KEYWORDS: Analytics, Sensors, Data centers, Cameras, Analytical research, Monte Carlo methods, Data storage, Image processing, Defense and security, Electrical engineering
With the rise of small, networked sensors, the volume of data generated increasingly require curation by AI to analyze which events are of sufficient importance to report to human operators. We consider the ultimate limit of edge computing, when it is impractical to employ external resources for the curation, but individual devices have insufficient computing resources to perform the analytics themselves. In a previous paper we introduced a decenralized method that distributes the analytics over the network of devices, employing simulated annealing, based on physics-inspired Metropolis Monte Carlo. If the present paper we discuss the capability of this method to balance the energy consumption of the placement on a network of heterogeneous resources. We introduce the balanced utilization index (BUI), an adaptation of Jain’s Fairness Index, to measure this balance.
Gamma rays produced passively by cosmic ray interactions and by the decay of radioelements convey information about the elemental makeup of planetary surfaces and atmospheres. Orbital missions mapped the composition of the Moon, Mars, Mercury, Vesta, and now Ceres. Active neutron interrogation will enable and/or enhance in situ measurements (rovers, landers, and sondes). Elemental measurements support planetary science objectives as well as resource utilization and planetary defense initiatives. Strontium iodide, an ultra-bright scintillator with low nonproportionality, offers significantly better energy resolution than most previously flown scintillators, enabling improved accuracy for identification and quantification of key elements. Lanthanum bromide achieves similar resolution; however, radiolanthanum emissions obscure planetary gamma rays from radioelements K, Th, and U. The response of silicon-based optical sensors optimally overlaps the emission spectrum of strontium iodide, enabling the development of compact, low-power sensors required for space applications, including burgeoning microsatellite programs. While crystals of the size needed for planetary measurements (>100 cm3) are on the way, pulse-shape corrections to account for variations in absorption/re-emission of light are needed to achieve maximum resolution. Additional challenges for implementation of large-volume detectors include optimization of light collection using silicon-based sensors and assessment of radiation damage effects and energetic-particle induced backgrounds. Using laboratory experiments, archived planetary data, and modeling, we evaluate the performance of strontium iodide for future missions to small bodies (asteroids and comets) and surfaces of the Moon and Venus. We report progress on instrument design and preliminary assessment of radiation damage effects in comparison to technology with flight heritage.
Immunoassays have been widely used in commercial, scientific and medical research for detection and quantification of analytes in complex mixtures. There is however a need for a point-of-care, multiplex diagnostic assays capable of providing rapid and quantitative measurements of analytes present in samples that are sufficiently simple to carry out without use of a laboratory or individuals trained in chemical analysis. We are developing a fluorescent lateral flow immunoassay platform to perform simultaneous, multiplexed detection of analytes in a complex fluid mixture along with instrumentation to optically quantitate the analytes in the sample. Our prototype imaging system is based on conventional 16-bit CCD optics, which enables the development of a rugged diagnostic instrument that can be further scaled down for point-of-care applications. We have compared protein microarrays with lateral flow assays (LFAs) to determine the sensitivity of each system for the measurement of distinct proteins in complex samples. We are pursuing the LFA platform such that it can easily be scaled to meet the requirements of any given screening application, and be implemented for use in a medical or surgical setting.
It has been suggested that spectroscopic analysis of the aqueous humor of the eye could be used to indirectly predict blood glucose levels in diabetics noninvasively. We have been investigating this potential using Raman spectroscopy in combination with partial least squares (PLS) analysis. We have determined that glucose at clinically relevant concentrations can be accurately predicted in human aqueous humor in vitro using a PLS model based on artificial aqueous humor. We have further determined that with proper instrument design, the light energy necessary to achieve clinically acceptable prediction of glucose does not damage the retinas of rabbits and can be delivered at powers below internationally acceptable safety limits. Herein we summarize our current results and address our strategies to improve instrument design.
A scanning laser ophthalmoscope (SLO) uses a novel principal to view the retina while simultaneously projecting high resolution targets onto the retina. Consequently, the SLO is potentially an excellent instrument to measure fixation stability in humans. We used a commercially available Rodenstock SLO to project a small cross onto the retina of normal subjects with the HeNe laser and simultaneously view their retinal vasculature with the SLO's infrared diode laser. The video images from the SLO were continuously recorded (at 30 frames per second) with a video-cassette recorder. The video was digitized in 16 consecutive frame increments with a 4 Mbyte frame grabber in a microcomputer. By marking the audio track of the video tape and measuring from the audio mark before digitizing, long segments (1,000's of consecutive frames) can be digitized. We developed software to automatically map the locations of venous crossings at multiple retinal locations. In early work with the system, we verified that the digitization process worked correctly by time-stamping the video and confirming that all video frames were captured without duplication or drop out. We measured the location of 2 retinal points in 1024 consecutive frames of 4 normal subjects and showed that these points could be accurately followed with the automatic system.
Numerical techniques are described which allow quantitative interpretation of 2D and 3D histological imagery obtained from tissue samples which are stained with the neuronal tracer Fast Blue. The methods illustrated in this investigation are readily extensible to many different types of micro neuro-anatomy, and are particularly well suited for investigating pharmacological or environmental perturbations on neuron development. These techniques were used to quantitatively describe neurological development of the optic nerve in the pigmented rat. This analysis was used to show that most of the significant refinement in the retinotectal map occurs during the second to fourth week of life and with coincident with eye opening.
A 100-Mbit/s FDDI network interface unit (NIU) is described that supports real-time data, voice and video. Its high-speed interrupt-driven hardware architecture efficiently manages stream and packet data transfers to the FDDI network. Other enhancements include modular single-mode laser-dioce fiber optic links to maximize node spacing, optic bypass switches for increased fault tolerance, and a hardware performance monitor to gather real-time network diagnostics.
An acousto-optic tunable filter imaging spectrometer is introduced. The design criterion meeting system issues such as
image quality, spectral response, field of view (FOV), programmability, and system compactness are discussed. Experimental
demonstration obtained from using a 1/2' x 1/2' x 2' AOTF imaging spectrometer breadboard is presented. Identification of
Nd+3 containei in a Bastnasite rock using the spectrogram recorded by this imaging spectrometer is also provided.
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