First order errors downstream of shocks are detected in computations with second order shock capturing schemes. Based on a matched asymptotic expansion analysis we show how to modify the artificial viscosity and raise...
Discusses how emerging object-relational database mediator technology can be used to integrate academic freeware and commercial-off-the-shelf software components to create a sequence of gradually more complex and powe...
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ISBN:
(纸本)0769512186
Discusses how emerging object-relational database mediator technology can be used to integrate academic freeware and commercial-off-the-shelf software components to create a sequence of gradually more complex and powerful, yet always syntactically and semantically homogeneous, database-centred image meta-analysis environments. We show how this may be done by defining and utilising a use-case-based evolutionary design and development process. This process allows subsystems to be produced largely independently by several small specialist subprojects, turning the system integration work into a high-level domain modelling task.
We study the computational complexity of solving systems of equations over a finite group. An equation over a group G is an expression of the form w/sub 1//spl middot/w/sub 2//spl middot//spl middot//spl middot//spl m...
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We study the computational complexity of solving systems of equations over a finite group. An equation over a group G is an expression of the form w/sub 1//spl middot/w/sub 2//spl middot//spl middot//spl middot//spl middot//spl middot/w/sub k/=id where each w/sub i/ is either a variable, an inverted variable, or group constant and id is the identity element of G. A solution to such an equation is an assignment of the variables (to values in G) which realizes the equality. A system of equations is a collection of such equations; a solution is then an assignment which simultaneously realizes each equation. We demonstrate that the problem of determining if a (single) equation has a solution is NP-complete for all nonsolvable groups G. For nilpotent groups, this same problem is shown to be in P. The analogous problem for systems of such equations is shown to be NP-complete if G is non-Abelian, and in P otherwise. Finally, we observe some connections between these languages and the theory of nonuniform automata.
This paper compares the two programming languages, Pascal and Ada. While Ada is based upon Pascal, its design objectives are very different. Pascal was designed for teaching whereas Ada was designed for major military...
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This paper compares the two programming languages, Pascal and Ada. While Ada is based upon Pascal, its design objectives are very different. Pascal was designed for teaching whereas Ada was designed for major military software systems. The simplicity of Pascal is advantageous only if its restrictions does not jeopardize the programming of an application. The improved modularity of Ada, as provided by packages, should be an important aspect for commercial development.
Operation counts and storage requirements are examined for the least squares solution of an idealized spline-fitting problem in several independent variables. Among the principal conclusions are that iterative methods...
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Operation counts and storage requirements are examined for the least squares solution of an idealized spline-fitting problem in several independent variables. Among the principal conclusions are that iterative methods of solution are faster than direct methods for problems in three or more dimensions, and require less storage space for problems in two or more dimensions.
Methods for linear least squares problems in which the observation matrix is banded or takes the form of a band plus several columns are considered. Algorithms using Givcns plane rotations to exploit these structures ...
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One of the most serious problems encountered in Naval steam plants following World War II was the unreliable performance of boiler and main feedpump pneumatic control systems. In addition to control component and syst...
One of the most serious problems encountered in Naval steam plants following World War II was the unreliable performance of boiler and main feedpump pneumatic control systems. In addition to control component and system design deficiencies, these control systems suffered from inadequate methods to measure and adjust system alignment. This paper describes the development of a set of procedures for on-line alignment verification (OLV) of pneumatic main boiler and feedpump control systems. The procedures are designed for use by N avy control system technicians and, in addition to on-line alignment verification, provide guidance for troubleshooting and for performing system alignment. Procedure static checks measure steady state steaming performance and OLV procedure dynamic checks measure the ability of the boiler and control systems to respond to load changes. The paper describes typical control system characteristics that influence OLV procedure content and the supporting analysis that was used to establish alignment criteria ranges that satisfy both steady state and transient performance requirements. Also described is the alignment criteria tolerance analysis along with the steps involved in a typical OLV check procedure development. Descriptions of the various OLV checks, troubleshooting procedures and alignment procedures are provided. Typical shipboard implementation requirements are described and experience to date with the procedures is provided along with a status report on OLV procedure implementations.
Practical formulae are developed for using implicit Runge-Kutta formulae to solve initial-value problems in ordinary differential equations. The region of absolute stability of the method is maximal and the resulting ...
This book provides an introduction to the field of periodic pattern mining, reviews state-of-the-art techniques, discusses recent advances, and reviews open-source software. Periodic pattern mining is a popular and em...
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ISBN:
(数字)9789811639647
ISBN:
(纸本)9789811639630;9789811639661
This book provides an introduction to the field of periodic pattern mining, reviews state-of-the-art techniques, discusses recent advances, and reviews open-source software. Periodic pattern mining is a popular and emerging research area in the field of data mining. It involves discovering all regularly occurring patterns in temporal databases. One of the major applications of periodic pattern mining is the analysis of customer transaction databases to discover sets of items that have been regularly purchased by customers. Discovering such patterns has several implications for understanding the behavior of customers. Since the first work on periodic pattern mining, numerous studies have been published and great advances have been made in this field. The book consists of three main parts: introduction, algorithms, and applications.
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