The cationic dye, E-N-alkyl-4-[2-(4-alkyloxynaphthyl) ethenyl] quinolinium bromide has a wide-bodied chromophore with alkyl groups at opposite ends, i. e. CmH2m+1-D-π-A+-CnH2n+1 X-, where D and A are electron-donor and electron-acceptor groups respectively, π is a conjugated bridge and X- is the bromide counterion. It forms non-centrosymmetric Langmuir-Blodgett (LB) structures in which the packing is dependent upon the combination and compatibility of the alkyl groups. Films of two isomeric analogues where m + n = 34, have a layer thickness of 4.3 nm when the groups are significantly different (m = 12 and n = 22) which decreases to 2.5 nm when they are similar (m = 18 and n = 16). The latter adopts an interdigitating layer arrangement at both the upper and lower interfaces and it is the first example of a Lego-type structure with non-centrosymmetric alignment of the optically nonlinear chromophores. This is evidenced by the second-harmonic intensity, which increases quadratically with the number of layers, i. e. as .

We present two estimation methods for camera rotation from two images obtained by the active camera before and after rotation. Based on the representation of the projected rotation group, quasi moment features are constructed. Camera rotation can be estimated by applying the singular value decomposition (SVD) or Newton's method to tensor quasi moment features. In both cases, we can estimate 3D rotation of the active camera from only two projected images. We also give some experiments for the estimation of the actual active camera rotation to show the effectiveness of these methods.

The present paper modifies the algorithm to estimate harmful event frequencies and examines the definition of modes of operation in IEC 61508. As far as the continuous mode concerns, the calculated results coincide with those obtained based on the standard. However, for the intermediate region of medium demand frequencies and/or medium demand durations, the standard gives much higher harmful event frequencies than the real values. In order to avoid this difficulty, a new definition of modes of operation and a shortcut method for allocation of SILs are presented.

A three-dimensional beam propagation method based on a finite element scheme is described for the analysis of second harmonic generation devices. For the wide-angle beam propagation analysis, the Pade approximation is applied to the differential operator along the propagation direction. In order to avoid spurious reflection from the computational windows edges, the transparent boundary condition is introduced. Numerical results are shown for quasi-phase matched second harmonic generation devices using periodically domain-inverted LiNbO3 and LiTaO3 waveguides. The influences of the shape of domain-inverted regions and the inversion width on the conversion efficiencies are investigated in detail.

The purpose of this note is to carry out study on a 3-out-of-4:G warm standby system with nonidentical components. By using Markov model, the general form solution of stationary availability of the system is obtained. Examples are given to illustrate the solutions of transient and stationary availability of such system.

This paper presents the several bifurcation phenomena generated in nonlinear three-phase circuit with symmetry. The circuit consists of delta-connected nonlinear inductors, capacitors and three-phase symmetrical voltage sources. Particular attention is paid to the subharmonic oscillations of order 1/2. We analyze the bifurcations of the oscillations from both theoretical and experimental points. As a tool of analysis, we use the homotopy method. Additionally, by comparing with single-phase and single-phase-like circuits, the special feature of the three-phase circuit is revealed.

In this paper, we study a new hybrid speech coder which employs a modified version of the harmonic sinusoidal analysis to encode the periodic contents of speech waveform and to split the speech spectrum into two frequency regions of harmonic and random components. A reliable fundamental frequency is estimated for the harmonic region using both speech and its linear predictive (LP) residual spectrum. The peak envelope of speech spectrum is encoded in terms of the coefficients of an all-pole spectrum. A harmonic tracking algorithm appropriately interpolates the sinusoidal parameters to achieve a smooth transition between the parameter update points and to reconstruct an essential level of periodicity in the synthetic voiced speech. The random part of spectrum and unvoiced speech are coded using the conventional CELP algorithm. The individual components are then combined at the decoder to obtain the synthetic speech. The proposed hybrid coder which combines the powerful features of the sinusoidal and CELP coding algorithms yeilds a high quality synthetic speech at 4.05 kbps.

As wireless communication is penetrating every corner of the globe, the optimum design and accurate analysis of RF, power semiconductor devices become one of the biggest challenges in EDA and TCAD (Technology CAD) tool development. The performance gauge for these devices is quite different from that for either digital or analog devices aimed at small-signal applications in that the power gain, efficiency, and distortion (or the range of linearity) are the utmost design concerns. In this article, the methodology and mathematical foundation for numerical analysis of large signal distortion at the device simulation level are discussed. Although the harmonic balance (HB) method has long been used in circuit simulation for large signal distortion analysis, the implementation of the same method in device simulation faces daunting challenges, among which are the tremendous computational cost and memory storage management. But the benefits from conducting such a device level simulation are also obvious--for the first time, the impact of technology and structural variation of device on large signal performance can directly be assessed. The necessary steps to make the HB analysis feasible in device simulation are outlined and algorithmic improvement to ease the computation/storage burden is discussed. The applications of the device simulator for various RF power devices, including GaAs MESFETs and silicon LDMOS (lateral diffusion MOS) are presented, and the insight gained from such an analysis is provided.

Second harmonic signal feedback technique is applied to an HBT power amplifier for Wide-band CDMA (W-CDMA) mobile communication system to improve its linearity and efficiency. This paper describes the feedback effect of the 2nd harmonic signal from the output of the amplifier to the input on the 3rd order intermodulation distortion (IMD) products and Adjacent Channel leakage Power (ACP) of the power amplifier. The feedback amplifier, using an InGaP/GaAs HBT with 48 fingers of 3 20 µ m emitter, exhibits a 10 dB reduction in the level of the 3rd order IMD products. In addition, an ACP improvement of 7 dB for the QPSK modulation signal with a chip rate of 4.096 Mcps at 1.95 GHz was realized. As a result, the amplifier achieves a power-added efficiency of 41.5%, gain of 15.3 dB, and ACP of 43.0 dBc at a 5 MHz offset frequency and output power of 27.5 dBm. At the output power of 28 dBm, the power-added efficiency increases to 43.3% with an ACP of 40.8 dBc.

An unbiased estimation method for symmetric noncausal ARMA model parameters is presented. The proposed algorithm works in two steps: first, a spectrally equivalent causal system is identified by lattice whitening filter and then the equivalent noncausal system is reconstructed. For AR system with noise or ARMA system without noise, the proposed method does not need any iteration method nor any optimization procedure. An estimation method of noise variance when the observation is made in noisy situation is discussed. The potential capabilities of the algorithm are demonstrated by using some numerical examples.

This paper proposes a method to transform a CORDIC ARMA lattice filter, which is originally realized for signal analysis, into a signal synthesis lattice filter (CORDIC ARMA lattice synthesis filter). In order to perform such a transformation and then obtain the CORDIC ARMA lattice synthesis filter, we must implement the followings with CORDIC: (1) the structure of the altered lattice filter; and (2) an angle calculation module. However, we cannot achieve such an implementation as an extension of the CORDIC ARMA lattice filter algorithm. Therefore, this paper proposes CORDIC implementation schemes for both the structure and module, and then we realize the CORDIC ARMA lattice synthesis filter. By using CORDIC processors, the elementary sections of the CORDIC ARMA lattice synthesis filter are efficiently implemented without any multipliers. Since the obtained signal synthesis lattice filter consists of dedicated CORDIC processors, it keeps the advantage of the CORDIC ARMA lattice filter, that is a simple structure.

A method for expanding the channels of data acquisition unit used in distributed microcomputer data measure & control systems and a technique to call assembly routines by C Language are introduced in the paper. The method may increase the number of data acquisition points ten to hundreds times. So it may raise the price performance ratio of all distributed data measure & control system greatly. And the programming method may optimize program performance.

Loosely wound short-arm two-wire Archimedean spiral antennas are investigated. It is shown that good circularly polarized waves with axial ratio less than 2 dB are obtained when the outer circumference C of the spiral antenna is in the range of about 1. 3λ < C < 1. 5λ, where λ is the free-space wavelength. To improve the antenna characteristics further, spiral antennas combined with a parasitic loop are examined. It is clarified that the parasitic loop greatly contributes to the improvement of the axial ratio and power gain.

An optimum filter for extracting a time-varying harmonic signal from the noise-corrupted measurement is proposed. It is derived as a solution of the least mean square estimation with consideration of the pitch estimation error even without any assumption on the filter model. We obtain a comb-like impulse response which consists of homologous and dilated distribution of weights just located periodically with a pitch interval. This remarkable structure is well suited to the proportionally expanding error of pitch repetition times. Examples of the filter design are presented, and the performance of noise suppression is examined by comparison with conventional comb filters.

This letter proposes a method to transform normalized ARMA lattice filters, which are originally realized for signal analysis, into signal synthesis lattice filters. Although the transformation method has been proposed for normalized ARMA lattice filters with the MA order which is greater than or equal to the AR order, it has not been done when the AR order is greater than the MA order. With the proposed method, once an ARMA lattice filter with the AR order greater than the MA order is realized, then it can be transformed to the signal synthesis filter.

The TMN that appears to operate the various communication networks generally and efficiently is developed under the different platform environment such as the different hardware and the different operating system. One of the main problems is that all the agents of the TMN system must be duplicated and maintain the software and the data blocks that perform the identical function. Therefore, the standard of the Q3 interface development cannot be defined and the multi-platform cannot be supported in the development of the TMN agent. In order to overcome these problems, the Farming methodology that is based on the Farmer model has been suggested. The main concept of the Farming methodology is that the software and the data components that are duplicated and stored in each distributed object are saved in the Platform Independent Class Repository (PICR) by converting into the format of the independent componentware in the platform, so that the componentwares that are essential for the execution can be loaded and used statically or dynamically from PICR as described in the framework of each distributed object. The distributed TMN agent of the personal communication network is designed and developed by using the Farmer model.

We propose a Generalized Order Statistic Cell Averaging (GOSCA) CFAR detector. The weighted sums of the order statistics in the leading and lagging reference windows are utilized for the background level estimate. The estimate is obtained by averaging the weighted sums. By changing the weighting values, various CFAR detectors are obtained. The main advantage of the proposed GOSCA CFAR detector over the GOS CFAR detector is to reduce a computational time which is critical factor for the real time operation. We also derive unified formulas of the GOSCA CFAR detector under the noncoherent integration scheme. For Swerling target cases, performances of various CFAR detectors implemented using the GOSCA CFAR detector are derived and compared in homogeneous environment, and in the case of multiple targets and clutter edges situations.

Recent advances in solid-state laser technology and ultrafast optics led to the generation of optical pulses as short as 5 femtoseconds with peak powers up to the subterawatt level from a compact kHz-repetition-rate all-solid-state laser. This source significantly pushes the frontiers of nonlinear optics. Exciting new possibilities include the investigation and exploitation of reversible nonlinear optical processes in solids at unprecedented intensity levels, the development of a compact laser-driven coherent soft-X ray source at photon energies near 1 keV, and the generation of attosecond xuv pulses. First, a brief review of recent milestones in the evolution of ultrafast laser technology is given, followed by a description of the high-power 5-fs source. The rest of the paper is devoted to applications in previously inaccessible regimes of nonlinear optics. We demonstrate that wide-gap dielectrics resist intensities in excess of 1014 W/cm2 in the sub-10 fs regime and the extension of high-harmonic generation in helium to wavelengths shorter than 2. 4 nm (Eph > 0. 5 keV).

This paper deals with a probabilistic formulation of the diffraction and scattering of a plane wave from a periodic surface randomly deformed by a binary sequence. The scattered wave is shown to have a stochastic Floquet's form, that is a product of a periodic stationary random function and an exponential phase factor. Such a periodic stationary random function is then represented in terms of a harmonic series representation similar to Fourier series, where `Fourier coefficients' are mutually correlated stationary processes rather than constants. The mutually correlated stationary processes are written by binary orthogonal functionals with unknown binary kernels. When the surface deformations are small compared with wavelength, an approximate solution is obtained for low-order binary kernels, from which the scattering cross section, coherently diffracted power and the optical theorem are numerically calculated and are illustrated in figures.

This paper presents the several bifurcation phenomena of harmonic oscillations occurred in nonlinear three-phase circuit. The circuit consists of delta-connected nonlinear inductors, capacitors and three-phase symmetrical voltage sources. We analyze the bifurcations of the oscillations by the homotopy method. Additionally, we confirm the bifurcation phenomena by real experiments. Furthermore, we reveal the effect of nonlinear couplings of inductors by the comparison of harmonic oscillations in a single-phase circuit.