• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 230
  • 120
  • 79
  • 48
  • 28
  • 13
  • 8
  • 8
  • 4
  • 3
  • 3
  • 3
  • 2
  • 2
  • 2
  • Tagged with
  • 615
  • 194
  • 86
  • 82
  • 61
  • 47
  • 46
  • 46
  • 44
  • 41
  • 40
  • 37
  • 36
  • 36
  • 35
  • 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.
301

Sorry, I apologize! : The difference between men’s and women’s usage of apologies in emails

Lindroth, Gustav, Ucar, Rebecca January 2022 (has links)
This essay aims to discover differences and similarities in the linguistic behavior ofpoliteness in apologetic expressions between men and women in emails. Material wastaken from the Enron Corpus. This Corpus includes information about the senders andrecipients of the chosen email, the context, and an email thread. We searched for twodifferent apologetic expressions, "sorry" and "I apologize", and chose 25 of eachexpression to analyze superficially. We also compared them to each other and by thegender of the user. Out of those 25, we chose ten to analyze more in-depth, five ofwhich used "sorry" and the other five used "I apologize" as apologetic expression. Weanalyzed the emails through the lens of politeness theory, which apologetic expressionwas used, if humour occurred, and to what email genre it belonged. Our results basedon this study showed that women used the apologetic expression "I apologize" morethan men, and that men used "sorry" more frequently than women. One possibleconclusion of this is that women appeared to be more formal in their emails. They alsoindicated tendencies to be nurturing, cohesive, and cooperative in their language. On theother hand, men showed less tendencies of formal behavior and more informallanguage.
302

Dissociating neural signatures of mental state retrodiction and classification based on facial expressions

Kang, K., Schneider, D., Schweinberger, S.R., Mitchell, Peter 04 June 2020 (has links)
Yes / Posed facial expressions of actors have often been used as stimuli to induce mental state inferences, in order to investigate 'Theory of Mind' processes. However, such stimuli make it difficult to determine whether perceivers are using a basic or more elaborated mentalizing strategy. The current study used as stimuli covert recordings of target individuals who viewed various emotional expressions, which caused them to spontaneously mimic these expressions. Perceivers subsequently judged these subtle emotional expressions of the targets: in one condition ('classification') participants were instructed to classify the target's expression (i.e. match it to a sample) and in another condition ('retrodicting') participants were instructed to retrodict (i.e. infer which emotional expression the target was viewing). When instructed to classify, participants showed more prevalent activations in event-related brain potentials (ERPs) at earlier and mid-latency ERP components N170, P200 and P300-600. By contrast, when instructed to retrodict participants showed enhanced late frontal and fronto-temporal ERPs (N800-1000), with more sustained activity over the right than the left hemisphere. These findings reveal different cortical processes involved when retrodicting about a facial expression compared to merely classifying it, despite comparable performance on the behavioral task. / Experimental Psychology Society (EPS) Study Visit Grant; Young Researcher Support Grant DRM/2014-02; Deutsche Forschungsgemeinschaft (SCHN 1481/2-1); Deutsche Forschungsgemeinschaft (FOR 1097)
303

Learning Statistical and Geometric Models from Microarray Gene Expression Data

Zhu, Yitan 01 October 2009 (has links)
In this dissertation, we propose and develop innovative data modeling and analysis methods for extracting meaningful and specific information about disease mechanisms from microarray gene expression data. To provide a high-level overview of gene expression data for easy and insightful understanding of data structure, we propose a novel statistical data clustering and visualization algorithm that is comprehensively effective for multiple clustering tasks and that overcomes some major limitations of existing clustering methods. The proposed clustering and visualization algorithm performs progressive, divisive hierarchical clustering and visualization, supported by hierarchical statistical modeling, supervised/unsupervised informative gene/feature selection, supervised/unsupervised data visualization, and user/prior knowledge guidance through human-data interactions, to discover cluster structure within complex, high-dimensional gene expression data. For the purpose of selecting suitable clustering algorithm(s) for gene expression data analysis, we design an objective and reliable clustering evaluation scheme to assess the performance of clustering algorithms by comparing their sample clustering outcome to phenotype categories. Using the proposed evaluation scheme, we compared the performance of our newly developed clustering algorithm with those of several benchmark clustering methods, and demonstrated the superior and stable performance of the proposed clustering algorithm. To identify the underlying active biological processes that jointly form the observed biological event, we propose a latent linear mixture model that quantitatively describes how the observed gene expressions are generated by a process of mixing the latent active biological processes. We prove a series of theorems to show the identifiability of the noise-free model. Based on relevant geometric concepts, convex analysis and optimization, gene clustering, and model stability analysis, we develop a robust blind source separation method that fits the model to the gene expression data and subsequently identify the underlying biological processes and their activity levels under different biological conditions. Based on the experimental results obtained on cancer, muscle regeneration, and muscular dystrophy gene expression data, we believe that the research work presented in this dissertation not only contributes to the engineering research areas of machine learning and pattern recognition, but also provides novel and effective solutions to potentially solve many biomedical research problems, for improving the understanding about disease mechanisms. / Ph. D.
304

Detection and Characterization of Multilevel Genomic Patterns

Feng, Yuanjian 28 June 2010 (has links)
DNA microarray has become a powerful tool in genetics, molecular biology, and biomedical research. DNA microarray can be used for measuring the genotypes, structural changes, and gene expressions of human genomes. Detection and characterization of multilevel, high-throughput microarray genomic data pose new challenges to statistical pattern recognition and machine learning research. In this dissertation, we propose novel computational methods for analyzing DNA copy number changes and learning the trees of phenotypes using DNA microarray data. DNA copy number change is an important form of structural variations in human genomes. The copy number signals measured by high-density DNA microarrays usually have low signal-to-noise ratios and complex patterns due to inhomogeneous composition of tissue samples. We propose a robust detection method for extracting copy number changes in a single signal profile and consensus copy number changes in the signal profiles of a population. We adapt a solution-path algorithm to efficiently solve the optimization problems associated with the proposed method. We tested the proposed method on both simulation and real CGH and SNP microarray datasets, and observed competitively improved performance as compared to several widely-adopted copy number change detection methods. We also propose a chromosome instability measure to summarize the extracted copy number changes for assessing chromosomal instabilities of tumor genomes. The proposed measure demonstrates distinct patterns between different subtypes of ovarian serous carcinomas and normal samples. Among active research on complex human diseases using genomic data, little effort and progress have been made in discovering the relational structural information embedded in the molecular data. We propose two stability analysis based methods to learn stable and highly resolved trees of phenotypes using microarray gene expression data of heterogeneous diseases. In the first method, we use a hierarchical, divisive visualization approach to explore the tree of phenotypes and a leave-one-out cross validation to select stable tree structures. In the second method, we propose a node bandwidth constraint to construct stable trees that can balance the descriptive power and reproducibility of tree structures. Using a top-down merging procedure, we modify the binary tree structures learned by hierarchical group clustering methods to achieve a given node bandwidth. We use a bootstrap based stability analysis to select stable tree structures under different node bandwidth constraints. The experimental results on two microarray gene expression datasets of human diseases show that the proposed methods can discover stable trees of phenotypes that reveal the relationships between multiple diseases with biological plausibility. / Ph. D.
305

Measuring Consumer Emotional Response to Tastes and Foods through Facial Expression Analysis

Arnade, Elizabeth Amalia 15 January 2014 (has links)
Emotions are thought to play a crucial role in food behavior. Non-rational emotional decision making may be credited as the reason why consumers select what, how, and when they choose to interact with a food product. In this research, three experiments were completed for the overall goal of understanding the usefulness and validity of selected emotional measurement tools, specifically emotion questionnaire ballots and facial expression analysis, as compared to conventional sensory methods in developing a holistic view of product interest and engagement. Emotional response to 1% low-fat unflavored and chocolate-flavored milk was evaluated by using an emotion-based questionnaire as well as facial expression analysis software, to measure post-experience cognitive and in-the-moment intrinsic (implicit) emotional response, respectively. The software correlated facial movements of participants to associated basic emotions to estimate with what degree consumers were expressing these measured emotions upon presentation of each sample. Finally, the adapted facial expression method was compared to expected measurements from previous studies by measuring emotional facial response to four (sweet, salt, sour, and bitter) basic tastes. The cognitive emotion ballot and implicit facial analysis were able to differentiate between milk samples and offer a greater understanding of the consumer experience. Validity of the facial expression method was lacking for reasons including high individual taste variability, social context, intensities of stimuli, quality of video data capture, calibration settings, sample size number, analysis duration, and software sensitivity limitations. To better validate automatic facial expression methodology, further study is needed to investigate and minimize method limitations. / Master of Science in Life Sciences
306

The effect of ad smiles on consumer attitudes and intentions: influence of model gender and consumer gender

Trivedi, Rohit, Teichert, T. 03 February 2019 (has links)
Yes / Firms widely use smiling models to create a positive background setting for advertisements. This study assesses the various effects of smiling in print advertisements across different stages of consumer decision-making, while also considering interaction effects between the genders of models and viewers. Empirical evidence comes from 175,647 consumer evaluations of 421 real advertisements across a broad spectrum of product categories (22). Beyond gender, a smiling model not only effects a positive attitude change but also influences a product's integration into a relevant set and a consumer's purchase intention. For female consumers, a smiling model of the same gender exerts a greater influence on positive brand attitude change and on purchase intention. Advertisers should avoid using non-smiling male models when targeting female consumers. In contrast, smiling models of both genders can positively influence male consumer reaction, while use of a female model should be avoided during the early stages.
307

Effect of transforming growth factor-β2 on biological regulation of multilayer primary chondrocyte culture

Khaghani, Seyed A., Akbarova, G., Soon, C.F., Dilbazi, G. 2018 October 1930 (has links)
Yes / Cytokines are extremely potent biomolecules that regulate cellular functions and play multiple roles in initiation and inhibition of disease. These highly specialised macromolecules are actively involved in control of cellular proliferation, apoptosis, cell migration and adhesion. This work, investigates the effect of transforming growth factor-beta2 (TGF-β2) on the biological regulation of chondrocyte and the repair of a created model wound on a multilayer culture system. Also the effect of this cytokine on cell length, proliferation, and cell adhesion has been investigated. Chondrocytes isolated from knee joint of rats and cultured at 4 layers. Each layer consisted of 2 × 105 cells/ml with and without TGF-β2. The expression of mRNA and protein levels of TGF-β receptors and Smad1, 3, 4, and 7 have been analysed by RT-PCR and western blot analysis. The effect of different supplementations in chondrocyte cell proliferation, cell length, adhesion, and wound repair was statistically analysed by One-way ANOVA test. Our results showed that the TGFβ2 regulates mRNA levels of its own receptors, and of Smad3 and Smad7. Also the TGF-β2 caused an increase in chondrocyte cell length, but decreased its proliferation rate and the wound healing process. TGF-β2 also decreased cell adhesion ability to the surface of the culture flask. Since, TGF-β2 increased the cell size, but showed negative effect on cell proliferation and adhesion of CHC, the effect of manipulated TGF-β2 with other growth factors and/or proteins needs to be investigated to finalize the utilization of this growth factor and design of scaffolding in treatment of different types of arthritis.
308

Incremental Matching on Word Chains

Nilsson, Wilmer January 2024 (has links)
Pattern matching, which is the process of finding a given pattern in a given text, is widely used in areas such as search and replace functions in text processing programs or in DNA sequence analysis, where the pattern can be a search term or a specific sequence of characters. Finding and analysing nucleic acid sequences in DNA data can in some cases require sequences to be found which in turn are made up of several specific sub sequences, where the nucleotides between them, as well as the number of them, are irrelevant. This pattern, also called a word chain, can more efficiently be found by pre-processing the pattern and text. This thesis explores, investigates and presents a data structure, used to match a word chain pattern, with the ability to incrementally alter this pre-computed information in order to more efficiently, time wise, handle text alterations such as split and concatenation operations.
309

L’utilisation de l’information visuelle en reconnaissance d’expressions faciales d’émotion

Blais, Caroline 09 1900 (has links)
L’aptitude à reconnaitre les expressions faciales des autres est cruciale au succès des interactions sociales. L’information visuelle nécessaire à la catégorisation des expressions faciales d’émotions de base présentées de manière statique est relativement bien connue. Toutefois, l’information utilisée pour discriminer toutes les expressions faciales de base entre elle demeure encore peu connue, et ce autant pour les expressions statiques que dynamiques. Plusieurs chercheurs assument que la région des yeux est particulièrement importante pour arriver à « lire » les émotions des autres. Le premier article de cette thèse vise à caractériser l’information utilisée par le système visuel pour discriminer toutes les expressions faciales de base entre elles, et à vérifier l’hypothèse selon laquelle la région des yeux est cruciale pour cette tâche. La méthode des Bulles (Gosselin & Schyns, 2001) est utilisée avec des expressions faciales statiques (Exp. 1) et dynamiques (Exp. 2) afin de trouver quelles régions faciales sont utilisées (Exps. 1 et 2), ainsi que l’ordre temporel dans lequel elles sont utilisées (Exp. 2). Les résultats indiquent que, contrairement à la croyance susmentionnée, la région de la bouche est significativement plus utile que la région des yeux pour discriminer les expressions faciales de base. Malgré ce rôle prépondérant de la bouche, c’est toute de même la région des yeux qui est sous-utilisée chez plusieurs populations cliniques souffrant de difficultés à reconnaitre les expressions faciales. Cette observation pourrait suggérer que l’utilisation de la région des yeux varie en fonction de l’habileté pour cette tâche. Le deuxième article de cette thèse vise donc à vérifier comment les différences individuelles en reconnaissance d’expressions faciales sont reliées aux stratégies d’extraction de l’information visuelle pour cette tâche. Les résultats révèlent une corrélation positive entre l’utilisation de la région de la bouche et l’habileté, suggérant la présence de différences qualitatives entre la stratégie des patients et celle des normaux. De plus, une corrélation positive est retrouvée entre l’utilisation de l’œil gauche et l’habileté des participants, mais aucune corrélation n’est retrouvée entre l’utilisation de l’œil droit et l’habileté. Ces résultats indiquent que la stratégie des meilleurs participants ne se distingue pas de celle des moins bons participants simplement par une meilleure utilisation de l’information disponible dans le stimulus : des différences qualitatives semblent exister même au sein des stratégies des participants normaux. / The ability to recognize facial expressions is crucial for the success of social communication. The information used by the visual system to categorize static basic facial expressions is now relatively well known. However, the visual information used to discriminate the basic facial expressions from one another is still unknown, and this is true for both static and dynamic facial expressions. Many believe that the eye region of a facial expression is particularly important when it comes to reading others' emotions. The aim of the first article of this thesis is to determine which information is used by the visual system in order to discriminate between the basic facial expressions and to verify the validity of the hypothesis that the eye region is crucial for this task. The Bubbles method (Gosselin & Schyns, 2001) is used with static (Exp. 1) and dynamic (Exp. 2) facial expressions in order to determine which facial areas are used for the task (Exp. 1) and in which temporal order these facial areas are used (Exp. 2). The results show that, in contrast with the aforementioned belief, the mouth region is significantly more useful than the eye region when discriminating between the basic facial expressions. Despite this preponderant role of the mouth, it is the eye area⎯not the mouth area⎯that is underutilized by many clinical populations suffering from difficulties in recognizing facial expressions. This observation could suggest that the utilization of the eye area varies as a function of the ability to recognize facial expressions. The aim of the second article in this thesis is thus to verify how individual differences in the ability to recognize facial expressions relate to the visual information extraction strategies used for this task. The results show a positive correlation between the ability of the participants and the utilization of the mouth region, suggesting the existence of qualitative differences between the strategy of clinical patients and of normal participants. A positive correlation is also found between the ability of the participants and the utilization of the left eye area, but no correlation is found between the ability and the utilization of the right eye area. These results suggest that the difference between the strategies of the best and the worst participants is not only that the best ones use the information available in the stimulus more efficiently: rather, qualitative differences in the visual information extraction strategies may exist even within the normal population.
310

L’influence du vieillissement normal et pathologique sur le traitement des expressions faciales et du jugement de confiance

Éthier-Majcher, Catherine 04 1900 (has links)
Déterminer si quelqu’un est digne de confiance constitue, tout au long de notre vie, une décision à la base de nos interactions sociales quotidiennes. Des études récentes chez les jeunes adultes ont proposé que le jugement de confiance basé sur un visage constituerait une extension des processus de reconnaissance des expressions faciales, particulièrement de la colère et de la joie (Todorov, 2008). Bien que le jugement de confiance soit d’une grande importance tout au long de notre vie, à notre connaissance, aucune étude n’a tenté d’explorer l’évolution de ce processus au cours du vieillissement. Pourtant, sachant que les personnes âgées saines sont moins efficaces que les jeunes adultes pour reconnaître les expressions faciales émotionnelles (Ruffman et al., 2008; Calder et al., 2003), des différences pourraient exister dans les capacités de ces deux groupes d’âge à poser un jugement de confiance. Le présent travail a permis d’explorer, pour une première fois, les processus perceptifs sous-jacents au jugement de confiance chez une population âgée saine ainsi que chez une population présentant une démence fronto-temporale. Les résultats démontrent que les représentations de colère, de joie et de confiance sont similaires chez les jeunes et les âgés sains et suggèrent qu’il existe bel et bien un lien entre le jugement de confiance et les jugements de joie et de colère. De plus, ils révèlent que ce lien persiste au cours vieillissement, mais que les adultes âgés sains se fient davantage à leur représentation de la colère que les jeunes adultes pour déterminer si un visage est digne de confiance ou non. Enfin, les patients présentant une démence fronto-temporale possèdent des représentations différentes des âgés sains en ce qui concerne la colère, la joie et la confiance, et ils semblent se fier davantage à leur représentation de la joie que les âgés sains pour déterminer le niveau de confiance d’un visage. / To determine whether someone looks trustworthy or not is, throughout our lives, a basic decision in our social interactions. Recent studies have suggested that this type of judgment may be an extension of facial expression judgments, more specifically of anger and happiness judgments (Todorov, 2008). Even though trustworthiness judgments play a great role in our social interactions throughout our lives, little is known about the evolution of this process through aging. However, knowing that older adults are less efficient than younger adults in identifying facial expressions (Ruffman et al., 2008; Calder et al., 2003), one could expect to find differences between young and older adults in the way they judge trustworthiness. This work aimed to explore, for the first time, perceptual processes underlying trustworthiness judgments in a healthy older adult population as well as in a population of fronto-temporal dementia (FTD) patients. Results show that anger, happiness and trustworthiness representations are similar between young and older adults, and they suggest that a relationship does exist between emotional judgments and trustworthiness judgments. Moreover, results show that this relationship persists throughout aging, but that older adults rely more on their representation of anger than younger in adults while judging trustworthiness. Finally, patients with fronto-temporal dementia show different representations of anger, happiness and trustworthiness than that of the controls. Also, for trustworthiness judgments, they rely more on their representation of happiness than controls.

Page generated in 0.0686 seconds