Context and time dependent risk based decision making

As there is a lack of central management in an ecommerce interaction carried out based on peer-to-peer architecture, it is obvious for the trusting peer to analyze the Risk beforehand that could be involved in dealing with a trusted peer in these types of interactions. Another characteristic of peer-to-peer architecture interactions is that the trusting peer might have to choose a peer to interact with, from a set of possible trusted peers. It can ease its decision making process of choosing a peer to interact with by analyzing the Risk that could be involved in dealing with each of the possible trusted peers. In this paper we highlight and propose a solution to this problem by which the trusting peer can decide with which peer to interact with after analyzing the Risk that could be associated in dealing with each of them

Intolerance of uncertainty and impulsivity in opioid dependency

Opioid abuse has reached epidemic status in the United States, and opioids are the leading cause of drug-related deaths in Australia and worldwide. One factor that has not received attention in the addiction literature is intolerance of uncertainty (IU). IU is personality trait characterised by exaggerated negative beliefs about uncertainty and its consequences. This thesis investigates the links between IU and impulsive decision-making in the context of opioid-dependency. Four experimental studies examined impulsive decision-making from multiple perspectives, and assessed for the first time how impulsivity interacts with IU in opioid-dependent individuals. Across all four studies, opioid-dependent adults reported markedly higher levels of IU compared to a healthy control group. This consistent result provides strong evidence that IU is a personality trait that is related to drug addiction, whether it may be a pre-morbid risk factor, a result of chronic drug use or a co-occurring phenomenon based on shared neural correlates. A common thread between studies was that IU and impulsivity were meaningfully related in opioid-dependent individuals, but not in control groups. Specifically, IU was correlated with self-reported impulsive personality traits, poor attentional control, risk taking for monetary losses and risk-aversion for health improvements. No meaningful correlations were found between IU and impulsivity in control participants. These findings have important implications for addiction prevention and therapy. It is commonly accepted that pharmaceutical opioids are a driving factor for the upsurge in heroin abuse, and IU may be helpful to screen for at-risk individuals. Furthermore, addiction treatment could benefit by addressing IU in order to improve faulty beliefs about and reactions to uncertainty

Understanding the Health Beliefs of First Time Mothers who Request an Elective Cesarean versus Mothers who Request a Vaginal Delivery

Little is known about how the decision for elective cesarean section comes about in the clinical environment. A prospective longitudinal study based on the Health Belief Model was conducted about first time mothers’ decision making processes and their health beliefs which led to their satisfaction with their decision about their mode of delivery. A convenience sample of 144 nulliparous women with singleton pregnancies and no medical indications requiring a cesarean delivery were recruited using internet based informational notices and with flyers. Women (n = 127) planning a vaginal delivery (VDMR) represented 88.2% of the sample and women (n = 17) requesting a cesarean delivery (CDMR) represented 11.8% of the sample. Data were collected during the third trimester and six weeks after the delivery using an internet-based questionnaire. Data were analyzed using t-tests and multiple linear regression to predict the effect of maternal health beliefs, maternal childbirth self efficacy, partner support, acceptance of the maternal role, and request group (VDMR vs. CDMR) on the dependent variables of maternal perception of the delivery and maternal satisfaction with her decision for the mode of delivery. Compared to women with VDMR, women with CDMR were significantly older, less educated, perceived more risk of emergent cesarean and less ability to deliver vaginally. Hypothesis testing indicated that the overall regression model did not significantly predict maternal perception of the delivery. The model accounted for a significant amount (15.1 %) of the variance in maternal satisfaction with the decision for mode of delivery. Acceptance of the maternal role and maternal request group significantly contributed to the model indicating that women with higher acceptance of the maternal role and women with CDMR had poorer satisfaction with their decision for the mode of delivery. The findings showed that factors influencing maternal perceptions of the delivery and satisfaction with the mode of delivery are different. Health beliefs had less relevance for perception of the delivery. It is possible that experiences that occur within the context of the delivery are more salient for maternal perception. Women with higher acceptance of the maternal role and who request a cesarean delivery are at risk for less satisfaction with their delivery decision and more decisional conflict and thus may need more support during decision-making processes and after delivery. Future research should examine the long-term impact of dissatisfaction with delivery decision on maternal outcomes

On risk-based decision-making for structural health monitoring

Structural health monitoring (SHM) technologies seek to detect, localise, and characterise damage present within structures and infrastructure. Arguably, the foremost incentive for developing and implementing SHM systems is to improve the quality of operation and maintenance (O&M) strategies for structures, such that safety can be enhanced, or greater economic benefits can be realised. Given this motivation, SHM systems can be considered primarily as decision-support tools. Although much research has been conducted into damage identification and characterisation approaches, there has been relatively little that has explicitly considered the decision-making applications of SHM systems. In light of this fact, the current thesis seeks to consider decision-making for SHM with respect to risk. Risk, defined as a product of probability and cost, can be interpreted as an expected utility. The keystone of the current thesis is a general framework for conducting risk-based, SHM generated by combining aspects of probabilistic risk assessment (PRA) with the existing statistical pattern recognition paradigm for SHM. The framework, founded on probabilistic graphical models (PGMs), utilises Bayesian network representations of fault-trees to facilitate the flow of information between observations of discriminative features to failure states of structures of interest. Using estimations of failure probabilities in conjunction with utility functions that capture the severity of consequences enables risk assessments -- these risks can be minimised with respect to candidate maintenance actions to determine optimal strategies. Key elements of the decision framework are examined; in particular, a physics-based methodology for initialising a structural degradation model defining health-state transition probabilities is presented. The risk-based framework allows aspects of SHM systems to be developed with explicit consideration for the decision-support applications. In relation to this aim, the current thesis proposes a novel approach to learn statistical classification models within an online SHM system. The approach adopts an active learning framework in which descriptive labels, corresponding to salient health states of a structure, are obtained via structural inspections. To account for the decision processes associated with SHM, structural inspections are mandated according to the expected value of information for data-labels. The resulting risk-based active learning algorithm is shown to yield cost-effective improvements in the performance of decision-making agents, in addition to reducing the number of manual inspections made over the course of a monitoring campaign. Characteristics of the risk-based active learning algorithm are further investigated, with particular focus on the effects of \sampling bias. Sampling bias is known to degrade decision-making performance over time, thus engineers have a vested interest in mitigating its negative effects. On this theme, two approaches are considered for improving risk-based active learning; semi-supervised learning, and discriminative classification models. Semi-supervised learning yielded mixed results, with performance being highly dependent on base distributions being representative of the underlying data. On the other hand, discriminative classifiers performed strongly across the board. It is shown that by mitigating the negative effects of sampling bias via classifier and algorithm design, decision-support systems can be enhanced, resulting in more cost-effective O&M strategies. Finally, the future of risk-based decision-making is considered. Particular attention is given to population-based structural health monitoring (PBSHM), and the management of fleets of assets. The hierarchical representation of structures used to develop the risk-based SHM framework is extended to populations of structures. Initial research into PBSHM shows promising results with respect to the transfer of information between individual structures comprising a population. The significance of these results in the context of decision-making is discussed. To summarise, by framing SHM systems as decision-support tools, risk-informed O&M strategies can be developed for structures and infrastructure such that safety is improved and costs are reduced

Spatial planning and urban resilience in the context of flood risk

Spatial planning is increasingly being considered as an important mechanism in coping with flood risk due to climate change. One of the reasons for this is that engineering approaches are increasingly expensive and cannot provide complete certainty of protection against climate-related floods. The thesis examines whether and how spatial planning is used in urban areas to promote resilience to flood risk and climate change. In this study, planning is considered as the regulation of physical implementation as well as the process of policy-making that guides spatial development. This process mainly involves the interaction and collaboration between actors (both public and private). The notion of resilience is being used more and more in discussions of complex issues like the impact of climate-related flood risks on spatial development. The interpretations of resilience can vary significantly depending on the local context, the focus of spatial development and the interests of the actors involved in decision- making. The study proposes six characteristics of planning decision-making that can help to promote the resilience of cities. These comprise: (i) considering the current situation, (ii) examining trends and future threats, (iii) learning from previous experience, (iv) setting goals, (v) initiating actions, and (vi) involving the public. The importance of these characteristics over time for policy and practice is examined according to empirical evidence from detailed case study analysis. Six case studies are presented, four in Taiwan and two in the Netherlands. In all of the case studies, the issue of flood risk and spatial development is considered important by policy- makers, but the planning strategies used to tackle climate-related flood risks are often different, as are the experiences of flooding and governance arrangements. The information gathered is primarily based on interviews and the review of planning policies, government reports and research documents. Comparative analysis is a central focus of the study. The analysis has both a national and international perspective, comparing cases within Taiwan and between Taiwan and the Netherlands. The national comparison examines the way in which local planning governance is addressed in shaping decisions to deal with flood risks. This can vary among cases which share similar spatial development objectives and national institutional framework. The international comparison between Taiwan and the Netherlands examines the roles of planning to promote urban resilience in the context of flood risk and climate change. Three conclusions can be drawn. First, the interpretation of resilience is dependent on the views and interests of the actors involved. These change over time and can be seen in different episodes of policy-making. Second, the importance of the different assessment characteristics varies from one case to another. The interests of the leading actors, the interpretations of flood risks and the framework of local collaboration are all major factors that shape these differences. These factors are often associated with planning traditions and relatively stable in resistant to change. Third, when there is a collaborative framework for planning involving multiple actors, the result is a more comprehensive set of strategies in dealing with flood risk

Spatial planning and urban resilience in the context of flood risk

Spatial planning is increasingly being considered as an important mechanism in coping with flood risk due to climate change. One of the reasons for this is that engineering approaches are increasingly expensive and cannot provide complete certainty of protection against climate-related floods. The thesis examines whether and how spatial planning is used in urban areas to promote resilience to flood risk and climate change. In this study, planning is considered as the regulation of physical implementation as well as the process of policy-making that guides spatial development. This process mainly involves the interaction and collaboration between actors (both public and private). The notion of resilience is being used more and more in discussions of complex issues like the impact of climate-related flood risks on spatial development. The interpretations of resilience can vary significantly depending on the local context, the focus of spatial development and the interests of the actors involved in decision- making. The study proposes six characteristics of planning decision-making that can help to promote the resilience of cities. These comprise: (i) considering the current situation, (ii) examining trends and future threats, (iii) learning from previous experience, (iv) setting goals, (v) initiating actions, and (vi) involving the public. The importance of these characteristics over time for policy and practice is examined according to empirical evidence from detailed case study analysis. Six case studies are presented, four in Taiwan and two in the Netherlands. In all of the case studies, the issue of flood risk and spatial development is considered important by policy- makers, but the planning strategies used to tackle climate-related flood risks are often different, as are the experiences of flooding and governance arrangements. The information gathered is primarily based on interviews and the review of planning policies, government reports and research documents. Comparative analysis is a central focus of the study. The analysis has both a national and international perspective, comparing cases within Taiwan and between Taiwan and the Netherlands. The national comparison examines the way in which local planning governance is addressed in shaping decisions to deal with flood risks. This can vary among cases which share similar spatial development objectives and national institutional framework. The international comparison between Taiwan and the Netherlands examines the roles of planning to promote urban resilience in the context of flood risk and climate change. Three conclusions can be drawn. First, the interpretation of resilience is dependent on the views and interests of the actors involved. These change over time and can be seen in different episodes of policy-making. Second, the importance of the different assessment characteristics varies from one case to another. The interests of the leading actors, the interpretations of flood risks and the framework of local collaboration are all major factors that shape these differences. These factors are often associated with planning traditions and relatively stable in resistant to change. Third, when there is a collaborative framework for planning involving multiple actors, the result is a more comprehensive set of strategies in dealing with flood risk

Spatial planning and urban resilience in the context of flood risk

Spatial planning is increasingly being considered as an important mechanism in coping with flood risk due to climate change. One of the reasons for this is that engineering approaches are increasingly expensive and cannot provide complete certainty of protection against climate-related floods. The thesis examines whether and how spatial planning is used in urban areas to promote resilience to flood risk and climate change. In this study, planning is considered as the regulation of physical implementation as well as the process of policy-making that guides spatial development. This process mainly involves the interaction and collaboration between actors (both public and private). The notion of resilience is being used more and more in discussions of complex issues like the impact of climate-related flood risks on spatial development. The interpretations of resilience can vary significantly depending on the local context, the focus of spatial development and the interests of the actors involved in decision- making. The study proposes six characteristics of planning decision-making that can help to promote the resilience of cities. These comprise: (i) considering the current situation, (ii) examining trends and future threats, (iii) learning from previous experience, (iv) setting goals, (v) initiating actions, and (vi) involving the public. The importance of these characteristics over time for policy and practice is examined according to empirical evidence from detailed case study analysis. Six case studies are presented, four in Taiwan and two in the Netherlands. In all of the case studies, the issue of flood risk and spatial development is considered important by policy- makers, but the planning strategies used to tackle climate-related flood risks are often different, as are the experiences of flooding and governance arrangements. The information gathered is primarily based on interviews and the review of planning policies, government reports and research documents. Comparative analysis is a central focus of the study. The analysis has both a national and international perspective, comparing cases within Taiwan and between Taiwan and the Netherlands. The national comparison examines the way in which local planning governance is addressed in shaping decisions to deal with flood risks. This can vary among cases which share similar spatial development objectives and national institutional framework. The international comparison between Taiwan and the Netherlands examines the roles of planning to promote urban resilience in the context of flood risk and climate change. Three conclusions can be drawn. First, the interpretation of resilience is dependent on the views and interests of the actors involved. These change over time and can be seen in different episodes of policy-making. Second, the importance of the different assessment characteristics varies from one case to another. The interests of the leading actors, the interpretations of flood risks and the framework of local collaboration are all major factors that shape these differences. These factors are often associated with planning traditions and relatively stable in resistant to change. Third, when there is a collaborative framework for planning involving multiple actors, the result is a more comprehensive set of strategies in dealing with flood risk

Preferences under risk: content-dependent behavior and psychological processing

A common view in economics and psychology is that decision agents achieve their choices and express their respective preferences by computing probabilistic properties (probabilities and money) from a decisionmaking context (e.g., von Neumann and Morgenstern, 1947; Tversky and Kahneman, 1992; Starmer, 2000). In this computational processing, the main psychological mechanism requires that decision agents are able to integrate economic (contextual) attributes such as money and probabilities into subjective values; in other words people are able to construct and employ psycho-economic scales. Subsequently, when making a choice, decision agents are supposed to perform tradeoffs between the computed outputs (psycho-economic variables such as expected values) and certain monetary alternatives (see Kahneman and Tversky, 1979; Tversky and Kahneman, 1992

Manipulating the contribution of approach-avoidance to the perturbation of economic choice by valence.

Economic choices are strongly influenced by whether potential outcomes entail gains or losses. We examined this influence of outcome valence in an economic risk task. We employed three experiments based on our task, each of which provided novel findings, and which together better characterize and explain how outcome valence influences risky choice. First, we found that valence perturbed an individual's choices around that individual's base-level of risk-taking, a base-level consistent across time, and context. Second, this perturbation by valence was highly context dependent, emerging when valence was introduced as a dimension within a decision-making setting, and being reversed by a change in task format (causing more gambling for gains than losses and the reverse). Third, we show this perturbation by valence is explicable by low-level approach-avoidance processes, an hypothesis not previously tested by a causal manipulation. We revealed such an effect, where individuals were less disposed to choose a riskier option with losses when they had to approach (go) as opposed to avoid (nogo) that option. Our data show valence perturbs an individual's choices independently of the impact of risk, and causally implicate approach-avoidance processes as important in shaping economic choice

Die Rolle der Zielnähe und der investierten Anstrengung für den erwarteten Wert einer Handlung

In human neuroscientific research, there has been an increasing interest in how the brain computes the value of an anticipated outcome. However, evidence is still missing about which valuation related brain regions are modulated by the proximity to an expected goal and the previously invested effort to reach a goal. The aim of this dissertation is to investigate the effects of goal proximity and invested effort on valuation related regions in the human brain. We addressed this question in two fMRI studies by integrating a commonly used reward anticipation task in differential versions of a Multitrial Reward Schedule Paradigm. In both experiments, subjects had to perform consecutive reward anticipation tasks under two different reward contingencies: in the delayed condition, participants received a monetary reward only after successful completion of multiple consecutive trials. In the immediate condition, money was earned after every successful trial. In the first study, we could demonstrate that the rostral cingulate zone of the posterior medial frontal cortex signals action value contingent to goal proximity, thereby replicating neurophysiological findings about goal proximity signals in a homologous region in non-human primates. The findings of the second study imply that brain regions associated with general cognitive control processes are modulated by previous effort investment. Furthermore, we found the posterior lateral prefrontal cortex and the orbitofrontal cortex to be involved in coding for the effort-based context of a situation. In sum, these results extend the role of the human rostral cingulate zone in outcome evaluation to the continuous updating of action values over a course of action steps based on the proximity to the expected reward. Furthermore, we tentatively suggest that previous effort investment invokes processes under the control of the executive system, and that posterior lateral prefrontal cortex and the orbitofrontal cortex are involved in an effort-based context representation that can be used for outcome evaluation that is dependent on the characteristics of the current situation.Derzeit besteht im Bereich der Neurowissenschaften ein großes Interesse daran aufzuklären, auf welche Weise verschiedene Variablen die Wertigkeit eines erwarteten Handlungsziels beeinflussen bzw. welche Hirnregionen an der Repräsentation der Wertigkeit eines Handlungsziels beteiligt sind. Die meisten Untersuchungen beziehen sich dabei auf Einflussgrößen wie die erwartete Belohnungshöhe, die Wahrscheinlichkeit, mit der ein bestimmtes Ereignis eintritt, oder die Dauer bis zum Erhalt einer Belohnung. Bisher liegen jedoch kaum Untersuchungen vor bezüglich zweier anderer Variablen, die ebenfalls den erwarteten Wert eines Handlungsergebnisses beeinflussen. Das sind (a) die Nähe zu dem erwarteten Ziel und (b) die bisher investierte Anstrengung, um ein Ziel zu erreichen. Das Ziel der vorliegenden Dissertation ist zu untersuchen, wie die Nähe zum Ziel und die bisher investierte Anstrengung Gehirnregionen beeinflussen, die mit der Repräsentation von Wertigkeit im Zusammenhang stehen. Dazu führten wir zwei fMRT-Studien durch, in denen wir eine klassische Belohnungs-Antizipationsaufgabe in unterschiedliche Versionen eines „Multitrial Reward Schedule“ Paradigmas integriert haben. Das bedeutet, dass die Probanden Belohnungs-Antizipationsaufgaben unter zwei unterschiedlichen Belohnungskontingenzen bearbeiteten: In der verzögerten Bedingung erhielten die Probanden einen Geldbetrag nach der erfolgreichen Bearbeitung von mehreren aufeinanderfolgenden Aufgaben, in der direkten Bedingung dagegen nach jeder korrekt ausgeführten Aufgabe. In der ersten Studie konnte eine sukzessiv ansteigende Aktivität in Abhängigkeit zur Zielnähe in der rostralen cingulären Zone identifiziert werden. Das deutet darauf hin, dass dieses Areal den Wert einer Handlung in Abhängigkeit zur Nähe zum Ziel kodiert. Die Ergebnisse der zweiten Studie zeigten, dass die bisher investierte Anstrengung kortikale Regionen moduliert, die klassischerweise mit kognitiven Kontrollfunktionen in Zusammenhang gebracht werden. Außerdem repräsentierten der posteriore laterale präfrontale Cortex und der orbitofrontale Cortex den motivationalen Kontext eines Trials anhand des Risikos des Verlustes von bisher investierter Anstrengung. Insgesamt weisen diese Befunde darauf hin, dass die rostrale cinguläre Zone eine entscheidende Rolle spielt für die Kontrolle sequenzieller Handlungsstufen, die auf eine verzögerte Belohnung ausgerichtet sind. Diese Kontrollfunktion scheint auf der kontinuierlichen Aktualisierung des Wertes einer Handlungsstufe zu basieren, der von der aktuellen Zielnähe bestimmt wird. Die Befunde der zweiten Studie lassen darauf schließen, dass sich die bisher investierte Anstrengung zur Erreichung eines Handlungsziels auf die Bereitstellung von allgemeinen kognitiven Ressourcen auswirkt. Das Risiko des Verlustes von bisher investierter Anstrengung kann außerdem ein kontextuelles Merkmal der Situation darstellen, das als Bezugsrahmen für die Evaluation des erwarteten Wertes dienen kann