ppxscal/embedding_network huggingface dataset:
Novel finite element algorithms with applications to skeletal muscle simulation
Authors: Ronald Fedkiw
Venue:  (2005)

This thesis develops a musculoskeletal simulation framework and showcases the algorithmic developments that arose in the process of creating it. Muscles are simulated as deformable Lagrangian solids with a transversely isotropic, quasi-incompressible constitutive model coupled to articulated rigid bones in the skeleton. Muscle and bone geometry is created from the visible human data set using an implicit surface based tetrahedral meshing algorithm for creating meshes that are well suited for large deformation. Additionally, a novel invertible finite element algorithm (IFEM) designed specifically for largely deforming skeletal muscles is presented. Typical finite element based simulations of elastic solids fail when the interpolating functions misinterpret large deformations as having locally negative volume at quadrature points, our approach extends the elastic response in a meaningful way to such configurations, drastically improving robustness to large deformation. Simulations are done with semi-implicit Newmark integration and quasistatic time stepping schemes. In the case of the latter, we present a novel quasistatic algorithm that alleviates geometric and material indefiniteness allowing one to use fast conjugate gradient solvers during Newton-Raphson iteration. Quasistatic and implicit time integration schemes are typically employed to alleviate the stringent time step restrictions imposed by their explicit counterparts. However, time step restrictions can also be ameliorated with regular mesh elements. As a result, we present a muscle geometry embedding framework that alleviates time step restrictions by virtue of this principle. A fascia/collision algorithm is also presented in the context of this embedding framework. Finally, though all musculoskeletal simulations in this thesis make use of kinematically prescribed skeletal motion, we would ultimately like to simulate the skeleton as a dynamic articulated rigid body. We present a preliminary step in this direction with a prestabilization framework for enforcing articulation constraints.
Verifying properties of well-founded linked lists
Authors: Shuvendu K. Lahiri, Shaz Qadeer
Venue: Conference record of the 33rd ACM SIGPLAN-SIGACT symposium on Principles of programming languages (2006)

We describe a novel method for verifying programs that manipulate linked lists, based on two new predicates that characterize reachability of heap cells. These predicates allow reasoning about both acyclic and cyclic lists uniformly with equal ease. The crucial insight behind our approach is that a circular list invariably contains a distinguished head cell that provides a handle on the list. This observation suggests a programming methodology that requires the heap of the program at each step to be well-founded, i.e., for any field f in the program, every sequence u.f, u.f.f,... contains at least one head cell. We believe that our methodology captures the most common idiom of programming with linked data structures. We enforce our methodology by automatically instrumenting the program with updates to two auxiliary variables representing these predicates and adding assertions in terms of these auxiliary variables.To prove program properties and the instrumented assertions, we provide a first-order axiomatization of our two predicates. We also introduce a novel induction principle made possible by the well-foundedness of the heap. We use our induction principle to derive from two basic axioms a small set of additional first-order axioms that are useful for proving the correctness of several programs.We have implemented our method in a tool and used it to verify the correctness of a variety of nontrivial programs manipulating both acyclic and cyclic singly-linked lists and doubly-linked lists. We also demonstrate the use of indexed predicate abstraction to automatically synthesize loop invariants for these examples.
Beyond Convex? Global Optimization is Feasible Only for Convex Objective Functions: A Theorem
Authors: Vladik Kreinovich, R. Baker Kearfott
Venue: Journal of Global Optimization (2005)

It is known that there are feasible algorithms for minimizing convex functions, and that for general functions, global minimization is a difficult (NP-hard) problem. It is reasonable to ask whether there exists a class of functions that is larger than the class of all convex functions for which we can still solve the corresponding minimization problems feasibly. In this paper, we prove, in essence, that no such more general class exists. In other words, we prove that global optimization is always feasible only for convex objective functions.
Printing processes and their potential for RFID printing
Authors: Anne Blayo, Bernard Pineaux
Venue: Proceedings of the 2005 joint conference on Smart objects and ambient intelligence: innovative context-aware services: usages and technologies (2005)

This paper explains the basics of a number of printing processes (offset lithography, gravure, flexography, ink jet, electrophotography and screen printing). Characteristics such as the process principles, the type of inks and substrates used, the resolution, but also the limitations of these processes (in terms of regularity, for instance) are tackled. Then, their potential for RFID printing is addressed.
PICHAFF2 — A Hierarchical Parallel SAT Solver
Authors: Tobias Schubert, Bernd Becker
Venue: Proceedings of the Fifth International Workshop on Microprocessor Test and Verification (2004)

We present a hierarchical distributed SAT procedure for Microchip PIC microcontrollers. The algorithm is an adaption of the state-of-the-art solver CHAFF optimised for the limited resources of the Microchip processors. The underlying hardware environment is a special multiprocessor system based on PC ISA slot cards, each of them holding up to 9 PIC microcontrollers. We propose a novel work stealing scheme, which is able to manage multiple of these multi-processor cards in parallel. Besides discussing technical aspects we also point out the efficiency of our approach by a set of experiments.
Linear approximations for factored markov decision processes
Authors: Relu-Eugen Patrascu
Venue:  (2005)

A Markov Decision Process (MDP) is a model employed to describe problems in which a decision must be made at each one of several stages, while receiving feedback from the environment. This type of model has been extensively studied in the operations research community and fundamental algorithms have been developed to solve associated problems. However, these algorithms are quite inefficient for very large problems, leading to a need for alternatives; since MDP problems are provably hard on compressed representations, one becomes content even with algorithms which may perform well at least on specific classes of problems. The class of problems we deal with in this thesis allows succinct representations for the MDP as a dynamic Bayes network, and for its solution as a weighted combination of basis functions. We develop novel algorithms for producing, improving, and calculating the error of approximate solutions for MDPs using a compressed representation. Specifically, we develop an efficient branch-and-bound algorithm for computing the Bellman error of the compact approximate solution regardless of its provenance. We introduce an efficient direct linear programming algorithm which, using incremental constraints generation, achieves run times significantly smaller than existing approximate algorithms without much loss of accuracy. We also show a novel direct linear programming algorithm which, instead of employing constraints generation, transforms the exponentially many constraints into a compact form more amenable for tractable solutions. In spite of its perceived importance, the efficient optimization of the Bellman error towards an approximate MDP solution has eluded current algorithms; to this end we propose a novel branch-and-bound approximate policy iteration algorithm which makes direct use of our branch-and-bound method for computing the Bellman error. We further investigate another procedure for obtaining an approximate solution based on the dual of the direct, approximate linear programming formulation for solving MDPs. To address both the loss of accuracy resulting from the direct, approximate linear program solution and the question of where basis functions come from we also develop a principled system able not only to produce the initial set of basis functions, but also able to augment it with new basis functions automatically generated such that the approximation error decreases according to the user's requirements and time limitations.
Image morphological processing
Authors: Frank Y. Shih
Venue:  (2003)

Mathematical Morphology with applications in image processing and analysis has been becoming increasingly important in today's technology. Mathematical Morphological operations, which are based on set theory, can extract object features by suitably shaped structuring elements. Mathematical Morphological filters are combinations of morphological operations that transform an image into a quantitative description of its geometrical structure based on structuring elements. Important applications of morphological operations are shape description, shape recognition, nonlinear filtering, industrial parts inspection, and medical image processing. In this dissertation, basic morphological operations, properties and fuzzy morphology are reviewed. Existing techniques for solving corner and edge detection are presented. A new approach to solve corner detection using regulated mathematical morphology is presented and is shown that it is more efficient in binary images than the existing mathematical morphology based asymmetric closing for corner detection. A new class of morphological operations called sweep mathematical morphological operations is developed. The theoretical framework for representation, computation and analysis of sweep morphology is presented. The basic sweep morphological operations, sweep dilation and sweep erosion, are defined and their properties are studied. It is shown that considering only the boundaries and performing operations on the boundaries can substantially reduce the computation. Various applications of this new class of morphological operations are discussed, including the blending of swept surfaces with deformations, image enhancement, edge linking and shortest path planning for rotating objects. Sweep mathematical morphology is an efficient tool for geometric modeling and representation. The sweep dilation/erosion provides a natural representation of sweep motion in the manufacturing processes. A set of grammatical rules that govern the generation of objects belonging to the same group are defined. Earley's parser serves in the screening process to determine whether a pattern is a part of the language. Finally, summary and future research of this dissertation are provided.
Closed-form dual perturb and combine for tree-based models
Authors: Pierre Geurts, Louis Wehenkel
Venue: Proceedings of the 22nd international conference on Machine learning (2005)

This paper studies the aggregation of predictions made by tree-based models for several perturbed versions of the attribute vector of a test case. A closed-form approximation of this scheme combined with cross-validation to tune the level of perturbation is proposed. This yields soft-tree models in a parameter free way. and preserves their interpretability. Empirical evaluations, on classification and regression problems, show that accuracy and bias/variance tradeoff are improved significantly at the price of an acceptable computational overhead. The method is further compared and combined with tree bagging.
Theoretical investigation and experimental verification of the nonanalytic form of the conversion equations in a frequency divider by two: Research Articles
Authors: Franco Di Paolo, Giorgio Leuzzi, Dominique Schreurs, Antonio Serino
Venue: International Journal of RF and Microwave Computer-Aided Engineering (2006)

The conversion matrix, usually represented in a conventional complex-number form, assumes a nonanalytic, real-imaginary form when the frequency of the small signal fs is equal to one-half the local oscillator (LO) frequency f0. This is due to interference phenomena between the input small signal at fs = f0&#x002F;2 and the converted signal again at f0 - fs = fs = f0&#x002F;2; the interference is dependent on the phase relation between the input small signal and the LO. The conversion matrix with fs = f0&#x002F;2 is used in the design of frequency dividers by two. The conversion equations have been rewritten for the case of fs = f0&#x002F;2, and the conversion matrix has been found to assume a real-imaginary form. Consequently, Barkhausen's criterion has been reassessed for this case. Experiments are performed that confirm this formalism, and computer simulations based on a nonlinear model for the nonlinear device are presented, showing similar results. &copy; 2005 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2006.
Temps Perdu: where does it go?
Authors: Frederick John Bethke
Venue: ACM SIGDOC Asterisk Journal of Computer Documentation (1976)

No, Temps Perdu is not the meteorologist brother of Frank, the tender chicken man. It is a French swan's way of saying "lost time."
Tradeoffs between reliability and conciseness of deterministic finite automata
Authors: Martin Kappes, Chandra M. R. Kintala
Venue: Journal of Automata, Languages and Combinatorics (2004)

In this paper, we propose a model for measuring the reliability of the description of a language L by a deterministic finite automaton M. Intuitively, the reliability M exhibits when used for L is high if the 'difference' between L and the language T(M) accepted by M is small. Using this model, we prove that the savings in the number of states between a fully reliable and a less reliable representation cannot be bounded by any function, even if the unreliable descriptions are required to exceed any given fixed level of reliability. Furthermore, we show that, for a single regular language, there is a level of reliability such that any description exceeding this level is at least as big as the smallest DFA for the language.
Fast Convolutional OCR with the Scanning N-Tuple Grid
Authors: Simon M. Lucas, Kyu Tae Cho
Venue: Proceedings of the Eighth International Conference on Document Analysis and Recognition (2005)

This paper introduces a novel high speed convolutional character recognition system. Convolutional mode operation means that no prior localization or segmentation of characters is required, making this mode extremely robust. The method uses a 2-d n-tuple grid to sample the image, but decomposes the address calculations into two onedimensional scans. This simple innovation leads to a very fast system, and speeds in excess of 100,000 recognitions per second have been achieved for a 10-class character recognition problem, when operated in convolutional mode. Quantitative performance results show an error rate of 4.3% on the MNist dataset of isolated hand-written characters. Qualitative results are presented on museum archive card images, indicating that the method has great potential for the character recognition component in a document image analysis system for images of this type.
A second-order method for three-dimensional particle simulation
Authors: Z. Zhang, A. Prosperetti
Venue: Journal of Computational Physics (2005)

This paper describes a numerical method for the direct numerical simulation of Navier-Stokes flows with one or more solid spheres. The particles may be fixed or mobile, and they may have different radii. The basic idea of the method stems from the observation that, due to the no-slip condition, in the reference frame of each particle, the velocity near the particle boundary is very small so that the Stokes equations constitute an excellent approximation to the full Navier-Stokes problem. The general analytic solution of the Stokes equations can then be used to ''transfer'' the no-slip condition from the particle surface to the adjacent grid nodes. In this way the geometric complexity arising from the irregular relation between the particle boundary and the underlying mesh is avoided and fast solvers can be used. The method is validated by a detailed comparison with spectral solutions for the flow past a sphere at Reynolds numbers of 50 and 100. The existence in these situations of a Stokes region near the particle is explicitly demonstrated. Other numerical experiments to show the performance of the code are also described. To illustrate the power and efficiency of the method, a simulation of decaying homogeneous turbulence in a cell containing 100 moveable spheres is described. As implemented here, the method can only be applied to simple body shapes such as spheres and cylinders. Extensions to more general situations are mentioned in the last section.
Centralized and Distributed Topology Discovery Service Implementations
Authors: Luca Valcarenghi, Francesco Paolucci, Luca Foschini, Filippo Cugini, Piero Castoldi
Venue: Proceedings of the 13th Symposium on High Performance Interconnects (2005)

In global grid computing, i.e. Wide Area Network (WAN) grid computing, Grid network services allow grid users or the programming environment to monitor the status of network resources and to reallocate them. Specifically, the Network Information and Monitoring Service (NIMS) provides up to date information on the grid network status. In this study two implementations of a specific NIMS component, i.e. the topology discovery service (TDS), are presented. The first implementation features a centralized broker that produces information for the consumers/users. In the second one, users are contemporarily producers and consumers of the required information. Both implementations are applicable to networks based on commercial routers without requiring any router protocol modification.
Discrete Wavelet Transform and Support Vector Machine Applied to Pathological Voice Signals Identification
Authors: Everthon S. Fonseca, Rodrigo C. Guido, Andre C. Silvestre, Jose Carlos Pereira
Venue: Proceedings of the Seventh IEEE International Symposium on Multimedia (2005)

An algorithm able to classify pathological and normal voice signals based on Daubechies Discrete Wavelet Transform (DWT- db) and Support Vector Machines (SVM) classifier is presented. DWT- db is used for time-frequency analysis giving quantitative evaluation of signal characteristics to identify pathologies in voice signals, particularly nodules in vocal folds, of subjects with different ages for both male and female. After using a Linear Prediction Coefficients (LPC) filter, the signals mean square values of a particular scale from wavelet analysis are entries to a non-linear Least Square Support Vector Machine (LS-SVM) classifier, which leads to an adequate larynx pathology classifier which over 95% of classification accuracy.
Rotation and Translation Mechanisms for Tabletop Interaction
Authors: Mark S. Hancock, Sheelagh Carpendale, Frederic D. Vernier, Daniel Wigdor, Chia Shen
Venue: Proceedings of the First IEEE International Workshop on Horizontal Interactive Human-Computer Systems (2006)

A digital tabletop, such as the one shown in Figure 1, offers several advantages over other groupware form factors for collaborative applications. However, users of a tabletop system do not share a common perspective for the display of information: what is presented right-side-up to one participant is upsidedown for another. In this paper, we survey five different rotation and translation techniques for objects displayed on a direct-touch digital tabletop display. We analyze their suitability for interactive tabletops in light of their respective input and output degrees of freedom, as well as the precision and completeness provided by each. We describe various tradeoffs that arise when considering which, when and where each of these techniques might be most useful.
Trend surface and residual analysis: a method for analyzing social ecological data
Venue: ACM SIGSOC Bulletin (1976)

Trend surfaces are continuous graphical and analytical representations by which the spatial distribution of a social variable can be evaluated. Analytical expressions, concepts and computational techniques of developing trend surfaces, residuals and criteria for evaluating them are presented. Contour mapping is employed as an integral part of the presentation and methodology of the analysis. Of computer graphic displays, contouring is the only one that lends itself to the type of further mathematical modeling such as by trend surfaces. Trend surfaces and residuals are complementary constructs. In contrast to usage of the residual in sociology as the error term in the general linear model, residuals are treated as probable loci of anomalous but significant variation of the mapped variable. Qualitative and quantitative aspects of, and theoretical and practical limitations to selection of best-fitting surfaces and residuals are discussed. Distortion of mapping can be encountered by clustering of data points and boundary effects. Applications of trend surfaces and residuals to social variables appearing in the economic georgraphy literature are reported.Contour mappings of unfiltered data, a trend surface model and complementary residuals demonstrate aspects and principles of the techniques applied to population data for Nassau and Suffolk Counties, New York, 1960-1970. Besides arrays of relative highs, lows, regional and local gradients, dominant features, such as a plateau of 100 percent change in population which covers most of the western portion of Suffolk County and the barrier effect of the Suffolk County line on population settlement over the period, emerge from the mapped models. Application of trend surfaces and residuals to social, ecological data is suggested as one model of computer data reduction and analysis of large volumes of regional and census data.
Review of "Systems Simulation: The Art and Science, by Robert E. Shannon", Prentice-Hall, 1975
Venue: ACM SIGSIM Simulation Digest (1976)

By far one of the most exciting and interesting texts in this area to reach the college market, although it should be on the reading list of all engaged in simulation work. A non-language oriented textbook (one to which the reviewer is partial) is a logical approach to the subject of simulating systems. Starting with a brief chapter on the concepts of mdeling, the reader is lead through the techniques of systems investigation and translation of systems into appropriate models. 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
Ubiquitous Computing Technologies for Ubiquitous Learning
Authors: Ken Sakamura, Noboru Koshizuka
Venue: Proceedings of the IEEE International Workshop on Wireless and Mobile Technologies in Education (2005)

Ubiquitous computing is a new information and communication technology that utilize a large number of cooperative small nodes with computing and/or communication capabilities such as handheld terminals, smart mobile phones, sensor network nodes, contactless smart cards, RFIDs (Radio Frequency IDentification), and so on. This paper proposes the concept of ubiquitous learning that enables anyone to learn at anytime and anywhere by fully utilizing ubiquitous computing technologies. As the pilot system of the ubiquitous learning, this paper briefly introduces Digital Ubiquitous Museum that makes our daily living environments learning materials.