ppxscal/embedding_network huggingface dataset:
Preserving Topology by a Digitization Process
Authors: Longin Jan Latecki, Christopher Conrad, Ari Gross
Venue: Journal of Mathematical Imaging and Vision (1998)

The main task of digital image processing is to recognize properties of real objects based on their digital images. These images are obtained by some sampling device, like a CCD camera, and represented as finite sets of points that are assigned some value in a gray-level or color scale. Based on technical properties of sampling devices, these points are usually assumed to form a square grid and are modeled as finite subsets of Z^2. Therefore, a fundamental question in digital image processing is which features in the digital image correspond, under certain conditions, to properties of the underlying objects. In practical applications this question is mostly answered by visually judging the obtained digital images. In this paper we present a comprehensive answer to this question with respect to topological properties. In particular, we derive conditions relating properties of real objects to the grid size of the sampling device which guarantee that a real object and its digital image are topologically equivalent. These conditions also imply that two digital images of a given object are topologically equivalent. This means, for example, that shifting or rotating an object or the camera cannot lead to topologically different images, i.e., topological properties of obtained digital images are invariant under shifting and rotation.
Formally Verified On-Line Diagnosis
Authors: Chris J. Walter, Patrick Lincoln, Neeraj Suri
Venue: IEEE Transactions on Software Engineering (1997)

A reconfigurable fault tolerant system achieves the attributes of dependability of operations through fault detection, fault isolation and reconfiguration, typically referred to as the FDIR paradigm. Fault diagnosis is a key component of this approach, requiring an accurate determination of the health and state of the system. An imprecise state assessment can lead to catastrophic failure due to an optimistic diagnosis, or conversely, result in underutilization of resources because of a pessimistic diagnosis. Differing from classical testing and other off-line diagnostic approaches, we develop procedures for maximal utilization of the system state information to provide for continual, on-line diagnosis and reconfiguration capabilities as an integral part of the system operations. Our diagnosis approach, unlike existing techniques, does not require administered testing to gather syndrome information but is based on monitoring the system message traffic among redundant system functions. We present comprehensive on-line diagnosis algorithms capable of handling a continuum of faults of varying severity at the node and link level. Not only are the proposed algorithms on-line in nature, but are themselves tolerant to faults in the diagnostic process. Formal analysis is presented for all proposed algorithms. These proofs offer both insight into the algorithm operations and facilitate a rigorous formal verification of the developed algorithms.
Performance Evaluation of Switch-Based Wormhole Networks
Authors: Lionel M. Ni, Yadong Gui, Sherry Moore
Venue: IEEE Transactions on Parallel and Distributed Systems (1997)

Multistage interconnection networks (MINs) are a popular class of switch-based network architectures for constructing scalable parallel computers. Four wormhole MINs built from k×k switches, where k = 2j for some j, are considered in this paper: traditional MINs (TMINs), dilated MINs (DMINs), MINs with virtual channels (VMINs), and bidirectional MINs (BMINs). The first three MINs are unidirectional networks, and we show that the cube interconnection pattern can provide contention-free and channel-balanced partitioning of binary cube clusters. BMINs based on butterfly interconnection are essentially a fat tree, and their routing properties are described. Performance comparison among these four networks using simulation experiments is presented with respect to different network traffic patterns. Both DMINs (dilation two) and BMINs have a similar hardware complexity. We conclude that a two-dilated MIN outperforms the corresponding BMIN (or fat tree) for most of the traffic conditions and is a better choice for the design of scalable parallel computers.
An efficient compactor for 45&deg; layout
Authors: David Marple, Michiel Smulders, Henk Hegen
Venue: Proceedings of the 25th ACM/IEEE Design Automation Conference (1988)

This paper describes a one-dimensional compactor which works efficiently on basic VLSI layout. The compactor operates on a tiled layout structure which represents any VLSI layout containing 45&deg; multiple angles. The compaction program performs both pitch minimization and wire length minimization in either X or Y directions. The compactor works quickly and efficiently due to the clever use of the layout structure and graph based Simplex method. The compactor corrects design rule violations and preserves wire widths. It does not yet introduce jogs or compact hierarchically. Results are given for a few CMOS examples.
A 6 &times; 6 Cells Interconnection-OrientedProgrammable Chip for CNN
Authors: Mario Salerno, Fausto Sargeni, Vincenzo Bonaiuto
Venue: Analog Integrated Circuits and Signal Processing (1998)

The implementation of a versatile VLSI chip certainly represents an important step to improve the research on Cellular Neural Networks. In this paper a VLSI realization of the multi-chip oriented, the 6 &times; 6 Digitally Programmable Cellular Neural Network (6 &times; 6 DPCNN) chip, will be presented. This chip covers most of the available one-neighbourhood templates for image processing applications. Moreover, it can be easily interconnected to others to carry out very large CNN arrays. The designs and some measured results of a single chip and a multi-chip board (the 720 DPCNN System) will be shown.
Internet routing instability
Authors: Craig Labovitz, G. Robert Malan, Farnam Jahanian
Venue: ACM SIGCOMM Computer Communication Review (1997)

This paper examines the network inter-domain routing information exchanged between backbone service providers at the major U.S. public Internet exchange points. Internet routing instability, or the rapid fluctuation of network reachability information, is an important problem currently facing the Internet engineering community. High levels of network instability can lead to packet loss, increased network latency and time to convergence. At the extreme, high levels of routing instability have lead to the loss of internal connectivity in wide-area, national networks. In this paper, we describe several unexpected trends in routing instability, and examine a number of anomalies and pathologies observed in the exchange of inter-domain routing information. The analysis in this paper is based on data collected from BGP routing messages generated by border routers at five of the Internet core's public exchange points during a nine month period. We show that the volume of these routing updates is several orders of magnitude more than expected and that the majority of this routing information is redundant, or pathological. Furthermore, our analysis reveals several unexpected trends and ill-behaved systematic properties in Internet routing. We finally posit a number of explanations for these anomalies and evaluate their potential impact on the Internet infrastructure.
A Dynamic Spatial Cournot-Nash Equilibrium Model and an Algorithm
Authors: Byung-Wook Wie, Roger L. Tobin
Venue: Computational Economics (1997)

The objective of this paper is to develop a quantitative methodology for the study of dynamic oligopolistic competition among spatially separated firms serving spatially separated markets. The problem is modeled as a N-person nonzero-sum differential game in the open-loop and closed-loop strategy spaces. Optimality conditions are derived and provided with economic interpretations. Iterative algorithms and numerical results are presented for the open-loop and closed-loop models.
A CORBA facility for network simulation
Authors: Chien-Chung Shen
Venue: Proceedings of the 28th conference on Winter simulation (1996)

Contemporary software development environments for discrete-event simulation have adopted either a language-based approach or a library-based approach. Although these approaches have advantages such as type checking and optimized code generation provided by the former and familiar programming environments facilitated by the latter, they suffer from the inherent limitations of model portability and interoperability, which may result in inflexible models and higher model development cost. This paper proposes a CORBA discrete-event simulation facility to facilitate portable and interoperable simulation models. The proposed facility is defined by a CORBA IDL interface which defines operations for object definition, inter-object communication and event scheduling. Based on the given IDL interface definition, different vendors could supply different products (at different costs) by using different simulation algorithms, different programming language, or on different operating system or hardware platforms. With respect to the simulation models, they see a consistent interface across all products. The paper presents the simulation facility IDL interface, describes its prototype implementation in C++, and illustrates its usage by a bounded-buffer producer-consumer example.
On Some Methods for Unconditionally Secure Key Distributionand Broadcast Encryption
Authors: Doug R. Stinson
Venue: Designs, Codes and Cryptography (1997)

This paper provides an exposition of methods by which a trusted authority can distribute keys and/or broadcast a message over a network, so that each member of a privileged subset of users can compute a specified key or decrypt the broadcast message. Moreover, this is done in such a way that no coalition is able to recover any information on a key or broadcast message they are not supposed to know. The problems are studied using the tools of information theory, so the security provided is unconditional (i.e., not based on any computational assumption).We begin by surveying some useful schemes for key distribution that have been presented in the literature, giving background and examples (but not too many proofs). In particular, we look more closely at the attractive concept of key distribution patterns, and present a new method for making these schemes more efficient through the use of resilient functions. Then we present a general approach to the construction of broadcast schemes that combines key predistribution schemes with secret sharing schemes. We discuss the Fiat-Naor Broadcast Scheme, as well as other, new schemes that can be constructed using this approach.
Surface Approximation and Geometric Partitions
Authors: Pankaj K. Agarwal, Subhash Suri
Venue: SIAM Journal on Computing (1998)

Motivated by applications in computer graphics, visualization, and scientific computation, we study the computational complexity of the following problem: given a set S of n points sampled from a bivariate function f(x,y) and an input parameter $\eps > 0$, compute a piecewise-linear function $\Sigma(x,y)$ of minimum complexity (that is, an xy-monotone polyhedral surface, with a minimum number of vertices, edges, or faces) such that $| \Sigma(x_p, y_p) \; - \; z_p | \:\:\leq\:\: \eps$ for all $(x_p, y_p, z_p) \in S$. We give hardness evidence for this problem, by showing that a closely related problem is NP-hard. The main result of our paper is a polynomial-time approximation algorithm that computes a piecewise-linear surface of size O(Ko log Ko), where Ko is the complexity of an optimal surface satisfying the constraints of the problem.The technique developed in our paper is more general and applies to several other problems that deal with partitioning of points (or other objects) subject to certain geometric constraints. For instance, we get the same approximation bound for the following problem arising in machine learning: given n "red" and m "blue" points in the plane, find a minimum number of pairwise disjoint triangles such that each blue point is covered by some triangle and no red point lies in any of the triangles.
Interconnect layout optimization under higher-order RLC model
Authors: Jason Cong, Cheng-Kok Koh
Venue: Proceedings of the 1997 IEEE/ACM international conference on Computer-aided design (1997)

Studies the interconnect layout optimization problem under a higher-order RLC model to optimize not just the delay but also the waveform for RLC circuits with non-monotone signal response. We propose a unified approach that considers topology optimization, wire-sizing optimization and waveform optimization simultaneously. Our algorithm considers a large class of routing topologies, ranging from shortest-path Steiner trees to bounded-radius Steiner trees and Steiner routings. We construct a set of required-arrival-time Steiner (RATS) trees, providing a smooth trade-off among signal delay, waveform and routing area. Using a new incremental moment computation algorithm, we interleave topology construction with moment computation to facilitate accurate delay calculation and evaluation of waveform quality. Experimental results show that our algorithm is able to construct a set of topologies providing a smooth trade-off among signal delay, signal settling time, voltage overshoot and routing cost.
The Search for the Elusive Electronic Medical Record System&mdash;Medical Liability, the Missing Factor
Authors: Ralph R. Grams, Ernest H. Moyer
Venue: Journal of Medical Systems (1997)

Over the past few years, the traditional paper-based medical record system has come under close scrutiny by every participant in the healthcare industry. Some groups, especially federal agencies such as Medicare and Medicaid, HMOs, and other third party payors, have begun to demand changes in medical record documentation, and have become very assertive as to what goals and objectives will be met. In contrast, the medical liability insurance industry has remained almost invisible during this period of transition. At a recent electronic medical records (EMR) conference participants attending a software development workshop were asked if they had their systems reviewed from a medicolegal standpoint by a malpractice insurance carrier. In response to this inquiry, not one software vendor raised their hand to indicate this had been accomplished, or was even contemplated. In the author's opinion, the key missing factor in the current quest for a paperless medical office system rests in the domain of those who represent the medical liability industry. All of these gate-keepers of medical loss and risk prevention will eventually be called upon, either by choice or necessity, to validate every working EMR system that is used in medical practices in the future. This article will explore the best information published from this currently silent sector of the industry, and proposes an active involvement by the medical liability industry in the current EMR design and development processes taking place. In addition, there are 10 minimum EMR design criteria contained in this article that are recommended for implementation based upon 16 years of medical malpractice experience and loss prevention input.
Adept_flex&mdash;Supporting Dynamic Changes of Workflows Without Losing Control
Authors: Manfred Reichert, Peter Dadam
Venue: Journal of Intelligent Information Systems (1998)

Today&lsquo;s workflow management systems (WFMS_s) are only applicable in a secure and safe manner if the business process (BP) to be supported is well-structured and there is no need for ad hoc deviations at run-time. As only few BPs are static in this sense, this significantly limits the applicability of current workflow (WF) technology. On the other hand, to support dynamic deviations from premodeled task sequences must not mean that the responsibility for the avoidance of consistency problems and run-time errors is now completely shifted to the (naive) end user. In this paper we present a formal foundation for the support of dynamic structural changes of running WF instances. Based upon a formal WF model (ADEPT), we define a complete and minimal set of change operations (ADEPT_flex) that support users in modifying the structure of a running WF, while maintaining its (structural) correctness and consistency. The correctness properties defined by ADEPT are used to determine whether a specific change can be applied to a given WF instance or not. If these properties are violated, the change is either rejected or the correctness must be restored by handling the exceptions resulting from the change. We discuss basic issues with respect to the management of changes and the undoing of temporary changes at the instance level. Recently we have started the design and implementation of ADEPT_workflow, the ADEPT workflow engine, which will make use of the change facilities presented in this paper.
On the Power of Finite Automata with both Nondeterministic and Probabilistic States
Authors: Anne Condon, Lisa Hellerstein, Samuel Pottle, Avi Wigderson
Venue: SIAM Journal on Computing (1998)

We study finite automata with both nondeterministic and random states (npfa's). We restrict our attention to those npfa's that accept their languages with a small probability of error and run in polynomial expected time. Equivalently, we study Arthur--Merlin games where Arthur is limited to polynomial time and constant space.Dwork and Stockmeyer [SIAM J. Comput., 19 (1990), pp. 1011--1023] asked whether these npfa's accept only the regular languages (this was known if the automaton has only randomness or only nondeterminism). We show that the answer is yes in the case of npfa's with a 1-way input head. We also show that if L is a nonregular language, then either L or $\bar{L}$ is not accepted by any npfa with a 2-way input head.Toward this end, we define a new measure of the complexity of a language L, called its 1-tiling complexity. For each $n$, this is the number of tiles needed to cover the 1's in the "characteristic matrix" of L, namely, the binary matrix with a row and column for each string of length $\le n$, where entry [x,y]=1 if and only if the string $xy \in L$. We show that a language has constant 1-tiling complexity if and only if it is regular, from which the result on 1-way input follows. Our main result regarding the general 2-way input tape follows by contrasting two bounds: an upper bound of polylog(n) on the 1-tiling complexity of every language computed by our model and a lower bound stating that the 1-tiling complexity of a nonregular language or its complement exceeds a function in $2^{\Omega (\sqrt{\log n})}$ infinitely often.The last lower bound follows by proving that the characteristic matrix of every nonregular language has rank n for infinitely many n. This is our main technical result, and its proof extends techniques of Frobenius and Iohvidov developed for Hankel matrices [Sitzungsber. der Königl. Preuss. Akad. der Wiss., 1894, pp. 407--431], [Hankel and Toeplitz Matrices and Forms: Algebraic Theory, Birkhauser, Boston, 1982].
Migration impact on load balancing&mdash;an experience on Amoeba
Authors: Weiping Zhu, Piotr Socko, Bartek Kiepuszewski
Venue: ACM SIGOPS Operating Systems Review (1997)

Load balancing has been extensive study by simulation, positive results were received in most of the researches. With the increase of the availability of distributed systems, a few experiments have been carried out on different systems. These experimental studies either depend on task initiation or task initiation plus task migration. In this paper, we present the results of an experimental study of load balancing using a centralized policy to manage the load on a set of processors. All experiments were carried out on an Amoeba system composed by a set of 386s and linked by 10Mbps Ethernet. The results on one hand indicate the necessity of a load balancing facility for a distributed system. On the other hand, the results question the impact of using process migration to increase system performance under the configuration used in our experiments.
Competitive Learning Algorithms and Neurocomputer Architecture
Authors: H. C. Card, G. K. Rosendahl, D. K. McNeill, R. D. McLeod
Venue: IEEE Transactions on Computers (1998)

This paper begins with an overview of several competitive learning algorithms in artificial neural networks, including self-organizing feature maps, focusing on properties of these algorithms important to hardware implementations. We then discuss previously reported digital implementations of these networks. Finally, we report a reconfigurable parallel neurocomputer architecture we have designed using digital signal processing chips and field-programmable gate array devices. Communications are based upon a broadcast network with FPGA-based message preprocessing and postprocessing. A small prototype of this system has been constructed and applied to competitive learning in self-organizing maps. This machine is able to model slowly-varying nonstationary data in real time.
Design for Testability Using State Distances
Authors: Frank F. Hsu, Janak H. Patel
Venue: Journal of Electronic Testing: Theory and Applications (1997)

The average distance between states is proposed as a new testability measure for finite state machines (FSMs). Also proposed is the concept of center state to reduce distances in FSMs. This test function embedding technique has been shown to improve the testability of sequential circuits with minimal overhead. An overview of several design-for-testability (DFT) and synthesis-for-testability (SFT) methods for sequential circuits will also be given in this paper. Experimental results have shown that the DFT approach is more advantageous than the SFT approach to implement our test function. The contribution of this paper is to analyze the trade-offs between several aspects of DFT and SFT techniques.
Derivation of the initial stock of bags&mdash;a Monte Carlo approach
Authors: Zubin Dowlaty, Chong Loo
Venue: Proceedings of the 28th conference on Winter simulation (1996)

The objective of this paper is to calculate the number of bags needed to successfully supply a large package delivery operation. These bags are used to consolidate many small packages into an easier to transport large container -- thus decreasing the handling cost associated with them. Presently, disposable plastic bags are being used. The hypothesis is that permanent bags may make economical sense if the net present value of this modification is positive. The major determinant in the financial success of this proposition is the number of bags needed to feed the operation. Through monte carlo simulation techniques, we were able to accurately model the inherent dynamic uncertainty in this calculation. Thereby enabling the financial calculation to be performed.
Fuzzy sets and secure computer systems
Authors: Sergei Ovchinnikov
Venue: Proceedings of the 1994 workshop on New security paradigms (1994)

Computer are finite discrete machines, the set of real numbers is an infinite continuum. So real numbers in computers are approximation. Rough set theory is the underlying mathematics. A &ldquo;computer&rdquo; version of Weistrass theorem states that every sequence, within the radius of error, repeats certain terms infinitely many times. In terms of applications, the theorem guarantees that the audit trail has repeating patterns. Examining further, based on fuzzy-rough set theory, hidden fuzzy relationships (rules) in audit data are uncovered. The information about the repeating data and fuzzy relationships reflect &ldquo;unconscious patterns&rdquo; of user's habits. They are some deeper &ldquo;signatures&rdquo; of computer users, which provide a foundation to detect abuses and misuses of computer systems. A &ldquo;sliding window information system&rdquo; is used to illustrate the detection of a &ldquo;simple&rdquo; virus attack. The complexity problem is believed to be controllable via rough set representation of data.