OpenRaiser/Intern-Atlas huggingface dataset:
E-prints and Journal Articles in Astronomy: a Productive Co-existence
Venue: arXiv cs.DL 2006
Year: 2006

Are the e-prints (electronic preprints) from the arXiv repository being used instead of the journal articles? In this paper we show that the e-prints have not undermined the usage of journal papers in the astrophysics community. As soon as the journal article is published, the astronomical community prefers to read the journal article and the use of e-prints through the NASA Astrophysics Data System drops to zero. This suggests that the majority of astronomers have access to institutional subscriptions and that they choose to read the journal article when given the choice. Within the NASA Astrophysics Data System they are given this choice, because the e-print and the journal article are treated equally, since both are just one click away. In other words, the e-prints have not undermined journal use in the astrophysics community and thus currently do not pose a financial threat to the publishers. We present readership data for the arXiv category "astro-ph" and the 4 core journals in astronomy (Astrophysical Journal, Astronomical Journal, Monthly Notices of the Royal Astronomical Society and Astronomy & Astrophysics). Furthermore, we show that the half-life (the point where the use of an article drops to half the use of a newly published article) for an e-print is shorter than for a journal paper. The ADS is funded by NASA Grant NNG06GG68G. arXiv receives funding from NSF award #0404553
One approach to the digital visualization of hedgehogs in holomorphic dynamics
Venue: arXiv cs.MS 2006
Year: 2006

In the field of holomorphic dynamics in one complex variable, hedgehog is the local invariant set arising about a Cremer point and endowed with a very complicate shape as well as relating to very weak numerical conditions. We give a solution to the open problem of its digital visualization, featuring either a time saving approach and a far-reaching insight.
A Predicative Harmonization of the Time and Provable Hierarchies
Venue: arXiv cs.LO 2006
Year: 2006

A decidable transfinite hierarchy is defined by assigning ordinals to the programs of an imperative language. It singles out: the classes TIMEF(n^c) and TIMEF(n_c); the finite Grzegorczyk classes at and above the elementary level, and the Σ_k-IND fragments of PA. Limited operators, diagonalization, and majorization functions are not used.
A Fast Block Matching Algorithm for Video Motion Estimation Based on Particle Swarm Optimization and Motion Prejudgment
Venue: arXiv cs.MM 2006
Year: 2006

In this paper, we propose a fast 2-D block-based motion estimation algorithm called Particle Swarm Optimization - Zero-motion Prejudgment(PSO-ZMP) which consists of three sequential routines: 1)Zero-motion prejudgment. The routine aims at finding static macroblocks(MB) which do not need to perform remaining search thus reduces the computational cost; 2)Predictive image coding and 3)PSO matching routine. Simulation results obtained show that the proposed PSO-ZMP algorithm achieves over 10 times of computation less than Diamond Search(DS) and 5 times less than the recent proposed Adaptive Rood Pattern Searching(ARPS). Meanwhile the PSNR performances using PSO-ZMP are very close to that using DS and ARPS in some less-motioned sequences. While in some sequences containing dense and complex motion contents, the PSNR performances of PSO-ZMP are several dB lower than that using DS and ARPS but in an acceptable degree.
Detection of Markov Random Fields on Two-Dimensional Intersymbol Interference Channels
Venue: arXiv cs.IT 2006
Year: 2006

We present a novel iterative algorithm for detection of binary Markov random fields (MRFs) corrupted by two-dimensional (2D) intersymbol interference (ISI) and additive white Gaussian noise (AWGN). We assume a first-order binary MRF as a simple model for correlated images. We assume a 2D digital storage channel, where the MRF is interleaved before being written and then read by a 2D transducer; such channels occur in recently proposed optical disk storage systems. The detection algorithm is a concatenation of two soft-input/soft-output (SISO) detectors: an iterative row-column soft-decision feedback (IRCSDF) ISI detector, and a MRF detector. The MRF detector is a SISO version of the stochastic relaxation algorithm by Geman and Geman in IEEE Trans. Pattern Anal. and Mach. Intell., Nov. 1984. On the 2 x 2 averaging-mask ISI channel, at a bit error rate (BER) of 10^{-5}, the concatenated algorithm achieves SNR savings of between 0.5 and 2.0 dB over the IRCSDF detector alone; the savings increase as the MRFs become more correlated, or as the SNR decreases. The algorithm is also fairly robust to mismatches between the assumed and actual MRF parameters.
Sensor Scheduling for Optimal Observability Using Estimation Entropy
Venue: arXiv cs.IT 2006
Year: 2006

We consider sensor scheduling as the optimal observability problem for partially observable Markov decision processes (POMDP). This model fits to the cases where a Markov process is observed by a single sensor which needs to be dynamically adjusted or by a set of sensors which are selected one at a time in a way that maximizes the information acquisition from the process. Similar to conventional POMDP problems, in this model the control action is based on all past measurements; however here this action is not for the control of state process, which is autonomous, but it is for influencing the measurement of that process. This POMDP is a controlled version of the hidden Markov process, and we show that its optimal observability problem can be formulated as an average cost Markov decision process (MDP) scheduling problem. In this problem, a policy is a rule for selecting sensors or adjusting the measuring device based on the measurement history. Given a policy, we can evaluate the estimation entropy for the joint state-measurement processes which inversely measures the observability of state process for that policy. Considering estimation entropy as the cost of a policy, we show that the problem of finding optimal policy is equivalent to an average cost MDP scheduling problem where the cost function is the entropy function over the belief space. This allows the application of the policy iteration algorithm for finding the policy achieving minimum estimation entropy, thus optimum observability.
Conditional Expressions for Blind Deconvolution: Multi-point form
Venue: arXiv cs.CV 2006
Year: 2006

We present conditional expression (CE) for finding blurs convolved in given images. The CE is given in terms of the zero-values of the blurs evaluated at multi-point. The CE can detect multiple blur all at once. We illustrate the multiple blur-detection by using a test image.
Embedding Metrics into Ultrametrics and Graphs into Spanning Trees with Constant Average Distortion
Venue: arXiv cs.DM 2006
Year: 2006

This paper addresses the basic question of how well can a tree approximate distances of a metric space or a graph. Given a graph, the problem of constructing a spanning tree in a graph which strongly preserves distances in the graph is a fundamental problem in network design. We present scaling distortion embeddings where the distortion scales as a function of $ε$, with the guarantee that for each $ε$ the distortion of a fraction $1-ε$ of all pairs is bounded accordingly. Such a bound implies, in particular, that the \emph{average distortion} and $\ell_q$-distortions are small. Specifically, our embeddings have \emph{constant} average distortion and $O(\sqrt{\log n})$ $\ell_2$-distortion. This follows from the following results: we prove that any metric space embeds into an ultrametric with scaling distortion $O(\sqrt{1/ε})$. For the graph setting we prove that any weighted graph contains a spanning tree with scaling distortion $O(\sqrt{1/ε})$. These bounds are tight even for embedding in arbitrary trees. For probabilistic embedding into spanning trees we prove a scaling distortion of $\tilde{O}(\log^2 (1/ε))$, which implies \emph{constant} $\ell_q$-distortion for every fixed $q<\infty$.
Full Text Searching in the Astrophysics Data System
Venue: arXiv cs.DL 2006
Year: 2006

The Smithsonian/NASA Astrophysics Data System (ADS) provides a search system for the astronomy and physics scholarly literature. All major and many smaller astronomy journals that were published on paper have been scanned back to volume 1 and are available through the ADS free of charge. All scanned pages have been converted to text and can be searched through the ADS Full Text Search System. In addition, searches can be fanned out to several external search systems to include the literature published in electronic form. Results from the different search systems are combined into one results list. The ADS Full Text Search System is available at: http://adsabs.harvard.edu/fulltext_service.html
NectaRSS, an RSS feed ranking system that implicitly learns user preferences
Venue: arXiv cs.IR 2006
Year: 2006

In this paper a new RSS feed ranking method called NectaRSS is introduced. The system recommends information to a user based on his/her past choices. User preferences are automatically acquired, avoiding explicit feedback, and ranking is based on those preferences distilled to a user profile. NectaRSS uses the well-known vector space model for user profiles and new documents, and compares them using information-retrieval techniques, but introduces a novel method for user profile creation and adaptation from users' past choices. The efficiency of the proposed method has been tested by embedding it into an intelligent aggregator (RSS feed reader), which has been used by different and heterogeneous users. Besides, this paper proves that the ranking of newsitems yielded by NectaRSS improves its quality with user's choices, and its superiority over other algorithms that use a different information representation method.
XString: XML as a String
Venue: arXiv cs.DB 2006
Year: 2006

Extensible markup language (XML) is a technology that has been much hyped, so that XML has become an industry buzzword. Behind the hype is a powerful technology for data representation in a platform independent manner. As a text document, however, XML suffers from being too bloated, and requires an XML parser to access and manipulate it. XString is an encoding method for XML, in essence, a markup language's markup language. XString gives the benefit of compressing XML, and allows for easy manipulation and processing of XML source as a very long string.
Iterative Decoding of Low-Density Parity Check Codes (A Survey)
Venue: arXiv cs.IT 2006
Year: 2006

Much progress has been made on decoding algorithms for error-correcting codes in the last decade. In this article, we give an introduction to some fundamental results on iterative, message-passing algorithms for low-density parity check codes. For certain important stochastic channels, this line of work has enabled getting very close to Shannon capacity with algorithms that are extremely efficient (both in theory and practice).
Spectra of large block matrices
Venue: arXiv cs.IT 2006
Year: 2006

In a frequency selective slow-fading channel in a MIMO system, the channel matrix is of the form of a block matrix. This paper proposes a method to calculate the limit of the eigenvalue distribution of block matrices if the size of the blocks tends to infinity. While it considers random matrices, it takes an operator-valued free probability approach to achieve this goal. Using this method, one derives a system of equations, which can be solved numerically to compute the desired eigenvalue distribution. The paper initially tackles the problem for square block matrices, then extends the solution to rectangular block matrices. Finally, it deals with Wishart type block matrices. For two special cases, the results of our approach are compared with results from simulations. The first scenario investigates the limit eigenvalue distribution of block Toeplitz matrices. The second scenario deals with the distribution of Wishart type block matrices for a frequency selective slow-fading channel in a MIMO system for two different cases of $n_R=n_T$ and $n_R=2n_T$. Using this method, one may calculate the capacity and the Signal-to-Interference-and-Noise Ratio in large MIMO systems.
A type-based termination criterion for dependently-typed higher-order rewrite systems
Venue: arXiv cs.LO 2006
Year: 2006

Several authors devised type-based termination criteria for ML-like languages allowing non-structural recursive calls. We extend these works to general rewriting and dependent types, hence providing a powerful termination criterion for the combination of rewriting and beta-reduction in the Calculus of Constructions.
Theoretical analysis of network cranback protocols performance
Venue: arXiv cs.IT 2006
Year: 2006

Suggested the decision of the network cranback protocols performance analyzing problem from Eyal Felstine, Reuven Cohen and Ofer Hadar, " Crankback Prediction in Hierarchical ATM networks", Journal of Network and Systems Management, Vol. 10, No. 3, September 2002. It show that the false alarm probability and probability of successful way crossing can be calculated. The main optimization equations are developed for cranback protocol parameters by using analytical expressions for statistical protocol characteristics.
An Application of the Mobile Transient Internet Architecture to IP Mobility and Inter-Operability
Venue: arXiv cs.NI 2006
Year: 2006

We introduce an application of a mobile transient network architecture on top of the current Internet. This paper is an application extension to a conceptual mobile network architecture. It attempts to specifically reinforce some of the powerful notions exposed by the architecture from an application perspective. Of these notions, we explore the network expansion layer, an overlay of components and services, that enables a persistent identification network and other required services. The overlay abstraction introduces several benefits of which mobility and communication across heterogenous network structures are of interest to this paper. We present implementations of several components and protocols including gateways, Agents and the Open Device Access Protocol. Our present identification network implementation exploits the current implementation of the Handle System through the use of distributed, global and persistent identifiers called handles. Handles are used to identify and locate devices and services abstracting any physical location or network association from the communicating ends. A communication framework is finally demonstrated that would allow for mobile devices on the public Internet to have persistent identifiers and thus be persistently accessible either directly or indirectly. This application expands IP inter-operability beyond its current boundaries.
On the Error Exponents of ARQ Channels with Deadlines
Venue: arXiv cs.IT 2006
Year: 2006

We consider communication over Automatic Repeat reQuest (ARQ) memoryless channels with deadlines. In particular, an upper bound L is imposed on the maximum number of ARQ transmission rounds. In this setup, it is shown that incremental redundancy ARQ outperforms Forney's memoryless decoding in terms of the achievable error exponents.
Interference Channels with Common Information
Venue: arXiv cs.IT 2006
Year: 2006

In this paper, we consider the discrete memoryless interference channel with common information, in which two senders need deliver not only private messages but also certain common messages to their corresponding receivers. We derive an achievable rate region for such a channel by exploiting a random coding strategy, namely cascaded superposition coding. We reveal that the derived achievable rate region generalizes some important existing results for the interference channels with or without common information. Furthermore, we specialize to a class of deterministic interference channels with common information, and show that the derived achievable rate region is indeed the capacity region for this class of channels.
A Markov Chain based method for generating long-range dependence
Venue: arXiv cs.NI 2006
Year: 2006

This paper describes a model for generating time series which exhibit the statistical phenomenon known as long-range dependence (LRD). A Markov Modulated Process based upon an infinite Markov chain is described. The work described is motivated by applications in telecommunications where LRD is a known property of time-series measured on the internet. The process can generate a time series exhibiting LRD with known parameters and is particularly suitable for modelling internet traffic since the time series is in terms of ones and zeros which can be interpreted as data packets and inter-packet gaps. The method is extremely simple computationally and analytically and could prove more tractable than other methods described in the literature
Markov-modulated on/off processes for long-range dependent internet traffic
Venue: arXiv cs.NI 2006
Year: 2006

The aim of this paper is to use a very simple queuing model to compare a number of models from the literature which have been used to replicate the statistical nature of internet traffic and, in particular, the long-range dependence of this traffic. The four models all have the form of discrete time Markov-modulated processes (two other models are introduced for comparison purposes). While it is often stated that long-range dependence has a critical effect on queuing performance, it appears that the models used here do not well replicated the queuing performance of real internet traffic. In particular, they fail to replicate the mean queue length (and hence the mean delay) and the probability of the queue length exceeding a given level.
Usage Impact Factor: the effects of sample characteristics on usage-based impact metrics
Venue: arXiv cs.DL 2006
Year: 2006

There exist ample demonstrations that indicators of scholarly impact analogous to the citation-based ISI Impact Factor can be derived from usage data. However, contrary to the ISI IF which is based on citation data generated by the global community of scholarly authors, so far usage can only be practically recorded at a local level leading to community-specific assessments of scholarly impact that are difficult to generalize to the global scholarly community. We define a journal Usage Impact Factor which mimics the definition of the Thomson Scientific's ISI Impact Factor. Usage Impact Factor rankings are calculated on the basis of a large-scale usage data set recorded for the California State University system from 2003 to 2005. The resulting journal rankings are then compared to Thomson Scientific's ISI Impact Factor which is used as a baseline indicator of general impact. Our results indicate that impact as derived from California State University usage reflects the particular scientific and demographic characteristics of its communities.
Considering users' behaviours in improving the responses of an information base
Venue: arXiv cs.LG 2006
Year: 2006

In this paper, our aim is to propose a model that helps in the efficient use of an information system by users, within the organization represented by the IS, in order to resolve their decisional problems. In other words we want to aid the user within an organization in obtaining the information that corresponds to his needs (informational needs that result from his decisional problems). This type of information system is what we refer to as economic intelligence system because of its support for economic intelligence processes of the organisation. Our assumption is that every EI process begins with the identification of the decisional problem which is translated into an informational need. This need is then translated into one or many information search problems (ISP). We also assumed that an ISP is expressed in terms of the user's expectations and that these expectations determine the activities or the behaviors of the user, when he/she uses an IS. The model we are proposing is used for the conception of the IS so that the process of retrieving of solution(s) or the responses given by the system to an ISP is based on these behaviours and correspond to the needs of the user.
Multigroup-Decodable STBCs from Clifford Algebras
Venue: arXiv cs.IT 2006
Year: 2006

A Space-Time Block Code (STBC) in $K$ symbols (variables) is called $g$-group decodable STBC if its maximum-likelihood decoding metric can be written as a sum of $g$ terms such that each term is a function of a subset of the $K$ variables and each variable appears in only one term. In this paper we provide a general structure of the weight matrices of multi-group decodable codes using Clifford algebras. Without assuming that the number of variables in each group to be the same, a method of explicitly constructing the weight matrices of full-diversity, delay-optimal $g$-group decodable codes is presented for arbitrary number of antennas. For the special case of $N_t=2^a$ we construct two subclass of codes: (i) A class of $2a$-group decodable codes with rate $\frac{a}{2^{(a-1)}}$, which is, equivalently, a class of Single-Symbol Decodable codes, (ii) A class of $(2a-2)$-group decodable with rate $\frac{(a-1)}{2^{(a-2)}}$, i.e., a class of Double-Symbol Decodable codes. Simulation results show that the DSD codes of this paper perform better than previously known Quasi-Orthogonal Designs.
Tree Automata Make Ordinal Theory Easy
Venue: arXiv cs.GT 2006
Year: 2006

We give a new simple proof of the decidability of the First Order Theory of (omega^omega^i,+) and the Monadic Second Order Theory of (omega^i,<), improving the complexity in both cases. Our algorithm is based on tree automata and a new representation of (sets of) ordinals by (infinite) trees.
Low-complexity modular policies: learning to play Pac-Man and a new framework beyond MDPs
Venue: arXiv cs.LG 2006
Year: 2006

In this paper we propose a method that learns to play Pac-Man. We define a set of high-level observation and action modules. Actions are temporally extended, and multiple action modules may be in effect concurrently. A decision of the agent is represented as a rule-based policy. For learning, we apply the cross-entropy method, a recent global optimization algorithm. The learned policies reached better score than the hand-crafted policy, and neared the score of average human players. We argue that learning is successful mainly because (i) the policy space includes the combination of individual actions and thus it is sufficiently rich, (ii) the search is biased towards low-complexity policies and low complexity solutions can be found quickly if they exist. Based on these principles, we formulate a new theoretical framework, which can be found in the Appendix as supporting material.
A near-optimal fully dynamic distributed algorithm for maintaining sparse spanners
Venue: arXiv cs.DS 2006
Year: 2006

In this paper we devise an extremely efficient fully dynamic distributed algorithm for maintaining sparse spanners. Our resuls also include the first fully dynamic centralized algorithm for the problem with non-trivial bounds for both incremental and decremental update. Finally, we devise a very efficient streaming algorithm for the problem.