ppxscal/embedding_network huggingface dataset:
Constrained EM estimates for harmonic source separation
Authors: P. Jinachitra
Venue: Proceedings of the 2003 International Conference on Multimedia and Expo - Volume 1 (2003)

A constrained iterative method for harmonic source parameter estimation is proposed based on an EM algorithm with intent for harmonic source separation. The problem of coinciding partials and interference among them in general is mitigated by the constraints on the "weak" partials on the stronger ones of the same harmonic source. A useful scheme to determine the weakness of a partial is proposed. The constrained iteration is shown to give more accurate estimates of the sinusoidal parameters, which results in good source separation even in most cases of highly overlapping spectra. 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
Energy aware multiple clock domain scheduling for a bit-serial, self-timed architecture
Authors: Heiner Giefers, Achim Rettberg
Venue: Proceedings of the 19th annual symposium on Integrated circuits and systems design (2006)

In this paper, we present an approach for low--power driven synthesis based on local frequency/voltage scaling. During the scheduling phase of the High--Level Synthesis (HLS) the design is partitioned into different frequency/voltage islands. Operators within these islands, are encapsulated by wrappers to ensure correct dataflow between the islands. A wrapper consists of a clock generator and input- and output ports. The local clocks are calculated by dividing the global clock signal. With the developed wrappers we are able to automatically integrate local frequency/voltage scaling for our target architecture by our HLS tool. As an example we implement the inverse discrete cosine transformation (IDCT).
Recognition and Modeling of RNA Pseudoknots Using Context-Sensitive Pattern Matching
Authors: Keum-Young Sung
Venue: Proceedings of the 2006 International Conference on Hybrid Information Technology - Volume 01 (2006)

In this study, a context-sensitive pattern matching is suggested to recognize and model various forms of RNA secondary structures, especially pseudoknots. Comparing with a conventional context-free grammar used to model secondary structures of RNA sequences, the use of contextsensitive searching of a particular pseudoknot gives us an advantage of more natural representation of RNA structures. The suggested technique directly reflects the appearance characteristic of each form of RNA secondary structure, i.e., hairpins, internal loops, double helixes, and bulge loops. Java language are used in this study to provide the user-interface, and also to implement the suggested context-sensitive searching of a specific pseudoknot.
Clustering Approach to Content Based Image Retrieval
Authors: P J. Dutta, D K. Bhattacharyya, J K. Kalita, M Dutta
Venue: Proceedings of the conference on Geometric Modeling and Imaging: New Trends (2006)

This paper presents an efficient spatial indexing technique based on Silhouette moments that makes the index robust subject to the three basic transformations for CBIR. Spatial index is generated based upon a fast and robust clustering technique, which can recognize color clusters of any shape. The new clustering technique has been found to be efficient in terms of time complexity and cluster quality than many of its counterparts. A matching engine has been devised to retrieve images from the image database, which has the capacity for global and regional similarity search.
Multi-agent stochastic control: models inspired from quantum physics
Authors: J. S. Baras
Venue: Proceedings of the 2003 International Conference on Physics and Control - Volume 3 (2003)

In this paper, we consider multi-agent stochastic optimization and control problems, with partial information. The agent can operate in a distributed and asynchronous fashion. We investigate new problems that arise out of the interaction between observations and control actions by the agent. We show that new non-classical and non-commutative probability models are needed in order to properly formulate such problems. The models we develop here are inspired by models developed for dynamical physics problems. We establish a series of fundamental results for the trade-off between information and control patterns in distributed stochastic control, detection and estimation.
Cognitive Engineering for Long Duration Missions: Human-Machine Collaboration on the Moon and Mars
Authors: M. A. Neerincx, J. Lindenberg, N. Smets, T. Grant, A. Bos, A. Olmedo-Soler, U. Brauer, M. Wolff
Venue: Proceedings of the 2nd IEEE International Conference on Space Mission Challenges for Information Technology (2006)

For manned long-duration missions to the Moon and Mars, there is a need for a Mission Execution Crew Assistant (MECA) that empowers the cognitive capacities of human-machine teams during planetary exploration missions in order to cope autonomously with unexpected, complex and potentially hazardous situations. MECA requirements are being derived via a cognitive engineering method, which addresses operational, human factors and technological aspects with their mutual dependencies. This method follows an iterative process of specification, evaluation and refinement to establish a sound--theoretical and empirical founded--set of requirements. It distinguishes three types of iterations: system-design review, scientific discourse and simulation-based evaluation. The first two iterations provided a set of requirements for distributed human-machine collaboration on the Moon or Mars.
Fully Distributed Three-Tier Active Software Replication
Authors: Carlo Marchetti, Roberto Baldoni, Sara Tucci-Piergiovanni, Antonino Virgillito
Venue: IEEE Transactions on Parallel and Distributed Systems (2006)

Keeping strongly consistent the state of the replicas of a software service deployed across a distributed system prone to crashes and with highly unstable message transfer delays (e.g., the Internet), is a real practical challenge. The solution to this problem is subject to the FLP impossibility result, and thus there is a need for "long enough” periods of synchrony with time bounds on process speeds and message transfer delays to ensure deterministic termination of any run of agreement protocols executed by replicas. This behavior can be abstracted by a partially synchronous computational model. In this setting, before reaching a period of synchrony, the underlying network can arbitrarily delay messages and these delays can be perceived as false failures by some timeout-based failure detection mechanism leading to unexpected service unavailability. This paper proposes a fully distributed solution for active software replication based on a three-tier software architecture well-suited to such a difficult setting. The formal correctness of the solution is proved by assuming the middle-tier runs in a partially synchronous distributed system. This architecture separates the ordering of the requests coming from clients, executed by the middle-tier, from their actual execution, done by replicas, i.e., the end-tier. In this way, clients can show up in any part of the distributed system and replica placement is simplified, since only the middle-tier has to be deployed on a well-behaving part of the distributed system that frequently respects synchrony bounds. This deployment permits a rapid timeout tuning reducing thus unexpected service unavailability.
Floating Point or LNS: Choosing the Right Arithmetic on an Aapplication Basis
Authors: Sylvain Collange, Jeremie Detrey, Florent de Dinechin
Venue: Proceedings of the 9th EUROMICRO Conference on Digital System Design (2006)

For applications requiring a large dynamic range, real numbers may be represented either in floating-point (FP), or in the logarithm number system (LNS). Which system is best for a given application is difficult to know in advance, because the cost and performance of LNS operators depend on the target accuracy in a highly non linear way. In doubt, designers will choose floating-point. This article demonstrates a methodology for a better informed choice thanks to FPLibrary, a freely available, dual FP/LNS arithmetic operator library. FPLibrary may be used in the prototype phase of an application to obtain, with low design effort, accurate measures of performance, cost and accuracy of both LNS and FP approaches. Two case studies demonstrate the benefits of this methodology.
Resolve-Impossibility for a Contract-Signing Protocol
Authors: Aybek Mukhamedov, Mark D. Ryan
Venue: Proceedings of the 19th IEEE workshop on Computer Security Foundations (2006)

A multi-party contract signing protocol allows a set of participants to exchange messages with each other with a view to arriving in a state in which each of them has a preagreed contract text signed by all the others. Such a protocol was introduced by Garay and MacKenzie in 1999; it consists of a main protocol and a sub-protocol involving a trusted party. Their protocol was shown to have a flaw by Chadha, Kremer and Scedrov in CSFW 2004. Those authors also presented a fix -a revised sub-protocol for the trusted party. In our work, we show an attack on the revised protocol for any number n gt 4 of signers. Furthermore, we generalise our attack to show that the message exchange structure of Garay and MacKenzie's main protocol is flawed: whatever the trusted party does will result in unfairness for some signer. This means that it is impossible to define a trusted party protocol for Garay and MacKenzie's main protocol; we call this "resolve-impossibility".
Pseudo-distributive laws and axiomatics for variable binding
Authors: Miki Tanaka, John Power
Venue: Higher-Order and Symbolic Computation (2006)

We give a general category theoretic formulation of the substitution structure underlying the category theoretic study of variable binding proposed by Fiore, Plotkin, and Turi. This general formulation provides the foundation for their work on variable binding, as well as Tanaka's linear variable binding and variable binding for other binders and for mixtures of binders as for instance in the Logic of Bunched Implications. The key structure developed by Fiore et al. was a substitution monoidal structure, from which their formulation of binding was derived; so we give an abstract formulation of a substitution monoidal structure, then, at that level of generality, derive the various category theoretic structures they considered. The central construction we use is that of a pseudo-distributive law between 2-monads on Cat, which suffices to induce a pseudo-monad on Cat, and hence a substitution monoidal structure on the free object on 1. We routinely generalise that construction to account for types.
Market Mechanism Designs with Heterogeneous Trading Agents
Authors: Zengchang Qin
Venue: Proceedings of the 5th International Conference on Machine Learning and Applications (2006)

Market mechanism design research is playing an important role in Computational Economics for resolving multi-agent allocation problems. A genetic algorithm was used to design auction mechanisms in order to automatically generate a desired market mechanism in agent based E-markets. In previous research, a hybrid market was studied, in which the probability that buyers rather than sellers are able to quote on a given time step, this probability was adapted by the GA which attempted to minimise Smith's coefficient of convergence. However, in previous experiments, all trading agents involved are of the same type or have identical preferences. This assumption does not hold in real-world markets which are always populated with heterogeneous agents. In this paper, the research of using evolutionary computing methods for auction designs is extended by using heterogeneous trading agents.
Portfolio credit risk analysis involving CDO tranches
Authors: Menghui Cao, William J. Morokoff
Venue: Proceedings of the 36th conference on Winter simulation (2004)

Credit risk analysis for portfolios containing CDO tranches is a challenging task for risk managers. We propose here a basis function approach for CDO tranche valuation and portfolio risk analysis at horizon, based on a multi-step Monte Carlo simulation model. The idea is to approximate the expected value of the tranche at horizon by a linear combination of basis functions, which are chosen to best characterize the current state of the associated CDO. It can be generalized for portfolio risk analysis involving any complex financial instruments.
Nodal and matrix analyses of communication patterns in small groups
Authors: Donald W. Wortham
Venue: Proceedings of the 1999 conference on Computer support for collaborative learning (1999)

This paper describes an analytic framework based on the methods of social network analysis pioneered by Nieminen (1974) and Freeman (1978/79) and used by structural anthropologists (e.g., Hage and Harary, 1996). It extends the methodology for use in evaluating computer-mediated communication in small groups and analyzes a sample dataset drawn from synchronous chat room interaction of five adults involved in a process of decision-making. The paper concludes with a discussion of possible applications of social network analysis to computer-supported learning, and limitations.
Faster algorithms for finding missing patterns
Authors: Shuai Cheng Li
Venue: Proceedings of the 12th Computing: The Australasian Theroy Symposium - Volume 51 (2006)

The missing pattern pair problem, introduced in (Inenaga, Kivioja & Mäakinen 2004), was motivated by the need for optimization in Polymerase Chain Reaction, a technique commonly used in bioinformatics. The problem is to find a pair of patterns of the shortest total length within a string of length n, where the two patterns do not occur within a distance α anywhere in the string. Inenaga et al. (Inenaga et al. 2004) gave an algorithm with time complexity O(min{αn log n, n2}) to solve this problem. In this paper we propose an algorithm of time complexity O(min{αn log n, n3/2}), improving on the quadratic bound part of the earlier algorithm. We also design a simple algorithm of time complexity O(n2/α log2 n), which is O(n log2 n) if α = Θ(n).
What's the deal with dependent types?
Authors: Conor McBride
Venue: Proceedings of the 2007 ACM SIGPLAN international workshop on Types in languages design and implementation (2007)

In this talk, I identify key ways in which dependently typed programming confounds our common expectations, and then transcends them. I expose language design issues where dependent types require a new deal. I hope to persuade you that this is not a big deal, and that it is a good deal. I discuss the impact of these issues on Epigram [3], the language designed by myself and James McKinna, and still evolving with help from Thorsten Altenkirch [1] and our colleagues in Nottingham and St Andrews.
Accurate Minkowski sum approximation of polyhedral models
Authors: Gokul Varadhan, Dinesh Manocha
Venue: Graphical Models (2006)

We present an algorithm to approximate the 3D Minkowski sum of polyhedral objects. Our algorithm decomposes the polyhedral objects into convex pieces, generates pairwise convex Minkowski sums, and computes their union. We approximate the union by generating a voxel grid, computing signed distance on the grid points, and performing isosurface extraction from the distance field. The accuracy of the algorithm is mainly governed by the resolution of the underlying volumetric grid. Insufficient resolution can result in unwanted handles or disconnected components in the approximation. We use an adaptive subdivision algorithm that overcomes these problems by generating a volumetric grid at an appropriate resolution. We guarantee that our approximation has the same topology as the exact Minkowski sum. We also provide a two-sided Hausdorff distance bound on the approximation. Our algorithm is relatively simple to implement and works well on complex models. We have used it for exact 3D translation motion planning, offset computation, mathematical morphological operations, and bounded-error penetration depth estimation.
A study of Nash equilibrium in contribution games for peer-to-peer networks
Authors: Jacomo Corbo, Antoni Calvó-Armengol, David Parkes
Venue: ACM SIGOPS Operating Systems Review (2006)

We consider a stylized model of content contribution in a peer-to-peer network. The model is appealing because it allows for linear-quadratic payoff functions and for very general interaction patterns among agents. Furthermore, when the model has a unique Nash equilibrium (NE) we find that it is defined by a network centrality measure (Bonacich 1987), with L1 and L2 norms of the Bonacich index vector providing aggregate contribution and social welfare. Furthermore, we find that NE are always (even when they are non-unique) computable by solving a linear complementarity problem. We study the network designer's problem of engineering the most efficient equilibrium outcome, proving that maximizing aggregate contribution can be reconciled with maximizing aggregate welfare. We also provide a partial characterization of optimal NE graphs and suggest different approaches for how a network designer can promote more efficient graph structures.
Capacity overprovisioning for networks with resilience requirements
Authors: Michael Menth, Rüdiger Martin, Joachim Charzinski
Venue: ACM SIGCOMM Computer Communication Review (2006)

This work focuses on capacity overprovisioning (CO) as an alternative to admission control (AC) to implement quality of service (QoS) in packet-switched communication networks. CO prevents potential overload while AC protects the QoS of the traffic during overload situations. Overload may be caused, e. g., by uctuations of the traffic rate on a link due to its normal stochastic behavior (a), by traffic shifts within the network due to popular contents (b), or by redirected traffic due to network failures (c). Capacity dimensioning methods for CO need to take into account all potential sources of overload while AC can block excess traffic caused by (a) and (b) if the capacity does not suffice. The contributions of this paper are (1) the presentation of a capacity dimensioning method for networks with resilience requirements and changing traffic matrices, (2) the investigation of the impact of the mentioned sources of overload (a-c) on the required capacity for CO in networks with and without resilience requirements, and (3) a comparison of this equired capacity with the one for AC. Our results show that in the presence of strong traffic shifts CO requires more capacity than AC. However, if resilience against network failures is required, both CO and AC need additional backup capacity for the redirected traffic. In this case, CO can use the backup capacity to absorb other types of overload. As a consequence, CO and AC have similar bandwidth requirements. These findings are robust against the network size.
Factors and measures of business process modelling: model building through a multiple case study
Authors: Wasana Bandara, Guy G. Gable, Michael Rosemann
Venue: European Journal of Information Systems (2005)

Business process modelling has gained widespread acceptance as a valuable design and management technique for a variety of purposes. While there has been much research on process modelling techniques and corresponding tools, there has been little empirical research into the success factors of effective process modelling, and the post hoc evaluation of process modelling success. This paper reports on the first attempt to identify process modelling success factors and measures, as empirically evidenced in case studies of nine process modelling projects in three leading Australian organizations.
Decidability analysis of self-stabilization for infinite-state systems
Authors: Hsu-Chun Yen, Lien-Po Yu
Venue: Fundamenta Informaticae (2005)

For a variety of infinite-state systems, the problem of deciding whether a given system is self-stabilizing or not is investigated from the decidability viewpoint. We develop a unified strategy through which checking self-stabilization is shown to be decidable for lossy vector addition systems with states, one-counter machines, and conflict-free Petri nets. For lossy counter machines and lossy channel systems, in contrast, the self-stabilization problem is shown to be undecidable.
Highly interactive distributed visualization
Authors: M. Scarpa, R. G. Belleman, P. M. A. Sloot, C. T. A. M. de Laat
Venue: Future Generation Computer Systems (2006)

We report on our iGrid2005 demonstration, called the "Dead Cat Demo"; an example of a highly interactive augmented reality application consisting of software services distributed over a wide-area, high-speed network. We describe our design decisions, analyse the implications of the design on application performance and show performance measurements.
GraphRank: Statistical Modeling and Mining of Significant Subgraphs in the Feature Space
Authors: Huahai He, Ambuj K. Singh
Venue: Proceedings of the Sixth International Conference on Data Mining (2006)

We propose a technique for evaluating the statistical significance of frequent subgraphs in a database. A graph is represented by a feature vector that is a histogram over a set of basis elements. The set of basis elements is chosen based on domain knowledge and consists generally of vertices, edges, or small graphs. A given subgraph is transformed to a feature vector and the significance of the subgraph is computed by considering the significance of occurrence of the corresponding vector. The probability of occurrence of the vector in a random vector is computed based on the prior probability of the basis elements. This is then used to obtain a probability distribution on the support of the vector in a database of random vectors. The statistical significance of the vector/subgraph is then defined as the p-value of its observed support. We develop efficient methods for computing p-values and lower bounds. A simplified model is further proposed to improve the efficiency. We also address the problem of feature vector mining, a generalization of itemset mining where counts are associated with items and the goal is to find significant sub-vectors. We present an algorithm that explores closed frequent sub-vectors to find significant ones. Experimental results show that the proposed techniques are effective, efficient, and useful for ranking frequent subgraphs by their statistical significance.
Performance analysis of MUSIC and Pencil-MUSIC algorithms for diversely-polarized array
Authors: Chi Cheng, Yingbo Hua
Venue: Proceedings of the Acoustics, Speech, and Signal Processing,1994. on IEEE International Conference - Volume 04 (1994)

This paper presents an asymptotical analysis of the MUSIC and Pencil-MUSIC methods proposed by Hua (1993) for estimating 2D angles and polarizations using crossed dipoles. The explicit first order perturbation expressions for the variances of the MUSIC and Pencil-MUSIC estimates are derived. These expressions are used to analyze and compare performances of the MUSIC and Pencil-MUSIC methods. A comparison of the angle-only Pencil-MUSIC method (Cheng and Hua, 1993) to the Pencil-MUSIC method is also presented. Simulation results agree well with theoretical results.