ppxscal/embedding_network huggingface dataset:
Exploring surface characteristics with interactive Gaussian images: a case study
Authors: Bradley Lowekamp, Penny Rheingans, Terry S. Yoo
Venue: Proceedings of the conference on Visualization '02 (2002)

The Gauss map projects surface normals to a unit sphere, providing a powerful visualization of the geometry of a graphical object. It can be used to predict visual events caused by changes in lighting, shading, and camera control. We present an interactive technique for portraying the Gauss map of polygonal models, mapping surface normals and the magnitudes of surface curvature using a spherical projection. Unlike other visualizations of surface curvature, we create our Gauss map directly from polygonal meshes without requiring any complex intermediate calculations of differential geometry. For anything other than simple shapes, surface information is densely mapped into the Gaussian normal image, inviting the use of visualization techniques to amplify and emphasize details hidden within the wealth of data. We present the use of interactive visualization tools such as brushing and linking to explore the surface properties of solid shapes. The Gauss map is shown to be simple to compute, easy to view dynamically, and effective at portraying important features of polygonal models.
False Sharing and Spatial Locality in Multiprocessor Caches
Authors: J. Torrellas, H. S. Lam, J. L. Hennessy
Venue: IEEE Transactions on Computers (1994)

The performance of the data cache in shared-memory multiprocessors has been shown to be different from that in uniprocessors. In particular, cache miss rates in multiprocessors do not show the sharp drop typical of uniprocessors when the size of the cache block increases. The resulting high cache miss rate is a cause of concern, since it can significantly limit the performance of multiprocessors. Some researchers have speculated that this effect is due to false sharing, the coherence transactions that result when different processors update different words of the same cache block in an interleaved fashion. While the analysis of six applications in the paper confirms that false sharing has a significant impact on the miss rate, the measurements also show that poor spatial locality among accesses to shared data has an even larger impact. To mitigate false sharing and to enhance spatial locality, we optimize the layout of shared data in cache blocks in a programmer-transparent manner. We show that this approach can reduce the number of misses on shared data by about 10% on average.
Impact of material/Process interactions on the properties of a porous CVD-O3 low-k dielectric film
Authors: Y. Travaly, B. Eyckens, L. Carbonel, A. Rothschild, Q. T. Le, S. H. Brongersma, I. Ciofi, H. Struyf, Y. Furukawa, M. Stucchi, M. Schaekers, H. Bender, E. Rosseel, S. Venhaelemeersch, K. Maex
Venue: Microelectronic Engineering (2002)

The impact of material/process interactions on low temperature CVD-O3 low-k dielectric film properties are presented. The film under investigation is deposited following a three-step process consisting of a low temperature chemical vapor deposition (CVD), an ex situ high temperature cure in a controlled ambient and a plasma treatment to seal the porous surface of the dielectric. In this paper, the extent to which the air break exposure, the cure, the nature of the plasma and the substrate can affect the material properties is investigated. The influence of the resist stripping plasmas on the material sealing and the mechanical properties during integration is also discussed. Finally, the dielectric k-value as extracted from damascene structures using Raphael™ simulations is presented and discussed.
Wire Ordering for Detailed Routing
Authors: Patrick Groeneveld
Venue: IEEE Design Test (1989)

In many automatic routing systems, the wiring area is broken into a number of regions. A detailed router, such as a channel or switch-box router, routes each region separately. A junction pin is placed on a region boundary whenever the path of a wire crosses to another region. The way these junction pins are placed can be either a boon or a detriment to the economy of the routing. An algorithm that determines a consistent order for the junction pins that avoids unnecessary wire twisting is presented. If wires have to cross, the algorithm selects the intersection that would least affect the chip area and places the pins in the corresponding position. Experimental results obtained by using the algorithm in a macrocell placement and routing system that uses a contour-based, gridless channel router to perform detailed routing in the regions are presented.
A New Design Technique for Column Compression Multipliers
Authors: Graham A. Jullien, Zhongde Wang, William C. Miller
Venue: IEEE Transactions on Computers (1995)

In this paper, a new design technique for column-compression (CC) multipliers is presented. Constraints for column compression with full and half adders are analyzed and, under these constraints, considerable flexibility for implementation of the CC multiplier, including the allocation of adders, and choosing the length of the final fast adder, is exploited. Using the example of an 8 × 8 bit CC multiplier, we show that architectures obtained from this new design technique are more area efficient, and have shorter interconnections than the classical Dadda CC multiplier. We finally show that our new technique is also suitable for the design of twos complement multipliers.
Self-Organization and Identification of Web Communities
Authors: Gary William Flake, Steve Lawrence, C. Lee Giles, Frans M. Coetzee
Venue: Computer (2002)

Millions of individuals operating independently author the Web's information. Despite its decentralized nature, the authors' work shows that the Web self-organizes and its link structure allows efficient identification of communities. This is significant because no central authority or process governs hyperlink formation and structure.A Web community is a collection of Web pages in which each member page has more hyperlinks within the community than outside it. Compared to previous methods of finding related Web pages,the authors describe an approach that retains the transparency of methods such as cocitation and bibliographic coupling in explaining why pages belong to a community,yet can identify Web communities of arbitrary dimensions. Applications of their method include creating improved search engines, content filtering, and objective analysis of Web content and the relationships between Web communities.
Linear and Incremental Acquisition of Invariant Shape Models From Image Sequences
Authors: Daphna Weinshall, Carlo Tomasi
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (1995)

We show how to automatically acquire Euclidian shape representations of objects from noisy image sequences under weak perspective. The proposed method is linear and incremental, requiring no more than pseudoinverse. A nonlinear, but numerically sound preprocessing stage is added to improve the accuracy of the results even further. Experiments show that attention to noise and computational techniques improves the shape results substantially with respect to previous methods proposed for ideal images.
Flexible Inner-Outer Krylov Subspace Methods
Authors: Valeria Simoncini, Daniel B. Szyld
Venue: SIAM Journal on Numerical Analysis (2002)

Flexible Krylov methods refers to a class of methods which accept preconditioning that can change from one step to the next. Given a Krylov subspace method, such as CG, GMRES, QMR, etc. for the solution of a linear system Ax=b, instead of having a fixed preconditioner M and the (right) preconditioned equation AM-1 y = b (Mx =y), one may have a different matrix, say Mk, at each step. In this paper, the case where the preconditioner itself is a Krylov subspace method is studied. There are several papers in the literature where such a situation is presented and numerical examples given. A general theory is provided encompassing many of these cases, including truncated methods. The overall space where the solution is approximated is no longer a Krylov subspace but a subspace of a larger Krylov space. We show how this subspace keeps growing as the outer iteration progresses, thus providing a convergence theory for these inner-outer methods. Numerical tests illustrate some important implementation aspects that make the discussed inner-outer methods very appealing in practical circumstances.
Blind separation methods based on Pearson system and its extensions
Authors: Juha Karvanen, Visa Koivunen
Venue: Signal Processing (2002)

we introduce a mutual lnformation-based method for blind separation ot statistically independent source signals. The Pearson system is used as a parametric model. Starting from the definition of mutual information we show using the results by Pham (IEEE Trans. Signal Process. 44(11) (1996) 2768-2779) that the minimization of mutual information contrast leads to iterative use of score functions as estimation functions. The Pearson system allows adaptive modeling of the score functions. The characteristics of the Pearson system are studied and estimators for the parameters are derived using the method of moments. The flexibility of the Pearson system makes it possible to model wide range of source distributions including asymmetric distributions. Skewed source distributions are common in many key application areas, such as telecommunications and biomedical signal processing. We also introduce an extension of the Pearson system that can model multimodal distributions. The applicability of the Pearson system-based method is demonstrated in simulation examples, including blind equalization of GMSK signals.
Building Real Computer Systems
Authors: Augustus K. Uht, Jien-Chung Lo, Ying Sun, James C. Daly, James Kowalski
Venue: IEEE Micro (2000)

The authors describe a multiyear student project on the design and construction of hardware and software for a complete computer system. Students use and build upon these systems over their undergraduate years.
The Realities of Language Conversions
Authors: Andrey A. Terekhov, Chris Verhoef
Venue: IEEE Software (2000)

Billions of lines of code that have been written in Cobol, PL/I, and other old programming languages are still in active use. Many commercial efforts to convert these to more modern languages have begun, but few have succeeded. These authors discuss the nuts and bolts of conversion between several pairs of languages and some of the possibilities and limitations of automating language conversion.
The L/sub 2/-Polynomial Spline Pyramid
Authors: M. Unser, A. Aldroubi, M. Eden
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (1993)

The authors are concerned with the derivation of general methods for the L/sub 2/ approximation of signals by polynomial splines. The main result is that the expansion coefficients of the approximation are obtained by linear filtering and sampling. The authors apply those results to construct a L/sub 2/ polynomial spline pyramid that is a parametric multiresolution representation of a signal. This hierarchical data structure is generated by repeated application of a REDUCE function (prefilter and down-sampler). A complementary EXPAND function (up-sampler and post-filter) allows a finer resolution mapping of any coarser level of the pyramid. Four equivalent representations of this pyramid are considered, and the corresponding REDUCE and EXPAND filters are determined explicitly for polynomial splines of any order n (odd). Some image processing examples are presented. It is demonstrated that the performance of the Laplacian pyramid can be improved significantly by using a modified EXPAND function associated with the dual representation of a cubic spline pyramid.
Backtracking in Independent And-Parallel Implementations of Logic Programming Languages
Authors: Enrico Pontelli, Gopal Gupta
Venue: IEEE Transactions on Parallel and Distributed Systems (2001)

In this paper, we present an implementation model which efficiently supports backtracking in an independent and-parallel nondeterministic system. The problem is tackled in the context of logic programming, although the solution proposed is sufficiently general to be easily extended to different nondeterministic systems, such as constraint programming systems. The complexity of the problem is demonstrated by the fact that most existing and-parallel systems either do not support backtracking over and-parallel calls or simply avoid analyzing the performance of their systems in the presence of nondeterministic benchmarks. The implementation model we present is an extension of the backtracking scheme developed by Hermenegildo and Nasr [31] and relies on a novel memory organization scheme and on the use of various optimizations to reduce communication and overhead. The solution developed has been implemented in the ACE Parallel Prolog system. The performance of the system is analyzed on a variety of benchmarks. The results obtained are remarkable: Speedups achieved during forward execution are not lost in heavy backtracking activities and, frequently, super-linear speedups are obtained thanks to a semi-intelligent backtracking scheme.
The Memory Stick
Authors: Shigeo Araki
Venue: IEEE Micro (2000)

The compact Memory Stick recording card connects various household electrical devices. It stores still images, moving images, voice, and music together on the same media, and protects copyrighted material.
Hybrid Feedforward Neural Networks for Solving Classification Problems
Authors: Iulian B. Ciocoiu
Venue: Neural Processing Letters (2002)

A novel multistage feedforward network is proposed for efficient solving of difficult classification tasks. The standard Radial Basis Functions (RBF) architecture is modified in order to alleviate two potential drawbacks, namely the &lsquo;curse of dimensionality&rsquo; and the limited discriminatory capacity of the linear output layer. The first goal is accomplished by feeding the hidden layer output to the input of a module performing Principal Component Analysis (PCA). The second one is met by substituting the simple linear combiner in the standard architecture by a Multilayer Perceptron (MLP). Simulation results for the 2-spirals problem and Peterson-Barney vowel classification are reported, showing high classification accuracy using less parameters than existing solutions.
Determining the Number of Remote Sites Accessed in Distributed Transaction Processing
Authors: A. Thomasian
Venue: IEEE Transactions on Parallel and Distributed Systems (1993)

The number of remote accesses and the number of distinct remote sites accessed byglobal transactions in a distributed database environment are characterized. Bothmeasures are important in determining the overhead of distributed transaction processingand are affected by the distribution of transaction size (number of distinct objectsaccessed by a transaction) and the distribution of remote accesses made by atransaction. Keeping the mean transaction size fixed, it is shown that in the case of somecommonly used distributions for the number of remote accesses variable size transactionsaccess fewer distinct remote sites on the average than fixed size transactions. Also, forthese and some other distributions the mean number of remote accesses is independentof the distribution of transaction size, but this is not generally true.
Diagonal and Toroidal Mesh Networks
Authors: K. W. Tang, S. A. Padubidri
Venue: IEEE Transactions on Computers (1994)

Diagonal and toroidal mesh are degree-4 point to point interconnection models suitable for connecting communication elements in parallel computers, particularly multicomputers. The two networks have a similar structure. The toroidal mesh is popular and well-studied whereas the diagonal mesh is relatively new. In this paper, we show that the diagonal mesh has a smaller diameter and a larger bisection width. It also retains advantages such as a simple rectangular structure, wirability and scalability of the toroidal mesh network. An optimal self-routing algorithm is developed for these networks. Using this algorithm and the existing routing algorithm for the toroidal mesh, we simulated and compare the performance of these two networks with N=35/spl times/71=2485, N=49/spl times/99=4851, and N=69/spl times/139=9591 nodes under a constant system with a fixed number of messages. Deflection routing is used to resolve conflicts. The effects of various deflection criteria are also investigated. We show that the diagonal mesh outperforms the toroidal mesh in all cases, and thus provides an attractive alternative to the toroidal mesh network.
Software Export from Developing Nations
Authors: Larry Press
Venue: Computer (1993)

It is shown that software export is an attainable goal for developing nations, especially when government policies are favorable, and that the industrialized nations dominating the worldwide market can expect some serious competition. Examples of the efforts of developing nations to export software to North America and Europe are cited.
On the Scheduling of Flexible and Reliable Real-Time Control Systems
Authors: Ramesh Chandra, Xue Liu, Lui Sha
Venue: Real-Time Systems (2003)

Many real-time systems, such as manufacturing plants, have long life cycles. To enable the realization of technological innovations and to mitigate the risk and cost of bringing new control technologies into functioning systems, flexible and reliable real-time software architectures such as Simplex have been developed. There is also an emerging trend that integrates the design of controllers and schedulers. For example, algorithms that identify the optimal frequencies of control tasks subject to schedulability constraints have been developed, and the notion of feedback schedulers has been investigated. However, the optimization of the performance of flexible and reliable architectures with analytically redundant software controllers has remained an open problem. In fact, a direct application of the existing optimization methods would not yield the optimal frequencies. In this paper, we present a method that correctly finds the optimal frequencies for systems using analytically redundant controllers. We also show that the proposed method is robust against inaccuracies in the estimation of failure rates of the controllers.
A chip-firing game and Dirichelt eigenvalues
Authors: Fan Chung, Robert B. Ellis
Venue: Discrete Mathematics (2002)

We consider a variation of the chip-firing game in an induced subgraph S of a graph G. Starting from a given chip configuration, if a vertex v has at least as many chips as its degree, we can fire v by sending one chip along each edge from v to its neighbors. Chips are removed at the boundary δS. The game continues until no vertex can be fired. We will give an upper bound, in terms of Dirichlet eigenvalues, for the number of firings needed before a game terminates. We also examine the relations among three equinumerous families, the set of spanning forests on S with roots in the boundary of S, a set of "critical" configurations of chips, and a coset group, called the sandpile group associated with S.
Mathematical Software: Plod
Authors: Elvira Argon, I-Lok Chang, Gamini Gunaratna, David K. Kahaner, Martin A. Reed
Venue: IEEE Micro (1988)

The authors present Plod (plotted solutions of ordinary differential equation), mathematical software Fortran package designed by integrating large systems of equations that are unstable with respect to initial conditions (stiff). It is intended for microcomputer users unfamiliar with programming techniques. The hardware needed to run Plod is described. Plod is designed to be used in two interactive steps, and an example of each is given. Graphics capabilities and extensibility are briefly considered.
Looking for Difference Sets in Groups with Dihedral Images
Authors: Emily H. Moore, Harriet Pollatsek
Venue: Designs, Codes and Cryptography (2003)

We prove four theorems about groups with a dihedral (or cyclic) image containing a difference set. For the first two, suppose G, a group of order 2p\tilde{q} with p an odd prime, contains a nontrivial (v, k, &lambda;) difference set D with order n &equals; k &minus; &lambda; prime to p and self-conjugate modulo p. If G has an image of order p, then 0 &le; 2a + &epsi; \sqrt{n} &le; 2\tilde{q} for a unique choice of &epsi; &equals; &plusmn;1, and for a &equals; (k &minus; &epsi; \sqrt{n})/2p. If G has an image of order 2p, then \sqrt{n} &le; \tilde{q} and &lambda; &ge; \sqrt{n}(\sqrt{n} &minus; 1)/(\tilde{q} &minus; 1). There are further constraints on n, a and &epsi;. We give examples in which these theorems imply no difference set can exist in a group of a specified order, including filling in some entries in Smith's extension to nonabelian groups of Lander's tables. A similar theorem covers the case when p&verbar;n. Finally, we show that if G contains a nontrivial (v, k, &lambda;) difference set D and has a dihedral image D2m with either (n, m) &equals; 1 or m &equals; pt for p an odd prime dividing n, then one of the C2 intersection numbers of D is divisible by m. Again, this gives some non-existence results.
Multiple light field rendering
Authors: Jarno van der Linden
Venue: Proceedings of the 1st international conference on Computer graphics and interactive techniques in Australasia and South East Asia (2003)

A light field is a 4D function describing the radiance across a boundary between the volume containing a scene, and the disjoint volume in which the eyepoint may be placed. Light field rendering is the process of rendering novel views of a scene captured by the light field function. It is a purely image-based rendering technique which uses no geometric knowledge of the scene. Although the lack of needed geometric information make light fields an attractive way of capturing real-world scenes, it has made it difficult to effectively use light fields in combination with other rendering techniques, or even rendering multiple light fields in the same scene.We present a rendering method for light fields which allows multiple instances of a light field to be rendered in combination with a polygon rendered scene. Of particular note is our ability to render multiple light fields which appear to intersect in space consistently when viewed from any direction. The method is demonstrated by creating a forest consisting of thousands of instances of a tree light field, rendered on a polygon terrain.
Local Reproducible Smoothing Without Shrinkage
Authors: J. Oliensis
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (1993)

A simple local smoothing filter is defined for curves or surfaces, combining the advantages of Gaussian smoothing and Fourier curve description. Unlike Gaussian filters, the filter described has no shrinkage problem. Repeated application of the filter does not yield a curve or surface smaller than the original but simply reproduces the approximate result that would have been obtained by a single application at the largest scale. Unlike Fourier description, the filter is local in space. The wavelet transform of Y. Meyer (1989) is also shown to have these properties.
A Formal Method for Building Concurrent Real-Time Software
Authors: Colin Fidge, Peter Kearney, Mark Utting
Venue: IEEE Software (1997)

The Quartz method treats time and functional behavior with equal importance in the development process. By modeling program development in a unified framework, argue the authors, we can increase our confidence in the correctness of real-time, concurrent code.