ppxscal/embedding_network huggingface dataset:
Detection of hidden metabolites by localized proton magnetic resonance spectroscopy in vivo
Authors: O. M. Weber, A. H. Trabesinger, C. O. Duc, D. Meier, P. Boesiger
Venue: Technology and Health Care (1997)

Magnetic resonance spectroscopy (MRS) allows the assessment of chemical substances in living tissue and the detection of biochemical changes associated with certain diseases. In vivo MRS, however, is usually limited in sensitivity and spectral resolution. Many resonance lines originating from metabolites of interest are overlapped by signals of other metabolites and are therefore not visible in conventional MR spectra. In order to overcome this limitation, three localized methods, a technique making use of a spectral difference, a multiple quantum filter technique, and a two-dimensional J-resolved technique, were evaluated theoretically and experimentally for the detection of \gamma-aminobutyric acid (GABA) both in vitro and in vivo. All three methods are able to produce the desired results at high metabolite concentrations in vitro. For in vivo measurements the spectral difference method proofed to be most appropriate due to its relatively high sensitivity and its short acquisition time.
A Search for Hidden Relationships: Data Mining with Genetic Algorithms
Authors: George G. Szpiro
Venue: Computational Economics (1997)

This paper presents an algorithm that permits the search for dependencies among sets of data (univariate or multivariate time-series, or cross-sectional observations). The procedure is modeled after genetic theories and Darwinian concepts, such as natural selection and survival of the fittest. It permits the discovery of equations of the data-generating process in symbolic form. The genetic algorithm that is described here uses parts of equations as building blocks to breed ever better formulas. Apart from furnishing a deeper understanding of the dynamics of a process, the method also permits global predictions and forecasts. The algorithm is successfully tested with artificial and with economic time-series and also with cross-sectional data on the performance and salaries of NBA players during the 94&ndash;95 season.
Will cell generation displace standard cells?
Authors: Alfred E. Dunlop
Venue: Proceedings of the 25th ACM/IEEE Design Automation Conference (1988)

Standard cells are now a mainstay of the ASIC industry. They are characterized by a well understood library of cells, each of which has a fixed geometry and, in particular, fixed transistor sizes. Their advantages include ease of use, predictability, and reasonably efficient use of silicon area. They normally require longer processing time than gate-array or sea-of-gates techniques because more fabrication steps are required, but in return provide higher levels of integration because of improved flexibility in placement and routing. Recently, a new design method has emerged. This consists of &ldquo;cell generation&rdquo; tools that do not depend on a library of predesigned cells, but instead create the cells they need for each job &ldquo;on the fly.&rdquo; Advantages include the ability to take any logic circuit directly, without massaging it into an existing cell (or group of cells) or going through the effort of manually adding custom cells. Furthermore, such tools are capable of handling circuits with individually sized transistors, from minimum size up to thousands of microns in channel width. Disadvantages include a larger CAD database (reflecting the additional information), and increased tool complexity. This panel will discuss the merits of these two approaches to ASIC design. The panelists are: Herman Beke - Silvar-Lisco Anton Domic - Digital Equipment Corporation Dwight Hill - AT T Bell Laboratories Jiri Soukup - SDA Systems Manfred Weisel - Intel
A group of APL functions for computer-assisted instruction
Authors: Vin Grannell
Venue: ACM SIGAPL APL Quote Quad (1985)

Computer-Assisted Instruction is claimed to be an important application of APL on microcomputers. Features are described that make APL the language of choice for one type of computer-assisted instruction.
Teaching social and ethical issues in the literacy course
Authors: Jane Turk, Samuel J. Wiley
Venue: ACM SIGCSE Bulletin (1997)

A growing number of colleges and universities educate their computer science majors in social and ethical issues relating to computers. This article presents the case for incorporating consciousness of social and ethical issues of computing into the computer literacy course. The article examines our ethical obligations as professional educators in this area. It notes the focus provided by Computing Curriculum 91 and CSAB on social and ethical issues for majors. It suggests social and ethical issues related to topics in computer competency and describes specific strategies used to incorporate social and ethical issues in a computer literacy course at one university.
Error Analysis of Krylov Methods In a Nutshell
Authors: Marlis Hochbruck, Christian Lubich
Venue: SIAM Journal on Scientific Computing (1998)

Error and residual bounds for the matrix iteration methods BiCG, QMR, FOM, and GMRES are derived in a simple and unified way.
CSPL: An Ada95-Like, Unix-Based Process Environment
Authors: Jen-Yen Jason Chen
Venue: IEEE Transactions on Software Engineering (1997)

This paper presents a new process-centered environment called "concurrent software process language" (CSPL). CSPL takes a unique and innovative approach to integrate the object-oriented Ada95-like syntax (for its modeling power) with Unix shell semantics (for its enactment capability) in a software process language. This paper depicts the following new CSPL features: 1) object orientation, 2) multirole and multiuser, and 3) unified object modeling. Language constructs specially designed for software process such as work assignment statement, communication-related statements, role unit, tool unit, relation unit and so on, are, respectively, described. The related work of this diversified field is also surveyed in some depth. The CSPL environment prototype has been built. A CSPL process program for the IEEE Software Process Modeling Example Problem has been developed and enacted to demonstrate the capabilities of this environment.
LINX&mdash;Ada in an open systems architecture
Authors: Patti J. Hicks, Jennifer M. Taulbee
Venue: Proceedings of the conference on TRI-ADA '90 (1990)

Experiences in developing Defense Logistics Agency's standard interface between applications and information management facilities in both a local and a wide-area environment.
Recent developments in input modeling with B&eacute;zier distributions
Authors: Mary Ann Flanigan Wagner, James R. Wilson
Venue: Proceedings of the 28th conference on Winter simulation (1996)

New methods are presented for estimating univariate and bivariate Bezier distributions. A likelihood ratio test is used to estimate the number of control points for a univariate Bezier distribution fitted to sample data. To estimate the control points of a bivariate Bezier distribution with fixed marginals based on either sample data or subjective information about the joint dependency structure, a linear-programming approach is formulated. These methods are implemented in the Windows-based software system called PRIME-PRobabilistic Input Modeling Environment. Several examples illustrate the application of these estimation procedures.
Providing non-hierarchical security through interface mechanisms
Authors: Deborah Hamilton
Venue: Proceedings of the 1994 workshop on New security paradigms (1994)

Common security models provide protection in an hierarchical fashion (i.e. there is a trusted core with outer circles of less secure code and data). There is only one method of providing protection. This model makes it difficult to protect code and data with multiple types of non-hierarchical policies. It implies complete trust in the core requiring thorough evaluation each time modifications are made. This paper first describes a paradigm shift to non-hierarchical security. It then describes an interface mechanism with the potential for providing an efficient, configurable and non-hierarchical security mechanism more suitable for commercial requirements.
Optimistic distributed simulation based on transitive dependency tracking
Authors: Om P. Damani, Yi-Min Wang, Vijay K. Garg
Venue: ACM SIGSIM Simulation Digest (1997)

In traditional optimistic distributed simulation protocols, a logical process (LP) receiving a straggler rolls back and sends out anti-messages. The receiver of an anti-message may also roll back and send out more anti-messages. So a single straggler may result in a large number of anti-messages and multiple rollbacks of some LPs. In the authors' protocol, an LP receiving a straggler broadcasts its rollback. On receiving this announcement, other LPs may roll back but they do not announce their rollbacks. So each LP rolls back at most once in response to each straggler. Anti-messages are not used. This eliminates the need for output queues and results in simple memory management. It also eliminates the problem of cascading rollbacks and echoing, and results in faster simulation. All this is achieved by a scheme for maintaining transitive dependency information. The cost incurred includes the tagging of each message with extra dependency information and the increased processing time upon receiving a message. They also present the similarities between the two areas of distributed simulation and distributed recovery. They show how the solutions for one area can be applied to the other area.
Annotation-directed run-time specialization in C
Authors: Brian Grant, Markus Mock, Matthai Philipose, Craig Chambers, Susan J. Eggers
Venue: Proceedings of the 1997 ACM SIGPLAN symposium on Partial evaluation and semantics-based program manipulation (1997)

We present the design of a dynamic compilation system for C. Directed by a few declarative user annotations specifying where and on what dynamic compilation is to take place, a binding time analysis computes the set of run-time constants at each program point in each annotated procedure's control flow graph; the analysis supports program-point-specific polyvariant division and specialization. The analysis results guide the construction of a specialized run-time specializer for each dynamically compiled region; the specializer supports various caching strategies for managing dynamically generated code and supports mixes of speculative and demand-driven specialization of dynamic branch successors. Most of the key cost/benefit trade-offs in the binding time analysis and the run-time specialize are open to user control through declarative policy annotations. Our design is being implemented in the context of art existing optimizing compiler.
Forecasting the next 50 years in information technology
Authors: Varun Grover
Venue: ACM SIGMIS Database (1996)

Predicting the information technology future? Nah! The great ones couldn't do it. How can we? Thomas Watson, the IBM chairman, said about 50 years ago that "there is a world market for maybe five computers." Ken Olson, founder of DEC couldn't find any "reason anyone would want a computer in their home" in 1977. And even Bill Gates thought in 1981, "640K ought to be enough for anybody." They were all dead wrong!
Communication Metrics for Software Development
Authors: Allen H. Dutoit, Bernd Bruegge
Venue: IEEE Transactions on Software Engineering (1998)

We present empirical evidence that metrics on communication artifacts generated by groupware tools can be used to gain significant insight into the development process that produced them. We describe a test-bed for developing and testing communication metrics, a senior level software engineering project course at Carnegie Mellon University, in which we conducted several studies and experiments from 1991-1996 with more than 400 participants. Such a test-bed is an ideal environment for empirical software engineering, providing sufficient realism while allowing for controlled observation of important project parameters. We describe three proof-of-concept experiments to illustrate the value of communication metrics in software development projects. Finally, we propose a statistical framework based on structural equations for validating these communication metrics.
Algorithm 782: codes for rank-revealing QR factorizations of dense matrices
Authors: C. H. Bischof, G. Quintana-Ortí
Venue: ACM Transactions on Mathematical Software (TOMS) (1998)

This article describes a suite of codes as well as associated testing and timing drivers for computing rank-revealing QR (RRQR) factorizations of dense matrices. The main contribution is an efficient block algorithm for approximating an RRQR factorization, employing a windowed version of the commonly used Golub pivoting strategy and improved versions of the RRQR algorithms for triangular matrices orginally suggersted by Chandrasekaran and Ipsen and by Pan and Tang, respectively, We highlight usage and features of these codes.
Evaluating the design and delivery of WWW based educational environments and courseware
Authors: Vincent P. Wade, Conor Power
Venue: ACM SIGCSE Bulletin (1998)

The mid 1990s has seen a significant growth in both the popularity and development of WWW based courseware and delivery. However, such efforts have been very variable in both effectiveness and comprehensiveness. This paper identifies a set of general requirements necessary in designing a pedagogically successful WWW based educational experience, which can be used in the assessment of WWW based educational courses. To illustrate how such requirements can be successfully addressed, the evaluation of a WWW based course which was trialed over a three-year period with approximately 300 students is presented.
Efficient view maintenance at data warehouses
Authors: D. Agrawal, A. El Abbadi, A. Singh, T. Yurek
Venue: ACM SIGMOD Record (1997)

We present incremental view maintenance algorithms for a data warehouse derived from multiple distributed autonomous data sources. We begin with a detailed framework for analyzing view maintenance algorithms for multiple data sources with concurrent updates. Earlier approaches for view maintenance in the presence of concurrent updates typically require two types of messages: one to compute the view change due to the initial update and the other to compensate the view change due to interfering concurrent updates. The algorithms developed in this paper instead perform the compensation locally by using the information that is already available at the data warehouse. The first algorithm, termed SWEEP, ensures complete consistency of the view at the data warehouse in the presence of concurrent updates. Previous algorithms for incremental view maintenance either required a quiescent state at the data warehouse or required an exponential number of messages in terms of the data sources. In contrast, this algorithm does not require that the data warehouse be in a quiescent state for incorporating the new views and also the message complexity is linear in the number of data sources. The second algorithm, termed Nested SWEEP, attempts to compute a composite view change for multiple updates that occur concurrently while maintaining strong consistency.
Analytical Performance Modeling of Hierarchical Mass Storage Systems
Authors: Odysseas I. Pentakalos, Daniel A. Menascé, Milton Halem, Yelena Yesha
Venue: IEEE Transactions on Computers (1997)

Mass storage systems are finding greater use in scientific computing research environments for retrieving and archiving the large volumes of data generated and manipulated by scientific computations. This paper presents a queuing network model that can be used to carry out capacity planning studies of hierarchical mass storage systems. Measurements taken on a Unitree mass storage system and a detailed workload characterization provided the workload intensity and resource demand parameters for the various types of read and write requests. The performance model developed here is based on approximations to multiclass Mean Value Analysis of queuing networks. The approximations were validated through the use of discrete event simulation and the complete model was validated and calibrated through measurements. The resulting model was used to analyze three different scenarios: effect of workload intensity increase, use of file compression at the server and client, and use of file abstractions.
Megaprogramming education
Authors: Hisham Haddad, Herbert Tesser, Steven Wartik
Venue: ACM SIGCSE Bulletin (1997)

In the computer science field, educators face several obstacles when attempting to introduce rigorous software engineering concepts and practices into the curriculum. This paper addresses the issue of software engineering education and the role of megaprogramming in introductory courses for high school and college students. We highlight the need for, and the initial effort in megaprogramming education. We provide a brief description of developed materials and a proposed approach to integrate megaprogramming into high school computer science curriculum.
Graph based retargetable microcode compilation in the MIMOLA design system
Authors: Lothar Nowak
Venue: Proceedings of the 20th annual workshop on Microprogramming (1987)

This paper describes a retargetable compiler, which is able to compile programs into the machine code of a specified hardware (target). The target is described at register-transfer structure level by module specifications and netlists. The program can be defined at several levels of abstraction, spanning the range from algorithmic description (e.g. PASCAL) down to RT-level behavioural description. If the program is the complete target's behavioural specification the compiler can be used to verify the structural against this behavioural description.
Junctions: Detection, Classification, and Reconstruction
Authors: Laxmi Parida, Davi Geiger, Robert Hummel
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (1998)

Junctions are important features for image analysis and form a critical aspect of image understanding tasks such as object recognition. We present a unified approach to detecting (location of the center of the junction), classifying (by the number of wedges¿lines, corners, three-junctions such as T or Y junctions, or four-junctions such as X-junctions), and reconstructing junctions (in terms of radius size, the angles of each wedge and the intensity in each of the wedges) in images. Our main contribution is a modeling of the junction which is complex enough to handle all these issues and yet simple enough to admit an effective dynamic programming solution. Broadly, we use a template deformation framework along with a gradient criterium to detect radial partitions of the template. We use the minimum description length principle to obtain the optimal number of partitions that best describes the junction. Kona [27] is an implementation of this model. We (quantitatively) demonstrate the stability and robustness of the detector by analyzing its behavior in the presence of noise, using synthetic/controlled apparatus. We also present a qualitative study of its behavior on real images.
Eliminating canceling edges from the simulation graph model methodology
Authors: Ricki G. Ingalls, Douglas J. Morrice, Andrew B. Whinston
Venue: Proceedings of the 28th conference on Winter simulation (1996)

Event Graphs and Simulation Graph Models provide a powerful and general modeling framework for discrete event simulation. Within this framework it has been shown that an event cancellation construct in the form of a canceling edge is a modeling convenience rather than a necessary modeling tool. As a result, very little work on the formal development of Event Graphs and Simulation Graph Models directly considers the canceling edge construct. However, to the simulation practitioner the modeling convenience and functionality provided by canceling edges is important. This is clearly demonstrated by the presence of event canceling edges in SIGMA, the commercial software implementation of Event Graphs. This paper proposes an extension of the Event Graph methodology that will completely eliminate canceling edges without loosing the functionality that canceling edges provide. Since this extension is formally developed within the Simulation Graph Model framework, it provides a general approach to handling event cancellation.
Contraint-based polymorphism in Cecil: towards a practical and static type system
Authors: Vassily Litvinov
Venue: ACM SIGPLAN Notices (1998)

We present a static type system for object-oriented languages which strives to provide static typechecking without resorting to dynamic "type casts," restricting what code the programmer can write, or being too verbose or difficult to use in practice. The type system supports bounded parametric polymorphism where the bounds on type variables can be expressed using general recursive subtype or signature constraints, with F-bounded polymorphism and covariant type parameters being special cases.We implemented this type system in the Cecil language and used it to successfully typecheck a 100,000-line Cecil program, the Vortex optimizing compiler. Our experience was very good: dynamically-typed code needed very little rewriting. We also observed several common programming situations that presented a challenge for our type system. We discuss these situations and ways to typecheck them statically.
Analysing the return of investment of reuse
Authors: Giancarlo Succi, Francesco Baruchelli
Venue: ACM SIGAPP Applied Computing Review (1996)

Software reuse can be very useful in increasing the productivity and the quality level of a company, but the costs of this kind of investment are not always covered by the advantages it brings. It is particularly important to be able to correctly analyze the cost implied by software reuse in order to decide whether to adopt it or not. Even when a reuse policy has been adopted, reuse is not always the right solution and there are situations in which it is more convenient to develop a component from scratch. It is difficult to obtain a mathematical model for the evaluation of the effort required by the adaptation of a component in a new context. A different approach is proposed where the estimation is made using the knowledge and the experience gained from previous cases and stored in an ad-hoc base.
Estimation of Generalized Multisensor Hidden Markov Chains and Unsupervised Image Segmentation
Authors: Nathalie Giordana, Wojciech Pieczynski
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (1997)

This paper attacks the problem of generalized multisensor mixture estimation. A distribution mixture is said to be generalized when the exact nature of components is not known, but each of them belongs to a finite known set of families of distributions. Estimating such a mixture entails a supplementary difficulty: One must label, for each class and each sensor, the exact nature of the corresponding distribution. Such generalized mixtures have been studied assuming that the components lie in the Pearson system. Adaptations of classical algorithms, such as Expectation-Maximization, Stochastic Expectation-Maximization, or Iterative Conditional Estimation, can then be used to estimate such mixtures in the context of independent identically distributed data and hidden Markov random fields. We propose a more general procedure with applications to estimating generalized multisensor hidden Markov chains. Our proposed method is applied to the problem of unsupervised image segmentation. The method proposed allows one to: (i) identify the conditional distribution for each class and each sensor, (ii) estimate the unknown parameters in this distribution, (iii) estimate priors, and (iv) estimate the "true" class image.