Abstract:
The disclosed embodiments relate to a system that preprocesses sensor data to facilitate prognostic-surveillance operations. During operation, the system obtains training data from sensors in a monitored system during operation of the monitored system, wherein the training data comprises time-series data sampled from signals produced by the sensors. The system also obtains functional requirements for the prognostic-surveillance operations. Next, the system performs the prognostic-surveillance operations on the training data and determines whether the prognostic-surveillance operations meet the functional requirements when tested on non-training data. If the prognostic-surveillance operations do not meet the functional requirements, the system iteratively applies one or more preprocessing operations to the training data in order of increasing computational cost until the functional requirements are met.
Abstract:
The disclosed embodiments relate to a system that performs microscopy imaging with an extended depth of field. This system includes a stage for holding a sample, and a light source for illuminating the sample, wherein the light source produces ultraviolet light with a wavelength in the 230 nm to 300 nm range to facilitate microscopy with ultraviolet surface excitation (MUSE) imaging. The system also includes an imaging device, comprising an objective that magnifies the illuminated sample, and a sensor array that captures a single image of the magnified sample. The system also includes a controller, which controls the imaging device and/or the stage to scan a range of focal planes for the sample during an acquisition time for the single image. The system additionally includes an image-processing system, which processes the single image using a deconvolution technique to produce a final image with an extended depth of field.
Abstract:
During operation of the system, a sample of the biological material is placed against a surface of a waveguide, which is comprised of a UV-transparent waveguide material. Then, the system launches UV light from a UV light source via side-illumination into an input end of the waveguide, wherein a launch angle for components of the UV light is greater than a critical angle between the waveguide material and air, so that the UV light propagates through the waveguide via total internal reflection to reach the sample. The launch angle is also less than a critical angle between the waveguide material and the sample, so that when the UV light reaches the sample, the UV light escapes the waveguide through refraction to illuminate the sample. Finally, an imaging mechanism located on an opposite side of the waveguide from the sample captures an image of the illuminated sample.
Abstract:
The system determines a fetal blood oxygenation level by activating two or more light sources, having different wavelengths, which are positioned on the maternal abdomen of a pregnant mammal to direct light into a maternal abdomen toward a fetus. The system then receives a maternal signal from a first photodetector, which is positioned on the maternal abdomen to receive reflected light that traverses maternal tissue. The system also receives a mixed signal from a second photodetector, which is positioned on the maternal abdomen to receive reflected light that traverses both maternal and fetal tissue. The system performs a filtering operation that removes maternal signal components from the mixed signal to produce a fetal signal. The system determines the fetal blood oxygenation level by performing a pulse-oximetry computation on the fetal signal. The system dynamically adjusts operational parameters in the face of changing variables, such as fetus position and depth.
Abstract:
A tunable laser includes a reflective silicon optical amplifier, RSOA (104) with a reflective end and an interface end and an array of narrow-band reflectors (118), which each have a different center wavelength. It also includes a silicon-photonic optical switch (116), having an input port and N output ports that are coupled to a different narrow-band reflector in the array of narrow-band reflectors. The tunable laser also includes an optical waveguide (107) coupled between the interface end of the RSOA and the input of the silicon- photonic optical switch. The frequency of this tunable laser can be tuned in discrete increments by selectively coupling the input port of the silicon-photonic optical switch to one of the N output ports, thereby causing the RSOA to form a lasing cavity with a selected narrow-band reflector coupled to the selected output port. The tunable laser also includes a laser output (110, 112) optically coupled to the lasing cavity.
Abstract:
The disclosed embodiments relate to a technique for detecting Huanglongbing (HLB) infection in a citrus plant. This technique involves first gathering one or more samples of volatile organic compounds (VOCs) emanating from the citrus plant. Next, a system measures VOCs in the gathered samples to determine a VOC profile for the citrus plant, wherein the VOC profile comprises measured values for a set of VOCs that comprise disease-specific biomarkers for HLB infection. Finally, the system determines an HLB infection status for the citrus plant by analyzing the VOC profile.
Abstract:
A technique for establishing connectivity between electronic devices is described. In particular, when an electronic device is first connected to a network, the electronic device may use a predefined location of a registrar device to request location information for a controller for the electronic device. The electronic device may provide a manufacturer certificate to the registrar device to confirm its identity. After receiving from the registrar device the location information and a registrar certificate that confirms its identity, the electronic device may use the location information to request the security information from a controller that allows the electronic device to establish connectivity with another electronic device. The electronic device may receive the security from the controller along with a controller certificate that confirms the identity of the controller. Moreover, the electronic device may establish a connection with the other electronic device based on the security information.
Abstract:
When an unsafe port with a loss of signal is detected, a transceiver may enable one laser in a group of lasers associated with the unsafe port and may disable the remaining lasers. Then, the transceiver may instruct a transmitter associated with the one laser to transmit an optical signal on the unsafe port using a reduced transmit power that is less than a threshold value associated with the Class 1 conditions and at a different time than enabled lasers in other groups of lasers. Alternatively, for a safe port on which valid communication is received, the transceiver may enable lasers in a group of lasers associated with the safe port. Then, the transceiver may instruct transmitters associated with the lasers in this group of lasers to transmit optical signals on the safe port using a normal transmit power for the lasers that is greater than the threshold value.
Abstract:
A technique for testing wireless-local-area-network ( WLAN ) infrastructure is described. In particular, a radio-frequency abstraction layer ( RFAL ) in a physical instance of an electronic device is used to simulate the physical layer communication hardware and radio channels. RFAL allows frames in initial packets that are compatible with a WLAN communication protocol (such as an IEEE 802.11 standard) to be encapsulated in the data-link layer into additional packets that are compatible with a network communication protocol (such as an IEEE 802.3 standard). These additional packets can include information that characterizes transmission of the packet through a simulated radio-frequency environment so that the software stack associated with a physical or virtual instance of an electronic device can be exercised as if the packet had been received over a wireless connection. Then, the additional packets can be communicated via Ethernet (i.e., without radio-frequency communication) among virtual instances of access points, clients and/or WLAN controllers.
Abstract:
In order to accurately determine the location of an electronic device in an environment, a computer selects a set of received-signal-strength ( RSS ) values based on wireless communication between the electronic device and access points in sub-regions of the environment. This set includes a largest RSS value associated with a sub-region and at least two RSS values associated with neighboring sub-regions. Then, the computer calculates pairwise distance estimates of the location of the electronic device in the environment based on predefined locations of the access points associated with the set, one or more differences of pairs of RSS values in the set and a predetermined path-loss factor in the environment, where a given pair of RSS values includes the largest RSS value and one of the two RSS values. Furthermore, the computer determines the location of the electronic device in the environment based on the pairwise distance estimates.