ppxscal/embedding_network huggingface dataset:
Region Tracking via Level Set PDEs without Motion Computation
Authors: Abdol-Reza Mansouri
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (2002)

Tracking regions in an image sequence is a challenging and difficult problem in image processing and computer vision and at the same time, one that has many important applications: automated video surveillance, video database search and retrieval, automated video editing, etc. So far, numerous approaches to region tracking have been proposed. Many of them suffer from excessive constraints imposed on the motion of the region being tracked and need an explicit motion model (e.g., affine, Euclidean). Some, which do not need a parametrized motion model, rely instead on a dense motion field. By and large, most rely on some kind or other of motion information. Those which do not use any motion information instead use a model of the region being tracked, typically by assuming strong intensity boundaries, or constraining the shape of the region to belong to a parametrized family of shapes. In this paper, we propose a novel approach to region tracking that is derived from a Bayesian formulation. The novelty of the approach is twofold: First, no motion field or motion parameters need to be computed. This removes a major burden since accurate motion computation has been and remains a challenging problem and the quality of region tracking algorithms based on motion critically depends on the computed motion fields and parameters. The second novelty of this approach, is that very little a priori information about the region being tracked is used in the algorithm. In particular, unlike numerous tracking algorithms, no assumption is made on the strength of the intensity edges of the boundary of the region being tracked, nor is its shape assumed to be of a certain parametric form. The problem of region tracking is formulated as a Bayesian estimation problem and the resulting tracking algorithm is expressed as a level set partial differential equation. We present further extensions to this partial differential equation, allowing the possibility of including additional information in the tracking process, such as priors on the region's intensity boundaries and we present the details of the numerical implementation. Very promising experimental results are provided using numerous real image sequences with natural object and camera motion.
On nesting of G-decompositions of &#x03BB;Kv where G has four nonisolated vertices or less
Authors: Salvatore Milici, Gaetano Quattrocchi
Venue: Discrete Mathematics (2002)

The complete multigraph λKυ is said to have a G-decomposition if it is the union of edge disjoint subgraphs of Kυ each of them isomorphic to a fixed graph G. The spectrum problem for G-decompositions of λKυ that have a nesting was first considered in the case G = K3 by Colbourn and Colbourn (Ars Combin. 16 (1983) 27-34) and Stinson (Graphs and Combin. 1 (1985) 189 -191). For λ = 1 and G = Cm (the cycle of length m) this problem was studied in many papers, see Lindner and Rodger (in: J.H. Dinitz, D.R. Stinson (Eds.), Contemporary Design Theory: A Collection of Surveys, Wiley, New York, 1992, p. 325-369), Lindner et al. (Discrete Math. 77 (1989) 191-203), Lindner and Stinson (J. Combin. Math. Combin. Comput. 8 (1990) 147-157) for more details and references. For λ = 1 and G = Pk (the path of length k - 1) the analogous problem was considered in Milici and Quattrocchi (J. Combin. Math. Combin. Comput. 32 (2000) 115-127). In this paper we solve the spectrum problem of nested G-decompositions of λKυ for all the graphs G having four nonisolated vertices or less, leaving eight possible exceptions.
On the Complexity of Optimal Bused Interconnections
Authors: Ahmed El-Amawy, Priyalal Kulasinghe
Venue: IEEE Transactions on Computers (1995)

This paper addresses the combinatorial problem of constructing a minimal cost, bused, interconnection among a set of modules (or processors). Although some work has been reported on bused interconnection between modules, the compuational complexity of the problem has not been previously addressed. We show that the optimization problem of finding a minimal cost interconnection among modules to realize a certain set of data transfers is NP-Hard.
Rational Approximations of Transfer Functions of Some Viscoelastic Rods with Applications to Robust Control
Authors: K. B. Hannsgen, O. J. Staffans, R. L. Wheeler
Venue: Journal of Dynamical and Control Systems (1999)

We study rational approximations of the transfer function \widehat {P} of a uniform or nonuniform viscoelastic rod undergoing torsional vibrations that are excited and measured at the same end. The approximation is to be carried out in a way that is appropriate, with respect to stability and performance, for the construction of suboptimal rational stabilizing compensators for the rod. The function \widehat {P} can be expressed as {\widehat P}(s)=s^{-2}g(\beta^2(s)), where g is an infinite product of fractional linear transformations and &beta; is a (generally transcendental) function that characterizes a particular viscoelastic material. First, g(&beta;2) is approximated by its partial products gN(&beta;2). For relevant values of &beta;2, convergence rates for gN are analyzed in detail. Convergence suitable for our problem requires the introduction of a new irrational convergence factor, which must be approximated separately. In addition, the fractional linear factors in &beta;2(s) that appear in gN(&beta;2(s)) must be replaced by something rational. When the damping is weak it is possible to do this by separating the oscillatory modes from the &ldquo;creep&rdquo; modes and ignoring the latter&semi; in general, this step remains incomplete. Some numerical data illustrating all the stages of the process as well as the final results for various viscoelastic constitutive relations are presented.
Spatial learning: cognitive mapping in abstract virtual environments
Authors: Cathryn Johns
Venue: Proceedings of the 2nd international conference on Computer graphics, virtual Reality, visualisation and interaction in Africa (2003)

This paper presents the novel idea of using the cognitive mapping process to teach relationships between data items, called the spatial learning method. To investigate the feasibility of the method, a VE based on a data set was created. Three studies using this VE were run concurrently on a single set of 40 participants. The findings showed that while most participants formed a cognitive map of the VE, the learning of the underlying data set varied greatly between participants and that participants who attended the conventional lecture performed significantly better at the learning test than participants who were taught via the spatial learning method.
Scalability Analysis of Declustering Methods for Multidimensional Range Queries
Authors: Bongki Moon, Joel H. Saltz
Venue: IEEE Transactions on Knowledge and Data Engineering (1998)

Efficient storage and retrieval of multiattribute data sets has become one of the essential requirements for many data-intensive applications. The Cartesian product file has been known as an effective multiattribute file structure for partial-match and best-match queries. Several heuristic methods have been developed to decluster Cartesian product files across multiple disks to obtain high performance for disk accesses. Although the scalability of the declustering methods becomes increasingly important for systems equipped with a large number of disks, no analytic studies have been done so far. In this paper, we derive formulas describing the scalability of two popular declustering methods¿Disk Modulo and Fieldwise Xor¿for range queries, which are the most common type of queries. These formulas disclose the limited scalability of the declustering methods, and this is corroborated by extensive simulation experiments. From the practical point of view, the formulas given in this paper provide a simple measure that can be used to predict the response time of a given range query and to guide the selection of a declustering method under various conditions.
Edge-Disjoint Spanning Trees on the Star Network with Applications to Fault Tolerance
Authors: Paraskevi Fragopoulou, Selim G. Akl
Venue: IEEE Transactions on Computers (1996)

Data communication and fault tolerance are important issues in parallel computers in which the processors are interconnected according to a specific topology. One way to achieve fault tolerant interprocessor communication is by exploiting and effectively utilizing the disjoint paths that exist between pairs of source and destination nodes. In this paper, we construct n - 1 directed edge-disjoint spanning trees, on the star network. These spanning trees are used to derive a near optimal single-node broadcasting algorithm, and fault tolerant algorithms for the single-node and multinode broadcasting, and for the single-node and multinode scattering problems. Broadcasting is the distribution of the same group of messages from one processor to all the other processors. Scattering is the distribution of distinct groups of messages from one processor to all the other processors. We consider broadcasting and scattering from a single processor of the network and simultaneously from all processors of the network. The single-node broadcasting algorithm offers a speed up of n - 1 for a large number of messages, over the straightforward algorithm that uses a single shortest path spanning tree. Fault tolerance is achieved by transmitting the same messages through a number of edge-disjoint spanning trees. The fault tolerant algorithms operate successfully in the presence of up to n - 2 faulty nodes or edges in the network. The degree of fault tolerance can be adjusted depending on the network reliability. The importance of this method lies in the fact that no prior knowledge of the faulty nodes or edges is required. All of the algorithms operate under the store-and-forward, all-port communication model.
Asymptotic shape of the Erlang capacity region of a multi-service shared resource
Authors: John A. Morrison, Debasis Mitra
Venue: Performance Evaluation (2002)

We consider a loss model of an unbuffered resource having C channels, which are shared by several different types of service connections. Connections of each type arrive in a Poisson stream and request a number of channels, which depends on the type. An arriving connection is blocked and lost if there are not enough free channels. Otherwise, the channels are held for the duration of the connection, and the holding period is generally distributed. It is assumed that C and the traffic intensities are proportionately large. The admission control problem is considered for specified upper bounds on the blocking probabilities, and the boundary of the admissible set is investigated asymptotically. Characterization of admissible sets is extremely useful, not only for connection-level admission control, which is the context in which this topic has typically been considered in the past, but also for higher level objectives, such as network economics, network design, and network control. The asymptotic view of the admissible set is particularly appropriate for the higher level objectives, where the fine details are not as important as the qualitative properties of the shape of the set and tractability of the numerical calculations for large systems. Our results are derived by investigating the local behavior with respect to the tangent hyperplane at a point on the boundary of the admissible set. The lowest order results that hold in the asymptotic limit C → ∞ are given first. Importantly, the boundary is linear for the key critically loaded and also for the overloaded regimes, and weakly convex for the underloaded regime. Next, refined results that hold for C ≥ 1 are given, which indicate that the boundary is not convex, although only slightly so.
Resizing Rules for MOS Analog-Design Reuse
Authors: Carlos Galup-Montoro, Márcio Cherem Schneider, Rafael Matos Coitinho
Venue: IEEE Design Test (2002)

The migration of an analog circuit to a new technology usually requires a complete redesign. With the procedure presented here, designers can calculate parameters for a given circuit in a new technology, starting from the same design in an earlier technology. The procedure's simple resizing rules have been verified with standard MOSFET simulation models.
Assisted navigation for large information spaces
Authors: Brent M. Dennis, Christopher G. Healey
Venue: Proceedings of the conference on Visualization '02 (2002)

This paper presents a new technique for visualizing large, complex collections of data. The size and dimensionality of these datasets make them challenging to display in an effective manner. The images must show the global structure of spatial relationships within the dataset, yet at the same time accurately represent the local detail of each data element being visualized. We propose combining ideas from information and scientific visualization together with a navigation assistant, a software system designed to help users identify and explore areas of interest within their data. The assistant locates data elements of potential importance to the user, clusters them into spatial regions, and builds underlying graph structures to connect the regions and the elements they contain. Graph traversal algorithms, constraint-based viewpoint construction, and intelligent camera planning techniques can then be used to design animated tours of these regions. In this way, the navigation assistant can help users to explore any of the areas of interest within their data. We conclude by demonstrating how our assistant is being used to visualize a multidimensional weather dataset.
BioSig: An Imaging Bioinformatic System for Studying Phenomic
Authors: Bahram Parvin, Qing Yang, Gerald Fontenay, Mary Helen Barcellos-Hoff
Venue: Computer (2002)

Using genomic information to understand complex organisms requires comprehensive knowledgeof the dynamics of phenotype generation and maintenance. A phenotype results from selective expression of the genome, creating a history of the cell and its response to the extracellular environment. Defining cell phenomes requires tracking the kinetics and quantities ofmultiple constituent proteins, their cellular context, and their morphologicalfeatures in large populations.The BioSig imaging bioinformatic system for characterizing phenomicsanswers these challenges. The BioSig approach to microscopy and quantitative image analysis helps to build a more detailed picture of the signaling that occurs between cells as a response toexogenous stimulus such as radiation or as a consequence of endogenous programs leading to biological functions. The system provides a data model for capturing experimental annotations and variables, computational techniques for summarizing large numbers of images, and a distributedarchitecture that facilitates distant collaboration.
Object-Oriented Program Tracing and Visualization
Authors: Danny B. Lange, Yuichi Nakamura
Venue: Computer (1997)

Object orientation has changed software development for the better, but it has not really made programs easier to understand. Object-oriented program analysis tools remain rare because OO concepts such as inheritance and polymorphism render conventional analysis and presentation techniques insufficient. The authors describe a way to obtain, manipulate, and visualize OO execution traces that provides fine-grained localization information for program understanding. Applying dynamic analysis along with interactive visualization makes it possible to determine the exact program paths that influence particular objects and facilitates recognition of execution patterns. Because an object can invoke methods in itself and in other objects, an interaction graph becomes an important tool for modeling object interaction. However, even small toy programs may produce so many invocations that the interaction graph becomes unmanageable. The solution is to use search-space-reducing techniques such as merging, pruning, and slicing to remove unwanted information from the interaction graph, thereby limiting its complexity and size. The research prototype Program Explorer takes a user through a series of executions and visualizations to explain a given program and its framework. Although it was originally designed for C++, a version developed for IBM's System Object Model demonstrated that the concepts are applicable to OO languages in general. The authors believe Program Explorer can be applied to a wide range of software engineering problems, such as framework understanding to improve reuse, application logic analysis for maintenance, and visual debugging of OO code.
A hierarchy of communication models for message sequence charts
Authors: A. G. Engels, S. Mauw, M. A. Reniers
Venue: Science of Computer Programming (2002)

In a Message Sequence Chart (MSC) the dynamical behaviour of a number of cooperating entities is depicted. An MSC defines a partial order on the communication events between these entities. This order determines the physical architecture needed for implementing the specified behaviour, such as a FIFO buffer between each of the entities. In a systematic way, we define 50 communication models for MSC and we define what it means for an MSC to be implementable by such a model Some of these models turn out to be equivalent, in the sense that they implement the same class of MSCs. After analysing the notion of implementability, only ten classes remain, for which we develop a hierarchy. We also develop algorithms to check whether a given MSC belongs to such a class.
Testing for Interconnect Crosstalk Defects Using On-Chip Embedded Processor Cores
Authors: Li Chen, Xiaoliang Bai, Sujit Dey
Venue: Journal of Electronic Testing: Theory and Applications (2002)

In deep-submicron technologies, long interconnects play an ever-important role in determining the performance and reliability of core-based system-on-chips (SoCs). Crosstalk effects degrade the integrity of signals traveling on long interconnects and must be addressed during manufacturing testing. External testing for crosstalk is expensive due to the need for high-speed testers. Built-in self-test, while eliminating the need for a high-speed tester, may lead to excessive test overhead as well as overly aggressive testing. To address this problem, we propose a new software-based self-test methodology for system-on-chips (SoC) based on embedded processors. It enables an on-chip embedded processor core to test for crosstalk in system-level interconnects by executing a self-test program in the normal operational mode of the SoC, thereby allowing at-speed testing of interconnect crosstalk defects, while eliminating the need for test overhead and the possibility of over-testing. We have demonstrated the feasibility of this method by applying it to test the interconnects of a processor-memory system. The defect coverage was evaluated using a system-level crosstalk defect simulation method.
A Discussion on Test Pattern Generation for FPGA&mdash;Implemented Circuits
Authors: M. Renovell, J. M. Portal, P. Faure, J. Figueras, Y. Zorian
Venue: Journal of Electronic Testing: Theory and Applications (2001)

The objective of this paper is to generate a Application-Oriented Test Procedure to be used by a FPGA user in a given application. General definitions concerning the specific problem of testing RAM-based FPGAs are first given such as the important concept of &lsquo;AC-non-redundant fault.&rsquo; Using a set of circuits implemented on a XILINX 4000E, it is shown that a classical test pattern generation performed on the circuit netlist gives a low AC-non-redundant fault coverage and it is pointed out that test pattern generation performed on a FPGA representation is required. It is then demonstrated that test pattern generation performed on the FPGA representation can be significantly accelerated by removing most of the AC-redundant faults. Finally, a technique is proposed to even more accelerate the test pattern generation process by using a reduced FPGA description.
Rotation and Gray Scale Transform Invariant Texture Identification using Wavelet Decomposition and Hidden Markov Model
Authors: J. L. Chen, A. Kundu
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (1994)

In this correspondence, we have presented a rotation and gray scale transform invariant texture recognition scheme using the combination of quadrature mirror filter (QMF) bank and hidden Markov model (HMM). In the first stage, the QMF bank is used as the wavelet transform to decompose the texture image into subbands. The gray scale transform invariant features derived from the statistics based on first-order distribution of gray levels are then extracted from each subband image. In the second stage, the sequence of subbands is modeled as a hidden Markov model (HMM), and one HMM is designed for each class of textures. The HMM is used to exploit the dependence among these subbands, and is able to capture the trend of changes caused by rotation. During recognition, the unknown texture is matched against all the models. The best matched model identifies the texture class. Up to 93.33% classification accuracy is reported.
Generalized Version Space Learning Algorithm for Noisy and Uncertain Data
Authors: Tzung-Pei Hong, Shian-Shyong Tseng
Venue: IEEE Transactions on Knowledge and Data Engineering (1997)

This paper generalizes the learning strategy of version space to manage noisy and uncertain training data. A new learning algorithm is proposed that consists of two main phases: searching and pruning. The searching phase generates and collects possible candidates into a large set; the pruning phase then prunes this set according to various criteria to find a maximally consistent version space. When the training instances cannot completely be classified, the proposed learning algorithm can make a trade-off between including positive training instances and excluding negative ones according to the requirements of different application domains. Furthermore, suitable pruning parameters are chosen according to a given time limit, so the algorithm can also make a trade-off between time complexity and accuracy. The proposed learning algorithm is then a flexible and efficient induction method that makes the version space learning strategy more practical.
On cubic Cayley graphs of finite simple groups
Authors: Xin Gui Fang, Cai Heng Li, Jie Wang, Ming Yao Xu
Venue: Discrete Mathematics (2002)

For a finite group G, a Cayley graph Cay(G,S) is said to be normal if the group GR of right translations on G is a normal subgroup of the full automorphism group of Cay(G,S). In this paper, we prove that, for most finite simple groups G, connected cubic Cayley graphs of G are all normal. Then we apply this result to study a problem related to isomorphisms of Cayley graphs, and a problem regarding graphical regular representations of finite simple groups. The proof of the main result depends on the classification of finite simple groups.
Reinforcement Learning Rules in a Repeated Game
Authors: Ann Maria Bell
Venue: Computational Economics (2001)

This paper examines the performance of simple reinforcement learning algorithms in a stationary environment and in a repeated game where the environment evolves endogenously based on the actions of other agents. Some types of reinforcement learning rules can be extremely sensitive to small changes in the initial conditions, consequently, events early in a simulation can affect the performance of the rule over a relatively long time horizon. However, when multiple adaptive agents interact, algorithms that performed poorly in a stationary environment often converge rapidly to a stable aggregate behaviors despite the slow and erratic behavior of individual learners. Algorithms that are robust in stationary environments can exhibit slow convergence in an evolving environment.