ITC/USA 2008 Conference Proceedings / The Forty-Fourth Annual International Telemetering Conference and Technical Exhibition / October 27-30, 2008 / Town and Country Resort & Convention Center, San Diego, California / A previous paper was presented detailing the design and testing of the first networked demonstration system (ITC 2006) for iNET. This paper extends that work by testing a commercial off the shelf (COTS) solution for the wireless network connection of the Telemetry Network System (TmNS). This paper will briefly discuss specific pieces of the airborne and ground station system but will concentrate on the new wireless network link, how it was tested, and how well it performed. Flight testing results will be presented accessing the performance of the wireless network link.

ITC/USA 2007 Conference Proceedings / The Forty-Third Annual International Telemetering Conference and Technical Exhibition / October 22-25, 2007 / Riviera Hotel & Convention Center, Las Vegas, Nevada / This paper baselines the performance of common, single band telemetry blade antennas in two telemetry bands and compares that performance to two very differing multi-band antenna designs. A description of each antenna is presented followed by flight testing results and conclusions. Results are in the form of received signal strength versus geographic location, derived in-flight antenna patterns, link availability, and bit error analysis.

The main focus of the thesis is to derive stability criteria for networked control system (NCS) models featuring imperfections such as time-varying and constant delays, quantization, packet dropouts, and non-uniform sampling intervals. The main method of proof is based on matrix algebra, as opposed to methods using Lyapunov functions or integral quadratic constraints (IQC). This work puts a particular focus on handling systems with a single integrator. This framework is elaborated in different specific directions as motivated by practical realizations of NCSs, as well as through numerical examples. A novel proof of the discrete time multivariate circle criterion and the Tsypkin criterion for systems including a single integrator is presented, as well as a stability criterion for linear systems with a single integrator subject to variable sampling periods and sector-bounded nonlinear feedback. Four stability criteria for different classes of systems subject to packet loss and time-varying delay are given. Stability criteria for a closed loop system switching between a set of linear time-invariant systems (LTIs) are proved. This result is applied to a single-link NCS with feedback subject to packet loss. Finally, necessary and sufficient conditions for delay-independent stability of an LTI system subject to nonlinear feedback are derived.

International Telemetering Conference Proceedings / October 23-26, 2000 / Town & Country Hotel and Conference Center, San Diego, California / Wireless data acquisition began with sensors connected to some form of radio. Emergence of the IEEE 802.11 specification made possible the evolution of a high-speed, multi-channel, wireless data acquisition system using COTS, Commercial Off-The-Shelf, technology. After developing a sub-miniature telemetry system in the S-band for the US Air Force, the system delivered to the Air Force evolved into a high-speed, wireless data acquisition system for the commercial market.

<p>Control systems utilizing wireless sensor and actuator networks can be severely affectedby the properties of the communication links. Radio fading and interferencemay cause communication losses and outages in situations when the radio environmentis noisy and low transmission power is desirable. This thesis proposes amethod to compensate for such unpredictable losses of data in the feedback controlloop by introducing a predictive outage compensator (POC). The POC is a filter tobe implemented at the receiver sides of networked control systems where it generatesartificial samples when data are lost. If the receiver node does not receive thedata, the POC suggests a command based on the history of past data. It is shownhow to design, tune and implement a POC. Theoretical bounds and simulationresults show that a POC can improve the closed-loop control performance undercommunication losses considerably. We provide a deterministic and a stochasticmethod to synthesize POCs. Worst-case performance bounds are given that relatethe closed-loop performance with the complexity of the compensator. We also showthat it is possible to achieve good performance with a low-order implementationbased on Hankel norm approximation. Tradeoffs between achievable performance,communication loss length, and POC order are discussed. The results are illustratedon a simulated example of a multiple-tank process. The thesis is concludedby an experimental validation of wireless control of a physical lab process. Herethe controller and the physical system are separated geographically and interfacedthrough a wireless medium. For the remote control we use a hybrid model predictivecontroller. The results reflect the difficulties in wireless control as well as theyhighlight the flexibility and possibilities one obtains by using wireless instead of awired communication medium.</p> / VR, SSF, VINNOVA via Networked Embedded Control Systems, EU Sixt Framework Program via HYCON and SOCRADES

International Telemetering Conference Proceedings / October 25-28, 1993 / Riviera Hotel and Convention Center, Las Vegas, Nevada / The US Air Force is required to protect the lives of individuals and property in areas potentially hazardous as a result of launch vehicle failures occurring from Vandenberg AFB, California. This paper describes the application of modern telemetry processing equipment to the Range Safety function.

The research reported in this dissertation investigates the impact that accountability systems have on the design and development of student centered learning environments. The nature of student-centered learning environments (SCLEs) in this study is framed theoretically by cultural historical activity theory (CHAT). The investigation itself occurred within a specific practice context: an urban charter school serving elementary-aged children. The efforts to design and develop SCLEs in the school focused on the use of improvement inquiry by groups of stakeholders organized into a developing human ecology in educational contexts called networked improvement communities. The research sought to determine (1) how accountability systems influenced instructional practices within the school and (2) how practicing teachers perceived the assessments embedded within the accountability systems. Data were collected via surveys, interviews, and a focus group. The data from the surveys and interviews informed the work for the focus group. The work from the focus group generated a stakeholder-generated “theory of practice improvement” in the form of an illustrative driver diagram. The driver diagram contributed an empirically generated proposal for how improved instructional practices might be pursued at the school. The investigation concluded with recommendations for implementing the plan within the school and recommendations to the broader field of education to engage more deeply in improvement inquiry. / School of Education; / Professional Doctorate in Educational Leadership (ProDEL) / EdD; / Dissertation;

Virginia Commonwealth University (VCU) is implementing a large scale exploration of digital pedagogies, including connected learning and open education, in an effort to promote digital fluency and integrative thinking among students. The purpose of this study was to develop a classroom assessment toolkit for faculty who wish to document student connectivity in course-related blogging and microblogging (“tweeting”) activities. Student use of digital annotation devices, including hyperlinks, embedded images, mentions, and hashtags, were studied in four university courses as potential indicators of student connectivity, defined as the ability to connect current thoughts and experience with other concepts and people across space and time. One thousand one hundred and eighty six (1186) hyperlinks and embedded images, 2708 mentions, and 135 hashtags were collected from 498 learner blog posts and 5343 tweets through mostly automated, digital workflows and analyzed through a combination of statistical, content, and network analysis. General criteria for “connected course” design, a model for connectivity as a form of learning, connectivity-based learning goals, and integrated, potentially scalable assessment practices are discussed. Content analysis led to the development of classification systems for the types, sources, and communicative impact of hyperlinked and embedded materials in blogging and tweeting contexts. Network analysis was adapted to visualize, document, and describe course-related social interactions and student use of web-based information sources. Real student data are used to describe annotation-focused assessment criteria, analytic assessment dashboards, rubrics, and approaches to real-time graphic visualization of student performance.

The use of interactive multimedia within live performance is now well established and a significant body of exciting and sophisticated work has been produced. However, almost all work in the field seems to start by creating at least some of the software and hardware systems that will provide the infrastructure for the project, an approach which might involve significant duplication of effort. The research described in this thesis sets out to discover if there are common features in the practice of artists from a range of performance backgrounds and, if so, whether the features of a system which might support these common aspects could be established. Based on evidence from a set of interviews, it is shown that there are indeed common factors in work in this field, especially the intensive linking of elements in performances and the use of triggering or cuing. A statement of requirements for a generic system to support work in digital performance is then established based on interview analysis and personal creative work. A general model of live performance, based on set theory, is described which provides a rationale for the integration of digital technology within live performance. A computational model outlining the formal requirements of a general system for use in live performance is then presented. The thesis then describes the creation of a domain specific language specifically for controlling live performance and the development of a prototype reference implementation of a generic system, the Live Interactive Multimedia Performance Toolkit (LIMPT). The system is then evaluated from a number of standpoints including a set of criteria established earlier in the study. It is concluded that, while there are many resources currently used by artists working in digital performance (a comprehensive survey of current resources is presented), none offer the combination of functionality, usability and scalability offered by the prototype LIMPT system. The thesis concludes with a discussion of possible future work and the potential for increased creative activity in multimedia and live performance.

Stochastic system identification is of great interest in the areas of control and communication. In stochastic system identification, a model of a dynamic system is determined based on given inputs and received outputs from the system, where stochastic uncertainties are also involved. The scope of the report is to consider continuous-time models used within control and communication and to estimate the model parameters from sampled data with high accuracy in a computational efficient way. Continuous-time models of systems controlled in a networked environment, stochastic closed-loop systems, and wireless channels are considered. The parameters of a transfer function based model for the process in a networked control system are first estimated by a covariance function based approach, relying upon the second order statistical properties of the output signal. Some other approaches for estimating the parameters of continuous-time models for processes in networked environments are also considered. Further, the parameters of continuous-time autoregressive exogenous models are estimated from closed-loop filtered data, where the controllers in the closed-loop are of proportional and proportional integral type, and where the closed-loop also contains a time-delay. Moreover, a stochastic differential equation is derived for Jakes's wireless channel model, describing the dynamics of a scattered electric field with the moving receiver incorporating a Doppler shift. / <p>Article I was still in manuscript form at the time of the defense.</p>