Stochastic quantization of the spherical model and supersymmetry.

In this work, we reported some results about the stochastic quantization of the spherical model. We started by reviewing some basic aspects of this method with emphasis in the connection between the Langevin equation and the supersymmetric quantum mechanics, aiming at the application of the corresponding connection to the spherical model. An intuitive idea is that when applied to the spherical model this gives rise to a supersymmetric version that is identified with one studied in Phys. Rev. E 85, 061109, (2012). Before investigating in detail this aspect, we studied the stochastic quantization of the mean spherical model that is simpler to implement than the one with the strict constraint. We also highlight some points concerning more traditional methods discussed in the literature like canonical and path integral quantization. To produce a supersymmetric version, grounded in the Nicolai map, we investigated the stochastic quantization of the strict spherical model. We showed in fact that the result of this process is an off-shell supersymmetric extension of the quantum spherical model (with the precise supersymmetric constraint structure). That analysis establishes a connection between the classical model and its supersymmetric quantum counterpart. The supersymmetric version in this way constructed is a more natural one and gives further support and motivations to investigate similar connections in other models of the literature.

Masking environmental feedback : Misfits between institutions and ecosystems in Belize and Thailand

The thesis analyses relationships between ecological and social systems in the context of coastal ecosystems. It examines human impacts from resource extraction and addresses management and governance behind resource exploitation. The main premises are that a lack of ecological knowledge leads to poor ecosystem management and that the dichotomy between social and natural systems is an artificial one. The thesis illustrates the importance of basing resource management on the ecological conditions of the resource and its ecosystem. It also demonstrates the necessity of accounting for the human dimension in ecosystem management and the challenges of organising human actions for sustainable use of ecosystem services in the face of economic incentives that push users towards short-term extraction. Many Caribbean coral reefs have undergone a shift from coral to macroalgal domination. An experiment on Glovers Reef Atoll in Belize manually cleared patch reefs in a no-take zone and a fished zone (Papers I and II). The study hypothesised that overfishing has reduced herbivorous fish populations that control macroalgae growth. Overall, management had no significant effect on fish abundance and the impacts of the algal reduction were short-lived. This illustrated that the benefits of setting aside marine reserves in impacted environments should not be taken for granted. Papers III and IV studied the development of the lobster and conch fisheries in Belize, and the shrimp farming industry in Thailand respectively. These studies found that environmental feedback can be masked to give the impression of resource abundance through sequential exploitation. In both cases inadequate property rights contributed to this unsustainable resource use. The final paper (V) compared the responses to changes in the resource by the lobster fisheries in Belize and Maine in terms of institutions, organisations and their role in management. In contrast to Maine’s, the Belize system seems to lack social mechanisms for responding effectively to environmental feedback. The results illustrate the importance of organisational and institutional diversity that incorporate ecological knowledge, respond to ecosystem feedback and provide a social context for learning from and adapting to change.

Interactive theorem provers: issues faced as a user and tackled as a developer

Interactive theorem provers (ITP for short) are tools whose final aim is to certify proofs written by human beings. To reach that objective they have to fill the gap between the high level language used by humans for communicating and reasoning about mathematics and the lower level language that a machine is able to “understand” and process. The user perceives this gap in terms of missing features or inefficiencies. The developer tries to accommodate the user requests without increasing the already high complexity of these applications. We believe that satisfactory solutions can only come from a strong synergy between users and developers. We devoted most part of our PHD designing and developing the Matita interactive theorem prover. The software was born in the computer science department of the University of Bologna as the result of composing together all the technologies developed by the HELM team (to which we belong) for the MoWGLI project. The MoWGLI project aimed at giving accessibility through the web to the libraries of formalised mathematics of various interactive theorem provers, taking Coq as the main test case. The motivations for giving life to a new ITP are: • study the architecture of these tools, with the aim of understanding the source of their complexity • exploit such a knowledge to experiment new solutions that, for backward compatibility reasons, would be hard (if not impossible) to test on a widely used system like Coq. Matita is based on the Curry-Howard isomorphism, adopting the Calculus of Inductive Constructions (CIC) as its logical foundation. Proof objects are thus, at some extent, compatible with the ones produced with the Coq ITP, that is itself able to import and process the ones generated using Matita. Although the systems have a lot in common, they share no code at all, and even most of the algorithmic solutions are different. The thesis is composed of two parts where we respectively describe our experience as a user and a developer of interactive provers. In particular, the first part is based on two different formalisation experiences: • our internship in the Mathematical Components team (INRIA), that is formalising the finite group theory required to attack the Feit Thompson Theorem. To tackle this result, giving an effective classification of finite groups of odd order, the team adopts the SSReflect Coq extension, developed by Georges Gonthier for the proof of the four colours theorem. • our collaboration at the D.A.M.A. Project, whose goal is the formalisation of abstract measure theory in Matita leading to a constructive proof of Lebesgue’s Dominated Convergence Theorem. The most notable issues we faced, analysed in this part of the thesis, are the following: the difficulties arising when using “black box” automation in large formalisations; the impossibility for a user (especially a newcomer) to master the context of a library of already formalised results; the uncomfortable big step execution of proof commands historically adopted in ITPs; the difficult encoding of mathematical structures with a notion of inheritance in a type theory without subtyping like CIC. In the second part of the manuscript many of these issues will be analysed with the looking glasses of an ITP developer, describing the solutions we adopted in the implementation of Matita to solve these problems: integrated searching facilities to assist the user in handling large libraries of formalised results; a small step execution semantic for proof commands; a flexible implementation of coercive subtyping allowing multiple inheritance with shared substructures; automatic tactics, integrated with the searching facilities, that generates proof commands (and not only proof objects, usually kept hidden to the user) one of which specifically designed to be user driven.

Uniquitous internet middleware: architecture design and prototype evaluation

Technology advances in recent years have dramatically changed the way users exploit contents and services available on the Internet, by enforcing pervasive and mobile computing scenarios and enabling access to networked resources almost from everywhere, at anytime, and independently of the device in use. In addition, people increasingly require to customize their experience, by exploiting specific device capabilities and limitations, inherent features of the communication channel in use, and interaction paradigms that significantly differ from the traditional request/response one. So-called Ubiquitous Internet scenario calls for solutions that address many different challenges, such as device mobility, session management, content adaptation, context-awareness and the provisioning of multimodal interfaces. Moreover, new service opportunities demand simple and effective ways to integrate existing resources into new and value added applications, that can also undergo run-time modifications, according to ever-changing execution conditions. Despite service-oriented architectural models are gaining momentum to tame the increasing complexity of composing and orchestrating distributed and heterogeneous functionalities, existing solutions generally lack a unified approach and only provide support for specific Ubiquitous Internet aspects. Moreover, they usually target rather static scenarios and scarcely support the dynamic nature of pervasive access to Internet resources, that can make existing compositions soon become obsolete or inadequate, hence in need of reconfiguration. This thesis proposes a novel middleware approach to comprehensively deal with Ubiquitous Internet facets and assist in establishing innovative application scenarios. We claim that a truly viable ubiquity support infrastructure must neatly decouple distributed resources to integrate and push any kind of content-related logic outside its core layers, by keeping only management and coordination responsibilities. Furthermore, we promote an innovative, open, and dynamic resource composition model that allows to easily describe and enforce complex scenario requirements, and to suitably react to changes in the execution conditions.

Technical innovations for the diagnosis and the rehabilitation of motor and perceptive impairments of the child with Cerebral Palsy

The treatment of the Cerebral Palsy (CP) is considered as the “core problem” for the whole field of the pediatric rehabilitation. The reason why this pathology has such a primary role, can be ascribed to two main aspects. First of all CP is the form of disability most frequent in childhood (one new case per 500 birth alive, (1)), secondarily the functional recovery of the “spastic” child is, historically, the clinical field in which the majority of the therapeutic methods and techniques (physiotherapy, orthotic, pharmacologic, orthopedic-surgical, neurosurgical) were first applied and tested. The currently accepted definition of CP – Group of disorders of the development of movement and posture causing activity limitation (2) – is the result of a recent update by the World Health Organization to the language of the International Classification of Functioning Disability and Health, from the original proposal of Ingram – A persistent but not unchangeable disorder of posture and movement – dated 1955 (3). This definition considers CP as a permanent ailment, i.e. a “fixed” condition, that however can be modified both functionally and structurally by means of child spontaneous evolution and treatments carried out during childhood. The lesion that causes the palsy, happens in a structurally immature brain in the pre-, peri- or post-birth period (but only during the firsts months of life). The most frequent causes of CP are: prematurity, insufficient cerebral perfusion, arterial haemorrhage, venous infarction, hypoxia caused by various origin (for example from the ingestion of amniotic liquid), malnutrition, infection and maternal or fetal poisoning. In addition to these causes, traumas and malformations have to be included. The lesion, whether focused or spread over the nervous system, impairs the whole functioning of the Central Nervous System (CNS). As a consequence, they affect the construction of the adaptive functions (4), first of all posture control, locomotion and manipulation. The palsy itself does not vary over time, however it assumes an unavoidable “evolutionary” feature when during growth the child is requested to meet new and different needs through the construction of new and different functions. It is essential to consider that clinically CP is not only a direct expression of structural impairment, that is of etiology, pathogenesis and lesion timing, but it is mainly the manifestation of the path followed by the CNS to “re”-construct the adaptive functions “despite” the presence of the damage. “Palsy” is “the form of the function that is implemented by an individual whose CNS has been damaged in order to satisfy the demands coming from the environment” (4). Therefore it is only possible to establish general relations between lesion site, nature and size, and palsy and recovery processes. It is quite common to observe that children with very similar neuroimaging can have very different clinical manifestations of CP and, on the other hand, children with very similar motor behaviors can have completely different lesion histories. A very clear example of this is represented by hemiplegic forms, which show bilateral hemispheric lesions in a high percentage of cases. The first section of this thesis is aimed at guiding the interpretation of CP. First of all the issue of the detection of the palsy is treated from historical viewpoint. Consequently, an extended analysis of the current definition of CP, as internationally accepted, is provided. The definition is then outlined in terms of a space dimension and then of a time dimension, hence it is highlighted where this definition is unacceptably lacking. The last part of the first section further stresses the importance of shifting from the traditional concept of CP as a palsy of development (defect analysis) towards the notion of development of palsy, i.e., as the product of the relationship that the individual however tries to dynamically build with the surrounding environment (resource semeiotics) starting and growing from a different availability of resources, needs, dreams, rights and duties (4). In the scientific and clinic community no common classification system of CP has so far been universally accepted. Besides, no standard operative method or technique have been acknowledged to effectively assess the different disabilities and impairments exhibited by children with CP. CP is still “an artificial concept, comprising several causes and clinical syndromes that have been grouped together for a convenience of management” (5). The lack of standard and common protocols able to effectively diagnose the palsy, and as a consequence to establish specific treatments and prognosis, is mainly because of the difficulty to elevate this field to a level based on scientific evidence. A solution aimed at overcoming the current incomplete treatment of CP children is represented by the clinical systematic adoption of objective tools able to measure motor defects and movement impairments. A widespread application of reliable instruments and techniques able to objectively evaluate both the form of the palsy (diagnosis) and the efficacy of the treatments provided (prognosis), constitutes a valuable method able to validate care protocols, establish the efficacy of classification systems and assess the validity of definitions. Since the ‘80s, instruments specifically oriented to the analysis of the human movement have been advantageously designed and applied in the context of CP with the aim of measuring motor deficits and, especially, gait deviations. The gait analysis (GA) technique has been increasingly used over the years to assess, analyze, classify, and support the process of clinical decisions making, allowing for a complete investigation of gait with an increased temporal and spatial resolution. GA has provided a basis for improving the outcome of surgical and nonsurgical treatments and for introducing a new modus operandi in the identification of defects and functional adaptations to the musculoskeletal disorders. Historically, the first laboratories set up for gait analysis developed their own protocol (set of procedures for data collection and for data reduction) independently, according to performances of the technologies available at that time. In particular, the stereophotogrammetric systems mainly based on optoelectronic technology, soon became a gold-standard for motion analysis. They have been successfully applied especially for scientific purposes. Nowadays the optoelectronic systems have significantly improved their performances in term of spatial and temporal resolution, however many laboratories continue to use the protocols designed on the technology available in the ‘70s and now out-of-date. Furthermore, these protocols are not coherent both for the biomechanical models and for the adopted collection procedures. In spite of these differences, GA data are shared, exchanged and interpreted irrespectively to the adopted protocol without a full awareness to what extent these protocols are compatible and comparable with each other. Following the extraordinary advances in computer science and electronics, new systems for GA no longer based on optoelectronic technology, are now becoming available. They are the Inertial and Magnetic Measurement Systems (IMMSs), based on miniature MEMS (Microelectromechanical systems) inertial sensor technology. These systems are cost effective, wearable and fully portable motion analysis systems, these features gives IMMSs the potential to be used both outside specialized laboratories and to consecutive collect series of tens of gait cycles. The recognition and selection of the most representative gait cycle is then easier and more reliable especially in CP children, considering their relevant gait cycle variability. The second section of this thesis is focused on GA. In particular, it is firstly aimed at examining the differences among five most representative GA protocols in order to assess the state of the art with respect to the inter-protocol variability. The design of a new protocol is then proposed and presented with the aim of achieving gait analysis on CP children by means of IMMS. The protocol, named ‘Outwalk’, contains original and innovative solutions oriented at obtaining joint kinematic with calibration procedures extremely comfortable for the patients. The results of a first in-vivo validation of Outwalk on healthy subjects are then provided. In particular, this study was carried out by comparing Outwalk used in combination with an IMMS with respect to a reference protocol and an optoelectronic system. In order to set a more accurate and precise comparison of the systems and the protocols, ad hoc methods were designed and an original formulation of the statistical parameter coefficient of multiple correlation was developed and effectively applied. On the basis of the experimental design proposed for the validation on healthy subjects, a first assessment of Outwalk, together with an IMMS, was also carried out on CP children. The third section of this thesis is dedicated to the treatment of walking in CP children. Commonly prescribed treatments in addressing gait abnormalities in CP children include physical therapy, surgery (orthopedic and rhizotomy), and orthoses. The orthotic approach is conservative, being reversible, and widespread in many therapeutic regimes. Orthoses are used to improve the gait of children with CP, by preventing deformities, controlling joint position, and offering an effective lever for the ankle joint. Orthoses are prescribed for the additional aims of increasing walking speed, improving stability, preventing stumbling, and decreasing muscular fatigue. The ankle-foot orthosis (AFO), with a rigid ankle, are primarily designed to prevent equinus and other foot deformities with a positive effect also on more proximal joints. However, AFOs prevent the natural excursion of the tibio-tarsic joint during the second rocker, hence hampering the natural leaning progression of the whole body under the effect of the inertia (6). A new modular (submalleolar) astragalus-calcanear orthosis, named OMAC, has recently been proposed with the intention of substituting the prescription of AFOs in those CP children exhibiting a flat and valgus-pronated foot. The aim of this section is thus to present the mechanical and technical features of the OMAC by means of an accurate description of the device. In particular, the integral document of the deposited Italian patent, is provided. A preliminary validation of OMAC with respect to AFO is also reported as resulted from an experimental campaign on diplegic CP children, during a three month period, aimed at quantitatively assessing the benefit provided by the two orthoses on walking and at qualitatively evaluating the changes in the quality of life and motor abilities. As already stated, CP is universally considered as a persistent but not unchangeable disorder of posture and movement. Conversely to this definition, some clinicians (4) have recently pointed out that movement disorders may be primarily caused by the presence of perceptive disorders, where perception is not merely the acquisition of sensory information, but an active process aimed at guiding the execution of movements through the integration of sensory information properly representing the state of one’s body and of the environment. Children with perceptive impairments show an overall fear of moving and the onset of strongly unnatural walking schemes directly caused by the presence of perceptive system disorders. The fourth section of the thesis thus deals with accurately defining the perceptive impairment exhibited by diplegic CP children. A detailed description of the clinical signs revealing the presence of the perceptive impairment, and a classification scheme of the clinical aspects of perceptual disorders is provided. In the end, a functional reaching test is proposed as an instrumental test able to disclosure the perceptive impairment. References 1. Prevalence and characteristics of children with cerebral palsy in Europe. Dev Med Child Neurol. 2002 Set;44(9):633-640. 2. Bax M, Goldstein M, Rosenbaum P, Leviton A, Paneth N, Dan B, et al. Proposed definition and classification of cerebral palsy, April 2005. Dev Med Child Neurol. 2005 Ago;47(8):571-576. 3. Ingram TT. A study of cerebral palsy in the childhood population of Edinburgh. Arch. Dis. Child. 1955 Apr;30(150):85-98. 4. Ferrari A, Cioni G. The spastic forms of cerebral palsy : a guide to the assessment of adaptive functions. Milan: Springer; 2009. 5. Olney SJ, Wright MJ. Cerebral Palsy. Campbell S et al. Physical Therapy for Children. 2nd Ed. Philadelphia: Saunders. 2000;:533-570. 6. Desloovere K, Molenaers G, Van Gestel L, Huenaerts C, Van Campenhout A, Callewaert B, et al. How can push-off be preserved during use of an ankle foot orthosis in children with hemiplegia? A prospective controlled study. Gait Posture. 2006 Ott;24(2):142-151.

Donor-Akzeptor-substituierte Oligo(phenylenethinylen)e und Oligo(thienylenethinylen)e

Die Dissertation beschäftigt sich mit der Synthese und den Eigenschaftsuntersuchungen von Oligo(phenylenethinylen)en (OPEs) und Oligo(thienylenethinylen)en (OTEs) mit terminaler Donor-Akzeptor-Substitution. Die Darstellung der Oligomerenreihen erfolgt über ein „Baukastensystem“ bestehend aus Start,- Synthese, - und dem jeweiligen Endbaustein. Die zentrale Synthesereaktion zum Aufbau der Push-Pull-Systeme ist eine moderne und effektive Pd-katalysierte Reaktion, die Sonogashira-Hagihara-Kupplung. Für die dialkylaminosubstituierten OPE-Systeme konnten die Cyano,- Formyl,- Nitro –und Dicyanovinylgruppe als Akzeptoren eingeführt werden. In der dodecylsulfanylsubstituierten OTE-Serie wurde als Akzeptor die Nitrogruppe verwendet, während in der methoxysubstituierten OTE-Reihe die Formyl,- Nitro –und Dicyanovinylgruppe als Akzeptoren eingeführt wurde. Alle Reihen konnten mittels 1H-, 13C-, IR-, MS- und UV/Vis-Spektroskopie vollständig charakterisiert werden. Die Lage des langwelligen Absorptionsmaximums zeigt eine starke Abhängigkeit von der Donor- und Akzeptorstärke der Substituenten sowie von der Länge des konjugierten Pie-Systems. Für beide Pie-Systeme ergibt sich bei hinreichend starker Donor- und Akzeptorsubstitution eine ungewöhnliche hypsochrome Verschiebung der langwelligen Absorptionsmaxima. Mit Hilfe der semiempirischen Quantenmechanik wird ein Modell vorgestellt, das die ungewöhnlichen spektroskopischen Eigenschaften der OPEs und OTEs erklären und vorhersagen kann. Mittels elektrooptischer Absorptionsmessungen ( EOAM ), EFISHG-Messungen sowie der Frequenzverdreifachungsspektroskopie ( THG ) werden die NLO-Eigenschaften in Abhängigkeit von der Konjugationslänge der nitrosubstituierten OPE-Serie bestimmt.

Conjugated semiconducting organic materials for electronic applications

Since conjugated polymers, i.e. polymers with spatially extended pi-bonding system have offered unique physical properties, unobtainable for conventional polymers, significant research efforts directed to better understanding of their chemistry, physics and engineering have been undertaken in the past two and half decades. In this thesis we discuss the synthesis, characterisation and investigation of conjugated semiconducting organic materials for electronic applications. Owing to the versatile properties of metal-organic hybrid materials, there is significant promise that these materials can find use in optical or electronic devices in the future. In addressing this issue, the synthesis of bisthiazol-2-yl-amine (BTA) based polymers is attempted and their metallation is investigated. The focus of this work has been to examine whether the introduction of coordinating metal ions onto the polymer backbone can enhance the conductivity of the material. These studies can provide a basis for understanding the photophysical properties of metal-organic polymers based on BTA. In their neutral (undoped) form conjugated polymers are semiconductors and can be used as active components of plastics electronics such as polymer light-emitting diodes, polymer lasers, photovoltaic cells, field-effect transistors, etc. Toward this goal, it is an objective of the study to synthesize and characterize new classes of luminescent polymeric materials based on anthracene and phenanthrene moieties. A series of materials based on polyphenylenes and poly(phenyleneethynylene)s with 9,10-anthrylene subunits are not only presented but the synthesis and characterization of step-ladder and ladder poly(p-phenylene-alt-anthrylene)s containing 9,10-anthrylene building groups within the main chain are also explored. In a separate work, a series of soluble poly-2,7- and 3,6-phenanthrylenes are synthesized. This can enable us to do a systematic investigation into the optical and electronic properties of PPP-like versus PPV-like. Besides, the self-organization of 3,6-linked macrocyclic triphenanthrylene has been investigated by 2D wide-angle X-ray scattering experiments performed on extruded filaments in solution and in the bulk. Additionally, from the concept that donor-acceptor materials can induce efficient electron transfer, the covalent incorporation of perylene tetracarboxydiimide (PDI) into one block of a poly(2,7-carbazole) (PCz)-based diblock copolymer and 2,5-pyrrole based on push-pull type material are achieved respectively.

The informal market of education in Egypt: Private tutoring and its implications /// Arbeitspapiere / Institut für Ethnologie und Afrikastudien ; 88

Education is generally perceived as a public good which should be provided by the state. In Egypt, free and equal access to education has been guaranteed to all citizens since President Nasser’s socialist reforms in the 1950s. However, due to high population growth rates and a lack of financial resources, the public education system has been struggling to accommodate rapidly increasing numbers of students. While enrolment rates have risen steadily, the quality of state-provided services has deteriorated. Teachers and students have to cope with high class densities, insufficient facilities, a rigid syllabus and a centralized examination system. Today, teaching is among the lowest-paying occupations in the public sector. One strategy to cope with this situation is the widespread practice of private tutoring, which usually takes place at students’ homes or in commercial tutoring centers. Based on research carried out in Cairo in 2004/05 and 2006, I use an actor-centered approach to analyze the motivations of Egyptian teachers and students for participating in private tutoring and the impact that this practice has on the relationship between teachers and students. Students of all socio-economic backgrounds resort to tutoring in order to succeed in a highly competitive and exam-oriented education system. However, the form and quality of tutoring that can be accessed depends on the financial means of the family. For teachers, tutoring provides a good opportunity not only to supplement their income, but also, in the case of renowned “star teachers”, to improve their professional status and autonomy. On the informal “market of education” that has developed in Egypt during the last decades, the educational responsibilities of the state are increasingly being taken over by private actors, i.e. the process of teaching and learning is dissociated from the direct control of the state and from school as an institution. At the same time, education is turned into a marketable commodity. Despite the government’s efforts to provide free education to all citizens, the quality of social services that can be accessed in Egypt, thus, depends mainly on the financial means of the individual or the family.

Pollen-placement and pollen-portioning in diverse Salvia-species

This dissertation addresses the staminal lever mechanism of the genus Salvia. Various hypotheses referring to its purpose and function are tested and elucidated. The first hypothesis maintains that the lever is a mechanical selection mechanism which excludes weak pollinators from the flower. This hypothesis is refuted and the respective results of force measurements and morphological investigations are presented, statistically evaluated and discussed. The force measurements and morphological investigations were conducted on the staminal levers and flowers of 8 bee pollinated (melittophilous) and 6 bird pollinated (ornithophilous) species. For comparison a ninth melittophilous species that lacks the staminal lever was investigated. In this species the force measurements were conducted on floral structures that were suspected to hinder a flower visitor. The hypotheses, which state that the staminal lever is a tool for pollen portioning and reduces the risk of pollen loss as well as hybridisation due to its ability to perform a repeatable, accurate and species-specific pollen placement on a wide range of diverse pollinators, are confirmed. Investigations with respect to pollen portioning were carried out on 13 sages. The lever mechanism can be released several times in a row, while the pollen sacs leave a dosed pollen portion on a well defined spot on the pollinator‘s body. Pollen placement was investigated for 12 sages. In sympatric sages, lever length and the area of pollen placement are of particular interest. A shared pollinator bears species-specific areas of pollen placement for different sages. The accurate pollen placement ensures an efficient pollination. However, the question of the functionality of the lever mechanism can not be answered with absolute certainty. The lever‘s backswing is not caused by the adaxial lever arm; the adaxial lever arm is too light and too short to be an adequate counterweight to the abaxial lever arm. Therefore, the adaxial lever arm can not pull the abaxial lever arm to return it to its neutral position. But there are indications of a cellular mainspring in the filament. According to the current state of knowledge, this is the most plausible explanation for the lever's backswing, but further histological investigations on the joint of the lever mechanism are necessary to confirm this assumption.

Internationalization intentions: micro-foundations and psychological distance perceptions in immigrant and non-immigrant entrepreneurs

This dissertation project aims at shedding light on the micro-foundations of international entrepreneurship, focusing on the pre-internationalization phase and taking an individual-level perspective. Three research questions are investigated building on a cognitive model of internationalization intentions. First, what are the antecedents to internationalization intentions, i.e. desirability and feasibility, and how they interact with psychological distance towards internationalization options. Second, what is the role of previous entrepreneurs’ experience on such antecedents, in particular for immigrant vs. non-immigrant entrepreneurs. Third, how are these antecedent elements influenced by entrepreneurs’ individual-level motivations and goals. Using a new data set from 140 independent, non-internationalized, high-tech SMEs and their 169 owners, a variety of analytical techniques are used to investigate the research questions, such as structural equation modeling, hierarchical regression and a "laddering" technique. This project advances our theoretical understanding of internationalization and international entrepreneurship and has relevant implications for entrepreneurs and policy-makers.

Entwicklung eines ökotouristischen Nutzungskonzeptes für den ehemaligen Militärstandort Hjerkinn Skytefelt im Nationalpark Dovrefjell-Sunndalsfjella in Mittel-Norwegen

Der Ökotourismus hat sich in den letzten Jahren zu einer Tourismussparte entwickelt, die nicht nur immer mehr Interessenten unter den Nutzern findet, sondern auch vielfältige Forschungsmöglichkeiten eröffnet.rnAus interdisziplinärer Betrachtungsweise kann man sowohl in den Gebieten der Biologie, der Wirtschaft, der Geographie, aber auch der Politik forschend tätig werden. rnDa der Tourismus in den letzten Jahren eine immer größere Bedeutung gerade für Länder mit weitestgehend intakten Naturressourcen erlangt hat, stellt sich die Frage inwieweit die Wirtschaft eines Landes auf diese Einnahmequelle angewiesen ist und ob nicht die ökologischen Belange immer weiter in den Hintergrund treten.rnAus diesem Ansatz heraus erfolgte zunächst eine qualitative und quantitative Bestandsaufnahme, die ein klares Bild vom derzeitigen Zustand in der Region ermöglicht. Darüber hinaus werden im Rahmen der Untersuchungen Zukunftsperspektiven aufgezeigt. Diese sollen verdeutlichen, inwieweit man steuernd in solche dynamischen Entwicklungsprozesse eingreifen kann oder soll.rnDie Schwerpunkte dieser Arbeit liegen in dem Bereich der Befragung von Touristen und in der Ausarbeitung eines digitalen Geländemodells zur späteren Nutzung in einem aufzubauenden Nationalpark-Infozentrum. Auf der Grundlage dieser Untersuchungen wurde ein touristisches Nutzungskonzept entwickelt und auf seine ökologischen Umsetzungschancen hin untersucht. Der Aspekt des Ökotourismus wird einleitend erörtert und definiert. Anschließend werden die Potenziale der norwegischen Tourismuswirtschaft untersucht. Die Befragungsergebnisse sowohl der norwegischen Besucher als auch der ausländischen Touristen werden in verschiedenen Korrelationen näher untersucht.rnEin gesonderter Bereich der Untersuchungen gilt dem Problemfeld des Wildcampings in Norwegen. Die dramatischen Entwicklungen der letzten Jahre rufen immer mehr Aktivisten auf den Plan. Da die Deutschen die größte Besuchergruppe darstellen, wurden innerhalb der Jahre 2003 bis 2006 Einzelinterviews geführt, um einen Überblick über das Übernachtungsverhalten der Deutschen in Norwegen gewinnen zu können. In den vergangenen 10 Jahren sind die deutschen Besucherzahlen in Norwegen leicht rückläufig, während die der Niederländer kontinuierlich steigen.rnAuf diesen Ergebnissen basierend wurden problemzentrierte Interviews mit Wohnmobilreisenden, der größten Gruppe der Individualreisenden, durchgeführt. rnMehr als 600.000 Nächte pro Jahr verbrachten die deutschen Wohnmobilreisenden außerhalb der Campingplätze, was ökologische und ökonomische Auswirkungen hat und nicht mehr mit dem in Norwegen geltenden „Allemansrett“, dem Jedermannsrecht, vereinbar ist. rnGerade die Touristen, die mit dem Wohnmobil reisen, können nur schwer mit anderen Reisenden verglichen werden, da sie mit einer völlig anderen Reiseauffassung mehr oder weniger autark unterwegs sind. Dabei legen sie besonders große Distanzen zurück und haben sich zum Ziel gesetzt, möglichst viel in kurzer Zeit zu sehen und zu erleben. Für alle Touristengruppen wurde untersucht, auf welchem Weg die Informationen für die geplante Reise beschafft wurden. Der Reiseführer ist der hauptsächliche Informationslieferant und ist teilweise für das Verhalten der Urlauber mitverantwortlich. Es konnte festgestellt werden, dass das Image des Landes und die Reisemotive das Reiseverhalten und die Wahrnehmung determinieren. Eine Untersuchung der so genannten Pull- und Push-Faktoren ergab, dass die nahezu noch unberührte Natur, die raue Landschaft sowie Ruhe und Erholung die entscheidenden Pull-Faktoren für Norwegenreisende sind. Dabei überprägt das Image Norwegens als „wildes Naturland“ die Wahrnehmung für verschiedene Problembereiche, die in Norwegen, wie auch in vielen anderen Ländern Europas, durchaus vorhanden sind. rnProblemfelder, wie Landschaftsausbeutung, Wildcamping, reduziertes Konsumverhalten und damit einhergehende rückläufige Besucherzahlen, können aber durch innovative Tourismuskonzepte und neue Reiseformen abgebaut werden. Hierbei sind Medien, wie Reiseführer, Internet und Reisemagazine, in die Pflicht zu nehmen.

Networking: the "making of" social networks. A closer look at the process and antecedents of some resourcing-oriented behaviors in organizations.

Social networks are one of the “hot” themes in people’s life and contemporary social research. Considering our “embeddedness” in a thick web of social relations is a study perspective that could unveil a number of explanations of how people may manage their personal and social resources. Looking at people’s behaviors of building and managing their social networks, seems to be an effective way to find some possible rationalization about how to help people getting the best from their resources . The main aim of this dissertation is to give a closer look at the role of networking behaviors. Antecedents, motivations, different steps and measures about networking behaviors and outcomes are analyzed and discussed. Results seem to confirm, in a different setting and time perspective, that networking behaviors include different types and goals that change over time. Effects of networking behaviors seem to find empirical confirmation through social network analysis methods. Both personality and situational self-efficacy seem to predict networking behaviors. Different types of motivational drivers seem to be related to diverse networking behaviors.

Earthquake forecasting and seismic hazard analysis: some insights on the testing phase and the modeling

This thesis is divided in three chapters. In the first chapter we analyse the results of the world forecasting experiment run by the Collaboratory for the Study of Earthquake Predictability (CSEP). We take the opportunity of this experiment to contribute to the definition of a more robust and reliable statistical procedure to evaluate earthquake forecasting models. We first present the models and the target earthquakes to be forecast. Then we explain the consistency and comparison tests that are used in CSEP experiments to evaluate the performance of the models. Introducing a methodology to create ensemble forecasting models, we show that models, when properly combined, are almost always better performing that any single model. In the second chapter we discuss in depth one of the basic features of PSHA: the declustering of the seismicity rates. We first introduce the Cornell-McGuire method for PSHA and we present the different motivations that stand behind the need of declustering seismic catalogs. Using a theorem of the modern probability (Le Cam's theorem) we show that the declustering is not necessary to obtain a Poissonian behaviour of the exceedances that is usually considered fundamental to transform exceedance rates in exceedance probabilities in the PSHA framework. We present a method to correct PSHA for declustering, building a more realistic PSHA. In the last chapter we explore the methods that are commonly used to take into account the epistemic uncertainty in PSHA. The most widely used method is the logic tree that stands at the basis of the most advanced seismic hazard maps. We illustrate the probabilistic structure of the logic tree, and then we show that this structure is not adequate to describe the epistemic uncertainty. We then propose a new probabilistic framework based on the ensemble modelling that properly accounts for epistemic uncertainties in PSHA.

On the car sequencing problem: analysis and solution methods

This work deals with the car sequencing (CS) problem, a combinatorial optimization problem for sequencing mixed-model assembly lines. The aim is to find a production sequence for different variants of a common base product, such that work overload of the respective line operators is avoided or minimized. The variants are distinguished by certain options (e.g., sun roof yes/no) and, therefore, require different processing times at the stations of the line. CS introduces a so-called sequencing rule H:N for each option, which restricts the occurrence of this option to at most H in any N consecutive variants. It seeks for a sequence that leads to no or a minimum number of sequencing rule violations. In this work, CS’ suitability for workload-oriented sequencing is analyzed. Therefore, its solution quality is compared in experiments to the related mixed-model sequencing problem. A new sequencing rule generation approach as well as a new lower bound for the problem are presented. Different exact and heuristic solution methods for CS are developed and their efficiency is shown in experiments. Furthermore, CS is adjusted and applied to a resequencing problem with pull-off tables.

Experiments on Pro-Sociality and Environmental Issues

The thesis comprises three essays that use experimental methods, one about other-regarding motivations in economic behavior and the others on pro-social behavior in two environmental economics problems. The first chapter studies how the expectations of the others and the concern to maintain a balance between effort exerted and rewards obtained interact in shaping the behavior in a modified dictator game. We find that dictators condition their choices on recipients' expectations only when there is a high probability that the the recipient will not be compensated for her effort. Otherwise, dictators tend to balance the efforts and rewards of the recipients, irrespective of the recipients' expectations. In the second chapter, I investigate the problem of local opposition to large public projects (e.g. landfills, incinerators, etc.). In particular, the experiment shows how the uncertainty about the project's quality makes the community living in the host site skeptical about the project. I also test whether side-transfers and costly information disclosure can help to increase the efficiency. Both tools succesfully make the host more willing to accept the project, but they lead to the realization of different types of projects. The last chapter is an experiment on climate negotiations. To avoid the global warming, countries are called to cooperate in the abatement of their emissions. We study whether the dynamic aspect of the climate change makes cooperation across countries behaviorally more difficult. We also consider inequality across countries as a possible factor that hinders international cooperation.