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排序方式: 共有880条查询结果,搜索用时 15 毫秒
31.
BCI Meeting 2005--workshop on signals and recording methods. 总被引:4,自引:0,他引:4
Jonathan R Wolpaw Gerald E Loeb Brendan Z Allison Emanuel Donchin Omar Feix do Nascimento William J Heetderks Femke Nijboer William G Shain James N Turner 《IEEE transactions on neural systems and rehabilitation engineering》2006,14(2):138-141
This paper describes the highlights of presentations and discussions during the Third International BCI Meeting in a workshop that evaluated potential brain-computer interface (BCI) signals and currently available recording methods. It defined the main potential user populations and their needs, addressed the relative advantages and disadvantages of noninvasive and implanted (i.e., invasive) methodologies, considered ethical issues, and focused on the challenges involved in translating BCI systems from the laboratory to widespread clinical use. The workshop stressed the critical importance of developing useful applications that establish the practical value of BCI technology. 相似文献
32.
Emma P. Bullock Allison L. Roxburgh Patricia S. Moyer-Packenham Elif Bektas Joseph S. Webster Kathleen A. Bullock 《Journal of Computer Assisted Learning》2021,37(2):557-586
This study focused on an examination of how type, quality and children's awareness of design features in digital math games, along with an awareness of the mathematics goals of the game, were related to learning outcomes. We conducted a parallel conversion mixed methods study with 45 students in Grades 3 and 4 (ages 9–10). Students participated in clinical interviews using three digital math games. The results suggest a moderated mediation relationship in which the quality of the design features moderated the mediating impact of children's awareness of the game's design features, specifically when the child was aware of the mathematics content learning goal (MCLG) of the game. These findings show how important it is that design features are of high quality in a digital math game, and how this is intertwined with children's awareness of the features and the MCLG. When these variables intertwined in just the right way, the interactions between the children and the digital math game afforded mathematical learning growth. 相似文献
33.
Allison Chang Cynthia Rudin Michael Cavaretta Robert Thomas Gloria Chou 《Machine Learning》2012,88(3):369-398
A good or bad product quality rating can make or break an organization. However, the notion of ??quality?? is often defined by an independent rating company that does not make the formula for determining the rank of a product publicly available. In order to invest wisely in product development, organizations are starting to use intelligent approaches for determining how funding for product development should be allocated. A critical step in this process is to ??reverse-engineer?? a rating company??s proprietary model as closely as possible. In this work, we provide a machine learning approach for this task, which optimizes a certain rank statistic that encodes preference information specific to quality rating data. We present experiments on data from a major quality rating company, and provide new methods for evaluating the solution. In addition, we provide an approach to use the reverse-engineered model to achieve a top ranked product in a cost-effective way. 相似文献
34.
This study investigated the extent and nature of university students’ use of digital technologies for learning and socialising. The findings show that students use a limited range of mainly established technologies. Use of collaborative knowledge creation tools, virtual worlds, and social networking sites was low. ‘Digital natives’ and students of a technical discipline (Engineering) used more technology tools when compared to ‘digital immigrants’ and students of a non-technical discipline (Social Work). This relationship may be mediated by the finding that Engineering courses required more intensive and extensive access to technology than Social Work courses. However, the use of technology between these groups is only quantitatively rather than qualitatively different. The study did not find evidence to support popular claims that young people adopt radically different learning styles. Their attitudes to learning appear to be influenced by lecturers’ teaching approaches. Students appear to conform to traditional pedagogies, albeit with minor uses of tools delivering content. The outcomes suggest that although the calls for transformations in education may be legitimate it would be misleading to ground the arguments for such change in students’ shifting patterns of learning and technology use. 相似文献
35.
Cyberbullying is a newer variation of bullying that utilizes technology to harass. This study investigated the psychological symptomology, suicidal behaviors, aggressive tendencies, and illegal behaviors of college cyberbullies. Sixty cyberbullies and 19 cyberbully/victims (participants who cyberbullied and were victims of cyberbullying) scored higher in psychological symptoms of depression, hostility, interpersonal sensitivity, paranoia, phobic anxiety, and psychoticism than participants who were uninvolved with cyberbullying. The cyberbullies also endorsed more suicidal behaviors and scored higher in aggression. The cyberbully/victims engaged in more violent and drug crimes than cyberbullies and controls. These findings indicate perpetrators of cyberbullying have more psychological distress, aggressive tendencies, and engage in more illegal behaviors than those who do not cyberbully. This is the first study to show the distress cyberbullies are experiencing. 相似文献
36.
G. G. Wright A. R. Sibbald J. S. Allison 《International journal of remote sensing》2013,34(11):2319-2336
In this paper, high resolution, remotely-sensed data are investigated as a source of management information for moorland vegetation communities on a hypothetical farm in a marginal farming area of Scotland. A hybrid technique for vegetation mapping is adopted. This involves unsupervised machine classification of spectral variation in digitally enhanced air photographs and satellite imagery, together with visual interpretation of the imagery in both the laboratory and the field. This technique enables relative estimates of annual gross biomass production, for a range of vegetation types, to be obtained. The data are integrated into a simple heather moorland management model (HMMM), to produce potential sheep-stocking capacities under a range of management scenarios, the possible financial implications of these scenarios are also assessed. 相似文献
37.
The widespread availability of digital learning resources in a variety of media formats offers the possibility to make a profound difference in education. This potential has not been fully realised for range of interrelated reasons. In this paper we study the key characteristics of learning resources that have proved effective in changing learning and teaching, and relate them to existing frameworks for understanding resources. We outline the relationships between resources, their users, and the way they are used, and explore issues that influence practitioners in choosing a particular resource. Our study is based on a review of resources for e-learning and chemistry in post-compulsory education, undertaken for the UK Joint Information Systems Committees (JISC), as part of a wider study examining ‘The Effectiveness of Resources, Tools and Support Services used by Tutors in Designing and Delivering E-Learning Activities’. 相似文献
38.
This work explores the effect of virtual fixture admittance on the performance, defined by error and time, of task execution with a human-machine cooperative system. A desired path is obtained using computer vision, and virtual fixtures for assistance in planar path following were implemented on an admittance-controlled robot. The admittance controller uses a velocity gain, so that the speed of the robot is proportional to the force applied by the operator. The level of virtual fixture guidance is determined by the admittance ratio, which is the ratio of the admittance gain of the force components orthogonal to the path to the gain of the force components parallel to the path. In Experiment 1, we found a linear relationship between admittance ratio and performance. In Experiment 2, we examined the effect of admittance ratio on the performance of three tasks: path following, off-path targeting, and obstacle avoidance. An algorithm was developed to select an appropriate admittance ratio based on the nature of the task. Automatic admittance ratio tuning is recommended for next-generation virtual fixtures. Actual or potential applications of this research include surgery, assembly, and manipulation at the macro and micro scales. 相似文献
39.
Ronald J Duchovic Yuri L VolobuevGillian C Lynch Donald G TruhlarThomas C Allison Albert F WagnerBruce C Garrett Jose C Corchado 《Computer Physics Communications》2002,144(2):169-187
POTLIB 2001 is a computer program library of global chemical potential energy surface (PES) functions (91 functions in version 1.0) along with test data, a suite of utility programs, and a convenient user interface. The PES programs are written in ANSI standard FORTRAN77 and can be used to determine the Born-Oppenheimer potential energy of chemical systems as a function of the internal coordinates. The accompanying test data allow users to verify local implementations of this library. Finally, the utility programs permit use of this library in conjunction with a variety of chemical dynamics and chemical kinetics computer codes. Interface routines are provided for the POLYRATE and ABCRATE program packages of Truhlar and co-workers, the VENUS96 program package of Hase and co-workers, and the VARIFLEX program package of Klippenstein and co-workers; the routines in this library can also be used in conjunction with the DYNASOL program package of Zhang and co-workers. This article describes the library and the utility programs and outlines the systematic conventions used for interfaces in the computer programs contained in the library. Adherence to these conventions will allow future PESs to be compatible with this library. 相似文献
40.
Clara Mata Ellen K. Longmire David H. McKenna Katie K. Glass Allison Hubel 《Microfluidics and nanofluidics》2008,5(4):529-540
A recently proposed application of microfluidics is the post-thaw processing of biological cells. Numerical simulations suggest
that diffusion-based extraction of the cryoprotective agent dimethyl sulfoxide (DMSO) from blood cells is viable and more
efficient than centrifugation, the conventional method of DMSO removal. In order to validate the theoretical model used in
these simulations, a prototype was built and the flow of two parallel streams, a suspension of Jurkat cells containing DMSO
and a wash stream that contained neither cells nor DMSO, was characterized experimentally. DMSO transport in a rectangular
channel (depth 500 μm, width 25 mm and overall length 125 mm) was studied as a function of three dimensionless parameters:
depth ratio of the streams, cell volume fraction in the cell solution, and the Peclet number (Pe) based on channel depth, average flow rate and the diffusion coefficient for DMSO in water. In our studies, values of Pe ranged from O(103) to O(104). Laminar flow was ensured by keeping the Reynolds number between O(1) and O(10). Experimental results based on visual and
quantitative data demonstrate conclusively that a microfluidic device can effectively remove DMSO from liquid and cell laden
streams without compromising cell recovery. Also, flow conditions in the microfluidic device appear to have no adverse effect
on cell viability at the outlet. Further, the results demonstrate that we can predict the amount of DMSO removed from a given
device with the theoretical model mentioned previously. 相似文献