ppxscal/embedding_network huggingface dataset:
Initializing weights of a multilayer perceptron network by using the orthogonal least squares algorithm
Authors: Mikko Lehtokangas, Jukka Saarinen, Kimmo Kaski, Pentti Huuhtanen
Venue: Neural Computation (1995)

Usually the training of a multilayer perceptron network starts by initializing the network weights with small random values, and then the weight adjustment is carried out by using an iterative gradient descent-based optimization routine called backpropagation training. If the random initial weights happen to be far from a good solution or they are near a poor local optimum, the training will take a lot of time since many iteration steps are required. Furthermore, it is very possible that the network will not converge to an adequate solution at all. On the other hand, if the initial weights are close to a good solution the training will be much faster and the possibility of obtaining adequate convergence increases. In this paper a new method for initializing the weights is presented. The method is based on the orthogonal least squares algorithm. The simulation results obtained with the proposed initialization method show a considerable improvement in training compared to the randomly initialized networks. In light of practical experiments, the proposed method has proven to be fast and useful for initializing the network weights.
A system for constructing configurable high-level protocols
Authors: Nina T. Bhatti, Richard D. Schlichting
Venue: ACM SIGCOMM Computer Communication Review (1995)

New distributed computing applications are driving the development of more specialized protocols, as well as demanding greater control over the communication substrate. Here, a network subsystem that supports modular, fine-grained construction of high-level protocols such as atomic multicast and group RPC is described. The approach is based on extending the standard hierarchical model of the x-kernel with composite protocols in which micro-protocol objects are composed within a standard runtime framework. Each micro-protocol realizes a separate semantic property, leading to a highly modular and configurable implementation. In contrast with similar systems, this approach provides finer granularity and more flexible inter-object communication. The design and prototype implementation runing on Mach are described. Performance results are also given for a micro-protocol suite implementing variants of group RPC.
The 1984 Snowbird Report: future issues in computer science
Authors: CORPORATE ASL Committee on Logic Education
Venue: Communications of the ACM (1985)

This workshop reports that no core description of computer science is universally accepted. A model of the discipline must emphasize global issues over isolated objectives, cooperation over competition.
Allocation and Scheduling of Precedence-Related Periodic Tasks
Authors: Krithi Ramamritham
Venue: IEEE Transactions on Parallel and Distributed Systems (1995)

This paper discusses a static algorithm for allocating and scheduling components of periodic tasks across sites in distributed systems. Besides dealing with the periodicity constraints, (which have been the sole concern of many previous algorithms), this algorithm handles precedence, communication, as well as replication requirements of subtasks of the tasks. The algorithm determines the allocation of subtasks of periodic tasks to sites, the scheduled start times of subtasks allocated to a site, and the schedule for communication along the communication channel(s). Simulation results show that the heuristics and search techniques incorporated in the algorithm are very effective.Index Terms¿Real-time systems, task allocation, scheduling, periodic tasks, precedence constraints, distributed systems.
Orders of Input/Output Differential Equations and State-Space Dimensions
Authors: Yuan Wang, Eduardo D. Sontag
Venue: SIAM Journal on Control and Optimization (1995)

This paper deals with the orders of input/output equations satisfied by nonlinear systems. Such equations represent differential (or difference, in the discrete-time case) relations between high-order derivatives (or shifts, respectively) of input and output signals. It is shown that, under analyticity assumptions, there cannot exist equations of order less than the minimal dimension of any observable realization; this generalizes the known situation in the classical linear case. The results depend on new facts, themselves of considerable interest in control theory, regarding universal inputs for observability in the discrete case, and observation spaces in both the discrete and continuous cases. Included in the paper is also a new and simple self-contained proof of Sussmann's universal input theorem for continuous-time analytic systems.
Problems with DCE security services
Authors: Gregory White, Udo Pooch
Venue: ACM SIGCOMM Computer Communication Review (1995)

Distributed computing is receiving an ever increasing amount of interest and with it come many challenges, not the least of which is how to maintain system and network security. Issues relating to user authentication, access authorization, and communication security must be addressed when multiple, heterogeneous systems are connected. While these issues have been addressed in OSFs DCE, several problems remain. This paper describes some of these problems.
Flexible modeling and analysis of large-scale AS/RS-AGV systems
Authors: Soemon Takakuwa
Venue: Proceedings of the 27th conference on Winter simulation (1995)

A method of modeling large-scale AS/RS-AGV systems is proposed in an attempt to describe the AS/RS precisely and flexibly in which a lot of items are stored and retrieved. The system considered in this study consists of the large-scale AS/RS with stacker cranes, the looped-track AGV system, aisle conveyors connecting these two systems, and incoming and outgoing conveyors. There are two major stages to model large-scale AS/RS-AGV systems flexibly and execute simulation experiments. The first stage is to generate a simulation program by inputting the selected parameters such as the number of banks, the number of bays, the number of levels of AS/RS, and the number of AGVs. The second stage is to perform simulation experiments. In the proposed model, every item number put on each rack, the corresponding number of cases for each item, the time of arriving at the warehouse, and the time of departing from the system are stored and recorded. Regarding a large-scale AS/RS system, three particular types of the rack arrangement, which have the same number of racks inside the warehouse, are analyzed to examine their performance. The analysis is performed using both average flowtime and equivalent annual cost as performance measures.
A Stable High-Order Interpolation Scheme for Superconvergent Data
Authors: Steven Pruess, Hongsung Jin
Venue: SIAM Journal on Scientific Computing (1996)

A local collocation scheme is developed that yields stable high-order accurate interpolants of discrete data arising from the numerical solution of a differential equation. It should prove to be especially attractive for applications where data are superconvergent, e.g., spline collocation at Gauss points. For simplicity, the formulas are initially developed for a scalar equation, but generalizations are later given for systems. Numerical examples are shown that illustrate the stability, even for the case of highly nonuniform meshes which have proven difficult in prior studies.
Comments on 'A Metrics Suite for Object Oriented Design'
Authors: Neville I. Churcher, Martin J. Shepperd
Venue: IEEE Transactions on Software Engineering (1995)

A suite of object oriented software metrics has recently been proposed. While the authors have taken care to ensure their metrics have a sound measurement theoretical basis, we argue that is premature to begin applying such metrics while there remains uncertainty about the precise definitions of many of the quantities to be observed and their impact upon subsequent indirect metrics. In particular, we show some of the ambiguities associated with the seemingly simple concept of the number of methods per class. The usefulness of the proposed metrics, and others, would be greatly enhanced if clearer guidance concerning their application to specific languages were to be provided. Such empirical considerations are as important as the theoretical issues raised by the authors.
QBI: query by icons
Authors: Antonio Massari, Stefano Pavani, Lorenzo Saladini, Panos K. Chrysanthis
Venue: Proceedings of the 1995 ACM SIGMOD international conference on Management of data (1995)

QBI is an icon-based query processing and exploration facility for large distributed databases [3]. As opposed to other interactive query interfaces, it combines (1) a pure iconic specification, i.e., no diagrams of any form, only icon manipulation, with (2) intensional browsing or metaquery tools that assist in the formulation of complete queries without involving path specification or access to the actual data in the database.Path expressions are automatically generated by QBI and irrespective of their length, represented by a single icon, allowing for better use of the screen. It requires no special knowledge of the content of the underlying database nor understanding of the details of the database schema. Hence, QBI is domain independent and equally useful to both unsophisticated and expert users.
Efficient vector and parallel manipulation of tensor products
Authors: Paul E. Buis, Wayne R. Dyksen
Venue: ACM Transactions on Mathematical Software (TOMS) (1996)

We present efficient vector and parallel methods for manipulating tensor products of matrices. We consider both computing the matrix-vector product (A1&Auml;&frac14;&Auml;AK)x and solving the system of linear equations (A1&Auml;&frac14;&Auml;AK)x=b. The methods described are independent of K. We accompany this article with a companion algorithm which describes an implementation of a complete set of tensor product routines based on LAPACK and the Level 2 and 3 Basic Linear Algebra Subprograms (BLAS) which provide vectorization and parallelization.
Three-Dimensional Steady Flow in a Dividing Channel Using Finite and Pseudospectral Differences
Authors: Roland Hunt
Venue: SIAM Journal on Scientific Computing (1996)

A numerical solution for the flow of a steady incompressible fluid in a general symmetric three-dimensional bifurcation having uniform thickness is presented for Reynolds numbers up to 100. The physical region is divided into three subdomains, each of which is transformed onto a rectangular parallelepiped upon which the calculations are made. The Navier--Stokes equations are differenced using standard second-order differences in the direction of each tube and pseudospectral differences in the two transverse directions. The use of such differences in the transverse plane greatly reduces the number of nodes required for a given accuracy, and this particular mix of differences minimizes the CPU time requirement when Newton's method is used to solve the resulting algebraic system. Two bifurcations have been considered with daughter tubes angled to the main tube at $60^\circ$ and $90^\circ$, respectively. By comparing results on different sized grids the estimated relative accuracy is typically of order $10^{-3}$. The resulting flows display novel three-dimensional features not present in two-dimensional flows. In particular, as fluid passes from main to daughter tubes it twists in a fairly complex vortex-like fashion.
A survey of power management techniques in mobile computing operating systems
Authors: Gregory F. Welch
Venue: ACM SIGOPS Operating Systems Review (1995)

Many factors have contributed to the birth and continued growth of mobile computing, including recent advances in hardware and communications technology. With this new paradigm however come new challenges in computer operating systems development. These challenges include heretofore relatively unusual items such as frequent network disconnections, communications bandwidth limitations, resource restrictions, and power limitations. It is the last of these challenges that we shall explore in this paper---that is the question of what techniques can be employed in mobile computer operating systems that can reduce the power consumption of today's mobile computing devices.
A New Approach to Formal Language Theory by Kolmogorov Complexity
Authors: Ming Li, Paul Vitanyi
Venue: SIAM Journal on Computing (1995)

We present a new approach to formal language theory using Kolmogorov complexity. The main results presented here are an alternative for pumping lemma(s), a new characterization for regular languages, and a new method to separate deterministic context-free languages and nondeterministic context-free languages. The use of the new "incompressibility arguments" is illustrated by many examples. The approach is also successful at the high end of the Chomsky hierarchy since one can quantify nonrecursiveness in terms of Kolmogorov complexity.
Advantages of the activity scanning approach in the modeling of complex construction processes
Authors: Julio C. Martinez, Photios G. Ioannou
Venue: Proceedings of the 27th conference on Winter simulation (1995)

Construction processes are very complex and include highly interdependent components subject to complex activity startup conditions. A simulation language based on activity cycle diagrams can express the logic of complex simulation models very effectively. This paper uses Stroboscope (STate- and ResOurce-Based Simulation of COnstruction ProcEsses), a three-phase activity scanning simulation language based on extended activity cycle diagrams, to model the operations of a quarry. Although simplified, this example is representative of the complex nature of construction operations.
Compatible class encoding in Roth-Karp decomposition for two-output LUT architecture
Authors: Juinn-Dar Huang, Jing-Yang Jou, Wen-Zen Shen
Venue: Proceedings of the 1995 IEEE/ACM international conference on Computer-aided design (1995)

Roth-Karp decomposition is one of the most popular techniques for LUT-based FPGA technology mapping because it can decompose a node into nodes with fewer numbers of fanins. In this paper, we show how to formulate the compatible class encoding problem in Roth-Karp decomposition as a symbolic-output encoding problem in order to exploit the feature of the two-output LUT architecture. Based on this formulation, we also develop an encoding algorithm to minimize the number of LUT's required to implement the logic circuit. Experimental results show that our encoding algorithm can produce promising results in the logic synthesis environment for the two-output LUT architecture.
A system level design methodology for the optimization of heterogeneous multiprocessors
Authors: M. Schwiegershausen, P. Pirsch
Venue: Proceedings of the 8th international symposium on System synthesis (1995)

Abstract: This paper presents a system level design methodology and its implementation as CAD tool for the optimization of heterogeneous multiprocessor systems. These heterogeneous systems, consisting of dedicated as well as programmable processors, are highly suitable for performing complex schemes of image processing algorithms under real time constraints. It starts from a specification of the image processing scheme, explores the design space based on a finite set of parametrizable processor modules, and by using mixed integer linear programming as mathematical framework derives heterogeneous systems, being optimal in terms of area expense and throughput rate.
Algorithms for Enumerating All Spanning Trees ofUndirected and Weighted Graphs
Authors: Sanjiv Kapoor, H. Ramesh
Venue: SIAM Journal on Computing (1995)

In this paper, we present algorithms for enumeration of spanning trees in undirected graphs, with and without weights. The algorithms use a search tree technique to construct a computation tree. The computation tree can be used to output all spanning trees by outputting only relative changes between spanning trees rather than the entire spanning trees themselves. Both the construction of the computation tree and the listing of the trees is shown to require $O(N+V+E)$ operations for the case of undirected graphs without weights. The basic algorithm is based on swapping edges in a fundamental cycle. For the case of weighted graphs (undirected), we show that the nodes of the computation tree of spanning trees can be sorted in increasing order of weight, in $O(N\log V+VE)$ time. The spanning trees themselves can be listed in $O(NV)$ time. Here $N$, $V$, and $E$ refer respectively to the number of spanning trees, vertices, and edges of the graph.
Performance analysis of future event sets
Authors: Halim Damerdji, Peter W. Glynn
Venue: Proceedings of the 27th conference on Winter simulation (1995)

The linked list and indexed list future event sets are investigated. The interaction hold model and the Jackson network model are the underlying stochastic models considered. For the interaction hold model and for the (doubly) linked list, we find, for example, the mean number of key comparisons performed in order to find a record's insertion point into the list; this is useful when deciding whether to scan from the head or the tail of the list. The distribution of the relative position of the to-be-inserted record is also obtained; for indexed lists, this is helpful when deciding the number of sublists and position(s) of the middle pointer(s). The Jackson network model has a realistic event logic, but events are restricted to be exponentially distributed. Because the stationary probabilities can be computed for this model, it is then possible to evaluate and compare the (steady-state) performance of certain future event sets (e.g. linked lists scanned from the head or the tail).
Design, implementation, and evaluation of a software-based real-time Ethernet protocol
Authors: Chitra Venkatramani, Tzi-cker Chiueh
Venue: ACM SIGCOMM Computer Communication Review (1995)

Distributed multimedia applications require performance guarantees from the underlying network subsystem. Ethernet has been the dominant local area network architecture in the last decade, and we believe that it will remain popular because of its cost-effectiveness and the availability of higher-bandwidth Ethernets. We present the design, implementation and evaluation of a software-based timed-token protocol called RETHER that provides real-time performance guarantees to multimedia applications without requiring any modifications to existing Ethernet hardware. RETHER features a hybrid mode of operation to reduce the performance impact on non-real-time network traffic, a race-condition-free distributed admission control mechanism, and an efficient token-passing scheme that protects the network against token loss due to node failures or otherwise. To our knowledge, this is the first software implementation of a real-time protocol over existing Ethernet hardware. Performance measurements from experiments on a 10 Mbps Ethernet indicate that up to 60% of the raw bandwidth can be reserved without deteriorating the performance of non-real-time traffic. Additional simulations for high bandwidth networks and faster workstation hardware indicate that the protocol allows reservation of a greater percentage of the available bandwidth.
The chaos strategy
Authors: L. B. S. Raccoon
Venue: ACM SIGSOFT Software Engineering Notes (1995)

"What line of code should I write next?" This paper resulted from my search for an answer that reflects my experiences in writing real programs, and reflects both the Chaos model and life cycle. After trying to infer an answer directly from the Chaos life cycle, in fact from any life cycle, I ultimately gave up. I concluded that while life cycles describe what I can do in a project, life cycles do not describe what I should do in a project. For that I need another concept, such as strategy.Strategies are idealized plans of how software development should work. Strategies help us to prioritize the things we do. A general strategy defines an overall approach for solving a problem that must be adapted to meet local circumstances. A specific strategy defines immediate goals. A good specific strategy balances short-term progress with long-term goals.Applying the concept of strategy to software development may seem inappropriate, or even absurd, to software developers who normally worry about concepts like correctness, specification, and quality. Developers have been taught to think of software development as totally predictable, with each step a perfectly understood element. Strategy implies a contest which admits that a developer could lose. On the other hand, developers may be more familiar applying strategy to investments, marketing, elections, and war. People do meaningfully use strategy for complex military and business problems.In The Chaos Model and the Chaos Life Cycle, I argued that each software development project is a chaotic, multi-level sequence of issues that arise and get resolved. Developers repeatedly select an issue to resolve, devise an approach, implement a solution, maintain the resulting program, and so forth. Software development is a project-to-project, situation-to-situation, minute-to-minute process, with many levels. Developers must deal with all levels from the "whole project" level down to the "one line of code" level. In The Complexity Gap, I argued that the middle levels of a project are not addressed by the traditional Stepwise Refinement and Object-Oriented Design strategies. The macro-process and top-down strategies address the top levels of a project. The micro-process and bottom-up strategies address the bottom levels of a project.In this paper, I propose the Chaos strategy to guide development on the levels of a project within the Complexity Gap. I begin by describing parallels between software development and games of strategy, and by defining the Software Development Game. I then define elements of the Chaos strategy, a middle-out, technology-independent strategy. Finally, I show how to adapt the Chaos strategy to fit the various circumstances that arise in complex software development projects.