7,496 research outputs found
RHEED studies of nucleation of Ge islands on Si(001) and optical properties of ultra-small Ge quantum dots
No full textERGODIKLIK TEOREMASINI MARKOV ZANJIRILARI UCHUN QO’LLASH
No full textMarkov zanjiri deb atalgan jarayonlar birinchi marta 1906-1907- yillarda A.A. Markovning rus tilida yozilgan asarlarida uchraydigan unli va undosh harflar ketma-ketligining xossalarini o`rganishda bag`ishlangan ishlarida ko`rilgan. Bu ishda Markov jarayonlarining muhim sinfi hisoblanadigan, holatlar fazosi chekli yoki sanoqli to`plamdan iborat bo`lgan, bir jinsli Markov zanjirlari bilan tanishamiz va ergodik teorema keltirilgan
Behavioural Modelling of Career Progression in the European Commission
Full text linkThough manpower planning models have been part of OR for many years, and simulation has always been acknowledged as a potential approach, there are few reported applications of its use. In this case-based study we report on a micro-simulation model that exploits the structure of the European Commission’s appraisal and promotion rules, and includes regression-based sampling schemes which allow for non-Normal error terms to represent behavioural factors that led to the need for a new system. With a suitably parsimonious formulation the 20,000 person model runs very effectively, and the transparency associated with simulation proves an important factor in the successful use of the model as the basis for designing a promotion box system that was implemented across the Commission in 2009. The simulation modelling incorporates many Markov-type elements, and we reflect on important lessons learned from this combined use of micro-simulation and Markov-based approaches to manpower modelling
Sampling from Dirichlet process mixture models with unknown concentration parameter: mixing issues in large data implementations
Full text linkWe consider the question of Markov chain Monte Carlo sampling from a general stick-breaking Dirichlet process mixture model, with concentration parameter (Formula presented.). This paper introduces a Gibbs sampling algorithm that combines the slice sampling approach of Walker (Communications in Statistics - Simulation and Computation 36:45-54, 2007) and the retrospective sampling approach of Papaspiliopoulos and Roberts (Biometrika 95(1):169-186, 2008). Our general algorithm is implemented as efficient open source C++ software, available as an R package, and is based on a blocking strategy similar to that suggested by Papaspiliopoulos (A note on posterior sampling from Dirichlet mixture models, 2008) and implemented by Yau et al. (Journal of the Royal Statistical Society, Series B (Statistical Methodology) 73:37-57, 2011). We discuss the difficulties of achieving good mixing in MCMC samplers of this nature in large data sets and investigate sensitivity to initialisation. We additionally consider the challenges when an additional layer of hierarchy is added such that joint inference is to be made on (Formula presented.). We introduce a new label-switching move and compute the marginal partition posterior to help to surmount these difficulties. Our work is illustrated using a profile regression (Molitor et al. Biostatistics 11(3):484-498, 2010) application, where we demonstrate good mixing behaviour for both synthetic and real examples. © 2014 The Author(s)
‘Born to Shop’: Malls, Dream-Worlds and Capitalism
Full text linkIt has been twenty years since the fall of the Berlin Wall, and a new generation, untouched by the previous communist regimes, has come to adulthood throughout the post-communist world. The Iulius Group’s logo – ‘Born to shop!’ – suggests that these are born shoppers: the capitalist babies of Central and Eastern Europe who are sustaining the largest growth in retail and shopping malls in Europe. With no living memory of shortages, queuing, or government restrictions, they know only the limit of their own – or their parents’ – pocket/credit. Their world could not be more different from the one that their parents and grandparents experienced: both the abundance of goods and services, as well as the opulent settings under which they are now sold, offer striking visual contrasts to the not-so-distant past. In addition, the very experience of consumption is directly connected to the way in which the current social fabric – and new social divisions within it – is interwoven with the physical and architectural changes taking place in the urban setting
Author Co-Citation Analysis (ACA): a powerful tool for representing implicit knowledge of scholar knowledge workers
Full text linkIn the last decade, knowledge has emerged as one of the most important and valuable organizational assets. Gradually this importance caused to emergence of new discipline entitled ―knowledge management‖. However one of the major challenges of knowledge management is conversion implicit or tacit knowledge to explicit knowledge. Thus Making knowledge visible so that it can be better accessed, discussed, valued or generally managed is a long-standing objective in knowledge management. Accordingly in this paper author co- citation analysis (ACA) will be proposed as an efficient technique of knowledge visualization in academia (Scholar knowledge workers)
Runs, scans and urn model distributions: A unified Markov chain approach
No full textThis paper presents a unified approach for the study of the exact distribution (probability mass function, mean, generating functions) of three types of random variables: (a) variables related to success runs in a sequence of Bernoulli trials (b) scan statistics, i.e. variables enumerating the moving windows in a linearly ordered sequence of binary outcomes (success or failure) which contain prescribed number of successes and (c) success run statistics related to several well known urn models. Our approach is based on a Markov chain imbedding which permits the construction of probability vectors satisfying triangular recurrence relations. The results presented here cover not only the case of identical and independently distributed Bernoulli variables, but the non-identical case as well. An extension to models exhibiting Markov dependence among the successive trials is also discussed in brief
Avaliação in vitro do efeito da desproteinização da dentina decídua de humanos na união de sistemas adesivos
Full text linkTese (doutorado) - Universidade Federal de Santa Catarina, Centro de Ciências da Saúde, Programa de Pós-Graduação em Odontologia, Florianópolis, 2009.O objetivo deste estudo, in vitro, foi avaliar a resistência de união à microtração e a nanoinfiltração, após desproteinização da dentina decídua humana. Foram utilizadas coroas de molares decíduos hígidos, as quais tiveram a superfície oclusal desgastada com lixas de carbeto de silício, até a completa exposição da superfície dentinária, e para padronização da smear layer. Os espécimes foram distribuídos em seis grupos, de acordo com o tipo de tratamento (condicionamento ácido - CA ou CA + hipoclorito de sódio - NaOCl) e os sistemas adesivos: One Step Plus - Bisco (OSP), Single Bond - 3M ESPE (SB), Prime & Bond 2.1 - Dentsply (PB). Para o procedimento de desproteinização foi utilizado hipoclorito de sódio 10% por 30s. Os sistemas adesivos e a resina (Filtek Z 250 - 3M ESPE) foram aplicados de acordo com as recomendações dos fabricantes e os espécimes armazenados em água destilada (37ºC/24h). As coroas foram seccionadas obtendo-se palitos (0,8mm2), os quais foram imediatamente submetidos ao teste de resistência à microtração (Instron - 0,5mm/min), até fratura dos corpos-de-prova. Os valores obtidos foram analisados por ANOVA e teste de Tukey (p<0,05). Os corpos-de-prova foram levados ao microscópio eletrônico de varredura (MEV), para visualização do tipo de fratura e os dados submetidos ao teste de Kruskal-Wallis (p<0,05).A nanoinfiltração foi avaliada utilizando-se palitos e nitrato de prata amoniacal como marcador químico. A deposição da prata foi visualizada ao MEV e analisada de duas formas: 1. Em porcentagem (%), em três regiões do palito, utilizando-se espectometria por energia dispersa por raio-x (EDS); 2. Atribuição de escores pela avaliação das fotomicrografias obtidas ao MEV. Os dados (%) foram analisados por ANOVA e teste de Tukey (p<0,05) e os escores submetidos aos testes de Kruskal-Wallis e U de Mann-Whitney (p<0,05).Os valores médios obtidos para o teste de microtração sem desproteinização foram [MPa(DP)]: PB - 35,95(6,12); SB - 28,82(6,38); OSP - 24,59(6,10); e após desproteinização: PB - 41,47(6,79); OSP - 31,09(9,16); SB - 25,55(7,23). Os padrões de fratura mais comumente encontrados foram coesiva do adesivo e mista, para todos os grupos. A nanoinfiltração, avaliada por porcentagem, apresentou diferença significante para as variáveis tratamento e adesivo. A desproteinização da dentina condicionada reduziu significativamente a infiltração para o adesivo OSP. Para a variável sistema adesivo, na análise por porcentagem e por escores, o adesivo SB apresentou significativamente maior infiltração pelo nitrato de prata quando comparado ao OSP e PB, que foram similares entre si. Conclui-se que a resistência adesiva não foi influenciada pela remoção do colágeno exposto pelo condicionamento ácido e que a nanoinfiltração não foi evitada pela desproteinização dentinária
MUALLIFLIK KORPUSINING AHAMIYATI VA FUNKSIONAL IMKONIYATLARI
Full text linkThis article examines the significance and functional potential of author-created corpora in contemporary scientific, educational,and cultural contexts. The role of digital technologies in the creation and use of author-created corpora is examined, highlightingtheir importance for corpus linguistics, pedagogy, philology, and the humanities in general. The author analyzes domestic andinternational experience in creating author corpora, including examples from the National Corpus of the Russian Language, as wellas works on A.P. Chekhov and F.M. Dostoevsky. Particular attention is paid to the lexical, grammatical, and stylistic characteristicsof texts, methods of their annotation, as well as issues of accessibility, standardization, and legal regulation.Статья посвящена значению и функциональному потенциалу авторских корпусов текстов в современном научном,образовательном и культурном пространстве. Рассматривается роль цифровых технологий в создании и использованииавторских корпусов, подчеркивается их значение для корпусной лингвистики, педагогики, филологии и гуманитарнойнауки в целом. Автор анализирует отечественный и международный опыт создания авторских корпусов, включаяпримеры из Национального корпуса русского языка, а также работы по А. П. Чехову, Ф. М. Достоевскому. Особоевнимание уделяется лексико-грамматическим и стилистическим характеристикам текстов, методам их разметки, а такжепроблемам доступности, стандартизации и правового регулирования.Ushbu maqola zamonaviy ilmiy, ta’lim va madaniy kontekstlarda muallif tomonidan yaratilgan korpusning ahamiyati va funksionalimkoniyatlarini o‘rganadi. Muallif tomonidan yaratilgan korpuslarni yaratish va ulardan foydalanishda raqamli texnologiyalarningroli ko‘rib chiqilib, ularning korpus lingvistika, pedagogika, filologiya va umuman gumanitar fanlar uchun ahamiyati ko‘rsatilgan.Mualliflik korpusini shakllantirishda mahalliy va global tajribalar, xususan, "Rus tili milliy korpusi" materiallari, shuningdek,A.P.Chexov va F.M. Dostoevskiy asarlari namunalari o‘rganiladi. Matnlarning lug‘aviy, grammatik va uslubiy jihatlari, ularnitahlil qilish usullari, qo‘llanilishi, standartlashtirish va huquqiy asoslari masalalariga alohida urg‘u beriladi
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