Aeronautical Engineering: A continuing bibliography with indexes (supplement 159)

This bibliography lists 347 reports, articles and other documents introduced into the NASA scientific and technical information system in February 1983

Aeronautical engineering: A continuing bibliography with indexes (supplement 193)

This bibliography lists 682 reports, articles and other documents introduced into the NASA scientific and technical information system in October 1985

An English Family Court Through The Lens of Complexity:An Ethnographic Study Of Modernisation in Practice

The thesis is formed of an ethnographic study of public law practice in a family court in England, with reference to reforms of family justice (commonly referred to as ‘modernisation’). It draws on Complexity Theory to analyse policy and practice. Direct observation of public law work, supplemented by professional interviews, facilitates close engagement with practice and thereby adds to the meagre ethnographic literature on family justice. The thesis examines the influence of rational thinking upon modernisation (characterised by a statutory timeframe for care proceedings and curbs on the court’s power to appoint expert witnesses), the short-term benefits and longer-term problems that have flowed from rational policymaking, and the ways professionals in the family court try to deliver fair justice and support children’s welfare despite modernisation, which many now consider problematic. The relationship between policymaking and practice is explored, including the ways that professionals interpret the law and thus make policy upstream. The complexities of public law work are uncovered: the commonly intractable social and health problems of families subject to care applications; a family justice system that is formally adversarial in nature but also incorporates elements of consensual justice; challenges to managing cases that do not neatly fit into the prescriptions of modernisation; and, finally, the impact of Covid-19. The thesis advocates a more responsive and pragmatic policymaking to acknowledge the role played by professionals in making policy and to enable family justice to recover from the pandemic. It also argues that expectations that the family court can resolve many families’ complex problems are unrealistic and makes the case for more concerted efforts to support families before and after proceedings

Advances in grasping and vehicle contact identification : analysis, design and testing of robust methods for underwater robot manipulation

Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution May 1999This thesis focuses on improving the productivity of autonomous and telemanipulation systems consisting of a manipulator arm mounted to a free flying underwater vehicle. Part I minimizes system sensitivity to misalignment by developing a gripper and a suite of handles that passively self align when grasped. After presenting a gripper guaranteed to passively align cylinders we present several other self aligning handles. The mix of handle alignment and load resisting properties enables handles to be matched to the needs of each task. Part I concludes with a discussion of successful field use of the system on the Jason Remotely Operated Undersea Vehicle operated by the Woods Hole Oceanographic Institution. To enable the exploitation of contact with the environment to help stabilize the vehicle, Part II develops a technique which identifies the contact state of a planar vehicle interacting with a fixed environment. Knowing the vehicle geometry and velocity we identify kinematically feasible contact points, from which we construct the set of feasible contact models. The measured vehicle data violates each model’s constraints; we use the associated violation power and work to select the best overall model. Part II concludes with experimental confirmation of the contact identification techniques efficacy

NASA Tech Briefs, February 1998

Topics: Test Tools; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Software; Mechanics; Machinery/Automation; Manufacturing/Fabrication; Life Sciences

Fingerprint-based biometric recognition allied to fuzzy-neural feature classification.

The research investigates fingerprint recognition as one of the most reliable biometrics identification methods. An automatic identification process of humans-based on fingerprints requires the input fingerprint to be matched with a large number of fingerprints in a database. To reduce the search time and computational complexity, it is desirable to classify the database of fingerprints into an accurate and consistent manner so that the input fingerprint is matched only with a subset of the fingerprints in the database. In this regard, the research addressed fingerprint classification. The goal is to improve the accuracy and speed up of existing automatic fingerprint identification algorithms. The investigation is based on analysis of fingerprint characteristics and feature classification using neural network and fuzzy-neural classifiers.The methodology developed, is comprised of image processing, computation of a directional field image, singular-point detection, and feature vector encoding. The statistical distribution of feature vectors was analysed using SPSS. Three types of classifiers, namely, multi-layered perceptrons, radial basis function and fuzzy-neural methods were implemented. The developed classification systems were tested and evaluated on 4,000 fingerprint images on the NIST-4 database. For the five-class problem, classification accuracy of 96.2% for FNN, 96.07% for MLP and 84.54% for RBF was achieved, without any rejection. FNN and MLP classification results are significant in comparison with existing studies, which have been reviewed

Twentieth Annual Conference on Manual Control, Volume 2

Volume II contains thirty two complete manuscripts and five abstracts. The topics covered include the application of event-related brain potential analysis to operational problems, the subjective evaluation of workload, mental models, training, crew interaction analysis, multiple task performance, and the measurement of workload and performance in simulation

Robust Stability Analysis of FJR Composite Controller with a Supervisory Loop

Abstract -In this paper a controller design method for flexible joint robots (FJR), considering actuator saturation is proposed and its robust stability is thoroughly analyzed. This method consists of a composite control structure, with a PD controller on the fast dynamics and a PID controller on slow dynamics. Moreover, the need of powerful actuator is removed by decreasing the bandwidth of the fast controller during critical occasions, with the use of a supervisory loop. Fuzzy logic is used in the supervisory law, in order to adjust the proper gain in the forward path. It is then shown that UUB stability of the overall system is guaranteed in presence of uncertainties, provided that the PD and the PID gains are tuned to satisfy certain conditions