Showing papers in "IEEE Transactions on Systems, Man, and Cybernetics in 1977"

Fuzzy logic controller for a traffic junction

Abstract: The system is a traffic junction and the problem of its control is considered as a classical example of nonprogrammed decisionmaking, i.e. , decisionmaking characterized by the lack of well-specified analytical means for coping with a particular problem. Thus a linguistic control algorithm is synthesized, capable of dealing with a continuously reproduced decisionmaking situation. The starting point is an adequate (though qualitative) knowledge of the system and a protocol of control instructions used by a human operator. A fuzzy set theoretic representation of these instructions which we call "a fuzzy logic controller" was tried as an answer to the control modeling problem, which gave very satisfactory results. The work done on the construction of the model of the system and the implementation of the fuzzy logic controller is presented.

Fourier Analysis of Time Series: An Introduction

Abstract: Fitting Sinusoids. The Search for Periodicity. Harmonic Analysis. The Fast Fourier Transform. Examples of Harmonic Analysis. Complex Demodulation. The Spectrum. Some Stationary Time Series Theory. Analysis of Multiple Series. Further Topics. References. Indexes.

Histogram modification for threshold selection

Abstract: : A standard approach to threshold selection for image segmentation is based on locating valleys in the image's gray level histogram. Several methods have been proposed that produce a transformed histogram in which the valley is deeper, or is converted into a peak, and is thus easier to detect. The transformed histograms used in these methods can all be obtained by creating (gray level, edge value) scatter plots, and computing various weighted projections of these plots on the gray level axis. Using this unified approach makes it easier to understand how the methods work and to predict when a particular method is likely to be effective. The methods are applied to a set of examples involving both real and synthetic images, and the characteristics of the resulting transformed histograms are discussed. (Author)

A Note on the Use of Second-Order Gray Level Statistics for Threshold Selection.

Abstract: : The gray level histogram of an image is commonly used as an aid in selecting thresholds for segmenting the image Various methods have been proposed to make threshold selection easier This note describes a class of such methods that make use of second-order gray level statistics to define improved histograms (Author)

Iterative Histogram Modification, 2

Abstract: : Histogram peaks can be sharpened using an iterative process in which large bins grow at the expense of nearby smaller bins. The modified histogram will consist of a few spikes corresponding to the peaks of the original histogram. The image corresponding to the modified histogram is often almost undestinguishable from the original image. The small number of different gray levels in that image can be used to facilitate compressing or segmenting it.

Sensor Transformations

Abstract: The problem of matching two images of the same scene taken by different sensors under different viewing geometries is a challenging problem in the field of computer applications to image processing and pattern recognition. The scenes are usually transformed so drastically by the different viewing geometries and sensor characteristics that it is extremely difficult, if not impossible, to match the original images without the proper data processing. Geometric transformation must be performed on the images to bring the matching elements into one-to-one correspondence. Because of the difference in operating conditions and sensor characteristics, images of the same object taken by two different sensors have different intensity values. A new intensity matching technique based on the Karhunen-Loeve transformation was developed to match the intensity values of one image to those of the other as closely as possible through the use of a digital computer.

Fuzzy Maps

Abstract: A graphical scheme (map) for representation and manipulation of fuzzy switching functions is described. Properties of the map and relationships between represented implicants are discussed. Emphasis is placed on illustrations of the use of the map in manipulation and minimization of fuzzy switching functions.

Decision Spaces

Abstract: In many decisionmaking situations a fundamental question to be answered is, "At what point do I stop looking for additional alternatives and make a decision based on those I have seen so far?" While not all decisionmaking situations pose this problem, there is a class of decisions where one must worry about when to stop looking and begin deciding. This occurs when the nunmber of alternatives available for potential consideration is virtually unlimited and the number currently on hand for evaluation and decisionmaking is comparatively small. Moreover, little is known about how the alternatives on hand stack up against those "out there somewhere" still waiting to be discovered. The central issue is the lack of a context for figuring out when to stop looking and begin deciding, and the central idea is to be able to provide such a context. Two technologies exist that can do just that when combined: multiattribute utility measurement and Monte Carlo simulation. Such a context, called a decision space, can help answer questions about whether or not costly, time-consuming searches for better alternatives are likely to pay off. This paper discusses decision spaces in general, gives one operational example of how to produce them, and then applies the example to illustrate their use.

Modeling the effect of atmospheric carbon dioxide on the global radiative heat balance

Abstract: Because of fossil fuel combustion, the amount of atmospheric carbon dioxide is increasing, and thereby raising the earth's average temperature through the greenhouse effect. Results of a radiative heat balance simulation of the future dynamic behavior of the average global temperature are reported. Based on projected fuel usage patterns, a 6..cap alpha..K temperature rise within the next 200 years is forecast. Such a temperature rise would be significant and would add weight to the theory that fossil fuel combustion will change climate. (2 graphs, 13 references)