ppxscal/embedding_network huggingface dataset:
Fast Fractal Image Compression
Authors: Pou-Yah Wu
Venue: Proceedings of the The International Conference on Information Technology: Coding and Computing (ITCC'00) (2000)

In this paper, we propose a method of regional search for fractal image compression and decompression. In this method, the search for fractal codes is carried out in a region of the image instead of over the whole image. Because the area surrounding a partitioned block has a high probability of being similar to the block, the use of regional search to find the fractal codes results in sharply reduced compression times with only minor increases in the compression ratio, as compared to conventional methods. By using a 128x128 search region, we can compress a 1024x1024 Lena image on a Pentium II-300 PC in 2.8 seconds, obtaining results of high visual quality, with a compression ratio of 87 and a PSNR of 36.67. By comparison, conventional fractal image compression requires 176 seconds, has a compression ratio of 84 and has a PSNR of 39.68. Moreover, if we reduce the search regions to 32x32 and accept a slightly more basic level of visual quality, the compression time is 1.0 second, the compression ratio is 91 and the PNSR is 33.98. The ACM Portal is published by the Association for Computing Machinery. Copyright © 2010 ACM, Inc. Terms of Usage Privacy Policy Code of Ethics Contact Us Useful downloads: Adobe Acrobat QuickTime Windows Media Player Real Player
Data Communications and Networking, 3 edition
Authors: Behrouz A. Forouzan
Venue:  (2003)

:Data Communications And Networking by Behrouz Forouzan provides a thorough introduction to the concepts that underlie networking technology. This book is accessible to students without technical backgrounds, and also provides material comprehensive enough to challenge the more experienced student. The seven-layer OSI model is used as a framework to provide the background necessary for explaining networking theory and showing interlying dependencies. The second edition of Forouzan's DATA COMMUNICATIONS AND NETWORKING includes new exercises and some more challenging ones. In addition, he has increased coverage of some new topics in networking such as some of the new encoding systems, fast Ethernet, 100VganyLan, ADSL and DSL.
Universally Closed Classes of Total Computable Functions
Authors: Robert L. Constable
Venue:  (1984)

One of the most important characteristics of universal programming languages is that they can express their own semantics, that is universal partial functions, say interpreters, can be defined in the language. A fundamental result of computability theory is that no class of total functions can contain its own universal function. In practical terms this is disappointing, one must give up the advantages of universality to gain those of totality. In this paper the fundamental negative result is circumvented for programming languages with a sufficiently rich type structure. A new method is given for building a universally closed class of total computable functions starting with any class of such functions. These results have direct practical application in programming logics, and they raise new questions for computability theory.
ARS: an adaptive runtime system for locality optimization
Authors: Jie Tao, Martin Schulz, Wolfgang Karl
Venue: Future Generation Computer Systems (2003)

Shared memory programs running on Non-Uniform Memory Access (NUMA) machines usually face inherent performance problems stemming from excessive remote memory accesses. A solution, called the Adaptive Runtime System (ARS), is presented in this paper. ARS is designed to adjust the data distribution at runtime through automatic page migrations. It uses memory access histograms gathered by hardware monitors to find access hot spots and, based on this detection, to dynamically and transparently modify the data layout. In this way, incorrectly allocated data can be moved to the most appropriate node and hence data locality can be improved. Simulations show that this allows to achieve a performance gain of as high as 40%.
VLSI Block Placement with Directional Graphs Based on the New Non-Slicing Representation
Authors: A. V. Kovalev, B. G. Konoplev
Venue: Proceedings of the 2002 IEEE International Conference on Artificial Intelligence Systems (ICAIS'02) (2002)

This paper describes a novel non-slicing floor plan representation. The designed representation of blocks, differ from existing ones for low requirements allocated to the volume of the memory used.The time required to decode a representation, i. e. construction ofits layout, is O (n).The described operations of conversion of the structure of a graph of representation is utilized in a genetic algorithm.The transparency of the geometrical relationships for the operations of conversion of the graph makes the findingfinal decision more effective.
Low-level programming for a massively parallel fine-grain computer: the Microflow approach
Authors: Laurie J. Hendren, Alexandru Nicolau, Jon A. Solworth, Patrick G. Xavier
Venue:  (1987)

A new programming language $MFL^{3}$ is described, which, while low level, combines both message passing and shared memory models. We examine both the programming style and implementation issues of such a language. The programming style splits the computation into a computation thread (one process per processor) and several server threads. The computation thread (which performs the bulk of the computation) is deterministic, while all of the non-deterministic code is in the server threads. Also described are several ways of making programming in message passing languages less tedious and more modular, in terms of compilation techniques, runtime structures and a new programming structure.
Fault-Tolerant and Deadlock-Free Routing in 2-D Meshes Using Rectilinear-Monotone Polygonal Fault Blocks
Authors: Jie Wu, Dajin Wang
Venue: Proceedings of the 2002 International Conference on Parallel Processing (2002)

We propose a deterministic fault-tolerant and deadlock-free routing protocol in 2-dimensional (2-D) meshes based on Wu's fault-tolerant odd-even turn model and Wang's rectilinear-monotone polygonal fault block model. The fault-tolerant odd-even turn protocol, also called extended X-Y routing, was originally proposed to achieve fault-tolerant and deadlock-free routing among traditional, rectangular fault blocks. It does not use any virtual channels. The number of faults to be tolerated is unbounded as long as nodes outside fault blocks are connected in the mesh network. The recently proposed rectilinear-monotonepolygonal fault blocks (also called minimal-connected-components or MCCs) are of the polygonal shapes, and is a refinement of rectangular fault blocks. The formation of MCCs depends on the relative locations of source and destination, and they include much fewer healthy nodes in resultant fault blocks. In this paper, we show that with a simple modification, the extended X-Y routing can also be applied to 2-D meshes using extended MCCs.
A Game-Theoretic Formulation of Multi-Agent Resource Allocation
Authors: Jonathan Bredin, Rajiv T. Maheswaran, Cagri Imer, Tamer Basar, David Kotz, Daniela Rus
Venue:  (1999)

This paper considers resource allocation in a network with mobile agents competing for computational priority. We formulate this problem as a multi-agent game with the players being agents purchasing service from a common server. We show that there exists a computable Nash equilibrium when agents have perfect information into the future. We simulate a network of hosts and agents using our strategy to show that our resource-allocation mechanism effectively prioritizes agents according to their endowments.
The Poisson problem in a three-dimensional plate
Authors: Alexandre Madureira
Venue:  (2000)

This note was the basis of a short course presented on June 23, 2000, at University of Pavia, Italy. Here we define and analyze dimension reduction models for the Poisson problem in a thin, three-dimensional plate. After introducing the Poisson problem, and a variational approach for dimendion reduction, we present the asymptotic expansion for the exact and model solutions. Then we estimate the modelling error. The ACM Portal is published by the Association for Computing Machinery. Copyright © 2010 ACM, Inc. Terms of Usage Privacy Policy Code of Ethics Contact Us Useful downloads: Adobe Acrobat QuickTime Windows Media Player Real Player
Approximating Dense Cases of Covering Problems
Authors: Marek Karpinski, Alexander Zelikovsky
Venue:  (1996)

We study dense cases of several covering problems. An instance of the set cover problem with $m$ sets is dense if there is $\epsilon<0$ such that any element belongs to at least $\epsilon m$ sets. We show that the dense set cover problem can be approximated with the performance ratio $c\log n$ for any $c<0$ and it is unlikely to be NP-hard. We construct a polynomial-time approximation scheme for the dense Steiner tree problem in $n$-vertex graphs, i.e. for the case when each terminal is adjacent to at least $\epsilon n$ vertices. We also study the vertex cover problem in $\epsilon$-dense graphs. Though thisproblem is shown to be still MAX-SNP-hard as in general graphs, we find a better approximation algorithm with the performance ratio $2\over{1+\epsilon}$. The {\em superdense} cases of all these problems are shown to be solvable in polynomial time.
Reducing Initial Latency in a Multimedia Storage System
Authors: E. Chang, H. Garcia-Molina
Venue: Proceedings of the 1996 International Workshop on Multi-Media Database Management Systems (IW-MMDBMS '96) (1996)

A multimedia server delivers presentations (e.g., videos, movies, games), providing high bandwidth and continuous reultime delivery. In this paper we present techniques for reducing the initial latency of presentations, i.e., for reducing the time between the arrival of a request and the start of the presentation. Traditionally, initial latency has not received much attention, This is because one major application of multimedia servers is ' movies on demand" where a delay of a few minutes before a new multi-hour movie starts is acceptable. However, latency reduction is important in interactive applications such as video games and browsing of multimedia documents. Various latency reduction schemes are proposed and analyzed, and their performance compared. We show that our techniques can significantly reduce (almost eliminate in some cases) initial latency without adversely affecting throughput. Moreover, a novel on-disk partial data replication scheme that we propose proves to be far more cost effective than any other previous attempts ut reducing initial latency. Keywords: multimedia, data placement, data replication.
Objects and classes, coalgebraically
Authors: Bart P.F. Jacobs
Venue:  (1995)

The coalgebraic perspective on objects and classes in object-oriented programming is elaborated: objects consist of a (unique) identifier, a local state, and a collection of methods described as a coalgebra; classes are coalgebraic (behavioural) specifications of objects. The creation of a ``new'''' object of a class is described in terms of the terminal coalgebra satisfying the specification. We present a notion of ``totally specified'''' class, which leads to particularly simple terminal coalgebras. We further describe local and global operational semantics for objects. Associated with the local operational semantics is a notion of bisimulation (for objects belonging to the same class), expressing observational indistinguishability.
Use of Physical Knowledge for Automation of the Initial Stages of Designing
Authors: Valery A. Kamaev, Sergey A. Fomenkov, Denis A. Davidov
Venue: Proceedings of the 2002 IEEE International Conference on Artificial Intelligence Systems (ICAIS'02) (2002)

The designing of new high-end technical objects on the basis of new, original principles of action, becomes more and more important design direction, which gives large economic benefit. Quality of taken decisions at the initial stages of designing largely depends on amount and quality of the physical information used.In a paper the analysis of the known techniques of physical knowledge application in designing are considered. Also one of the most perspective approaches based on the automatic synthesis of structures of physical principles of operation is introduced (PPO is a structure reflecting some interrelations of physical effects and phenomena, which are resulting, in their own interaction, in execution of the user-defined function).The fund, containing more than 1200 structured descriptions of physical effects, applies to synthesis support. The fund efficiency for information support of the design process is shown.
Properties of the V-C Dimension
Authors: Andrew Fyfe
Venue:  (1989)

No abstract available.
A System for Monitoring and Management of Computational Grids
Authors: Warren Smith
Venue: Proceedings of the 2002 International Conference on Parallel Processing (2002)

As organizations begin to deploy large computational grids, it has become apparent that systems for observation and control of the resources, services, and applications that make up such grids are needed. Administrators must observe resources and services to ensure that they are operating correctly and must control resources and services to ensure that their operation meets the needs of users. Users are also interested in the operation of resources and services so that they can choose the most appropriate ones to use. In this paper we describe a prototype system to monitor and manage computational grids and describe the general software framework for control and observation in distributed environments that itis based on.
Workload Scheduling for Task Graphs with Communication Cost on Parallel Systems
Authors: Carolyn McCreary, Yahui Zhu
Venue:  (1991)

In this paper we extend the classical work on multiprocessor scheduling in several major ways. We define a new notion of scheduling, called the workload schedule, which captures the essence of the communication/computation trade-off. It is a mechanism by which optimal schedules can be generated while considering both execution and communication costs. We extend the theory of scheduling by proving that the parallel scheduling of programs with tree dependence structures is an NP-complete problem when arbitrary communication and execution costs are assigned and when the processes are scheduled on an unbounded number of processors. This contrasts sharply to the situation that occurs if communication costs must be bounded by execution costs. In this case, an optimal schedule can be found in O(n) time [PY90]. We also present three algorithms for scheduling trees efficiently. The algorithms range from determining the optimal schedule, intractable in the general setting, to an efficient greedy algorithm with a sound heuristic basis.
Search-control knowledge for the interoperability problem between conceptual and preliminary structural design
Authors: M. Eisfeld, R. J. Scherer
Venue: Proceedings of the sixth international conference on Application of artificial intelligence to civil & structural engineering (2001)

In this paper, we discuss a computational framework for the conceptual and preliminary structural design process. The framework provides control facilities by reasoning tasks that work on a structural model. These reasoning tasks are integrated into the design process domain by encapsulation into primitive tasks from an hierarchical task network. The initial task network is executed in the same order as planned for and the current design state is taken into account for controlling the compositional design task. Thus, the overall complexity of the design process can be reduced to cope with realistic structural design problems. First, we categorize the conceptual and preliminary structural design process in terms of its tractability by methods from Artificial Intelligence. Thereby, we define the various knowledge types and methods that are used by practitioners as common sense knowledge. We formulate on this basis a problem for conceptual and preliminary structural design, which respects the former introduced knowledge types that are applicable to solve the problem. Second, we specify the constituents of the conceptual and preliminary structural design process on the background of a F-B-S design model and assign inference procedures that accomplish the envisaged functionality in the structural design domain. Third, we introduce the knowledge level for control in order to analyse carried out design studies in regard to available methods for the representation of the found knowledge types. They enable reasoning tasks on the structural evolutionary model. Fourth, the reasoning tasks are defined in a logical framework. The tasks are finally presented along a realistic design sequence and feature their contribution to the overall control of the design process comprised of different sub-problem design spaces.
Analysis of Dynamic Memory Access using Amorphous Slicing
Authors: Mark Harman, Yoga Sivagurunathan, Sebastian Danicic
Venue: Proceedings of the International Conference on Software Maintenance (1998)

Problems associated with understanding, verifying and re-engineering the way in which a system allocates and releases dynamic memory present significant challenges to the software maintainer. Because the questions underlying these problems are undecidable, no system can provide a completely fail safe certification. For example, in checking for memory leaks, a system can only warn of potential problems, but cannot guarantee that no leaks remain.We present an approach to modelling the dynamic memory access properties of a program using amorphous program slicing to create a Dynamic Memory Model (DMM). The slices are constructed from a transformed version of the original program in which heap access has been made explicit using a pseudo variable to denote the top of the heap. The DMM is a simplified version of the original program which is concerned solely with the dynamic memory access behaviour of the original. We illustrate the use of DMMs in problems of comprehension, verification and re-engineering.We introduce a proof-of-concept DMM construction algorithm, showing how slicing simplification power can be dramatically improved using domain-specific transformation rules.
Group communication approach for flexible distributed systems
Authors: H. Kigaki
Venue: Proceedings of the 1996 International Symposium on Parallel Architectures, Algorithms and Networks (1996)

Recently, large-scale distributed systems are being developed. Owing to the high construction cost, the lifetime of the systems are prolonged. Therefore, it is an important problem to achieve flexible distributed systems by introducing some mechanism in the system software for updating application software. The system cannot be kept highly available by the conventional updating methods because multiple processes have to be suspended simultaneously. This paper discusses a new method which allows each process to invoke the updating procedure asynchronously. The key idea is that multiple versions of processes can co-exist temporarily. Each pair of an old-version process and a new-version one is managed as a process group. The group communication protocol proposed in this paper supports message transmission among the process groups. Moreover, the protocol detects and resolves protocol errors caused by the mixture of multiple versions of processes by using checkpointing, timeout and rollback recovery.
Characterizing and Optimizing Parallel File Systems
Authors: Apratim Purakayastha
Venue:  (1996)

%x High-performance parallel file systems are needed to satisfy tremendous I/O requirements of parallel scientific applications. The design of such parallel file systems depends on a comprehensive understanding of the expected workload, but so far there have been very few usage studies of multiprocessor file systems. In the first part of this dissertation, we attempt to fill this void by measuring a real file-system workload on a production parallel machine, namely the CM-5 at the National Center for Supercomputing Applications. We collect information about nearly every individual I/O request from the mix of jobs running on the machine. Analysis of the traces leads to various recommendations for design of future parallel file systems. Our usage study showed that writes to write-only files are a dominant part of the workload. Therefore, optimizing writes could have a significant impact on overall performance. In the second part of this dissertation, we propose ENWRICH, a compute-processor write-caching scheme for write-only files in parallel file systems. Within its framework, ENWRICH uses a recently proposed high performance implementation of collective I/O operations called disk-directed I/O, but it eliminates a number of limitations of disk-directed I/O. ENWRICH combines low-overhead write caching at the compute processors with high performance disk-directed I/O at the I/O processors to achieve both low latency and high bandwidth. This combination facilitates the use of the powerful disk-directed I/O technique independent of any particular choice of interface, and without the requirement for mapping libraries at the I/O processors. By collecting writes over many files and applications, ENWRICH lets the I/O processors optimize disk I/O over a large pool of requests. We evaluate our design of ENWRICH using simulated implementation and extensive experimentation. We show that ENWRICH achieves high performance for various configurations and workloads. We pinpoint the reasons for ENWRICH`s failure to perform well for certain workloads, and suggest possible enhancements. Finally, we discuss the nuances of implementing ENWRICH on a real platform and speculate about possible adaptations of ENWRICH for emerging multiprocessing platforms.
Quality Function Deployment (QFD): an effective technique for requirements acquisition and reuse
Authors: T. Tran, J. S. Sherif
Venue: Proceedings of the 2nd IEEE Software Engineering Standards Symposium (1995)

This paper proposes Quality Function Deployment (QFD) as an effective tool for the capture and refinement of requirements. When applied to a project, QFD will enable its success. More specifically, QFD will: (1) improve product quality by focusing on customer requirements up-front and throughout the development cycle; (2) improve communications between customers, system engineers, programmers and testers and thus contribute to a better decision-making process; (3) facilitate the management of change, through rigorous rating and systematic traceability of requirements; (4) reduce costs of projects, by enabling concurrent engineering and by reducing costs associated with late-in-the life-cycle rework, (5) enable alignment between customer requirements, product requirements, and cost requirements (or constraints), and (6) enable cataloguing of key performance requirements, for parameter-based modeling of the target application and systematic reuse of requirements across projects.
Direct multifractal spectrum calculation from the wavelet transform
Authors: Zbigniew R. Struzik
Venue:  (1999)

We present a direct method of calculation of the multifractal spectrum from the wavelet decomposition. Information pertinent to singular structures in time series is captured by the WTMM method and the local effective Hoelder exponent is evaluated locally for each singular point of the time series. The direct multifractal spectrum is obtained from the scaling of the histograms of the local effective Hoelder exponent. In addition, we illustrate the possibility of estimation of the spectrum from the entire continuous wavelet transform.