ppxscal/embedding_network huggingface dataset:
A treecode for potentials of the form r-λ
Authors: Kasthuri Srinivasan, Vivek Sarin
Venue: International Journal of Computer Mathematics (2007)

It is known that the classical multilevel fast multipole method is a good technique for accelerating the iterative solution of integral equations with the Green's function kernel 1/r. However, few methods have been proposed for problems in molecular dynamics and computational chemistry where the Green's function is of the form r-λ, λ≥1. In this paper, we describe an efficient algorithm for computing potentials in which the integral equations have r-λ kernels. We propose a treecode algorithm which uses spherical harmonics to compute multipole coefficients that are used to evaluate these potentials. The key idea in this algorithm is the use of ultraspherical polynomials to represent r-λ in a manner analogous to the use of Legendre polynomials for the expansion of the Coulomb potential r-1. We exploit the relationship between ultraspherical and Legendre polynomials to develop a natural generalization of the multipole expansion theorem which was used in the multilevel fast multipole method. This theorem is used along with a hierarchical scheme to compute potentials of the form r-λ. The complexity of the algorithm is O(p3Nlog N) where N is the number of interacting particles and p is a small constant. We discuss the advantages of our algorithm over existing single level methods based on Cartesian coordinate expansion schemes. The efficiency of the algorithm is illustrated with numerical experiments.
Research of PMU optimal placement in power systems
Authors: Tian-Tian Cai, Qian Ai
Venue: Proceedings of the 5th WSEAS/IASME International Conference on Systems Theory and Scientific Computation (2005)

The analysis of power system observability and the rules of PMU placement are concisely presented. Several algorithms of PMU placement as well as their differences and relations are discussed in details: a graph-theoretic procedure based on Depth First Search can find the optimal placement the most quickly; Simulated Annealing Method can help the algorithm converge to global optimum. Base on these two algorithms, an improved algorithm: Minimum Spanning Tree Method is proposed. It keeps good balance of quality and efficiency of the optimal placement, and improves the multiformity of the results by improving the optimization rule of Depth First Search Method.
Intensive Programme on Information and Communication Security
Authors: Christian Schläger, Ludwig Fuchs, Günther Pernul
Venue: Proceedings of the 2008 Third International Conference on Availability, Reliability and Security (2008)

IT Security is a problem that can only be addressed and taught holistically. Just as broad as the field of ICT itself, IT Security is an integral part of all network and software applications. Security must be guaranteed throughout services. Too often, a single university or department cannot offer the complete range of IT Security subjects to their students or provide the up-to-date information and knowledge needed. Consequently, the demand of keeping up with hackers, threats, and risks is hardly met. Our proposal is a combination of the know-how of multiple institutions, aligned in an Intensive Programme for Master- and PhD Students of Computer Science, Information Systems, and Business Informatics. The proposed Intensive Programme on Information and Communication Security (IPICS) uses e-learning and traditional learning methods to form a blended learning course. Using the synergies of 19 contracted European Universities and their IT Security experts, IPICS will deliver momentum for IT Security education and training to those who take part and furthermore through their networks.
An interdisciplinary accounting forensics course to improve computer science enrollments
Authors: Suvineetha Herath, Ajantha Herath, Robert Kachur, Susantha Herath
Venue: Journal of Computing Sciences in Colleges (2008)

Nationwide undergraduate enrollments in Computer Science classes have been declining over the years. Enrollments can be increased by introducing interdisciplinary information assurance and security courses with interfaces to other majors. This paper emphasizes the importance of introducing a general Computer Forensics course and a more specific Accounting Forensics course addressing current issues to interface with Business and Criminal Justice majors.
Context-Aware Environment-Role-Based Access Control Model for Web Services
Authors: Chun-Dong Wang, Ting Li, Li-Chun Feng
Venue: Proceedings of the 2008 International Conference on Multimedia and Ubiquitous Engineering (2008)

The paper presents a context-aware environment-role-based access control model (CERBAC). Unlike traditional systems where access control has been explored, access decisions may depend on the context in which requests are made. It illustrated how the well-developed notion of roles can be used to capture security relevant context of the environment in which access requests are made. By introducing environment roles, a novel access control framework that incorporates context-based access control it creates. Moreover a architecture is presented that supports security policies that make use of environment roles to control access to resources. Furthermore, it outlines the configuration mechanism needed to apply our model to the Web services environment, and describes the implementation architecture for the system.
Extreme streaming: business optimization driving algorithmic challenges
Authors: William O'Connell
Venue: Proceedings of the 2008 ACM SIGMOD international conference on Management of data (2008)

Organizations are striving for competitive advantage. As a result, business optimization is being pushed to new heights in terms of volume and speed. Areas such as customer profitability, campaign profitability or customer insight for better service are driving new analytical challenges as well as new algorithms over large volumes of data. Using Telecom as an example, this talk will discuss business demands which are driving an evolution of analytics over extremely high volumes of streaming data being ingested into a warehouse -- this business direction is forcing algorithms to evolve. In this environment, we are forced to deal with (1) massive continuous ingest rates, data changes/updates while the same data is being consumed by applications, users and processes, (2) dealing with scalability without disruption, and (3) overcoming the physical limits of the infrastructure (e.g., IO). This talk will address both how these technical challenges are being addressed at a high-level, as well as known problem areas for further research. This talk will also highlight issues of new algorithmic approaches arising from the business needs and the research issues associated with them. Examples include (1) streaming analytics, (2) social analytical algorithms integrated into data mining approaches within these continuously streamed environments and (3) new data types such as voice and textual analytics for customer calling pattern and churn analysis.
Modeling and Simulation of Hospital Material Flows
Authors: Tiina I. Rimpiläinen, Heikki Koivo
Venue: Proceedings of the Tenth International Conference on Computer Modeling and Simulation (2008)

Hospital support activities have received little attention and there is very little literature available about this subject. Rather than a literature study, this research is mostly based on interviews, findings, and observations. The purpose of this work is to model and simulate hospital material flows and to study their behavior in different circumstances. The model is made for the Meilahti hospital complex. With some extra work it can be tailored to fit other hospitals also. The model has been used to investigate the capacity needs in the event that transportation needs in the future increase. The model is a tool that assists in decision-making. Simulated experiments can be made with different alternatives before making any changes in the physical system.
A hierarchical abstraction model for software engineering
Authors: Yingxu Wang
Venue: Proceedings of the 2nd international workshop on The role of abstraction in software engineering (2008)

Abstraction is a basic foundation and a powerful means in science and engineering, such as philosophy, mathematics, cognitive informatics, computing, and software engineering, because any complex inference process is based on it. A Hierarchical Abstraction Model (HAM) is presented in this paper, which elaborates the five levels of abstraction known as the analogue objects, diagrams, natural languages, professional notation systems, and mathematics. On the basis of the HAM model, main roles of abstraction in software engineering are explained, and a number of fundamental principles for software engineering practice are derived. The cognitive constraints, limitations of conventional descriptive means and modeling methodologies, as well as the need for more powerful denotational mathematics for software engineering are identified.
Optimal maintenance of a spanning tree
Authors: Baruch Awerbuch, Israel Cidon, Shay Kutten
Venue: Journal of the ACM (JACM) (2008)

In this article, we show that keeping track of history enables significant improvements in the communication complexity of dynamic network protocols. We present a communication optimal maintenance of a spanning tree in a dynamic network. The amortized (on the number of topological changes) message complexity is O(V), where V is the number of nodes in the network. The message size used by the algorithm is O(log &verbar;ID&verbar;) where &verbar;ID&verbar; is the size of the name space of the nodes. Typically, log &verbar;ID&verbar; &equals; O(log V). Previous algorithms that adapt to dynamic networks involved &Omega; (E) messages per topological change&mdash;inherently paying for re-computation of the tree from scratch. Spanning trees are essential components in many distributed algorithms. Some examples include broadcast (dissemination of messages to all network nodes), multicast, reset (general adaptation of static algorithms to dynamic networks), routing, termination detection, and more. Thus, our efficient maintenance of a spanning tree implies the improvement of algorithms for these tasks. Our results are obtained using a novel technique to save communication. A node uses information received in the past in order to deduce present information from the fact that certain messages were NOT sent by the node's neighbor. This technique is one of our main contributions.
The changing research funding regime in Australia and academic productivity
Authors: Dora Marinova, Peter Newman
Venue: Mathematics and Computers in Simulation (2008)

Australian university research output has been questioned by the Federal Government. A new research funding system is soon to be introduced which is likely to place a heavier weight on publications. Although the importance of publications is not disputed, the article argues that there is no reason for the performance of the Australian academics to be doubted. Data on research publications is used to show that Australia outperforms the UK and New Zealand whose systems are being used as the model for the proposed changes in Australia. The gap between Australia and these two countries has in fact widened since their research funding reforms were introduced. Further data is provided on different citation systems, research funding and PhD completions in one academic unit, namely the Institute for Sustainability and Technology Policy (ISTP) as a case study to demonstrate productivity and quality gains during the period under question. It is usual practice for the Australian Federal Government to shape the country's research priorities to better reflect and care for the needs of the economy, society and the physical environment where they exist. The funding for research should provide the basis for achieving such long-term sustainability. A country with a long-term vision for the future should use universities as a social pillar, which can guarantee brighter prospects for its coming generations. For Australia to have a strong and world-class university research sector, adequate resources should be provided to match its current achievements. Also, a (new) funding model should allow for diversity and flexibility in research to properly reflect the complexity of the academic world.
Identity Management, Privacy, and Price Discrimination
Authors: Alessandro Acquisti
Venue: IEEE Security and Privacy (2008)

In the economics literature, privacy is usually discussed in the context of consumers' preferences and price discrimination: merchants are interested in finding out a consumer's preferences, because from the latter they can infer the consumer's maximum willingness to pay for a good. However, economists also acknowledge that consumer privacy is not just about hiding the price you may pay for a good: during any economic transaction a consumer may rationally want to share with a merchant certain types of personal data while keeping others private. Identity management systems can support such selective information revelation strategies, allowing for economic transactions in which some level of information sharing is accompanied by some level of information hiding. In this paper we discuss what forms of privacy of personal data are compatible with merchants' interests in knowing more about their consumers and their preferences, and examine several ways in which identity management systems can protect certain types of information privacy while simultaneously enabling personalization and price discrimination.
SOA Simulation and Verification by Event-Driven Policy Enforcement
Authors: W. T. Tsai, Xinyu Zhou, Yinong Chen
Venue: Proceedings of the 41st Annual Simulation Symposium (anss-41 2008) (2008)

The verification of SOA (Service-Oriented Architecture) applications is important, and, simulation is a promising method because it provides runtime behavior and performance analysis. This paper uses a BPEL engine as a simulation engine to simulate SOA applications, and proposes an event drivenpolicy enforcement framework to verify the SOA applications during simulation.
Design of nonlinear PI controller for velocity control of induction motor
Authors: Tae-Seok Oh, Nam-Euk Her, Il-Hwan Kim
Venue: Proceedings of the 5th WSEAS International Conference on Computational Intelligence, Man-Machine Systems and Cybernetics (2006)

This paper presents a robust speed control method of induction motors(IM) using a non-linear PI controller(NPI), NPI is high gain controller in region of small error, and low gain controller in region of large error. So in steady state, system will be robust against variation of load torque. The simulation and experiment results show the validity of proposed control scheme.
Petaflop/s, seriously
Authors: David E. Keyes
Venue: Proceedings of the 22nd annual international conference on Supercomputing (2008)

Sustained floating-point rates on real applications, as tracked by the Gordon Bell Prize, have increased by over five orders of magnitude from 1988, when 1 Gigaflop/s was reported on a structural simulation, to 2006, when 200 Teraflop/s were reported on a molecular dynamics simulation. Various versions of Moore's Law over the same interval provide only two to three orders of magnitude of improvement for an individual processor; the remaining factor comes from concurrency, which is of order 100,000 for the BlueGene/L computer, the platform of choice for the majority of recent Bell Prize finalists. As the semiconductor industry begins to slip relative to its own roadmap for silicon-based logic and memory, concurrency will play an increasing role in attaining the next order of magnitude, to arrive at the long-awaited milepost of 1 Petaflop/s sustained on a practical application, which should occur around 2009. Simulations based on Eulerian formulations of partial differential equations can be among the first applications to take advantage of petascale capabilities, but not the way most are presently being pursued. Only weak scaling can get around the fundamental limitation expressed in Amdahl's Law and only optimal implicit formulations can get around another limitation on scaling that is an immediate consequence of Courant-Friedrichs-Lewy stability theory under weak scaling of a PDE. Many PDE-based applications and other lattice-based applications with petascale roadmaps, such as quantum chromodynamics, will likely be forced to adopt optimal implicit solvers. However, even this narrow path to petascale simulation is made treacherous by the imperative of dynamic adaptivity, which drives us to consider algorithms and queuing policies that are less synchronous than those in common use today. Drawing on the SCaLeS report (2003-2004), the latest ITRS roadmap, some back-of-the-envelope estimates, and numerical experiences with PDE-based codes on recently available platforms, we will attempt to project the pathway to Petaflop/s for representative applications.
Enhancing student learning using concept mapping and learning by teaching environment
Authors: Xudong Yu, Steve Klein
Venue: Journal of Computing Sciences in Colleges (2008)

This paper describes our effort to incorporate concept maps into a Computer Science introductory course. Studies were conducted that analyze student performance in relation to concept map activities to determine the benefit of concept maps as a learning tool. Our results not only support the idea of concept mapping as a teaching tool, they also suggest that students gain the most when they are directly involved in creating the concept map. A long term objective of this research project is to create a generic Learning-by-Teaching Environment (LTE) that can function in a variety of domains including general Computer Science. Our experience also suggests that a sophisticated and adaptive LTE could be successful in helping college students acquire a deeper understanding of course material and a better clarification of any prior topic-based misconceptions.
Inspiring future IT professionals with Mars rovers
Authors: Isaac Rieksts, Glenn Blank
Venue: Journal of Computing Sciences in Colleges (2008)

With the goal of inspiring at-risk middle school students, we have developed an innovative curriculum using one sixth replicas of the rovers currently on Mars. Each student receives hands-on experience by performing missions in a simulation program. These missions allow students to relate to the process of controlling the actual rovers. Furthermore, students have an opportunity to remotely program and control the replicas in a realistic Martian landscape created in the basement of a middle school. Programming robots in this landscape is the centerpiece of a Technology curriculum in all four middle schools in the Allentown School District as well as a summer and Saturday program at Lehigh University.
Calculation from the current-voltage and capacitance-voltage measurements of characteristics parameters of Cd/CdS/n-Si/Au-Sb structure with CdS interface layer grown on n-Si substrate by SILAR method
Authors: M. Sağlam, A. Ateş, B. Güzeldir, M. A. Yıldırım, A. Astam
Venue: Microelectronic Engineering (2008)

The CdS thin film has been directly formed on n-type Si substrate to form an interfacial layer between cadmium (Cd) and n-type Si with Successive Ionic Layer Adsorption and Reaction (SILAR) method. An Au-Sb electrode has been used as an ohmic contact. The Cd/CdS/n-Si/Au-Sb structure has demonstrated clearly rectifying behaviour by the current-voltage (I-V) curves studied at room temperature. The characteristics parameters such as barrier height, ideality factor and series resistance of Cd/CdS/n-Si/Au-Sb structure have been calculated from the forward bias I-V and reverse bias C^-^2-V characteristics. The diode ideality factor and the barrier height have been calculated as n=2.06 and @F"b=0.92eV by applying a thermionic emission theory, respectively. The diode shows non-ideal I-V behaviour with an ideality factor greater than unity that can be ascribed to the interfacial layer, the interface states and the series resistance. At high current densities in the forward direction, the series resistance (R"s) effect has been observed. The values of R"s obtained from dV/d(lnI)-I and H(I)-I plots are near to each others (R"s =182.24@W and R"s =186.04@W, respectively). This case shows the consistency of the Cheung's approach. In the same way, the barrier height calculated from C^-^2 -V characteristics varied from 0.698 to 0.743eV. Furthermore, the density distribution of interface states (N"s"s) of the device has been obtained from the forward bias I-V characteristics. It has been seen that, the N"s"s has almost an exponential rise with bias from the mid gap toward the bottom of conduction band.
Implicit Detection of Hidden Processes with a Local-Booted Virtual Machine
Authors: Yan Wen, Jinjing Zhao, Huaimin Wang
Venue: Proceedings of the 2008 International Conference on Information Security and Assurance (isa 2008) (2008)

Currently stealth malware is becoming a major threat to the PC computers. Process hiding is the technique commonly used by stealth malware to evade detection by anti-malware scanners. On the defensive side, previous host-based approaches will be defeated once the privileged stealth malware controls a lower reach of the system. The virtual machine (VM) based solutions gain tamper resistance at the cost of losing the OS-level process view. Moreover, existing VM-based approaches cannot introspect the preinstalled OS which is just the protecting concern for PC users. In this paper, we present a new VM-based approach called Libra which accurately reproduces the software environment of the underlying preinstalled OS within the Libra VM and provides an OS-level semantic view of the processes. With our new local-booting technology, Libra VM just boots from the underlying host OS but not a newly installed OS image. Thus, Libra provides a way to detect the existing process-hiding stealth malware in the host OS. In addition, instead of depending on the guest information which is subvertable to the privileged guest malware, Libra adopts a unique technique to implicitly construct the Trusted View of Process List (TVPL) from within the virtualized hardware layer. Our evaluation results with real-world hiding-process rootkits, which are widely used by stealth malware, demonstrate its practicality and effectiveness.
Fabric defect detection using modified local binary patterns
Authors: F. Tajeripour, E. Kabir, A. Sheikhi
Venue: EURASIP Journal on Advances in Signal Processing (2008)

Local binary patterns (LBPs) are one of the features which have been used for texture classification. In this paper, a method based on using these features is proposed for fabric defect detection. In the training stage, at first step, LBP operator is applied to an image of defect free fabric, pixel by pixel, and the reference feature vector is computed. Then this image is divided into windows and LBP operator is applied to each of these windows. Based on comparison with the reference feature vector, a suitable threshold for defect free windows is found. In the detection stage, a test image is divided into windows and using the threshold, defective windows can be detected. The proposed method is multiresolution and gray scale invariant and can be used for defect detection in patterned and unpatterned fabrics. Because of its simplicity, online implementation is possible as well.
Bifurcation analysis on a discrete-time tabu learning model
Authors: Min Xiao, Jinde Cao
Venue: Journal of Computational and Applied Mathematics (2008)

In this paper, we consider a discrete-time tabu learning single neuron model. After investigating the stability of the given system, we demonstrate that Pichfork bifurcation, Flip bifurcation and Neimark-Sacker bifurcation will occur when the bifurcation parameter exceed a critical value, respectively. A formula is given for determining the direction and stability of Neimark-Sacker bifurcation by applying the normal form theory and the center manifold theorem. Some numerical simulations for justifying the theoretical results are also provided.