Development of a distributed knowledge-based system

This paper describes the development of a distributed knowledge-based system. A software system, namely Distributed Algorithmic and Rule-based Blackboard System (DARBS), was developed from its predecessor ARBS, which lacked the distributed computing feature. ARBS has been used in solving a number of engineering problems [1-3]. DARBS now utilises client/server technology. It consists of a centralised database server, called the 'Blackboard' and a number of Knowledge Source Clients (experts). It distributes the workload to a number of clients which are rule-based or other AI systems with specific knowledge in various areas. DARBS is being applied to automatic interpretation of non-destructive evaluation (NDE) data and control of plasma deposition processes

DARBS: a distributed blackboard system

Prior to this work, an algorithmic and rule-based blackboard system (ARBS) had been developed over a ten-year period. ARBS benefited from a versatile rule structure and the ability to mix computational styles either as separate knowledgesources or by embedding algorithms within rules. It was a serial system – any knowledge source that was able to contribute had to wait its turn. We report here on a new distributed system, DARBS, in which the knowledge sources are parallel processes. Based around the client/server model, DARBS comprises a centralised database server, i.e. the blackboard, and a number of knowledge source clients. As the clients are separate processes, possibly on separate networked computers, they can contribute to the solution of a problem whenever they have a contribution to make. DARBS therefore achieves the well-established but elusive ideal of opportunism. It behaves as a distributed agent-based system, with the proviso that all communication is via the blackboard. DARBS is currently being applied to automatic interpretation of nondestructive evaluation (NDE) data and control of plasma deposition processes

Screening for auditory neuropathy in a school for hearing impaired children

Objective: Hearing loss in children may be due to a wide variety of pathologies. Recently, use of otoacoustic emission technology has led to identification of auditory neuropathy as a distinct hearing disorder. Children with auditory neuropathy require audiological and educational management that may differ from that required by other hearing impaired students. For this reason, screening for auditory neuropathy may be appropriate for children attending schools for the hearing impaired. The study investigated the utility of using otoacoustic emission measures for school screening of hearing impaired children. Methods: In this study, 81 children aged 6-12 years who attended one school for the deaf were screened for indications of auditory neuropathy. Children found to have consistent otoacoustic emissions were given a full diagnostic audiological test battery. Results: Two children had transient otoacoustic emission results indicating normal outer hair cell function in one or both ears. A follow-up diagnostic assessment for the two positive cases was strongly suggestive of auditory neuropathy. Conclusions: There is a need for routine auditory neuropathy screening at schools for hearing impaired children. Copyright © 2001 Elsevier Science Ireland Ltd.link_to_subscribed_fulltex

Auditory neuropathy/auditory dys-synchrony in school children with hearing loss: Frequency of occurrence

Objective: The frequency of occurrence of a recently identified hearing disorder, auditory neuropathy/auditory dys-synchrony (AN/AD), was investigated in children with hearing impairment in Hong Kong. Methods: In this study, 56 students, aged 7-18 years, attending primary divisions in schools for the hearing impaired were screened using otoacoustic emission procedures. Results: One student in the study group was found to have intact outer hair cell function. A detailed diagnostic assessment of this case strongly suggested AN/ AD was involved. Combining the study results with those of a previously conducted survey in Hong Kong, the frequency of occurrence of AN/AD in children attending schools for the hearing impaired was estimated to be 2.44% (3 out of 123 children screened). Estimates of the frequency of occurrence of AN/AD in various other educational settings in Hong Kong were also derived. Conclusions: The study indicates that AN/AD is not an extremely rare disorder. Educational audiologists and other health care professionals need to be actively involved in the identification and management of AN/AD. Research should be directed at technological innovations that may help to overcome the limitations of present screening procedures, in order to more accurately identify the disorder. © 2003 Elsevier Ireland Ltd. All rights reserved.link_to_subscribed_fulltex