ppxscal/embedding_network huggingface dataset:
A Reduced Complexity 3rd Order Digital Delta-Sigma Modulator for Fractional-N Frequency Synthesis
Authors: R. Dehghani, S. M. Atarodi, B. Bornoosh, A. Afzali Kusha
Venue: Proceedings of the 17th International Conference on VLSI Design (2004)

A reduced complexity third-order digital delta-sigmamodulator is presented. The modulator consists of twocascaded sections to produce proper shaping ofquantization noise with minimum hardware. A newarchitecture for a digital third-order delta-sigmamodulator based on Ritchie structure is proposed. Themeasurement results show 94dB SNR and 65% dynamicrange.
Fault Tolerant Hopfield Associative Memory on Torus
Authors: R. A. Ayoubi, H. A. Ziade, M. A. Bayoumi
Venue: Proceedings of the 18th IEEE International Symposium on Defect and Fault Tolerance in VLSI Systems (2003)

The associative Hopfield memory is a very useful Artificial Neural Network (ANN) that can be utilized in numerous applications. Examples include, pattern recognition, noise removal, information retrieval, and combinatorial optimization problems. This paper provides an efficient and fault tolerant algorithm for implementing the Hopfield ANN on torus parallel architecture. The main advantage of this algorithm is fault tolerance, high performance, and cost effectiveness. The developed algorithm is much faster than other known algorithms of its class and comparable in speed to more complex architecture such as hypercube without the added cost; it requires O(1) multiplications and O(log N) additions, whereas most others require O(N)multiplications and O(N) additions. Moreover, the developed algorithm has an added advantage over other known algorithms due to its fault tolerance feature, which is based on ABFT techniques. The main advantage of our ABFT method over other existing ABFT methods is its ability to detect and correct several faults without any additional hardware overhead (i.e. no extra row or column is needed).
On a lower bound on the number of perfect binary codes
Authors: S. A. Malyugin
Venue: Discrete Applied Mathematics (2004)

It is proved that the number of perfect binary codes of length n is greater than 22(n+1)/2-log(n+1). 22(n-3)/4.
Addressing the Ramification Problem in a Temporal Context: The Case of Concurrent Actions
Authors: Nikos Papadakis, Dimitris Plexousakis
Venue: Proceedings of the 15th IEEE International Conference on Tools with Artificial Intelligence (2003)

The ramification problem is a hard and ever present problem in systems exhibiting a dynamic behavior. The area of temporal databases in particular is still lacking satisfactory solutions to the ramification problem. In this paper, we address the problem for the concurrent execution of both instantaneous actions and actions with duration. The proposed solution advances previous work by considering actions with effects occurring in any of the possible future situations resulting from an action's execution.
Automatic tuning of PID and gain scheduling PID controllers by a derandomized evolution strategy
Authors: Leandro Dos Santos Coelho, Antonio Augusto Rodrigues Coelho
Venue: Artificial Intelligence for Engineering Design, Analysis and Manufacturing (1999)

This paper evaluates an evolution strategy to tune conventional proportional plus integral plus derivative (PID) and gain scheduling PID control algorithms. The approach deals with the utilization of an evolution strategy with learning acceleration by derandomized mutative step-size control using accumulated information. This technique is useful to obtain the following characteristics: (1) freedom of choice of a performance index, (2) increase of the convergence speed of evolution strategies to get a local minimum to determine controller design parameters, and (3) flexibility and robustness in the automatic design of controllers. Performance analysis and experimental results are carried out using a laboratory scale nonlinear process fan and plate. The practical prototype contains features such as nonminimum phase, dead time, resonant, and turbulent disturbance behavior that motivate the utilization of intelligent control techniques.
Discovering knowledge in DNA and protein data
Authors: Lawrence Holder
Venue: ACM SIGBIO Newsletter (1998)

This research investigates a method for discovering knowledge in structural data. We have implemented the SUBDUE substructure discovery system which discovers interesting and repetitive subgraphs in a labeled graph representation using the minimum description length principle. Experiments have shown SUBDUE's applicability in a variety of domains. We are currently applying SUBDUE to both DNA and protein data from the Brookhaven PDB, where SUBDUE was able to find patterns in secondary structure that are both characteristic and unique to categories of proteins, such as hemoglobin and myoglobin. Ultimately, we plan to use SUBDUE to find structural patterns in functional groups of proteins and the boundaries of genes in DNA.
A Phenomenological Exploration of Adaptation in a Polycontextual Work Environment
Authors: Paul C. van Fenema, Sajda Qureshi
Venue: Proceedings of the Proceedings of the 37th Annual Hawaii International Conference on System Sciences (HICSS'04) - Track 8 - Volume 8 (2004)

The rise of new ways of working through the use of information and communication technology brings about new phenomena that are powerful in the effects that they have on people. The potency of phenomenology lies in its philosophical simplicity and it provides the researcher with the ability to study the essence of an observable but scarcely understoodphenomena: How do people perform effectively and efficiently in a geographically and temporally dispersed work environment? Collective action across multiple time zones continues to challenge both academics and practitioners. This study provides a unique view of how globally dispersed participants achieve collective action. It throws light into how thecreation of shared understanding is tempered by differences in time zones and how participants adapt through their choice of media, work practices and communication. Following an analysis of a case studied using phenomenology, this paper concludes with a model of adaptation in polycontextual work environments.
On Some Nonendoreversible Engine Models with Nonlinear Heat Transfer Laws
Authors: L. A. Arias-Hernández, G. Ares De Parga, F. Angulo-Brown
Venue: Open Systems Information Dynamics (2003)

In this work, we analyze a nonendoreversible thermal engine model with a nonlinear heat transfer law between the heat reservoirs and the working fluid under two optimization criteria: the maximum power regime and the so-called ecological criterion. We find that this nonendoreversible model has a similar behaviour to that shown by De Vos (Am. J. Phys. 53, 570 (1985)) for endoreversible models with two thermal conductances with only one superior conductance and with only one inferior conductance, respectively. The model is compared with two sets of real power plants, the first one containing power plants of old design (before 1960's) and the second one being formed by modern nuclear power plants. Our results suggest that the first group was designed under conditions which, are reminiscent of a maximum power regime and the second one under an ecological-like criterion. We also study some general properties of nonendoreversible thermal engine models.
Making information cities livable
Authors: Lee Sproull, John F. Patterson
Venue: Communications of the ACM (2004)

Let the most rewarding aspects of our virtual experience and online social interaction also guide participation in our real-world physical communities.
A tutorial on the universality and expressiveness of fold
Authors: Graham Hutton
Venue: Journal of Functional Programming (1999)

In functional programming, fold is a standard operator that encapsulates a simple pattern of recursion for processing lists. This article is a tutorial on two key aspects of the fold operator for lists. First of all, we emphasize the use of the universal property of fold both as a proof principle that avoids the need for inductive proofs, and as a definition principle that guides the transformation of recursive functions into definitions using fold. Secondly, we show that even though the pattern of recursion encapsulated by fold is simple, in a language with tuples and functions as first-class values the fold operator has greater expressive power than might first be expected.
Computing Rate-Distortion Optimized Policies for Streaming Media with Rich Acknowledgments
Authors: Jacob Chakareski, Bernd Girod
Venue: Proceedings of the Conference on Data Compression (2004)

We consider the problem of rate-distortion optimized streaming of packetized media over the Internet from a server to a client using rich acknowledgments. Instead of separately acknowledging each media packet as it arrives, theclient periodically sends to the server a single acknowledgment packet, denotedrich acknowledgment, that contains information about all media packets thathave arrived at the client by the time the rich acknowledgment is sent. Computing the optimal transmission policy for the server involves estimation of theprobability that a single packet will be communicated in error as a functionof the expected redundancy (or cost) used to communicate the packet. In thispaper, we show how to compute this error-cost function, and thereby optimizethe server's transmission policy, in this scenario.
Digital storytelling for reflective practice in communities of learners
Authors: Natasha Freidus, Michelle Hlubinka
Venue: ACM SIGGROUP Bulletin (2002)

This paper will present the use of digital storytelling in community development settings to promote reflective practice and foster connections in communities of learners. Through digital storytelling, individuals learn to tell a story, and in doing so, become more effective actors in collaborative work environments. This particular form of digital storytelling encourages participants to communicate meaning on multiple levels (voice, point, emotional content, tension, story arc), and it allows storytellers to take fresh perspective on their work. Participants abstract meaning, but also give it a concrete form, as story, which can then be shared. We consider the benefits of this approach as a way to strengthen ties among participants in the creative and social outreach work in which they engage.
Making way for Java in an information technology masters program
Authors: Wendy Lucas
Venue: Current issues in IT education (2003)

The object-oriented programming paradigm has gained popularity in industry and academia, and Java is becoming the language of choice. Yet, it can be a difficult language to learn, with many hurdles for novice programmers. This chapter describes our experiences transitioning to Java as the first programming language in an information technology Masters program. Careful consideration was given to a variety of factors, including when to introduce object-oriented concepts, which integrated development environment to use, and how to support students with minimal prior experience. The impact of these choices on the learning experience is described, and the factors that led to the successful implementation of Java as a first programming language are presented.
An Integrated Fault-Tolerant Design Framework for VLIW Processors
Authors: Yung-Yuan Chen, Shi-Jinn Horng, Hung-Chuan Lai
Venue: Proceedings of the 18th IEEE International Symposium on Defect and Fault Tolerance in VLSI Systems (2003)

In this study, a fault-tolerant design framework of VLIW processor is proposed. Specifically, this paper concentrates on the issue of dependable data path design. We first use three identical functional modules in the data paths to demonstrate our fault-tolerant technique. Basically, we add one spare module in this illustration and refine on the concepts of triple modular redundancy and comparison to achieve fault detection, fault location and error recovery. A real-time error recovery process is developed to conquer the faults. Hardware architecture and its implementation in VHDL are presented. The analysis of hardware overhead and performance degradation is conducted to validate our scheme. We show that the proposed scheme can be easily extended to data paths, which contains more than three identical functional modules. In addition, for a specific number of identical modules, the fault-tolerant framework provides a design choice among several feasible solutions in terms of hardware overhead, performance degradation and dependability requirements. Finally, hardware overhead and performance degradation of the proposed technique decreases while the number of identical modules increases in the data path of VLIW processors.
Fine-grain process modelling
Authors: Bashar Nuseibeh, Anthony Finkelstein, Jeff Kramer
Venue: Proceedings of the 7th international workshop on Software specification and design (1993)

In this paper, we propose the use of fine-grain process modelling as an aid to software development. We suggest the use of two levels of granularity, one at the level of the individual developer and another at the level of the representation scheme used by that developer. The advantages of modelling the software development process at these two levels, we argue, include respectively: (1) the production of models that better reflect actual development processes because they are oriented towards the actors who enact them, and (2) models that are vehicles for providing guidance because they may be expressed in terms of the actual representation schemes employed by those actors. We suggest that our previously published approach of using multiple "ViewPoints" to model software development participants, the perspectives that they hold, the representation schemes that they deploy and the process models that they maintain, is one way of supporting the fine-grain modelling we advocate. We point to some simple, tool-based experiments we have performed that support our proposition.
Introducing a New Problem: Shape-from-Silhouette when the Relative Positions of the Viewpoints is Unknown
Authors: Andrea Bottino, Aldo Laurentini
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (2003)

3D shapes can be reconstructed from 2D silhouettes by back-projecting them from the corresponding viewpoints and intersecting the resulting solid cones. However, in many practical cases as observing an aircraft or an asteroid, the positions of the viewpoints with respect to the object are not known. In these cases, the relative position of the solid cones is not known and the intersection cannot be performed. The purpose of this paper is introducing and stating in a theoretical framework the problem of understanding 3D shapes from silhouettes when the relative positions of the viewpoints are unknown. The results presented provide a first insight into the problem. In particular, the case of orthographic viewing directions parallel to the same plane is thoroughly discussed, and sets of inequalities are presented which allow determining objects compatible with the silhouettes.
A Java API for polynomial arithmetic
Authors: Claire Whelan, Adam Duffy, Andrew Burnett, Tom Dowling
Venue: Proceedings of the 2nd international conference on Principles and practice of programming in Java (2003)

This paper looks at the development of a Java application programming interface (API) for performing unbounded Polynomial Arithmetic. It shows how Java can be used to perform large integer mathematical operations by using the BigInteger class. By demonstrating how the API might be used in a real application the paper shows how easy the API is to use with very little knowledge of polynomial arithmetic.
Performance Analysis of DECK Collective Communication Service
Authors: Rafael Silva, Delcino Picinin, Marcos Barreto, Rafael Ávila, Tiarajú Diverio, Philippe Navaux
Venue: Proceedings of the 15th Symposium on Computer Architecture and High Performance Computing (2003)

Collective communication is very useful for parallel applications, especially those in which matrix and vector data structures need to be manipulated by a group of processes. This paper presents a performance analysis of collective communication primitives designed for the DECK parallel programming environment, with the aid of different numerical methods used to solvehydrodynamics and mass transportation models.
Comparing the expressive power of the synchronous and asynchronous $pi$-calculi
Authors: Catuscia Palamidessi
Venue: Mathematical Structures in Computer Science (2003)

The Asynchronous $\pi$-calculus, proposed in Honda and Tokoro (1991) and, independently, in Boudol (1992), is a subset of the $\pi$-calculus (Milner et al. 1992), which contains no explicit operators for choice and output prefixing. The communication mechanism of this calculus, however, is powerful enough to simulate output prefixing, as shown in Honda and Tokoro (1991) and Boudol (1992), and input-guarded choice, as shown in Nestmann and Pierce (2000). A natural question arises, then, as to whether or not it is as expressive as the full $\pi$-calculus. We show that this is not the case. More precisely, we show that there does not exist any uniform, fully distributed translation from the $\pi$-calculus into the asynchronous $\pi$-calculus, up to any &lsquo;reasonable&rsquo; notion of equivalence. This result is based on the incapability of the asynchronous $\pi$-calculus to break certain symmetries that may be present in the initial communication graph. By similar arguments, we prove a separation result between the $\pi$-calculus and CCS, and between the $\pi$-calculus and the $\pi$-calculus with internal mobility, a subset of the $\pi$-calculus proposed by Sangiorgi where the output actions can only transmit private names.
Existential second-order logic over graphs: Charting the tractability frontier
Authors: Georg Gottlob, Phokion G. Kolaitis, Thomas Schwentick
Venue: Journal of the ACM (JACM) (2004)

Fagin's theorem, the first important result of descriptive complexity, asserts that a property of graphs is in NP if and only if it is definable by an existential second-order formula. In this article, we study the complexity of evaluating existential second-order formulas that belong to prefix classses of existential second-order logic, where a prefix class is the collection of all existential second-order formulas in prenex normal form such that the second-order and the first-order quantifiers obey a certain quantifier pattern. We completely characterize the computational complexity of prefix classes of existential second-order logic in three different contexts: (1) over directed graphs, (2) over undirected graphs with self-loops and (3) over undirected graphs without self-loops. Our main result is that in each of these three contexts a dichotomy holds, that is to say, each prefix class of existential second-order logic either contains sentences that can express NP-complete problems, or each of its sentences expresses a polynomial-time solvable problem. Although the boundary of the dichotomy coincides for the first two cases, it changes, as one moves to undirected graphs without self-loops. The key difference is that a certain prefix class, based on the well-known Ackermann class of first-order logic, contains sentences that can express NP-complete problems over graphs of the first two types, but becomes tractable over undirected graphs without self-loops. Moreover, establishing the dichotomy over undirected graphs without self-loops turns out to be a technically challenging problem that requires the use of sophisticated machinery from graph theory and combinatorics, including results about graphs of bounded tree-width and Ramsey's theorem.
Numerical verification of solutions for obstacle problems
Authors: Cheon Seoung Ryoo, Mitsuhiro T. Nakao
Venue: Journal of Computational and Applied Mathematics (2003)

This article is an extension of the previous paper (Numer. Math. 81 (1998) 305) by the same authors. We propose a method to prove the existence of solutions for more general obstacle problems by numerical computations. The main task in this paper consists of the numerical determination of some constants which appear in a priori error estimations for the finite element approximation of a simple variational inequality. We present a numerical example for verification.
Hyperplane ranking, nonlinearity and the simple genetic algorithm
Authors: Darrell Whitley, Robert B. Heckendorn, Soraya Stevens
Venue: Information Sciences: an International Journal (2003)

We examine the role of hyperplane ranking during genetic search by developing a metric for measuring the degree of ranking that exists with respect to static hyperplane averages taken directly from the function, as well as the dynamic ranking of hyperplanes during genetic search. We show that the degree of dynamic ranking induced by a simple genetic algorithm is highly correlated with the degree of static ranking that is inherent in the function, especially during the initial generations of search. The φ metric is designed to measure the consistency of an arbitrary ranking of hyperplanes in a partition with respect to a target string. Walsh coefficients can be calculated for small functions in order to characterize sources of linear and nonlinear interactions. Correlations between the φ metric and convergence behavior of a simple genetic algorithm are studied over large sets of functions with varying degrees of nonlinearity.
An agent-based approach to modeling electricity spot markets
Authors: Poonsaeng Visudhiphan
Venue:  (2003)

Current approaches used for modeling electricity spot markets are static oligopoly models that provide top-down analyses without considering dynamic interactions among market participants. This thesis presents an alternative model, an agent-based model, and uses it to analyze the markets under various conditions. These markets, in which the participants engage in sealed-bid auctions to sell and/or buy electricity regularly, are viewed as multiagent systems, or as repeated games, played by participants with incomplete information. To represent these market characteristics, the agent-based model is selected, consisting of several power-producing agents with non-uniform portfolios of generating units. These agents employ learning algorithms, including Auer et al.'s, softmax action selection, or Visudhiphan and Ili&cacute;'s model-based algorithms, in determining bid-supply functions from available information. The simulated outcomes from the agent-based model depend on the choice of non-uniform portfolios and on the learning algorithms that the agents employ. Model verifications against the actual markets are suggested; however, due to a lack of certain confidential information, numerical examples cannot be presented. Nevertheless, the model is used to analyze the effects of market structures and the effect of load-serving entities on the power-producer bidding behavior and market outcomes. This model could provide one of the main tools for regulators, system planners, and market participants to use scenario simulations to investigate market conditions that could lead to high electricity prices. The model could also be used to analyze market factors (such as new market rules) and their effects on market price dynamics and market participants' behaviors, as well as to identify the &ldquo;best&rdquo; response action of one participant against the opponents' actions. (Copies available exclusively from MIT Libraries, Rm. 14-0551, Cambridge, MA 02139-4307. Ph. 617-253-5668; Fax 617-253-1690.)