\u3cem\u3eJack\u3c/em\u3e/TTES: A System for Production and Real-Time Playback of Human Figure Motion in a DIS Environment

This document describes a modified Jack system for off-line motion production and on-line (real-time) motion playback to an external IRIS-Performer-based host rendering system. This work was done in partial fulfillment of Contract #N61339-94-C-0005 for the US Marine Corps through NAWCTSD (Naval Air Warfare Center, Training Systems Division). The work described herein was contributed by several of the members of the Center for Human Modeling and Simulation: John Granieri (Design/Engineering/Integration), Rama Bindiganavale (animator, posture transitions), Hanns-Oskar Poor (animator, posture transitions, Hyeongseok Ko (walking and running motion), Micheal Hollick (locomotion playback control), Bond-Jay Ting (body sculpting), Francisco Azoula (body sculptin, anthropometry), Pei-Hwa Ho (body normalization), Jonathan Crabtree (Performaer, TIPS file format), Xinmin Zhao (slaving), Zhongyang Feng (DIS logfile player), Welton Becket and Barry Reich (terrain reasoning and reactive agent control)

Production and Playback of Human Figure Motion 3D Virtual Environments

We describe a system for off-line production and real-time playback of motion for articulated human figures in 3D virtual environments. The key notions are (1) the logical storage of full body motion in posture graphs, which provides a simple motion access method for playback, and (2) mapping the motions of higher DOF figures using slaving to provide human models at several levels of detail, both in geometry and articulation, for later playback. We present our system in a context of a simple problem: Animating human figures in a distributed simulation, using DIS protocols for communication the human state information. We also discuss several related techniques for real-time animation of articulated figures in visual simulation

Real-Time Control of a Virtual Human Using Minimal Sensors

We track, in real-time, the position and posture of a human body, using a minimal number of 6 DOF sensors to capture full body standing postures. We use 4 sensors to create a good approximation of a human operator\u27s position and posture, and map it on to our articulated computer graphics human model. The unsensed joints are positioned by a fast inverse kinematics algorithm. Our goal is to realistically recreate human postures while minimally encumbering the operator

Stability Analysis of the LHC Cables for Transient Heat Depositions

The commissioning and the exploitation of the LHC require a good knowledge of the stability margins of the superconducting magnets with respect to beam induced heat depositions. Previous studies showed that simple numerical models are suitable to carry out stability calculations of multi-strands cables, and highlighted the relevance of the heat transfer model with the surrounding helium. In this paper we present a systematic scan of the stability margin of all types of LHC cables working at 1.9 Kagainst transient heat depositions. We specifically discuss the dependence of the stability margin on the parameters of the model, which provide an estimate of the uncertainty of the values quoted. The stability margin calculations have been performed using a zero-dimensional (0-D) numerical model, and a cooling model taking into account the relevant helium phases which may appear during a stability experiment: it includes Kapitza thermal resistance in superfluid He, boundary layer formation and heat transfer in He I, and considers the transition from nucleating boiling to film boiling during He gas formation

Smart Avatars in JackMOO

Creation of compelling 3-dimensional, multi-user virtual worlds for education and training applications requires a high degree of realism in the appearance, interaction, and behavior of avatars within the scene. Our goal is to develop and/or adapt existing 3-dimensional technologies to provide training scenarios across the Internet in a form as close as possible to the appearance and interaction expected of live situations with human participants. We have produced a prototype system, JackMOO, which combines Jack, a virtual human system, and LambdaMOO, a multiuser, network-accessible, programmable, interactive server. Jack provides the visual realization of avatars and other objects. LambdaMOO provides the web-accessible communication, programability, and persistent object database. The combined JackMOO allows us to store the richer semantic information necessitated by the scope and range of human actions that an avatar must portray, and to express those actions in the form of imperative sentences. This paper describes JackMOO, its components, and a prototype application with five virtual human agents

Posture Interpolation with Collision Avoidance

While interpolating between successive postures of an articulated figure is not mathematically difficult, it is much more useful to provide postural transactions that are behaviorally reasonable and that avoid collisions with nearby objects. We describe such a posture interpolator which begins with a number of pre-defined static postures. A finite state machine controls the transactions from any posture to a goal posture by finding the shortest path of required motion sequences between the two. If the motion between any two postures is not collision free, a collision avoidance strategy is invoked and the posture is changed to one that satisfies the required goal while respecting object and agent integrity

Models and experimental results from the wide aperture Nb-Ti magnets for the LHC upgrade

MQXC is a Nb-Ti quadrupole designed to meet the accelerator quality requirements needed for the phase-1 LHC upgrade, now superseded by the high luminosity upgrade foreseen in 2021. The 2-m-long model magnet was tested at room temperature and 1.9 K. The technology developed for this magnet is relevant for other magnets currently under development for the high-luminosity upgrade, namely D1 (at KEK) and the large aperture twin quadrupole Q4 (at CEA). In this paper we present MQXC test results, some of the specialized heat extraction features, spot heaters, temperature sensor mounting and voltage tap development for the special open cable insulation. We look at some problem solving with noisy signals, give an overview of electrical testing, look at how we calculate the coil resistance during at quench and show that the heaters are not working We describe the quench signals and its timing, the development of the quench heaters and give an explanation of an Excel quench calculation and its comparison including the good agreement with the MQXC test results. We propose an improvement to the magnet circuit design to reduce voltage to ground values by factor 2. The program is then used to predict quench Hot-Spot and Voltages values for the D1 dipole and the Q4 quadrupole.Comment: 8 pages, Contribution to WAMSDO 2013: Workshop on Accelerator Magnet, Superconductor, Design and Optimization; 15 - 16 Jan 2013, CERN, Geneva, Switzerlan

Analytical Model of Thermo-electrical Behaviour in Superconducting Resistive Core Cables

High field superconducting Nb$_{3}$Sn accelerators magnets above 14 T, for future High Energy Physics applications, call for improvements in the design of the protection system against resistive transitions. The longitudinal quench propagation velocity (vq) is one of the parameters defining the requirements of the protection. Up to now vq has been always considered as a physical parameter defined by the operating conditions (the bath temperature, cooling conditions, the magnetic field and the over all current density) and the type of superconductor and stabilizer used. It is possible to enhance the quench propagation velocity by segregating a percent of the stabilizer into the core, although keeping the total amount constant and tuning the contact resistance between the superconducting strands and the core. Analytical model and computer simulations are presented to explain the phenomenon. The consequences with respect to minimum quench energy are evidenced and the strategy to optimize the cable designed is discussed