ppxscal/embedding_network huggingface dataset:
Pitfalls in teaching development and testing of concurrent programs and how to overcome them
Authors: Eitan Farchi
Venue: Proceedings of the 6th workshop on Parallel and distributed systems: testing, analysis, and debugging (2008)

This lecture captures industrial and academic experience in teaching concurrent programming for several years. While the statement of a concurrent protocol is typically small taking only a few pages to complete, the statement implicitly introduces an exponential or possibly infinite space of possible interleavings. The novice is not aware of this, and as a result sometimes does not understand the lecture. To overcome this pitfall, exploration of the protocol interleaving is practiced from day one. A classical example being how many results does 100 threads executing i++ have? Separation of concerns is used to minimize the interleaving space at design time. Specifically, abstract primitives, such as atomic block and a conditional atomic block are introduced as a design tool. They are typically not to be found in practical programming languages. This reduces the space of interleavings to be considered at design time and facilitate verification and review of the protocol. On the other hand, the approach introduces pitfalls encountered in the translation/implementation stage. Once the abstract design is verified and/or tested, it needs to be translated to a commercial language where the synchronization primitives, for performance reasons, are weaker. For example, an atomic block is implemented using a lock unlock pair. But now atomicity needs to be ensured by the protocol implementer---a typical pitfall being the confusion of a lock/unlock code segment with an atomic block. Locations in the code that access the protected shared resources should be identified and access needs to follow the lock/unlock protocol. Exceptions and signals needs to be handled appropriately and adhere to the lock/unlock protocol. To avoid translation pitfalls, bug patterns are taught and precise understanding of the synchronization primitives is emphasized. Testing of the implemented protocol is taught. Testing should be aggressive, at unit test, and attempt to cover the interleaving space instead of common practice of testing concurrency at system test in a round about way through stress. Tools like ConTest or CHESS can be applied to this end.
Quality-driven model-based architecture synthesis for real-time embedded SoCs
Authors: Lech Jówiak, Sien-An Ong
Venue: Journal of Systems Architecture: the EUROMICRO Journal (2008)

The recent spectacular progress in modern microelectronics created a big stimulus towards development of embedded systems. Unfortunately, it also introduced unusual complexity which results in many serious issues that cannot be resolved without new more adequate development methods and electronic design automation tools for the system-level design. This paper discusses the problem of an efficient model-based multi-objective optimal architecture synthesis for complex hard real-time embedded systems, when using as an example a system-level architecture exploration and synthesis method that we developed.
2D tracking control algorithms
Authors: Popescu Marius-Constantin, Petrisor Anca
Venue: Proceedings of the 5th WSEAS International Conference on Computational Intelligence, Man-Machine Systems and Cybernetics (2006)

The paper deals with the problem of control algorithms design and implementation, necessary to position a working tool in a fix point or to track a determined pattern. In this paper is described the way to accomplished the electrical and mechanical part of a working tool and also the way to design and implement a control algorithm necessary to optimize 2D trajectory. Finally the proposed control algorithm is validated through computer simulations.
A parallel protein surface reconstruction system
Authors: Ivan Merelli, Alessandro Orro, Daniele D'Agostino, Andrea Clematis, Luciano Milanesi
Venue: International Journal of Bioinformatics Research and Applications (2008)

In this paper we propose a parallel system for protein surface reconstruction based on techniques of computational geometry. The advantage of our modelling system is the production of both superficial and volumetric description of proteins. This is very important in protein analysis from the functional point of view, because many binding sites are buried inside the macromolecule. However the amount of data to process, both in the volume modelling and in extraction phase, may be huge, in proportion to the selected resolution of the output. For this reason the parallel implementation of the system represents a fundamental aspect in reducing the processing time.
Anonymous and Traceable Authentication Scheme using Smart Cards
Authors: Seil Kim, Hyun Sook Rhee, Ji Young Chun, Dong Hoon Lee
Venue: Proceedings of the 2008 International Conference on Information Security and Assurance (isa 2008) (2008)

Recently, remote user authentication schemes using smart cards has been researched to provide user privacy because of increasing interest and demands. Previously, provided authentication schemes were only concerned about providing user privacy against outside attackers, but the scheme, which guarantees user privacy against both a remote server and outside attackers, has been recently demanded because the user's information has leaked out through the service providers. When the remote server perceives a user doing a malicious act, the server should be able to trace the malicious user by receiving help from a trust agency. In this paper, we suggest a scheme which not only guarantees user privacy against both a remote server and outside attackers, but also provides traceable anonymity authentication.
Transforming learning of programming: a mentoring project
Authors: Daryl D'Souza, Margaret Hamilton, James Harland, Peter Muir, Charles Thevathayan, Cecily Walker
Venue: Proceedings of the tenth conference on Australasian computing education - Volume 78 (2008)

Programming is central to Computer Science and cognate disciplines, and poses early-learning challenges in problem-solving and coding. Since the recent past the School of Computer Science & Information Technology (RMIT University) has provided a student mentoring service to assist novice student programmers with their programming, indeed, to build up their confidence in programming. The service has received favourable feedback from students and, as an interesting aside, has had the added benefit of increasing mentors' confidence and improving mentors' communication skills. Mentors volunteer their services under a University leadership initiative, and are not paid to assist students. In light of such success, we secured a University action-research teaching and learning grant, to investigate aspects of the service delivered to date. While mentoring has been shown to be helpful for novice student programmers to learn and improve their programming, less recognised, but of equal importance, is the value to mentors through the skills and experience they gain. This paper reports early findings of a dual-purpose research investigation into the mentoring service. The research project seeks to discover ways to improve the mentoring service for novice student programmers, as well as to enhance a range of qualities in mentors.
Virtual Organizations
Authors: Matei Ripeanu, Munindar P. Singh, Sudharshan S. Vazhkudai
Venue: IEEE Internet Computing (2008)

Today's organizations are no longer constrained by traditional time and place barriers. Instead, information technology supports virtual organizations: flexible networks of independent, globally distributed entities that share knowledge and resources and work toward a common goal. Resources aren't limited to computing power, but include elements as diverse as storage, network links, data sets, analysis tools, sensors, and scientific instruments. Sharing policies are highly diverse, given that sharing must be controlled, secure, flexible, and limited in time.
An extended arbitrary Lagrangian-Eulerian finite element method for large deformation of solid mechanics
Authors: A. R. Khoei, M. Anahid, K. Shahim
Venue: Finite Elements in Analysis and Design (2008)

In this paper, a new computational technique is presented based on the eXtended arbitrary Lagrangian-Eulerian finite element method (X-ALE-FEM) for large deformation of solid mechanic problems. An arbitrary Lagrangian-Eulerian (ALE) technique is employed to capture the advantages of both Lagrangian and Eulerian methods and alleviate the drawbacks of the mesh distortion in Lagrangian formulation. The X-FEM procedure is implemented to capture the discontinuities independently of element boundaries. The process is accomplished by performing a splitting operator to separate the material (Lagrangian) phase from convective (Eulerian) phase, and partitioning the Lagrangian and relocated meshes with some triangular sub-elements whose Gauss points are used for integration of the domain of elements. In order to demonstrate the efficiency of X-ALE-FEM technique in large deformations, several numerical examples including the die pressing with flexible and rigid central cores and coining problem are presented and the results are compared with those of classical FE and X-FEMs.
Determining termhood for learning domain ontologies in a probabilistic framework
Authors: Wilson Wong, Wei Liu, Mohammed Bennamoun
Venue: Proceedings of the sixth Australasian conference on Data mining and analytics - Volume 70 (2007)

Many existing techniques for term extraction are heuristically-motivated and criticised as ad-hoc. The definitions and assumptions critical to set the boundary for the effectiveness of the techniques are often implicit and unclear. Here we present a probabilistic framework for measuring termhood to address the lack of mathematical foundation in existing techniques.
A multilevel partitioning approach for efficient tasks allocation in heterogeneous distributed systems
Authors: Bassel Arafeh, Khalid Day, Abderezak Touzene
Venue: Journal of Systems Architecture: the EUROMICRO Journal (2008)

This work addresses the problem of allocating parallel application tasks to heterogeneous distributed computing resources, such as multiclusters or Grid environments. The proposed allocation scheme is based on a multilevel graph partitioning and mapping approach. The objective is to find an efficient allocation that minimizes the application completion time, subject to the specified constraints pertinent to the application and system environment. The allocation scheme consists of three phases; the clustering phase, the initial mapping phase and the refinement and remapping phase. The scheme introduces an efficient heuristic in the clustering phase for contracting (coarsening) large size application graphs to the number of processors, called the VHEM method. An initial mapping technique based on a tabu-search approach has been introduced as a basis for the process of refinement and remapping phase. The simulation study shows that the VHEM coarsening heuristic can achieve optimal or near-optimal communication, compared to the HEM method, when the ratio of the number of tasks to the number of processors exceeds a threshold value. The simulation study shows that those optimal or near-optimal VHEM-coarsened graphs have an effect of generating very efficient mappings, when they are compared to the HEM-coarsened graphs.
A new approach for adding browser functionality
Authors: Ronen Vaisenberg, Arjun Satish, Keith A. Mogensen, Ramesh Jain, Sharad Mehrotra
Venue: Proceedings of the nineteenth ACM conference on Hypertext and hypermedia (2008)

In this paper we address the problem of browser extensibility, needed to support the evolving nature of the web. Standards for supporting multimedia content by browsers are constantly updated, extended and introduced while the browser support is left behind. We present a novel approach to add browser support for content adhering to a new standard. Only a small set of requirements needs to be implemented as part of the browser's software, the rest is accounted by client-side code. Client-side code has the advantage that it can account for missing functionality with no changes to the browser, thus making it more dynamic, easier to implement, and enabling third-party developers to contribute. At the same time, it is risk-free for users accessing other content types. On the downside, client-side code suffers from degraded performance and potentially introduces security concerns.
Human resources as facilitators of the adoption of information and communication technologies
Authors: Ana Gargallo-Castel, Marisa Ramirez-Aleson
Venue: International Journal of Information Technology and Management (2008)

This paper studies the importance of human resources, among other factors, as facilitators of the adoption of Information and Communication Technologies (ICTs). We have worked with a sample of 1685 Spanish firms. The results of our analyses (conditioned probit) show that higher employee qualifications, the use of related technologies and greater firm size have a positive impact on both the adoption of ICTs and the volume of investment made.
Automatic recognition of features from freeform surface CAD models
Authors: V. B. Sunil, S. S. Pande
Venue: Computer-Aided Design (2008)

This paper reports the design and implementation of a system for automatic recognition of features from freeform surface CAD models of sheet metal parts represented in STL format. The developed methodology has three major steps viz. STL model preprocessing, Region segmentation and automated Feature recognition. The input CAD model is preprocessed to get a healed and topology enriched STL model. A new hybrid region segmentation algorithm based on both edge- and region-based approaches has been developed to segment the preprocessed STL model into meaningful regions. Geometrical properties of facets, edges and vertices such as gauss and mean curvature at vertices, orientations of facet normals, shape structure of triangles, dihedral edge angle (angle between facets), etc. have been computed to identify and classify the regions. Feature on a freeform surface is defined as a set of connected meaningful regions having a particular geometry and topology which has some significance in design and manufacturing. Feature recognition rules have been formulated for recognizing a variety of protrusion and depression features such as holes, bends, darts, beads, louvres, dimples, dents, ridges/channels (blind and through) etc. occurring on automotive sheet metal panels. The developed system has been extensively tested with various industrial sheet metal parts and is found to be robust and consistent. The features data can be post processed and linked to various downstream CAD/CAM applications like automated process planning, sheet metal tool design, refinement of FEM meshes and product redesign.
Augmentation of Elman Recurrent Network Learning with Particle Swarm Optimization
Authors: Mohamad Firdaus Ab Aziz, Haza Nuzly Abdull Hamed, Siti Mariyam Hj Shamsuddin
Venue: Proceedings of the 2008 Second Asia International Conference on Modelling & Simulation (AMS) (2008)

Despite a variety of Artificial Neural Network (ANN) categories, Backpropagation Network (BP) and Elman Recurrent Network (ERN) are the widespread modus operandi in real applications. However, there are many drawbacks in BP network, for instance, confinement in finding local minimum and may get stuck at regions of a search space or trap in local minima. To solve these problems, various optimization techniques such as Particle Swarm Optimization (PSO) and Genetic Algorithm (GA) have been executed to improve ANN performance. In this study, we exploit errors optimization of Elman Recurrent Network with Backpropagation (ERNBP) and Elman Recurrent Network with Particle Swarm Optimization (ERNPSO) to probe the performance of both networks. The comparisons are done with PSO that is integrated with Neural Network (PSONN) and GA with Neural Network (GANN). The results show that ERNPSO furnishes promising outcomes in terms of classification accuracy and convergence rate compared to ERNBP, PSONN and GANN.
Elusive functions and lower bounds for arithmetic circuits
Authors: Ran Raz
Venue: Proceedings of the 40th annual ACM symposium on Theory of computing (2008)

A basic fact in linear algebra is that the image of the curve f(x)=(x1,x2,x3,...,xm), say over C, is not contained in any m-1 dimensional affine subspace of Cm. In other words, the image of f is not contained in the image of any polynomial-mapping Γ:Cm-1 → Cm of degree~1 (that is, an affine mapping). Can one give an explicit example for a polynomial curve f:C → Cm, such that, the image of f is not contained in the image of any polynomial-mapping Γ:Cm-1 → Cm of degree 2? In this paper, we show that problems of this type are closely related to proving lower bounds for the size of general arithmetic circuits. For example, any explicit f as above (with the right notion of explicitness implies super-polynomial lower bounds for computing the permanent over~C. More generally, we say that a polynomial-mapping f:Fn → Fm is (s,r)-elusive, if for every polynomial-mapping Γ:Fs → Fm of degree r, Im(f) ⊄ Im(Γ). We show that for many settings of the parameters n,m,s,r, explicit constructions of elusive polynomial-mappings imply strong (up to exponential) lower bounds for general arithmetic circuits. Finally, for every r n → Fn2, of degree O(r), that is (s,r)-elusive for s = n1+Ω(1/r). We use this to construct for any r, an explicit example for an n-variate polynomial of total-degree O(r), with coefficients in {0,1,}such that, any depth r arithmetic circuit for this polynomial (over any field) is of size ≥ n1+Ω(1/r). In particular, for any constant r, this gives a constant degree polynomial, such that, any depth r arithmetic circuit for this polynomial is of size ≥ n1+Ω(1). Previously, only lower bounds of the type Ω(n • λr (n)), where λr (n) are extremely slowly growing functions (e.g., λ5(n) = log n, and λ7(n) = log* log*n), were known for constant-depth arithmetic circuits for polynomials of constant degree.
A pen-based tool for efficient labeling of 2D sketches
Authors: Aaron Wolin, Devin Smith, Christine Alvarado
Venue: Proceedings of the 4th Eurographics workshop on Sketch-based interfaces and modeling (2007)

High quality labeled data is essential for developing and evaluating sketch recognition algorithms. Unfortunately, labeling freely-drawn sketches is time-consuming and difficult, if not impossible, using current technologies. These difficulties and the resulting lack of labeled data fundamentally limit the development of recognition algorithms. We present an intuitive, direct manipulation pen-based application for labeling sketch data in any two-dimensional domain. Our labeling tool supports the three essential sketch recognition labeling tasks: stroke fragmentation, stroke grouping and label application. Our interface integrates standard and novel interaction techniques to make each task efficient and natural. In a user study, all users felt that labeling data with our tool was quick and efficient.
lambda-Connectedness Determination for Image Segmentation
Authors: Li Chen
Venue: Proceedings of the 36th Applied Imagery Pattern Recognition Workshop (2007)

Image segmentation is to separate an image into distinct homogeneous regions belonging to different objects. It is an essential step in image analysis and computer vision. This paper compares some segmentation technologies and attempts to find an automated way to better determine the parameters for image segmentation, especially the connectivity value of λ in λ-connected segmentation. Based on the theories on the maximum entropy method and Otsu’s minimum variance method, we propose:(1)maximum entropy connectedness determination: a method that uses maximum entropy to determine the best λ value in λ-connected segmentation, and (2) minimum variance connectedness determination: a method that uses the principle of minimum variance to determine λ value. Applying these optimization techniques in real images, the experimental results have shown great promise in the development of the new methods. In the end, we extend the above method to more general case in order to compare it with the famous Mumford-Shah method that uses variational principle and geometric measure.
Gridless DSMC
Authors: Spencer E. Olson, Andrew J. Christlieb
Venue: Journal of Computational Physics (2008)

This work concerns the development of a gridless method for modeling the inter-particle collisions of a gas. Conventional fixed-grid algorithms are susceptible to grid-mismatch to the physical system, resulting in erroneous solutions. On the contrary, a gridless algorithm can be used to simulate various physical systems without the need to perform grid-mesh optimization. An octree algorithm provides the gridless character to a direct simulation Monte Carlo (DSMC) code by automatically sorting nearest-neighbor gas particles into local clusters. Automatic clustering allows abstraction of the DSMC algorithm from the physical system of the problem in question. This abstraction provides flexibility for domains with complex geometries as well as a decreased code development time for a given physical problem. To evaluate the practicality of this code, the time required to perform the gridless overhead from the octree sort is investigated. This investigation shows that the gridless method can indeed be practical and compete with other DSMC codes. To validate gridless DSMC, results of several benchmark simulations are compared to results from a fixed-grid code. The benchmark simulations include several Couette flows of differing Knudsen number, low-velocity flow past a thin plate, and two hypersonic flows past embedded objects at a Mach number of 10. The results of this comparison to traditional DSMC are favorable. This work is intended to become part of a larger gridless simulation tool for collisional plasmas. Corresponding work includes a gridless field solver using an octree for the evaluation of long range electrostatic forces. We plan to merge the two methods creating a gridless framework for simulating collisional-plasmas.
Linguistic object-oriented web-usage mining
Authors: Tzung-Pei Hong, Cheng-Ming Huang, Shi-Jinn Horng
Venue: International Journal of Approximate Reasoning (2008)

Web mining has become a very important research topic in the field of data mining due to the vast amount of world wide web services in recent years. The fuzzy and the object concepts have also been very popular and used in a variety of applications, especially for complex data description. This paper thus proposes a new fuzzy object-oriented web mining algorithm to derive fuzzy knowledge from object data log on web servers. Each web page itself is thought of as a class, and each web page browsed by a client is thought of as an instance. Instances with the same class (web page) may have different quantitative attribute values since they may appear in different clients. The proposed fuzzy mining algorithm can be divided into two main phases. The first phase is called the fuzzy intra-page mining phase, in which the linguistic large itemsets associated with the same classes (pages) but with different attributes are derived. Each linguistic large itemset found in this phase is then thought of as a composite item used in phase 2. The second phase is called the fuzzy inter-page mining phase, in which the large sequences are derived and used to represent the relationship among different web pages. Both the intra-page linguistic association rules and inter-page linguistic browsing patterns can thus be easily derived by the proposed algorithm at the same time. An example is given to illustrate the proposed algorithm. Experimental results also show the effects of the parameters used in the algorithm.