Time evolution of the extremely diluted Blume-Emery-Griffiths neural network

The time evolution of the extremely diluted Blume-Emery-Griffiths neural network model is studied, and a detailed equilibrium phase diagram is obtained exhibiting pattern retrieval, fluctuation retrieval and self-sustained activity phases. It is shown that saddle-point solutions associated with fluctuation overlaps slow down considerably the flow of the network states towards the retrieval fixed points. A comparison of the performance with other three-state networks is also presented.Comment: 8 pages, 5 figure

Oklahoma Cooperative Extension Service Educators Accessibility to Resources and Training Regarding Communications And Marketing: a Needs Assessment

The purpose of this study is to determine the perceptions of Oklahoma Cooperative Extension Service (OCES) educators regarding their communications and marketing efforts, training needs, and resources. Through a quantitative survey administered at a statewide conference in January 2008, OCES educators shared how often and how well they use specific media, how they prefer to deliver information to clientele, where they learned mass communication skills, and what communications training they desired. According to andragogy theory, adults will accept and implement a new marketing/communications plan better if they are part of the planning process. Data were gathered and analyzed using descriptive statistics. The survey response rate was 60.78%. Educators are "satisfied" with the time they devote to their job. "Increasing capacity to reach new and diverse audiences" is the greatest challenge as an OCES educator. OCES educators spend 15.13 hours per month marketing and communicating. They focus a majority of that time on youth and adult residents. OCES educators perceive media relations, article placement, and direct mail as effective county programming efforts. OCES educators have access to a newspaper publisher in town, a radio station in town, a television station in a non-adjacent county, and a multi-media agency in town. Educators perceive their highest skills in communications and marketing are writing a story for a newspaper, developing an Extension flier or newsletter, or communicating via e-mail. Educators indicated they have most of their training through on-the-job experience. The five areas selected by educators for more training were Web site maintenance, creating electronic media, writing for a newspaper story, writing or editing an Extension flier or newsletter, and using electronic media. A moderate positive relationship exists between educators' skill rating of using and maintaining Web sites and their year of birth.Department of Agricultural Education, Communications, and Leadershi

A canonical ensemble approach to graded-response perceptrons

Perceptrons with graded input-output relations and a limited output precision are studied within the Gardner-Derrida canonical ensemble approach. Soft non- negative error measures are introduced allowing for extended retrieval properties. In particular, the performance of these systems for a linear and quadratic error measure, corresponding to the perceptron respectively the adaline learning algorithm, is compared with the performance for a rigid error measure, simply counting the number of errors. Replica-symmetry-breaking effects are evaluated.Comment: 26 pages, 10 ps figure

First evidence of the feasibility of gaze-contingent attention training for school children with autism

A number of authors have suggested that attention control may be a suitable target for cognitive training in children with autism spectrum disorder. This study provided the first evidence of the feasibility of such training using a battery of tasks intended to target visual attentional control in children with autism spectrum disorder within school-based settings. Twenty-seven children were recruited and randomly assigned to either training or an active control group. Of these, 19 completed the initial assessment, and 17 (9 trained and 8 control) completed all subsequent training sessions. Training of 120 min was administered per participant, spread over six sessions (on average). Compliance with the training tasks was generally high, and evidence of within-task training improvements was found. A number of untrained tasks to assess transfer of training effects were administered pre- and post-training. Changes in the trained group were assessed relative to an active control group. Following training, significant and selective changes in visual sustained attention were observed. Trend training effects were also noted on disengaging visual attention, but no convincing evidence of transfer was found to non-trained assessments of saccadic reaction time and anticipatory looking. Directions for future development and refinement of these new training techniques are discussed

Correlation of internal representations in feed-forward neural networks

Feed-forward multilayer neural networks implementing random input-output mappings develop characteristic correlations between the activity of their hidden nodes which are important for the understanding of the storage and generalization performance of the network. It is shown how these correlations can be calculated from the joint probability distribution of the aligning fields at the hidden units for arbitrary decoder function between hidden layer and output. Explicit results are given for the parity-, and-, and committee-machines with arbitrary number of hidden nodes near saturation.Comment: 6 pages, latex, 1 figur

Retrieval behavior and thermodynamic properties of symmetrically diluted Q-Ising neural networks

The retrieval behavior and thermodynamic properties of symmetrically diluted Q-Ising neural networks are derived and studied in replica-symmetric mean-field theory generalizing earlier works on either the fully connected or the symmetrical extremely diluted network. Capacity-gain parameter phase diagrams are obtained for the Q=3, Q=4 and $Q=\infty$ state networks with uniformly distributed patterns of low activity in order to search for the effects of a gradual dilution of the synapses. It is shown that enlarged regions of continuous changeover into a region of optimal performance are obtained for finite stochastic noise and small but finite connectivity. The de Almeida-Thouless lines of stability are obtained for arbitrary connectivity, and the resulting phase diagrams are used to draw conclusions on the behavior of symmetrically diluted networks with other pattern distributions of either high or low activity.Comment: 21 pages, revte