The TAVERNS emulator: An Ada simulation of the space station data communications network and software development environment

The Space Station DMS (Data Management System) is the onboard component of the Space Station Information System (SSIS) that includes the computers, networks and software that support the various core and payload subsystems of the Space Station. TAVERNS (Test And Validation Environment for Remote Networked Systems) is a distributed approach for development and validation of application software for Space Station. The TAVERNS concept assumes that the different subsystems will be developed by different contractors who may be geographically separated. The TAVERNS Emulator is an Ada simulation of a TAVERNS on the ASD VAX. The software services described in the DMS Test Bed User's Manual are being emulated on the VAX together with simulations of some of the core subsystems and a simulation of the DCN. The TAVERNS Emulator will be accessible remotely from any VAX that can communicate with the ASD VAX

Design study of a feedback control system for the Multicyclic Flap System rotor (MFS)

The feasibility of automatically providing higher harmonic control to a deflectable control flap at the tip of a helicopter rotor blade through feedback of selected independent parameter was investigated. Control parameters were selected for input to the feedback system. A preliminary circuit was designed to condition the selected parameters, weigh limiting factors, and provide a proper output signal to the multi-cyclic control actuators. Results indicate that feedback control for the higher harmonic is feasible; however, design for a flight system requires an extension of the present analysis which was done for one flight condition - 120 kts, 11,500 lbs gross weight and level flight

TAVERNS and the space station software support environment

The Space Station Information System (SSIS) provides the data processing capability for the Space Station Program (SSP). The Software Support Environment (SSE) System for the SSP is the collection of software, procedures, standards, hardware specification, documentation, policy, and training materials. The Ada programming language was baselined by the Space Station Program Office as the language for development and maintenance of all space station software including the software of the SSE itself. The Test And Validation Environment for Remote Networked Systems (TAVERNS) is a distributed philosophy for development and validation of Ada applications software for the space station and as such is closely related to the SSE. An overview of the system is provided

Project management control utilising innovative forecasting and computerised data bases

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.The prime objective of this thesis is to research and develop a new system of project budgeting, monitoring and forecasting to meet the needs of the Construction Industry. It is intended that this work will facilitate the means for more efficient control of projects from inception to final completion, utilising where possible the latest developments in computer technology. The initial stage of the work involves an investigation and appraisal of existing methods of formulating project budgets. In particular attention is paid to previous work in the development of mathematical 's' curve models, together with their limitations in use and application. Potential for future development is also identified. The thesis then focuses on the evolution of an improved modelling philosophy for project budgets and forecasts which overcomes previously known problems. In parallel with this work is the development of a computerised system intended to enable the testing of the model against live project data. The model finally selected is then tested against the extensive research work previously undertaken by the DHSS and the data collected from sixteen construction projects. To facilitate the development of a suitable control system to act as a vehicle for the application of the principles developed, a contextual survey is included. This survey is intended to provide an update of previous survey work undertaken by the author in 1977 and to further investigate factors orientated specifically to the objectives of the thesis. The research then concentrates on the development of an integrated set of sub-systems which contribute to the budgeting, monitoring and prediction of project expenditure. These systems are developed in accordance with the need to establish the financial status of projects both before, during and after they are completed. The overall system is based on the latest computer technology available and is designed to be flexible in its application. Tests documented in the text prove that the system operates both in principle and in practice. A further extension of the research is the use of the various project data bases to provide information for a corporate control system which has been developed in principle. This thesis provides a significant step forward in computerised project budgeting and control utilisng 's' curve philosophy and provides a basis for further development. Potential exists for future development of the prediction and corporate control systems, together with software developments to improve general application over a wide range of industries and disciplines where project work is undertaken

Evidence of Critical Balance in Kinetic Alfven Wave Turbulence Simulations

A numerical simulation of kinetic plasma turbulence is performed to assess the applicability of critical balance to kinetic, dissipation scale turbulence. The analysis is performed in the frequency domain to obviate complications inherent in performing a local analysis of turbulence. A theoretical model of dissipation scale critical balance is constructed and compared to simulation results, and excellent agreement is found. This result constitutes the first evidence of critical balance in a kinetic turbulence simulation and provides evidence of an anisotropic turbulence cascade extending into the dissipation range. We also perform an Eulerian frequency analysis of the simulation data and compare it to the results of a previous study of magnetohydrodynamic turbulence simulations.Comment: 10 pages, 9 figures, accepted for publication in Physics of Plasma

Inertial range turbulence in kinetic plasmas

The transfer of turbulent energy through an inertial range from the driving scale to dissipative scales in a kinetic plasma followed by the conversion of this energy into heat is a fundamental plasma physics process. A theoretical foundation for the study of this process is constructed, but the details of the kinetic cascade are not well understood. Several important properties are identified: (a) the conservation of a generalized energy by the cascade; (b) the need for collisions to increase entropy and realize irreversible plasma heating; and (c) the key role played by the entropy cascade--a dual cascade of energy to small scales in both physical and velocity space--to convert ultimately the turbulent energy into heat. A strategy for nonlinear numerical simulations of kinetic turbulence is outlined. Initial numerical results are consistent with the operation of the entropy cascade. Inertial range turbulence arises in a broad range of space and astrophysical plasmas and may play an important role in the thermalization of fusion energy in burning plasmas.Comment: 11 pages, 2 figures, submitted to Physics of Plasmas, DPP Meeting Special Issu

Analysis of Subcellular Localization Patterns Suggest Non-enzymatic Roles for Select Arogenate Dehydratases

The final step of phenylalanine biosynthesis in planta is catalyzed by arogenate dehydratases (ADTs). Previously cloned ADT-CFP fusion genes were used to provide an in depth study of the subcellular localization of all six ADTs from Arabidopsis thaliana. Through co-localization of ADT-CFPs with a stroma-marker it is shown that most ADTs localize to stroma-filled projections from chloroplasts called stromules. The localization of ADT5 and ADT2 provide evidence for additional, non-enzymatic roles. In the case of ADT5, it is found to localize to the nucleus, suggestive of an uncharacterized nuclear role. The localization patterns of ADT2 are suggestive of a role in chloroplast division. This secondary role is investigated through analysis of localization patterns in N. benthamiana, A. thaliana and several chloroplast division mutants. In addition, chloroplast morphology is examined in adt2 mutant plants, and the effect of this mutation on the localization of a known chloroplast division protein is examined

Dynamic Project Control Utilising a New Approach to Project Control

A new system has been developed for dynamic project management and control known as Planning Orientation Evaluation Methods (POEM) which has been considered as a core project evaluation system incorporating cost and time analysis. The performance control gives the manager a direct influence on the project completion date and rate of spend

Freely decaying turbulence in two-dimensional electrostatic gyrokinetics

In magnetized plasmas, a turbulent cascade occurs in phase space at scales smaller than the thermal Larmor radius ("sub-Larmor scales") [Phys. Rev. Lett. 103, 015003 (2009)]. When the turbulence is restricted to two spatial dimensions perpendicular to the background magnetic field, two independent cascades may take place simultaneously because of the presence of two collisionless invariants. In the present work, freely decaying turbulence of two-dimensional electrostatic gyrokinetics is investigated by means of phenomenological theory and direct numerical simulations. A dual cascade (forward and inverse cascades) is observed in velocity space as well as in position space, which we diagnose by means of nonlinear transfer functions for the collisionless invariants. We find that the turbulence tends to a time-asymptotic state, dominated by a single scale that grows in time. A theory of this asymptotic state is derived in the form of decay laws. Each case that we study falls into one of three regimes (weakly collisional, marginal, and strongly collisional), determined by a dimensionless number D*, a quantity analogous to the Reynolds number. The marginal state is marked by a critical number D* = D0 that is preserved in time. Turbulence initialized above this value become increasingly inertial in time, evolving toward larger and larger D*; turbulence initialized below D0 become more and more collisional, decaying to progressively smaller D*.Comment: 12 pages, 12 figures; replaced to match published versio