http://www.springeropen.com/ The latest research articles published by Springer Open 2012-02-22T00:00:00Z In this study, Mann-type iterative process is considered for finding a common element in the fixed point set of strict pseudocontractions and in the zero point set of the operator which is the sum of inverse strongly-monotone operators and maximal monotone operators. Weak convergence theorems of common elements are established in the framework of Hilbert spaces. Some applications of main results are also provided. http://www.fixedpointtheoryandapplications.com/content/2012/1/21 Mingliang Zhang Fixed Point Theory and Applications 2012, 2012:21 2012-02-22T00:00:00Z ${item.identifier} /content/figures/1687-1812-2012-21-toc.gif Fixed Point Theory and Applications 1687-1812 2012 21 2012-02-22T00:00:00Z PDF Let E be a real uniformly convex Banach space and, and let K be anonempty closed convex subset of E. Let \{T_i\}_{i=1}^{\infty} be a sequence of nonexpansive mappings from K to itself with F:=\{x\in K:T_ix=x,\forall i\geq1\}\neq\emptyset. For an arbitrary initial point x_1\in K, the modified hybrid iteration scheme \{x_n\}is defined as follows:x_{n+1}=\alpha_nx_n+(1-\alpha_n)(T^*_nx_n-\lambda_{n+1}\mu A(T^*_nx_n)), n\geq1,where A:K\rightarrow K is an L-Lipschitzian mapping, T^*_n=T_i with i satisfying:n=[(k-i+1)(i+k)/2]+[1+(i-1)(i+2)/2],k\geq i-1(i = 1, 2, \ldots),\{\lambda_n\}\subset[0, 1), and \{\alpha_n\} is a sequence in [a, 1-a] for some a \in (0, 1). Under some suitable conditions, the strong and weak convergence theorems of \{x_n\} to a common fixed point of the nonexpansive mappings \{T_i\}_{i=1}^{\infty} are obtained. The results in this article extend those of the authors whose related researches are restricted to the situation of finite families of nonexpansive mappings.Keywordsinfinite family of nonexpansive mappings; strong and weak convergence; common fixed point; hybrid iteration. http://www.fixedpointtheoryandapplications.com/content/2012/1/22 Wei-Qi Deng Fixed Point Theory and Applications 2012, 2012:22 2012-02-22T00:00:00Z ${item.identifier} /content/figures/1687-1812-2012-22-toc.gif Fixed Point Theory and Applications 1687-1812 2012 22 2012-02-22T00:00:00Z PDF Elasto-plastic mechanical deformation behaviors of c-plane (0001) and nonpolar GaN single crystals are studied using nanoindentation, cathodoluminescence, and transmission electron microscopy. Nanoindentation tests show that c-plane GaN is less susceptible to plastic deformation and has higher hardness and Young's modulus than the nonpolar GaN. Cathodoluminescence and transmission electron microscopy characterizations of indent-induced plastic deformation reveal that there are two primary slip systems for the c-plane GaN, while there is only one most favorable slip system for the nonplane GaN. We suggest that the anisotropic elasto-plastic mechanical properties of GaN are relative to its anisotropic plastic deformation behavior. http://www.nanoscalereslett.com/content/7/1/150 Jun Huang Ke Xu Ying Min Fan Mu Tong Niu Xiong Hui Zeng Jian Feng Wang Hui Yang Nanoscale Research Letters 2012, 7:150 2012-02-22T00:00:00Z ${item.identifier} /content/figures/1556-276X-7-150-toc.gif Nanoscale Research Letters 1556-276X 7 150 2012-02-22T00:00:00Z PDF One of the key factors in distributed sensor networks is their reliability in packets delivery even in the event of failure of one or a few nodes. Another factor - often underestimated - is the intra-network interference experienced by individual nodes from other transmitting counterparts. Common network spanning algorithms, however, neither posses the reliability feature nor keep the interference at minimum. It can be demonstrated that by enforcing a planar network topology combined with the requirement of minimum-pathloss between connections, one can achieve a gain in SNIR by a few decibels with respect to standards spanning methods. The use of directional antennas and controlled duty cycle improves the situation even further - by carefully controlling the beamwidth, one may adjust the SNIR to a desired level at a high range of dynamics. http://jwcn.eurasipjournals.com/content/2012/1/56 Kamil Staniec Grzegorz Debita EURASIP Journal on Wireless Communications and Networking 2012, 2012:56 2012-02-22T00:00:00Z ${item.identifier} /content/figures/1687-1499-2012-56-toc.gif EURASIP Journal on Wireless Communications and Networking 1687-1499 2012 56 2012-02-22T00:00:00Z PDF The purpose of this is to introduce and study total asymptotically strict pseudocontractive semigroup, asymptotically strict pseudocontractive semigroup etc. the strong convergence theorems of the explicit iteration process for the new semigroups in arbitrary Banach spaces are established. The results presented in the paper extend and improve some recent results announced by many authors. http://www.fixedpointtheoryandapplications.com/content/2012/1/24 Li Yang Fu Hai Zhao Fixed Point Theory and Applications 2012, 2012:24 2012-02-22T00:00:00Z ${item.identifier} /content/figures/1687-1812-2012-24-toc.gif Fixed Point Theory and Applications 1687-1812 2012 24 2012-02-22T00:00:00Z PDF In this article, we introduce the notion of multi-valued domination of metric spaces, which is a generalization of domination in the sense of Borsuk and which encompasses previous generalizations. http://www.fixedpointtheoryandapplications.com/content/2012/1/23 Miroslaw Slosarski Fixed Point Theory and Applications 2012, 2012:23 2012-02-22T00:00:00Z ${item.identifier} /content/figures/1687-1812-2012-23-toc.gif Fixed Point Theory and Applications 1687-1812 2012 23 2012-02-22T00:00:00Z PDF A unified view of the area of sparse signal processing is presented in tutorial form by bringing together various fields in which the property of sparsity has been successfully exploited. For each of these fields, various algorithms and techniques, which have been developed to leverage sparsity, are described succinctly. The common potential benefits of significant reduction in sampling rate and processing manipulations through sparse signal processing are revealed. The key application domains of sparse signal processing are sampling, coding, spectral estimation, array processing, component analysis, and multipath channel estimation. In terms of the sampling process and reconstruction algorithms, linkages are made with random sampling, compressed sensing, and rate of innovation. The redundancy introduced by channel coding in finite and real Galois fields is then related to over-sampling with similar reconstruction algorithms. The error locator polynomial (ELP) and iterative methods are shown to work quite effectively for both sampling and coding applications. The methods of Prony, Pisarenko, and MUltiple SIgnal Classification (MUSIC) are next shown to be targeted at analyzing signals with sparse frequency domain representations. Specifically, the relations of the approach of Prony to an annihilating filter in rate of innovation and ELP in coding are emphasized; the Pisarenko and MUSIC methods are further improvements of the Prony method under noisy environments. The iterative methods developed for sampling and coding applications are shown to be powerful tools in spectral estimation. Such narrowband spectral estimation is then related to multi-source location and direction of arrival estimation in array processing. Sparsity in unobservable source signals is also shown to facilitate source separation in sparse component analysis; the algorithms developed in this area such as linear programming and matching pursuit are also widely used in compressed sensing. Finally, the multipath channel estimation problem is shown to have a sparse formulation; algorithms similar to sampling and coding are used to estimate typical multicarrier communication channels. http://asp.eurasipjournals.com/content/2012/1/44 Farokh Marvasti Arash Amini Farzan Haddadi Mehdi Soltanolkotabi Babak Khalaj Akram Aldroubi Saeid Sanei Jonathon Chambers EURASIP Journal on Advances in Signal Processing 2012, 2012:44 2012-02-22T00:00:00Z ${item.identifier} /content/figures/1687-6180-2012-44-toc.gif EURASIP Journal on Advances in Signal Processing 1687-6180 2012 44 2012-02-22T00:00:00Z PDF We consider the joint estimation of the direction-of-arrival (DOA) and parameters of wideband polynomial-phase signals (PPSs) in sensor array. Unlike concurrent methods that require multidimensional searches, the proposed method requires 1D searches for all the parameters of interest. In this way, we can efficiently estimate the considered parameters in applications where large antenna arrays, containing tens or hundreds of sensors, are used. As special cases, we consider in detail the estimation of the second- and third-order PPSs. The former are estimated using the high-order ambiguity function (HAF), while the latter are estimated using the cubic phase function (CPF), known to outperform the HAF in terms of both accuracy and signal-to-noise ratio (SNR) threshold. In both cases, the estimation of the highest order parameter reaches the Cramer-Rao lower bound (CRLB), while the DOA estimation is above the CRLB for around 1 dB (second-order PPS) and around 6 dB (third-order PPS). http://asp.eurasipjournals.com/content/2012/1/43 Igor Djurovic Slobodan Djukanovic Marko Simeunovic Predrag Rakovic Braham Barkat EURASIP Journal on Advances in Signal Processing 2012, 2012:43 2012-02-22T00:00:00Z ${item.identifier} /content/figures/1687-6180-2012-43-toc.gif EURASIP Journal on Advances in Signal Processing 1687-6180 2012 43 2012-02-22T00:00:00Z PDF Next Generation Networks will comprise dif-ferent wireless networks including cellular technologies,WLAN and indoor technologies. To support these het-erogeneous environments, there is a need to considera new design of the network infrastructure, where cur-rently closed systems such as 3G will have to operatein an open environment. Furthermore, this open en-vironment implies that future mobile devices need toroam between different networks using vertical han-dover techniques. When a mobile user moves into anew foreign network, data confidentiality and mutualauthentication between the user and the network arevital issues in this heterogeneous environment. This pa-per deals with these issues by first examining the im-plication of moving towards an open architecture, andthen looking at how current approaches such as the 3GPP, HOKEY and Mobile Ethernet respond to thenew environment while trying to address the securityissue. The results indicate that a new Authenticationand Key Agreement protocol is required to secure han-dover in this environment. Casper/FDR, is used in theanalysis and development of the protocol. The proposedprotocol has been proven to be successful in this het-erogeneous environment. http://jwcn.eurasipjournals.com/content/2012/1/57 Mahdi Aiash Glenford Mapp Aboubaker Lasebae Raphael Phan Jonathan Loo EURASIP Journal on Wireless Communications and Networking 2012, 2012:57 2012-02-22T00:00:00Z ${item.identifier} /content/figures/1687-1499-2012-57-toc.gif EURASIP Journal on Wireless Communications and Networking 1687-1499 2012 57 2012-02-22T00:00:00Z PDF (no abstract) http://asp.eurasipjournals.com/content/2012/1/41 Francesco Verde Yao-Win Peter Hong Dragan Samardzija Robert Schober Zhifeng Tao EURASIP Journal on Advances in Signal Processing 2012, 2012:41 2012-02-22T00:00:00Z ${item.identifier} /content/figures/1687-6180-2012-41-toc.gif EURASIP Journal on Advances in Signal Processing 1687-6180 2012 41 2012-02-22T00:00:00Z PDF