Explaining Education to Engineers: Feedback Control Theory as a Metaphor

One of the barriers for engaging engineering faculty in the scholarship of learning and teaching is thechallenge of learning a new vocabulary. Becoming fluent in engineering education requires the acquisitionof new concepts and ideas that are often expressed in unfamiliar terms. Feedback control is a technical fieldcommon to a range of engineering disciplines that can be used as a model to help bridge the conceptual gapbetween traditional engineering and engineering education. Many of the key elements of engineering education can be represented by the elements of a feedback control system, with their behaviour in a learning environment paralleling their behaviour in a process control context. The feedback control model can be used to explain: the importance of timely feedback to students, the significance of assessment and evaluation in the learning process, the impact of learning styles upon learning outcomes, and the need for student-centered teaching approaches. While both fields have complexities that cannot be captured by simple models, the basic ideas can be explained simply. Feedback control metaphors make the basics accessible to a wider audience of engineering faculty

Slow Dynamics in Glasses

Minimalist theories of complex systems are broadly of two kinds: mean-field and axiomatic. So far all theories of complex properties absent from simple systems and intrinsic to glasses are axiomatic. Stretched Exponential Relaxation (SER) is the prototypical complex temporal property of glasses, discovered by Kohlrausch 150 years ago, and now observed almost universally in microscopically homogeneous, complex non-equilibrium materials, including luminescent electronic (Coulomb) glasses. Critical comparison of alternative axiomatic theories with both numerical simulations and experiments strongly favors dynamical trap models over static percolative or energy landscape models. PACS: 61.20.Lc; 67.40.F

Special session: utopia university - building a roadmap for educating the next millennium's engineers

Ailing multibillionaire P. Oscar Utopia wishes to endow a university in honor of Rose B. Utopia, his beloved wife and long-practicing engineer. He will be at FIE to draw upon the expertise of our community to design the master plan for a university of the next millennium, unburdened by the assumptions of the present and the past. Conference attendees who subscribe to Utopia's vision are encouraged to participate in this workshop, challenge the assumptions inherent to the current practice, and brainstorm a plan for educating the engineer of 3030. During this session, we will identify and challenge assumptions that are inherent to the current practice of how we educate engineers. Participants will engage in a series of rapid planning sessions based on the “what if” scenario of being able to establish a new engineering schoolunfettered by standard constraints of money, facilities,or current educational practice

Cost effectiveness of telecare management for pain and depression in patients with cancer: results from a randomized trial

OBJECTIVE: Pain and depression are prevalent and treatable symptoms among patients with cancer, yet they are often undetected and undertreated. The Indiana Cancer Pain and Depression (INCPAD) trial demonstrated that telecare management can improve pain and depression outcomes. This article investigates the incremental cost effectiveness of the INCPAD intervention. METHODS: The INCPAD trial was conducted in 16 community-based urban and rural oncology practices in Indiana. Of the 405 participants, 202 were randomized to the intervention group and 203 to the usual-care group. Intervention costs were determined, and effectiveness outcomes were depression-free days and quality-adjusted life years. RESULTS: The intervention group was associated with a yearly increase of 60.3 depression-free days (S.E. = 15.4; P < 0.01) and an increase of between 0.033 and 0.066 quality-adjusted life years compared to the usual care group. Total cost of the intervention per patient was US$1189, which included physician, nurse care manager and automated monitoring set-up and maintenance costs. Incremental cost per depression-free day was US$19.72, which yields a range of US$18,018 to US$36,035 per quality-adjusted life year when converted to that metric. When measured directly, the incremental cost per quality-adjusted life year ranged from US$10,826 based on the modified EQ-5D to US$73,286.92 based on the SF-12. CONCLUSION: Centralized telecare management, coupled with automated symptom monitoring, appears to be a cost effective intervention for managing pain and depression in cancer patients

Measurement and noise characterization of optically induced index changes using THz interferometry

A Michelson interferometer designed for broadband single-cycle THz pulses is used to characterize optically induced index changes in semiconductors which result in submicron changes in optical path length. The interferometric measurements are compared both to standard THz time-domain spectroscopy (THz-TDS) and differential THz-TDS based on modulation of the sample. By analyzing noise contributions in THz spectroscopy systems, it is shown that the destructive interference achieved in THz interferometry reduces both some sources of random errors as well as errors due to system drift.Peer reviewedElectrical and Computer Engineerin

Part-per-million gas detection from long-baseline THz spectroscopy

We report a long-baseline THz time domain spectrometer based on a White cell design capable of detecting gas species in the low part-per-million range in near real time. Coherent transients from methyl chloride vapor are observed directly in the time domain using a 5.0 m path length at pressures down to 1 Pa. Both phase sensitive (lock-in) detection and direct signal averaging using a rapid-scanning delay line are used for data acquisition.Peer reviewedElectrical and Computer Engineerin

Technical Report: Final project report for Terahertz Spectroscopy of Complex Matter

This project designed characterization techniques for thin films of complex matter and other materials in the terahertz spectral region extending from approximately 100 GHz to 4000 GHz (4 THz) midway between radio waves and light. THz has traditionally been a difficult region of the spectrum in which to conduct spectroscopic measurements. The “THz gap” arises from the nature of the sources and detectors used in spectroscopy both at the optical (high frequency) side and electronic (low frequency) side of the gap. To deal with the extremely rapid oscillations of the electric field in this frequency region this research project adapted techniques from both the electronics and optics technologies by fabricating microscopic antennas and driving them with short optical pulses. This research technique creates nearly single cycle pulses with extremely broad spectral bandwidth that are able to cover the THz spectral range with a single measurement. The technique of THz time domain spectroscopy (THz-TDS) has seen increasing use and acceptance in laboratories over the past fifteen years. However significant technical challenges remain in order to allow THz-TDS to be applied to measurement of solid materials, particularly thin films and complex matter. This project focused on the development and adaptation of time domain THz measurement techniques to investigate the electronic properties of complex matter in the terahertz frequency region from 25 GHz to beyond 5 THz (165 inv. cm). This project pursued multiple tracks in adapting THz Time Domain Spectroscopy (THz-TDS) to measurement of complex matter. The first, and most important, is development of a reliable methods to characterize the complex dielectric constant of thin films with high accuracy when the wavelength of the THz radiation is much longer than the thickness of the film. We have pursued several techniques for measurement of thin films. The most promising of these are waveguide spectroscopy and THz interferometry. Since THz spectroscopy measures the changes of the transmitted spectra, any noise on the THz signal contributes to measurement errors. The dynamic range—defined as the RMS noise of the THz detector compared to the peak THz signal—of THz spectroscopy using photoconductive antennas is extremely high, typically over 10,000. However the precision with which spectroscopic data can be measured is limited by the noise on the laser source which is typically 0.1% to 1%. For low values of the sample absorbance and for values of optical thickness less than approximately 0.01, the change in transmission approaches the measurement accuracy. The sample refractive index can be measured with better accuracy since the index causes a temporal shift of the THz pulse by an amount time shift of nd/c where n is the refractive index, d the sample thickness, and c the speed of light. Time shifts of tens of femtoseconds can generally be resolved so that index-thickness values of nd > ten microns can be accurately measured. Waveguide spectroscopy is a way to increase the path length in thin film by several orders of magnitude, and thus have a large interaction length even when the film is much less than a wavelength in thickness. Film thicknesses of 10’s of nm have been measured. THz interferometry cancels out many of the noise sources of THz spectroscopy and can thus result in measurements of films of several hundred nm in thickness and is additionally suitable for optical pump, THz probe spectroscopic techniques. A large amount of additional work was performed in support of the main project direction or to explore promising alternative avenues for research. This report discussed work on the the confinement of low density species for measurement of nanogram or picogram quantities of material. Whispering gallery mode resonators to achieve long path lengths were also investigated as were imaging techniques for sub-wavelength imaging of thin films. The report concludes with a report on investigations of fundamental issues in THz beam propagation and coupling that impact THz spectroscopy and the other spectroscopic techniques developed during this project

Direct observation of the Gouy phase shift in THz impulse ranging

Here we present a direct observation of the Gouy effect through THz impulse scattering from cylindrical and spherical targets. A pi/2 Gouy phase shift through a one-axis focus compared to the more common pi phase shift of the two-axis focus is required to interpret the scattering results using a physical optics model.Peer reviewedElectrical and Computer Engineerin

Properties of surface waves determined via bistatic terahertz impulse ranging

A bistatic terahertz impulse ranging system has permitted the full isolation and direct measurements of the surface wave loss and dispersion for terahertz frequencies on a dielectric cylinder. This system permits ranging investigations with variable bistatic angles between the source and detector. Direct, frequency dependent comparisons of surface wave loss and propagation velocity are compared to Mie theory and previous measurements of surface wave propagation over a 1 THz bandwidth. The observed radiation from the surface waves is seen to depend on the path of the radiation in and along the scatterer.Peer reviewedElectrical and Computer Engineerin