ppxscal/embedding_network huggingface dataset:
An improved procedure for 2D unstructured Delaunay mesh generation
Authors: S. Secchi, L. Simoni
Venue: Advances in Engineering Software (2003)

This paper presents a procedure for the discretization of 2D domains using a Delaunay triangulation. Improvements over existing similar methods are introduced, proposing in particular a multi-constraint insertion algorithm, very effective in the presence of highly irregular domains, and the topological structure used together with its primitives. The method obtained requires limited input and can be applied to a wide class of domains. Quadrilateral subdivisions with a control of the aspect ratio of the generated elements can also be reached. Further it is suitable for evolutionary problems, which require continuous updating of the discretization. Presented applications and comparisons with other discretization methods demonstrate the effectiveness of the procedure.
Discrete Wavelet Transform: Architectures, Design and Performance Issues
Authors: Michael Weeks, Magdy Bayoumi
Venue: Journal of VLSI Signal Processing Systems (2003)

Due to the demand for real time wavelet processors in applications such as video compression [1], Internet communications compression [2], object recognition [3], and numerical analysis, many architectures for the Discrete Wavelet Transform (DWT) systems have been proposed. This paper surveys the different approaches to designing DWT architectures. The types of architectures depend on whether the application is 1-D, 2-D, or 3-D, as well as the style of architecture: systolic, semi-systolic, folded, digit-serial, etc. This paper presents an overview and evaluation of the architectures based on the criteria of latency, control, area, memory, and number of multipliers and adders. This paper will give the reader an indication of the advantages and disadvantages of each design.
A JPEG Chip for Image Compression and Decompression
Authors: Sung-Hsien Sun, Shie-Jue Lee
Venue: Journal of VLSI Signal Processing Systems (2003)

JPEG is an international standard for still-image compression/decompression and has been widely implemented in hardware. In this paper, we describe the development of a JPEG chip which employs a single-chip implementation and an efficient architecture of Huffman codec. Firstly, we use VHDL (VHSIC Hardware Description Language) to describe the behavior of the chip. Each functional block of the chip is defined and simulated. An architecture consisting of two RAMs is adopted to reduce the size of the Huffman tables. Then we verify the functionality of our design with field programmable gate arrays (FPGAs) on circuit boards. Finally, a single chip is implemented using the standard cell design approach with the 0.6 &mu; triple-metal process. The chip is compliant with the JPEG baseline system and can work in real time at any compression ratio. The chip contains 411,745 transistors, with a chip size of 6.6 &times; 6.9 mm2.
A hybrid adiabatic content addressable memory for ultra low-power applications
Authors: Aiyappan Natarajan, David Jasinski, Wayne Burleson, Russell Tessier
Venue: Proceedings of the 13th ACM Great Lakes symposium on VLSI (2003)

This paper presents a hybrid adiabatic content addressable memory (CAM). The CAM uses an adiabatic switching technique to reduce the energy consumption in the match line while keeping the performance for the read/write operation. The adiabatic CAM is suitable for ultra low-power, low performance applications such as smart cards and portable devices. This CAM uses a clocked power supply for the match line while the rest of the circuit is the same as the basic CAM. A novel smart card application which uses the adiabatic CAM is illustrated. The circuit simulations for a 16x16 and 32x32 CAM were done in Hspice using 0.18 μm Berkeley models and the energy dissipation was compared with a basic CAM. The results show three orders of magnitude in energy savings for the 16x16 CAM and one order of magnitude savings for the 32x32 CAM when operated at 2Mhz. The maximum frequency of operation for which there was considerable energy savings was found to be 200 Mhz with a 20% and 45% energy savings for 16x16 and 32x32 CAM respectively.
Inverse Optimization
Authors: Ravindra K. Ahuja, James B. Orlin
Venue: Operations Research (2001)

In this paper, we study inverse optimization problems defined as follows. LetS denote the set of feasible solutions of an optimization problemP, letc be a specified cost vector, andx0 be a given feasible solution. The solutionx0 may or may not be an optimal solution ofP with respect to the cost vectorc. The inverse optimization problem is to perturb the cost vectorc tod so thatx0 is an optimal solution ofP with respect tod and ||d- c || p is minimum, where ||d- c || p is some selectedLp norm. In this paper, we consider the inverse linear programming problem underL1 norm (where ||d- c || p= ? j?Jw j|d j-c j|, withJ denoting the index set of variablesx jandw jdenoting the weight of the variablej) and underL8 norm (where||d- c || p= max j?J{w j|d j-c j|} ). We prove the following results: (i) If the problemP is a linear programming problem, then its inverse problem under theL1 as well asL8 norm is also a linear programming problem. (ii) If the problemP is a shortest path, assignment or minimum cut problem, then its inverse problem under theL1 norm and unit weights can be solved by solving a problem of the same kind. For the nonunit weight case, the inverse problem reduces to solving a minimum cost flow problem. (iii) If the problemP is a minimum cost flow problem, then its inverse problem under theL1 norm and unit weights reduces to solving a unit-capacity minimum cost flow problem. For the nonunit weight case, the inverse problem reduces to solving a minimum cost flow problem. (iv) If the problemP is a minimum cost flow problem, then its inverse problem under theL8 norm and unit weights reduces to solving a minimum mean cycle problem. For the nonunit weight case, the inverse problem reduces to solving a minimum cost-to-time ratio cycle problem. (v) If the problemP is polynomially solvable for linear cost functions, then inverse versions ofP under theL1 andL8 norms are also polynomially solvable.
Localizer: a Modeling Language for Local Search
Authors: Laurent Michel, Pascal Van Hentenryck
Venue: INFORMS Journal on Computing (1999)

Local search is a traditional technique to solve combinatorial search problems and has raised much interest in recent years. The design and implementation of local search algorithms is not an easy task in general and may require considerable experimentation and programming effort. However, contrary to global search, little support is available to assist the design and implementation of local search algorithms. This paper is an attempt to support the implementation of local search. It presents the preliminary design of LOCALIZER, a modeling language which makes it possible to express local search algorithms in a notation close to their informal descriptions in scientific papers. Experimental results on our first implementation show the feasibility of the approach.
On the location of resonances of exponentially decaying Sturm-Liouville potentials
Authors: B. M. Brown, M. S. P. Eastham
Venue: Journal of Computational and Applied Mathematics (2002)

The paper is concerned with analytic continuation into the unphysical sheet for Sturm-Liouville potentials whose decay at infinity is no faster than O(e-ax). A resonance-free region is found and the existence of a natural boundary is discussed. An example related to the Bessel equation is examined in some detail.
An Incremental Branch-And-Bound Method for the Satisfiability Problem
Authors: Hachemi Bennaceur, Idir Gouachi, Gerard Plateau
Venue: INFORMS Journal on Computing (1998)

The satisfiability problem is to check whether a set of clauses in propositional logic is satisfiable. If it is satisfiable, the incremental satisfiability problem is then to check whether satisfiability remains given additional clauses. This paper deals with an incremental branch-and-bound method which solves exactly both problems. This method includes flexible Lagrangean relaxations, metaheuristics, and judicious jumping back. This leads to an efficient implementation which compares favorably with the classical Davis-Putnam-Loveland procedure and its incremental version designed by Hooker. Numerous computational results are detailed.
Keiretsu, Governance, and Learning: Case Studies in Change from the Japanese Automotive Industry
Authors: Christina L. Ahmadjian, James R. Lincoln
Venue: Organization Science (2001)

Thekeiretsu structuring of assembler-supplier relations historically enabled Japanese auto assemblers to remain lean and flexible while enjoying a level of control over supply akin to that of vertical integration. Yet currently there is much talk of breakdowns inkeiretsu networks. This paper examines some recent developments in Japanese parts-supplykeiretsu.We argue thatkeiretsu relationships are drifting from "hybrid" or "network" (i.e.,keiretsu) governance modes toward the extremes of arms-length contracting and top-down administration. These changes are best understood through a combination of transaction cost and learning perspectives on alliance. Consistent with transaction-cost economics, the shift in purchase-supply relationships can be traced to changes in the nature of parts transactions andkeiretsu-governance structures. A learning perspective on alliance complements and extends transaction-cost theory, providing additional explanation of the sources of change and the specific governance choices being made.Our first two cases document a drift in Toyota'skeiretsu supply network toward a hierarchical form in the management of parts-supply transactions. Toyota has effectively internalized its transactions with Daihatsu by taking a controlling interest. Toyota's strategy toward long-term partner Denso, on the other hand, was very different. Toyota built, from the ground up, an in-house capability in electronic components, thus scaling down its dependence on Denso. A third case considers a general trend in the Japanese auto industry toward greater standardization of parts. With the routinization of quality, reliability, and speed in supply management, the need forkeiretsu-style governance has declined. The withering ofkeiretsu obligations is also traceable to globalization and the continuing weakness of the Japanese economy, which have prompted Japanese firms to question received business practice.
Platform independent tool for local event correlation
Authors: Risto Vaarandi
Venue: Acta Cybernetica (2002)

Event correlation plays a crucial role in network management systems, helping to reduce the amount of event messages and making their meaning clearer to a human operator. In early network management systems, events were correlated only at network management servers. Most modern network management systems also provide means for local event correlation at agents, in order to increase the scalability of the system and to reduce network load. Unfortunately all event correlation tools currently available are commercial, quite expensive, and highly platform dependent. The author presents a free platform independent tool called sec for correlating network management events locally at an agent's side.
Fabrication technology for improving pattern quality in focusing waveguide grating coupler manufacture
Authors: Hae-Sung Kim, Tae-Youb Kim, Yark-Yeon Kim, Gee-Pyeong Han, Mun-Cheol Paek, Dong-Hoon Shin, Jin-Koo Rhee
Venue: Microelectronic Engineering (2003)

This paper presents several exposure strategies that greatly improve pattern quality in delineating curved gratings in the nanometer range. A focusing waveguide grating coupler (FWGC) was not fabricated by the 'continuous path control' writing strategy but by a single-step e-beam lithography system with conventional exposure mode. The exposure strategies proposed are to match the address grid, which is an exposure scan direction, to the grating period, and also to apply the grating period to an integer multiple of the address grid resolution (5 nm). The grating pitch period and aperture feature size of the FWGC designed and fabricated here are 384.3-448.2 nm and 0.5 × 0.5-mm2, respectively. The presented fabrication method will also reduce processing time and improve grating pattern quality through address grid resolution, grating direction, pitch size and shapes in the e-beam exposure. Here our investigations concentrate on the design and efficient fabrication of the FWGC for coupling from slab waveguide to a spot in free space.
Frames in the human-operator behavior analysis
Authors: Alexander M. Yemelyanov
Venue: Second international workshop on Intelligent systems design and application (2002)

The idea of presenting knowledge on various objects and phenomena in the form of frames developed within the theory of artificial intelligence proves helpful in the studies of human intelligence as well. The paper presents some results pertaining to the applications of frames in human behavior studies. Frames and special modal logic are used as a basis for a method of describing and analyzing of causes for human-operator error. Unlike routine methods this one facilitates an analysis operator's characteristics and the situation in which the error occurred. The method makes it possible for every error to reveal its intrinsic sources, which can be used for making recommendations concerning their elimination. On the basis of the suggested method, an expert system SAFE was developed which was implemented in aviation.
An equational notion of lifting monad
Authors: Anna Bucalo, Carsten Führmann, Alex Simpson
Venue: Theoretical Computer Science (2003)

We introduce the notion of an equational lifting monad: a commutative strong monad satisfying one additional equation (valid for monads arising from partial map classifiers). We prove that any equational lifting monad has a representation by a partial map classifier such that the Kleisli category of the former fully embeds in the partial category of the latter. Thus, equational lifting monads precisely capture the equational properties of partial maps as induced by partial map classifiers. The representation theorem also provides a tool for transferring nonequational properties of partial map classifiers to equational lifting monads. It is proved using a direct axiomatization of Kleisli categories of equational lifting monads. This axiomatization is of interest in its own right.
A Robust Heuristic for Minimizing Cell Loss in ATM Networks
Authors: Sridhar Seshadri, Vijay Srinivasan
Venue: Proceedings of the 3rd International Workshop on Modeling, Analysis, and Simulation of Computer and Telecommunication Systems (1995)

Limited buffers in ATM network elements will inevitably result in cell loss. We model an ATM network as a tandem network with finite buffers and investigate the performance of a cell-level control policy (the HILO heuristic) that is designed to minimize cell loss rates. The HILO heuristic is based on limited feedback about the cells awaiting transmission in adjacent network nodes. We demonstrate via analysis and simulation that this scheme can reduce cell loss by substantial amounts over the simple FCFS scheme. The parameters of the control policy can be modified adaptively to maximize the reduction in loss rates. The heuristic is robust in the sense that it is relatively insensitive to values of the control parameters, and is effective for different traffic loads and arrival patterns.
Building Marketing Models That Make Money
Authors: Benjamin Avi-Itzhak, Hanoch Levy, Leonard M. Lodish
Venue: Interfaces (2001)

Building models that help marketers make productive decisions and that they actually use is hard. I learned some lessons in my 30+ years of building and applying models for sizing and deploying sales forces, for estimating brand health, and for estimating the impact on revenue of marketing mix and of the attractiveness to consumers of product attributes. One is that building scientific models that improve productivity is an art. Other lessons include these: to balance model complexity versus ease of understanding and estimation; to involve managers in any subjective estimates for models they will implement; to make measures available to managers when they need them and at the level of organization they need; to use the predictive validity of a hold-out sample to persuade managers of a model's credibility; and to recognize that even for empirical models, subjective estimates about the future may be necessary. Productive marketing models may have different attributes than those published in prestigious academic journals.
Applying Dialectic Agents to Argumentation in E-Commerce
Authors: Hajime Sawamura, Masashi Yamashita, Yuichi Umeda
Venue: Electronic Commerce Research (2003)

Reaching an agreement or understanding through argumentation is an important aspect of decision making in a virtual society as well as in our real society. In this paper, we consider &lsquo;compromise&rsquo; (Aufheben) and &lsquo;concession&rsquo; (weaker Aufheben) as a simple form of Hegelian dialectical reasoning, which we think are desiderata to deliberate or cognitive agents. We then propose an argument-based agent system that allows for the issue modification among agents concerned during argumentation and reaching an agreement or understanding through argumentation with the dialectical reasoning capability. We illustrate its potential usefulness by showing applications to seller and buyer agents and traveling salesman agents in e-commerce.
Generalized projection and approximation of fixed points of nonself maps
Authors: C. E. Chidume, M. Khumalo, H. Zegeye
Venue: Journal of Approximation Theory (2003)

Let K be a nonempty closed convex proper subset of a real uniformly convex and uniformly smooth Banach space E; T : K → E be an asymptotically weakly suppressive, asymptotically weakly contractive or asymptotically nonextensive map with F(T) = {x ∈ K: Tx = x} ≠ θ. Using the notion of generalized projection, iterative methods for approximating fixed points of T are studied. Convergence theorems with estimates of convergence rates are proved. Furthermore, the stability of the methods with respect to perturbations of the operators and with respect to perturbations of the constraint sets are also established.
Finite difference method to solve Maxwell's equations for soliton propagation
Authors: Hafid Bachiri, Luis Vázquez
Venue: Applied Mathematics and Computation (2002)

We present a finite-difference (FD) scheme for the nonlinear Maxwell's equations describing one-dimensional scalar optical soliton propagation in polarization-preserving nonlinear dispersive media. The existence of a discrete analog of the underlying continuous energy conservation law is shown to play a central role in the global accuracy of the scheme and a proof of its generalized nonlinear stability using energy methods is given. Numerical simulations of initial fundamental-, second- and third-order hyperbolic secant ultra-short soliton pulses of full width at half peak intensity equal to 25.7 fs (FWHM) containing as few as four and eight optical carrier cycles, confirm the stability, accuracy and efficiency of the algorithm. The decay of such solitons under the combined effects of higher-order dispersion and self-steepening is clearly evidenced.
Managing Learning and Turnover in Employee Staffing
Authors: Noah Gans, Yong-Pin Zhou
Venue: Operations Research (2002)

We study the employee staffing problem in a service organization that uses employee service capacity to meet random, nonstationary service requirements. The employees experience learning and turnover on the job, and we develop a Markov Decision Process (MDP) model which explicitly represents the stochastic nature of these effects. Theoretical results show that the optimal hiring policy is of a state-dependent "hire-up-to" type, similar to an inventory "order-up-to" policy. For two important special cases, a myopic policy is optimal. We also test a linear programming (LP) based heuristic, which uses average learning and turnover behavior, in stationary environments. In most cases, the LP-based policy performs quite well, within 1% of optimality. When flexible capacity--in the form of overtime or outsourcing--is expensive or not available, however, explicit modeling of stochastic learning and turnover effects may improve performance significantly.
Designing processor-time optimal systolic configurations
Authors: O. B. Efremides, M. P. Bekakos
Venue: Highly parallel computaions: algorithms and applications (2001)

One of the most challenging problems in systolic processing is the development of a methodology for mapping an algorithm into a systolic architecture. It becomes more and more obvious that systolic arrays can be produced not only using trial and error approaches, but also that they can be mechanically produced through the use of optimal synthetic methods. Herein, a new approach is investigated regarding the synthesis of processor-time optimal systolic arrays. The proposed procedure is based on the dependence method, but nonlinear transformations and the concept of double processing streams for the input data of the algorithm are also used. The result is efficient systolic designs from both aspects, the hardware used and the overall time complexity achieved.
Informational environments: organizational contexts of online information use
Authors: Roberta Lamb, John Leslie King, Rob Kling
Venue: Journal of the American Society for Information Science and Technology (2003)

Before the Web, the story of online information services was largely one of over-estimates and unmet expectations. This study examines sustained use and non-use of online services within organizations in a way that overcomes limitations of the traditional approaches that repeatedly led to exuberant usage projections. By adopting an open-systems view, we see that firms in highly technical and highly institutional environments have many more incentives to gather data and go online than do firms in low-tech, unregulated industries. But firms make important choices about partnering and outsourcing that can shift informational activities across organizational boundaries. Our analysis focuses on the informational environments of firms in three industries: law, real estate and biotech/pharmaceuticals. This environmental model provides richer conceptualizations about the use of information and communication technologies, including Internet technologies, and better projections about future use. In support of our analysis, we briefly discuss insights from an ongoing intranets study informed by an informational environments perspective.
View-based query containment
Authors: Diego Calvanese, Giuseppe De Giacomo, Maurizio Lenzerini, Moshe Y. Vardi
Venue: Proceedings of the twenty-second ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems (2003)

Query containment is the problem of checking whether for all databases the answer to a query is a subset of the answer to a second query. In several data management tasks, such as data integration, mobile computing, etc., the data of interest are only accessible through a given set of views. In this case, containment of queries should be determined relative to the set of views, as already noted in the literature. Such a form of containment, which we call view-based query containment, is the subject of this paper. The problem comes in various forms, depending on whether each of the two queries is expressed over the base alphabet or the alphabet of the view names. We present a thorough analysis of view-based query containment, by discussing all possible combinations from a semantic point of view, and by showing their mutual relationships. In particular, for the two settings of conjunctive queries and two-way regular path queries, we provide both techniques and complexity bounds for the different variants of the problem. Finally, we study the relationship between view-based query containment and view-based query rewriting.