Computation Research Papers - Academia.edu (original) (raw)

In the first part of the study, nine estimators of the first-order autoregressive parameter are reviewed and a new estimator is proposed. The relationships and discrepancies between the estimators are discussed in order to achieve a clear... more

In the first part of the study, nine estimators of the first-order autoregressive parameter are reviewed and a new estimator is proposed. The relationships and discrepancies between the estimators are discussed in order to achieve a clear differentiation. In the second part of the study, the precision in the estimation of autocorrelation is studied. The performance of the ten lag-one autocorrelation estimators is compared in terms of Mean Square Error (combining bias and variance) using data series generated by Monte Carlo simulation. The results show that there is not a single optimal estimator for all conditions, suggesting that the estimator ought to be chosen according to sample size and to the information available on the possible direction of the serial dependence. Additionally, the probability of labelling an actually existing autocorrelation as statistically significant is explored using Monte Carlo sampling. The power estimates obtained are quite similar among the tests ass...

Calculia is considered to be the ability of performing arithmetic operations, the preconditions for the development of mathematical skills in the complex functioning of psychological functions represented in neuro-anatomical systems, as... more

Calculia is considered to be the ability of performing arithmetic operations, the preconditions for the development of mathematical skills in the complex functioning of psychological functions represented in neuro-anatomical systems, as well in the interaction with the environment. Problems in acquiring arithmetic skills can be described as difficulties in counting as well as developmental dyscalculia. Reported prevalence rate for this problem in general population is 6%-10%. The most common difficulties in counting are: difficulties in logic, difficulties in planning, perseverance of inappropriate (responses) procedures and poor understanding of arithmetic operations. This paper aims to identify the influence of assessed arithmetic skills and to clarify to what extent the assessed cognitive skills affect each other in children with difficulties in counting. The relations between the level of working memory and acquiring of arithmetic skills, between the attention and the conceptual...

Computation is now regarded as an equal and indispensable partner, along with theory and experiment, in the advance of scientific knowledge and engineering practice. Numerical simulation enables the study of complex systems and natural... more

Computation is now regarded as an equal and
indispensable partner, along with theory and experiment, in the
advance of scientific knowledge and engineering practice.
Numerical simulation enables the study of complex systems and
natural phenomena that would be too expensive or dangerous, or
even impossible, to study by direct experimentation. The quest
for ever higher levels of detail and realism in such simulations
requires enormous computational capacity, and has provided the
impetus for dramatic breakthroughs in computer algorithms and
architectures. Due to these advances, computational scientists
and engineers can now solve large-scale problems that were once
thought intractable. Computational science and engineering
(CSE) is a rapidly growing multidisciplinary area with
connections to the sciences, engineering, and mathematics and
computer science. CSE focuses on the development of problemsolving
methodologies and robust tools for the solution of
scientific and engineering problems. We believe that CSE will
play an important if not dominating role for the future of the
scientific discovery process and engineering design. The
computation science is now being used widely for environmental
engineering calculations. The behavior of environmental
engineering systems and processes can be studied with the help
of computation science and understanding as well as better
solutions to environmental engineering problems can be
obtained.

Nunes and Bryant (Children doing mathematics, Blackwell, Oxford, 1996) proposed that an understanding of the additive composition of number could be a precursor to an understanding of the decimal structure. If this is so, children should... more

Nunes and Bryant (Children doing mathematics, Blackwell, Oxford, 1996) proposed that an understanding of the additive composition of number could be a precursor to an understanding of the decimal structure. If this is so, children should achieve an understanding of additive composition before they can handle the decimal structure. The aim of our study was to determine the developmental timing

On May 18, 2009, British computer scientist Stephen Wolfram officially launched a new search product called Wolfram j Alpha (WA). This launch was preceded by months of speculation and hype online about exactly what WA would be and how it... more

On May 18, 2009, British computer scientist Stephen Wolfram
officially launched a new search product called Wolfram
j
Alpha
(WA). This launch was preceded by months of speculation and
hype online about exactly what WA would be and how it would
compare to Google and other search engines. This article will
explore the basic features of WA, show some example queries
and results, and discuss the usefulness and limitations of this
new tool.
KEYWORDS Computation, Internet, search engines, Wolfram
|Alpha

Data security plays a crucial role in healthcare monitoring systems, since critical patient information is transacted over the Internet, especially through wireless devices, wireless routes such as optical wireless channels, or optical... more

Data security plays a crucial role in healthcare monitoring systems, since critical patient information is transacted over the Internet, especially through wireless devices, wireless routes such as optical wireless channels, or optical transport networks related to optical fibers. Many hospitals are acquiring their own metro dark fiber networks for collaborating with other institutes as a way to maximize their capacity to meet patient needs, as sharing scarce and expensive assets, such as scanners, allows them to optimize their efficiency. The primary goal of this article is to develop of an attack detection model suitable for healthcare monitoring systems that uses internet protocol (IP) virtual private networks (VPNs) over optical transport networks. To this end, this article presents the vulnerabilities in healthcare monitoring system networks, which employ VPNs over optical transport layer architecture. Furthermore, a multilayer network architecture for closer integration of the...

Most of the statistical procedures in meta-analysis are based on the estimation of average effect sizes from a set of primary studies. The optimal weight for averaging a set of independent effect sizes is the inverse variance of each... more

Most of the statistical procedures in meta-analysis are based on the estimation of average effect sizes from a set of primary studies. The optimal weight for averaging a set of independent effect sizes is the inverse variance of each effect size, but in practice these weights have to be estimated, being affected by sampling error. When assuming a random-effects model, there are two alternative procedures for averaging independent effect sizes: Hunter and Schmidt’s estimator, which consists of weighting by sample size as an approximation to the optimal weights; and Hedges and Vevea’s estimator, which consists of weighting by an estimation of the inverse variance of each effect size. In this article, the bias and mean squared error of the two estimators were assessed via Monte Carlo simulation of meta-analyses with the standardized mean difference as the effect-size index. Hedges and Vevea’s estimator, although slightly biased, achieved the best performance in terms of the mean square...

Recent advances in real-time structural analysis has given architects the freedom to design and manufacture forms and structures that previously would have been difficult if not impossible to achieve. Until recently these advances had not... more

Recent advances in real-time structural analysis has given architects the freedom to design and manufacture forms and structures that previously would have been difficult if not impossible to achieve. Until recently these advances had not been seen as a driving force within the area of asymmetrically designed tensegrity structures. This paper presents a new design method that is integrating analysis tools into a computational design process. Through the lens of the recently completed Underwood Pavilion this paper demonstrates how this process of designing tensegrity structures can be streamlined. This process allows for greater access to such structures and a higher level of flexibility in designing tensegrity systems by the design community at large. Acting as a case study, the Underwood Pavilion describes a process where traditional methods of form finding are complimented by a new parametric approach to design tensegrity based lightweight structures and envelope systems.

Researchers from the University of Melbourne's New Technologies for Teaching Mathematics project created a lesson for the Year 10 students at their Victorian research schools. Two important goals of secondary school mathematics... more

Researchers from the University of Melbourne's New Technologies for Teaching Mathematics project created a lesson for the Year 10 students at their Victorian research schools. Two important goals of secondary school mathematics education are to build students' conceptual knowledge and to teach students to think mathematically. Mathematics education research supports the notion that seeing concepts represented in multiple ways both supports students' sense-making and enriches their learning. The design of lessons must be carefully considered in order not to create excessive cognitive load for the learner. The study focused on one 'lesson', designed to provide exemplars for lessons where new powerful, mathematically able integrated documents (Nspire) are used to support students' exploration of various representations of a given mathematical problem. Based on applications of quadratic functions, 'Marina's Fish Shop' was designed as a capstone lesson...

The purpose of this study is to compare the maximum likelihood (ML) and Bayesian estimation methods for polychoric correlation (PCC) under diverse conditions using a Monte Carlo simulation. Two new Bayesian estimates, maximum a posteriori... more

The purpose of this study is to compare the maximum likelihood (ML) and Bayesian estimation methods for polychoric correlation (PCC) under diverse conditions using a Monte Carlo simulation. Two new Bayesian estimates, maximum a posteriori (MAP) and expected a posteriori (EAP), are compared to ML, the classic solution, to estimate PCC. Different types of prior distributions are used to investigate the sensitivity of a prior distribution onto the Bayesian PCC estimation. In this simulation study, it appears that the MAP would be the estimator of choice for the PCC. The performance of the MAP is not only better than the ML but also appears to overcome the limitations of the EAP (i.e., the shrinkage effect).

This paper discusses changes in young children’s learning performance and efficiency during clinical interviews in which each child interacted with a variety of virtual manipulative mathematics apps on iPads. Researchers interviewed 100... more

This paper discusses changes in young children’s learning performance and efficiency during clinical interviews in which each child interacted with a variety of virtual manipulative mathematics apps on iPads. Researchers interviewed 100 children ages 3 to 8 using a protocol format with two pre-assessment apps, four learning apps, and two post-assessment apps. Data were gathered quantitatively and qualitatively, using wall and screen-capture videos, pre and post assessments of performance, and time-stamping to record efficiency. Following 30-40 minute interviews where children interacted individually with the mathematics apps, results showed that children in the Preschool group increased efficiency while maintaining performance, children in the Kindergarten group increased performance while maintaining efficiency, and children in the Grade 2 group increased their performance and efficiency in skip counting, but not in place value. Overall, children in different age groups responded i...

The definition of mental disorders describes them as “health conditions involving changes in emotion, thinking or behavior or a combination of these”. Contemporary societies of 2020 still fall short in recognizing some of the most common... more

The definition of mental disorders describes them as “health conditions involving changes in emotion, thinking or behavior or a combination of these”. Contemporary societies of 2020 still fall short in recognizing some of the most common afflictions as actual problems in people. Some of those are depression, anxiety and stress disorders. This paper proposes a Machine Learning based approach wherein the analysis of the multiple-choice inputs along with a neatly curated questionnaire based on feature extraction will be done and then supervised classification algorithms will be used to generate a mental health score as well as a detailed report based on responses the user gives.

Evaluation of planar algebraic curves arises in the context of intersections of algebraic surfaces with piecewise continuous rational polynomial parametric surface patches useful in geometric modeling. We address a method of evaluating... more

Evaluation of planar algebraic curves arises in the context of intersections of algebraic surfaces with piecewise continuous rational polynomial parametric surface patches useful in geometric modeling. We address a method of evaluating these curves of intersection that combines the advantageous features of analytic representation of the governing equation of the algebraic curve in the Bernstein basis within a rectangular domain, adaptive subdivision and polyhedral faceting techniques, and the computation of turning and singular points, to provide the basis for a reliable and efficient solution procedure. Using turning and singular points, the intersection problem can be partitioned into subdomains that can be processed independently and which involve intersection segments that can be traced with faceting methods. This partitioning and the tracing of individual segments is carried out using an adaptive subdivision algorithm for Bezier/B-spline surfaces followed by Newton correction o...