摘要:

Many kinds of problems in physics and engineering can be cast as optimization problems in which a solution must be picked out of a very large and ‘‘complicated’’ solution candidate space. The simulated annealing algorithm, which derives from statistical mechanical theory, and Bayes’ theorem are introduced and it is shown how they can be combined to solve such problems. As an example, the problem of image recovery from noisy data is considered.

ISSN:0002-9505    

DOI:10.1119/1.16732

出版商:American Association of Physics Teachers    

年代:1991

数据来源: AIP

摘要:

Newton’s concept of force was developed over a period of time, starting with a collisional model in hisWasteBook, and culminating in his measure of the centripetal force at a point found inDeMotuand again inPrincipia, Book I, Prop. VI. Newton kept developing his force concept, adding to it and making it many faceted. This rich concept of force has often posed difficulties for historians of science [for example, R. S. Westfall,ForceinNewton’sPhysics(MacDonald and American Elsevier, New York, 1971) and J. Herivel,TheBackgroundtoNewton’sPrincipia(Oxford U.P., New York, 1965)] and others. These difficulties are related to at least six things as follows: (1) lack of understanding that Newton’s ‘‘motive force’’ is an abbreviation for ‘‘motive quantity of a force,’’ so that Newton’s ‘‘motive force’’ and his ‘‘force’’ are not two different types of force. Motive force (motive quantity) is used to quantify force; (2) lack of understanding of Newton’s model for instantaneous impulses; (3) lack of understanding that although Newton’s motive force has directionality Newton added it as a scalar in his analysis of uniform circular motion; (4) lack of understanding of Newton’s polygon model; (5) lack of understanding that Newton’s measure of the motive value of a force, the motive force, was always used to obtain a comparative measure of forces in his early mechanics; and (6) lack of understanding that Newton’s Prop. VI measure of centripetal force at a point permitted Newton to bring the time dimension into his motive force concept, thus developing it into something very close to our modern definition of force. This paper analyzes Newton’s development of his motive force concept, and discusses the difficulties that some scholars have had with various aspects of this concept.

ISSN:0002-9505    

DOI:10.1119/1.16733

出版商:American Association of Physics Teachers    

年代:1991

数据来源: AIP

ISSN:0002-9505    

DOI:10.1119/1.16734

出版商:American Association of Physics Teachers    

年代:1991

数据来源: AIP

ISSN:0002-9505    

DOI:10.1119/1.16735

出版商:American Association of Physics Teachers    

年代:1991

数据来源: AIP

ISSN:0002-9505    

DOI:10.1119/1.16736

出版商:American Association of Physics Teachers    

年代:1991

数据来源: AIP

ISSN:0002-9505    

DOI:10.1119/1.16738

出版商:American Association of Physics Teachers    

年代:1991

数据来源: AIP

ISSN:0002-9505    

DOI:10.1119/1.16739

出版商:American Association of Physics Teachers    

年代:1991

数据来源: AIP

ISSN:0002-9505    

DOI:10.1119/1.16741

出版商:American Association of Physics Teachers    

年代:1991

数据来源: AIP

ISSN:0002-9505    

DOI:10.1119/1.16742

出版商:American Association of Physics Teachers    

年代:1991

数据来源: AIP

ISSN:0002-9505    

DOI:10.1119/1.16744

出版商:American Association of Physics Teachers    

年代:1991

数据来源: AIP