Matrix Representations and Computer Storage of Graphs

2012 ◽  
pp. 39-65
Author(s):  
D.R. Ensor ◽  
C.G. Jensen ◽  
J.A. Fillery ◽  
R.J.K. Baker

Because periodicity is a major indicator of structural organisation numerous methods have been devised to demonstrate periodicity masked by background “noise” in the electron microscope image (e.g. photographic image reinforcement, Markham et al, 1964; optical diffraction techniques, Horne, 1977; McIntosh,1974). Computer correlation analysis of a densitometer tracing provides another means of minimising "noise". The correlation process uncovers periodic information by cancelling random elements. The technique is easily executed, the results are readily interpreted and the computer removes tedium, lends accuracy and assists in impartiality.A scanning densitometer was adapted to allow computer control of the scan and to give direct computer storage of the data. A photographic transparency of the image to be scanned is mounted on a stage coupled directly to an accurate screw thread driven by a stepping motor. The stage is moved so that the fixed beam of the densitometer (which is directed normal to the transparency) traces a straight line along the structure of interest in the image.


1969 ◽  
Vol 8 (02) ◽  
pp. 53-59 ◽  
Author(s):  
John Mayne

For the past several years, experimental studies have been undertaken at the Mayo Clinic to evaluate the feasibility of utilizing electronic data processing to handle medical information, especially the medical information which makes up a medical record. We have experimented with automated techniques for collecting and storing medical-history data, specifically with techniques for computer generation and processing of health questionnaires, for computer-controlled administration of health questionnaires, and for computer-controlled entry and retrieval of medical-history data directly by physicians in ordinary English language by use of a video-screen and light-pen computer terminal.The questionnaire studies are concerned with ways of entering into computer storage medical-history data obtained from patients without physician involvement; the video-screen studies are concerned with entry into computer storage of medical-history data obtained by physicians in their interview with the patient. The paper describes our experiences in these studies.


Mathematics ◽  
2021 ◽  
Vol 9 (13) ◽  
pp. 1522
Author(s):  
Anna Concas ◽  
Lothar Reichel ◽  
Giuseppe Rodriguez ◽  
Yunzi Zhang

The power method is commonly applied to compute the Perron vector of large adjacency matrices. Blondel et al. [SIAM Rev. 46, 2004] investigated its performance when the adjacency matrix has multiple eigenvalues of the same magnitude. It is well known that the Lanczos method typically requires fewer iterations than the power method to determine eigenvectors with the desired accuracy. However, the Lanczos method demands more computer storage, which may make it impractical to apply to very large problems. The present paper adapts the analysis by Blondel et al. to the Lanczos and restarted Lanczos methods. The restarted methods are found to yield fast convergence and to require less computer storage than the Lanczos method. Computed examples illustrate the theory presented. Applications of the Arnoldi method are also discussed.


2000 ◽  
Vol 16 (3-4) ◽  
pp. 177-186 ◽  
Author(s):  
Kaihuai Qin

1965 ◽  
Vol 36 (142) ◽  
pp. 59
Author(s):  
A.J. Cole
Keyword(s):  

Author(s):  
Hong-Sen Yan ◽  
Chin-Hsing Kuo

A mechanism that encounters a certain changes in its topological structure during operation is called a mechanism with variable topologies (MVT). This paper is developed for the structural and motion state representations and identifications of MVTs. For representing the topological structures of MVTs, a set of methods including graph and matrix representations is proposed. For representing the motion state characteristics of MVTs, the idea of finite-state machines is employed via the state tables and state graphs. And, two new concepts, the topological homomorphism and motion homomorphism, are proposed for the identifications of structural and motion state characteristics of MVTs. The results of this work provide a logical foundation for the topological analysis and synthesis of mechanisms with variable topologies.


Sign in / Sign up

Export Citation Format

Share Document