ppxscal/embedding_network huggingface dataset:
A cubically convergent Newton-type method under weak conditions
Authors: Liang Fang, Guoping He, Zhongyong Hu
Venue: Journal of Computational and Applied Mathematics (2008)

Under weak conditions, we present an iteration formula to improve Newton's method for solving nonlinear equations. The method is free from second derivatives, permitting f^'(x)=0 in some points and per iteration it requires two evaluations of the given function and one evaluation of its derivative. Analysis of convergence demonstrates that the new method is cubically convergent. Some numerical examples illustrate that the algorithm is more efficient and performs better than classical Newton's method.
Artistic thresholding
Authors: Jie Xu, Craig S. Kaplan
Venue: Proceedings of the 6th international symposium on Non-photorealistic animation and rendering (2008)

We consider the problem of depicting continuous-tone images using only black and white. Traditional solutions to this problem include halftoning, which approximates tones, and line drawing, which approximates edges. We introduce "artistic thresholding" as a technique that attempts to depict forms in an image. We apply segmentation to a source image and construct a planar subdivision that captures segment connectivity. Our artistic thresholding algorithm is a combinatorial optimization over this graph. The optimization is controlled by parameters that can be tuned to achieve different artistic styles.
A New Era
Authors: James Maurer
Venue: Queue (2008)

I want to remind you that this will be the last printed issue of Queue but also to reassure you that Queue is not going away. As I mentioned in my letter in the last issue, ACM has decided to migrate Queue to the Web. As of July 2008, Queue will expand its publication frequency to 10 issues per year and publish those issues online using the most cutting-edge digital-editions technology available, as well as revamp the existing Queue Web site to provide an overall improved user experience.
How to Open a File and Not Get Hacked
Authors: James A. Kupsch, Barton P. Miller
Venue: Proceedings of the 2008 Third International Conference on Availability, Reliability and Security (2008)

Careless attention to opening files, often caused by problems with path traversal or shared directories, can expose applications to attacks on the file names that they use. In this paper we present criteria to determine if a path is safe from attack and how previous algorithms are not sufficient to protect against such attacks. We then describe an algorithm to safely open a file when in the presence of an attack (and how to detect the presence of such an attack), and provide a new library of file open routines that embodies our algorithm. These routines can be used as one-for-one substitutes for conventional POSIX open and fopen calls.
Complex networks in recommendation systems
Authors: Massimiliano Zanin, Pedro Cano, Javier M. Buldú, Oscar Celma
Venue: Proceedings of the 2nd WSEAS International Conference on Computer Engineering and Applications (2008)

Complex network theory was boosted in 1967 thanks to the experiment of Milgram: since then, the application of this special kind of graphs has given fruitful results in social science problems, from sexual disease control to music communities identification. When focusing on the problem of recommending items to a user (i.e. a customer of an e-store), the underlying transaction data can be seen as a complex network (specifically, a bipartite network): inside this structure, information about customer tastes is codified and can be of good use for future suggestions.
Detection of Malcodes by Packet Classification
Authors: Irfan Ahmed, Kyung-suk Lhee
Venue: Proceedings of the 2008 Third International Conference on Availability, Reliability and Security (2008)

In this paper, we propose an anomaly detection approach that classifies packets into code-type and data-type. Our objective is to detect a packet containing codes flowing into a network port, which normally expects data packets only. The proposed approach can detect potentially malicious packets such as worms, viruses, and shellcodes. We propose a time-efficient algorithm and show the results of our initial experiments.
Genetic algorithms to reduce diagnostic information
Authors: S. V. Mironov, D. V. Speranskii
Venue: Automation and Remote Control (2008)

A new genetic algorithm-based approach to the problem of reducing the diagnostic information acquired by testing discrete devices was proposed. Consideration was given to minimization and optimization of the diagnostic information for which the corresponding fitness functions and chromosome structures used in the genetic algorithms were suggested. Statistical data corroborating efficiency of the developed genetic algorithms for the problems under consideration were presented.
k-noncrossing and k-nonnesting graphs and fillings of ferrers diagrams
Authors: Anna de Mier
Venue: Combinatorica (2007)

We give a correspondence between graphs with a given degree sequence and fillings of Ferrers diagrams by nonnegative integers with prescribed row and column sums. In this setting, k-crossings and k-nestings of the graph become occurrences of the identity and the antiidentity matrices in the filling. We use this to show the equality of the numbers of k-noncrossing and k-nonnesting graphs with a given degree sequence. This generalizes the analogous result for matchings and partition graphs of Chen, Deng, Du, Stanley, and Yan, and extends results of Klazar to k > 2. Moreover, this correspondence reinforces the links recently discovered by Krattenthaler between fillings of diagrams and the results of Chen et al.
WESTT (workload, error, situational awareness, time and teamwork): an analytical prototyping system for command and control
Authors: Robert J. Houghton, Chris Baber, Malcolm Cowton, Guy H. Walker, Neville A. Stanton
Venue: Cognition, Technology and Work (2008)

Modern developments in the use of information technology within command and control allow unprecedented scope for flexibility in the way teams deal with tasks. These developments, together with the increased recognition of the importance of knowledge management within teams present difficulties for the analyst in terms of evaluating the impacts of changes to task composition or team membership. In this paper an approach to this problem is presented that represents team behaviour in terms of three linked networks (representing task, social network structure and knowledge) within the integrative WESTT software tool. In addition, by automating analyses of workload and error based on the same data that generate the networks, WESTT allows the user to engage in the process of rapid and iterative &#x201c;analytical prototyping&#x201d;. For purposes of illustration an example of the use of this technique with regard to a simple tactical vignette is presented.
3D reconstruction and visualization of astrophysical wind volumes using physical models
Authors: Ioannis Pachoulakis
Venue: ACM Transactions on Modeling and Computer Simulation (TOMACS) (2008)

This article reports on the application of a framework used to model, simulate and visualize the 3D structure of astrophysical wind volumes. The modeling methodology is similar to multidirectional medical tomography in that the spatial structure of an extended target can be reconstructed from a sequence of images obtained by scanning that target from several directions. Even though the controlled environment realized in diagnostic radiology cannot be replicated in the study of astrophysical phenomena, strong candidates for astrophysical tomography do exist in hot, close double stars locked in orbits around a common center of mass. As the Keplerian orbit is traced out, the geometry presented to the observer varies so that each star constitutes an analyzer upon its companion's wind and probes its structure. Since these targets are too far to be resolved spatially, we study and model the UV spectral lines of prominent wind ions, which scatter photospheric UV light so that line shapes vary as the stars revolve and as inhomogeneities form, propagate, and evolve in the composite wind. The framework presented is applied to two hot close binaries near the applicability limits of the discussed methodology. Two novel custom-made tools that aid the analysis of the spectra and the visualization of the results are also presented. The first of these, the Spectrum Analyzer and Animator, automates the derivation of light curves from the observed spectra and the generation of synthetic binary wind-line profiles, which reproduce the morphologies and variabilities of the observed wind profiles. After the composite wind structure of a binary has been recovered, the second tool, the Binary 3D Renderer &mdash;also authored in IDL&mdash;aids the visualization of the results by simulating the motion of the system (stars, winds and wind-interaction effects) around the binary's center of mass. The Binary 3D Renderer thus repackages the end product of a lengthy physical modeling process to generate physically sound, realistic multimedia content and increase the effectiveness and communication impact of the research results.
The computability and complexity of optical beam tracing
Authors: J. H. Reif
Venue: Proceedings of the 31st Annual Symposium on Foundations of Computer Science (1990)

The ray-tracing problem is considered for optical systems consisting of a set of refractive or reflective surfaces. It is assumed that the position and the tangent of the incident angle of the initial light ray are rational. The computability and complexity of the ray-tracing problems are investigated for various optical models. The results show that, depending on the optical model, ray tracing is sometimes undecidable, sometimes PSPACE-hard, and sometimes in PSPACE.
A case study for monitoring-oriented programming in multi-core architecture
Authors: Lu Yang, Jianwen Tang, Jianhua Zhao, Xuandong Li
Venue: Proceedings of the 1st international workshop on Multicore software engineering (2008)

Along with the development of the multi-core architecture, high performance computing platform is produced to satisfy users' requirement for solving large and complex problems. Multi-core architecture has become a new trend in the verification field to improve the performance. With the explosion of software size, Monitoring-Oriented Programming (MOP) is considered as a design trend to increase reliability of the software systems. In this paper, we have done the experiment for a case study which is a preliminary exploration for integrating MOP with multi-core architecture. Our work shows that multi-core architecture can improve the efficiency of MOP. It will be the groundwork of our discussion about "how to design a good monitor?" in the future work.
Can blog communication dynamics be correlated with stock market activity?
Authors: Munmun De Choudhury, Hari Sundaram, Ajita John, Dorée Duncan Seligmann
Venue: Proceedings of the nineteenth ACM conference on Hypertext and hypermedia (2008)

In this paper, we develop a simple model to study and analyze communication dynamics in the blogosphere and use these dynamics to determine interesting correlations with stock market movement. This work can drive targeted advertising on the web as well as facilitate understanding community evolution in the blogosphere. We describe the communication dynamics by several simple contextual properties of communication, e.g. the number of posts, the number of comments, the length and response time of comments, strength of comments and the different information roles that can be acquired by people (early responders / late trailers, loyals / outliers). We study a "technology-savvy" community called Engadget (http://www.engadget.com). There are two key contributions in this paper: (a) we identify information roles and the contextual properties for four technology companies, and (b) we model them as a regression problem in a Support Vector Machine framework and train the model with stock movements of the companies. It is interestingly observed that the communication activity on the blogosphere has considerable correlations with stock market movement. These correlation measures are further cross-validated against two baseline methods. Our results are promising yielding about 78% accuracy in predicting the magnitude of movement and 87% for the direction of movement.
X-hinter: a framework for implementing social oriented recommender systems
Authors: André Panisson, Giancarlo Ruffo, Rossano Schifanella
Venue: Proceedings of the nineteenth ACM conference on Hypertext and hypermedia (2008)

Accordingly to the nature of data-driven applications that produce information overload, users need a support to make choices, even without sufficient personal experience of the alternatives. In this context, social networking techniques could be useful applied for finding affinities between users and filter information in a personalized way. After proposing a generalized model for social recommender systems, called X-Hinter, we describe a Java API that provides a set of libraries and tools to build social filtering systems in a wide range of domains. A prototype implementation, named DeHinter, shows the feasibility of the proposed approach in a P2P file sharing application.
Simulating Biological Pathways with a Continuous Petri Net Using Runge-Kutta Methods
Authors: Sunku Kang, Byungwoo Lee, Jihoon Yang, Seonho Kim, Saejoon Kim
Venue: Proceedings of the 2007 Frontiers in the Convergence of Bioscience and Information Technologies (2007)

The application of Petri nets to analyze and simulate biological pathways has been developed vigorously. Some of the modifications of Petri nets appeared to perform quantitative analysis of biological pathways: hybrid Petri net, timed Petri net, stochastic Petri net and so on. For a quantitative analysis of biological pathways, we propose to adopt Runge-Kutta methods to act on a continuous Petri net. We show that Runge-Kutta methods are applicable to a continuous Petri net in glycolysis and apoptosis pathways with reliable and efficient simulation results.
A power comparison and simulation study of goodness-of-fit tests
Authors: Barış Sürücü
Venue: Computers Mathematics with Applications (2008)

We give the results of a comprehensive simulation study of the power properties of prominent goodness-of-fit tests. For testing the normal N(@m,@s^2), we propose a new omnibus goodness-of-fit statistic C which is a combination of the Shapiro-Wilk statistic W and the correlation statistic R. We show that the test of normality based on C is overall more powerful than other prominent goodness-of-fit tests and is effective against both symmetric as well as skew alternatives. We also show that the null distribution of C can be approximated by a four-moment F. For the exponential E(@q,@s), Tiku statistic Z (using sample spacings) and modified Anderson-Darling A are the most powerful. For testing other distributions, the statistics based on generalized sample spacings and the modified Anderson-Darling statistic provide the most powerful tests.
Multi-layer faults in the architectures of mobile, context-aware adaptive applications: a position paper
Authors: Michele Sama, David S. Rosenblum, Zhimin Wang, Sebastian Elbaum
Venue: Proceedings of the 1st international workshop on Software architectures and mobility (2008)

Five cellphones are sold every second, and there are four times more cellphones than computers, meaning there are some billions of mobile handheld devices in existence. Modern cellphones are equipped with multiple context sensors used by increasingly sophisticated software applications that exploit the sensors, allowing the applications to adapt automatically to changes in the surrounding environment, such as by responding to the location and speed of the user. The architecture of such applications is typically layered and incorporates a context-awareness middleware to support processing of context values. While this layered architecture is very natural for the design and implementation of applications, it gives rise to new kinds of faults and faulty behavior modes, which are difficult to detect using existing validation techniques. In this paper we provide scenarios illustrating such faults and exploring how they manifest in context-aware adaptive applications.
Operand-Load-Based Split Pipeline Architecture for High Clock Rate and Commensurable IPC
Authors: Rama Sangireddy, Jatan Shah
Venue: IEEE Transactions on Parallel and Distributed Systems (2008)

The increase in the complexity of a wide-issue processor with its pipeline width is one of the primary concerns of the processor designers. In the conventional design, hardware in the processor core is laid out to handle multiple instructions with two-source operands in each pipeline stage. However, analysis of SPEC2000 programs reveals that an integer program on average constitutes 25.2% of two-op (both source registers) integer instructions and 72.5% one-op/zero-op integer instructions. Floating-point programs (FP) are found to constitute on average 15.8% of two-op integer instructions and 44.1% one-op/zero-op integer instructions. The analysis observes that the hardware laid out for worst case requirements in the integer pipeline is highly under-utilized for a significant portion of time. To alleviate the complexity issues we propose split pipeline architecture, a novel technique to distinguish and process instructions based on their source operand requirements. The conventional pipeline is split into two after the decode stage, and the two pipelines are again converged at the execution stage. This leads to a capability of processing instructions at a higher clock rate and at almost the same IPC, as compared to a conventional processor. Various flavors of the proposed architecture are simulated and analyzed in this paper, with a circuit level analysis to determine the impact on the critical path delays. Results show that a processor that can fetch, decode, and commit eight instructions each cycle and with split pipelines of two two-source integer instruction and six zero/one-source integer instruction can achieve a clock rate that is 15.8% faster than an 8-wide conventional processor while losing the IPC throughput by only 0.7% for SPEC2000 benchmarks. Similarly, in a 4-wide processor and with split pipelines of one two-source integer instruction and three zero/one-source integer instruction can achieve a clock rate that is 19.69% faster than a 4-wide conventional processor while losing the IPC throughput by only 1.9%
Ontology change: Classification and survey
Authors: Giorgos Flouris, Dimitris Manakanatas, Haridimos Kondylakis, Dimitris Plexousakis, Grigoris Antoniou
Venue: The Knowledge Engineering Review (2008)

Ontologies play a key role in the advent of the Semantic Web. An important problem when dealing with ontologies is the modification of an existing ontology in response to a certain need for change. This problem is a complex and multifaceted one, because it can take several different forms and includes several related subproblems, like heterogeneity resolution or keeping track of ontology versions. As a result, it is being addressed by several different, but closely related and often overlapping research disciplines. Unfortunately, the boundaries of each such discipline are not clear, as the same term is often used with different meanings in the relevant literature, creating a certain amount of confusion. The purpose of this paper is to identify the exact relationships between these research areas and to determine the boundaries of each field, by performing a broad review of the relevant literature.
On Backoff Timer Scheduling for Smart-DCF and Performance Evaluation
Authors: Siwaruk Siwamogsatham
Venue: Proceedings of the 22nd International Conference on Advanced Information Networking and Applications - Workshops (2008)

In this work, we present a generic backoff-timer scheduling algorithm for the Smart-DCF scheme. In Smart-DCF, the master station schedules the backoff timer value for each client station, and the backoff timer information is sent to the client station via an acknowledgment frame. The proposed backoff-timer scheduling mechanism enables the Smart-DCF access point to provide differentiated services to different classes of wireless stations or traffic. The simulation results demonstrate that the proposed scheduling algorithm is effective. The results also show that the Smart-DCF scheme noticeably outperforms the existing DCF scheme. In addition, the throughput performance of Smart-DCF starts to reach the saturated level when each data burst is longer than 5 frames.
Towards Maude-Tla based Foundation for Complex Concurrent Systems Specification and Certification
Authors: Nasreddine Aoumeur, Kamel Barkaoui, Gunter Saake
Venue: Proceedings of the Fifth International Conference on Information Technology: New Generations (2008)

This paper contributes towards a multi-paradigm approach for the specification validation verification and refinement of concurrent agile systems. It brings together two complementary rigorous and largely accepted frameworks: Meseguer’s true-concurrent Rewriting Logic (RL) with its Maude prototype and Lamport’s Temporal Logic of Actions (Tla) with its current prototype Tla+. At the specification / validation phase, we adopt a variant of Maude that we endow with strategy for controlling rules and state splitting / recombining for exhibiting full intra-concurrency. For the verification / refinement phase, we automatically derive Tla’s formulas from validated Maude specification, on which crucial properties are checked using Tla’s deductions and invariants. A production system is considered as proof-of-concept.
Fast and Space Efficient Linear Suffix Array Construction
Authors: Sen Zhang, Ge Nong
Venue: Proceedings of the Data Compression Conference (2008)

We propose a novel fast and space efficient linear suffix array construction algorithm (SACA) to break the performance and design bottlenecks for the existing linear SACAs. By sampling the fixed-size d-critical substrings to divide-and-conquer the problem, our new algorithm is very simple, for which a fully-functioning sample implementation is embodied in only about 100 lines of C code. The experimental results on the Canterbury and Manzini-Ferragina corpora show that our algorithm outperforms boththe K\"arkk\"ainen-Sanders (KS) and the Ko-Aluru (KA) algorithms: compared with the KS, ours can be more than twice faster and use more than 50% fewer space; compared with the KA, ours can be 9% faster and use 40% fewer space. To approach the lightweight space extreme, we further improve our linear algorithm to use an extra working space of only 0.25n+O(1) bytes to construct the suffix array for any size-n string of a constant or integer alphabet,where the characters of an integer alphabet are in [0..n-1]. Besides using less space, our lightweight linear algorithm stil lruns more than 1.5 times faster than the KS algorithm in the experiments.