1,741 research outputs found
Autonomous real-time surveillance system with distributed IP cameras
An autonomous Internet Protocol (IP) camera based object tracking and behaviour identification system, capable of running in real-time on an embedded system with limited memory and processing power is presented in this paper. The main contribution of this work is the integration of processor intensive image processing algorithms on an embedded platform capable of running at real-time for monitoring the behaviour of pedestrians. The Algorithm Based Object Recognition and Tracking (ABORAT) system architecture presented here was developed on an Intel PXA270-based development board clocked at 520 MHz. The platform was connected to a commercial stationary IP-based camera in a remote monitoring station for intelligent image
processing. The system is capable of detecting moving objects and their shadows in a complex environment with varying lighting intensity and moving foliage. Objects
moving close to each other are also detected to extract their trajectories which are then fed into an unsupervised neural network for autonomous classification. The novel intelligent video system presented is also capable of performing simple analytic functions such as tracking and generating alerts when objects enter/leave regions or cross tripwires superimposed on live video by the operator
Optimal Flow Control Design
In support of the Blended-Wing-Body aircraft concept, a new flow control hybrid vane/jet design has been developed for use in a boundary-layer-ingesting (BLI) offset inlet in transonic flows. This inlet flow control is designed to minimize the engine fan-face distortion levels and the first five Fourier harmonic half amplitudes while maximizing the inlet pressure recovery. This concept represents a potentially enabling technology for quieter and more environmentally friendly transport aircraft. An optimum vane design was found by minimizing the engine fan-face distortion, DC60, and the first five Fourier harmonic half amplitudes, while maximizing the total pressure recovery. The optimal vane design was then used in a BLI inlet wind tunnel experiment at NASA Langley's 0.3-meter transonic cryogenic tunnel. The experimental results demonstrated an 80-percent decrease in DPCPavg, the reduction in the circumferential distortion levels, at an inlet mass flow rate corresponding to the middle of the operational range at the cruise condition. Even though the vanes were designed at a single inlet mass flow rate, they performed very well over the entire inlet mass flow range tested in the wind tunnel experiment with the addition of a small amount of jet flow control. While the circumferential distortion was decreased, the radial distortion on the outer rings at the aerodynamic interface plane (AIP) increased. This was a result of the large boundary layer being distributed from the bottom of the AIP in the baseline case to the outer edges of the AIP when using the vortex generator (VG) vane flow control. Experimental results, as already mentioned, showed an 80-percent reduction of DPCPavg, the circumferential distortion level at the engine fan-face. The hybrid approach leverages strengths of vane and jet flow control devices, increasing inlet performance over a broader operational range with significant reduction in mass flow requirements. Minimal distortion level requirements are met using vanes alone, avoiding engine stall and increasing robustness of this hybrid inlet flow control approach. This design applies to aerospace applications needing flush-mounted boundary-layer-ingesting inlets
Boundary-layer-ingesting inlet flow control system
A system for reducing distortion at the aerodynamic interface plane of a boundary-layer-ingesting inlet using a combination of active and passive flow control devices is disclosed. Active flow control jets and vortex generating vanes are used in combination to reduce distortion across a range of inlet operating conditions. Together, the vortex generating vanes can reduce most of the inlet distortion and the active flow control jets can be used at a significantly reduced control jet mass flow rate to make sure the inlet distortion stays low as the inlet mass flow rate varies. Overall inlet distortion, measured and described as average SAE circumferential distortion descriptor, was maintained at a value of 0.02 or less. Advantageous arrangements and orientations of the active flow control jets and the vortex generating vanes were developed using computational fluid dynamics simulations and wind tunnel experimentations
Nurse Anesthetists in Southeastern Kentucky: A Survey of Supply Versus Demand
Examines the geographic maldistribution of nurse anesthetists in Kentucky and the status of their positions and vacancies at all 19 hospitals in the southeastern part of the state. UK Center for Excellence in Rural Health-Hazard researchers found that southeastern Kentucky has 12.5 percent of Kentucky’s total population and performs 11.5 percent of the state’s total surgeries - but has only 6.5 percent of the state’s total resident nurse anesthetists
High-Speed Boundary-Layer Transition Induced by an Isolated Roughness Element
Progress on an experimental effort to quantify the instability mechanisms associated with roughness-induced transition in a high-speed boundary layer is reported in this paper. To simulate the low-disturbance environment encountered during high-altitude flight, the experimental study was performed in the NASA-Langley Mach 3.5 Supersonic Low-Disturbance Tunnel. A flat plate trip sizing study was performed first to identify the roughness height required to force transition. That study, which included transition onset measurements under both quiet and noisy freestream conditions, confirmed the sensitivity of roughness-induced transition to freestream disturbance levels. Surveys of the laminar boundary layer on a 7deg half-angle sharp-tipped cone were performed via hot-wire anemometry and pitot-pressure measurements. The measured mean mass-flux and Mach-number profiles agreed very well with computed mean-flow profiles. Finally, surveys of the boundary layer developing downstream of an isolated roughness element on the cone were performed. The measurements revealed an instability in the far wake of the roughness element that grows exponentially and has peak frequencies in the 150 to 250 kHz range
Supersonic Crossflow Transition Control in Ground and Flight Tests
This paper describes the use of distributed-roughness-element (DRE) patterns along a Mach 2 design swept-wing leading edge to increase the laminar flow extent and thereby reduce drag. One swept-wing model was tested in a supersonic wind tunnel as well as beneath a supersonic flight vehicle. Wing model surface data acquired during these tests included pressures, temperatures, and boundary-layer transition locations. Similarities and differences in experimental results are discussed. While wind tunnel and flight results show some differences, the wind tunnel results still provide key insights necessary for understanding how to design effective DRE patterns for use in flight applications. Experimental results demonstrate a DRE flow control effect observed in flight similar to that observed in the wind tunnel. Finally, a different perspective is discussed concerning what flow control role RE patterns might perform in any future swept-wing laminar flow control applications
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Remember, remember the fifth of November: was that thunder I heard or not?
‘Thunder days’ are simple records of thunderstorm activity, logging whether a human observer heard thunder on a particular day or not. Despite their low dynamic range and inherent subjectivity, thunder days are invaluable as the only long-term observations of thunderstorm occurrence, with some records stretching back into the nineteenth century. Thunder days, however, are potentially susceptible to false positives, particularly from explosions. Thus one might expect UK thunder days to show anomalously high counts on New Year's Eve and the days around 5 November, Bonfire Night, both of which are celebrated with large firework displays across the country. It is demonstrated that UK Met Office records of thunder days between 1980 and 2010 do not show any significant increase in thunder reporting around 5 November or 31 December. In fact, the days around 5 November exhibit the largest reduction in the amount of reported thunder relative to annual climatology. While meteorological variability cannot be completely ruled out, this result is suggestive of observer bias; it is speculated that human observers, armed with a priori knowledge of the likelihood of false positives, ‘second guess’ themselves to a greater degree around 5 November than the rest of the year. In fact, the data suggest they should trust in their ability to correctly discriminate between thunder and fireworks
Interdisciplinary Workshop to Increase Collaboration Between Medical Students and Standardized Patient Instructors in Teaching Physical Diagnosis to Novices
Traditionally, full-time faculty members have assumed major responsibility for teaching physical examination skills to first- and second-year medical students. Problems with faculty recruitment and adhering to a standardized way of teaching have challenged educators to seek alternatives to teaching the physical examination to novices. To address these problems, we created and implemented a novel curriculum that has standardized the teaching of physical examination skills to novice students by using standardized patient instructors and fourth-year medical students working as an interdisciplinary team (known as a dyad). Feedback after the first iteration of this course revealed confusion about roles, goals, and responsibilities for feedback and evaluation amongst the dyads. To address these issues, an interdisciplinary workshop was created using the theoretical constructs of the GRPI (goals, roles and responsibilities, process, and interpersonal skills) model and Mezirow’s transformative learning theory, both of which address gaps in the dyad relationship. Initial feedback from fourth-year students and standardized patient instructors was enthusiastically positive. Evidence showed the dyad could be strengthened by (1) providing time to learn the theoretical scaffolding underlying working together, (2) meeting and planning approaches to teaching efforts, and (3) enabling medical students and standardized patient instructors to apply the theoretical constructs as the foundation to reflect on their teaching roles in effectively instructing novices in physical exam skills
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