ppxscal/embedding_network huggingface dataset:
Simulating population dependent PCS network models using time warp
Authors: Christopher D. Carothers, Yi-Bing Lin, Richard M. Fujimoto
Venue: Proceedings of the 27th conference on Winter simulation (1995)

The demand for mobile communications has led to intensive research and development efforts for complex PCS (personal communication service) networks. Capacity planning and performance modeling is necessary to maintain a high quality of service to the mobile subscriber while minimizing cost to the PCS provider. A question of pragmatic interest concerns the modeling of subscriber or portable movement in a PCS network. Typically, portable movement models are based on a probabilistic distribution function with fixed mean. These models may be an over simplification of real portable movement patterns. For example, portable movements during rush hour traffic may be slowed due to traffic jams. However, when the volume of vehicular traffic is less, portables are allowed to move more freely and with greater speed. To capture this type of portable movement behavior, we develop a population dependent PCS model where portable movement is based on the number of portables currently residing in that service area or cell. Because of the large amount of computation required to simulate PCS networks, we implement this model on a distributed Time Warp simulator, which has been shown to reduce the execution time of a single run from 20 hours down to 3.5 hours. Using this simulation model, we study the effect of different call workloads and population dependent portable movement patterns on PCS blocking statistics and present our preliminary results.
Patricia tries again revisited
Authors: Wojciech Szpankowski
Venue: Journal of the ACM (JACM) (1990)

The Patricia trie is a simple modification of a regular trie. By eliminating unary branching nodes, the Patricia achieves better performance than regular tries. However, the question is: how much on the average is the Patricia better? This paper offers a thorough answer to this question by considering some statistics of the number of nodes examined in a successful search and an unsuccessful search in the Patricia tries. It is shown that for the Patricia containing n records the average of the successful search length Sn asymptotically becomes 1/h1 &middot; ln n + O(1), and the variance of Sn is either var Sn = c &middot; ln n + 0(1) for an asymmetric Patricia or var Sn = 0(1) for a symmetric Patricia, where h1 is the entropy of the alphabet over which the Patricia is built and c is an explicit constant. Higher moments of Sn are also assessed. The number of nodes examined in an unsuccessful search Un is studied only for binary symmetric Patricia tries. We prove that the mth moment of the unsuccessful search length EUmn satisfies limn&rarr;&infin; EUmn/logm2n = 1, and the variance of Un is var Un = 0.87907. These results suggest that Patricia tries are very well balanced trees in the sense that a random shape of Patriciatries resembles the shape of complete trees that are ultimately balanced trees.
The GOMS family of user interface analysis techniques: comparison and contrast
Authors: Bonnie E. John, David E. Kieras
Venue: ACM Transactions on Computer-Human Interaction (TOCHI) (1996)

Sine the publication of The Psychology of Human-Computer Interaction, the GOMS model has been one of the most widely known theoretical concepts in HCI. This concept has produced severval GOMS analysis techniques that differ in appearance and form, underlying architectural assumptions, and predictive power. This article compares and contrasts four popular variantsof the GOMS family (the Keystroke-Level Model, the original GOMS formulation, NGOMSL, and CPM-GOMS) by applying them to a single task example.
A rule-based and object-oriented AI programming language
Authors: Tao Li
Venue: ACM SIGPLAN Notices (1995)

This paper presents a new artificial intelligence programming language called ROOP which is machine independent and has the ability to deal with logical programming in general. ROOP is a multiple paradigm language which combines rule-based, procedure, logic and object-oriented programming techniques.
A maximum-likelihood interpretation of batch means estimators
Authors: Kevin J. Healy
Venue: Proceedings of the 27th conference on Winter simulation (1995)

We show how the classical batch means estimator of the variance parameter of a strictly stationary dependent stochastic process can be viewed as a maximum likelihood estimator based on asymptotic properties of the standardized time series of observations from the process.
Implementing self-reproducing artificial organisms with Ada
Authors: Philippe Laval
Venue: ACM SIGAda Ada Letters (1995)

Artificial Life techniques have a potential use in ecological models, but they have not yet been programmed in Ada. Ada tasks provide a powerful means to express the behavior of self-reproductive autonomous individuals. This article shows how artificial organisms with a complicated reproduction (alternation of sexual and asexual generations) have been implemented in an ecological simulation software written in Ada.
A brief review of the command forces (CFOR) program
Authors: Marnie R. Salisbury, David W. Seidel, Lashon B. Booker
Venue: Proceedings of the 27th conference on Winter simulation (1995)

The command forces (CFOR) program is implementing a new aspect of warfare simulation: explicit modeling of command and control. The program presents several aspects: a concept of operations where command and control nodes populate the battlespace in the same manner as weapons systems; an architecture where software simulation of command and control interacts with the battlefield through a set of common services; a software design for the services that forms an infrastructure that integrates with underlying semi-automated forces simulation; a mechanism that facilitates automated integration of real world C2 systems with simulations; and an implementation plan that integrates the efforts of multiple developers to produce a functioning multi-service command forces simulation. The CFOR program has passed through the concept and planning phases and is being implemented. Lessons learned from progress to date are presented along with a plan for further development and integration.
An overview of the design and implementation of a large and complex simulation effort: the Naval Research Laboratory's Tactical Oceanography Simulation Laboratory
Authors: Mark R. Fernandez, John W. Ellis, James E. Miller
Venue: ACM SIGSIM Simulation Digest (1995)

As one would anticipate, there is considerable interest within the military community for developing the capability to accurately simulate the behavior of sound in any of the oceans of the world under any of the conditions which might arise there [1,2,3]. With this capability the quality of training could be increased and the associated training costs could be reduced; performance requirements for new systems could be examined under a variety of conditions which include working with all combinations of proposed, prototype, and operational systems functioning in both familiar as well as untested environments; tactics for deploying defenses, searching for an enemy and counter measures against that enemy could be evaluated; the impact of technological advances or the advantages gained through espionage by an enemy force could be evaluated, real and realistic situations could be recreated and thoroughly studied, and finally, the value of better environmental data could be determined prior to allocating both the time and money needed to collect, process, store and distribute that data [4].
Sample size selection for improved Nelder-Mead performance
Authors: John J. Tomick, Steven F. Arnold, Russell R. Barton
Venue: Proceedings of the 27th conference on Winter simulation (1995)

The Nelder-Mead (1965) simplex algorithm has been used for sequential optimization of simulation response functions. The rescaling operations of this algorithm can lead to inappropriate termination at non-optimal points. We have used the probabilistic characterization of this behaviour to develop special rules for determining the number of replications to take for each experimental design point. Computational experiments indicate that the quality of the solution is often improved.
Network and single user performance evaluation of a mobile data system over flat fading transmission channels
Authors: Piero Castoldi, Gianni Immovilli, Maria Luisa Merani
Venue: Wireless Networks (1995)

In this paper the contrasting effects of transmission impairments and capture on both the network and single user performance of a slotted Aloha system are investigated in a mobile radio environment, accounting for frequency non-selective random propagation phenomena, and employing the packet error probability in order to define packet losses and capture. With this study we demonstrate that it is possible to generalize in a real propagation context a method previously proposed in literature for evaluating the network behavior in terms of steady-state throughput, backlog and stability in conventional transmission conditions, i.e., when all the transmission channels were error-free and the collisions caused the loss of all the packets involved. Moreover, we indicate under which specific constraints on the terminal mobility we can apply this method to analytically predict the single user performance, which we show being an important design parameter. Through the numerical results reported we quantitatively point out that in the absence of coding capture increases system stability and moderately improves the overall system throughput and backlog. We also outline the trade-off between an increased capture gain obtained by means of coding and the corresponding system cost in terms of complexity and bandwidth occupancy. Furthermore, we demonstrate the unfairness which affects the single user performance and the consequent need for countermeasures in order not to discriminate among users differently located within the network; yet, this last solution is detrimental as regards the positive capture effects.
Nonlinear $H^\infty$ Optimization: A Causal Power Series Approach
Authors: Ciprian Foias, Caixing Gu, Allen Tannenbaum
Venue: SIAM Journal on Control and Optimization (1995)

In this paper, using a power series methodology a design procedure applicable to analytic nonlinear plants is described. The technique used is a generalization of the linear $H^\infty$ theory. In contrast to previous work on this topic ([Indiana J. Math., 36 (1987), pp.~693--709], [Oper. Theory Adv. Appl., 41 (1989), pp.~255--277], [SIAM J. Control Optim., 27 (1989), pp.~842--860]), the authors are now able to incorporate explicitly a causality constraint into the theory. In fact, it is shown that it is possible to reduce a causal optimal design problem (for nonlinear systems) to a classical interpolation problem solvable by the commutant lifting theorem [Harmonic Analysis of Operators on Hilbert Space, North-Holland, Amsterdam, 1970], [The Commutant Lifitng Approach to Interpolation Problems, Birkhauser, Boston, 1990].
High performance synchronization algorithms for multiprogrammed multiprocessors
Authors: Robert W. Wisniewski, Leonidas I. Kontothanassis, Michael L. Scott
Venue: ACM SIGPLAN Notices (1995)

Scalable busy-wait synchronization algorithms are essential for achieving good parallel program performance on large scale multiprocessors. Such algorithms include mutual exclusion locks, reader-writer locks, and barrier synchronization. Unfortunately, scalable synchronization algorithms are particularly sensitive to the effects of multiprogramming: their performance degrades sharply when processors are shared among different applications, or even among processes of the same application. In this paper we describe the design and evaluation of scalable scheduler-conscious mutual exclusion locks, reader-writer locks, and barriers, and show that by sharing information across the kernel/application interface we can improve the performance of scheduler-oblivious implementations by more than an order of magnitude.
Fractional Covers and Communication Complexity
Authors: Mauricio Karchmer, Eyal Kushilevitz, Noam Nisan
Venue: SIAM Journal on Discrete Mathematics (1995)

It is possible to view communication complexity as the minimum solution of an integer programming problem. This integer programming problem is relaxed to a linear programming problem and from it information regarding the original communication complexity question is deduced. A particularly appealing avenue this opens is the possibility of proving lower bounds on the communication complexity (which is a minimization problem) by exhibiting upper bounds on the maximization problem defined by the dual of the linear program. This approach works very neatly in the case of nondeterministic communication complexity. In this case a special case of Lovasz's fractional cover measure is obtained. Through it the amortized nondeterministic communication complexity is completely characterized. The power of the approach is also illustrated by proving lower and upper bounds on the nondeterministic communication complexity of various functions. In the case of deterministic complexity the situation is more complicated. Two attempts are discussed and some results using each of them are obtained. The main result regarding the first attempt is negative: one cannot use this method for proving superpolynomial lower bounds for formula size. The main result regarding the second attempt is a "direct-sum" theorem for two-round communication complexity.
Switching Codes for Delta-I Noise Reduction
Authors: C. L. Chen, Brian W. Curran
Venue: IEEE Transactions on Computers (1996)

In this paper, we address the off-chip driver delta-I or switching noise problem. We propose a novel approach based on switching codes to reduce this noise. These codes are designed to lower the number of drivers which switch in any given system cycle. A formal theoretic framework for switching codes is developed which provides an upper bound on the number of switching drivers as a function of bit width of the data bus and number of redundant switch bits. Switching codes with error detecting and error correcting capabilities are also presented. Switching codes also reduce the average switching activity and power consumed by the off-chip drivers.
A framework for the realization of cooperative systems
Authors: P. E. Clements, R. M. Jones, R. H. Weston, E. A. Edmonds
Venue: ACM SIGOIS Bulletin (1995)

It is now timely to build upon output of research worldwide into Computer Supported Cooperative Work (CSCW) so that new forms of computing infrastructure can be provided to facilitate cooperative working. Three new technologies can collectively provide means of addressing this requirement; they are (a) multi-media information systems, (b) high performance networks and (c) intelligent autonomous agents. Multi-media information technology is now available to provide rich communication facilities including text, image, sound and video in both synchronous and asynchronous modes. Thus, computer -based systems can combine many of the media commonly used for communication and can transmit the results over a very wide distances, High performance networks enable multi-media communication to take place over wide areas. This is particularly important for essential international user links. The richness of the communication cannot be the only criterion used because the problem of "information overload" is only too well understood by users. Thus the application of knowledge-based systems to the construction of autonomous support agents has an important role to play . These again act on behalf of users to manage the communications by, for example, altering messages or assisting with the organisation of group exchanges. This paper details a system that will allow each of these technologies to be incorporated in to a framework such that a cooperative system can be built in a flexible and highly configurable manner and be responsive to the needs of the cooperative group.
Parallel gate-level circuit simulation on shared memory architectures
Authors: Rajive Bagrodia, Yu-an Chen, Vikas Jha, Nicki Sonpar
Venue: Proceedings of the ninth workshop on Parallel and distributed simulation (1995)

This paper presents the results of an experimental study to evaluate the effectiveness of parallel simulation in reducing the execution time of gate-level models of VLSI circuits. Specific contributions of this paper include (i) the design of a gate-level parallel simulator that can be executed, without any changes on both distributed memory and shared memory parallel architectures, (ii) demonstrated speedups with both conservative and optimistic simulation protocols (almost all previous studies on circuit simulation have failed to extract speedups with conservative protocols); in particular we showed that a speedup of about 3 was obtained on 8 processors of Sparc1000 for conservative algorithms and about 2 for optimistic algorithms for circuits in the ISCAS85 benchmark suite; and (iii) performance comparison between shared memory and distributed memory implementations of the simulator.
A wireless local area network employing distributed radio bridges
Authors: Victor C. M. Leung, Andrew W. Y. Au
Venue: Wireless Networks (1996)

This paper presents a novel distributed wireless local area network (WLAN) architecture, where each wireless terminal (WT) accesses a backbone local area network (LAN) segment via multiple radio bridges (RB's). We introduce a self-learning routing algorithm for the RB's, which automatically adapts to changes in terminal locations, and prevents multiple copies of each data frame from being forwarded over the backbone LAN segment. The distributed WLAN architecture eases the management of network topological changes and terminal mobility, compared to centralized cellular architectures. We consider the use of direct-sequence spread-spectrum (DS/SS) signaling and the slotted Aloha medium access control (MAC) protocol over the wireless links, with multiple uplink receivers and downlink transmitters at the RB's for each MAC frame. Simulation results for the uplink show that the multi-receiver site diversity and the capture effect of DS/SS signaling effectively combat multipath and multiaccess interference, resulting in high throughput capacity and stable operation for the channel. Under overload traffic, the system is able to maintain a high level of throughput with bounded delays. It is shown that the use of multiple receiver reduces the access fairness problem for WT's at different locations caused by the near-far effect.
Parallelizing Navier-Stokes computations on a variety of architecture platforms
Authors: D. N. Jayasimha, M. E. Hayder, S. K. Pillay
Venue: Proceedings of the 1995 ACM/IEEE conference on Supercomputing (CDROM) (1995)

We study the computational, communication, and scalability characteristics of a Computational Fluid Dynamics application, which solves the time accurate flow field of a jet using the compressible Navier-Stokes equations, on a variety of parallel architectural platforms. The platforms chosen for this study are a cluster of workstations (the LACE experimental testbed at NASA Lewis), a shared memory multiprocessor (the Cray YMP), distributed memory multiprocessors with different topologies ¿ the IBM SP and the Cray T3D. We investigate the impact of various networks, connecting the cluster of workstations, on the performance of the application and the overheads induced by popular message passing libraries used for parallelization. The work also highlights the importance of matching the memory bandwidth to the processor speed for good single processor performance. By studying the performance of an application on a variety of architectures, we are able to point out the strengths and weaknesses of each of the example computing platforms
Spectral-based multi-way FPGA partitioning
Authors: Pak K. Chan, Martine D. F. Schlag, Jason Y. Zien
Venue: Proceedings of the 1995 ACM third international symposium on Field-programmable gate arrays (1995)

Recent research on FPGA partitioning has focussed on finding minimum cuts between partitions without regard to the routability of the partitioned subcircuits. In this paper we develop a spectral approach to multi-way partitioning in which the primary goal is to produce routable subcircuits while maximizing FPGA device utilization. To assist the partitioner in assessing the routability of the partitioned subcircuits, we have developed a theory to predict the routability of the partitioned subcircuits prior to partitioning. Advancement over the current work is evidenced by results of experiments on the standard MCNC benchmarks.
Steps for proper simulation project management
Authors: William B. Nordgren
Venue: Proceedings of the 27th conference on Winter simulation (1995)

Summarizes the steps and procedures of performing a simulation study. Simulation studies are complicated by nature and without any formal procedure can present a large challenge for engineers. This paper develops a step-by-step approach to aid in the management of real-life simulation projects. A list of tasks needed to complete each step is presented to help the engineer document and validate the project. This approach has been used for the successful development and conclusion of several real-life simulation projects.
Goal driven business modelling: supporting decision making within information systems development
Authors: Stephan Jacobs, Roland Holten
Venue: Proceedings of conference on Organizational computing systems (1995)

Within information systems development business modelling is often used to structure goal decomposition and goal satisfaction. Business modells serve as a framework for a concrete information systems project. However, the concept of goal is not explicit in the leading business reference models.In this paper we show how goals can be used to drive the modelling process. Goals are not only used as a starting point of development but serve as criteria to evaluate actions and decisions throughout the design.We show how business and goal models can be integrated using a common process meta model. An environment to support decision making in the business modelling process has been developed to demonstrate our approach.
Will I still be writing code when I'm forty?
Authors: Vance Christiaanse
Venue: 3C ON-LINE (1996)

I had just told a community college instructor that in industry, where I teach and work, a typical software engineer spends little time coding. "So what do you do all day?", she asked.
Noninteraction and Stability Via Invertible Feedback Laws and Some Existence Conditions
Authors: S. Battilotti
Venue: SIAM Journal on Control and Optimization (1995)

For a wide class of nonlinear systems with more inputs than outputs, the authors show that the asymptotic stability of suitable dynamics and the asymptotic stabilizability via dynamic state feedback of suitable systems are necessary to achieve noninteraction and stability via invertible feedbacklaws. These conditions generalize some recent results obtained for the same class of systems. Some interesting existence conditions are also given, and relationships with the above necessary conditions are identified.
A type system equivalent to flow analysis
Authors: Jens Palsberg, Patrick O'Keefe
Venue: ACM Transactions on Programming Languages and Systems (TOPLAS) (1995)

Flow-based safety analysis of higher-order languages has been studied by Shivers, and Palsberg and Schwartzbach. Open until now is the problem of finding a type system that accepts exactly the same programs as safety analysis. In this article we prove that Amadio and Cardelli's type system with subtyping and recursive types accepts the same programs as a certain safety analysis. The proof involves mappings from types to flow information and back. As a result, we obtain an inference algorithm for the type system, thereby solving an open problem.