1,293 research outputs found
PROVENTRICULAR INTUSSUSCEPTION IN A YELLOW ROSELLA (PLATYCERCUS FLAVEOLUS)
An intussusception is a situation in which a part of the gastrointestinal tract has prolapsed into another section of intestine, similar to the way in which the parts of a collapsible telescope slide into one another. The part which prolapses into the other is called the intussusceptum, and the part which receives it is called the intussuscipiens. This type of pathology is usually associated to the intestine tract of mammalian species. The author witnessed an unusual case of intussusception, affecting the proventriculus and ventriculus of a Yellow Rosella (Platycercus flaveolus) presented in advanced stage of disease. Although the diagnosis was made post-mortem, the bird was in a too severely debilitated status to have survived surgery, the only effective resolution for these cases. The following article gives a description of the case
Supervised Machine Learning in SAS Viya: Development of a Supervised Machine Learning pipeline in SAS Viya for comparison with a pipeline developed in Python
Internship Report presented as the partial requirement for obtaining a Master's degree in Data Science and Advanced Analytics, specialization in Business AnalyticsThis internship report details the development of a supervised ML pipeline in SAS Viya, a cloud-based environment composed of several solutions for importing, managing and transforming data and building and deploying predictive models into production environments. As a practical case study, this report showcases the SAS Viya features and capabilities which can be offered to the end-user. A comparison with a similar supervised ML pipeline in Python was made, to highlight both tools’ advantages and disadvantages. Thus, analytical tasks were employed, to demonstrate which different supervised ML techniques can be used in each technology.
Furthermore, it was shown that, depending on the experience and knowledge of the end-user, both SAS Viya and Jupyter Notebook/Python are able to produce satisfactory results, being the latter more suited to data scientists with some experience in programming and ML. At the same time, SAS Viya fits more for employees who are getting started in the ML field, due to its point-and-click user interface. On the other hand, building a supervised ML pipeline in SAS Viya can be more straightforward than in Jupyter Notebook/Python, since the code is already developed and the process automatized, while pipeline templates are made available to the user. However, due to its open-source nature, Python has more supervised ML techniques available to be used in Jupyter Notebook.
This report shows that these two solutions can complement each other, as SAS Viya offers good visualizations for data exploration, while Jupyter Notebook/Python can be dedicated to data transformation and predictive models’ development
Working capital management and profitability: the Telecom case
The Working Capital Management should be carried out as efficiently as possible in order to maximize value creation for the various stakeholders. This relationship between efficiency and profitability has been examined by several authors who have attempted to establish this relationship through the analysis of three elements: current financial management policies, size and industry.
The purpose of this study is to examine empirically the specific relationship between profitability and efficiency of working capital management in the worldwide telecommunication services industry. The sample consists of 48 companies classified by Reuters® as Integrated Telecommunication Operators, resulting in 488 firm-year observations for the period 1998-2009.
Through the analysis of descriptive statistics, Pearson correlation and of the regressions performed by the Fixed Effects Model, it is possible to conclude that the Net Trade Cycle is a better measure of efficiency of Working Capital Management in the telecommunication industry, when compared with the Cash Conversion Cycle. Another conclusion is that increasing the Net Trade Cycle represents an enhance of profitability of the telecom operators. This increase at the Net Trade Cycle level can be generated by reducing the number of days sales of accounts payable.
Overall, the telecommunication services companies may be facing some needs for investment at the Working Capital level.A Gestão das Necessidades em Fundo de Maneio deve ser efectuada da forma mais eficiente possível, de modo a potenciar a criação de valor para os diferentes stakeholders. Esta relação entre eficiência e rentabilidade tem sido objecto de análise por parte de diversos autores, os quais têm tentado estabelecer esta relação através da análise de três elementos: políticas de gestão financeira corrente, dimensão e indústria.
O objectivo do presente estudo é analisar, empiricamente, a relação específica entre rentabilidade e a eficiência da Gestão das Necessidades em Fundo de Maneio no sector dos serviços de telecomunicações a nível mundial. A amostra contém 48 empresas classificadas pela Reuters® como Operadores Integrados de Telecomunicações, traduzindo-se em 488 observações empresa-ano, com referência ao período de 1998 a 2009.
Através da análise da estatística descritiva, da correlação de Pearson e das regressões efectuadas pelo Método dos Efeitos Fixos, é possível concluir que o Ciclo Financeiro de Exploração se apresenta como melhor medida de eficiência da Gestão das Necessidades em Fundo de Maneio no sector das telecomunicações, quando comparado com o Ciclo de Conversão Monetário. Conclui-se também que aumentar o Ciclo Financeiro de Exploração se traduz num acréscimo na rentabilidade dos operadores de telecomunicações. Este aumento ao nível do Ciclo Financeiro de Exploração poderá ser gerado pela redução do número de dias de vendas de contas a pagar a fornecedores.
Em termos globais, os operadores de telecomunicações poderão estar defronte de necessidades de investimento ao nível das Necessidades de Fundo de Maneio
Study of neuromorphic properties of circuits based on resonant tunneling diodes
Tese de Mestrado Integrado, Engenharia Física, 2022, Universidade de Lisboa, Faculdade de CiênciasRTDs, with their negative differential conductance, small size, capability of high frequency of operation and excitable response have the potential to be implemented as basic components in spiking
neuromorphic circuits, i.e as nodes that produce and detect spikes.
The present study addresses the neuromorphic properties of resonant tunneling diodes (RTDs),
namely their spike generation and detection dynamics. The layout consists firstly on the basic requirements for neuromorphic implementations, followed by a description of the physics behind the RTDs
non-linear current voltage characteristic that creates the conditions for spike generation. The mechanisms and conditions by which the RTDs create an excitable response are then put-forward. After this, a
series of experimental measurements were carried out for different sized RTDs provided by the ChipAi
project. First the measurements of the RTDs I-V curves, followed by a characterisation on their operation
as a VCO, concluded with a study on their excitable all-or-nothing response to electrical perturbations.
Finally, several experimental activities were carried out to infer the properties and requirements of these
devices to work as potential neuromorphic devices. These parameters were the voltage thresholds, resting potentials and refractory times. these were then discussed for all of the different sized RTDs and
operation points. On top of this experimental study, tools of simulation were also designed and constructed for these RTDs devices followed by a verification study on not only on their VCO mode but also
their neuromorphic properties i.e. excitable response.
It was found that the RTDs can indeed function as spike generators when an appropriate disturbance
is applied in their bias voltage. The prospect for the scaling down of these devices to work as nanoneuromorphic devices seems promising due to the fact that smaller RTDs presented higher frequencies
of operation leading to shorter periods of oscillation and refractory times. The simulation tool, based on
the RLC model of the RTDs, developed using Matlab Simulink/Simscape and the I-V curves of these
devices, was able to emulate the oscillatory behaviour of the RTDs when biased in their NDC regions
and the neuromorphic property of excitability, again it was found that the scaling down of these devices
can lead to faster communication rates
Development and Application Of A Strategic Rail Network Optimization Model for Freight Transport
Estudo de Validação em Contexto Educativo da Versão Portuguesa da Escala Multidimensional de Motivação no Trabalho
A teoria da autodeterminação propõe uma conceptualização multidimensional da motivação e distingue como os diferentes tipos de motivação podem ser promovidos ou desencorajados. Para a sua aplicação ao contexto educativo, o presente estudo teve como objetivo a adaptação e validação da Escala Multidimensional de Motivação no Trabalho (MWMS). A escala foi respondidapor 468 professores em 30 agrupamentos de escolas do norte e centro de Portugal. A análise fatorial indicou uma escala de 19 itens com estrutura de fatores semelhante à obtida nos estudos originais. Neste estudo foi possível constatar que os itens que constituem o MWMS são bons indicadores dos construtos que se pretendem medir em contexto educativo e que os fatores se encontram devidamente individualizados. A escala demonstrou cinco dimensões robustas que admitem um entendimento lato da motivação, comuns aos estudos da escala original. A dimensão com melhor consistência interna é a desmotivação e a regulação introjetada é a mais baixa.La teoría de la autodeterminación propone una conceptualización multidimensional de la motivación y distingue como los diferentes tipos de motivación pueden ser promovidos o desalentados. Para su aplicación en el contexto educativo, la presente investigación tuvo como objetivo la adaptación e validación de la Escala Multidimensional de Motivación en el Trabajo (MWMS). La escala fue aplicada a 468 profesores en 30 Escuelas del Norte y Centro de Portugal. El análisis factorial indicó una escala de 19 ítems con una estructura de factores semejante a la obtenida en los estudios originales. En esta investigación fue posible constatar que los ítems que constituyen el MWMS son buenos indicadores de los constructos que se pretenden medir en contexto educativo y que los factores se encuentran debidamente individualizados. La escala demostró cinco dimensiones robustas que admiten una comprensión amplia de la motivación, comunes a los estudios de la escala original. La dimensión con mejor consistencia interna es la desmotivación, mientras que la regulación introyectada es la más baja.Abstrac The self-determination theory proposes a multidimensional concept of motivation and distinguishes how different types of motivation can be promoted or discouraged. For the application of the theory of self-determination to the educational context, this study aimed to adapt and validate the Multidimensional Work Motivation Scale (MWMS) in the educational context. The scale was answered by 419 teachers from 30 schools from the North and Center of Portugal. Factor analysis indicated that the 19-item scale has the same factor structure as that obtained in the original study. In this study, it was possible to identify that the items that constitute the MWMS are good indicators of constructs to be measured in an educational context and the factors are properly individualized. The scale showed five robust dimensions that permit a broad understanding of motivation, similar to the studies of the original scale. The dimension with the best internal consistency is demotivation, while introjected regulation obtained the lowest coefficient
- …