ppxscal/embedding_network huggingface dataset:
Communities of Practice of E-learning "CoPE - Definition and Concepts
Authors: Azeddine Chikh, Lamia Berkani, Akila Sarirete
Venue: Proceedings of the 2008 International Workshop on Advanced Information Systems for Enterprises (2008)

Communities of Practice (CoPs) focus on several fields such as engineering, management, and teaching. They offer numerous advantages: exchanging and sharing expertise, collaboration, training and joint development of tacit and explicit knowledge. Our purpose is to extend the application of these communities to the e-learning field. The result of this extension is a new category of CoPs called CoPE (Communities of Practice of E-learning) which combines two fields, 1) CoPs as basic field, and 2) E-learning as an application domain. We define the concept of CoPE and the underlying concepts such as learning situations, actors and their roles, activities and possible types of interactions, as well as the environment composed of services, tools and resources.
Generic arithmetic units for high-performance FPGA designs
Authors: John R. Humphrey, Daniel K. Price, Michael R. Bodnar, Petersen F. Curt, James P. Durbano
Venue: Proceedings of the 10th WSEAS International Conference on APPLIED MATHEMATICS (2006)

As PLD applications expand to include high-speed computing, the number of data types required grows commensurately. Current applications of programmable devices require operations on various integer, fixed-point, and floating-point precisions, in both real and complex (a+jb) formats. Moreover, simulating large, high-precision systems that include arithmetic units requires significant time. In this paper, we present a method of VHDL programming that addresses the growing number of data types and simulation time to allow for rapid development and simulation of mathematical-based hardware designs.
Robust estimating equations and bias correction of correlation parameters for longitudinal data
Authors: Guo You Qin, Zhong Yi Zhu, Wing K. Fung
Venue: Computational Statistics Data Analysis (2008)

The estimation of correlation parameters has received attention for both its own interest and improvement of the estimation efficiency of mean parameters by the generalized estimating equations (GEE) approach. Many of the well-established methods for the estimation of correlation parameters can be constructed under the GEE framework which is, however, sensitive to outliers. In this paper, we consider two ways of constructing robust estimating equations for achieving robust estimation of the correlation parameters. Furthermore, the estimators of the correlation parameters from the robustified GEE may be still biased as the expectation of the estimating equation is biased from zero when the underlying distribution is not symmetric. Therefore, bias-corrected robust estimators of correlation parameters are proposed. The performance of the proposed methods are investigated by simulation. The results show that the proposed robust and bias-corrected robust estimators can reduce the bias successfully. Two real data sets are analyzed for illustration.
Interactive 3D facial expression posing through 2D portrait manipulation
Authors: Tanasai Sucontphunt, Zhenyao Mo, Ulrich Neumann, Zhigang Deng
Venue: Proceedings of graphics interface 2008 (2008)

Sculpting various 3D facial expressions from a static 3D face model is a process with intensive manual tuning efforts. In this paper, we present an interactive 3D facial expression posing system through 2D portrait manipulation, where a manipulated 2D portrait serves a metaphor for automatically inferring its corresponding 3D facial expression with fine details. Users either rapidly assemble a face portrait through a pre-designed portrait component library or intuitively modify an initial portrait. During the editing procedure, when the users move one or a group of 2D control points on the portrait, other portrait control points are adjusted in order to automatically maintain the faceness of the edited portrait if the automated propagation function (switch) is optionally turned on. Finally, the 2D portrait is used as a query input to search for and reconstruct its corresponding 3D facial expression from a pre-recorded facial motion capture database. We showed that this system is effective for rapid 3D facial expression sculpting through a comparative user study.
Derivation of the lattice vehicular model from the Boltzmann transport equation
Authors: Shih-Ching Lo
Venue: Proceedings of the 5th WSEAS International Conference on Applied Mathematics (2004)

In this paper, the lattice vehicular model, which is in the form the lattice Boltzmann equation is directly derived from the Boltzmann equation. It is shown that the lattice Boltzmann equation is a special discretized form of the Boltzmann equation. A 3-bit approximation, which describe uncongested traffic flow, for the discretization of the Boltzmann equation in both time and phase space is discussed in detail. The lattice vehicular Boltzmann model ensures vehicles would not travel backward. A general procedure to derive the vehicular lattice Boltzmann model from the continuous Boltzmann equation is demonstrated explicitly.
Development of a teleoperation system and an operation assist user interface for a humanoid robot
Authors: Shin-Ichiro Kaneko, Yasuo Nasu, Shungo Usui, Mitsuhiro Yamano, Kazuhisa Mitobe
Venue: Proceedings of the 9th WSEAS International Conference on Systems (2005)

This paper describes a humanoid robot teleoperation system through the Internet/LAN. The developed system is a server-client system based on Common Object Request Broker Architecture (CORBA). The main target is that a human operator can remotely control the humanoid robot arms by on-line as if own arms naturally. In order to achieve the operation, we have developed a user-friendly Virtual Reality (VR) user interface that is composed of ultrasonic 3D mouse system and a Head Mounted Display (HMD) with a gyro sensor. The preliminary experiments show that the system is available as a teleoperation tool for the humanoid robot.
A ranking and exploration service based on large-scale usage data.
Authors: Johan Bollen, Herbert Van de Sompel, Lyudmilla Balakireva, Ryan Chute
Venue: Proceedings of the 8th ACM/IEEE-CS joint conference on Digital libraries (2008)

This poster presents the architecture and user interface of a prototype service that was designed to allow end-users to explore the structure of science and perform assessments of scholarly impact on the basis of large-scale usage data. The underlying usage data set was constructed by the MESUR project which collected 1 billion usage events from a wide range of publishers, aggregators, and institutional consortia.
Fuzzy logic-based real-time robot navigation in unknown environment with dead ends
Authors: Meng Wang, James N. K. Liu
Venue: Robotics and Autonomous Systems (2008)

The proposed approach in this paper involves a new grid-based map model called ''memory grid'' and a new behavior-based navigation method called ''minimum risk method''. The memory grid map records not only the environmental information, but also the robot experience. The minimum risk method is just one of the applications of the memory grid technique, which addresses the local minimum problem faced by a goal-oriented robot navigating in unknown indoor environments. The Minimum Risk implies that the robot is able to choose the safest region that can avoid colliding with obstacles and prevent the robot from iterating previous trajectory. This method is demonstrated to work in long wall, large concave, recursive U-shaped, unstructured, cluttered, maze-like, and dynamic indoor environments. It adopts a strategy of multi-behavior coordination in which a novel path-searching behavior is developed to recommend the region offering the minimum risk. Fuzzy logic is used to implement the behavior design and coordination. The proposed approach is verified with simulation and real-world tests.
An improved three-dimensional model for interface pressure calculations in free-surface flows
Authors: Ali Jafari, Ebrahim Shirani, Nasser Ashgriz
Venue: International Journal of Computational Fluid Dynamics (2007)

A three-dimensional method for the calculation of interface pressure in the computational modeling of free surfaces and interfaces is developed. The methodology is based on the calculation of the pressure force at the interfacial cell faces and is mainly designed for volume of fluid (VOF) interface capturing approach. The pressure forces at the interfacial cell faces are calculated according to the pressure imposed by each fluid on the portion of the cell face that is occupied by that fluid. Special formulations for the pressure in the interfacial cells are derived for different orientations of an interface. The present method, referred to as pressure calculation based on the interface location (PCIL), is applied to both static and dynamic cases. First, a three-dimensional motionless drop of liquid in an initially stagnant fluid with no gravity force is simulated as the static case and then two different small air bubbles in water are simulated as dynamic cases. A two-fluid, piecewise linear interface calculation VOF method is used for numerical simulation of the interfacial flow. For the static case, both the continuum surface force (CSF) and the continuum surface stress (CSS) methods are used for surface tension calculations. A wide range of Ohnesorge numbers and density and viscosity ratios of the two fluids are tested. It is shown that the presence of spurious currents (artificial velocities present in case of considerable capillary forces) is mainly due to the inaccurate calculation of pressure forces in the interfacial computational cells. The PCIL model reduces the spurious currents up to more than two orders of magnitude for the cases tested. Also for the dynamic bubble rise case, it is shown that using the numerical solver employed here, without PCIL, the magnitude of spurious currents is so high that it is not possible to simulate this type of surface tension dominated flows, while using PCIL, we are able to simulate bubble rise and obtain results in close agreement with the experimental data.
AI system in MANET
Authors: Ritu Soni, Sudhir Dawra
Venue: Proceedings of the 12th WSEAS International Conference on Applied Mathematics (2007)

Mobile ad-hoc networks have been deployed in various scenarios, but their scalability is severely restricted by the human operators' ability to configure and manage the network in the face of rapid change of the network structure and demand patterns. In this paper, we present a self-organizing approach to MANET management which have AI in their nodes that follows general principles of engineering for communicating between each other.
Test-Pattern Ordering for Wafer-Level Test-During-Burn-In
Authors: Sudarshan Bahukudumbi, Krishnendu Chakrabarty
Venue: Proceedings of the 26th IEEE VLSI Test Symposium (2008)

Wafer-level test during burn-in (WLTBI) is a promising technique to reduce test and burn-in costs in semiconductor manufacturing. However, scan-based testing leads to significant power variations in a die during test-pattern application. This variation adversely affects the accuracy of predictions of junction temperatures and the time required for burn-in. We present a test-pattern ordering technique for WLTBI, where the objective is to minimize the variation in power consumption during test application. The test-pattern ordering problem for WLTBI is formulated and it is solved using an efficient heuristic technique. Simulation results are presented for the ISCAS’89 and the IWLS’05 benchmark circuits, and the proposed ordering technique is compared with two baseline methods that carry out pattern-ordering to minimize peak power and average power,respectively. A third baseline method that randomly orders test patterns is also used to evaluate the proposed methods.
Fast Shape Optimization of Metallization Patterns for DMOS Based Driver
Authors: Bo Yang, Shigetoshi Nakatake, Hiroshi Murata
Venue: Proceedings of the 9th international symposium on Quality Electronic Design (2008)

This paper addresses the problem of optimizing Metallization patterns of back-end connections for the DMOS based driver since the back-end connections trend to dominate the overall on-resistance Ron. we propose a heuristic algorithmto seek for better shapes for the patterns targeting at minimizing Ron and at balancing the current distribution. In order to speed up the analysis, the equivalent resistance network of the driver is modified by inserting ideal switches to keep the conductance matrix constant. Simulation on two drivers from industrial TEG data demonstrates that our algorithm can reduce Ron effectively by shaping metals appropriately within a given routing area.
The Hopf algebra of uniform block permutations
Authors: Marcelo Aguiar, Rosa C. Orellana
Venue: Journal of Algebraic Combinatorics: An International Journal (2008)

We introduce the Hopf algebra of uniform block permutations and show that it is self-dual, free, and cofree. These results are closely related to the fact that uniform block permutations form a factorizable inverse monoid. This Hopf algebra contains the Hopf algebra of permutations of Malvenuto and Reutenauer and the Hopf algebra of symmetric functions in non-commuting variables of Gebhard, Rosas, and Sagan. These two embeddings correspond to the factorization of a uniform block permutation as a product of an invertible element and an idempotent one.
Development of a three-dimensional, regional, coupled wave, current, and sediment-transport model
Authors: John C. Warner, Christopher R. Sherwood, Richard P. Signell, Courtney K. Harris, Hernan G. Arango
Venue: Computers Geosciences (2008)

We are developing a three-dimensional numerical model that implements algorithms for sediment transport and evolution of bottom morphology in the coastal-circulation model Regional Ocean Modeling System (ROMS v3.0), and provides a two-way link between ROMS and the wave model Simulating Waves in the Nearshore (SWAN) via the Model-Coupling Toolkit. The coupled model is applicable for fluvial, estuarine, shelf, and nearshore (surfzone) environments. Three-dimensional radiation-stress terms have been included in the momentum equations, along with effects of a surface wave roller model. The sediment-transport algorithms are implemented for an unlimited number of user-defined non-cohesive sediment classes. Each class has attributes of grain diameter, density, settling velocity, critical stress threshold for erosion, and erodibility constant. Suspended-sediment transport in the water column is computed with the same advection-diffusion algorithm used for all passive tracers and an additional algorithm for vertical settling that is not limited by the CFL criterion. Erosion and deposition are based on flux formulations. A multi-level bed framework tracks the distribution of every size class in each layer and stores bulk properties including layer thickness, porosity, and mass, allowing computation of bed morphology and stratigraphy. Also tracked are bed-surface properties including active-layer thickness, ripple geometry, and bed roughness. Bedload transport is calculated for mobile sediment classes in the top layer. Bottom-boundary layer submodels parameterize wave-current interactions that enhance bottom stresses and thereby facilitate sediment transport and increase bottom drag, creating a feedback to the circulation. The model is demonstrated in a series of simple test cases and a realistic application in Massachusetts Bay.
Adversarial Information Retrieval on the Web (AIRWeb 2007)
Authors: Carlos Castillo, Kumar Chellapilla, Brian D. Davison
Venue: ACM SIGIR Forum (2008)

The ubiquitous use of search engines to discover and access Web content shows clearly the success of information retrieval algorithms. However, unlike controlled collections, the vast majority of Web pages lack an authority asserting their quality. This openness of the Web has been the key to its rapid growth and success, but this openness is also a major source of new adversarial challenges for information retrieval methods.
Relative keyboard input system
Authors: Daniel R. Rashid, Noah A. Smith
Venue: Proceedings of the 13th international conference on Intelligent user interfaces (2008)

This paper describes a "relative keyboard," where keystrokes are treated as inputs in a continuous space relative to each other, instead of a discrete, unambiguous sequence. A user with the ability to touch-type may type anywhere on the sensing surface without the need for a visual keyboard. An implementation of such a system is explored and evaluated on simulated data and real user data.
Model-Driven Automation in Grid Environments
Authors: Cameron Kiddle, Derek Kivi, Rob Simmonds
Venue: Proceedings of the 22nd International Conference on Advanced Information Networking and Applications - Workshops (2008)

Grid computing environments are heterogeneous in terms of the types of computer systems, the applications being run, and the policies governing the use of systems. To support automation in such environments common models to describe systems, applications and scheduling policies are needed. Common models enable the interoperation and reuse of tools transparent to the underlying differences in the environment. This paper relates our experiences in using modelling to support automation in grid environments. We have developed RDF-based models for describing systems, applications and scheduling policy. A GT4-based grid environment consisting of computer systems from across Canada has been established with model information deployed and published via WS MDS. Several examples demonstrating the use of modelling to support automation in the established grid environment are presented.
Space-efficient static trees and graphs
Authors: G. Jacobson
Venue: Proceedings of the 30th Annual Symposium on Foundations of Computer Science (1989)

Data structures that represent static unlabeled trees and planar graphs are developed. The structures are more space efficient than conventional pointer-based representations, but (to within a constant factor) they are just as time efficient for traversal operations. For trees, the data structures described are asymptotically optimal: there is no other structure that encodes n-node trees with fewer bits per node, as N grows without bound. For planar graphs (and for all graphs of bounded page number), the data structure described uses linear space: it is within a constant factor of the most succinct representation.
Compact FinFET Memory Circuits with P-Type Data Access Transistors for Low Leakage and Robust Operation
Authors: Sherif A. Tawfik, Volkan Kursun
Venue: Proceedings of the 9th international symposium on Quality Electronic Design (2008)

A new six transistor (6T) SRAM cell with PMOS access transistors is proposed in this paper for reducing the leakage power consumption while enhancing the data stability and the integration density of FinFET memory circuits. With the proposed SRAM circuit, the voltage disturbance at the data storage nodes during a read operation is reduced by utilizing PMOS access transistors. The read stability is enhanced by 60% while reducing the leakage power by 21% as compared to a standard tied-gate FinFET SRAM cell with the same size transistors. One gate of each pull-up FinFET of the crosscoupled inverters is permanently disabled in order to achieve write-ability with minimum sized transistors. The proposed independent-gate FinFET SRAM circuit with P-type data access transistors reduces the idle mode leakage power, the read power, the write power, and the cell area by 61%, 20%, 11.4%, and 17.5%, respectively, as compared to a standard tied-gate FinFET SRAM cell sized for similar data stability in a 32nm FinFET technology.
Replication degree customization for high availability
Authors: Ming Zhong, Kai Shen, Joel Seiferas
Venue: ACM SIGOPS Operating Systems Review (2008)

Object replication is a common approach to enhance the availability of distributed data-intensive services and storage systems. Many such systems are known to have highly skewed object request probability distributions. In this paper, we propose an object replication degree customization scheme that maximizes the expected service availability under given object request probabilities, object sizes, and space constraints (e.g., memory/storage capacities). In particular, we discover that the optimal replication degree of an object should be linear in the logarithm of its popularity-to-size ratio. We also study the feasibility and effectiveness of our proposed scheme using applications driven by real-life system object request traces and machine failure traces. When the data object popularity distribution is known a priori, our proposed customization can achieve 1.32-2.92 "nines" increase in system availability (or 21-74% space savings at the same availability level) compared to uniform replication. Results also suggest that our scheme requires a moderate amount of replica creation/removal overhead (weekly changes involve no more than 0.24% objects and no more than 0.11% of total data size) under realistic object request popularity changes.
Expectation-maximization for sparse and non-negative PCA
Authors: Christian D. Sigg, Joachim M. Buhmann
Venue: Proceedings of the 25th international conference on Machine learning (2008)

We study the problem of finding the dominant eigenvector of the sample covariance matrix, under additional constraints on the vector: a cardinality constraint limits the number of non-zero elements, and non-negativity forces the elements to have equal sign. This problem is known as sparse and non-negative principal component analysis (PCA), and has many applications including dimensionality reduction and feature selection. Based on expectation-maximization for probabilistic PCA, we present an algorithm for any combination of these constraints. Its complexity is at most quadratic in the number of dimensions of the data. We demonstrate significant improvements in performance and computational efficiency compared to other constrained PCA algorithms, on large data sets from biology and computer vision. Finally, we show the usefulness of non-negative sparse PCA for unsupervised feature selection in a gene clustering task.
Force Reflecting Bilateral Control of Master---Slave Systems in Teleoperation
Authors: A. Alfi, M. Farrokhi
Venue: Journal of Intelligent and Robotic Systems (2008)

In this paper, a simple structure design with arbitrary motion/force scaling to control teleoperation systems, with model mismatches is presented. The goal of this paper is to achieve transparency in presence of uncertainties. The master---slave systems are approximated by linear dynamic models with perturbed parameters, which is called the model mismatch. Moreover, the time delay in communication channel with uncertainties is considered. The stability analysis will be considered for two cases: (1) stability under time delay uncertainties and (2) stability under model mismatches. For the first case, two local controllers are designed. The first controller is responsible for tracking the master commands, while the second controller is in charge of force tracking as well as guaranteeing stability of the overall closed-loop system. In the second case, an additional term will be added to the control law to provide robustness to the closed-loop system. Moreover, in this case, the local slave controller guarantees the position tracking and the local master controller guarantees stability of the inner closed-loop system. The advantages of the proposed method are two folds: (1) robust stability of the system against model mismatches is guaranteed and (2) structured system uncertainties are well compensated by applying independent controllers to the master and the slave sites. Simulation results show good performance of the proposed method in motion tracking as well force tracking in presence of model mismatches and time delay uncertainties.