10,143 research outputs found
Spatially Dependent Parameter Estimation and Nonlinear Data Assimilation by Autosynchronization of a System of Partial Differential Equations
Given multiple images that describe chaotic reaction-diffusion dynamics,
parameters of a PDE model are estimated using autosynchronization, where
parameters are controlled by synchronization of the model to the observed data.
A two-component system of predator-prey reaction-diffusion PDEs is used with
spatially dependent parameters to benchmark the methods described. Applications
to modelling the ecological habitat of marine plankton blooms by nonlinear data
assimilation through remote sensing is discussed
Performance of a tandem-rotor/tandem-stator conical-flow compressor designed for a pressure ratio of 3
A conical-flow compressor stage with a large radius change through the rotor was tested at three values of rotor tip clearance. The stage had a tandem rotor and a tandem stator. Peak efficiency at design speed was 0.774 at a pressure ratio of 2.613. The rotor was tested without the stator, and detailed survey data were obtained for each rotor blade row. Overall peak rotor efficiency was 0.871 at a pressure ratio of 2.952
Advising Communication in Finance
Communication is an important factor in relationships. When it comes to financial advising and the advisors’ relationship with their clients, it is no different. However, the driving factor of what makes a client choose one advisor over another remains in question. As such a question builds: what does an advisor do to maintain a client and promote gaining new ones? This study examines the experiences current advisors have had in their respective careers. To examine this topic, communication theories (Social Cognitive Theory, Source Credibility Theory, and Uncertainty Reduction Theory) are called upon to inform the outcomes of advisors\u27 experiences. The study findings align with each theory to an extent, but most align with Source Credibility Theory and Uncertainty Reduction Theory. Lastly, this study investigates the relationship between advisor and client, ultimately finding what makes an advisor better than other advisors. Ultimately, this study shows that advisors incorporate communication themes of (1) style, (2) methods, (3) trust, (4) figure of speech, (5) personality, (6) relatable, and (7) efforts, and (8) pandemic efforts it can strengthen and guide their client relationships
Experimental performance of a 16.10-centimeter-tip-diameter sweptback centrifugal compressor designed for a 6:1 pressure ratio
A backswept impeller with design mass flow rate of 1.033 kg/sec was tested with both a vaned diffuser and a vaneless diffuser to establish stage and impeller characteristics. Design stage pressure ratio of 5.9:1 was attained at a flow slightly lower than the design value. Flow range at design speed was 6 percent of choking flow. Impeller axial tip clearance at design speed was varied to determine effect on stage and impeller performance
Runtime Analysis with R2U2: A Tool Exhibition Report
We present R2U2 (Realizable, Responsive, Unobtrusive Unit), a hardware-supported tool and framework for the continuous monitoring of safety-critical and embedded cyber-physical systems. With the widespread advent of autonomous systems such as Unmanned Aerial Systems (UAS), satellites, rovers, and cars, real-time, on-board decision making requires unobtrusive monitoring of properties for safety, performance, security, and system health. R2U2 models combine past-time and future-time Metric Temporal Logic, “mission time” Linear Temporal Logic, probabilistic reasoning with Bayesian Networks, and model-based prognostics. The R2U2 monitoring engine can be instantiated as a hardware solution, running on an FPGA, or as a software component. The FPGA realization enables R2U2 to monitor complex cyber-physical systems without any overhead or instrumentation of the flight software. In this tool exhibition report, we present R2U2 and demonstrate applications on system runtime monitoring, diagnostics, software health management, and security monitoring for a UAS. Our tool demonstration uses a hardware-based processor-in-the-loop “iron-bird” configuration
Experimental performance of a 13.65-centimeter-tip-diameter tandem-bladed sweptback centrifugal compressor designed for a pressure ratio of 6
A 13.65 cm tip diameter backswept centrifugal impeller having a tandem inducer and a design mass flow rate of 0.907 kg/sec was experimentally investigated to establish stage and impeller characteristics. Tests were conducted with both a cascade diffuser and a vaneless diffuser. A pressure ratio of 5.9 was obtained near surge for the smallest clearance tested. Flow range at design speed was 6.3 percent for the smallest clearance test. Impeller exit to shroud axial clearance at design speed was varied to determine the effect on stage and impeller performance
Effect of area ratio on the performance of a 5.5:1 pressure ratio centrifugal impeller
A centrifugal impeller which was initially designed for a pressure ratio of approximately 5.5 and a mass flow rate of 0.959 kg/sec was tested with a vaneless diffuser for a range of design point impeller area ratios from 2.322 to 2.945. The impeller area ratio was changed by successively cutting back the impeller exit axial width from an initial value of 7.57 mm to a final value of 5.97 mm. In all, four separate area ratios were tested. For each area ratio a series of impeller exit axial clearances was also tested. Test results are based on impeller exit surveys of total pressure, total temperature, and flow angle at a radius 1.115 times the impeller exit radius. Results of the tests at design speed, peak efficiency, and an exit tip clearance of 8 percent of exit blade height show that the impeller equivalent pressure recovery coefficient peaked at a design point area ratio of approximately 2.748 while the impeller aerodynamic efficiency peaked at a lower value of area ratio of approximately 2.55. The variation of impeller efficiency with clearance showed expected trends with a loss of approximately 0.4 points in impeller efficiency for each percent increase in exit axial tip clearance for all impellers tested
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