertension. The differences between two same percentiles of systolic and diastolic blood pressure were varying from 51 mmHg to 93 mmHg for hypertensive respondents where it is same for normotensive. Hence, the abnormality (>40 mmHg) of the differences is an indicator of hypertension or prehypertension. From the view of proper critical analysis of impact of some key factors on hypertension, the study was divided into four aspects such as socio-demographic, feminine and nuptial, health complication and body composition aspects. About 28.10% hypertensive patients were due to socio-demographic aspect. Applying binary logistic regression model in the study of causal relationship, age was found as the most significant variable. i. e. age had positive significant impact on hypertension. Secondly, education had second most significant negative impact on hypertension and its odds ratio focus that for every increase of one year in education, the risk of hypertension increased 0.958 time. It was also found that sedentary life style, working hour (>8 hrs) per day, social stress, occupational stress and mental stress, hereditary hypertension, smoking, taking alcohol and taking excess salt had positive significant impact on raising hypertension where taking regular exercise had negative significant impact on hypertension. Hence, sedentary life style, working hour (>8) per day, social stress, occupational stress, mental stress, hereditary hypertension, smoking, taking alcohol, taking excess salt may be considered as risk factors for raising high blood pressure or hypertension. Though the age was found to be as the highest risk factor, but age increasing is out of human control. In the health complication aspect, the adult hypertensive patients were 30.60%. In the analysis of causal relationship (applying binary backward logistic regression method) between hypertension and other health complication, kidney disease was found as a significant variable. i. e. kidney disease had positive significant impact on hypertension and its odds ratio 5.428 indicates that the respondents with kidney disease had 5.428 times risk to occur hypertension than the respondent without kidney disease. Also, tumor, diabetes, sleep apnea, hypothyroidism, hyperthyroidism, tachycardia and overweight had the positive significant impact for occurring hypertension. After discussing the binary logistic regression it was further found that kidney disease, tumor, diabetes, sleep apnea, hypothyroidism, hyperthyroidism, tachycardia and overweight might be considered as risk factors for raising high blood pressure or hypertension. In selected feminine and nuptial aspect, the active married female hypertensive patients were 28.90%. In the study of causal relationship (applying backward binary logistic regression model) between hypertension and other feminine and nuptial characteristics, first menstruation age was found to be as significant variable. i. e. first menstruation age had negative significant impact on hypertension. Duration of couple life had significant positive significant impact on hypertension. Use of contraceptive method, menopause, pregnancy and miscarriage had positive significant impact for occurring hypertension compared with those who do not possesses the characteristics. Hence, first menstruation age, duration of couple life, use of contraceptive method, menopause, pregnancy and miscarriage might be considered as risk factors or determinants for raising high blood pressure or hypertension. Using path analysis, the total effect of body mass index, abdominal circumference and ratio of waist to hip on systolic blood pressure were 0.207, 0.185 and 0.118 respectively in which their direct effect were respectively 0.146, 0.082 and 0.047. The total effect of body mass index, abdominal circumference and ratio of waist to hip on diastolic blood pressure were 0.289, 0.231 and 0.138 respectively in which their direct effect were respectively 0.231, 0.079 and 0.043.
Modeling and Forecasting Selected Indicators of Dhaka Stock Exchange
(University of Rajshahi, 2020) Hossain, Ahammad; Ali, Md. Ayub
This study was an attempt to build a suitable time series model to forecast selected indicators of Dhaka Stock Exchange (DSE). Time series data of STR, IMC, TEC during 1990-2012 in annual scale; DGI, GDP, GNI, GS, GI, DIR and GFI during 2005-2012 in annual scale; capital, volume, value, trade, DGI during 2004- 2013 in monthly scale; and DSEX, DSES, and DSE30 indices during 2014-2018 in monthly scale were used for modeling and forecasting purposes. The data were collected from the World Bank and DSE websites. Exploratory Data Analysis (EDA) was used to uncover the hidden information carried out through the observed data. The time series plot showed that DSE indicators had a rightly upward trend over time but non-seasonality was present in the series. Cobb-Douglas (CD) functional regression of STR on IMC and TEC was estimated. There was a negative STR trend during the period from 1990 to 2012. There was no multicollinearity problem among the regressors in the CD regression model. The estimated residuals of the CD model satisfied that the model was free from the problem of outliers and also confirmed the normality condition. To investigate the indirect and long-run impact on the portfolios of DSE prices, the multiple log-linear regression model was estimated considering the DGI as the dependent variable and the macroeconomic indicators like GDP, GNI, GS, GI, DIR, and GFI, respectively as the independent variables. A negative DGI trend (α = -44.936) was found during the period 2005 to 2012. Multicollinearity, normality, and outliers were checked for this model too. For the multicollinearity problem, the multiple linear regression model was re-estimated by dropping GNI due to very severe multicollinearity and for severe/moderate multicollinearity, standardized GDP, standardized GS, and standardized GFI were used as the explanatory variables. A positive DGI trend during the period 2005 to 2012 was found.
Prediction of Adult Stature of Japanese Boys and Girls
(University of Rajshahi, 2003) Rahman, J.A.M. Shoquilur; Ali, Md. Ayub
The longitudinal growth of individual's stature of the present study was characterized from early childhood to adulthood. The samples used here were 509 males and 311 females. A triphasic generalized logistic model (BTT model) and diphasic growth model (JPA-2 model) applied respectively on the above two sets of data through the software AUXAL for characterizing individual growth of stature. The default values of the population mean and covariance matrix in AUXAL for both the models were substituted by estimated population mean and covariance matrix based on Japanese population. The individuals without mid growth spurt for both sexes show that predicted adult stature (PAS) was significantly positive correlated with stature at onset of adolescent and adolescent growth phases, and for only girls VTO and PHV was positively correlated. The individuals with mid growth spurt for both sexes show that PAS was significantly positively correlated with statures at early childhood minimum, mid-childhood maximum, onset of adolescent and adolescent growth phases. Also positive significant correlations were found between VECM and VMC, VTO and PHV but in case of PHV and VMC, negative significant correlation was found. On the basis of JPA-2 model the mean adult stature were 171.27cm for Japanese boys and 158.51 for Japanese girls. On the basis of BTT model this study demonstrates that, on average, 46. 1 %, 39.5%, and 14.4% of the total adult stature were completed during early, middle and adolescent phase of growth, respectively, for the Japanese male population. For the female population, these percentages were 42.6%, 44.6%, and 12.8%, respectively. The distributions of predicted stature that do not have the mid growth spurt, on average, shows that the Japanese girls become taller than boys from age 1 to 5 and 10 to 12, and then again become shorter than boys. The distributions of predicted stature that have the mid growth spurt, on average, shows that the Japanese girls become taller than boys from age 8 and 11 to 12, and then again become shorter than boys. Japanese boys who do not have the mid growth spurt are, on average, 13.26 cm taller than their opposite sex. Moreover, Japanese boys who have the mid growth spurt are, on average, 13. 77 cm taller than their opposite sex. Several equations, after removing the problem of outliers and influential data points, are proposed to predict the adult stature of the Japanese based on growth parameters and statures at different ages.
Prediction of Final Stature from a New 3D Two-Stage Growth Model
(University of Rajshahi, 2015) Shahin, Md. Abu; Ali, Md. Ayub
The purpose of the present study was to establish higher dimensional growth model and then to predict the final stature from a new 3D two-stage growth model. To check the validity of the models, a secondary longitudinal data on age, weight and stature of Japanese boys and girls were used. The proposed 3D growth model showed more precise than that of the existing 2D growth models. After extracting the final stature and stature at different ages from the well fitted proposed model and eliminating the problem of multicollinearity using ‘Forward Stepwise Ridge Regression’ and ‘Least Absolute Shrinkage and Selection Operator (LASSO)’ techniques, this study propose four different equations for predicting final stature with higher precession, validity and stability compared to others. These equations are perfectly applicable in Japanese population. But, the form of the proposed model and its procedures can be applied to others populations.
Statistical Study of Child Growth: A Case Study of Rajshahi City
(University of Rajshahi, 2008) Pervin, Mst. Khurshida; Mian, Md. Abul Basher; Ali, Md. Ayub
Longitudinal data on 11 preselected variables of child growth was collected during the period of 25 May to 17 December, 2002 for a group of children from birth to 48 months of age from the study area. The study started with 296 children. There was about 38% loss of the study children during the 4 years of study. Finally, we have 169 children. Details of data collection and the underlines problems are given in Chapters 3 and 4. Chapter 5 of this dissertation is a contributory one which contains findings of the study. Fourteen tables and 14 charts are appended in this chapter. This tables and charts explain the growth patterns of children in study area. The most interesting of the findings are that growth patterns show two remarkable drifts, one just before the age of 1 year and the second just after the age of about 30 months which are absent in standard growth charts like that of CDC and WHO. There is another interesting finding, that is right and left wrist-elbow length differs by more than 2 cm among the children of the study area. There are some other variations in the growth velocities within and between the sexes. Chapter 6 is the concluding remarks where major findings, short coming of the study and scope for further research, specially the impact of varying sample size,socio-economic, environmental, nutritional variables, seasonality of birth, reproductive health, etc may be studied.