Properly efficient and efficient solutions for vector maximization problems in euclidean space

Recently Benson proposed a definition for extending Geoffrion's concept of proper efficiency to the vector maximization problem in which the domination cone K is any nontrivial, closed convex cone. We give an equivalent definition of his notion of proper efficiency. Our definition, by means of perturbation of the cone K, seems to offer another justification of Benson's choice above Borwein's extension of Geoffrion's concept. Our result enables one to prove some other theorems concerning properly efficient and efficient points. Among these is a connectedness result.     

Peirce e dedekind: La definizione di insieme finito

Starting from Peirce's repeated claims of priority with respect to Dedekind's definition of finite set [R. Dedekin, Was sind und was sollen die Zahlen? (Braunschweig: Vieweg, 1888), Definizione 64], this paper traces the history of Peirce's definition and its role in his research on the foundations of arithmetic. This brings to light some remarkable and neglected achievements of Peirce in this field. It also shows that his priority claims are unjustified, although understandable in terms of his desire for acknowledgment of his pioneering work on the foundations of arithmetic.     

Babbage,peacock and modern algebra

George Peacock's A Treatise on Algebra of 1830, contained in its preface the first published recognition that Algebra need not necessarily be always associated with Arithmetic, and that non-arithmetical Algebras were possible. The work also contains the first statement of Peacock's principle of the permanence of equivalent forms. It is shown in this paper that Charles Babbage had all these ideas in almost identical or superior form in an unpublished work The Philosophy of Analysis written in 1821. Peacock certainly had access to his friend Babbage's writings, and the suggestion is made of unconscious assimilation rather than deliberate plagiarism.     

Discussions on Newton's infinitesimals in eighteenth-century Anglo-America

The controversy in England over Newton's fluxionary calculus following the publication in 1734 of Bishop George Berkeley's The Analyst was reflected in the correspondence between Cadwallader Colden of New York and his friends in the middle 1740s. Colden wrote “An Introduction to the Doctrine of Fluxions” after reading The Analyst, and it was the occasion for the discussions that followed. His friends either doubted the value of the calculus and the validity of infinitesimals, or were noncommittal. Colden's essay was the only published defense of Newton's calculus by a colonist in eighteenth-century Anglo-America. There was a lack of interest in the calculus in both Great Britain and America until well into the nineteenth century. In the following we suggest reasons for that lack of interest.     

Euler's 1760 paper on divergent series

That Euler was quite aware of the subtleties of assigning a sum to a divergent series is amply demonstrated in his paper De seriebus divergentibus which appeared in Novi commentarii academiae scientiarum Petropolitanae 5 (1754/55), 205–237 (= Opera Omnia (1) 14, 585–617) in the year 1760. The first half of this paper contains a detailed exposition of Euler's views which should be more readily accessible to the mathematical community.The authors present here a translation from Latin of the summary and first twelve sections of Euler's paper with some explanatory comments. The remainder of the paper, treating Wallis' hypergeometric series and other technical matter, is described briefly. Appended is a short bibliography of works concerning Euler which are available to the English-speaking reader.     

The Chinese concept of Cavalieri's principle and its applications

Bonaventura Cavalieri (1598–1647) was noted for his method of indivisibles which led to the principle which bears his name. In the third century, while attempting to derive the volume of a sphere, Liu Hui applied a similar principle to determine the ratio of the volumes of a sphere and a solid circumscribing the sphere. This solid is formed by the intersection of two perpendicular cylinders circumscribing the sphere and is called mou he fang gai. Liu Hui left unresolved the problem of finding the volume of the mou he fang gai. In the fifth century Zu Geng, also applying Cavalieri's principle, solved this problem and thus derived the volume of a sphere. The influence of Zu Geng's method on later mathematicians is discussed in the latter part of the article.     

Euclid and the fundamental theorem of arithmetic

Slight changes or benevolent interpretations of certain theorems and proofs in Euclid's Elements make his demonstration of the fundamental theorem of arithmetic satisfactory for square-free numbers, but Euclid's methods cannot be adapted to prove the uniqueness for numbers containing square factors.     

Nicolai Nicolaevich Luzin and the Moscow school of the theory of functions

Shortly before the revolution of 1917, four papers written by participants in N. N. Luzin's analysis seminar at Moscow University appeared in the Comptes Rendus of the Paris Academy of Sciences. The publication of these papers--written by A. Ya. Khinchin, D. E. Menshov, P. S. Aleksandrov and M. Ya. Suslin--and Luzin's monograph, The Integral and Trigono-metric Series 1915, marked the emergence of Moscow University as a center of research in the theory of functions of a real variable. This paper describes Luzin's early mathematical education at Moscow University and the three year period he spent abroad (mainly in Paris) where he wrote a series of papers whose results form the core of his influential and widely praised monograph. Finally, we will show how Luzin's ideas formed the basis for the early investigations of a series of young Moscow mathematicians.     

Gregory's converging double sequence: A new look at the controversy between huygens and gregory over the “analytical” quadrature of the circle

As is well known, upon publication of his Vera circuli et hyperbolae quadratura (Padua 1667), James Gregory became involved in a bitter controversy with Christiaan Huygens over the truth of one of his major propositions. It stated that the area of a sector of a central conic cannot be expressed “analytically” in terms of the areas of an inscribed triangle and a circumscribed quadrilateral. Huygens objected to Gregory's method of proof, and expressed doubts as to its validity. As Gregory's iterative limiting process, employing an infinite double sequence, uses a combination of geometric and harmonic means, one may apply to it methods developed by the young Gauss for dealing with a similar process based on the combination of arithmetic and geometric means. This yields both the Leibnizian series forπ/4 and the product found by Vie`te for2/π, and thus serves to illuminate the structure of Gregory's procedure and the nature of Huygens' criticism.     

On a generalization of Kaplansky's game

In this paper, games of the following general kind are studied: Two players move alternately by selecting unselected integer coordinate points in the plane. On each move, the first player selects exactly r points and the second player selects exactly one point. The first player wins if he can select p points on a line having none of his opponent's points before his opponent selects q points on a line having none of his own. If this latter eventuality occurs first, the second player wins. It is shown that if p ? c(r)q, then the second player can always win.     

Felix Klein's “Erlanger Antrittsrede”: A Transcription with English Translation and Commentary

One of Felix Klein's leading interests was the role of mathematics education not only in the German universities but in the secondary schools as well. Klein played a leading role in the educational reform movements that flourished during the twenty-year period prior to World War I, and in 1908 he was elected President of the International Mathematics Instruction Commission. The “Erlanger Antrittsrede” of 1872, presented herein, gives a clear expression of Klein's views on mathematics education at the very beginning of his career. While previous writers, including Klein himself, have stressed the continuity between the Antrittsrede and his later views on mathematics education, the following commentary presents an analysis of the text together with external evidence supporting exactly the opposite conclusion.     

Two counterfeit coins

We consider the problem of ascertaining the minimum number of weighings which suffice to determine the counterfeit (heavier) coins in a set of n coins of the same appearance, given a balance scale and the information that there are exactly two heavier coins present. An optimal procedure is constructed for infinitely many n's, and for all other n's a lower bound and an upper bound for the maximum number of steps of an optimal precedure are determined which differ by just one unit. Some results of Cairns are improved, and his conjecture at the end of [3] is proved in a slightly modified form.     

The Principia's theory of the motion of the lunar apse

An analysis of Newton's theory of the lunar apsidal motion in the Principia shows an inadequacy for which he attempted to compensate by adjusting his numerical assumptions.     

Archimedes and the spirals: The heuristic background

In his work, The Method, Archimedes displays the heuristic technique by which he discovered many of his geometric theorems, but he offers there no examples of results from Spiral Lines. The present study argues that a number of theorems on spirals in Pappus' Collectio are based on early Archimedean treatments. It thus emerges that Archimedes' discoveries on the areas bound by spirals and on the properties of the tangents drawn to the spirals were based on ingenious constructions involving solid figures and curves. A comparison of Pappus' treatments with the Archimedean proofs reveals how a formal stricture against the use of solids in problems relating exclusively to plane figures induced radical modifications in the character of the early treatments.     

On the convergence region for decomposition solutions

The author's decomposition method using his A_n polynomials for the nonlinearities has been shown to apply to wide classes of nonlinear (or nonlinear stochastic) operator equations providing a computable, accurate solution which converges rapidly. In computation the above is sufficient for a rapid test of convergence region.     

Descartes and the birth of analytic geometry

The traditional thesis that analytic geometry evolved from the concepts of axes of reference, co-ordinates, and loci, is rejected. The origins of this science are re-defined in terms of Egyptian, Greek, Babylonian, and Arabic influences merging in Vieta's Isagoge in artem analyticam (1591) and culminating in a work of his pupil Ghetaldi published posthumously in 1630. Descartes' Vera mathesis, conceived over a decade earlier, served to revive and strengthen the important link with logic and thereby to extend the field of application of this analytic method to the corporeal and moral worlds.     

A proof of the existence of Batanin's initial operad

In this paper we prove the existence of the n-globular operad used in Batanin's definition of weak n-category. This operad is initial in the category of n-globular operads equipped with two extra pieces of structure: a system of compositions and a contraction. Our approach closely follows a proof by Leinster of the existence of a similar n-globular operad used in his definition of weak n-category (itself a variant of Batanin's definition) – we show that there is a functor giving the free operad equipped with a contraction and system of compositions on an n-globular collection, and applying this functor to the initial collection gives the desired initial operad. Since there is no interaction between the contraction and operad structures we are able to treat their free constructions separately. This is not true of the system of compositions structure, which cannot exist separately from the operad structure, so we use an interleaving-style construction to describe the free operad with system of compositions.     

The astronomical work of Carl Friedrich Gauss (1777–1855)

Gauss's interest in astronomy dates from his student-days in Göttingen, and was stimulated by his reading of Franz Xavier von Zach's Monatliche Correspondenz… where he first read about Giuseppe Piazzi's discovery of the minor planet Ceres on 1 January 1801. He quickly produced a theory of orbital motion which enabled that faint star-like object to be rediscovered by von Zach and others after it emerged from the rays of the Sun. Von Zach continued to supply him with the observations of contemporary European astronomers from which he was able to improve his theory to such an extent that he could detect the effects of planetary perturbations in distorting the orbit from an elliptical form. To cope with the complexities which these introduced into the calculations of Ceres and more especially the other minor planet Pallas, discovered by Wilhelm Olbers in 1802, Gauss developed a new and more rigorous numerical approach by making use of his mathematical theory of interpolation and his method of least-squares analysis, which was embodied in his famous Theoria motus of 1809. His laborious researches on the theory of Pallas's motion, in which he enlisted the help of several former students, provided the framework of a new mathematical formulation of the problem whose solution can now be easily effected thanks to modern computational techniques.Up to the time of his appointment as Director of the Göttingen Observatory in 1807, Gauss had little opportunity for engaging himself in practical astronomical work. His first systematic observations were concerned with re-establishing the latitude of of that observatory, which had been well-determined by Tobias Mayer more than fifty years earlier. However, he found a small but not negligible discrepancy between results obtained independently from stellar and solar observations, as well as irregularities among later measurements of polar altitudes (made at the new observatory completed in 1816), which he was never able to explain, despite repeated attempts to do so using different instruments and observational techniques. Similar anomalies were also detected by a number of other astronomers at around this time. These may have been associated--at any rate, partially--with the phenomenon identified later in the century as a “variation of latitude” due to minor periodic fluctuations in the Earth's axis of rotation produced by meteorological and geological factors.