Controller arm for a remotely related slave arm

A segmented controller arm configured and dimensioned to form a miniature kinematic replica of a remotely related slave arm is disclosed. The arm includes: (1) a plurality of joints for affording segments of the arm simultaneous angular displacement about a plurality of pairs of intersecting axes, (2) a plurality of position sensing devices for providing electrical signals indicative of angular displacement imparted to corresponding segments of the controller shaft about the axes, and (3) a control signal circuit for generating control signals to be transmitted to the slave arm. The arm is characterized by a plurality of yokes, each being supported for angular displacement about a pair of orthogonally related axes and counterbalanced against gravitation by a cantilevered mass

Gauge Fixing and Observables in General Relativity

The conventional group of four-dimensional diffeomorphisms is not realizeable as a canonical transformation group in phase space. Yet there is a larger field-dependent symmetry transformation group which does faithfully reproduce 4-D diffeomorphism symmetries. Some properties of this group were first explored by Bergmann and Komar. More recently the group has been analyzed from the perspective of projectability under the Legendre map. Time translation is not a realizeable symmetry, and is therefore distinct from diffeomorphism-induced symmetries. This issue is explored further in this paper. It is shown that time is not "frozen". Indeed, time-like diffeomorphism invariants must be time-dependent. Intrinsic coordinates of the type proposed by Bergmann and Komar are used to construct invariants. Lapse and shift variables are retained as canonical variables in this approach, and therefore will be subject to quantum fluctuations in an eventual quantum theory. Concepts and constructions are illustrated using the relativistic classical and quantum free particle. In this example concrete time-dependent invariants are displayed and fluctuation in proper time is manifest.Comment: Contribution to the Proceedings of Spacetime and Fundamental Interactions: Quantum Aspects, May, 2003, honoring the 65'th birthday of A. P. Balachandra

Playing with value: player engagements with videogames as a negotiation of net cultural worth

This thesis explains the results of a research programme which set out to empirically create a theory relating to players’ experience of videogame playing and the methodology employed in doing so. With the perspective that many empirically derived or tested contemporary theories are not sufficient for accounting for engagement in the majority of cases, a semi-inductive theory generation methodology was selected, interpreted, and employed. The theoretical concept so derived is that in order to engage with a videogame product players must find an overall sense of cultural value in the products they encounter. This sense of value corresponds to games at a feature level, the user making judgements about salient design features, and is not fixed but is constantly evaluated as the player encounters the game, from when they are selecting the concept of a game, through play, to when they are reflecting on the experience in relation to other products. The evaluation of features seems to involve the player 'identifying' with the individual design features in that there is an implicit intra personal questioning of “Am I the kind of person who would play a game with this feature?” which might be described as an expression of the user's personal culture or assumed socially relative self sense. If they feel that they are the kind of person who would play a game with that feature then this value judgement will have a positive influence on their engagement, if they are not then it will affect the user’s engagement negatively. The features so evaluated in this way can be any personally salient design feature at all, such as game mechanics, graphical representation or even packaging. These weighted judgements then act together in summation to determine the player's potential engagement. Also included is a justification for the selection, interpretation, application, and pragmatics of the Classic Grounded Theory Methodology (CGT), as employed in this programme of research. Grounded Theory (GT) was selected as it initially promised to be suitably open and exploratory, and advice relating to CGT was employed most often as it frequently provided the most reasonable set of methods for proceeding. However substantial effort was required in both understanding what the published advice on applying the methodology meant, and how it applied to the current problem. Sections are included which tell the story of the practical process of both attempting to apply the methodology, and understand the implications of that application at the same time, and an attempt is made to summarise tricky areas (potential misunderstandings and seeming myths) and explain the understanding of the methodology relative to these issues as it was was employed in this research. In conclusion the derived theory seems to demonstrate a reasonable degree of 'fit' and 'relevance'; a conclusion which is supported by a survey of academic and industry specialists. As such, the methodology employed might be said to be useful in generating novel theoretical results. Also, the theory can be expressed as a substantive instantiation of existing general theories of human cultural behaviour such as Cooley's 'Looking Glass Self' (1902). It is also felt that the theory could be readily modified to account for further insights into the domain. These conclusions suggest that the hypotheses generated are useful for investigating the domain of videogame play and engagement

Study to design and develop remote manipulator systems

A description is given of part of a continuing effort both to develop models for and to augment the performance of humans controlling remote manipulators. The project plan calls for the performance of several standard tasks with a number of different manipulators, controls, and viewing conditions, using an automated performance measuring system; in addition, the project plan calls for the development of a force-reflecting joystick and supervisory display system

Learning to Represent Haptic Feedback for Partially-Observable Tasks

The sense of touch, being the earliest sensory system to develop in a human body [1], plays a critical part of our daily interaction with the environment. In order to successfully complete a task, many manipulation interactions require incorporating haptic feedback. However, manually designing a feedback mechanism can be extremely challenging. In this work, we consider manipulation tasks that need to incorporate tactile sensor feedback in order to modify a provided nominal plan. To incorporate partial observation, we present a new framework that models the task as a partially observable Markov decision process (POMDP) and learns an appropriate representation of haptic feedback which can serve as the state for a POMDP model. The model, that is parametrized by deep recurrent neural networks, utilizes variational Bayes methods to optimize the approximate posterior. Finally, we build on deep Q-learning to be able to select the optimal action in each state without access to a simulator. We test our model on a PR2 robot for multiple tasks of turning a knob until it clicks.Comment: IEEE International Conference on Robotics and Automation (ICRA), 201

Numerical investigation of the effects of pedestrian barriers on aeroelastic stability of a proposed footbridge

A numerical investigation into the aerodynamic characteristics and aeroelastic stability of a proposed footbridge across a motorway in the north of England has been undertaken. The longer than usual span, along with the unusual nature of the pedestrian barriers, indicated that the deck configuration was likely to be beyond the reliable limits of the British design code BD 49/01. In particular, the investigation focussed on the susceptibility of the bridge due to flutter, and to assess if the design wind speeds could be met satisfactorily. The calculations were performed using the discrete vortex method, DIVEX, developed at the Universities of Glasgow and Strathclyde. DIVEX has been successfully validated on a wide range of problems, including the aeroelastic response of bridge deck sections. The proposed deck configuration, which incorporated a pedestrian barrier comprised of angled flat plates, was found to be unstable at low wind speeds with the plates having a strong turning effect on the flow at the leading edge of the deck. DIVEX was used to assess a number of alternative design options, investigating the stability with respect to flutter for each configuration. Reducing the number of flat plates and their angle to the deck lessened the effect of the barrier on the overall aerodynamic characteristics and increased the stability of the bridge to an acceptable level, with the critical flutter speed in excess of the specified design speed

Technology Use for Extra-Curricular Activities and Academic Performance in Library Instruction Sessions

This poster reports on a study that investigated: a. The impact of students’ use of technology for extracurricular purposes during instruction sessions and its effects on their learning and retention of information. b. Whether attendance at a previous library instruction session provided the students with the advantage of scoring higher in the assessment, and c. Whether the use of these technologies in class sessions was disruptive to other students