ppxscal/embedding_network huggingface dataset:
Simplifying Data Access: The Energy Data Collection Project
Authors: José Luis Ambite, Yigal Arens, Eduard Hovy, Andrew Philpot, Luis Gravano, Vasileios Hatzivassiloglou, Judith Klavans
Venue: Computer (2001)

Using technology developed at the University of Southern California's Information Sciences Institute and Columbia University's Department of Computer Science and its Center for Research on Information Access, the Digital Government Research Center seeks to make government statistical data more accessible through the Internet. The authors face major challenges of integrating dispersed data compiled at different times and for different purposes and over-coming the Web browser paradigm's limitations to disseminate complex information derived from multiple sites.Collaborating with government experts, the DGRC analyzes advanced information systems; develops standards, interfaces, and a shared infrastructure; and manages pilot systems. To address access problems, the authors developed a unified, Web-based user interface for querying and presenting statistical information. Their robust, portable, and efficient interface prototype facilitates user access to data from multiple sources and agencies.
Construction of Extremal Type II Codes over \mbox{\zZ}_4
Authors: Philippe Gaborit, Masaaki Harada
Venue: Designs, Codes and Cryptography (1999)

In this paper, we give a pseudo-random method to construct extremal Type II codes over\ZZ_4 . As an application, we give a number of new extremal Type II codes of lengths 24, 32 and 40, constructed from some extremal doubly-even self-dual binary codes. The extremal Type II codes of length 24 have the property that the supports of the codewords of Hamming weight 10 form 5-(24,10,36) designs. It is also shown that every extremal doubly-even self-dual binary code of length 32 can be considered as the residual code of an extremal Type II code over \ZZ_4.
hp-Discontinuous Galerkin Finite Element Methods with Least-Squares Stabilization
Authors: Paul Houston, Max Jensen, Endre Süli
Venue: Journal of Scientific Computing (2002)

We consider a family of hp-version discontinuous Galerkin finite element methods with least-squares stabilization for symmetric systems of first-order partial differential equations. The family includes the classical discontinuous Galerkin finite element method, with and without streamline-diffusion stabilization, as well as the discontinuous version of the Galerkin least-squares finite element method. An hp-optimal error bound is derived in the associated DG-norm. If the solution of the problem is elementwise analytic, an exponential rate of convergence under p-refinement is proved. We perform numerical experiments both to illustrate the theoretical results and to compare the various methods within the family.
FTC Piles onto Rambus' Standardization Skullduggery
Authors: Richard H. Stern
Venue: IEEE Micro (2002)

The Rambus standardization skullduggery saga continues. As related in the May/June, July/August, and September/October 2001 Micro Law columns, SDRAM technology licensor Rambus sued chipmaker Infineon for patent infringement because Infineon refused to take a license under Rambus' patents. (SDRAMs are synchronous dynamic random-access memory chips. Instead of running asynchronously (like ordinary DRAMs), SDRAMs are refreshed by a synchronous system clock. By 1999, SDRAM had largely replaced asynchronous DRAM.) Infineon then countersued for common-law fraud based on Rambus' alleged abuse of the standard-setting process.
A new lower bound on upper irredundance in the queens' graph
Authors: Matthew D. Kearse, Peter B. Gibbons
Venue: Discrete Mathematics (2002)

The queens' graph Qn has the squares of the n × n chessboard as its vertices, with two squares adjacent if they are in the same row, column, or diagonal. An irredundant set of queens has the property that each queen in the set attacks at least one square which is attacked by no other queen. IR(Qn) is the cardinality of the largest irredundant set of vertices in Qn. Currently the best lower bound for IR(Qn) is IR(Qn) ≥ 2.5n -O(1), while the best upper bound is IR(Qn) ≤ ⌊6n+6 - 8 √n+√n+1⌋ for n ≥ 6. Here the lower bound is improved to IR(Qn) ≥ 6n - O(n2/3). In particular, it is shown for even k ≥ 6 that IR(Qk3)≥ 6k3 - 29k2 - O(k).
Application of a Spectral Element Method to Two-Dimensional Forward-Facing Step Flow
Authors: D. Wilhelm, L. Kleiser
Venue: Journal of Scientific Computing (2002)

In the present study, we investigate the two-dimensional laminar flow through a one-sided constriction of a plane channel with a ratio of h&emsp14;:&emsp14;H&equals;1&emsp14;:&emsp14;4 (where h is the step height and H is the channel height). The computational approach employed is based on a mixed implicit/explicit time discretization scheme together with a highly accurate spatial discretization using a PN&minus;PN&minus;2 spectral-element method. It is well known that this so-called forward-facing step (FFS) flow exhibits a singularity in the pressure and the velocity derivatives at the corner point. We account for this singularity by a geometric mesh refinement strategy that was proposed in a hp-FEM context. A detailed numerical study of the FFS flow reveals that length and height of the recirculation zone in front of the step are almost constant for creeping flow. In the limit of high Reynolds numbers the length and height of the recirculation zone increase proportional to Re0.6 and Re0.2, respectively.
The LDL System Prototype
Authors: D. Chimenti, R. Gamboa, R. Krishnamurthy, S. Naqvi, S. Tsur, C. Zaniolo
Venue: IEEE Transactions on Knowledge and Data Engineering (1990)

The logic data language (LDL) system provides a declarative logic-based language and integrates relational database and logic programming technologies so as to support advanced data and knowledge-based applications. A comprehensive overview of the system and a description of LDL language and the compilation techniques employed to translate LDL queries into target query execution plans on the stored data are presented. The architecture and runtime environment of the system and the optimization techniques employed in order to improve the performance and assure the safety of the compiled queries are given. The experience gained so far with the system and application areas where the LDL approach appears to be particularly effective are discussed.
Virtual Prototyping of Embedded Microcontroller-Based DSP Systems
Authors: Vijay K. Madisetti, Thomas W. Egolf
Venue: IEEE Micro (1995)

The authors propose a new hardware/software codesign process that is based on a design methodology called Virtual Prototyping, wherein VHDL models of hardware components are integrated with application, control, and diagnostic software to rapidly prototype complex multiboard embedded microcontroller-based DSP systems. We discuss this new methodology, compare the process with current system design practice, and describe the improvement in engineering prototyping practice that results.A case study describes a collaboration between Lockheed Sanders, Hughes Avionics Corp., Motorola, and the DSP Laboratory at Georgia Tech, under the auspices of US Department of Defense's ARPA RASSP program, that resulted in the successful virtual prototyping of a 4-GFLOP Infrared Search and Track (IRST) demonstration avionics system. In this study, HW/SW integration and system test completion times are shown to be reduced from the typical industry figure of 10-24 months to less than a month.
Watermarking scheme capable of resisting attacks based on availability of inserter
Authors: Xinpeng Zhang, Shuozhong Wang
Venue: Signal Processing (2002)

Attacks based on the presence of watermark inserter are easy to perform since they make use of similarity between an original watermark and additionally added ones by using the same inserter and key. In this paper, a novel watermarking scheme capable of resisting inserter attacks is proposed. Watermark signals corresponding to the same key are mutually independent if they are randomly selected using the described technique. Thus the inserter attack is invalidated. Performance of the proposed method is studied, and simulation experiments presented.
On Load Balancing for Distributed Multiagent Computing
Authors: Ka-Po Chow, Yu-Kwong Kwok
Venue: IEEE Transactions on Parallel and Distributed Systems (2002)

Multiagent computing on a cluster of workstations is widely envisioned to be a powerful paradigm for building useful distributed applications. The agents of the system span across all the machines of a cluster. Just like the case of traditional distributed systems, load balancing becomes an area of concern. With different characteristics between ordinary processes and agents, it is both interesting and useful to investigate whether conventional load-balancing strategies are also applicable and sufficient to cope with the newly emerging needs, such as coping with temporally continuous agents, devising a performance metric for multiagent systems, and taking into account the vast amount of communication and interaction among agent. This paper discusses the above issues with reference to agent properties and load balancing techniques and outlines the space of load-balancing design choices in the arena of multiagent computing. In view of the special agent characteristics, a novel communication-based load-balancing algorithm is proposed, implemented, and evaluated. The proposed algorithm works by associating a credit value with each agent. The credit of an agent depends on its affinity to a machine, its current workload, its communication behavior, and mobility, etc. When a load imbalance occurs, the credits of all agents are examined and an agent with a lower credit value is migrated to relatively lightly loaded machine in the system. Quasi-simulated experiments of this algorithm show load-balancing improvement compared with conventional workload-oriented load-balancing schemes.
Design and Evaluation of Effective Load Sharing in Distributed Real-Time Systems
Authors: K. G. Shin, C. J. Hou
Venue: IEEE Transactions on Parallel and Distributed Systems (1994)

In a distributed real-time system, uneven task arrivals temporarily overload some nodesand leave others idle or underloaded. Consequently, some tasks may miss their deadlineseven if the overall system has the capacity to meet the deadlines of all tasks. Aneffective load-sharing (LS) scheme is proposed as a solution to this problem. Upon arrival of a task at a node, the node determines whether the node can complete the task in time under the minimum-laxity first-served policy. If the task cannot be guaranteed, or if guarantees of some other tasks are to be violated as a result of the addition of this taskto the existing schedule, the node looks up the list of loss-minimizing decisions anddetermines the best node among a set of nodes in its physical proximity, called its buddyset, to which the task(s) may be transferred. This list of decisions is periodically updatedusing Bayesian decision analysis and prior/posterior state distributions. These probabilitydistributions are derived from the information collected via time-stamped state-regionchange broadcasts within each buddy set. By characterizing the inconsistency between anode's "observed" state and the corresponding true state with prior and posteriordistributions, the node can first estimate the states of other nodes, and then use themto reduce the probability of transferring a task to an "incapable") node. Moreover, the useof prior and posterior distributions and Bayesian analysis has made the proposed schemerobust to the variation of design parameters that usually require fine-tuning for adaptiveLS. The performance of the proposed scheme is evaluated via simulation, along with fiveother schemes: no LS, LS with state probing, LS with random selection, LS with focusedaddressing, and perfect LS.
Reduction design for generic universal switch blocks
Authors: Hongbing Fan, Jiping Liu, Yu-Liang Wu, C. K. Wong
Venue: ACM Transactions on Design Automation of Electronic Systems (TODAES) (2002)

A k-side switch block with W terminals per side is said to be a universal switch block ((k, W)-USB) if every set of the nets satisfying the routing constraint (i.e., the number of nets on each side is at most W) is simultaneously routable through the switch block. The (4, W)-USB was originated by designing better switch modules for 2-D FPGAs, such as Xilinx XC4000-type FPGAs, whereas the generic USBs can be applied in multidimensional or some nonconventional 2-D FPGA architectures. The problem we study in this article is to design (k, W)-USBs with the minimum number of switches for any given pair of (k, W). We provide graph models for routing requirements and switch blocks and develop a series of decomposition theorems for routing requirements with the help of a new graph model. The powerful decomposition theory leads to the automatic generation of routing requirements and a detailed routing algorithm, as well as the reduction design method of building large USBs by smaller ones. As a result, we derive a class of well-structured and highly scalable optimum (k, W)-USBs for k &le; 6, or even Ws, and near-optimum (k, W)-USBs for k &ge; 7 and odd Ws. We also give routing experiments to justify the routing improvement upon the entire chip using the USBs. The results demonstrate the usefulness of USBs.
Optimal Distribution of Signatures in Signature Hashing
Authors: M. V. Ramakrishna, E. A. Ramos
Venue: IEEE Transactions on Knowledge and Data Engineering (1992)

G.H. Gonnet and P.A. Larson (1982) proposed a hashing scheme for external files which guarantees single access retrieval. They provided an asymptotic analysis of the scheme assuming uniform distribution of the signatures. This paper addresses an open problem posed by them in a second work (J. ACM, vol.35, no.1, p.161-84, 1988) about the performance of signatures having a skew distribution. An optimization problem is formulated to obtain the optimal signature distribution which maximizes the resulting load factor. Numerical results indicate that the optimal signature distribution results in significant reduction in the cost of insertions, which is of practical significance.
Direct Estimation of Shape from Texture
Authors: J. Garding
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (1993)

Witkin (1981) has proposed a maximum likelihood (ML) estimator of surface orientation based on the observed directional bias of projected texture elements. However, a drawback of this procedure is that the estimate is only defined indirectly in terms of a set of nonlinear equations. An alternative method is proposed, which allows an estimate of the surface orientation to be computed directly in a single step from certain simple statistics of the image data. We also show that this direct estimate allows Witkin's ML estimate to be computed to within 0.05 degrees in only two or three iterative steps. The performance of the new estimator is demonstrated experimentally and compared to that of the ML estimator, using both synthetic data and real gray-level images.
Liability for Autonomous Agent Design
Authors: Carey Heckman, Jacob O. Wobbrock
Venue: Autonomous Agents and Multi-Agent Systems (1999)

Though exciting scientifically, autonomous agent design can result in legal liability. This paper surveys those legal concerns, focusing on issues arising from the unique qualities of agents not found in conventional software. Informed designers can more effectively reduce their liability exposure and influence emerging agent liability law and policies.
A Database Approach for Modeling and Querying Video Data
Authors: Mohand-Saïd Hacid, Cyril Decleir, Jacques Kouloumdjian
Venue: IEEE Transactions on Knowledge and Data Engineering (2000)

Indexing video data is essential for providing content-based access. In this paper, we consider how database technology can offer an integrated framework for modeling and querying video data. As many concerns in video (e.g., modeling and querying) are also found in databases, databases provide an interesting angle to attack many of the problems. From a video applications perspective, database systems provide a nice basis for future video systems. More generally, database research will provide solutions to many video issues, even if these are partial or fragmented. From a database perspective, video applications provide beautiful challenges. Next generation database systems will need to provide support for multimedia data (e.g., image, video, audio). These data types require new techniques for their management (i.e., storing, modeling, querying, etc.). Hence, new solutions are significant. This paper develops a data model and a rule-based query language for video content-based indexing and retrieval. The data model is designed around the object and constraint paradigms. A video sequence is split into a set of fragments. Each fragment can be analyzed to extract the information (symbolic descriptions) of interest that can be put into a database. This database can then be searched to find information of interest. Two types of information are considered: 1) the entities (objects) of interest in the domain of a video sequence, and 2) video frames which contain these entities. To represent this information, our data model allows facts as well as objects and constraints. The model consists of two layers: 1) Feature & Content Layer (or Audiovisual Layer), intended to contain video visual features such as colors, contours, etc., 2) Semantic Layer, which provides the (conceptual) content dimension of videos. We present a declarative, rule-based, constraint query language that can be used to infer relationships about information represented in the model. Queries can refer to the form dimension (i.e., information of the Feature & Content Layer), to the content dimension (i.e., information of the Semantic Layer), or to both. A program of the language is a rule-based system formalizing our knowledge of a video target application and it can also be considered as a (deductive) video database on its own right. The language has both a clear declarative and operational semantics.
Integrating Calendar Dates and Qualitative Temporal Constraints in the Treatment of Periodic Events
Authors: Paolo Terenziani
Venue: IEEE Transactions on Knowledge and Data Engineering (1997)

The paper describes a framework for representing and reasoning with periodic events. In particular, it proposes a temporal formalism which deals with both 1) quantitative information concerning the frame of time (e.g., between 1990 and 1993) and the user-defined calendar-dates (e.g., on the first Mondays of April) in which periodic events are located and 2) the qualitative relations between periodic events (e.g., Sam visits the branch office X01 before going to his office). The meaning of the temporal specifications in our formalism is described in logical terms. The paper defines the basic operations of inversion, intersection and composition of temporal specifications. These operations are correct (with respect to the logical definition of the specifications) and do not lose information. Finally, the paper also describes a correct algorithm which takes advantage of these operations for performing temporal reasoning, and analyses its complexity. An application of the temporal framework to the scheduling in an office is shown in an example.
Higher Order May Be Better or May Not Be Better: Investigations with the FDEM (Finite Difference Element Method)
Authors: Willi Schönauer, Torsten Adolph
Venue: Journal of Scientific Computing (2002)

The FDEM program package is a black-box solver for nonlinear systems of elliptic and parabolic PDEs. A FDM of arbitrary consistency order q on an unstructured basic FEM mesh is used. With the difference formula of order q+2 an error estimate is computed. A sophisticated algorithm has been developed to generate reliable difference formulae of order q on an unstructured grid. Completely new is the usage of the error estimate to determine under such general conditions for each node i its individual optimal order q(i) out of the orders 2, 4, 6. This order control tells us that higher order may be better or may not be better, depending on the character of the solution and the used mesh.
Divergence-Free Wavelet Analysis of Turbulent Flows
Authors: Cem M. Albukrek, Karsten Urban, Dietmar Rempfer, John L. Lumley
Venue: Journal of Scientific Computing (2002)

In this paper we study the application of divergence-free wavelet bases for the analysis of incompressible turbulent flows and perform several experiments. In particular, we analyze various nominally incompressible fields and study the influence of compressible perturbations due to experimental and computational errors. In addition, we investigate the multiscale structure of modes obtained from the Proper Orthogonal Decomposition (POD) method. Finally, we study the divergence-free wavelet compression of turbulent flow data and present results on the energy recovery. Moreover, we utilize wavelet decompositions to investigate the regularity of turbulent flow fields in certain non-classical function spaces, namely Besov spaces. In our experiments, we have observed significantly higher Besov regularity than Sobolev regularity, which indicates the potential for adaptive numerical simulations.
Calibration of Microprocessor Performance Models
Authors: Bryan Black, John Paul Shen
Venue: Computer (1998)

The microprocessor industry can capably predict the clock frequency and functionality of first siliconýthe first small set of chips made for a new design. However, predicting first silicon's performance on real programs remains a challenge. Microprocessor designers use performance models to evaluate how new ideas affect performance. However, it is very difficult to know if these models are accurate. The problem lies in understanding the true performance effect of a new feature. In an unstable performance model, model changes may inadvertently remove existing bugs, introduce new bugs, or reduce the performance impact of an existing bug. This effect can mislead designers into implementing features that do not actually improve performance or not implementing features that would. This article presents experimental results on calibrating a performance model against actual hardware, and on the basis of these results, suggests a systematic method for validating performance models. These results highlight the difficulty in developing an accurate performance model. As microarchitecture complexity continues to increase, especially with the incorporation of aggressive speculation techniques, accurate performance modeling and the validation of performance models will continue to be a great challenge.
Is APL really processing arrays?
Authors: Kevin E. Jordan
Venue: ACM SIGAPL APL Quote Quad (1979)

This paper describes a study of the performance of APL. The study was carried out by placing code in an existing APL interpreter (APLUM running on a CDC CYBER 175 computer) to monitor the distribution of data types, element counts, and ranks of arrays. The effect of reference counts on data blocks was also monitored. Although the results of the study may not be surprising, they are very interesting. For example, it turns out that nearly half of all allocations of data are made for scalars or one-element vectors, and that although the over-all average number of elements in APL arrays is 30, most users achieve average element counts of around 10. From these figures, it can be shown that set-up time dominates the execution of APL expressions.