ppxscal/embedding_network huggingface dataset:
On the Hopf Algebraic Structure of Lie Group Integrators
Authors: H. Z. Munthe-Kaas, W. M. Wright
Venue: Foundations of Computational Mathematics (2008)

A commutative but not cocommutative graded Hopf algebra HN, based on ordered (planar) rooted trees, is studied. This Hopf algebra is a generalization of the Hopf algebraic structure of unordered rooted trees HC, developed by Butcher in his study of Runge-Kutta methods and later rediscovered by Connes and Moscovici in the context of noncommutative geometry and by Kreimer where it is used to describe renormalization in quantum field theory. It is shown that HN is naturally obtained from a universal object in a category of noncommutative derivations and, in particular, it forms a foundation for the study of numerical integrators based on noncommutative Lie group actions on a manifold. Recursive and nonrecursive definitions of the coproduct and the antipode are derived. The relationship between HN and four other Hopf algebras is discussed. The dual of HN is a Hopf algebra of Grossman and Larson based on ordered rooted trees. The Hopf algebra HC of Butcher, Connes, and Kreimer is identified as a proper Hopf subalgebra of HN using the image of a tree symmetrization operator. The Hopf algebraic structure of the shuffle algebra HSh is obtained from HN by a quotient construction. The Hopf algebra HP of ordered trees by Foissy differs from HN in the definition of the product (noncommutative concatenation for HP and shuffle for HN) and the definitions of the coproduct and the antipode, however, these are related through the tree symmetrization operator.
Maximum thick paths in static and dynamic environments
Authors: Esther M. Arkin, Joseph S.B. Mitchell, Valentin Polishchuk
Venue: Proceedings of the twenty-fourth annual symposium on Computational geometry (2008)

We consider the problem of finding a maximum number of disjoint paths for unit disks moving amidst static or dynamic obstacles. For the static case we give efficient exact algorithms, based on adapting the "continuous uppermost path" paradigm. As a by-product, we establish a continuous analogue of Menger's Theorem. (In this extended abstract we only state these results.) Next we study the dynamic problem in which the obstacles may move, appear and disappear, and otherwise change with time in a known manner; in addition, the disks are required to enter/exit the domain during prescribed time intervals. We observe that (unless P=NP), for any α,β > 0, one cannot decide in polynomial time whether there exist [αΚ] paths for disks of radius βR, where K is the maximum number of paths for radius-R disks. The problem is hard even if the obstacles are static, and only the entry/exit time intervals are specified for the disks. This motivates studying "dual" approximations, compromising on the radius of the disks and on the maximum speed of motion. Our main result is a pseudopolynomial-time dual-approximation algorithm: if K unit disks, each with unit bound on the speed, may be routed through an environment, our algorithm finds (at least) K paths for disks of radius Ω(1) moving with speed O(1). The algorithm computes a maxflow with "forbidden pairs" in an "adaptive" grid, laid out in space-time. Although (as we show) in general finding even an approximation to the maxflow with forbidden pairs is not possible (unless P=NP), a careful choice of time discetization and a non-uniform grid of "way-points" allows us to give provable approximation guarantees on the quality of the solution produced by the algorithm. Our algorithm extends to higher dimensions and to finding paths for translational motion of arbitrary-shape objects.
An Efficient Task Serializer for Hard Real-Time TMO Systems
Authors: Hyun-Joo Kim, Jung-Guk Kim, Chunhyon Chang, Sunyoung Han, Shin Hue
Venue: Proceedings of the 2008 11th IEEE Symposium on Object Oriented Real-Time Distributed Computing (2008)

Timeliness-guaranteed computing considering the worst case can hardly be accomplished at run time because of the uncertainty caused by resource sharing, asynchronous events and conflicting timing constraints between tasks. An easier way to reach it is to do some off-line analysis from design time with predictable characteristics of tasks. The TMO model supporting time-triggered (SpM) and message-triggered (SvM) member-threads is a well-known real-time object-oriented task model that aims the design-time guaranteed computing. In this paper, a new efficient task serializer that allocates the executions of time-triggered periodic tasks of multiple TMOs without delay and preemption to avoid resource conflicts is presented. The serializer tries to find scheduling scenarios in that each SpM is executed at its exact trigger-time without delay based on the given WCET. This is done by recasting the initial offsets of SpMs to avoid overlaps of executions. And several methods to handle SvMs according to the types of SvMs using the serializer are also proposed.
Named entity normalization in user generated content
Authors: Valentin Jijkoun, Mahboob Alam Khalid, Maarten Marx, Maarten de Rijke
Venue: Proceedings of the second workshop on Analytics for noisy unstructured text data (2008)

Named entity recognition is important for semantically oriented retrieval tasks, such as question answering, entity retrieval, biomedical retrieval, trend detection, and event and entity tracking. In many of these tasks it is important to be able to accurately normalize the recognized entities, i.e., to map surface forms to unambiguous references to real world entities. Within the context of structured databases, this task (known as record linkage and data de-duplication) has been a topic of active research for more than five decades. For edited content, such as news articles, the named entity normalization (NEN) task is one that has recently attracted considerable attention. We consider the task in the challenging context of user generated content (UGC), where it forms a key ingredient of tracking and media-analysis systems. A baseline NEN system from the literature (that normalizes surface forms to Wikipedia pages) performs considerably worse on UGC than on edited news: accuracy drops from 80% to 65% for a Dutch language data set and from 94% to 77% for English. We identify several sources of errors: entity recognition errors, multiple ways of referring to the same entity and ambiguous references. To address these issues we propose five improvements to the baseline NEN algorithm, to arrive at a language independent NEN system that achieves overall accuracy scores of 90% on the English data set and 89% on the Dutch data set. We show that each of the improvements contributes to the overall score of our improved NEN algorithm, and conclude with an error analysis on both Dutch and English language UGC. The NEN system is computationally efficient and runs with very modest computational requirements.
A new paradigm for mobile agent computing
Authors: R. B. Patel, K. Garg
Venue: Proceedings of the 2nd WSEAS International Conference on Electronics, Control and Signal Processing (2003)

With the recent surge in Internet based users, the idea of Mobile Agent based computing systems has gained popularity. This is because agent based computing systems provide a very simple and powerful mechanism by which complex distributed computations can be constructed and performed over the Internet. This paper presents a new mobile agent paradigm which is an integration of the existing mobile agent paradigm with a stationary agent. We have developed a new mobile agent platform using this paradigm. A comparison study of the proposed paradigm with some existing mobile agent platforms with respect to reliability and computation power is also reported.
Phase estimation in data channelization for video transmitting
Authors: Satish Chand, Hari Om
Venue: Multidimensional Systems and Signal Processing (2008)

Channelization is one of the important techniques for sharing a single physical channel among the multiple videos. In channelization, the videos are partitioned into segments and the bandwidth of the physical channel is partitioned into logical channels. The first segment of each video is transmitted through the first logical channel, the second segment of each video is transmitted through the second logical channel, and so forth. The segments are transmitted periodically through the logical channels. In this paper, the video signals to be transmitted through the logical channels are estimated. Furthermore, the phase is estimated in terms of jitter delays that occur among the video segments, while transmitting them through the logical channels. The phase is an important parameter in video communication latency. Using the phase, the group delay can be estimated and based on the group delay, the storage space required at the client's site can be determined so that the continuous and jerk-free delivery of the videos is provided to the users.
Design and optimization of on-chip interconnects using wave-pipelined multiplexed routing
Authors: Ajay J. Joshi, Gerald G. Lopez, Jeffrey A. Davis
Venue: IEEE Transactions on Very Large Scale Integration (VLSI) Systems (2007)

Every new VLSI technology generation has resulted in interconnects increasingly limiting the performance, area, and power dissipation of new processors. Subsequently, it is necessary to devise efficient interconnect design techniques to reduce the impact of VLSI interconnects on overall system design. New optimizations of a wave-pipelined multiplexed (WPM) interconnect routing circuit are described in this paper. These WPM circuits can be used with current interconnect repeater circuits to further reduce interconnect delay, interconnect area, transistor area, and/or power dissipation. For example, new area constrained WPM circuit optimizations illustrate that the interconnect circuit power can be reduced by 26% or the interconnect performance can be improved by 74%. Moreover, in both these cases, because a significant number of repeaters are eliminated, the transistor area can reduce by 41% or 29%, respectively. Finally, the tolerance of WPM circuits to crosstalk noise, power supply noise, clock skew, and manufacturing variations is also presented. This study of tolerance levels defines the conditions under which the WPM circuit will function correctly, and it is shown in this paper for the first time that WPM circuits are robust enough to operate with variability that can be encountered in deep submicrometer technologies.
Decomposing graphs with girth at least five under degree constraints
Authors: Ajit A. Diwan
Venue: Journal of Graph Theory (2000)

We prove that the vertex set of a simple graph with minimum degree at least s + t - 1 and girth at least 5 can be decomposed into two parts, which induce subgraphs with minimum degree at least s and t, respectively, where s, t are positive integers &ge; 2. &copy; 2000 John Wiley & Sons, Inc: J Graph Theory 33: 237&ndash;239, 2000
Prototype of an expert system for aluminum welding
Authors: V. Tsoukalas, M. Kontesis, E. Badogiannis, D. papachristos, N. Fragiadakis
Venue: Proceedings of the 5th WSEAS International Conference on Computational Intelligence, Man-Machine Systems and Cybernetics (2006)

Increasing demand for high quality aluminum welding and the international competition has been leading the ship industry to adopt new advanced IT tools. Prototype knowledge based expert system named WELDES (WELDing Expert System) has been developed under the frame of the Archimedes project 259 (03). The system is able to identify the aluminum welding defects, to correlate them with the welding parameters, which cause them, and to offer advice regarding the necessary corrective actions. The first step in the construction of this program was the systematic classification of the aluminum welding defects and the analysis of the reasons, which cause them. The WELDES system is aiming to be used as an industrial tool for the identification, assessment, and correction of aluminum welding defects. The system consists of two modules: the Diagnostic Module, and the Adviser Module. The structure of the program is ideally suited to the knowledge domain of the welding and the ship industry as it makes productive the previous knowledge and uses the acquiring experience of many years in the research and production of high quality welding. The next step is the expert system to be tested in real industrial environment.
Computation and communication schedule optimization for jobs with shared data
Authors: En-Jan Chou, Pangfeng Liu, Jan-Jan Wu
Venue: Proceedings of the 13th International Conference on Parallel and Distributed Systems - Volume 01 (2007)

Almost every computation job requires input data in order to find the solution, and the computation cannot proceed without the required data becoming available. As a result a proper interleaving of data transfer and job execution has a significant impact on the overall efficiency. In this paper we analyze the computational complexity of the shared data job scheduling problem, with and without consideration of storage capacity constraint. We show that if there is an upper bound on the server capacity, the problem is NP-complete, even when each job depends on at most three data. On the other hand, if there is no upper bound on the server capacity, we show that there exists an efficient algorithm that gives optimal job schedule when each job depends on at most two data. We also give an efficient heuristic algorithm that gives good schedule for cases where there is no limit on the number of data a job may access.
Data Pre-Processing Methodology for Computational Experiment in Analyzing Protein Interaction Networks
Authors: Jamaludin Sallim, Rosni Abdullah, Ahamad Tajudin Abdul Khader
Venue: Proceedings of the 2008 Second Asia International Conference on Modelling & Simulation (AMS) (2008)

This paper describes a process flow of data preprocessing for computational experiment in analyzing protein interaction networks. The aim of this process flow is to fulfill the requirement of our graph-based algorithm’s solution and to ensure that the representation of protein interaction network which consist of nodes and edges are accurate. The raw data is obtained from one of protein interaction database called Database of interacting Proteins (here-on known as DIP)). We describe briefly the DIP and since our algorithm requires the distance matrix as an input; a few important steps need to be taken to process the data. We limit this paper to data pre-preprocessing only and the algorithmic process is not discussed.
2-factors with prescribed and proscribed edges
Authors: R. E. L. Aldred, D. A. Holton, J. Sheehan
Venue: Journal of Graph Theory (2005)

Let G be a finite k-edge-connected simple graph. We consider when a set of independent edges can be extended to a 2-factor such that this 2-factor avoids a fixed set of independent edges. A complete characterization is provided in those cases, where this is feasible. &copy; 2005 Wiley Periodicals, Inc. J Graph Theory 49: 48&ndash;58, 2005
Towards a Dependable Architecture for Highly Available Internet Services
Authors: Narjess Ayari, Pablo Neira Ayuso, Laurent Lefèvre, Denis Barbaron, Rafael M. Gasca
Venue: Proceedings of the 2008 Third International Conference on Availability, Reliability and Security (2008)

For an improved QoS provisioning, operators are strongly concerned both with the availability and ther eliability of their performance critical servers. Among these entities, we mention the firewalls used to filter the offered network traffic to the operator's information system as well as the end processing servers which service each incoming client request. In this work, we advocate and evaluate a full architecture for highly available services. Performance evaluations show that our proposed framework incurs a minimal overhead to the end-to-end communications during failsafe periods and performs well during failures.
DW-MAC: a low latency, energy efficient demand-wakeup MAC protocol for wireless sensor networks
Authors: Yanjun Sun, Shu Du, Omer Gurewitz, David B. Johnson
Venue: Proceedings of the 9th ACM international symposium on Mobile ad hoc networking and computing (2008)

Duty cycling is a widely used mechanism in wireless sensor networks (WSNs) to reduce energy consumption due to idle listening, but this mechanism also introduces additional latency in packet delivery. Several schemes have been proposed to mitigate this latency, but they are mainly optimized for light traffic loads. A WSN, however, could often experience bursty and high traffic loads, such as due to broadcast or convergecast traffic. In this paper, we present a new MAC protocol, called Demand Wakeup MAC (DW-MAC), that introduces a new low-overhead scheduling algorithm that allows nodes to wake up on demand during the Sleep period of an operational cycle and ensures that data transmissions do not collide at their intended receivers. This demand wakeup adaptively increases effective channel capacity during an operational cycle as traffic load increases, allowing DW-MAC to achieve low delivery latency under a wide range of traffic loads including both unicast and broadcast traffic. We compare DW-MAC with S-MAC (with and without adaptive listening) and with RMAC using ns-2 and show that DW-MAC outperforms these protocols, with increasing benefits as traffic load increases. For example, under high unicast traffic load, DW-MAC reduces delivery latency by 70% compared to S-MAC and RMAC, and uses only 50% of the energy consumed with S-MAC with adaptive listening. Under broadcast traffic, DW-MAC reduces latency by more than 50% on average while maintaining higher energy efficiency.
A proximal subgradient projection algorithm for linearly constrained strictly convex problems
Authors: Adam Ouorou
Venue: Optimization Methods Software (2007)

We propose a new algorithm for linearly constrained strictly convex problems. This algorithm follows the characterization of saddle points introduced earlier in ref. [Ouorou, A., 2000, A primal-dual algorithm for monotropic programming and its application to network optimization. Computational Optimization and Applications, 15(2), 125-143.], using two different augmented Lagrangian functions defined for the primal problem and its dual. The saddle points may be computed in a variety of ways. We propose a scheme that results in a special implementation of Martinet's proximal algorithm ref. [Martinet, B. 1970, Régularisation d'inéquations variationnelles par approximations successives. Revue Franç'Informatique et de Recherche Opérationnelle, 3, 154-179.]. In the primal space, the resulting algorithm appears as a nonsmooth version of the projection algorithm by Rosen ref. [Rosen, J.B., 1960, The gradient projected method for nonlinear programming, part I: Linear Constraints. Journal of the Society for Industrial and Applied Mathematics, 8, 181-217.]. The dual iterates are generated through an unconstrained subproblem which can be solved efficiently by L-BFGS refs. [Byrd, R., Lu, P., Nocedal, J. and Zhu, C. 1995, A limited memory algorithm for bound constrained optimization. SIAM Journal on Scientific Computation, 16(5), 1190-1208.; Liu, D. and Nocedal, J., 1989, On the limited memory BFGS method for large scale optimization. Mathematical Programming B 45, 503-528.]. We establish convergence with no use of the concept of resolvent of maximal monotone operators. To assess the numerical behaviour of the algorithm, we use some randomly generated quadratic network flow problems and compare it with PPRN, a specialized code for linear and nonlinear cost network flow problems.
Towards Better Outliers Detection for Gene Expression Datasets
Authors: R. Kashef, M. S. Kamel
Venue: Proceedings of the 2008 International Conference on Biocomputation, Bioinformatics, and Biomedical Technologies (2008)

This paper compares the performance of three clustering algorithms on the task of outlier's detection. The goal is to illustrate that better clustering indicates better detection of outliers. k-means (KM), Bisecting k-means (BKM) and the Partitioning Around Medoids (PAM) algorithms are each combined with the clustering-based outliers detection (Find CBLOF) method. Undertaken experimental results over four gene expression datasets where outliers are presented show that the clustering solutions of the PAM algorithm enable the Find CBLOF algorithm to discover more outliers than those of both the k-means and the bisecting k-means algorithms. The main reason for this is that PAM provides better clustering quality than that of the other two clustering algorithms on the tested datasets measured by external and internal quality measures.
A boosting algorithm for learning bipartite ranking functions with partially labeled data
Authors: Massih Reza Amini, Tuong Vinh Truong, Cyril Goutte
Venue: Proceedings of the 31st annual international ACM SIGIR conference on Research and development in information retrieval (2008)

This paper presents a boosting based algorithm for learning a bipartite ranking function (BRF) with partially labeled data. Until now different attempts had been made to build a BRF in a transductive setting, in which the test points are given to the methods in advance as unlabeled data. The proposed approach is a semi-supervised inductive ranking algorithm which, as opposed to transductive algorithms, is able to infer an ordering on new examples that were not used for its training. We evaluate our approach using the TREC-9 Ohsumed and the Reuters-21578 data collections, comparing against two semi-supervised classification algorithms for ROCArea (AUC), uninterpolated average precision (AUP), mean precision@50 (TP) and Precision-Recall (PR) curves. In the most interesting cases where there are an unbalanced number of irrelevant examples over relevant ones, we show our method to produce statistically significant improvements with respect to these ranking measures.
A Novel Partial Prediction Algorithm for Fast 4x4 Intra Prediction Mode Decision in H.264/AVC
Authors: Y. N. Sairam, Nan Ma, Neelu Sinha
Venue: Proceedings of the Data Compression Conference (2008)

This paper proposes a partial prediction approach for fast mode decision in H.264/AVC 4x4 intra-prediction, exploiting the inherent symmetry existing in the spatial prediction modes. The high compression efficiency of H.264 comes with a price of high computational complexity. The intra-prediction process with its robust full intra mode search rate distortion optimization (RDO) technique to select the best mode for each macroblock is one such computational bottleneck. Unlike many fast algorithms which search for dominant edge in each block the existence of which is never assured, our algorithm quickly tries to find a closer prediction mode for each 4x4 block using a simple cost measure derived from the symmetry in all the prediction modes. The proposed algorithm only searches 3 or lesser modes instead of 9 for the 4x4 luma blocks. Experimental results reveal the significant computational savings achieved with slight PSNR degradation and bit-rate increase.
Regularized Structured Total Least Norm for the Identification of Bilinear Systems in the Errors-in-Variables Framework
Authors: Tomasz Larkowski, Jens G. Linden, Benoit Vinsonneau, Keith J. Burnham
Venue: Proceedings of the Third International Conference on Systems (2008)

The paper addresses the identification of time-invariant bilinear system (BS) models in the errors-in-variables (EIV) framework. The proposed scheme is based on the structured total least norm (STLN) technique extended here to handle BS. The performance of the presented approach, i.e. the bilinear STLN (BSTLN) with its further extension incorporating the Tikhonov regularization is compared to several other EIV identification techniques via an extensive Monte-Carlo simulation study. The results obtained demonstrate a considerable noise robustness and, therefore, the applicability of the BSTLN algorithm in the EIV framework.