Si presentano un saggio empirico e due modelli teorici originali sul rapporto tra geografia economica e crescita. Nel saggio empirico si presentano alcuni fatti stilizzati sull'evoluzione della concentrazione spaziale delle attività innovative in Italia nel periodo 1971-2001. Si mostra, con metodologie non-parametriche su base markoviana, come la concentrazione spaziale sia diminuita nel tempo, con una persistenza del Core di regioni specializzate. Nel primo saggio teorico si propone un modello di crescita romeriana e localizzazione caratterizzato da costi di congestione. È possibile, in questo caso, un processo di divergenza e agglomerazione non permanente. Nel secondo saggio teorico si mostra come le predizioni principali dei modelli di geografia e crescita si estendano anche ad un modello di crescita schumpeteriana. / I present one empirical and two theoretical models on the relationship between geography and growth. in the empirical paper, I present some stylized facts on the evolution of the spatial concentration of innovative activities in Italy in the period 1971-2001. Using markov-based non parametric techniques, I show that spatial concentration decreased but regional specialization is highly persistent. in the first theoretical paper, I present a model of romerian growth and industrial location characterized by congestion costs. I show how a process of agglomeration and divergence might be reverted once trade integration deepens. in the second theoretical paper, I show how usual predictions of the geography and growth models apply to a Schumpeterian growth model.

Objective. Major depressive disorder (MDD) is a common condition following treatment in the Intensive Care Unit (ICU). Long-term data on MDD in chronically critically ill (CCI) patients are scarce. Hence, the primary aim of the present study was to investigate the frequency and predictors of MDD after intensive care of CCI patients. Materials and Methods. In a prospective cohort study, patients with long-term mechanical ventilation requirements () were assessed with respect to a diagnosis of MDD, using the Structured Clinical Interview for DSM-IV, three and six months after the transfer from acute ICU to post-acute ICU. Sociodemographic, psychological, and clinical risk factors with values ≤ 0.1 were identified in a univariate logistic regression analysis and entered in a multivariable logistic regression model. A mediator analysis was run using the bootstrapping method, testing the mediating effect of perceived helplessness during the ICU stay, between the recalled traumatic experience from the ICU and a post-ICU MDD. Results. 17.6% () of the patients showed a full- or subsyndromal MDD. Perceived helplessness, recalled experiences of a traumatic event from the ICU, symptoms of acute stress disorder, and the diagnosis of posttraumatic stress disorder (PTSD) after ICU could be identified as significant predictors of MDD. In a mediator analysis, perceived helplessness could be proved as a mediator. Conclusions. Every fifth CCI patient suffers from MDD up to six months after being discharged from ICU. Particularly, perceived helplessness during the ICU stay seems to mainly affect the long-term evolvement of MDD. CCI patients with symptoms of acute stress disorder/PTSD should also be screened for MDD.

The movements of two vervet monkey troops were studied to determine whether they optimize their rate of food intake in relation to seasonal energy availability. The effect of variation in habitat structure on the troops’ foraging strategies while utilizing temporally and spatially distributed resources was determined. Troop home range boundaries were delineated, the various plant communities and species utilised by the troops identified and classified, and variations in home range and vegetation structure were reported. The diets of the troops were determined and compared. Effects of coexistence on competition were assessed. Vervet food trees were randomly selected, marked and seasonal phenological data collected. Samples of food items constituting the two troops diets were collected for energy analysis. Using geostatistical interpolation techniques, monthly energy values were extrapolated onto home range grids for the two vervet monkey troops. Grids were stored as database files that were interrogated through GIS simulation models. Using the stochastic processes inherent in Markov chain theory, a series of non-returning random walks were simulated for comparison to original routes taken by the two troops. Results from comparisons of home range energy, day range lengths and areas, shortest route energy to actual route energy, time spent in high energy areas, and energy utilisation from actual and randomly generated routes indicated that the two troops optimize resource energy available to them by adopting flexible foraging strategies. In environments where temporal and spatial variations in habitat structure affect the distribution of resources, it is essential that animals develop optimal foraging strategies to survive. For the two troops investigated, foraging strategies fluctuate between being time minimizers in more heterogeneous environments where resources are abundant, and energy maximisers in homogeneous environments where resources are constrained by low diversity and seasonality. / Environmental Sciences (Department) / D.Litt et Phil (Environmental Management)

This thesis examines product innovation processes in small established enterprises. The research questions are: (1) what motivates small established enterprises to innovate, (2) how do small established enterprises perform product innovation, and (3) how do small established enterprises manage resource scarcity in their product innovation processes? To answer the research questions, a multiple case study approach was chosen with three small established enterprises as cases and different product innovation processes as embedded units of study. The data collection method used was observation during a period of five months, complemented by interviews and secondary data. Product innovation in small established enterprises seems to be motivated by solving existing customers’ problems and the need for a sustained steady cash flow. A steady cash flow is also found to be a prerequisite during the product innovation processes. Product innovation seems to occur when there is a risk of decreased cash flow and/or when existing customers can be satisfied with new products that increase their loyalty so as to secure future sales, cash flow, and the enterprise’s survival in the long run. Promising innovation ideas alone do not result in product innovation. An innovation idea must also have supportive existing customers for product innovation to occur. Product innovation processes in the studied small established enterprises are found highly context dependent, intertwined in operational processes and made possible by a small organic organization and closeness to existing customers. The product innovation processes are further found to follow a flexible and informal overall scheme optimized for decreasing market and technology uncertainty and risk, dealing with resource scarcity, and facilitating fast and easy commercialization to avoid or moderate dips in cash flow. The design processes within the innovation processes can be linearly structured or cyclical and experimental, depending on the experienced novelty. To manage resource scarcity during the product innovation processes, the studied small enterprises used many different bootstrapping methods in combination. These methods can be divided into three categories according to their overall functions: for using existing resources more efficiently, for increasing resources and to secure a fast payback on resources invested in NPD. The studied small enterprises were due to their resource scarcity further found to favor an innovation strategy, only involving new products done with known technology and targeting existing markets. This way to innovate, which creates new products in a resource-efficient way that are accepted by the enterprises’ existing markets, seems to prevent unsuccessful product innovation, while at the same time excluding technologically radical innovation and innovation targeting new markets.

本論文是二篇探討與股票價格平均數復歸現象有關的實證文章。在第一篇文章中，我們將探討由於廠商特質所產生資金供需雙方訊息的非對稱，而引發的流動性限制對廠商股票價格行為的潛在影響；在第二篇文章中，我們研究的課題是在漲跌幅限制下，交易量與股票報酬自我相關的關係。 第一篇文章主要在探討由於廠商特質所產生資金供需雙方訊息的非對稱，而引發的流動性限制對廠商股票價格行為的影響。我們利用五個廠商特質－所有權結構、集團企業成員、上市時間、公司規模與現金股利的發放，定義面臨流動性限制的廠商，並使用變異數比率衡量股票價格平均數復歸的現象，由於小樣本的問題，我們將利用拔靴法檢定假說：廠商的流動性限制會強化其股票價格平均數復歸的行為。我們的實證結果並不一致，所有權結構、公司規模和集團企業成員的分組實證結果支持我們的假說，流動性限制會強化平均數復歸的行為；而上市時間與現金股利發放的分組實證結果並不支持我們的假說。 在第二篇文章中，我們使用與Campbell et. al. (1993)相同的實證模型，討論在漲跌幅限制下，交易量與股票日報酬自我相關的關係。由於漲跌幅限制的存在，當股票價格觸及漲跌幅上下限時，即停止交易，而使得真正的股票價格無法觀察到，因而未實現之需求或供給將會傳遞至下一個交易日，將使傳統OLS或其衍生方法的估計產生偏誤，而使用Chou和Chib (1995)與Chou (1995)所提的Gibbs抽樣法則可以成功地克服這些困難。所以，本文將應用Chou和Chib (1995)與Chou (1995)的Gibbs抽樣法來衡量台灣股票市場交易量對股票日報酬自我相關係數的影響，以避免漲跌幅限制的影響。本文採用台灣證交所編製的綜合股價指數所採樣的二十四家公司為樣本，利用日資料進行實證分析，實證結果支持「交易量效果」的存在。且在實證過程中，發現台灣股票市場股票日報酬的正自我相關有可能是漲跌幅限制的存在而造成的。

This thesis examines product innovation processes in small established enterprises. The research questions are: (1) what motivates small established enterprises to innovate, (2) how do small established enterprises perform product innovation, and (3) how do small established enterprises manage resource scarcity in their product innovation processes? To answer the research questions, a multiple case study approach was chosen with three small established enterprises as cases and different product innovation processes as embedded units of study. The data collection method used was observation during a period of five months, complemented by interviews and secondary data. Product innovation in small established enterprises seems to be motivated by solving existing customers’ problems and the need for a sustained steady cash flow. A steady cash flow is also found to be a prerequisite during the product innovation processes. Product innovation seems to occur when there is a risk of decreased cash flow and/or when existing customers can be satisfied with new products that increase their loyalty so as to secure future sales, cash flow, and the enterprise’s survival in the long run. Promising innovation ideas alone do not result in product innovation. An innovation idea must also have supportive existing customers for product innovation to occur. Product innovation processes in the studied small established enterprises are found highly context dependent, intertwined in operational processes and made possible by a small organic organization and closeness to existing customers. The product innovation processes are further found to follow a flexible and informal overall scheme optimized for decreasing market and technology uncertainty and risk, dealing with resource scarcity, and facilitating fast and easy commercialization to avoid or moderate dips in cash flow. The design processes within the innovation processes can be linearly structured or cyclical and experimental, depending on the experienced novelty. To manage resource scarcity during the product innovation processes, the studied small enterprises used many different bootstrapping methods in combination. These methods can be divided into three categories according to their overall functions: for using existing resources more efficiently, for increasing resources and to secure a fast payback on resources invested in NPD. The studied small enterprises were due to their resource scarcity further found to favor an innovation strategy, only involving new products done with known technology and targeting existing markets. This way to innovate, which creates new products in a resource-efficient way that are accepted by the enterprises’ existing markets, seems to prevent unsuccessful product innovation, while at the same time excluding technologically radical innovation and innovation targeting new markets. / <p>QC 20140102</p>

The three chapters of this thesis investigate social aspects of judgment and decision making. Chapter One analyses the consequences of making decisions based on predictions of future well-being, and the conditions under which advice can improve these decisions. It shows that an interaction between errors in affective forecasts and the choice process leads to suboptimal decisions and disappointment, and establishes conditions under which advice reduces these effects. The second chapter investigates the boundaries of the result that eliciting more than one estimate from the same person and averaging these can lead to accuracy gains in judgment tasks. It reveals that the technique works only for specific kinds of questions, and people are reluctant to average their initial answers when asked for a final estimate. Finally, Chapter Three reviews experimental results regarding individual and small group behaviour in strategic decision tasks and provides a theoretical framework to analyse the observed differences. / Aquesta tesi investiga diferents aspectes socials de la presa de decisions. El primer capítol analitza les decisions preses en base a les prediccions del benestar futur, i en quines situacions els consells d’altres persones poden millorar aquestes decisions. Es mostra que una interacció entre el procés de l’elecció i les imperfeccions de les prediccions condueix a decisions subòptimes i a la decepció, i s’estableixen les condicions sota les quals els consells redueixen aquests efectes. El segon capítol investigaels casos en què les persones poden millorar les seves prediccions numèriques donant més d’una estimació i prenent-ne la mitjana. A base d’un experiment, es mostra que la tècnica funciona només amb determinats tipus de preguntes, i que les persones són averses a prendre mitjanes de les seves estimacions inicials quan es pregunta per una estimació final. L’últim capítol revisa els resultats experimentals referents a la presa de decisions estratègiques de la persona individual comparats amb els de la persona que forma part d’un grup reduït i proporciona un marc teòric en el que analitza les diferències que s’observen en el seu comportament

The movements of two vervet monkey troops were studied to determine whether they optimize their rate of food intake in relation to seasonal energy availability. The effect of variation in habitat structure on the troops’ foraging strategies while utilizing temporally and spatially distributed resources was determined. Troop home range boundaries were delineated, the various plant communities and species utilised by the troops identified and classified, and variations in home range and vegetation structure were reported. The diets of the troops were determined and compared. Effects of coexistence on competition were assessed. Vervet food trees were randomly selected, marked and seasonal phenological data collected. Samples of food items constituting the two troops diets were collected for energy analysis. Using geostatistical interpolation techniques, monthly energy values were extrapolated onto home range grids for the two vervet monkey troops. Grids were stored as database files that were interrogated through GIS simulation models. Using the stochastic processes inherent in Markov chain theory, a series of non-returning random walks were simulated for comparison to original routes taken by the two troops. Results from comparisons of home range energy, day range lengths and areas, shortest route energy to actual route energy, time spent in high energy areas, and energy utilisation from actual and randomly generated routes indicated that the two troops optimize resource energy available to them by adopting flexible foraging strategies. In environments where temporal and spatial variations in habitat structure affect the distribution of resources, it is essential that animals develop optimal foraging strategies to survive. For the two troops investigated, foraging strategies fluctuate between being time minimizers in more heterogeneous environments where resources are abundant, and energy maximisers in homogeneous environments where resources are constrained by low diversity and seasonality. / Environmental Sciences (Department) / D.Litt et Phil (Environmental Management)

This thesis deals with interest rate swaps. In addition to chapters on basic principles of interest rate swaps also provides insight into the current situation in the derivative markets. The main part is devoted to the valuation of interest rate swaps, where is in addition to the theoretical site also solved the problem of obtaining the necessary data for calculations in practice. The conclusion of this work is devoted to two practical examples, which are dealing with the problem of the valuation of interest rate swaps.

The master's thesis provides a comprehensive overview of resampling methods for testing the correctness topology of the phylogenetic trees which estimate the process of phylogeny on the bases of biological sequences similarity. We focused on the possibility of errors creation in this estimate and the possibility of their removal and detection. These methods were implemented in Matlab for Bootstrapping, jackknifing, OTU jackknifing and PTP test (Permutation tail probability). The work aims to test their applicability to various biological sequences and also to assess the impact of the choice of input analysis parameters on the results of these statistical tests.