Wireless sensor networks (WSNs) have attracted a significant amount of interest from many researchers because they have great potential as a means of obtaining information of various environments remotely. WSNs have a wide range of applications, such as natural environmental monitoring in forest regions and environmental control in office buildings. In WSNs, hundreds or thousands of micro-sensor nodes with such resource limitations as battery capacity, memory, CPU, and communication capacity are deployed without control in a region and used to monitor and gather sensor information of environments. Therefore, a scalable and efficient network control and/or data gathering scheme for saving energy consumption of each sensor node is needed to prolong WSN lifetime. In this paper, assuming that sensor nodes synchronize to intermittently communicate with each other only when they are active for realizing the long-term employment of WSNs, we propose a new synchronization scheme for gathering sensor information using chaotic pulse-coupled neural networks (CPCNN). We evaluate the proposed scheme using computer simulations and discuss its development potential. In simulation experiments, the proposed scheme is compared with a previous synchronization scheme based on a pulse-coupled oscillator model to verify its effectiveness.

In this letter, we propose a novel approach to speech/music classification based on the support vector machine (SVM) to improve the performance of the 3GPP2 selectable mode vocoder (SMV) codec. We first analyze the features and the classification method used in real time speech/music classification algorithm in SMV, and then apply the SVM for enhanced speech/music classification. For evaluation of performance, we compare the proposed algorithm and the traditional algorithm of the SMV. The performance of the proposed system is evaluated under the various environments and shows better performance compared to the original method in the SMV.

For the purpose of the application of odor to information technology, we have developed an odor-emitting apparatus coupled with chemical capsules made of alginic acid polymer. This apparatus consists of a chemical capsule cartridge including chemical capsules of odor ingredients, valves to control odor emission, and a temperature control unit. Different odors can be easily emitted by using the apparatus. We have developed an integrated system of vision, audio and olfactory information in which odor strength can be controlled coinciding with on-screen moving images based on analytical results from the odor scanner.

In this paper, a criterion for nonlinear stability analysis of microwave oscillator has been devised. The circuit envelope method has been used for analyzing the perturbed circuit. The proposed approach is evaluated by analyzing the nonlinear stability of a practical FET oscillator.

We present a 10-bit 1-MS/s successive approximation analog-to-digital converter core including a charge redistribution digital-to-analog converter and a comparator. A new linearity calibration technique enables use of a nearly minimum capacitor limited by kT/C noise. The ADC core without digital control blocks has been fabricated in a 0.18-µm CMOS process and consumes 118 µW at 1.8 V power supply. Also, the active area of ADC core is realized to be 0.027 mm2. The calibration improves the SNDR by 13.4 dB and the SFDR by 21.0 dB. The measured SNDR and SFDR at 1 kHz input are 55.2 dB and 73.2 dB respectively.

The body area network (BAN) has attracted attention because of its potential for high-grade wireless communication technology and its safety and high durability. Also, human area transmission of a BAN propagating at an ultra-wide band (UWB) has been demonstrated recently. When considering the efficiency of electromagnetic (EM) propagation inside the human body for BAN and hyperthermia treatment using RF, it is important to determine the mechanism of EM dissipation in the human body. A body heating system for hyperthermia must deposit EM energy deep inside the body. Also, it is important that the EM field generated by the implant system is sufficiently strong. In this study, the specific absorption rate (SAR) distribution is simulated using an EM simulator to consider the biological transmission mechanism and its effects. To utilize the EM field distribution using an implant system for hyperthermia treatment, the SAR distribution inside the human body is simulated. As a result, the SAR distribution is concentrated on the surface of human tissue, the muscle-bolus interface, the pancreas, the stomach, the spleen and the regions around bones. It can also be concentrated in bone marrow and cartilage. From these results, the appropriate location for the implant system is revealed on the basis of the current distribution and differences in the wave impedance of interfacing tissues. The possibility of accurate data transmission and suitable treatment planning is confirmed.

We demonstrated all-optical demultiplexing of 160-Gb/s signal to 40- and 80-Gb/s by a Mach-Zehnder Interferometric all-optical switch, where the picosecond cross-phase modulation (XPM) induced by intersubband excitation in InGaAs/AlAsSb coupled double quantum wells is utilized. A bi-directional pump configuration, i.e., two control pulses are injected from both sides of a waveguide chip simultaneously, increases a nonlinear phase shift twice in comparison with injection of single pump beam with forward- and backward direction. The bi-directional pump configuration is the effective way to avoid damaging waveguide facets in the case where high optical power of control pulse is necessary to be injected for optical gating at repetition rate of 40/80 GHz. Bit error rate (BER) measurements on 40-Gb/s demultiplexed signal show that the power penalty is decreased slightly for the bi-directional pump case in the BER range less than 10-6. The power penalty is 1.3 dB at BER of 10 - 9 for the bi-directional pump case, while it increases by 0.3-0.6 dB for single pump cases. A power penalty is influenced mainly by signal attenuation at "off" state due to the insufficient nonlinear phase shift, upper limit of which is constrained by the current low XPM efficiency of 0.1 rad/pJ and the damage threshold power of 100 mW in a waveguide facet.

The purpose of this study is the real-time estimation of Doppler spectral moments for precipitation in the presence of ground clutter overlap. The proposed method is a frequency domain approach that uses a Gaussian model both to remove clutter spectrum and to estimate weather spectrum. The main advantage of this method is that it does not use processes like several fitting procedures and enables to estimate profiles of precipitation in a short processing time. Therefore this method is efficient for real-time radar observation with high range and time resolution. The performance of this method is evaluated based on simulation data and the observation data acquired by the Ku-band broad band radar (BBR) [1].

This paper is concerned with timing synchronization of high rates UWB signals operating in a dense multipath environment, where access must tackle inter-frame interference (IFI), inter-symbol interference (ISI) and even multi-user interference (MUI). A training-based joint timing and channel estimation scheme is proposed, which is resilient to IFI, ISI, MUI and pulse distortion. A low-complexity detection scheme similar to transmit-reference (TR) scheme comes out as a by-product. For saving the training symbols, we further develop an extended decision-directed (DD) scheme. A lower bound on the probability of correct detection is derived which agrees well with the simulated result for moderate to high SNR values. The results show that the proposed algorithm achieves a significant performance gain in terms of mean square error and bit error rate in comparison to the "timing with dirty templates" (TDT) algorithms.

In low bit-rate video transmission, the payload of a single packet can often contain a whole coded frame due to the high compression ratio in both spatial and temporal domains. Thus, the loss of a single packet can lead to the loss of a whole video frame. In this paper, we propose a novel error concealment algorithm that can effectively reconstruct the lost frame and protect the quality of video streams from the degradation caused by propagation errors. The proposed algorithm employs a bilateral motion estimation scheme where the weighted sum of the received motion vectors (MVs) in the neighboring frames is utilized to construct the MV field for the concealed frame. Unlike the conventional algorithms, the proposed scheme does not produce any overlapped pixel and hole region in the reconstructed frame. The proposed algorithm can be applied not only to the case of single frame loss but also adaptively extended to the case of multiframe loss. Experimental results show that the proposed algorithm outperforms other conventional techniques in terms of both peak signal-to-noise ratio (PSNR) performance and subjective visual quality.

An efficient and practical algorithm is proposed for finding all DC solutions of nonlinear circuits. This algorithm is based on interval analysis and linear programming techniques. The proposed algorithm is very efficient and can be easily implemented by using the free package GLPK (GNU Linear Programming Kit). By numerical examples, it is shown that the proposed algorithm could find all solutions of a system of 2 000 nonlinear circuit equations in practical computation time.

A Feedback Error Learning (FEL) scheme was found to be applicable to joint angle control by Functional Electrical Stimulation (FES) in our previous study. However, the FEL-FES controller had a problem in learning of the inverse dynamics model (IDM) in some cases. In this paper, methods of applying the FEL to FES control were examined in controlling 1-DOF movement of the wrist joint stimulating 2 muscles through computer simulation under several control conditions with several subject models. The problems in applying FEL to FES controller were suggested to be in restricting stimulation intensity to positive values between the minimum and the maximum intensities and in the case of very small output values of the IDM. Learning of the IDM was greatly improved by considering the IDM output range with setting the minimum ANN output value in calculating ANN connection weight change.

This paper deals with a new formulation for the diffraction of a plane wave by a periodic grating. As a simple example, the diffraction of a transverse magnetic wave by a perfectly conductive periodic array of rectangular grooves is discussed. On the basis of a shadow hypothesis such that no diffraction takes place and only the reflection occurs with the reflection coefficient -1 at a low grazing limit of incident angle, this paper proposes the scattering factor as a new concept. In terms of the scattering factor, several new formulas on the diffraction amplitude, the diffraction efficiency and the optical theorem are obtained. It is newly found that the scattering factor is an even function due to the reciprocity. The diffraction efficiency is defined for a propagating incident wave as well as an evanescent incident wave. Then, it is theoretically found that the 0th order diffraction efficiency becomes unity and any other order diffraction efficiencies vanish when a real angle of incidence becomes low grazing. Numerical examples of the scattering factor and diffraction efficiency are illustrated in figures.

A single chip NFC transceiver with Dual Antenna structure supporting not only NFC active and passive mode but also 13.56 MHz RFID reader and tag mode is designed and fabricated. The proposed NFC transceiver can operate as a RFID tag even without external power supply thanks to a dual antenna structure for initiator and target. The area increment due to additional target antenna is negligible because the target antenna is constructed by using a shielding layer of the initiator antenna.

In this paper, we propose an Adaptation Decision-Taking Engine (ADTE) that targets the delivery of scalable video content in mobile usage environments. Our ADTE design relies on an objective perceptual quality metric in order to achieve video adaptation according to human visual perception, thus allowing to maximize the Quality of Service (QoS). To describe the characteristics of a particular usage environment, as well as the properties of the scalable video content, MPEG-21 Digital Item Adaptation (DIA) is used. Our experimental results show that the proposed ADTE design provides video content with a higher subjective quality than an ADTE using the conventional maximum-bit-allocation method.

This paper presents an easy and efficient modification of simplified 2D ray-launching method, by approximately including multiple reflection effect inside walls for indoor environment. In order to precisely carry out the ray-launching procedure inside lossy wall, a simple modification using a true real refraction angle is first introduced, instead of complex one. Furthermore, an efficient approximation is carried out to collect the internal multiple reflected rays into the primary one. We here call it collective ray approach. Consequently, it is confirmed from the detailed considerations that the present ray representations obtained by introducing the real refraction angle are well suitable for indoor propagation analysis, and in particular the collective ray solution can be utilized confidently even when the internal reflections strongly contribute to the propagation feature of the considered indoor environment.

In this paper, we present a high-performance VC-1 main-profile decoder for high-definition (HD) video applications, which can decode HD 720p video streams with 30 fps at 80 MHz. We implemented the decoder with a one-poly eight-metal 0.13 µm CMOS process, which contains about 261,900 logic gates and on-chip memories of 13.9 KB SRAM and 13.1 KB ROM and occupies an area of about 5.1 mm2. In designing the VC-1 decoder, we used a template-based SoC design flow, with which we performed the design space exploration of the decoder by trying various configurations of communication channels. Moreover, we also describe architectures of the computation blocks optimized to satisfy the requirements of VC-1 HD applications.

In the electromagnetic theory, the vacuum impedance Z0 is a universal constant, which is as important as the velocity of light c0 in vacuum. Unfortunately, however, its significance is not appreciated so well and sometimes the presence itself is ignored. It is partly because in the Gaussian system of units, which has widely been used for long time, Z0 is a dimensionless constant and of unit magnitude. In this paper, we clarify that Z0 is a fundamental parameter in electromagnetism and plays major roles in the following scenes: reorganizing the structure of the electromagnetic formula in reference to the relativity; renormalizing the quantities toward natural unit systems starting from the SI unit system; and defining the magnitudes of electromagnetic units.

In this paper, a multiplication algorithm in extension field Fpm is proposed. Different from the previous works, the proposed algorithm can be applied for an arbitrary pair of characteristic p and extension degree m only except for the case when 4p divides m(p-1) and m is an even number. As written in the title, when p>m, 4p does not divide m(p-1). The proposed algorithm is derived by modifying cyclic vector multiplication algorithm (CVMA). We adopt a special class of Gauss period normal bases. At first in this paper, it is formulated as an algorithm and the calculation cost of the modified algorithm is evaluated. Then, compared to those of the previous works, some experimental results are shown. Finally, it is shown that the proposed algorithm is sufficient practical when extension degree m is small.

This paper presents a technique for high-accuracy estimation of image rotation using 1D Phase-Only Correlation (POC). The rotation angle between two images is estimated as follows: (i) compute the amplitude spectra of the given images, (ii) transform the coordinate system of amplitude spectra from Cartesian coordinates to polar coordinates, and (iii) estimate the translational displacement between the polar-mapped amplitude spectra to obtain the rotation angle. While the conventional approach is to employ 2D POC for high-accuracy displacement estimation in (iii), this paper proposes the use of 1D POC with an adaptive line selection scheme. The proposed technique makes possible to improve the accuracy of rotation estimation for low contrast images of artificial objects with regular geometric shapes and to reduce the total computation cost by 50%.