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The article presents information on a research paper related to computer programming and debugging, which won an award in the 1981 George E. Forsythe Student Paper Competition. The research paper "A Program Testing Assistant," by David Chapman, a graduate student, was selected because of its original and incisive research into program development and debugging. The competition memorializes George E. Forsythe, president of the Association for Computing Machinery from 1964 to 1966, and leader in the development of computer science as a separate discipline. Chapman will receive a cash award of 500 dollars and a certificate. The papers of the first competition were refereed and judged by a committee of graduate students. The tradition has continued, with each competition administered by the graduate students at a major university with the assistance of a faculty advisor. For 1981, it was a committee of graduate students in computer science at Cornell University, New York, with professor David J. Gries serving as faculty advisor.

The Burrows-Wheeler Transform (BWT) is an invertible text transformation that permutes symbols of a text according to the lexicographical order of its suffixes. BWT is the main component of popular lossless compression programs (such as bzip2) as well as recent powerful compressed indexes (such as the r-index7), central in modern bioinformatics. The compressibility of BWT is quantified by the number r of equal-letter runs in the output. Despite the practical significance of BWT, no nontrivial upper bound on r is known. By contrast, the sizes of nearly all other known compression methods have been shown to be either always within a polylog n factor (where n is the length of the text) from z, the size of Lempel--Ziv (LZ77) parsing of the text, or much larger in the worst case (by an nε factor for ε > 0). In this paper, we show that r = O (z log² n) holds for every text. This result has numerous implications for text indexing and data compression; in particular: (1) it proves that many results related to BWT automatically apply to methods based on LZ77, for example, it is possible to obtain functionality of the suffix tree in O (z polylog n) space; (2) it shows that many text processing tasks can be solved in the optimal time assuming the text is compressible using LZ77 by a sufficiently large polylog n factor; and (3) it implies the first nontrivial relation between the number of runs in the BWT of the text and of its reverse. In addition, we provide an O (z polylog n)-time algorithm converting the LZ77 parsing into the run-length compressed BWT. To achieve this, we develop several new data structures and techniques of independent interest. In particular, we define compressed string synchronizing sets (generalizing the recently introduced powerful technique of string synchronizing sets11) and show how to efficiently construct them. Next, we propose a new variant of wavelet trees for sequences of long strings, establish a nontrivial bound on their size, and describe efficient construction algorithms. Finally, we develop new indexes that can be constructed directly from the LZ77 parsing and efficiently support pattern matching queries on text substrings. [ABSTRACT FROM AUTHOR]

The article presents information which provides a calendar of events on computer programming to be conducted in various parts of the world. Association for Computing Machine's (ACM) calendar policy is to list open computer science meetings that are held on a not-for-profit basis. Annual Meeting of the Australasian Association for Logic will be held on October 20-21, 1979 in Australia. Symposium on Formal Language Theory will be held in California during the period of December 13-14, 1979. Workshop on Interconnection Networks for Parallel and Distributed Processing will be conducted during April 21-22, 1980. The 4th International Symposium on Programming will be conducted during April 20-22, 1980 in France.

Similarity search is a fundamental algorithmic primitive, widely used in many computer science disciplines. Given a set of points S and a radius parameter r > 0, the r-near neighbor (r-NN) problem asks for a data structure that, given any query point q, returns a point p within distance at most r from q. In this paper, we study the r-NN problem in the light of individual fairness and providing equal opportunities: all points that are within distance r from the query should have the same probability to be returned. The problem is of special interest in high dimensions, where Locality Sensitive Hashing (LSH), the theoretically leading approach to similarity search, does not provide any fairness guarantee. In this work, we show that LSH-based algorithms can be made fair, without a significant loss in efficiency. We propose several efficient data structures for the exact and approximate variants of the fair NN problem. Our approach works more generally for sampling uniformly from a subcollection of sets of a given collection and can be used in a few other applications. We also carried out an experimental evaluation that highlights the inherent unfairness of existing NN data structures. [ABSTRACT FROM AUTHOR]

The article presents a calendar of activities for the Association for Computing Machinery (ACM). The ACM Special Interest Group on University and College Computing Services (SIGUCCS) conference will be held on November 11 to 14 in Reno, Nevada. The ACM SIGGRAPH sponsors the Computational Geometry conference on June 5 to 7 in Baltimore, Maryland. The ACM SIGOPS Workshop will be held on January 28 to 30 in Ruschlikon, Switzerland.

The article focuses on how revisiting key algorithms from computing history can unlock the hidden efficiency in computer science problems. The author discusses the shortest-path problem that has been long-standing, explores the use of the Bellman-Ford algorithm, and examines the work of Aaron Bernstein, Danupon Nanongkai, and Christian Wulff-Nilsen.

The article presents information on professional activities within the Association for Computing Machines (ACM). ACM Southeastern Regional Meeting will be conducted on April 18-20, the ACM Southeastern Region will hold a meeting at the Sheraton-Nashville Hotel in Nashville, Tennessee. The Association for Computing Machinery will sponsor the Sixth International Users Conference on May 14-17 at the Sheraton-Anaheim Hotel in Anaheim California. Coast Community. The Boy Scouts of America (BSA) recently published a booklet for use in its merit badge program on Computing. BSA is now looking for computer professionals to help Scouts attain the required skilk for this badge interested persons should contact their local Boy Scout offices.

A previous paper presented an efficient algorithm, called the Recomputation Algorithm, for evaluating a rational expression to within any desired tolerance on a computer which performs variable-precision arithmetic operations. The Recomputation Algorithm can be applied to expressions involving any variable-precision operations having O(10-... + Σ ∣ε∣) error bounds, where p denotes the operation's precision and ε, denotes the error in the operation's with argument. This paper presents an efficient variable-precision exponential operation with an error bound of the above order. Other operations, such as log, sin, and cos, which have simple series expansions, can be handled similarly. [ABSTRACT FROM AUTHOR]

The article presents information on various chapters of the Association for Computing Machinery (ACM) across the U.S. The Greater Rio Grande Chapter of ACM has recently extracted from its files a list of the titles of all technical papers presented at Chapter meetings since its inception in 1957. Using a program developed by D.K. Robbins of Sandia Corp., a KWIC-type listing of permuted titles of these papers has been made. This listing has been distributed to all members of the Chapter. Topics and speakers at ACM Chapters across the U.S. indicate the current trends of interest in computer science and data processing. The ACM Tidewater Chapter is sponsoring this spring a professional development course on "Real-Time Computing." The course is given by the Chapter's professional development chairman, Cecil Frost, who is applications staff specialist for Control Data Corp. At its April 21, 1966 meeting, the Westchester-Fairfield Chapter heard William Orchard-Hays speak on "Linear Programming of Computational Techniques."

The volume, moments of inertia, and similar properties of solids are defined by triple (volumetric) integrals over subsets of three-dimensional Euclidean space. The automatic computation of such integral properties for geometrically complex solids is important in CAD/CAM, robotics, and other fields and raises interesting mathematical and computational problems that have received little attention from numerical analysts and computer scientists. This paper summarizes the known methods for calculating integral properties of solids that may be geometrically complex and identifies some significant gaps in our current knowledge. [ABSTRACT FROM AUTHOR]

This paper describes the design and implementation of a program testing assistant which aids a programmer in the definition, execution, and modification of test cases during incremental program development. The testing assistant helps in the interactive definition of test cases and executes them automatically when appropriate. It modifies test cases to preserve their usefulness when the program they test undergoes certain types of design Changes. The testing assistant acts as a fully integrated part of the programming environment and cooperates with existing programming tools such as a display editor, compiler, interpreter, and debugger. [ABSTRACT FROM AUTHOR]

Criteria are suggested for determining if a statement is a folk theorem. The ideas are then illustrated with a detailed example from the theory of programming. [ABSTRACT FROM AUTHOR]

As computer technology matures, our growing ability to create large systems is leading to basic changes in the nature of programming. Current programming language concepts will not be adequate for building and maintaining systems of the complexity called for by the tasks we attempt. Just as high level languages enabled the programmer to escape from the intricacies of a machine's order code, higher level programming systems can provide the means to understand and manipulate complex systems and components. In order to develop such systems, we need to shift our attention away from the detailed specification of algorithms, towards the description of the properties of the packages and objects with which we build. This paper analyzes some of the shortcomings of programming languages as they now exist, and lays out some possible directions for future research. [ABSTRACT FROM AUTHOR]

This paper defines exception conditions, discusses the requirements exception handling language features must satisfy, and proposes some new language features for dealing, with exceptions in an orderly and reliable way. The proposed language features serve to highlight exception handling issues by showing how deficiencies in current approaches can be remedied. [ABSTRACT FROM AUTHOR]

This paper discusses the multiplication of conformable sequences of row vectors, column vectors, and square matrices. The minimum time required to evaluate such products on ordinary serial computers as well as parallel computers is discussed. Algorithms are presented which properly parse suck matrix sequences subject to the constraints of the machine organization. [ABSTRACT FROM AUTHOR]

Exploiting the multiprocessors that have recently become ubiquitous requires high-performance and reliable concurrent systems code, for concurrent data structures, operating system kernels, synchronization libraries, compilers, and so on. However, concurrent programming, which is always challenging, is made much more so by two problems. First, real multiprocessors typically do not provide the sequentially consistent memory that is assumed by most work on semantics and verification. Instead, they have relaxed memory models, varying in subtle ways between processor families, in which different hardware threads may have only loosely consistent views of a shared memory. Second, the public vendor architectures, supposedly specifying what programmers can rely on, are often in ambiguous informal prose (a particularly poor medium for loose specifications), leading to widespread confusion. In this paper we focus on x86 processors. We review several recent Intel and AMD specifications, showing that all contain serious ambiguities, some are arguably too weak to program above, and some are simply unsound with respect to actual hardware. We present a new x86-TSO programmer's model that, to the best of our knowledge, suffers from none of these problems. It is mathematically precise (rigorously defined in HOL4) but can be presented as an intuitive abstract machine which should be widely accessible to working programmers. We illustrate how this can be used to reason about the correctness of a Linux spinlock implementation and describe a general theory of data-race freedom for x86-TSO. This should put x86 multiprocessor system building on a more solid foundation; it should also provide a basis for future work on verification of such systems. [ABSTRACT FROM AUTHOR]

The article presents a list of papers, courses and magazines downloaded, in July 2005, from the Association of Computing Machinery's digital library. Some of the papers that were downloaded are: "Architectures for a Temporal Workflow Management System," by Carlo Combi, Giuseppe Pozzi and published in the March 2004 issue of the journal "Proceedings of the 2004 ACM Symposium on Applied Computing"; and "The Google File System," by Sanjay Ghemawat, Howard Gobioff and Shun-Tak Leung and published in the October 2003 issue of the journal "Proceedings of the 19th ACM Symposium on Operating Systems Principles." Some of the courses that were downloaded are: Introduction to the Java Programming Language; UML Fundamentals; Data Modeling; Beginning to Program With the Java Programming Language; Project Management: Initiation and Plan Launch; and Basic Programming in C.

Many methods for resolving collisions in hashing techniques have been proposed. They are classified into two main categories: open addressing and chaining. In this paper, other methods are presented that are intermediate between the two categories. The basic idea of our methods is the use of one or more predictors reserved per cell instead of a link field as in the chaining method. The predictors are used to maintain loose synonym chains. After describing the methods, the efficiencies are estimated theoretically and verified experimentally. In comparison with the chaining method, we prove that our methods significantly reduce the average number of probes necessary to retrieve a key without expending extra space. [ABSTRACT FROM AUTHOR]

Hierarchical programming is being increasingly recognized as helpful in the construction of large programs. Users of hierarchical techniques claim or predict substantial increases in productivity and in the reliability of the programs produced. In this paper we describe a formal method for hierarchical program specification, implementation, and proof. We apply this method to a significant list processing problem and also discuss a number of extensions to current programming languages that ease hierarchical program design and proof. [ABSTRACT FROM AUTHOR]

A data abstraction can be naturally specified using algebraic axioms. The virtue of these axioms is that they permit a representation-independent formal specification of a data type. An example is given which shows how to employ algebraic axioms at successive levels of implementation. The major thrust of the paper is twofold. First, it is shown how the use of algebraic axiomatizations can simplify the process of proving the correctness of an implementation of an abstract data type. Second, semi-automatic tools are described which can be used both to automate such proofs of correctness and to derive an immediate implementation from the axioms. This implementation allows for limited testing of programs at design time, before a conventional implementation is accomplished. [ABSTRACT FROM AUTHOR]

Recent curricular development in computer science together with student interest in pursuing topics in computer science beyond the usual programming courses have encouraged small liberal arts colleges to expand their offerings. This paper summarizes the results of a survey taken to determine the type of computer science programs being offered in these colleges. The results indicate that over half of these colleges either have no computer science program or offer only programming courses. [ABSTRACT FROM AUTHOR]

The issue of program control structures has had a history of heated controversy. To put this issue on a solid footing, this paper reviews numerous theoretical results on control structures and explores their practical implications. The classic result of Böhm and Jacopini on the theoretical completeness of if-then-else and while-do is discussed. Several recent ideas on control structures are then explored. These include a review of various other control structures, results on time/space limitations, and theorems relating the relative power of control structures under several notions of equivalence. In conclusion, the impact of theoretical results on the practicing programmer and the importance of one-in, one-out control structures as operational abstractions are discussed. It is argued further that there is insufficient evidence to warrant more than if-then-else, while-do, and their variants. [ABSTRACT FROM AUTHOR]

Various kinds of interference between communicating parallel processes have been examined by Dijkstra, Knuth and others. Solutions have been given for the mutual exclusion problem and associated subproblems, in the form of parallel programs, and informal proofs of correctness have been given for these solutions. In this paper a system of parallel processes is regarded as a machine which proceeds from one state S (i.e. a collection of pertinent data values and process configurations) to a next state 5' in accordance with a transition rule S ⇒ S . A set of such rules yields sequences of states, which dictate the system's behavior. The mutual exclusion problem and the associated subproblems are formulated as questions of inclusion between sets of states, or of the existence of certain sequences. A mechanical proof procedure is shown, which will either verify (prove the correctness of) or discredit (prove the incorrectness of) an attempted solution, with respect to any of the interference properties. It is shown how to calculate transition rules from the "partial rules" by which the individual processes operate. The formation of partial rules and the calculation of transition rules are both applicable to hardware processes as well as to software processes, and symmetry between processes is not required. [ABSTRACT FROM AUTHOR]

This paper presents an approach to writing specifications for parts of software systems. The main goal is to provide specifications sufficiently precise and complete that other pieces of software can be written to interact with the piece specified without additional information. The secondary goal is to include in the specification no more information than necessary to meet the first goal. The technique is illustrated by means of a variety of examples from a tutorial system. [ABSTRACT FROM AUTHOR]

In this paper an attempt is made to explore the logical foundations of computer programming by use of techniques which were first applied in the study of geometry and have later been extended to other branches of mathematics. This involves the elucidation of sets of axioms and rules of inference which con be used in proofs of the properties of computer programs. Examples are given of such axioms and rules, and a formal proof of a simple theorem is displayed. Finally, it is argued that important advantages, both theoretical and practical, may follow from a pursuance of these topics. [ABSTRACT FROM AUTHOR]

In this general paper the role of programming in advanced graduate training is discussed. Subject matter related to programming as well as programming per se is considered. The importance and application of formalism are considered and also the need for good empirical experimentation. A brief outline for a sequence of courses is included, and subject headings that have been obtained from an extensive bibliography are given. A bibliography of programming references is included. [ABSTRACT FROM AUTHOR]

Computer programming deals with an enormous variety of activities and is carried on by people with a great variety of backgrounds. It seems clear that part but not all of this activity h evolving toward a distinct professional field, but that the scope of this emerging profession, and some of its economic, social, and educational characteristics are as yet by no means well defined. In this paper, these issues are examined and some opinions about them are expressed. [ABSTRACT FROM AUTHOR]

The article focuses on the Internet's essential simplicity. The authors discuss the fundamental Internet design choices that have been in place since the 1980s, examines the rationale behind these design choices in an effort to understand the "why, not how" of the Internet, and offers insights for all computer scientists. A "Brief Internet Timeline" is also provided.

The article presents information on the second annual Computer Science Conference (CSC) that was held in Detroit, Michigan, from February 12 to February 14, 1974. All the components of the first CSC were present: the invited addresses, the short-paper sessions of 12-15 minute presentations, the employment register, the book exhibit, the banquet, the department chairmen's luncheon, and the overlap with the annual SIGCSE Technical Symposium. New features were a terminal exhibit of commercial products and an academic and research display of materials and systems developed in various educational contexts by computer science departments and others. Over 400 abstracts were presented at the 49 short-paper sessions; approximately 250 available positions were listed by employers, about equally divided between academia and industry, and some 400 prospective employees were registered. Total conference attendance topped 1,200. All of which indicates a favorable prognosis for the future of the Conference. The banquet speaker was John Opel, senior vice-president of IBM.

The article describes solutions to bridging the performance gap between CPUs (central processing units) and networks. These solutions can be either software or hardware based and include Linux’s eXpress Data Path—XDP and Field Programmable Gate Arrays—FPGA. The author suggests that by using XDP programmers will be free from learning new programming languages, design paradigms or hardware architectures.

This paper presents an efficient algorithm based on Quicksort. The Quicksort algorithm is known to be one of the most efficient sorting techniques; however, one of the drawbacks of this method is its worst case situation of 0 (n²) comparisons. The algorithm presented here improves the average behavior of Quicksort and reduces the occurrence of worst case situations. [ABSTRACT FROM AUTHOR]

COMPUTATIONAL THINKING, WHICH centers around devising abstractions for problems so they can be solved with computational steps and efficient algorithms, is a concept that serves not only computer science (CS) but progressively more of science and everyday life. [ABSTRACT FROM AUTHOR]

The article discusses graph partitioning within the computing industry, presenting a survey of articles and research on the topic. Graph partitioning concerns itself with vertices of a graph that need to be partitioned into two or more large pieces while at the same time minimizing the number of edges that cross the cut. Topics include the use of divide and cut algorithms, laying out large circuits on silicon chips, and computation distribution among processors. Also discussed is the design of algorithms with the best provable approximation guarantees.

The article presents a conversation with educationists Seymour Papert, Marvin Minsky and Alan Kay on educational reform, artificial intelligence, computer science and human-computer interaction. The importance of the computer is how you learn mathematics, and how it allows children to think about powerful ideas in mathematics. Children are capable of learning plenty more mathematics than anyone gives them credit for with or without a computer. The most important thing in learning is copying how other people think. The way to learn something hard is by getting new ideas. Programming is the most powerful medium of developing the sophisticated and rigorous thinking needed for mathematics, for grammar, for physics, for statistics, and all the hard subjects. Programming should be a key part of the intellectual development of people growing up. The idea of programming itself is something in evolution so it will not mean exactly what it is thought to mean.

Several letters to the editor are presented in response to the article on cognitive strategies and looping constructs by E. Soloway, J. Bonar and K. Ehrlich, which was published on November 1983 issue.

Several letters to the editor are presented in response to the article "A Generalized Control Structure and Its Formal Definition," by David Parnas in the August 1983 issue.

Numerical mathematics is viewed as the analysis of continuous algorithms. Four of the components of numerical mathematics are discussed. These are: foundations (finite precision number systems, computational complexity), synthesis and analysis of algorithms, analysis of error, programs and program libraries. [ABSTRACT FROM AUTHOR]

Describes a general purpose macro processor called ML/I. Capability of the ML/I to extend any computer programming language; User-oriented features and specifications; Applications of typical macro-assemblers in computer science.

This article presents information related to developments in the computer industry. Five universities have been selected to share $10 million in cash grants from the International Business Machines Corp. to establish new programs for graduate-level engineering education in manufacturing systems. The schools each will receive approximately $2 million. Over the next four years, the five universities will develop curricula leading to advanced degrees in manufacturing systems. The courses will integrate the disciplines of engineering, computer science and business planning. Richard D. DeLauer, Under Secretary of Defense for Research and Engineering, has issued a Department of Defense Directive that will be the interim policy on computer programming languages for the department. It specifically addresses high order languages in mission-critical defense applications. The Computer Science Department of the University of Southwestern Louisiana is forming a repository for raw materials related to microprogramming and firmware engineering.

The article presents updates concerning the Association for Computing Machinery (ACM). Information on the various awards presented by ACM is offered. The ACM Nominating Committee's report on the nominees for the May 1979 election is presented. The results of the 1978-1979 Southeast Regional ACM Scholastic Programming Contest are reported.

The article discusses the history of the "stored program":in computer science since John von Neumann's 1945 description of the EDVAC mainframe computer. The etymological origins of "program" in the radio broadcasting industry and "program clocks" which scheduled factory production are examined along with the alleged importance of establishing a narrative history of computing.

Presents several letters to the editor commenting on various topics related to the field of computer science. Arguments pertaining to the publication of computer programs; Publication of computer algorithm and programs; Discussion on structured computer programming; Discussion on the computer models of psychopathic behavior.

The article discusses the decline of classical computer programming due to technological advances in AI systems and the author's belief that such programming is becoming obsolete.

The article discusses dynamic networks. Topics include the consideration of time as an integral element of dynamic networks, and traditional approaches and measures for static and dynamic networks.

Abstract: Evolutionary membrane computing is an important research direction of membrane computing that aims to explore the complex interactions between membrane computing and evolutionary computation. These disciplines are receiving increasing attention. In this paper, an overview of the evolutionary membrane computing state-of-the-art and new results on two established topics in well defined scopes (membrane-inspired evolutionary algorithms and automated design of membrane computing models) are presented. We survey their theoretical developments and applications, sketch the differences between them, and compare the advantages and limitations. [Copyright &y& Elsevier]

Abstract: This paper aims to incorporate intelligent mechanisms based on Soft Computing in Geographical Information Systems (GIS). The proposal here is to present a spatio-temporal prediction method of forestry evolution for a sequence of binary images by means of fuzzy inference systems (FIS), genetic algorithm (GA) and genetic programming (GP). The main inference is based on a fuzzy system which processes a set of crisp/fuzzy relations and infers a crisp relation representing the predicted image at a predefined date. The fuzzy system is formed by a fixed fuzzy rule base and a partition set that may be defined by an expert or optimized by means of a GA. Genetic programming may also be adopted to generate the size of predicted area used in the final stage of the inference process. The developed methodology is applied in regions of Venezuela, France and Guatemala to identify their forestry evolution trends. The proposed approaches are compared with other techniques to validate the system. [Copyright &y& Elsevier]

Abstract: This paper describes software for computing eigenvalue bounds to the standard and generalized hermitian eigenvalue problem as described in [Y. Zhou, R. Shepard, M. Minkoff, Computing eigenvalue bounds for iterative subspace matrix methods, Comput. Phys. Comm. 167 (2005) 90–102]. The software discussed in this manuscript applies to any subspace method, including Lanczos, Davidson, SPAM, Generalized Davidson Inverse Iteration, Jacobi–Davidson, and the Generalized Jacobi–Davidson methods, and it is applicable to either outer or inner eigenvalues. This software can be applied during the subspace iterations in order to truncate the iterative process and to avoid unnecessary effort when converging specific eigenvalues to a required target accuracy, and it can be applied to the final set of Ritz values to assess the accuracy of the converged results. Program summary: Title of program: SUBROUTINE BOUNDS_OPT Catalogue identifier: ADVE Program obtainable from: CPC Program Library, Queen''s University of Belfast, N. Ireland Program summary URL: http://cpc.cs.qub.ac.uk/summaries/ADVE Computers: any computer that supports a Fortran 90 compiler Operating systems: any computer that supports a Fortran 90 compiler Programming language: Standard Fortran 90 High speed storage required: working-precision and integer for m Ritz values No. of bits in a word: The floating point working precision is parameterized with the symbolic constant WP No. of lines in distributed program, including test data, etc.: 2452 No. of bytes in distributed program, including test data, etc.: 281 543 Distribution format: tar.gz Nature of physical problem: The computational solution of eigenvalue problems using iterative subspace methods has widespread applications in the physical sciences and engineering as well as other areas of mathematical modeling (economics, social sciences, etc.). The accuracy of the solution of such problems and the utility of those errors is a fundamental problem that is of importance in order to provide the modeler with information of the reliability of the computational results. Such applications include using these bounds to terminate the iterative procedure at specified accuracy limits. Method of solution: The Ritz values and their residual norms are computed and used as input for the procedure. While knowledge of the exact eigenvalues is not required, we require that the Ritz values are isolated from the exact eigenvalues outside of the Ritz spectrum and that there are no skipped eigenvalues within the Ritz spectrum. Using a multipass refinement approach, upper and lower bounds are computed for each Ritz value. Typical running time: While typical applications would deal with , for , the running time is 0.12 s on an Apple PowerBook. [Copyright &y& Elsevier]

In this paper a modified algorithm is suggested for developing polynomial neural network (PN N) models. Optimal partial description (PD) modeling is introduced at each layer of the PNN expansion, a task accomplished using the orthogonal least squares (OLS) method. Based on the initial PD models determined by the polynomial order and the number of PD inputs, OLS selects the most significant regressor terms reducing the output error variance. The method produces PN N models exhibiting a high level of accuracy and superior generalization capabilities. Additionally, parsimonious models are obtained comprising a considerably smaller number of parameters compared to the ones generated by means of the conventional PNN algorithm. Three benchmark examples are elaborated, including modeling of the gas furnace process as well as the iris and wine classification problems. Extensive simulation results and comparison with other methods in the literature, demonstrate the effectiveness of the suggested modeling approach. [ABSTRACT FROM AUTHOR]

The paper formalizes an open-problem (called by the authors the pairwise-consistency problem) which is relevant in the context of cardinal directions among extended objects, proposes an efficient algorithmic solution for it, discusses the implementation of the algorithm and briefly reports the numerical results obtained by running the code. [ABSTRACT FROM AUTHOR]

The article discusses space leaks, which is when a computer program uses more of the computer's memory than is necessary. The control of a computer program's evaluation to reduce the time between allocating and discarding memory to eliminate space leaks is discussed. Lazy evaluations, when an evaluation of an expressing is delayed until its value is needed, and closures, a function combined with its environment are both considered as a cause of space leaks and attributed to lazy functional programming languages.