ppxscal/embedding_network huggingface dataset:
The dirichlet, neumann, and robin problems for the plane deformation of a thin plate on an elastic foundation
Authors: Christine Constanda, Roger Wainwright
Venue:  (2008)

The Dirichlet, Neumann, and Robin boundary value problems for the in-plane deformation of a thin plate on an elastic foundation are studied. For each of the problems, both the finite plate and the infinite plate with a hole are considered. First, the existence of analytical solutions to the six problems is proved, then numerical solutions to four of the problems are calculated. The analytical solutions are derived by starting with the equilibrium equations and the expression of the internal energy density. Next, the mathematical model&mdash;an elliptic system of equations&mdash;is derived. A (3 x 3)-matrix partial differential boundary operator, T, representing the stress on the lateral surface of the plate is introduced. The Betti formulas for the model are established and used to show the uniqueness of the solutions for the six boundary valued problems. A matrix of fundamental solutions and a related matrix of singular solutions are computed. The behavior of these two matrices is investigated both near the singularity and at infinity. The single-layer and double-layer elastic potentials are subsequently defined and their properties are investigated. These elastic potentials are used to define some boundary operators that are fundamental in the development of the solutions to the six boundary value problems. For each problem, two methods for obtaining solutions are proposed: a direct method and an indirect method. For the numerical solutions, the Galerkin method is used in conjunction with the Mathematica software. Finally, the reliability of the computed numerical solutions is discussed.
Montgomery Residue Representation Fault-Tolerant Computation in GF(2k)
Authors: Silvana Medoš, Serdar Boztaş
Venue: Proceedings of the 13th Australasian conference on Information Security and Privacy (2008)

In this paper, we are concerned with protecting elliptic curve computation in a tamper proof device by protecting finite field computation against active side channel attacks, i.e., fault attacks. We propose residue representation of the field elements for fault tolerant Montgomery residue representation multiplication algorithm, by providing fault models for fault attacks, and countermeasures to some fault inducing attacks.
Cyberinfrastructure for Contamination Source Characterization in Water Distribution Systems
Authors: Sarat Sreepathi, Kumar Mahinthakumar, Emily Zechman, Ranji Ranjithan, Downey Brill, Xiaosong Ma, Gregor Laszewski
Venue: Proceedings of the 7th international conference on Computational Science, Part I: ICCS 2007 (2007)

This paper describes a preliminary cyberinfrastructure for contaminant characterization in water distribution systems and its deployment on the grid. The cyberinfrastructure consists of the application, middleware and hardware resources. The application core consists of various optimization modules and a simulation module. This paper focuses on the development of specific middleware components of the cyberinfrastructure that enables efficient seamless execution of the application core in a grid environment. The components developed in this research include: (i) a coarse-grained parallel wrapper for the simulation module that includes additional features for persistent execution, (ii) a seamless job submission interface, and (iii) a graphical real time application monitoring tool. The performance of the cyberinfrastructure is evaluated on a local cluster and the TeraGrid.
Theoretical Bound and Practical Analysis of Connected Dominating Set in Ad Hoc and Sensor Networks
Authors: Alireza Vahdatpour, Foad Dabiri, Maryam Moazeni, Majid Sarrafzadeh
Venue: Proceedings of the 22nd international symposium on Distributed Computing (2008)

Connected dominating set is widely used in wireless ad-hoc and sensor networks as a routing and topology control backbone to improve the performance and increase the lifetime of the network. Most of the distributed algorithms for approximating connected dominating set are based on constructing maximal independent set. The performance of such algorithms highly depends on the relation between the size of the maximum independent set (mis(G)) and the size of the minimum connected dominating set (cds(G)) in the graph G. In this paper, after observing the properties of such subgraphs, we decrease the previous ratio of 3.453 to 3.0 by showing that mis(G) ≤ 3·mcds(G) + 3. Additionally, we prove that this bound is tight and cannot be improved. Finally, we present practical analysis of constructing connected dominating set based on maximal independent set in wireless networks. It is shown that the theoretical bound for unit disk graph is still practically applicable for general wireless networks.
The PIM: an innovative robot coordination model based on Java thread migration
Authors: Raffaele Quitadamo, Danilo Ansaloni, Niranjan Suri, Kenneth M. Ford, James Allen, Giacomo Cabri
Venue: Proceedings of the 6th international symposium on Principles and practice of programming in Java (2008)

There is a growing demand to apply multi-robot systems to address many current problems ranging from search and rescue to distributed surveillance to coordination of small satellites in space. Solving these problems effectively requires that teams of robots coordinate effectively. Many of the algorithms for coordination are based on the so-called centralized paradigm, where a central controlling authority is responsible for coordinating the entire team of robots. Unfortunately, centralized approaches often fall short when dealing with rapidly changing situations, unreliability of communications, and failure of robots, especially in hostile environments. Distributed approaches, in an effort to address such issues, tend to introduce complex negotiation or market-based strategies for distributed task execution, sometimes resulting in cumbersome programming models and suboptimal solutions. In this paper, we introduce the readers to the PIM (Process Integrated Mechanism) approach to multi-robot coordination grounded in research on Java thread migration. The core idea of the PIM is to retain the perspective of the single controlling authority but abandon the notion that it must have a fixed location within the system. Instead, the single coordinating thread is rapidly moved among the team members. The PIM leverages on Java thread mobility to preserve the optimality of the centralized approach, while effectively addressing most of its weaknesses (e.g. sluggish response to dynamic conditions, communication difficulties, and a single point of failure). A prototype implementation of such a model is presented on top of the Mobile JikesRVM framework for Java thread migration, along with some preliminary performance results.
A 3D Shape Descriptor for Human Pose Recovery
Authors: Laetitia Gond, Patrick Sayd, Thierry Chateau, Michel Dhome
Venue: Proceedings of the 5th international conference on Articulated Motion and Deformable Objects (2008)

This paper deals with human body pose recovery through a multicamera system, which is a key task in monitoring of human activity. The proposed algorithm reconstructs the 3D visual hull of the observed body and characterizes its shape with a new 3D shape descriptor. The body pose is then infered through an original two-stage regression process. As the learning step is independant of the camera configuration, the resulting system is easy to set up. This solution is evaluated on synthetic scenes and promising results on real images are also presented.
Ring Signature with Weak Linkability and Its Applications
Authors: Ik Rae Jeong, Jeong Ok Kwon, Dong Hoon Lee
Venue: IEEE Transactions on Knowledge and Data Engineering (2008)

We suggest a linkable ring signature scheme providing strong anonymity and weak linkability. We show that our linkable ring signature scheme can be used to construct a selectively linkable ring signature scheme, an efficient convertible (verifiable) ring signature scheme, and an efficient deductible ring signature scheme.
SuMo: A Framework for Prototyping Distributed and Mobile Software
Authors: Hervé Paulino
Venue: Proceedings of the 8th international conference on Algorithms and Architectures for Parallel Processing (2008)

The current trend in the organization of computational systems is propitious to the definition of run-time infrastructures that embed distribution and mobility. Most of these grow from existent virtual machines that execute sequential or concurrent code. In this paper we present SuMo, a platform that factorizes all communication and mobility dependent operations into a reusable layer. Our purpose is to provide a framework to intuitively and easily extend existing virtual machines to execute mobile distributed computations.
Energy and Timing Constrained System Reward Maximization on Wireless Networks
Authors: Jiayu Gong, Xiliang Zhong, Cheng-Zhong Xu
Venue: Proceedings of the 2008 The 28th International Conference on Distributed Computing Systems (2008)

Power efficiency is an important design issue in embedded devices with limited power supplies. In this paper, we study a reward-based packet scheduling problem in wireless environments. We consider a general scenario in which a transmitter communicates with multiple receivers periodically. To guarantee timely transmission of data, each packet is associated with a delay constraint. The periodic data streams have different importance levels, power functions, and levels of data sizes. The more data a transmitter delivers, the more rewards it obtains. Our objective is to develop schemes that selectively transmit data streams of different data sizes at different transmission rates to maximize the system reward under given time and energy constraints. We show that this problem is NP-hard and develop a dynamic programming algorithm for the optimal solution in pseudo-polynomial time. A fast polynomial-time heuristic approach is presented to achieve close approximation. Simulation results demonstrate that the proposed heuristic approach can achieve a significant improvement over other approaches adapted from existing studies at a small runtime overhead.
Magnetohydrodynamic state estimation with boundary sensors
Authors: Rafael Vazquez, Eugenio Schuster, Miroslav Krstic
Venue: Automatica (Journal of IFAC) (2008)

We present a PDE observer that estimates the velocity, pressure, electric potential and current fields in a magnetohydrodynamic (MHD) channel flow, also known as Hartmann flow. This flow is characterized by an electrically conducting fluid moving between parallel plates in the presence of an externally imposed transverse magnetic field. The system is described by the inductionless MHD equations, a combination of the Navier-Stokes equations and a Poisson equation for the electric potential under the so-called inductionless MHD approximation in a low magnetic Reynolds number regime. We identify physical quantities (measurable on the wall of the channel) that are sufficient to generate convergent estimates of the velocity, pressure, and electric potential field away from the walls. Our observer consists of a copy of the linearized MHD equations, combined with linear injection of output estimation error, with observer gains designed using backstepping. Pressure, skin friction and current measurements from one of the walls are used for output injection. For zero magnetic field or nonconducting fluid, the design reduces to an observer for the Navier-Stokes Poiseuille flow, a benchmark for flow control and turbulence estimation. We show that for the linearized MHD model the estimation error converges to zero in the L^2 norm. Despite being a subject of practical interest, the problem of observer design for nondiscretized 3-D MHD or Navier-Stokes channel flow has so far been an open problem.
Analysis and design of effective and low-overhead transmission power control for VANETs
Authors: Jens Mittag, Felix Schmidt-Eisenlohr, Moritz Killat, Jérôme Härri, Hannes Hartenstein
Venue: Proceedings of the fifth ACM international workshop on VehiculAr Inter-NETworking (2008)

The control of vehicles' radio communication behavior to deal with the constrained available wireless bandwidth has been identified as a key challenge in VANETs. As an element of congestion control, this paper addresses distributed transmission power control as a means to control the impact of periodic transmissions (`beacons') on the overall channel load. By also considering recently discussed fairness issues, we first examine the trade-off between the effectiveness of controlling the channel load on the one hand and the corresponding costs in terms of the required packet overhead on the other hand. We provide insights to the underlying estimation problems and present a sensitivity analysis with respect to non-homogeneous vehicular traffic densities and non-perfect channel conditions. Second, based on the analysis, we propose a segment-based power adjustment approach based on a distributed vehicle density estimation. The approach put forward in this paper reduces overhead by two orders of magnitude compared to previous approaches while still being effective in controlling the channel load.
Analysis of a modification of Gusfield's recursive algorithm for reconstructing ultrametric trees
Authors: Volker Heun
Venue: Information Processing Letters (2008)

The reconstruction of an ultrametric tree from a distance matrix is a very frequent subproblem in clustering or reconstructing evolutionary trees, both are common problems in Bioinformatics. In his famous book, Gusfield presented a very simple, but not time-optimal recursive algorithm for this problem. We show that a simple modification of Gusfield's algorithm allows a time-optimal solution.
Using the Rasch model to assess a university service on the basis of student opinions
Authors: Fabio Aiello, Vincenza Capursi
Venue: Applied Stochastic Models in Business and Industry (2008)

In this paper we use the Rasch model (RM) as a tool to measure the perceived quality of student services at the Reception Office of an Italian university faculty. This paper has both a substantive and a methodological aim. The former is concerned with measuring the service quality of the Reception Office, while the latter concerns the definition and validation of an instrument for measuring perceived quality. The sample comprised 273 students enrolled at the Faculty of Economics at the University of Palermo (Aiello F. Il modello di Rasch per la costruzione di uno strumento di misura della qualit&agrave; di un Servizio. Ph.D. Thesis, University of Palermo, Palermo, 2005). The RM is applied to produce specific measurements of the perceived quality for each service feature in order to conduct a critical analysis of the results. We sought to verify some important assumptions and desiderata of the RM: (i) Unidimensionality: in the user's opinion, are the single features of the service &lsquo;good&rsquo; at defining the whole construct of global quality? (ii) Targeting: is the range of the measurements provided by the RM for each item able to cover all the possible satisfaction levels required by the students? (iii) Measurement of the perceived quality of each feature: is it possible to rank the items according to their level of perceived quality (which may be a good way of identifying the weaknesses of the service in order to allocate additional resources to make due adjustments)? (iv) Item separation: are the service features (items) redundant with respect to the satisfaction levels required by the students? (v) Differential item functioning: is the item-difficulty hierarchy invariant across the student factors? In our opinion the last issue was of great interest as it can identify assessment differences. Indeed, there appeared to emerge a different severity of judgment towards the single features of the service from the students, according to their length of stay in the system. Copyright &copy; 2008 John Wiley & Sons, Ltd.
Data-Embeddable Texture Synthesis
Authors: Hirofumi Otori, Shigeru Kuriyama
Venue: Proceedings of the 8th international symposium on Smart Graphics (2007)

Data hiding techniques onto images provide tools for protecting copyright or sending secret messages, and they are currently utilized as a simple input device of a cell phone by detecting a data embedded in an image with an equipped digital camera. This paper presents a method of synthesizing texture images for embedding arbitrary data by utilizing the smart techniques of generating repetitive texture patterns through feature learning of a sample image. We extended the techniques so that a synthesized image can effectively conceal the embedded pattern, and the pattern can be robustly detected from a photographed image. We demonstrate the feasibility of our techniques using texture samples including an image scanned from real material.
Role ambiguity: impact on job satisfaction of call center agents
Authors: Marc Muchnick
Venue:  (2008)

The call center agent (CCA) profession is growing rapidly because organizations are learning that a competitive advantage can be attained through their CCAs. By providing front-line support, CCAs shape much of the perception that customers have about the organization. This study assessed the relationship between role ambiguity and job satisfaction for CCAs. Role ambiguity can occur in situations where an individual has a lack of understanding around his or her role and/or expectations. Job satisfaction refers to his or her response to the conditions of work as these perceptions are shaped by different interpretations of objective differences in work conditions. It is considered at both the overall and facet levels. Extensively used role ambiguity and job satisfaction instruments were administered to CCAs in a Web survey, then analyzed quantitatively. Demographic characteristics were gathered to determine if they impact this relationship. Prior research has repeatedly concluded that a negative relationship exists between role ambiguity and job satisfaction for various professions. However, little research of this kind has been devoted to CCAs. No single study has considered the impact of demographics on the relationship between role ambiguity and facet level job satisfaction for CCAs. This study found a significant negative correlation, both at the overall and facet level measurements. In addition, each of the nine demographic characteristics considered played a moderating role to a varying degree. Regarding future research, this topic can be explored qualitatively to determine if the same conclusions are reached. Alternatively, other survey instruments can be used. Also, call centers can be studied categorically. Finally, other consequences of role ambiguity, antecedents of job satisfaction, and demographic variables can be included.
The Application of ICA to the X-Ray Digital Subtraction Angiography
Authors: Songyuan Tang, Yongtian Wang, Yen-Wei Chen
Venue: Proceedings of the 4th international symposium on Neural Networks: Part II--Advances in Neural Networks (2007)

The traditional enhancement of X-ray digital subtraction angiography (DSA) is to subtract the mask image and living image so as to remove the background such as ribs, spine, cathers, organs and etc, and obtain the enhanced vessel trees. However, the DSA have serious motion artifacts, poor local contrast and noises, when subtraction technique is used, some tiny vessels are broken, and even disappeared when visualized. To attack the problem, we use independent component analysis instead of subtraction technique. This technique is proved to be very efficient to enhance vessels. Experimental results of simulated data and several clinical data show that the proposed method is robust and can obtain good vessel trees.
Radar Data Transmission
Authors: John V. Harrington
Venue: IEEE Annals of the History of Computing (1983)

The paper reviews the development of radar data transmission and its role in the SAGE system. The work leading to the design of the FST-1 and FST-2 radar data-compression systems is described.
Proceedings of the third international workshop on Graph and model transformations
Venue: International Conference on Software Engineering (2008)

It is our pleasure to welcome you to the 3rd International Workshop on Graph and Model Transformations -- GraMoT '08. This year's workshop continues with the tradition of being the premier forum for presentation of research results and experience reports on graph and model transformations. The goal of the workshop is to foster interaction between the graph transformation and the model transformation community to facilitate exchange of results and challenge problems. The graph transformation research community has built up a significant body of knowledge over the past 30 years and in addition to the theoretical base several practical implementations have been created. The research area of model transformations has recently been identified as a key subject in model-driven development. Graph transformations could offer an elegant theory and powerful concepts for the model-driven engineering of software systems, while the software engineering community can generate interesting challenges for the graph transformation community. Therefore, there is a need for strong interaction and inter-operation between these communities: the intellectual interchange of ideas, problems, and solutions will lead to major advances in both fields. The call for papers attracted a number of submissions, seven of which have been accepted for presentation at the workshop. Each paper was peer-reviewed. The papers were grouped into the following categories: (1) Correspondence issues of model transformations, (2) Graph transformation for model transformation, and (3) Correctness Properties of model transformations. In addition to the presentations of the papers, the program includes discussion sessions on challenges of multi-directional model transformations, and on the maturity of model transformations. We hope that these proceedings will serve as a valuable reference for researchers and developers in the area of graph and model transformations.
On-Line 3D Geometric Model Reconstruction
Authors: H. Zolfaghari, K. Khalili
Venue: Proceedings of the 8th international conference on Computational Science, Part II (2008)

Triangulation techniques along with laser technology have been widely used for 3D scanning, however, 3D scanning of moving object and on-line modeling have received less attention. The current work describes a system developed for on-line CAD model generation using scanned data. The system developed uses structured laser light pattern and a digital CCD camera to generate and capture images from which the range data is extracted. The data is then analyzed to reconstruct the geometric model of the moving object. To exploit the potential of a geometric modeler the model is represented in a commercial CAD software. To reduce errors the system employs on-line calibration, light distribution correction algorithm, camera calibration, and subpixeling techniques. A data reduction scheme has also been incorporated to eliminate redundant data.