ppxscal/embedding_network huggingface dataset:
Color image quantization by minimizing the maximum intercluster distance
Authors: Zhigang Xiang
Venue: ACM Transactions on Graphics (TOG) (1997)

One of the numerical criteria for color image quantization is to minimize the maximum discrepancy between original pixel colors and the corresponding quantized colors. This is typically carried out by first grouping color points into tight clusters and then finding a representative for each cluster. In this article we show that getting the smallest clusters under a formal notion of minimizing the maximum intercluster distance does not guarantee an optimal solution for the quantization criterion. Nevertheless our use of an efficient clustering algorithm by Teofilo F. Gonzalez, which is optimal with respect to the approximation bound of the clustering problem, has resulted in a fast and effective quantizer. This new quantizer is highly competitive and excels when quantization errors need to be well capped and when the performance of other quantizers may be hindered by such factors as low number of quantized colors or unfavorable pixel population distribution. Both computer-synthesized and photographic images are used in experimental comparison with several existing quantization methods.
Reuse in a simulation environment for flexible manufacturing systems
Authors: Sándor Kopácsi, Daniela Gavalocová, George L. Kovács, Ildikó Kmecs
Venue: ACM SIGAPP Applied Computing Review (1996)

Software developers often meet the problem of creating new components of an application that someone probably has already produced. Without having effective reuse tools usually it is more natural to create new components from scratch than to seek for useful elements in other programmes and/or systems.In the field of simulation of Flexible Manufacturing Systems (FMS) this issue often occurs, when different systems with some similar features have to be managed. FMSs are highly automated production systems with minimal human control. FMS usually consist Flexible Manufacturing Cells (FMCs). An FMC is considered as a group of one or more machine tools, robots, adjacent mechanical elements, tool and fixture supporting workstations and an internal transport system.The components of different FMSs and FMCs are the same type of machine tools, transfer equipment, etc. In the relevant aspects they usually differ from each other only in their amounts and working parameters. This fact itself breeds the idea of reuse of FMS and FMC simulation model elements.Simulation can be used for analysing the behaviour of an existing or would-be system. It is useful for calculating utilisation statistics, finding bottlenecks, pointing out scheduling errors, and even for creating manufacturing schedules. Simulation is a very effective technique for dynamic analysis, but it is short of optimising ability. A satisfactory solution can be obtained through modelling and simulating alternative approaches with iteration.There are many concepts, object classes, and lines of source code created, that could be reused in the new applications. Usage of reuse methodology and practice will reduce our efforts in developing new systems.In this paper the reuse of the components of simulation models in a hybrid simulation and scheduling system for new simulation applications will be introduced. This simulation-scheduler system has been implemented as a combination of a traditional simulation language (SIMAN/Cinema) and an intelligent expert environment (G2). The design methodology used for model development is based on the object-oriented Rational Rose CASE tool and on a use-case model.
A New Table of Binary/Ternary Mixed Covering Codes
Authors: Patric R. J. Östergård, Heikki O. Hämäläinen
Venue: Designs, Codes and Cryptography (1997)

A table of upper bounds for K3,2(n1,n2;R), the minimum number of codewords in a covering code with n1 ternary coordinates, n2 binary coordinates, and covering radius R, in the range n = n1 + n2 &le; 13, R &le; 3, is presented. Explicit constructions of codes are given to prove the new bounds and verify old bounds. These binary/ternary covering codes can be used as systems for the football pool game. The results include a new binary code with covering radius 1 proving K2(13,1) &le; 736, and the following upper bound for the football pool problem for 9 matches: K3(9,1) &le; 1356.
Type-driven defunctionalization
Authors: Jeffrey M. Bell, Françoise Bellegarde, James Hook
Venue: ACM SIGPLAN Notices (1997)

In 1972, Reynolds outlined a general method for eliminating functional arguments known as defunctionalization. The idea underlying defunctionalization is encoding a functional value as first-order data, and then realizing the applications of the encoded function via an apply function. Although this process is simple enough, problems arise when defunctionalization is used in a polymorphic language. In such a language, a functional argument of a higher-order function can take different type instances in different applications. As a consequence, its associated apply function can be untypable in the source language. In the paper we present a defunctionalization transformation which preserves typability. Moreover, the transformation imposes no restriction on functional arguments of recursive functions, and it handles functions as results as well as functions encapsulated in constructors. The key to this success is the use of type information in the defunctionalization transformation. Run-time characteristics are preserved by defunctionalization; hence, there is no performance improvement coming from the transformation itself. However closures need not be implemented to compile the transformed program.
Pc-based Shared Memory Architecture and Language
Authors: Dominique Houzet, Abdelkrim Fatni
Venue: The Journal of Supercomputing (1998)

The Image Processing applications require both computing and communication power. The object of the GFLOPS project was to study all aspects concerning the design of such computers. The project&lsquo;s aim was to develop a parallel architecture as well as its software environment to implement these applications efficiently. A development environment, especially a C data-parallel language, has been built for this purpose. The C parallel language presented here, simplifies the use of such architectures by providing the programmer with a global name space and a control mechanism to exploit fine and medium grain parallelism of its applications. The main advantage of our paradigm is that it allows a unique framework to express both data and control parallelism. We have implemented this programming environment on the GFLOPS machine which supports up to 512 processor nodes, which are PC mother boards, connected over a scaleable and cost-effective network, via the PCI-bus, at a constant cost per node. The aim is to obtain at low cost a scaleable virtually shared memory machine. In this paper we discuss the design of the GFLOPS machine and its C parallel language, and evaluate the effectiveness of the mechanisms incorporated. The analysis of the architecture&lsquo;s behaviour was conducted with microbenchmarks and image processing algorithms, written in C.
Pruning Algorithms for Rule Learning
Authors: Johannes Fürnkranz
Venue: Machine Learning (1997)

Pre-pruning and Post-pruning are two standard techniques for handling noise in decision tree learning. Pre-pruning deals with noise during learning, while post-pruning addresses this problem after an overfitting theory has been learned. We first review several adaptations of pre- and post-pruning techniques for separate-and-conquer rule learning algorithms and discuss some fundamental problems. The primary goal of this paper is to show how to solve these problems with two new algorithms that combine and integrate pre- and post-pruning.
Safe query languages for constraint databases
Authors: Peter Z. Revesz
Venue: ACM Transactions on Database Systems (TODS) (1998)

In the database framework of Kanellakis et al. [1990] it was argued that constraint query languages should take constraint databases as input and give other constraint databases that use the same type of atomic constraints as output. This closed-form requirement has been difficult to realize in constraint query languages that contain the negation symbol. This paper describes a general approach to restricting constraint query languages with negation to safe subsets that contain only programs that are evaluable in closed-form on any valid constraint database input.
High-level synthesis: current status and future directions
Authors: Gaetano Borriello, Ewald Detjens
Venue: Proceedings of the 25th ACM/IEEE Design Automation Conference (1988)

The third High-Level Synthesis Workshop was held in January of this year at Orcas Island, Washington*. What distinguished this workshop from its predecessors was that participants were asked to submit papers describing the application of their systems and algorithms to a set of benchmarks. This proved to be a successful method for comparing the extensive research being conducted in this area of CAD. In this paper, we will briefly describe the benchmarks and use them as a foundation for outlining the major themes in the research work presented at the workshop. The paper concludes with a summary of the discussions held during the course of the workshop on the future development of the high-level synthesis benchmark suite.
Performance of centralized bandwidth reservation protocol in AVPNs
Authors: Ashish Verma, Pallapa Venkataram
Venue: ACM SIGCOMM Computer Communication Review (1997)

ATM based Virtual Private Networks(AVPNs) are embedded in public ATM network to provide an efficient transport service to a multisite customer using virtual levels of ATM. In this paper we propose a centralized protocol for resource allocation in AVPNs and compare its performance with that of the previously proposed strategies. We analyze the protocol to get average burst delay and burst loss probability in case of finite buffering at the customer sites.
Optimal Polling in Communication Networks
Authors: Adele A. Rescigno
Venue: IEEE Transactions on Parallel and Distributed Systems (1997)

Polling is the process in which an issuing node of a communication network (polling station) broadcasts a query to every other node in the network and waits to receive a unique response from each of them. Polling can be thought of as a combination of broadcasting and gathering and finds wide applications in the control of distributed systems. In this paper, we consider the problem of polling in minimum time. We give a general lower bound on the minimum number of time units to accomplish polling in any network and we present optimal polling algorithms for several classes of graphs, including hypercubes and recursively decomposable Cayley graphs.
Analog compilation based on successive decompositions
Authors: E. Berkcan, M. d'Abreu, W. Laughton
Venue: Proceedings of the 25th ACM/IEEE Design Automation Conference (1988)

This paper describes an approach to silicon compilation of analog functional blocks and the physical assembly of mixed analog and digital blocks. The initial driving applications are High Voltage ASICs. Details of behavior to layout synthesis, or decompositions, are presented together with the results from an implementation of the compiler. The compiler has been used to compile CMOS operational amplifiers. Results and examples are given in which device sizes, bias currents and layout are obtained from performance specifications and process parameters.
Financial Asset-Pricing Theory and Stochastic Programming Models for Asset/ Liability Management: a Synthesis
Authors: P. S. Bradley, O. L. Mangasarian, W. N. Street, Debra E. Meyerson, Pieter Klaassen
Venue: Management Science (1998)

Practical portfolio investment problems under uncertainty can be modeled well as multiperiod stochastic programs. However, the numerical optimization methods that need to be used to solve such models seriously limit the level of detail in the uncertainty about future asset rices and returns that can be incorporated. Somewhat surprisingly, the question how this necessarily approximate description of the uncertainty should be constructed has received relatively little attention in the stochastic programming literature. Moreover, many of the descriptions that have been used are not arbitrage-free, and therefore inconsistent with modern financial asset-pricing theory. In this paper we will present aggregation methods that can be used in combination with financial asset-pricing models to obtain a description of the uncertainty that is arbitrage-free, consistent with observed market prices as well as concise enough for a stochastic programming model. Furthermore, we will discuss how these aggregation methods can form the basis of an iterative solution approach.
A prototype for a data communications laboratory
Authors: Martin H. Levin
Venue: ACM SIGCSE Bulletin (1997)

This paper describes the development of a small laboratory to serve as a prototype for a Data Communications Laboratory. We discuss the planning, construction, capabilities and use of the prototype lab by our three data communications courses. The capabilities and use of the lab in entry level microcomputer communications course, the entry level course, is demonstrated and explained, along with our plans for a larger lab in the near future based on a successful NSF-ILI grant request for additional equipment.
Event-based detection of concurrency
Authors: Jonathan E. Cook, Alexander L. Wolf
Venue: Proceedings of the 6th ACM SIGSOFT international symposium on Foundations of software engineering (1998)

Understanding the behavior of a system is crucial in being able to modify, maintain, and improve the system. A particularly difficult aspect of some system behaviors is concurrency. While there are many techniques to specify intended concurrent behavior, there are few, if any, techniques to capture and model actual concurrent behavior. This paper presents a technique to discover patterns of concurrent behavior from traces of system events. The technique is based on a probabilistic analysis of the event traces. Using metrics for the number, frequency, and regularity of event occurrences, a determination is made of the likely concurrent behavior being manifested by the system. The technique is useful in a wide variety of software engineering tasks, including architecture discovery, reengineering, user interaction modeling, and software process improvement.
Correction to "Recovery of SHGCs From a Single Intensity View"
Authors: Ari D. Gross
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (1996)

Generalized Cylinders are a flexible, loosely-defined class of parametric shapes capable of modeling many real-world objects. Straight Homogeneous Generalized Cylinders are an important subclass of Generalized Cylinders, whose cross-sections are scaled versions of a reference curve. Although there has been considerable research into recovering the shape of SHGCs from their contour, this work has almost exclusively involved methods that couple contour and heuristic constraints. A rigorous approach to the problem of recovering solid parametric shape from a single intensity view should involve at least two stages: 1) deriving the contour constraints, and 2) determining if additional image constraints, e.g., intensity, can be used to uniquely determine the 3D object shape. In this paper, the authors follow the approach just described. This methodology is also important for the recovery of object classes like tubes, where contour and heuristic constraints are shown to be insufficient for shape recovery. First, we prove that SHGC contours generated under orthography have exactly two degrees of freedom. Next, we show that the remaining free parameters can be resolved using reflectance-based constraints, without knowledge of the number of light sources, their positions, intensities, the amount of ambient light, or the surface albedo. Finally, the reflectance-based recovery algorithm is demonstrated on both synthetic and real SHGC images.
Modeling TCP throughput: a simple model and its empirical validation
Authors: Jitendra Padhye, Victor Firoiu, Don Towsley, Jim Kurose
Venue: ACM SIGCOMM Computer Communication Review (1998)

In this paper we develop a simple analytic characterization of the steady state throughput, as a function of loss rate and round trip time for a bulk transfer TCP flow, i.e., a flow with an unlimited amount of data to send. Unlike the models in [6, 7, 10], our model captures not only the behavior of TCP's fast retransmit mechanism (which is also considered in [6, 7, 10]) but also the effect of TCP's timeout mechanism on throughput. Our measurements suggest that this latter behavior is important from a modeling perspective, as almost all of our TCP traces contained more time-out events than fast retransmit events. Our measurements demonstrate that our model is able to more accurately predict TCP throughput and is accurate over a wider range of loss rates.
Educating the next generation of information specialists: industry and university collaborative learning pilot project
Authors: Kathleen A. Williams
Venue: ACM SIGCSE Bulletin (1997)

This collaborative learning pilot project was in support of a major revision of computer information science (CIS)-oriented curricula. The entire CIS project, sponsored by the National Science Foundation (NSF), will develop detailed curriculum guidelines, supporting laboratory material, original learning and teaching paradigms, and methodology for dealing with complex information systems. The pilot project addressed many of the issues in the latter two areas: new paradigms for teaching and learning and dealing with complex information systems.Specifically, the many aspects of having CIS students gain experience with large information systems problems in industry environment are addressed. This pilot project was developed and supported by Boeing Information amp; Support Services and the University of Washington Department of Computer Science and Engineering (UWCSE).
Computer performance evaluation with GIST: a tool for specifying extended queueing network models
Authors: J. B. Sinclair, K. A. Doshi, S. Madala
Venue: Proceedings of the 17th conference on Winter simulation (1985)

GIST (Graphical Input Simulation Tool) is a powerful and user-friendly performance evaluation tool for the specification and simulation of Extended Queueing Network models of computer and other systems. It includes a number of modeling abstractions for active and passive resource management, job creation and destruction, synchronization, routing, and statistics collection. Two interfaces are provided: a graphical interface (GUIDE) that allows the user to describe much of the simulation model pictorially; and a textual interface (TIDE) that has the same modeling capabilities but uses a menu-driven, window-oriented approach for use on non-graphics terminals. Object and run-time parameters in both interfaces are specified through menus that reduce the probability of specification-time errors. A number of extensions planned for GIST are also described.
Implementing typed intermediate languages
Authors: Zhong Shao, Christopher League, Stefan Monnier
Venue: Proceedings of the third ACM SIGPLAN international conference on Functional programming (1998)

Recent advances in compiler technology have demonstrated the benefits of using strongly typed intermediate languages to compile richly typed source languages (e.g., ML). A type-preserving compiler can use types to guide advanced optimizations and to help generate provably secure mobile code. Types, unfortunately, are very hard to represent and manipulate efficiently; a naive implementation can easily add exponential overhead to the compilation and execution of a program. This paper describes our experience with implementing the FLINT typed intermediate language in the SML/NJ production compiler. We observe that a type-preserving compiler will not scale to handle large types unless all of its type-preserving stages preserve the asymptotic time and space usage in representing and manipulating types. We present a series of novel techniques for achieving this property and give empirical evidence of their effectiveness.
Exact Finite-Dimensional Filters for Maximum Likelihood Parameter Estimation of Continuous-time Linear Gaussian Systems
Authors: Robert J. Elliott, Vikram Krishnamurthy
Venue: SIAM Journal on Control and Optimization (1997)

In this paper, we derive a new class of finite-dimensional filters for integrals and stochastic integrals of moments of the state for continuous-time linear Gaussian systems. Apart from being of significant mathematical interest, these new filters can be used with the expectation maximization (EM) algorithm to yield maximum likelihood estimates of the model parameters.
Wavesched: a novel scheduling technique for control-flow intensive behavioral descriptions
Authors: Ganesh Lakshminarayana, Kamal S. Khouri, Niraj K. Jha
Venue: Proceedings of the 1997 IEEE/ACM international conference on Computer-aided design (1997)

In this paper, we present a novel scheduling algorithm targeted towards minimizing the average execution time of control-flow intensive behavioral descriptions. Our algorithm uses a CDFG model, which preserves the parallelism inherent in the application. It explores previously unexplored regions of the solution space by its ability to overlap the schedules of independent iterative constructs, whose bodies share resources. It also incorporates well known optimization techniques like loop unrolling in a natural fashion. This is made possible by a general loop-handling technique, which we have devised. Application of the algorithm to several common benchmarks demonstrates up to 4.8-fold improvement in expected schedule length over existing scheduling algorithms, without paying a price in terms of the best- and worst-case schedule lengths required to execute the behavioral description (in fact, frequently, the best/worst-case schedule lengths are also better for our algorithm).
Ultrasonographically Assessed Carotid Intima-Media Thickness and Risk for Asymptomatic Cerebral Infarction
Authors: M. Yamakado, I. Fukuda, H. Kiyose
Venue: Journal of Medical Systems (1998)

Cerebral infarction (CI) is still a leading cause of death in Japan. Thus, the management of risk factors for CI as primary prevention is one of the most important tasks in multiphasic health testing and services. To determine whether carotid intima-media thickness (IMT) is a risk for CI, ultrasonographically assessed carotid IMT was compared between normal subjects (N) and subjects with asymptomatic CI (ACI) in 243 subjects who underwent human brain dry dock. ACI was found in 68 people (28.0%). Age, body mass index, and mean blood pressure were higher in ACI than in N. Also, atherogenic index was higher in ACI than in N. Carotid IMT was significantly thicker in ACI than in N. Furthermore, incidence of atherogenic plaque in ACI was significantly higher than that in N. In conclusion, not only aging, obesity, blood pressure, and plasma lipids, but also carotid IMT may be a risk for ACI.