High Gain Settings Research Articles

The Simulation of Frequency Stability Settings of PV-Diesel Electric Hybrid Power Plant

In power generation, several problems, such as high gain settings in the automatic voltage regulator and many transmission networks, can increase low-frequency oscillations in the line. This study aims to determine the stability adjustment of Hybrid PV - Diesel Generating Load Frequency. In this study, simulation was done by using the Simulink Matlab program. The control design is applied by finding the optimum proportional-integral (PI) to set the program’s load frequency. The transfer function from the photovoltaic and diesel diagrams was changed to a matrix and applied in the M-File to get the control value by tuning the damping ratio. The real part of the simulation was obtained to get the optimal overshoot and rise time. The lowest fundamental element, the faster the system responds. Regulations and monitoring systems are carried out to maintain power quality and maintain the stability of frequency fluctuations caused by arbitrary power at generation and on the load side. It also supports the stability of power flow fluctuations in the power line tie-line due to frequency fluctuations from the system interconnection hybrid.

Blind estimation of sound coloration in rooms using chi-square distributions of damping constants.

Depending on the room type and various other assumptions, the damping distribution of a room will follow a specific "reference distribution," i.e., any deviation from the distribution should indicate sound coloration. In this paper, sound coloration will be caused by the acoustic feedback when operating sound reinforcement systems at relatively high gain settings. A sound reinforcement system based on measured impulse responses as well as an "emulated" system are studied using two speech and two music samples with system gains ranging from low to just before instability. Using one microphone placed in the audience area, blind estimation of sound coloration is achieved by computing decay times of non-harmonic components in the time-frequency domain. The results show that the computed damping distributions agree well with the chi-square distributions at low system gains. As the system gain increases, the distributions are shifted toward lower damping constants, and their shapes deviate more and more from the reference distribution, thus, giving a clear indication of sound coloration. The suggested objective measures show that deviations from the reference damping distribution can be detected at substantially lower system gains compared to results of related listening tests where audible coloration is evaluated.

Experience Gained When Using the Yuneec E10T Thermal Camera in Environmental Research

Thermal imaging is an important source of information for geographic information systems (GIS) in various aspects of environmental research. This work contains a variety of experiences related to the use of the Yuneec E10T thermal imaging camera with a 320 × 240 pixel matrix and 4.3 mm focal length dedicated to working with the Yuneec H520 UAV in obtaining data on the natural environment. Unfortunately, as a commercial product, the camera is available without radiometric characteristics. Using the heated bed of the Omni3d Factory 1.0 printer, radiometric calibration was performed in the range of 18–100 °C (high sensitivity range–high gain settings of the camera). The stability of the thermal camera operation was assessed using several sets of a large number of photos, acquired over three areas in the form of aerial blocks composed of parallel rows with a specific sidelap and longitudinal coverage. For these image sets, statistical parameters of thermal images such as the mean, minimum and maximum were calculated and then analyzed according to the order of registration. Analysis of photos taken every 10 m in vertical profiles up to 120 m above ground level (AGL) were also performed to show the changes in image temperature established within the reference surface. Using the established radiometric calibration, it was found that the camera maintains linearity between the observed temperature and the measured brightness temperature in the form of a digital number (DN). It was also found that the camera is sometimes unstable after being turned on, which indicates the necessity of adjusting the device’s operating conditions to external conditions for several minutes or taking photos over an area larger than the region of interest.

Evaluation of robustness against external vibrations for long-range MEMS lidar with one-dimensional resonant micromirror

We describe the verification of a long-range one-dimensional (1D) scanning micro-electro-mechanical systems (MEMS) lidar specifically considering the robustness against external vibration influences. The 1D scanning MEMS lidar exploits a multichannel horizontal line laser to scan the scene vertically for a 10 deg × 11 deg horizontal and vertical field of view at a frame rate of up to 29 Hz. To evaluate the robustness against vibrations, a vibration evaluation setup is developed to apply a wideband vibration based on the automotive standard LV124. The vibration tests are performed in three conditions open loop without control and two phase-locked loops (PLLs) with default and high gain settings. The test results demonstrate that vibration can cause wobbly distortion along the scan angle in the open loop case and the PLLs can suppress effectively this influence in the mean and standard deviation of the standard point to surface error up to 69.3% and 90.0%, respectively. This verifies the benefits of the MEMS mirror control, ensuring stable point cloud measurements under vibrations in harsh automotive environments.

Nonlinear Positioning Technique via Dynamic Current Cut-Off Frequency and Observer-Based Pole-Zero Cancellation Approaches for MAGLEV Applications

This article solves the problem caused by high level current feedback gain setting for fast responsiveness of magnetic levitation systems considering the current dynamics and presents advanced nonlinear positioning technology without plant parameter information. The main features of this study are summarized as follows: First, current control demonstrates current ripple reduction and overall performance guarantee through a low feedback gain in the steady state, including a dynamic feedback loop increased by an error variable magnitude in the transient period. Second, the plant parameter information-free velocity observer replaces the observer output error integral action with the disturbance estimation action to improve the closed-loop performance. The simulation results reveal the practical advantages derived from the contributions of this study.

A Fractional-N Reference Sampling PLL With Linear Sampler and CDAC Based Fractional Spur Cancellation

In this article, a fractional- $N$ reference sampling phase-locked loop (PLL) (RSPLL) is presented. A capacitor-based digital-to-analog converter (CDAC) is implemented at the output of the reference sampling phase detector (RSPD) to cancel the divider quantization error in fractional mode. The RSPD is linearized by maintaining a constant discharge current from the sampling capacitor. Although the discharging current source may induce some noise compared to a sampling PD. However, its noise can be effectively suppressed with the high-gain setting for the RSPD when the loop is in lock. The linear range of RSPD can be programmed to cover the quantization error in a frac- $N$ mode without degrading the PLL in-band phase noise. To mitigate the nonlinearity of RSPD, the CDAC is implemented with a high-order cancellation scheme using only one capacitor array but multiple reference voltages. The prototype chip was fabricated in a 45-nm partially depleted silicon-on-insulator (PDSOI) CMOS process. The measurement showed an output frequency range covering 7.7–9.1 GHz with an integrated jitter (10 kHz–50 MHz) of 135 fs and an in-band fractional spur level of −55 dBc at an offset frequency of 50 kHz. The entire PLL consumes 4.5 mW and achieves an figure of merit (FoM) of −250.8 dB.

Automatic Detection and Measurement of Fetal Biparietal Diameter and Femur Length —Feasibility on a Portable Ultrasound Device

An automatic method able to recognize a presented section through the biparietal plane of the fetal head and a section through the fetal femur in ultrasound images is developed. Once the correct anatomical section for measurement is identified by the machine, the placement of the measurement calipers is automatically determined by fitting an active contour model to the structure of interest. The fetal biparietal diameter (BPD) and femur length (FL) are then measured automatically. The validation data set contained 167 and 197 B-mode images for BPD and FL measurements, respectively. The images were acquired using 4 different ultrasound scanners, which resulted in varied image quality and gain settings. The mean gestational age (GA) of the fetuses was 19.4 weeks, range 16 to 41 weeks. A measurement success rate of 90% was achieved for both BPD and FL. The correlation coefficients between the manual and automatic measurements were 0.995 (BPD) and 0.967 (FL), mean errors were 0.5 mm (BPD) and -1.7 mm (FL) and error range with 95% confidence interval (CI) were ﹣3.8 - 4.8 mm (BPD) and ﹣11.4 - 8.1 mm (FL). The automatic measurement results were consistent in both high and low gain settings. The intraclass correlation coefficients between manual and automatic measurements were 0.995 (95% CI; 0.981 - 0.999) for BPD in high gain, 1.0 (95% CI; 0.998 - 1.0) for BPD in low gain, 0.998 (95% CI; 0.991 - 0.999) for FL in high gain and 0.999 (95% CI; 0.996 - 1.0) for FL in low gain settings. The method was implemented on a prototype, portable ultrasound machine designed to be used in low- and middle-income countries (LMIC). The overall performance of the method supports our hypothesis that automated methods can be used and are beneficial in a clinical setting.

Innovations in seismic sensors driven by the search for gravitational waves

An example is provided of how technology from a seemingly far-removed field of science has found its way into seismic surveying equipment. In order to achieve affordable dense sampling to remove adverse seismic-noise effects from gravitational-wave measurements, autonomous, integrated seismic nodes were developed for flexible deployment around the gravitational-wave detector's key components. The required sensitivity is achieved by utilizing a high-sensitivity, 5 Hz geophone in combination with a low noise recording channel, resulting in a self noise of < 1 ng/√Hz at 1 Hz. This specification is also promising for low-frequency single-sensor passive and active seismic acquisition. Ninety-six nodes were deployed during a field trial to demonstrate various novel passive seismic techniques for subsurface and microearthquake characterization using dense surface arrays. This showed the value of an affordable and practical dense surface array in extracting useful subsurface information from seismic noise and characterizing small earthquakes. The nodes were shown to have the long battery life required to be practical in their intended surveys, showing only 50% battery consumption after a 21-day survey at high-gain setting.

Optic disc drusen demonstrate a hyperechogenic artifact in B mode ultrasound

We describe a new, specific, hyperechogenic artifact spot in B-mode ultrasound (US) in patients diagnosed with optic nerve drusen (OND). This is a retrospective chart review of 34 consecutive patients with OND using B-scan US. The patients underwent full ophthalmic evaluation and neuro-ophthalmic examination. In all cases, a typical hyperechogenic spot was seen within the acoustic shadows on medium or high gain settings. The length between the US probe and the OND, and the distance between the OND and the artifact were recorded for each patient. In all cases, a typical hyperechogenic spot was seen within the acoustic shadows on medium or high gain settings. Sonograms showed a hyperechogenic focus in all eyes. The average ratio between the cornea–OND distance (25.5mm) and the OND–hyperechogenic spot (32.1mm) distance was 1.26. The size of the hyperechogenic spot was proportional to the size of the deposit on the disc, with the most marked attenuation of the beam seen in the largest lesions. B-scan US is a very sensitive and reliable detector of both superficial and buried OND. The described hyperechogenic artifact spot may be an additional mode to support diagnosis of OND. This finding might be helpful for making a differential diagnosis between OND and papilledema.

DMSP-OLS Radiance Calibrated Nighttime Lights Time Series with Intercalibration

The Defense Meteorological Satellite Program-Operational Linescan System (DMSP-OLS) stable lights products are made using operational OLS data collected at high gain settings, resulting in sensor saturation on brightly lit areas, such as city centers. This has been a paramount shortcoming of the DMSP-OLS stable lights time series. This study outlines a methodology that greatly expands the dynamic range of the OLS data using observations made at different fixed-gain settings, and by incorporating the areas not affected by saturation from the stable lights product. The radiances for the fixed-gain data are computed based on each OLS sensor’s pre-flight calibration. The result is a product known as the OLS radiance calibrated nighttime lights. A total of eight global datasets have been produced, representing years from 1996 to 2010. To further facilitate the usefulness of these data for time-series analyses, corrections have been made to counter the sensitivity differences of the sensors, and coefficients are provided to adjust the datasets to allow inter-comparison.

Acquisition of data at multiple gains within a single thermal melt experiment using the Rotor-Gene Q instrument

Abstract Background Rotor-Gene Q instrument was used to perform high-resolution protein thermal melt studies to characterize protein-small-molecule interaction. Fluorescent dye (1-anilino-8-naphthalenesulfonate (1,8-ANS)) is used as a reporter of protein unfolding to measure the protein melting temperature (T m). Variations in the fluorescence yield upon titration of small molecules with the protein resulted in poor melting curves at low gain while a high gain setting caused signal saturation leading to data loss. Findings Acquisition of data at multiple gains within a single experiment provided high-quality data for samples with both low and high fluorescence yields. The melting temperatures were measured for all the samples in one run, while avoiding loss of data due to signal saturation. This method was successfully used to measure the binding constant by titration of a small-molecule ligand with the target protein. Conclusion Protein thermal melt experiments using the Rotor-Gene Q instrument have been made feasible for samples that show variations in fluorescence yield. Furthermore, since protein melting is irreversible, using multiple gains in the same experiment prevented loss of sample and saved gain optimization time.

Radiofrequency pulse design for the selective excitation of dissolved 129Xe

To optimize radiofrequency (RF) pulses for the selective excitation of dissolved phase (129)Xe that take into account the very short T2*, while simultaneously, minimally exciting the much larger gas signal. Numerical simulations of Shinnar le-Roux pulses and binomial coefficient composite-element pulses were performed and experimentally implemented on a 1.5 Tesla (T) clinical scanner. These were compared with pulses commonly used for short T2* imaging from the literature. The pulses were then experimentally tested in vivo with healthy volunteers inhaling hyperpolarized (129)Xe using nuclear MR spectroscopy on a 1.5T clinical scanner. Standard RF excitation pulses inadvertently excite the gas compartment, or are long enough that the T2* of the dissolved compartment deteriorates the received signal. Amplitude modulated binomial composite pulses perform well being short and having high selectivity, however, deteriorate at high amplifier gain setting. Composite pulses using pulse width modulation provide the desired frequency response even in these nonlinear, high gain regimes. Composite pulses provide a means of very narrow band frequency selectivity in a short duration pulse that is well suited to dissolved (129)Xe imaging. Pulse width modulation maintains the desired frequency response even in the presence of amplitude distortion.

Targeted and Nontargeted Wine Analysis by 1H NMR Spectroscopy Combined with Multivariate Statistical Analysis. Differentiation of Important Parameters: Grape Variety, Geographical Origin, Year of Vintage

The authenticity, the grape variety, the geographical origin, and the year of vintage of wines produced in Germany were investigated by (1)H NMR spectroscopy in combination with several steps of multivariate data analysis including principal component analysis (PCA), linear discrimination analysis (LDA), and multivariate analysis of variance (MANOVA) together with cross-validation (CV) embedded in a Monte Carlo resampling approach (MC) and others. A total of about 600 wines were selected and carefully collected from five wine-growing areas in the southern and southwestern parts of Germany. Simultaneous saturation of the resonances of water and ethanol by application of a low-power eight-frequency band irradiation using shaped pulses allowed for high receiver gain settings and hence optimized signal-to-noise ratios. Correct prediction of classification of the grape varieties of Pinot noir, Lemberger, Pinot blanc/Pinot gris, Müller-Thurgau, Riesling, and Gewürztraminer of 95% in the wine panel was achieved. The classification of the vintage of all analyzed wines resulted in correct predictions of 97 and 96%, respectively, for vintage 2008 (n = 318) and 2009 (n = 265). The geographic origin of all wines from the largest German wine-producing regions, Rheinpfalz, Rheinhessen, Mosel, Baden, and Württemberg, could be predicted 89% correctly on average. Each NMR spectrum could be regarded as the individual "fingerprint" of a wine sample, which includes information about variety, origin, vintage, physiological state, technological treatment, and others.

Double-Gilbert mixer with enhanced linearity in 65 nm low-power CMOS technology

An innovative double-Gilbert-type down-conversion mixer is presented. It is designed and fabricated in a 65 nm low-power digital CMOS process. The mixer is based on the simple Gilbert-type mixer and utilizes a second mixer as active load. A second parallel mixer branch with switchable RC elements enables a high gain or a high linearity setting. A high 3rd-order input referred intercept point of +11.1 dBm is measured at a clock frequency of 1.5 GHz. A maximum conversion gain of 10.9 dB is achieved. A total power consumption of 6.0 mW from a 1.2 V supply is measured at the high-gain setting.

Pulse-Encoded Ultrasound Imaging of the Vitreous With an Annular Array

The vitreous body is nearly transparent both optically and ultrasonically. Conventional 10- to 12-MHz diagnostic ultrasound can detect vitreous inhomogeneities at high gain settings, but has limited resolution and sensitivity, especially outside the fixed focal zone near the retina. To improve visualization of faint intravitreal fluid/gel interfaces, the authors fabricated a spherically curved 20-MHz five-element annular array ultrasound transducer, implemented a synthetic-focusing algorithm to extend the depth-of-field, and used a pulse-encoding strategy to increase sensitivity. The authors evaluated a human subject with a recent posterior vitreous detachment and compared the annular array with conventional 10-MHz ultrasound and spectral-domain optical coherence tomography. With synthetic focusing and chirp pulse-encoding, the array allowed visualization of the formed and fluid components of the vitreous with improved sensitivity and resolution compared with the conventional B-scan. Although optical coherence tomography allowed assessment of the posterior vitreoretinal interface, the ultrasound array allowed evaluation of the entire vitreous body.

Methods Used For the 2006 Radiance Lights

The Operational Linescan System (OLS) flown on the Defense Meteorological Satellite Program (DMSP) satellites, has a unique capability to record low light imaging data at night worldwide. These data are archived at the National Oceanic and Atmospheric Administration (NOAA) National Geophysical Data Center (NGDC). The useful data record stretches back to 1992 and is ongoing. The OLS visible band detector observes radiances about one million times dimmer than most other Earth observing satellites. The sensor is typically operated in a high gain setting to enable the detection of moonlit clouds. However, with six bit quantization and limited dynamic range, the recorded data are saturated in the bright cores of urban centers. A limited set of observations have been obtained at low lunar illumination were obtained where the gain of the detector was set significantly lower than its typical operational setting (sometimes by a factor of 100). By combining these sparse data acquired at low gain settings with the operational data acquired at high gain settings, we have produced a global nighttime lights product for 2006 with no sensor saturation. This product can be related to radiances based on the pre-flights sensor calibration.

Quantitative Assessment of Renal Cortical Echogenicity in Clinically Normal Cats

In this study, we assessed the renal cortical echogenicity of clinically normal adult cats by histogram analysis to obtain basic ultrasonographic data. Ultrasound images were taken under the following sets of conditions: (1) high contrast and low gain setting using a convex probe, (2) low contrast and high gain setting using a convex probe, (3) high contrast and low gain setting using a linear probe and (4) low contrast and high gain setting using a linear probe. Echogenicity of the region of interest (ROI) in the right and left renal cortices, liver and spleen was determined by histogram analysis; kidney/spleen (Kid/Sp) and kidney/liver (Kid/Liv) echogenicity ratios were calculated. Kid/Sp and Kid/Liv values varied among different ROI sites in the kidney when obtained using the convex probe, but were constant when obtained using the linear probe. Kid/Sp measured in the middle sites of the kidney showed similar values for the different settings; however, Kid/Liv differed between probes. The present findings suggest that determination of Kid/Sp using a linear probe is a feasible method for quantitative evaluation of renal cortical echogenicity in cats.

3D Echocardiography: A Review of the Current Status and Future Directions

Ultrasound technology has improved markedly in the past 10 to 15 years, prompting echocardiographers to extend its use in studying cardiac structure and function. New ultrasound equipment and techniques offer superior image quality, greater accuracy, and expanding capabilities. As a result, more and improved imaging modalities are available for evaluating cardiac anatomy, ventricular function, blood flow velocity, and valvular diseases. Threedimensional (3D) echocardiography offers the ability to improve and expand the diagnostic capabilities of cardiac ultrasound. However, as with any emerging technology, the enthusiasm to embrace a new technique must be tempered by a critical appraisal of the evidence supporting its use. It is essential to assess the limitations as well as the unique capabilities it provides. Cardiac imaging should be safe, accurate, versatile, comprehensive, and cost-effective, while providing important clinical information. Criteria for appropriate utilization should be based on current evidence and updated as new information becomes available. To justify the use of a new 3D modality, its unique contribution to clinical practice must be critically analyzed. In this article we review the status of 3D echocardiography, examine the evidence for its use in various clinical situations, and propose guidelines for appropriate application of this technique based on available evidence.

Echoscintigraphy: a new imaging modality for the reduction of color blooming and acoustic shadowing in contrast sonography.

The purpose of this study was to develop and evaluate a new imaging modality (echoscintigraphy) to reduce color blooming and acoustic shadowing in contrast sonography. After injection of various amounts (700 to 40,000 bubbles/mL) of the echo contrast agent SH-U 563A into a flow phantom, artificial vessels were insonated in the intermittent harmonic-power Doppler imaging (H-PDI) mode. The receive gain was varied from 50% to 75%. The cross-sectional area (CSA) of the tube was assessed using a new summation algorithm (echoscintigraphy) and a conventional single-frame analysis (S-FA) of the H-PDI-signals. Echoscintigraphy is based on the recording and summation of low-intensity signals that are emitted during the ultrasound (US)-induced destruction of microbubbles. Application of the summation algorithm at low-contrast concentration allowed a gain-independent automatic calculation of the CSA at medium and high gain settings. Using the S-FA method, the assessment of the vessel diameter and the CSA was gain-dependent and allowed correct measurements only from 60% to 65% gain. At a high receive-gain and high contrast concentration, S-FA resulted in an overestimation of the CSA up to 35.5%. Echoscintigraphy allows correct display of contrast-filled vessels over a wide range of gain settings at low contrast concentrations, where S-FA does not adequately display echo contrast. Thus, echoscintigraphy minimizes artefacts resulting from color blooming and acoustic shadowing.

リニアモータの重心点速度推定オブザーバを用いた機械共振抑制高速位置決め制御

High gain is necessary in order to realize high-speed feedback control of the linear motor. However, high gain setting is not generally possible as it causes resonance of the machine structure. In order to realize high gain while restraining resonance, a method has been devised with an observer, which includes a resonance model of the linear motor. The motion information of the linear motor moving element is used while disregarding vibration. The observer calculates motion of the center of gravity. Proposed method has been successfully experimented with an actual linear motor in that high gain feedback control and high speed positioning have been effectively demonstrated.