OpenRaiser/Intern-Atlas huggingface dataset:
What the Cited and Citing Environments Reveal of "Advances in Atmospheric Sciences"?
Venue: arXiv cs.DL 2010
Year: 2010

The networking ability of journals reflects their academic influence among peer journals. This paper analyzes the cited and citing environments of the journal--Advances in Atmospheric Sciences--using methods from social network analysis. The journal has been actively participating in the international journal environment, but one has a tendency to cite papers published in international journals. Advances in Atmospheric Sciences is intensely interrelated with international peer journals in terms of similar citing pattern. However, there is still room for an increase in its academic visibility given the comparatively smaller reception in terms of cited references.
Stiffness Analysis of Parallel Manipulators with Preloaded Passive Joints
Venue: arXiv cs.RO 2010
Year: 2010

The paper presents a methodology for the enhanced stiffness analysis of parallel manipulators with internal preloading in passive joints. It also takes into account influence of the external loading and allows computing both the non-linear "load-deflection" relation and the stiffness matrices for any given location of the end-platform or actuating drives. Using this methodology, it is proposed the kinetostatic control algorithm that allows to improve accuracy of the classical kinematic control and to compensate position errors caused by elastic deformations in links/joints due to the external/internal loading. The results are illustrated by an example that deals with a parallel manipulator of the Orthoglide family where the internal preloading allows to eliminate the undesired buckling phenomena and to improve the stiffness in the neighborhood of its kinematic singularities.
Performance evaluation of parallel manipulators for milling application
Venue: arXiv cs.RO 2010
Year: 2010

This paper focuses on the performance evaluation of the parallel manipulators for milling of composite materials. For this application the most significant performance measurements, which denote the ability of the manipulator for the machining are defined. In this case, optimal synthesis task is solved as a multicriterion optimization problem with respect to the geometric, kinematic, kinetostatic, elastostostatic, dynamic properties. It is shown that stiffness is an important performance factor. Previous models operate with links approximation and calculate stiffness matrix in the neighborhood of initial point. This is a reason why a new way for stiffness matrix calculation is proposed. This method is illustrated in a concrete industrial problem.
Entropy Rate for Hidden Markov Chains with rare transitions
Venue: arXiv cs.IT 2010
Year: 2010

We consider Hidden Markov Chains obtained by passing a Markov Chain with rare transitions through a noisy memoryless channel. We obtain asymptotic estimates for the entropy of the resulting Hidden Markov Chain as the transition rate is reduced to zero.
Bisimulations for fuzzy transition systems
Venue: arXiv cs.AI 2010
Year: 2010

There has been a long history of using fuzzy language equivalence to compare the behavior of fuzzy systems, but the comparison at this level is too coarse. Recently, a finer behavioral measure, bisimulation, has been introduced to fuzzy finite automata. However, the results obtained are applicable only to finite-state systems. In this paper, we consider bisimulation for general fuzzy systems which may be infinite-state or infinite-event, by modeling them as fuzzy transition systems. To help understand and check bisimulation, we characterize it in three ways by enumerating whole transitions, comparing individual transitions, and using a monotonic function. In addition, we address composition operations, subsystems, quotients, and homomorphisms of fuzzy transition systems and discuss their properties connected with bisimulation. The results presented here are useful for comparing the behavior of general fuzzy systems. In particular, this makes it possible to relate an infinite fuzzy system to a finite one, which is easier to analyze, with the same behavior.
Affine Invariant, Model-Based Object Recognition Using Robust Metrics and Bayesian Statistics
Venue: arXiv cs.CV 2010
Year: 2010

We revisit the problem of model-based object recognition for intensity images and attempt to address some of the shortcomings of existing Bayesian methods, such as unsuitable priors and the treatment of residuals with a non-robust error norm. We do so by using a refor- mulation of the Huber metric and carefully chosen prior distributions. Our proposed method is invariant to 2-dimensional affine transforma- tions and, because it is relatively easy to train and use, it is suited for general object matching problems.
openPC : a toolkit for public cluster with full ownership
Venue: arXiv cs.DC 2010
Year: 2010

The openPC is a set of open source tools that realizes a parallel machine and distributed computing environment divisible into several independent blocks of nodes, and each of them is remotely but fully in any means accessible for users with a full ownership policy. The openPC components address fundamental issues relating to security, resource access, resource allocation, compatibilities with heterogeneous middlewares, user-friendly and integrated web-based interfaces, hardware control and monitoring systems. These components have been deployed successfully to the LIPI Public Cluster which is open for public use. In this paper, the unique characteristics of openPC due to its rare requirements are introduced, its components and a brief performance analysis are discussed.
Context Aware End-to-End Connectivity Management
Venue: arXiv cs.LG 2010
Year: 2010

In a dynamic heterogeneous environment, such as pervasive and ubiquitous computing, context-aware adaptation is a key concept to meet the varying requirements of different users. Connectivity is an important context source that can be utilized for optimal management of diverse networking resources. Application QoS (Quality of service) is another important issue that should be taken into consideration for design of a context-aware system. This paper presents connectivity from the view point of context awareness, identifies various relevant raw connectivity contexts, and discusses how high-level context information can be abstracted from the raw context information. Further, rich context information is utilized in various policy representation with respect to user profile and preference, application characteristics, device capability, and network QoS conditions. Finally, a context-aware end-to-end evaluation algorithm is presented for adaptive connectivity management in a multi-access wireless network. Unlike the currently existing algorithms, the proposed algorithm takes into account user QoS parameters, and therefore, it is more practical.
An Efficient Security Mechanism for High-Integrity Wireless Sensor Networks
Venue: arXiv cs.CR 2010
Year: 2010

Wireless sensor networks (WSNs) have recently attracted a lot of interest in the research community due their wide range of applications. Unfortunately, these networks are vulnerable to numerous security threats that can adversely affect their proper functioning. This problem is more critical if the network is deployed for some mission-critical applications such as in a tactical battlefield. Random failure of nodes and intentional compromise of nodes by an insider attack in a WSN pose particularly difficult challenges to security engineers as these attacks cannot be defended by traditional cryptography-based mechanisms. In this paper, a security solution is proposed for detecting compromised and faulty nodes in a WSN. The mechanism also isolates a compromised node from the network so that it cannot participate in any network activity. The proposed mechanism is based on misbehavior classification, behaviour monitoring and trust management. It involves minimum computation and communication overhead and is ideally suited for a resource-constrained, high-integrity WSN.
A Survey on Cross-Layer Design Frameworks for Multimedia Applications over Wireless Networks
Venue: arXiv cs.NI 2010
Year: 2010

In the last few years, the Internet throughput, usage and reliability have increased almost exponentially. The introduction of broadband wireless mobile ad hoc networks (MANETs) and cellular networks together with increased computational power have opened the door for a new breed of applications to be created, namely real-time multimedia applications. Delivering real-time multimedia traffic over a complex network like the Internet is a particularly challenging task since these applications have strict quality -of-service (QoS) requirements on bandwidth, delay, and delay jitter. Traditional IP-based best effort service will not be able to meet these stringent requirements. The time-varying nature of wireless channels and resource constrained wireless devices make the problem even more difficult. To improve perceived media quality by end users over wireless Internet, QoS supports can be addressed in different layers, including application layer, transport layer and link layer. Cross layer design is a well-known approach to achieve this adaptation. In cross-layer design, the challenges from the physical wireless medium and the QoS-demands from the applications are taken into account so that the rate, power, and coding at the physical layer can adapted to meet the requirements of the applications given the current channel and network conditions. A number of propositions for cross-layer designs exist in the literature. In this paper, an extensive review has been made on these cross-layer architectures that combine the application-layer, transport layer and the link layer controls. Particularly the issues like channel estimation techniques, adaptive controls at the application and link layers for energy efficiency, priority based scheduling, transmission rate control at the transport layer, and adaptive automatic repeat request (ARQ) are discussed in detail.
A Survey on Reputation and Trust-Based Systems for Wireless Communication Networks
Venue: arXiv cs.CR 2010
Year: 2010

Traditional approach of providing network security has been to borrow tools and mechanisms from cryptography. However, the conventional view of security based on cryptography alone is not sufficient for the defending against unique and novel types of misbehavior exhibited by nodes encountered in wireless communication networks. Reputation-based frameworks where nodes maintain reputation of other nodes and use it to evaluate their trustworthiness are deployed to provide scalable, diverse and a generalized approach for countering different types of misbehavior resulting form malicious and selfish nodes in these networks. In this paper, we present a comprehensive discussion on reputation and trust-based systems for wireless communication networks. Different classes of reputation system are described along with their unique characteristics and working principles. A number of currently used reputation systems are critically reviewed and compared with respect to their effectiveness and efficiency of performance. Some open problems in the area of reputation and trust-based system within the domain of wireless communication networks are also discussed.
Extended Generalized-K (EGK): A New Simple and General Model for Composite Fading Channels
Venue: arXiv cs.IT 2010
Year: 2010

In this paper, we introduce a generalized composite fading distribution (termed extended generalized-K (EGK)) to model the envelope and the power of the received signal in millimeter wave (60 GHz or above) and free-space optical channels. We obtain the first and the second-order statistics of the received signal envelope characterized by the EGK composite fading distribution. In particular, expressions for probability density function, cumulative distribution function, level crossing rate and average fade duration, and fractional moments are derived. In addition performance measures such as amount of fading, average bit error probability, outage probability, average capacity, and outage capacity are offered in closed-form. Selected numerical and computer simulation examples validate the accuracy of the presented mathematical analysis.
A Tutorial on Bayesian Optimization of Expensive Cost Functions, with Application to Active User Modeling and Hierarchical Reinforcement Learning
Venue: arXiv cs.LG 2010
Year: 2010

We present a tutorial on Bayesian optimization, a method of finding the maximum of expensive cost functions. Bayesian optimization employs the Bayesian technique of setting a prior over the objective function and combining it with evidence to get a posterior function. This permits a utility-based selection of the next observation to make on the objective function, which must take into account both exploration (sampling from areas of high uncertainty) and exploitation (sampling areas likely to offer improvement over the current best observation). We also present two detailed extensions of Bayesian optimization, with experiments---active user modelling with preferences, and hierarchical reinforcement learning---and a discussion of the pros and cons of Bayesian optimization based on our experiences.
Throughput and Latency in Finite-Buffer Line Networks
Venue: arXiv cs.IT 2010
Year: 2010

This work investigates the effect of finite buffer sizes on the throughput capacity and packet delay of line networks with packet erasure links that have perfect feedback. These performance measures are shown to be linked to the stationary distribution of an underlying irreducible Markov chain that models the system exactly. Using simple strategies, bounds on the throughput capacity are derived. The work then presents two iterative schemes to approximate the steady-state distribution of node occupancies by decoupling the chain to smaller queueing blocks. These approximate solutions are used to understand the effect of buffer sizes on throughput capacity and the distribution of packet delay. Using the exact modeling for line networks, it is shown that the throughput capacity is unaltered in the absence of hop-by-hop feedback provided packet-level network coding is allowed. Finally, using simulations, it is confirmed that the proposed framework yields accurate estimates of the throughput capacity and delay distribution and captures the vital trends and tradeoffs in these networks.
Personalized Data Set for Analysis
Venue: arXiv cs.DB 2010
Year: 2010

Data Management portfolio within an organization has seen an upsurge in initiatives for compliance, security, repurposing and storage within and outside the organization. When such initiatives are being put to practice care must be taken while granting access to data repositories for analysis and mining activities. Also, initiatives such as Master Data Management, cloud computing and self service business intelligence have raised concerns in the arena of regulatory compliance and data privacy, especially when a large data set of an organization are being outsourced for testing, consolidation and data management. Here, an approach is presented where a new service layer is introduced, by data governance group, in the architecture for data management and can be used for preserving privacy of sensitive information.
Cusp points in the parameter space of RPR-2PRR parallel manipulator
Venue: arXiv cs.RO 2010
Year: 2010

This paper investigates the existence conditions of cusp points in the design parameter space of the R\underline{P}R-2P\underline{R}R parallel manipulators. Cusp points make possible non-singular assembly-mode changing motion, which can possibly increase the size of the aspect, i.e. the maximum singularity free workspace. The method used is based on the notion of discriminant varieties and Cylindrical Algebraic Decomposition, and resorts to Gröbner bases for the solutions of systems of equations.
On the determination of cusp points of 3-R\underline{P}R parallel manipulators
Venue: arXiv cs.RO 2010
Year: 2010

This paper investigates the cuspidal configurations of 3-RPR parallel manipulators that may appear on their singular surfaces in the joint space. Cusp points play an important role in the kinematic behavior of parallel manipulators since they make possible a non-singular change of assembly mode. In previous works, the cusp points were calculated in sections of the joint space by solving a 24th-degree polynomial without any proof that this polynomial was the only one that gives all solutions. The purpose of this study is to propose a rigorous methodology to determine the cusp points of 3-R\underline{P}R manipulators and to certify that all cusp points are found. This methodology uses the notion of discriminant varieties and resorts to Gröbner bases for the solutions of systems of equations.
On the Role of Feedback in LT Codes
Venue: arXiv cs.IT 2010
Year: 2010

This paper concerns application of feedback in LT codes. The considered type of feedback is acknowledgments, where information on which symbols have been decoded is given to the transmitter. We identify an important adaptive mechanism in standard LT codes, which is crucial to their ability to perform well under any channel conditions. We show how precipitate application of acknowledgments can interfere with this adaptive mechanism and lead to significant performance degradation. Moreover, our analysis reveals that even sensible use of acknowledgments has very low potential in standard LT codes. Motivated by this, we analyze the impact of acknowledgments on multi layer LT codes, i.e. LT codes with unequal error protection. In this case, feedback proves advantageous. We show that by using only a single feedback message, it is possible to achieve a noticeable performance improvement compared to standard LT codes.
Beamsteering on Mobile Devices: Network Capacity and Client Efficiency
Venue: arXiv cs.NI 2010
Year: 2010

Current and emerging mobile devices are omni directional in wireless communication. Such omni directionality not only limits device energy efficiency but also poses a significant challenge toward the capacity of wireless networks through inter-link interference. In this work, we seek to make mobile clients directional with beamsteering. We first demonstrate that beamsteering is already feasible to mobile devices such as Netbooks and eBook readers in terms of form factor, power efficiency, and device mobility. We further reveal that beamsteering mobile clients face a unique challenge to balance client efficiency and network capacity. There is an optimal operating point for a beamsteering mobile client in terms of the number of antennas and transmit power that achieve the required capacity with lowest power. Finally, we provide a distributed algorithm called BeamAdapt that allows each client to closely approach its optimal point iteratively without central coordination. We also offer a cellular system realization of BeamAdapt. Using Qualnet-based simulation, we show that BeamAdapt with four antennas can reduce client power consumption by 55% while maintaining a required network throughput for a large-scale network, compared to the same network with omni directional mobile clients.
E = I + T: The internal extent formula for compacted tries
Venue: arXiv cs.DS 2010
Year: 2010

It is well known that in a binary tree the external path length minus the internal path length is exactly 2n-2, where n is the number of external nodes. We show that a generalization of the formula holds for compacted tries, replacing the role of paths with the notion of extent, and the value 2n-2 with the trie measure, an estimation of the number of bits that are necessary to describe the trie.
New generation of mobile phone viruses and corresponding countermeasures
Venue: arXiv cs.NI 2010
Year: 2010

The fast growing market for smart phones coupled with their almost continuous online presence makes these devices the new targets of virus writers. It has been recently found that the topological spread of MMS (Multimedia Message Services) viruses is highly restricted by the underlying fragmentation of the call graph. In this paper, we study MMS viruses under another type of spreading behavior: scanning. We find that hybrid MMS viruses including some level of scanning are more dangerous to the mobile community than their standard topological counterparts. However, the effectiveness of both scanning and topological behaviors in MMS viruses can generally be limited by two controlling methods: (i) decreasing susceptible handsets' market share (OS it runs) and (ii) improving monitoring capacity to limit the frequency in which MMS messages can be sent by the mobile viruses.
TILT: Transform Invariant Low-rank Textures
Venue: arXiv cs.CV 2010
Year: 2010

In this paper, we show how to efficiently and effectively extract a class of "low-rank textures" in a 3D scene from 2D images despite significant corruptions and warping. The low-rank textures capture geometrically meaningful structures in an image, which encompass conventional local features such as edges and corners as well as all kinds of regular, symmetric patterns ubiquitous in urban environments and man-made objects. Our approach to finding these low-rank textures leverages the recent breakthroughs in convex optimization that enable robust recovery of a high-dimensional low-rank matrix despite gross sparse errors. In the case of planar regions with significant affine or projective deformation, our method can accurately recover both the intrinsic low-rank texture and the precise domain transformation, and hence the 3D geometry and appearance of the planar regions. Extensive experimental results demonstrate that this new technique works effectively for many regular and near-regular patterns or objects that are approximately low-rank, such as symmetrical patterns, building facades, printed texts, and human faces.
Collaborative Knowledge Creation and Management in Information Retrieval
Venue: arXiv cs.IR 2010
Year: 2010

The final goal of Information Retrieval (IR) is knowledge production. However, it has been argued that knowledge production is not an individual effort but a collaborative effort. Collaboration in information retrieval is geared towards knowledge sharing and creation of new knowledge by users. This paper discusses Collaborative Information Retrieval (CIR) and how it culminates to knowledge creation. It explains how created knowledge is organized and structured. It describes a functional architecture for the development of a CIR prototype called MECOCIR. Some of the features of the prototype are presented as well as how they facilitate collaborative knowledge exploitation. Knowledge creation is explained through the knowledge conversion/transformation processes proposed by Nonaka and CIR activities that facilitate these processes are high-lighted and discussed
A new Recommender system based on target tracking: a Kalman Filter approach
Venue: arXiv cs.AI 2010
Year: 2010

In this paper, we propose a new approach for recommender systems based on target tracking by Kalman filtering. We assume that users and their seen resources are vectors in the multidimensional space of the categories of the resources. Knowing this space, we propose an algorithm based on a Kalman filter to track users and to predict the best prediction of their future position in the recommendation space.
Detecting Image Forgeries using Geometric Cues
Venue: arXiv cs.CV 2010
Year: 2010

This chapter presents a framework for detecting fake regions by using various methods including watermarking technique and blind approaches. In particular, we describe current categories on blind approaches which can be divided into five: pixel-based techniques, format-based techniques, camera-based techniques, physically-based techniques and geometric-based techniques. Then we take a second look on the geometric-based techniques and further categorize them in detail. In the following section, the state-of-the-art methods involved in the geometric technique are elaborated.