Study of Pioneer spacecraft oscillator stability Final report

Pioneer spacecraft oscillator stability studies for telemetry link performance optimizatio

Free-stream disturbances, continuous eigenfunctions, boundary-layer instability and transition

A rational foundation is provided for the application of the linear stability theory of parallel shear flows to transition prediction. An explicit method is given for carrying out the necessary calculations. The expansions are shown to be complete. Sample calculations show that a typical boundary layer is very sensitive to vorticity disturbance in the inner boundary layer near the critical layer. Vorticity disturbances three or four boundary layer thicknesses above the boundary are nearly uncoupled from the boundary layer, in that the amplitudes of the discrete Tollmein-Schlichting waves are an extremely small fraction of the amplitude of the disturbance

Part I - Application of ultra-stable oscillators to one-way ranging systems. Part II - Fluctuation spectra of ultra- stable oscillators - Measurement and estimation Final report

Application of ultrastable oscillators to one-way ranging systems - Measurement technique for determining phase fluctuation spectrum of highly stable oscillator

Optical altimeter receiver systems study and design for a spaceborne laser altimeter

Design and specifications for optical altimeter receiver system

Retrodirective transponder feasibility experiment

Test program on feasibility of digital phase measuring subsystem of pulse-coherent retrodirective transponde

Statistical Communication Theory

Contains reports on six research projects.National Institutes of Health (Grant MH-04737-02

Improved results for N=(2,2) super Yang-Mills theory using supersymmetric discrete light-cone quantization

We consider the (1+1)-dimensional ${\cal N}=(2,2)$ super Yang--Mills theory which is obtained by dimensionally reducing ${\cal N}=1$ super Yang--Mills theory in four dimension to two dimensions. We do our calculations in the large-$N_c$ approximation using Supersymmetric Discrete Light Cone Quantization. The objective is to calculate quantities that might be investigated by researchers using other numerical methods. We present a precision study of the low-mass spectrum and the stress-energy correlator $$. We find that the mass gap of this theory closes as the numerical resolution goes to infinity and that the correlator in the intermediate $r$ region behaves like $r^{-4.75}$.Comment: 18 pages, 8 figure

Airway stent complications: the role of follow-up bronchoscopy as a surveillance method.

Background: Airway stenting has become an integral part of the therapeutic endoscopic management of obstructive benign and malignant central airway diseases. Despite increased use of airway stents and frequent stent-associated complications, no clear guidelines for surveillance and maintenance exist. This study aim is to elucidate predictive factors associated with development of stent complications, as well as an optimal surveillance period for follow-up bronchoscopy for early detection and possible prevention of stent-associated complications. Methods: Retrospective cohort study of all patients who underwent airway stent placements at our institution from April 2010 to December 2013 for benign and malignant airway diseases. Metallic, silicone (straight, Y stent, T-tube) and hybrid stents were included in the study. Stent complications were analyzed at the time of follow-up bronchoscopy performed four to six weeks after initial stent placement or earlier if patients became symptomatic. Results: The study included 134 patients of which 147 stents were placed. Follow-up bronchoscopy was performed in 94 patients. Symptomatic status at the time of follow-up bronchoscopy was not associated with stent complications [odds ratio (OR) =1.88; 95% CI: 0.79-4.45; P=0.15]. Patient age, sex, indication for stent placement, and stent location, were not associated with development of complications (all P\u3e0.05). Compared to all other stents, hybrid stents were more likely to migrate (OR =6.60; 95% CI: 2.16-20.2; P=0.001) or obstruct by secretions (OR =2.53; 95% CI: 1.10-5.84; P=0.03). There were no complications associated with surveillance bronchoscopy. Conclusions: Surveillance bronchoscopy within 4 to 6 weeks of stent placement may be useful for early detection of complications and their subsequent management, regardless of symptomatic status and indication for stent placement. Prospective multicenter studies are needed to compare optimal surveillance methods and the impact on patient mortality, morbidity and healthcare costs