Search

Stability analysis of decentralized control mechanisms for networked coordinating systems has generally focused on specific controller implementations, such as nearest-neighbor and other types of proximity graph control laws. This approach often misses the need for the addition of other control structures to improve global characteristics of the network. An example of such a situation is the use of a Gabriel graph, which is essentially a nearest-neighbor rule modified to ensure global connectivity of the network if the agents are pairwise connected through their sensor inputs. We present a method of ensuring provable stability of decentralized switching systems by employing a hysteresis rule that uses a zero-sum consensus algorithm. We demonstrate the application of this result to several special cases, including nearest-neighbor control laws, Gabriel graph rules, diffuse target tracking, and hierarchical heterogeneous systems. Index Terms--Formation control, multirobot control, swarm robotics.

Purpose: To assess the feasibility and effectiveness of a newly developed assistive technology system, Lee Silverman Voice Treatment Companion (LSVT® Companion™, hereafter referred to as "Companion"), to support the delivery of LSVT®LOUD, an efficacious speech intervention for individuals with Parkinson disease (PD). Method: Sixteen individuals with PD were randomized to an immediate (n = 8) or a delayed (n = 8) treatment group. They participated in 9 LSVT LOUD sessions and 7 Companion sessions, independently administered at home. Acoustic, listener perception, and voice and speech rating data were obtained immediately before (pre), immediately after (post), and at 6 months post treatment (follow-up). System usability ratings were collected immediately post treatment. Changes in vocal sound pressure level were compared to data from a historical treatment group of individuals with PD treated with standard, in-person LSVT LOUD. Results: All 16 participants were able to independently use the Companion. These individuals had therapeutic gains in sound pressure level, pre to post and pre to follow-up, similar to those of the historical treatment group. Conclusions: This study supports the use of the Companion as an aid in treatment of hypokinetic dysarthria in individuals with PD. Advantages and disadvantages of the Companion, as well as limitations of the present study and directions for future studies, are discussed. [ABSTRACT FROM AUTHOR]

Despite huge investment, and the best of intentions, most development projects fail. This is particularly true of Information and Communication Technology for Development (ICTD) projects. We contend that a significant contributor to this failure is the lack of breadth in project design and implementation, and in the training of project implementers. Successful ICTD interventions, in addition to being based on the best computer science research has to offer, must be guided by the relevant social, cultural, political, economic and gender factors that underlie the interaction of the technology with the community into which it is being placed. We therefore argue that efforts to distance computer science from the broader context of ICTD scholarship and practice are misguided. ICTD should be recognized as a truly interdisciplinary area of research and practice. We further argue that ICTD as a discipline has a particular need for academic practitioners. We close with a compilation of current known ICTD academic efforts worldwide. [ABSTRACT FROM AUTHOR]