ppxscal/embedding_network huggingface dataset:
Density Based Clustering algorithm for Vehicular Ad-Hoc Networks
Authors: Slawomir Kuklinski, Grzegorz Wolny
Venue: International Journal of Internet Protocol Technology (2009)

In this paper we present a new multilevel clustering algorithm for Vehicular Ad-Hoc Networks (VANET), which we call the Density Based Clustering (DBC). Our solution is focused on the formation of stable, long living clusters. Cluster formation is based on a complex clustering metric which takes into account the density of the connection graph, the link quality and the road traffic conditions. The tests performed in the simulation environment composed of VanetMobiSim and Java in Simulation Time (JiST)&#47;SWANS have shown that DBC performs better than the popular approach (the Lowest Id algorithm) &ndash; the clusters stability has been significantly increased.
Sorting Genomes by Translocations and Deletions, Dealing with Duplicated Genes
Authors: Xingqin Qi, Guojun Li
Venue: Proceedings of the 2009 WRI Global Congress on Intelligent Systems - Volume 02 (2009)

The problem of sorting by reciprocal translocations (abbreviated as SBT) arises from the field of comparative genomics, which is to find a shortest sequence of reciprocal translocations that transforms one genome \Pi into another genome \Gamma, with the restriction that \Pi and \Gamma contain the same genes. SBT has been proved to be polynomial-time solvable, and several polynomial algorithms have been developed, including Bergeron's SBT algorithm. Recently, an algorithm allowing to compare genomes with different genes but without duplications is given by extending Bergeron's SBT algorithm. Here, we will improve the approach to handle genomes with duplicated genes. Obviously, the existence of duplications will make the problem more difficult. We should decide which one of the duplications in the subject genome \Pi should be assigned to a particular homolog in the target genome \Gamma; resolving such a problem appears to require exponential time. In this paper, by a similar method developed by Mark Marron et. al., which was used to sort two chromosomes containing different genes, we present an approximation algorithm for computing near minimal sorting sequences involving translocations and deletions between two (multi-chromosomes) genomes containing different genes allowing non-tails duplications. We derive the error bound for the polynomial-time distance computation. This is the first constant approximation algorithm for SBT with duplications.
Performance Enhancement with Cooperation Based Transmission in the Cognitive Radio Networks
Authors: Zhi Gang Duan
Venue: Proceedings of the 2009 WASE International Conference on Information Engineering - Volume 01 (2009)

Cognitive radio has been considered as a promisingparadigm to achieve efficient spectrum usage by allowing the coexistence of the primary and secondary networks. Onefundamental challenge is to ensure the quality of service (QoS) of the primary link while maximizing the transmission rate of the secondary links. In this paper, we investigate cooperation based spectrum access at the secondary networks. If the QoS requirement of primary link is stringent, low power is allowed at the cognitive radio user and the transmission rate is limited. It is beneficial that the cognitive radio user obtains cooperation from the surrounding users to increase the rate. The best relay which provides the maximal transmission rate is selected for cooperation. The transmission rate performance is investigated under the peak and average interference constraints (IC). Thesimulation results show that the transmission rate of cognitive radio link can be improved by cooperation, especially when the power of the direct link is limited. The achieved transmission rate under the average IC is higher than that under the peak IC, due to power adaptation between the transmitter and relay. And higher gain can be obtained as the number of potential relays increases.
Improved Approximation of Linear Threshold Functions
Authors: Ilias Diakonikolas, Rocco A. Servedio
Venue: Proceedings of the 2009 24th Annual IEEE Conference on Computational Complexity (2009)

We prove two main results on how arbitrary linear threshold functions $f(x) = \sign(w\cdot x - \theta)$ over the $n$-dimensional Boolean hypercube can be approximated by simple threshold functions. Our first result shows that every $n$-variable threshold function $f$ is $\eps$-close to a threshold function depending only on $\Inf(f)^2 \cdot \poly(1/\eps)$ many variables, where $\Inf(f)$ denotes the total influence or average sensitivity of $f.$ This is an exponential sharpening of Friedgut's well-known theorem \cite{Friedgut:98}, which states that every Boolean function $f$ is $\eps$-close to a function depending only on $2^{O(\Inf(f)/\eps)}$ many variables, for the case of threshold functions. We complement this upper bound by showing that $\Omega(\Inf(f)^2 + 1/\epsilon^2)$ many variables are required for $\epsilon$-approximating threshold functions. Our second result is a proof that every $n$-variable threshold function is $\eps$-close to a threshold function with integer weights at most $\poly(n) \cdot 2^{\tilde{O}(1/\eps^{2/3})}.$ This is a significant improvement, in the dependence on the error parameter $\eps$, on an earlier result of \cite{Servedio:07cc} which gave a $\poly(n) \cdot 2^{\tilde{O}(1/\eps^{2})}$ bound. Our improvement is obtained via a new proof technique that uses strong anti-concentration bounds from probability theory. The new technique also gives a simple and modular proof of the original \cite{Servedio:07cc} result, and extends to give low-weight approximators for threshold functions under a range of probability distributions beyond just the uniform distribution.
Fast Multiscale Operator Development for Hexagonal Images
Authors: Bryan Gardiner, Sonya Coleman, Bryan Scotney
Venue: Proceedings of the 31st DAGM Symposium on Pattern Recognition (2009)

For many years the concept of using hexagonal pixels for image capture has been investigated, and several advantages of such an approach have been highlighted. Recently there has been a renewed interested in using hexagonal pixel based images for various image processing tasks. Therefore, we present a design procedure for scalable hexagonal gradient operators, developed within the finite element framework, for use on hexagonal pixel based images. We highlight the efficiency of our approach, based on computing just one small neighbourhood operator and generating larger scale operators via linear additions of the small operator. We also demonstrate that scaled salient feature maps can be generated from one low level feature map without the need for application of larger operators.
Experimental Study of Independent and Dominating Sets in Wireless Sensor Networks Using Graph Coloring Algorithms
Authors: Dhia Mahjoub, David W. Matula
Venue: Proceedings of the 4th International Conference on Wireless Algorithms, Systems, and Applications (2009)

The domatic partition problem seeks to maximize the partitioning of the nodes of the network into disjoint dominating sets. These sets represent a series of virtual backbones for wireless sensor networks to be activated successively, resulting in more balanced energy consumption and increased network robustness. In this study, we address the domatic partition problem in random geometric graphs by investigating several vertex coloring algorithms both topology and geometry-aware, color-adaptive and randomized. Graph coloring produces color classes with each class representing an independent set of vertices. The disjoint maximal independent sets constitute a collection of disjoint dominating sets that offer good network coverage. Furthermore, if we relax the full domination constraint then we obtain a partitioning of the network into disjoint dominating and nearly-dominating sets of nearly equal size, providing better redundancy and a near-perfect node coverage yield. In addition, these independent sets can be the basis for clustering a very large sensor network with minimal overlap between the clusters leading to increased efficiency in routing, wireless transmission scheduling and data-aggregation. We also observe that in dense random deployments, certain coloring algorithms yield a packing of the nodes into independent sets each of which is relatively close to the perfect placement in the triangular lattice.
The Research of Security Technology on E-commerce Based on the Second Generation Identity ID Card and Fingerprint
Authors: Minwei He
Venue: Proceedings of the 2009 Second International Symposium on Electronic Commerce and Security - Volume 01 (2009)

With the extensive application of E-commerce , identity authentication has become one of the key technologies that influences its development. Based on RSA Algorithm of unsymmetrical cryptographic system and MD5 message digest algorithm, the paper presents an identity authentication infrastructure base on second generation identity card and fingerprint.
Finding state similarities for faster planning
Authors: Christian Fritz
Venue: Proceedings of the 23rd national conference on Artificial intelligence - Volume 2 (2008)

In many planning applications one can find actions with overlapping effects. If for optimally reaching the goal all that matters is within this overlap, there is no need to consider all these actions -for the task at hand they are equivalent. Using this structure for speed-up has previously been proposed in the context of least commitment planning. Of a similar spirit is the approach for improving best-first search based planning we present here: intuitively, given a set of start states, reachable from the initial state, we plan in parallel for all of them, exploiting the similarities between them to gain computational savings. Since the similarity of two states is problem specific, we explicitly infer it by regressing all relevant entities, goal, heuristic function, action preconditions and costs, over the action sequences considered in planning. If the resulting formulae mention only fluents whose values the two states have in common, it suffices to evaluate the formulae in one of them. This leads to computational savings over conventional best-first search.
Advances in Quantum Computation: Representation Theory, Quantum Field Theory, Category Theory, Mathematical Physics, September 20-23, 2007, University of Texas at Tyler
Authors: Kazem Mahdavi, Deborah Koslover
Venue:  (2009)

This volume represents the talks given at the Conference on Interactions between Representation Theory, Quantum Field Theory, Category Theory, Mathematical Physics, and Quantum Information Theory, held in September 2007 at the University of Texas at Tyler. The papers in this volume, written by top experts in the field, address physical aspects, mathematical aspects, and foundational issues of quantum computation. This volume will benefit researchers interested in advances in quantum computation and communication, as well as graduate students who wish to enter the field of quantum computation.
Sharp thresholds of two-components Bose-Einstein condensates
Authors: Lü Zhongxue, Liu Zuhan
Venue: Computers Mathematics with Applications (2009)

In this paper, we establish a sharp condition of global existence for the solution of two-components Bose-Einstein Condensates. This condition is related to the ground state solution of some steady-state two-coupled nonlinear Schrodinger equations.
Reliable Key Distribution for Secure Multicast by SRDP-Sign
Authors: Franco Tommasi, Simone Molendini, Elena Scialpi
Venue: Proceedings of the 2009 First International Conference on Advances in Future Internet (2009)

Security is an important concern in today's networking and particularly in satellite communication, where eavesdropping and active intrusion is much easier than in terrestrial fixed or mobile networks because of the broadcast nature of satellites. Many applications require the security feature of data confidentiality; in order to offer such capability, encryption keys must be constantly changed upon a membership change. If the keys are sent via multicast, that it is particularly useful for large groups, reliable multicast is required. In this paper we propose an efficient, reliable and multicast distribution of the encryption keys with SRDP-Sign (Satellite Reliable Distribution Protocol for Signaling). We guarantee reliability for all the receivers with a high degree of scalability. Total reliability error and the overall latency in the key distribution will be evaluated.
Mobile Robot Navigation in Unknown Dynamic Environment Based on Ant Colony Algorithm
Authors: Zeng Bi, Yang Yimin, Xu Yisan
Venue: Proceedings of the 2009 WRI Global Congress on Intelligent Systems - Volume 03 (2009)

In view of the navigation problem of mobile robot in unknown dynamic environment, this paper proposes a new method of robot rolling navigation using improved ant colony system algorithm. The method first utilize the fuzzy logistic description to establish the fuzzy environment model of robot local area, and then adopts the improved ant colony system algorithm to quickly search each local optimal path. With the optimal path leading, the robot achieves navigation in unknown dynamic environment combine with the method of rolling path planning. The methods not only overcome the influences of fuzziness and uncertainty of environmental information which causes by sensor’s inferior detection, but also has fully exploited the ant colony algorithm superiority in the community intelligence. The simulation result indicates the validity and the feasibility of this algorithm.
Void Avoidance in Three-Dimensional Mobile Underwater Sensor Networks
Authors: Peng Xie, Zhong Zhou, Zheng Peng, Jun-Hong Cui, Zhijie Shi
Venue: Proceedings of the 4th International Conference on Wireless Algorithms, Systems, and Applications (2009)

Mobile underwater sensor networks are usually featured with three-dimensional topology, high node mobility and long propagation delays. For such networks, geographic routing has been shown to be very suitable. However, routing voids pose great challenges on the greedy policy used in most geographic routing protocols. The problem is more severe for underwater sensor networks because of node mobility and three-dimensional topology. In this paper, we propose a void avoidance protocol, called Vector-Based Void Avoidance (VBVA), to address the routing void problem in mobile underwater sensor networks. VBVA adopts two mechanisms, vector-shift and back-pressure, to handle voids. Vector-shift mechanism is used to route data packets along the boundary of a void. Back-pressure mechanism routes data packets backward to bypass a concave void. VBVA handles the routing void problem on demand and thus does not need to know network topology and void information in advance. Therefore, it is very robust to cope with mobile voids in mobile networks. To the best of our knowledge, VBVA is the first void avoidance protocol to address the three-dimensional and mobile void problems in underwater sensor networks. Our simulation results show that VBVA works effectively and efficiently in mobile underwater sensor networks.
Somewhat Non-committing Encryption and Efficient Adaptively Secure Oblivious Transfer
Authors: Juan A. Garay, Daniel Wichs, Hong-Sheng Zhou
Venue: Proceedings of the 29th Annual International Cryptology Conference on Advances in Cryptology (2009)

Designing efficient cryptographic protocols tolerating adaptive adversaries, who are able to corrupt parties on the fly as the computation proceeds, has been an elusive task. In this paper we make progress in this area. First, we introduce a new notion called semi-adaptive security which is slightly stronger than static security but significantly weaker than fully adaptive security. The main difference between adaptive and semi-adaptive security is that semi-adaptive security allows for the case where one party starts out corrupted and the other party becomes corrupted later on, but not the case where both parties start out honest and become corrupted later on. As such, semi-adaptive security is much easier to achieve than fully adaptive security. We then give a simple, generic protocol compiler which transforms any semi-adaptively secure protocol into a fully adaptively secure one. The compilation effectively decomposes the problem of adaptive security into two (simpler) problems which can be tackled separately: the problem of semi-adaptive security and the problem of realizing a weaker variant of secure channels.We solve the latter problem by means of a new primitive that we call somewhat non-committing encryption resulting in significant efficiency improvements over the standard method for realizing secure channels using (fully) non-committing encryption. Somewhat non-committing encryption has two parameters: an equivocality parameter ¿ (measuring the number of ways that a ciphertext can be "opened") and the message sizes k. Our implementation is very efficient for small values ¿, even when k is large. This translates into a very efficient compilation of semi-adaptively secure protocols for tasks with small input/output domains (such as bit-OT) into fully adaptively secure protocols.Indeed, we showcase our methodology by applying it to the recent Oblivious Transfer protocol by Peikert etal [Crypto 2008], which is only secure against static corruptions, to obtain the first efficient, adaptively secure and composable OT protocol. In particular, to transfer an n-bit message, we use a constant number of rounds and O(n) public key operations.
Induction of cross-language affix and letter sequence correspondence
Authors: Ari Rappoport, Tsahi Levent-Levi
Venue: Proceedings of the International Workshop on Cross-Language Knowledge Induction (2006)

We introduce the problem of explicit modeling of form relationships between words in different languages, focusing here on languages having an alphabetic writing system and affixal morphology. We present an algorithm that learns the cross-language correspondence between affixes and letter sequences. The algorithm does not assume prior knowledge of affixes in any of the languages, using only a simple single letter correspondence as seed. Results are given for the English-Spanish language pair.
Automatic Dominant Motion Characterization in the Video
Authors: Hua Man, Luo Yinhui
Venue: Proceedings of the 2009 International Forum on Information Technology and Applications - Volume 01 (2009)

Dominant motion detection is essential for automated video analysis. Traditional methods usually set an empirical threshold to detect pan/tilt/zoom. In this paper, we propose a novel approach of automatic detecting video dominate motion which is parameter-free. Based on the motion trajectories of feature points, the distribution of motion is estimated by kernel density estimation. A Kullback-Leibler divergence based K-Nearest Neighbor classifier is used to classify the motion into pan/tilt/zoom etc category. Experiments results on both standard test video and real world video show this method significantly out-performs a baseline parametric method for dominate motion detection in both precision and recall
Implicit Dynamic Frames: Combining Dynamic Frames and Separation Logic
Authors: Jan Smans, Bart Jacobs, Frank Piessens
Venue: Proceedings of the 23rd European Conference on ECOOP 2009 --- Object-Oriented Programming (2009)

The dynamic frames approach has proven to be a powerful formalism for specifying and verifying object-oriented programs. However, it requires writing and checking many frame annotations. In this paper, we propose a variant of the dynamic frames approach that eliminates the need to explicitly write and check frame annotations. Reminiscent of separation logic's frame rule, programmers write access assertions inside pre- and postconditions instead of writing frame annotations. From the precondition, one can then infer an upper bound on the set of locations writable or readable by the corresponding method. We implemented our approach in a tool, and used it to automatically verify several challenging programs, including subject-observer, iterator and linked list.
Human-Biometric Sensor Interaction: Impact of Training on Biometric System and User Performance
Authors: Eric P. Kukula, Robert W. Proctor
Venue: Proceedings of the Symposium on Human Interface 2009 on Human Interface and the Management of Information. Information and Interaction. Part II: Held as part of HCI International 2009 (2009)

Increasingly sophisticated biometric methods are being used for a variety of applications in which accurate authentication of people is necessary. Because all biometric methods require humans to interact with a device of some type, effective implementation requires consideration of human factors issues. One such issue is the training needed to use a particular device appropriately. In this paper, we review human factors issues in general that are associated with biometric devices and focus more specifically on the role of training.
On dependence of dynamical structure of numerical solutions of fluid simulations on forcibly added randomness
Authors: Itaru Hataue
Venue: Journal of Computational and Applied Mathematics (2009)

In the present paper, the dependencies of the numerical results of fluid simulations on forcibly added randomness are discussed. The incompressible Navier-Stokes equations and the continuity equation are solved numerically by using the MAC (Maker-And-Cell) method and implicit temporal scheme. The model adopted in the present study is a flow around a two-dimensional circular cylinder and the Reynolds number is 1500. The randomness which is given by using the pseudo-random number is forcibly added in the time marching step of the discretized Navier-Stokes equations. Dependencies of the averaged structure of asymptotic numerical solutions on the randomness are discussed. Furthermore, the dependence of the qualitative structure of the asymptotic solution of each sample calculation on the amplitude of randomness is also studied. It is clarified that forcibly added random errors may cover the nonlinear errors which make the system unstable.
Statistical Characterization of a Computer Grid
Authors: Lovro Ilijašić, Lorenza Saitta
Venue: Proceedings of the 18th International Symposium on Foundations of Intelligent Systems (2009)

Large-scale statistical analysis of more than 28 million jobs collected during 20 months of grid activity was undertaken in order to examine the relations between users, computing elements and jobs in the network. The results give insight into the global system behaviour and can be used to build models applicable in various contexts of grid computing. As an example, we here construct probabilistic models that prove to be able to accurately predict job abortion.
Using Trust and Self-Confidence for Coalition Formation in Migrating Workflow
Authors: Lei Guo, Xiaolin Wang, Guangzhou Zeng
Venue: Proceedings of the 2009 International Forum on Information Technology and Applications - Volume 01 (2009)

An experience based trust model in migrating workflow is proposed. In the trust model, security and capability are considered in a cooperation evaluation, a cooperation evaluation sequence is updated according to update strategies and the trust degree is acquired using the trust degree formula. Self-confidence of the workplace is defined based on our former research in agent ability self-confidence. After that, a coalition formation mechanism based on trust and self-confidence in migrating workflow is presented. Compared with related works, our trust and self-confidence based coalition formation mechanism can not only ensure former agents with high trust degree to remain their membership, but also allow fresh efficient agents to join in the coalition. Therefore, the security and efficiency of business process execution is well guaranteed.