Abstract: Unauthorized entry into controlled access areas using tailgating or reverse entry methods is detected using machine vision methods. Camera images of the controlled area are processed to identify and track objects in the controlled area. In a preferred embodiment, this processing includes 3D surface analysis to distinguish and classify objects in the field of view. Feature extraction, color analysis, and pattern recognition may also be used for identification and tracking of objects. Integration with security monitoring and control systems provides notification when a tailgating or reverse entry event has occurred. More reliable operation in practical circumstances is thus obtained, such as when multiple people are using an entrance or exit under variable light and shadow conditions. Electronic access control systems may further be combined with the machine vision methods of the invention to more effectively prevent tailgating or reverse entry.

Abstract: Unauthorized entry into controlled access areas using tailgating or reverse entry methods is detected using machine vision methods. Camera images of the controlled area are processed to identify and track objects in the controlled area. In a preferred embodiment, this processing includes 3D surface analysis to distinguish and classify objects in the field of view. Feature extraction, color analysis, and pattern recognition may also be used for identification and tracking of objects. Integration with security monitoring and control systems provides notification when a tailgating or reverse entry event has occurred. More reliable operation in practical circumstances is thus obtained, such as when multiple people are using an entrance or exit under variable light and shadow conditions. Electronic access control systems may further be combined with the machine vision methods of the invention to more effectively prevent tailgating or reverse entry.

Abstract: Unauthorized entry into controlled access areas using tailgating or reverse entry methods is detected using machine vision methods. Camera images of the controlled area are processed to identify and track objects in the controlled area. In a preferred embodiment, this processing includes 3D surface analysis to distinguish and classify objects in the field of view. Feature extraction, color analysis, and pattern recognition may also be used for identification and tracking of objects. Integration with security monitoring and control systems provides notification when a tailgating or reverse entry event has occurred. More reliable operation in practical circumstances is thus obtained, such as when multiple people are using an entrance or exit under variable light and shadow conditions. Electronic access control systems may further be combined with the machine vision methods of the invention to more effectively prevent tailgating or reverse entry.

Abstract: A packing for sealing between a valve stem 31 and valve bonnet 21 which receives the valve stem in a bore 34 formed therein. The packing is accommodated in a packing chamber 41 formed in the valve stem bore 34 which comprises a lower set of packing rings 51 in stacked coaxial relation about the valve stem and a second upper set of packing rings 55 similarly arranged in the upper portion of the packing chamber. A spring means 61, 62, 63 comprising at least one frusto-conical washer is interposed in the packing chamber 41 between the sets of packing rings for axial compression of the upper and lower sets of packing rings to thereby urge the radial expansion of the packing rings and provide an enhanced and substantially uniform sealing effectiveness of the packing rings.

Abstract: A fire-resistant valve 10 with a valve stem 40 mounted for linear motion through a valve stem bore 41 in the valve body 12 and connected to a valve element 20 by a connection means which effects movement of the valve element 20 between its valve open and its valve closed positions in response to axial linear motion of the valve stem 40. The valve includes a valve stem actuator 46 and a valve stem seal assembly comprising a primary seal in the form of an axially extensible and compressible metallic bellows 50 disposed in sleeved relation to the valve stem 40. The bellows is connected at one end by an annular weld 41 to the valve stem and at its other end by an annular weld 52 to the valve body in encircling relation to the valve stem and valve stem bore so as to effect a fluid-tight, gas-tight seal therebetween. A packing structure mounted in the annulus between the valve stem and wall of the valve stem bore provides a secondary valve stem seal.

Abstract: A segmented ball valve has a rotatably mounted segmented ball valve element positioned to rotate eccentrically in a valve body with respect to three valve body sealing elements about the sealing opening for the valve body. The sealing elements include a compression seal of a flexible sealing element operative at one angular closure position of the ball valve element, a metal-to-metal seal with a flexible metal element operative in a second angular closure position and a metal-to-metal compression seal operative in a third angular closure position.