4,247 research outputs found
A PC parallel port button box provides millisecond response time accuracy under Linux
No full textFor psychologists, it is sometimes necessary to measure people's reaction times to the nearest millisecond. This article describes how to use the PC parallel port to receive signals from a button box to achieve millisecond response time accuracy. The workings of the parallel port, the corresponding port addresses, and a simple Linux program for controlling the port are described. A test of the speed and reliability of button box signal detection is reported. If the reader is moderately familiar with Linux, this article should provide sufficient instruction for him or her to build and test his or her own parallel port button box. This article also describes how the parallel port could be used to control an external apparatus
Millisecond accuracy video display using OpenGL under Linux
No full textTo measure people’s reaction times to the nearest millisecond, it is necessary to know exactly when
a stimulus is displayed. This article describes how to display stimuli with millisecond accuracy on a
normal CRT monitor, using a PC running Linux. A simple C program is presented to illustrate how this
may be done within X Windows using the OpenGL rendering system. A test of this system is reported
that demonstrates that stimuli may be consistently displayed with millisecond accuracy. An algorithm
is presented that allows the exact time of stimulus presentation to be deduced, even if there are relatively
large errors in measuring the display time
Frontmatter (Titlepage, Table of Contents, Author List, PC List, Reviewer List)
No full textFront matter including table of contents, author list, PC list, and reviewer list
High efficiency implementation of PC and PC stable algorithms yields three-dimensional graphs of information flow for the Earth' atmosphere
No full textSeptember 3, 2014.Causal discovery algorithms have recently been applied to several climate applications. In particular, in prior work we have developed methods to recover pathways of interaction in the global climate system, using the classic PC algorithm. However, standard implementations of the PC algorithm cannot handle the large number of variables and temporal models required for this application. This technical report shows that a more efficient implementation of the PC algorithm can provide speed gains of a factor of 1,000 or more. This in turn enables us to calculate graphs of information flow with much higher resolution grids. Furthermore, we can now - for the first time ever - calculate information flow graphs that extend over three dimensions, i.e. rather than just including one layer of the planet's atmosphere we can now capture interactions across several height layers
State variable simulation package for IBM-PC
No full textThis thesis was scanned from the print manuscript for digital preservation and is copyright the author.
Researchers can access this thesis by asking their local university, institution or public library to
make a request on their behalf. Monash staff and postgraduate students can use the link in the References field
Degradation of bisphenol-a-polycarbonate (BPA-PC) optical lenses under simulated harsh environment conditions
No full textThis paper investigates degradation and failure mechanisms of BPA-PC lenses in simulated harsh environment conditions. Exposure of secondary optics in Light Emitting Diode LED-based systems or any other similar applications to environmental stresses can adversely effect the performance and lifetime of products. This paper simulates a harsh environment condition, using a salt bath oven. Salt spray exposure/ageing tests at 45° C were carried out up to four months. Fourier transform infrared-attenuated total reflection FTIR-ATR spectrometer and Lambda 950 Ultraviolet-Visible (UV-VIS) spectrophotometer were used to study the optical and chemical characteristics of aged plates. Results showed that salt bath exposure test resulted in the severe deterioration of optical characteristics BPA-PC samples. Degradation of optical properties of BPA-PC plates is attributable to the oxidation of samples.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Electronic Components, Technology and Material
Heavy pentaquark states Pc(4380) and Pc(4450) in the J/ψ production induced by pion beams off the nucleon
No full textAbstractIn this study, we investigate the J/ψ production induced by pion beams off the nucleon, particularly the heavy pentaquarks Pc(4380) and Pc(4450) in intermediate states, based on a hybridized Regge model. The process involving ρ and π meson exchange in the t channel is considered as background, and the heavy pentaquark exchange is included in the s channel. The coupling constants such as the ρNN and πNN vertices are taken from the NN potentials, whereas those for the J/ψρπ and J/ψππ vertices are determined by using experimental data based on the branching ratios. In order to estimate the Pc(4380) and Pc(4450) coupling constants, we use the experimental upper limit on the total cross section as a guide for the πN→J/ψN reaction. The background total cross section is the order of 10−4–10−3 nb. In the vicinity of the heavy pentaquark masses, the total cross section reaches about 1 nb
Data Assimilation for Full 4D PC-MRI Measurements: Physics-Based Denoising and Interpolation
No full textPhase-Contrast Magnetic Resonance Imaging (PC-MRI) surpasses all other imaging methods in quality and completeness for measuring time-varying volumetric blood flows and has shown potential to improve both diagnosis and risk assessment of cardiovascular diseases. However, like any measurement of physical phenomena, the data are prone to noise, artefacts and has a limited resolution. Therefore, PC-MRI data itself do not fulfil physics fluid laws making it difficult to distinguish important flow features. For data analysis, physically plausible and high-resolution data are required. Computational fluid dynamics provides high-resolution physically plausible flows. However, the flow is inherently coupled to the underlying anatomy and boundary conditions, which are difficult or sometimes even impossible to adequately model with current techniques. We present a novel methodology using data assimilation techniques for PC-MRI noise and artefact removal, generating physically plausible flow close to the measured data. It also allows us to increase the spatial and temporal resolution. To avoid sensitivity to the anatomical model, we consider and update the full 3D velocity field. We demonstrate our approach using phantom data with various amounts of induced noise and show that we can improve the data while preserving important flow features, without the need of a highly detailed model of the anatomy.Computer Graphics and Visualisatio
Web 2.0, PC e EFA: impactes de uma oficina de formação de professores
No full textDoutoramento em Multimédia em EducaçãoAs competências em Tecnologia da Informação e Comunicação (TIC) e o
Pensamento Crítico (PC) são duas das linhas orientadoras da Aprendizagem
ao Longo da Vida (ALV) que reconhecendo que todos os contextos (informais,
não-formais e formais) podem ser de aprendizagem, assumiram no quadro da
Educação e Formação de Adultos (EFA), em Portugal, uma expressividade
plasmada no Referencial de Competências-Chave de Educação e Formação
de Adultos, nível secundário (EFA-NS). Contudo a orientação PC/TIC não tem
sido explicitamente conciliada nas práticas de educação e formação de
adultos.
Neste contexto desenvolveu-se uma Oficina de Formação para
professores/formadores de cursos EFA-NS, na qual se trabalhou a integração
de ferramentas da Web 2.0 com a infusão de PC em materiais/atividades para
cursos EFA-NS. No desenvolvimento da Oficina foram consideradas três
vertentes. Primeira, conceções dos professores sobre EFA/TIC e EFA/PC.
Segunda, a formação sobre PC/TIC. Terceira, produção e implementação de
materiais/atividades com orientação PC/TIC. A componente de trabalho
autónomo da Oficina passou essencialmente pela dinâmica de uma
comunidade online de nome EF@. O grupo de formação era constituído por 17
professores do ensino secundário, e pela investigadora/formadora, autora
deste estudo. Acrescente-se que no conjunto das 10 sessões de trabalho
presencial a investigadora/formadora foi coadjuvada por mais três formadores.
Estudar os impactes da Oficina no desenvolvimento profissional dos
professores, conjuntamente com a avaliação da influência dos
materiais/atividades produzidos (na Oficina) no nível de PC dos alunos,
assumiram-se como as duas questões de investigação a que este estudo
pretendeu dar resposta. Neste sentido estudámos o grupo de professores em
formação – estudo de caso – e o grupo de alunos – plano quasi experimental
do tipo grupo de controlo/experimental, pré/pós-teste, pelo que o
enquadramento da metodologia num estudo misto, predominantemente de
natureza qualitativa, foi a adotada. A recolha e o tratamento de dados foram
feitos mediante várias técnicas – observação, inquérito, análise e testagem –
associadas a diferentes instrumentos: dois questionários, diário de investigador
e Teste de Pensamento Crítico – Cornell (Nível X).
A análise dos dados recolhidos possibilitou a compreensão de como a Oficina
contribui para a reflexão: (i) nas práticas anteriores dos professores; (ii) nas
competências adquiridas na Oficina e (iii) nas práticas implementadas. Ao nível
do PC dos alunos, podemos dizer que os materiais/atividades produzidos na
Oficina influenciaram o nível de PC dos alunos, já que os resultados da média
do PC do pós-teste foram estatisticamente significativos para o grupo
experimental, quando comparado com a média do PC no grupo de controlo.Skills in Information and Communication Technologies (ICT) and Critical
Thinking (CT) are two of the guidelines of Lifelong Learning (LLL)
acknowledging that all learning contexts (informal, formal and non-formal)
learning can be assumed under Adult Education (AE), in Portugal, an
expression enshrined in the Guidelines to Key Competencies for Adult
Education, secondary level. However, the CT/ICT guidance has not explicitly
been accommodated in the practice of adult education.
In this context a training workshop was developed for AE teachers/trainers,
which worked on the integration of Web 2.0 tools with the infusion of CT
activities for AE courses. In developing the workshop three aspects were
considered. First, teachers' conceptions on AE/ICT and AE/CT. Second,
training in CT/ICT. Third, production and implementation of CT/ICT oriented
activities. The autonomous component of the workshop passed mainly through
a dynamic online community with the name EF@. The training group consisted
of 17 secondary school teachers, and the trainer/researcher author of this
study. We underline that in the 10 work sessions the trainer/researcher was
assisted by three trainers.
Studying the impacts of the Workshop in the professional development of
teachers together with assessing of the influence of the activities produced (in
the workshop) at the level of CT students were the two research questions that
this study intended to answer. So we studied the group of teachers – case
study – and the group of students – a quasi-experimental type
control/experimental group, pre/post-test plan. The mixed study methodology,
predominantly qualitative, was the one that seemed most appropriate. The
collection and processing of data were obtained by various techniques -
observation, investigation, analysis and testing – associated with different
instruments: two questionnaires, researcher diary and the Cornell Critical
Thinking Test (Level X).
The analysis of data collected allowed us to understand how the workshop
contributed to the debate: (i) in the previous practices of teachers, (ii) the skills
acquired in the workshop and (iii) implemented in practice. At the level of CT of
the students, we can say that the activities produced in the workshop
influenced the students’ level of CT, since the results of the average CT post
test were statistically significant for the experimental group when compared
with the average of the CT in the control group
Study of surface mechanical characteristics of abs/pc blends using nanoindentation
No full textAcrylonitrile butadiene styrene (ABS) and polycarbonate (PC) are considered a well-known class of engineering thermoplastics due to their efficient use in automotive, 3D printing, and elec-tronics. However, improvement in toughness, processability, and thermal stability is achieved by mixing together ABS and PC. The present study focuses on the understanding of surface mechanical characterization of acrylonitrile butadiene styrene (ABS) and polycarbonate (PC) blends using nano-indentation. Polymer blends sheets with three different proportions of ABS/PC (75:25, 50:50, and 25:75) were fabricated via melt-processing and thermal press. Fourier transform infrared (FTIR) spectroscopy was performed to analyze the intermolecular interactions between the blends’ compo-nents. To understand the surface mechanical properties of ABS and PC blends, a sufficient number of nano-indentation tests were performed at a constant loading rate to a maximum load of 100 mN. Creeping effects were observed at the end of loading and start of unloading section. Elastic modulus, indentation hardness, and creep values were measured as a function of penetration displacement in the quasi-continuous stiffness mode (QCSM) indentation. Load-displacement curves indicated an increase in the displacement with the increase in ABS contents while a decreasing trend was observed in the hardness and elastic modulus values as the ABS content was increased. We believe this study would provide an effective pathway for developing new polymer blends with enhanced mechanical performance.Aerospace Manufacturing Technologie
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