Mobile positioning using Received Signal Strength (RSS) measurements is regarded as a low cost solution which is applicable in a wide range of wireless networks. In this paper, we propose a cooperative RSS-based positioning algorithm, that relies on the promising idea of mobile to mobile communications in the next generation of cellular networks. Simulations performed in this paper indicate that utilizing the additional RSS data of the short range communications between Mobile Stations (MS's), enhances the accuracy of the traditional RSS-based positioning algorithms.

A lexicon-driven segmentation-recognition scheme on Bangla handwritten city-name recognition is proposed for Indian postal automation. In the proposed scheme, at first, binarization of the input document is done and then to take care of slanted handwriting of different individuals a slant correction technique is performed. Next, due to the script characteristics of Bangla, a water reservoir concept is applied to pre-segment the slant corrected city-names into possible primitive components (characters or its parts). Pre-segmented components of a city-name are then merged into possible characters to get the best city-name using the lexicon information. In order to merge these primitive components into characters and to find optimum character segmentation, dynamic programming (DP) is applied using total likelihood of the characters of a city-name as an objective function. To compute the likelihood of a character, Modified Quadratic Discriminant Function (MQDF) is used. The features used in the MQDF are mainly based on the directional features of the contour points of the components. We tested our system on 84 different Bangla city-names and 94.08% accuracy was obtained from the proposed system.

In this letter, we propose a simple but accurate calculation method, that is, an approximate closed-form equation of average bit error rate in DPSK/OFDM systems with post-detection diversity reception over both time- and frequency-selective Rayleigh fading channels. The validity of the proposed method is verified by the fact that BER performances given by the derived equation coincide with those by Monte Carlo simulation.

In this letter, we propose new digital audio watermarking methods using interval wavelet decomposition. We develop not only non-blind type method, but also blind one. Experimental results demonstrate that the proposed methods give a watermarked audio clip of better quality and are robust against some attacks.

This letter describes combining OSGi and Web Services in service composition. According to our approach, a composite service is described in WS-BPEL. Each component service in the description may be resolved to either an OSGi service or Web Service at runtime. The proposal can overcome current limitations with OSGi technology in terms of its geographical coverage and candidate service population available for service composition.

Properties of Kripke structures can be expressed by formulas of the modal µ-calculus. Despite its strong expressive power, the validity problem of the modal µ-calculus is decidable, and so are some of its variants enriched by inverse programs, graded modalities, and nominals. In this study, we show that the pre- and post-conditions of transformations of Kripke structures, such as addition/deletion of states and edges, can be expressed using variants of the modal µ-calculus. Combined with decision procedures we have developed for those variants, the properties of sequences of transformations on Kripke structures can be deduced. We show that these techniques can be used to verify the properties of pointer-manipulating programs.

Tracking a large quantity of moving target tags simultaneously is essential for the localization and guidance of people in welfare facilities like hospitals and sanatoriums for the aged. The locating system using active RFID technology consists of a number of fixed RFID readers and tags carried by the target objects, or senior people. We compare the performances of several determination algorithms which use the power measurement of received signals emitted by the moving active RFID tags. This letter presents a study on the effect of collision in tracking large quantities of objects based on active RFID real time location system (RTLS). Traditional trilateration, fingerprinting, and well-known LANDMARC algorithm are evaluated and compared with varying number of moving tags through the SystemC-based computer simulation. From the simulation, we show the tradeoff relationship between the number of moving tags and estimation accuracy.

In this letter, we propose a novel signal detection method, reduced complexity QRM-MLD, which achieves almost identical error performance to that of the conventional QRM-MLD while significantly reducing the computational complexity.

It is a very important and intriguing problem in digital image-processing to decompose an input image into intuitively convincible image-components such as a structure component and a texture component, which is an inherently nonlinear problem. Recently, several numerical schemes to solve the nonlinear image-decomposition problem have been proposed. The use of the nonlinear image-decomposition as a pre-process of several image-processing tasks will possibly pave the way to solve difficult problems posed by the classic approach of digital image-processing. Since the new image-processing approach via the nonlinear image-decomposition treats each separated component with a processing method suitable to it, the approach will successfully attain target items seemingly contrary to each other, for instance invisibility of ringing artifacts and sharpness of edges and textures, which have not attained simultaneously by the classic image-processing approach. This paper reviews quite recently developed state-of-the-art schemes of the nonlinear image-decomposition, and introduces some examples of the decomposition-and-processing approach.

A desired property of large distributed systems is self adaptability against the faults that occur more frequently as the size of the distributed system grows. Self-stabilizing protocols provide autonomous recovery from finite number of transient faults. Fault-containing self-stabilizing protocols promise not only self-stabilization but also containment of faults (quick recovery and small effect) against small number of faults. However, existing composition techniques for self-stabilizing protocols (e.g. fair composition) cannot preserve the fault-containment property when composing fault-containing self-stabilizing protocols. In this paper, we present Recovery Waiting Fault-containing Composition (RWFC) framework that provides a composition of multiple fault-containing self-stabilizing protocols while preserving the fault-containment property of the source protocols.

For the acquisition of visual information, the nonuniform sampling process by photoreceptors on the retina occurs at the earliest stage of visual processing. From objects of interest, the human eye receives high visual resolution through nonuniform distribution of photoreceptors. Therefore, this paper proposes auto exposure and focus algorithms for the real-time video camera system based on the visual characteristic of the human eye. For given moving objects, the visual weight is modeled for quantifying the visual importance and the associated auto exposure and focus parameters are derived by applying the weight to the traditional numerical expression, i.e., the DoM (Difference of Median) and Tenengrad methods for auto focus.

In this paper we present hybrid positioning schemes that combine time of arrival (TOA) and angle of arrival (AOA) measurements from only two base stations (BSs) to locate the mobile station (MS) in non-line-of-sight (NLOS) environments. The proposed methods utilize two TOA circles and two AOA lines to find all the possible intersections to locate the MS without requiring a priori information about the NLOS error. The commonly known Taylor series algorithm (TSA) and the hybrid lines of position algorithm (HLOP) have convergence problems, and the relative positioning between the MS and the BSs greatly affects the location accuracy. The resulting geometry creates a situation where small measurement errors can lead to significant errors in the estimated MS location. Simulation results show that the proposed methods always perform better than TSA and HLOP for different levels of NLOS errors, particularly when the MS/BSs have an undesirable geometric layout.

Eigen-beamforming (EB) transmission for multiple-input multiple-output (MIMO) systems is an effective means to maximize the receiver signal-to-noise ratio (SNR) in a noise-limited environment, but suffers a performance degradation when strong interference signals exist. In this letter, we propose an interference cancellation method for EB signals by constructing a new receive beamforming vector which jointly utilizes the EB matrix and minimum mean-square error (MMSE) spatial demultiplexing. The proposed method is shown to outperform the conventional EB receiver in the entire cell range, with a significant increase in the effective signal-to-interference plus noise ratio (SINR) near the cell boundary.

Wireless communication devices in the field of medical implant, such as cardiac pacemakers and capsule endoscopes, have been studied and developed to improve healthcare systems. Especially it is very important to know the range and position of each device because it will contribute to an optimization of the transmission power. We adopt the time-based approach of position estimation using ultra wideband signals. However, the propagation velocity inside the human body differs in each tissue and each frequency. Furthermore, the human body is formed of various tissues with complex structures. For this reason, propagation velocity is different at a different point inside human body and the received signal so distorted through the channel inside human body. In this paper, we apply an adaptive template synthesis method in multipath channel for calculate the propagation time accurately based on the output of the correlator between the transmitter and the receiver. Furthermore, we propose a position estimation method using an estimation of the propagation velocity inside the human body. In addition, we show by computer simulation that the proposal method can perform accurate positioning with a size of medical implanted devices such as a medicine capsule.

In this letter, we propose a novel singular value decomposition zero-forcing beamforming (SVD-ZFBF) relaying scheme in the multiuser downlink MIMO broadcasting channel with fixed relays. Based on the processing scheme, we apply SUS [5] to select users at the relay station (RS) and develop a joint power allocation strategy at the base station (BS) and RS. By increasing the power at RS or selecting active users to obtain more multiuser diversity, SVD-ZFBF can approach an upper bound and outperform SVD-ZFDPC [1] with much lower complexity. Moreover, we show that the noise power ratio of RS to users significantly impacts the performance.

The aperture feed with an air cavity in a LTCC (Low Temperature Co-fired Ceramics) post-wall waveguide with dielectric constant εr more than 5 is proposed for bandwidth enhancement in the millimeter wave band. A rectangular cavity is adopted because only one mask pattern of a rectangular can be used for each layer of LTCC for reducing the number of the design parameters and the cost. The fabrication limitation such as the spacing between the post edge and the aperture edge reduces the bandwidth. The feeding structures are designed at 61.25 GHz for a range of εr from 2.0 to 9.0. In the case of εr = 7.0, the bandwidth for reflection below -15 dB with the air cavity is 4.25 times that without the air cavity in simulation, and 3.10 times in measurement.

Minimizing the residual impurity gases is a key factor for reducing temporal dark image sticking. Therefore, this paper uses a vacuum-sealing method that minimizes the residual impurity gases by enhancing the base vacuum level, and the resultant change in temporal dark image sticking is then examined in comparison to that with the conventional sealing method using 42-in. ac-PDPs with a high Xe (11%) content. As a result of monitoring the difference in the display luminance, infrared emission, and perceived luminance between the cells with and without temporal dark image sticking, the vacuum-sealing method is demonstrated to reduce temporal dark image sticking by decreasing the residual impurity gases and increasing the oxygen vacancy in the MgO layer. Furthermore, the use of a modified driving waveform along with the vacuum-sealing method is even more effective in reducing temporal dark image sticking.

The control of the organic field-effect transistor characteristics is necessary to produce the integrated circuits using organic semiconductors. Variations in the poly (3-hexylthiophene) field-effect transistor characteristics upon post-treatment such as thermal treatment and voltage treatment in N2 atmosphere have been investigated. The controllability and reproducibility of the threshold voltage and mobility were achieved as a result of the post-treatments.

In this letter, a two channel frequency domain speech enhancement algorithm is proposed. The algorithm is designed to achieve better overall performance with relatively small array size. An improved version of adaptive null-forming is used, in which noise cancelation is implemented in auditory subbands. And an OM-LSA based postfiltering stage further purifies the output. The algorithm also features interaction between the array processing and the postfilter to make the filter adaptation more robust. This approach achieves considerable improvement on signal-to-noise ratio (SNR) and subjective quality of the desired speech. Experiments confirm the effectiveness of the proposed system.

In this letter, we suggest a simple way of implementing a post-FFT pilot-assisted sampling frequency offset and residual frequency offset estimator with reduced complexity in an orthogonal frequency division multiplexing (OFDM) system. In order to devise the low-complexity post-FFT frequency estimator, some modifications on the conventional estimator are highlighted with an emphasis on the selection of pilot subset.