New subspace algorithm for blind channel estimation in OFDM systems

In order to increase the transmission efficiency,a subspace-based algorithm for blind channel estimation using second-order statistics is proposed in orthogonal frequency division multiplexing (OFDM) systems.Because the transmission equation of OFDM systems does not exactly have the desired structure to directly derive a subspace algorithm,the algorithm first divides the OFDM signals into three parts,then,by exploiting the redundancy introduced by the cyclic prefix (CP) in OFDM signals,a new equation with Toeplitz channel matrix is derived.Based on the equation,a new blind subspace algorithm is developed.Toeplitz structure eases the derivation of the subspace algorithm and practical computation.Moreover the algorithm does not change the existing OFDM system,is robust to channel order overdetermination,and the channel zero locations.The performances are demonstrated by simulation results.

德化陶瓷学院图书馆建筑设计随笔

德化陶瓷学院图书馆的建筑设计以突出以人为本及突出人、建筑、环境三者的和谐组合为主导思想,强调使用功能空间的优化组合及空间的深化,和建筑造型、景观环境相结合的整体设计。构筑建筑的自身魅力及良好的环境效应。

Design and Implementation of mobile GIS application based on Android

This paper analyzes the key technology of mobile GIS development, discusses the design method of mobile GIS spatial data management, visualization of spatial data And Spatial data query, tinder Object oriented mode. And we develop a set of mobile GIS basic software platform in the Android platform, and tested in the mainstream smart mobile phone with Android operating system, test results show that the software platform can run smoothly. Other users can development a variety of mobile GIS to call the platform through an application service interface.

Three-Dimensional Ocean Sensor Networks:A Survey

The past decade has seen a growing interest in ocean sensor networks because of their wide applications in marine research,oceanography,ocean monitoring,offshore exploration,and defense or homeland security.Ocean sensor networks are generally formed with various ocean sensors,autonomous underwater vehicles,surface stations,and research vessels.To make ocean sensor network applications viable,efficient communication among all devices and components is crucial.Due to the unique characteristics of underwater acoustic channels and the complex deployment environment in three dimensional(3D) ocean spaces,new efficient and reliable communication and networking protocols are needed in design of ocean sensor networks.In this paper,we aim to provide an overview of the most recent advances in network design principles for 3D ocean sensor networks,with focuses on deployment,localization,topology design,and position-based routing in 3D ocean spaces.

Channel estimation for MIMO-OFDM systems in mobile wireless channels

A channel estimation method is proposed for nmltiple-input multiple-output orthogonal frequency division muhiplexing （MIMO-OFDM） systems in time-varying fading channels. In this method, a decision-directed space-alternating generalized expectation-maximization （SAGE） algorithm is introduced to the tracking of time-varying fading. In order to improve the estimation performance of the SAGE algorithm, a low rank approximation method is presented by using the signal subspace of the channel frequency autocorrelation matrix. The study reveals that this method can be incorporated into the SAGE algorithm. Furthermore, a modified fast sub- space tracking algorithm is given to adaptively estimate the signal subspace by utilizing training OFDM blocks sent at regular interval. Simulation results demonstrate the considerable benefits of the proposed channel estimation method.

Space-Use Analysis in the Design of Neighborhood Walking Paths

SUA （space-use analysis） is about techniques that objectively describe environments and relate this description to specific problems of use. The purpose of this paper is to explore a space-use analytical tool--POE （post-occupation evaluation）--regarding a neighborhood accessibility condition. Based on a site-specific approach, the main research question is focused on how far neighborhood walking paths are compatible with different user needs, guaranteeing their safety and autonomy, as well as easiness of perception and use, thus providing access to local services and resources they need for participation in the day-to-day activities of community life. This paper is organized in three parts： The first one introduces the main concepts and explains how to ensure it in a practical application in urban design; The second part presents the practical approach, referring to the used methodology, the specific case-study and reached results; The third one establishes correlations between the two approaches and discusses the main findings.

Skin Detection Using Simple Arithmetic Operations

Skin detection is the primary step in a large number of computer vision applications. Speed and simplicity are vital components in many of these applications. Various methods have been implemented. However they lack either speed or simplicity or both. In previous studies, simple color component subtraction and threshold in RGB color space were used. However, in this research study, the threshold is found empirically using a known images database. In addition, all the RGB color components were used in the calculation. Optimistic results were obtained. The obtained results illustrate that this method is a promising approach used in skin detection applications.

Spectroscopic Parameters of X^3∑^-, a^1△, and A^＇3△ Electronic States of SO Radical

The potential energy curves （PECs） of three low-lying electronic states （X^3∑, a^1△, and a^3△） of SO radical have been studied by ab initio quantum chemical method. The calcula- tions were carried out with the full valence complete active space self-consistent field method followed by the highly accurate valence internally contracted multireference configuration in- teraction （MRCI） approach in combination with correlation-consistent basis sets. Effects of the core-valence correlation and relativistic corrections on the PECs are taken into account. The core-valence correlation correction is carried out with the cc-pCVDZ basis set. The way to consider the relativistic correction is to use the second-order Douglas-Kroll Hamiltonian approximation, and the correction is performed at the level of cc-pV5Z basis set. To obtain more reliable results, the PECs determined by the MRCI calculations are also corrected for size-extensivity errors by means of the Davidson modification （MRCI＋Q）. These PECs are extrapolated to the complete basis set limit by the two-point energy extrapolation scheme. With these PECs, the spectroscopic parameters are determined.

Applications of Orlicz-Hardy spaces associated with operators satisfying Poisson estimates

Let L be a linear operator in L^2（R^n） and generate an analytic semigroup {e^-tL}t≥0 with kernel satisfying an upper bound estimate of Poisson type, whose decay is measured by θ（L） ∈ （0, ∞）. Let 4） be a positive, continuous and strictly increasing function on （0, ∞）, which is of strictly critical lower type pФ （n/（n ＋ θ（L））, 1]. Denote by HФ, L（R^n） the Orlicz-Hardy space introduced in Jiang, Yang and Zhou＇s paper in 2009. If Ф is additionally of upper type 1 and subadditive, the authors then show that the Littlewood-Paley g-function gL maps HФ, L（R^n） continuously into LФ（R^n） and, moreover, the authors characterize HФ, L（R^n） in terms of the Littlewood-Paley gλ^＊-function with λ ∈ （n（2/pФ ＋ 1）, ∞）. If Ф is further slightly strengthened to be concave, the authors show that a generalized Riesz transform associated with L is bounded from HФ, L（R^n） to the Orlicz space L^Ф（R^n） or the Orlicz-Hardy space HФ （R^n）; moreover, the authors establish a new subtle molecular characterization of HФ, L （R^n） associated with L and, as applications, the authors then show that the corresponding fractional integral L^-γ for certain γ∈ E （0,∞） maps HФ, L（R^n） continuously into HФ, L（R^n）, where Ф satisfies the same properties as Ф and is determined by Ф and λ and also that L has a bounded holomorphic functional calculus in HФ, L（R^n）. All these results are new even when Ф（t） = t^p for all t ∈ （0, ∞） and p ∈ （n/（n ＋ θ（L））, 1].

Climate and extrema of ocean waves in the East China Sea

Wave climate plays an important role in the air-sea interaction over marginal seas. Extreme wave height provides fundamental information for various ocean engineering practices, such as hazard mitigation, coastal structure design, and risk assessment. In this paper, we implement a third generation wave model and conduct a high-resolution wave hindcast over the East China Sea to reconstruct a 15-year wave field from 1988 to 2002 for derivation of monthly mean wave parameters and analysis of extreme wave conditions. The numerical results of the wave field are validated through comparison with satellite altimetry measurements, low-resolution reanalysis, and the ocean wave buoy record. The monthly averaged wave height and wave period show seasonal variation and refined spatial patterns of surface waves in the East China Sea. The climatological significant wave height and mean wave period decrease from the open ocean in the southeast toward the continental area in the northwest, with the pattern generally following the bathymetry. Extreme analysis on the significant wave height at the buoy station indicates the hindcast data underestimate the extreme values relative to the observations. The spatial pattern of extreme wave height shows single peak emerges at the southwest of Ryukyu Island although a wind forcing with multi-core structure at the extreme is applied.

Non-integer power estimate in modulation spaces and its applications

We give a method to estimate non-integer power function|u|~ku in modulation space which is an open question in the study of modulation space.As an application,we can study Cauchy problem for the nonlinear Klein-Gordon equation with nonlinear term|u|~ku in modulation space,where k is not an integer.Moreover,we also study the global solution with small initial value for the Klein-Gordon-Hartree equation.The results show some advantages of modulation space both in high and low regularity cases.

A hyperspectral image endmember extraction algorithm based on generalized morphology

Generalized morphological operator can generate less statistical bias in the output than classical morphological operator. Comprehensive utilization of spectral and spatial information of pixels, an endmember extraction algorithm based on generalized morphology is proposed. For the limitations of morphological operator in the pixel arrangement rule and replacement criteria, the reference pixel is introduced. In order to avoid the cross substitution phenomenon at the boundary of different object categories in the image, an endmember is extracted by calculating the generalized opening-closing(GOC) operator which uses the modified energy function as a distance measure. The algorithm is verified by using simulated data and real data. Experimental results show that the proposed algorithm can extract endmember automatically without prior knowledge and achieve relatively high extraction accuracy.

Optimization of Neutrino Oscillation Parameters Using Differential Evolution

We show how the traditional grid based method for finding neutrino oscillation parameters △m2 and tan2θ can be combined with an optimization technique, Differential Evolution （DE）, to get a significant decrease in computer processing time required to obtain minimal chi-square （χ2） in four different regions of the parameter space. We demonstrate efficiency for the two-neutrinos case. For this, the χ2 function for neutrino oscillations is evaluated for grids with different density of points in standard allowed regions of the parameter space of △m2 and tan2θ using experimental and theoretical total event rates of ehlorine （Homestake）, Gallex＋GNO, SAGE, Superkamiokande, and SNO detectors. We find that using DE in combination with the grid based method with smail density of points can produce the results comparable with the one obtained using high density grid, in much lesser computation time.

STATISTICAL DETECTION OF SPATIAL PLANT PATTERNS UNDER THE EFFECT OF FOREST USE

The analysis of the consequences of land use （in particular forest use） may be considered as a partial step towards an integrated modeling of a land system. In the paper a forest territory is considered, where a gapcut is made, and after a given time period the eventual change in the spatial distribution of undergrowth plants and tree seedlingsis to be detected. Floristic data are collected along a line transect. A method for the detection of the change in the plant distributions along the transect is proposed to see whether this occurs at the geometric frontier of the human intervention. Since in the considered case the distribution of the changepoint estimate is not known, as a substitute of its confidence interval, the socalled changeinterval is calcu lated, using an adaptation of the bootstrap method. As an illustration, for a concrete plant species, the maximum likelihood estimation of the changepoint and the calcu lation of the above mentioned changeinterval is presented. Finally, the validation of the proposed method against some typical ecological situations is also presented, which provides a justification of the used algorithms.