ppxscal/embedding_network huggingface dataset:
Efficient algorithms for mining outliers from large data sets
Authors: Sridhar Ramaswamy, Rajeev Rastogi, Kyuseok Shim
Venue: ACM SIGMOD Record (2000)

In this paper, we propose a novel formulation for distance-based outliers that is based on the distance of a point from its kth nearest neighbor. We rank each point on the basis of its distance to its kth nearest neighbor and declare the top n points in this ranking to be outliers. In addition to developing relatively straightforward solutions to finding such outliers based on the classical nested-loop join and index join algorithms, we develop a highly efficient partition-based algorithm for mining outliers. This algorithm first partitions the input data set into disjoint subsets, and then prunes entire partitions as soon as it is determined that they cannot contain outliers. This results in substantial savings in computation. We present the results of an extensive experimental study on real-life and synthetic data sets. The results from a real-life NBA database highlight and reveal several expected and unexpected aspects of the database. The results from a study on synthetic data sets demonstrate that the partition-based algorithm scales well with respect to both data set size and data set dimensionality.
CoRR: a computing research repository
Authors: Joseph Y. Halpern
Venue: ACM Journal of Computer Documentation (JCD) (2000)

This paper describes the decisions by which teh Association for Computing Machinery integrated good features from the Los Alamos e-print (physics) archive and from Cornell University's Networked Computer Science Technical Reference Library to form their own open, permanent, online &ldquo;computing research repository&rdquo; (CoRR). Submitted papers are not refereed and anyone can browse and extract CoRR material for free, so Corr's eventual success could revolutionize computer science publishing. But several serious challenges remain: some journals forbid online preprints, teh CoRR user interface is cumbersome, submissions are only self-indexed, (no professional library staff manages teh archive) and long-term funding is uncertain.
A predictive system shutdown method for energy saving of event-driven computation
Authors: Chi-Hong Hwang, Allen C.-H. Wu
Venue: ACM Transactions on Design Automation of Electronic Systems (TODAES) (2000)

This paper presents a system-level power management technique for energy savings of event-driven application. We present a new predictive system-shutdown method to exploit sleep mode operations for energy saving. We use an exponential-average approach to predict the upcoming idle period. We introduce two mechanisms, prediction-miss correction and prewake-up, to improve the hit ratio and to reduce the delay overhead. Experiments on four different event-driven applications show that our proposed method achieves high hit ratios in a wide range of delay overheads, which results in a high degree of energy with low delay penaties.
An empirical study of how people establish interaction: implications for CSCW session management models
Authors: Steinar Kristoffersen, Fredrik Ljungberg
Venue: Proceedings of the SIGCHI conference on Human factors in computing systems: the CHI is the limit (1999)

In this paper, we report the results of an empirical study of how people, as part of their daily work activities, go about to establish collaboration. We examine the empirical findings and relate them to existing research on CSCW session management models, i.e., the mechanisms in CSCW systems that define the way in which people can join together in collaboration. Existing models leave a lot to be desired, in particular because they tend to assume that indexical elements of interaction management are substitutable by objective representation of artifacts. Based on the empirical findings, we derive three principles to consider in the design of CSCW session management models.
Exact Minimization of Binary Decision Diagrams Using Implicit Techniques
Authors: Arlindo L. Oliveira, Luca P. Carloni, Tiziano Villa, Alberto L. Sangiovanni-Vincentelli
Venue: IEEE Transactions on Computers (1998)

This paper addresses the problem of binary decision diagram (BDD) minimization in the presence of don't care sets. Specifically, given an incompletely specified function g and a fixed ordering of the variables, we propose an exact algorithm for selecting f such that f is a cover for g and the binary decision diagram for f is of minimum size. The approach described is the only known exact algorithm for this problem not based on the enumeration of the assignments to the points in the don't care set. We show also that our problem is NP-complete. We show that the BDD minimization problem can be formulated as a binate covering problem and solved using implicit enumeration techniques. In particular, we show that the minimum-sized binary decision diagram compatible with the specification can be found by solving a problem that is very similar to the problem of reducing incompletely specified finite state machines. We report experiments of an implicit implementation of our algorithm, by means of which a class of interesting examples was solved exactly. We compare it with existing heuristic algorithms to measure the quality of the latter.
Control CPR: a branch height reduction optimization for EPIC architectures
Authors: Michael Schlansker, Scott Mahlke, Richard Johnson
Venue: ACM SIGPLAN Notices (1999)

The challenge of exploiting high degrees of instruction-level parallelism is often hampered by frequent branching. Both exposed branch latency and low branch throughput can restrict parallelism. Control critical path reduction (control CPR) is a compilation technique to address these problems. Control CPR can reduce the dependence height of critical paths through branch operations as well as decrease the number of executed branches. In this paper, we present an approach to control CPR that recognizes sequences of branches using profiling statistics. The control CPR transformation is applied to the predominant path through this sequence. Our approach, its implementation, and experimental results are presented. This work demonstrates that control CPR enhances instruction-level parallelism for a variety of application programs and improves their performance across a range of processors.
Multiple mass-market applications as components
Authors: David Coppit, Kevin J. Sullivan
Venue: Proceedings of the 22nd international conference on Software engineering (2000)

Truly successful models for component-based software development continue to prove elusive. One of the few is the use of operating system, database and similar programs in many systems. We address three related problems in this paper. First, we lack needed models. Second, we do not know the conditions under which such models can succeed. In particular, it is unclear whether the notable success with operating systems can be replicated. Third, we do not know whether certain specific models can succeed. We are addressing these problems by evaluating a particular model that shares important characteristics with the successful operating system example: using compatible PC packages as components. Our approach to evaluating such a model is to engage in a case study that aims to build an industrially successful system representative of an important class of systems. We report on our use of the model to develop a computational tool for reliability engineering. We draw two conclusions. First, this kind of model has the potential to succeed. Second, even today, the model can produce significant returns, but it clearly carries considerable risks.
Ultraspherical Gauss--Kronrod Quadrature Is Not Possible for $\lambda > 3$
Authors: Franz Peherstorfer, Knut Petras
Venue: SIAM Journal on Numerical Analysis (2000)

With the help of a new representation of the Stieltjes polynomial it is shown by using Bessel functions that the Stieltjes polynomial with respect to the ultraspherical weight function with parameter $\lambda$ has only few real zeros for $\lambda > 3$ and sufficiently large $n$. Since the nodes of the Gauss--Kronrod quadrature formulae subdivide into the zeros of the Stieltjes polynomial and the Gaussian nodes, it follows immediately that Gauss--Kronrod quadrature is not possible for $\lambda > 3$. On the other hand, for $\lambda = 3$ and sufficiently large $n$, even partially positive Gauss--Kronrod quadrature is possible.
The Design of the PROMIS Compiler&mdash;Towards Multi-Level Parallelization
Authors: Hideki Saito, Nicholas J. Stavrakos, Constantine D. Polychronopoulos, Alex Nicolau
Venue: International Journal of Parallel Programming (2000)

Most systems that are under design and likely to be built in the future will employ hierarchical organization with many levels of memory hierarchy and parallelism. In order to efficiently utilize the multiple levels of parallelism available in the target architecture, a parallelizing compiler must orchestrate the interactions of fine-grain and coarse-grain program transformations. This article describes issues of multi-grain parallelization and how they are addressed in the PROMIS compiler design. PROMIS is a multilingual, parallelizing, and retargetable compiler with an integrated frontend and backend operating on a single unified and universal intermediate representation. PROMIS exploits multiple levels of static and dynamic parallelism, ranging from task- and loop-level parallelism to instruction-level parallelism, based on a target architecture description. The frontend and the backend are integrated through a unified internal representation common to the high-level, the low-level, and the instruction-level analyses and transformations.
Distance tutorials in a systems design course
Authors: Joakim von Wright
Venue: Proceedings of the 5th annual SIGCSE/SIGCUE ITiCSEconference on Innovation and technology in computer science education (2000)

An experiment with distance technology in a second-year Object-Oriented Systems Design course is described. Video and computer conferencing were used in tutorial sessions where a teacher and a student group developed and discussed solutions (both textual and graphical) to systems design problems. The experiment is evaluated, both from a technical, an economic and an educational point of view.
Pointwise and Uniformly Convergent Sets of Matrices
Authors: Adam L. Cohen, Leiba Rodman, David P. Stanford
Venue: SIAM Journal on Matrix Analysis and Applications (1999)

Pointwise and uniform convergence properties of sets of real matrices are investigated. In particular, topological properties of uniformly and pointwise convergent sets are studied, as well as uniformly and pointwise convergent sets of matrices with special features: entrywise nonnegative or triangular. A detailed description of pointwise and uniformly convergent sets of two 2 X 2 matrices is presented.
A Buffer-Oriented Methodology for Microarchitecture Validation
Authors: Noppanunt Utamaphethai, R. D. (Shawn) Blanton, John Paul Shen
Venue: Journal of Electronic Testing: Theory and Applications (2000)

We propose a methodology for validating microarchitecture specifications. We view microarchitecture features as specific operations on entries of various buffers in the processor. Our validation approach is to determine the functionality of a buffer type, model its operations at the microarchitecture level using abstract finite state machine (FSM) models, and rigorously generate instruction sequences that systematically exercise the model of each instance of that buffer type. A high-level test sequence is derived based on the abstract FSM model using FSM testing techniques, and then translated to a test program that exercises the functionality of each buffer entry. This methodology is applied to the microarchitecture specifications of the PowerPC 604. The effectiveness of the sequences generated using our methodology is compared with that of some real and randomly-generated programs. Simulation results show that all targeted FSM transitions are covered by our sequences with at least 1000 &times; and 3 &times; fewer instructions than real and randomly-generated programs, respectively.
Relationships between personal demographics and motivation of information technology professionals to participate in professional development research-in-progress
Authors: J. Ellis Blanton, Stephen C. Wingreen, Thomas Schambach
Venue: Proceedings of the 2000 ACM SIGCPR conference on Computer personnel research (2000)

Modern organizations are increasingly dependent on information technology (IT) enabled business systems. Development of IT systems requires a competent IT professional (ITP) staff, however, organizations are hampered by a severe shortage of qualified ITPs. Government studies recommend retaining existing ITPs and establishing professional development programs to help them obtain and maintain desired competencies. Research from related disciplines indicate that over time technical workers participate less in professional development, but still little is known about the relationships between personal demographics and participation in professional development. The major premise of this study is that since most professional development programs are voluntary, ITPs must first be motivated to participate before participation will occur. In addition, research suggests that motivation of ITPs may be related to personal demographics and, therefore, should be considered when designing and implementing professional development programs. Based upon this premise, the major objective of this study is to examine the relationships between selected personal demographics and the motivation of ITPs to participate in professional development. Survey data collected from a sample of ITPs will be analyzed first using descriptive statistics to identify graphical relationships between selected personal demographics and motivation to participate in professional development activities. Next correlation and regression analysis will be used to determine the significance of those relationships. Finding of significant relationships will improve the understanding the professional development process of ITPs, leading to more effective organizational interventions for promoting the professional development of existing ITPs.
Some Recent Results on The Linear Complementarity Problem
Authors: G. S. R. Murthy, T. Parthasarathy, B. Sriparna
Venue: SIAM Journal on Matrix Analysis and Applications (1998)

In this article we present some recent results on the linear complementarity problem. It is shown that (i) within the class of column adequate matrices, a matrix is in $\Qnot$ if and only if it is completely $\Qnot$ (ii) for the class of $\Cnotf$-matrices introduced by Murthy and Parthasarathy [SIAM J. Matrix Anal. Appl., 16 (1995), pp. 1268--1286], we provide a sufficient condition under which a matrix is in $\Pnot$ and as a corollary of this result, we give an alternative proof of the result that $\Cnotf \cap \Qnot \sset \Pnot$ (iii) within the class of INS-matrices introduced by Stone [Department of Operations Research, Stanford University, Stanford, CA, 1981], a nondegenerate matrix must necessarily have the block property introduced by Murthy, Parthasarathy, and Sriparna [G. S. R. Murthy, T. Parthasarathy, and B. Sriparna, Linear Algebra Appl., 252 (1997), pp. 323--337]. Furthermore, we conjecture that if a matrix has block property, then it must be Lipschitzian. This problem is an important one from two angles: if the conjecture is true, it provides a finite test to check whether a given matrix is Lipschitzian or nondegenerate INS; and it settles an open problem posed by Stone. It is shown that the conjecture is true in the cases of 2 x 2-matrices, nonnegative and nonpositive matrices of general order.
Failure Detection and Randomization: A Hybrid Approach to Solve Consensus
Authors: Marcos Kawazoe Aguilera, Sam Toueg
Venue: SIAM Journal on Computing (1999)

We present a consensus algorithm that combines unreliable failure detection and randomization, two well-known techniques for solving consensus in asynchronous systems with crash failures. This hybrid algorithm combines advantages from both approaches: it guarantees deterministic termination if the failure detector is accurate, and probabilistic termination otherwise. In executions with no failures or failure detector mistakes, the most likely ones in practice, consensus is reached in only two asynchronous rounds.
Computational Study of the Relationships Between Feasible and Efficient Sets and an Approximation
Authors: A. Mateos, S. Rios-Insua, L. Prieto
Venue: Computational Optimization and Applications (1999)

The computational difficulty of obtaining the efficient set in multi-objective programming, specially in nonlinear problems, suggest the need of considering an approximation approach to this problem. In this paper, we provide the computational results of the relationships between an approximation to the efficient set and the feasible and efficient sets. Random problem generation is considered for different sizes of the feasible set and we study the implications with respect to the number of objective functions and various kinds of objective functions. Computational experience with this approximation suggests that we obtain a substantial improvement when it increases the number of objective functions.
Illuminating micro geometry based on precomputed visibility
Authors: Wolfgang Heidrich, Katja Daubert, Jan Kautz, Hans-Peter Seidel
Venue: Proceedings of the 27th annual conference on Computer graphics and interactive techniques (2000)

Many researchers have been arguing that geometry, bump maps, and BRDFs present a hierarchy of detail that should be exploited for efficient rendering purposes. In practice however, this is often not possible due to inconsistencies in the illumination for these different levels of detail. For example, while bump map rendering often only considers direct illumination and no shadows, geometry-based rendering and BRDFs will mostly also respect shadowing effects, and in many cases even indirect illumination caused by scattered light. In this paper, we present an approach for overcoming these inconsistencies. We introduce an inexpensive method for consistently illuminating height fields and bump maps, as well as simulating BRDFs based on precomputed visibility information. With this information we can achieve a consistent illumination across the levels of detail. The method we propose offers significant performance benefits over existing algorithms for computing the light scattering in height fields and for computing a sampled BRDF representation using a virtual gonioreflectometer. The performance can be further improved by utilizing graphics hardware, which then also allows for interactive display. Finally, our method also approximates the changes in illumination when the height field, bump map, or BRDF is applied to a surface with a different curvature.
A Hierarchical Test Generation Approach for Large Controllers
Authors: Franco Fummi, Donatella Sciuto
Venue: IEEE Transactions on Computers (2000)

A testing approach targeted at Hardware Description Language (HDL)-based specifications of complex control devices is proposed. For such architectures, gate-level test pattern generators require insertion of scan paths to enable the flat gate-level representations to be efficiently handled. In contrast, we present a testing methodology based on the hierarchical finite state machine model. Our approach allows the generation of compact test sets with very high stuck-at fault coverages, without any design-for-testability logic other than hardware reset. This method can be used any time the functional information is available together with the gate-level structural description. High fault coverages are achieved with smaller test lengths and execution times with respect to state-of-the-art gate-level test pattern generators.
Minimal Decomposition of Model-Based Invariants
Authors: Daphna Weinshall
Venue: Journal of Mathematical Imaging and Vision (1999)

Model-based invariants are relations between model parameters and image measurements, which are independent of the imaging parameters. Such relations are true for all images of the model. Here we describe an algorithm which, given L independent model-based polynomial invariants describing some shape, will provide a linear re-parameterization of the invariants. This re-parameterization has the properties that: (i) it includes the minimal number of terms, and (ii) the shape terms are the same in all the model-based invariants. This final representation has 2 main applications: (1) it gives new representations of shape in terms of hyperplanes, which are convenient for object recognition&semi; (2) it allows the design of new linear shape from motion algorithms. In addition, we use this representation to identify object classes that have universal invariants.
New Efficient Structure for a Modular Multiplier for RNS
Authors: Ahmad A. Hiasat
Venue: IEEE Transactions on Computers (2000)

Modular multiplication is a very important arithmetic operation in residue-based real-time computing systems. In realizing these multipliers, ROM-based structures are more efficient for small moduli. Due to the exponential growth of ROM sizes, implementations with arithmetic components are more suitable for medium and large moduli. This paper presents a new modular multiplier that can deal efficiently with medium and large size moduli. The design of this modular multiplier that multiplies two $n$ bit residue digits consists, basically, of a $(n\times n)$ binary multiplier, a $((n-1-k)\times k)$ binary multiplier $(k
Codes from Affine Permutation Groups
Authors: Markku Kaikkonen
Venue: Designs, Codes and Cryptography (1998)

It is shown that A(22,10) \geq 50, A(23,10) \geq 76, A(25,10) \geq 166, A(26,10) \geq 270, A(29,10) \geq 1460, and A(28,12) \geq 178, where A(n,d) denotes the maximum cardinality of a binary code of length n and minimum Hamming distance d. The constructed codes are invariant under permutations of some affine (or closely related) permutation group and have been found using computer search.
Curriculum and teaching delivery change in an international context
Authors: Bogdan Zoltowski, Roger Boyle, John Davy
Venue: ACM SIGCSE Bulletin (1999)

Poland and its education system have been undergoing radical and fast change since 1989 as the country "westernises". The pressures on HE in some ways mirror those of western Europe (growing classes, industrial and commercial demands), but the starting point is quite different. Attempting to meet these challenges, a TEMPUS PHARE [2] project has brought together 6 western universities and the Technical University of Lodz in a 3 year programme to redesign programmes and delivery across the Faculty of Technical Physics, Computer Science and Applied Mathematics. A progress report on this attempt at major change management is presented.