ppxscal/embedding_network huggingface dataset:
Global Optimization for Satisfiability (SAT) Problem
Authors: J. Gu
Venue: IEEE Transactions on Knowledge and Data Engineering (1994)

The satisfiability (SAT) problem is a fundamental problem in mathematical logic, inference, automated reasoning, VLSI engineering, and computing theory. Following CNF and DNF local search methods, we introduce the Universal SAT problem model, UniSAT, which transforms the discrete SAT problem on Boolean space {0, 1}/sup m/ into an unconstrained global optimization problem on real space E/sup m/. A direct correspondence between the solution of the SAT problem and the global minimum point of the UniSAT objective function is established. Many existing global optimization algorithms can be used to solve the UniSAT problems. Combined with backtracking/resolution procedures, a global optimization algorithm is able to verify satisfiability as well as unsatisfiability. This approach achieves significant performance improvements for certain classes of conjunctive normal form (CNF) formulas. It offers a complementary approach to the existing SAT algorithms.
E-Policy: How to Develop Computer, E-Mail and Internet Guidelines to Protect Your Company and Its Assets
Authors: Michael R. Overly
Venue:  (1998)

:With clear, legally sound policies any company can reduce, even eliminate the dangers posed by computer/e-mail use, protect their interests - and reap the rewards of these technologies without any of the risks. e-policy is the first book written to help you do just that. A one-stop computer/e-mail policy writing kit, it examines the potentially astronomical costs of e-mail and Internet misuse, and gives you step-by-step guidelines for creating up-to-date, legally sound policies that explicitly define the rights and obligations of employees. e-policy is packed with background information, detailed instructions, sample clauses, prewritten policies you can put to immediate use, and real-life horror stories that emphasize how explosive these problems really can be - and how crucial the solution it provides is. 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
A Methodology for Learning Across Application Domains for Database Design Systems
Authors: V. C. Storey, D. Dey
Venue: IEEE Transactions on Knowledge and Data Engineering (2002)

Although database design tools have been developed that attempt to automate (or semiautomate) the design process, these tools do not have the capability to capture common sense knowledge about business applications and store it in a context-specific manner. As a result, they rely on the user to provide a great deal of ¿trivial¿ details and do not function as well as a human designer who usually has some general knowledge of how an application might work based on his or her common sense knowledge of the real world. Common sense knowledge could be used by a database design system to validate and improve the quality of an existing design or even generate new designs. This requires that context-specific information about different database design applications be stored and generalized into information about specific application domains (e.g., pharmacy, daycare, hospital, university, manufacturing). Such information should be stored at the appropriate level of generality in a hierarchically structured knowledge base so that it can be inherited by the subdomains below. For this to occur, two types of learning must take place. First, knowledge about a particular application domain that is acquired from specific applications within that domain are generalized into a domain node (e.g., entities, relationships, and attributes from various hospital applications are generalized to a hospital node). This is referred to as within domain learning. Second, the information common to two (or more) related application domain nodes is generalized to a higher-level node; for example, knowledge from the car rental and video rental domains may be generalized to a rental node. This is called across domain learning. This paper presents a methodology for learning across different application domains based on a distance measure. The parameters used in this methodology were refined by testing on a set of representative cases; empirical testing provided further validation.
Validated Roundings of Dot Products by Sticky Accumulation
Authors: Marc Daumas, David W. Matula
Venue: IEEE Transactions on Computers (1997)

The dot product operation is very prevalent in scientific computation and has therefore been incorporated as a primitive operation in some languages. The implementation of the dot product operation by a sequence of IEEE standard multiplications and additions does not prevent a substantial accumulation of the round-off errors or warn the user about a catastrophic cancellation. We present the design of a double precision dot product operation employing sticky accumulation, where the final rounded result is validated by raising a new exception flag if the result incurred catastrophic cancellation. Sticky accumulation can be implemented in a pipeline or parallel environment to sustain double precision with an extended control of the error. Our design allows that, in the absence of catastrophic cancellation, one ulp accuracy is guaranteed.
A Systolic Power-Sum Circuit for GF(2/sup m/)
Authors: Shyue-Win Wei
Venue: IEEE Transactions on Computers (1994)

A systolic power-sum circuit designed to perform AB/sup 2/+C computations in the finite field GF(2/sup m/) is presented, where A, B, and C are arbitrary elements of GF(2/sup m/). This new circuit is constructed by m/sup 2/ identical cells, each of which consists of three 2-input AND logical gates, one 2-input XOR gate, one 3-input XOR gate, and ten latches. The AB/sup 2/+C computation is required in decoding many error-correcting codes. The paper shows that a decoder implemented using the new power-sum circuit will have less complex circuitry and shorter decoding delay than one implemented using conventional product-sum multipliers.
An Introduction to Landin&lsquo;s &ldquo;A Generalization of Jumps and Labels&rdquo;
Authors: Hayo Thielecke
Venue: Higher-Order and Symbolic Computation (1998)

This note introduces Peter Landin&lsquo;s 1965 technical report &ldquo;A Generalization of Jumps and Labels&rdquo;, which is reprinted in this volume. Its aim is to make that historic paper more accessible to the reader and to help reading it in context. To this end, we explain Landin&lsquo;s control operator J in more contemporary terms, and we recall Burge&lsquo;s solution to a technical problem in Landin&lsquo;s original account.
First-Order Logic Characterization of Program Properties
Authors: K. Wang, L. Y. Yuan
Venue: IEEE Transactions on Knowledge and Data Engineering (1994)

A program is first-order reducible (FO-reducible) w.r.t. a set IC of integrity constraints if there exists a first-order theory T such that the set of models for T is exactly the set of intended models for the program w.r.t. all possible EDBs. In this case, we say that P is FO-reducible to T w.r.t. IC. For FO-reducible programs, it is possible to characterize, using first-order logic implications, properties of programs that are related to all possible EDBs as in the database context. These properties include, among others, containment of programs, independence of updates w.r.t. queries and integrity constraints, and characterization and implication of integrity constraints in programs, all of which have no known proof procedures. Therefore, many important problems formalized in a nonstandard logic can be dealt with by using the rich reservoir of first-order theorem-proving tools, provided that the program is FO-reducible. The following classes of programs are shown to be FO-reducible: (1) a stratified acyclic program P is FO-reducible to comp(P)/spl cup/IC w.r.t. IC for any set IC of constraints; (2) a general chained program P is FO-reducible to comp(P')/spl cup/IC w.r.t. certain acyclicity constraints IC; and (3) a bounded program P is FO-reducible to comp(P')/spl cup/IC w.r.t. any set IC of constraints, where P' is a nonrecursive program equivalent to P. Some heuristics for constructing FO-reducible programs are described.
MBE-Growth of a Ge-CoSi2-Si heterostructure for vertical metal-semiconductor-metal photodetectors
Authors: S. Winnerl, L. Kappius, D. Buca, St. Lenk, Ch. Buchal, S. Mantl
Venue: Microelectronic Engineering (2002)

We report on the growth and structural characterisation of a novel single crystalline, epitaxial Ge-CoSi2- Si(111) heterostructure suitable for the fabrication of a vertical metal-semiconductor-metal photodetector for the wavelength of 1.55 µm. The CoSi2 layer was grown by a special epitaxy method, named allotaxy. The Ge layer was grown by surfactant-mediated epitaxy. The growth parameters for the CoSi2 layer were optimised in order to suppress the formation of pinholes. A thin layer of silicon and Sb as a surfactant allowed layer-by-layer growth of Ge on the CoSi2 layer.
Compiler optimization of scalar value communication between speculative threads
Authors: Antonia Zhai, Christopher B. Colohan, J. Gregory Steffan, Todd C. Mowry
Venue: ACM SIGPLAN Notices (2002)

While there have been many recent proposals for hardware that supports Thread-Level Speculation (TLS), there has been relatively little work on compiler optimizations to fully exploit this potential for parallelizing programs optimistically. In this paper, we focus on one important limitation of program performance under TLS, which is stalls due to forwarding scalar values between threads that would otherwise cause frequent data dependences. We present and evaluate dataflow algorithms for three increasingly-aggressive instruction scheduling techniques that reduce the critical forwarding path introduced by the synchronization associated with this data forwarding. In addition, we contrast our compiler techniques with related hardware-only approaches. With our most aggressive compiler and hardware techniques, we improve performance under TLS by 6.2-28.5% for 6 of 14 applications, and by at least 2.7% for half of the other applications.
An iterative bounding method for stochastic automata networks
Authors: Peter Buchholz
Venue: Performance Evaluation (2002)

A method to bound stationary distributions of large Markov chains resulting from networks of stochastic automata is presented. It combines the concepts for bounding the stationary distribution using eigenvector polyhedra with the exploitation of the specific structure of Markov chains resulting from stochastic automata networks. The quality of the bounds depends on the coupling between automata. Three consecutive steps of the method are presented. In the first step bounds are computed using information about single automata in isolation. Bounds for single automata are refined in a second step by considering the environment of an automaton given by the other automata in the network. In a third step, bounds are further improved using a disaggregation step. By means of two small examples it is shown that the method yields tight bounds for loosely coupled automata and that the approach is extremely efficient compared to other bounding methods, let alone compared to an exact numerical analysis.
Allocating Tree Structured Programs in a Distributed System with Uniform Communication Costs
Authors: A. Billionnet
Venue: IEEE Transactions on Parallel and Distributed Systems (1994)

Studies the complexity of the problem of allocating m modules to n processors in adistributed system to minimize total communication and execution costs. When thecommunication graph is a tree, Bokhari has shown that the optimum allocation can bedetermined in O(mn/sup 2/) time. Recently, this result has been generalized byFernandez-Baca, who has proposed an allocation algorithm in O(mn/sup k+1/) when thecommunication graph is a partial k-tree. The author shows that in the case wherecommunication costs are uniform, the module allocation problem can be solved in O(mn)time if the communication graph is a tree. This algorithm is asymptotically optimum.
Development and achievement of NAL numerical wind tunnel (NWT) for CFD computations
Authors: H. Miyoshi, M. Fukuda, T. Iwamiya, T. Nakamura, M. Tuchiya, M. Yoshida, K. Yamamoto, Y. Yamamoto, S. Ogawa, Y. Matsuo, T. Yamane, M. Takamura, M. Ikeda, S. Okada, Y. Sakamoto, T. Kitamura, H. Hatama, M. Kishimoto
Venue: Proceedings of the 1994 ACM/IEEE conference on Supercomputing (1994)

NAL Numerical Wind Tunnel (NWT) is a distributed memory parallel computer developed through joint research and development of NAL and Fujitsu. It is based on the analysis of CFD codes developed in NAL. The target performance is more than 100 times faster than VP400.In this paper, the parallel computation model employed in the development of the NWT is described. The specification and feature of the NWT and the NWT Fortran are discussed. Finally, Performance evaluations and some applications are presented.We find that the target performance is attained.
Texture Roughness Analysis and Synthesis via Extended Self-Similar (ESS) Model
Authors: Lance M. Kaplan, C. -C. Jay Kuo
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (1995)

The 2D fractional Brownian motion (fBm) model provides a useful tool to model textured surfaces whose roughness is scale-invariant. To represent textures whose roughness is scale-dependent, we generalize the fBm model to the extended self-similar (ESS) model in this research. We present an estimation algorithm to extract the model parameters from real texture data. Furthermore, a new incremental Fourier synthesis algorithm is proposed to generate the 2D realizations of the ESS model. Finally, the estimation and rendering methods are combined to synthesize real textured surfaces.
Automatic versus manual model differentiation to compute sensitivities and solve non-linear inverse problems
Authors: D. Elizondo, B. Cappelaere, Ch. Faure
Venue: Computers Geosciences (2002)

Emerging tools for automatic differentiation (AD) of computer programs should be of great benefit for the implementation of many derivative-based numerical methods such as those used for inverse modeling. The Odyssée software, one such tool for Fortran 77 codes, has been tested on a sample model that solves a 2D non-linear diffusion-type equation. Odyssée offers both the forward and the reverse differentiation modes, that produce the tangent and the cotangent models, respectively. The two modes have been implemented on the sample application. A comparison is made with a manually-produced differentiated code for this model (MD), obtained by solving the adjoint equations associated with the model's discrete state equations. Following a presentation of the methods and tools and of their relative advantages and drawbacks, the performances of the codes produced by the manual and automatic methods are compared, in terms of accuracy and of computing efficiency (CPU and memory needs). The perturbation method (finite-difference approximation of derivatives) is also used as a reference. Based on the test of Taylor, the accuracy of the two AD modes proves to be excellent and as high as machine precision permits, a good indication of Odyssée's capability to produce error-free codes. In comparison, the manually-produced derivatives (MD) sometimes appear to be slightly biased, which is likely due to the fact that a theoretical model (state equations) and a practical model (computer program) do not exactly coincide, while the accuracy of the perturbation method is very uncertain. The MD code largely outperforms all other methods in computing efficiency, a subject of current research for the improvement of AD tools. Yet these tools can already be of considerable help for the computer implementation of many numerical methods, avoiding the tedious task of hand-coding the differentiation of complex algorithms.
A Survey of Wormhole Routing Techniques in Direct Networks
Authors: Lionel M. Ni, Philip K. McKinley
Venue: Computer (1993)

Several research contributions and commercial ventures related to wormhole routing, a switching technique used in direct networks, are discussed. The properties of direct networks are reviewed, and the operation and characteristics of wormhole routing are discussed in detail. By its nature, wormhole routing is particularly susceptible to deadlock situations, in which two or more packets may block one another indefinitely. Several approaches to deadlock-free. routing, along with a technique that allows multiple virtual channels to share the same physical channel, are described. In addition, several open issues related to wormhole routing are discussed.
q-analogs of symmetric function operators
Authors: Michael Zabrocki
Venue: Discrete Mathematics (2002)

For any homomorphism V on the space of symmetric functions, we introduce an operation that creates a q-analog of V. By giving several examples we demonstrate that this quantization occurs naturally within the theory of symmetric functions. In particular, we show that the Hall-Littlewood symmetric functions are formed by taking this q-analog of the Schur symmetric functions and the Macdonald symmetric functions appear by taking the q-analog of the Hall-Littlewood symmetric functions in the parameter t. This relation is then used to derive recurrences on the Macdonald q,t-Kostka coefficients.
HARP: An Open Architecture for Parallel Matrix and Signal Processing
Authors: E. M. Dowling, Z. Fu, R. S. Drafz
Venue: IEEE Transactions on Parallel and Distributed Systems (1993)

Describes and analyzes the Hybrid Array Ring Processor (HARP) architecture. The HARP is an application specific architecture built around a host processor, shared memory, and a set of memory mapped processing cells that are connected both into an open backplane and a bidirectional systolic ring. The architecture is analyzed through detailed simulation of a system implementation based on the Texas Instruments TMS34082 floating point RISC. A bus controller is designed that provides a tightly coupled DMA function that accelerates systolic communication and supports new interleaved transparent communications and reduced overhead message passing. The architecture is benchmarked with the matrix multiplication, FFT, QRD, and SVD algorithms.
Curvature Based Image Registration
Authors: Bernd Fischer, Jan Modersitzki
Venue: Journal of Mathematical Imaging and Vision (2003)

A fully automated, non-rigid image registration algorithm is presented. The deformation field is found by minimizing a suitable measure subject to a curvature based constraint. It is a well-known fact that non-rigid image registration techniques may converge poorly if the initial position is not sufficiently near to the solution. A common approach to address this problem is to perform a time consuming rigid pre-registration step. In this paper we show that the new curvature registration not only produces accurate and smooth solutions but also allows for an automatic rigid alignment. Thus, in contrast to other popular registration schemes, the new method no longer requires a pre-registration step. Furthermore, we present an implementation of the new scheme based on the numerical solution of the underlying Euler-Lagrange equations. The real discrete cosine transform is the backbone of our implementation and leads to a stable and fast {\cal O}(N log N) algorithm, where N denotes the number of voxels. Finally, we report on some numerical test runs.
A partition-based approach towards constructing Galois (concept) lattices
Authors: P. Valtchev, R. Missaoui, P. Lebrun
Venue: Discrete Mathematics (2002)

Galois lattices and formal concept analysis of binary relations have proved useful in the resolution of many problems of theoretical or practical interest. Recent studies of practical applications in data mining and software engineering have put the emphasis on the need for both efficient and flexible algorithms to construct the lattice. Our paper presents a novel approach for lattice construction based on the apposition of binary relation fragments. We extend the existing theory to a complete characterization of the global Galois (concept) lattice as a substructure of the direct product of the lattices related to fragments. The structural properties underlie a procedure for extracting the global lattice from the direct product, which is the basis for a full-scale lattice construction algorithm implementing a divide-and-conquer strategy. The paper provides a complexity analysis of the algorithm together with some results about its practical performance and describes a class of binary relations for which the algorithm outperforms the most efficient lattice-constructing methods.
A Meta-Level Control Architecture for Production Systems
Authors: Toru Ishida, Yutaka Sasaki, Keiko Nakata, Yoshimi Fukuhara
Venue: IEEE Transactions on Knowledge and Data Engineering (1995)

Recent production system applications have been experiencing exceedingly difficult software maintenance problems. This is because the control of rule firings has been buried in the production rules themselves. To cope with this problem, we propose a meta-level control architecture for production systems, where procedural programming languages, such as Lisp and C, are employed to explicitly describe the control plans of production systems. The key idea of the architecture is to view production systems as a collection of independent rule processes, each of which monitors the global database and performs actions when its conditions are satisfied by the database. Procedural Control Macros (PCMs), which are based on Hoare¿s CSP, are then introduced into procedural programming languages to establish communication with the collection of rule processes.Although the PCMs are simple and easy to implement, the readability and maintainability of production system applications are greatly enhanced. Together with the original facilities of procedural languages, the PCMs enable users to efficiently specify the control plans for production systems. Furthermore, since control information is gathered into control plans, production rules can be declarative and thereby application-independent. This new feature makes it possible to develop large-scale shared rule bases. Experiments of redescribing 370 rules have been performed based on the proposed meta-level control architecture. The results demonstrate significant improvements in the readability and maintainability of those rules without any significant representation (file volumes) and runtime (processing time) overheads.
Synching or Sinking: Global Software Outsourcing Relationships
Authors: Richard Heeks, S. Krishna, Brian Nicholson, Sundeep Sahay
Venue: IEEE Software (2001)

Clients and software developers need to move their global outsourcing relationships up the value chain to reap greater benefits. Yet such moves bring costs and risks. The authors investigate the strategies that differentiate successful and unsuccessful value chain moves. Case studies from longitudinal research identified synching as a key success strategy: building client- developer congruence along six identified dimensions. Synching can be problematic because distance still matters in our supposedly borderless world. Distance particularly constrains the synching of tacit knowledge, informal information, and cultural values. Clients must recognize this-- and the external shocks to synching that occur over time--and adopt appropriate buffering tactics.