Super W-Symmetries, Covariantly Constant Forms And Duality Transformations

On a supersymmetric sigma model the covariantly constant forms are related to the conserved currents that are generators of a super W-algebra extending the superconformal algebra. The existence of covariantly constant forms restricts the holonomy group of the manifold. Via duality transformation we get new covariantly constant forms, thus restricting the holonomy group of the new manifold.Comment: 10 pages, Late

Control Of Flexible Structures-2 (COFS-2) flight control, structure and gimbal system interaction study

The second Control Of Flexible Structures Flight Experiment (COFS-2) includes a long mast as in the first flight experiment, but with the Langley 15-m hoop column antenna attached via a gimbal system to the top of the mast. The mast is to be mounted in the Space Shuttle cargo bay. The servo-driven gimbal system could be used to point the antenna relative to the mast. The dynamic interaction of the Shuttle Orbiter/COFS-2 system with the Orbiter on-orbit Flight Control System (FCS) and the gimbal pointing control system has been studied using analysis and simulation. The Orbiter pointing requirements have been assessed for their impact on allowable free drift time for COFS experiments. Three fixed antenna configurations were investigated. Also simulated was Orbiter attitude control behavior with active vernier jets during antenna slewing. The effect of experiment mast dampers was included. Control system stability and performance and loads on various portions of the COFS-2 structure were investigated. The study indicates possible undesirable interaction between the Orbiter FCS and the flexible, articulated COFS-2 mast/antenna system, even when restricted to vernier reaction jets

Consistent two--dimensional chiral gravity

We study chiral induced gravity in the light-cone gauge and show that the theory is consistent for a particular choice of chiralities. The corresponding Kac--Moody central charge has no forbidden region of complex values. Generalized analysis of the critical exponents is given and their relation to the $SL(2,R)$ vacuum states is elucidated. All the parameters containing information about the theory can be traced back to the characteristics of the group of residual symmetry in the light--cone gauge.Comment: 38 pages, LateX, to appear in Int.J.Mod.Phys.

The Nonlinear Multiplet Revisited

Using a reformulation of the nonlinear multiplet as a gauge multiplet, we discuss its dynamics. We show that the nonlinear ``duality'' that appears to relate the model to a conventional $\sigma$-model introduces a new sector into the theory.Comment: 11 pages, ITP-SB-94-23, USITP-94-1

Global Diffusion of the Internet XV: Web 2.0 Technologies, Principles, and Applications: A Conceptual Framework from Technology Push and Demand Pull Perspective

Web 2.0, the current Internet evolution, can be described by several key features of an expanded Web that is more interactive; allows easy social interactions through participation and collaboration from a variety of human sectors; responds more immediately to users\u27 queries and needs; is easier to search; and provides a faster, smoother, realistic and engaging user search capability, often with automatic updates to users. The purpose of this study is three-fold. First, the primary goal is to propose a conceptual Web 2.0 framework that provides better understanding of the Web 2.0 concept by classifying current key components in a holistic manner. Second, using several selective key components from the conceptual framework, this study conducts case analyses of Web 2.0 applications to discuss how they have adopted the selective key features (i.e., participation, collaboration, rich user experience, social networking, semantics, and interactivity responsiveness) of the conceptual Web 2.0 framework. Finally, the study provides insightful discussion of some challenges and opportunities provided by Web 2.0 to education, business, and social life

Quantum cosmology in the models of 2d and 4d dilatonic supergravity with WZ matter

We consider N=1 two-dimensional (2d) dilatonic supergravity (SG), 2d dilatonic SG obtained by dimensional reduction from N=1 four-dimensional (4d) SG, N=2 2d dilatonic SG and string-inspired 4d dilatonic SG. For all the theories, the corresponding action on a bosonic background is constructed and the interaction with $N$ (dilatonic) Wess-Zumino (WZ) multiplets is presented. Working in the large-N approximation, it is enough to consider the trace anomaly induced effective action due to dilaton-coupled conformal matter as a quantum correction (for 2d models s-waves approximation is additionally used). The equations of motion for all such models with quantum corrections are written in a form convenient for numerical analysis. Their solutions are numerically investigated for 2d and 4d Friedmann-Robertson-Walker (FRW) or 4d Kantowski-Sacks Universes with a time-dependent dilaton via exponential dilaton coupling. The evolution of the corresponding quantum cosmological models is given for different choices of initial conditions and theory parameters. In most cases we find quantum singular Universes. Nevertheless, there are examples of Universe non-singular at early times. Hence, it looks unlikely that quantum matter back reaction on dilatonic background (at least in large $N$ approximation) may really help to solve the singularity problem.Comment: LaTeX file of the text (36 pages) and 3 ps files of 14 figures, few misprints are corrected and references adde

Enveloping Aerodynamic Decelerator

An inflatable aerodynamic deceleration method and system is provided for use with an atmospheric entry payload. The inflatable aerodynamic decelerator includes an inflatable envelope and an inflatant, wherein the inflatant is configured to fill the inflatable envelope to an inflated state such that the inflatable envelope surrounds the atmospheric entry payload, causing aerodynamic forces to decelerate the atmospheric entry payload

Mass Degeneracies In Self-Dual Models

An algebraic restriction of the nonabelian self-dual Chern-Simons-Higgs systems leads to coupled abelian models with interesting mass spectra. The vacua are characterized by embeddings of $SU(2)$ into the gauge algebra, and in the broken phases the gauge and real scalar masses coincide, reflecting the relation of these self-dual models to $N=2$ SUSY. The masses themselves are related to the exponents of the gauge algebra, and the self-duality equation is a deformation of the classical Toda equations.Comment: 10 pages LaTeX (previous copy truncated

Sizing Up Worker Center Income (2008-2014): A Study of Revenue Size, Stability, and Stream

Since the publication of Janice Fine’s path-breaking book, Worker Centers: Communities at the Edge o f the Dream in 2006, scholars and commentators on the left and the right of the political spectrum have grappled with how to characterize these emergent worker organizations on the US labor relations scene. This chapter deepens our understanding of the nature of worker centers by examining the funding trends that underlay the wide range of experimental organizing and advocacy strategies highlighted in other chapters of this volume. Undoubtedly, to emerge and survive, these organizations need money (Bobo and Pabellon 2016). But how financially stable are worker centers? How big are they? Where does the funding come from? How do they compare to labor unions? To address some of these questions, we compiled a large collection of available data to complete the first systematic empirical analysis of worker center funding across multiple years (2008 through 2014)

Sizing Up Worker Center Income (2008-2014): A Study of Revenue Size, Stability, and Streams

[Excerpt] Since the publication of Janice Fine’s path-breaking book, Worker Centers: Communities at the Edge of the Dream in 2006, scholars and commentators on the left and the right of the political spectrum have grappled with how to characterize these emergent worker organizations on the US labor relations scene. This chapter deepens our understanding of the nature of worker centers by examining the funding trends that underlay the wide range of experimental organizing and advocacy strategies highlighted in other chapters of this volume. Undoubtedly, to emerge and survive, these organizations need money (Bobo and Pabellon 2016). But how financially stable are worker centers? How big are they? Where does the funding come from? How do they compare to labor unions? To address some of these questions, we compiled a large collection of available data to complete the first systematic empirical analysis of worker center funding across multiple years (2008 through 2014)