In this thesis,we study how a meta-analysis of genetic association studies is influenced by the degree of genotype imputation uncertainty in the studies combined and the size of meta-analysis. We consider the fixed effect meta-analysis model to evaluate the accuracy and efficiency of imputation-based meta-analysis results under different levels of imputation accuracy. We also examine the impact of genotype imputation on the between-study heterogeneity and type 1 error in the random effects meta-analysis model. Simulation results reaffirm that meta-analysis boosts the power of detecting genetic associations compared to individual study results. However, the power deteriorates with increasing uncertainty in imputed genotypes. Genotype imputation affects a random effects meta-analysis in a non-obvious way as estimation of between-study heterogeneity and interpretation of association results depend heavily on the number of studies combined. We propose an adjusted fixed effect meta-analysis approach for adding imputation-based studies to a meta-analysis of existing typed studies in a controlled way to improve precision and reliability. The proposed method should help in designing an effective meta-analysis study.

This thesis consists of four papers that are related to commonly used propensity score-based estimators for average causal effects. The first paper starts with the observation that researchers often have access to data containing lots of covariates that are correlated. We therefore study the effect of correlation on the asymptotic variance of an inverse probability weighting and a matching estimator. Under the assumptions of normally distributed covariates, constant causal effect, and potential outcomes and a logit that are linear in the parameters we show that the correlation influences the asymptotic efficiency of the estimators differently, both with regard to direction and magnitude. Further, the strength of the confounding towards the outcome and the treatment plays an important role. The second paper extends the first paper in that the estimators are studied under the more realistic setting of using the estimated propensity score. We also relax several assumptions made in the first paper, and include the doubly robust estimator. Again, the results show that the correlation may increase or decrease the variances of the estimators, but we also observe that several aspects influence how correlation affects the variance of the estimators, such as the choice of estimator, the strength of the confounding towards the outcome and the treatment, and whether constant or non-constant causal effect is present. The third paper concerns estimation of the asymptotic variance of a propensity score matching estimator. Simulations show that large gains can be made for the mean squared error by properly selecting smoothing parameters of the variance estimator and that a residual-based local linear estimator may be a more efficient estimator for the asymptotic variance. The specification of the variance estimator is shown to be crucial when evaluating the effect of right heart catheterisation, i.e. we show either a negative effect on survival or no significant effect depending on the choice of smoothing parameters.   In the fourth paper, we provide an analytic expression for the covariance matrix of logistic regression with normally distributed regressors. This paper is related to the other papers in that logistic regression is commonly used to estimate the propensity score.

No description available.

In this study, a method is proposed for decision making for multiobjective recreational areas, by using multi attribute decision making rules within GIS. The method provides integration of ecological, sociocultural and economic considerations of an ecologically valuable area in a systematic way. The first stage of the methodology includes determination of suitable areas for three usages of forest area / outdoor recreation, timber production and protection needed areas. The second stage comprises decision making analyses. In this stage, two of multi attribute decision rule methods / simple additive weighting method and ideal point method, are used. As a result of these analyses alternative proposal maps for study area and ideal areas for recreation and timber production are acquired. Finally, in the third stage these alternative proposal maps and ideal area are compared with each other and with defined protection zone in the study area. Ideal areas for recreation and timber production are defined by also considering the protection needed areas. The methodology is applied on Eastern Black Sea Region. As a result of the study, ideal areas both for recreational usage and timber production are defined. According to these ideal areas, best fitting alternative map is selected. Finally recreation and timber production proposals are compared with protection needed areas. Results of this study provide a general decision for multipurposed areas in regional scale. The suggested protection zones and suitable areas for recreation and timber production should provide a primary information for forest management studies which must be done in more detailed scales.

No description available.

Abstract This thesis presents innovative applications of Multi-Objective Decision Support Systems (MODSS) to forestry decision support. New MODSS methodologies were developed to assess and evaluate forestry practices and finance regimes. The assessment of forestry investments draw on case studies conducted in the Hodgson Creek catchment on the Darling Downs in south Queensland and on the Atherton Tablelands in north Queensland, Australia. MODSS are systems that aid decision-making, in which a set of alternative management options are evaluated against a set of decision criteria. The criteria, that represent the stakeholders’ goals and objectives, are weighted to reflect stakeholder preferences regarding their relative importance. The weighted criteria scores are then aggregated to create an overall measure of option performance. In the first case study, MODSS procedures identified from the literature as being most suitable to forestry and the MODSS software package DEFINITE was used. After a critical review of the first study, a new MODSS was developed to address the particular needs of forestry evaluations and the weaknesses of current MODSS for addressing these needs. Limitations of the Hodgson Creek MODSS included lack of stakeholder engagement in the MODSS development process, inefficient use of the stakeholder time and an excessive work load on the experts in the scoring process. The new MODSS development process included the combined use of weighted sum and Electré aggregation methods, these being compensatory and non-compensatory aggregation methods. This combination of aggregation methods provided a measure of overall option performance and identified the presence of fatal flaws in the options. Various criteria weighting methods were trialled – including rank order methods, the analytical hierarchy process and direct assessments – to assess their utility for defining weights that reflected stakeholder priorities. A new hybrid weighting technique was developed using a combination of rank order methods and direct assessments. A new and innovative process for scoring options and criteria was developed, using an adaption of the Nominal Group Technique (NGT) in conjunction with a new computer-based Group Decision Support System (GDSS). This iterative process involved repeated rounds of individual scoring and group discussions. In the workshop conducted to elicit scores from experts, the GDSS was used to identify criteria where the elicited scores differed and discussions were focused on these criteria. After the discussions the options were rescored against the criteria and discussed further. This analysis was innovative in that uncertainty around the individual option scores was addressed for the first time using MODSS. This new application was developed in a spreadsheet using the risk analysis package @RISK. Evaluations of forestry options were undertaken at various time scales to address the long delay between incurring costs of tree planting and receiving returns from harvest. The various time scales identify the periods in which environmental and social benefits occurred as the trees grow and the economic benefits occurred at clearfell (or selective) harvest. This thesis specifically focuses on situations where measured and modelled data is not available, and seeks to increase the scientific rigour of the use of expert and stakeholder opinion in MODSS. The MODSS analyses revealed that forestry in the case study areas had the potential to offer considerable economic, environmental and social benefits to both landholders and the wider community. However, these benefits (and the associated costs) were not viewed as equally important. The MODSS developed in this study addressed these concerns. The benefits and costs of an option were reflected in its performance against the criteria. The degree of importance of the individual criteria varied from minor to high and overriding all other considerations. Criteria against which an option performed highly (the option’s strengths) were identified, as were criteria against which an option performed poorly (the option’s weaknesses). When these weaknesses occurred in highly important criteria, these were identified as fatal flaws in the option. The first case study in the Hodgson Creek catchment considered eight forestry options against 17 economic criteria, 12 environmental criteria and 12 social criteria. The second case study on the Atherton Tablelands considered 16 forestry options against eight economic criteria, six environmental criteria and five social criteria. The MODSS analysis identified the most preferred forestry options and the strengths and weaknesses of the options. In both case studies the most preferred options were large or medium-sized plantations with monoculture plantings with an element of non-landholder funding, in the form of government funding, joint ventures or land leasing agreements. These options had the highest performance against the economic criteria at all time scales and satisfactory environmental and social performance. Other forestry options that performed well included plantings focused on under-utilised land areas and salinity prevention areas, agroforestry, and selective harvesting of private native forest. These options generally had a higher level of performance against the social and environmental criteria, but lower levels of performance against economic criteria. These plantings would be undertaken for environmental and social reasons and not for financial returns. The application of MODSS developed in this thesis presents a significant scientific contribution to MODSS methodology. This thesis includes: the use of multiple time-periods to address the temporal differences in the delivery of benefits and costs, the use of NGT and a GDSS to provide a process for rapidly eliciting expert opinion, and the use of the combination of Electré and weighted sum aggregation methods to provide an overall measure of option performance and to identify fatal flaws in the options.

Abstract This thesis presents innovative applications of Multi-Objective Decision Support Systems (MODSS) to forestry decision support. New MODSS methodologies were developed to assess and evaluate forestry practices and finance regimes. The assessment of forestry investments draw on case studies conducted in the Hodgson Creek catchment on the Darling Downs in south Queensland and on the Atherton Tablelands in north Queensland, Australia. MODSS are systems that aid decision-making, in which a set of alternative management options are evaluated against a set of decision criteria. The criteria, that represent the stakeholders’ goals and objectives, are weighted to reflect stakeholder preferences regarding their relative importance. The weighted criteria scores are then aggregated to create an overall measure of option performance. In the first case study, MODSS procedures identified from the literature as being most suitable to forestry and the MODSS software package DEFINITE was used. After a critical review of the first study, a new MODSS was developed to address the particular needs of forestry evaluations and the weaknesses of current MODSS for addressing these needs. Limitations of the Hodgson Creek MODSS included lack of stakeholder engagement in the MODSS development process, inefficient use of the stakeholder time and an excessive work load on the experts in the scoring process. The new MODSS development process included the combined use of weighted sum and Electré aggregation methods, these being compensatory and non-compensatory aggregation methods. This combination of aggregation methods provided a measure of overall option performance and identified the presence of fatal flaws in the options. Various criteria weighting methods were trialled – including rank order methods, the analytical hierarchy process and direct assessments – to assess their utility for defining weights that reflected stakeholder priorities. A new hybrid weighting technique was developed using a combination of rank order methods and direct assessments. A new and innovative process for scoring options and criteria was developed, using an adaption of the Nominal Group Technique (NGT) in conjunction with a new computer-based Group Decision Support System (GDSS). This iterative process involved repeated rounds of individual scoring and group discussions. In the workshop conducted to elicit scores from experts, the GDSS was used to identify criteria where the elicited scores differed and discussions were focused on these criteria. After the discussions the options were rescored against the criteria and discussed further. This analysis was innovative in that uncertainty around the individual option scores was addressed for the first time using MODSS. This new application was developed in a spreadsheet using the risk analysis package @RISK. Evaluations of forestry options were undertaken at various time scales to address the long delay between incurring costs of tree planting and receiving returns from harvest. The various time scales identify the periods in which environmental and social benefits occurred as the trees grow and the economic benefits occurred at clearfell (or selective) harvest. This thesis specifically focuses on situations where measured and modelled data is not available, and seeks to increase the scientific rigour of the use of expert and stakeholder opinion in MODSS. The MODSS analyses revealed that forestry in the case study areas had the potential to offer considerable economic, environmental and social benefits to both landholders and the wider community. However, these benefits (and the associated costs) were not viewed as equally important. The MODSS developed in this study addressed these concerns. The benefits and costs of an option were reflected in its performance against the criteria. The degree of importance of the individual criteria varied from minor to high and overriding all other considerations. Criteria against which an option performed highly (the option’s strengths) were identified, as were criteria against which an option performed poorly (the option’s weaknesses). When these weaknesses occurred in highly important criteria, these were identified as fatal flaws in the option. The first case study in the Hodgson Creek catchment considered eight forestry options against 17 economic criteria, 12 environmental criteria and 12 social criteria. The second case study on the Atherton Tablelands considered 16 forestry options against eight economic criteria, six environmental criteria and five social criteria. The MODSS analysis identified the most preferred forestry options and the strengths and weaknesses of the options. In both case studies the most preferred options were large or medium-sized plantations with monoculture plantings with an element of non-landholder funding, in the form of government funding, joint ventures or land leasing agreements. These options had the highest performance against the economic criteria at all time scales and satisfactory environmental and social performance. Other forestry options that performed well included plantings focused on under-utilised land areas and salinity prevention areas, agroforestry, and selective harvesting of private native forest. These options generally had a higher level of performance against the social and environmental criteria, but lower levels of performance against economic criteria. These plantings would be undertaken for environmental and social reasons and not for financial returns. The application of MODSS developed in this thesis presents a significant scientific contribution to MODSS methodology. This thesis includes: the use of multiple time-periods to address the temporal differences in the delivery of benefits and costs, the use of NGT and a GDSS to provide a process for rapidly eliciting expert opinion, and the use of the combination of Electré and weighted sum aggregation methods to provide an overall measure of option performance and to identify fatal flaws in the options.

Abstract This thesis presents innovative applications of Multi-Objective Decision Support Systems (MODSS) to forestry decision support. New MODSS methodologies were developed to assess and evaluate forestry practices and finance regimes. The assessment of forestry investments draw on case studies conducted in the Hodgson Creek catchment on the Darling Downs in south Queensland and on the Atherton Tablelands in north Queensland, Australia. MODSS are systems that aid decision-making, in which a set of alternative management options are evaluated against a set of decision criteria. The criteria, that represent the stakeholders’ goals and objectives, are weighted to reflect stakeholder preferences regarding their relative importance. The weighted criteria scores are then aggregated to create an overall measure of option performance. In the first case study, MODSS procedures identified from the literature as being most suitable to forestry and the MODSS software package DEFINITE was used. After a critical review of the first study, a new MODSS was developed to address the particular needs of forestry evaluations and the weaknesses of current MODSS for addressing these needs. Limitations of the Hodgson Creek MODSS included lack of stakeholder engagement in the MODSS development process, inefficient use of the stakeholder time and an excessive work load on the experts in the scoring process. The new MODSS development process included the combined use of weighted sum and Electré aggregation methods, these being compensatory and non-compensatory aggregation methods. This combination of aggregation methods provided a measure of overall option performance and identified the presence of fatal flaws in the options. Various criteria weighting methods were trialled – including rank order methods, the analytical hierarchy process and direct assessments – to assess their utility for defining weights that reflected stakeholder priorities. A new hybrid weighting technique was developed using a combination of rank order methods and direct assessments. A new and innovative process for scoring options and criteria was developed, using an adaption of the Nominal Group Technique (NGT) in conjunction with a new computer-based Group Decision Support System (GDSS). This iterative process involved repeated rounds of individual scoring and group discussions. In the workshop conducted to elicit scores from experts, the GDSS was used to identify criteria where the elicited scores differed and discussions were focused on these criteria. After the discussions the options were rescored against the criteria and discussed further. This analysis was innovative in that uncertainty around the individual option scores was addressed for the first time using MODSS. This new application was developed in a spreadsheet using the risk analysis package @RISK. Evaluations of forestry options were undertaken at various time scales to address the long delay between incurring costs of tree planting and receiving returns from harvest. The various time scales identify the periods in which environmental and social benefits occurred as the trees grow and the economic benefits occurred at clearfell (or selective) harvest. This thesis specifically focuses on situations where measured and modelled data is not available, and seeks to increase the scientific rigour of the use of expert and stakeholder opinion in MODSS. The MODSS analyses revealed that forestry in the case study areas had the potential to offer considerable economic, environmental and social benefits to both landholders and the wider community. However, these benefits (and the associated costs) were not viewed as equally important. The MODSS developed in this study addressed these concerns. The benefits and costs of an option were reflected in its performance against the criteria. The degree of importance of the individual criteria varied from minor to high and overriding all other considerations. Criteria against which an option performed highly (the option’s strengths) were identified, as were criteria against which an option performed poorly (the option’s weaknesses). When these weaknesses occurred in highly important criteria, these were identified as fatal flaws in the option. The first case study in the Hodgson Creek catchment considered eight forestry options against 17 economic criteria, 12 environmental criteria and 12 social criteria. The second case study on the Atherton Tablelands considered 16 forestry options against eight economic criteria, six environmental criteria and five social criteria. The MODSS analysis identified the most preferred forestry options and the strengths and weaknesses of the options. In both case studies the most preferred options were large or medium-sized plantations with monoculture plantings with an element of non-landholder funding, in the form of government funding, joint ventures or land leasing agreements. These options had the highest performance against the economic criteria at all time scales and satisfactory environmental and social performance. Other forestry options that performed well included plantings focused on under-utilised land areas and salinity prevention areas, agroforestry, and selective harvesting of private native forest. These options generally had a higher level of performance against the social and environmental criteria, but lower levels of performance against economic criteria. These plantings would be undertaken for environmental and social reasons and not for financial returns. The application of MODSS developed in this thesis presents a significant scientific contribution to MODSS methodology. This thesis includes: the use of multiple time-periods to address the temporal differences in the delivery of benefits and costs, the use of NGT and a GDSS to provide a process for rapidly eliciting expert opinion, and the use of the combination of Electré and weighted sum aggregation methods to provide an overall measure of option performance and to identify fatal flaws in the options.

Chez l’Homme, le contrôle de tout mouvement nécessite la prise en compte d’informations sensorielles issues de différents systèmes. Une partie de ces informations constitue la proprioception, un « sixième sens » méconnu mais primordial dans le contrôle du mouvement. Ce sens permet aux personnes de déterminer les positions spatiales et les vitesses de déplacement des différents segments corporels les uns par rapport aux autres. Le système de traitement des informations proprioceptives repose sur des mécanismes nerveux complexes, et dont l’évaluation est difficile. Il est toutefois possible, à l’instar d’une acuité visuelle relative au sens de la vision par exemple de déterminer une acuité proprioceptive. Des travaux portant sur l’articulation de la cheville ont établi un lien entre acuité proprioceptive et niveau de performance dans une activité donnée. Dans ce contexte une optimisation du système proprioceptif, basé sur une stimulation de la peau présente un grand intérêt. Diverses solutions de supports externes de cheville ont ainsi été développées pour ce travail de thèse qui s’est intéressé à la possibilité d’intégration d’une « fonction proprioceptive » à une chaussure de sport destinée notamment à la course à pied et/ou au tennis. Les effets comportementaux de cette fonction dans des tâches motrices globales ont été étudiés. Ce travail a mis en évidence i) que l’application d’un support externe de cheville permettait d’augmenter la quantité de signal proprioceptif transmise au système nerveux lors d’une tâche simple d’équilibre orthostatique et ii) que ce signal n’était pris en compte que chez certains individus possédant un profil sensoriel intégrant peu les informations proprioceptives de la cheville. Enfin, il semble que les effets comportementaux de supports externes de cheville dans des tâches plus complexes soient en revanche très limités. / In humans, every single movement needs regulation based on sensory information arising from different systems. A part of this sensory information forms the sense of proprioception, a little known “sixth sense” that is yet essential in movement regulation. This sense allows people to know the position and speed of their body segments relative to each other. The central processing of proprioceptive information is complex, and its assessment is difficult. It is yes possible to determine a proprioceptive acuity, in the manner of a visual acuity related to the sense of vision. Studies on the ankle joint evidenced that the proprioceptive acuity correlates to the performance level in a given activity. In this context, optimizing the proprioceptive system by stimulating the skin would be of great interest. Various external ankle supports solutions were developed for this thesis that interested in the possibility to implement a “proprioceptive function” in a sport shoe, especially intended for running and/or playing tennis. Behavioral effects of this function in global motor tasks were specifically studied. This thesis showed that (i) wearing an external ankle support increase the amount of proprioceptive signal conveyed to the central nervous system in a simple upright standing task and (ii) that this signal is effectively used only in individuals with a preferred sensory strategy that do not use much of the ankle proprioceptive information. Eventually, the behavioral effects of such external ankle supports in more complex tasks are very limited.

Dioxins are highly toxic persistent environmental pollutants that occur in marine harbour sediments as the results of industrial practices around the world and pose a significant risk to human health. To adequately remediate contaminated sediments, the spatial extent of contamination must first be determined by spatial interpolation. The ability to lower sampling frequency and perform laboratory analysis on fewer samples, yet still produce an adequate pollutant distribution map, would reduce the initial cost of new remediation projects. Fuzzy Set Theory has been shown as a way to reduce uncertainty due to data sparsity and provides an advantageous way to quantify gradational changes like those of pollutant concentrations through fuzzing clustering based approaches; Fuzzy modelling has the ability to utilize these advantages for making spatial predictions. To assess the ability of fuzzy modeling to make spatial predictions using fewer sample points, its predictive ability was compared to Ordinary Kriging (OK) and Inverse Distance Weighting (IDW) under increasingly sparse data conditions. This research used a Takagi-Sugeno (T-S) fuzzy modelling approach with fuzzy c-means clustering to make spatial predictions of lead concentrations in soil to determine the efficacy of the fuzzy model for applications of modeling dioxins in marine sediment. The spatial density of the data used to make the predictions was incrementally reduced to simulate increasingly sparse spatial data conditions. To determine model performance, the data at each increment not used for making the spatial predictions was used as validation data, which the model attempted to predict and the performance was analyzed. Initially, the parameters associated with the T-S fuzzy model were determined by the optimum observed performance, where the combination of parameters that produced the most accurate prediction of the validation data were retained as optimal for each increment of the data reduction. To determine performance Mean Absolute Error, the Coefficient of Determination, and Root Mean Squared Error were selected as metrics. To give each metric equal weighting a binned scoring system was developed where each metric received a score from 1 to 10, the average represented that methods score. The Akaike Information Criterion (AIC) was also employed to determine the effect of the varied validation set lengths on performance. For the T-S fuzzy model as the amount of data used to solve the respective validation set points was reduced the number of clusters was lower and the cluster centres were more spread out, the fuzzy overlap between clusters was larger, and the widths of the membership function in the T-S fuzzy model were wider. Although it was possible to determine an optimal number of clusters, fuzzy overlap, and membership function width that yielded an optimal prediction of the validation data, gain in performance was minor compared to many other combinations of parameters. Therefore, for the data used in this study the T-S fuzzy model was insensitive to parameter choice. For OK, as the data was reduced, the range of spatial dependence in the data from variography became lower, and for IDW the power parameters optimal value became lower to give a greater weighting to more widely spread points. For the TS fuzzy model, OK, and IDW the increasingly sparse data conditions resulted in an increasingly poor model performance for all metrics. This was supported by AIC values for each method at each increment of the data reduction that were within 1 point of each other. The ability of the methods to predict outlier points and reproduce the variance in the validation sets was very similar and overall quite poor. Based on the scoring system IDW did exhibit a slight outperformance of the T-S fuzzy model, which slightly outperformed OK. However, the scoring system employed in this research was overly sensitive and so was only useful for assessing relative performance. The performance of the T-S model was very dependent on the number of outliers in the respective validation set. For modeling under sparse data conditions, the T-S fuzzy modeling approach using FCM clustering and constant width Gaussian shaped membership functions used in this research did not show any advantages over IDW and OK for the type of data tested. Therefore, it was not possible to speculate on a possible reduction in sampling frequency for delineating the extent of contamination for new remediation projects. / Graduate