ppxscal/embedding_network huggingface dataset:
Initial estimation of communication efficiency of indoor wireless channels
Authors: G. J. Foschini, R. A. Valenzuela
Venue: Wireless Networks (1997)

We report theoretical/numerical estimation of ultimate limits of bandwidth efficient delivery of high bit-rate digital signals indoors. Specifically, we analyze the Crawford Hill Bell Laboratories building. Single omni transmit and receive antennas are assumed. The signals incur attenuation and distortion due to multipath and at high bit-rates this frequency selectivity causes ISI. Moreover, there is impairment by gaussian noise. Transmit power and bandwidth constraints limit communications efficiency. We illustrate this limiting of efficiency in examples assuming 5.2 GHz carrier, 10 MHz bandwidth and up to 1 W transmitted power. The experimentally based WiSE ray-tracing tool models the channels from a base on the ceiling to workspaces in various rooms. Movement within a workspace causes channel changes. Computing the probability distribution of capacity shows substantial capacity for the omni-omni case with 10 MHz bandwidth for 100 mW transmitted. For the most distant offices, for at least 95% of the area in a workspace, we obtain 3.6 bps/Hz. We also examine diversity methods, illustrating substantial gains with nth order optimum combining (OC(n)):OC(2) improves capacity by over 35% in rooms where capacity is the lowest while OC(4) improves it 70%. We put the results in a pragmatic perspective by highlighting the bit-rates achievable with decision feedback equalization
Personalized, interactive news on the Web
Authors: Krishna Bharat, Tomonari Kamba, Michael Albers
Venue: Multimedia Systems (1998)

We present <i>Krakatoa Chronicle,</i> an interactive, personalized newspaper on the World Wide Web implemented as a Java applet. The newspaper is similar in appearance to newspapers in the real world, with a multicolumn layout and justified text. At the same time, it provides various interaction techniques for browsing the content of articles, giving relevance feedback, and dynamically changing layout. As users interact with the system, individual 'user profiles' are built up at the webserver site. These are used to tailor the newspaper's content and layout to each user's declared and inferred preferences. The system allows for a balancing of personal and community interests, allowing the user to navigate through a space of newspapers corresponding to a range of viewpoints.
An Approximate Method for Sampling Correlated Random Variables From Partially-Specified Distributions
Authors: Philip M. Lurie, Matthew S. Goldberg
Venue: Management Science (1998)

This paper presents an algorithm for generating correlated vectors of random numbers. The user need not fully specify the joint distribution function; instead, the user "partially specifies" only the marginal distributions and the correlation matrix. The algorithm may be applied to any set of continuous, strictly increasing distribution functions; the marginal distributions need not all be of the same functional form. The correlation matrix is first checked for mathematical consistency (positive semi and adjusted if necessary. Then the correlated random vectors are generated using a combination of Cholesky decomposition and Gauss-Newton iteration. Applications are made to cost analysis, where correlations are often present between cost elements in a work breakdown structure.
SUSAN&mdash;A New Approach to Low Level Image Processing
Authors: Stephen M. Smith, J. Michael Brady
Venue: International Journal of Computer Vision (1997)

This paper describes a new approach to low level image processing; in particular, edge and corner detection and structure preserving noise reduction.Non-linear filtering is used to define which parts of the image are closely related to each individual pixel; each pixel has associated with it a local image region which is of similar brightness to that pixel. The new feature detectors are based on the minimization of this local image region, and the noise reduction method uses this region as the smoothing neighbourhood. The resulting methods are accurate, noise resistant and fast.Details of the new feature detectors and of the new noise reduction method are described, along with test results.
Bounding the Power of Preemption in Randomized Scheduling
Authors: Ran Canetti, Sandy Irani
Venue: SIAM Journal on Computing (1998)

We study on-line scheduling in overloaded systems. Requests for jobs arrive one by one as time proceeds; the serving agents have limited capacity and not all requests can be served. Still, we want to serve the "best" set of requests according to some criterion. In this situation, the ability to preempt (i.e., abort) jobs in service in order to make room for better jobs that would otherwise be rejected has proven to be of great help in some scenarios. We show that, surprisingly, in many other scenarios this is not the case. In a simple, generic model, we prove a polylogarithmic lower bound on the competitiveness of randomized and preemptive on-line scheduling algorithms. Our bound applies to several recently studied problems. In fact, in certain scenarios our bound is quite close to the competitiveness achieved by known deterministic, nonpreemptive algorithms.
Application of a 2-stage group-screening design to a whole-line semiconductor manufacturing simulation model
Authors: Theodora Ivanova, Mansooreh Mollaghasemi, Linda C. Malone
Venue: Proceedings of the 28th conference on Winter simulation (1996)

The focus of the paper is on the application of an experimental design methodology to a semi-conductor manufacturing simulation model. A complex whole line simulation model of a semiconductor fab is built. Seventeen input factors are set for investigation through a 2-stage group-screening experimental design. A multiple response regression metamodel is built to define the relationships between the significant input factors and the four response variables of interest. The combination of simulation modeling methods with experimental design and regression analysis techniques allows the development of a flexible tool for capacity analysis of a semiconductor manufacturing facility.
An Efficient Sorting Algorithm on the Multi-Mesh Network
Authors: Malika De, Debasish Das, Mabhin Ghosh, Bhabani P. Sinha
Venue: IEEE Transactions on Computers (1997)

The shear-sort algorithm [19] on an SIMD mesh model requires $4\sqrt N+o\left( {\sqrt N} \right)$ time for sorting N elements arranged on a $\sqrt N\times \sqrt N$ mesh. In this paper, we present an algorithm for sorting N elements in time O(N1/4) on an SIMD Multi-Mesh architecture, thereby significantly improving the order of the time complexity. The Multi-Mesh architecture [23], [24] is built around n2 blocks, where each block is an n×n mesh with n = N1/4, so that each processor will uniformly have four neighbors in the final topology.
Inducing Features of Random Fields
Authors: Stephen Della Pietra, Vincent Della Pietra, John Lafferty
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (1997)

We present a technique for constructing random fields from a set of training samples. The learning paradigm builds increasingly complex fields by allowing potential functions, or features, that are supported by increasingly large subgraphs. Each feature has a weight that is trained by minimizing the Kullback-Leibler divergence between the model and the empirical distribution of the training data. A greedy algorithm determines how features are incrementally added to the field and an iterative scaling algorithm is used to estimate the optimal values of the weights. The random field models and techniques introduced in this paper differ from those common to much of the computer vision literature in that the underlying random fields are non-Markovian and have a large number of parameters that must be estimated. Relations to other learning approaches, including decision trees, are given. As a demonstration of the method, we describe its application to the problem of automatic word classification in natural language processing.
Array oriented exception handling: a proposal for dealing with &ldquo;invalid&rdquo; data
Authors: Jim Lucas
Venue: ACM SIGAPL APL Quote Quad (1985)

APL still deals poorly with some aspects of real world problems. For instance, frequently to mark entries in an otherwise numeric database as &ldquo;not applicable&rdquo; or &ldquo;not entered,&rdquo; one picks arbitrarily one or more numbers to represent the attributes. But this and other approaches suffer difficulties ranging from ambiguity to inefficiencies in both programming and execution. Further, APL errors which might logically be associated with individual elements of data arrays are not reported by existing APL systems in any detail. This paper proposes an enhancement to APL which would overcome both these difficulties, discussing considerations of both use and implementation.
A Clock Methodology for High-Performance Microprocessors
Authors: Keith M. Carrig, Albert M. Chu, Frank D. Ferraiolo, John G. Petrovick, P. Andrew Scott, Richard J. Weiss
Venue: Journal of VLSI Signal Processing Systems (1997)

This paper discusses an effective clock methodology for the design of high-performance microprocessors. Key attributes include the clustering and balancing of clock loads, multiple clock domains, a balanced clock router with variable width wires to minimize skew, hierarchical clock wiring, automated verification, an interface to the Cadence Design Framework II&trade; environment, and a complete network model of the clock distribution, including loads. This clock methodology enabled creation of the entire clock network, including verification, in less than three days with approximately 180 ps of skew.
On the Shape of the Symmetric, Persymmetric, and Skew-Symmetric Solution Set
Authors: Götz Alefeld, Vladik Kreinovich, Günter Mayer
Venue: SIAM Journal on Matrix Analysis and Applications (1997)

We present a characterization of the solution set $ S $, the symmetric solution set $ S_{sym} $, the persymmetric solution set $ S_{per}, $ and the skew-symmetric solution set $ S_{skew} $ of real linear systems $ A x = b $ with the $ n \times n $ coefficient matrix $ A $ varying between a lower bound $ \ul A $ and an upper bound $ \ol A $, and with $ b $ similarly varying between $ \ul b,\ \ol b $. We show that in each orthant the sets $ S_{sym} $, $ S_{per}, $ and $ S_{skew} $ are, respectively, the intersection of $ S $ with sets, the boundaries of which are quadrics.
Post-layout logic restructuring for performance optimization
Authors: Yi-Min Jiang, Angela Krstic, Kwang-Ting Cheng, Malgorzata Marek-Sadowska
Venue: Proceedings of the 34th annual Design Automation Conference (1997)

We propose a new methodology based on incrementallogic restructuring for post-layout performance improvement.The new post-layout logic restructuring techniqueallows to use accurate interconnection delays for performanceoptimization, while the incremental nature of thetechnique guarantees convergence between logic synthesisand layout. The technique can be further integrated withother post-layout optimization techniques such as gate sizingand buffer insertion. Experimental results show that thistechnique combined with post-layout buffer insertion canachieve an additional 15% improvement in performancecompared to designs produced by timing-driven logic optimizationfollowed by pre-layout buffer insertion followedby timing-driven physical design.
Dynamics for Controlled Navier--Stokes Systems with Distributed Controls
Authors: L. S. Hou, Y. Yan
Venue: SIAM Journal on Control and Optimization (1997)

The long-time behavior of solutions for an optimal distributed control problem associated with the Navier--Stokes equations is studied. First, a linear feedback solution for the Navier--Stokes equations is constructed; this feedback solution possesses decay (in time) properties. Then, some preliminary estimates for the long-time behavior of all solutions of the Navier--Stokes equations are derived. Next, the existence of a solution for the optimal control problem is proved. Finally, the long-time decay properties for the optimal solutions are established.
Activity Measures for Fast Relative Power Estimation in Numerical Transformation for Low Power DSP Synthesis
Authors: Huy T. Nguyen, Abhijit Chatterjee, Rabindra K. Roy
Venue: Journal of VLSI Signal Processing Systems (1998)

In this paper, we propose a method for power optimization of digital signal processing (DSP) systems through reduction of circuit switching activity estimated from high levels in the synthesis hierarchy, namely at numerical and algorithmic levels. The optimization involves application of a numerical transformation called number-splitting on the system characteristic coefficients. The transformation alters the system characteristic coefficients while preserving the input/output relations. For each set of candidate coefficients, the corresponding signal flow-graph is constructed for evaluation of power consumption. First, the switching activity at all computation nodes of the graph are estimated using our novel activity transformation models, which quickly estimate the activity at the output of the adders and multipliers based on the activity at the inputs. Next, the activity at the inputs of each computation node are used to compute the average power consumption by that node, using our heuristic power estimators.The optimization framework can be applied to hardware-dedicated bit-serial, nibble-serial, as well as programmable word-parallel architectures. We focus on hardware-dedicated bit-serial systems, and show that up to 35 percent savings in power is achievable.
A compilation technique for software pipelining of loops with conditional jumps
Authors: Kemal Ebcioğlu
Venue: Proceedings of the 20th annual workshop on Microprogramming (1987)

We describe a compilation algorithm for efficient software pipelining of general inner loops, where the number of iterations and the time taken by each iteration may be unpredictable, due to arbitrary if-then- else statements and conditional exit statements within the loop. As our target machine, we assume a wide instruction word architecture that allows multi-way branching in the form of if-then-else trees, and that allows conditional register transfers depending on where the microinstruction branches to (a hardware implementation proposal for such a machine is briefly described in the paper). Our compilation algorithm, which we call the pipeline scheduling technique, produces a software- pipelined version of a given inner loop, which allows a new iteration of the loop to begin on every cycle whenever dependencies and resources permit. The correctness and termination properties of the algorithm are studied in the paper.
Timestamp representations for virtual sequences
Authors: John G. Cleary, J. A. David McWha, Murray Pearson
Venue: Proceedings of the eleventh workshop on Parallel and distributed simulation (1997)

The problem of executing sequential programs in parallel using the optimistic algorithm Time Warp is considered. This is done by first mapping the sequential execution to a control tree and then assigning timestamps to each node in the tree.For such timestamps to be effective in either hardware or software they must be finite, this implies that they must be periodically rescaled to allow old timestamps to be reused. A number of timestamp representations are described and compared on the basis of: their complexity; the frequency and cost of rescaling; and the cost of performing basic operations, including comparison and creation of new timestamps.
Guidance for the use of the Ada programming language in high integrity systems
Authors: B. A. Wichmann
Venue: ACM SIGAda Ada Letters (1998)

This paper is the current result of a study by the ISO HRG Rapporteur group which is being circulated for comment. Many people have contributed to this, but those who have either attended two recent meetings of group or have made substantial e-mail comments are: Praful V Bhansali (Boeing, USA), Alan Burns (University of York, UK), Bernard Carre' (Praxis Critical Systems, UK), Dan Craigen (ORA, Canada), Nick Johnson MoD, UK), Stephen Michell (Canada), Gilles Motet (DGEI/INSA, France), George Romanski (AONIX, USA), Mark Saaltink (ORA, Canada), Gareth Rowlands (MoD, UK), Adam Tacy (MoD, UK), (Phil) JP Thornley (BAe, UK), David Tombs (DERA, UK), Tullio Vardanega (ESA/ESTEC, Netherlands), Brian Wichmann (NPL, UK).
An Unboxed Operational Semantics for ML Polymorphism
Authors: Atsushi Ohori, Tomonobu Takamizawa
Venue: Lisp and Symbolic Computation (1997)

We present an unboxed operational semantics for an ML-style polymorphic language. Different from the conventional formalisms, the proposed semantics accounts for actual representations of run-time objects of various types, and supports a refined notion of polymorphism that allows polymorphic functions to be applied directly to values of various different representations. In particular, polymorphic functions can receive multi-word constants such as floating-point numbers without requiring them to be &ldquo;boxed&rdquo; (i.e., heap allocated.) This semantics will serve as an alternative basis for implementing polymorphic languages. The development of the semantics is based on the technique of the type-inference-based compilation for polymorphic record operations [20]. We first develop a lower-level calculus, called a polymorphic unboxed calculus, that accounts for direct manipulation of unboxed values in a polymorphic language. This unboxed calculus supports efficient value binding through integer representation of variables. Different from de Bruijn indexes, our integer representation of a variable corresponds to the actual offset to the value in a run-time environment consisting of objects of various sizes. Polymorphism is supported through an abstraction mechanism over argument sizes. We then develop an algorithm that translates ML into the polymorphic unboxed calculus by using type information obtained through type inference. At the time of polymorphic let binding, the necessary size abstractions are inserted so that a polymorphic function is translated into a function that is polymorphic not only in the type of the argument but also in its size. The ML type system is shown to be sound with respect to the operational semantics realized by the translation.
Stablity of Set-Valued Mappings In Infinite Dimensions: Point Criteria and Applications
Authors: Boris S. Mordukhovich, Yongheng Shao
Venue: SIAM Journal on Control and Optimization (1997)

This paper deals with effective characterizations of stability and regularity properties of set-valued mappings in infinite dimensions, which are of great importance for applications to many aspects in optimization and control. The main purpose is to obtain verifiable necessary and sufficient conditions for these properties that are expressed in terms of constructive generalized differential structures at reference points and are convenient for applications. Based on advanced techniques in nonsmooth analysis, new dual criteria are proven in this direction under minimal assumptions. Applications of such point conditions are given to sensitivity analysis for parametric constraint and variational systems which describe sets of feasible and optimal solutions to various optimization and related problems.
A Recursive Orthogonal Least Squares Algorithm for Training RBF Networks
Authors: D. L. Yu, J. B. Gomm, D. Williams
Venue: Neural Processing Letters (1997)

A recursive orthogonal least squares (ROLS) algorithm for multi-input, multi-output systems is developed in this paper and is applied to updating the weighting matrix of a radial basis function network. An illustrative example is given, to demonstrate the effectiveness of the algorithm for eliminating the effects of ill-conditioning in the training data, in an application of neural modelling of a multi-variable chemical process. Comparisons with results from using standard least squares algorithms, in batch and recursive form, show that the ROLS algorithm can significantly improve the neural modelling accuracy. The ROLS algorithm can also be applied to a large data set with much lower requirements on computer memory than the batch OLS algorithm.
A Novel Integrated CMOS Switch Circuit for High PrecisionSample-and-Hold Technique
Authors: M. F. Li, S. Y. Yep, Y. C. Lim
Venue: Analog Integrated Circuits and Signal Processing (1997)

A new CMOS switch circuit is proposed for the implementation of high precision sample-and-hold. The switch includes a current mirror and switching action is controlled by current pulses. This reduces charge injection due to clock feedthrough and the charge injection is input signal independent, resulting in a greatly improved sample-and-hold accuracy.
Multisignature algorithms for ISO 9796
Authors: Selwyn Russell
Venue: ACM SIGSAC Review (1997)

Digital multisignatures improve security of digital signatures and reduce fraud by collusion. ISO 9796 is specified for a single signer only. This letter explains how multisignatures may be incorporated, including alterations to the key generation algorithms.
Learning groupware through using groupware-computer supported collaborative learning with face to face students
Authors: Ashok Tiwari, Clive Holtham
Venue: ACM SIGCSE Bulletin (1998)

There is a long history of Computer Supported Collaborative Learning (CSCL) being applied to students on distance learning courses, and there is a significant body of literature in this area [5,6,10]. This paper reports by contrast the use of CSCL for conventional full time face to face students. It comprised part of the final phase of a research council funded study of innovative CSCW applications.
MedModel&mdash;healthcare simulation software
Authors: Diana F. Carroll
Venue: Proceedings of the 28th conference on Winter simulation (1996)

In response to the expressed needs of MedModel users, PROMODEL Corporation has made substantial improvements in its MedModel healthcare simulation software. Beginning with its inception in 1993, MedModel was specifically designed to be simple to use and tailorable to the needs of healthcare managers, engineers and clinicians. As such, it provides a basis for the comprehensive evaluation of large, complex problems which are representative of healthcare systems in general. This paper serves as a preliminary examination of some of MedModel's comprehensive features and capabilities. Special emphasis is placed on the new and modified features of MedModel. 3.0. Preemption logic, pre and post shift logic, and new statements and functions have been carefully'designed to solve unique hospital and healthcare specific simulation problems. 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
Community Support for Constructionist Learning
Authors: Amy Bruckman
Venue: Computer Supported Cooperative Work (1998)

MOOSE Crossing is a text-based virtual reality environment (or &ldquo;MUD&rdquo;) designed to be a constructionist learning environment for children ages eight to thirteen. The constructionist philosophy of education argues that learning through designing and constructing personally meaningful projects is better than learning by being told. Children on MOOSE Crossing learn computer programming and improve their reading and writing by working on self-selected projects in a self-motivated, peer-supported fashion. In experience with over 180 children and 90 adults using the system since October 1995, we have found that the community provides essential support for the children&lsquo;s learning experiences. The community provides role models; situated, ubiquitous project models; emotional support to overcome technophobia; technical support; and an appreciative audience for completed work. This paper examines the nature of that support in detail, and argues that community support for learning is an essential element in collaborative work and learning on the Internet.