A Novel Optimized V-VLC Receiver Sensor Design Using μGA in Automotive Applications

Vehicular visible light communication is known as a promising way of inter-vehicle communication. Vehicular VLC can ensure the significant advancement of safety and efficiency in traffic. It has disadvantages, such as unexpected glare on drivers in moving conditions, i.e., non-line-of-sight link at night. While designing a receiver, the most important factor is to ensure the optimal quality of the received signal. Within this context, to achieve an optimal communication quality, it is necessary to find the optimal maximum signal strength. Hereafter, a new receiver design is focused on in this paper at the circuit level, and a novel micro genetic algorithm is proposed to optimize the signal strength. The receiver can calculate the SNR, and it is possible to modify its structural design. The micro GA determines the alignment of the maximum signal strength at the receiver point rather than monitoring the signal strength for each angle. The results showed that the proposed scheme accurately estimates the alignment of the receiver, which gives the optimum signal strength. In comparison with the conventional GA, the micro GA results showed that the maximum received signal strength was improved by −1.7 dBm, −2.6 dBm for user Location 1 and user Location 2, respectively, which proves that the micro GA is more efficient. The execution time of the conventional GA was 7.1 s, while the micro GA showed 0.7 s. Furthermore, at a low SNR, the receiver showed robust communication for automotive applications.

Полупроводниковый сенсор термоэлектрического однофотонного детектора для регистрации излучения ближнего ИК диапазона

We proposed the design of a four-layer detection pixel of the single-photon thermoelectric detector with semiconductor FeSb2 sensor. The processes of heat propagation in a detection pixel after the absorption of a photon were studied using computer simulation. The calculations were based on the equation of heat propagation from a limited volume using the three-dimensional matrix method for differential equations. The temporal dependences of the detector signal amplitude were calculated for various thicknesses of the detection pixel’s layers and the following parameters were determined: signal delay, timing jitter, maximum signal value, time to reach the maximum signal, decay time and count rate. It was proved that a detector with such a detection pixel can provide detection efficiency above 95% for near-infrared photons. At the same time, the terahertz count rate was achieved.

Using modulation acousto-optic spectrometry to locate spectral features in overlapping spectra

The spectrometer is not able to accurately determine the spectral position of the smaller maximum if it is located against the background of a powerful broad peak. The solution of the problem is known it is enough to differentiate the existing dependence, and the position of the smaller peak is determined with sufficient accuracy. Based on a quasi-collinear acousto-optic (AO) cell, a prototype spectrometer was created, which makes it possible to record both the spectrum of the optical signal and its derivative in real time. In the course of the work, a more detailed research of the work of the created model was carried out: the value of the phase shift was changed programmatically from zero to 360°, and the spatial modulation period - from zero to the length of the AO cell L. A neon lamp and all the data presented were used as a radiation source, were obtained for the same emission line. The maximum signal for the derivative corresponds to the phase values of 90° and 270°. In another series of experiments, the work of the model was investigated with a change in the modulation period (the phase shift is fixed, ψ=π/2). The maximum signal for the derivative corresponds to the values of the modulation period duration equal to L/2, half the length of the acousto-optic cell. The graphs of the results of "physical" and "mathematical" differentiation do not coincide. We assume that the differences are related to the shape of the instrumental function of the acousto-optical spectrometer. However, at the tops of the spectral peaks, in the regions of intersection of derivatives with a zero line, the results coincide, which makes it possible to use acousto-optic differentiation to reveal the "fine structure" of optical spectra, and in real time. Thus, as a result of the work carried out: a method was proposed for the precise determination of the position of spectral maxima in complex overlapping spectra in real time; an instrumental implementation of the proposed method was created, and it was shown that for the visible range (532 nm) the accuracy of determining the spectral position of the maxima is 0.2 nm.

SAT-621 Framingham Cardiovascular Disease 10-Year-Risk Score Is Associated with Myocardial Perfusion in Asymptomatic Diabetic Patients

Background: Even without atherosclerosis, diabetes increases the risk of death from coronary heart disease and heart failure. Myocardial perfusion dysfunction may occur in the early stage of diabetic cardiomyopathy, but its examination method is relatively complex. It is very important to carry out targeted cardiac screening to find the factors related to diabetic myocardial perfusion in the early stage. Methods: We enrolled 77 patients with diabetes and 30 controls, performed anthropometric and laboratory tests such as blood glucose and lipids, and calculated Framingham Cardiovascular Disease 10-year-risk Score (FRS). All participants underwent cardiac magnetic resonance examinations and recorded their cardiac structure, functional indicators (such as ejection fraction (EF), end-diastolic volume (EDV), end-systolic volume (ESV), stroke volume(SV), peak filling rate (PFR),myocardial perfusion index (maximum upslope (Slope), half time to maximum signal intensity (Time50Max (s)), time to maximum signal intensity (TimeMax (s)), the maximum signal intensity (MaxSI),, basic signal intensity (Baseline),the ratio of MaxSI and Baseline ((MaxSI (BL) %), the difference value between MaxSI and Baseline (MaxSI (BL))). Results: Compared with normal group, no cardiovascular symptoms of left ventricular and right ventricular systolic function in patients with diabetes and end-diastolic and end systolic volume had no obvious difference, left ventricular PFR is lower than normal (279.65 + 57.62 vs. 322.57 + / - 78.29, p = 0.02), in the subgroup analysis we found that the FRS high-risk groups, ventricular septal thickening tend to, and Slope, MaxSI, MaxSI BL (%), MaxSI (BL) were significantly lower than the high risk group, Time50Max and TimeMax were significantly longer than the non-high-risk group, and FRS was negatively correlated with Slope, MaxSI(%BL) and positively correlated with TimeMax(s) and Time50Max(s), with statistical significance. Conclusion: Systolic function remains and diastolic function decreases in asymptomatic diabetic patients. Moreover, the patients with high risk of FRS had significant decreased perfusion function, and the quantitative indexes of perfusion function were closely related to FRS. It is of great value to pay attention to the changes of FRS score for early screening and diagnosis of diabetic heart disease.

Wavelength-Proportional Interpolation and Extrapolation of Virtual Microphone for Underdetermined Speech Enhancement

We previously proposed the virtual microphone technique to improve speech enhancement performance in underdetermined situations, in which the number of channels is virtually increased by estimating extra microphone signals at arbitrary positions along the straight line formed by real microphones. The effectiveness of the interpolation of virtual microphone signals for speech enhancement was experimentally confirmed. In this work, we apply the extrapolation of a virtual microphone as preprocessing of the maximum signal-to-noise ratio (SNR) beamformer and compare its speech enhancement performance with that of using the interpolation of a virtual microphone. Furthermore, we aim to improve speech enhancement performance by solving a trade-off relationship between performance at low and high frequencies, which can be controlled by adjusting the microphone interval. We propose a new arrangement where a virtual microphone is placed at a distance from the reference real microphone proportional to the wavelength at each frequency. From the results of our experiment in an underdetermined situation, we confirmed speech enhancement performance using the extrapolation of a virtual microphone is higher than that of using the interpolation of a virtual microphone. Moreover, the proposed wavelength-proportional interpolation and extrapolation method improves speech enhancement performance compared with the interpolation and extrapolation. Furthermore, we present the directivity patterns of a spatial filter and confirmed the behavior that improves speech enhancement performance.

An Over 120dB Dynamic Range Linear Response Single Exposure CMOS Image Sensor with Two-stage Lateral Overflow Integration Trench Capacitors

This paper presents a prototype linear response single exposure CMOS image sensor with two-stage lateral overflow integration trench capacitors (LOFITreCs) exhibiting over 120dB dynamic range with 11.4Me- full well capacity (FWC) and maximum signal-to-noise ratio (SNR) of 70dB. The measured SNR at all switching points were over 35dB thanks to the proposed two-stage LOFITreCs.