Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Mathematical Computing”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources
PubMed1992

The effects of computer-based attribution retraining on the attributions, persistence, and mathematics computation of students with learning disabilities.

The purpose of the present study was to examine the impact of attribution retraining, embedded within a mathematics computer-assisted instructional (CAI) program, on students' attributions, persistence, and mathematics computation. Twenty-nine school-identified students with learning disabilities from five urban schools participated in the study. The sample's mean age was 13.3 years. After blocking on initial attributional patterns, students were randomly assigned to a mathematics CAI program that provided either attribution retraining or neutral feedback. Students used their assigned program for eight 30-minute sessions. Results did not support the contention that attribution retraining would have a significant impact on students' attributions. However, students who participated in the attribution retraining condition completed significantly more levels of the program than their counterparts who received neutral feedback. Attribution retraining students also obtained significantly higher scores on a test of problems practiced during the CAI program. These results suggest that attribution retraining may be a desirable addition to the type of feedback typically provided by CAI programs. However, they also highlight the need for further research that examines the conditions under which specific attributions are most advantageous.

Achievement↗
PubMed2005

Minimal-memory bit-vector architecture for computational mathematical morphology using subspace projections.

Computational mathematical morphology (CMM) is a nonlinear filter representation particularly amenable to real-time image processing. A windowed, translation-invariant filter is represented by a set of less-than-or-equal decisions that are executed by a parallel arrangement of comparators. In the state-of-the-art implementation, each pixel value of a windowed observation is indexed into separate lookup tables to retrieve a set of bit vectors which are "anded" together to produce a bit vector with a unique nonzero bit. The position of that bit is used to look up a filter value in a table. The number of stored bit vectors is proportional to the number of image gray levels. An architecture for CMM is presented that uses a minimal number of bit vectors so that required memory is less sensitive to the number of gray levels. The number of pixels in the observation window is the dimension of the image space. In the proposed architecure, basis elements are projected to subspaces of the image space and only bit vectors unique to each subspace are stored. Each projection corresponds to a subspace partition. Filter memory is greatly reduced by using intermediate lookup tables to map observations to unique bit vectors. We investigate two possible projection strategies: A fixed, singleton architecture, in which each subspace is one dimension, and a minimal architecture, in which a large number of subspace projections are searched for, one with minimal memory. Insensitivity to the number of gray levels is demonstrated through simulated, random-image space tessellations. We also present memory savings in a digital photocopier application.

Algorithms↗
PubMed2005

The challenge of computer mathematics.

Progress in the foundations of mathematics has made it possible to formulate all thinkable mathematical concepts, algorithms and proofs in one language and in an impeccable way. This is not in spite of, but partially based on the famous results of Gödel and Turing. In this way statements are about mathematical objects and algorithms, proofs show the correctness of statements and computations, and computations are dealing with objects and proofs. Interactive computer systems for a full integration of defining, computing and proving are based on this. The human defines concepts, constructs algorithms and provides proofs, while the machine checks that the definitions are well formed and the proofs and computations are correct. Results formalized so far demonstrate the feasibility of this 'computer mathematics'. Also there are very good applications. The challenge is to make the systems more mathematician-friendly, by building libraries and tools. The eventual goal is to help humans to learn, develop, communicate, referee and apply mathematics.

Algorithms↗
PubMed1983

Computing, mathematics, and the nephrologist.

The potential of computing and mathematics to make major contributions to nephrology by making information retrieval and presentation more accurate, more complete, and more rapid and by providing immediate access to computational and graphic facilities is emphasized in this symposium issue. The realization that disordered physiology due to disease may not prevent the course of an illness being described in mathematical terms should encourage physicians, and others interested in pathophysiology, to integrate mathematics and statistics into their thinking and their practice.

Computers↗
PubMed1991

A mathematical computer stimulation model for the development of colonic polyps and colon cancer.

Currently known information about the development and progression of colon polyps and cancer is summarized and organized into a mathematical computer simulation model that successfully predicts the natural history of colon polyp and cancer development for an average patient with (1) familial polyposis coli (2) genetic susceptibility as measured by a positive family history, and (3) negative family history with a high fat diet. The mathematical model uses four distinct types of cells (normal, transformed, polypoid, and cancerous) and two kinetic processes (mutation and promotion). Arachidonic acid metabolites play a role in the model in the promotion of cancer from polyps, and account for that promotion through: (1) their effect on encouraging more polypoid cells in mitosis to move toward cancer; and (2) their immunosuppressive effect over time. The model also shows that one defect in allowing more cells to mutate to the transformed state is sufficient to account for the chain of events leading to the clinical sequelae of familial polyposis coli. A second genetic effect at another point in the process is unnecessary. The mechanism of action of Sulindac on colon polyps is explained by the model through inhibition of production of arachidonic acid metabolites, most notably prostaglandin E.

Adenomatous Polyposis Coli↗
PubMed1986

Histopathological diagnosis of brain tumours with the help of a computer: mathematical fundaments and practical application.

With the help of a personal computer we have subjected 1684 tumours of the central and peripheral nervous systems to a discriminant analysis to test whether the different brain tumours can be classified. By ascribing a coefficient value which belongs to a linear function to the objective criteria for each tumour these can be ordered in groups, and a classification is then possible. This has been termed discriminant analysis. Fifty histological characteristics were the criteria taken into consideration for each tumour. By using Bayes' formula with a correction for binomial distribution we obtained a correct diagnosis in 98% of the cases studied. The differential diagnosis with its percentage of probabilities is given by the computer. The mathematical fundaments are given. The valuability and precision of this method are discussed.

Brain Neoplasms↗
PubMed2001

Overview of mathematical computer models of striated sphincter muscles.

The present paper compares current mathematical striated sphincter models. Current models are subdivided in four categories: (1) simple models, (2) implementations of the urethral resistance relation, (3) models with realistic muscle dynamics and (4) finite element models. In our research group a neural network model, representing Onuf's nucleus, the spinal motor nucleus that innervates the external urethral and anal sphincters, was developed. A realistic sphincter model is needed to test the neural network. To decide whether or not a model is applicable in our research two requirements should be fulfilled: (1) the presence of realistic muscle dynamics preferably by implementation of a Huxley type muscle model and (2) the model should consist of more than one muscle unit to form a more dimensional model. Reviewing the literature, if a myogenic sphincter is modelled, mainly the Hill-equation is applied. Moreover, single muscle unit models are published. In general a multi-unit muscle model of the sphincter is lacking, prohibiting the study of the inherent properties of sphincter muscles, which could give information on the realistic behaviour of elements in circular muscles. It is concluded that the functionality of current sphincter models is limited for our purpose.

Animals↗
PubMed1994

[Continuous administration of drugs by infusion pumps. Presentation of an infusion rate mathematical computing software].

Intensive therapy includes continuous delivery of drugs with infusion pump. This article describes an infusion rate computing programme using a Macintosh micro-computer and the HyperCard 2 software. The latter permits the classification of data onto cards collected in stacks. The card that is displayed when the programme is launched shows fifteen buttons assigned to various drugs. Click upon a button opens the corresponding card which displays the presentation of the drug and suggests a dilution. The next step associates input of patient's weight into the appropriate field and a click on the main button. A display then indicates for various standard dosages, the corresponding rate of infusion in mL.h-1 and the daily consumption of the drug. In order to avoid casual or voluntary changes of the setting, soft securities have been inserted in the programme.

Humans↗
PubMed1995

Interventional telemedicine for noninvasive neuroradiosurgery: remote-site high-performance computing, mathematical optimization, and virtual scenario simulation.

Interventional Telemedicine may have potential utility in providing connectivity and access to specialized high performance computing and advanced software resources in support of clinical procedures in the field of Minimally-Invasive Surgery and Stereotactic Linear Accelerator (LINAC) Radiosurgery. Such interventions may benefit from application of nonlinear quadratic inverse solution methods designed to provide the capability to reverse optimize a 'best case' treatment plan. The formidable decision-making challenges posed by increasingly complex optimized data and progressively versatile LINAC delivery systems require volume visualization of projected treatment data and imaging anatomy via photorealistic rendering and virtual scenario simulation techniques. Both these new directions are heavily dependent on access to specialized high performance computing platforms solely accessible via broad-bandwidth network connectivity. This pilot project presents resimulation of retrospective radiosurgical case data using inverse solution optimization models running on workstation clusters and then volume rendered and simulated on the Princeton Graphics Engine Supercomputer. Evidence for effective utilization of such optimization and virtual simulation methods running on remotely accessed, distant high performance computing resources is discussed in view of the potential for long-term clinical investigation and eventual development of Interventional Telemedicine as a clinically practical approach for providing support to remote or non-urban radiosurgery centers in the industrialized and developing world.

Algorithms↗
PubMed2003

Computational mathematics and physics of fusion reactors.

Theory has contributed significantly to recent advances in magnetic fusion research. New configurations have been found for a stellarator experiment by computational methods. Solutions of a free-boundary problem are applied to study the performance of the plasma and look for islands in the magnetic surfaces. Mathematical analysis and numerical calculations have been used to study equilibrium, stability, and transport of optimized fusion reactors.

Journal Article↗
PubMed2001

The relations between phonological processing abilities and emerging individual differences in mathematical computation skills: a longitudinal study from second to fifth grades.

The primary purpose of this longitudinal correlational study was to examine relations between phonological processing abilities and emerging individual differences in math computation skills and also to investigate the source of covariation between reading and math computation skills in a random sample (n = 201). Phonological memory, rate of access to phonological codes in long-term memory, and phonological awareness were uniquely associated with growth in estimated total number of computation procedures mastered (general computation skills) from 92.5 to 134.8 months in age, although the contributions of the first two abilities were developmentally limited. Phonological processing almost completely accounted for the associations between reading and general computation skills. Evidence of bidirectional relations between general computation skills and simple arithmetic problem solving speed was found.

Child↗