A Bayesian Approach for Decision Making on the Identification of Genes with Different Expression Levels: An Application to Escherichia coli Bacterium Data

A common interest in gene expression data analysis is to identify from a large pool of candidate genes the genes that present significant changes in expression levels between a treatment and a control biological condition. Usually, it is done using a statistic value and a cutoff value that are used to separate the genes differentially and nondifferentially expressed. In this paper, we propose a Bayesian approach to identify genes differentially expressed calculating sequentially credibility intervals from predictive densities which are constructed using the sampled mean treatment effect from all genes in study excluding the treatment effect of genes previously identified with statistical evidence for difference. We compare our Bayesian approach with the standard ones based on the use of the t-test and modified t-tests via a simulation study, using small sample sizes which are common in gene expression data analysis. Results obtained report evidence that the proposed approach performs better than standard ones, especially for cases with mean differences and increases in treatment variance in relation to control variance. We also apply the methodologies to a well-known publicly available data set on Escherichia coli bacterium.

A new method for decision making in multi-objective optimization problems

Many engineering sectors are challenged by multi-objective optimization problems. Even if the idea behind these problems is simple and well established, the implementation of any procedure to solve them is not a trivial task. The use of evolutionary algorithms to find candidate solutions is widespread. Usually they supply a discrete picture of the non-dominated solutions, a Pareto set. Although it is very interesting to know the non-dominated solutions, an additional criterion is needed to select one solution to be deployed. To better support the design process, this paper presents a new method of solving non-linear multi-objective optimization problems by adding a control function that will guide the optimization process over the Pareto set that does not need to be found explicitly. The proposed methodology differs from the classical methods that combine the objective functions in a single scale, and is based on a unique run of non-linear single-objective optimizers.

Post-decision Processes : Consolidation and value conflicts in decision making

The studies in the present thesis focus on post-decision processes using the theoretical framework of Differentiation and Consolidation Theory. This thesis consists of three studies. In all these studies, pre-decision evaluations are compared with post-decision evaluations in order to explore differences in evaluations of decision alternatives before and after a decision. The main aim of the studies was to describe and gain a clearer and better understanding of how people re-evaluate information, following a decision for which they have experienced the decision and outcome. The studies examine how the attractiveness evaluations of important attributes are restructured from the pre-decision to the post-decision phase; particularly restructuring processes of value conflicts. Value conflict attributes are those in which information speaks against the chosen alternative in a decision. The first study investigates an important real-life decision and illustrates different post-decision (consolidation) processes following the decision. The second study tests whether decisions with value conflicts follow the same consolidation (post-decision restructuring) processes when the conflict is controlled experimentally, as in earlier studies of less controlled real-life decisions. The third study investigates consolidation and value conflicts in decisions in which the consequences are controlled and of different magnitudes. The studies in the present thesis have shown how attractiveness restructuring of attributes in conflict occurs in the post-decision phase. Results from the three studies indicated that attractiveness restructuring of attributes in conflict was stronger for important real-life decisions (Study 1) and in situations in which real consequences followed a decision (Study 3) than in more controlled, hypothetical decision situations (Study 2). Finally, some proposals for future research are suggested, including studies of the effects of outcomes and consequences on consolidation of prior decisions and how a decision maker’s involvement affects his or her pre- and post-decision processes.

On uncertainty and robustness in evolutionary optimization-based multicriterio decision-making

Programa de Doctorado: Sistemas Inteligentes y Aplicaciones Numéricas en Ingeniería

Sustainability indicators for environmental management and decision making

The general objective of this research is to explore theories and methodologies of sustainability indicators, environmental management and decision making disciplines with the operational purpose of producing scientific, robust and relevant information for supporting system understanding and decision making in real case studies. Several tools have been applied in order to increase the understanding of socio-ecological systems as well as providing relevant information on the choice between alternatives. These tools have always been applied having in mind the complexity of the issues and the uncertainty tied to the partial knowledge of the systems under study. Two case studies with specific application to performances measurement (environmental performances in the case of the K8 approach and sustainable development performances in the case of the EU Sustainable Development Strategy) and a case study about the selection of sustainable development indicators amongst Municipalities in Scotland, are discussed in the first part of the work. In the second part of the work, the common denominator among subjects consists in the application of spatial indices and indicators to address operational problems in land use management within the territory of the Ravenna province (Italy). The main conclusion of the thesis is that a ‘perfect’ methodological approach which always produces the best results in assessing sustainability performances does not exist. Rather, there is a pool of correct approaches answering different evaluation questions, to be used when methodologies fit the purpose of the analysis. For this reason, methodological limits and conceptual assumptions as well as consistency and transparency of the assessment, become the key factors for assessing the quality of the analysis.

Integration of cognitive and affective processes in perception and decision-making

The relationship between emotion and cognition is a topic that raises great interest in research. Recently, a view of these two processes as interactive and mutually influencing each other has become predominant. This dissertation investigates the reciprocal influences of emotion and cognition, both at behavioral and neural level, in two specific fields, such as attention and decision-making. Experimental evidence on how emotional responses may affect perceptual and attentional processes has been reported. In addition, the impact of three factors, such as personality traits, motivational needs and social context, in modulating the influence that emotion exerts on perception and attention has been investigated. Moreover, the influence of cognition on emotional responses in decision-making has been demonstrated. The current experimental evidence showed that cognitive brain regions such as the dorsolateral prefrontal cortex are causally implicated in regulation of emotional responses and that this has an effect at both pre and post decisional stages. There are two main conclusions of this dissertation: firstly, emotion exerts a strong influence on perceptual and attentional processes but, at the same time, this influence may also be modulated by other factors internal and external to the individuals. Secondly, cognitive processes may modulate emotional prepotent responses, by serving a regulative function critical to driving and shaping human behavior in line with current goals.

Diversity and local democracy. The case of Republic of Macedonia - implications of ethnic diversity on municipal decision making and organizational performance

This research seeks to review the level of knowledge achieved in interpreting the relationship between the ethnic diversity at the workplace in the public sector and the organizational performance; as well as seeks to contribute in understanding the implications of this relationship. The study commenced with investigating the academic research in the relevant area addressing the following research questions: (a) How are diversity management and organizational performance conceptualized? (b) What are the existing findings of research concerning diversity at the workplace in the public organizations and organizational performance? (c) What factors intervene the relationship between the diversity and organizational performance? Based on the findings from the review of the academic research, this study seeks to contribute in understanding the ethnic diversity – performance relationship and its mplications at the local level in the Macedonian context. The reform process in Macedonia as a multicultural society, where for many years, inter-ethnic relations have been one of the most sensitive political issues, affecting both the stability of the country and the progress, focused mainly on the implementation of the decentralization and inclusion of ethnic minorities in the decision making process. With the implementation of the Ohrid Framework Agreement workforce at the units of local self-government in Republic of Macedonia is becoming more balanced with respect to ethnic minorities, with more workforce participation than ever by Albanians, Turks, Roma and other minorities. As public organizations at local level become more diverse along ethnic lines, it makes sense to pay more attention to how different ethnic groups interact with one another at work. Thus it gives additional importance on the research question addressed in the study and gives significance of the research in a broader scope.

Teoria dei giochi e Multi-criteria decision-making per reti mobili Ad-hoc: un protocollo di routing

Nell'elaborato si analizzano aspetti della teoria dei giochi e della multi-criteria decision-making. La riflessione serve a proporre le basi per un nuovo modello di protocollo di routing in ambito Mobile Ad-hoc Networks. Questo prototipo mira a generare una rete che riesca a gestirsi in maniera ottimale grazie ad un'acuta tecnica di clusterizzazione. Allo stesso tempo si propone come obiettivo il risparmio energetico e la partecipazione collaborativa di tutti i componenti.

Strategic decision making in international firms: effect of top management team internationalization on international strategic decision process

In this research project, I have integrated two research streams on international strategic decisions making in international firms: upper echelons or top management teams (TMT) internationalization research and international strategic decision making process research. Both research streams in international business literature have evolved independently, but there is a potential in combining these two streams of research. The first empirical paper “TMT internationalization and international strategic decision making process: a decision level analysis of rationality, speed, and performance” explores the influence of TMT internationalization on strategic decision rationality and speed and, subsequently, their effect on international strategic decision effectiveness (performance). The results show that the internationalization of TMT is positively related to decision effectiveness and this relationship is mediated by decision rationality while the hypotheses regarding the association between TMT internationalization and decision speed, and the mediating effect of speed were not supported. The second paper “TMT internationalization and international strategic decision rationality: the mediating role of international information” of my thesis is a simple but logical extension of first paper. The first paper showed that TMT Internationalization has a significant positive effect on international strategic decision rationality. The second paper explicitly showed that TMT internationalization affect on international strategic decision rationality comes from two sources: international experience (personal international knowledge and information) and international information collected from managerial international contacts. For this research project, I have collected data from international software firms in Pakistan. My research contributes to the literature on upper echelons theory and strategic decision making in context of international business and international firms by explicitly examining the link between TMT internationalization and characteristics of strategic decisions making process (i.e. rationality and speed) in international firms and their possible mediating effect on performance.

Cost-Effectiveness of Alternative Retrofit Options to Support Decision Making

How to evaluate the cost-effectiveness of repair/retrofit intervention vs. demolition/replacement and what level of shaking intensity can the chosen repairing/retrofit technique sustain are open questions affecting either the pre-earthquake prevention, the post-earthquake emergency and the reconstruction phases. The (mis)conception that the cost of retrofit interventions would increase linearly with the achieved seismic performance (%NBS) often discourages stakeholders to consider repair/retrofit options in a post-earthquake damage situation. Similarly, in a pre-earthquake phase, the minimum (by-law) level of %NBS might be targeted, leading in some cases to no-action. Furthermore, the performance measure enforcing owners to take action, the %NBS, is generally evaluated deterministically. Not directly reflecting epistemic and aleatory uncertainties, the assessment can result in misleading confidence on the expected performance. The present study aims at contributing to the delicate decision-making process of repair/retrofit vs. demolition/replacement, by developing a framework to assist stakeholders with the evaluation of the effects in terms of long-term losses and benefits of an increment in their initial investment (targeted retrofit level) and highlighting the uncertainties hidden behind a deterministic approach. For a pre-1970 case study building, different retrofit solutions are considered, targeting different levels of %NBS, and the actual probability of reaching Collapse when considering a suite of ground-motions is evaluated, providing a correlation between %NBS and Risk. Both a simplified and a probabilistic loss modelling are then undertaken to study the relationship between %NBS and expected direct and indirect losses.

Decision making nella robotica collettiva

Nel testo viene esposta la presa di decisione nella robotica collettiva, cioè il comportamento collettivo esibito dagli animali sociali in sciame migrato in un gruppo di robot. Questa tesi si prefigge di analizzare come un insieme di individui, all'interno di un gruppo, possano giungere tutti ad avere una stessa opinione comune, o come essi siano in grado di dividersi autonomamente il lavoro senza alcun bisogno di controllo centrale. Inizialmente, viene introdotta la robotica collettiva, esponendone origini, caratteristiche e ambiti di ricerca. Viene in seguito presentato il collective decision making, all'interno del comportamento collettivo generale, esponendone le origini biologiche fino ai primi esperimenti su dei semplici robot. Vengono poi analizzati i due aspetti del decision making, vale a dire il raggiungimento del consenso e la suddivisione del lavoro. Per entrambi gli argomenti, sono presentati studi sia di carattere biologico che robotico, allo scopo di trarne similitudini e differenze e realizzare una valida analisi critica. Infine, vengono esposti i possibili sviluppi del comportamento e della robotica collettiva, mostrando possibili scenari di utilizzo futuro e gli attuali limiti allo sviluppo.

[Molecular analyses for (early) recognition of hematologic diseases - sense and sensibility for molecular analysis: the art of intelligent decision-making]

During the last 10 years several molecular markers have been established as useful tools among the armamentarium of a hematologist. As a consequence, the number of performed hematologic molecular analyses has immensely increased. Often, such tests replace or complement other laboratory methods. Molecular markers can be useful in many ways: they can serve for diagnostics, describe the prognostic profile, predict which types of drugs are indicated, and can be used for the therapeutic monitoring of the patient to indicate an adequate response or predict resistance or relapse of the disease. Many markers fulfill more than one of these aspects. Most important, however, is the right choice of analyses at the right time-points!