ppxscal/embedding_network huggingface dataset:
Self-organized trail systems in groups of humans: Research Articles
Authors: Robert L. Goldstone, Michael E. Roberts
Venue: Complexity (2006)

We have developed an experimental platform for studying the trail systems that spontaneously emerge when people are motivated to take advantage of the trails left by others. In this virtual environment, the participants' task is to reach randomly selected destinations while minimizing travel costs. The travel cost of every patch in the environment is inversely related to the number of times the patch was visited by others. The resulting trail systems are a compromise between people going to their destinations and going where many people have previously traveled. We compare the results from our group experiments to the Active Walker model of pedestrian motion from biophysics. The Active Walker model accounted for deviations of trails from the beeline paths, the gradual merging of trails over time, and the influences of scale and configuration of destinations on trail systems, as well as correctly predicting the approximate spatial distribution of people's steps. Two deviations of the model from empirically obtained results were corrected by (1) incorporating a distance metric sensitive to canonical horizontal and vertical axes, and (2) increasing the influence of a trail's travel cost on an agent's route as the agent approaches its destination. &copy; 2006 Wiley Periodicals, Inc. Complexity 11: 43&ndash;50, 2006This paper was submitted as an invited paper resulting from the &ldquo;Understanding Complex Systems&rdquo; conference held at the University of Illinois&ndash;Urbana Champaign, May 2005
PAST: Probabilistic Authentication of Sensor Timestamps
Authors: Ashish Gehani, Surendar Chandra
Venue: Proceedings of the 22nd Annual Computer Security Applications Conference (2006)

Sensor networks are deployed to monitor the physical environment in public and vulnerable locations. It is not economically viable to house sensors in tamper-resilient enclosures as they are deployed in large numbers. As a result, an adversary can subvert the integrity of the data being produced by gaining physical access to a sensor and altering its code. If the sensor output is timestamped, then tainted data can be distinguished once the time of attack is determined. To prevent the adversary from generating fraudulent timestamps, the data must be authenticated using a forward-secure protocol. Previous work requires the computation of n hashes to verify the (n+1)th reading. This paper describes PAST, a protocol that allows timestamps to be authenticated with high probability using a small constant number of readings. In particular, PAST is parameterized so that the metadata overhead (and associated power consumption) can be reduced at the cost of lower confidence in the authentication guarantee. Our protocol allows arbitrary levels of assurance for the integrity of timestamps (with logarithmically increasing storage costs) while tolerating any predefined fraction of compromised base stations. Unlike prior schemes, PAST does not depend on synchronized clocks.
Certified reputation: how an agent can trust a stranger
Authors: Trung Dong Huynh, Nicholas R. Jennings, Nigel R. Shadbolt
Venue: Proceedings of the fifth international joint conference on Autonomous agents and multiagent systems (2006)

Current computational trust models are usually built either on an agent's direct experience of an interaction partner (interaction trust) or reports provided by third parties about their experiences with a partner (witness reputation). However, both of these approaches have their limitations. Models using direct experience often result in poor performance until an agent has had a sufficient number of interactions to build up a reliable picture of a particular partner and witness reports rely on self-interested agents being willing to freely share their experience. To this end, this paper presents Certified Reputation (CR), a novel model of trust that can overcome these limitations. Specifically, CR works by allowing agents to actively provide third-party references about their previous performance as a means of building up the trust in them of their potential interaction partners. By so doing, trust relationships can quickly be established with very little cost to the involved parties. Here we empirically evaluate CR and show that it helps agents pick better interaction partners more quickly than models that do not incorporate this form of trust.
Synergetic interaction of components of rarefied comb filtration of the speech signal
Authors: S. M. Petrov, A. V. Borshchev
Venue: Proceedings of the 2003 International Conference on Physics and Control - Volume 2 (2003)

At complete deleting of a part of high or low speech frequencies 100% intelligibility of speech is saved. Research of speech perception with mosaic deleting of frequency bands is more interesting. It gives possibility to estimate redundancy of a speech from the point of view of the spectral contents. We divided speech spectrum on the frequency bands with separate summation of with even and odd bands:1) width of even and odd bands was identical; 2) we simulated speech perceived by the cochlear implanted patients; 3) at a constant odd bands width we increased width of even bands so long as the speech intelligibility did not decrease from 100%; and 4) research is conducted in relation of comfortable loudness of speech with different parameters of comb filter. We found that redundancy of speech achieves 95%. Comfortable loudness of comb filtered speech depends on test bands width and period of the filter. The problem of speech perception of cochlear implanted patients and in noise background is discussed.
Specialization of Neural Mechanisms Underlying Face Recognition in Human Infants
Authors: Michelle De Haan, Olivier Pascalis, Mark H. Johnson
Venue: Journal of Cognitive Neuroscience (2002)

Newborn infants respond preferentially to simple face-like patterns, raising the possibility that the face-specific regions identified in the adult cortex are functioning from birth. We sought to evaluate this hypothesis by characterizing the specificity of infants' electrocortical responses to faces in two ways: (1) comparing responses to faces of humans with those to faces of nonhuman primates; and 2) comparing responses to upright and inverted faces. Adults' face-responsive N170 event-related potential (ERP) component showed specificity to upright human faces that was not observable at any point in the ERPs of infants. A putative "infant N170" did show sensitivity to the species of the face, but the orientation of the face did not influence processing until a later stage. These findings suggest a process of gradual specialization of cortical face processing systems during postnatal development.
Creative destruction of computing systems: analysis and modeling
Authors: Natali Hritonenko, Yuri Yatsenko
Venue: The Journal of Supercomputing (2006)

The paper analyzes the problem of rational replacement of computing systems. Such systems, especially high-performance computers, are expensive, but quickly become obsolete. A system analysis of the replacement problem is provided and the relevant modeling problems are identified and studied. The obtained results give certain rules for calculating the optimal lifetime of computing systems, which are based on the given rates of technological change in the related computer industry. Two simulation examples estimate the optimal lifetime of PCs and high-performance computers in the current US economy. The results are in good agreement with other recommendations and existing business practice.
An EOQ model with fuzzy inflation rate and fuzzy deterioration rate when a delay in payment is permissible
Authors: Sujit Kumar De, A. Goswami
Venue: International Journal of Systems Science (2006)

Through the investigation of an Economic Order Quantity (EOQ) model, it has been observed that the estimated inventory cost and starting time inventory cost are not necessarily the same. This arises as a result of the time gap in between the time of estimation and the starting time of the EOQ system, and a permissible delay in payment will affect the inventory total cost. Moreover, the political instability or uncertainty of a country (as well as the whole world) leads to a much more unstable situation in the present world economy. Thus, a change in inflation takes place, and the inflation rate is uncertain in nature. This study develops an EOQ model with a fuzzy inflation rate and fuzzy deterioration rate, and a delay in payment is also permissible. We have derived the corresponding fuzzy cost function, and the solution procedure has been explained with the help of a numerical example. A sensitivity analysis has also been carried out.
Efficient Query Processing in Arbitrary Subspaces Using Vector Approximations
Authors: Hans-Peter Kriegel, Peer Kroger, Matthias Schubert, Ziyue Zhu
Venue: Proceedings of the 18th International Conference on Scientific and Statistical Database Management (2006)

In this paper, we introduce the partial vector approximation file, an extension of the well known vector approximation file that is constructed to efficiently answer partial similarity queries in any possible subspace which is not known beforehand. The idea of the partial VA-File is to divide the VA-File into a separate file for each dimension and only load the dimensions that are necessary to answer the query. Thus, the partial VA-File is constructed to improve the query performance for systems that have to cope with a wide variety of previously unknown query subspaces. We propose novel algorithms for partial kNN and å-range queries based on the new partial VA-File. In our experiments, we demonstrate that our proposed partial VA-File with the novel algorithms improves the average query performance in comparison to the original VA-File when answering partial similarity queries.
A general model for long-tailed network traffic approximation
Authors: Junfeng Wang, Hongxia Zhou, Mingtian Zhou, Lei Li
Venue: The Journal of Supercomputing (2006)

The long-tailed distribution characterizes many Internet traffic properties which are often modeled by Lognormal distribution, Weibull or Pareto distribution theoretically. However, it is rather difficult to directly apply these models in traffic analysis and performance evaluation studies due to their complex representations and theoretical properties.This paper proposes a Hyper-Erlang Model (Mixed Erlang distribution) for such long-tailed network traffic approximation. It fits network traffic with long-tailed characteristic into a mixed Erlang distribution directly to facilitate our further analysis. Compared with the well-known hyperexponential based method, the mixed Erlang model is more accurate in fitting the tail behavior and also computationally efficient. Further investigations on the M/G/1 queueing behavior also prove the efficiency of the Mixed Erlang based approximation.
Designing DCCP: congestion control without reliability
Authors: Eddie Kohler, Mark Handley, Sally Floyd
Venue: ACM SIGCOMM Computer Communication Review (2006)

Fast-growing Internet applications like streaming media and telephony prefer timeliness to reliability, making TCP a poor fit. Unfortunately, UDP, the natural alternative, lacks congestion control. High-bandwidth UDP applications must implement congestion control themselves-a difficult task-or risk rendering congested networks unusable. We set out to ease the safe deployment of these applications by designing a congestion-controlled unreliable transport protocol. The outcome, the Datagram Congestion Control Protocol or DCCP, adds to a UDP-like foundation the minimum mechanisms necessary to support congestion control. We thought those mechanisms would resemble TCP's, but without reliability and, especially, cumulative acknowledgements, we had to reconsider almost every aspect of TCP's design. The resulting protocol sheds light on how congestion control interacts with unreliable transport, how modern network constraints impact protocol design, and how TCP's reliable bytestream semantics intertwine with its other mechanisms, including congestion control.
Analysis of Felder-Silverman Index of Learning Styles by a Data-Driven Statistical Approach
Authors: Silvia Rita Viola, Sabine Graf, Kinshuk, Tommaso Leo
Venue: Proceedings of the Eighth IEEE International Symposium on Multimedia (2006)

In this paper a data driven analysis of Felder- Silverman Index of Learning Styles (ILS) is given. Results, obtained by Multiple Correspondence Analysis and cross-validated by correlation analysis, show the consistent dependencies between some styles; some latent dimensions present in data, that are unexpected, are discussed. Results are then compared with the ones given by literature concerning validity and reliability of ILS questionnaire. Both the results and the comparisons show the effectiveness of data driven methods for patterns extraction even when unexpected dependencies are found and the importance of coherence and consistency of mathematical representation of data with respect to the methods selected for an effective, precise and accurate modeling.
A High Level Power Model for the Nostrum NoC
Authors: Sandro Penolazzi, Axel Jantsch
Venue: Proceedings of the 9th EUROMICRO Conference on Digital System Design (2006)

We propose a power model for the Nostrum NoC. For this purpose an empirical power model of links and switches has been formulated and validated with the Synopsys Power Compiler. The model, which from now on will be called Nos-HPM (Nostrum High-Level Power Model) allows a fast power analysis and is accurate within 5%. System simulations with Nos-HPM run up to 500 times faster than with Power Compiler for a 4 x 4 network. We find a maximum power consumption of 0.7 W for a 4 x 4 mesh and 3.5 W for an 8 x 8 mesh, both implemented in 0.18ìm UPC CMOS technology. In the worst case the average energy per cycle for a 128-bit packet is 508 pJ, while it is 20 pJ for a payload byte. The power consumption of all the links is equivalent or slightly higher than the power consumption of all the switches. A comparison between our results and some related work is also presented.
Some new advances in the theory of dynamic materials
Authors: K. A. Lurie, S. L. Weekes
Venue: Proceedings of the 2003 International Conference on Physics and Control - Volume 4 (2003)

In this paper, we present some recent advances in the theory of dynamic materials or spatio-temporal composites. We discuss the technique used to determine the set of invariant characteristics of material mixtures in one spatial dimension and time, in the context of electrodynamics of moving dielectrics, versus the relevant results in traditional electrostatics. Energy transformation in spatio-temporal laminates is discussed. We also present some results on dynamic materials with a rectangular microstructure. Some special features of dynamic materials demonstrated through material design are given as well. Among them, we mention the possibility to eliminate the cut-off frequency in the waveguides with activated dielectric filling.
Quality Assessment of Mutation Operators Dedicated for C# Programs
Authors: Anna Derezinska
Venue: Proceedings of the Sixth International Conference on Quality Software (2006)

The mutation technique inserts faults in a program under test in order to assess or generate test cases, or evaluate the reliability of the program. Faults introduced into the source code are defined using mutation operators. They should be related to different, also object-oriented features of a program. The most research on OO mutations was devoted to Java programs. This paper describes analytical and empirical study performed to evaluate the quality of advanced mutation operators for C# programs. Experimental results demonstrate effectiveness of different mutation operators. Unit tests suites and functional tests were used in experiments. A detailed analysis was conducted on mutation operators dealing with delegates and exception handling.
Application driven traffic modeling for NoCs
Authors: Leonel Tedesco, Aline Mello, Leonardo Giacomet, Ney Calazans, Fernando Moraes
Venue: Proceedings of the 19th annual symposium on Integrated circuits and systems design (2006)

The network on chip (NoC) design process requires an adequate characterization of the application running on it to optimize communication resources utilization and dimensioning. The traffic modeling process is the most essential step for characterizing complex applications. It is possible to identify three methods to model traffic in NoC literature. The first one assumes sources continually send data at a constant rate to the network and it is the most commonly used. The second method employs probabilistic functions to model the traffic behavior for typical applications, as audio and video streams. The accuracy of this method is better, at the extra cost of modeling complexity and simulation time. The third method employs traffic traces to evaluate network performance. Even with small traces, simulation time can be prohibitive. The advantage is accuracy, superior to the previous models. Even if a given application is correctly modeled, other flows interfere on how the application traffic behaves within the network. Results about the mutual interference of different traffic flows in NoCs are scarce. This work has two main objectives: (i) compare NoC performance, in terms of throughput and latency, when different traffic models are used for the same application; (ii) evaluate the impact of network noise traffic on some specific modeled flow. Preliminary results show how far is the real NoC performance for a given application when an oversimplified model is employed. The conclusion is that NoCs must employ internal mechanisms to ensure QoS, since noise traffic makes modeled traffic to depart from its predicted behavior.
Situations in Conceptual Modeling of Context
Authors: Patricia Dockhorn Costa, Giancarlo Guizzardi, Joao Paulo A. Almeida, Luis Ferreira Pires, Marten van Sinderen
Venue: Proceedings of the 10th IEEE on International Enterprise Distributed Object Computing Conference Workshops (2006)

In previous work, we have defined conceptual foundations that can be beneficially used in context modeling. These conceptual foundations include the separation of entity and context, and the characterization of context as either Intrinsic or Relational. This paper aims at extending this approach by introducing the ontological concept of Situation as means of composing the elements of our ontology (entities, intrinsic and relational contexts) to model particular states of affairs of interest. Our concepts have been inspired by and aligned with conceptual theories from the fields of philosophy and cognitive sciences.
A Non-uniform Quantizing Approach to Protect Biometric Templates
Authors: Qi Han, Zhifang Wang, Xiamu Niu
Venue: Proceedings of the 2006 International Conference on Intelligent Information Hiding and Multimedia (2006)

In this paper, a novel methodology to achieve the security of the biometric templates in biometric systems is proposed. An adaptive non-uniform quantization (ANUQ) algorithm is introduced to eliminate the contradiction between the fuzziness of the biometric information and the sensitive of the Hash function. The ANUQ algorithm maps different biometric feature vectors from the same individual to a unique quantized feature vector. Then the quantized feature vector can be saved and identified by its hash. A biometric template protection scheme is designed which avoids the storage of users' biometric templates, and further reduce the risk of losing of users' sensitive information. Simulations on an iris recognition algorithm show the feasibility of this method.
The effectiveness of strategic information systems planning under environmental uncertainty
Authors: Henry E. Newkirk, Albert L. Lederer
Venue: Information and Management (2006)

Researchers have suggested that more extensive strategic information systems planning (SISP) in an uncertain environment produces greater planning success. Managers must decide whether, and if so when, to perform such SISP. Our study tested the effect of SISP phases on planning success in more and less uncertain environments.A questionnaire assessed SISP in terms of strategic awareness, situation analysis, strategy conception, strategy formulation, and strategy implementation planning phases. It inquired about environmental uncertainty as dynamism, heterogeneity, and hostility. Finally, it measured SISP success as a composite of alignment, analysis, cooperation, and capabilities. One hundred and sixty-one IS executives provided data in a postal survey.More extensive strategy formulation uniformly predicted successful planning in more uncertain environments, whereas strategic awareness generally predicted it in less uncertain ones. Strategy conception predicted it in neither more nor less uncertain environments. More extensive planning is thus not uniformly successful in either environment but depends on the nature of the uncertainty.
A Method for Reducing False Hits in Querying Encrypted Databases
Authors: Yi Tang, Jun Yun
Venue: Proceedings of the The 8th IEEE International Conference on E-Commerce Technology and The 3rd IEEE International Conference on Enterprise Computing, E-Commerce, and E-Services (2006)

The emerging trend of outsourcing database to third parties motivates the research of protecting sensitive data from database service providers. The bucket-based method is one of the feasible methods to store those data encrypted. Since a bucket may contain many different attribute values, this method also introduces some false query results when performing queries over encrypted databases. Strategies are needed to balance the data secrecy and query efficiency. In this paper, we use the expected number of false hits in query results to measure the query efficiency and formulate the tradeoff between security and efficiency as an optimization problem. Constrained by a given range of the bucket set entropies, a local search based method is applied to regulate the elements between neighboring bucket pairs and reconstruct a new set of buckets with fewer false hits. We validate this method with some experiments on range queries. Experiment results show that it can decrease the number of false hits in two different range query behaviors.
Battery power-aware encryption
Authors: R. Chandramouli, S. Bapatla, K. P. Subbalakshmi, R. N. Uma
Venue: ACM Transactions on Information and System Security (TISSEC) (2006)

Minimizing power consumption is crucial in battery power-limited secure wireless mobile networks. In this paper, we (a) introduce a hardware/software set-up to measure the battery power consumption of encryption algorithms through real-life experimentation, (b) based on the profiled data, propose mathematical models to capture the relationships between power consumption and security, and (c) formulate and solve security maximization subject to power constraints. Numerical results are presented to illustrate the gains that can be achieved in using solutions of the proposed security maximization problems subject to power constraints.