Studies of dynamics of physical agent ecosystems

This thesis addresses the problem of learning in physical heterogeneous multi-agent systems (MAS) and the analysis of the benefits of using heterogeneous MAS with respect to homogeneous ones. An algorithm is developed for this task; building on a previous work on stability in distributed systems by Tad Hogg and Bernardo Huberman, and combining two phenomena observed in natural systems, task partition and hierarchical dominance. This algorithm is devised for allowing agents to learn which are the best tasks to perform on the basis of each agent's skills and the contribution to the team global performance. Agents learn by interacting with the environment and other teammates, and get rewards from the result of the actions they perform. This algorithm is specially designed for problems where all robots have to co-operate and work simultaneously towards the same goal. One example of such a problem is role distribution in a team of heterogeneous robots that form a soccer team, where all members take decisions and co-operate simultaneously. Soccer offers the possibility of conducting research in MAS, where co-operation plays a very important role in a dynamical and changing environment. For these reasons and the experience of the University of Girona in this domain, soccer has been selected as the test-bed for this research. In the case of soccer, tasks are grouped by means of roles. One of the most interesting features of this algorithm is that it endows MAS with a high adaptability to changes in the environment. It allows the team to perform their tasks, while adapting to the environment. This is studied in several cases, for changes in the environment and in the robot's body. Other features are also analysed, especially a parameter that defines the fitness (biological concept) of each agent in the system, which contributes to performance and team adaptability. The algorithm is applied later to allow agents to learn in teams of homogeneous and heterogeneous robots which roles they have to select, in order to maximise team performance. The teams are compared and the performance is evaluated in the games against three hand-coded teams and against the different homogeneous and heterogeneous teams built in this thesis. This section focuses on the analysis of performance and task partition, in order to study the benefits of heterogeneity in physical MAS. In order to study heterogeneity from a rigorous point of view, a diversity measure is developed building on the hierarchic social entropy defined by Tucker Balch. This is adapted to quantify physical diversity in robot teams. This tool presents very interesting features, as it can be used in the future to design heterogeneous teams on the basis of the knowledge on other teams.

The formation of learning sets by the chinchilla in an auditory discrimination procedure

This paper discusses a study conducted to test sound discrimination abilities of the chinchilla.

Applicability of the Test of Visual Perceptual Abilities (TVPA) in diagnosing learning disabilities in hearing-impaired children

This paper studies the validity of the Test of Visual Perceptual Abilities (TVPA) as an indicator of learning problems in hearing-impaired children and how it correlates with other measures of learning disabilities.

A comparison of the performance of aphasoid and non-aphasoid children in learning to discriminate among auditory stimuli

This paper discusses auditory perception differences in aphasic and non-aphasic children

Novel word-learning for normal-hearing and hearing-impaired children

The study was designed to determine the appropriateness of a novel word-learning paradigm for normal-hearing and hearing-impaired children as well as to explore the nature of word-learning abilities for both groups. Pilot data was gathered to determine the number of words learned following separate intervals and throughout the test session.

Learning disabled and hearing-impaired

This paper discusses learning disabilities in children who are hearing impaired.

An experimental base to cognitive learning: its application in the education of young hearing-impaired children

This paper reviews a program of study for language development using a cognitive approach.

Cooperative learning: a guide for teachers of the deaf

This paper examines cooperative learning, a strategy of teaching in which students work together in groups, thus acquiring both academic and social skills

The relation of E.Q and I.Q. to learning from the standard self-instructional programs in spelling and english

This paper reviews a study that was done with hearing and hearing impaired children to test the effectiveness of self-instructional programs and whether the results can be correlated with Educational Quotient and Intelligence Quotient.

A comparison of scores of deaf and hearing children on the Hiskey Test of learning ability and on performance scales

This paper discusses the Hiskey Test of learning ability and its use on hearing impaired and normal hearing children.

Cooperative learning: helping hearing impaired students build success

This paper examines the importance of cooperative learning and its use in the education of hearing-impaired children.

Threshold adaptation, temporal integration and frequency discrimination-learning in hearing impaired children

This paper is a review of a study to evaluate the usefulness of a laboratory approach to auditory training with hearing impaired children.

New Hope learning center

This paper reviews the field of speech pathology and whether it is of benefit to helping profoundly retarded children develop verbal/functional language skills.

Resources for non-english speaking parents of children who are deaf or hard of hearing and learning english as their primary language

This study examined culturally and linguistically diverse families with deaf and hard of hearing children. A literature review consisted of looking at the rate of immigration to the United States, English speaking parents of children who are deaf and hard of hearing, bilingual education, and the obstacles bilingual parents of children who are deaf and hard of hearing may face. The data obtained was used to compile a list of resources for parents of children who are deaf and hard of hearing available in languages other than English in order to assist these families.

Students who are deaf/hard of hearing with learning challenges: Strategies for classroom instruction

This paper discusses the prevalence of children who are deaf or hard of hearing with additional learning challenges and the need for further trainings for strategies to better serve this population.