Paper Session I-A - A Strategy for Implementation of Integrated Vehicle Health Management into the Space Shuttle Program

A Strategy for Implementation of Integrated Vehicle Health Management (IVHM) into the Space Shuttle Program

Process Mapping of Transient Melt Pool Response in Wire Feed E-Beam Additive Manufacturing of Ti-6Al-4V

Wire feed electron beam additive manufacturing processes are candidates for manufacturing and repair in the aerospace industry. In order to implement feedback or feedforward control approaches, the time needed for a change in process variables to translate into changes in melt pool dimensions is a critical concern. In this research, results from 3D finite element simulations of deposition of Ti-6Al-4V are presented quantifying the transient response of melt pool dimensions to rapid changes in beam power and travel velocity. Results are plotted in beam power vs. beam velocity space, following work by the authors developing P-V Process Maps for steady-state melt pool geometry. Transient responses are determined over a wide range of process variables. Simulation results are compared to initial results from experiments performed at NASA Langley Research Center.Mechanical Engineerin

R-parity Violation and General Soft Supersymmetry Breaking

We consider the most general class possible of soft supersymmetry breaking terms that can be added to the MSSM, with and without R-parity violation, consistent with the sole requirement that no quadratic divergences are induced. We renormalise the resulting theory through one loop and give an example of how a previously ignored term might affect the sparticle spectrum.Comment: 11 pages, 1 figure. Plain TeX, uses Harvmac (Big) and epsf. Added references and typo corrected (v2

Can CBT effectively treat adult insomnia disorder?

Q: Can CBT effectively treat adult insomnia disorder? Evidence-based answer: Yes. Cognitive behavioral therapy (CBT) administered individually, in a group setting, or on the internet is effective for treating insomnia in adults compared with control (strength of recommendation [SOR]: A, meta-analyses). CBT is comparable to pharmacotherapy for improving measures of sleep (SOR: A, comparative meta-analysis). CBT produces sustainable improvements in subjective sleep quality for adults with comorbid insomnia (SOR: A, metaanalysis).Steven Fox, MD (University of Tennessee, College of Medicine, Chattanooga) ; Joan Nashelsky, MLS (Family Physicians Inquiries Network, Iowa City, Iowa) ; Michael Jack, BA (Erlanger Health System Medical Library, Chattanooga, Tenn.

Origins and History of NASA

No abstract availabl

An evaluation of SNOMED CT® in the domain of complex chronic conditions

<p style="margin: 0pt; line-height: 200%; mso-layout-grid-align: none;"><strong>Objective</strong>: To determine the content coverage in SNOMED CT<strong style="mso-bidi-font-weight: normal;">®</strong> to represent the multidisciplinary terms and concepts in the domain for complex chronic conditions</p><p style="margin: 0pt; line-height: 200%; mso-layout-grid-align: none;"><strong>Methods</strong>: An evaluation of the coverage of multidisciplinary health factors in SNOMED CT<strong style="mso-bidi-font-weight: normal;">®</strong> for the complex and chronic condition, Multiple Chemical Sensitivity (MCS) is conducted in the study. The methodology included a retrospective audit of patient charts and feedback from multidisciplinary clinicians in the creation of a controlled vocabulary used in the generation of patient profiles for MCS. Clinicians and experts in the field reviewed and tested the vocabulary for its usefulness (scope, specificity and structure) by re-coding 3 patient profiles using the vocabulary. Cohen's kappa analysis was conducted to determine inter-rater reliability. Cronbach's alpha analysis was conducted to determine the internal reliability of the survey questionnaire.</p><p style="margin: 0pt; line-height: 200%; mso-layout-grid-align: none;"><strong>Results</strong>: One hundred patient charts and 9 clinicians from varying health disciplines participated in the study. SNOMED CT<strong style="mso-bidi-font-weight: normal;">®</strong> was shown to capture nearly 82% of the concepts spanning multidisciplinary areas of health focus. The nutrition area of health focus had the highest level of exact matches Furthermore post-coordination was applied in an attempt to improve coverage of concepts to 75% ( of 45 terms) of the missing terms in SNOMED CT ® . Seventy-five percent (n=9) of the clinicians agreed on the overall usefulness of the vocabulary.</p><p style="margin: 0pt; line-height: 200%; mso-layout-grid-align: none;"><strong>Conclusions</strong>: SNOMED CT® had a reasonable coverage of the multidisciplinary health concepts required to describe a complex and chronic condition. Standardizing the multidisciplinary vocabulary with reference tag to a widely used reference terminology such as SNOMED CT® to discuss the terms and concepts used may improve the understanding across disciplines and communities of practice. Overall, based on the availability of concepts in SNOMED CT® and the feedback from clinicians, the approach looks promising and should be further explored.</p

Control variates for stochastic gradient MCMC

It is well known that Markov chain Monte Carlo (MCMC) methods scale poorly with dataset size. A popular class of methods for solving this issue is stochastic gradient MCMC (SGMCMC). These methods use a noisy estimate of the gradient of the log-posterior, which reduces the per iteration computational cost of the algorithm. Despite this, there are a number of results suggesting that stochastic gradient Langevin dynamics (SGLD), probably the most popular of these methods, still has computational cost proportional to the dataset size. We suggest an alternative log-posterior gradient estimate for stochastic gradient MCMC which uses control variates to reduce the variance. We analyse SGLD using this gradient estimate, and show that, under log-concavity assumptions on the target distribution, the computational cost required for a given level of accuracy is independent of the dataset size. Next we show that a different control variate technique, known as zero variance control variates, can be applied to SGMCMC algorithms for free. This post-processing step improves the inference of the algorithm by reducing the variance of the MCMC output. Zero variance control variates rely on the gradient of the log-posterior; we explore how the variance reduction is affected by replacing this with the noisy gradient estimate calculated by SGMCMC

Microwave Temperature Profiler Mounted in a Standard Airborne Research Canister

Many atmospheric research aircraft use a standard canister design to mount instruments, as this significantly facilitates their electrical and mechanical integration and thereby reduces cost. Based on more than 30 years of airborne science experience with the Microwave Temperature Profiler (MTP), the MTP has been repackaged with state-of-the-art electronics and other design improvements to fly in one of these standard canisters. All of the controlling electronics are integrated on a single 4 ~5-in. (.10 ~13- cm) multi-layer PCB (printed circuit board) with surface-mount hardware. Improved circuit design, including a self-calibrating RTD (resistive temperature detector) multiplexer, was implemented in order to reduce the size and mass of the electronics while providing increased capability. A new microcontroller-based temperature controller board was designed, providing better control with fewer components. Five such boards are used to provide local control of the temperature in various areas of the instrument, improving radiometric performance. The new stepper motor has an embedded controller eliminating the need for a separate controller board. The reference target is heated to avoid possible emissivity (and hence calibration) changes due to moisture contamination in humid environments, as well as avoiding issues with ambient targets during ascent and descent. The radiometer is a double-sideband heterodyne receiver tuned sequentially to individual oxygen emission lines near 60 GHz, with the line selection and intermediate frequency bandwidths chosen to accommodate the altitude range of the aircraft and mission