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81.
过拟合现象是心理学走向预测科学的重要阻碍。文章综述了机器学习在解决过拟合现象中的价值和实现途径:(1)介绍了过拟合的两种表现形式和现状;(2)分析过拟合的根因,即“高解释力≠高预测力”;(3)厘清机器学习的建模逻辑与核心技术在解决过拟合中的作用;(4)利用样例数据和代码说明机器学习统计思想在模型拟合中的具体应用过程。文章指出心理学应从解决实际问题的角度出发,借鉴机器学习的分析思想,避免过拟合,进而提供更准确更稳定的结论和预测模型。 相似文献
82.
Emmanuel Cadel Sebastien Launois Anna Fraczkiewicz Didier Blavette 《Philosophical Magazine Letters》2013,93(11):725-736
In 1949, on the basis of theoretical considerations, Cottrell proposed the concept of 'atmospheres' (called later by his name) to explain some specific behaviour of materials during plastic deformation, such as sharp yield-point formation or the Portevin-LeChatelier effect. In this letter, atomic-scale observations and three-dimensional analyses of a Cottrell atmosphere are reported. They have been performed by three-dimensional atom-probe field-ion microscopy techniques. The ability of this new experimental method to provide atomic-resolution images, both structural and chemical, was confirmed; the basic stacking structure of (001) planes in FeAl could be visualized with success. Moreover the presence of a <001> edge dislocation was also detected in the analysed zone. Further, B enrichment was measured in the vicinity of this defect; the B-rich region appeared as a pipe 5 nm in diameter, parallel to the dislocation line. The concentration of B in the core reached 3 at.%; this local enrichment in boron was accompanied by an Al depletion of more than 10 at.%. Boron in FeAl has a well known tendency to segregate to internal interfaces. In this letter, we show experimental evidence of the solute segregation to dislocation lines. The observed effects of this segregation on mechanical properties of FeAl, both at room temperature and high temperatures, are also discussed. 相似文献
83.
New Concepts for New Dynamics: Generating Theory for the Study of Religious Innovation and Social Change 下载免费PDF全文
Gerardo Martí 《Journal for the scientific study of religion》2017,56(1):6-18
The Emerging Church movement (ECM) is sociologically interesting—not due to the size of its membership or the centrality of its congregations. Rather, the ECM is significant because it provides an opportunity to generate new concepts for the study religious innovation and social change. Using theoretical language, the ECM consists of institutional entrepreneurs who drive their religiously concerned movement by continually deconstructing and reframing beliefs, practices, and identities from “mainstream” Christianity while at the same time promoting newly formulated and broadly resonant religious imperatives. As Emerging Christians cultivate new or altered religious practices, these must be continually legitimized. Furthermore, their renegotiated beliefs (heterodoxies) require new forms of organization (alternative congregations). Such action is not the work of isolated individuals, nor is it independent of societal conditions. Ultimately, the ECM consists of Emerging Christians who creatively operate through diffuse network structures across wide geographic spaces and among disparate social groups to enact a collective institutional entrepreneurship that seeks to reimagine the assumptions of conventional Christian congregational life. 相似文献
84.
The aim of this paper is to propose a two-dimensional hybrid logic in order to formalize inferences containing both spatial and temporal propositions. The semantic idea behind the proposal is to name both horizontal and vertical lines in a 2D-plane by two kinds of nominals. This is a generalization of the idea of naming a point in one-dimensional hybrid logic. I give an axiomatization of the proposed two-dimensional hybrid logic and show that it enjoys a general completeness result (called pure completeness) with respect to product Kripke frames. Moreover, in order to capture -frames studied by R.H. Thomason (1984), I introduce the notion of a dependent product frame, which enables us to represent the dependence of space over time. I also give a complete axiomatization of this dependent two-dimensional hybrid logic, and, as a corollary, reveal that a hybridization of -logic enjoys strong completeness. 相似文献
85.
86.
We introduce Gentzen calculi for intuitionistic logic extended with an existence predicate. Such a logic was first introduced
by Dana Scott, who provided a proof system for it in Hilbert style. We prove that the Gentzen calculus has cut elimination
in so far that all cuts can be restricted to very simple ones. Applications of this logic to Skolemization, truth value logics
and linear frames are also discussed. 相似文献
87.
Clare Dixon 《Journal of Applied Logic》2006,4(1):50-78
Temporal logics of knowledge are useful for reasoning about situations where the knowledge of an agent or component is important, and where change in this knowledge may occur over time. Here we use temporal logics of knowledge to reason about the game Cluedo. We show how to specify Cluedo using temporal logics of knowledge and prove statements about the knowledge of the players using a clausal resolution calculus for this logic. We discuss the advantages and disadvantages of using this logic to specify and verify the game Cluedo and describe related implementations. 相似文献
88.
We generalise the result of [H. Ganzinger, C. Meyer, M. Veanes, The two-variable guarded fragment with transitive relations, in: Proc. 14th IEEE Symposium on Logic in Computer Science, IEEE Computer Society Press, 1999, pp. 24–34] on decidability of the two variable monadic guarded fragment of first order logic with constraints on the guard relations expressible in monadic second order logic. In [H. Ganzinger, C. Meyer, M. Veanes, The two-variable guarded fragment with transitive relations, in: Proc. 14th IEEE Symposium on Logic in Computer Science, IEEE Computer Society Press, 1999, pp. 24–34], such constraints apply to one relation at a time. We modify their proof to obtain decidability for constraints involving several relations. Now we can use this result to prove decidability of multi-modal modal logics where conditions on accessibility relations involve more than one relation. Our main application is intuitionistic modal logic, where the intuitionistic and modal accessibility relations usually interact in a non-trivial way. 相似文献
89.
Walter Hussak 《Studia Logica》2008,88(2):247-261
We consider the decision problem for cases of first-order temporal logic with function symbols and without equality. The monadic
monodic fragment with flexible functions can be decided with EXPSPACE-complete complexity. A single rigid function is sufficient
to make the logic not recursively enumerable. However, the monadic monodic fragment with rigid functions, where no two distinct
terms have variables bound by the same quantifier, is decidable and EXPSPACE-complete.
Presented by Robert Goldblatt 相似文献
90.
In the paper we explore the idea of describing Pawlak’s rough sets using three-valued logic, whereby the value t corresponds to the positive region of a set, the value f — to the negative region, and the undefined value u — to the border of the set. Due to the properties of the above regions in rough set theory, the semantics of the logic is
described using a non-deterministic matrix (Nmatrix). With the strong semantics, where only the value t is treated as designated, the above logic is a “common denominator” for Kleene and Łukasiewicz 3-valued logics, which represent
its two different “determinizations”. In turn, the weak semantics—where both t and u are treated as designated—represents such a “common denominator” for two major 3-valued paraconsistent logics.
We give sound and complete, cut-free sequent calculi for both versions of the logic generated by the rough set Nmatrix. Then
we derive from these calculi sequent calculi with the same properties for the various “determinizations” of those two versions
of the logic (including Łukasiewicz 3-valued logic). Finally, we show how to embed the four above-mentioned determinizations
in extensions of the basic rough set logics obtained by adding to those logics a special two-valued “definedness” or “crispness”
operator. 相似文献