Dissertations / Theses on the topic 'Cluster'
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1
Thompson, Bernard Robert. "Theory of cluster-cluster aggregation." Thesis, University of Cambridge, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.238123.
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2
Warren, Patrick Bewick. "Scaling laws in cluster-cluster aggregation." Thesis, University of Cambridge, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.386210.
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3
Saleh, Ibrahim A. "Cluster automorphisms and hyperbolic cluster algebras." Diss., Kansas State University, 2012. http://hdl.handle.net/2097/14195.
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Doctor of PhilosophyDepartment of Mathematics
Zongzhu Lin
Let A[subscript]n(S) be a coefficient free commutative cluster algebra over a field K. A cluster automorphism is an element of Aut.[subscript]KK(t[subscript]1,[dot, dot, dot],t[subscript]n) which leaves the set of all cluster variables, [chi][subscript]s invariant. In Chapter 2, the group of all such automorphisms is studied in terms of the orbits of the symmetric group action on the set of all seeds of the field K(t[subscript]1,[dot,dot, dot],t[subscript]n). In Chapter 3, we set up for a new class of non-commutative algebras that carry a non-commutative cluster structure. This structure is related naturally to some hyperbolic algebras such as, Weyl Algebras, classical and quantized universal enveloping algebras of sl[subscript]2 and the quantum coordinate algebra of SL(2). The cluster structure gives rise to some combinatorial data, called cluster strings, which are used to introduce a class of representations of Weyl algebras. Irreducible and indecomposable representations are also introduced from the same data. The last section of Chapter 3 is devoted to introduce a class of categories that carry a hyperbolic cluster structure. Examples of these categories are the categories of representations of certain algebras such as Weyl algebras, the coordinate algebra of the Lie algebra sl[subscript]2, and the quantum coordinate algebra of SL(2).
4
Lublinski, Alf Erko. "Geographical business clusters concepts for cluster identification with an application to an alleged aeronautics cluster in Northern Germany /." [S.l. : s.n.], 2002. http://deposit.ddb.de/cgi-bin/dokserv?idn=965586456.
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5
Kozovska, Kornelia <1981>. "Business Clusters in Eastern Europe: Policy Analysis and Cluster Performance." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2009. http://amsdottorato.unibo.it/1611/2/Tesi_Kornelia_Kozovska.pdf.
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Clusters have increasingly become an essential part of policy discourses at all levels, EU, national, regional, dealing with regional development, competitiveness, innovation, entrepreneurship, SMEs. These impressive efforts in promoting the concept of clusters on the policy-making arena have been accompanied by much less academic and scientific research work investigating the actual economic performance of firms in clusters, the design and execution of cluster policies and going beyond singular case studies to a more methodologically integrated and comparative approach to the study of clusters and their real-world impact. The theoretical background is far from being consolidated and there is a variety of methodologies and approaches for studying and interpreting this phenomenon while at the same time little comparability among studies on actual cluster performances. The conceptual framework of clustering suggests that they affect performance but theory makes little prediction as to the ultimate distribution of the value being created by clusters. This thesis takes the case of Eastern European countries for two reasons. One is that clusters, as coopetitive environments, are a new phenomenon as the previous centrally-based system did not allow for such types of firm organizations. The other is that, as new EU member states, they have been subject to the increased popularization of the cluster policy approach by the European Commission, especially in the framework of the National Reform Programmes related to the Lisbon objectives. The originality of the work lays in the fact that starting from an overview of theoretical contributions on clustering, it offers a comparative empirical study of clusters in transition countries. There have been very few examples in the literature that attempt to examine cluster performance in a comparative cross-country perspective. It adds to this an analysis of cluster policies and their implementation or lack of such as a way to analyse the way the cluster concept has been introduced to transition economies.
Our findings show that the implementation of cluster policies does vary across countries with some countries which have embraced it more than others. The specific modes of implementation, however, are very similar, based mostly on soft measures such as funding for cluster initiatives, usually directed towards the creation of cluster management structures or cluster facilitators. They are essentially founded on a common assumption that the added values of clusters is in the creation of linkages among firms, human capital, skills and knowledge at the local level, most often perceived as the regional level. Often times geographical proximity is not a necessary element in the application process and cluster application are very similar to network membership. Cluster mapping is rarely a factor in the selection of cluster initiatives for funding and the relative question about critical mass and expected outcomes is not considered. In fact, monitoring and evaluation are not elements of the cluster policy cycle which have received a lot of attention. Bulgaria and the Czech Republic are the countries which have implemented cluster policies most decisively, Hungary and Poland have made significant efforts, while Slovakia and Romania have only sporadically and not systematically used cluster initiatives.
When examining whether, in fact, firms located within regional clusters perform better and are more efficient than similar firms outside clusters, we do find positive results across countries and across sectors. The only country with negative impact from being located in a cluster is the Czech Republic.
6
Kozovska, Kornelia <1981>. "Business Clusters in Eastern Europe: Policy Analysis and Cluster Performance." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2009. http://amsdottorato.unibo.it/1611/.
Full textAbstract:
Clusters have increasingly become an essential part of policy discourses at all levels, EU, national, regional, dealing with regional development, competitiveness, innovation, entrepreneurship, SMEs. These impressive efforts in promoting the concept of clusters on the policy-making arena have been accompanied by much less academic and scientific research work investigating the actual economic performance of firms in clusters, the design and execution of cluster policies and going beyond singular case studies to a more methodologically integrated and comparative approach to the study of clusters and their real-world impact. The theoretical background is far from being consolidated and there is a variety of methodologies and approaches for studying and interpreting this phenomenon while at the same time little comparability among studies on actual cluster performances. The conceptual framework of clustering suggests that they affect performance but theory makes little prediction as to the ultimate distribution of the value being created by clusters. This thesis takes the case of Eastern European countries for two reasons. One is that clusters, as coopetitive environments, are a new phenomenon as the previous centrally-based system did not allow for such types of firm organizations. The other is that, as new EU member states, they have been subject to the increased popularization of the cluster policy approach by the European Commission, especially in the framework of the National Reform Programmes related to the Lisbon objectives. The originality of the work lays in the fact that starting from an overview of theoretical contributions on clustering, it offers a comparative empirical study of clusters in transition countries. There have been very few examples in the literature that attempt to examine cluster performance in a comparative cross-country perspective. It adds to this an analysis of cluster policies and their implementation or lack of such as a way to analyse the way the cluster concept has been introduced to transition economies.
Our findings show that the implementation of cluster policies does vary across countries with some countries which have embraced it more than others. The specific modes of implementation, however, are very similar, based mostly on soft measures such as funding for cluster initiatives, usually directed towards the creation of cluster management structures or cluster facilitators. They are essentially founded on a common assumption that the added values of clusters is in the creation of linkages among firms, human capital, skills and knowledge at the local level, most often perceived as the regional level. Often times geographical proximity is not a necessary element in the application process and cluster application are very similar to network membership. Cluster mapping is rarely a factor in the selection of cluster initiatives for funding and the relative question about critical mass and expected outcomes is not considered. In fact, monitoring and evaluation are not elements of the cluster policy cycle which have received a lot of attention. Bulgaria and the Czech Republic are the countries which have implemented cluster policies most decisively, Hungary and Poland have made significant efforts, while Slovakia and Romania have only sporadically and not systematically used cluster initiatives.
When examining whether, in fact, firms located within regional clusters perform better and are more efficient than similar firms outside clusters, we do find positive results across countries and across sectors. The only country with negative impact from being located in a cluster is the Czech Republic.
7
Jeltema, Tesla Erin. "Cosmology with clusters of galaxies : high-redshift clusters and the evolution of cluster substructure." Thesis, Massachusetts Institute of Technology, 2004. http://hdl.handle.net/1721.1/28372.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Physics, 2004.Includes bibliographical references (p. 85).
Clusters of galaxies have become an important cosmological tool, yet we do not un-erstand many aspects of their formation and development. In this thesis, I pursue two projects aimed at using clusters to constrain cosmology and better understanding cluster evolution. First, I examine the Chandra observation of MS1054-0321. MS1054-0321 is the highest redshift cluster in the Einstein Medium Sensitivity Survey (EMSS), and it was one of the first high-redshift clusters observed with Chandra. I confirm that this cluster is hot and massive, although its temperature is slightly lower than inferred previously. I also detected an iron line in this cluster, one of the first detections of iron in a cluster at these redshifts, with an abundance consistent with early enrichment of the ICM. MS1054-0321 exhibits significant substructure, which I study in detail for the first time. In X-rays, it appears to be a nearly equal mass double cluster in the process of merging. Both the cluster galaxies and mass associated with the western subclump are offset from the X-ray peak, possibly indicating that the gas in the subclump is being stripped off as it falls into the cluster. Despite the lower temperature, I find that the detection of this cluster in the EMSS constrains Qm to be less than one.
(cont.) In the second project, I investigate the evolution of cluster substructure with redshift, quantifying for the first time cluster structure out to z [approx.] 1. My sample includes 40 X-ray selected, luminous clusters from the Chandra archive, and I quantify cluster morphology using the power ratio method (Buote & Tsai 1995). I find that, as expected qualitatively from hierarchical models of structure formation, high-redshift clusters have more substructure and are dynamically more active than low-redshift clusters. Specifically, the clusters with z > 0.5 have significantly higher average third and fourth order power ratios than the lower redshift clusters. This observation of structure evolution indicates that dynamical state may be an important systematic effect in cluster studies seeking to constrain cosmology, and when calibrated against numerical simulations, structure evolution will itself provide interesting bounds on cosmological models.
by Tesla Erin Jeltema.
Ph.D.
8
Bozkirlioglu, Ali. "Cluster Potential In Industrial Sectors Of Samsun: Kutlukent Furniture Cluster Study." Master's thesis, METU, 2004. http://etd.lib.metu.edu.tr/upload/3/12605603/index.pdf.
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The present study investigated whether cluster potentials could be identified in the geographical area within the boundaries of Samsun province, and if identified, how such a potential could be promoted through corresponding support measures. Development of policy recommendations for promotion of identified cluster potential was the principal goal of the study. The course of the study was characterized by a cluster-based policy-making process in the policy environment, i.e. Samsun province. The process includes a descriptive part, i.e. cluster analysis, and a prescriptive part, i.e. determining policy goals and designing policy instruments. In the literature review, a guide to the field study was developed by review of various approaches to cluster conceptcommon features of clusters and the competitive advantages these give rise to
various practices in cluster-based policy development, and various cluster analysis methods. The field study starts with the initial identification of need for policy intervention, at which stage the rationale for pursuing a cluster-based policy in the specific conditions of Samsun and Turkey was discussed. The &ldquo
clusters as sectors&rdquo
approach was utilized in the identification of region&rsquo
s (potential) clusters and selection of the cluster as the subject of analysis and policy development. The analysis of industrial sectors in Samsun&rsquo
s economy was followed by selection of the target sector via employing various criteria assessing the importance of these sectors in terms of value added to the regional economy, and the clustering potential. Accordingly, furniture sector was selected, and the agglomeration of furniture sector enterprises in Kutlukent locality was identified as the potential cluster to be the subject of analysis and policy development. Following the identification of the potential cluster, the descriptive part was completed by second-stage micro-level analysis of the identified potential cluster, by which detailed information about the potential cluster was presented. At that phase, cluster potential of the structure was assessed by examining the elements in cluster value and production chain
public and private business support infrastructure
the flow of materials and goods in the chain
untraded relationships between the elements
characteristics of enterprises and workforce
and innovation performance. This comprehensive in-depth analysis of the cluster provided the required information to identify the specific needs of the cluster for cluster-based policy intervention. In the last part of the thesis, i.e. prescriptive part, cluster-oriented policy recommendations were developed including the determination of policy goal and the design/selection of policy instruments. The necessary information was collected by two-stage expert interviews, and by overall scan of the enterprises involved in the cluster via enterprise survey, which was realized in interviews with all of the enterprises. Six experts and 283 enterprises participated in the study. The results of the analysis showed that, while Kutlukent furniture cluster had some features, which are common in effective cluster models, the cluster lacks some critical features, which are crucial for effective functioning of a successful cluster. Hence, Kutlukent furniture cluster was defined as a &ldquo
potential&rdquo
cluster, which should be promoted by utilizing the existing potentials and strengths, and by addressing the weaknesses and obstacles identified in the analysis of the cluster, via appropriate cluster-oriented policy measures, which were proposed in the prescriptive part of the policy-making process. By these measures, the elements of Kutlukent potential cluster would be able to realize competitive advantages associated with clustering as in successful cluster models.
9
Terry, William David. "Cluster production in the matrix assembly cluster source." Thesis, University of Birmingham, 2017. http://etheses.bham.ac.uk//id/eprint/7726/.
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This thesis focuses on the development of the Matrix Assembly Cluster Source (MACS). Firstly, a transmission mode MACS instrument has been upgraded and integrated with a Time-Of-Flight mass filter. An equivalent cluster beam current of 100 nA of silver nanoclusters has been achieved (previously several nA). Furthermore, an intrinsic size control has been demonstrated in the 1-5 nm range by varying the silver concentration in the matrix. The MACS has been demonstrated in a reflection regime, reaching a ~1% conversion of incident ions to clusters (~0.03% in transmission). The effect of the beam-plate geometry has been investigated and a new reflection mode system commissioned, producing a maximum equivalent silver cluster current of 170±16 nA. An average equivalent current of 40 nA has been deposited for 45 minutes. Nanocluster arrays have been demonstrated to preferentially immobilize dye molecules, the primary step towards label-free cluster-based biochips. Finally, visible range ion-induced light emission from the matrix was studied. Optical measurements demonstrate significant change in the ion-induced light emission spectra with the addition of O2, N2, or Ag to the matrix. By careful analysis of the emission spectra, the thickness, composition, and in certain cases, molecular composition of the matrix can be accessed.
10
Hess, Cassiano Ricardo. "MDX-cc: ambiente de programação paralela aplicado a cluster de clusters." Pontifícia Universidade Católica do Rio Grande do Sul, 2003. http://hdl.handle.net/10923/1655.
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Previous issue date: 2003Due to the appearance of fast communication networks, such as Myrinet and SCI, it becames possible the construction of new architectures based on commodity, off-the-shelf machines (PCs and workstations) connected by this kind of network - which are been called clusters. Such architectures are becoming an alternative execution platform for complex parallel applications, mainly due to the cost/benefit relation they present. The diversity of fast networks leads to the interconnection of clusters, building an architecture called cluster of clusters. One of the main problems in the use of clusters of clusters is the programming software used for parallel application development, since this kind of architecture has some characteristics that must be addressed by the programming language or environment in order to provide high performance. This work describes the development of a message passing parallel programming environment for cluster of clusters, the MDX-cc. This environment was projected based on the MDX system [PRE98][HES01] and a first version has been implemented supporting communication over Fast-Ethernet, SCI and Myrinet networks. The main goal of MDX-cc is to provide communication and synchronization of processes that run on interconnected clusters. Thanks to its modular architecture and the use of specific communication protocols dedicated to each network interface, MDX-cc provides a simple programming interface, with a small set of primitives, and also provides a transparent communication among processes running on different network-based clusters.
Em razão do surgimento de redes de comunicação de alta velocidade, tais como Myrinet e SCI, a construção de arquiteturas baseadas em máquinas comuns (PCs e estações de trabalho) conectadas por esse tipo de rede - o que se denomina agregado (ou cluster) - tornou-se viável. Tais arquiteturas vêm se consolidando como plataformas alternativas para a execução de aplicações paralelas complexas, principalmente devido à relação custo/benefício que oferecem. Esse avanço das tecnologias de redes possibilita também a agregação de clusters, formando uma estrutura de cluster de clusters, como uma única máquina paralela. Um dos principais problemas no uso de cluster de clusters é o software utilizado para o desenvolvimento de aplicações paralelas, visto que cada agregado envolvido na estrutura possui certas características que precisam ser tratadas pela linguagem ou ambiente de programação, visando o alcance de alto desempenho. Esta dissertação tem como objetivo apresentar uma ferramenta de programação paralela por troca de mensagens que executa sobre uma estrutura de cluster de clusters: o MDX-cc. A ferramenta foi concebida tendo como base o sistema MDX [PRE98][HES01] e uma primeira versão foi implementada oferecendo suporte à comunicação em agregados com redes SCI, Myrinet e Fast-Ethernet. O principal objetivo do MDX-cc é oferecer recursos de comunicação e sincronização de processos que rodam em agregados interligados. Por sua arquitetura modular e abstração do uso de protocolos de comunicação dedicados a cada tecnologia de rede, o MDX-cc oferece uma interface de programação simples, com um conjunto reduzido de primitivas, e provê transparência total na comunicação entre processos que executam em nós de clusters com tecnologias de rede distintas.
11
Bahra, Anish. "Cluster headache." Thesis, University College London (University of London), 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.397164.
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Delong, Marek. "Cluster World." Master's thesis, Vysoké učení technické v Brně. Fakulta výtvarných umění, 2015. http://www.nusl.cz/ntk/nusl-232466.
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In my thesis I focus mainly on omnipresence of the internet and technology. Additionally on colapse of physical environment in online culture and infinite reproduction ability and transformability of digital matter. However, I’m also concerned about their feedback application into exhibition areas. The thesis deals with change of authorship – after an art piece gets documented, it becomes a circulating material. Authorship of an artwork is almost impossible to track down, same as the initial context. Artistic outcome switches from auratic object into a file which is a subject to the network architecture. In the last two decades the relationship between image, text, language, meaning, body, space, subject and object changed radically. The task is no longer to create unique and original art but to observe existing supplies of images and spaces as de-subjectivized.
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Queiroz, Dayane Andrade. "Categorias Cluster." Universidade Federal de Viçosa, 2015. http://www.locus.ufv.br/handle/123456789/6656.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
Neste trabalho apresentamos as categorias cluster, que foram introduzidas por Aslak Bakke Buan, Robert Marsh, Markus Reineke, Idun Reiten e Gordana Todorov, com o objetivo de categoriíicar as algebras cluster criadas em 2002 por Sergey Fomin e Andrei Zelevinsky. Os autores acima, em [4], mostraram que existe uma estreita relação entre algebras cluster e categorias cluster para quivers cujo grafo subjacente é um diagrama de Dynkin. Para isto desenvolveram uma teoria tilting na estrutura triangulada das categorias cluster. Este resultado foi generalizado mais tarde por Philippe Caldero e Bernhard Keller em [8] para quivers do tipo acíclico. O objetivo principal desta dissertação e estudar como a teoria tilting sobre cluster permite estabelecer a relação entre estas estruturas e apresentar exemplos.
In this work we present the cluster categories, which were introduced by Aslak Bakke Buan, Robert Marsh, Markus Reineke, Idun Reiten and Gordana Todorov, with objective of categoriíication cluster algebras created in 2002 by Sergey Fornin and Andrei Zelevinsky. The authors above, on [4], showed that there is a close relationship between cluster algebras and cluster categories for quivers whose un- derlying graph is a Dynkin diagrarn. For this they develOped a tilting theory in the triangulated structure of the cluster categories. This result was later generalized by Philippe Caldero and Bernhard Keller on [8] for quivers of the acyclic type. The main objective of this dissertation is to study how the tilting theory about cluster enables establish the relationship between these structures and present examples.
14
Harrison, Mark B. J. "Computer simulation of cluster-cluster aggregation in two dimensions." Thesis, Queen's University Belfast, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.266709.
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Blakeslee, John Paul. "The globular cluster luminosity functions of brightest cluster galaxies." Thesis, Massachusetts Institute of Technology, 1997. http://hdl.handle.net/1721.1/42589.
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16
Jones, Peter P. "Determining cluster-cluster aggregation rate kernals using inverse methods." Thesis, University of Warwick, 2013. http://wrap.warwick.ac.uk/57480/.
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We investigate the potential of inverse methods for retrieving adequate information about the rate kernel functions of cluster-cluster aggregation processes from mass density distribution data. Since many of the classical physical kernels have fractional order exponents the ability of an inverse method to appropriately represent such functions is a key concern. In early chapters, the properties of the Smoluchowski Coagulation Equation and its simulation using Monte Carlo techniques are introduced. Two key discoveries made using the Monte Carlo simulations are briefly reported. First, that for a range of nonlocal solutions of finite mass spectrum aggregation systems with a source of mass injection, collective oscillations of the solution can persist indefinitely despite the presence of significant noise. Second, that for similar finite mass spectrum systems with (deterministic) stable, but sensitive, nonlocal stationary solutions, the presence of noise in the system can give rise to behaviour indicative of phase-remembering, noise-driven quasicycles. The main research material on inverse methods is then presented in two subsequent chapters. The first of these chapters investigates the capacity of an existing inverse method in respect of the concerns about fractional order exponents in homogeneous kernels. The second chapter then introduces a new more powerful nonlinear inverse method, based upon a novel factorisation of homogeneous kernels, whose properties are assessed in respect of both stationary and scaling mass distribution data inputs.
17
Jiang, Xiaohu 1968. "A scalable parallel inter-cluster communication system for clustered multiprocessors." Thesis, Massachusetts Institute of Technology, 1997. http://hdl.handle.net/1721.1/43537.
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Pavlou, M. "Analysis of clustered data when the cluster size is informative." Thesis, University College London (University of London), 2012. http://discovery.ucl.ac.uk/1357842/.
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Clustered data arise in many scenarios. We may wish to fit a marginal regression model relating outcome measurements to covariates for cluster members. Often the cluster size, the number of members, varies. Informative cluster size (ICS) has been defined to arise when the outcome depends on the cluster size conditional on covariates. If the clusters are considered complete then the population of all cluster members and the population of typical cluster members have been proposed as suitable targets for inference, which will differ between these populations under ICS. However if the variation in cluster size arises from missing data then the clusters are considered incomplete and we seek inference for the population of all members of all complete clusters. We define informative covariate structure to arise when for a particular member the outcome is related to the covariates for other members in the cluster, conditional on the covariates for that member and the cluster size. In this case the proposed populations for inference may be inappropriate and, just as under ICS, standard estimation methods are unsuitable. We propose two further populations and weighted independence estimating equations (WIEE) for estimation. An adaptation of GEE was proposed to provide inference for the population of typical cluster members and increase efficiency, relative to WIEE, by incorporating the intra-cluster correlation. We propose an alternative adaptation which can provide superior efficiency. For each adaptation we explain how bias can arise. This bias was not clearly described when the first adaptation was originally proposed. Several authors have vaguely related ICS to the violation of the ‘missing completely at random’ assumption. We investigate which missing data mechanisms can cause ICS, which might lead to similar inference for the populations of typical cluster members and all members of all complete clusters, and we discuss implications for estimation.
19
STADENBERG, IDA. "Innovative Cluster Organizations in Tanzania : A Minor Field Study evaluating cluster performance and actor collaborations within the clusters included in ISCP-Tz." Thesis, KTH, Nationalekonomi, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-198691.
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Cluster Organizations, as a means of promoting competition and innovation in industrial clusters, have become increasingly popular over the world. Cluster organizations aim to increase growth and competitiveness of clusters within a region, and have become a central part of economic policy-making across the world. Recently, the concept has been used to a larger extent as a tool for economic development and poverty alleviation. This thesis seeks to examine the cluster organizations that are part of the Sida funded program Innovation Systems and Cluster development in Tanzania (ISCP-Tz), by evaluating performance, goals and development of the program based on cluster facilitators perceptions, and assess linkages and actor collaborations between clustered actors. The data in this thesis is collected through a telephone-administered questionnaire, as well as interviews and visits to cluster sites. The results show a positive impact on cluster firms performance as assessed by cluster facilitators, but show that actor collaborations in many cases are inadequate and need to be improved.
20
Bowlan, John. "Electric dipole moments, cluster metallicity, and the magnetism of rare earth clusters." Diss., Georgia Institute of Technology, 2010. http://hdl.handle.net/1853/34751.
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One of the fundamental properties of bulk metals is the cancellation of electric
fields. The free charges inside of a metal will move until they find an arrangement where
the internal electric field is zero. This implies that the electric dipole moment of a metal
particle should be exactly zero, because an electric dipole moment requires a net separation
of charge and thus a nonzero internal electric field.
This thesis is an experimental study to see if this property continues to hold for tiny sub-
nanometer metal particles called clusters (2 - 200 atom, R < 1 nm). We have measured the
electric dipole moments of metal clusters made from 15 pure elements using a molecular
beam electric deflection technique. We find that the observed dipole moments vary a great
deal across the periodic table. Alkali metals have zero dipole moments, while transition
metals and lanthanides all have dipole moments which are highly size dependent. In most
cases, the measured dipole moments are independent of temperature (T = 20 - 50 K), and
when there is a strong temperature dependence this suggests that there is a new state of
matter present. Our interpretation of these results are that those clusters which have a non-
zero dipole moment are non-metallic, in the sense that their electrons must be localized
and prevented from moving to screen the internal field associated with a permanent dipole
moment.
This interpretation gives insight to several related phenomena and applications. We
briefly discuss an example cluster system RhN where the measured electric dipole moments
appear to be correlated with a the N2O reactivity.
Finally, we discuss a series of magnetic deflection experiments on lanthanide clusters
(Pr, Ho, Tb, and Tm). The magnetic response of these clusters is very complex and highly
sensitive to size and temperature. We find that PrN (which is non-magnetic in the bulk) becomes magnetic in clusters and TmN clusters have magnetic moments lower than the atomic value as well as the bulk saturation value implying that the magnetic order in the cluster involves non-collinear or antiferromagnetic order. HoN and TbN show very similar size dependent trends suggesting that these clusters have similar structures.
21
Jefferson, Bea A. "Clusters and cluster policy : advanced manufacturing and metals industries in South Yorkshire." Thesis, University of Sheffield, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.412792.
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Hess, Cassiano Ricardo. "MDX-cc : ambiente de programa??o paralela aplicado a cluster de clusters." Pontif?cia Universidade Cat?lica do Rio Grande do Sul, 2003. http://tede2.pucrs.br/tede2/handle/tede/5121.
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Previous issue date: 2003-03-28Em raz?o do surgimento de redes de comunica??o de alta velocidade, tais como Myrinet e SCI, a constru??o de arquiteturas baseadas em m?quinas comuns (PCs e esta??es de trabalho) conectadas por esse tipo de rede - o que se denomina agregado (ou cluster) - tornou-se vi?vel. Tais arquiteturas v?m se consolidando como plataformas alternativas para a execu??o de aplica??es paralelas complexas, principalmente devido ? rela??o custo/benef?cio que oferecem. Esse avan?o das tecnologias de redes possibilita tamb?m a agrega??o de clusters, formando uma estrutura de cluster de clusters, como uma ?nica m?quina paralela. Um dos principais problemas no uso de cluster de clusters ? o software utilizado para o desenvolvimento de aplica??es paralelas, visto que cada agregado envolvido na estrutura possui certas caracter?sticas que precisam ser tratadas pela linguagem ou ambiente de programa??o, visando o alcance de alto desempenho. Esta disserta??o tem como objetivo apresentar uma ferramenta de programa??o paralela por troca de mensagens que executa sobre uma estrutura de cluster de clusters: o MDX-cc. A ferramenta foi concebida tendo como base o sistema MDX [PRE98][HES01] e uma primeira vers?o foi implementada oferecendo suporte ? comunica??o em agregados com redes SCI, Myrinet e Fast-Ethernet. O principal objetivo do MDX-cc ? oferecer recursos de comunica??o e sincroniza??o de processos que rodam em agregados interligados. Por sua arquitetura modular e abstra??o do uso de protocolos de comunica??o dedicados a cada tecnologia de rede, o MDX-cc oferece uma interface de programa??o simples, com um conjunto reduzido de primitivas, e prov? transpar?ncia total na comunica??o entre processos que executam em n?s de clusters com tecnologias de rede distintas.
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Murphy, Graham James. "Cluster combinatorics and derived equivalences for m-cluster tilted algebras." Thesis, University of Leeds, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.490965.
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Using the polygonal models for the m-cluster complexes developed in [25] we classify maximal m-orthogonal subsets, defined in [38], of the translation quiver Z~ where t1 is a Dynkin diagram of type Am En/en or Dn by describing explicitly a bijective correspondence between the maximal facets of the m-cluster complexes and the maximal m-orthogonal subsets of Z~. This generalizes results appearing in [38]. We then apply our result to classify the blocks of group algebras whose defect group is not quatemion and for which a maximal m-orthogonal module exists. We also describe the m-cluster tilted algebras of type An using the facets of the m-cluster complex. We introduce tilting complexes which correspond in a natural way to the algebra mutations induced by the exchange relation between facets of the m-cluster complex of type An- We prove that known necessary conditions on the Cartan matrix for the derived equivalence of two m-cluster tilted algebras of type An [17], are in fact sufficient, thereby classifying up to derived equivalence the m-cluster tilted algebras of type An. To achieve this we provide an algorithm which uses the tilting complexes associated with the algebra mutations in type An in order to reduce connected components of m-cluster tilted algebras of type An with the same number of simple modules and cycles in their quivers to a normal form. This generalizes a result of Buan and Vatne [22] which classifies the I-cluster tilted algebras of type An up to derived equivalence.
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Rooney, Philip. "The XMM Cluster Survey : a new cluster catalogue and applications." Thesis, University of Sussex, 2016. http://sro.sussex.ac.uk/id/eprint/62178/.
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In this thesis, we present the XMM Cluster Survey Second Data Release (XCS-DR2) and use it to test possible spectroscopic biases, fit scaling relations, and find massive, relaxed galaxy clusters. XCS finds clusters in the XMM public archive. The new cluster candidate list includes 15,642 objects found in the 688 square degrees of sky suitable for cluster detection. XCS-DR2 is the largest X-ray selected cluster catalogue to date. It contains 7,129 unique preliminary cluster identifications and 1,177 unique firm cluster identifications. Where redshifts were available, a spectral fitting was made leading to 4,987 unique cluster temperature and luminosity measurements. XCS-DR2 is more than an order of magnitude larger than XCS-DR1. As XCS-DR2 is a catalogue of homogeneously processed galaxy clusters, it is an ideal dataset to test possible spectroscopic biases during X-ray spectral fitting. This thesis answers seven questions related to the combining and fitting of multi-observational data and the instrumental calibration of XMM. Notably we present strong evidence that spectral selection must take place before any final X-ray spectral fitting takes place. XCS-DR1 clusters have been used to fit a luminosity temperature scaling relation. This thesis presents new spectral fitting pipelines, so the previous scaling relations work was revisited to ascertain how the results have changed. Additionally, by using the latest SPT cluster catalogue, a scaling relation was fit between the X-ray and the SunyaevZel'dovich effect properties of XCS-DR2 clusters. Massive, relaxed galaxy clusters have been used to fit cosmological parameters through measurements of their baryon fractions. XCS-DR2 contains 342 clusters observed on-axis with temperature, TX ≥ 4:5 keV. A morphological analysis of these clusters shows that 20 of them appear to be relaxed. When added to the latest analysis, a subsample of six relaxed clusters, can improve ΩM and w estimates by 18% and 12% respectively.
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Harris, William E., Stephanie M. Ciccone, Gwendolyn M. Eadie, Oleg Y. Gnedin, Douglas Geisler, Barry Rothberg, and Jeremy Bailin. "GLOBULAR CLUSTER SYSTEMS IN BRIGHTEST CLUSTER GALAXIES. III. BEYOND BIMODALITY." IOP PUBLISHING LTD, 2017. http://hdl.handle.net/10150/622870.
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We present new deep photometry of the rich globular cluster (GC) systems around the Brightest Cluster Galaxies UGC 9799 (Abell 2052) and UGC 10143 (Abell 2147), obtained with the Hubble Space Telescope (HST) ACS and WFC3 cameras. For comparison, we also present new reductions of similar HST/ACS data for the Coma supergiants NGC 4874 and 4889. All four of these galaxies have huge cluster populations (to the radial limits of our data, comprising from 12,000 to 23,000 clusters per galaxy). The metallicity distribution functions (MDFs) of the GCs can still be matched by a bimodal-Gaussian form where the metal-rich and metal-poor modes are separated by similar or equal to 0.8 dex, but the internal dispersions of each mode are so large that the total MDF becomes very broad and nearly continuous from [Fe/H] similar or equal to-2.4 to solar. There are, however, significant differences between galaxies in the relative numbers of metal-rich clusters, suggesting that they underwent significantly different histories of mergers with massive gas-rich halos. Last, the proportion of metal-poor GCs rises especially rapidly outside projected radii R >= 4 R-eff, suggesting the importance of accreted dwarf satellites in the outer halo. Comprehensive models for the formation of GCs as part of the hierarchical formation of their parent galaxies will be needed to trace the systematic change in structure of the MDF with galaxy mass, from the distinctly bimodal form in smaller galaxies up to the broad continuum that we see in the very largest systems.
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Yasar, Suna Senem. "Knowledge Networks And Cognitive Communities In Clusters: The Case Of Ict Cluster Of Metu Technopolis And Agricultural Tools And Machinery Cluster Of Konya." Phd thesis, METU, 2010. http://etd.lib.metu.edu.tr/upload/12612621/index.pdf.
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Knowledge is defined one of the fundamental resources for development, competitiveness and power of firms, industrial clusters and regions. Their competitiveness and development have a strong relationship with their ability to create, absorb and utilize knowledge and to learn, i.e. their cognitive capabilities.
This thesis is focused on clusters as cognitive and learning systems. Clusters are the agglomerations where collective learning may take place. New knowledge is created and shared within the clusters'knowledge networks. Knowledge networks and cognitive communities as a part of these networks are seen as the significant topics in the literature to explain both the cognitive processes in firms, in industrial clusters and between industrial clusters. The main aim of the thesis is to explore the creation, absorption and transfer of knowledge in networks and cognitive communities in industrial clusters based on different technologies. To achieve this aim two empirical studies on different clusters with different technologies have been elaborated. The first one is an ICT cluster in METUTech and the second one is agricultural tools and machinery cluster in Konya. The data for the analysis collected through two different types of questionnaire, firm questionnaire and employee questionnaire. The first questionnaire is realized with producer firms in those sectors. The second questionnaire is conducted with the engineers. The data acquired from the questionnaire were evaluated based on descriptive analysis, correlation and social network analysis. Results are used to evaluate and compare the knowledge structures and cognitive communities in those clusters.
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Borrmann, Peter. "Pfadintegrale und Cluster." Phd thesis, Carl von Ossietzky University Oldenburg - Department of Physics, 1998. http://www.physik.uni-oldenburg.de/Docs/THEO3/publications/borrmann_diss.pdf.
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Wen, Shihua. "Semiparametric cluster detection." College Park, Md. : University of Maryland, 2007. http://hdl.handle.net/1903/7204.
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Thesis (Ph. D.) -- University of Maryland, College Park, 2007.Thesis research directed by: Mathematical Statistics. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.
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Koepke, Hoyt Adam. "Bayesian cluster validation." Thesis, University of British Columbia, 2008. http://hdl.handle.net/2429/1496.
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We propose a novel framework based on Bayesian principles for validating clusterings and present efficient algorithms for use with centroid or exemplar based clustering solutions. Our framework treats the data as fixed and introduces perturbations into the clustering procedure. In our algorithms, we scale the distances between points by a random variable whose distribution is tuned against a baseline null dataset. The random variable is integrated out, yielding a soft assignment matrix that gives the behavior under perturbation of the points relative to each of the clusters. From this soft assignment matrix, we are able to visualize inter-cluster behavior, rank clusters, and give a scalar index of the the clustering stability. In a large test on synthetic data, our method matches or outperforms other leading methods at predicting the correct number of clusters. We also present a theoretical analysis of our approach, which suggests that it is useful for high dimensional data.
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Bocquet, Sebastian. "Galaxy cluster cosmology." Diss., Ludwig-Maximilians-Universität München, 2015. http://nbn-resolving.de/urn:nbn:de:bvb:19-183812.
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Islam, S. S. "Coherent dependence cluster." Thesis, University College London (University of London), 2014. http://discovery.ucl.ac.uk/1452982/.
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This thesis introduces coherent dependence clusters and shows their relevance in areas of software engineering such as program comprehension and mainte- nance. All statements in a coherent dependence cluster depend upon the same set of statements and affect the same set of statements; a coherent cluster’s statements have ‘coherent’ shared backward and forward dependence. We introduce an approximation to efficiently locate coherent clusters and show that its precision significantly improves over previous approximations. Our empirical study also finds that, despite their tight coherence constraints, coherent dependence clusters are to be found in abundance in production code. Studying patterns of clustering in several open-source and industrial programs reveal that most contain multiple significant coherent clusters. A series of case studies reveal that large clusters map to logical functionality and pro- gram structure. Cluster visualisation also reveals subtle deficiencies of program structure and identify potential candidates for refactoring efforts. Supplemen- tary studies of inter-cluster dependence is presented where identification of coherent clusters can help in deriving hierarchical system decomposition for reverse engineering purposes. Furthermore, studies of program faults find no link between existence of coherent clusters and software bugs. Rather, a longi- tudinal study of several systems find that coherent clusters represent the core architecture of programs during system evolution. Due to the inherent conservativeness of static analysis, it is possible for unreachable code and code implementing cross-cutting concerns such as error- handling and debugging to link clusters together. This thesis studies their effect on dependence clusters by using coverage information to remove unexecuted and rarely executed code. Empirical evaluation reveals that code reduction yields smaller slices and clusters.
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Casewell, Sarah Louise. "Galactic cluster dwarfs." Thesis, University of Leicester, 2007. http://hdl.handle.net/2381/30592.
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This work describes the results of studies into galactic cluster brown and white dwarfs. Galactic cluster dwarfs have a known age increasing their use to the observer and allowing meaningful comparisons to models to be made. For brown dwarfs this is to increase knowledge of the initial mass function and star formation. For white dwarfs it is to increase understanding of the relationship between the progenitor star and its resultant white dwarf.;Chapter 4 describes a deep, large area (2.5 square degrees) survey of the Pleiades using optical (I and Z) and infrared (J) data. Three possible L dwarfs and six possible T dwarf new members of the cluster remain after proper motion measurements and follow up infrared photometry.;Chapter 5 presents results of a catalogue survey of Melotte 111 which more than doubled the number of stellar members of the cluster. Also described is a deep survey of the cluster centre, with follow up photometry, proper motions and spectra. Thirteen brown dwarf candidates are discovered.;Chapter 6 describes work which measured proper motions of 143 known brown dwarfs using WFCAM and 2MASS. Five candidate wide binaries are discovered, as well as 8 fast moving L dwarfs that may belong to the thick disc. The moving group method was used to identify 25 dwarfs as possible members of the Hyades, Ursa Major and Pleiades moving groups.;Chapter 7 presents the results of a spectroscopic study of 9 Praesepe white dwarfs. One is shown to be a non member of the cluster and another a possible double degenerate. A more precise initial-final mass relation is calculated.
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Rupel, Dylan, and Dylan Rupel. "Quantum Cluster Characters." Thesis, University of Oregon, 2012. http://hdl.handle.net/1794/12400.
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We de ne the quantum cluster character assigning an element of a quantum torus to each
representation of a valued quiver (Q; d) and investigate its relationship to external and internal
mutations of a quantum cluster algebra associated to (Q; d). We will see that the external mutations
are related to re
ection functors and internal mutations are related to tilting theory. Our
main result will show the quantum cluster character gives a cluster monomial in this quantum
cluster algebra whenever the representation is rigid, moreover we will see that each non-initial
cluster variable can be obtained in this way from the quantum cluster character.
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Vorrakitpokatorn, Rak. "Cluster policy - competitiveness or myth? : the case of Thailand's automotive cluster." Thesis, University of Strathclyde, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.442026.
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Ito, Hiroshi T. "Charge transfer model and(2-cluster)→(2-cluster) three-body scattering." 京都大学 (Kyoto University), 1991. http://hdl.handle.net/2433/86439.
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Steiner, Roland. "Innovative Cluster Konzept zur Lancierung eines innovativen Clusters, mit starkem Fokus auf KMU /." St. Gallen, 2005. http://www.biblio.unisg.ch/org/biblio/edoc.nsf/wwwDisplayIdentifier/02602191001/$FILE/02602191001.pdf.
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Huang, Hung-Jin, Rachel Mandelbaum, Peter E. Freeman, Yen-Chi Chen, Eduardo Rozo, and Eli Rykoff. "Intrinsic alignment in redMaPPer clusters – II. Radial alignment of satellites towards cluster centres." OXFORD UNIV PRESS, 2018. http://hdl.handle.net/10150/627131.
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We study the orientations of satellite galaxies in redMaPPer clusters constructed from the Sloan Digital Sky Survey at 0.1 < z < 0.35 to determine whether there is any preferential tendency for satellites to point radially towards cluster centres. We analyse the satellite alignment (SA) signal based on three shape measurement methods (re-Gaussianization, de Vaucouleurs, and isophotal shapes), which trace galaxy light profiles at different radii. The measured SA signal depends on these shape measurement methods. We detect the strongest SA signal in isophotal shapes, followed by de Vaucouleurs shapes. While no net SA signal is detected using re-Gaussianization shapes across the entire sample, the observed SA signal reaches a statistically significant level when limiting to a subsample of higher luminosity satellites. We further investigate the impact of noise, systematics, and real physical isophotal twisting effects in the comparison between the SA signal detected via different shape measurement methods. Unlike previous studies, which only consider the dependence of SA on a few parameters, here we explore a total of 17 galaxy and cluster properties, using a statistical model averaging technique to naturally account for parameter correlations and identify significant SA predictors. We find that the measured SA signal is strongest for satellites with the following characteristics: higher luminosity, smaller distance to the cluster centre, rounder in shape, higher bulge fraction, and distributed preferentially along the major axis directions of their centrals. Finally, we provide physical explanations for the identified dependences and discuss the connection to theories of SA.
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He, Shaowei. "Structural embeddedness, clusters, and cluster policy : a case study of the West Midlands." Thesis, University of Birmingham, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.440930.
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Marquezan, Clarissa Cassales. "Integrated Cluster Environment (ICE) : plataforma de gerenciamento e de acesso a múltiplos clusters." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2006. http://hdl.handle.net/10183/10270.
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Facilitar o gerenciamento e o acesso a sistemas de alto desempenho vem sendo uma área de pesquisa explorada nos últimos anos. Isto acontece uma vez que se verifica o aumento do número de usuários, muitos pertencentes a outras áreas, como por exemplo, biologia, geologia, hidrologia, etc e, desta forma, é preciso facilitar os meios de interação destes usuários com tais sistemas, assim como melhorar as técnicas de gerenciamento dos mesmos. Além do aumento do número e da multidisciplinaridade desses usuários, existe também o fato de que grande parte deles tem acesso a diferentes tipos de sistemas de alto desempenho. Em geral, estes sistemas possuem ferramentas não padronizadas, sendo que cada uma apresenta uma interface e um conjunto de ações e comandos a serem realizados para que possam dispor de suas funcionalidades. Este trabalho propõe a definição de uma arquitetura de gerenciamento e acesso a múltiplos clusters, que seja capaz de ser facilmente extensível, transparente, interoperável e de fácil utilização configuração e manutenção. Como resultado da arquitetura proposta, foi desenvolvido um protótipo, denominado ICE - Integrated Cluster Environment. Os principais objetivos da arquitetura e do ambiente ICE são: (i) capacidade de uniformização do modo como as ferramentas de clusters são utilizadas e, também, uniformização na maneira como os clusters são acessados; (ii) transparência na forma de acesso e uso dos clusters; e (iii) capacidade de extensibilidade em dois níveis: o primeiro refere-se á extensibilidade do número de funcionalidades (serviços) providos pelo sistema e o segundo está relacionado á capacidade do sistema lidar com o uso de diferentes ferramentas que possuem a mesma funcionalidade. Além da descrição da arquitetura e do protótipo, neste trabalho, também é realizada uma avaliação do ambiente ICE. Essa avaliação foi dividida em dois momentos. O primeiro traz a comparação das características do ambiente proposto com algumas ferramentas relacionadas. No segundo momento são apresentados alguns experimentos que visam identificar o overhead inserido pelo ambiente ICE na execução das operaçõess do módulo de gerenciamento de aplicações, desenvolvido e descrito neste trabalho.Some researches have been done over the last years in order to improve the management and access of high performance systems. One of the motivations of these researches is the continuously increase in the number of users who, not rarely, belong to other areas, such as biology, geology, hydrology, etc; so it is necessary to provide some access and also management facilities in these kinds of systems. Furthermore, the users also have access to different kinds of high performance systems, and they have to deal with distinct tools of their underlying, which are not standardize. Therefore, the users need to learn the specificities of each tool in each high performace system that they have permission to access. Aiming to solve this problem, this work proposes an architecture to provide access and management of multiple clusters with extensibility, transparance, interoperability, user-friendly, manageability and maintainability. As a result of the proposed architecture, a prototype called ICE - Integrated Cluster Environment - was developed. The main goals of the architecture and the ICE environment are: (i) the capability of uniforming the manner the cluster tools are used and accessed; (ii) cluster access and transparence use; and (iii) two extensibility levels: the first one refers to capability of extending the number of functionalities/services provided by the environment and the second one concerns to the capability of extending the number of tools, with the same functionality, the system is able to manage. Beyond the architecture and prototype description, this research presents the evaluation of ICE environment, which is divided in two parts. The first one brings the comparison of the features between ICE and some related work. The second part shows some experiments that intend to verify the overhead inserted by ICE environment when performing the tasks of the job management module, also developed and explained in this work.
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Cluver, Michelle E. "Probing distant clusters : a pre-SALT photometric study of intermediate redshift galaxy cluster." Master's thesis, University of Cape Town, 2005. http://hdl.handle.net/11427/4415.
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Popescu, Bogdan. "MASSCLEAN - MASSive CLuster Evolution and ANalysis Package - A New Tool for Stellar Clusters." University of Cincinnati / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1276526207.
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Cuciti, Virginia <1989>. "Cluster-scale radio emission: analysis of a mass-selected sample of galaxy clusters." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2018. http://amsdottorato.unibo.it/8540/1/Tesi_PhD.pdf.
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Radio halos are Mpc scale diffuse sources located at the center of a fraction of galaxy clusters. In the current theoretical picture, they form via the re-acceleration of electrons in the ICM by means of turbulence, injected during cluster mergers. This scenario allows basic predictions on the formation history of radio halos that can only be tested by analysing large samples of galaxy clusters with adequate radio and X-ray data.
The main goal of this Thesis is to study the first complete large sample of mass-selected galaxy clusters to obtain solid statistical constraints on the connection between radio halos and the dynamics and mass of the host clusters.
We used the Planck SZ catalogue to select a sample of 75 massive galaxy clusters (M500>6x10^{14}Msun) at redshift z=0.08-0.33 and we collected information on the presence or absence of diffuse emission from the literature and from the large observational (GMRT and JVLA) campaign carried out during this PhD project.
We analysed X-ray Chandra and XMM-Newton data to investigate the dynamical properties of clusters.
We updated the radio power-mass scaling relation for radio halos and we found clear evidence for a bimodal behaviour of clusters in both the radio power-mass plane and, for the first time, in the radio emissivity-mass diagram, with radio halos and non-radio halo clusters following two distinct distributions. Similarly to previous studies, we found that this bimodality is clearly connected to the cluster dynamics. For the very first time, we found an increase of the radio halo fraction with the cluster mass, which is remarkably in agreement with theoretical models.
In addition to the statistics of radio halos, the amount of data available in this Thesis led to the discovery of new radio relics, mini halos and head tail radio galaxies in our clusters.
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Greab, Maria Corina <1990>. "Inter-Cluster Networks in Europe: Relationships between Biomedical Clusters in Italy and Germany." Master's Degree Thesis, Università Ca' Foscari Venezia, 2016. http://hdl.handle.net/10579/7685.
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The thesis investigates the relationships between Italian and German cluster and RIS actors in the biomedical industry. Both countries are main actors in the red biotechnology field, counting on two highly specialized clusters (Mirandola in Italy and Tuttlingen in Germany). Also, other innovative life sciences clusters have developed in the last decades and are at the heart of dynamic regional innovation systems. Literature on the matter is not very extensive yet, so the work attempts to give an overview of the extent of such relations. The aim is to understand what are the relationships between biomedical clusters of Italy and Germany. Based on interviews with RIS and cluster actors and experts in the field, along with publicly available data, the outcome of the research is that relationships between the cluster and RIS actors of the two countries in the biomedical field are still to be developed. Market relations and collaborations research networks exist, but knowledge transfer relations and milieu informal networks are still weak. Such outcome is due to different factors, e.g. differences in public funding for research in the field, or the costly research of partners in the other country. Such causes need further investigation, through a more structured approach and involving more cluster and RIS actors between the two countries, along with a thorough empirical research on the causes that could favor stronger research collaborations between the two countries.
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Junior, Paulo Vanderlei Cassanego. "Governança em clusters de negócios: um estudo em clusters do Rio Grande do Sul." Universidade de São Paulo, 2014. http://www.teses.usp.br/teses/disponiveis/12/12139/tde-06012015-120214/.
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Esta tese teve como objetivo apresentar quais os elementos que devem constar em um modelo descritivo para representar o que ocorre na realidade na governança em clusters. Para atingir este objetivo desenvolveu-se uma pesquisa para compreender que elementos eram considerados por pesquisadores ao escreveram sobre a governança de aglomerados produtivos. De posse destes dados, o material resultante foi classificado considerando sua natureza. Se descritivos ou normativos. Assim foram constituídos os Elementos da Governança em Cluster com sua conceituação a partir do que indica a literatura da área. Os Elementos da Governança, a saber: Estrutura da Governança, Funções da Governança, Mecanismos /Meios da Governança, Objetivos da Governança, Agentes da Governança e Requisitos da governança. Após, para atingir o objetivo da Tese, fez-se necessária a confrontação das informações teóricas com dados empíricos. Então se desenvolveu pesquisa em 5 Clusters no Estado Rio Grande do Sul. Foram estudados os seguintes casos: Cluster de Doces, na região de Pelotas-RS; Cluster Bovinocultura de Corte, na região da Campanha Gaúcha; Cluster Vitivinícola, na Região da Fronteira Oeste de Campanha; Cluster Moveleiro, na Região Central do Estado; e Cluster Metal-Mecânico. Na Serra Gaúcha. Os dados coletados constituíram-se em um modelo descritivo visando representar como estão apresentados os Elementos da Governança na realidade. A Estrutura da Governança foi definida como a forma como se organiza a governança em um cluster. De forma hierárquica ou heterárquica, apresentando firmas independentes que operam como uma entidade única. A Função da Governança foi definida como o ato de influenciar a tomada de decisão das empresas no aglomerado, indicando formas de interação entre as organizações. Os Mecanismos da Governança foram definidos como contratos formais e informais que organizam o relacionamento entre organizações em um cluster. O Objetivo da Governança foi definido como Garantir vitalidade do agrupamento compondo competitividade e maximização do valor para toda a cadeia de produção. Os Agentes da Governança foram definidos como empresas independentes, ligadas por vínculos de proximidade geográfica, relacionamento transacional, processos competitivos e/ou cooperativos, governo local, instituições científicas e de apoio. Como requisito para a existência de Governança foi definido que a confiança é o principal atributo.This thesis aims to show what elements should be included in a descriptive model to represent what actually occurs in governance in clusters. To achieve this goal developed a survey to understand what factors were considered by the researchers wrote about the governance of production clusters. Using these data, the resulting material was classified considering their nature. If descriptive or normative. Thus were formed the Elements of Governance Cluster with its concept from the literature would suggest the area. Elements of Governance, namely: Governance Structure, Functions Governance Mechanisms / Media Governance, Governance Goals, Agents and Governance Requirements governance. After, to achieve the objective of the thesis, it was necessary to confrontation of theoretical information with empirical data. Then developed in 5 research clusters in Rio Grande do Sul state the following cases were studied: Cluster Candy, in the region of Pelotas; Cluster Beef Cattle in the Campanha Gaucha region; Wine Cluster in the Border Campaign West Region; Cluster Furniture in the State Central Region; Cluster and Metal-mechanic. In the Serra Gaucha. The data collected consisted of a descriptive model, to represent how the elements are shown Governance in reality. The Structure of Governance was defined as how governance is organized in a cluster. Hierarchical or heterarchical form, with independent firms that operate as a single entity. The Role of Governance has been defined as the act of influencing the decision making of firms in the cluster, indicating ways of interaction between organizations. The Mechanisms of Governance were defined as formal and informal contracts that organize the relationship between organizations in a cluster. The Purpose of the Governance was set to ensure the vitality and competitiveness cluster composing maximizing value for the whole chain of production. Agents of the Governance were defined as independent companies linked by bonds of geographical proximity, transactional relationships, competitive and / or cooperative processes, local government, scientific institutions and support. As a requirement for the existence of Governance has been defined that trust is the main attribute.
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Pham, Thi Diep. "Études théoriques et expérimentales de matériaux à base de clusters de molybdène." Thesis, Rennes, Ecole nationale supérieure de chimie, 2020. https://www.ensc-rennes.fr/formations/doctorats/.
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Des matériaux à base de clusters octaédriques de molybdène à faces coiffées ont été étudiés à la fois d’un point de vue expérimental et théorique. Après une description des outils utilisés dans le cadre de ce travail de thèse, les deux premières parties du manuscrit sont dédiées à l’étude théorique de clusters octaédriques de molybdène. Les propriétés structurales et électroniques de clusters octaédriques halogénées déficients en électrons sont étudiées à l’aide de calculs de chimie quantique. Les résultats montrent notamment la difficulté à oxyder à deux électrons et plus ces espèces. Les propriétés structurales de clusters chalco-halogénés de molybdène ont également étudiées in silico en fonction du nombre de chalcogène coiffant. Les calculs sur les clusters di- et tri-substitués ont montré la plus grande stabilité des espèces présentant le plus grand nombre de fragments MoXi2Qi2Xa (X = halogène, Q = chalcogène) constituant le cluster octaédrique où les deux chalcogènes sont positionnés en trans. Des hétérostructures composites CsPbBr3/Cs2Mo6I14 (CPB/CMI) et Cs4PbBr6/Cs2Mo6Br14 (Cs4PbBr6/CMB) ont été synthétisées et mises en forme. Les systèmes CPB/CMI présentent un intérêt pour le photovoltaïque tandis que les systèmes Cs4PbBr6/CMB semblent prometteurs pour les applications liées à l’éclairage. De nouvelles électrodes verre/FTO/TiO2/CPB/CMI sont prometteuses puisque la couche de clusters de Mo6 de la photoélectrode limite la dégradation de la couche pérovskite CPBMaterials based on capped faces octahedral molybdenum clusters have been studied fusing experimental and theoretical approaches. After a description of the tools used in this work, the first two parts of the manuscript are dedicated to the theoretical study of octahedral clusters of molybdenum. The structural and electronic properties of electron-deficient halogenated octahedral clusters are studied using quantum chemistry calculations. The results show the difficulty of oxidizing these species with two or more electrons. The structural properties of chalco-halogenated molybdenum clusters have also been studied in silico as a function of the number of capping chalcogens. The calculations on the di- and tri-substituted clusters showed the greatest stability of the species with the largest number of MoXi2Qi2Xa fragments (X = halogen, Q = chalcogen) constituting the octahedral cluster where the two chalcogens are positioned in trans. Composite heterostructures CsPbBr3/Cs2Mo6I14 (CPB/CMI) and Cs4PbBr6/Cs2Mo6Br14 (Cs4PbBr6/CMB) were synthesized. CPB/CMI systems are of interest for photovoltaic applications while Cs4PbBr6/CMB systems are promising for lighting applications. New glass/FTO/TiO2/CPB/CMI electrodes are promising since the layer of Mo6 cluster of the photoelectrode limits the degradation of the perovskite layer
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Melax, Sigrun. "An implementation and management framework for cluster initiatives in South Africa." Thesis, Stellenbosch : Stellenbosch University, 2013. http://hdl.handle.net/10019.1/80339.
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Thesis (MScEng)--Stellenbosch University, 2013.ENGLISH ABSTRACT: Clustering has emerged as one of the drivers for economic growth and improved competitiveness for specific industries. In order for cluster initiatives to be successful, they need to be managed in a certain way. The importance of excellent cluster management has been increasingly realised in the past years. Certain factors of cluster management are considered to lead to success in the management of cluster initiatives as identified in published research. In the same vain, certain aspects of cluster program management are considered to lead to success. A cluster program run by the Western Cape Provincial Government (WCPG) in South Africa is analysed and compared to the generic success factors in cluster program management. Selected cluster initiatives in the Western Cape are analysed and compared with each other as well as to these success factors in cluster management. The Western Cape Tooling Initiative (WCTI), a cluster initiative in the tool, die and mould making industry, is analysed in more detail, and compared to the other cluster initiatives, all of which but one are part of the cluster program. WCTI is found to not have been following success factors in cluster management, and the rate of progress of the WCTI from when it was started supports that fact. However, recent changes in the leadership of the cluster initiative have brought about changes in WCTI’s cluster management emphasis and signs of increased success can be noticed, even though the full effect will not be felt until after some years as success in cluster management takes years to be realised.
AFRIKAANSE OPSOMMING: Trosvervaardiging het in die onlangse verlede ontwikkel tot een van die drywers vir ekonomiese groei en verhoogde kompeterendheid in spefifieke industrië. Tros inisiatiewe vereis ‘n spesifieke bestuursraamwerk om hulle potensiaal te bereik, en die belangrikheid van uitstekende bestuurspraktyke word al hoe meer beklemtoon. Sekere faktore, beskryf in literatuur, van bestuur bleik te lei na sukses in die bestuur van sulke inisiatiewe. Op ‘n soortgelyke basis is daar aspekte van trosprogram bestuur wat voorvereistes vir sukses is. ‘n Trosprogram onder leiding van die Wes Kaapse Provinsiale Regering in Suid Afrika word analiseer en vergelyk met die generiese sukses faktore van trosprogrambestuur. Verskeie trosinisiatiewe in die Wes Kaap word ondersoek en met mekaar vergelyk asook gemeet aan hierdie suksesfaktore. Meer spesifiek word die “Western Cape Tooling Initiative” (WCTI) in meer detail analiseer, en vergelyk met die ander inisiatiewe wat almal, met een uitsondering, deel is van die trosprogram self. Daar is gevind dat die WCTI nie streng volgens die riglyne en/of binne die raamwerk van suksesvolle trosbestuur opgetree het nie, en dit word gestaaf deur die relatief lae sukseskoers tot dusver. Met die onlangse veranderinge aan die leierskap van die inisiatief bleik dit egter dat meer aandag aan hierdie praktyke gegee word, en daar is tekens van ‘n verbetering in die prestasie van die program. Die volle effek van hierdie veranderinge sal egter ‘n rukkie neem om volledig tot uitwerking te kom.
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Nielson, Curtis R. "A Descriptive Performance Model of Small, Low Cost, Diskless Beowulf Clusters." Diss., CLICK HERE for online access, 2003. http://contentdm.lib.byu.edu/ETD/image/etd280.pdf.
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McCarthy, Deborah A. "Synthesis, characterization, and reactivity studies of a tetraruthenium boride cluster and a hexaruthenium cluster : conversions to a hexaruthenium boride cluster /." The Ohio State University, 1990. http://rave.ohiolink.edu/etdc/view?acc_num=osu148768520496931.
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Bailey, Philip John. "Carbide formation and cluster build-up reactions in ruthenium carbonyl cluster chemistry." Thesis, University of Cambridge, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.335689.
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Bergman, Edward M., and Patrick Lehner. "Industrial cluster formation in European regions. U.S. cluster templates and Austrian evidence." Institut für Wirtschaftsgeographie, Abt. Stadt- und Regionalentwicklung, WU Vienna University of Economics and Business, 1998. http://epub.wu.ac.at/748/1/document.pdf.
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The paper will be organized in the following manner. We first provide a concise review of how industrial trade clusters were developed from available I/O coefficients (see box), including how regional industrial data may be embedded within their "templates". Second, we will review the steps taken, using available industrial concordances, that permit regional data from other advanced national industrial systems to be embedded within these templates. Third, we will illustrate the results of applying the U.S. template for the motor vehicle industrial trade cluster to regions in both Austria and North Carolina over 5-10 year time periods. Finally, we will offer some speculative observations about what the results may indicate about regional cluster development in these two regions. (authors' abstract, ed. M.Putz)Series: SRE - Discussion Papers