ppxscal/embedding_network huggingface dataset:
Transmission line design of clock trees
Authors: Rafael Escovar, Robert Suaya
Venue: Proceedings of the 2002 IEEE/ACM international conference on Computer-aided design (2002)

We investigate appropriate regimes for transmission line propagation of signals on digital integrated circuits. We start from exact solutions to the transmission line equations proposed by Davis and Meindl. We make appropriate modifications due to finite rise time. They affect the delay calculation and hypothesis pertaining the constancy of the electromagnetic parameters. We study these effects in detail. To find the domain of physical variables where transmission line behavior is feasible, we pose the problem as a nonlinear minimization problem in a space spanned by two continuous variables, with four parameters. From the resulting solutions and employing monotonicity properties of the functional we extract regimes of validity. These regimes of validity happen to be commensurate with what is reachable and doable with todays leading technologies. We complete this study with a qualitative analysis of driver insertion in the presence of transmission lines. The resulting configurations are suitable for the development of an improved clock design discipline.
Semantic caching of Web queries
Authors: Boris Chidlovskii, Uwe M. Borghoff
Venue: The VLDB Journal &mdash; The International Journal on Very Large Data Bases (2000)

In meta-searchers accessing distributed Web-based information repositories, performance is a major issue. Efficient query processing requires an appropriate caching mechanism. Unfortunately, standard page-based as well as tuple-based caching mechanisms designed for conventional databases are not efficient on the Web, where keyword-based querying is often the only way to retrieve data. In this work, we study the problem of semantic caching of Web queries and develop a caching mechanism for conjunctive Web queries based on signature files. Our algorithms cope with both relations of semantic containment and intersection between a query and the corresponding cache items. We also develop the cache replacement strategy to treat situations when cached items differ in size and contribution when providing partial query answers. We report results of experiments and show how the caching mechanism is realized in the Knowledge Broker system.
A Foundation for Flexible Automated Electronic Communication
Authors: Scott A. Moore
Venue: Information Systems Research (2001)

In this paper the author describes a formal language for communication based on linguistics--more specifically, a theory of natural language communication and models of natural language conversations. The language has a small number of general message types that are formally defined by their intended effects on the recipient. For each message type he defines a standard automated method of responding that depends only on the message type and is independent of the message's content. For more complex conversations he provides methods for responding that do depend on the content. In this system, a message's sender--automated or human--constructs and sends a message knowing that he cannot know, but can only predict, how it will be interpreted. The agent receiving the message interprets it and then uses it as a basis for inferring how he should respond. The message interpretation mechanism for this language is reusable, modular, and shared by all applications. The benefit of this communication system is that it makes the communication infrastructure more flexible, easier to modify, easier to expand, and more capable.
Nested Parallel Call Optimization
Authors: Enrico Pontelli, Gopal Gupta
Venue: Proceedings of the 10th International Parallel Processing Symposium (1996)

We present a novel optimization called Last Parallel Call Optimization (LPCO) for parallel systems. The last parallel call optimization can be regarded as a parallel extension of last call optimization found in sequential systems. While the LPCO is fairly general, we use and-parallel logic programming systems to illustrate it and to report its performance on multiprocessor systems.The last parallel call optimization leads to improved time and space performance for a majority of and-parallel programs. We also present a generalization of the Last Parallel Call Optimization called Nested Parallel Call Optimization (NPCO). A major advantage of LPCO and NPCO is that parallel systems designed for exploiting control parallelism can automatically exploit data parallelism efficiently.
Pruning-based energy-optimal device scheduling for hard real-time systems
Authors: Vishnu Swaminathan, Krishnendu Chakrabarty
Venue: Proceedings of the tenth international symposium on Hardware/software codesign (2002)

Dynamic Power Management (DPM) provides a simple, elegant and flexible method for reducing energy consumption in embedded real-time systems. However, I/O-centric DPM techniques have been studied largely for non-real-time environments. We present an offline device scheduling technique for real-time systems that generates an energy-optimal device schedule for a given task set while guaranteeing that all real-time deadlines are met. Our method takes as inputs a task set and a device-usage list for each task, and it schedules the tasks such that the energy consumed by the set of I/O devices is minimized. We compare our algorithm to an exhaustive enumeration method and show that the proposed algorithm is very efficient in terms of memory usage and computation time. We also present case studies to show that I/O-centric DPM methods can result in significant energy savings.
What is a place?: allowing users to name and define places
Authors: Petra Fagerberg, Fredrik Espinoza, Per Persson
Venue: CHI '03 extended abstracts on Human factors in computing systems (2003)

From working with location-based information systems we know that positioning is problematic. A different approach was tested, where users themselves were allowed to name and define the places they wanted to use. The question was if they would do so, and if they would understand the notion of "place". In a user study, 78 users created 84 place labels. The user study also gave us some unexpected input to the users' perception of place: not only physical, but also virtual places were created.
Single-pass low-storage arbitrary quantile estimation for massive datasets
Authors: John C. Liechty, Dennis K. J. Lin, James P. McDermott
Venue: Statistics and Computing (2003)

We present a single-pass, low-storage, sequential method for estimating an arbitrary quantile of an unknown distribution. The proposed method performs very well when compared to existing methods for estimating the median as well as arbitrary quantiles for a wide range of densities. In addition to explaining the method and presenting the results of the simulation study, we discuss intuition behind the method and demonstrate empirically, for certain densities, that the proposed estimator converges to the sample quantile.
Text Mining in the SOMLib Digital Library System: The Representation of Topics and Genres
Authors: Andreas Rauber, Dieter Merkl
Venue: Applied Intelligence (2003)

With the increasing amount of textual information available in electronic form, more powerful methods for exploring, searching, and organizing the available mass of information are needed to cope with this situation. This paper presents the SOMLIb digital library system, built on neural networks to provide text mining capabilities. At its foundation we use the Self-Organizing Map to provide content-based clustering of documents. By using an extended model, i.e. the Growing Hierarchical Self-Organizing Map, we can further detect subject hierarchies in a document collection, with the neural network adapting its size and structure automatically during its unsupervised training process to reflect the topical hierarchy. By mining the weight vector structure of the trained maps our system is able to select keywords describing the various topical clusters. Text mining has to incorporate more than the mere analysis of content. Structural and genre information are key in organizing and locating information. Using color-coding techniques we can integrate a structural analysis of documents based on Self-Organizing Maps into the subject-based clustering relying on metaphor graphics for intuitive visualization. We demonstrate the capabilities of the SOMLib system using collections of articles from various newspapers and magazines.
A Conceptual and Operational Definition of Personal Innovativeness in the Domain of Information Technology
Authors: Ritu Agarwal, Jayesh Prasad
Venue: Information Systems Research (1998)

The acceptance of new information technologies by their intended users persists as an important issue for researchers and practitioners of information systems. Several models have been developed in the literature to facilitate understanding of the process by which new information technologies are adopted. This paper proposes a new construct that further illuminates the relationships explicit in the technology acceptance models and describes an operational measure for this construct that possesses desirable psychometric properties. The construct, personal innovativeness in the domain of information technology, is hypothesized to exhibit moderating effects on the antecedents as well as the consequences of individual perceptions about a new information technology. The construct was developed and validated in the context of the innovation represented by the World-Wide Web. Implications for theory and practice are discussed.
Text Retrieval from Document Images Based on Word Shape Analysis
Authors: Chew Lim Tan, Weihua Huang, Sam Yuan Sung, Zhaohui Yu, Yi Xu
Venue: Applied Intelligence (2003)

In this paper, we propose a method of text retrieval from document images using a similarity measure based on word shape analysis. We directly extract image features instead of using optical character recognition. Document images are segmented into word units and then features called vertical bar patterns are extracted from these word units through local extrema points detection. All vertical bar patterns are used to build document vectors. Lastly, we obtain the pair-wise similarity of document images by means of the scalar product of the document vectors. Four corpora of news articles were used to test the validity of our method. During the test, the similarity of document images using this method was compared with the result of ASCII version of those documents based on the N-gram algorithm for text documents.
Mutual Informational Coordination in Incompletely Connected Multicomputer Systems
Authors: I. V. Asharina, A. V. Lobanov, I. G. Mishenko
Venue: Automation and Remote Control (2003)

Conditions for mutual informational coordination in incompletely connected multicomputer systems were considered. An algorithm of mutual informational coordination in such systems was presented.
Identification of chemical species emission and sensitivity analysis with variational assimilation of restricted artificial observations
Authors: S. Massart, J. P. Argaud, A. Piacentini, O. Thual
Venue: Development and application of computer techniques to environmental studies (2002)

Recent developments in the field of chemical data assimilation have led to a variational analysis where the results are generally used as the initial condition for forecasting. Such analysis method is able to adjust other model parameters like emissions which are not available with conventional techniques. Using a simplified one-dimensional urban chemistry transport model, this paper presents the identification of the ground flux pollutants with data assimilation twin experiments. It also describes the initial effort in the understanding of the influence of each observed species on the quality of a two-dimensional variational analysis system.
Interface specification for reconfigurable components
Authors: Satnam Singh
Venue: Proceedings of the 2002 IEEE/ACM international conference on Computer-aided design (2002)

This paper presents a way of encoding some kinds of dynamic reconfiguration behaviour in the interface portion of circuit descriptions. This has many advantages. The user of a reconfigurable circuit has some knowledge about the reconfigurable interface of the circuit. Static analysis tools can make better decisions about how to schedule virtual hardware. And most importantly the compiler can automatically synthesize the required interface between reconfigurable portions of the system and the regular portions of the design. Several existing models of dynamic reconfiguration from the literature are captured using our type system extension based on sum types. This is especially important in System-on-Chip (SoC) contexts where a reconfigurable IP block may have to communicate over a non-trivial IP bus like CoreConnect&trade;.
Energy saving and capacity improvement potential of power control in multi-hop wireless networks
Authors: Jeffrey Monks, Jean-Pierre Ebert, Wen-Mei W. Hwu, Adam Wolisz
Venue: Computer Networks: The International Journal of Computer and Telecommunications Networking (2003)

This study investigates the potential of using transmission power control in wireless packet networks with differing number of hops between source and destination nodes. Here we exploit the benefits of power control in the context of multi-hop wireless ad hoc type networks with a distributed media access control. For our investigations we choose several general ad hoc network topologies and study the effects of power control with respect to energy consumption and network capacity, We show that power control largely improves the network capacity and energy savings in all investigated scenarios, and that utilizing a greater number of intermediate hops between source and destination nodes improves the energy savings though may cause a tradeoff in capacity, depending on the network topology considered.
Event-driven simulation of spiking neurons with stochastic dynamics
Authors: Jan Reutimann, Michele Giugliano, Stefano Fusi
Venue: Neural Computation (2003)

We present a new technique, based on a proposed event-based strategy (Mattia & Del Giudice, 2000), for efficiently simulating large networks of simple model neurons. The strategy was based on the fact that interactions among neurons occur by means of events that are well localized in time (the action potentials) and relatively rare. In the interval between two of these events, the state variables associated with a model neuron or a synapse evolved deterministically and in a predictable way. Here, we extend the event-driven simulation strategy to the case in which the dynamics of the state variables in the inter-event intervals are stochastic. This extension captures both the situation in which the simulated neurons are inherently noisy and the case in which they are embedded in a very large network and receive a huge number of random synaptic inputs. We show how to effectively include the impact of large background populations into neuronal dynamics by means of the numerical evaluation of the statistical properties of single-model neurons under random current injection. The new simulation strategy allows the study of networks of interacting neurons with an arbitrary number of external afferents and inherent stochastic dynamics.
Supporting efficient multimedia database exploration
Authors: Wen-Syan Li, K.Selçuk Candan, Kyoji Hirata, Yoshinori Hara
Venue: The VLDB Journal &mdash; The International Journal on Very Large Data Bases (2001)

Due to the fuzziness of query specification and media matching, multimedia retrieval is conducted by way of exploration. It is essential to provide feedback so that users can visualize query reformulation alternatives and database content distribution. Since media matching is an expensive task, another issue is how to efficiently support exploration so that the system is not overloaded by perpetual query reformulation. In this paper, we present a uniform framework to represent statistical information of both semantics and visual metadata for images in the databases. We propose the concept of query verification, which evaluates queries using statistics, and provides users with feedback, including the strictness and reformulation alternatives of each query condition as well as estimated numbers of matches. With query verification, the system increases the efficiency of the multimedia database exploration for both users and the system. Such statistical information is also utilized to support progressive query processing and query relaxation.
Who participates and why?: an analysis of citizens on the internet and the mass public
Authors: Lori M. Weber, Alysha Loumakis, James Bergman
Venue: Social Science Computer Review (2003)

Scholars continue to find that political participation, especially beyond voting, is in limited supply in the United States. However, the rise of the Internet provides possibilities to mitigate such circumstances. Some scholars suggest that the Internet disconnects citizens from public life, while other studies note that it provides a venue for further participation in public life. The question remains as to whether the Internet mobilizes or demobilizes citizens. The article explores this question using Survey2000, a comprehensive, Internet-based, social scientific survey conducted in 1998 by scholars at Northwestern University in conjunction with the National Geographic Society. A positive relationship is found between engagement on the Internet and civic and political participation. However, the article also finds that the Internet appears to exacerbate the socioeconomic bias already exhibited by civic and political participation prior to the rise of the Internet.
The Cauchy problem for the nonlinear integro-partial differential equation in quantitative sociodynamics
Authors: Minoru Tabata, Nobuoki Eshima
Venue: Applied Mathematics and Computation (2002)

The master equation is a nonlinear integro-partial differential equation, which describes the evolution of various quantities in quantitative sociodynamics. For example, the master equation can describe interregional migration. The purpose of this paper is to obtain asymptotic estimates for solutions to the Cauchy problem for the equation.
Infinitary lambda calculus and discrimination of Berarducci trees
Authors: Mariangiola Dezani-Ciancaglini, Paula Severi, Fer-Jan de Vries
Venue: Theoretical Computer Science (2003)

We propose an extension of lambda calculus for which the Berarducci trees equality coincides with observational equivalence, when we observe rootstable or rootactive behavior of terms. In one direction the proof is an adaptation of the classical Böhm out technique. In the other direction the proof is based on confluence for Strongly converging reductions in this extension.
Network-Optimized Road Pricing: Part II: Algorithms and Examples
Authors: Robert B. Dial
Venue: Operations Research (1999)

The conclusion of a two-part series, this paper devises an algorithm that finds a system of optimal tolls in a road network whose trips have a stochastic value of time. As formulated in Part I, the model is a variational inequality, equivalent to a specialized bicriterion equilibrium traffic assignment whose solution reflects a traffic flow simultaneously user- and system-optimal. To compute these optimal tolls, our algorithm uses restricted simplicial decomposition. It solves the subproblem (direction step) with a novel multipath traffic assignment that obviates path enumeration. It solves the master problem (averaging step) using nonlinear complementarity. For real-world applications, where the algorithm's precondition that every congested arc may have a toll is impractical, this paper enhances the model to include link-specific upper and lower bounds on tolls. This more realistic model is solved with an heuristic using the optimization algorithm to its advantage. As our performance statistics show, the algorithm's speed makes it a practical planning tool. Experiments with the heuristic support the welcome hypothesis that a few well placed and properly priced tolls can reduce traffic congestion dramatically.
The time-rescaling theorem and its application to neural spike train data analysis
Authors: Emery N. Brown, Riccardo Barbieri, Valérie Ventura, Robert E. Kass, Loren M. Frank
Venue: Neural Computation (2002)

Measuring agreement between a statistical model and a spike train data series, that is, evaluating goodness of fit, is crucial for establishing the model's validity prior to using it to make inferences about a particular neural system. Assessing goodness-of-fit is a challenging problem for point process neural spike train models, especially for histogram-based models such as perstimulus time histograms (PSTH) and rate functions estimated by spike train smoothing. The time-rescaling theorem is a well-known result in probability theory, which states that any point process with an integrable conditional intensity function may be transformed into a Poisson process with unit rate. We describe how the theorem may be used to develop goodness-of-fit tests for both parametric and histogram-based point process models of neural spike trains. We apply these tests in two examples: a comparison of PSTH, inhomogeneous Poisson, and inhomogeneous Markov interval models of neural spike trains from the supplementary eye field of a macque monkey and a comparison of temporal and spatial smoothers, inhomogeneous Poisson, inhomogeneous gamma, and inhomogeneous inverse gaussian models of rat hippocampal place cell spiking activity. To help make the logic behind the time-rescaling theorem more accessible to researchers in neuroscience, we present a proof using only elementary probability theory arguments. We also show how the theorem may be used to simulate a general point process model of a spike train. Our paradigm makes it possible to compare parametric and histogram-based neural spike train models directly. These results suggest that the time-rescaling theorem can be a valuable tool for neural spike train data analysis.
Modeling the Impacts of the 1990 Clean Air Act Amendments
Authors: Thanh Luong, Frederic H. Murphy, Reginald Sanders, Susan H. Holte, Peter Whitman
Venue: Interfaces (1998)

The Clean Air Act Amendments of 1990 changed the regulations for air pollution by replacing a set of mandated actions with a market mechanism for pollution rights, where electric utilities can buy or sell rights to emit sulphur dioxide (SO2). We implemented the provisions related to the reduction in SO2 in the National Energy Modeling System (NEMS) to assess their impacts on energy markets. Because of the decentralized design of NEMS, the implementation was quite complex. We had to use Lagrangian relaxation, which turned out to be more difficult than first envisioned, and other techniques to arrive at a consistent equilibrium among the relevant energy sectors. As a result of these difficulties, we revised the NEMS model. This exercise illustrates that often an organization should be ready to take a step back from what exists to take a step forward.
An extremal problem and an estimation of the Wronskian of certain Jacobi polynomials
Authors: Xin Li
Venue: Journal of Computational and Applied Mathematics (2003)

We study an extremal problem related to "splitted" Jacobi weights: for α, β 0, find the largest value of maxx∈[-1,1][(1 + x)β pm(x)2 + (1 - x)αqn(x)2] among all polynomials pm and qn of degree at most m and n, respectively, satisfying ∫-11 [(1 + x)β pm(x)2 + (1 - x)αqn(x)2]dx = 1. We show that the solution of this problem is related to an estimation of the Christoffel functions and the Wronskians associated with certain Jacobi polynomials.