bluuebunny/crossref_metadata_2025 huggingface dataset:
Sparse matrix technology tools in APL
Authors: Hendriks Ferdinand , Ching Wai-Mee
Published: January 2007

We have implemented sparse matrix technology tools in APL. Such tools have been conspicuously scarce, because APL has not been the language of choice for solving boundary value problems governed by partial differential equations. But when carefully coded, APL is able to tackle problems governed by partial differential equations in a way that ads flexibility and, on account of its compactness, maintainability. The main criticism of APL in numerically intensive applications has been execution speed. APL compilation addresses this drawback and shows factors of speed improvement of better than about three. Timings will be presented for some benchmark elliptical boundary value problems, both for interpretive and compiled APL.

Examples are given of common tasks that are encountered in conjunction with the finite element method, such as determination of the symbolic form of the stiffness matrix, and the more universal task of solution of a sparse (symmetric) set of equations using the conjugate gradient method.
End-user KESSU
Authors: Kaski Eeva-Liisa
Published: January 2007

Since 1982, when the Finnish macro-economic model (KESSU) was presented in Heidelberg, its DP system has undergone substantial changes: it now runs wholly in APL both on mainframe and in micros (PC/AT, PS2/80).

A short history of the model used by the Finnish Ministry of Finance and its ADP history is presented in the paper.

The present version of the model management system is less complicated for the user than a teller machine. Behind the deceptively simple menu facade runs a complicated and powerful model, whose successive generations had been used as an instrument for economic policy design during a quarter of a century.

The system has common modules containing the model logic and environment dependent variable modules that conceal interpreter specific features such as device controls. This technique allows the use of KESSU in different environments, from PCs to IBM 3090s.

Next version of the model is in the pipeline and it's introduction will take place in near future. Some technical improvements such as generation of executable APL code from a very concise vector notation will be presented in the paper.
The family of Soviet APL systems
Authors: Kondrashev Andrew V.
Published: January 2007

This paper deals with the original implementation of the family of APL systems for widely spread class of mini, micro and personal Soviet computers.
Implementing the recursive APL code for dynamic programming
Authors: Lin Edward Y. H. , Bricker Dennis L.
Published: January 2007

Despite the importance and wide applicability of dynamic programming technique in optimization, the complexity and uniqueness of various dynamic programming models often make the comprehension of their solution procedures difficult, particularly for a novice. Although it can be argued that, unlike the Simplex method in linear programming, no general dynamic programming algorithm exists, with the recursive capability of APL, it is feasible to develop a “systematic” solution approach for deterministic dynamic programming. In this paper, we introduce a set of such APL code developed be solve various types of dynamic programming problems with minor modifications on some of its key functions to accommodate the nature of each type of dynamic programming problems.
Programming ecology or APL and the world at large
Authors: Lucas Jim
Published: January 2007

APL, like any programming language, interacts with various environments and individuals. How it does so and how it evolves in response to these external influences are important to the continuing health and survival of the language. It can also have a profound effect on the evolution of these same environments and individuals, since APL is a part of their universe, just as they are part of its universe.

This paper examines the demands and opportunities of interacting with these external influences and the means by which APL has tried to deal with them as a set of mutually interdependent systems, i.e., an ecology. It also proposes some future evolutionary directions for APL which should not only insure its survival but gain it a dominant position in the programming ecology. Not the least conclusion is that APL must be responsible for its own success.
Multi-axis NC postprocessor for machining centers
Authors: Olsen Thomas M.
Published: January 2007

APL2 is applied to postprocessing CL (cutter location) datafiles output from CADCAM systems APT, CATIA, and CADAM NC. For MULTAX (multi-axis; XYZ with one or two rotary axes) applications, and APL PP (postprocessor) was found more convenient and expedient than commercially-available PPs. The availability of “source code” plus immediate response to user need outweigh higher cost of processing with an APL interpreter. The paper briefly reviews the concept of NC postprocessing and evolution of the subject PP from an earlier version marketed by IBM Germany. Implementation notes include use of ADRS to maintain NC machine characteristics and APL2 functions, a FORTRAN interface to CL-data, and WSSIZE minimization.
IBM system/370 channel programming using APL
Authors: Pritchard Thomas J.
Published: January 2007

This paper describes how disk, tape and other devices attached to an IBM System/370 class machine running the VM operating system can be programmed directly from APL. The techniques rely on a few surprisingly simple APL functions and a simple auxiliary processor.
Object-oriented programming of X Window System graphical user interfaces
Authors: Rutiser William A.
Published: January 2007

An object-oriented programming style facilitates programming graphical user interfaces with APL and an external processor interface to the X Window System interface library of C functions. Objects are represented by global nested variables. Methods are represented by APL functions whose names are stored in the objects.
A parallel APL machine
Authors: Sauermann Jügen
Published: January 2007

The suitability of APL as a programming language for parallel computers seems to be obvious. Nevertheless, integral concepts of parallel APL machines are rare. Some ideas published so far are either not feasible with today's technology (e.g. needing large crossbar switches, which are expensive) or not detailed enough to prove their feasibility

At SaarbrUcken university, we developed a 32-processor prototype of a parallel APL machine along with a high performance network designed for up to 256 processors. Besides building the prototype (which shows the feasibility with today's technology), we specified in detail, in which way the parallel APL machine is operating.

In this paper, we present the basic principles of the parallel APL machine together with the efficiency of the machine for the most important APL functions. The details are described in [Sa].
A shading approach to non-convex clipping
Authors: Springall Thomas L. , Tollet Gustav
Published: January 2007

The conventional way of clipping a graphic object with a rectangular window or any convex polygon is to cut the object along a line tangent to each side of the polygon. Parts of the object on the exterior side of the line are thrown away. After repeating the process for all of the sides, what remains is the clipped object.

However, this process fails if the clipping window is non-convex, i.e., has one or more corners that point inward, or if the window consists of more than one polygon. Too much then gets clipped away. One way of dealing with this situation is to break up the window into simple convex polygons. The object is clipped with each polygon in turn, and the results are joined together to form the final result.

A different approach, presented here, is to use shading logic. The window is seen as an area to be shaded, and the object, as the shading pattern. That is, the window is shaded with the object. The method yields not only the clipped object, but also, as a by-product, the reverse clipping, i.e., that part of the object that lies outside the window. This is an advantage in graphics editing where both clippings are often needed in parallel.
Very high quality user interfaces and fast data filing using a PC
Authors: Österman Jonny
Published: January 2007

The user response to a computer system is very dependent on the user interface. In order to compete with other software products for the PC, it is important that it is easy for APL programmers to use the possibilities in the PC environment. These possibilities include a number of qualities which are not available in the mainframe environment.

With a PC, speed is usually more important than in a mainframe. This increases the demand for fast file handling functions. This paper introduces a new way to implement fast and flexible file handling for data files with a fixed record length.
Efficient routing in PAN and sensor networks
Authors: Trakadas P. , Zahariadis Th. , Voliotis S. , Manasis Ch.
Published: January 2007

Routing in both PANs and sensor networks can be significantly improved, if each node knows the network topology. However, this leads to high signalling overhead and power loss, given the frequent network topology changes. In order to compromise between efficient routing and communications /power limitations, various algorithms have been proposed. In this paper, a selection of algorithms proposed for ad-hoc networks are classified according to their relevancy and efficiency, when applied to PANs and sensor networks.
GNU TeXmacs
Authors: van der Hoeven Joris
Published: January 2007

GNU TeXmacs [vdH01, vdH02, Gro01] is a free software, which can both be used as a scientific text editor and as a front-end for computer algebra systems. The editor allows you to write structured documents via a wysiwyg (what-you-see-is-what-you-get) and user friendly interface. New styles may be created by the user. The program implements high-quality typesetting algorithms and T
E
X fonts, which allow the user to produce professionally looking documents.The high typesetting quality still goes through for automatically generated formulae, which makes TeXmacs suitable as an interface for computer algebra systems, or other types of "plugins". Currently, there are interfaces with Axiom, Giac, GNUplot, Graphviz, Gtybalt, Macaulay2, Maxima, Mupad, GNU Octave, Pari, Qcl, GNU R, Reduce, Scilab and Yacas. TeXmacs also supports the Guile/Scheme extension language, so that you may customize the interface and write your own extensions to the editor.In our demonstration, we plan to show briefly how to edit mathematical texts with TeXmacs, how to use computer algebra systems, and how to add interfaces with new systems in a very efficient way.
Classification of heterogeneous gene expression data
Authors: Fung Benny Y. M. , Ng Vincent T. Y.
Published: January 2007

Recent advanced technologies in DNA microarray analysis are intensively applied in disease classification, especially for cancer classification. Most recent proposed gene expression classifiers can successfully classify testing samples obtained from the same microarray experiment as training samples with the assumption that the symmetric errors are constant among training and testing samples. However, the classification performance is degraded with heterogeneous testing samples obtained from different microarray experiments. In this paper, we propose the "impact factors" (IFs) to measure the variations between individual classes in training samples and heterogeneous testing samples, and integrate the IFs to classifiers for classification of heterogeneous samples. Two publicly available lung adenocarcinomas gene expression data sets are used in our experiments to demonstrate the effectiveness of the IFs. It shows that, with the integration of the IFs to the Golub and Slonim (GS) and k-nearest neighbors (kNN) classifiers, the classifiers can be further improved on the classification accuracy of heterogeneous samples. Even more, the classification accuracy of the integrated GS classifier is around 90%.
Mining biologically active patterns in metabolic pathways using microarray expression profiles
Authors: Mamitsuka Hiroshi , Okuno Yasushi , Yamaguchi Atsuko
Published: January 2007

We present a new probabilistic framework for analyzing a metabolic pathway with microarray expression profiles. Our purpose is to find biologically significant paths and patterns in a given metabolic pathway. Our approach first builds a Markov model using a graph structure of a known metabolic pathway, and then estimates parameters of a mixture of the Markov models using microarray data, based on an EM algorithm. In our experiments, we used a main pathway of glycolysis to evaluate the effectiveness of our method. We first measured the performance of our method comparing with that of another method, in a supervised learning manner, and found that our method significantly outperformed another method, which was trained by microarray data only. We further analyzed the trained models and obtained a number of new biological findings on frequent patterns (paths) and long-range correlations in a metabolic pathway.
A data cleaning solution by Perl scripts for the KDD Cup 2003 task 2
Authors: Cadot Martine , di Martino Joseph
Published: January 2007

In this paper, we present our solution for the KDD CUP 2003 task 2 competition. Our approach is based on a data cleaning methodology using Perl scripts. These scripts contain regular expression for automatically extracting relevant information from the 35472 LaTeX texts. These expressions were optimized by statistical investigations on the texts. Our solution has permitted us to obtain 144,087 associations.
The myth of the double-blind review?
Authors: Hill Shawndra , Provost Foster
Published: January 2007

Prior studies have questioned the degree of anonymity of the double-blind review process for scholarly research articles. For example, one study based on a survey of reviewers concluded that authors often could be identified by reviewers using a combination of the author's reference list and the referee's personal background knowledge. For the KDD Cup 2003 competition's "Open Task," we examined how well various automatic matching techniques could identify authors within the competition's very large archive of research papers. This paper describes the issues surrounding author identification, how these issues motivated our study, and the results we obtained. The best method, based on discriminative self-citations, identified authors correctly 40--45% of the time. One main motivation for double-blind review is to eliminate bias in favor of well-known authors. However, identification accuracy for authors with substantial publication history is even better (60% accuracy for the top-10% most prolific authors, 85% for authors with 100 or more prior papers).
Semantic paging on intelligent discs
Authors: Lipovski G. Jack
Published: January 2007

In order to apply Artificial Intelligence techniques like inferencing to large (10
9
-10
12
bit) data bases, an intelligent secondary memory is proposed that is capable of extracting a subgraph from a graph stored in it for further processing in a conventional or special purpose computer. The "pointer transfer" technique developed for CASSM is used to efficiently mark and output a subgraph stored in one file, and a simple technique is proposed to link parts of the subgraph stored on different files. Besides proposing a useful secondary memory system for applying Artificial Intelligence techniques to large data bases, this paper attacks one of the most difficult problems in distributed data base systems, which is the generation of "homomorphic query fragments" that automatically carry the query from one file to other files needed to resolve the query.
A specialized computer architecture for text retrieval
Authors: Roberts David C.
Published: January 2007

This paper describes a specialized computer architecture for text retrieval that provides a wide range of query capabilities, without the use of indexes of the material retrieved. A distributed approach is employed, with direct search processors. Each search processor is closely associated with one or more disk drives that store the data to be searched and each consists of a comparator for matching query terms, logic elements to combine query terms, a disk controller and a control minicomputer.The key element of the architecture is the comparator, which can store over 64,000 characters of query terms and compare all of these terms simultaneously with data arriving from a disk continuously at more than one million bytes per second. Exact match, partical match, numeric comparison and context limitation are among the capabilities provided. The comparator is implemented as three similar universal finite-state automata, with special features to facilitate text retrieval and reduce hardware costs.A breadboard version of the system with one searcher is operational and has undergone detailed evaluation. A prototype system with two searchers is being implemented and will be placed into regularly scheduled use.
Coordinating concurrent access in a distributed database architecture
Authors: Stucki M. J. , Cox J. R. , Roman G. C. , Turcu P. N.
Published: January 2007

A distributed architecture for an interactive information system is described, and a scheme for coordinating concurrent access to its data is presented. The scheme is deadlock free and is carried out without the need for centralized control. Conflicts are detected as they occur, and competing processes are given exclusive access to the data they need.
A hierarchical controller for concurrent accessing of distributed databases
Authors: Gouda Mohamed G.
Published: January 2007

An access controller for a distributed database is a (central or distributed) structure which routes access requests to the different components of the database. Such a controller is also supposed to resolve the conflicts between concurrent requests, if any, such that deadlock situations never arise.In this paper, some architectures for distributed access controllers of distributed databases are investigated. In particular, three controllers with hierarchical architectures are considered. The controllers are evaluated based on three criteria: (i) freedom of deadlocks, (ii) robustness, and (iii) parallelism. The third criterion implies that the added redundancy to increase the controller robustness against failure conditions should also contribute to the amount of achieved parallelism during the no-failure periods. We then define a controller architecture which satisfies all the three criteria.
An extensible architecture for data flow processing
Authors: Gavish Bezalel , Koch Harvey
Published: January 2007

In this research, we propose a general model for computer architectures. This model allows us to integrate some of the existing system architecture approaches for increasing computer capacity and indicates new possibilites for improving the cost/performance ratio of future computer systems. The model leads to the development of general purpose data flow machines and to different degrees of sophistication within these machines. Our fundamental approach is to separate the CPU into elementary components. This allows us to make a distinction between components for control and components for performing various processing functions, thus yielding a high degree of resource sharing.
Functional parallelism in an operand state saving computer
Authors: Harvill J. B.
Published: January 2007

Multiple, high-level operators are assigned to a general operand. The operators are implemented with individual micro-processors and are "attached" dynamically to the memory location representing the "current" value of the operand. The operators then asynchronously use each new operand value as it is stored and perform their operations in parallel. The proposed architecture represents a true M I S D (Multiple Instruction Stream - Single Data Stream) computer. Its architecture can provide effective parallelism and reduced programming complexity for a large class of both numeric and non-numeric computer problems.
Madman machine
Authors: Hutchison J. S. , Roman W. G.
Published: January 2007

A back-end data base machine is discussed in which the back-end is closely coupled to the host system as an intelligent I/O device. The design of the hardware and software is such that the data base disks can be on either the host or back-end computers. The design is motivated by memory size considerations on mini-computer systems and also by cost considerations of large disks. The implementations of such a system on PDP-11s is discussed.
A distributed structure for the automization of the catalog of the national cultural heritage
Authors: Matteucci Dante R.
Published: January 2007

Efforts to automate the handling of information concerning the Catalog of the Italian cultural and artistic heritage have been made in the past by the Institute for the Catalog and Documentation (ICCD) of the Ministry of Cultural and Environmental Heritage.A feasibility study for the realization of a data base of the national cultural heritage has been conducted by CNUCE, the scientific computing center of the Italian National Research Council and ICCD. This study led to the determination of the caracteristics of data contained on the record cards, to the location of some samples areas, sufficiently representative of the Italian situation, for the setting up of a model of information system and to the implementation of a data bank on CNUCE computers using the IBM STAIRS information retrieval system.Following this study, a project is presently conducted by the two institutions, with the aim of setting up a distributed structure for the preparation, acquisition, access to and dissemination of the information concerning the Italian cultural and artistic heritage.This paper describes the functions of this proposed structure, with reference to the results of the first experiences and implementations.
A Bayesian approach to fault classification
Authors: Lin Tein-Hsiang , Shin Kang G.
Published: January 2007

According to their temporal behavior, faults in computer systems are classified into permanent, intermittent, and transient faults. Since it is impossible to identify the type of a fault upon its first detection, the common practice is to retry the failed instruction one or more times and then use other fault recovery methods, such as rollback or restart, if the retry is not successful. To determine an “optimal” (in some sense) number of retries, we need to know several fault parameters, which can be estimated only after classifying all the faults detected in the past.

In this paper we propose a new fault classification scheme which assigns a fault type to each detected fault based on its detection time, the outcome of retry, and its detection symptom. This classification procedure utilizes the Bayesian decision theory to sequentially update the estimation of fault parameters whenever a detected fault is classified. An important advantage of this classification is the early identification of presence of an intermittent fault so that appropriate measures can be taken before it causes a serious damage to the system. To assess the goodness of the proposed scheme, the probability of incorrect classification is also analyzed and compared with simulation results.
Quartz: a tool for tuning parallel program performance
Authors: Anderson Thomas E. , Lazowska Edward D.
Published: January 2007

Initial implementations of parallel programs typically yield disappointing performance. Tuning to improve performance is thus a significant part of the parallel programming process. The effort required to tune a parallel program, and the level of performance that eventually is achieved, both depend heavily on the quality of the instrumentation that is available to the programmer.

This paper describes Quartz, a new tool for tuning parallel program performance on shared memory multiprocessors. The philosophy underlying Quartz was inspired by that of the sequential UNIX tool gprof: to appropriately direct the attention of the programmer by efficiently measuring just those factors that are most responsible for performance and by relating these metrics to one another and to the structure of the program. This philosophy is even more important in the parallel domain than in the sequential domain, because of the dramatically greater number of possible metrics and the dramatically increased complexity of program structures.

The principal metric of Quartz is
normalized processor time
: the total processor time spent in each section of code divided by the number of other processors that are concurrently busy when that section of code is being executed. Tied to the logical structure of the program, this metric provides a “smoking gun” pointing towards those areas of the program most responsible for poor performance. This information can be acquired efficiently by checkpointing to memory the number of busy processors and the state of each processor, and then statistically sampling these using a dedicated processor.

In addition to describing the design rationale, functionality, and implementation of Quartz, the paper examines how Quartz would be used to solve a number of performance problems that have been reported as being frequently encountered, and describes a case study in which Quartz was used to significantly improve the performance of a CAD circuit verifier.
Performance analysis of the connection machine
Authors: Gelenbe Erol
Published: January 2007

This paper presents an analysis of the performance of the Connection Machine, with special emphasis on estimating the effect of its interprocessor communication architecture. A queueing model of the network architecture, including the NEWS and ROUTER networks, is used to compute the slow-down induced by message exchange between processors. Locality of the message exchanges is modelled by message sending probabilities which depend on whether a message is sent by a processor to another processor placed on the same NEWS network, or on the same ROUTER, or at a “remote” location which is only accessible via the ROUTER network. The specific slotted TDMA structure of the ROUTER Network communications is taken into account. The performance degradation of the Connection Machine as a function of the communication and architecture parameters is derived.
Dynamic partitioning in a transputer environment
Authors: Dussa K. , Carlson B. , Dowdy L. , Park K.-H.
Published: January 2007

Parallel programs are characterized by their speedup behavior. As more processors are allocated to a particular parallel program, the program (potentially) executes faster. However, there is often a point of diminishing returns, beyond which extra allocated processors cannot be used effectively. Extra processors would be better utilized by allocating them to another program. Thus, given a set of processors in a multiprocessor system, and a set of parallel programs, a partitioning problem naturally arises which seeks to allocate processors to programs optimally.

The problem addressed in this paper is dynamic partitioning. When the number of executable parallel programs changes, the optimal partition sizes also change. To realize the new partition settings, a dynamic repartitioning of all processors is triggered. When extra processors suddenly become available to a running program due to a program departure, or when processors suddenly are taken away from a running program due to a program arrival, a nontrivial repartitioning overhead occurs. Depending upon the specific environment, this overhead cost may negate any potential repartitioning benefit.

To gain insight into this dynamic partitioning problem, a specific system, a specific workload, and a specific analytical model are studied. The specific system is an INMOS transputer system consisting of an IIP Vectra front-end, an INMOS B004 evaluation board with a single T414 transputer, and an EB8-10 board with eight T800 transputers. The specific workload consists of parallel versions of a classical N-body problem and a classical search problem. The specific analytical model is a Markov model which is parameterized using the concept of program execution signatures. The sensitivity analysis experiments both validate the model and indicate the characteristics of those workloads which benefit from dynamic partitioning.
Processor scheduling in shared memory multiprocessors
Authors: Zahorjan John , McCann Cathy
Published: January 2007

Existing work indicates that the commonly used “single queue of runnable tasks” approach to scheduling shared memory multiprocessors can perform very poorly in a multiprogrammed parallel processing environment. A more promising approach is the class of “two-level schedulers” in which the operating system deals solely with allocating processors to jobs while the individual jobs themselves perform task dispatching on those processors.

In this paper we compare two basic varieties of two-level schedulers. Those of the first type, static, make a single decision per job regarding the number of processors to allocate to it. Once the job has received its allocation, it is guaranteed to have exactly that number of processors available to it whenever it is active. The other class of two-level scheduler, dynamic, allows each job to acquire and release processors during its execution. By responding to the varying parallelism of the jobs, the dynamic scheduler promises higher processor utilizations at the cost of potentially greater scheduling overhead and more complicated application level task control policies.

Our results, obtained via simulation, highlight the tradeoffs between the static and dynamic approaches. We investigate how the choice of policy is affected by the cost of switching a processor from one job to another. We show that for a wide range of plausible overhead values, dynamic scheduling is superior to static scheduling. Within the class of static schedulers, we show that, in most cases, a simple “run to completion” scheme is preferable to a round-robin approach. Finally, we investigate different techniques for tuning the allocation decisions required by the dynamic policies and quantify their effects on performance.

We believe our results are directly applicable to many existing shared memory parallel computers, which for the most part currently employ a simple “single queue of tasks” extension of basic sequential machine schedulers. We plan to validate our results in future work through implementation and experimentation on such a system.
Ray tracing on distributed memory parallel systems
Authors: Jensen David W. , Reed Daniel A.
Published: January 2007

Among the many techniques in computer graphics, ray tracing is prized because it can render realistic images, albeit at great computational expense. In this note we explore the performance of several approaches to ray tracing on a distributed memory parallel system. A set of performance instrumentation tools and their associated visualization software are used to identify the underlying causes of performance differences.
The performance of multistage interconnection networks with finite buffers
Authors: Garofalakis John D. , Spirakis Paul G.
Published: January 2007

Multistage interconnection networks with crossbar switches are a major component of parallel machines. In this paper we analyze Banyan networks of k by k switches and with finite buffers. The exact solution of the steady state distribution of the first stage is derived in the situation where packets are lost when they encounter a full buffer (Assumption A). The solution is a linear combination of k-1 geometrics. We use this to get an approximation for the steady state distributions in the second stage and beyond. As a side effect, the infinite buffer case is solved, confirming known results. Our results are validated by extensive simulations. An alternate situation of networks where full buffers may block previous switches is also analyzed through an approximation technique (Assumption B).
On the relationship between the Dixon-based resultant construction and the supports of polynomial systems
Authors: Chtcherba Arthur D. , Kapur Deepak
Published: January 2007

Different matrix based resultant formulations use the support of the polynomials in a polynomial system in various ways for setting up resultant matrices for computing resultants. Every formulation suffers, however, from the fact that for most polynomial systems, the output is not a resultant, but rather a nontrivial multiple of the resultant, called a
projection operator
. It is shown that for the Dixon-based resultant methods, the degree of the projection operator of unmixed polynomial systems is determined by the
support hull
of the support of the polynomial system. This is similar to the property that the Newton polytope of a support determines the degree of the resultant for toric zeros.The support hull of a given support is similar to its convex hull (Newton polytope) except that instead of the Euclidean distance, the support hull is defined using relative quadrant (octant) position of points. The concept of a
support hull interior
point with respect to a support is defined. It is shown that for unmixed polynomial systems, generic inclusion of terms corresponding to support hull interior points does not change the size of the Dixon matrix (hence, the degree of the projection operator). The support hull of a support is the closure of the support with respect to support-interior points.The above results are shown to hold both for the generalized Dixon formulation as well as for Sylvester-type Dixon dialytic matrices constructed using the Dixon formulation.It is proved that for an unmixed polynomial system, the size of the Dixon matrix is less than or equal to the Minkowski sum of the alternating sums of the successive projections of the support of the polynomial system. This is a refinement of the result in Kapur and Saxena 1996 about the size of the Dixon matrix of a polynomial system, where it was shown that for the unmixed polynomial system, the size of the Dixon matrix is less than or equal to the Minkowski sum of the successive projection of the support.Many other combinatorial properties of the size of the Dixon matrix and the structure of the Dixon polynomial of a given polynomial system are related to the support hull of the polynomial system and their projections along different dimensions.This research is supported in part by NSF grant nos. CCR-0203051, CDA-9503064 and a grant from the Computer Science Research Institute at Sandia National Labs.
Polynomial solutions for first order ODEs with constant coefficients
Authors: Feng Ruyong , Gao Xiao-Shan
Published: January 2007

Most work on finding elementary function solutions for differential equations focussed on linear equations [4, 2, 6, 1, 3]. In this paper, we try to find polynomial solutions to non-linear differential equations. Instead of finding arbitrary polynomial solutions, we will find the polynomial general solutions. For example, the general solution for (d
y
/d
x
)
2
- 4
y
= 0 is
y
= (
x + c
)
2
, where
c
is an arbitrary constant. We give a necessary and sufficient condition for an ODE with constant coefficients to have polynomial general solutions. For a first order ODE of degree
n
and with constant coefficients, we give an algorithm of complexity
O
(
n
9
) to decide if it has a polynomial general solution and to compute the solution if it exists.
Polynomial transformations of Tschirnhaus, Bring and Jerrard
Authors: Adamchik Victor S. , Jeffrey David J.
Published: January 2007

Tschirnhaus gave transformations for the elimination of some of the intermediate terms in a polynomial. His transformations were developed further by Bring and Jerrard, and here we describe all these transformations in modem notation. We also discuss their possible utility for polynomial solving, particularly with respect to the Mathematica poster on the solution of the quintic.
Random numbers for stochastic simulation
Authors: Guinier Daniel
Published: January 2007

A method, that generates 36-bit machine-independent sets of pseudo-random numbers uniformly distributed in the interval (0.0 to 1.0), is proposed. The method has been tested on several computers, including the PDP 11/10 (16 bit), VAX 11/780 (32 bit), CII 10070 (32 bit), and UNIVAC 1110 (36 bit). The pseudo-random sequences. Normal, Log-normal, Binomial, Poisson, and Chi-squared, are calculated from the Uniform distribution. These pseudo-random numbers give perfect reproducibility regardless of the operating system and/or kind of computer used. This is of the first importance in simulation methods, like the Monte Carlo method. The cycle of the pseudo-random sequence has been tested up to 10**7.
Effect of data compression of ERP sign preprocessed by FWT algorithm upon a neural network classifier
Authors: DasGupta S. , Hohenberger M. , Trejo Len , Kaylani T.
Published: January 2007

Earlier research at the Navy Personnel Research and Development Center revealed that measures of the brain response to sensory stimuli, known as Event Related Potentials (ERP) may be used to assess unique process-related variance that is dependent upon human performance. For example, it was found that the sensitivity of individual subjects to dynamic color contrast in computer displays can be assessed by visual ERP's. It has also been observed that RMS measures of the P1-N1-P2 complex and the P300 component of the ERP are related to signal detection and classification measures of performance. The present effort is to classify the ERP response to stimuli followed by a motor action of the subject, using neural networks. The stimuli consist of flashing a light which could be either one of two distinct colors. The following motor-action corresponds to pushing one of the two available buttons representing the two colors. The features will be selected from the Fast Walsh Transformation (FWT) of ERP observations and will be applied to appropriate Neural Networks to obtain a prediction of a possible response. Since a small number of features is derived from a large section of available processed data and since the ERP data is diluted with noise and artifacts, there is a need to evaluate the effectiveness of this data compression towards efficient prediction of the future action of the subject. The present paper deals with this study.
Simulation of ram-based asynchronous sequential circuits
Authors: Goel Ashok K. , Kalia Apurva
Published: January 2007

We have developed a computer simulator for the asynchronous sequential circuits (ASCs) constructed by using the random access memories (RAMs). This is a generic simulator with respect to the manufacturing technology of the RAM because all the time delays are variables and can be changed by the user. In addition, there is no restriction on the RAM size. The simulated RAM can be programmed and then the simulator simulates the ASC with its direct feedback connections. The durations of the transition states are generated in a random fashion. The user can change the input state interactively from the keyboard and the output state of the ASC is continuously displayed on the monitor screen.
Numerical modeling of the conformational transition of a spiral focusing surface
Authors: Steenblik Richard A. , Ho Dar-Veig
Published: January 2007

A new class of focusing reflectors was created by modeling the conformational transitions between a wound spiral focusing surface and its planar, non-focusing, unwound spiral state. Two solutions to the problem were found; one by modeling the process of unwinding the focusing spiral surface, the other by modeling the winding of the planar spiral surface. Both the mathematical derivations and the resulting equations relating the two states of the spiral surface proved markedly different for the two approaches. Implementation of each solution was accomplished by specifying the locations of marker points and tracking them through the conformational transitions. Although the mathematics and the algorithms employed are completely different between the two solutions, both result in identical sets of marker points for a given spiral. However, the solution based on the winding conformational transition is completely general, while the solution based on unwinding is limited to a narrow set of focusing geometries.
Survey on network mobility support
Authors: Perera Eranga , Sivaraman Vijay , Seneviratne Aruna
Published: January 2007

Providing unperturbed Internet connectivity to mobile hosts has been studied in the IETF for some years now, and protocols such as Mobile IP and Mobile IPv6 have been developed. We are now witnessing the emergence of mobile networks, namely a set of hosts that move collectively as a unit, such as on ships and aircrafts. The protocols for mobility support therefore need to be extended from supporting an individual mobile device to supporting an entire mobile network. In this paper we examine the state-of-the-art in network mobility support. We first motivate the problem by considering typical network mobility scenarios and identify the characteristics that require new solutions. We then study the design requirements of the protocols that support network mobility. Thereafter, we review some of the current approaches for network mobility support, and discuss their strengths and weaknesses in addressing the design requirements. We conclude by identifying some open research issues in the realization of mobile networks.
Ketone bodies alter dinitrophenol-induced glucose uptake through AMPK inhibition and oxidative stress generation in adult cardiomyocytes
Authors: Pelletier Amélie , Coderre Lise
Published: January 2007

In aerobic conditions, the heart preferentially oxidizes fatty acids. However, during metabolic stress, glucose becomes the major energy source, and enhanced glucose uptake has a protective effect on heart function and cardiomyocyte survival. Thus abnormal regulation of glucose uptake may contribute to the development of cardiac disease in diabetics. Ketone bodies are often elevated in poorly controlled diabetics and are associated with increased cellular oxidative stress. Thus we sought to determine the effect of the ketone body β-hydroxybutyrate (OHB) on cardiac glucose uptake during metabolic stress. We used 2,4-dinitrophenol (DNP), an uncoupler of the mitochondrial oxidative chain, to mimic hypoxia in cardiomyocytes. Our data demonstrated that chronic exposure to OHB provoked a concentration-dependent decrease of DNP action, resulting in 56% inhibition of DNP-mediated glucose uptake at 5 mM OHB. This was paralleled by a diminution of DNP-mediated AMP-activated protein kinase (AMPK) and p38 MAPK phosphorylation. Chronic exposure to OHB also increased reactive oxygen species (ROS) production by 1.9-fold compared with control cells. To further understand the role of ROS in OHB action, cardiomyocytes were incubated with H2O2. Our results demonstrated that this treatment diminished DNP-induced glucose uptake without altering activation of the AMPK/p38 MAPK signaling pathway. Incubation with the antioxidant N-acetylcysteine partially restored DNP-mediated glucose but not AMPK/p38 MAPK activation. In conclusion, these results suggest that ketone bodies, through inhibition of the AMPK/p38 MAPK signaling pathway and ROS overproduction, regulate DNP action and thus cardiac glucose uptake. Altered glucose uptake in hyperketonemic states during metabolic stress may contribute to diabetic cardiomyopathy.
Determination of protein replacement rates by deuterated water: validation of underlying assumptions
Authors: Belloto Emmanuelle , Diraison Frédérique , Basset Alexandra , Allain Gwenola , Abdallah Pauline , Beylot Michel
Published: January 2007

H2O administration has recently been proposed as a simple and convenient method to measure protein synthesis rates.2H2O administration results in deuterium labeling of free amino acids such as alanine, and incorporation into proteins of labeled alanine can then be used to measure protein synthesis rates. We examined first whether during2H2O administration plasma free alanine enrichment is a correct estimate of the enrichment in the tissue amino acid pools used for protein synthesis. We found that, after2H2O administration, deuterium labeling in plasma free alanine equilibrated rapidly with body water, and stable enrichment values were obtained within 20 min. Importantly, oral administration of2H2O induced no difference of labeling between portal and peripheral circulation except for the initial 10 min after a loading dose. The kinetics of free alanine labeling were comparable in various tissues (liver, skeletal muscle, heart) and in plasma with identical plateau values. We show next that increased glycolytic rate or absorption of unlabeled amino acids from ingested meals do not modify alanine labeling. Calculated synthesis rates of mixed proteins were much higher (20- to 70-fold) in plasma and liver than in muscle and heart. Last, comparable replacement rates of apoB100-VLDL were obtained in humans by using the kinetics of incorporation into apoB100 of infused labeled leucine or of alanine labeled by2H2O administration. All of these results support2H2O as a safe, reliable, useful, and convenient tracer for studies of protein synthesis, including proteins with slow turnover rate.
Long-term estrogen deficiency lowers regional blood flow, resting systolic blood pressure, and heart rate in exercising premenopausal women
Authors: O'Donnell Emma , Harvey Paula J. , Goodman Jack M. , De Souza Mary Jane
Published: January 2007

The cardiovascular consequences of hypoestrogenism in premenopausal women are unclear. Accordingly, the influence of menstrual status and endogenous estrogen (E2) exposure on blood pressure (BP), heart rate (HR), and calf blood flow in young (18–35 yr) regularly exercising premenopausal women with exercise-associated menstrual aberrations was investigated. Across consecutive menstrual cycles, daily urinary ovarian steroid levels were analyzed, and the area under the curve was calculated to determine menstrual status and E2exposure. BP, HR, blood flow, vascular conductance, and resistance were measured at baseline and following ischemic calf exercise. Exercising subjects consisted of 14 ovulatory (ExOv), 10 short-term (anovulatory and ≤100 days amenorrhea; ST-E2Def), and 8 long-term (>100 days amenorrhea; LT-E2Def) E2-deficient women. Nine sedentary ovulatory subjects (SedOv) were also studied. All groups were similar in age (24.8 ± 0.7 yr), height (164.8 ± 1.3 cm), weight (57.9 ± 0.9 kg), and body mass index (21.3 ± 0.3 kg/m2). E2-deficient groups had lower ( P < 0.002) E2exposure compared with ovulatory groups. Resting systolic BP, HR, blood flow, and vascular conductance were lower ( P < 0.05) and vascular resistance higher ( P < 0.05) in LT-E2Def compared with both ovulatory groups. Peak ischemic blood flow, vascular conductance, and HR were also lower ( P < 0.05) and vascular resistance higher ( P < 0.05) in LT-E2Def compared with all other groups. Our findings show that exercising women with long-term E2deficiency have impaired regional blood flow and lower systolic BP and HR compared with exercising and sedentary ovulatory women. These cardiovascular alterations represent markers of altered vascular function and autonomic regulation of which the long-term effects remain unknown.