Display system employing acousto-optic tunable filter

An acousto-optic tunable filter (AOTF) is employed to generate a display by driving the AOTF with a RF electrical signal comprising modulated red, green, and blue video scan line signals and scanning the AOTF with a linearly polarized, pulsed light beam, resulting in encoding of color video columns (scan lines) of an input video image into vertical columns of the AOTF output beam. The AOTF is illuminated periodically as each acoustically-encoded scan line fills the cell aperture of the AOTF. A polarizing beam splitter removes the unused first order beam component of the AOTF output and, if desired, overlays a real world scene on the output plane. Resolutions as high as 30,000 lines are possible, providing holographic display capability

Context Imaging Raman Spectrometer

Methods and systems for Raman spectroscopy and context imaging are disclosed. One or two lasers can be used to excite Raman scattering in a sample, while a plurality of LEDs can illuminate the sample at a different wavelength. The LED light is collected by a lenslet array in order to enable a high depth of field. Focusing of the image can be carried out at specific points of the image by processing the light collected by the lenslet array

Display system employing acousto-optic tunable filter

An acousto-optic tunable filter (AOTF) is employed to generate a display by driving the AOTF with a RF electrical signal comprising modulated red, green, and blue video scan line signals and scanning the AOTF with a linearly polarized, pulsed light beam, resulting in encoding of color video columns (scan lines) of an input video image into vertical columns of the AOTF output beam. The AOTF is illuminated periodically as each acoustically-encoded scan line fills the cell aperture of the AOTF. A polarizing beam splitter removes the unused first order beam component of the AOTF output and, if desired, overlays a real world scene on the output plane. Resolutions as high as 30,000 lines are possible, providing holographic display capability

MANAGING PHOSPHOROUS SOIL DYNAMICS OVER SPACE AND TIME

Understanding the relationship between soil fertility dynamics and crop response is conceptually appealing. Even more appealing is comprehension of the spatial and temporal heterogeneity of these connections over a production surface and across seasons. Knowledge of these interactions is complicated because nutrient carryover dynamics and crop response to inputs are determined simultaneously on the one-hand, and sequentially on the other. A second problem enters when crops are rotated, for example, in the corn-soybean system commonly practiced in the Corn Belt. This paper examines the nutrient carryover-crop response nexus using data from a corn-soybean, variable-rate nitrogen (N) and phosphorous (P) experiment conducted over five years. Site-specific corn response to N and P and soybean response to P are simultaneously estimated with a P carryover equation. These estimates are used in a dynamic programming model to map site-specific optimal N and P fertilizer policies, soil P evolution, and profitability. The net present value of managing N and P site-specifically is compared to a strategy where these inputs are managed uniformly following extension guidelines. The results suggest that when P-carryover is managed, site-specific returns to the variable-rate strategies are higher than returns to a conventional, uniform strategy.Crop Production/Industries,

A SYSTEMS APPROACH FOR EVALUATING ON-FARM SITE-SPECIFIC MANAGEMENT TRIALS: A CASE STUDY WITH VARIABLE RATE MANURE AND CROP QUALITY RESPONSE TO INPUTS

Site-specific application of manure has the potential to improve crop production and environmental quality. If manure is applied where it is needed, in the quantity required by the crop, over application, with attendant runoff and leaching problems can be reduced. To implement this approach growers need site-specific crop response information. Increasing availability of site-specific yield information offers a way to estimate such crop responses. The objective of this study is to develop a methodology for estimating site-specific response of corn and soybeans to manure given soil test information, and to use that methodology to analyze an on-farm manure management trial conducted near Sleepy Eye, Minnesota. Both quantity and quality of the crop is considered.Research Methods/ Statistical Methods,

Improved real-time imaging spectrometer

An improved AOTF-based imaging spectrometer that offers several advantages over prior art AOTF imaging spectrometers is presented. The ability to electronically set the bandpass wavelength provides observational flexibility. Various improvements in optical architecture provide simplified magnification variability, improved image resolution and light throughput efficiency and reduced sensitivity to ambient light. Two embodiments of the invention are: (1) operation in the visible/near-infrared domain of wavelength range 0.48 to 0.76 microns; and (2) infrared configuration which operates in the wavelength range of 1.2 to 2.5 microns

Non-invasive method of measuring cerebral spinal fluid pressure

The invention provides a method of non-invasively determining intracranial pressure from measurements of an eye. A parameter of an optic nerve of the eye is determined, along with an intraocular pressure of the eye. The intracranial pressure may be determined from the intraocular pressure and the parameter

Assessing blood brain barrier dynamics or identifying or measuring selected substances, including ethanol or toxins, in a subject by analyzing Raman spectrum signals

A non-invasive method for analyzing the blood-brain barrier includes obtaining a Raman spectrum of a selected portion of the eye and monitoring the Raman spectrum to ascertain a change to the dynamics of the blood brain barrier.Also, non-invasive methods for determining the brain or blood level of an analyte of interest, such as glucose, drugs, alcohol, poisons, and the like, comprises: generating an excitation laser beam at a selected wavelength (e.g., at a wavelength of about 400 to 900 nanometers); focusing the excitation laser beam into the anterior chamber of an eye of the subject so that aqueous humor, vitreous humor, or one or more conjunctiva vessels in the eye is illuminated; detecting (preferably confocally detecting) a Raman spectrum from the illuminated portion of the eye; and then determining the blood level or brain level (intracranial or cerebral spinal fluid level) of an analyte of interest for the subject from the Raman spectrum. In certain embodiments, the detecting step may be followed by the step of subtracting a confounding fluorescence spectrum from the Raman spectrum to produce a difference spectrum; and determining the blood level and/or brain level of the analyte of interest for the subject from that difference spectrum, preferably using linear or nonlinear multivariate analysis such as partial least squares analysis. Apparatus for carrying out the foregoing methods are also disclosed

Non-invasive glucose monitor

A non-invasive method for determining blood level of an analyte of interest, such as glucose, comprises: generating an excitation laser beam (e.g., at a wavelength of 700 to 900 nanometers); focusing the excitation laser beam into the anterior chamber of an eye of the subject so that aqueous humor in the anterior chamber is illuminated; detecting (preferably confocally detecting) a Raman spectrum from the illuminated aqueous humor; and then determining the blood glucose level (or the level of another analyte of interest) for the subject from the Raman spectrum. Preferably, the detecting step is followed by the step of subtracting a confounding fluorescence spectrum from the Raman spectrum to produce a difference spectrum; and determining the blood level of the analyte of interest for the subject from that difference spectrum, preferably using linear or nonlinear multivariate analysis such as partial least squares analysis. Apparatus for carrying out the foregoing method is also disclosed

Risk Management Decision Making for Security and Trust in Hardware Supply Chains

Modern cyber-physical systems are enabled by electronic hardware and embedded systems. The security of these sub-components is a concern during the design and operational phases of cyber-physical system life cycles. Compromised electronics can result in mission-critical failures, unauthorized access, and other severe consequences. As systems become more complex and feature greater connectivity, system owners must make decisions regarding how to mitigate risks and ensure resilience and trust. This paper provides an overview of research efforts related to assessing and managing risks, resilience, and trust with an emphasis on electronic hardware and embedded systems. The research takes a decision-oriented perspective, drawing from the perspectives of scenario planning and portfolio analysis, and describes examples related to the risk-based prioritization of cyber assets in large-scale systems