Signal Generation Method Research Articles

A Novel Reference Signal Generation Method for Power-Quality Improvement of Unified Power-Quality Conditioner

This paper proposes a novel reference signal generation method for the unified power quality conditioner (UPQC) adopted to compensate current and voltage-quality problems of sensitive loads. The UPQC consists of a shunt and series converter having a common dc link. The shunt converter eliminates current harmonics originating from the nonlinear load side and the series converter mitigates voltage sag/swell originating from the supply side. The developed controllers for shunt and series converters are based on an enhanced phase-locked loop and nonlinear adaptive filter. The dc link control strategy is based on the fuzzy-logic controller. A fast sag/swell detection method is also presented. The efficacy of the proposed system is tested through simulation studies using the Power System Computer Aided Design/Electromagnetic Transients dc analysis program. The proposed UPQC achieves superior capability of mitigating the effects of voltage sag/swell and suppressing the load current harmonics under distorted supply conditions.

An Arithmetic System over Finite Fields

This paper propose the method of constructing the highly efficiency adder and multiplier systems over finite fields. The addition arithmetic operation over finite field is simple comparatively because that addition arithmetic operation is analyzed by each digit modP summation independently. But in case of multiplication arithmetic operation, we generate maximum k=2m-2 degree of <TEX>${\alpha}^k$</TEX> terms, therefore we decrease k into m-1 degree using irreducible primitive polynomial. We propose two method of control signal generation for the purpose of performing above decrease process. One method is the combinational logic expression and the other method is universal signal generation. The proposed method of constructing the highly adder/multiplier systems is as following. First of all, we obtain algorithms for addition and multiplication arithmetic operation based on the mathematical properties over finite fields, next we construct basic cell of A-cell and M-cell using T-gate and modP cyclic gate. Finally we construct adder module and multiplier module over finite fields after synthesizing <TEX>${\alpha}^k$</TEX> generation module and control signal CSt generation module with A-cell and M-cell. Next, we constructing the arithmetic operation unit over finite fields. Then, we propose the future research and prospects.

Alternative Method for SSB Signal Generation

This paper presents an alternative scheme for generation of single sideband (SSB) signal. The proposed scheme is a combination of frequency discrimination method and phase discrimination method with emphasis on simplifying the filter design. Modified version of the given message signal is created by selecting the portion of the frequency translated version of the original message signal (the spectrum is shifted by an amount equal to the sum of the lowest and highest frequency components present in the message signal) that lies within the bandwidth of the original message signal. The modified version of the signal is scaled and given a phase shift of 180° and translated in frequency by the desired amount (depends on which sideband is to be eliminated). This version is added to the frequency shifted (equal to carrier frequency) version of the given message signal thereby canceling the undesired sideband. However, filtering is needed to eliminate the other sideband associated with the frequency shifted modified version of the message signal. The filter design is simple as the ratio of the centre frequency to the frequency gap between desired sideband and undesired sideband is relatively larger. The proposed method requires 180° phase shifter and a bandpass filter whose designs are much simpler than those in the conventional case. The mathematical analysis of the proposed scheme along with simulation results has been proposed.

75-km SMF Transmission of Optical 16 QAM Signal Generated by a Monolithic Quad-Parallel Mach–Zehnder Optical Modulator

We demonstrate 75-km single-mode fiber transmission of a 40-Gb/s optical 16-level quadrature amplitude modulation (16QAM) signal generated by a quad-parallel Mach-Zehnder optical modulator (QPMZM), where four Mach-Zehnder structures are embedded in parallel monolithically on a lithium niobate substrate. Owing to the optical 16QAM signal generation method based on the coherent superposition in the QPMZM and improved coherent receiver utilizing digital filters, improvement of receiver sensitivity has been achieved as well. The experimentally obtained receiver sensitivity for near the forward-error correction limit and power penalty due to transmission are experimentally evaluated as 16.3 dB and about 2-3 dB, respectively.

Biological Information—Definitions from a Biological Perspective

The objective of this paper is to analyze the properties of information in general and to define biological information in particular.

Hearing Aid Employing Electret And Silicon Microphones

In a hearing device with multiple microphones, and a signal generation method, the dynamic range of hearing devices is improved by using a combination including a silicon microphone and an electret microphone for the hearing device input. Low frequencies thus can be acquired by the silicon microphone and high frequencies can be acquired by the electret microphone, in order to generate a wide-band hearing device input signal. The fact that a silicon microphone possesses a lower internal noise than a conventional electret microphone at low frequencies is utilized.

디지털 고주파 메모리 구현에 관한 연구

Digital Radio Frequency Memory, ( as DRFM ), is a device with the ability to restore output to the input RF signal in the required time after storing the incoming RF signals. Therefore DRFM is widely used in Jammer, EW Simulator, Target Echo Generator, and so on. This paper proposes its hardware implementation composed with the high frequency part and the digital processing part consisting of RF input/output module and local oscillator module. It is also proposed the replicated signal generation method which is consisted of the Analog-Digital conversion in the form of pulsed RF signal quantization, and FPGA to save and produce the playback signal, and RF signals to produce a Digital-Analog Conversion in the digital processing unit. This proposed scheme applied to test board and confirmed the validity of the proposed scheme through the test results obtained by the simulated input signals.

Millimeter-Wave Harmonic Signal Generation and Distribution Using a Tunable Single-Resonance Microwave Photonic Filter

A millimeter-wave (mm-wave) harmonic signal generation method is proposed and verified experimentally. The mm-wave harmonic signals of high order are generated through the intrinsic nonlinear transfer characteristics of the Mach-Zehnder amplitude modulator. A tunable single-resonance microwave photonic filter is used to select the specific order of harmonic signal. Signals up to the fourth harmonic at 20 GHz can be generated by low-frequency driving signal at 5 GHz.

Optical enzyme-linked immunosorbent assay on a strip for detection of Salmonella typhimurium

A rapid and sensitive enzyme-linked immunosorbent assay (ELISA) on an immunochromatographic strip was evaluated for the measurement of Salmonella typhimurium. Two different optical signal generation methods (colorimetric and chemiluminescent) were used to develop the proposed immunostrip system. Colorimetric and chemiluminescent signals could be successfully generated using the proposed immunostrip system, and S. typhimurium could be quantitatively measured in the range of 9.2×103 to 9.2×106 CFU/mL within 20 min (colorimetric method) and 16 min (chemiluminescent method). The selectivity and feasibility of the proposed immunostrip was confirmed by conducting experiments with spiked samples using real river water.

Performance Comparison with Various Methods for Optical Single Sideband Signal Generation

Performance Comparison with Various Methods for Optical Single Sideband Signal Generation

Recent advances in rapid and ultrasensitive biosensors for infectious agents: lesson from Bacillus anthracis diagnostic sensors

Here, we review the cumulative efforts to develop rapid and ultrasensitive diagnostic systems, especially for the infectious agent, Bacillus anthracis, as a model system. This Minireview focuses on demonstrating the features of various probes for target molecule detection and recent methods of signal generation within the biosensors. Also, we discuss the possibility of using peptides as next-generation probe molecules.

New position error signal generation method for SPM based data storage system

A new position error signal (PES) generation method for scanning probe microscope (SPM) based Data Storage (SDS) system is proposed. In this paper, instead of pits used by the conventional methods, two stripe patterns (sync and PES patterns) are used. The two patterns can be either etched or nano imprinted for mass production. In the proposed method analog-to-digital converters are no longer needed. Instead, a simple digital counter and phase locked loop logic along with analog comparators are used. We present how to construct PES, and investigate its quality degradation due to manufacturing uncertainties such as misalignment during assembly process and scanning speed jitters. Simulation and experimental results with PES quality analysis were presented to confirm the validity of the proposed patterns.

Implementation of a Position Error Signal for Scanning Probe Microscopy-Based Data Storage Systems

In this paper, we propose a method of position error signal (PES) generation for read-only-memory (ROM) type scanning probe microscopy (SPM)-based data storage (SDS) systems. Conventionally, PES is generated by using servo bursts similar to those of hard disk drives. Recently, it was reported that stripe patterned media enables the generation of PES without using servo bursts as hard disk drives. In this paper, we report the fabrication of patterned media and its experimental results. Servo patterns are nano-imprinted on polymer medium film. We succeed in reading data and the servo patterns with a 1times 3 cantilever. We also demonstrate track follow control with the PES of the ROM type SDS through simulations.

Effect of Date of Drug Marketing on Disproportionality Measures in Pharmacovigilance

Warnings concerning an increased risk of suicide in patients treated with selective serotonin reuptake inhibitors (SSRIs) re-emerged in early 2003, culminating in the broadcast of a television programme in the UK. In the following months, cumulated proportional reporting ratios showed that the most recently marketed drug, escitalopram, had a much higher proportion of reports of suicide to other adverse drug reactions (ADRs) than the other drugs in the class. To study the reporting patterns over time concerning suicide with the six SSRIs marketed in the UK as of March 2003 and their potential effect on disproportionality signal detection. Monthly cumulated numbers of reports were obtained from the UK Medicines and Healthcare products Regulatory Agency (MHRA), from the time of the first marketing of the drugs concerned and monthly for the 2 months prior to and the 9 months following the broadcast of the television programme (broadcast date: 11 May 2003), and the monthly ratio of suicide to other reports was computed for each SSRI individually and for all SSRIs combined. Of the six SSRIs studied, five (citalopram, paroxetine, fluoxetine, sertraline and venlafaxine) had been marketed for several years and escitalopram for only a few months. At the end of the analysis period, 1.42% (4/281) of all ADR reports for escitalopram were of suicide versus 0.58% for the other five drugs combined (146/25 197). For all SSRIs combined, suicide represented 0.5% (123/24 315) of reports before the broadcast of the television programme, and increased to 2.3% (27/1163) following the programme. For escitalopram, suicide represented 1.1% (1/89) of all ADR reports before the television programme and 1.6% (3/192) afterwards. For the five other drugs combined, suicide represented 0.5% (122/24 226) of ADR reports before the television programme and 2.5% (24/971) afterwards (varying from 1.4% to 4.7% for the various drugs). The post-programme events represented 68% of all reports and 75% of suicides for escitalopram, whereas for older drugs they represented 3.6% of reports and 13% of suicides. For older drugs, the events reported during the high-reporting post-television programme period were diluted by years of low reporting. For escitalopram, although the television programme had little absolute impact on the number of reports, because the drug had been on the market for such a short period of time, a large relative effect was observed. Differential effects related to time on market on cumulated reporting of adverse drug reactions should be taken into account when analysing spontaneous reporting databases with automated signal generation methods after an alert has changed the spontaneous reporting patterns. Proper use of measures of disproportionality requires thorough knowledge of potential biases and careful analysis of reporting patterns. We found no obvious differences between SSRIs once these were taken into account.

All-fiber incoherent frequency-to-time mapping method for microwave signal generation with baseband transmission and multicasting support

We present a proof-of-principle experiment for achieving simultaneous distribution of baseband radio-frequency data and up-conversion with broadcasting support over a passive optical network. The technique is based on an incoherent frequency-to-time mapping method for pulse shaping. Specifically, we synthesize the spectral density function of sliced ASE noise from an EDFA with a periodic Mach–Zehnder fiber interferometer optical filter. By using external intensity modulation combined with propagation in an optical fiber, after photodetection, the resultant averaged temporal pulse profile resembles the shape of the incoherent source. The photodetected signal contains both the baseband data and an up-frequency converted copy with central wavelength for the microwave carrier into the ultra-wideband range and tuning capability by selection of the fiber length.

FLAG assay as a novel method for real-time signal generation during PCR: application to detection and genotyping of KRAS codon 12 mutations

Real-time signal generation methods for detection and characterization of low-abundance mutations in genomic DNA are powerful tools for cancer diagnosis and prognosis. Mutations in codon 12 of the oncogene KRAS, for example, are frequently found in several types of human cancers. We have developed a novel real-time PCR technology, FLAG (FLuorescent Amplicon Generation) and adapted it for simultaneously (i) amplifying mutated codon 12 KRAS sequences, (ii) monitoring in real-time the amplification and (iii) genotyping the exact nucleotide alteration. FLAG utilizes the exceptionally thermostable endonuclease PspGI for real-time signal generation by cleavage of quenched fluorophores from the 5′-end of the PCR products and, concurrently, for selecting KRAS mutations over wild type. By including peptide-nucleic-acid probes in the reaction, simultaneous genotyping is achieved that circumvents the requirement for sequencing. FLAG enables high-throughput, closed-tube KRAS mutation detection down to ∼0.1% mutant-to-wild type. The assay was validated on model systems and compared with allele-specific PCR sequencing for screening 27 cancer specimens. Diverse applications of FLAG for real-time PCR or genotyping applications in cancer, virology or infectious diseases are envisioned.

Fast rate‐distortion optimized coding mode decision for H.264

AbstractIn H.264/MPEG‐4 AVC a wide range of different prediction block forms and prediction signal generation methods are available. By selecting an optimal combination of coding modes from the multiple possible combinations of such modes, improvements in coding efficiency can be achieved. However, when using the rate‐distortion optimized coding mode decision method based on the Lagrange multipliers, at the same time as seeing a significant improvement in coding efficiency, we are faced with the problem that the mode decision procedure becomes extremely demanding computationally. The H.264/MPEG‐4 AVC high profile introduces adaptive block size transformations thereby making the number of combinations of coding mode that can be selected even larger than under the main profile. In this paper we investigate a method for hierarchically and adaptively reducing the number of mode combinations. Specifically we propose a method for quickly deciding the coding mode while limiting the reductions in coding efficiency by the correlation information between two mode decision cost functions in accordance with a quantization parameter. The results of experiments confirm that by using the proposed method, the encoding time excluding the motion search can be reduced by up to 4 times for the main profile and by up to 7 times for the high profile as compared to rate‐distortion optimized coding mode decision. © 2007 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 90(9): 41– 55, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjc.20342

A frequency-domain method for generation of discrete-time analytic signals

We consider a common frequency-domain procedure hilbert for generating discrete-time analytic signals and show how it fails for a specific class of signals. A new frequency-domain technique ehilbert is formulated that solves the defect. Moreover, the new technique is applicable to all discrete-time real signals of even length. It is implemented by the introduction of one additional zero of the continuous spectrum of the analytic signal hilbert at a negative frequency. Both frequency-domain methods generate equal length discrete-time analytic signals. The new analytic signal preserves the original signal (real part) and also the zeros of the discrete spectrum hilbert in the negative frequencies. The greater attenuation at the negative frequencies affects the degree of aliasing of the analytic signal. It is measured by applying the analytic signal to an orthogonal wavelet transform and determining the improved transform shiftability

Photonic generation of microwave signal using a rational harmonic mode-locked fiber ring laser

A novel method for microwave signal generation using a rational harmonic actively mode-locked fiber ring laser is proposed and demonstrated. The microwave signal is generated by beating the actively mode-locked longitudinal modes from the rational mode-locked fiber ring laser at a photodetector. The phases of the longitudinal modes are phased locked, which ensures a generated microwave signal with very low phase noise. In the proposed approach, the generated microwave signal has a frequency a few times higher than the microwave drive signal. Therefore, only a low-frequency reference source and a low-speed modulator are required. A rational harmonic actively mode-locked fiber ring laser is experimentally demonstrated. With a microwave drive signal at 5.52 GHz, a microwave signal with a frequency that is four times the frequency of the microwave drive signal at 22.08 GHz is generated. The generated microwave signal is very stable with a spectral width of less than 1 Hz.

Real-time gating system for mouse cardiovascular MR imaging

Mouse cardiac MR gating using ECG is affected by the hostile MR environment. It requires appropriate signal processing and correct QRS detection, but gating software methods are currently limited. In this study we sought to demonstrate the feasibility of digital real-time automatically updated gating methods, based on optimizing a signal-processing technique for different mouse strains. High-resolution MR images of mouse hearts and aortic arches were acquired using a chain consisting of ECG signal detection, digital signal processing, and gating signal generation modeled using Simulink (The MathWorks, Inc., Natick, MA, USA). The signal-processing algorithms used were respectively low-pass filtering, nonlinear passband, and wavelet decomposition. Both updated and nonupdated gating signal generation methods were tested. Noise reduction was assessed by comparison of the ECG signal-to-noise ratio (SNR) before and after each processing step. Gating performance was assessed by measuring QRS detection accuracy before and after online trigger-level adjustments. Low-pass filtering with trigger-level adjustment gave the best performance for mouse cardiovascular imaging using gradient-echo (GE), spin-echo (SE), and fast SE (FSE) sequences with minimum induced delay and maximum gating efficiency (99% sensitivity and R-peak detection). This simple digital gating interface will allow various gating strategies to be optimized for cardiovascular MR explorations in mice.