Showing papers on "Object detection published in 1978"

A 3-D Iterative Reconstruction Method for Stationary Planar Positron Cameras

Abstract: Positron cameras using two opposed area detectors for the coincidence detection of 511 keV annihilation photons have been available for some time. Image reconstruction from the collected annihilation data in this camera configuration is usually based on focal plane tomography. However, this method suffers from structured background existing in the images from the contribution of offfocal plane activity, resulting in low contrast, poorly resolved images. This paper presents a method which reduces this off-focal plane background through an iterative approach which weights individual picture elements according to the activity computed by the previous iteration.

On the detection of target trajectories in a multi target environment

Abstract: The tracking and ultimate identification of closely spaced objects is an area of interest to many surveillance systems. Much effort in recent years has been concentrated on the more "front-end" problem of optimizing the initial detection. However, the sorting and processing of crossing tracks and parallel tracks is a problem regardless of signal to noise ratio. In this paper, the application of a pattern recognition approach is investigated. A simulated track scenario is developed and the approach evaluated using the scenario. Examples of performance and results of the simulation study are given.

Moving object detection system

Abstract: This invention relates to a detection system for detecting presence of moving objects such as vehicles, etc through utilization of ultrasonic energy which includes a predetermined location provided in memory unit and having stored therein time from transmission of ultrasonic energy till reception of reflected energy corresponding thereto from a road surface, circuitry for computing difference a between immediately preceding time from transmission of ultrasonic energy till reception of reflected energy corresponding thereto stored in the predetermined memory location and current time from transmission of ultrasonic energy and reception of reflected energy corresponding thereto, circuitry for storing in the predetermined memory location the current time from transmission of ultrasonic energy till reception of reflected energy corresponding thereto when the difference a is less than a predetermined time α, and circuitry for outputting vehicle detection signal when the difference a is larger than a preset time β which is larger than the time α

Magnetic object detection device

Abstract: A variable permeability magnetic object detection device including an electromagnetic sensing coil; a core disposed in the electromagnetic sensing coil having a first permeability when the core is magnetically saturated and a second different permeability when the core is magnetically unsaturated; a magnetic member proximate the electromagnetic sensing coil for providing a magnetic field in the core for operating the core in a magnetically saturated state without a magnetic object to be detected present in the area proximate the electromagnetic sensing coil, interacting with the magnetic field, and for operating the core in a magnetically unsaturated state with the magnetic object to be detected present in the area proximate the magnetic sensing coil, interacting with the field; and a detector responsive to said electromagnetic sensing coil to detect the presence of a magnetic object.

Microprocessor control system for object detection

Abstract: PURPOSE:To secure a transfer of the setting data even though the power source is cut off and thus to ensure a smooth control, by having a control through the micropropocessor with every projection period of the ultrasonic wave based on the setting data transfer from the setting unit to the memory.