ppxscal/embedding_network huggingface dataset:
Parallel Implementations of Irregular Problems Using High-Level Actor Language
Authors: R. Panwar, W. Kim, Gul Agha
Venue: Proceedings of the 10th International Parallel Processing Symposium (1996)

In this paper we present our experience in implementing several irregular problems using a high-level actor language. The problems studied require dynamic computation of object placement and may result in load imbalance as the computation proceeds, thereby requiring dynamic load balancing. The algorithms are expressed as fine-grained computations providing maximal flexibility in adapting the computation load to arbitrary parallel architectures. Such an algorithm may be composed with different partitioning and distribution strategies (PDS's) to result in different performance characteristics. The PDS's are implemented for specific data structures or algorithms and are reusable for different parallel algorithms. We demonstrate how our methodology provides portability of algorithm specification, reusability and ease of expressibility.
Folding spatial image filters on the CM-5
Authors: Sandra G. Dykes, Xiaodong Zhang
Venue: Proceedings of the 9th International Symposium on Parallel Processing (1995)

This paper presents an efficient data-parallel algorithm for general convolutions, and compares its performance on the CM-5 to FFT frequency filtering. Sequential FFT filters are faster than sequential convolutions for windows beyond a very small size, typically 6/spl times/6 pixels. Our folded convolution algorithm shifts the convolution/FFT performance crossover to much larger filter sizes. For 256/spl times/256 images on a 512 node CM-5, the folded convolution is faster than FFT-filtering up to 36/spl times/36 windows. Results are reported for a naively implemented convolution, our folded convolution with default and optimized memory layouts, and FFT filtering using FFTs from the CM-5 scientific library (CMSSL). The data yield two important results: 1. Parallel convolutions on the CM-5 are faster than FFT filtering for a substantial and important range of window sizes. This is in contrast to sequential systems, where convolutions are more efficient only for very small windows. 2. Considerable performance gains are realized by folding the convolution and optimizing layout.
A Visual Attention Model for Tracking Regions Based on Color Correlograms
Authors: Leandro Luís Galdino, Díbio Leandro Borges
Venue: Proceedings of the 13th Brazilian Symposium on Computer Graphics and Image Processing (2000)

The amount of information contained in a single color shot of a scene is extreme considering the variety of tasks that can be performed relying on visual data only. For the purpose of analyzing scenes dynamically, where objects come and go, one has to work under a structure of a visual attention model which prioritizes what type of visual data the system has to follow. This paper presents a novel visual attention model for region tracking based on color correlograms. First, a reference frame is picked and it is segmented for the most significant color regions present in the shot. Color correlograms are then run on every frame after in order to provide spectral and spatial information, for the visual attention control, about the past and the new objects appearing on the scenes. The visual attention (VA) model then keeps track of old and new color regions appearing on the scene until a different frame is chosen. We have run experiments which show the performance of this proposed VA model.
A Clustering Approach for XML Linked Documents
Authors: Barbara Catania, Anna Maddalena
Venue: Proceedings of the 13th International Workshop on Database and Expert Systems Applications (2002)

Clustering algorithms for hypertext documents consider not only the document content but also the links existing between them. All the similarity functions proposed in the literature assume that just one type of link exists between documents, with a unique semantic meaning. With the rapid diffusion of XML documents, a specific language, called XLink, has been proposed to specify inside XML documents different types of links. Each type of link forces a differentdegree of similarity between the documents on which it is defined, thus we claim it must influence in a different way the computation of distance values. In this paper, after presentinga graph-based formalization of the hypertexts we consider, we introduce a distance function, based on both the number and the type of the links connecting documents. Some preliminary experimental results on clustering algorithms based on the proposed function conclude the paper.
Quantifying the Effects of Communication Optimizations
Authors: Sung-Eun Choi, Lawrence Snyder
Venue: Proceedings of the international Conference on Parallel Processing (1997)

Using a specially constructed machine independent communication optimizer that allows control over optimization selection, we quantify the performance benefit of three well known communication optimizations: redundant communication removal, communication combination, and communication pipelining. The numbers are shown relative to the base performance of benchmark programs using the standard communication optimization of message vectorization. The effects on the number of calls to communication routines, both static and dynamic, are tabulated. We consider a variety of communication primitives including those found in Intel's NX library, PVM and the T3D's SHMEM library. The results show substantial improvement, with two combinations of optimizations being most effective.
Where to Provide Support for Efficient Multicasting in Irregular Networks: Network Interface or Switch?
Authors: Rajeev Sivaram, Ram Kesavan, Dhabaleswar K. Panda, Craig B. Stunkel
Venue: Proceedings of the 1998 International Conference on Parallel Processing (1998)

Recent research has proposed methods for enhancing the performance of multicast in networks with irregular topologies. These methods fall into two broad categories: (a) network interface (NI) based schemes that make use of enhanced functionality of the software/firmware running at the NI processor, and (b) switch-based methods that use enhancements to the switch architecture to support hardware multicast. However, it is not clear how these methods compare to each other and when it makes sense to use one over the other. In order to answer such questions, we perform a number of simulation experiments to compare the performance of three efficient multicasting schemes: an NI-based multicasting scheme that uses a $k$-binomial tree, a switch-based multicasting scheme that uses path-based multidestination worms, and a switch-based multicasting scheme that uses a single tree-based multidestination worm. We first study the performance of the three schemes for single multicast traffic while changing a number of system parameters one at a time to isolate their impact. We then study the performance of these schemes under increasing multicast load. Our results show that the switch-based multicasting scheme using a single tree-based multidestination worm performs the best among the three schemes. However, the NI-based multicasting scheme is capable of delivering high performance compared to the switch-based multicast using path-based worms especially when the software overhead at the network interface is less than half of the overhead at the host. We therefore conclude that support for multicast at the NI is an important first step to improving multicast performance. However, there is still considerable gain that can be achieved by supporting hardware multicast in switches. Finally, while supporting such hardware multicast, it is better to support schemes that can achieve multicast in one phase.
An Information Systems Approach to Support Decision Makers Selecting Group Decision Processes
Authors: Nuno Pina Goncalves, Pedro Antunes
Venue: Proceedings of the 6th International Workshop on Groupware (2000)

This paper describes a support system for group decision-making. The system is based on a database of typical decision cases and also an underlying model of the group decision process. The model serves to organize the way users interact with the database, exploring, analysing and selecting cases. Currently the database has 75 group decision cases.
A Quantitative Comparison of Load Balancing Approaches in Distributed Object Computing Systems
Authors: Lap-Sun Cheung, Yu-Kwong Kwok
Venue: Proceedings of the 25th International Computer Software and Applications Conference on Invigorating Software Development (2001)

Several load balancing schemes are recently proposed for distributed object computing systems, which are widely envisioned to be the desired distributed software development paradigm due to the higher modularity and the capability of handling machine and operating system heterogeneity. However, while the rationales and mechanisms employed are dramatically different, the relative strengths and weaknesses of these approaches are unknown, making it difficult for a practitioner to choose an appropriate approach for the problem at hand. In this paper, we describe in detail three representative approaches, which are all practicable, and present a quantitative comparison using our experimental distributed object computing platform. Among these three approaches, namely, JavaSpaces based, request redirection based, and fuzzy decision based, we find that the fuzzy decision based algorithm outperforms the other two considerably.
A formal verification technique for embedded software
Authors: Olivier Thiry, Luc J. M. Claesen
Venue: Proceedings of the 1996 International Conference on Computer Design, VLSI in Computers and Processors (1996)

A method for the verification of embedded software correctness is presented. A formal model for an actual commercial microprocessor is established. This is done by modeling the instruction set and processor architecture. Embedded software takes the form of the assembly program code to be run on the processor. Specifications are given as CTL temporal logic formulae. The method has been implemented in the SMV model checker and is illustrated by a practical embedded system application: a mouse controller. The inconsistency of the specification and the implementation as an assembly language program as it has been published in the applications book of the manufacturer has been uncovered.
Characterization of Deadlocks in Interconnection Networks
Authors: Sugath Warnakulasuriya, Timothy Mark Pinkston
Venue: Proceedings of the 11th International Symposium on Parallel Processing (1997)

Deadlock-free routing algorithms have been developed recently without fully understanding the frequency and characteristics of deadlocks. Using a simulator capable of true deadlock detection, we measure a network's susceptibility to deadlock due to various design parameters. The effects of bidirectionality, routing adaptivity, virtual channels, buffer size and node degree on deadlock formation are studied. In the process, we provide insight into the frequency and characteristics of deadlocks and the relationship between routing flexibility blocked messages, resource dependencies and the degree of correlation needed to form deadlock.
Efficient Splitting Rules Based on the Probabilities of Pre-assigned Intervals
Authors: June-Suh Cho, Nabil R. Adam
Venue: Proceedings of the 2001 IEEE International Conference on Data Mining (2001)

This paper describes new methods for classification in orderto find an optimal tree. Unlike the current splitting rules that areprovided by searching all threshold values, this paper proposes thesplitting rules that are based on the probabilities of pre-assignedintervals.
A Chinese Bank Check Recognition System Based on the Fault Tolerant Technique
Authors: Song Wong, Feng Ma, Shaowei Xia
Venue: Proceedings of the 4th International Conference on Document Analysis and Recognition (1997)

The contradiction between the high recognition accuracy and the low rejection rate in automatic bank check recognition has not been solved successfully. In this paper, a fault tolerant Chinese bank check recognition system is presented to solve the contradiction between the need of low error-recognition probability and the need of low refused-recognition probability. The main idea is to use dynamic cipher code which will be widely applied in China to lower both of them. This system reaches high recognition rate and the high reliability simultaneously when automatic processing a Chinese bank check with the dynamic cipher code. A practical scheme of fault-tolerant recognition to bank-check is given in the paper and experiments show the performance of our fault-tolerant technique.
Dense Real-Time Games
Authors: Marco Faella, Salvatore La Torre, Aniello Murano
Venue: Proceedings of the 17th Annual IEEE Symposium on Logic in Computer Science (2002)

The rapid development of complex and safety-critical systems requires the use of reliable verification methods and tools for system design (synthesis). Many systems of interest are reactive, in the sense that their behavior depends on the interaction with the environment. A natural framework to model them is a two-player game: the system versus the environment. In this context, the central problem is to determine the existence of a winning strategy according to a given winning condition. We focus on real-time systems, and choose to model the related game as a nondeterministic timed automaton. We express winning conditions by formulas of the branching-time temporal logic TCTL. While timed games have been studied in the literature, timed games with dense-time winning conditions constitute a new research topic. The main result of this paper is an exponential-time algorithm to check for the existence of a winning strategy for TCTL games where equality is not allowed in the timing constraints. Our approach consists on translating to timed tree automata both the game graph and the winning condition, thus reducing the considered decision problem to the emptiness problem for this class of automata. The proposed algorithm matches the known lower bound on timed games.Moreover, if we relax the limitation we have placed on the timing constraints, the problem becomes undecidable.
Estimation of sequential circuit activity considering spatial and temporal correlations
Authors: Tan-Li Chou, Kaushik Roy
Venue: Proceedings of the 1995 International Conference on Computer Design: VLSI in Computers and Processors (1995)

We present an exact and an approximate method for estimating signal activity at the internal nodes of sequential logic circuits. The methodology takes spatial and temporal correlations of logic signals into consideration. Given the state transition graph (STG) of a finite state machine (FSM), we create an extended state transition graph (ESTG), where the temporal correlations of the input signals are explicitly represented. From the graph we derive the equations to calculate exact signal probabilities and activities. For large circuits an approximate method for calculating the activities by unrolling the next state logic is proposed. Experimental results show that if temporal and spatial correlations are not considered, the switching activities of the internal nodes can be off by more than 40% compared to simulation based techniques. However, the results of the approximate method proposed in the paper is within 5% of logic simulation results.
Efficiently Mining Maximal Frequent Itemsets
Authors: Karam Gouda, Mohammed Javeed Zaki
Venue: Proceedings of the 2001 IEEE International Conference on Data Mining (2001)

We present GenMax, a backtrack search based algorithm for mining maximal frequent itemsets. GenMax uses a number of optimizations to prune the search space.It usesa novel technique called progressive focusing to perform maximality checking, and diffset propagation to perform fast frequency computation. Systematic experimental comparison with previous work indicates that different methods have varying strengths and weaknesses based on dataset characteristics. We found GenMax to be a highly efficient method to mine the exact set of maximal patterns.
Program Comprehension as a Learning Process
Authors: Václav Rajlich
Venue: Proceedings of the 1st IEEE International Conference on Cognitive Informatics (2002)

The paper describes the process of program comprehension from the point of view of constructivist theory of learning. According to this view, program comprehension starts with the pre-existing knowledge and continues through processes of assimilation and adaptation. The assimilation means that the facts encountered in the program are either added to theknowledge or rejected. Adaptation means that the existing knowledge is reorganized in order to absorb new facts. These processes are illustrated by a case study where the knowledge of the program is represented by UML class diagrams.
Understanding the Behavior of the Conflict-Rate Metric in Optimistic Peer Replication
Authors: An-I Wang, Peter L. Reiher, Rajive Bagrodia, Geoffrey H. Kuenning
Venue: Proceedings of the 13th International Workshop on Database and Expert Systems Applications (2002)

Optimistic replication of data is a widely used tool for mobile environments, but the behavior of concurrent conflicting updates caused by the relaxed consistency model is poorly understood.Through analytical modeling, we derive an exact bound for conflict rates for the common case of two replicas. The shape of the two-replica analytic curve matches well with simulation results at 50 replicas.Our result shows that (1) both frequently and infrequently synchronized mobile machines operate in the low regions of the conflict-rate curve; (2) conflict rate is notwell suited for comparing systems, since multiple system settings can result in the same conflict rate number; and (3) the conflict rate is highly dependent on the characteristics of data flow paths.
Multispectral Image Data Fusion Using Projections onto Convex Sets Techniques
Authors: Marcia L. S. Aguena, Nelson D. A. Mascarenhas
Venue: Proceedings of the 15th Brazilian Symposium on Computer Graphics and Image Processing (2002)

Abstract. The problem of image data fusion includes several techniques for data integration from different sensors about a given object. The process can be divided in two stages: (a) pixel interpolation on each observed image to equalize their resolutions; and (b) synthesis of the fused image using the interpolated images. This work proposes the use of projection onto convex sets (POCS) techniques in both stages of the image data fusion process: on the interpolation stage, by creating intermediate pixels more adapted to the local characteristics of the observed images; and on the synthesis stage, by generating a final multispectral image that incorporates the best spatial and spectral characteristics of the initial images. As an example, the algorithm is applied to Spot satellite images.
Recognition of Character Strings from Color Urban Map Imageson the Basis of Validation Mechanism
Authors: Toyohide Watanabe, Rui Zhang
Venue: Proceedings of the 4th International Conference on Document Analysis and Recognition (1997)

The map recognition is one of interesting subjects to distinguish the meaningful information automatically from map images and construct resource data in information systems such as GIS( Geographic Information System). However, it is difficult to identify individual information because the map components are mutually intersected or overlayed, and because the properties of map components are not well defined so as to be applicable to the recognition procedure algorithmically. In this paper, we propose an extraction method of character strings from color map images. The characteristic in our method is to validate candidates of identified character strings with map composition rules such as the properties of individual map components and mutual relationships among different map components. Our recognition process of charater strings from color urban map images is composed of two phases: extraction of character strings; and classification of character strings. The extraction phase of character strings is organized by a bottom-up approach, based on the measurement/estimation among pixels, while the classification phase of character strings is composed by means of a top-down approach, based on the interpretation/validation among map components.
Fat-tree for local area multiprocessors
Authors: Qiang Li, David B. Gustavson
Venue: Proceedings of the 9th International Symposium on Parallel Processing (1995)

The local area multiprocessor (LAMP) is a newly-feasible approach for achieving high-performance low-cost parallel computing. LAMP allows a large number of machines distributed over a LAN-size area to operate as a distributed-shared-memory multiprocessor. Latency is kept low by using the scalable coherent interface and by caching remote data. SCI keeps the caches consistent and provides a high performance multiprocessor "bus" using only point-to-point physical connections (links), which can operate at far higher speeds than any bus. Large numbers of links may be used concurrently for extremely high system throughput, interconnected by a packet switch using any of a wide range of topologies and technologies. This paper examines the use of a fat-tree topology for this (possibly distributed) switch. Simulation results are presented to show the latency, throughput, buffer requirements, and the effect of cable length. Link clock speeds assumed are 250 MHz (GaAs or biCMOS chips) and 32 MHz (CMOS).
PICSDesk: A Case Study on Business Process Re-engineering
Authors: Manolis M. Tsangaris, Madhur Kohli, Shamim A. Naqvi, Richard Nunziata, Yatin P. Saraiya
Venue: Proceedings of the Twelfth International Conference on Data Engineering (1996)

Presents first-hand experiences from an actual re-engineering project. Business re-engineering is a process affecting not only the software system involved, but the underlying business model as well. Indeed, it is the changed business model along with the new technologies that determine the design of the new system. This paper is a walkthrough of the design of PICSDESK, a prototype incorporating some modern technologies to support the old business model of its predecessor and its evolution to a new business model. PICSDESK may be thought of as an example of a new breed of inventory control systems.
Stride-directed Prefetching for Secondary Caches
Authors: Sunil Kim, Alexander V. Veidenbaum
Venue: Proceedings of the international Conference on Parallel Processing (1997)

This paper studies hardware prefetching for second-level (L2) caches. Previous work on prefetching has been extensive but largely directed at primary caches. In some cases only L2 prefetching is possible or is more appropriate. By studying L2 prefetching characteristics we show that existing stride-directed methods [1, 8] for L1 caches do not work as well in L2 caches. We propose a new stride-detection mechanism for L2 prefetching and combine it with stream buffers used in [16]. Our evaluation shows that this new prefetching scheme is more effective than stream buffer prefetching particularly for applications with long-stride accesses. Finally,we evaluate an L2 cache prefetching organization which combines a small L2 cache with our stride-directed prefetching scheme. Our results show that this system performs significantly better than stream buffer prefetching or a larger non-prefetching L2 cache without suffering from a significant increase in the memory traffic.