Adaptive Control of a Generic Hypersonic Vehicle

This paper presents an adaptive augmented, gain-scheduled baseline LQR-PI controller applied to the Road Runner six-degree-of-freedom generic hypersonic vehicle model. Uncertainty in control effectiveness, longitudinal center of gravity location, and aerodynamic coefficients are introduced in the model, as well as sensor bias and noise, and input time delays. The performance of the baseline controller is compared to the same design augmented with one of two different model-reference adaptive controllers: a classical open- loop reference model design, and modified closed-loop reference model design. Both adaptive controllers show improved command tracking and stability over the baseline controller when subject to these uncertainties. The closed-loop reference model controller offers the best performance, tolerating a reduced control effectiveness of 50%, rearward center of gravity shift of up to -1.6 feet (11% of vehicle length), aerodynamic coefficient uncertainty scaled 4× the nominal value, and sensor bias of up to +3.2 degrees on sideslip angle measurement. The closed-loop reference model adaptive controller maintains at least 70% of the delay margin provided by the robust baseline design when subject to varying levels of uncertainty, tolerating input time delays of between 15-41 ms during 3 degree angle of attack doublet, and 80 degree roll step commands.Approved for Public Release; Distribution Unlimited. Case Number 88ABW-2013-3392

Adaptive Output Feedback Based on Closed-Loop Reference Models for Hypersonic Vehicles

This paper presents a new method of synthesizing an output feedback adaptive controller for a class of uncertain, non-square, multi-input multi-output systems that often occur in hypersonic vehicle models. The main challenge that needs to be addressed is the determination of a corresponding square and strictly positive real transfer function. This paper proposes a new procedure to synthesize two gain matrices that allows the realization of such a transfer function, thereby allowing a globally stable adaptive output feedback law to be generated. The unique features of this output feedback adaptive controller are a baseline controller that uses a Luenberger observer, a closed-loop reference model, manipulations of a bilinear matrix inequality, and the Kalman-Yakubovich Lemma. Using these features, a simple design procedure is proposed for the adaptive controller, and the corresponding stability property is established. The proposed adaptive controller is compared to the classical multi-input multi-output adaptive controller. A numerical example based on a scramjet powered, blended wing-body generic hypersonic vehicle model is presented. The 6 degree-of-freedom nonlinear vehicle model is linearized, giving the design model for which the controller is synthesized. The adaptive output feedback controller is then applied to an evaluation model, which is nonlinear, coupled, and includes actuator dynamics, and is shown to result in stable tracking in the presence of uncertainties that destabilize the baseline linear output feedback controller.This research is funded by the Air Force Research Laboratory/Aerospace Systems Directorate grant FA 8650-07-2-3744 for the Michigan/MIT/AFRL Collaborative Center in Control Sciences and the Boeing Strategic University Initiative. Approved for Public Release; Distribution Unlimited. Case Number 88ABW- 2014-2551

Exploration disclosures of internal control as the impact of earnings quality and audit committee

Information disclosure carried out by management as an appointed agent is increasing in importance and hence, a source of concerns to users. It is widely believed that information received by the stakeholders should be appropriate and sufficient for useful decision making, especially in the era of the Fourth industrial revolution. An appropriate and sufficient disclosure in the Annual report indicates a reflection of the effective implementation of the company's operational, strategic, financial and compliance objectives that have been carried out by the management. This study employed secondary data obtained from the annual report for the banks listed in the Indonesia Stock Exchange (IDX). The data for internal control disclosure was observed through a content analysis approach by calculating the internal control system index obtained in the annual report. This study has shown that companies with high earnings quality report more openly convey the application of internal controls system disclosure. This study demonstrated that company with the high characteristics of the audit committee would significantly increase disclosure of internal controls system than a company without audit committee. Supervision, as one of the internal controls established by the management, enhances the performances of the audit committee in ensuring compliance through full disclosure of the financial statements. Thus, restoring users’ trust and confidence in making informed and useful decisions on information emanating from the management

Oxidative Protein Folding Is Driven by the Electron Transport System

AbstractDisulfide bond formation is catalyzed in vivo by DsbA and DsbB. Here we reconstitute this oxidative folding system using purified components. We have found the sources of oxidative power for protein folding and show how disulfide bond formation is linked to cellular metabolism. We find that disulfide bond formation and the electron transport chain are directly coupled. DsbB uses quinones as electron acceptors, allowing various choices for electron transport to support disulfide bond formation. Electrons flow via cytochrome bo oxidase to oxygen under aerobic conditions or via cytochrome bd oxidase under partially anaerobic conditions. Under truly anaerobic conditions, menaquinone shuttles electrons to alternate final electron acceptors such as fumarate. This flexibility reflects the vital nature of the disulfide catalytic system

Extensive DNA mimicry by the ArdA anti-restriction protein and its role in the spread of antibiotic resistance

The ardA gene, found in many prokaryotes including important pathogenic species, allows associated mobile genetic elements to evade the ubiquitous Type I DNA restriction systems and thereby assist the spread of resistance genes in bacterial populations. As such, ardA contributes to a major healthcare problem. We have solved the structure of the ArdA protein from the conjugative transposon Tn916 and find that it has a novel extremely elongated curved cylindrical structure with defined helical grooves. The high density of aspartate and glutamate residues on the surface follow a helical pattern and the whole protein mimics a 42-base pair stretch of B-form DNA making ArdA by far the largest DNA mimic known. Each monomer of this dimeric structure comprises three alpha–beta domains, each with a different fold. These domains have the same fold as previously determined proteins possessing entirely different functions. This DNA mimicry explains how ArdA can bind and inhibit the Type I restriction enzymes and we demonstrate that 6 different ardA from pathogenic bacteria can function in Escherichia coli hosting a range of different Type I restriction systems

Hypothalamic Protein Kinase C Regulates Glucose Production

OBJECTIVE—A selective rise in hypothalamic lipid metabolism and the subsequent activation of SUR1/Kir6.2 ATP-sensitive K+ (KATP) channels inhibit hepatic glucose production. The mechanisms that link the ability of hypothalamic lipid metabolism to the activation of KATP channels remain unknown