The Role of Modern Control Theory in the Design of Controls for Aircraft Turbine Engines

Accomplishments in applying Modern Control Theory to the design of controls for advanced aircraft turbine engines were reviewed. The results of successful research programs are discussed. Ongoing programs as well as planned or recommended future thrusts are also discussed

A digital computer propulsion control facility: Description of capabilities and summary of experimental program results

Flight weight digital computers are being used today to carry out many of the propulsion system control functions previously delegated exclusively to hydromechanical controllers. An operational digital computer facility for propulsion control mode studies has been used successfully in several experimental programs. This paper describes the system and some of the results concerned with engine control, inlet control, and inlet engine integrated control. Analytical designs for the digital propulsion control modes include both classical and modern/optimal techniques

River and Inshore Beam Trawl Fishery Scoping Study

The Queensland Ecological Risk Assessment Guideline (the Guideline) was released in March 2018 as part of the Queensland Sustainable Fisheries Strategy 2017–2027. This Guideline provides an overview of strategy being employed to develop Ecological Risk Assessments (ERAs) for Queensland’s fisheries. The Guideline describes a four-stage framework consisting of a Scoping Study; a Level 1, whole of fishery qualitative assessment; a Level 2, species-specific semi-quantitative or low-data quantitative assessment and; a Level 3 quantitative assessment (if applicable). The Scoping Study establishes a baseline of information on the key characteristics of the River and Inshore Beam Trawl Fishery (RIBTF). It includes information on the broader management regime, key species, gear configurations and catch and effort trends. Information contained in the scoping study for the RIBTF will be used to inform subsequent assessments including the whole of fishery (Level 1) and species-specific (Level 2)

The Arrival Of A New GAAP: International Financial Reporting Standards

This article examines the International Accounting Standards Board’s efforts to create greater comparability and uniformity in global financial reporting.   Prefacing this will be an examination of 1) the reasons for past and present inter-country reporting differences and 2) the changes that have affected the governing structure of the international financial reporting environment.  Most importantly, however, this article explores the areas that will be most impacted when companies move to a uniform group of international accounting standards.  An understanding of the accounting regulatory process and the changes underway is important for all businesses professionals, including those in large and small businesses alike, and understanding how to read and interpret the language of business is important to competing in today’s smaller world

Risk Manage Capital Investment Decisions: A Lease vs. Purchase Illustration

This paper demonstrates how to build risk into capital investment decisions.  We illustrate how to combine distribution theory, technology, and a business professional’s skills and insight into a capital investment analysis.  In addition, we show how management can approximate the risk of each cash flow estimate and display the overall capital investment results.  This framework is extended by showing how a mutually exclusive decision can be improved, using a lease versus purchase example.[1]  An Excel template is readily available from the authors allowing a hands-on application of the framework presented in this paper.  In addition, this paper positions the reader to comfortably use more advanced analytics, such as Monte Carlo simulation, a tool that is readily available in commercial software applications.This paper focuses on the application of net present value.  The advantage of using net present value in a capital budgeting decision is that it shows the potential stakeholder wealth creation and wealth destruction.  An internal rate of return analysis is intentionally left out of this paper.  According to Brealey, Myers and Allen, Principles of Corporate Finance, New York, NY: McGraw-Hill/Irwin 2006, pp. 91-99, internal rate of return should not be used to evaluate mutually exclusive capital investments.&nbsp

Gulf of Carpentaria Inshore Fin Fish Fishery Scoping Study

The Queensland Ecological Risk Assessment Guideline (the Guideline) was released in March 2018 as part of the Queensland Sustainable Fisheries Strategy 2017–2027. This Guideline provides an overview of strategy being employed to develop Ecological Risk Assessments (ERAs) for Queensland’s fisheries. The Guideline describes a four-stage framework consisting of a Scoping Study; a Level 1, whole of fishery qualitative assessment; a Level 2, species-specific semi-quantitative or low-data quantitative assessment and; a Level 3 quantitative assessment (if applicable). The Scoping Study establishes a baseline of information on the key characteristics of the Gulf of Carpentaria Inshore Fin Fish Fishery (GOCIFFF). It includes information on the broader management regime, key species, gear configurations and catch and effort trends. Information contained in the scoping study for the GOCIFFF will be used to inform subsequent assessments including the whole of fishery (Level 1) and species-specific (Level 2)

Control technology for future aircraft propulsion systems

The need for a more sophisticated engine control system is discussed. The improvements in better thrust-to-weight ratios demand the manipulation of more control inputs. New technological solutions to the engine control problem are practiced. The digital electronic engine control (DEEC) system is a step in the evolution to digital electronic engine control. Technology issues are addressed to ensure a growth in confidence in sophisticated electronic controls for aircraft turbine engines. The need of a control system architecture which permits propulsion controls to be functionally integrated with other aircraft systems is established. Areas of technology studied include: (1) control design methodology; (2) improved modeling and simulation methods; and (3) implementation technologies. Objectives, results and future thrusts are summarized

Ionization signals from electrons and alpha-particles in mixtures of liquid Argon and Nitrogen - perspectives on protons for Gamma Resonant Nuclear Absorption applications

In this paper we report on a detailed study of ionization signals produced by Compton electrons and alpha-particles in a Time Projection Chamber (TPC) flled with different mixtures of liquid Argon and Nitrogen. The measurements were carried out with Nitrogen concentrations up to 15% and a drift electric feld in the range 0-50 kV/cm. A prediction for proton ionization signals is made by means of interpolation. This study has been conducted in view of the possible use of liquid Ar-N2 TPCs for the detection of gamma-rays in the resonant band of the Nitrogen absorption spectrum, a promising technology for security and medical applications

Real space first-principles derived semiempirical pseudopotentials applied to tunneling magnetoresistance

In this letter we present a real space density functional theory (DFT) localized basis set semi-empirical pseudopotential (SEP) approach. The method is applied to iron and magnesium oxide, where bulk SEP and local spin density approximation (LSDA) band structure calculations are shown to agree within approximately 0.1 eV. Subsequently we investigate the qualitative transferability of bulk derived SEPs to Fe/MgO/Fe tunnel junctions. We find that the SEP method is particularly well suited to address the tight binding transferability problem because the transferability error at the interface can be characterized not only in orbital space (via the interface local density of states) but also in real space (via the system potential). To achieve a quantitative parameterization, we introduce the notion of ghost semi-empirical pseudopotentials extracted from the first-principles calculated Fe/MgO bonding interface. Such interface corrections are shown to be particularly necessary for barrier widths in the range of 1 nm, where interface states on opposite sides of the barrier couple effectively and play a important role in the transmission characteristics. In general the results underscore the need for separate tight binding interface and bulk parameter sets when modeling conduction through thin heterojunctions on the nanoscale.Comment: Submitted to Journal of Applied Physic