Abstract:
A multistage interconnect network (MIN) capable of supporting massive parallel processing, including point-to-point and multicast communications between processor modules (PMs) which are connected to the input and output ports of the network. The network is built using interconnected switch nodes arranged in 2 log.sub.b N stages, wherein b is the number of switch node input/output ports, N is the number of network input/output ports and log.sub.b N indicates a ceiling function providing the smallest integer not less than log.sub.b N. The additional stages provide additional paths between network input ports and network output ports, thereby enhancing fault tolerance and lessening contention.
Abstract:
The intensity 2 of radiation coming from an object 1 to be measured and illuminated by collimated radiation is measured at several wavelengths by focusing the radiation, via a lens 4 and a planar mirror 6, on a detector group 3 having several detector elements (3a to 3d). The radiation coming from the object is directed by the lens and the mirror such that, by rotating the mirror, tilted at a small angle with respect to its axis 5, around this axis and by keeping the radiation on the surface of the mirror, the focus F of radiation is moved in a detector plane D along an uninterrupted circular path R crossing each detector element positioned substantially in the same plane and excited at a different wavelength.
Abstract:
A multi-slit type spectrometer includes a diffractor by which an incident light is diffracted according to wavelengths; an optical shutter array member including a plurality of optical shutter elements arranged in correspondence with wavelength bands diffracted by the diffractor, operable to transmit an incident ray according to an applied voltage, and made of PLZT. Each optical shutter element is applied with a voltage corresponding to the band of the ray incident upon the optical shutter element at a specified timing so that the ray passes through the optical shutter element. The spectrometer further includes a photosensor to convert the ray passed through the optical shutter element to an electrical signal, and a calculator to calculate the intensity of the incident ray for each band in accordance with the electrical signal output from the photosensor and the specified applying timing.
Abstract:
A multistage interconnect network (MIN) capable of supporting massive parallel processing, including point-to-point and multicast communications between processor modules (PMs) which are connected to the input and output ports of the network. The network is built using interconnected switch nodes arranged in 2 log.sub.b N stages, wherein b is the number of switch node input/output ports, N is the number of network input/output ports and log.sub.b N indicates a ceiling function providing the smallest integer not less than log.sub.b N. The additional stages provide additional paths between network input ports and network output ports, thereby enhancing fault tolerance and lessening contention.
Abstract:
A spectrophotometer useful for measuring absorption or emission bands of a substance irradiated with optical radiation, comprises a light source for producing the optical radiation, a monochromator for isolating light of wavelength (W) from the optical radiation and which modulates the wavelength (W) by a predetermined wavelength amplitude (.delta.W), and a photodetector for detecting the intensity of light passing through the monochromator and for producing a measuring signal in response thereto. The monochromator operates under the control of an electronic control unit which produces a control signal that causes the monochromator to scan across a portion of the spectrum of the optical radiation at a frequency (f.sub.2) to transmit a narrow band of radiation at the wavelength (W). The control unit includes a modulation generator which produces a signal that causes the monochromator to modulate the wavelength (W) by the predetermined wavelength amplitude (.delta.W) at a frequency (f.sub.1). The spectrophotometer also includes an electronic evaluation unit which amplifies an a.c. component of the measuring signal that is attributable to the wavelength modulation in synchronization with the signal produced by the modulation generator. In one preferred embodiment, the monochromator comprises a diffraction grating and a drive unit which causes the diffraction to rotate about a pivot axis and which superimposes an oscillatory motion on the rotational movement. In another preferred embodiment, the monochromator comprises a Fabry-Perot resonator and a drive unit which adjusts the optical length of the Fabry-Perot resonator under the control of the control unit.
Abstract:
A multichannel imaging spectrometer for low speed, low altitude airborne geological, geophysical and environmental surveys, particularly adapted to provide detector limited noise threshold. An optical scanner employs a rotating polygon allowing reduced scan optics with increased data acquisition efficiency. Scan speeds from 5 to 50 scan/sec with up to 2048 pixels per scan are available. Multiple spectrometers integrally registered allow channelization of the received signal to optimize noise performance in the range from ultraviolet through infrared. Output data is in a form for recording and real time display. All channels are acquired simultaneously resulting in perfect band-to-band registration with continuous spectral curves for each pixel.
Abstract:
A calibration method and apparatus for economical and rapid calibration of a scientific instrument utilizing a monochromator to generate monochromatic light utilizing controllable means for determining the angular position of a light dispersing element in the monochromator and a filter having a narrow absorption band(s) to determine a relationship between the wavelength of the monochromatic light generated by the monochromator and an angular position of the dispersing element so that the dispersing element can be rotated to an exact position for the monochromator to generate a selected wavelength of monochromatic light.
Abstract:
A dispersion-type spectral element designed for reflecting an incident sample light is rotated by a drive mechaism. The sample light reflected by the element is applied to a sample-light receiving device. The device converts the light into a first signal representing the intensity of the sample light. Reference light consisting of beams having various wavelengths over a broad range is supplied from a reference light source to the spectral element. Further, standard light consisting of one beam of a known wavelength is also supplied from a standard light source to the spectral element. The reference light reflected by the element is applied to a reference-light receiving device. The reference-light receiving device converts the reference light into a second signal representing the intensity of the light. An etalon is located in the optical path between the spectral element and the reference-light receiving device. The standard light reflected by the element is applied to the standard-light receiving device. The standard-light receiving device converts the standard light into a third signal representing the intensity of the standard light. An arithmetic unit receives the first, second, and third signals separately, and obtains from the second and third signals a wavelength scale used for calculating from the first signal the wavelength of the sample light.
Abstract:
In quantitative analysis of a sample by using the spectrum thereof by means of a spectrophotometer, at a specific wavelength or in a specific wavelength range where a quantitative determination is to be conducted, wavelength scanning is temporarily stopped or its speed is slowed down so as to obtain spectral data from the sample, so that the accuracy of the data obtained is improved. In the wavelength range where no quantitative determination is to be conducted, the scanning operation is conducted at an ordinary relatively fast speed, so that the total time required for the analysis will not be lengthened.
Abstract:
To provide sufficient sensitivity, spectral resolution and speed of measurement for field environmental measurements in a portable spectroradiometer, a silicon photodiode receives light: (1) having a bandwidth in the range of between 2 and 15 nm (nanometers) from a pivotable concave holographic diffraction grating within the wavelength range of between 250 and 1150 nm at a scanning rate in the range of 20 to 100 nm per second; (2) having stray light of high intensity and undesired frequencies and the shorter wavelength harmonics of the selected frequency range blocked by filters; and (3) having flux of at least 10 microwatts per square meter of diffuser plate for each nanometer of bandwidth. Automatic electrical zeroing is obtained by blocking all light once at the beginning of each scan, obtaining an electrical drift-related signal and using the drift signal to adjust the measured signal during the scan. Several different sensing interfaces can be used, including a quartz, light fiber probe having at least a 50% packing density and a cone angle of at least 24 degrees. The data and the programming storage is at least 30K bytes but the instrument uses no more than watts of power when the instrument is not scanning.