ppxscal/embedding_network huggingface dataset:
Parameter Extraction from RVS Stellar Spectra by Means of Artificial Neural Networks and Spectral Density Analysis
Authors: Diego Ordóñez, Carlos Dafonte, Minia Manteiga, Bernardino Arcay
Venue: Proceedings of the 3rd international workshop on Hybrid Artificial Intelligence Systems (2008)

The Gaia Galactic Survey Satellite is among the key future missions of the European Space Agency, who plans its launch near the end of 2011. Gaia will carry out what is being called a "Galaxy Survey", gathering exact information on the nature of the galaxy's main constituents, including the spectra of objects. A first approach to the extraction of atmospheric parameters from spectra (Effective Temperature (Teff), Gravity (log G), Metallicity ([Fe/H]), and Alpha elements abundance ([¿/Fe])) was their indirect measurement by means of the Morgan-Keenan (MK) classification system. However, traditional methods based on MK are slow and subjective. This is why an automatic and robust method has become an essential requirement. This work presents the preliminary results of a study on the automatic extraction potential of the main atmospheric stellar parameters: Teff, log G, [Fe/H], and [¿/Fe] in the spectral region of the RVS, between 8470 and 8740 Å. The study was carried out by means of an algorithm based on artificial neural networks which is a technique widely used in that kind of automatic spectral parameterisation.
A new approach to cooperative pathfinding
Authors: Renee Jansen, Nathan Sturtevant
Venue: Proceedings of the 7th international joint conference on Autonomous agents and multiagent systems - Volume 3 (2008)

In the multi-agent pathfinding problem, groups of agents need to plan paths between their respective start and goal locations in a given environment, usually a two-dimensional map. Existing approaches to this problem include using static or dynamic information to help coordination. However, the resulting behaviour is not always desirable, in that too much information is hand-coded into the problem, agents take paths which look unintelligent, or because the agents collide and must re-plan frequently. We present a distributed approach in which agents share information about the direction in which they traveled when passing through each location. This information is then used to encourage agents passing through the same location to travel in the same direction as previous agents. In addition to this new approach, we present performance metrics for multi-agent path planning as well as experimental results for the new approach. These results indicate that the number of collisions between agents is reduced and that the visual fidelity is improved.
Locally stratified Boolean grammars
Authors: Christos Nomikos, Panos Rondogiannis
Venue: Information and Computation (2008)

We introduce locally stratified Boolean grammars, a natural subclass of Boolean grammars with many desirable properties. Informally, if a grammar is locally stratified then the set of all pairs of the form (nonterminal, string) of the grammar can be mapped to a (possibly infinite) set of strata so as that the following holds: if the membership of a string w in the language defined by nonterminal A depends on the membership of string w^' in the language defined by nonterminal B, then (B,w^') cannot belong to a stratum higher than the stratum of (A,w); furthermore, if the above dependency is obtained through negation, (B,w^') must belong to a stratum lower than the stratum of (A,w). We prove that local stratifiability can be tested in linear time with respect to the size of the given grammar. We then develop the semantics of locally stratified grammars and prove that it is independent of the choice of the stratification mapping. We argue that the class of locally stratified Boolean grammars appears at present to be the broadest subclass of Boolean grammars that can be given a classical semantics (ie., without resorting to three-valued formal language theory).
Security Mediated Certificateless Signatures
Authors: Wun-She Yap, Sherman S. Chow, Swee-Huay Heng, Bok-Min Goi
Venue: Proceedings of the 5th international conference on Applied Cryptography and Network Security (2007)

In PKC 2006, Chow, Boyd and González Neito introduced the notion of security mediated certificateless (SMC) cryptography. SMC cryptography equips certificateless cryptography with instantaneous revocation. They presented a formal security model with two constructions for SMC encryption. This paper studies SMC signatures. We first present a security analysis of a previous attempt by Ju et al. in constructing a SMC signature scheme. We then formalize the notion of SMC signatures and propose the first concrete provable scheme without bilinear pairing. Our scheme is existential unforgeable in the random oracle model based on the intractability of the discrete logarithm problem, has a short public key size, and achieves a trust level which is the same as that of a traditional public key signature.
Vortex Identification in the Wall Region of Turbulent Channel Flow
Authors: Giancarlo Alfonsi, Leonardo Primavera
Venue: Proceedings of the 7th international conference on Computational Science, Part I: ICCS 2007 (2007)

Four widely-used techniques for vortex detection in turbulent flows are investigated and compared. The flow of a viscous incompressible fluid in a plane channel is simulated numerically by means of a parallel computational code based on a mixed spectral-finite difference algorithm for the numerical integration of the Navier-Stokes equations. The DNS approach (Direct Numerical Simulation) is followed in the calculations, performed at friction Reynolds number Re ¿ = 180. A database representing the turbulent statistically steady state of the velocity field through 10 viscous time units is assembled and the different vortex-identification techniques are applied to the database. It is shown that the method of the "imaginary part of the complex eigenvalue pair of the velocity-gradient tensor" gives the best results in identifying hairpin-like vortical structures in the wall region of turbulent channel flow.
Homogenization design method for biomorphic composite materials
Authors: Ronald H. W. Hoppe, Svetozara I. Petrova
Venue: Journal of Computational Methods in Sciences and Engineering (2004)

A structural optimization method based on the homogenization approach (the homogenization design method) has been applied to the modeling of the recently produced biomorphic composite materials. The design itself involves a structural optimization problem which is solved under a set of equality and inequality constraints on the state variables (displacements) and design parameters (lengths of the layers in the microstructure and angle of cell rotation). Primal-dual Newton-type interior-point method with proper optimality criteria is applied to the resulting nonconvex nonlinear optimization problem.
Knowledge Base Learning of Linguistic Fuzzy Rule-Based Systems in a Multi-objective Evolutionary Framework
Authors: P. Ducange, R. Alcalá, F. Herrera, B. Lazzerini, F. Marcelloni
Venue: Proceedings of the 3rd international workshop on Hybrid Artificial Intelligence Systems (2008)

We propose a multi-objective evolutionary algorithm to generate a set of fuzzy rule-based systems with different trade-offs between accuracy and complexity. The novelty of our approach resides in performing concurrently learning of rules and learning of the membership functions which define the meanings of the labels used in the rules. To this aim, we represent membership functions by the linguistic 2-tuple scheme, which allows the symbolic translation of a label by considering only one parameter, and adopt an appropriate two-variable chromosome coding. Results achieved by using a modified version of PAES on a real problem confirm the effectiveness of our approach in increasing the accuracy and decreasing the complexity of the solutions in the approximated Pareto front with respect to the single objective-based approach.
Application of Interactive Genetic Algorithms to Boid Model Based Artificial Fish Schools
Authors: Yen-Wei Chen, Kanami Kobayashi, Hitoshi Kawabayashi, Xinyin Huang
Venue: Proceedings of the 12th international conference on Knowledge-Based Intelligent Information and Engineering Systems, Part II (2008)

In this paper, we present an extended boid model for simulating the aggregate moving of fish schools in a complex environment. The boids model is an example of an individual-based model. The global behavior of the school is simulated by a large number of interesting individual boid (fish). In our proposed model, each boid is an agent that following six behavior rules: avoiding collision against schoolmates; gathering together; following a feed; avoiding obstacle; avoiding enemy boids; boundaries. The moving vector of each boid is a linear combination of five behavior rule vectors, and the coefficients are optimized by using an interactive genetic algorithm (IGA). Unlike the classical GA, interactive GA can adopt a user's subjective evaluation as fitness, which is useful when a fitness function cannot be exactly determined.
Access Denied
Authors: Jean Camp
Venue: IEEE Security and Privacy (2003)

The core flaw in DRM laws and technology is the model of author as sole creator, rather than as a part of a system. In this department, I will enumerate the dramatic threats to the system of creation and innovation that I believe exist in DRM law and technology.
Efficient Self-healing Key Distribution with Revocation for Wireless Sensor Networks Using One Way Key Chains
Authors: Ratna Dutta, Ee-Chien Chang, Sourav Mukhopadhyay
Venue: Proceedings of the 5th international conference on Applied Cryptography and Network Security (2007)

Security of group communication for large mobile wireless sensor network hinges on efficient key distribution and key management mechanism. As the wireless medium is characterized by its lossy nature, reliable communication cannot be assumed in the key distribution schemes. Therefore, self-healing is a good property for key distribution in wireless applications. The main idea of self-healing key distribution scheme is that even if during a certain session some broadcast messages are lost due to network faults, the users are capable of recovering lost session keys on their own, without requesting additional transmission from the group manager. The only requirement for a user to recover the lost session keys, is its membership in the group both before and after the sessions in which the broadcast packets containing the keys are sent. Self-healing approach of key distribution is stateless in the sense that a user who has been off-line for some period is able to recover the lost session keys immediately after coming back on-line. In this paper, we propose two constructions for scalable self-healing key distribution with t revocation capability. The novelty of our constructions are that we apply a different and more efficient self-healing mechanism compared to the ones in the literature using one-way key chain. The main improvements that our proposed schemes achieve over previous approaches are (a) communication bandwidth reduces from O((tj + j ¿ t ¿ 1)logq) to O((t + 1)logq), and (b) computation costs for our first and second constructions reduce from O(2tj + j) to O(2t + 1) and O(2(t 2 + t)) respectively, where m is the maximum number of sessions, j is the current session number, t is the maximum number of compromised group members that may collude and q is a large prime number. We achieve this result without any increase in the storage complexity. The schemes are scalable to very large groups in highly mobile, volatile and hostile network. We prove in an appropriate security framework that our constructions are computationally secure and achieve both forward secrecy and backward secrecy.
Packet caches on routers: the implications of universal redundant traffic elimination
Authors: Ashok Anand, Archit Gupta, Aditya Akella, Srinivasan Seshan, Scott Shenker
Venue: ACM SIGCOMM Computer Communication Review (2008)

Many past systems have explored how to eliminate redundant transfers from network links and improve network efficiency. Several of these systems operate at the application layer, while the more recent systems operate on individual packets. A common aspect of these systems is that they apply to localized settings, e.g. at stub network access links. In this paper, we explore the benefits of deploying packet-level redundant content elimination as a universal primitive on all Internet routers. Such a universal deployment would immediately reduce link loads everywhere. However, we argue that far more significant network-wide benefits can be derived by redesigning network routing protocols to leverage the universal deployment. We develop "redundancy-aware" intra- and inter-domain routing algorithms and show that they enable better traffic engineering, reduce link usage costs, and enhance ISPs' responsiveness to traffic variations. In particular, employing redundancy elimination approaches across redundancy-aware routes can lower intra and inter-domain link loads by 10-50%. We also address key challenges that may hinder implementation of redundancy elimination on fast routers. Our current software router implementation can run at OC48 speeds.
Using Dynamic Time Warping of T0 Contours in the Evaluation of Cycle-to-Cycle Pitch Detection Algorithms
Authors: Carlos Ferrer, Diana Torres, María E. Hernández-Díaz
Venue: Proceedings of the 13th Iberoamerican congress on Pattern Recognition: Progress in Pattern Recognition, Image Analysis and Applications (2008)

This paper addresses the comparison of Pitch Detection Algorithms working on a cycle to cycle basis. An alignment problem between detected and reference pitch contours is described and a Dynamic Time Warping procedure to correct it is proposed. The method is evaluated using hand-marked real signals and three well known Pitch Detection Algorithms. Results demonstrate the occurrence of shifts in practice and the usefulness of the proposed Dynamic Time Warping procedure.
Modeling Attack Behaviors in Rating Systems
Authors: Qinyuan Feng, Yafei Yang, Yan Lindsay Sun, Yafei Dai
Venue: Proceedings of the 2008 The 28th International Conference on Distributed Computing Systems Workshops (2008)

Online feedback-based rating systems are gaining popularity. Dealing with unfair ratings in such systems has been recognized as an important problem and many unfair rating detection approaches have been developed. Currently, these approaches are evaluated against simple attack models, but complicated attacking strategies can be used by attackers in the real world. The lack of unfair rating data from real human users and realistic attack behavior models has become an obstacle toward developing reliable rating systems. To solve this problem, we design and launch a rating challenge to collect unfair rating data from real human users. In order to broaden the scope of the data collection, we also develop a comprehensive signal-based unfair rating detection system. Based on the analysis of real attack data, we discover important features in unfair ratings, build attack models, and develop an unfair rating generator. The models and generator developed in this paper can be directly used to evaluate current rating aggregation systems, as well as to assist the design of future rating systems.
Plenary lecture VIII: a survey of some automotive integrated-starter-generators and their control
Authors: Dorin Dumitru Lucache
Venue: Proceedings of the 9th WSEAS International Conference on International Conference on Automation and Information (2008)

Integrated starter generator (ISG) uses one machine to replace conventional starter and alternator onboard vehicles and provides greater electrical generation capacity and improves the fuel economy and emissions. The main requirements of the ISG control are to ensure: the necessary cranking torque as starter in the most unfavorable conditions; a constant output voltage irrespective of the input speed (typically between 600 and 8000 rpm) and load, as generator; a high efficiency as generator in the speed range of 600...4000 rpm that corresponds both to I4 and V8 engines; an acceptable cost. The idea is not new, but needs a high complexity control system because of the differences between motoring and generating regimes, so that only modern motors and high-developed power electronics and digital signal processors made it practically possible. This presentation reviews the challenges and opportunities brought by the integration of the internal combustion engine and ISG into a single power unit. The structure evolution, material enhancement, and major design challenges are discussed. The electric motors types that are suited to play the role of an ISG are mostly the alternating current motors and their control algorithms are analyzed and exemplified.
Simulation of Artificial Near-Fault Ground Motions Based on the S-Transform
Authors: Jian Fan, Ping Dong
Venue: Proceedings of the 2008 Congress on Image and Signal Processing, Vol. 5 - Volume 05 (2008)

S transform is one of the effective modern time-frequency analysis techniques. A new method of applying S transform to simulate artificial near-fault ground motions is presented. The artificial near-fault ground motions are simulated by combining filtered real or artificial far-fault ground motions by time–frequency filter with equivalent pulse, which can reflect the local characteristics of site and the pulse characteristics of near-fault ground motions. Numerical analysis shows the time-frequency characteristics of artificial near-fault ground motions are similar to that of parents ground motions, and the PSD in high frequency range is compatible with a target PSD of code for seismic design of buildings of China. The PGA of artificial near-fault ground motions are identical to the PGA corresponding to earthquake intensity in this code. So the artificial near-fault ground motions presented in the paper can be used for seismic analysis of the structures in near-fault seismic zone.
Exploring Cohesion, Flexibility, Communication Overhead and Distribution for Web Services Interfaces in Computational Science
Authors: Miguel-Angel Sicilia, Daniel Rodríguez
Venue: Proceedings of the 8th international conference on Computational Science, Part III (2008)

Computational science studies often rely on the availability of large datasets through the Web. Web services (WS) provide a convenient way for making those datasets available, since they rely on a standard and widely available technology. However, there are many ways to devise a Web service interface for a given dataset, and the resulting interfaces vary in their properties related to cohesion, distribution, flexibility and communication overhead, among other parameters. This paper explores these attributes and provides some directions on how they can be measured. Concretely, a well-known cohesion metric is explored as a way to characterize the possible kinds of Web service interface designs. This is discussed for a concrete distributed context of service-oriented architectures.
The correlation between student demographics and student attitude toward computer-assisted instruction
Authors: Cynthia Rena Jackson
Venue:  (2008)

Computers are and have transformed nearly every aspect of contemporary society. The transformation is no less true in education. Computers are becoming a common tool for integrating classroom instruction and improving students' skills through the use of computer assisted-instruction (CAI). One factor determining the successful implementation of CAI is the users' attitudes about computers. The relationship between demographic characterisitcs of students in the military service environment and the students' computer-related attitudes and attitudes toward CAI were assess through a quantitative correlation study. The population consisted of 220 high school student attending Department of Defense Dependent Schools (DoDDS) located outside of the United States. The results revealed no strong correlation between the mean scores of computer experience and attitudes toward CAI instruments. While the differences between male and female attitudes were not statistically significant, the results revealed a correlation between computer experience and a positive perception toward CAI. Recommended future studies include conducting similar research within other high school educational environments. The ACM Portal is published by the Association for Computing Machinery. Copyright © 2010 ACM, Inc. Terms of Usage Privacy Policy Code of Ethics Contact Us Useful downloads: Adobe Acrobat QuickTime Windows Media Player Real Player
Latency Estimation of the Asynchronous Pipeline Using the Max-Plus Algebra
Authors: Jian Ruan, Zhiying Wang, Kui Dai, Yong Li
Venue: Proceedings of the 7th international conference on Computational Science, Part IV: ICCS 2007 (2007)

This paper presents a methodology to estimate the latency of the asynchronous pipeline without choices. We propose modeling an asynchronous pipeline with the timed event graph and characterizing its specification via the max-plus algebra. An evolution equation of the event firing epoch can be obtained, which is linear under the max-plus algebraic formalism. In terms of the above-mentioned equation, we can formulate the latency of the pipeline successfully. The case study shows that our method is simple, fast and effective.
Extractors for Jacobians of Binary Genus-2 Hyperelliptic Curves
Authors: Reza Rezaeian Farashahi
Venue: Proceedings of the 13th Australasian conference on Information Security and Privacy (2008)

Extractors are an important ingredient in designing key exchange protocols and secure pseudorandom sequences in the standard model. Elliptic and hyperelliptic curves are gaining more and more interest due to their fast arithmetic and the fact that no subexponential attacks against the discrete logarithm problem are known.In this paper we propose two simple and efficient deterministic extractors for $J(\mathbb{F}_q)$, the Jacobian of a genus 2 hyperelliptic curve H defined over $\mathbb{F}_q$, where q = 2 n , called the sum and product extractors.For non-supersingular hyperelliptic curves having a Jacobian with group order 2m, where m is odd, we propose the modified sum and product extractors for the main subgroup of $J(\mathbb{F}_q)$. We show that, if $D\in J(\mathbb{F}_q)$ is chosen uniformly at random, the bits extracted from D are indistinguishable from a uniformly random bit-string of length n.
Extraction of High-Resolution Face Image from Low-Resolution and Variant Illumination Video Sequences
Authors: Zhifei Wang, Zhenjiang Miao, Chao Zhang
Venue: Proceedings of the 2008 Congress on Image and Signal Processing, Vol. 4 - Volume 04 (2008)

In video surveillance, resolution and illumination are two main factors affecting the performance of face detection and recognition. In this paper, a new framework is proposed to extract face images from low resolution and variant illumination video sequences, which includes two parts: face detection and face hallucination. We create skin GMMs in CbCr and H-SV space to detect face in different low resolutions and lighting conditions. Next, eigentransformation by 2DPCA is used to face hallucination, and produce a global high-resolution face. Furthermore, we adopt Coupled PCA method to obtain facial local residue. Then global- and local-face are combined into a high equality face image. Experimental results show that we can obtain high resolution face images for recognition.