Microdisk resonator assisted all-optical switching with improved speed using a reverse-biased p-n diode

ABSTRACTAs elastic electrical connectors, fuzz buttons provide a vertical and solderless electrical interconnection in microwave modules to enhance the integration. However, prolonged use in harsh environments poses a risk of potential failure in electronic components, potentially compromising communication system reliability. This work studies the impact of fuzz button degradation in harsh environments on analog modulation (AM) and pseudo random binary sequence (PRBS) signal transmission using theoretical analysis and experimental testing. Accelerated tests are designed to obtain the fuzz button samples with different degradation levels. The surface morphology observation and elemental analysis are conducted to analyse the degradation mechanism. In addition, a transmission channel with fuzz button interconnections is designed and the corresponding equivalent circuit model is developed. Based on the proposed circuit model, the effects of fuzz button degradation on the integrity of both AM signal and PRBS signal are investigated by analysing the metrics such as waveform, eye diagram and bit error rate (BER) of the output signal. In addition, the effects of the carrier frequency of AM signals, and the transmission rate of the PRBS signals on signal transmission are also investigated. The simulation results of the circuit model show good agreements with experimental tests. The research results provide a better understanding regarding the potentially corrosive effects of harsh environments on fuzz button connectors and the negative effects on the signal integrity. Moreover, the research results provide comprehensive data support for identifying key features that are used for the development of machine learning models for fault diagnosis and localisation in radio frequency (RF) circuits with fuzz button interconnections.

Pseudo-random binary sequence design for finite impulse response identification

This paper presents an active vibration control (AVC) scheme based on artificial immune system (AIS) algorithm with application to a thin plate system. A model-based control design approach, intergrating identification of the system model based on AIS is carried out to design the controller. The investigations concentrate on the first five resonance modes of the structure, and assesses the ability of developed control approach in attenuating the deflection of the plate structure. The performance of the AVC system is presented in both time and frequency domains with random, pseudo random binary sequence (PRBS) and finite duration step disturbance signals. Simulation results reveal that good performance is achieved with this approach.

This paper presents the investigations of possible EM emission from automotive Multi-Gig Ethernet bus system by mean of EMC simulations. The transfer function between the high-speed shielded twisted pair (STP) cable and rear window antenna in the vehicle is obtained in the FM and DAB frequency ranges. Multi-level Pulse Amplitude Modulations (PAM-N) of 31-bit Pseudo Random Binary Sequence (PRBS) signal are implemented for different data rates (1 Gbps, 2.5 Gbps, 5 Gbps, and 10 Gbps). Influence of the increasing data rate and dependence on the PAM modulation level are shown.

New Tuning Method for Generalized Predictive Control of the Production of S. cerevisiae

A frequency-hopping communication receiver based on Rydberg atoms, whose carrier frequency changes in accordance with a predetermined sequence, is proposed for what we believe to be the first time and experimentally verified. Based on the coherent population trapping (CPT) effect of atoms, a five-level system is built under the assumption of a constant laser wavelength, where the carrier is the resonance band corresponding to different separated quantum states. Pseudo-random binary sequence (PRBS) and complex image signals undergo keying modulation to achieve frequency-domain hopping reception. In the experiment, a dynamic range of 62 dB is demonstrated. The digital transmission with a data rate of 1 Mbps is performed reliably, within a tunable bandwidth of 50 MHz, an instantaneous bandwidth of 700 kHz and a max hopping rate of 20000 hop/s. The proposed atom-based frequency-hopping receiver is suitable for secure communications, satellite uplinks, quantum cryptography, and high-precision scientific research.

Modelling of the Puma Robot for Control of Grinding Applications

We present an integrable solution for the detection of defective sensor elements using sigma-delta-(/spl Sigma//spl Delta/)-modulation and a matched filter. The sensor element is stimulated using a pseudo random binary sequence (PRBS). The sensor signal is read out and the analog output is digitized using a /spl Sigma//spl Delta/-modulator. The binary pulse density stream of the /spl Sigma//spl Delta/-modulator is the output of the sensor system and thus should ideally contain the PRBS. A matched filter has the task of detecting the pseudo random sequence in the pulse density stream and its sampled output is compared to a threshold thus making it possible to judge the functionality of the sensor element. By evaluating the magnitude of the matched filter output it is also possible to measure the sensor sensitivity. We present a discrete solution of this method, but an integrated chip using a standard 1.2 /spl mu/m CMOS process has been designed and is being fabricated.

Nonlinear adaptive generic model control and self-tuning PID control systems were applied to control the top and bottom product temperature of a packed distillation column separating methanol-water mixture. In the first control algorithm, an adaptive generic model control (AGMC) structure was proposed for dual temperature control of the system. In the second control algorithm, nonlinear self tuning PID (NLSTPID) control based on pole-placement technique was used to control the same system. For NLSTPID control purposes pseudo random binary sequence (PRBS) signal and recursive identification algorithm were used to estimate the relevant parameters of a polynomial NARMAX model. In this work, real-time application has been carried out. In both dynamic and control studies, perturbations in feed composition were utilized as the disturbance, and the reboiler heat duty and the reflux ratio were selected as the manipulated variables. The control performances have been obtained by using ISE and, in general, AGMC results were better than those of the STPID control algorithm.

In this paper equivalent circuit models of potential transformers with model parameters determined by three different estimation methods are set up. The objective is to compare the complexity and the accuracy of the three methods. The model parameters in the first model are determined by measurements of the open-circuit and short-circuit impedance as function of the frequency and by measurements of the voltage ratio at different loads. From the open-circuit impedance measured by a pseudo random binary sequence signal, the parameters in the second model are found. In the third model the parameters are determined from a frequency sweep of the open-circuit and short-circuit impedances. All three methods describe the frequency spectrum from 100 Hz to 1 MHz. The models and the methods to find the model parameters are compared and verified by measurements on a commercial potential transformer.

The purpose of this study was to compare the test-retest reliability of oxygen uptake (VO2) kinetics with carbon dioxide output (VCO2) kinetics using a pseudo random binary sequence (PRBS) exercise test. A reliable test of gas exchange kinetics would have the potential of being applied as a sports fitness test. Ten healthy male subjects agreed to participate in the study and all subjects completed two identical PRBS exercise tests (test 1 and test 2), separated by a 30 min period of inactivity. Three consecutive 300 s PRBS cycles were completed in each test with 20 s exercise intensity changes between 25 and 85 W using an electrically braked cycle ergometer. Fourier analysis was computed for frequencies 3.3, 6.7 and 10 mHz. Statistical analysis by two-way ANOVA with repeated measures did not reveal significant differences between test 1 and test 2 for either VO2 kinetics or VCO2 kinetics. Static gain of VO2 for test 1 [9.11 (SD 0.59) ml.min-1.W-1] and test 2 [9.23 (SD 0.64) ml.min-1.W-1] did not differ significantly between tests. The 95% limits of agreement for VCO2 kinetics displayed increased variability in comparison to VO2 kinetics at each frequency of amplitude ratio and phase shift. Systematic bias ranged between 0% and 4%, except at frequency 10 mHz of VCO2 kinetics phase shift which showed a 10% bias for slower VO2 kinetics in test 2. It is possible that the increased variability of VCO2 kinetics compared to VO2 kinetics might be attributable to a lower signal to noise ratio in VCO2 kinetics, variations in ventilation or the storage mechanisms of CO2. The lower variability of VO2 kinetics compared with VCO2 kinetics suggests that the PRBS test of VO2 kinetics has the greater potential for further development as an indicator of aerobic fitness.

All-optical switches are used for many different applications. Broadcast-enhanced switches allow connection of a single input channel to numerous output channels, thus increasing further the possible application span. A compact multichannel all-optical broadcast-enhanced switch is described. This switch setup allows electronic alignment thus requires only simple construction procedures. A special importance of the proposed switch is for multistage interconnection networks where the alignment plays a major role. The switch structure is described and experimentally demonstrated.

The investigation of patients who are unable to fixate the pattern visual stimulus generally requires the use of diffuse flash stimulation to elicit the visual evoked response. However, by comparison with pattern, flash stimulation has proved relatively insensitive in identifying lesions of the visual pathway. We investigated a more complex method of flash stimulation. A pseudorandom binary sequence has been used to generate the diffuse visual evoked response stimulus. The pseudorandom binary sequence, rather than producing a single flash, switches in a pseudorandom fashion between two levels of illumination. The result is a diffuse visual stimulus approximating band-limited white noise. The series is periodic, enabling signal averaging to be performed. By applying the methods of random signal analysis, the impulse or transient response of the visual pathway can be determined. Our normal pseudo-random binary sequence visual evoked response impulse function, derived from 29 normal subjects, had the morphologic characteristics of the conventional flash visual evoked response and a major positive component (P100), whose latency mean and standard deviation closely matched that of our normative pattern visual evoked response. However, the P100 amplitude standard deviation was significantly greater than that produced by conventional pattern and flash stimulation. We investigated 140 patients by means of pattern, flash and pseudorandom binary sequence stimulation. The pseudorandom binary sequence visual evoked response proved to be almost 12 times more effective than flash visual evoked response in detecting lesions of the visual system.

With the increasing reliance on technology, it has become crucial to secure every aspect of online information where pseudo random binary sequences (PRBS) can play an important role in today’s world of Internet. PRBS work in the fundamental mathematics behind the security of different protocols and cryptographic applications. This paper proposes a new PRBS namely MK (Mamun, Kumu) sequence for security applications. Proposed sequence is generated by primitive polynomial, cyclic difference set in elements of the field and binarized by quadratic residue (QR) and quadratic nonresidue (QNR). Introduction of cyclic difference set makes a special contribution to randomness of proposed sequence while QR/QNR-based binarization ensures uniformity of zeros and ones in sequence. Besides, proposed sequence has maximum cycle length and high linear complexity which are required properties for sequences to be used in security applications. Several experiments are conducted to verify randomness and results are presented in support of robustness of the proposed MK sequence. The randomness of proposed sequence is evaluated by popular statistical test suite, i.e., NIST STS 800-22 package. The test results confirmed that the proposed sequence is not affected by approximations of any kind and successfully passed all statistical tests defined in NIST STS 800-22 suite. Finally, the efficiency of proposed MK sequence is verified by comparing with some popular sequences in terms of uniformity in bit pattern distribution and linear complexity for sequences of different length. The experimental results validate that the proposed sequence has superior cryptographic properties than existing ones.

In this paper, Auto Regressive eXogenous input (ARX), Auto Regressive Moving Average eXogenous input (ARMAX), Output error and BJ models of class D voltage-source half-bridge series-resonant inverter used for induction heating are identified and studied based on prior knowledge and measured data from PSIM simulation Environment. The output data are generated by applying Pseudo-Random-Binary-sequence (PRBS) as an input through the inverter MOSFET gate in the PSIM software. PRBS signal is generated using standard components such as flip-flops or XOR gates to approximate the white noise in the PSIM software. The generated output and input data are loaded in the MATLAB to identify the unknown system parameters of induction heating inverter by using MATLAB system identification toolbox. Estimation of models with pre-selected structures can be performed using system identification toolbox. To validate the models and their limitations, the fitness properties of the models based on percentage best fit and their resonant frequencies are examined.