ppxscal/embedding_network huggingface dataset:
A Fortran 90 Genetic Algorithm Module for Composite Laminate Structure Design
Authors: McMahon M.T., Watson L.T., Soremekun G.A., Gurdal Z., Haftka R.T.
Venue:  (1998)

The design of the stacking sequence for a composite laminate involves a set of discrete variables (ply material and ply orientation), and is thus well-suited to genetic algorithms for design optimization. Such algorithms have typically been custom-designed in FORTRAN 77 to suit specific optimization problems. Fortran 90 is a modern, powerful language with features that support important programming concepts, including those used in object-oriented programming. The Fortran 90 genetic algorithm module is used to define genetic data types, the functions which use these data types, and to provide a general framework for solving composite laminate structure design problems. The language''s support of abstract data types is used to build genetic structures such as populations, subpopulaions, individuals, chromosomes, and genes, and these data types are combined and manipulated by module subroutines. The use of abstract data types and long variable names makes the code useful and easily understood, while dynamic memory allocation makes the module flexible enough to be used in design problems of varying size and specification.
Dynamic Mapping with Self-Organizing Maps
Authors: Andreas D. Haidt, Jurgen W. Quittek
Venue:  (1996)

A complex problem in parallel processing is called the mapping problem. The parts of a parallel program are to be mapped to components of a parallel computer such that the total program execution time becomes minimal. This contribution presents a new dynamic mapping algorithm based on self-organizing maps. These maps have proven to be an efficient method for static mapping. In order to apply the static algorithm to dynamic mapping it is parallelized in a way that high scalability and low computational expenditure are reached. Different to other approaches this mapping algorithm considers not only computation load but also communication load and process migration cost. By the use of virtual process locations gradual migration of processes is supported. The properties of the dynamic mapping algorithm have been studied at two massively parallel systems based on Transputers and PowerPC processors, respectively.
A Design Tool Used to Quantitatively Evaluate Student Projects
Authors: Calvin Selig, Sallie M. Henry
Venue:  (1987)

In the last decade, the field of Computer Science has undergone a revolution. It has started the move from a mysterious art form to a detailed science. The vehicle for this progress has been the rising popularity of the field of Software Engineering. This innovative area of computer science has brought about a number of changes in the way we think of, and work with, the development of software. Due to this renovation, a field that started with little or no design techniques and unstructured, unreliable software has progressed to a point where a plethora of techniques exist to improve the quality of a program design as well as that of the resultant software. The popularity of structured design and coding techniques prove that there is widespread belief that the overall product produced using these ideas is somehow better, and statistics seem to indicate that this belief is true. Until recently, however, there existed no technique for quantitatively showing one program better than its functional equivalent. In the past few years, the use of software quality metrics seems to indicate that such a comparison is not only possible, but is also valid. The advent of Software Engineering has demanded that most universities offer a Software Engineering course which entails a "Real-World" group project. Students participating in the class design a system using a program design language (PDL). Other students then write code from the design and finally the design team integrates the modules into a working system. For a complete description of the class see [HENS83] and [TOMJ87].
A Scalable Real-Time Synchronization Protocol for Distributed Systems
Authors: I. Rhee, G. R. Martin
Venue:  (1995)

A distributed protocol is proposed for the synchronization of real-time tasks that have variable resource requirements. The protocol is simple to implement and is intended for large-scale distributed or parallel systems in which processes communicate by message passing. Critical sections, even when nested, may be executed on any processor. Thus, given an adequate number of processors, the execution of critical sections can be completely distributed. More significantly, since the protocol enables the distributed allocation of critical sections, the benefits of various allocations can be analyzed and the system optimized to provide minimal blocking. This has important application in global optimization techniques for allocating large numbers of hard real-time tasks in multiprocessor systems.
Abduction to Plausible Causes: An Event-Based Model of Belief Update
Authors: Craig Boutilier
Venue:  (1994)

The Katsuno and Mendelzon theory of belief update has been proposed as a reasonable model for revising beliefs about a changing world. However, the semantics of update relies on information which is not readily available. We describe an alternative semantical view of update in which observations are incorporated into a belief set by: a) explaining the observation in terms of a set of plausible events that might have caused that observation; and b) predicting further consequences of those explanations. We also allow the possibility of conditional explanations. We show that this picture naturally induces an update operator under certain assumptions. However, we argue that these assumptions are not always reasonable, and they restrict our ability to integrate update with other forms of revision when reasoning about action.
Selecting tile shape for minimal execution time
Authors: Karin Hogstedt, Larry Carter, Jeanne Ferrante
Venue:  (1999)

Many computationally-intensive programs, such as those for differential equations, spatial interpolation, and dynamic programming, spend a large portion of their execution time in multiply-nested loops which have a regular stencil of data dependences. Tiling is a well-known optimization that improves performance on such loops, particularly for computers with a multi-levelled hierarchy of parallelism and memory. Most previous work on tiling restricts the tile shape to be rectangular. Our previous work and its extension by Desprez, Dongarra, Rastello and Robert Showed that for doubly nested loops, using parallelograms can improve parallel execution time by decreasing the idle time, the time that a processor spends waiting for data or synchronization. In this technical report, we extend that work to more deeply nested loops, as well as to more complex loop bounds. We introduce a model which allows us to demonstrate the equivalence in complexity of linear programming and determining the execution time of a tiling in the model. We then identify a sub-class of these loops that constitute rectilinear iteration spaces for which we derive a closed form formula for their execution time. This formula can be used by a compiler to predict the execution tome of a loop nest. We then derive the tile shape that minimizes this formula. Using the duality property of linear programming, we also study how the longest path of dependent tiles within a rectilinear iteration space depends on the slope of only four of the facets defining the iteration space, independent of its dimensionality.
Evaluation of the Maintainability of Object-Oriented Software
Authors: Sallie M. Henry, Matthew C. Humphrey, John A. Lewis
Venue:  (1990)

Empirical research is one way of testing software engineering methodologies. Many claims of the advantages of the object oriented paradigm have been made by research. Our work involves empirical projects in an attempt to validate these claims. This paper describes an experiment which compares the maintainability of the two functionally equivalent systems in order to explore the claim that systems developed with object-oriented languages are more easily maintained than those programmed with procedural languages. We found supporting evidence that programmers produce more maintainable code with an object-oriented language than with a standard procedural language. Another on-going research effort attempts to measure the reusability of objects (written in C++) versus the reusability of procedures (written in Pascal). These experiments involve students, but unlike other published reports, deal with large systems.
Gaussians are better than Guessing
Authors: Christopher J.S. deSilva, Mike Alder, Yianni Attikiouzel
Venue:  (1991)

This paper describes the use of Gaussian mixture models in pattern classification. It is argued that there is a process model underlying the Gaussian mixture model which is a better model for the production of many patterns than the peicewise linear model that underlies backpropagation neural networks.
History in the Computer Science Curriculum
Authors: John A. N. Lee
Venue:  (1995)

IFIP Working Group 9.7 (History of Computing) is charged with not only encouraging the preservation of computer artifacts, the recording of the memoirs of pioneers, and the analysis of the downstream impact of computer innovations, but also on the development of educational modules on the history of computing. This paper presents an initial report on the study of the history of computing and informatics and preliminary proposals for the inclusion of aspects of the history of computing and informatics in the curriculum of university and college students. The ACM Portal is published by the Association for Computing Machinery. Copyright © 2010 ACM, Inc. Terms of Usage Privacy Policy Code of Ethics Contact Us Useful downloads: Adobe Acrobat QuickTime Windows Media Player Real Player
A Systematic Approach to Optimizing and Verifying Synthesized High-Speed ASICs
Authors: T. C. Landon, M. H. Salinas, R. H. Klenke, J. H. Aylor, S. A. McKee, K. L. Wright
Venue:  (1995)

This paper describes the design process used in developing a Stream Memory Controller (SMC)*. The SMC can reorder processor-memory accesses dynamically to increase the effective memory bandwidth for vector operations. A 132-pin ASIC was implemented in static CMOS using a 0.75mm process and has been tested at 36MHz.
The Blocking Probability of Spider-Web Networks
Authors: Nicholas Pippenger
Venue:  (1990)

We determine the limiting behaviour of the blocking probability for spider-web networks, a class of crossbar switching networks proposed by Ikeno. We use a probabilistic model proposed by the author, in which the busy links always form disjoint routes through the network. We show that if the occupancy probability is below the 0.5857 \ldots$, then the blocking probability tends to zero, whereas above this threshold it tends to one. This provides a theoretical explanation for results observed empirically in simulations by Bassalygo, Neiman and Vvedenskaya.
Singularity-Robust Trajectory Generation for Robotic Manipulators
Authors: John E. Lloyd
Venue:  (1998)

An algorithm is presented which, given a prescribed manipulator path and corresponding kinematic solution, computes a feasible trajectory in the presence of kinematic singularities. The resulting trajectory is close to minimum time, subject to explicit bounds on joint velocities and accelerations, and follows the path with precision. The algorithm has complexity O(M log M), with respect to the number of joint coordinates M, and works using "coordinate pivoting", in which the path timing near singularities is controlled using the fastest changing joint coordinate. This allows the handling of singular situations, including linear self-motions (e.g., wrist singularities), where the path speed is zero but other joint velocities are non-zero. To compute the trajectory, knots points are inserted along the input path, with increased knot density near singularities. Appropriate path velocities are then computed at each knot point, and the resulting knot-velocity sequence can be integrated to yield the path timing. Examples involving the PUMA manipulator are shown.
Strengthened Results on Nonregular PDL
Authors: D. Harel, M. Kaminsky
Venue:  (1999)

We continue the ongoing investigation of decidability and undecidability of nonregular extensions of propositional dynamic logic (PDL), by proving two results. The first strengthens the undecidability result of Harel and Singerman regarding one-letter Fibonacci-like extensions, by showing undecidability for a more general class of exponentially growing sequences. The second strengthens the decidability result of Harel and Raz for languages accepted by simple-minded pushdown automata, by showing that the important thing for decidability is that the stack behavior depends only on the input symbol.
Random Walks and Catalan Factorization
Authors: Omer Egecioglu, Alastair King
Venue:  (1999)

In the theory of random walks, it is notable that the central binomial coefficients ${2n \choose n}$ count the number of walks of three different special types, which may be described as `balanced'', `non-negative'' and `non-zero''. One of these coincidences is equivalent to the well-known convolution identity \[ \sum_{p+q=n} {2p \choose p}{2q \choose q} = 2^{2n}. \] This article brings together several proofs of this `ubiquity of central binomial coefficients'' by presenting various relations between these classes of walks and combinatorial constructions that lead to the convolution identity. In particular, new natural bijections for the convolution identity based on the unifying idea of Catalan factorization are described.
Visual Interactive Simulation: History, Recent Developments, and Major Issues
Authors: Peter C. Bell, Robert M. O''Keefe
Venue:  (1986)

Visual Interactive Simulation (VIS) has dominated discrete-event simulation in the United Kingdom throughout the eighties. Conceived and initially implemented by Hurrion, who also coined the phrase, VIS first gained widespread exposure through the package SEE-WHY. The ideas behind VIS are fundamentally different from what is referred to in the United States as animation, since the prime motivater is user interaction with the running simulation, rather than just portrayal of the simulation. This paper presents a short history of VIS, and discusses some of the research and development that has been undertaken in the the United Kingdom and North America. Following presentation of an example of VIS, the state of VIS is discussed, and a number of generally accepted guidelines for doing VIS are presented. a number of recent developments in VIS, many of them also relevant to animation, are discussed, and four major issues in the research and practice of VIS are presented.
Attempto Controlled English (ACE)Language ManualVersion 3.0
Authors: Norbert E. Fuchs, Uta Schwertel, Rolf Schwitter
Venue:  (1999)

Attempto Controlled English (ACE) is a language specifically designed to write specifications. ACE is a controlled natural language, i.e. a subset of English with a domain specific vocabulary and a restricted grammar in the form of a small set of construction and interpretation principles. This means that all ACE sentences are correct English, but that not all English sentences are allowed in ACE. The restriction of full natural language to a controlled subset is essential for ACE to be suitable for specification purposes. The main goals of this restriction are: to support the writing of precise specifications, to reduce ambiguity and vagueness inherent in full natural language, to encourage domain specialists to deliberately choose a clear and unambiguous writing style so that readers of a specification understand it in the same way as the writer, to make specifications computer processable, to render specifications unambiguously translatable into formal specification languages, particularly into first-order logic, and to make specifications executable. In brief, ACE allows domain specialists to express specifications in familiar natural language and to combine this with the rigor of formal specification languages. ACE has been used to specify a simple automatic teller machine, Kemmerer''s library data base problem, Schubert''s steamroller, and a number of smaller problems. Recently, ACE has also been used as the input language of a theorem prover, and first attempts have been made to interface it to a program synthesiser. Clearly, ACE can be adapted and extended for other purposes requiring precise input, e.g. writing technical documentation or updating databases. The use of ACE presupposes only basic knowledge of English grammar. Note however, that because ACE is a controlled natural language not all standard grammatical notions are directly applicable or suitable for the description of the ACE grammar. Some grammatical notions have a restricted meaning in ACE, while other notions are especially coined for an effective description of the language. The divergences are kept to a minimum so that ACE can be easily learned extending basic grammatical knowledge.
Bestimmung des optischen Flusses aus Bildfolgen unter Berucksichtigung vonDiskontinuitat und Okklusion
Authors: An Luo, Hans Burkhardt
Venue:  (1993)

This paper presents a new MAP-algorithm of directly estimating the optical flow from a grey image sequence. The discontinuities are considered implicitely too that leads to a nonconvex energy-function. But the global optimization of this nonconvex function can be implemented efficiently by a pyramidal two-step algorithm. The occlusion that normally makes the estimation of optical flow difficult is detected by two cooprative bidirectional processes of estimation and used to improve the estimation at the same time. Finally, a few examples are given to illustrate the performance of the new algorithms.
Begin with the end (user) in mind: planning for the San Diego state university campus portal
Authors: James P. Frazee, Rebecca Vaughan Frazee, David Sharpe
Venue: Designing portals: opportunities and challenges (2003)

This chapter presents a case study of the campus portal planning process at San Diego State University. The authors describe the use of participative decision-making strategies that capture the voices of key stakeholders, identify their concerns and priorities, and facilitate a successful portal rollout. Data was collected from faculty, students and campus leaders through a series of focus groups, interviews and online surveys. Findings were examined in light of the literature on technology adoption and the authors' familiarity with portal initiatives at other large public universities. Participants described their vision of the ideal portal solution in terms of features, user interface and functionality. While faculty and students expressed enthusiasm about a campus portal, they also had concerns regarding training, support, reliability, security and standards. The authors make recommendations for addressing user concerns such as providing direction and leadership, segmenting the rollout, communicating the benefits and providing organizational support.
Merging Inheritance Hierarchies for Schema Integration based on Concept Lattices
Authors: I. Schmitt, G. Saake
Venue:  (1997)

Merging inheritance hierarchies is an essential task of schema integration as part of the design of a federated database. Based on the formalization of inheritance hierarchies as concept lattices we present an efficient algorithm for deriving an integrated inheritance hierarchy as result of merging two inheritance hierarchies with overlapping extensions and types. Several methods are presented to modify the integrated hierarchy to optimize the resulting object-oriented schema with respect to certain quality criteria (disjoint specialization, number of classes, support of null values, etc). These methods are necessary to adjust the integrated schema to specific requirements and for realizing application-specific views
Parallel Depth First Search, Part I: Implementation
Authors: V. N Rao, Vipin Kumar
Venue:  (1988)

This paper presents a parallel formulation of depth-first search which retains the storage efficiency of sequential depth-first search and can be mapped on to any MIMD architecture. To study its effectiveness it has been implemented to solve the 15-puzzle problem on three commercially available microprocessors - Sequent Balance 21000, the Intel Hypercube and BBN Butterfly. We have been able to achieve fairly linear speedup on Sequent up to 30 processors (the maximum configuration available) and on the Intel Hypercube and BBN Butterfly up to 128 processors (the maximum configurations available). Many researchers considered the ring architecture to be quite suitable for parallel depth-first search. Our experimental results show that hypercube and shared-memory architectures are significantly better. At the heart of our parallel formulation is a dynamic work distribution scheme that divides the work between different processors. The effectiveness of the parallel formulation is strongly influenced by the work distribution scheme and architectural features such as presence/absence of shared memory, the diameter of the network, relative speed of the communication network, etc. In a companion paper [16], we analyze the effectiveness of different load-balancing schemes and architectures, and also present new improved work distribution schemes.
Polygon Triangulation in $0(N \log \log N)$ Time with Simple Data Structures
Authors: David G. Kirkpatrick, Maria M. Klawe, Robert E. Tarjan
Venue:  (1990)

We give a new $O (n \log \log n )$-time deterministic algorithm for triangulating simple $n$-vertex polygons, which avoids the use of complicated data structures. In addition, for polygons whose vertices have integer coordinates of polynomially bounded size, the algorithm can be modified to run in $O (n \log^{*} n )$ time. The major new techniques employed are the efficient location of horizontal visibility edges that partition the interior of the polygon into regions of approximately equal size, and a linear-time algorithm for obtaining the horizontal visibility partition of a subchain of a polygonal chain, from the horizontal visibility partition of the entire chain. The latter technique has other interesting applications, including a linear-time algorithm to convert a Steiner triangulation of a polygon into a true triangulation.
Geometric Aspects of Empirical Modelling: Issues of Design and Implementation
Authors: R. I. Cartrwight
Venue:  (2000)

This thesis examines the relationship between empirical modelling and geometric modelling on computer systems. The ACM Portal is published by the Association for Computing Machinery. Copyright © 2010 ACM, Inc. Terms of Usage Privacy Policy Code of Ethics Contact Us Useful downloads: Adobe Acrobat QuickTime Windows Media Player Real Player
Efficient I/O Scheduling in Tertiary Libraries
Authors: Sunil Prabhakar, Divyakant Agrawal, Amr El Abbadi, Ambuj Singh
Venue:  (1996)

With the recent improvements in network and processor speeds, several data intensive applications have become much more feasible than ever before. The only practical solution for storing such enormous amounts of data is tertiarystorage. Automated access to tertiary storage is made possible through robotic libraries for tapes and optical disks. Due to the slow speeds of operation of the drives and library robotics, access times for such librariesare high resulting in the accumulation of I/O requests. In this paper we study the problem of scheduling these requests for efficient performance. We focus on scheduling policies that process all requests on a loaded medium before unloading it. For single drive settings an efficient algorithm that produces optimal schedules is developed. For multiple drives the problem is shown to be NP-Complete. Efficient and effective heuristics are presented for the multiple drive case. The scheduling policies developed achieve significant performance gains over more naive policies. The algorithms developed are simple to implement and are not restrictive. The study is general enough to be applicable to any storage library handling removable media, such as tapes and optical disks.