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1.
Under steady-state conditions, the current equations of the second-order EC, ECE and DISPI reactions at microdisk, microspherical and microring electrodes are derived with the aid of the concept of the reaction layer. The conditions under which these equations would be valid are also discussed. Using these equations, methods to determine the kinetic parameters for the second-order EC, ECE and DISPI reactions are presented. The reduction of 2,6-diphenyl-pyrylium cation and oxidation of triphenylamine were investigated as examples of the second-order EC and ECE reactions. 相似文献
2.
《Journal of computational science》2014,5(4):675-683
Analytical processing on multi-dimensional data is performed over data warehouse. This, in general, is presented in the form of cuboids. The central theme of the data warehouse is represented in the form of fact table. A fact table is built from the related dimension tables. The cuboid that corresponds to the fact table is called base cuboid. All possible combination of the cuboids could be generated from base cuboid using successive roll-up operations and this corresponds to a lattice structure. Some of the dimensions may have a concept hierarchy in terms of multiple granularities of data. This means a dimension is represented in more than one abstract form. Typically, neither all the cuboids nor all the concept hierarchy are required for a specific business processing. These cuboids are resided in different layers of memory hierarchy like cache memory, primary memory, secondary memory, etc. This research work dynamically finds the most cost effective path from the lattice structure of cuboids based on concept hierarchy to minimize the query access time. The knowledge of location of cuboids at different memory elements is used for the purpose. 相似文献
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This study explored sixth grade students’ concept images of geometric translations and the possible sources of their conceptions in a non-technological environment. The data were gathered through a written instrument, student and teacher interviews and document analyses. Analyses of student responses revealed two major concept images of geometric translations: (a) translation as translational motion, and (b) translation as both translational and rotational motion. Students who held these conceptions showed various levels of understanding, such as conceiving translations as undefined motion, partially-defined motion, and defined-motion of a single geometric figure on the plane. The findings of the study suggested, in general, consistencies between students’ concept images and their concept definitions. However, most of the students’ concept definitions were inconsistent with the formal concept definition of geometric translations.Data analyses also revealed five interpretations of a translation vector: (a) vector as a reference line, (b) vector as a symmetry line, (c) vector as a direction indicator, (d) vector as a parameter, and (e) vector as an abstract tool. Furthermore, classroom instruction, mathematics and science textbooks, real-life examples and everyday language were the major sources of students’ concept images of geometric translations. 相似文献
4.
The Nordic forest industry requires just-in-time wood deliveries. Operations must continue regardless of season, weather and terrain. Soil compaction and deep ruts must be avoided while providing high performance and a reasonable working environment for operators.The Xt28 pendulum arm forwarder is a full-size concept forwarder with six hydrostatic propelled wheels on pendulum arms built on a three-piece frame connected with two articulation joints. The Xt28 concept machine was tested according to Skogforsk standard machine tests. Rut depth test focused on soil interaction where rut depth was measured related to number of passes. Machine dynamics were measured using standardized test track with focus on operator comfort.The project proved the potential of pendulum arm technology in off-road transportation. Automatic pendulum arm levelling, equalized ground pressure between wheels and improved operator comfort through reducing adverse vibrations and roll angles, simultaneously reducing dynamic forces transferred to the forest floor. Pendulum arm technology improves travel speed in adverse terrain, providing unparalleled side slope capability and enhanced productivity. 相似文献
5.
We report a case study that explored how three college students mentally represented the knowledge they held of inferential statistics, how this knowledge was connected, and how it was applied in two problem solving situations. A concept map task and two problem categorization tasks were used along with interviews to gather the data. We found that the students’ representations were based on incomplete statistical understanding. Although they grasped various concepts and inferential tests, the students rarely linked key concepts together or to tests nor did they accurately apply that knowledge to categorize word problems. We suggest that one reason the students had difficulty applying their knowledge is that it was not sufficiently integrated. In addition, we found that varying the instruction for the categorization task elicited different mental representations. One instruction was particularly effective in revealing students’ partial understandings. This finding suggests that modifying the task format as we have done could be a useful diagnostic tool. 相似文献
6.
Gregg C. Oden 《Fuzzy Sets and Systems》1984,14(1):29-41
To successfully understand a natural language utterance, a person must simultaneously consider information about its perceptual, syntactic, semantic, and pragmatic structure. At each of these levels of analysis, the linguistic information is continuously but systematically variable. It is argued that in order to cope with and, in fact, exploit this continuous information requires fuzzy propositional representations of linguistic knowledge. Such a fuzzy propositional theoretical framework is proposed and models of several specific language processing components are developed and empirically evaluated within this framework. The model system incorporates many of the major principles of current cognitive psychological theory and extends them into the fuzzy domain. 相似文献
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The purpose of this paper is to further the notion of defining as a mathematical activity by elaborating a framework that structures the role of defining in student progress from informal to more formal ways of reasoning. The framework is the result of a retrospective account of a significant learning experience that occurred in an undergraduate geometry course. The framework integrates the instructional design theory of Realistic Mathematics Education (RME) and distinctions between concept image and concept definition and offers other researchers and instructional designers a structured way to analyze or plan for the role of defining in students’ mathematical progress. 相似文献
9.
Charlie Pelling 《Acta Analytica》2007,22(3):169-182
According to the conceptualist view in the philosophy of perception, we possess concepts for all the objects, properties,
and relations which feature in our experiences. Richard Heck has recently argued that the phenomenon of illusory experience
provides us with conclusive reasons to reject this view. In this paper, I examine Heck’s argument, I explain why I think that
Bill Brewer’s conceptualist response to it is ineffective, and I then outline an alternative conceptualist response which
I myself endorse. My argument turns on the fact that both Heck, in constructing his objection to conceptualism, and Brewer,
in responding to it, miss a crucial distinction between perceptual demonstrative concepts of objects, on the one hand, and
perceptual demonstrative concepts of properties, on the other.
相似文献
Charlie PellingEmail: |
10.
Radim Blohlvek 《Mathematical Logic Quarterly》2001,47(1):111-116
We give a characterization of the fixed points and of the lattices of fixed points of fuzzy Galois connections. It is shown that fixed points are naturally interpreted as concepts in the sense of traditional logic. 相似文献