In this thesis we will consider waves in excitable media. These waves can be found in different biological settings, from signalling in the amoeba Dictyostelium discoideum to cardiac fibrillation...Show moreIn this thesis we will consider waves in excitable media. These waves can be found in different biological settings, from signalling in the amoeba Dictyostelium discoideum to cardiac fibrillation and spiral galaxies. Depending on the number of spatial dimensions, the waves can be of different types. In one spatial dimension travelling waves and travelling pulses occur. The existence and uniqueness of such waves will be proven. It follows that there there is a unique velocity, depending on the level of a so-called controller species, for which there exists a corresponding travelling wave. In two spatial dimensions the spiral waves will be considered. It follows that the normal velocity of a spiral wave front is not only determined by the level of controller species in the front, but also by the curvature of the front.Show less
Bachelor thesis | Cultural Anthropology and Development Sociology (BSc)
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De overheden van Oezbekistan en Tadzjikistan maken veelvuldig gebruik van cultureel erfgoed bij het ontwikkelen van een nationale identiteit en het creëren van nationalisme onder de bevolking....Show moreDe overheden van Oezbekistan en Tadzjikistan maken veelvuldig gebruik van cultureel erfgoed bij het ontwikkelen van een nationale identiteit en het creëren van nationalisme onder de bevolking. Hierbij zijn met name verwijzingen naar mythische helden en een glorieus verleden van belang.Show less
This thesis is concerned with an object called ’arithmetic codex’ which has been introduced recently in [6], and generalizes a number of notions which have been used both in cryptography (in the...Show moreThis thesis is concerned with an object called ’arithmetic codex’ which has been introduced recently in [6], and generalizes a number of notions which have been used both in cryptography (in the areas of secret sharing and multiparty computation) and algebraic complexity theory. The field of secure multi-party computation is concerned with finding protocols that offer the possibility to compute a function in several variables by a number of parties. The extra requirement for these protocols is that all the players have an input for the function of which they do not want others to find out the value. A common example is that of two millionaires that want to determine who of them is the richest without having to reveal the value of their assets [14]. Secret sharing schemes were introduced by Shamir [12] and Blakley [4]. They later turned out to provide an important building block for many multiparty computation protocols, especially when we want to achieve information-theoretic security, i.e., security which holds regardless of the computational power of the adversary. The fundamental results in this area were given by Ben-Or, Goldwasser and Wigderson [3] and, independently, Chaum, Cr´epeau and Damgaard [8]. They both use Shamir’s secret sharing scheme in which certain multiplicative properties are essential. Cramer Damgaard and Maurer [9] captured these algebraic properties in the notion of multiplicative and strongly multiplicative secret sharing schemes. Both notions are encompassed by the concept of arithmetic codex. On the other hand, the codex also has use in the field of algebraic complexity theory, that analyses the amount of operations one needs to perform algebraic calculations. Namely, the notion of codex encompasses that of symmetric bilinear multiplication algorithm [5]. In this thesis, we first introduce the notion of codex and provide some basic theory. Then we study the conditions under which these objects exist by establishing several bounds on its parameters. We consider first a fruitful approach to finding bounds on some of the integer parameters, based on the relation of codices with coding theory. This approach however does not exploit the multiplicative nature of codices and so we turn to a strategy that depends on the algebra attached to a codex. We can compare the latter bounds with several results known in algebraic complexity. In particular, Fiduccia and Zalcstein and later Adler and Strassen established some results on the multiplicative complexity of algebras. These, in turn, imply as a special case bounds on certain codices. The results in this thesis allow to find alternative and comparatively simple proofs for the same codex bounds in some cases. Furthermore the arguments can be generalized to find bounds on codices which are not direct consequences of the results in [1] and [10].Show less
Master thesis | Cultural Anthropology and Development Sociology (MSc)
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In voormalig Somalië is het percentage besneden vrouwen het hoogste van de wereld. Door verschillende partijen, zoals NGO’s, regeringen en individuen, wordt vrouwenbesnijdenis aan de orde gesteld...Show moreIn voormalig Somalië is het percentage besneden vrouwen het hoogste van de wereld. Door verschillende partijen, zoals NGO’s, regeringen en individuen, wordt vrouwenbesnijdenis aan de orde gesteld als zijnde onderdrukkend voor de vrouw. Deze scriptie beschrijft welke samenhang er bestaat tussen de mate van succes van anti-vrouwenbesnijdenis bewegingen, de gekozen benadering en de manier waarop vrouwenbesnijdenis is ingebed in het sociale en culturele leven in voormalig Somalië.Show less
Master thesis | Cultural Anthropology and Development Sociology (MSc)
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This study shows that Afrikaans speaking South African immigrants living in the Netherlands create a sense of home and belonging through a variety of products, activities and networks. They do this...Show moreThis study shows that Afrikaans speaking South African immigrants living in the Netherlands create a sense of home and belonging through a variety of products, activities and networks. They do this within the institutional framework, consisting of rules, regulations and constraints of the Netherlands. Like the respondent who smuggles in Grandpa powder, a headache powder used in South Africa, although EU regulations do not allow this. Blockages thus also exist after one has migrated, and are not only of influence during the process of migration from one place to another. Within the institutional framework of the Netherlands, Afrikaans speaking South Africans have found several ways to make use of products, activities and networks in their efforts to feel at ease.Show less
Dit onderzoek bestudeert hoe leerkrachten in het cluster 4 speciaal onderwijs de leerkracht-leerlingrelatie typeren uitgesplitst naar psychopathologie. Hiervoor vulden 54 deelnemende leerkrachten...Show moreDit onderzoek bestudeert hoe leerkrachten in het cluster 4 speciaal onderwijs de leerkracht-leerlingrelatie typeren uitgesplitst naar psychopathologie. Hiervoor vulden 54 deelnemende leerkrachten op 12 scholen in Midden-Nederland de Leerkracht Leerling Relatie Vragenlijst (LLRV) in. De onderzoeksgroep bestond uit 564 leerlingen, waarvan 75 meisjes (13%) en 489 jongens (87%) van 4 tot 14 jaar (M=10.1, SD=1.62). De resultaten lieten zien dat participerende leerkrachten vergeleken met collega’s in het reguliere onderwijs meer conflicten en een hogere afhankelijkheid ervaren van alle leerlingen en alleen minder nabijheid met jongens uit de onderbouw en meisjes. Leerlingen met gedragsproblemen hebben meer conflicten dan leerlingen met een autismespectrumstoornis en eventuele comorbide stoornissen. Bovendien draagt gedragsproblematiek bij aan minder nabijheid met de leerkracht aan het eind van het jaar vergeleken met leerlingen met een autismespectrumstoornis. Hieruit blijkt dat het belangrijk is leerkrachten bewust te maken een goede verstandshouding te hebben en houden over het jaar heen met leerlingen met gedragsproblemen.Show less
Master thesis | Cultural Anthropology and Development Sociology (MSc)
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Men beschouwt het vermogen om te communiceren vaak als evident. Wanneer we echter gaan praten met doven en slechthorenden merken we hoe zeer we een zintuig als ons gehoor moeten waarderen. Het...Show moreMen beschouwt het vermogen om te communiceren vaak als evident. Wanneer we echter gaan praten met doven en slechthorenden merken we hoe zeer we een zintuig als ons gehoor moeten waarderen. Het verliezen van het gehoor, of het nu veel of weinig is, zal gevolgen hebben voor de communicatie met anderen, en dus voor de toegang tot sociale relaties, locaties en het vervullen van behoeften. Het missen van een communicatiemiddel zoals gehoor zorgt ervoor dat men nieuwe manieren moet zoeken om sociale relaties te kunnen onderhouden. Daarnaast zullen bepaalde locaties niet meer gemakkelijk of zelfs helemaal niet toegankelijk zijn. Dit alles heeft tot gevolg dat men niet meer in alle eigen behoeftes kan voorzien. Denk hierbij aan zoiets simpels als naar de favoriete muziek luisteren of tot het kunnen communiceren met een vriend enzovoorts. Of iemand nu doof of slechthorend wordt geboren of dit op latere leeftijd meemaakt, het zal hoe dan ook de persoon beperken in zijn of haar toegang.Show less
Advanced master thesis | Political Science (Advanced Master)
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While the European Union is attempting to overcome the obstacles of the various crises which plague the institution, it is of the utmost importance to address the underlying problems of democracy....Show moreWhile the European Union is attempting to overcome the obstacles of the various crises which plague the institution, it is of the utmost importance to address the underlying problems of democracy. The Lisbon Treaty has made necessary and valuable changes to the democratic model of the EU, but has not gone far enough. As the analysis in this thesis demonstrates, there are still various dimensions of democratic deficit in the EU which need to be resolved. Further democratization and deeper integration, as is argued in this work, would be able to solve many of the identified deficits.Show less
Wars have substantial consequences for the consolidation of democracy, and have caused demographic, socio-economic and social problems in the countries of the Former Yugoslavia. However, what is...Show moreWars have substantial consequences for the consolidation of democracy, and have caused demographic, socio-economic and social problems in the countries of the Former Yugoslavia. However, what is striking is that not only has their Europeanization process differed from other Central and Eastern European countries, but also that among them a differentiated form of integration has taken place. On the one hand there are countries like Slovenia, a full EU member state, and Croatia, an acceding country set to join in July 2013, and on the other hand, countries like Serbia, a candidate country, and Bosnia i Herzegovina, a potential candidate, which have a long way to go on the path to membership. What are the reasons for these differences? How can we explain such variation in degrees of EU membership given that these countries were part of the same state a mere twenty-two years ago? What factors explain the quick democratic consolidation and compliance with EU conditionality of some FY states, on one hand, and the fragmented, problematic and generally slow Europeanization process of other FY states on the other? In order to answer these questions, this thesis examines the role of two key factors in determining different degrees of EU membership – the role of ethnicity, and the legacy of civil war in the internal political environment.Show less
Advanced master thesis | Political Science (Advanced Master)
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Why is it that some separatist movements remain united while others fragment into competing factions? While one would expect supporters of a separatist movement to be united in the struggle against...Show moreWhy is it that some separatist movements remain united while others fragment into competing factions? While one would expect supporters of a separatist movement to be united in the struggle against their common enemy, the state, recent literature has shown that they often spend valuable time and resources on internal rivalries – yet little research has been done to explain this phenomenon. Based on a comparison of the cases of the Armenians in Azerbaijan, the Chechens in Russia, and the Abkhaz in their struggle with Georgia, this thesis shows that the ability of the separatist movement to establish institutions capable of providing effective governance is essential in understanding processes of cohesion and fragmentation. It further illustrates that the strength of the incumbent state as well as the amount of external support a separatist movement receives play into these processes in important ways. Future research will have to show whether these variables hold the same explanatory power in other contexts.Show less
