ppxscal/embedding_network huggingface dataset:
Applying a Macro Model of Ad Hoc Networks to Access Control
Authors: Congzhou Zhou, N. F. Maxemchuk
Venue: Proceedings of the Seventh International Conference on Networking (2008)

Our previous work proposes a macro model that controls the flows across naturally occurring bottlenecks in multi-hop wireless networks. The macro model resembles a conventional wired network, and allows us to apply extant research on flow control directly to ad hoc networks. In this paper, we further justify the feasibility of applying our macro model of ad hoc networks to access control and the validity of only controlling the flows across bottlenecks. We describe a simple rule that partitions the network into super-nodes. We then introduce a probabilistic geographic routing protocol that routes packets between bottlenecks to avoid congestion within super-nodes. Simulation results show that not only is the average flow in non-bottlenecked areas less than the average flow across bottlenecks, but the flows in each of the transmission areas that is not in a bottleneck are less than the flows in the transmission areas within the bottleneck.
Effective one-dimensional electronic structure of InGaAs quantum dot molecules
Authors: N. Thudsalingkarnsakul, T. Limwongse, N. Siripitakchai, S. Panyakeow, S. Kanjanachuchai
Venue: Microelectronic Engineering (2008)

Self-assembled InGaAs quantum dot molecules (QDMs) are grown by molecular beam epitaxy. Their optical characteristics at 77K have been characterized by photoluminescent (PL) measurements. The ground- and excited-state emissions of the quantum dot ensembles are explained by solving for a self-consistent solution of Schrodinger-Poisson equations in one dimension. Our simplified approach provides an effective cross-sectional structure of the QDM that predicts emission peaks with an accuracy of better than 1meV.
Two noniterative algorithms for computing posteriors
Authors: Jun Yang, Guohua Zou, Yu Zhao
Venue: Computational Statistics (2008)

In this paper, we first propose a noniterative sampling method to obtain an i.i.d. sample approximately from posteriors by combining the inverse Bayes formula, sampling/importance resampling and posterior mode estimates. We then propose a new exact algorithm to compute posteriors by improving the PMDA-Exact using the sampling-wise IBF. If the posterior mode is available from the EM algorithm, then these two algorithms compute posteriors well and eliminate the convergence problem of Markov Chain Monte Carlo methods. We show good performances of our methods by some examples.
The dynamic hierarchical Dirichlet process
Authors: Lu Ren, David B. Dunson, Lawrence Carin
Venue: Proceedings of the 25th international conference on Machine learning (2008)

The dynamic hierarchical Dirichlet process (dHDP) is developed to model the time-evolving statistical properties of sequential data sets. The data collected at any time point are represented via a mixture associated with an appropriate underlying model, in the framework of HDP. The statistical properties of data collected at consecutive time points are linked via a random parameter that controls their probabilistic similarity. The sharing mechanisms of the time-evolving data are derived, and a relatively simple Markov Chain Monte Carlo sampler is developed. Experimental results are presented to demonstrate the model.
Facial feature extraction using complex dual-tree wavelet transform
Authors: Turgay Çelik, Hüseyin Özkaramanlı, Hasan Demirel
Venue: Computer Vision and Image Understanding (2008)

In this paper, we propose a novel method for facial feature extraction using the directional multiresolution decomposition offered by the complex wavelet transform. The dual-tree implementation of complex wavelet transform offered by Selesnick is used (DT-DWT(S)) [I.W., Selesnick, R.G. Baraniuk, N.C. Kingsbury, The dual-tree complex wavelet transform, IEEE Signal Processing Magazine, 6, s.l., IEEE, November 2005, vol. 22, pp. 123-151.]. In the dual-tree implementation, two parallel discrete wavelet transform (DWT) with different lowpass and highpass filters in different scales are used. The linear combination of subbands generated by two parallel DWT is used to generate 6 different directional subbands with complex coefficients. A test statistic, which is derived with absolute value of complex coefficient, whose distribution matches very closely with the directional information in the 6 subbands of the DT-DWT(S) is derived and used for detecting facial feature edges. The use of the complex wavelet transform is motivated by the fact that it helps eliminate the effects of non-uniform illumination, and the directional information provided by the different subbands makes it possible to detect edge features with different directionalities in the corresponding image. Edge information of facial area is enhanced using multiresolution structure of DT-DWT(S). The proposed method also employs an adaptive skin colour model instead of a predefined skin colour statistic. The model is developed with a unimodal Gaussian distribution using the skin region which is extracted excluding the detected edge map obtained from the DT-DWT(S). By combining the edge information obtained by using DT-DWT(S) and the non-skin areas obtained from the pixel statistics, the facial features are extracted. The algorithm is tested over the well known Carnegie Mellon University (CMU) and Marks Weber face databases. The average detection rate of the proposed method using DT-DWT(S) provides up to 9.6% improvement over the same method using discrete wavelet transform (DWT).
Effects of frequency of pulsatile flow on morphology and integrin expression of vascular endothelial cells
Authors: Kazushi Ito, Naoya Sakamoto, Toshiro Ohashi, Masaaki Sato
Venue: Technology and Health Care (2007)

Endothelial cells are known to adapt their morphology and functions in response to different types of fluid flow. In vivo, endothelial cells are exposed to varying frequencies of pulsatile flow. Therefore, in this study, the effects of frequency of pulsatile flow on morphology and &alpha;$_{v}$&beta;$_{3}$ integrin expression of bovine aortic endothelial cells (BAEC) were investigated. A newly developed flow-system was used to apply pulsatile flow at frequencies of 0.5, 1.0, and 1.5 Hz to BAEC for 12 h. At 1.0 Hz, the expression of &alpha;$_{v}$&beta;$_{3}$ integrin was significantly higher at the central regions of cells than at the upstream regions. In contrast, at 0.5 and 1.5 Hz, the expression of &alpha;$_{v}$&beta;$_{3}$ integrin was significantly higher at the upstream regions than at the central regions. Morphological observation revealed that BAEC under pulsatile flow frequencies of 0.5 and 1.0 Hz exhibited elongated morphologies and oriented with the direction of flow. In addition, stress fibers developed parallel to the cell major axis. Similar results were obtained under steady flow conditions. In contrast, BAEC under 1.5 Hz elongated but with a random orientation. These results suggest that BAEC morphology and integrin expression may be modulated by the frequency of pulsatile flow. In particular, BAEC exposed to 1.5 Hz pulsatile flow may not be able to align with the direction of flow, possibly indicating the presence of a critical value for living systems.
A Design Approach for Soft Error Protection in Real-Time Embedded Systems
Authors: Muhammad Sheikh Sadi, D. G. Myers, and Cesar Ortega Sanchez
Venue: Proceedings of the 19th Australian Conference on Software Engineering (2008)

The decreasing line widths employed in semiconductor technologies means that soft errors are an increasing problem in modern system on a chip designs. Approaches adopted so far have focused on recovery after detection. In real-time systems, though, that can easily lead to missed deadlines. This paper proposes a preventative approach. Specifically a design methodology that uses metrics in design space exploration that highlight where in the structure of the systems model and at what point in its behaviour, protection is needed against soft errors. The approach does not eliminate the impact of soft errors completely, but aims to significantly reduce their impact.
On the radial solutions for some nonlinear initial value problems
Authors: Gabriella Bognar, Erika Rozgonyi
Venue: Proceedings of the 12th WSEAS International Conference on Applied Mathematics (2007)

We consider the positive radial symmetric solutions to the nonlinear problem div (|∇u|p-2∇u) + f(u) = 0 in BR = {x ∈ Rn: |x| < R}, 1 < p < n, where f(u) = uγ + uδ for u ≥ 0: For some special values of parameters γ and δ we give the positive entire solution. We examine the existence of local solutions and give a method for its determination. Comparing the local and entire solution, the error can be investigated.
Algebraic Structure of Web Services
Authors: Peter Höfner, Florian Lautenbacher
Venue: Electronic Notes in Theoretical Computer Science (ENTCS) (2008)

Web Services and Service-Oriented Architecture in general are promising concepts to overcome difficulties such as heterogeneity, scalability, etc. In this paper we present an algebraic structure of Web Services which assist users in Web Service composition and formal description of their services. Using relation algebra, tests and iteration offer the possibility of an automatic composition of Web Services based on a specified goal.
Design optimization with GA fitness functions based on total lifecycle value or cost
Authors: Damir Vučina, Željan Lozina
Venue: Proceedings of the 7th WSEAS International Conference on Evolutionary Computing (2006)

The decision making process in multicriterial optimization problems is in many cases based on the apriori articulation of the compromise integral criterion based on preferences which are frequently of rather intuitive nature. This reduces the comprehensive search for the Pareto front to simpler single-criterion optimization. In this paper, this approach is followed in a specific manner. Instead of the rather arbitrary setting of weight factors in a weighted sum of partial objectives, or compromise selection using the min-max concept related to distance to utopia optima, a lifetime-cost-based integral criterion is used. The GA fitness function is based on the total-lifespan-value aggregate optimality criterion. All nonrecurring investment costs (eg. production costs, mass of material) and recurring operational expenses (maintenance, labour) are discounted accordingly and aggregated into a combined best-compromise fitness metric based on the net present value (NPV) and/or internal rate of return (IRR), which construct the overall fitness function. This approach allows for coupled engineering & financial optimization which approximates real-world decision making.
A new taxonomy for parallel Java models applied on cluster computing
Authors: Mohamed Galal, Hesham Eldeeb, Salwa Nassar
Venue: Proceedings of the 4th WSEAS International Conference on Systems Theory and Scientific Computation (2004)

The efficient Java parallel programming models that make it easier for parallel programmers to synchronize and exchange data between processors in network of PCs cluster with different levels of parallelism, are needed. A cluster of PCs provides a scalable parallel hardware platform for high performance computing. Moreover, Parallel and distributed computing on a cluster of PC's is being increasingly applied to a variety of large size computational problems. A huge computational infrastructure can be presented by building a Java programming with its advantages on cluster computing which is characterized by its scalability, flexibility, and improvement of cost and time. In this paper, we propose a new taxonomy that is considered useful for describing the different models of parallelism that can be used for writing a parallel Java programs. Firstly, we present the taxonomy models including usage, advantages, and disadvantages of each model. Secondly, we provide a set of criteria to be used as a reference for evaluation and comparison of each model. In addition, we describe the design and the implementation of three parallel models and extract their features to make it easy for the parallel programs developers to choose appropriate Java model for there application.
Collective computing based on swarm intelligence
Authors: Seetharam Narasimhan, Somnath Paul, Swarup Bhunia
Venue: Proceedings of the 45th annual Design Automation Conference (2008)

We present a novel computing framework consisting of multiple processing cores that exhibits swarm-like behavior. Conventional parallel processing paradigm typically requires a central controller for job assignment, inter-core communications and defect-tolerance. The proposed system leverages on the collective intelligence of a swarm of processing elements to avoid the bottleneck imposed by a central scheduler. Preliminary simulations show promising results for common signal processing applications.
Incomplete Jacobian Newton method for nonlinear equations
Authors: Hao Liu, Qin Ni
Venue: Computers Mathematics with Applications (2008)

This paper presents a new modified Newton method for nonlinear equations. This method uses a part of elements of the Jacobian matrix to obtain the next iteration point and is refereed to as the incomplete Jacobian Newton (IJN) method. The IJN method may be fit for solving large scale nonlinear equations with dense Jacobian. The conditions of linear, superlinear and quadratic convergence of the IJN method are given and the local convergence results are analyzed and proved. Some special IJN algorithms are designed and numerical experiments are given. The results show that the IJN method is promising.
Secure Spatial Authentication for Mobile Stations In Hybrid 3G-WLAN Serving Networks
Authors: Arjan Durresi, Mimoza Durresi, Leonard Barolli
Venue: Proceedings of the 2008 Third International Conference on Availability, Reliability and Security (2008)

The coexistence of cellular and Wireless Local Area Networks (WLAN) is enabling very interesting scenarios from both business and technical point of view. Various integration scenarios between third generation cellular (3G) and WLAN technologies have the potential to create seamless communication environments and increase theefficiency in using wireless spectrum. One of the major challenges to the integration of 3G and WLAN are related to security. More specifically, providing secure access to 3G through WLAN is a concern and object of research. Due to their centralized management nature, 3G technologies enable the implementation of stronger security solutions, compared to the highly distributed WLAN environments. One very interesting aspect of security in hybrid 3G-WLAN scenarios is location authentication. Apotential risk is presented to 3G operators since no prior relationship or trust may exist with specific WLAN-s' owners. The mobile stations may collude with the WLAN operator to falsify its location. In this paper, we propose to use hybrid 3G-WLAN devices to help for the location authentication of WLAN devices, when they tryto access 3G services though WLANs. In order to avoid security problems created by the potential collusion among hybrid and WLAN devices we propose threshold cryptographic tools. We analyze the tradeoff between number of hybrid devices, their trust level, overhead and risk factors.
The isomorphism conjecture holds relative to an oracle
Authors: S. Fenner
Venue: Proceedings of the 33rd Annual Symposium on Foundations of Computer Science (1992)

The authors introduce symmetric perfect generic sets. these sets vary from the usual generic sets by allowing limited infinite encoding into the oracle. They then show that the Berman-Hartmanis (1977) isomorphism conjecture holds relative to any sp-generic oracle, i.e., for any symmetric perfect generic set A, all NP/sup A/-complete sets are polynomial-time isomorphic relative to A. As part of the proof that the isomorphism conjecture holds relative to symmetric perfect generic sets they also show that P/sup A/=FewP/sup A/ for any symmetric perfect generic/sup /A.
Determination of camera parameters for character motions using motion area
Authors: Ji-Yong Kwon, In-Kwon Lee
Venue: The Visual Computer: International Journal of Computer Graphics (2008)

We propose a method to determine camera parameters for character motion, which considers the motion by itself. The basic idea is to approximately compute the area swept by the motion of the character&#x2019;s links that are orthogonally projected onto the image plane, which we call &#x201c;motion area&#x201d;. Using the motion area, we can determine good fixed camera parameters and camera paths for a given character motion in the off-line or real-time camera control. In our experimental results, we demonstrate that our camera path generation algorithms can compute a smooth moving camera path while the camera effectively displays the dynamic features of character motion. Our methods can be easily used in combination with the method for generating occlusion-free camera paths. We expect that our methods can also be utilized by the general camera planning method as one of heuristics for measuring the visual quality of the scenes that include dynamically moving characters.
Two-point boundary value problems of undamped uncertain dynamical systems
Authors: Minghao Chen, Yongqiang Fu, Xiaoping Xue, Congxin Wu
Venue: Fuzzy Sets and Systems (2008)

In this paper we study two-point boundary value problems of a class of uncertain dynamical systems, i.e., undamped uncertain dynamical systems. We introduce the concept of large solutions and small solutions for two-point boundary value problems of undamped uncertain dynamical systems, and under some conditions establish the existence and uniqueness of large solutions and small solutions and settle the relationship between large solutions and small solutions.
Hybrid differentiation strategies for simulation and analysis of applications in C++
Authors: Roscoe A. Bartlett, Bart G. Van Bloemen Waanders, Martin Berggren
Venue: ACM Transactions on Mathematical Software (TOMS) (2008)

Computationally efficient and accurate derivatives are important to the success of many different types of numerical methods. Automatic differentation (AD) approaches compute truncation-free derivatives and can be efficient in many cases. Although present AD tools can provide a convenient implementation mechanism, the computational efficiency rarely compares to analytically derived versions that have been carefully implemented. The focus of this work is to combine the strength of these methods into a hybrid strategy that attempts to achieve an optimal balance of implementation and computational efficiency by selecting the appropriate components of the target algorithms for AD and analytical derivation. Although several AD approaches can be considered, our focus is on the use of template overloading forward AD tools in C++ applications. We demonstrate this hybrid strategy for a system of partial differential equations in gas dynamics. These methods apply however to other systems of differentiable equations, including DAEs and ODEs.
Relation discovery from web data for competency management
Authors: Jianhan Zhu, Alexandre L. Gonçalves, Victoria S. Uren, Enrico Motta, Roberto Pacheco, Marc Eisenstadt, Dawei Song
Venue: Web Intelligence and Agent Systems (2007)

In current organizations, valuable enterprise knowledge is often buried under rapidly expanding huge amount of unstructured information in the form of web pages, blogs, and other forms of human text communications. We present a novel unsupervised machine learning method called CORDER (COmmunity Relation Discovery by named Entity Recognition) to turn these unstructured data into structured information for knowledge management in these organizations. CORDER exploits named entity recognition and co-occurrence data to associate individuals in an organization with their expertise and associates. We discuss the problems associated with evaluating unsupervised learners and report our initial evaluation experiments in an expert evaluation, a quantitative benchmarking, and an application of CORDER in a social networking tool called BuddyFinder.
UMOST: Ubiquitous Multimedia Framework for Context-Aware Session Mobility
Authors: Yong-Ju Lee, Choon-Seo Park, Jin-Whan Jeong, Hag-Young Kim
Venue: Proceedings of the 2008 International Conference on Multimedia and Ubiquitous Engineering (2008)

With the increasing use of small portable devices and wireless networks, a trend to support computing on the move has emerged.This trend is referred to as 'anytime/anywhere computing' for mobility support.In particular, multimedia service with heterogeneous devices, location-free access and user-context awareness is still a very active and evolving field of research in broad areas.In this paper, a movable multimedia framework, namely UMOST(Ubiquitous Middleware Of Streaming Technology), is proposed for multimedia session mobility.It provides various levels of quality of service management, as well as seamless user-level handoffs using MPEG-21 Digital Item Adaptation(DIA). It serves scalable streaming adaptive to the user, and deploys a back-end content distribution network for adapting dynamically to environmental changes through prefetching.The implemented framework employs a smart space aimed at demonstrating the feasibility of multimedia session mobility.
SZZ revisited: verifying when changes induce fixes
Authors: Chadd Williams, Jaime Spacco
Venue: Proceedings of the 2008 workshop on Defects in large software systems (2008)

Automatically identifying commits that induce fixes is an important task, as it enables researchers to quickly and efficiently validate many types of software engineering analyses, such as software metrics or models for predicting faulty components. Previous work on SZZ, an algorithm designed by Sliwerski et al and improved upon by Kim et al, provides a process for automatically identifying the fix-inducing predecessor lines to lines that are changed in a bug-fixing commit. However, as of yet no one has verified that the fix-inducing lines identified by SZZ are in fact responsible for introducing the fixed bug. Also, the SZZ algorithm relies on annotation graphs, which are imprecise in the face of large blocks of modified code, for back-tracking through previous revisions to the fix-inducing change. In this work we outline several improvements to the SZZ algorithm: First, we replace annotation graphs with line-number maps that track unique source lines as they change over the lifetime of the software; and second, we use DiffJ, a Java syntax-aware diff tool, to ignore comments and formatting changes in the source. Finally, we begin verifying how often a fix-inducing change identified by SZZ is the true source of a bug.