The role of biases in on-line learning of two-layer networks

The influence of biases on the learning dynamics of a two-layer neural network, a normalized soft-committee machine, is studied for on-line gradient descent learning. Within a statistical mechanics framework, numerical studies show that the inclusion of adjustable biases dramatically alters the learning dynamics found previously. The symmetric phase which has often been predominant in the original model all but disappears for a non-degenerate bias task. The extended model furthermore exhibits a much richer dynamical behavior, e.g. attractive suboptimal symmetric phases even for realizable cases and noiseless data.

Brand extensions in emerging markets:theory development and testing in China

Brand extensions are increasingly used by multinational corporations in emerging markets such as China. However, understanding how consumers in the emerging markets evaluate brand extensions is hampered by a lack of research in the emerging markets contexts. To address the knowledge void, we built on an established brand extension evaluation framework in the West, namely Aaker and Keller (1990)1. Aaker , D. A. and Keller , K. L. 1990 . Consumer evaluations of brand extensions . Journal of Marketing , 54 ( 1 ) : 27 – 41 . [CrossRef], [Web of Science ®] View all references, and extended the model by incorporating two new factors: perceived fit based on brand image consistency and competition intensity in the brand extension category. The additions of two factors are made in recognition of the uniqueness of the considerations of consumers in the emerging markets in their brand extension evaluations. The extended model was tested by an empirical experiment using consumers in China. The results partly validated the Aaker and Keller model, and evidence that both newly added factors were significant in influencing consumers' evaluation of brand extensions was also found. More important, one new factor proposed, namely, consumer-perceived fit based on brand image consistency, was found to be more significant than all the factors in Aaker and Keller's original model, suggesting that the Aaker and Keller model may be limited in explaining how consumers in the emerging markets evaluate brand extensions. Further research implications and limitations are discussed in the paper.

Még egyszer a motivációról, avagy "Hogyan ösztönözzük alkalmazottainkat itt és most?" (Once again on the motivation or "how to motivate our employees here and now?")

A szerzők a Budapesti Corvinus Egyetem Vezetéstudományi Intézetében számos vezetőképző program, posztgraduális kurzus és mesterképzés hallgatóinak részvételével végeztek feltáró jellegű kutatásokat a munkahelyi motiváció elméletének és gyakorlatának témájában. A résztvevők saját élményeikből és tapasztalataikból kiindulva sorolták be a megélt eseteket a herzbergi kategóriákba. Ezek alapjában véve megerősítették Herzberg motivátorokról és higiénés tényezőkről alkotott elképzeléseit. Nem egyértelmű ugyanakkor, hogy kikre is érvényesek Herzberg tézisei. Az eddigi mintákba ugyanis általában azok kerültek, akik vagy már vezető pozíciókban voltak, vagy erre készültek, azaz alapvetően a „vezetői motivációkkal” bíró emberek motivációs, illetve higiénés tényezőire kaptak eddig rálátást. De vajon mi a helyzet azokkal, akik a szervezeti hierarchia más szintjein helyezkednek el? Elméleti és gyakorlati szempontból egyaránt releváns kérdés, hogy az eredeti elmélet érvényességét hogyan lehetne kimondottan beosztottakon megvizsgálni, itt és most? A szerzők írásukban ezekre a kérdésekre keresik a választ: az eredeti modellt egy kérdőíves és interjús módszertanra épülő kutatás eredményein értelmezik (illetve értelmezik újra) és igyekeznek pontosítani Herzberg elméletének mai mondanivalóit. / === / The authors have created exploratory researches in the theory and practice of the workplace motivation with the participation of mba, postgraduate and master students in the institute of management of corvinus university of budapest. The participants were classified their lived cases into categories of Herzberg starting from own experiences. These basically confirmed Herzberg’s visions from motivators and hygiene factors. In this study the authors search motivations of employees based on Herzberg’s categories. The original model is interpreted the results of a questionnaire and an interview-based methodology, and the authors try to clarify the contemporary meanings of Herzberg’s theory.

Extending the Theory of Planned Behavior in the exercise domain: A study of community college students in an urban multicultural setting

The purpose of this study was to assess the intention to exercise among ethnically and racially diverse community college students using the Theory of Planned Behavior (TPB). In addition to identifying the variables associated with motivation or intention of college students to engage in physical activity, this study tested the model of the Theory of Planned Behavior, asking: Does the TPB model explain intention to exercise among a racially/ethnically diverse group of college students? ^ The relevant variables were the TPB constructs (behavioral beliefs, normative beliefs, and control beliefs), which combined to form a measure of intention to exercise. Structural Equation Modeling was used to test the predictive power of the TPB constructs for predicting intention to exercise. Following procedures described by Ajzen (2002), the researcher developed a questionnaire encompassing the external variables of student demographics (age, gender, work status, student status, socio-economic status, access to exercise facilities, and past behavior), major constructs of the TPB, and two questions from the Godin Leisure Time Questionnaire (GLTQ; Godin & Shephard, 1985). Participants were students (N = 255) who enrolled in an on-campus wellness course at an urban community college. ^ The demographic profile of the sample revealed a racially/ethnically diverse study population. The original model that was used to reflect the TPB as developed by Ajzen was not supported by the data analyzed using SEM; however, a revised model that the researcher thought was theoretically a more accurate reflection of the causal relations between the TPB constructs was supported. The GLTQ questions were problematic for some students; those data could not be used in the modeling efforts. The GLTQ measure, however, revealed a significant correlation with intention to exercise (r = .27, p = .001). Post-hoc comparisons revealed significant differences in normative beliefs and attitude toward exercising behavior between Black students and Hispanic students. Compared to Black students, Hispanic students were more likely to (a) perceive “friends” as approving of them being physically active and (b) rate being physically active for 30 minutes per day as “beneficial”. No statistically significant difference was found among groups on overall intention to exercise. ^

Formulações e algoritmos para o problema das p-medianas heterogêneo livre de penalidade

This work presents a new model for the Heterogeneous p-median Problem (HPM), proposed to recover the hidden category structures present in the data provided by a sorting task procedure, a popular approach to understand heterogeneous individual’s perception of products and brands. This new model is named as the Penalty-free Heterogeneous p-median Problem (PFHPM), a single-objective version of the original problem, the HPM. The main parameter in the HPM is also eliminated, the penalty factor. It is responsible for the weighting of the objective function terms. The adjusting of this parameter controls the way that the model recovers the hidden category structures present in data, and depends on a broad knowledge of the problem. Additionally, two complementary formulations for the PFHPM are shown, both mixed integer linear programming problems. From these additional formulations lower-bounds were obtained for the PFHPM. These values were used to validate a specialized Variable Neighborhood Search (VNS) algorithm, proposed to solve the PFHPM. This algorithm provided good quality solutions for the PFHPM, solving artificial generated instances from a Monte Carlo Simulation and real data instances, even with limited computational resources. Statistical analyses presented in this work suggest that the new algorithm and model, the PFHPM, can recover more accurately the original category structures related to heterogeneous individual’s perceptions than the original model and algorithm, the HPM. Finally, an illustrative application of the PFHPM is presented, as well as some insights about some new possibilities for it, extending the new model to fuzzy environments

Solitons in Exciton-Polariton System: Reduced Modelling, Analysis, and Numerical Studies

In this dissertation, we study the behavior of exciton-polariton quasiparticles in semiconductor microcavities, under the sourceless and lossless conditions.

First, we simplify the original model by removing the photon dispersion term, thus effectively turn the PDEs system to an ODEs system,

and investigate the behavior of the resulting system, including the equilibrium points and the wave functions of the excitons and the photons.

Second, we add the dispersion term for the excitons to the original model and prove that the band of the discontinuous solitons now become dark solitons.

Third, we employ the Strang-splitting method to our sytem of PDEs and prove the first-order and second-order error bounds in the $H^1$ norm and the $L_2$ norm, respectively.

Using this numerical result, we analyze the stability of the steady state bright soliton solution. This solution revolves around the $x$-axis as time progresses

and the perturbed soliton also rotates around the $x$-axis and tracks closely in terms of amplitude but lags behind the exact one. Our numerical result shows orbital

stability but no $L_2$ stability.

Extending the Theory of Planned Behavior in the Exercise Domain: A Study of Community College Students in an Urban Multicultural Setting

The purpose of this study was to assess the intention to exercise among ethnically and racially diverse community college students using the Theory of Planned Behavior (TPB). In addition to identifying the variables associated with motivation or intention of college students to engage in physical activity, this study tested the model of the Theory of Planned Behavior, asking: Does the TPB model explain intention to exercise among a racially/ethnically diverse group of college students? The relevant variables were the TPB constructs (behavioral beliefs, normative beliefs, and control beliefs), which combined to form a measure of intention to exercise. Structural Equation Modeling was used to test the predictive power of the TPB constructs for predicting intention to exercise. Following procedures described by Ajzen (2002), the researcher developed a questionnaire encompassing the external variables of student demographics (age, gender, work status, student status, socio-economic status, access to exercise facilities, and past behavior), major constructs of the TPB, and two questions from the Godin Leisure Time Questionnaire (GLTQ; Godin & Shephard, 1985). Participants were students (N = 255) who enrolled in an on-campus wellness course at an urban community college. The demographic profile of the sample revealed a racially/ethnically diverse study population. The original model that was used to reflect the TPB as developed by Ajzen was not supported by the data analyzed using SEM; however, a revised model that the researcher thought was theoretically a more accurate reflection of the causal relations between the TPB constructs was supported. The GLTQ questions were problematic for some students; those data could not be used in the modeling efforts. The GLTQ measure, however, revealed a significant correlation with intention to exercise (r = .27, p = .001). Post-hoc comparisons revealed significant differences in normative beliefs and attitude toward exercising behavior between Black students and Hispanic students. Compared to Black students, Hispanic students were more likely to (a) perceive “friends” as approving of them being physically active and (b) rate being physically active for 30 minutes per day as “beneficial”. No statistically significant difference was found among groups on overall intention to exercise.

Assimetria na volatilidade - O impacto das más notícias nas rendibilidades do PSI 20

Mestrado em Contabilidade e Gestão das Instituições Financeiras

Reconstructability of 3-Dimensional Upper Ocean Circulation from SWOT Sea Surface Height Measurements

Utilizing the framework of effective surface quasi-geostrophic (eSQG) theory, we explored the potential of reconstructing the 3D upper ocean circulation structures, including the balanced vertical velocity (w) field, from high-resolution sea surface height (SSH) data of the planned SWOT satellite mission. Specifically, we utilized the 1/30°, submesoscale-resolving, OFES model output and subjected it through the SWOT simulator that generates the along-swath SSH data with expected measurement errors. Focusing on the Kuroshio Extension region in the North Pacific where regional Rossby numbers range from 0.22 to 0.32, we found that the eSQG dynamics constitutes an effective framework for reconstructing the 3D upper ocean circulation field. Using the modeled SSH data as input, the eSQG-reconstructed relative vorticity (ζ) and w fields are found to reach a correlation of 0.7–0.9 and 0.6–0.7, respectively, in the 1,000m upper ocean when compared to the original model output. Degradation due to the SWOT sampling and measurement errors in the input SSH data for the ζ and w reconstructions is found to be moderate, 5–25% for the 3D ζ field and 15-35% for the 3D w field. There exists a tendency for this degradation ratio to decrease in regions where the regional eddy variability (or Rossby number) increases.

Towards the systematic simplification of mechanistic models

Mechanistic models used for prediction should be parsimonious, as models which are over-parameterised may have poor predictive performance. Determining whether a model is parsimonious requires comparisons with alternative model formulations with differing levels of complexity. However, creating alternative formulations for large mechanistic models is often problematic, and usually time-consuming. Consequently, few are ever investigated. In this paper, we present an approach which rapidly generates reduced model formulations by replacing a model’s variables with constants. These reduced alternatives can be compared to the original model, using data based model selection criteria, to assist in the identification of potentially unnecessary model complexity, and thereby inform reformulation of the model. To illustrate the approach, we present its application to a published radiocaesium plant-uptake model, which predicts uptake on the basis of soil characteristics (e.g. pH, organic matter content, clay content). A total of 1024 reduced model formulations were generated, and ranked according to five model selection criteria: Residual Sum of Squares (RSS), AICc, BIC, MDL and ICOMP. The lowest scores for RSS and AICc occurred for the same reduced model in which pH dependent model components were replaced. The lowest scores for BIC, MDL and ICOMP occurred for a further reduced model in which model components related to the distinction between adsorption on clay and organic surfaces were replaced. Both these reduced models had a lower RSS for the parameterisation dataset than the original model. As a test of their predictive performance, the original model and the two reduced models outlined above were used to predict an independent dataset. The reduced models have lower prediction sums of squares than the original model, suggesting that the latter may be overfitted. The approach presented has the potential to inform model development by rapidly creating a class of alternative model formulations, which can be compared.

Conservadorismo e herança institucional de financiamento das companhias abertas do Brasil

Tese (doutorado)—Universidade de Brasília, Universidade Federal da Paraíba, Universidade Federal do Rio Grande do Norte, Programa Multi-Institucional e Inter-Regional de Pós-Graduação em Ciências Contábeis, 2015.

Expetativas, perceções e a qualidade do serviço : estudo da prestação de serviços dentários da clínica Dental7

Mestrado em Ciências Empresariais

Formulação do quadro estratégico e plano de marketing da Fundação Rebikoff-Niggeler

Mestrado em Marketing

Avaliação da performance organizacional e gestão estratégica no sector público; contributos para a construção de um balanced scorecard na Universidade de Évora: Trabalho de projecto

A Administração Pública tem sido alvo de uma reflexão sistemática, que pretende encontrar políticas de gestão que consigam solucionar os problemas de performance dos serviços públicos, evidenciando as suas potencialidades e procurando responder aos desafios com que se confrontam na atualidade. O fenómeno da globalização está na origem de acelerados ciclos de mudança que exigem das organizações urna gestão mais cativa e objetiva, alicerçada em métodos de gestão moderna que vão de encontro às exigências do mundo atual. Eficiência e eficácia dos serviços públicos são, mais do que nunca, duas imposições de uma sociedade crítica e carente de qualidade. A melhoria da performance do serviço público, mais do que urna necessidade, é uma exigência. Como responder a este desafio? Regra geral, os serviços públicos possuem urna fraca cultura de gestão estratégica, o que justifica parte da dificuldade que sentem em transformar a estratégia em objetivos operacionais, de forma a estabelecer ações que visem a obtenção de resultados, definindo medidas para a sua monitorização. O Balanced Scorecard (BSC) poderá contribuir para a implementação de uma cultura de gestão estratégica no Sector Público. A formulação dos objetivos estratégicos, das metas e dos indicadores, para cada uma das perspetivas subjacentes a esta metodologia, permite às organizações efetuarem uma gestão mais adequada dos sistemas que são objeto da sua acão. Este trabalho, partindo da identificação dos ajustamentos que é necessário efetuar ao modelo original de BSC de Kaplan e Norton, propõe um BSC adequado às Instituições de Ensino Superior Público (IESP) em geral e à Universidade de Évora em particular, assumindo-se que esse BSC poderá constituir uma importante ferramenta de gestão estratégica, essencial na avaliação e gestão da performance organizacional. ABSTRACT: The Public Administration has been the target of a systematic reflexion, who wish to find management policies that can resolve the performance problems on public services, showing their potential and aim to respond to the challenges they are facing today. The phenomenon of globalization is the cause of accelerated cycles of change that require organizations a more active and objective management, based on modern management methods that meet the demands of today’s world. Efficiency and effectiveness of public services are more than ever, two charges of a society criticism and lacking in quality. Improving the performance of public service, rather than a necessity is a requirement. How to respond to this challenge? Generally, the public services have a weak culture of strategic management, which explains part of the difficulty they feel in turning the strategy into operational objectives in order to establish measures aimed at achieving results, defining measures for its monitoring. The Balanced Scorecard can contribute to the implementation of a culture of strategic management in the Public Sector. The formulation of strategic objectives, targets and indicators for each of the perspectives that underlie this methodology enables organizations to make better management systems that are the subject of its action. This work, leaving from the identification of the adjustments that is necessary to effectuate to an original model of BSC of Kaplan and Norton, proposes a BSC appropriate to the Institutions of Superior Public Teaching (IESP) in general and to the University of Évora in individual, when are assumed that this BSC will be able to constitute an important tool of strategic, essential management in the evaluation and management of the organizational performance.

The hierarchic structure of fears: A cross-cultural replication with the fear survey schedule in a portuguese sample

A confirmatory attempt is made to assess the validity of a hierarchic structural model of fears. Using a sample comprising 1,980 adult volunteers in Portugal, the present study set out to delineate the multidimensional structure and hierarchic organization of a large set of feared stimuli by contrasting a higher-order model comprising general fear at the highest level against a first-order model and a unitary fear model. Following a refinement of the original model, support was found for a five-factor model on a first-order level, namely (1) Social fears, (2) Agoraphobic fears, (3) Fears of bodily injury, death and illness, (4) Fears of display to aggressive scenes, and (5) Harmless animals fears. These factors in turn loaded on a General fear factor at the second-order level. However, the firstorder model was as parsimonious as a hierarchic higher-order model. The hierarchic model supports a quantitative hierarchic approach which decomposes fear disorders into agoraphobic, social, and specific (animal and bloodinjury) fears.