ppxscal/embedding_network huggingface dataset:
Empirical Evidence of the Chaotic Behavior of the Hopfield-Tank TSP Model
Authors: Stamatis Vassiliadis, Nikos P. Pitsianis, Gerald G. Pechanek
Venue:  (1994)

Since its introduction, the Hopfield-Tank model for the Traveling Salesman Problem (TSP) has been surrounded by controversial evidence regarding its viability as a model and its capabilities to produce good results to this hard optimization problem. In this paper we investigate the reasons behind the difficulty of obtaining verifiable results and the viability of the model, by investigating the behavior the Hopfield-Tank neural network for the TSP has in circumstances when it is expected to produce identical tours. Our investigations strongly suggest that, when it is expected from the network to converge in a predetermined tour, the neural network converges to almost all possible tours when an insignificant perturbation to the initial conditions is applied. The overall consequence of our findings regarding the viability of the Hopfield-Tank model and the cause of the controversy surrounding the Hopffield-Tank model for the TSP can be summarized by the following: The cause of the Hopfield-Tank neural network for the TSP controversy and the difficulties in reproducing results is the chaotic behavior of the model. The finding of useful results for the TSP using the Hopfield-Tank network are purely casual and not to be attributed to the viability of the model. In essence the Hopfield-Tank neural network for the TSP is as viable as chaotic systems can be.
Persistent dropping: an efficient control of traffic aggregates
Authors: Hani Jamjoom, Kang G. Shin
Venue: Proceedings of the 2003 conference on Applications, technologies, architectures, and protocols for computer communications (2003)

Flash crowd events (FCEs) present a real threat to the stability of routers and end-servers. Such events are characterized by a large and sustained spike in client arrival rates, usually to the point of service failure. Traditional rate-based drop policies, such as Random Early Drop (RED), become ineffective in such situations since clients tend to be persistent, in the sense that they make multiple retransmission attempts before aborting their connection. As it is built into TCP's congestion control, this persistence is very widespread, making it a major stumbling block to providing responsive aggregate traffic controls. This paper focuses on analyzing and building a coherent model of the effects of client persistence on the controllability of aggregate traffic. Based on this model, we propose a new drop strategy called persistent dropping to regulate the arrival of SYN packets and achieves three important goals: (1) it allows routers and end-servers to quickly converge to their control targets without sacrificing fairness, (2) it minimizes the portion of client delay that is attributed to the applied controls, and (3) it is both easily implementable and computationally tractable. Using a real implementation of this controller in the Linux kernel, we demonstrate its efficacy, up to 60% delay reduction for drop probabilities less than 0.5.
Determining the Expected Load of Dynamic Tree Embeddings in Hypercubes
Authors: Keqin Li
Venue: Proceedings of the 17th International Conference on Distributed Computing Systems (ICDCS '97) (1997)

The main contribution of this paper is to use recurrence relations in analyzing the performance of a dynamic tree embedding algorithm in hypercubes. These recurrence relations characterize the expected load on each processor in a randomized tree embedding, and enable us to evaluate expected loads numerically and analytically. As a matter of fact, our methodology does not depend on the hypercube topology, and can be applied to study dynamic tree growing in other networks.
Techno-Economic Risk in Designing Complex Systems: Algorithms for Analysis and Optimization
Authors: V. A. Prourzin
Venue: Automation and Remote Control (2003)

Methods and algorithms for analysis and optimization of the reliability and risk of large technical systems are presented. Algorithms are based on the construction of failure trees. Special attention is paid to methods of solving large-dimensional problems. Systems with and without renewal are studied. For these systems, effective algorithms for computing probability indexes (risk levels) and loss expectation (risk measures) for undesirable random events (failures, emergencies, etc.) associated with the operation of a system are designed.
Electrical Characterization of Signal Routability and Performance
Authors: Mehdi M. Mechaik
Venue: Proceedings of the 1st International Symposium on Quality of Electronic Design (2000)

Electrical characterization and performance of signal routing layers are analyzed for two substrates. The implications of layer routability, signal width, signal thickness are also analyzed for optimum performance. Numerical values are tabulated for impedance, cross talk, and attenuation for signal geometries. Effective signal trace inductance, signal characteristic impedance, forward and backward crosstalk coefficients are derived from an electromagnetic 3D field solver. A case study is conducted to show the general trends of characteristic impedance and its consequences on multiple reflections, signal degradation, and performance. Effects of signal coupling, crosstalk, and simultaneous switching noise are also examined in order to assess signal performance. A comparison is made between a shielded and unshielded pair of transmission lines. The effects of the insulating material covering the transmission lines is also investigated to show loss of energy as it propagates from one end of a signal trace to the other end. Also effects of the per-unit length resistance, inductance, and capacitance of the lines are also analyzed to provide a set of good conditions and system requirements for minimizing the loss of data transmission in the mixed signal environment.Electromagnetic compatibility (EMC) of mixed signals, crosstalk, emissions and immunity noises are also analyzed for optimum data propagation in two distinct substrates. In one case, it will be shown that the data transmission generates a common mode current on two twisted pair lines. In the other case, the data transmission will be shown to generate a differential mode current. It will also be shown that the crosstalk can be minimized on data transmission lines by using a balanced transmission line. This study will also unveil the maximum usable part of the frequency range and its limitation to signal attenuation in mixed data signal transmission in high frequency applications.
Pipelining in multi-query optimization
Authors: Nilesh N. Dalvi, Sumit K. Sanghai, Prasan Roy, S. Sudarshan
Venue: Journal of Computer and System Sciences (2003)

Database systems frequently have to execute a set of related queries, which share several common subexpressions. Multi-query optimization exploits this, by finding evaluation plans that share common results. Current approaches to multi-query optimization assume that common subexpressions are materialized. Significant performance benefits can be had if common subexpressions are pipelined to their uses, without being materialized. However, plans with pipelining may not always be realizable with limited buffer space, as we show. We present a general model for schedules with pipelining, and present a necessary and sufficient condition for determining validity of a schedule under our model. We show that finding a valid schedule with minimum cost is NP-hard. We present a greedy heuristic for finding good schedules. Finally, we present a performance study that shows the benefit of our algorithms on batches of queries from the TPCD benchmark.
Self-Timed FIFO: An Exercise in Compiling Programs with VLSI Circuits
Authors: Alain J. Martin
Venue:  (1986)

No Abstract.
The Control of Teams of Autonomous Objects in the Time-Constrained Environments
Authors: I. Kotenko, L. Stankevitch
Venue: Proceedings of the 2002 IEEE International Conference on Artificial Intelligence Systems (ICAIS'02) (2002)

The paper considers problems of control of teams of autonomous objects in the time-constrained or real-time environments. The generic models of teamwork are determined. The common approach to support of teamwork in conditions of temporary limitations based oncombination of the approximation calculations and anytime-algorithms is offered. The models of the agents' teamwork realizing this approach for three different application areas are described: (1) virtual soccer (Robocup), (2) simulations of battle operations realized by a group of autonomous flight vehicles, (3) simulations of distributed coordinated computer attacks fulfilled by the hackers' team.
On the density of subgraphs in a graphwith bounded independence number
Authors: Pavel Valtr
Venue:  (1997)

Let $\sigma(n,m,k)$ be the largest number $\sigma\in[0,1]$ such that any graph on $n$ vertices with independence number at most $m$ has a subgraph on $k$ vertices with at least $\sigma\cdot{k\choose 2}$ edges. Up to a constant multiplicative factor, we determine $\sigma(n,m,k)$ for all $n,m,k$. For $\log n\le m=k\le n$, our result gives $\sigma(n,m,m)=\Theta({\log(n/m)\over m})$, which was conjectured by Alon.
The subresultant and clusters of close roots
Authors: Tateaki Sasaki
Venue: Proceedings of the 2003 international symposium on Symbolic and algebraic computation (2003)

This paper investigates the subresultant of univariate polynomials from the viewpoint of close roots. First, we derive formulas which express the subresultant and its cofactors in the root-differences. Then, we consider the case that the given polynomials contain one or more clusters of mutually close roots of closeness ß. We derive formulas showing the dependences of the coefficients of subresultant and its cofactors on ß and the number of clusters. Finally, we determine the magnitudes of cancellations which occur when we apply the Euclidean algorithm to polynomials having close roots.
Tracing Object-Oriented Code into Functional Requirements
Authors: G. Antoniol, G. Canfora, A. de Lucia, G. Casazza, E. Merlo
Venue: Proceedings of the 8th International Workshop on Program Comprehension (2000)

Software system documentation is usually expressed informally, in natural language and free text. Examples include requirement specifications, design documents, manual pages, system development journals, error logs and related maintenance reports.We propose an approach to establish and maintain traceability links is that programmers use meaningful names for program items, such as functions, variables, types, classes, and methods. We believe that the application-domain knowledge that programmers process when writing the code is often captured by the mnemonics for identifiers; therefore, the analysis of these mnemonics can help to associate high-level concepts with program concepts, and vice-versa. In this paper, the approach is applied to software written in an object-oriented language, namely Java, to trace classes to functional requirements.
A Simulation Based Trainer for Software Reliability Modeling
Authors: Edward L. Jones, Aubrey J. Rembert
Venue: Proceedings of the 12th International Symposium on Software Reliability Engineering (2001)

This paper presents RANDREL, a simulator based trainer for reliability testing. Reliability testing is modeled as a random walk through the program execution state space into which an initial set of faults has been seeded.When a fault is encountered during the simulation,a failure is reported, the tester fIxes the fault and resumes reliability testing. After each failure, the reliability growth model is updated and used to determine whether the reliability goal has been achieved.RANDREL provides a low-cost environment for learning reliability testing and modeling, and for exploring factors that contribute to the effectiveness of reliability testing. This paper describes the capabilities of RANDREL and the methodology being used to validate the model.
Improving Internet multicast with routing labels
Authors: B. N. Levine, J. J. Garcia-Luna-Aceves
Venue: Proceedings of the 1997 International Conference on Network Protocols (ICNP '97) (1997)

The IP-multicast architecture is extended with addressing information along multicast routing trees that permits more efficient and sophisticated multicast routing options and encourages communication and cooperation between IP and higher-layer protocols. The Addressable Internet Multicast (AIM) architecture is introduced that enables sources to restrict the delivery of packets to a subset of the receivers in a multicast group on a per-pocket basis, permits receivers to listen to subsets of sources on a subscription basis, provides nearest-host routing, and allows higher-layer protocols to place packets into application-defined logical streams, so that hosts may direct the multicast routing of packets based on application-defined contexts. In addition, the Reliable Multicast Architecture (RMA) is introduced to support end-to-end reliable multicasting using heterogeneous reliable multicast protocols and providing acknowledgment trees implicitly, thereby eliminating the ACK implosion problem and allowing NAK-avoidance algorithms to work within local groups.
Trees and Ehrenfeucht-Fraisse games
Authors: Stevo Todorcevic, Jouko Vaananen
Venue:  (1997)

We study trees T of height at most omega-1 with no uncountable branches, and their applications in the study of pairs (A,B) of non-isomorphic structures over a fixed vocabulary. There is a natural quasi-ordering of such trees in terms of the existence of a strictly increasing mapping from one tree to another. We investigate in depth the structure of this quasi-ordering and relate its properties to properties of pairs (A,B) of structures. Many new constructions of pairs of highly equivalent non-isomorphic structures are given.
Howard Aiken''s Children: The Harvard Computation Laboratory and its Students
Authors: Gerard Salton
Venue:  (1983)

NO SUPPLIED 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
Macromedia Dreamweaver MX Advanced for Windows and Macintosh: Visual QuickPro Guide
Authors: J. Tarin Towers, Sasha Magee, Abie Hadjitarkhani
Venue:  (2003)

:You don't have to write SQL or other database code to build interactivity into your site-you just need Dreamweaver MX, Macromedia's powerful new Web design tool, access to an application server, and a copy of Macromedia Dreamweaver MX Advanced for Windows and Macintosh: Visual QuickPro Guide. This valuable reference picks up where the Visual QuickStart Guide leaves off with advanced step-by-step tutorials on dynamic page serving, site management, and basic dynamic page building-and that's just in the first half of the book! The book's second half includes clear, concise instructions on how to create complex page designs, build cascading menus and toolbars, use Dreamweaver's accessibility features, and set up a page with head tags to attract search engines. Throughout this task-based reference, the authors illustrate key features with real-world examples of how and when features should be put to use. Combining tons of illustrations and example Web pages with concise, easy-to-follow how-tos, authors Towers, Hadjitarkhani, and Magee make it easy for anyone to create a dynamic Web site using Dreamweaver-including you!
A General Approach to Constraint Solving for Declarative Modeling Domain
Venue: Proceedings of the 1999 International Conference on Information Visualisation (1999)

Research in declarative modeling started some years ago, and an important progress has been accomplished and different orientations have been studied. However, some fundamental problems are not exhaustively explored: the role of the constraint solvers in maintaining the scene, detecting the incoherence and the contradictions between constraints, reducing the number of generated solutions by dynamically adding new constraints, are not sufficiently distinct.In this paper, our main contribution concerns the declarative modeling with constraints. We have developed a constraint solver called ORANOS that offers an extended model of constraint satisfaction problems. The solver supports two independent domains of artificial intelligence research: hierarchical constraints and dynamical constraints.The former offers efficient solving techniques for over-constrained problems; the latter allows development of interactive applications. These essential features allow the solver to extend the range of declarative modeling applications.
Transformations between Signed and Classical Clause Logic
Authors: Bernhard Beckert, Reiner Hähnle, Felip Manyà
Venue: Proceedings of the Twenty Ninth IEEE International Symposium on Multiple-Valued Logic (1999)

In the last years two automated reasoning techniques for clause normal form arose in which the use of labels are prominently featured: signed logic and annotated logic programming, which can be embedded into the first. The underlying basic idea is to generalise the classical notion of a literal by adorning an atomic formula with a sign or label which in general consists of a possibly ordered set of truth values. In this paper we relate signed logic and classical logic more closely than before by defining two new transformations between them. As a byproduct we obtain a number of new complexity results and proof procedures for signed logics.
A Theory of Processes
Authors: Van L Nguyen
Venue:  (1985)

NOT SUPPLIED
Load Balancing a Cluster of Web Servers using Distributed Packet Rewriting
Authors: Luis Aversa, Azer Bestavros
Venue:  (1999)

Abstract In this paper, we propose and evaluate an implementation of a prototype scalable web server. The prototype consists of a load-balanced cluster of hosts that collectively accept and service TCP connections. The host IP addresses are advertised using the Round Robin DNS technique, allowing any host to receive requests from any client. Once a client attempts to establish a TCP connection with one of the hosts, a decision is made as to whether or not the connection should be redirected to a different host---namely, the host with the lowest number of established connections. We use the low-overhead Distributed Packet Rewriting (DPR) technique to redirect TCP connections. In our prototype, each host keeps information about connections in hash tables and linked lists. Every time a packet arrives, it is examined to see if it has to be redirected or not. Load information is maintained using periodic broadcasts amongst the cluster hosts.
Specification and Verification of a Wavefront Algorithm for the Algebraic Path Problem
Authors: Stephen B. Seidman
Venue:  (1994)

In recent papers, Rice and Seidman have proposed a model of wavefront computation on a general interconnection network and used it to develop a language for specifying wavefront algorithms on an n-dimensional grid of processors. In this paper, the semantics for the language is used to specify and verify a wavefront algorithm for the algebraic path problem.
Object-Oriented Real-Time Distributed Programming and Support Middleware
Authors: K. H. (Kane) Kim
Venue: Proceedings of the Seventh International Conference on Parallel and Distributed Systems (2000)

The object-oriented (OO) distributed real-time (RT) programming movement started in 1990's and is growing rapidly at this turn of the century. The motivations are reviewed and then a brief overview is given of the particular programming scheme, which this author and his collaborators have been establishing. The scheme is called the time-triggered message triggered object (TMO) programming scheme and it is used to make specific illustrations of the issues and potentials of OO RT programming. The desirable features of middleware providing execution support for OO RT distributed programs are then discussed. The issue of fault-tolerant execution of distributed RT objects and that of RT distributed / parallel simulation are also discussed.
Debugger Visualizations for Shared-Memory Multiprocessors
Authors: Cherri M. Pancake, Sue Utter
Venue:  (1991)

The production of error-free code has always been challenging, but the incorporation of parallelism makes the task truly formidable. Although the idea of exploiting multiple processors in order to decrease wall-clock time is simple conceptually, understanding the complexity of parallel behavior is not. This paper reviews recent developments in parallel debuggers, focusing on techniques for program behavior visualization. The exploitation of graphical techniques enhances the partnership between user and tool, making better use of human creative and analytic capabilities. Two general visualization approaches are contrasted. The first characterizes behavior by the flow of execution control, portraying changes in process state or sequences of lower-level events. The second employs the framework of data structures to describe patterns of access to shared data. Each approach is appropriate in certain debugging situations. Experience suggests that parallel debuggers need a variety of techniques and levels of presentation if they are to provide comprehensive support for applications programmers.
Workload Scheduling for Task Graphs with Communication Costs on Parallel Systems
Authors: C. L. McCreary, Yahui Zhu
Venue:  (1991)

In this paper we extend the classical work on multiprocessor scheduling for four major ways: (1) A new notion of scheduling, called the workload schedule, is defined. The workload captures the essence of the communication/computation tradeoff, and it is a mechanism by which optimal schedules can be generated. (2) The theory of scheduling is extended by the statement and proof of a new NP-complete result. We prove 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 processes. 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 [18]. (3) Several algorithms for scheduling trees are presented. These range from determining the optimal schedule to an efficient greedy algorithm with a sound heuristic basis. The optimal algorithm is intractable with running time O(4**n) while the greedy algorithm runs in O(n) time. (4) The tradeoff between generating optimal schedules and creating scheduling programs that execute in a reasonable amount of time is demonstrated through analysis of data output from seven programs. The analysis shows a "near-optimal" schedule is obtained by one algorithm with "near-greedy" running time.
A study of the spontaneous air flow through a moving porous medium
Authors: Jianyao Mou, G. Randall Straley, Xiaodong Wang
Venue: Advances in Engineering Software (2003)

When a layer of porous material such as the felt moves with respect to the surrounding air, the induced pressure difference will drive the air through the moving porous material. In many industrial applications including the paper machine drying pocket ventilation, this spontaneous air-flow phenomenon is significant and needs to be taken into consideration in the design process. This paper addresses the issues such as the velocity distribution along the moving felt and how the flow rate through the porous material correlates with the felt permeability and thickness. In particular, computational approaches are compared with existing experimental results and validated with an analytical model.