Abstract: A Mid-Wave Infrared (MWIR) objective lens having an F # of 2.64 and a 33.6° angular field of view. It is deployed, with a focal plane and scanning system, on an airborne platform for remote sensing applications. Focal length is 9 inches, and the image is formed on a focal plane constituting CCD or CMOS with micro lenses. The lens has, from object to image, three optical element groups with a cold shield/aperture stop. Group 1 has a positive optical power and three optical elements; Group 2 has a positive optical power and four optical elements; Group 3 has a positive optical power and three optical elements. The objective lens is made of two Germanium and Silicon. The lens is both apochromatic and orthoscopic, and corrected for monochromatic and chromatic aberrations over 3.3 to 5.1 micrometers.

Abstract: A Mid-Wave Infrared (MWIR) objective lens having an F # of 2.64 and a 33.6° angular field of view. It is deployed, with a focal plane and scanning system, on an airborne platform for remote sensing applications. Focal length is 9 inches, and the image is formed on a focal plane constituting CCD or CMOS with micro lenses. The lens has, from object to image, three optical element groups with a cold shield/aperture stop. Group 1 has a positive optical power and three optical elements; Group 2 has a positive optical power and four optical elements; Group 3 has a positive optical power and three optical elements. The objective lens is made of two Germanium and Silicon. The lens is both apochromatic and orthoscopic, and corrected for monochromatic and chromatic aberrations over 3.3 to 5.1 micrometers.

Abstract: An orthoscopic, apochromatic lens is suitable for deployment such as on aerial platforms provides distortion less than 0.2% over a full field of view of more than 60° with F # less than 6.5 and focal length greater than 3?, and in embodiments greater than 5?. Embodiments are apochromatic from 500 to 950 nm to within 7 microns. Embodiments have an overall length of less than 7?. The lens includes five optical groups with an aperture stop between the second and third groups. The optical groups have one, one, two, one and one optical element each, as ordered from the object to the image plane, and have positive, negative, positive, positive, and negative optical powers, respectively. Embodiments are telephoto. In embodiments the focal length is temperature invariant within 0.0015 inches from 0° C. to 40° C.

Abstract: An orthoscopic, apochromatic lens is suitable for deployment such as on aerial platforms provides distortion less than 0.2% over a full field of view of more than 60° with F# less than 6.5 and focal length greater than 3?, and in embodiments greater than 5?. Embodiments are apochromatic from 500 to 950 nm to within 7 microns. Embodiments have an overall length of less than 7?. The lens includes five optical groups with an aperture stop between the second and third groups. The optical groups have one, one, two, one and one optical element each, as ordered from the object to the image plane, and have positive, negative, positive, positive, and negative optical powers, respectively. Embodiments are telephoto. In embodiments the focal length is temperature invariant within 0.0015 inches from 0° C. to 40° C.

Abstract: A computer implemented system and method is used to identify groups of entities based on bipartite directed graphs. Each group consists of two sets of entities, which have some association between each other. Two parameters, typicality and coverage, are taken into account in the computation for identifying the groups.

Abstract: A computer implemented system and method is used to identify groups of entities based on bipartite directed graphs. Each group consists of two sets of entities, which have some association between each other. Two parameters, typicality and coverage, are taken into account in the computation for identifying the groups.

Abstract: A drive for driving a displacer in a cryogenic refrigerator includes a rotatable cam having a cam surface. The cam is rotatable about a pivot point with a cam follower contacting the cam surface. Rotational motion of the cam is converted into reciprocating motion of the cam follower. A displacer rod is coupled between the cam follower and the displacer for transferring the reciprocating motion of the cam follower to the displacer for driving the displacer.