Open Access. Powered by Scholars. Published by Universities.^{®}

Articles **1** - **30** of ** 41**

## Full-Text Articles in Computer Engineering

Aerospace Applications Of Soft Computing And Interval Computations (With An Emphasis On Multi-Spectral Satellite Imaging), Scott A. Starks, Vladik Kreinovich

#### Aerospace Applications Of Soft Computing And Interval Computations (With An Emphasis On Multi-Spectral Satellite Imaging), Scott A. Starks, Vladik Kreinovich

*Departmental Technical Reports (CS)*

This paper presents a brief overview of our research in applications of soft computing and interval computations to aerospace problems, with a special emphasis on multi-spectralsatellite imaging.

Intervals (Pairs Of Fuzzy Values), Triples, Etc.: Can We Thus Get An Arbitrary Ordering?, Vladik Kreinovich, Masao Mukaidono

#### Intervals (Pairs Of Fuzzy Values), Triples, Etc.: Can We Thus Get An Arbitrary Ordering?, Vladik Kreinovich, Masao Mukaidono

*Departmental Technical Reports (CS)*

Traditional fuzzy logic uses real numbers as truth values. This description is not always adequate, so in interval-valued fuzzy logic, we use pairs (t-,t+) of real numbers, t-<=t+, to describe a truth value. To make this description even more adequate, instead of using real numbers to described each value t- and t+, we can use intervals, and thus get fuzzy values which can be described by 4 real numbers each. We can iterate this procedure again and again. The question is: can we get an arbitrary partially ordered set in this manner? An arbitrary lattice? In this paper, we show that although we cannot thus generate arbitrary lattices, we can actually generate an arbitrary partially ordered set in this manner. In this sense, the "intervalization" operation is indeed universal.

Extracting Fuzzy Sparse Rule Base By Cartesian Representation And Clustering, Yeung Yam, Vladik Kreinovich, Hung T. Nguyen

#### Extracting Fuzzy Sparse Rule Base By Cartesian Representation And Clustering, Yeung Yam, Vladik Kreinovich, Hung T. Nguyen

*Departmental Technical Reports (CS)*

Sparse rule base and interpolation have been proposed as possible solution to alleviate the geometric complexity problem of large fuzzy set. However, no formal method to extract sparse rule base is yet available. This paper combines the recently introduced Cartesian representation of membership functions and a mountain method-based clustering technique for extraction. A case study is included to demonstrate the effectiveness of the approach.

For Interval Computations, If Absolute-Accuracy Optimization Is Np-Hard, Then So Is Relative-Accuracy Optimization, Vladik Kreinovich

#### For Interval Computations, If Absolute-Accuracy Optimization Is Np-Hard, Then So Is Relative-Accuracy Optimization, Vladik Kreinovich

*Departmental Technical Reports (CS)*

One of the basic problems of interval computations is to compute a range of a given function f(x1,...,xn) over a given box (i.e., to compute the maximum and the minimum of the function on the box). For many classes of functions (e.g., for quadratic functions) this problem is NP-hard; it is even NP-hard if instead of computing the minimum and maximum exactly, we want to compute them with a given (absolute) accuracy. In practical situations, it is more realistic to ask for a relative accuracy; are the corresponding problems still NP-hard? We show that under some ...

Geombinatoric Aspects Of Processing Large Images And Large Spatial Databases, Jan Beck, Vladik Kreinovich, Brian Penn

#### Geombinatoric Aspects Of Processing Large Images And Large Spatial Databases, Jan Beck, Vladik Kreinovich, Brian Penn

*Departmental Technical Reports (CS)*

Computer processing can drastically improve the quality of an image and the reliability and accuracy of a spatial database. A large image (database) does not easily fit into the computer memory, so we process it by downloading pieces of the image. Each downloading takes a lot of time, so, to speed up the entire processing, we must use as few pieces as possible.

Many algorithms for processing images and spatial databases consist of comparing the value at a certain spatial location with values at nearby locations. For such algorithms, we must select (possibly overlapping) sub-images in such a way that ...

An Optimal Fft-Based Algorithm For Mosaicking Images, With Applications To Satellite Imaging And Web Search, Stephen Gibson, Olga Kosheleva, Luc Longpre, Brian Penn, Scott A. Starks

#### An Optimal Fft-Based Algorithm For Mosaicking Images, With Applications To Satellite Imaging And Web Search, Stephen Gibson, Olga Kosheleva, Luc Longpre, Brian Penn, Scott A. Starks

*Departmental Technical Reports (CS)*

Digital data storage is becoming ever more abundant and cheap. This, along with other technological advances, has brought about an age of mass storage of information, much of it in the form of images. In order to be able to process these stockpiles of image data, new and faster computer algorithms are needed.

One area of interest is that of image mosaicking, i.e., comparing two overlapping images and finding the proper scaling, angle of rotation, and translation needed to fit one with the other. Early methods for mosaicking images included visual inspection or exhaustive, pixel by pixel, search for ...

Towards Mathematical Foundations Of Information Retrieval: Dependence Of Website's Relevance On The Number Of Occurrences Of A Queried Word, Laszlo Koczy, Vladik Kreinovich, Yohanz Mendoza, Hung T. Nguyen, Harry Schulte

#### Towards Mathematical Foundations Of Information Retrieval: Dependence Of Website's Relevance On The Number Of Occurrences Of A Queried Word, Laszlo Koczy, Vladik Kreinovich, Yohanz Mendoza, Hung T. Nguyen, Harry Schulte

*Departmental Technical Reports (CS)*

In response to a query, web search tools often return many websites which are not really relevant. One reason for this is that the queried word may have several meanings different to the one which the user has in mind. To eliminate these undesirable meanings, it is reasonable to look for occurrences not only of the queried word itself, but also for other words related to this particular meaning, and then select only the websites for which, based on this information, we are confident about their relevance. For this strategy to work, we must be able to estimate the degree ...

Interval Methods In Non-Destructive Testing Of Material Structures, Keith Worden, Roberto A. Osegueda, Carlos M. Ferregut, Soheil Nazarian, Debra L. George, Mary J. George, Vladik Kreinovich, Olga Kosheleva, Sergio Cabrera

#### Interval Methods In Non-Destructive Testing Of Material Structures, Keith Worden, Roberto A. Osegueda, Carlos M. Ferregut, Soheil Nazarian, Debra L. George, Mary J. George, Vladik Kreinovich, Olga Kosheleva, Sergio Cabrera

*Departmental Technical Reports (CS)*

In many practical situations, e.g., in aerospace applications and in mammography, it is important to test the structural integrity of material structures. We show that interval methods can help.

From Fuzzy Values To Intuitionistic Fuzzy Values To Intuitionistic Fuzzy Intervals Etc.: Can We Get An Arbitrary Ordering?, Vladik Kreinovich, Masao Mukaidono, Krassimir Atanassov

#### From Fuzzy Values To Intuitionistic Fuzzy Values To Intuitionistic Fuzzy Intervals Etc.: Can We Get An Arbitrary Ordering?, Vladik Kreinovich, Masao Mukaidono, Krassimir Atanassov

*Departmental Technical Reports (CS)*

Traditional fuzzy logic uses real numbers as truth values. This description is not always adequate, so in intuitionistic fuzzy logic, we use pairs of real numbers to describe a truth value. Such pairs can be described either as pairs (t,f) for which t+f<=1, or, alternatively, as pairs (t,1-f) for which t<=1-f. To make this description even more adequate, instead of using real numbers to described each value t and f, we can use intervals, and thus get interval-valued intuitionistic fuzzy values which can be described by 4 real numbers each. We can iterate this procedure again and again. The question is: can we get an arbitrary partially ordered set in this manner? An arbitrary lattice? In this paper, we show that although we cannot thus generate arbitrary lattices, we can actually generate an arbitrary partially ordered set in this manner. In this sense, the "intervalization" operation which underlies the notion of an intuitionistic fuzzy set, is indeed universal.

Candidate Sets For Complex Interval Arithmetic, Juergen Wolff Von Gundenberg, Vladik Kreinovich

#### Candidate Sets For Complex Interval Arithmetic, Juergen Wolff Von Gundenberg, Vladik Kreinovich

*Departmental Technical Reports (CS)*

Uncertainty of measuring complex-valued physical quantities can be described by complex sets. These sets can have complicated shapes, so we would like to find a good approximating family of sets. Which approximating family is the best? We reduce the corresponding optimization problem to a geometric one: namely, we prove that, under some reasonable conditions, an optimal family must be shift-, rotation- and scale-invariant. We then use this geometric reduction to conclude that the best approximating low-dimensional families consist of sets with linear or circular boundaries. This result is consistent with the fact that such sets have indeed been successful in ...

A Geometric Approach To Classification Of Trash In Ginned Cotton, Murali Siddaiah, Michael A. Lieberman, Nadipuram R. Prasad, Vladik Kreinovich

#### A Geometric Approach To Classification Of Trash In Ginned Cotton, Murali Siddaiah, Michael A. Lieberman, Nadipuram R. Prasad, Vladik Kreinovich

*Departmental Technical Reports (CS)*

This paper discusses the use of geometric approach to classify different types of trash (non-lint, non-fiber material) in ginned cotton. Pieces of trash can have complicated shapes, so we would like to find a good approximating family of sets. Which approximating family is the best? We reduce the corresponding optimization problem to a geometric one: namely, we show that, under some reasonable conditions, an optimal family must be shift-, rotation- and scale-invariant. We then use this geometric reduction to conclude that the best approximating low-dimensional families consist of sets with linear or circular boundaries.

This result is in good agreement ...

On Combining Statistical And Fuzzy Techniques: Detection Of Business Cycles From Uncertain Data, Hung T. Nguyen, Berlin Wu, Vladik Kreinovich

#### On Combining Statistical And Fuzzy Techniques: Detection Of Business Cycles From Uncertain Data, Hung T. Nguyen, Berlin Wu, Vladik Kreinovich

*Departmental Technical Reports (CS)*

Detecting the beginning and the end of the business cycle is an important and difficult economic problem. One of the reasons why this problem is difficult is that for each year, we have only expert estimates (subjective probabilities) indicating to what extent the economy was in growth or recession. In our previous papers, we used fuzzy techniques to process this uncertain information; namely, we used the operation min(a,b) to combine the subjective probabilities (expert estimates) of two events into a probability that both events happen. This function corresponds to the most optimistic estimate of the joint probability. In ...

From Interval Methods Of Representing Uncertainty To A General Description Of Uncertainty, Vladik Kreinovich, Scott Ferson, Lev Ginzburg, Harry Schulte, Matthew R. Barry, Hung T. Nguyen

#### From Interval Methods Of Representing Uncertainty To A General Description Of Uncertainty, Vladik Kreinovich, Scott Ferson, Lev Ginzburg, Harry Schulte, Matthew R. Barry, Hung T. Nguyen

*Departmental Technical Reports (CS)*

Measurements do not result in an exact value of the measured quantity; even after the most accurate measurement, there is still some uncertainty about the actual value of the measured quantity. Traditionally, in science and engineering, this uncertainty is characterized by a probability distribution; however, often, we do not know this probability distribution exactly. So, to get a more adequate description of this uncertainty, we must consider classes of possible probability distributions. A natural question is: Are all possible classes needed for this description? In this paper, we show that even for simple situations, we indeed need arbitrary closed convex ...

Chu Spaces - A New Approach To Describing Uncertainty In Systems, Vladik Kreinovich, Guoqing Liu, Hung T. Nguyen

#### Chu Spaces - A New Approach To Describing Uncertainty In Systems, Vladik Kreinovich, Guoqing Liu, Hung T. Nguyen

*Departmental Technical Reports (CS)*

This paper proposes the use of a specific type of categories for modeling and fusing information in complex systems in which uncertainty of various types need to be taken into account.

Neural Network Approach To Speech Pathology, Antonio P. Salvatore, Nicole A. Thorne, Charlotte M. Gross

#### Neural Network Approach To Speech Pathology, Antonio P. Salvatore, Nicole A. Thorne, Charlotte M. Gross

*Departmental Technical Reports (CS)*

A speech problem can be caused by different reasons, from psychological to organic. The existing diagnostic of speech pathologies relies on skilled doctors who can often diagnose by simply listening to the patient. We show that neural networks can simulate this ability and thus provide an automated (preliminary) diagnosis.

Kolmogorov Complexity-Based Ideas For Locating Text In Web Images, Martin Schmidt, Vladik Kreinovich, Luc Longpre

#### Kolmogorov Complexity-Based Ideas For Locating Text In Web Images, Martin Schmidt, Vladik Kreinovich, Luc Longpre

*Departmental Technical Reports (CS)*

The gaining popularity of the World Wide Web increases security risks. Search tools monitor plain text in web pages, but search for text in graphical images is still difficult. For this search, we use the fact that the compressed images with text have different size than images without text.

Theoretical Explanation For The Empirical Probability Of Detection (Pod) Curve: A Neural Network-Motivated Approach, Yohans Mendoza, Roberto Osegueda

#### Theoretical Explanation For The Empirical Probability Of Detection (Pod) Curve: A Neural Network-Motivated Approach, Yohans Mendoza, Roberto Osegueda

*Departmental Technical Reports (CS)*

For non-destructive testing of aerospace structures, it is extremely important to know how the probability of detecting a fault depends on its size. Recently, an empirical formula has been found which described this dependence. In this paper, we provide the theoretical justification for this formula by using methods motivated by the neural network approach.

Fuzzy Logic In Non-Destructive Testing Of Aerospace Structures, Murali Krishna, Vladik Kreinovich, Roberto Osegueda

#### Fuzzy Logic In Non-Destructive Testing Of Aerospace Structures, Murali Krishna, Vladik Kreinovich, Roberto Osegueda

*Departmental Technical Reports (CS)*

In nondestructive testing, to locate the faults, we send an ultrasonic signal and measure the resulting vibration at different points. To describe and combine the uncertainty corresponding to different measurements and fuzzy estimates, we used fuzzy logic. As a result, we get reasonably simple computational models which lead to as good fault detection as the known more complicated models.

Decision Making Under Interval Probabilities, Ronald R. Yager, Vladik Kreinovich

#### Decision Making Under Interval Probabilities, Ronald R. Yager, Vladik Kreinovich

*Departmental Technical Reports (CS)*

If we know the probabilities p(1),...,p(n) of different situations s1,...,sn, then we can choose a decision Ai for which the expected benefit C(i)=p(1)*c(i,1)+...+p(n)*c(i,n) takes the largest possible value, where c(i,j) denotes the benefit of decision Ai in situation sj. In many real life situations, however, we do not know the *exact* values of the probabilities p(j); we only know the *intervals* [p-(j),p+(j)] of possible values of these probabilities. In order to make decisions under such interval probabilities, we would ...

Multi-Resolution Techniques In The Rules-Based Intelligent Control Systems: A Universal Approximation Result, Yeung Yam, Hung T. Nguyen, Vladik Kreinovich

#### Multi-Resolution Techniques In The Rules-Based Intelligent Control Systems: A Universal Approximation Result, Yeung Yam, Hung T. Nguyen, Vladik Kreinovich

*Departmental Technical Reports (CS)*

Intelligent control is a very successful method of transforming expert knowledge of control rules (formulated in terms of natural language, like "small") into a precise control strategy. It has led to many spectacular applications, ranging from appliances to automatic subway control to super-precise temperature control on a Space Shuttle mission.

It is known that fuzzy control is a universal approximator, i.e., that it can approximate every possible control strategy within an arbitrary accuracy. One of the main problems of fuzzy control is that the number of rules which are necessary to represent a given control strategy with a given ...

Fuzzy/Probability ~ Fractal/Smooth, Hung T. Nguyen, Vladik Kreinovich, Berlin Wu

#### Fuzzy/Probability ~ Fractal/Smooth, Hung T. Nguyen, Vladik Kreinovich, Berlin Wu

*Departmental Technical Reports (CS)*

Many applications of probability theory are based on the assumption that, as the number of cases increase, the relative frequency of cases with a certain property tends to a number - probability that this property is true. L. Zadeh has shown that in many real-life situations, the frequency oscillates and does not converge at all. It is very difficult to describe such situations by using methods from traditional probability theory. Fuzzy logic is not based on any convergence assumptions and therefore, provides a natural description of such situations. However, a natural next question arises: how can we describe this oscillating behavior ...

Multi-Resolution Methods In Non-Destructive Testing Of Aerospace Structures And In Medicine, Roberto Osegueda, Yohans Mendoza, Olga Kosheleva, Vladik Kreinovich

#### Multi-Resolution Methods In Non-Destructive Testing Of Aerospace Structures And In Medicine, Roberto Osegueda, Yohans Mendoza, Olga Kosheleva, Vladik Kreinovich

*Departmental Technical Reports (CS)*

A fault in an aerospace structure can lead to catastrophic consequences; therefore, it is extremely important to test these structures regularly. Thorough testing of a huge aerospace structures results in a large amount of data, and processing this data takes a lot of time. To decrease the processing time, we use a "multi-resolution" technique, in which we first separate the data into data corresponding to different vibration modes, and then combine these data together. There are many possible ways to transform each mode's data into the probability of a fault, and many possible way of combining these mode-based probabilities ...

Chu Spaces - A New Approach To Diagnostic Information Fusion, Hung T. Nguyen, Vladik Kreinovich, Berlin Wu

#### Chu Spaces - A New Approach To Diagnostic Information Fusion, Hung T. Nguyen, Vladik Kreinovich, Berlin Wu

*Departmental Technical Reports (CS)*

This paper is rather theoretical. Its aim is to describe a general algebraic framework, known as Chu spaces, in which different type of information can be transformed into the same form, so that fusion procedures can be investigated in a single general framework.

We Live In The Best Of Possible Worlds: A Proof, Guoqing Liu, Vladik Kreinovich

#### We Live In The Best Of Possible Worlds: A Proof, Guoqing Liu, Vladik Kreinovich

*Departmental Technical Reports (CS)*

It is well known that equations of motions and equations which describe the dynamics of physical fields can be deduced from the condition the action S (determined by the corresponding Lagrange function) is optimal. In other words, there is an optimality criterion on the set of all trajectories, and the actual trajectory is optimal with respect to this criterion.

The next reasonable question is: where does this optimality criterion on the set of all trajectories (i.e., the corresponding Lagrange function) come from? It is reasonable to assume that (similarly) on the set of all Lagrange functions, there is an ...

Locating The Whole Pattern Is Better Than Locating Its Pieces: A Geometric Explanation Of An Empirical Phenomenon, Scott A. Starks, Vladik Kreinovich

#### Locating The Whole Pattern Is Better Than Locating Its Pieces: A Geometric Explanation Of An Empirical Phenomenon, Scott A. Starks, Vladik Kreinovich

*Departmental Technical Reports (CS)*

In many practical problems, we must find a pattern in an image. For situations in which the desired pattern consists of several simple components, the traditional approach is first to look for such components, and then to see whether the relative locations of these components are consistent with the pattern. Recent experiments have shown that a much more efficient pattern recognition can be achieved if we look for the whole pattern (without decomposing it first). In this paper, we give a simple geometric explanation of this empirical fact.

Chu Spaces: Towards New Foundations For Fuzzy Logic And Fuzzy Control, With Applications To Information Flow On The World Wide Web, Hung T. Nguyen, Vladik Kreinovich, Guoqing Liu

#### Chu Spaces: Towards New Foundations For Fuzzy Logic And Fuzzy Control, With Applications To Information Flow On The World Wide Web, Hung T. Nguyen, Vladik Kreinovich, Guoqing Liu

*Departmental Technical Reports (CS)*

We show that Chu spaces, a new formalism used to describe parallelism and information flow, provide uniform explanations for different choices of fuzzy methodology, such as choices of fuzzy logical operations, of membership functions, of defuzzification, etc.

Towards Faster, Smoother, And More Compact Fuzzy Approximation, With An Application To Non-Destructive Evaluation Of Space Shuttle's Structural Integrity, Yeung Yam, Roberto Osegueda, Vladik Kreinovich

#### Towards Faster, Smoother, And More Compact Fuzzy Approximation, With An Application To Non-Destructive Evaluation Of Space Shuttle's Structural Integrity, Yeung Yam, Roberto Osegueda, Vladik Kreinovich

*Departmental Technical Reports (CS)*

It is known that fuzzy systems are universal approximators, i.e., any input-output system can be approximated, within any given accuracy, by a system described by fuzzy rules. Fuzzy rules work well in many practical applications. However, in some applications, the existing fuzzy rule approximation techniques are not sufficient:

First, in many practical problems (e.g., in many control applications), derivatives of the approximated function are very important, and so, we want not only the approximating function to be close to the approximated one, but we also want their derivatives to be close; however, standard fuzzy approximation techniques do not ...

Towards Intelligent Virtual Environment For Training Medical Doctors In Surgical Pain Relief, Richard Alo, Kenneth Alo, Vladik Kreinovich

#### Towards Intelligent Virtual Environment For Training Medical Doctors In Surgical Pain Relief, Richard Alo, Kenneth Alo, Vladik Kreinovich

*Departmental Technical Reports (CS)*

Chronic pain is a serious health problem affecting millions of people worldwide. Spinal cord stimulation is one of the most effective methods of easing the chronic pain. For most patients, a careful selection of weak electric currents drastically decreases the pain level. Engineering progress leads to more and more flexible devices that offer a wide variety of millions of possible simulation regimes. It is not possible to test all of them on each patient, we need an intelligent method of choosing an appropriate simulation regime. In this paper, we describe the need for an intelligent virtual environment for training medical ...

From Fuzzy Models To Fuzzy Control, Chitta Baral, Vladik Kreinovich, Hung T. Nguyen, Yeung Yam

#### From Fuzzy Models To Fuzzy Control, Chitta Baral, Vladik Kreinovich, Hung T. Nguyen, Yeung Yam

*Departmental Technical Reports (CS)*

Traditional (non-fuzzy) control methodology deals with situations when we know exactly how the system behaves and how it will react to different controls, and we want to choose an appropriate control strategy. This methodology enables us to transform the description of the plant's (system's) behavior into an appropriate control strategy. In many practical situations, we do not have the exact knowledge of the system's behavior, but we have expert-supplied fuzzy rules which describe this behavior. In such situations, it is desirable to transform these description rules into rules describing control. There exist several reasonable heuristics for such ...

A New Look At Fuzzy Theory Via Chu Spaces, Hung T. Nguyen, Berlin Wu, Vladik Kreinovich

#### A New Look At Fuzzy Theory Via Chu Spaces, Hung T. Nguyen, Berlin Wu, Vladik Kreinovich

*Departmental Technical Reports (CS)*

We propose to use Chu categories as a general framework for uncertainty analysis, with a special attention to fuzzy theory. We emphasize the fact that by viewing fuzzy concepts as Chu spaces, we can discover new aggregation operators, and model interactions and relationship between fuzzy data; these possibilities are due, in essence, to the category structure of Chu spaces, and especially to their morphisms. This paper is a tutorial introduction to the subject.