ppxscal/embedding_network huggingface dataset:
The Uniform Memory Hierarchy Model of Computation
Authors: Bowen Alpern, Larry Carter, Ephraim Feig, Ted Selker
Venue:  (1993)

The Uniform Memory Hierarchy (UMH) model introduced in this paper captures performance-relevant aspects of the hierarchical nature of computer memory. It is used to quantify architectural requirements of several algorithms and to ratify the faster speeds achieved by tuned implementations that use improved data-movement strategies. A sequential computer''s memory is modelled as a sequence [M0, M1, ...] of increasingly large memory modules. Computation takes place in M0. Thus, M0 might model a computer''s central processor, while M1 might be cache memory, M2 main memory, and so on. For each module Mu, a bus Bu connects it with the next larger module Mu+1. All buses may be active simultaneously. Data is transferred along a bus in fixed-size blocks. The size of these blocks, the time required to transfer a block, and the number of blocks that fit in a module are larger for modules farther from the processor. The UMH model is parameterized by the rate at which the blocksizes increase and by the ratio of the blockcount to the blocksize. A third parameter, the transfer cost (inverse bandwidth) function, determines the time to transfer blocks at different levels of the hierarchy. UMH analysis refines traditional methods of algorithm analysis by including the cost of data movement throughout the memory hierarchy. The communications efficiency of a program is a ratio measuring the portion of UMH running time during which M0 is active. An algorithm that can be implemented by a program with positive asymptotic communication efficiency is said to be communication-efficient. The communication efficiency of a program depends on the parameters of the UMH model, most importantly on the transfer cost function. A threshold function separates those transfer cost functions for which an algorithm is communication-efficient from those that are too costly. Threshold functions for matrix transpose, standard matrix multiplication, and Fast Fourier Transform algorithms are established by exhibiting communication-efficient programs at the threshold and showing that more expensive transfer cost functions are too costly. A parallel computer can be modelled as a tree of memory modules with computation occurring at the leaves. Threshold functions are established for multiplication of N x N matrices using up to N2 processors in a tree with constant branching factor.
Coloring Graphs with Sparse Neighborhoods
Authors: Noga Alon, Michael Krivelevich, Benny Sudakov
Venue:  (1998)

It is shown that the chromatic number of any graph with maximum degree d in which the number of edges in the induced subgraph on the set of all neighbors of any vertex does not exceed d^2/f is at most O( d/ \log f). This is tight (up to a constant factor) for all admissible values of d and f.
Integrated Access Control and Intrusion Detection for Web Servers
Authors: Tatyana Ryutov, Clifford Neuman, Dongho Kim, Li Zhou
Venue: Proceedings of the 23rd International Conference on Distributed Computing Systems (2003)

Current intrusion detection systems work in isolationfrom access control for the application the systems aim toprotect. The lack of coordination and inter-operation betweenthese components prevents detecting and respondingto ongoing attacks in real time, before they cause damage.To address this, we apply dynamic authorization techniquesto support fine-grained access control and application levelintrusion detection and response capabilities. This paperdescribes our experience withintegrationof the Generic Authorizationand Access Control API (GAA-API) to providedynamic intrusion detection and response for the ApacheWeb Server. The GAA-API is a generic interface which maybe used to enable such dynamic authorization and intrusionresponse capabilities for many applications.
How does TCP generate Pseudo-self-similarity?
Authors: Liang Guo, Mark Crovella, Ibrahim Matta
Venue:  (2001)

Abstract Long-range dependence has been observed in many recent Internet traffic measurements. In addition, some recent studies have shown that under certain network conditions, TCP itself can produce traffic that exhibits dependence over limited timescales, even in the absence of higher-level variability. In this paper, we use a simple Markovian model to argue that when the loss rate is relatively high, TCP''s adaptive congestion control mechanism indeed generates traffic with OFF periods exhibiting power-law shape over several timescales and thus introduces pseudo-long-range dependence into the overall traffic. Moreover, we observe that more variable initial retransmission timeout values for different packets introduces more variable packet inter-arrival times, which increases the burstiness of the overall traffic. We can thus explain why a single TCP connection can produce a time-series that can be misidentified as self-similar using standard tests.
Evolvable Hardware: From On-Chip Circuit Synthesis to Evolvable Space Systems
Authors: Adrian Stoica
Venue: Proceedings of the 30th IEEE International Symposium on Multiple-Valued Logic (2000)

Evolvable Hardware (EHW) refers to HW design and self-reconfiguration using evolutionary/genetic mechanisms. The paper presents an overview of some key concepts of EHW, comments on selected applications, and presents a perspective on the development of the field. A fine-grained Field Programmable Transistor Array (FPTA) architecture for reconfigurable hardware is presented as an example of an initial effort toward evolution-oriented devices. Evolutionary experiments in simulations and with a FPTA chip in the loop demonstrate automatic synthesis of electronic circuits. Unconventional circuits, for which there are no textbook design guidelines, are particularly appealing to evolvable hardware. To illustrate this situation, one demonstrates here the evolution of circuits implementing parametrical connectives for fuzzy logics. In addition to synthesizing circuits for new functions, evolvable hardware can be used to preserve existing functions, and achieve fault-tolerance determining circuit configurations that circumvent the faults. These characteristics are extremely important for enabling spacecraft to survive harsh environments and to have long life. Expanding reconfiguration to other types of spacecraft hardware (i.e. optics, MEMS, etc) could lead to evolvable space systems.
Modelling prioritized MPEG video using TES and a frame spreading strategy for transmission in ATM networks
Authors: M. R. Ismail, I. E. Lambadaris, M. Devetsikiotis, A. R. Kaye
Venue: Proceedings of the Fourteenth Annual Joint Conference of the IEEE Computer and Communication Societies (Vol. 2)-Volume - Volume 2 (1995)

This paper presents an efficient transmission mechanism, using frame spreading, for variable bitrate (VBR) MPEG compressed video, through an ATM multiplexer, such as a cable head-end. A priority scheme is implemented in a software MPEG encoder which produces a proportionate traffic in both (i.e., high and low) priority partitions for all three frame types (intraframe, predicted and interpolated) used in MPEG. An ATM multiplexer with a pushout buffer scheme is implemented for the study, in order to provide priority scheduling at the multiplexer for the two priority partitions. The multiplexer is fed with VBR MPEG traffic and performance statistics such as the cell loss ratios are studied for various frame spreading scenarios. Two statistical models are developed using TES (transform expand sample) for VBR MPEG video having two levels of priority. The first model is matched with the empirical histogram and autocorrelation function of each frame type (I, P and B). The second model is created with the assumption of a gamma distribution for the number of bits in each frame type. Experiments are conducted using both models and the results are compared.
Business and Economic Forecasting for the Information Age: A Practical Approach
Authors: A. Reza Hoshmand
Venue:  (2002)

:The globalization of business and the ubiquity of available data in the information age are the driving forces behind the increasing importance of economic forecasting. In order to remain competitive, private and public organizations alike must employ forecasting techniques effectively. Hoshmand emphasizes the application and practical use of such techniques rather than their theoretical grounding. Decision makers and students who have a solid background in economics and statistics will find this book eminently useful. After discussing the role of forecasting in business decisions, the author moves on to smoothing techniques, regression models, and the advanced time series models of Box-Jenkins. Of particular help to practitioners is the concluding chapter on how to communicate forecasts to management. 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
A Survey of Secure Multi-Domain Distributed Architectures
Authors: Paul Ashley, Bradley Broom
Venue:  (1997)

Security in a modern distributed computing system is becoming more and more important. Users want to securely access remote resources both in the local domain and across multi-domains. Recently, a number of new architectures for securing a distributed system have been proposed. This paper outlines the issues important to securing a multi-domain distributed system and surveys a number of secure distributed architectures. The architectures surveyed include SESAME (Secure European System For Applications in a Multivendor Environment), Kerberos, Yaksha, KryptoKnight, DCE (Distributed Computing Environment), and DSSA (Distributed System Security Architecture). For each architecture an outline of its strengths and limitations is included.
The Dynamic Adaptation of Parallel Mesh-Based Computation
Authors: Jos Casta\~nos, John E. Savage
Venue:  (1996)

We present efficient algorithms and data structures for dynamic refinement/coarsening (adaptation) of unstructured FE meshes on loosely coupled parallel processors. We describe a) a parallel adaptation algorithm, b) an online parallel repartitioning algorithm based on mesh adaptation histories, c) an algorithm for the migration of mesh elements between processors, and d) an integrated object-oriented framework for the adaptation, repartitioning and migration of the mesh at runtime. A two-dimensional triangle-based prototype demonstrates the feasibility of these ideas.
Cost-Analysis of 4-Valued Unary Functions Implemented Using Current-Mode CMOS Circuits
Authors: Mostafa Abd-El-Barr, Abdullah Al-Mutawa
Venue: Proceedings of the 30th IEEE International Symposium on Multiple-Valued Logic (2000)

In this paper, we consider the use of the incremental-cost approach for synthesis of 4-valued one-variable functions for implementation using current-mode CMOS (CMCL) circuits. One of the main features of CMCL circuits is the availability of currents flowing in both directions. This should add a degree of freedom, which in turn facilitate the use of both positive and negative current values. Intermediate signed functions (both negative and positive) can then be readily available inside the circuits. In this paper, we show that efficient use of signed intermediate functions can lead to substantial cost reduction, in terms of the number of devices needed for the implementation of functions. The results obtained using two techniques that use incremental-cost approach for synthesis of 4-valued one-variable functions for CMCL implementation and which use signed intermediate functions are presented and compared.
A World-Wide Distributed System Using Java and the Internet
Authors: K. M Chandy, Boris Dimitrov, Huy Le, Jakob Mandelson, Matthew Richardson, Adam Rifkin, Paolo A. G. Sivilotti, Wesley Tanaka, Luke Weisman
Venue:  (1996)

This paper describes the design of a distributed system built using Java that supports peer-to-peer communication among processes spread across a network. We identify the requirements of a software layer that supports distributed computing, and we propose a design that meets those requirements. Our primary concern is the identification, specification, and implementation of software components that can be composed in different ways to develop correct distributed applications. Though our implementation uses Java, the fundamental ideas apply to any object-oriented language that supports messaging and threads.
Resource Coordination in Single Agent and Multiagent Systems
Authors: Gifty Edwin, Michael T. Cox
Venue: Proceedings of the 13th IEEE International Conference on Tools with Artificial Intelligence (2001)

An intelligent multiagent system includes a number of software agents interacting to solve a problem.Various agents are responsible for planning different tasks. These tasks must be coordinated to solve complex problems.A number of reasons exist for which coordination among the agents is necessary,and numerous issues have to be tackled to achieve efficient coordination.The focus of this paper is resource coordination.When an agent lacks a resource to achieve a goal,it may choose one of two options.It can acquire another resource,or it can change the goal so that it can achieve it with the resource at hand.We present a cost- benefit analysis that can be performed to determine if the requesting agent receives the requested resource.We present empirical results that show the relative goal satisfaction achieved in the PRODIGY planner with and without resource coordination.We have implemented a multiagent system called COMAS that implements resource coordination.
Scalable object-tracking through unattended techniques (SCOUT)
Authors: S. Kumar, C. Alaettinglu, D. Estrin
Venue: Proceedings of the 2000 International Conference on Network Protocols (2000)

A scalable object location service can enable users to search for various objects in an environment where many small, networked devices are attached to objects. We investigate two hierarchical, self-configuring or unattended approaches for an efficient object location service. Each approach has its advantages and disadvantages based on the anticipated load. The first approach, SCOUT-AGG, is based on aggregation of object names. The second approach, SCOUT-MAP, is based on indirection, where information about an object is stored at the locator sensor for the object. The relative efficiency of SCOUT-AGG and SCOUT-MAP can be characterized by the query to mobility, update rate of the system. SCOUT-AGG performs better for low query to update rate but its performance deteriorates in general relative to SCOUT-MAP as the queries to update rate increases. The rate of performance deterioration depends on query specificity (i.e., queries for a specific object or for any object of a particular type). SCOUT-MAP generally exhibits better load balancing than SCOUT-AGG for various scenarios. We support the above results through simple analytical modeling and simulation.
Ideograms in Polyscopic Modeling
Venue: Proceedings of the International Conference on Information Visualisation (2000)

We argue that the task of representing interrelationships between things requires the use of visual techniques. Our common verbal and factual approaches to information tend to miss something essential - the ¿perspective¿. In the article, the perspective is defined and explained with the help of a visual technique, the ideograms. It is shown how ideograms can be used for expressing and correcting the perspective. Methodologically, the article is an introduction to ideograms as an information design technique. Eight applications of ideograms are discussed.
Mean value analysis for computer systems with variabilities in workload
Authors: J. Luthi, S. Majumdar, G. Haring
Venue: Proceedings of the 2nd International Computer Performance and Dependability Symposium (IPDS '96) (1996)

When evaluating the performance of computer systems, often uncertainties or variabilities in service demands may be observed. Applying well known mean valve analysis (MVA) for single- or multiclass queueing network models of such systems is inappropriate and ineffective, because these models fail to represent variations within a class. This paper proposes to use histograms for characterizing model parameters that are associated with uncertainty or variability and presents an adaptation of the single class MVA algorithm, which traditionally accepts single (mean) values for service demands, so that one or more input parameters can be specified as a histogram. The adapted algorithm generates a histogram output for the performance measures, thus providing a more detailed information (e.g. percentile values) than the mean valves obtained from conventional MVA. The proposed technique is demonstrated on selected examples in different problem domains. It is shown, that the computational complexity is reasonable given that the number of parameters specified as histograms is not too high. Although the algorithm produces accurate results in many situations inaccuracies have been observed for certain systems. A technique called interval splitting that can be used for controlling such inaccuracies is described.
Avoiding the Undefined by Underspecification
Authors: David Gries, Fred B. Schneider
Venue:  (1995)

We use the appeal of simplicity and an aversion to complexity in selecting a method for handling partial functions in logic. We conclude that avoiding the undefined by using underspecification is the preferred choice.
TMOES: A CORBA Service Middleware Enabling High-Level Real-Time Object Programming
Authors: K. H. (Kane) Kim, J. Q. Liu, H. Miyazaki, E. H. Shokri
Venue: Proceedings of the Fifth International Symposium on Autonomous Decentralized Systems (2001)

Extending the CORBA programming and execution environments to support real-time distributed applications is a subject of growing interests to both research and industry community. The time-triggered message triggered object (TMO) programming scheme has been established to remove the severe limitations of conventional object structuring techniques in developing real-time distributed applications. To facilitate the construction of TMO-structured real-time distributed applications consisting of CORBA-compliant components, a middleware named TMO Execution Support (TMOES) has been created. TMOES instantiations residing in cooperating computing nodes also communicate among themselves only via ORBs conforming to the standard specifications. TMOES instantiations cooperate among themselves to support timely execution of TMO methods and interactions among remote TMOs. This paper presents the architecture and an implementation model of TMOES.
Local Search Algorithm to Improve the Local Search
Authors: Mohamed Tounsi, Philippe David
Venue: Proceedings of the 14th IEEE International Conference on Tools with Artificial Intelligence (2002)

In this paper, we present a new coopemtive framework based on using successively two local search algorithms to solve constraint satisfaction and optimization problems. Our technique is based on the integration of local search algorithms as a mechanism to diversify the search instead of using a build on diversification mechanisms. Thus we avoid tuning the multiple parameters to escape from a local optimum. This technique improves the existing methods: it is generic especially when the given problem can be expressed as a constraint satisfaction problem. We present the way the local search algorithm can be used to diversify the search in order to solve real examination timetabling problems. We describe how the local search algorithm can be used to assist any other specific local search algorithm to escape from local optimality.
Iterative Grid-Based Computing Using Mobile Agents
Authors: Hairong Kuang, Lubomir F. Bic, Michael B. Dillencourt
Venue: Proceedings of the 2002 International Conference on Parallel Processing (2002)

We describe an environment for the distributed solution of iterative grid-based applications. The environment is built using the MESSENGERS mobile agent system. The main advantage of paradigm-oriented distributed computing is that the user only needs to specify application-specific sequential code, while the underlying infrastructure takes care of the parallelization and distribution. The two paradigms discussed in this papers are the finite difference method, and individual-based simulation. These paradigms present some interesting challenges, both in terms of performance (because they require frequent synchronized communication between nodes) and in terms of repeatability (because the mapping of the user space onto the network may change due to load balancing or due to changes in the underlying logical network). We describe their use, implementation, and performance within a mobile agent-based environment.
Hybrid finite element methods for the Signorini problem
Authors: F. Ben Belgacem, Y. Renard
Venue: Mathematics of Computation (2003)

We study three mixed linear finite element methods for the numerical simulation of the two-dimensional Signorini problem. Applying Falk's Lemma and saddle point theory to the resulting discrete mixed variational inequality allows us to state the convergence rate of each of them. Two of these finite elements provide optimal results under reasonable regularity assumptions on the Signorini solution, and the numerical investigation shows that the third method also provides optimal accuracy.
Area Requirement of Gabriel Drawings
Authors: G. Liotta, R. Tamassia, I. G. Tollis, Paola Vocca
Venue:  (1996)

In this paper we investigate the area requirement of proximity drawings and we prove an exponential lower bound. Namely, our main contribution is to show the existence of a class of Gabriel-drawable graphs that require exponential area for any Gabriel drawing and any resolution rule. Also, we extend the result to an infinite class of proximity drawings.
Distributed coordination based on temporal planning for tactical aircraft simulation
Authors: F. Marc, A. El Fallah-Seghrouchni, I. Degirmenciyan
Venue: Proceedings of the second international joint conference on Autonomous agents and multiagent systems (2003)

This paper deals with the modeling of agents plans thanks to hybrid automata which support the evolution of time and resources. The main advantage of the formalism we chose is the control and the validation of both individual and multi-agent plans. The paper presents significant operators e.g. merging, reallocation, etc.) to manage the multi-agent plans and to avoid replanning the multi-agent plan from scratch.
Issues in the design and use of a distributed file system
Authors: H. Sturgis, J. Mitchell, J. Israel
Venue: ACM SIGOPS Operating Systems Review (1980)

This paper discusses an independent file facility, one that is not embedded in an operating system. The distributed file system (DFS) is so named because it is implemented on a cooperating set of server computers connected by a communications, network, which together create the illusion of a single, logical system for the creation, deletion, and random accessing of data. Access to the DFS can only be accomplished over the network; a computer (or, more precisely, a program running on one) that uses the DFS is called a client. This paper describes the division of responsibility between servers and clients. The basic tool for maintaining data consistency in these situations is the atomic property of transactions, which protects clients from system malfunctions and from the competing activities of other clients. Several cooperating clients may share a transaction. The DFS provides an unconventional locking mechanism between transactions that supports client caches and eliminates a novel form of deadly embrace. We have implemented and put into service a system based on these concepts.