ppxscal/embedding_network huggingface dataset:
Applying differential privacy to search queries in a policy based interactive framework
Authors: Palanivel Kodeswaran, Evelyne Viegas
Venue: Proceeding of the ACM first international workshop on Privacy and anonymity for very large databases (2009)

Web search logs are of growing importance to researchers as they help understanding search behavior and search engine performance. However, search logs typically contain sensitive information about users and therefore considerable caution must be exercised when considering releasing the logs to the research community. Current approaches to releasing search logs focus on either protecting the privacy of users or enhancing the utility of data to researchers. In this work, we address the privacy-utility tradeoff by providing safe access to search logs, instead of releasing them. We propose a policy based safe interactive framework built on semantic policies and differential privacy to allow researchers access to search logs, while maintaining the privacy of the users. Semantic policies are used to infer the higher levels of information that can be mined from a dataset based on the fields accessed by a researcher. The accessed fields are then used to build research profile(s) that guide the amount of privacy to be enforced using differential privacy. We show the additional utility that can be obtained in our framework by two demonstrative experiments that involve access to user level information. Our results indicate that valid research can be conducted in our framework without forgoing the privacy of individuals.
Record linkage performance for large data sets
Authors: Jordi Gómez-Bao, Josep-L. Larriba-Pey, Josepa Ribes Puig
Venue: Proceeding of the ACM first international workshop on Privacy and anonymity for very large databases (2009)

We propose new data structures to speed up Record Linkage that take advantage of the value distribution of usual string attributes, like name or surname. Using some additional memory, we increase the processing speed by almost an order of magnitude without losing recall or precision at all. The improvement achieved is independent from the methods used for reducing the number of record comparisons, like Blocking or Sliding Window, and the specific string comparison functions.
Short Signatures for Multi-source Network Coding
Authors: Wenjie Yan, Mingxi Yang, Layuan Li, Huajing Fang
Venue: Proceedings of the 2009 International Conference on Multimedia Information Networking and Security - Volume 01 (2009)

It has been proven that network coding can provide significant benefits to network protocols. However, network coding is very vulnerable to pollution attacks. In recent years, many schemes have been designed to defend against these attacks, but as far as we know that almost all of them are merely suitable for single-source network coding system. In this paper, we proposed a homomorphic signature scheme based on bilinear pairings to stand against the security challenges in multi-source network coding, which is more prevalent than single-source network coding. This scheme can filter out all the forged packets coming from not only intermediate nodes but also source nodes. The signatures in our scheme have short size about 160 bits, and the senders needn't know all the message packets in advance.
PSGRN/PSCMP-a new code for calculating co- and post-seismic deformation, geoid and gravity changes based on the viscoelastic-gravitational dislocation theory
Authors: Rongjiang Wang, Francisco Lorenzo-Martín, Frank Roth
Venue: Computers Geosciences (2006)

We present a new numerical code for modeling co- and post-seismic response of the Earth's crust to earthquakes. The code consists of two FORTRAN programs: the first program, PSGRN, calculates the time-dependent Green functions of a given layered viscoelastic-gravitational half-space for four fundamental dislocation sources [the strike-slip double-couple, the dip-slip double-couple, the compensated linear vertical dipole (CLVD) and the point inflation] at different depths. The results provide a data base for the second program, PSCMP, which automatically discretizes the earthquake's extended rupture area into a number of discrete point dislocations and calculates the co- and post-seismic deformation by linear superposition. According to the correspondence principle, the same propagator algorithm used in our previously published elastic modeling software, EDGRN/EDCMP, is adopted to compute the spectral Green functions. The temporal Green functions are then obtained by the fast Fourier transform extended with an anti-aliasing technique, that ensures numerical stability when calculating the post-seismic transients. Moreover, the new software considers the coupling between the deformation and the Earth's gravity field, so that its output includes not only the complete deformation field consisting of 3 displacement components, 6 stress (strain) components and 2 tilt components, but also the geoid and gravity changes. In particular, the gravity effect is treated using a new consistent approach that remedies an incorrect formulation used in many earlier publications. The performance of the software is shown by an example.
A swarm algorithm for a self-structured P2P information system
Authors: Agostino Forestiero, Carlo Mastroianni
Venue: IEEE Transactions on Evolutionary Computation (2009)

This paper introduces Antares, which is a bioinspired algorithm for the construction of a decentralized and self-organized P2P information system in computational grids. This algorithm exploits the properties of ant systems, in which a number of entities/agents perform simple operations at the local level but together engender an advanced form of "swarm intelligence" at the global level. Here, the work of ant-inspired agents is tailored to the controlled replication and relocation of "descriptors," that is, documents that contain metadata information about grid resources. Agents travel the grid through P2P interconnections, and replicate and spatially sort descriptors so as to accumulate those represented by identical or similar indexes into neighbor grid hosts. The resulting information system is here referred to as self-structured, because it exploits the self-organizing characteristics of ant-inspired agents, and the association of descriptors with hosts is not predetermined but adapts to the varying conditions of the grid. This self-structured organization combines the benefits of both unstructured and structured P2P information systems. Indeed, being basically unstructured, Antares is easy to maintain in a dynamic grid, in which joins and departs of hosts can be frequent events. On the other hand, the aggregation and spatial ordering of descriptors can improve the rapidity and effectiveness of discovery operations, which is a beneficial feature typical of structured systems. Performance analysis proves that ant operations allow the information system to be efficiently reorganized, thus improving the efficacy of both simple and range queries.
Knowledge representation in the semantic web for Earth and environmental terminology (SWEET)
Authors: Robert G. Raskin, Michael J. Pan
Venue: Computers Geosciences (2005)

The semantic web for Earth and environmental terminology (SWEET) is an investigation in improving discovery and use of Earth science data, through software understanding of the semantics of web resources. Semantic understanding is enabled through the use of ontologies, or formal representations of technical concepts and their interrelations in a form that supports domain knowledge. The ultimate vision of the semantic web consists of web pages with XML namespace tags around terms, enabling search tools to ascertain their meanings by following the link to the defining ontologies. Such a scenario both reduces the number of false hits (where a search returns alternative, unintended meanings of a term) and increases the number of successful hits (where searcher and information provider have a syntax mismatch of the same concept). For SWEET, we developed a collection of ontologies using the web ontology language (OWL) that include both orthogonal concepts (space, time, Earth realms, physical quantities, etc.) and integrative science knowledge concepts (phenomena, events, etc.). This paper describes the development of a knowledge space for Earth system science and related concepts (such as data properties). Some of the ontology contents are ''virtual'' by means of an OWL wrapper associated with terms in large external databases (including gazetteers and Earthquake databases). We developed a search tool that finds alternative search terms (based on the semantics) and redirects the expanded set of terms to a search engine.
Performance of single-relay cooperative ARQ retransmission strategies
Authors: Juan J. Alcaraz, Joan García-Haro
Venue: IEEE Communications Letters (2009)

In Cooperative Automatic Repeat reQuest (C-ARQ) protocols, the retransmission process between a pair of nodes can be assisted by a relay node. We investigate the performance of C-ARQ algorithms in cellular access networks, where the use of relays is a promising strategy for future evolutions. By means of Markov analysis and simulation we show that the implementation of acknowledgment signals from the relays and the retransmission policy at the base station have a notable impact on the throughput of the system.
Enhancing privacy and authorization control scalability in the grid through ontologies
Authors: I. Blanquer, V. Hernández, D. Segrelles, E. Torres
Venue: IEEE Transactions on Information Technology in Biomedicine (2009)

The use of data Grids for sharing relevant data has proven to be successful in many research disciplines. However, the use of these environments when personal data are involved (such as in health) is reduced due to its lack of trust. There are many approaches that provide encrypted storages and key shares to prevent the access from unauthorized users. However, these approaches are additional layers that should be managed along with the authorization policies. We present in this paper a privacy-enhancing technique that uses encryption and relates to the structure of the data and their organizations, providing a natural way to propagate authorization and also a framework that fits with many use cases. The paper describes the architecture and processes, and also shows results obtained in a medical imaging platform.
The impact of WebCT on learning: a students' perspective
Authors: Tshepo Batane, Spoon Mafote
Venue: Proceedings of the 10th IASTED International Conference on Computers and Advanced Technology in Education (2007)

Online learning has become mainstream in many institutions of higher education. Most institutions add an online component to their education so as to enhance their students' learning. It is important therefore to find out what the students think about the impact of this reform on their learning. This paper reports on an investigation that was done among University of Botswana students to find out their perception about the impact of WebCT on their learning and whether they thought it was worth the resources invested in it. Students in the study reported that WebCT greatly improved their learning in that it easily made available course material that they would otherwise struggle to get through searching the library or laboriously writing extensive notes in class. Students also reported that WebCT enabled them to participate in online discussions that greatly contribute to their course understanding. However, students cited lack of computer access on campus as the biggest obstacle that hinders them from fully benefiting from WebCT. Students in the study called for a wider use of WebCT in the university so that more students can benefit from it but also go through the struggle of gaining computer access to do WebCT related material
On the implementation of the discrete Fourier transform in the encrypted domain
Authors: Tiziano Bianchi, Alessandro Piva, Mauro Barni
Venue: IEEE Transactions on Information Forensics and Security (2009)

Signal-processing modules working directly on encrypted data provide an elegant solution to application scenarios where valuable signals must be protected from a malicious processing device. In this paper, we investigate the implementation of the discrete Fourier transform (DFT) in the encrypted domain by using the homomorphic properties of the underlying cryptosystem. Several important issues are considered for the direct DFT: the radix-2 and the radix-4 fast Fourier algorithms, including the error analysis and the maximum size of the sequence that can be transformed. We also provide computational complexity analyses and comparisons. The results show that the radix-4 fast Fourier transform is best suited for an encrypted domain implementation in the proposed scenarios.
Alkali Solution Concentration Monitoring System for Cotton Goods Mercerizing Based on ZigBee
Authors: FangWu Dong, NaiQing Zhang
Venue: Proceedings of the 2009 Second International Workshop on Computer Science and Engineering - Volume 02 (2009)

Aiming at the real time monitoring requirement of alkali solution concentration in cotton goods mercerizing, a ZigBee-based monitoring system is proposed for alkali solution concentration. its application of electrochemical theory, ZigBee wireless networks and sensor technology. supply a network structure of monitoring system. monitoring system node controller of data acquisition, data transmission and control node, which is TI's CC2430 based on ZigBee technology. sensors of alkali solution concentration use electrochemical, designed circuit diagram of sensor node and system master control node, CC2430 as a data processing chip. through the analysis of data transmission of system, simplifying the ZigBee protocol stack, designed data transmission protocols and communication formats of the system. given program flow chart of sensors nodes and main node. Finally the operational results demonstrate: System performance parameters are better than the wired monitoring system, especially in real-time systems and anti-jamming, it so superior on the current forms of alkali solution cable system, which cost lower than the cable system about 30%, measurement accuracy of Alkali concentration less than 0.6%.
A Regularized Visibility-Based Approach to Astronomical Imaging Spectroscopy
Authors: M. Prato, M. Piana, A. G. Emslie, G. J. Hurford, E. P. Kontar, A. M. Massone
Venue: SIAM Journal on Imaging Sciences (2009)

We develop a formal procedure for the analysis of imaging spectroscopy data, i.e., remote sensing observations of the structure of a radiation source as a function of an observed parameter (e.g., radiation wavelength, frequency, or energy) and two-dimensional location in the observation plane of the instrument used. In general, imaging spectroscopy involves inversions of both spatial and spectral information. &ldquo;Traditional&rdquo; approaches typically proceed by performing the spatial inversion first, and then applying spectral deconvolution algorithms on a &ldquo;pixel-by-pixel&rdquo; basis across the source to deduce the (line-of-sight-weighted) form of the &ldquo;source function&rdquo; (a function involving only physical properties of the source itself) at each location in the observation plane. However, in the special case where spatial information is encoded in the form of visibilities (two-dimensional spatial Fourier transforms of the source structure), it is advantageous, both conceptually and computationally, to reverse the order of the steps in this procedure. In such an alternative approach, the spectral inversion is performed first, yielding visibilities of the unknown source function, and then these source function visibilities are spatially transformed to yield in situ information on the source, as a function of both energy and position. We illustrate the power and fidelity of this method using simulated data and apply it to hard X-ray observations of a solar flare on April 15, 2002. We also discuss briefly its broader applicability.
Time-domain analysis of a lossy nonuniform transmission line
Authors: Jaehoon Jeong, Robert Nevels
Venue: IEEE Transactions on Circuits and Systems II: Express Briefs (2009)

An analytical solution of the coupled Telegrapher's equations for the voltage and current on a homogeneous lossy transmission line is presented. The resulting expression is obtained in the form of an exact time-domain propagator operating on the line voltage and current. It is shown that an application of Simpson's rule yields a simple accurate numerical representation of the propagator that can be used to analyze both homogeneous and inhomogeneous transmission lines. Numerical dispersion in lossy media is examined proving that this method has no numerical dispersion.
Robust Image Copy Detection Using Local Invariant Feature
Authors: Fuhao Zou, Hefei Ling, Xiaowei Li, Zhihua Xu, Ping Li
Venue: Proceedings of the 2009 International Conference on Multimedia Information Networking and Security - Volume 01 (2009)

This paper proposes a novel geometric distortion resilient image copy detection scheme based on Scale Invariant Feature Transform (SIFT) detector. By using the SIFT detector, the proposed copy detection scheme first construct a series of robust, homogenous, and larger size circular patches. And then, the cirque track division strategy and ordinal measure concept are introduced to generate a cirque-based ordinal measure feature vector for each circular patch. Besides, the ROC graph and MAP probability are utilized to estimate the two parameters (vector dimension and detection threshold) respectively. Experimental results and the related analysis show that the proposed scheme is robust to most of geometric and photometric distortions. 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
Blind JPEG Steganalysis Based on Correlations of DCT Cofficients in Multi-directions and Calibrations
Authors: Yong Wang, JiuFen Liu, WeiMing Zhang
Venue: Proceedings of the 2009 International Conference on Multimedia Information Networking and Security - Volume 01 (2009)

This paper presents a universal steganalysis scheme to detect popular JPEG steganography effectively. First, a new kind of transition probability matrix is constructed to describe correlations of the quantized DCT coefficients in the multi-directions. Second, by merging two different calibrations, a 96-dimensional feature vector is extracted, and then the SVM is trained to build the steganalyzer. The results of a series of experiments performed on 4 kinds of typical steganography in different embedding ratios show that the new method outperforms previous methods to make a more reliable blind detection for these typical stegangraphic methods.
Sentiment analysis of movie reviews on discussion boards using a linguistic approach
Authors: Tun Thura Thet, Jin-Cheon Na, Christopher S.G. Khoo, Subbaraj Shakthikumar
Venue: Proceeding of the 1st international CIKM workshop on Topic-sentiment analysis for mass opinion (2009)

We propose a linguistic approach for sentiment analysis of message posts on discussion boards. A sentence often contains independent clauses which can represent different opinions on the multiple aspects of a target object. Therefore, the proposed system provides clause-level sentiment analysis of opinionated texts. For each sentence in a message post, it generates a dependency tree, and splits the sentence into clauses. Then it determines the contextual sentiment score for each clause utilizing grammatical dependencies of words and the prior sentiment scores of the words derived from SentiWordNet and domain specific lexicons. Negation is also delicately handled in this study, for instance, the term "not superb" is assigned a lower negative sentiment score than the term "not good". We have experimented with a dataset of movie review sentences, and the experimental results show the effectiveness of the proposed approach.
Algorithm for dealing with depressions in dynamic landscape evolution models
Authors: A. J. A. M. Temme, J. M. Schoorl, A. Veldkamp
Venue: Computers Geosciences (2006)

Depressions in landscapes function as buffers for water and sediment. A landscape with depressions has less runoff, less erosion and more sedimentation than a landscape without depressions. Sinks in digital elevation models (DEMs) can be existing features that correctly represent depressions in actual landscapes or spurious features that result from errors in DEM creation. In many erosion, landscape and hydrological models, all sinks are considered spurious features and, as a result, these models do not deal with sinks that do represent real depressions. Consequently, erosion is overestimated and sedimentation is underestimated. Dynamic geomorphological models that simulate soil redistribution in modelled landscapes in multiple timesteps have this problem in every timestep. A method that allows these models to deal with depressions in a realistic way is needed. This paper presents an algorithm that allows models in general, and dynamic geomorphological model LAPSUS in particular, to deal with sinks in a DEM and, thus, with depressions in a landscape. An application is presented where LAPSUS runs with the new algorithm are compared to the conventional runs. Results indicate that the new algorithm can realistically model the sediment buffer function of depressions. The inclusion of the new depression algorithm allows modelling landscape processes that can result in depressions, like landsliding, glacial processes and tectonics. It is also demonstrated that static models, running only once with a DEM without sinks, display effects from the filling of the sinks before running.
Detection of unknown signals in a fading environment
Authors: Kalle Ruttik, Konstantinos Koufos, Riku Jäntti
Venue: IEEE Communications Letters (2009)

In this letter we consider the effect of combined slow and fast fading on the energy detection. We model the received signal power distribution and propose a simplified approximation to this distribution. The approximation allows us to derive the distribution of the decision variable at the detector's output in closed-form. By using the suggested distribution, we find that in the block fading channel the impact of slow fading is not significant. In the case of multiple independent fast fading realizations with common slow fading value we can show how the slow fading starts to dominate the detection performance.
Lossy distributed source coding using LDPC codes
Authors: Mina Sartipi, Faramarz Fekri
Venue: IEEE Communications Letters (2009)

In this paper, we propose a practical scheme for lossy distributed source coding with side information available at the decoder. Our proposed scheme is based on sending parity bits using LDPC codes. We provide the design procedure for the LDPC code that guarantees performance close to the Wyner-Ziv limit for long LDPC codes. Using simulation results, we show that the proposed method performs close to the theoretical limit for even short length codes.