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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
531

Study on Size Effect of Cluster Ion Beam Irradiation / クラスターイオンビーム照射におけるサイズ効果の研究

Ichiki, Kazuya 26 March 2012 (has links)
Kyoto University (京都大学) / 0048 / 新制・課程博士 / 博士(工学) / 甲第16847号 / 工博第3568号 / 新制||工||1539(附属図書館) / 29522 / 京都大学大学院工学研究科原子核工学専攻 / (主査)教授 伊藤 秋男, 准教授 柴田 裕実, 准教授 松尾 二郎 / 学位規則第4条第1項該当
532

Impact of health care professional training on adolescent hay fever : cluster randomised controlled trial of a complex intervention in primary care

Hammersley, Victoria Suzan January 2015 (has links)
Background Hay fever is typically poorly managed, particularly in adolescents, in whom it is responsible for considerable morbidity and impairment in educational performance. Evidence-based training of professionals has the potential to improve outcomes, but it can be expensive and so warrants formal evaluation. This trial sought to evaluate the effectiveness of a training intervention for primary care-based health care professionals on adolescent disease-specific quality of life. Methods A cluster randomised controlled trial was conducted in UK general practices. Practices were centrally randomised to a short, intensive training course on the evidence-based management of hay fever (intervention arm) or distribution of guidelines (control arm). The primary outcome measure was the change in the validated Rhinoconjunctivitis Quality of Life Questionnaire with Standardized Activities (RQLQ(S)) score in adolescents with hay fever between baseline and six weeks post-intervention (minimal clinically important difference = 0.5). Secondary outcome measures included health care professionals’ knowledge and confidence in managing hay fever, number of hay fever-related consultations, relevant treatments prescribed and symptom scores. Multi-level modelling using a random effects model was used to take account of between and within cluster variation, adjusting for strata, individual covariates and year of study. Results Thirty-eight general practices were randomised (20 in the intervention arm) and 246/341 patients (50.2% male, mean age 15 years) were included in the primary outcome analysis. Health care professionals’ self-assessed knowledge and confidence improved (prescribing/recommending treatment mean score 95% CI 1.4, 2.8), and the training was perceived to be of value. This did not however result in clinically or statistically significant improvements in RQLQ(S): -0.15, 95% CI -0.52 to +0.21. There were no differences in consultation frequency (95% CI -0.02, +0.63), treatments issued for hay fever (95% CI -0.24, +0.08) or symptom scores (95% CI - 1.03, +0.54). Conclusions Although attendance on this short, intensive hay fever training course was associated with professionals’ increased self-assessed confidence and understanding of the clinical management of hay fever, this did not translate into improvements in disease-specific quality of life or reduction in rhinitis symptoms in adolescents with hay fever.
533

Algorithmic and geometric aspects of the random-cluster model

Elçi, E. January 2015 (has links)
In this thesis we investigate the geometric and algorithmic aspects of the random-cluster model, a correlated bond percolation model of great importance in the field of mathematics and statistical mechanics. We focus on the computational and statistical efficiency of the single-bond or heat-bath Markov chain for the random-cluster model and develop algorithmic techniques that allow for an improvement from a previously known polynomial to a poly-logarithmic runtime scaling of updates for general graphs. The interplay between the (critical) cluster structure of the random-cluster model and algorithmic, as well as statistical, efficiencies is considered, leading to new exact identities. A complementary analysis of certain fragility properties of the Fortuin-Kasteleyn clusters provides new insights into fragmentation phenomena, culminating in a revised scaling relation for a related fragmentation power law exponent, previously only shown for the marginal bond percolation case. By utilising the established structural results, a dynamic fragmentation process is studied that allows for an extraction of characteristics of the equilibrium cluster structure by a careful analysis of the limiting fragments, as well as the entire evolution of the fragmentation process. Besides focussing on structural and computational aspects, in this dissertation we also analyse the efficiency of the coupling from the past perfect sampling algorithm for the random-cluster model via large-scale numerical simulations. Two key results are the particular, close to optimal, efficiency in the off-critical setting and the intriguing observation of its superiority compared to the alternative Chayes-Machta-Swendsen-Wang approach in three dimensions. Governed by a random runtime, the efficiency of the coupling from the past algorithm depends crucially on the fluctuations of the runtime. In this connection a compelling appearance of universal Gumbel fluctuations in the distribution of the runtime of the coupling from the past algorithm is established, both at and off criticality. Fluctuations at a tricritical point and at a discontinuous phase transition are shown to deviate from this Gumbel law. The above findings in two and three dimensions are supported by a rigorous analysis of certain aspects of the algorithm in one dimension, including a proof of the limiting Gumbel law.
534

Some algorithmic studies in high-dimensional categorical data clustering and selection number of clusters

Li, Junjie 01 January 2008 (has links)
No description available.
535

Using cluster analysis to quantify systematicity in a face image sorting task

Campbell, Alison 29 August 2017 (has links)
Open sorting tasks that include multiple face images of the same person require participants to make identity judgments in order to group images of the same person. When participants are unfamiliar with the identity, natural variation in the images due to changes in lighting, expression, pose, and age lead participants to divide images of the same person into different “identity” piles. Although this task is being increasingly used in current research to assess unfamiliar face perception, no previous work has examined whether there is systematicity across participants in how identity groups are composed. A cluster analysis was performed using two variations of the original face sorting task. Results identify groups of images that tend to be grouped across participants and even across changes in task format. These findings suggest that participants responded to similar signals such as tolerable change and similarity across images when ascribing identity to unfamiliar faces. / Graduate
536

Situación de la ilegalidad de comunicaciones en Perú según las actividades realizadas por los inspectores mediante análisis cluster jerárquico

Paniagua Mendez, Elida Maribel January 2016 (has links)
Determina en qué departamento existe mayor ilegalidad en comunicaciones según la actividad proactiva (de oficio) y la actividad reactiva (son requerimiento de los ciudadanos, como denuncias o solicitudes dentro del ministerio por otras áreas), para reducir la informalidad de estaciones no autorizadas. / Trabajo de suficiencia profesional
537

Linear clustering with application to single nucleotide polymorphism genotyping

Yan, Guohua 11 1900 (has links)
Single nucleotide polymorphisms (SNPs) have been increasingly popular for a wide range of genetic studies. A high-throughput genotyping technologies usually involves a statistical genotype calling algorithm. Most calling algorithms in the literature, using methods such as k-means and mixturemodels, rely on elliptical structures of the genotyping data; they may fail when the minor allele homozygous cluster is small or absent, or when the data have extreme tails or linear patterns. We propose an automatic genotype calling algorithm by further developing a linear grouping algorithm (Van Aelst et al., 2006). The proposed algorithm clusters unnormalized data points around lines as against around centroids. In addition, we associate a quality value, silhouette width, with each DNA sample and a whole plate as well. This algorithm shows promise for genotyping data generated from TaqMan technology (Applied Biosystems). A key feature of the proposed algorithm is that it applies to unnormalized fluorescent signals when the TaqMan SNP assay is used. The algorithm could also be potentially adapted to other fluorescence-based SNP genotyping technologies such as Invader Assay. Motivated by the SNP genotyping problem, we propose a partial likelihood approach to linear clustering which explores potential linear clusters in a data set. Instead of fully modelling the data, we assume only the signed orthogonal distance from each data point to a hyperplane is normally distributed. Its relationships with several existing clustering methods are discussed. Some existing methods to determine the number of components in a data set are adapted to this linear clustering setting. Several simulated and real data sets are analyzed for comparison and illustration purpose. We also investigate some asymptotic properties of the partial likelihood approach. A Bayesian version of this methodology is helpful if some clusters are sparse but there is strong prior information about their approximate locations or properties. We propose a Bayesian hierarchical approach which is particularly appropriate for identifying sparse linear clusters. We show that the sparse cluster in SNP genotyping datasets can be successfully identified after a careful specification of the prior distributions. / Science, Faculty of / Statistics, Department of / Graduate
538

Theoretical nuclear physics

Merchant, A. C. January 1979 (has links)
No description available.
539

Klastry, potenciál a dotace v Ústeckém kraji / Clusters, Potential and Subsidies in the Usti Region

Rezek, Jiří January 2011 (has links)
The aim of this thesis is to explain the functioning of cluster grouping of small and medium enterprises, to show the method of completing the application for cluster project funding by EU structural funds and to assess the benefits of the cluster.
540

Categorias Cluster / Cluster Categories

Queiroz, Dayane Andrade 30 January 2015 (has links)
Submitted by Marco Antônio de Ramos Chagas (mchagas@ufv.br) on 2015-11-12T13:17:51Z No. of bitstreams: 1 texto completo.pdf: 1082850 bytes, checksum: e652565e5953a1e93915f35cfdcaf7f4 (MD5) / Made available in DSpace on 2015-11-12T13:17:51Z (GMT). No. of bitstreams: 1 texto completo.pdf: 1082850 bytes, checksum: e652565e5953a1e93915f35cfdcaf7f4 (MD5) Previous issue date: 2015-01-30 / 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.

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