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1.
It has recently been shown that orientation and retinotopic position, both of which are mapped in primary visual cortex, can show correlated jumps (Das & Gilbert, 1997). This is not consistent with maps generated by Kohonen's algorithm (Kohonen, 1982), where changes in mapped variables tend to be anticorrelated. We show that it is possible to obtain correlated jumps by introducing a Hebbian component (Hebb, 1949) into Kohonen's algorithm. This correspondents to a volume learning mechanism where synaptic facilitation depends not only on the spread of a signal from a maximally active neuron but also requires postsynaptic activity at a synapse. The maps generated by this algorithm show discontinuities across which both orientation and retinotopic position change rapidly, but these regions, which include the orientation singularities, are also aligned with the edges of ocular dominance columns, and this is not a realistic feature of cortical maps. We conclude that cortical maps are better modeled by standard, non-Hebbian volume learning, perhaps coupled with some other mechanism (e.g., that of Ernst, Pawelzik, Tsodyks, & Sejnowski, 1999) to produce receptive field shifts.  相似文献   

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Research on self-regulated learning (SRL) in hypermedia-learning environments is a growing area of interest, and prior knowledge can influence how students interact with these systems. One hundred twelve (N = 112) undergraduate students’ interactions with MetaTutor, a multi-agent, hypermedia-based learning environment, were investigated, including how prior knowledge affected their use of SRL strategies. We expected that students with high prior knowledge would engage in significantly more cognitive and metacognitive SRL strategies, engage in different sequences of SRL strategies, spend more time engaging in SRL processes, and visit more pages that were relevant to their sub-goals than students with low prior knowledge. Results showed significant differences in the total use of SRL strategies between prior knowledge groups, and more specifically, revealed significant differences in the use of each metacognitive strategy (e.g., judgment of learning), but not each cognitive strategy (e.g., taking notes) between prior knowledge groups. Results also revealed different sequences of use of SRL strategies between prior knowledge groups, and that students spent different amounts of time engaging in SRL processes; however, all students visited similar numbers of relevant pages. These results have important implications on designing multi-agent, hypermedia environments; we can design pedagogical agents that adapt to students’ learning needs, based on their prior knowledge levels.  相似文献   

3.
Zero is an experimental statically typed, fully object-oriented reflective programming language. Reflective features cover introspection as well as structural and behavioural reflection. The reflective facilities include safe method and class replacements and detailed modification of methods. These enable Zero programs to quickly accommodate to run-time requirements. Behavioural reflection is realised using handlers (hooks), which may be attached to all language constructs based on closures. Zero provides an efficient static typing system with run-time extensions. Methods are first class values and are represented as objects when such representation is required. By using such representation, Zero provides elegant use of statically typed higher-order methods.  相似文献   

4.

Background

In recent years, the importance of emotions in learning has been increasingly recognized. Applying emotional design to induce positive emotions has been considered a means to enhance the instructional effectiveness of digital learning environments. However, only a few studies have examined the specific effects of emotional design in game-based learning.

Objectives

This quasi-experimental study utilized a value-added research approach to investigate whether emotional design applied to scaffolding in a game-based learning environment improves learning and motivational outcomes more than emotionally neutral scaffolding.

Methods

A total of 138 participants, mean age of 11.5 (SD = 0.73) participated in the study. A total of 68 participants played the base version of a fraction learning game (Number Trace), where scaffolding was provided with emotionally neutral mathematical notations, and 70 participants played the value-added version of the game using emotionally designed animated scaffolding agents. Pre-and post-tests were used to measure conceptual fraction knowledge and self-reported measures of situational interest and situational self-efficacy to evaluate motivational outcomes.

Results and Conclusions

Our results indicate that the emotional design applied to scaffolds can improve the educational value of a game-based learning environment by enhancing players' situational interest and situational self-efficacy. However, although the intervention improved the participants' conceptual fraction knowledge, there was no significant difference between the scaffolding conditions in participants' learning outcomes.

Takeaways

The results suggest that emotional design can increase the educational impact of game-based learning by promoting the development of interest, as well as improving self-efficacy.  相似文献   

5.
Companies’ Facebook pages have emerged as a commonly used marketing channel and their importance as a sales channel is likely to increase. Details about consumers’ underlying motivations to use these pages need to be linked to their effect on the host company’s business. This study distinguishes between consumers’ hedonic and utilitarian motivations for using company-hosted Facebook pages and relates them to two types of community usage behavior: browsing and participation. The effects on variables closely linked to business performance are examined. Analysis of data collected from 1162 members of a travel agency’s Facebook page reveals that hedonic motivations indicate a higher propensity to participate in the community whereas utilitarian motivations relate more strongly to merely browsing the community page. The participating members, however, do not show intentions to buy from the host company or refer it to others, while the browsers do. For practitioners, the finding that hedonic community participants are needed to maintain the community, but that they are unlikely to profit the company, is crucial.  相似文献   

6.
The Journal of Supercomputing - With the emergence of heterogeneous architectures, developing parallel software has become an increasingly complex task. The ability of using multiple devices in a...  相似文献   

7.
Learning analytics is the analysis of electronic learning data which allows teachers, course designers and administrators of virtual learning environments to search for unobserved patterns and underlying information in learning processes. The main aim of learning analytics is to improve learning outcomes and the overall learning process in electronic learning virtual classrooms and computer-supported education. The most basic unit of learning data in virtual learning environments for learning analytics is the interaction, but there is no consensus yet on which interactions are relevant for effective learning. Drawing upon extant literature, this research defines three system-independent classifications of interactions and evaluates the relation of their components with academic performance across two different learning modalities: virtual learning environment (VLE) supported face-to-face (F2F) and online learning. In order to do so, we performed an empirical study with data from six online and two VLE-supported F2F courses. Data extraction and analysis required the development of an ad hoc tool based on the proposed interaction classification. The main finding from this research is that, for each classification, there is a relation between some type of interactions and academic performance in online courses, whereas this relation is non-significant in the case of VLE-supported F2F courses. Implications for theory and practice are discussed next.  相似文献   

8.
A set of non-parametric tests which includes the stochastic dominance criteria is developed here for evaluating the performance of mutual fund portfolios in relation to the market index. The empirical results support the hypothesis that some funds tend to dominte the market on the average, when a second-order stochastic dominance criterion is used.  相似文献   

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In domains with limited data, such as ballistic impact, prior researches have proven that the optimization of artificial neural models is an efficient tool for improving the performance of a classifier based on MultiLayer Perceptron. In addition, this research aims to explore, in the ballistic domain, the optimization of other machine learning strategies and their application in regression problems. Therefore, this paper presents an optimization methodology to use with several approaches of machine learning in regression problems, maximizing the limited dataset and locating the best network topology and input vector of each network model. This methodology is tested in real regression scenarios of ballistic impact with different artificial neural models, obtaining substantial improvement in all the experiments. Furthermore, the quality stage, based on criteria of information theory, enables the determination of when the complexity of the network design does not penalize the fit over the data and thereby the selection of the best neural network model from a series of candidates. Finally, the results obtained show the relevance of this methodology and its application improves the performance and efficiency of multiple machine learning strategies in regression scenarios.  相似文献   

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Neural Computing and Applications - Parkinson’s disease (PD) is a chronic and progressive neurological illness affecting millions of people in the world. The cure for PD is not available....  相似文献   

14.
It has been recently claimed [arXiv: 1510.00126], that the 143 GHz excess line in the Cosmic MicrowaveBackground (CMB) spectrumcould be explained by a collision of our Universe with an alternate Universe in which the baryon to entropy ratio is 65 times larger than the corresponding value measured for ourUniverse. This 143 GHz excess line is due to baryons, as was claimed, since the excess line corresponds to the recombination epoch, while the rest of the CMB signal is free of such excess lines. Thus the excess line is ascribed to an effect of collision of our Universe with a parallel universe. In this paper, we propose an alternative mechanism to explain the 143 GHz excess CMB line by using a simple bimetric gravity model which makes use of two metrics, the foreground metric g μν and the background metric f μν. The foreground Universe describes our Universe, and the background Universe is assumed to be underlying. The metrics are chosen to satisfy \({f_{\mu \nu }} = D_{{g_{\mu \nu }}}^2\), and the bimetric gravity model is constrained in such a way that the resulting Einstein equations for the background and foreground Universe are identical. In effect, the foreground and background Universe are indistinguishable at the cosmological solutions level. However, for the choices of the metrics we made, the scalar curvatures of the foreground and background Universes, namely R g and R f, are related by R f = 1/D 2, which can effectively result in different baryon to entropy ratios for the two Universes, via the gravitational baryogenesis mechanism. According to the gravitational baryogenesis mechanism, the baryon to entropy ratio is \(\eta B = \dot R/M_*^2T\), which means that the baryon to entropy ratio for the foreground and the background Universes we chose, namely ηB(g) and ηB(f), satisfy the relation \(\eta B\left( f \right) = \frac{1}{{{D^2}}}\eta B\left( g \right)\), and if D is chosen as \(D = 1/\sqrt {65} \), this could explain the 143 GHz excess line. The resulting phenomenological picture is quite appealing, since in the context of our bimetric gravity model, the foreground and background Universes coexist and are indistinguishable at the cosmological solutions level, but they are distinguishable only via the gravitational baryogenesis mechanism, which results in a baryon to entropy ratio for the background Universe, which is 65 time larger from the one corresponding to our Universe.  相似文献   

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In Java software, one important flexibility mechanism is dynamic class loading. Unfortunately, the vast majority of static analyses for Java treat dynamic class loading either unsoundly or too conservatively. We present a novel semi-static approach for resolving dynamic class loading by combining static string analysis with dynamically gathered information about the execution environment. The insight behind the approach is that dynamic class loading often depends on characteristics of the environment that are encoded in various environment variables. Such variables are not static elements; however, their run-time values typically remain the same across multiple executions of the application. Thus, the string values reported by our technique are tailored to the current installation of the system under analysis. Additionally, we propose extensions of string analysis to increase the number of sites that can be resolved purely statically, and to track the names of environment variables. An experimental evaluation on the Java 1.4 standard libraries shows that a state-of-the-art purely static approach resolves only 28% of non-trivial sites, while our approach resolves 74% of such sites. We also demonstrate how the information gained from resolved dynamic class loading can be used to determine the classes that can potentially be instantiated through the use of reflection. Our extensions of string analysis greatly increase the number of resolvable reflective instantiation sites. This work is a step towards making static analysis tools better equipped to handle the dynamic features of Java. This material is based upon work supported by the National Science Foundation under CAREER grant CCF-0546040.  相似文献   

17.
This article reviews the recent management literature and LIS literature looking for practical help for academic librarians seeking to lead effectively in the current economic recession. A number of pointers are found under the broad headings of embracing change, focusing on people and focusing on value. There is a lot of overlap and agreement between the two literatures on what is needed, and although both call for a different style of leadership for the future, the difference appears to be one of emphasis rather than a fundamental change.  相似文献   

18.
This study aims to investigate how interactivity influence learners' use of interactive functions in the course-management system (CMS) and their online learning performance. A two-tier mediation framework is proposed to examine the mediating effects of different actual-use records concerning the CMS's interactive functions. Data are collected from 381 undergraduate students who enrolled in a general-education asynchronous online course from three universities in Taiwan. The results indicate that the relationships among students' self-reported use of interactive functions, students' perceptions of the usefulness of interactive functions, and students' actual-use logs have some direct influences on students' online learning performance (online-discussion scores, exam scores, and group-project scores). In addition, students' actual-use logs (the number of times of log-ins to the online course, the number of times students read learning materials, and the number of postings on the discussion board) have a mediated effect on students' self-reported frequency of logging into the CMS, students' self-reported frequency of using the learner–instructor/learner–learner interactive functions, and online learning performance. The findings and implications could constitute a useful guide for educational practitioners and designers concerned with the effective integration of interactivity into future online courses.  相似文献   

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As the COVID-19 pandemic expands, the shortening of medical equipment is swelling. A key piece of equipment getting far-out attention has been ventilators. The difference between supply and demand is substantial to be handled with normal production techniques, especially under social distancing measures in place. The study explores the rationale of human-robot teams to ramp up production using advantages of both the ease of integration and maintaining social distancing. The paper presents a model for faster integration of collaborative robots and design guidelines for workstations. The scenario is evaluated for an open source ventilator through continuous human-robot simulation and amplification of results in a discrete event simulation.  相似文献   

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