Projection of a binary criterion into a model of hierarchical classes

A formal analysis is made of how to project an attribute criterion into the hierarchical classes model for object by attribute data proposed by De Boeck and Rosenberg. The projection is conceptualized as the prediction of the attribute criterion by means of a logical rule defined on the basis of attribute combinations from the model. Eliminative and constructive strategies are proposed to find logical rules with maximal predictive power and minimal formula complexity. Logical analyses of a real data set are reported and compared with a logistic regression to demonstrate the usefulness of the logical strategies, and to show the complementarity of logical and probabilistic approaches.The first suthor is Senior Research Assistant of the National Fund for Scientific Research (Belgium). We would like to thank the Editor, the reviewers, Seymour Rosenberg, and Luc Delbeke for their helpful comments on earlier drafts of this article.     

Overshadowing by fixed- and variable-duration stimuli

Two experiments investigated the effect of the temporal distribution form of a stimulus on its ability to produce an overshadowing effect. The overshadowing stimuli were either of the same duration on every trial, or of a variable duration drawn from an exponential distribution with the same mean duration as that of the fixed stimulus. Both experiments provided evidence that a variable-duration stimulus was less effective than a fixed-duration cue at overshadowing conditioning to a target conditioned stimulus (CS); moreover, this effect was independent of whether the overshadowed CS was fixed or variable. The findings presented here are consistent with the idea that the strength of the association between CS and unconditioned stimulus (US) is, in part, determined by the temporal distribution form of the CS. These results are discussed in terms of time-accumulation and trial-based theories of conditioning and timing.     

Clarifying Amateurism: A Logical Approach to Resolving the Exploitation of College Athletes Dilemma

In this paper we investigate the logical consequences of the common understanding of amateurism in the context of big-time US college athletics, and in so doing, illustrate a method based on linguistic analysis and logic. The initial thrust of the paper centres on the term ‘amateur’ as presupposed by the late Professor Brand in his attempt to justify the ‘business’ of NCAA-sponsored Division I sports by decoupling the ‘participants from the enterprise’. Next, we examine a more rigorous definition of the term ‘amateur’ in order to show more clearly the difficulties posed by the current situation in college athletics. Additionally, our use of linguistic analysis exposes a flaw in the NCAA's recent move to amend by-law 12.02 in an attempt to avoid the charge of exploitation. Lastly, we put forth a new proposal for better dealing with the central issues swirling around the NCAA as it strives to formulate sound policy at this ‘tectonic’ juncture of players, fans, college programmes and academic integrity.     

Frege,Boolos, and Logical Objects

In this paper, the authors discuss Frege's theory of logical objects (extensions, numbers, truth-values) and the recent attempts to rehabilitate it. We show that the eta relation George Boolos deployed on Frege's behalf is similar, if not identical, to the encoding mode of predication that underlies the theory of abstract objects. Whereas Boolos accepted unrestricted Comprehension for Properties and used the eta relation to assert the existence of logical objects under certain highly restricted conditions, the theory of abstract objects uses unrestricted Comprehension for Logical Objects and banishes encoding (eta) formulas from Comprehension for Properties. The relative mathematical and philosophical strengths of the two theories are discussed. Along the way, new results in the theory of abstract objects are described, involving: (a) the theory of extensions, (b) the theory of directions and shapes, and (c) the theory of truth values.     

Choice and Logic

There is a little known paradox the solution to which is a guide to a much more thoroughgoing solution to a whole range of classic paradoxes. This is shown in this paper with respect to Berrys Paradox, Heterologicality, Russells Paradox, and the Paradox of Predication, also the Liar and the Strengthened Liar, using primarily the epsilon calculus. The solutions, however, show not only that the first-order predicate calculus derived from Frege is inadequate as a basis for a clear science, and should be replaced with Hilbert and Bernays conservative extension. Standard second-order logic, and quantified propositional logic also must be substantially modified, to incorporate, in the first place, nominalizations of predicates, and whole sentences. And further modifications must be made, so as to insist that predicates are parts of sentences rather than forms of them, and that truth is a property of propositions rather than their sentential expressions. In all, a thorough reworking of what has been called logic in recent years must be undertaken, to make it more fit for use.Portions of this paper have previously been published in Logical Studies, vol. 9, http://www.logic.ru/LogStud/09/No9-06.html, and the Australasian Journal of Logic, vol. 2, http://www.philosophy.unimelb.edu.au/ajl/2004/2004_4.pdf.     

政府环境伦理责任论

作为一种特殊经济主体,政府承担着必不可少的环境伦理责任。政府的环境伦理责任是指政府在参与社会经济活动过程中应该为环境保护事业承担的道德责任,它主要是通过政府制定和推行环境政策、法规、规划、标准的情况得到体现的。为了有效地开展环境保护工作,我们应该实行“政府为主,市场为辅”的环保机制。     

Note on the Scope of Truth-functional Logic

A plausible and popular rule governing the scope of truth-functional logic is shown to be indequate. The argument appeals to the existence of truth-functional paraphrases which are logically independent of their natural language counterparts. A more adequate rule is proposed.     

Ray on Tarski on Logical Consequence

In Logical consequence: A defense of Tarski (Journal of Philosophical Logic, vol. 25, 1996, pp. 617–677), Greg Ray defends Tarski"s account of logical consequence against the criticisms of John Etchemendy. While Ray"s defense of Tarski is largely successful, his attempt to give a general proof that Tarskian consequence preserves truth fails. Analysis of this failure shows that de facto truth preservation is a very weak criterion of adequacy for a theory of logical consequence and should be replaced by a stronger absence-of-counterexamples criterion. It is argued that the latter criterion reflects the modal character of our intuitive concept of logical consequence, and it is shown that Tarskian consequence can be proved to satisfy this criterion for certain choices of logical constants. Finally, an apparent inconsistency in Ray"s interpretation of Tarski"s position on the modal status of the consequence relation is noted.     

Visual evoked potentials to the geometric forms in the randomized presentation

Two outlined geometric figures, an equilateral triangle and a circle, of equal contour length, were randomly presented at a fixed position in the lower or upper part of the visual field (LVF and UVF). Transient visual evoked potentials (VEPs) were recorded monopolarly from the inion (I), 5, 10, 15 cm above it (I5, I10, I15) and Fz, for 12 subjects. Grand-averaged VEPs were computed. A negative (N) wave (averaged peak latency 155 ms) was identified in the LVF and a positive (P) wave (130 ms) in the UVF. In the LVF, the N amplitude of the triangle was significantly larger than that of the circle at I5 and I. Regarding the P wave in the UVF, the triangle was of a significantly longer latency than the circle at I15, I10 and I5. The enhancement of the N amplitude for the triangle in the LVF is not attributable to the arousal caused by the preparatory state for the figure, since the subject could not predict the figure to be presented next or its position.     

帕金森病人的图形辨别障碍

对56名帕金森病人用视觉形状辨别测验(VFDT)进行了测查,44名年龄、文化水平与帕金森组相当的正常人作为对照组。结果发现帕金森病人对图形辨别有明显障碍。对帕金森病人在图形辨别障碍中的特点进行了分析,并对其可能机制进行了讨论。