Simple, multiple and multiway correspondence analysis applied to spatial census-based population microsimulation studies using R

As a bivariate and multivariate multidimensional exploratory method, simple and multiple correspondence analyses have been used successfully in social science for survey or questionnaire results descriptions. Nonetheless, the complexity of social interactions including health status indicators, with also the need to take into account the spatial and temporal realm of the survey, may incline to look at variable associations in a multiway approach instead of a two-way matrix analysis. This means for example, that interaction of order three between the spatial configuration (say the Output Areas of an urban zone), the set of categorical variables (say selected from a census survey) and the evolution (say every 5 years over a 30 years period) would be considered in order to differentiate spatio-temporal associations across categorical variables. For census-based spatial simulation models such as microsimulations, exhibiting this kind of properties is useful as forecasts moves of population characteristics to be considered for healthcare policy scenario analysis. In this paper it is shown how to run this type of analysis within R using a package dedicated to multiway analysis (the R package PTAk), that is, working on multi-entry array data using an algorithm extending classical multidimensional analysis. A didactic approach from two-way analyses to multiway ones, of the same dataset generated from a population spatial simulation model allows a critical demonstration of the potential of the different t methods. Particular attention is also given to the different choices of spatial units and the scale variation effect within a nested administrative zoning system that can be analysed by a correspondence analysis with respect to a model (extending the approach using the independence model) and which can be done for a simple, multiple of multiway correspondence analysis

Statistical models to analyse a baseline survey on rural KwaZulu-Natal adults’ HIV prevalence and associated risk factors.

Masters Degree. University of KwaZulu-Natal, Durban.South Africa is at the global epicentre of the HIV-AIDS pandemic. Though there has been an increase in prevention and control measures that has led to a significant reduction in HIV-AIDS mortality rates globally, South Africa has experienced a high share of the HIV burden. HIV-AIDS imposes a substantial economic burden on both individuals and governments. It has had a considerable effect on poverty by affecting potentially economically active citizens who would otherwise have entered the workforce and contributed to the local and national economy. This has hindered economic growth and development in South Africa. The 2016 UNAIDS Gap Report estimates that in 2015 there were seven million people living with HIV in South Africa and that this resulted in 180,000 AIDS related deaths in the same year. The same year saw an unprecedented 380,000 new reported infections. The prevalence of HIV-AIDS in South Africa remains high at 19.2% among the general population. This study was an investigation into the determinants of HIV in adults in the age group 15-49 years. The study used the HIV Incidence Provincial Surveillance System (HIPSS) to collect data between June 2014 and June 2015. The final data set comprised 9,804 observations and consisted of explanatory variables pertaining to individuals’ socio-economic, socio-demographic and behavioural circumstances. The response variable was binary indicating whether a participant tested positive or negative for HIV. Incorporating survey weights into the data owing to the complex sample design, necessitated the use multilevel regression procedures. To this end, survey logistic regression and the generalised linear mixed models were employed. The results emanating from these models revealed that factors encompassing socioi economic, demographic and selected behavioural characteristics were significantly associated with HIV prevalence in the study location. In some instances, it is possible that households in close proximity exhibit some similarities with the inevitable result of spatial autocorrelation requiring the use of geographically weighted regression techniques able to account for spatial autocorrelation. The application of a spatial multilevel model showed that the influence between households in close proximity is greater than between those further away, a phenomenon that would be ignored in conventional multilevel models.Abbreviations on page xii

Sickness absence in Troms County. Trends and risk factors

This thesis examines the dynamics of the sickness absence in Troms county. High level of sickness absence in Norway causes substantial costs for sick pay scheme and replacement workers likewise significant reduction in productivity. Awareness of the trends of sickness absence and the risk factors which increase the likelihood of sick leave contributes to the establishment of proper policies aimed to reduce it. Until now the measures did not show expected efficiency. My method of analysis is a combination of descriptive statistics and regression analysis performed by using RStudio software (RStudio, 2015). I examined the relationship between variables day of week, month, year, mean temperature, sum of precipitation and wind power, gender, sector, age and profession and the frequency of the registered sick leaves in Troms county for the period 2010-2017. Key findings are: 1) the sickness absence showed pronounced seasonality and steadily growth during the estimated period, 2) weather describing variables did not show significant effect on the frequency of sick leaves, 3) women have more sickness absence than men, 4) municipality sector has the highest sickness absence rate, followed by private and governments sectors, 5) younger population showed significant ongoing increase in sickness absence compared to older population, 6) significant changes in the economy reflecting on GDP cause fluctuations and deviations from the general trend of sickness absence in all sectors, age and profession groups

Occupational mobility among blacks in South Africa

Bibliography: leaf 200-205.This study seeks to examine the extent, pattern, implications and determinants of occupational mobility among Blacks in South Africa and the economic context in response to which such mobility is occurring. Analysis is concentrated on the period 1960 to 1981 with particular emphasis on the 1970's. It is indicated that during this period notable changes occurred in the division of labour which was characterised by the rapid entry of blacks into 'petty bourgeois' and skilled manual occupations. This process took place in the context of rapid economic growth and particularly of rapid industrialisation. Emphasis is placed on an analysis of the determinants of occupational mobility among blacks in two cities in South Africa. The influence of socio-economic background and education are identified as being of primary importance as determinants of mobility. Particular attention is paid to an investigation of the effects that the legal status of black workers in urban areas has on the variables identified as notable determinants of occupational mobility, and directly on mobility itself. The emergent pattern of mobility and the determinants thereof are compared to the findings of studies in several other countries which provide the yardstick against which the domestic results can be measured. Finally, projections are made of the demand for and supply of labour till 1990. The implications of these projections, particularly for the educational system and skilled labour shortages are analysed

The impact of marketing consultancy on small/medium sized firms

This study looks at a programme designed to influence the practice of marketing planning in small/medium sized firms and analyses the impact of marketing planning on the firms when they are provided with such a plan. The study confirms that the incidence of marketing planning in small firms is very low. The results suggest that an evaluation of the programme based only on producing a plan and then implementing it, is inadequate. The real effect of the exercise is also its impact on knowledgeability within firms. Involvement of firms in the marketing planning process increases awareness and knowledgeability of marketing planning. It is argued that the effect will result in the gradual adoption of formal marketing planning by firms. Not only does the experience increase knowledgeability, but the results also indicate that the value of marketing planning to a firm is related to knowledgeability. Firms regard the exercise as valuable if it has had a positive impact on their understanding of marketing and strategic issues. More importantly, increased knowledgeability encourages firms to implement more of the recommendations contained in a plan, which can lead to better performance. The results also indicate that the marketing consultant can have an important role in fostering strategic orientation and marketing awareness in managers of small/medium sized firms. The effectiveness of the programme depends greatly on both the performance of the consultant who prepares the plan and the way the scheme operates

Comparative Analysis of Student Learning: Technical, Methodological and Result Assessing of PISA-OECD and INVALSI-Italian Systems .

PISA is the most extensive international survey promoted by the OECD in the field of education, which measures the skills of fifteen-year-old students from more than 80 participating countries every three years. INVALSI are written tests carried out every year by all Italian students in some key moments of the school cycle, to evaluate the levels of some fundamental skills in Italian, Mathematics and English. Our comparison is made up to 2018, the last year of the PISA-OECD survey, even if INVALSI was carried out for the last edition in 2022. Our analysis focuses attention on the common part of the reference populations, which are the 15-year-old students of the 2nd class of secondary schools of II degree, where both sources give a similar picture of the students

Transportation Systems Analysis and Assessment

The transportation system is the backbone of any social and economic system, and is also a very complex system in which users, transport means, technologies, services, and infrastructures have to cooperate with each other to achieve common and unique goals.The aim of this book is to present a general overview on some of the main challenges that transportation planners and decision makers are faced with. The book addresses different topics that range from user's behavior to travel demand simulation, from supply chain to the railway infrastructure capacity, from traffic safety issues to Life Cycle Assessment, and to strategies to make the transportation system more sustainable