Abstract: A system of evaluating automatic message accounting records associated with telephony calls is disclosed. The system includes correlation logic to collect originating AMA records having an originating call code to identify a record of an originating long distance call and further to collect terminating AMA records that correspond to the collected originating automatic message accounting records. The system also includes evaluation logic to determine when a call may be by-passing terminating access charges by identifying calls that have been correlated with an originating AMA record having the originating code and with a terminating AMA record having a local termination code.

Abstract: A method of evaluating automatic message accounting records associated with telephony calls that originate at a local exchange carrier telephony office and that are routed over an inter-exchange carrier telephony facility is disclosed. The method comprises collecting originating automatic message accounting records associated with the originating local exchange carrier telephony office, and collecting terminating automatic message accounting records that correspond to the originating automatic message accounting records. A first portion of the terminating automatic message accounting records have a terminating access code and a second portion of the terminating automatic message accounting records have a local termination code.

Abstract: A lightweight, free-standing, expandable shelter (10) providing protection against chemical and biological agents and against nuclear fallout. The shelter (10) has a frame comprising a series of U-shaped ribs (12) spaced and held parallel by a series of reinforcing members (16) connecting each adjacent pair of ribs (12) on each side of the shelter (10). A cover (11) made of flexible material which is resistant to chemical and biological agents is attached to the frame. An airtight floor (18) is attached to the cover material (11) so that the shelter (10) can be pressurized to a pressure of about one inch water gauge above ambient pressure, to prevent reverse air flow of contaminated air into the shelter (10). A blower (20) for pressurizing the shelter (10) and a filter (22) capable of filtering out chemical and biological agents are connected to the shelter (10).

Abstract: A snap slit door having at least one panel and a flat closure means used to reate tension in the door panel or panels, such tension acting as the closure force generated by the closure means for the door panel or panels. The flat closure means may be adjustable such that the tension and resulting resistance to opening is variable. Said door panel or panels may be of any pliable material to enable use of the panel or panels without hinges, and further to render the flat closure means operational. The panel or panels may be held in the closed position by any means which will self-release upon the exertion of a requisite pressure differential between the inside and outside of the panel or panels, effectively relieving the pressure differential. One such effective self-releasing closure means is a hook and pile patch arrangement.

Abstract: A gas particulate filter system is provided for supplying clean heated air o an operator subjected to ambient environments containing nuclear, biological or chemical contaminants. The filter unit includes replaceable radial flow canister means, centrifugal blower/heater means, continuously variable electronic control means for regulating air temperature and air flow, and clamping means for easy assembly of the components under adverse field conditions.