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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.
51

高密度寡核甘酸基因陣列晶片正規化方法之研究 / The Research of Normalization Methods for High Density Oligonucleotide Array

薛慧芬, Hsueh ,Hui-Fen Unknown Date (has links)
高密度寡核甘酸基因陣列實驗是新的生物技術,可在一個晶片上蒐集到數千至上萬個基因資料,資料處理的過程相當繁複,包括背景訊號的修正、正規化、探針背景的修正及探針組資料的整合,本研究首先將介紹各資料處理步驟。其中正規化的目的是要修正資料中由實驗產生的系統化變異,去除實驗誤差,使資料更為純淨,則後續所做的統計分析才會更為精確。之後再詳細介紹三種正規化方法,包括:尺度調整法、循環平滑調整法及百分位調整法。並將以一組實際資料來說明正規化後的結果。最終採取電腦模擬的方式,以平均四分位距、平均標準差、Diff統計量及離群值的個數這四個量化準則,來研究各正規化方法的效果,以及比較這三種正規化方法的優劣,同時也將探討此四種準則的適當性。 / High-density oligonucleotide array gene experiment is a new biological technology. More than thousands of gene data can be obtained in an array. The data processing includes background correction, normalization, probe specific background correction and summarizing the probe set value into one expression measure. The goal of normalization is to remove the systematic variation induced in the experiment while keeping the biological variation of interest. Using the purified data, one will obtain more accurate conclusions in subsequent statistical analysis. Firstly, we introduce the data processing procedures. Three normalization methods, which include Scaling, Cyclic Loess and Quantile, are explained in detail and illustrated by a real data set. Moreover, a simulation study is conducted to compare the three methods. Four quantities, Mean of IQR, Mean of Standard Deviation, Diff Statistics and Outlier, are proposed for assessment. Not only the performances of the three normalization methods but also the properties of the four proposed criteria are given and studied in this research.
52

A general mechanism for tuning: Gain control circuits and synapses underlie tuning of cortical neurons

Kouh, Minjoon, Poggio, Tomaso 31 December 2004 (has links)
Tuning to an optimal stimulus is a widespread property of neurons in cortex. We propose that such tuning is a consequence of normalization or gain control circuits. We also present a biologically plausible neural circuitry of tuning.
53

[en] CONFORMITY ASSESSMENT IN SUSTAINABLE GREEN COFFEE AGRIBUSINESS: RECOMMENDATIONS FOR SMALL-SCALE COFFEE GROWERS FROM GUATEMALA / [es] EVALUACIÓN DE LA CONFORMIDAD EN EL AGRONEGOCIO SOSTENIBLE DEL CAFÉ VERDE: RECOMENDACIONES PARA PEQUEÑOS PRODUCTORES DE CAFÉ DE GUATEMALA / [pt] AVALIAÇÃO DA CONFORMIDADE NO AGRONEGÓCIO SUSTENTÁVEL DO CAFÉ VERDE: RECOMENDAÇÕES PARA PEQUENOS CAFEICULTORES DA GUATEMALA

CAROLA BERIOSKA GARCIA GARCIA 24 March 2010 (has links)
[pt] O objetivo da dissertação é analisar a importância dos mecanismos da avaliação da conformidade para o agronegócio sustentável do café verde, tendo em vista a proposição de recomendações para os pequenos cafeicultores da Guatemala. As oportunidades de segmentação e diferenciação que se abrem para os produtos agroindustriais, dentre eles o café, estão entre os fatores mais relevantes que vem influenciando a sustentabilidade dos agronegócios. Nesse contexto, um dos impactos positivos da diferenciação no mercado de café verde é o fortalecimento da posição competitiva dos pequenos cafeicultores nessa cadeia agroindustrial. A motivação da pesquisa é destacar os benefícios da avaliação da conformidade e, em particular, de seu mecanismo de certificação, para os pequenos cafeicultores da Guatemala, na perspectiva da adoção de boas práticas agrícolas, da rastreabilidade e do cumprimento dos padrões internacionais já aceitos no agronegócio de café verde. A metodologia compreende: (i) pesquisa bibliográfica sobre métodos de avaliação de sustentabilidade agrícola, boas práticas agrícolas (BPA), normalização, rastreabilidade e avaliação da conformidade aplicadas a agronegócios sustentáveis; (ii) descrição das práticas internacionais para o agronegócio do café verde; (iii) descrição dos panoramas internacional e guatemalteco do agronegócio em foco; (iv) estudo de caso sobre a Fedecocagua, uma federação de pequenos produtores de café da Guatemala, e três de suas cooperativas; (v) formulação de recomendações para os pequenos produtores de café verde daquele país, à luz das práticas internacionais e da iniciativa brasileira de produção integrada do café (PIC). Destacam-se como resultados: (i) visão global das condições competitivas do agronegócio do café verde em nível mundial e na Guatemala; (ii) mapeamento dos modelos de cafeicultura sustentável; e (iii) diagnóstico situacional da Fedecocagua e de três de suas cooperativas conforme as grades analíticas desta pesquisa. Como conclusão, o trabalho identifica práticas internacionais que podem ser integradas em um código de conduta mínimo para o agronegócio sustentável do café verde da Guatemala. / [en] The main objective of this dissertation is to analyze the importance of conformity assessment mechanims within agribusiness context, with the view of proposing a set of recommendations for small-scale coffee growers from Guatemala. The increasing demand for healthy and social and environmentally-sound products have fostered the presence of these attributes in food products worldwide. Focusing on green coffee agribusiness, the scope of differentiation and quality concept should encompass social and environmental concerns, such as the adoption of sustainable productive systems and labor conditions under which coffee is grown, besides physical and sensorial characteristics of final product. In this context, a positive social and economical impact of differentiation in coffee market is the possibility to strengthen the position of small coffee growers in the production chain. The motivation for carrying out this research is to identify potential benefits of applying quality management and conformity assessment practices in the context of small-scale coffee growers from Guatemala, within the perspective of their continuous improvement in adopting Good Agricultural Practices (GAP), traceability procedures and their compliance with international standards already accepted by green coffee agribusiness markets, at regional and international levels. The methodology encompasses: (i) bibliographical review on methods to assess agricultural sustainability, good agricultural practices (GAP), and infrastructural technologies, more specifically standardization, traceability and conformity assessment, including certification; (ii) international practices survey concerning green coffee agribusiness, (iii) international and Guatemalan outlooks of coffee agribusiness; (iv) case study on Fedecocagua, a federation of small-scale coffee growers from Guatemala, and three of its cooperatives; (v) formulation of recommendations for small-scale coffee growers from that country, in the light of international practices and also from the experience accumulated by the Program on Coffee Integrated Production (CIP), which has been carried out in Brazil. The main results can be summarized as follows: (i) an overview of competitive drivers of green coffee agribusiness, at international and Guatemalan levels; (ii) mapping models of sustainable coffee production; and (iii) situational diagnosis of Fedecocagua according to the analytical framework designed for this research. As a conclusion, this dissertation identifies some international sustainable practices which could be integrated in a minimal conduct code concerning green coffee agribusiness in Guatemala. / [es] El objetivo de la disertación es analizar la importancia de la evaluación de la conformidad en el agronegocio del café verde sostenible, en vista de una propuesta de recomendaciones para los pequeños productores de café de Guatemala. Las oportunidades de segmentación y de diferenciación que se abren para los productos agroindustriales, entre ellos el café, están entre los factores más relevantes que vienen influenciando a la sustentabilidad en los agronegocios. En consecuencia, algunos atributos de la calidad, susceptibles de certificación, están siendo agregados como instrumentos de competencia del producto final. La creciente demanda, en particular en países desarrollados, por productos saludables, ambientalmente y socialmente aceptados, que posibilitan la incorporación de nuevos atributos de calidad. En ese contexto, uno de los impactos positivos de la diferenciación en el mercado del café verde, es la posibilidad de fortalecer el posicionamiento competitivo de los pequeños productores de café en Guatemala, en esta cadena agroindustrial. La motivación de la investigación es destacar los beneficios que tiene la evaluación de la conformidad, en forma particular su mecanismo de certificación, para pequeños productores de café verde de Guatemala, en la perspectiva de la adopción de buenas prácticas agrícolas, de la trazabilidad y del cumplimiento de las normas internacionales aceptadas en el agronegocio de café verde. La metodología comprende: (i) investigación bibliográfica sobre buenas prácticas agrícolas, normalización, trazabilidad y evaluación de la conformidad aplicadas a los agronegocios sostenibles; (ii) descripción de las practicas internacionales para el agronegocio de café verde; (iii) descripción de los panoramas internacionales y guatemalteco del agronegocio en estudio. (iv) estudios de casos múltiples, comprendiendo a la Fedecocagua, una federación de pequeños productores de café de Guatemala, y tres de sus cooperativas; (v) formulación de recomendaciones para los pequeños productores de café de aquel país, a la luz de las prácticas internacionales y de la experiencia brasileña de la producción integrada de café (PIC). Se destacan como resultados: (i) visión global de las condiciones competitivas del agronegocio del café verde a nivel mundial y en Guatemala; (ii) descripción de los modelos de caficultora sostenible; (iii) diagnóstico situacional de la Fedecocagua y de tres de sus cooperativas conforme el marco analítico de la investigación. Como conclusión, el trabajo identifica prácticas internacionales que pueden ser integradas en un código de conducta mínimo para el agronegocio sostenible del café verde en Guatemala.
54

Properties of Sequent-Calculus-Based Languages

Johnson-Freyd, Philip 10 April 2018 (has links)
Programmers don't just have to write programs, they are have to reason about them. Programming languages aren't just tools for instructing computers what to do, they are tools for reasoning. And, it isn't just programmers who reason about programs: compilers and other tools reason similarly as they transform from one language into another one, or as they optimize an inefficient program into a better one. Languages, both surface languages and intermediate ones, need therefore to be both efficiently implementable and to support effective logical reasoning. However, these goals often seem to be in conflict. This dissertation studies programming language calculi inspired by the Curry-Howard correspondence, relating programming languages to proof systems. Our focus is on calculi corresponding logically to classical sequent calculus and connected computationally to abstract machines. We prove that these calculi have desirable properties to help bridge the gap between reasoning and implementation. Firstly, we explore a persistent conflict between extensionality and effects for lazy functional programs that manifests in a loss of confluence. Building on prior work, we develop a new rewriting theory for lazy functions and control which we first prove corresponds to the desired equational theory and then prove, by way of reductions into a smaller system, to be confluent. Next, we turn to the inconsistency between weak-head normalization and extensionality. Using ideas from our study of confluence, we develop a new operational semantics and series of abstract machines for head reduction which show us how to retain weak-head reduction's ease of implementation. After demonstrating the limitations of the above approach for call-by-value or types other than functions, we turn to typed calculi, showing how a type system can be used not only for mixing different kinds of data, but also different evaluation strategies in a single program. Building on variations of the reducibility candidates method such as biorthogonality and symmetric candidates, we present a uniform proof of strong normalization for our mixed-strategy system which works so long as all the strategies used satisfy criteria we isolate. This dissertation includes previously published co-authored material.
55

Poder sobre a vida: Herbert Marcuse e a biopolítica / Power over life: Herbert Marcuse and biopolitics

Silvio Ricardo Gomes Carneiro 12 September 2014 (has links)
A pesquisa apresenta a teoria marcuseana do poder como perspectiva crítica no debate contemporâneo acerca do conceito foucaultiano de biopolítica. À primeira vista, tal relação parece controversa, ao reconhecer que Foucault desenvolve seu conceito paralelamente à crítica contra Marcuse. Ora, o conceito foucaultiano de biopolítica descreve jogos de poder como administração dos corpos e também como um modo de cálculo da vida da população. Tal concepção contraria diretamente a hipótese marcuseana do poder repressivo, um modelo crítico que tem em vista uma camada verdadeira e subjacente de poder, recalcada nas formações sociais e subjetivas estabelecidas. Com esse quadro, como reunir os dois autores na crítica do poder, assumindo a biopolítica como premissa da teoria do poder? De fato, a aproximação seria impossível ao partir da aposta marcuseana em uma civilização nãorepressiva, presente em Eros e Civilização. Contudo, com a análise do avanço da racionalidade instrumental no pós-Guerra em O Homem Unidimensional, Marcuse avalia a possibilidade de um poder não-repressiva. Afinal, na nova ordem social não se apresenta mais um controle repressivo dos corpos, mas sim uma excitação da vida e dos corpos em movimento. Seria este um sinal de concordância entre os autores? E ainda, dada esta nova correspondência, é possível aproveitar a crítica foucaultiana à biopolítica para redimensionar não apenas as reflexões de Marcuse sobre o poder, como também as passagens contemporâneas entre a teoria crítica e a genealogia do poder? / This research presents Marcuses theory of power as an essential perspective for the contemporary debate on the Foucaultian concept of biopolitics. This would seem a rather controversial choice at a first glance, as, admittedly, the development of Foucaults concept occurred alongside that of his critique of Marcuse. Indeed, Foucaults conception of biopolitics describes games of power that include the administration of the bodies and the calculated management of the life of a given population a notion entirely adverse to Marcuses repressive hypothesis of power, a critical model that assumes a real, subjacent layer of power that is repressed in established social and subjective formations. Given these differences, as well as an adoption of biopolitics as a fundamental premise for a theory of power, how are the two authors to be brought together for a critique of power? Such an approximation would certainly be impossible in light of Marcuses arguments, in Eros and Civilization, for the possibility of a non-repressive civilization. Still, through the analysis of the advancement of instrumental rationality in the postwar period conducted in One- Dimensional Man, Marcuse will revise his former perspective on non-repressive power; after all, the new social order no longer features a repressive control of bodies, but rather an excitation of life, and of bodies to motion. Could that be understood as a sign of agreement between the authors? Furthermore, given this new correspondence, would it be possible to employ Foucaults critique to add dimensions not only to Marcuses reflections on power, but to contemporary mediations between critical theory and the genealogy of power?
56

[en] THE ROLE OF METROLOGY AND METROLOGY-RELATED FUNCTIONS IN THE REGULATION OF THE FREE MOVEMENT OF GOODS: CONSIDERATIONS ON THE REVISION OF THE EUROPEAN REGULATORY FRAMEWORK / [pt] O PAPEL DA METROLOGIA E DE SUAS FUNÇÕES CORRELATAS NA LIVRE CIRCULAÇÃO DE PRODUTOS: CONSIDERAÇÕES SOBRE A REVISÃO DO MARCO REGULATÓRIO EUROPEU

CARL MARTIN WEHMER 01 June 2010 (has links)
[pt] A presente dissertação de mestrado tem como objetivo analisar, à luz das funções da infraestrutura tecnológica, as proposições do novo marco regulatório europeu para a livre circulação de produtos no mercado comum. Mais especificamente responder à questão formulada pela pesquisa: conseguirá esse novo marco regulatório equacionar e mitigar as deficiências do modelo anterior? Tendo em vista a atualidade do tema, o trabalho discute a importância da metrologia, da normalização, da acreditação e da avaliação da conformidade na eficiência da fiscalização do mercado em nível global e a relevância técnica e econômica que resultam desses processos. No campo institucional, a motivação pelo tema se deu pelo compromisso do Programa de Pós-Graduação em Metrologia de contribuir para o avanço do conhecimento sobre a regulação de mercados e de explorar o tema como oportunidade de fortalecer a ponte em temas da metrologia com a cidadania. No que concerne a metodologia, a pesquisa desenvolveu-se de forma estruturada segundo as seguintes fases complementares: (i) pesquisa bibliográfica e documental dos textos legais e regulamentos europeus aplicáveis; (ii) pesquisa de campo (iii) construção e aplicação do instrumento da pesquisa (questionário) junto a especialistas atuantes nas funções da infraestrutura tecnológica para a qualidade. Consubstanciando os propósitos da pesquisa de mestrado, o trabalho explicitou os resultados mais relevantes consolidados pelo amplo e participativo processo de revisão da legislação européia para a livre circulação de produtos e disponibilizou uma metodologia de avaliação. Finalmente, como conclusão, o trabalho definiu os determinantes da revisão do marco regulatório europeu à luz das mudanças de critérios de aplicação das funções da infraestrutura tecnológica. / [en] The aim of this M.Sc. dissertation is to analyze the New Regulatory Framework for the free movement of goods in the European market, in the light of the functions of the national quality infrastructure. More specifically, to answer the question posed by the study: will the New (and recently revised) Regulatory Framework be able to mitigate the shortcomings of the previous model? Moreover, the study discusses the significance of metrology, standardization, conformity assessment and accreditation for the effectiveness of market surveillance at a global level and the economic and technical relevance of these processes. The commitment of the Postgraduate Metrology Program (Metrology for Quality and Innovation) to contribute to the improvement of technical regulation, while bridging metrology to citizenship, reflect the motivation of this work. The methodology included: (i) a review of the specialized literature (e.g.: legal documentation and applicable European regulation); (ii) a field research and (iii) the development and application of the structured questionnaire to experts in functions of the quality infrastructure and European legislation. The study highlights the most relevant results of the thorough revision of the European regulation for the free movement of goods. It also provided a methodology of assessment for related issues. In tune with the precepts of the Postgraduate Metrology Programme committed to participate in the debate of current topics in metrology and related matters, the dissertation made available to Brazilian legislators lessons learnt by the European Union on the building of a common market. In conclusion, an experience particularly valuable to those committed to make MERCOSUR a successful undertaking. An endeavor of great proportions where goods, services, capital and labor can circulate freely providing the foundation for prosperity.
57

Normalization and Informed Decision-making in Public Health Programs: A Case Study of HPV Vaccination in Canada

Navaneelan, Tanya January 2012 (has links)
This thesis examined the evidence, policy decision-making, and implementation of HPV vaccination in Canada as a case study to explore normalization versus individualized decision making in public health programs. Mixed methods were used: a systematic review, content analyses and policy document analysis. Overall, the scientific evidence supported an effect of vaccination against HPV infection and precancerous cervical lesions, but evidence regarding cervical cancer incidence or mortality is lacking. Scientific and medical communities appeared optimistic about the vaccine, but cautious about its readiness for routine implementation. Policy decision-making was initially cautious, but shifted towards active program implementation, possibly related to the availability of federal funding. The educational materials and media coverage both sent clearly normalizing messages about HPV vaccination. The discussion suggests that HPV vaccination might be more suited to an individualized than population approach, but many factors coincided to promote its implementation, in Canada, within a traditional public health model.
58

Top-down influences on response properties in human visual cortex

Bloem, Ilona M. 28 January 2021 (has links)
The brain is highly efficient at processing complicated patterns of information, filtering ambiguous input it receives from the senses. Competition between these representations is regulated by multiple mechanisms, together forming a coherent percept of our environment. One approach to regulating incoming sensory information is the recruitment of a canonical neural computation: divisive normalization. Another approach to further steer processing towards behaviorally relevant goals is by means of cognitive influences. In this project I examined the degree to which cognitive processes interact with normalization to shape human visual perception. First, a set of fMRI experiments (Exps 1-3: n=6) examined the hypothesis that attention-driven gain modulation within human visual cortex is dependent on the magnitude of normalization. Leveraging the fact that normalization is modulated by similarity of visual features, my results illustrated that attentional modulation of BOLD responses is larger when visual cortex is put under stronger normalization. These results suggest that the degree to which a subpopulation exhibits normalization plays a role in dictating its potential for attentional benefits. Second, I examined how attention modulates visual population responses (n=7). Neurons within visual cortex exhibit a well-characterized relationship between stimulus intensity and the neural response, known as a contrast response function. While animal and psychophysical studies suggest that attention improves visual processing by multiplicatively increasing the gain of the contrast response, human fMRI studies instead report additive attentional effects, which act independently of stimulus contrast. Consistent with prior work, I demonstrated using a fMRI model-based analysis that attentional modulation indeed appears additive within early visual cortex. Lastly, I examined whether perceptual and memory representations are distinct from one another (Exp 1: n=12, Exp 2: n=10). A prevailing theory posits that the retention of visual memories involves maintenance of information within visual cortices. I tested the degree to which representations in visual memory undergo contrast normalization, by leveraging a classic demonstration: center- surround suppression. I obtained psychophysical measurements of perceived contrast and found robust normalization in perception, yet no signature of normalization occurring between visual memory representations. Taken together, this work helps unravel the underlying neural mechanisms by which cognitive influences shape visual perception.
59

Normalized in the public sphere : A quantitative content analysis and a qualitative framing analysis of the media coverage surrounding The Sweden Democrats from 2005 to 2021.

Skogli Andersson, Hanna January 2022 (has links)
A sudden rise in right wing parties has occurred throughout Europe, and this is no exception in Sweden. The Sweden Democrats have gone from a small, extremist party with founders who have roots in nazism and fascism, into the third largest party in Sweden. This study have analyzed articles from 2005, 2006, 2013, 2014, 2018 and 2021 in two of the biggest newspapers in Sweden, Aftonbladet and Expressen in order to discover patterns in media material that showcases how traditional and established media outlets such as the ones mentioned have changed, or not changed, their coverage surrounding The Sweden Democrats. The aim of the study is to analyze the apparent normalization of The Sweden Democrats through frames such as labeling, tonality and topics present in news articles from Aftonbladet and Expressen throughout their rise to power.The research questions were: Quantitative research question: - Has The Sweden Democrats been normalized in Aftonbladet and Expressen from 2005 to 2021 based on labeling, topic and tonality? If so, how? Qualitative research question:- What is the discourse(s) and frames surrounding The Sweden Democrats in Aftonbladet and Expressen in the consecutive years? In order to answer the quantitative research questions, and to fulfill the aim of the study, a content analysis was first done in a large number of articles throughout the years. In order to answer the qualitative research questions, a framing analysis with purposive sampling followed the content analysis, in order to take a closer look into the frames and discourses present in the material throughout the years. The findings of the study showed that there has been a shift in tonality, topics and labeling throughout the years. The findings showcased that the party in the beginning were labeled as extremists, while gradually becoming labeled as neutral and eventually established in the later years. This showcased a normalization of the party in the media throughout their rise in power.
60

Validation of a Radiometric Normalization Procedure for Satellite-Derived Imagery Within a Change Detection Framework

Callahan, Karin E. 01 May 2003 (has links)
Detecting changes in land cover through time using remotely sensed imagery is a powerful application that has seen increased use as imagery has become more widely available and inexpensive. Before a time series of remotely sensed imagery can be used for change detection, images must first be standardized for effects outside of real surface change. This thesis established a validation protocol to evaluate the effectiveness of an automated technique for normalizing temporally separate but spatially coincident imagery. Using the concept of pseudo-invariant features between master-slave image pairs, spatially coincident dark and bright points are identified from images and a regression equation is calculated to normalize slave images to a master. I used two sets of imagery to test the performance of the standardization process, a spatially coincident, but temporally variable time series, and spatially and temporally variable images. I tested the underlying statistical assumptions of this approach, and performed simple image subtraction to validate the reduction of master-slave differences using invariant locations. In addition I tested the possibility of reducing between-sensor differences by applying simple linear regression to comparable bands of MSS and TM sensors. Image subtraction showed decreases in master-slave differences as a result of the standardization process, and the process behaved appropriately when there should be no difference between master and slave images (adjacent, but temporally identical imagery). I also found that comparable bands between MSS and TM sensors are similar enough that linear regression may not significantly reduce between-sensor differences.

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