ppxscal/embedding_network huggingface dataset:
Minimizing Pattern Count for Interconnect Test under a Ground Bounce Constraint
Authors: Erik Jan Marinissen, Bart Vermeulen, Henk Hollmann, R. G. (Ben) Bennetts
Venue: IEEE Design Test (2003)

Editor's note:When testing the interconnect structures on a board, test programmers sometimes ask, How can I control the test pattern generation process to avoid ground bounce problems during Extest mode? Those wishing to satisfy a simultaneously-switching-outputs constraint will find several new solutions in this article.ýMonica Lobetti-BodoniSiemens Mobile Communications
Learning elementary formal systems with queries
Authors: Hiroshi Sakamoto, Kouichi Hirata, Hiroki Arimura
Venue: Theoretical Computer Science (2003)

The elementary formal system (EFS) is a kind of logic programs which directly manipulates strings, and the learnability of the subclass called hereditary EFSs (HEFSs) has been investigated in the frameworks of the PAC-learning, query-learning, and inductive inference models. The hierarchy of HEFS is expressed by HEFS(m,k,t,r), where m, k, t and r denote the number of clauses, the occurrences of variables in the head, the number of atoms in the body, and the arity of predicate symbols. The present paper deals with the learnability of HEFS in the query learning model using equivalence queries and additional queries such as membership, predicate membership, entailment membership, and dependency queries. We show that the class HEFS(*, k, t, r) is polynomial-time learnable with the equivalence and predicate membership queries and the class HEFS(*,k,*,r) with termination property is polynomial-time learnable with the equivalence, entailment membership, and dependency queries for the unbounded parameter *. A lowerbound on the number of queries is presented. We also show that the class HEFS(*,k,t,r) is hard to learn with the equivalence and membership queries under the cryptographic assumptions. Furthermore, the learnability of the class of unions of regular pattern languages, which is a subclass of HEFSs, is investigated. The bounded unions of regular pattern languages are polynomial-time predictable with membership query. However, all unbounded unions of regular pattern languages are not polynomial-time predictable with membership queries if neither are the DNF formulas.
List-ranking on interconnection networks
Authors: Jop F. Sibeyn
Venue: Information and Computation (2003)

The list-ranking problem is considered for parallel computers which communicate through an interconnection network. Each PU holds k nodes of a set of linked lists. A novel randomized algorithm gives a considerable improvement over earlier ones: for a large class of networks and sufficiently large k, it takes only twice the number of steps required by a k-k routing. For hypercubes the condition is k = ω(log2 N). Even better results are achieved for d-dimensional meshes: we show that the ranking time exceeds the routing time only by lower-order terms for all k = ω(d2). We also show that list-ranking requires at least the time required for k-k routing. Thus, the results are within a factor two from optimal, those for meshes even match the lower bound up to lower-order terms.
Improving Access to Science and Math Education in Western Pennsylvania
Authors: Ashok Srinivasan, Robert P. Strauss
Venue: Interfaces (1999)

Seven out of every 10 American jobs are expected to be related to technologies using advanced computers and electronics, requiring workers with strong math and science skills. However, school systems in several regions in the US that have suffered economic and demographic declines are having problems maintaining and improving math and science education. We conducted a study and engendered cooperation between school districts to improve student access to math and science courses in one such region. We first examined the math and science curricula, predicted enrollment rates, forecasted teacher availability, and analyzed access characteristics for a set of school districts in Western Pennsylvania known as the Mon Valley Education Consortium. We then proposed strategies for cooperation between the school districts that included moving students to multiple centers for advanced math and science courses, moving teachers between schools, and using an area vo-tech school as a math and science center. As a result of the study a pilot project was implemented signaling the beginning of regional cooperation in the area.
ANOVA for unbalanced data: Use Type II instead of Type III sums of squares
Authors: Øyvind Langsrud
Venue: Statistics and Computing (2003)

Methods for analyzing unbalanced factorial designs can be traced back to Yates (1934). Today, most major statistical programs perform, by default, unbalanced ANOVA based on Type III sums of squares (Yates's weighted squares of means). As criticized by Nelder and Lane (1995), this analysis is founded on unrealistic models&mdash;models with interactions, but without all corresponding main effects. The Type II analysis (Yates's method of fitting constants) is usually not preferred because of the underlying assumption of no interactions. This argument is, however, also founded on unrealistic models. Furthermore, by considering the power of the two methods, it is clear that Type II is preferable.
Continuous-Time Airline Overbooking with Time-Dependent Fares and Refunds
Authors: William Cook, Andre Rohe, Richard E. Chatwin
Venue: Transportation Science (1999)

We analyze a model of airline overbooking in which customer cancellations and no-shows are explicitly considered. We model the reservations process as a continuous-time birth-and-death process with rewards representing the fares received and refunds paid and a terminal-value function representing the bumping penalty. The airline controls the reservation acceptance (birth) rate by declining reservation requests. Assuming that the fares and refunds are piecewise-constant functions of the time to flight, we demonstrate that a piecewise-constant booking limit policy is optimal, i.e., at all times, the airline accepts reservation requests up to a booking limit if the current number of reservations is less than that booking limit, and declines reservation requests otherwise. When the fare is constant over time or falls toward flight time, the optimal booking limit falls toward flight-time.
Information and Communication: Alternative Uses of the Internet in Households
Authors: Robert Kraut, Tridas Mukhopadhyay, Janusz Szczypula, Sara Kiesler, Bill Scherlis
Venue: Information Systems Research (1999)

the Internet a superhighway to information or a high-tech extension of the home tele- phone? We address this question by operationalizing information acquisition and enter- tainment as the use of the World Wide Web and interpersonal communication as the use of electronic mail (e-mail), and examine how 229 members of 110 households used these services during their first year on the Internet. The results show that e-mail drives people's use of the Internet. Participants used e-mail in more Internet sessions and more consistently than they used the World Wide Web, and they used e-mail first in sessions where they used both. Participants used the Internet more after they had used e-mail heavily, but they used the Internet less after they had used the Web heavily. While participants' use of both e-mail and the Web declined with time, the decline in Web use was steeper. Those who used e-mail more than they used the Web were also more likely to continue using the Internet over the course of a year. Our findings have implications for engineering and policies for the Internet and, more generally, for studies of the social impact of new technology.
Modeling and Solving the Train Timetabling Problem
Authors: Alberto Caprara, Matteo Fischetti, Paolo Toth
Venue: Operations Research (2002)

The train timetabling problem aims at determining a periodic timetable for a set of trains that does not violate track capacities and satisfies some operational constraints. In particular, we concentrate on the problem of a single, one-way track linking two major stations, with a number of intermediate stations in between. Each train connects two given stations along the track (possibly different from the two major stations) and may have to stop for a minimum time in some of the intermediate stations. Trains can overtake each other only in correspondence of an intermediate station, and a minimum time interval between two consecutive departures and arrivals of trains in each station is specified.In this paper, we propose a graph theoretic formulation for the problem using a directed multigraph in which nodes correspond to departures/arrivals at a certain station at a given time instant. This formulation is used to derive an integer linear programming model that is relaxed in a Lagrangian way. A novel feature of our model is that the variables in the relaxed constraints are associated only with nodes (as opposed to arcs) of the aforementioned graph. This allows a considerable speed-up in the solution of the relaxation. The relaxation is embedded within a heuristic algorithm which makes extensive use of the dual information associated with the Lagrangian multipliers. We report extensive computational results on real-world instances provided from Ferrovie dello Stato SpA, the Italian railway company, and from Ansaldo Segnalamento Ferroviario SpA.
Exploring Beowulf clusters
Authors: Marsha Meredith, Teresa Carrigan, James Brockman, Timothy Cloninger, Jaroslav Privoznik, Jeffery Williams
Venue: Journal of Computing Sciences in Colleges (2003)

Beowulf clusters provide the computational power of parallel programming at minimal cost, making this technology available to small colleges and individual labs. In this paper, we explore the construction and programming of four distinct varieties of Beowulf clusters over the Linux operating system. We compare the clusters for: ease of construction; ease of use and support; and (in a preliminary way) computational efficiency. As newcomers to both Beowulf and Linux, our experiences may be useful to others considering experimenting with cluster computing. In this spirit, we provide many useful links and references.
A delay metric for RC circuits based on the Weibull distribution
Authors: Frank Liu, Chandramouli Kashyap, Charles J. Alpert
Venue: Proceedings of the 2002 IEEE/ACM international conference on Computer-aided design (2002)

Physical design optimizations such as placement, interconnect synthesis, oorplanning, and routing require fast and accurate analysis of RC networks. Because of its simple close form and fast evaluation, the Elmore delay metric has been widely adopted. The recently proposed delay metrics PRIMO and H-gamma match the rst three circuit moments to the probability density function of a Gamma statistical distribution. Although these methods demonstrate impressive accuracy compared to other delay metrics, their implementations tend to be challenging. As an alternative to matching to the Gamma distribution, we propose to match the rst two circuit moments to a Weibull distribution. The result is a new delay metric called Weibull based Delay (WED). The primary advantages of WED over PRIMO and H-gamma are its efciency and ease of implementation. Experiments show that WED is robust and has satisfactory accuracies at both near and far-end nodes.
Ordinal sums of aggregation operators
Authors: Bernard De Baets, Radko Mesiar
Venue: Technologies for constructing intelligent systems: tools (2002)

In this work, aggregation operators are to be understood in their most general sense, i.e. as families of operators, one for each arity. We characterize the smallest and greatest aggregation operators with a predefined behaviour in case all arguments are taken from the same interval (belonging to a system of pairwise disjoint open intervals). Similarly, we characterize the smallest and greatest idempotent aggregation operators with a predefined idempotent behaviour. Relationships with classical ordinal sum constructions are investigated.
Rook polynomials to and from permanents
Authors: Gi-Sang Cheon, Suk-Geun Hwang, Seok-Zun Song
Venue: Discrete Mathematics (2003)

In this paper, we find an expression of the rook vector of a matrix A (not necessarily square) in terms of permanents of some matrices associated with A, and obtain some simple exact formulas for the permanents of all n × n Toeplitz band matrices of zeros and ones whose bands are of width not less than n - 1.
Separated high-bandwidth and low-latency communication in the cluster interconnect Clint
Authors: Hans Eberle, Nils Gura
Venue: Proceedings of the 2002 ACM/IEEE conference on Supercomputing (2002)

An interconnect for a high-performance cluster has to be optimized in respect to both high throughput and low latency. To avoid the tradeoff between throughput and latency, the cluster interconnect Clint has a segregated architecture that provides two physically separate transmission channels: A bulk channel optimized for high-bandwidth traffic and a quick channel optimized for low-latency traffic. Different scheduling strategies are applied. The bulk channel uses a scheduler that globally allocates time slots on the transmission paths before packets are sent off. This way collisions as well as blockages are avoided. In contrast, the quick channel takes a best-effort approach by sending packets whenever they are available thereby risking collisions and retransmissions.Simulation results clearly show the performance advantages of the segregated architecture. The carefully scheduled bulk channel can be loaded nearly to its full capacity without exhibiting head-of-line blocking that limits many networks while the quick channel provides low-latency communication even in the presence of high-bandwidth traffic.
Design of pipeline analog-to-digital converters via geometric programming
Authors: Maria del Mar Hershenson
Venue: Proceedings of the 2002 IEEE/ACM international conference on Computer-aided design (2002)

In this paper we present a method for the design of analog-todigital converters (ADCs). This method computes the sizes of the different components (transistors, capacitors, etc.) in a predefined ADC topology so that the design specifications are met in the desired process technology.The method is based on formulating the ADC design constraints such as specifications on power, signal-to-noise ratio (SNR), area, and sampling frequency in special convex form in terms of the component sizes of the ADC and intermediate design variables. More specifically, we cast the problem of sizing the components of the ADC as a geometric program. Therefore, all design constraints are formulated as posynomial inequality or monomial equality constraints. Very efficient numerical algorithms are then used to solve the resulting geometric program and to compute the component sizes of an ADC that meets the desired specifications. The synthesis method is fast, and determines the globally optimal design; in particular the final solution is completely independent of the starting point (which can even be infeasible), and infeasible specifications are unambiguously detected.This paper introduces the concept of hierarchical problem formulation within a geometric programming framework. This modular formulation allows a high re-use of the ADC posynomial model.
Towards numerical procedures for those technical phenomena whose mathematical models lead to non-standard conservation laws a survey
Authors: R. Ansorge
Venue: Mathematics and Computers in Simulation (2003)

An introduction to modelling of physical phenomena by conservation laws will be given, particularly in case of phenomena for which the conservation-law-models do not show the standard properties usually assumed to be fulfilled in order to prove theoretical or numerical results. Numerical procedures for this sort of non-standard conservation laws (NSCL) are not yet available in the literature. An abstract theorem for the convergence of discretisation procedures in case of problems whose solutions are uniquely determined by inequalities will be presented. First steps towards numerical methods for solving NSCL-problems could be successfully done by means of this general theory and will be presented in this paper.
A Stakeholder Model of Organizational Leadership
Authors: Marguerite Schneider
Venue: Organization Science (2002)

Organizations are evolving from the bureaucratic form based upon hierarchy to the new-form or radix organization that has the value chain as its relatively fluid foundation. This article explores the relationship between the radix organization and leadership, viewed through an organization-environment coevolution framework. It explicates the changes in the leader's role-sets and relationships brought about with the evolution from bureaucracy to the radix organization, developing a model of leadership that is referred to as the stakeholder model of organizational leadership. Stakeholder theory provides the appropriate theoretical basis for this model, as it offers the flexibility to accommodate various leader relationships. The stakeholder model of organizational leadership helps to predict leader effectiveness in organizations characterized by fuzzy organizational boundaries, flattened hierarchies, and work relationships sometimes brought about through contracts instead of employment.
A propositional policy algebra for access control
Authors: Duminda Wijesekera, Sushil Jajodia
Venue: ACM Transactions on Information and System Security (TISSEC) (2003)

Security-sensitive environments protect their information resources against unauthorized use by enforcing access control mechanisms driven by access control policies. Due to the need to compare, contrast, and compose such protected information resources, access control policies regulating their manipulation need to be compared, contrasted, and composed. An algebra for manipulating such access control policies at a higher (propositional) level, where the operations of the algebra are abstracted from their specification details, is the subject of this paper. This algebra is applicable to policies that have controlled nondeterminism and all or nothing assignments of access privileges in their specification. These requirements reflect current practices in discretionary and role-based access control models. Therefore, the proposed algebra can be used to reason about role-based access control policies combined with other forms of discretionary policies. We show how to use algebraic identities to reason about consistency, completeness, and determinacy of composed policies using similar properties of their constituents.
Multivariate Stancu operators defined on a simplex
Authors: Ruyue Yang, Jingyi Xiong, Feilong Cao
Venue: Applied Mathematics and Computation (2003)

In this paper, we introduce a sequence of multivariate linear operators called Stancu operators defined on a simplex, which generalizes the famous Bernstein operators. We first prove that when the parameter s in the definition of the Stancu operators is 0 or 1 the Stancu operators reduce to the Bernstein operators. Then, we give a symmetric property for these operators. Finally, we prove that the Lipschitz property of function is retained by the Stancu operators.
UPC performance and potential: a NPB experimental study
Authors: Tarek El-Ghazawi, Francois Cantonnet
Venue: Proceedings of the 2002 ACM/IEEE conference on Supercomputing (2002)

UPC, or Unified Parallel C, is a parallel extension of ANSI C. UPC follows a distributed shared memory programming model aimed at leveraging the ease of programming of the shared memory paradigm, while enabling the exploitation of data locality. UPC incorporates constructs that allow placing data near the threads that manipulate them to minimize remote accesses.This paper gives an overview of the concepts and features of UPC and establishes, through extensive performance measurements of NPB workloads, the viability of the UPC programming language compared to the other popular paradigms. Further, through performance measurements we identify the challenges, the remaining steps and the priorities for UPC.It will be shown that with proper hand tuning and optimized collective operations libraries, UPC performance will be comparable to that of MPI. Furthermore, by incorporating such improvements into automatic compiler optimizations, UPC will compare quite favorably to message passing in ease of programming.
Parallelizing the Dual Simplex Method
Authors: Robert E. Bixby, Alexander Martin
Venue: INFORMS Journal on Computing (2000)

We study the parallelization of the steepest-edge version of the dual simplex algorithm. Three different parallel implementations are examined, each of which is derived from the CPLEX dual simplex implementation. One alternative uses PVM, one general-purpose System V shared-memory constructs, and one the PowerC extension of C on a Silicon Graphics multi-processor. These versions were tested on different parallel platforms, including heterogeneous workstation clusters, Silicon Graphics multi-processors, and an IBM SP2. We report on our computational experience.
The Relative Entropy of Entanglement of Schmidt Correlated States and Distillation
Authors: Yi-Xin Chen, Dong Yang
Venue: Quantum Information Processing (2002)

We show that a mixed state &rho; = &sum;mnamn|m&rang;&lang;n| can be realized by an ensemble of pure states {pk, |&phis;k&rang;} where |\phi_k\rangle\ = \sum_m \sqrt{a_mm} e^{i\theta^k_m}|m\rangle. Employing this form, we discuss the relative entropy of entanglement of Schmidt correlated states. Also, we calculate the distillable entanglement of a class of mixed states.PACS: 03.67.-a; 03.65.Bz; 03.65.Ud
Life beyond the bubbles
Authors: Dennis Tsichritzis
Venue: Communications of the ACM (2003)

The technology, Internet, bandwidth, and content bubbles all burst, scattering not only broken dreams but new seeds of innovation and enterprise.
A shared-aperture tracking display for augmented reality
Authors: Winyu Chinthammit, Eric J. Seibel, Thomas A. Furness,  III
Venue: Presence: Teleoperators and Virtual Environments (2003)

The operation and performance of a six degree-of-freedom (DOF) shared-aperture tracking system with image overlay is described. This unique tracking technology shares the same aperture or scanned optical beam with the visual display, virtual retinal display (VRD). This display technology provides high brightness in an AR helmet-mounted display, especially in the extreme environment of a military cockpit. The VRD generates an image by optically scanning visible light directly to the viewer's eye. By scanning both visible and infrared light, the head-worn display can be directly coupled to a head-tracking system, As a result, the proposed tracking system requires minimal calibration between the user's viewpoint and the tracker's viewpoint. This paper demonstrates that the proposed shared-aperture tracking system produces high accuracy and computational efficiency. The current proof-of-concept system has a precisior of +/- 0.05 and +/- 0.01 deg, in the horizontal and vertical axes. respectively. The static registration error was measured to be 0.08 +/- 0.04 and 0.03 +/- 0.02 deg, for the horizontal and vertical axes, respectively. The dynamic registration error or the system latency was measured to be within 16.67 ms, equivalent to our display refresh rate of 60 Hz. In all testing, the VRD was fixed and the calibrated motion of a robot arm was tracked. By moving the robot arm within a restricted volume, this real-time shared-aperture method of tracking was extended to six-DOF measurements. Future AR applications of our shared-aperture tracking and display system will be highly accurate head tracking when tne VRD is helmet mounted and worn within an enclosed space, such as an aircraft cockpit.
On a equation of Smarandache and its integer solutions
Authors: Zhang Wenpeng
Venue: Smarandache notions (2002)

Let Q denotes the set of all rational numbers, a ∈ Q\ {-1, 0, 1}. The main purpose of this paper is to prove that the equation x.a1/x + 1/x.ax = 2a has one and only one integer solution x = 1. This solved a problem of Smarandache in book [1].