Use of aerial thermography in Canadian energy conservation programs

Recent developments in the use of aerial thermography in energy conservation programs within Canada were summarized. Following a brief review of studies conducted during the last three years, methodologies of data acquisition, processing, analysis and interpretation was discussed. Examples of results from an industrial oriented project were presented and recommendations for future basic work were outlined

Conditions for Survival: changing risk and the performance of hedge fund managers and CTAs

Investors in hedge funds and commodity trading advisors [CTA] are naturally concerned with risk as well as return. In this paper, we investigate whether hedge fund and CTA return variance depends upon whether the manager is doing well or poorly. Our results are consistent with the Brown, Harlow and Starks (1996) findings for mutual fund managers. We find that good performers in the first half of the year reduce the volatility of their portfolios, and poor performers increase volatility. These “variance strategies" depend upon the fund’s ranking relative to other funds. Interestingly enough, despite theoretical predictions, changes in risk are not conditional upon distance from the high water mark threshold, i.e. a ratcheting absolute manager benchmark. This result may be explained by the relative importance of fund termination. We analyze factors contributing to fund disappearance. Survival depends on both absolute and relative performance. Excess volatility can also lead to termination. Finally, other things equal, the younger a fund, the more likely it is to fail. Therefore our results strongly confirm an hypothesis of Fung and Hsieh (1997b) that reputation costs have a mitigating effect on the gambling incentives implied by the manager contract. Particularly for young funds, a volatility strategy that increases the value of a performance fee option may lead to the premature death of that option through termination of the fund. The finding that hedge fund and CTA volatility is conditional upon past performance has implications for investors, lenders and regulators

Careers and Survival: Competition and Risk in the Hedge Fund and CTA Industry

Investors in hedge funds and commodity trading advisors [CTA’s] are naturally concerned with risk as well as return. In this paper, we investigate risk of hedge funds and CTA’s in light of managerial career concerns. We find an association between past performance and risk levels consistent with Brown, Harlow and Starks (1996) findings for mutual fund managers. Good performers in the first half of the year reduce the volatility of their portfolios, and poor performers increase volatility. These “variance strategies" depend upon the fund’s ranking relative to other funds. The importance of relative rankings as opposed to the absolute ranking suggested by analysis of hedge fund and CTA manager contracts points to the importance of reputation costs. These costs are best thought of in the context of the career concerns of managers and the relative importance of fund termination. We analyze factors contributing to fund disappearance. Survival depends on both absolute and relative performance. Excess volatility can also lead to termination. Finally, other things equal, the younger a fund, the more likely it is to disappear from the sample. Therefore our results strongly confirm an hypothesis of Fung and Hsieh (1997b) that reputation costs have a mitigating effect on the gambling incentives implied by the manager contract. Particularly for young funds, a volatility strategy that increases the value of a performance fee option may lead to the premature death of that option through termination of the fund. The finding that hedge fund and CTA volatility is conditional upon past performance has implications for investors, lenders and regulators. An important result of our finding is that variance strategy depends upon relative rather than absolute performance evaluation

Detection of Single Ion Spectra by Coulomb Crystal Heating

The coupled motion of ions in a radiofrequency trap has been used to connect the frequency- dependent laser-induced heating of a sympathetically cooled spectroscopy ion with changes in the fluorescence of a laser-cooled control ion. This technique, sympathetic heating spectroscopy, is demonstrated using two isotopes of calcium. In the experiment, a few scattered photons from the spectroscopy ion are transformed into a large deviation from the steady-state fluorescence of the control ion. This allows us to detect an optical transition where the number of scattered photons is below our fluorescence detection limit. Possible applications of the technique to molecular ion spectroscopy are briefly discussed.Comment: 7 Pages,10 Figure

Medical Technology Transfer

The Biomedical Applications Team program sponsored by the National Aeronautics and Space Administration is an effective means for transferring aerospace technology to applications in medicine. A conceptual framework for medical technology transfer is presented to describe the transfer process in medicine and to supply a rationale for the Biomedical Applications Team methodology. Examples illustrate medical technology transfer at the material, design, and capacity levels. The roles of donor, recipient, and transfer agent are illustrated and factors essential to the success of medical technology transfer are summarized

Universally Sloppy Parameter Sensitivities in Systems Biology

Quantitative computational models play an increasingly important role in modern biology. Such models typically involve many free parameters, and assigning their values is often a substantial obstacle to model development. Directly measuring \emph{in vivo} biochemical parameters is difficult, and collectively fitting them to other data often yields large parameter uncertainties. Nevertheless, in earlier work we showed in a growth-factor-signaling model that collective fitting could yield well-constrained predictions, even when it left individual parameters very poorly constrained. We also showed that the model had a `sloppy' spectrum of parameter sensitivities, with eigenvalues roughly evenly distributed over many decades. Here we use a collection of models from the literature to test whether such sloppy spectra are common in systems biology. Strikingly, we find that every model we examine has a sloppy spectrum of sensitivities. We also test several consequences of this sloppiness for building predictive models. In particular, sloppiness suggests that collective fits to even large amounts of ideal time-series data will often leave many parameters poorly constrained. Tests over our model collection are consistent with this suggestion. This difficulty with collective fits may seem to argue for direct parameter measurements, but sloppiness also implies that such measurements must be formidably precise and complete to usefully constrain many model predictions. We confirm this implication in our signaling model. Our results suggest that sloppy sensitivity spectra are universal in systems biology models. The prevalence of sloppiness highlights the power of collective fits and suggests that modelers should focus on predictions rather than on parameters.Comment: Submitted to PLoS Computational Biology. Supplementary Information available in "Other Formats" bundle. Discussion slightly revised to add historical contex