ppxscal/embedding_network huggingface dataset:
References to graphical objects in interactive multimodal queries
Authors: Daqing He, Graeme Ritchie, John Lee
Venue: Knowledge-Based Systems (2008)

Traditionally, interactive natural language systems assume a semantic model in which the entities referred to are in some abstract representation of a real or imagined world. In a system where graphical objects such as diagrams may be on the screen during the language interaction, there is possibility that the user may want to allude to these visual entities. Since graphical objects have their own properties (colour, shape, position on the screen, etc.) but may also represent items in a knowledge base which have other associated properties (price, geographical location, technical specifications, etc.), some systematic way is needed to enable such objects to be referred to in terms of either their screen properties or their associated attributes from the domain under discussion. In this paper, we present a formalisation for these arrangements, and show how our logical definitions can be used to generate constraints suitable for reference resolution within a natural language interpreter.
On the Salsa20 Core Function
Authors: Julio Cesar Hernandez-Castro, Juan M. Tapiador, Jean-Jacques Quisquater
Venue: Fast Software Encryption: 15th International Workshop, FSE 2008, Lausanne, Switzerland, February 10-13, 2008, Revised Selected Papers (2008)

In this paper, we point out some weaknesses in the Salsa20 core function that could be exploited to obtain up to 231 collisions for its full (20 rounds) version. We first find an invariant for its main building block, the quarterround function, that is then extended to the rowround and columnround functions. This allows us to find an input subset of size 232 for which the Salsa20 core behaves exactly as the transformation f(x) = 2x. An attacker can take advantage of this for constructing 231 collisions for any number of rounds. We finally show another weakness in the form of a differential characteristic with probability one that proves that the Salsa20 core does not have 2 nd preimage resistance.
Improved search strategies and extensions to k-medoids-based clustering algorithms
Authors: Shu-Chuan Chu, John F. Roddick, Jeng-Shyang Pan
Venue: International Journal of Business Intelligence and Data Mining (2008)

In this paper two categories of improvements are suggested that can be applied to most k-medoids-based algorithms - conceptual/algorithmic improvements, and implementational improvements. These include the revisiting of the accepted cases for swap comparison and the application of partial distance searching and previous medoid indexing to clustering. Various hybrids are then applied to a number of k-medoids-based algorithms and the method is shown to be generally applicable. Experimental results on both artificial and real datasets demonstrate that when applied to CLARANS the number of distance calculations can be reduced by up to 98%.
Bandwidth-Aware Design of Large-Scale Clusters for Scientific Computations
Authors: Mitsuhisa Sato
Venue: Proceedings of the 3rd international conference on High Performance Computing and Communications (2007)

The bandwidth of memory access and I/O, network is the most important issue in designing a large-scale cluster for scientific computations. We have been developing a large scale PC cluster named PACS-CS (Parallel Array Computer System for Computational Sciences) at Center for Computational Sciences, University of Tsukuba, for wide variety of computational science applications such as computational physics, computational material science, etc. For larger memory access bandwidth, a node is equipped with a single CPU which is different from ordinary high-end PC clusters. The interconnection network for parallel processing is configured as a multi-dimensional Hyper-Crossbar Network based on trunking of GigabitEthernet to support large scale scientific computation with physical space modeling. Based on the above concept, we are developing an original mother board to configure a single CPU node with 8 ports of Gigabit Ethernet, which can be implemented in the half size of 19 inch rack-mountable 1U size platform. PACS-CS started its operation on July 2006 with 2560 CPUs and 14.3 TFops of peak performance.Recently, we have newly established an alliance to draw up the specification of a supercomputer, called Open Supercomputer Specification. The alliance consists of three Japanese universities: University of Tsukuba, University of Tokyo, and Kyoto University (T2K alliance). The Open Supercomputer Specification defines fundamental hardware and software architectures on which each university will specify its own requirement to procure the next generation of their supercomputer systems in 2008. This specification requests the node to be composed of commodity multicore processors with high aggregated memory bandwidth, and the bandwidth of internode communication to be 5 GB/s or more in physical link level and 4 GB/s or more in MPI level with Link aggregation technology using commodity fabric. We expect several TFlops in each system. In order to support scalable scientific computations in a large-scale cluster, the bandwidth-aware design will be important.
CPBPV: A Constraint-Programming Framework for Bounded Program Verification
Authors: Hélène Collavizza, Michel Rueher, Pascal Hentenryck
Venue: Proceedings of the 14th international conference on Principles and Practice of Constraint Programming (2008)

This paper studies how to verify the conformity of a program with its specification and proposes a novel constraint-programming framework for bounded program verification (CPBPV). The CPBPV framework uses constraint stores to represent the specification and the program and explores execution paths nondeterministically. The input program is partially correct if each constraint store so produced implies the post-condition. CPBPV does not explore spurious execution paths as it incrementally prunes execution paths early by detecting that the constraint store is not consistent. CPBPV uses the rich language of constraint programming to express the constraint store. Finally, CPBPV is parametrized with a list of solvers which are tried in sequence, starting with the least expensive and less general. Experimental results often produce orders of magnitude improvements over earlier approaches, running times being often independent of the variable domains. Moreover, CPBPV was able to detect subtle errors in some programs while other frameworks based on model checking have failed.
Managing coherent groups
Authors: Renato Silveira
Venue: Computer Animation and Virtual Worlds (2008)

The animation of groups of characters involves the generation of some interesting steering behaviors like following a single path, moving toward a common objective, and moving while keeping a formation. This paper presents a new approach to manage the movement of groups in dynamic environments using a simple and robust algorithm that includes a strategy to keep formations during the displacement of the group. Our method is based on a boundary value problem (BVP) involving Laplace's equation and has two layers. In the first one, a group map is built to allow for local control of each individual, while in the second one a path planning is performed for each group as a whole. Results show that our technique is robust to several situations and can be implemented on GPU, which results in real-time performance for large groups. Copyright &copy; 2008 John Wiley & Sons, Ltd.
Web-Based Services for Real Estate: Model and Implementation
Authors: Zhangxi Lin, Gary D. Anderson
Venue: IT Professional (2004)

A Web-based service for real estate provides complex database access controls across multiple organizations.
Derivation of ME estimator of a mixture of two normal distributions
Authors: Senay Asma
Venue: Proceedings of the 6th WSEAS International Conference on Applied Electromagnetics, Wireless and Optical (2008)

In this study, we obtain the parameters of a mixture density by using the principle of maximum equality which is based on Shannon's entropy measure. Since this procedure doesn't require constructing the likelihood function and give more accurate fitting values, it can be preferable instead of maximum likelihood method. Consequently, goodness of the derived estimator is shown by applying in order to obtain a mixture model under a real data application. The empirical study is done on the basis of MATLAB and R-packages.
Shape from Specular Reflection and Optical Flow
Authors: J. Lellmann, J. Balzer, A. Rieder, J. Beyerer
Venue: International Journal of Computer Vision (2008)

Inferring scene geometry from a sequence of camera images is one of the central problems in computer vision. While the overwhelming majority of related research focuses on diffuse surface models, there are cases when this is not a viable assumption: in many industrial applications, one has to deal with metal or coated surfaces exhibiting a strong specular behavior. We propose a novel and generalized constrained gradient descent method to determine the shape of a purely specular object from the reflection of a calibrated scene and additional data required to find a unique solution. This data is exemplarily provided by optical flow measurements obtained by small scale motion of the specular object, with camera and scene remaining stationary. We present a non-approximative general forward model to predict the optical flow of specular surfaces, covering rigid body motion as well as elastic deformation, and allowing for a characterization of problematic points. We demonstrate the applicability of our method by numerical experiments on synthetic and real data.
Analyzing several musical instrument tones using the randomly modulated periodicity model
Authors: Shlomo Dubnov, Melvin J. Hinich
Venue: Signal Processing (2009)

The waveform of a simple sustained tone emitted from musical instruments such as a flute played by even the best musician is never exactly periodic. There is always some variation over time in the waveform of a single pitch that is characteristic of the instrument itself. In this paper, we employ the signal-coherence function introduced by Hinich [A statistical theory of signal coherence, J. Oceanic Eng. 25(2) (2000) 256-261] to study the subtle variation of tones from several instruments played by accomplished musicians. This measure characterizes the amount of variation in each Fourier component as a random amplitude-modulation component added to a coherent narrowband sinusoid. The signal-coherence function is computed from several digitized acoustic signals of several musical instruments. The signal-coherence functions show that there are important differences between the same notes produced from different instruments. The signal coherence of a vibrato, a deliberate modulation of a tone, is analyzed for the first time using the signal-coherence function. We show that for most practical playing conditions it has a small effect for lower frequencies. This allows characterization of modulation variations in sustained portions of sound with and without vibrato. The signal-coherence processing method applied to musical acoustics could lead to more realistic music synthesizers.
A parallel FE-FV scheme to solve fluid flow in complex geologic media
Authors: Dim Coumou, Stephan Matthäi, Sebastian Geiger, Thomas Driesner
Venue: Computers Geosciences (2008)

Field data-based simulations of geologic systems require much computational time because of their mathematical complexity and the often desired large scales in space and time. To conduct accurate simulations in an acceptable time period, methods to reduce runtime are required. A parallelization approach is attractive because fast multi-processor clusters are nowadays readily available. Here we report on our recent efforts to parallelize our multiphysics code CSMP++ (Complex System Modelling Platform). In particular, we describe a parallel finite element-finite volume method for multi-phase fluid flow in heterogeneous porous media. We take a domain partitioning approach where the finite element mesh is partitioned into sub-domains, assigning each of them to a single processor. For each sub-domain a local finite volume mesh is constructed. We can now solve advection-dispersion type equations taking an operator splitting approach: Pressure diffusion is calculated with an implicit finite element method and advection with an implicit or explicit finite volume scheme. We have tested the accuracy, robustness and computational speedup of our new parallel scheme on a Linux cluster by means of three geologic applications. All tests give excellent computational speedup with increasing number of up to 32 processors. These results broaden the range of possible simulations in terms of spatial and temporal scale and resolution as well as numerical accuracy up to two orders of magnitude.
Inclusive Social Tagging: A Paradigm for Tagging-Services in the Knowledge Society
Authors: Michael Derntl, Thorsten Hampel, Renate Motschnig-Pitrik, Tomáš Pitner
Venue: Proceedings of the 1st world summit on The Knowledge Society: Emerging Technologies and Information Systems for the Knowledge Society (2008)

This paper investigates the Web 2.0 phenomenon of social tagging in the context of existing approaches to semantic data structuring. Social tagging is embedded into the space spanned by current structuring approaches like taxonomies, metadata, or ontologies in order to identify its semantic and pragmatic foundations. Thereby, we use the Inclusive Universal Access paradigm to assess social tagging with respect to socio-technical criteria for inclusive and barrier-free provision and usage of web services. From this analysis we propose criteria for a paradigm we chose to call "Inclusive Social Tagging." We subsequently use these criteria to assess the tagging functionality of popular Web 2.0 services.
An Ensemble Approach for the Diagnosis of Cognitive Decline with Missing Data
Authors: Patricio García Báez, Carlos Fernández Viadero, José Regidor García, Carmen Paz Araujo
Venue: Proceedings of the 3rd international workshop on Hybrid Artificial Intelligence Systems (2008)

This work applies new techniques of automatic learning to diagnose neuro decline processes usually related to aging. Early detection of cognitive decline (CD) is an advisable practice under multiple perspectives. A study of neuropsychological tests from 267 consultations on 30 patients by the Alzheimer's Patient Association of Gran Canaria is carried out. We designed neural computational CD diagnosis systems, using a multi-net and ensemble structure that is applied to the treatment of missing data present in consultations. The results show significant improvements over simple classifiers. These systems would allow applying policies of early detection of dementias in primary care centers where specialized professionals are not present.
Latecomer and Crash Recovery Support in Fault-Tolerant Groupware
Authors: Milail Ionescu, Ivan Marsic
Venue: IEEE Distributed Systems Online (2001)

In a real-time collaborative system, one user's actions must be instantaneously propagated to all the other current participants. A session might start with some users, others might join inlater, and still others might leave and join again. Unlike stateless collaborative applications such as videoconferencing and discussion groups, state-full collaborative applications must offer latecomer and crash recovery support. Such applications include shared electronicwhiteboards, chat rooms, collaborative design, collaborative virtual worlds, and multiplayer games.
Vision-Based Pursuit-Evasion in a Grid
Authors: Adrian Dumitrescu, Howi Kok, Ichiro Suzuki, Paweł Żyliński
Venue: Proceedings of the 11th Scandinavian workshop on Algorithm Theory (2008)

We revisit the problem of pursuit-evasion in the grid introduced by Sugihara and Suzuki in the line-of-sight vision model. Consider an arbitrary evader Z with the maximum speed of 1 who moves (in a continuous way) on the streets and avenues of an n ×n grid G n . The cunning evader is to be captured by a group of pursuers, possibly only one. The maximum speed of the pursuers is s ¿ 1 (s is a constant for each pursuit-evasion problem considered, but several values for s are studied). We prove several new results; no such algorithms were available for capture using one, two or three pursuers having a constant maximum speed limit: (i) A randomized algorithm through which one pursuer A with a maximum speed of s ¿ 3 can capture an arbitrary evader Z in G n in expected polynomial time. For instance, the expected capture time is $O(n^{1+\log_{6/5}{16}})=O(n^{16.21})$ for s = 3, O(n 1 + log12) = O(n 4.59) for s = 4, O(n 1 + log60/13) = O(n 3.21) for s = 6, and it approaches O(n 3) with the further increase of s. (ii) A randomized algorithm for capturing an arbitrary evader in O(n 3) expected time using two pursuers who can move slightly faster than the evader (s = 1 + ¿, for any ¿> 0). (iii) Randomized algorithms for capturing a certain "passive" evader using either a single pursuer who can move slightly faster than the evader (s = 1 + ¿, for any ¿> 0), or two pursuers having the same maximum speed as the evader (s = 1). (iv) A deterministic algorithm for capturing an arbitrary evader in O(n 2) time, using three pursuers having the same maximum speed as the evader (s = 1).
Characterization of low-k SiOCH dielectric for 45nm technology and link between the dominant leakage path and the breakdown localization
Authors: M. Vilmay, D. Roy, F. Volpi, J. -M. Chaix
Venue: Microelectronic Engineering (2008)

Electrical characterizations have been performed on porous low-k SiOCH dielectric used in the 45nm technology. The present paper demonstrates that the conduction follows the Poole-Frenkel (PF) mechanism at medium and high fields. The apparent deviation from the PF mechanism at high field is explained by the trapping phenomenon due to the large amount of defects in the dielectric. This trapping deforms the band diagram and lowers the electron injection within the dielectric. A study of two key process steps is also performed and shows that the dominant conduction mechanism localization (bulk versus interface) is not necessarily at the origin of the breakdown mechanism.
Detection and analysis of connection chains in network forensics
Authors: Ahmad Almulhem
Venue:  (2007)

Network forensics is a young member of the bigger family of digital forensics discipline. In particular, it refers to digital forensics in networked environments. It represents an important extension to the model of network security where emphasis is traditionally put on prevention and to a lesser extent on detection. It focuses on the collection, and analysis of network packets and events caused by an intruder for investigative purposes. A key challenge in network forensics is to ensure that the network itself is forensically-ready, by providing an infrastructure to collect and analyze data in real-time. In this thesis, we propose an agent-based network forensics system, which is intended to add real-time network forensics capabilities into a controlled network. We also evaluate the proposed system by deploying and studying it in a real-life environment. Another challenge in network forensics arises because of attackers ability to move around in the network, which results in creating a chain of connections; commonly known as connection chains. In this thesis, we provide an extensive review and taxonomy of connection chains. Then, we propose a novel framework to detect them. The framework adopts a black-box approach by passively monitoring inbound and outbound packets at a host, and analyzing the observed packets using association rule mining. We assess the proposed framework using public network traces, and demonstrate both its efficiency and detection capabilities. We, finally, propose a profiling-based framework to investigate connection chains that are distributed over several ip addresses. The framework utilizes a simple yet extensible hacker model that integrates information about a hacker's linguistic, operating system and time of activity. We establish the effectiveness of the proposed approach through several simulations and an evaluation with real attack data.
Minimizing Deterministic Weighted Tree Automata
Authors: Andreas Maletti
Venue: Language and Automata Theory and Applications: Second International Conference, LATA 2008, Tarragona, Spain, March 13-19, 2008. Revised Papers (2008)

The problem of efficiently minimizing deterministic weighted tree automata (wta) is investigated. Such automata have found promising applications as language models in Natural Language Processing. A polynomial-time algorithm is presented that given a deterministic wta over a commutative semifield, of which all operations including the computation of the inverses are polynomial, constructs an equivalent minimal (with respect to the number of states) deterministic and total wta. If the semifield operations can be performed in constant time, then the algorithm runs in time O(rmn 4) where r is the maximal rank of the input symbols, m is the number of transitions, and n is the number of states of the input wta.
Differential methods for intuitive three-dimensional shape modeling
Authors: Chiew-Lan Tai
Venue:  (2007)

Modeling 3D digital shapes, such as curves and meshes, manually is challenging for three main reasons. First, realistic shapes are generally complex and involve many unknown degrees of freedom. Second, users usually only have 2D input and output devices, which are inadequate for manipulating 3D shapes in a virtual world. Third, unlike sculptors, ordinary people usually have no precise space perception, making precisely adjusting relative positions of 3D shapes even harder. This thesis presents several novel intuitive techniques that make the modeling process significantly less labor-intensive. We achieve a balance between the control intuitiveness of tools and the geometric complexity of modeling output. Our techniques allow the user to intuitively control the modeling effect through only a small set of easy-to-use manipulators. The unknown vertex positions of the final models are then computed by solving a system of linear partial differential equations (i.e., the Laplace or Poisson equations) subject to the constraints derived from the manipulators. These differential-based techniques contribute to three important modeling applications: mesh deformation, mesh merging and hairstyle design. The differential mesh deformation technique allows the user to manipulate a small set of handles to deform highly detailed meshes interactively and to achieve physically plausible deformation effects. The differential mesh merging framework relieves the user&rsquo;s burden of both precise locating of 3D models and precise specification of merging boundaries over the meshes to be merged. For hairstyle modeling, we design a sketching interface and adapt an incremental solver to allow users to design compelling hairstyles by drawing only a small set of strokes. For all these algorithms, we pre-compute the most computationally expensive components to achieve interactive modeling with fast response. Extensive experiments demonstrate the robustness and usefulness of our techniques.
First Steps in Building a Verb Valency Lexicon for Romanian
Authors: Ana-Maria Barbu
Venue: Proceedings of the 11th international conference on Text, Speech and Dialogue (2008)

This paper presents some steps in manually building a verb valency lexicon for Romanian. We refer to some major previous works by focusing on their information representation. We select that information for different stages of our project and we show the conceptual problems encountered during the first phase. Finally we present the gradually building procedure of the lexicon and we exemplify the manner in which the information is represented in a lexicon entry.