Showing papers on "Change detection published in 1987"

The asymptotic local approach to change detection and model validation

Abstract: We present a systematic approach for the design of change detection and model validation algorithms for dynamical systems. We show how to associate to any identification algorithm a change detection and a model validation procedure, which are optimal in some asymptotic sense. The foundations of our method go back to the asymptotic local approach in statistics, and our method generalizes this approach.

Inland wetland change detection using aircraft MSS data

Abstract: Effet de decharges d'eau provenant d'un reacteur nucleaire sur l'evolution d'une foret ripariale en Caroline du Sud

Sequential method of change detection and adaptive prediction of municipal water demand

Abstract: An on-line recursive prediction algorithm for peak hourly flow rates of municipal water demands is presented. A simple state space model, which can be identified by using only the past hourly water flow rates time series, is proposed. Prediction accuracies are enhanced by means of sequential changes, detection/acceptance decision rules and an adaptive filter, which revises the gain of the prediction algorithm to respond to the most recent process changes. A simulation test of the algorithm, using real historical water demand data from the city of Columbus, demonstrates the validity of the proposed algorithm.

Knowledge-based real-time change detection, target image tracking & threat assessment

Abstract: This paper describes the overall hardware and software architecture of a knowledge-based change detection, target tracking and threat assessment system. It ultimately assigns threat level and threat scenario labels to the observed scene, based on time dependent target features or changes in the scene, as well as target maneuvers and target number. The aims are: reduced scene interpretation workload, shorter reaction time, reduced false-alarm rates, and simple adaptation to changing fields of view/sensors.

Transient change tracking type digital filter

Abstract: PURPOSE:To improve the tracking performance of an output signal with respect to an input signal by providing a transient change detection detecting a transient change from the difference between an input signal and an output signal of a digital filter and providing a filter processing section so as to give the smoothing performance at the steady-state of the input signal and so as to change sequentially the time constant of the digital filter. CONSTITUTION:An interface, A/D converter or a D/A converter is used for an input section 1 and an output section 4 depending whether an external signal is a digital signal or an analog signal. A transient change detection section 2 obtains the absolute value D of the difference between an input signal Xi to a filter processing section 3 from the input section 1 and an output signal Yi from the filter processing section 3 to the output section 4, and when the value D exceeds a reference value D0, it is discriminated as the occurrence of a transient change and a signal informing the detection of transient change is inputted to the filter processing section 3. As the reference value D0, a value being n-time of the standard deviation of the input signal Xi, for example, is used, where (n) is a value decided by which of the smoothing and the tracking performance to be emphasized. The filter processing section 3 changes sequentially the time constant K to improve the tracking performance when a signal of transient change detection comes from the transient change detection section 2.

Clock switching circuit

Abstract: PURPOSE:To perform a clock switching without noise, by switching the first clock, and the second clock, by the second change point detection signal obtained from the first change point detection signal, and the second clock, after obtaining the first change point detection signal from the first clock, and a clock switching signal. CONSTITUTION:The titled circuit is formed by a change point de tecting means 6 which obtains the second change point detection signal by detecting the change point of the second clock from the first change point detection signal, and the second clock, after obtaining the first change point detection signal by detecting the change point of the first clock from the first clock, and the clock switching signal out of inputted first clock, second clock, and clock switching signal, and a switching means 5 which switches the first clock, and the second clock by the second change point detection signal from the change point detecting means. And by driving the switching means 5 by the second change point detection signal, and switching the first clock, and the second clock, the clock switching without noise can be performed.

Land cover classification of landsat thematic mapper images using pseudo invariant feature normalization applied to change detection

Abstract: A radiometric normalization technique for compensating illumination and atmospheric differences between multi-temporal images should allow classification of the images with a single classification algorithm. This allows a simpler approach to land cover change detection. Land cover classification of Landsat Thematic Mapper Imagery with and without Pseudo Invariant Feature Normalization was performed to demonstrate the effect on classification and change detection accuracy. A post-classification change detection method using two separate classification algorithms, one for each date, was performed as a baseline comparison. Land cover classification using one classification algorithm was attempted with and without gain and offset correction to serve as another comparison. Accuracy verification was performed on the classification results by comparing random samples against ground truth.

Model-based building verification in aerial photographs

Abstract: : This paper concerns the design of a computer vision system for change detection. Here, change detection is defined as figuring out the differences between an object model and the newly sensed image. The target objects are confined to the cultural features, such as roads and buildings. We divide the task into two modules: model verification and image interpretation. In this report, the verification stage will be discussed in detail. In general there exists a lot of domain specific heuristics to judge the status of changes. For example, to verify the existence of a building, we can check its shape, size, height, surface direction, and surface material, etc. The expert system approach is a natural approach which can code all information together. while different photo interpreters and field specialists may have different viewpoints about the status of an object, expert systems can be modified easily to reflect a particular one's viewpoint.

Line state supervising equipment

Abstract: PURPOSE:To reduce ineffective processing time while making the processing capability of a controller independent of the number of bits by allowing a host controller to read a line state change holding circuit periodically, supervising change detection information subjected to bit multiplexing and reading the line state of a line whose change detection information corresponds to the bit. CONSTITUTION:A line state display signal extraction circuit 10 extracts a line state display signal of a present period from an input signal fed to an input terminal 1 and gives the display signal to a line state holding circuit 20 and a line state change detection circuit 30. The line state holding circuit 20 holds the line state display signal for one period and outputs the signal to the line state change detection circuit 30 as a line state display signal of the preceding period at the next period. The line state change detection circuit 30 compares the line state display signals between the present period and the preceding period to detect the change in the line state nd outputs change detection information to a line state change detection holding circuit 40 at the detection change. The line state change detection holding circuit 40 at the detection change. The line state change detection holding circuit 40 holds the change detection information as a change detection flag and when a read command is received from an input terminal 2a, and the change detection flag information corresponding to the read command information is outputted to an output terminal 2b.