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To address the high power consumption associated with image refresh operations in EPDs, this paper proposes a low-power driving waveform that reduces the refresh power of EPDs by lowering the system's peak power. Compared to traditional waveforms, this waveform first activates the particles before erasing them, thus reducing voltage polarity changes. Additionally, it introduces a specific duration of 0 V voltage during the activation phase based on the physical characteristics of the electrophoretic particles to reduce the voltage span. Finally, a particular duration of 0 V voltage is introduced during the erasure phase to minimize the voltage span while ensuring the stability and consistency of the reference gray scale. The experimental results demonstrate that, in standard power tests, the new driving waveform reduces the power fluctuation value by 1.33% and the energy fluctuation value by 37.24% compared to the traditional driving waveform. This reduction in refresh power also mitigates screen flicker and ghosting phenomena. [ABSTRACT FROM AUTHOR]

Voltage fluctuations are one of the most common problems in low-voltage networks. Very often, these disturbances cause damage to or the incorrect operation of electrical devices. Unfortunately, at present, the monitoring of these disturbances relies on short-term and long-term flicker indicators, which only assess the severity of one of the effects of voltage fluctuations. Another measure of voltage fluctuations that has greater diagnostic potential is voltage fluctuation indices, i.e., the amplitude and rate of voltage fluctuations. One advantage of these indices that has been highlighted in recent years is their potential ability to recreate voltage fluctuations using these indices. This article presents research results that allow for the verification of the potential of voltage fluctuation indices as a method for recreating voltage fluctuations. For verification purposes, various cases of voltage variation recorded in a modern low-voltage network are used. The analysis of the possibility of recreating voltage fluctuations from voltage fluctuation indices presented in this article, in association with previously carried out numerical simulation studies and experimental laboratory studies, constitutes a complementary whole and indicates further directions in voltage fluctuation research in terms of the electromagnetic compatibility of low-frequency conducted disturbances. [ABSTRACT FROM AUTHOR]

Flicker and patterns of stripes in the modern environment can evoke visual illusions, discomfort migraine, and seizures. We measured reading speed while striped and less striped texts were illuminated with LED lights. In Experiment 1, the lights flickered at 60 Hz and 120 Hz compared to 60 kHz (perceived as steady light). In Experiment 2, the lights flickered at 60 Hz or 600 Hz (at which frequency the phantom array is most visible), and were compared to continuous light. Two types of text were used: one containing words with high horizontal autocorrelation (striped) and another containing words with low autocorrelation (less striped). We measured the number of illusions participants saw in the Pattern Glare (PG) Test. Overall, reading speed was slowest during the 60 Hz and 600 Hz flicker and was slower when reading the high autocorrelation text. Interestingly, the low PG group showed greater effects of flicker on reading speed than the high PG group, which tended to be slower overall. In addition, reading speed in the high PG group was reduced when the autocorrelation of the text was high. These findings suggest that uncomfortable visual environments reduce reading efficiency, the more so in individuals who are visually sensitive. [ABSTRACT FROM AUTHOR]

Many distribution system operators are installing PQ monitoring systems in their medium-voltage networks. Installation of PQ monitors in all the nodes of the network is uneconomical, and power quality monitors are rather expensive. Therefore, the optimal placement of PQ monitors has to be found, while minimising cost and maximising observability. Researches published so far have presented PQ placement algorithms, but only from the aspect of one PQ disturbance (either dips or harmonics). In this paper, an algorithm for PQ monitor placement is presented, and its novelty is that it is the first research work accounting for several key PQ disturbances at once: harmonics, flicker, unbalance and dips. The chosen PQ disturbances are also modelled using novel modelling techniques, with the PQ disturbance behaviour modelled for a longer time period of one week or month. PQ disturbance behaviour is modelled for a real study case, where known real network topology, customer structure and measurements are used to develop a model validated by PQ measurements. Obtained synthetic PQ data, which are validated by PQ measurements, are used to optimise the PQ monitor locations. To choose the optimal PQ monitor locations, multiple linear regression was used, with the coefficient of determination R2 being the selection criterion. The results show that only two PQ monitors are necessary to monitor the analysed large real medium-voltage distribution grid, with high confidence. The methodology is straightforward and relatively easy to apply, and can be implemented for other medium-voltage distribution networks. [ABSTRACT FROM AUTHOR]

We develop the positive dielectric liquid crystals for flicker free that saves the power consumption and improves the image quality. The dielectric constant was optimized for a low flexoelectric effect and flicker is advanced by adding the LC component which reduces the luminance difference between frames. We confirmed that the a‐Si TFT LCD Panel incorporating the developed LC operates without flicker at the driving frequency of 40Hz. [ABSTRACT FROM AUTHOR]

The FRC algorithm is a commonly employed technique in LCD displays, aimed at enhancing the data bit depth through pixel dithering. However, it can also give rise to certain display issues such as noise, scrolling stripes, and flickering [1]. To address these problems comprehensively, this paper conducts an analysis from both temporal and spatial dimensions. It reveals that screen noise is closely associated with the uniformity of pixel data distribution throughout the entire FRC cycle time, while rolling stripes are linked to the spatial distribution of pixel data in both row and column directions. Furthermore, flickering arises due to variations in the number of FRC pattern pixels actually displayed per frame. The validity of these theories has been verified on an FPGA platform. [ABSTRACT FROM AUTHOR]

With his behaviour, Object – the main character in Samuel Beckett’s Film (1965) – aims to escape from everybody else's gaze, and even from his own, according to George Berkeley's core idea "to be is to be perceived". This guiding thread will show us how perceptive substraction implies as much of an escape as an alternative: by substracting visual material, the subject endeavours to stay on the sidelines and to distance himself from what he perceives. With this, he tries to reach a degree zero where he will no lonfer be able to see and/or be seen, and from which he will be able to see and/or be anew. This radical rupture with what is given to perceive is repeated in art trends such as the Structural Film. Its vertiginous flicker of monochromes aims to refresh an exhausted gaze absorbed by the media. This is the way the Benaminian destructive character, known by "the need for fresh air and open space", operates as much in film structuralists as in Object. It is a way to take a breath and start anew.

Current measurement systems based on the IEEE-1159 standard have some limitations and robustness problems under noisy and fast-changing conditions. Besides, applying different methods for each Power Quality Disturbance (PQD) to every window is required but time-consuming and not feasible. Therefore, different kinds of two-stage methods, Detection and Classification (D&C), have been improved in many studies. Then, the required measurement can be performed to define disturbance. For this purpose, a new approach based on features of subcomponents with Machine Learning Algorithms (MLAs) to detect and classify PQDs is proposed. 21-class dataset including single and multiple PQDs under different noisy conditions was prepared randomly. Of this dataset, determined features were extracted and some of these were selected. Then, selected features were trained and tested with some MLAs in a workstation. Results obtained from comparative MLAs and the other classification methods show that the best MLA with related features is Random Forest with 96.97% while LightGBM, k-Nearest Neighbors, and XGBoost 96.85%, 96.73%, and 92.82% accuracy, respectively. Because the selected features, optimized parameters, and the related MLA were obtained by investigating for features provided from the PQDs in the whole parameter space, this approach brings the advantages of high accuracy, low D&C complexity, and computing load. [ABSTRACT FROM AUTHOR]

Alternating current can result in flickering—or pulsing—in the brightness of light emitted by luminaires. Lighting flicker typically occurs in the range of 100 to 140 cycles per second (Hz), which is too fast for visual perception by most organisms. However, evidence indicates that many organisms perceive flicker with non-visual photoreceptors present on the retinas. Exposure to flickering lights at night disrupts the circadian rhythm of organisms, leading to symptoms similar to blue light exposure at night. The traditional method for detecting flickering is with a flickermeter held near a single light. In this paper, we explore the use of high-speed camera data in the collection of temporal profiles for groups of luminaires simultaneously at distances ranging from several meters to several kilometers. Temporal profiles are extracted for individual lighting features and the full scene. The identification of luminaire types is based on their spectral signatures. With the camera data, it is possible to identify flickering and non-flickering lights, to determine the flicker frequency, to calculate percent flicker and the flicker index, and to identify groups of lights whose flickers are synchronized. Both flickering and non-flickering luminaires can be found for LED, metal halide, fluorescent, and compact fluorescent lights. To date, flickering has been detected in all of the incandescent, high-pressure sodium, and low-pressure sodium luminaires that we measured. We found that flicker synchronization is often present for lights installed within a single facility and also for strings of streetlights. We also found that flicker exposure can come from the light reflected off of the earth's surface. Luminaires designed to illuminate large areas often saturate high-speed camera data collection. This saturation can be reduced or eliminated using neutral density filters on the camera. Published experimental data on the impacts of flicker on organisms remains sparse. Many studies have drawn inferences on the impacts of spectral and lighting brightness on organisms without controlling for flicker. Our conclusion is that lighting flicker is a type of light pollution. The use of high-speed camera data makes it easier to include flicker as a variable in studies regarding the impacts of lighting on organisms. [ABSTRACT FROM AUTHOR]

The current method of Vcom adjustment in VR products is to start with the smallest Vcom and increase the voltage with a larger adjustment step while testing the change in flicker value, the flicker value will slowly decrease and when the flicker value starts to get bigger, reduce the adjustment step and adjust the Vcom in the opposite direction until the second flicker gets bigger and meets the specification, then the optimum Vcom will be found (quotes) [1].There are obvious drawbacks to this current approach: 1. Dueto the different optimal Vcom of different modules, the time to find the optimal Vcom is long and not fixed;2. Vcom will drift with time (Vcom Drift), the problem of irregular time will lead to increased risk of Flicker NG. In order to solve the shortcomings of the current Vcom adjustment methods, we introduced the mathematical theory and deduced the Vcom calculation process to establish the deterministic‐Vcom (D‐Vcom) algorithm. After experiments, the DVcom algorithm can effectively reduce the Vcom adjustment time and has the advantage of fixed adjustment time. This is very helpful for the actual production efficiency and optical stability of the products. [ABSTRACT FROM AUTHOR]

The FRC algorithm is a commonly employed technique in LCD displays, aimed at enhancing the data bit depth through pixel dithering. However, it can also give rise to certain display issues such as noise, scrolling stripes, and flickering [1]. To address these problems comprehensively, this paper conducts an analysis from both temporal and spatial dimensions. It reveals that screen noise is closely associated with the uniformity of pixel data distribution throughout the entire FRC cycle time, while rolling stripes are linked to the spatial distribution of pixel data in both row and column directions. Furthermore, flickering arises due to variations in the number of FRC pattern pixels actually displayed per frame. The validity of these theories has been verified on an FPGA platform. [ABSTRACT FROM AUTHOR]

Low refresh rate liquid crystal displays have been proposed to reduce power consumption, which is already the trend. In our early low‐temperature polycrystalline silicon liquid crystal displays, low‐frequency driving caused the screen to flicker. We investigated the flicker mechanism and improvement solutions in this paper. The flicker mechanism is mainly related to thin‐film transistor leakage current, capacitive coupling effect, and cell material property. By adopting some solutions, the flicker of gray level 127 can reach‐60dB in a 20Hz 13.5‐inch 2.8K demo. These results contribute to the development of low‐power consumption displays. [ABSTRACT FROM AUTHOR]

Global energy policies have urged power consumption reductions for electronic devices. However, this is inconsistent with the users' need for enhanced device performance. In this work, converse flexoelectricity is used to reduce power consumption while maintaining the superior display image quality of liquid crystal display (LCD). The first 1 Hz‐refresh‐rate and flicker‐free fringe‐field switching (FFS) LCD for a 13.4‐inch laptop are reported. A noticeable brightness deviation is inevitable when driving voltage polarity is altered during low‐frequency driving, which is caused by the flexoelectric effect and voltage‐holding failure. The nature of the converse flexoelectric contribution of mesogenic systems with the optimum flexoelectric coefficients and molecular polarity, and developed materials based on findings is investigated. The quality of static images and videos at 1‐ and 10 Hz refresh rates, respectively, is maintained, and the measured power consumptions are reduced by 83% and 47% compared to that at a 60 Hz refresh rate, and minimal flicker level is measured by −68 dB. It is believed that this will serve as a new paradigm for energy consumption in electronic devices with superior display performance of FFS LCDs. [ABSTRACT FROM AUTHOR]

Purpose: Visual snow syndrome is a debilitating neurological condition. A comprehensive eye examination may not detect any abnormalities in this condition. Presently the condition is recognized only through the history elicited. Hence, it becomes important to understand the presenting complaints and profile of these patients. A retrospective study at a tertiary eye care center was undertaken to achieve this goal. Methods: Electronic medical records of patients presenting to a Binocular Vision and Orthoptics clinic were reviewed. Records of the patients containing keywords such as “light sensitivity, shadowing, visual snow, multiple images, and night vision” were retrieved and inspected. Those matching the diagnostic criteria of visual snow syndrome were included in the study. Results: A total of 33 patients (average age ± standard deviation: 29.7 ± 9.8 years) were identified. Majority of the patients were males (69%). All the patients had logMAR visual acuity 0 or better in each eye. The most prominent (84.4%) presenting symptom was palinopsia (or afterimage or trailing). About 34.4% complained of floaters (including snow-like appearance). More than half (54.6%) of the patients also had binocular dysfunction. Conclusion: Visual snow syndrome is a relatively new condition on the rise, with unclear pathology. The symptoms of this condition can easily be confused with regular floaters or black spots seen in vitreous and retinal pathologies. In the absence of such pathology, an elaborate history should be elicited, and the distress of the patient should be acknowledged. The patient should also be reassured that this is not a blinding condition.

Purpose: Visual snow syndrome is a debilitating neurological condition. A comprehensive eye examination may not detect any abnormalities in this condition. Presently the condition is recognized only through the history elicited. Hence, it becomes important to understand the presenting complaints and profile of these patients. A retrospective study at a tertiary eye care center was undertaken to achieve this goal. Methods: Electronic medical records of patients presenting to a Binocular Vision and Orthoptics clinic were reviewed. Records of the patients containing keywords such as "light sensitivity, shadowing, visual snow, multiple images, and night vision" were retrieved and inspected. Those matching the diagnostic criteria of visual snow syndrome were included in the study. Results: A total of 33 patients (average age ± standard deviation: 29.7 ± 9.8 years) were identified. Majority of the patients were males (69%). All the patients had logMAR visual acuity 0 or better in each eye. The most prominent (84.4%) presenting symptom was palinopsia (or afterimage or trailing). About 34.4% complained of floaters (including snow-like appearance). More than half (54.6%) of the patients also had binocular dysfunction. Conclusion: Visual snow syndrome is a relatively new condition on the rise, with unclear pathology. The symptoms of this condition can easily be confused with regular floaters or black spots seen in vitreous and retinal pathologies. In the absence of such pathology, an elaborate history should be elicited, and the distress of the patient should be acknowledged. The patient should also be reassured that this is not a blinding condition. [ABSTRACT FROM AUTHOR]

This paper investigates how the integration of wind farms into traditional electrical grids impacts energy quality, focusing on phenomena such as flicker and voltage dips. The analysis is guided by the IEC 61400-21-1:2019 standards, which provide a methodology for assessing the short-term and long-term impact of wind energy. The results indicate significant variations in energy quality generated by the power fluctuations of wind turbines. The study highlights the necessity of implementing advanced technical solutions to minimize these disturbances, including optimizing turbine control, using power compensation devices, and adapting network infrastructure. Additionally, the crucial role of emerging technologies, such as smart grids and energy storage systems, in improving energy quality is discussed. The importance of continuous training for engineers and network planners is emphasized to effectively address the challenges posed by renewable sources. In conclusion, the sustainable integration of wind energy requires periodic reassessments and adaptations of network management strategies to ensure stability and efficiency in the context of an evolving energy system. [ABSTRACT FROM AUTHOR]

Temporal light modulation (TLM) describes variations in light output from a light source or lighting system and can be a characteristic of their normal operation. TLM at 100 or 120 Hz can disrupt eye movements and reduce visual performance compared to 40 kHz, but little is known of the effects between those frequencies. Such evidence could provide the basis for lighting product and application standards to support the development of energy-efficient lighting systems. This repeated-measures experiment compared the effects of three stimuli (no TLM [DC], 100 Hz, and 500 Hz [both rectangular-wave, 100% modulation depth, 50% duty cycle]) on state anxiety, eye movements (blinks, saccades, fixations, and pupil size), cognitive performance (Stroop task and sentence reading speed), and visual event-related potentials (ERPs). Post-processing of EEG data included dipole source analysis and estimates of source dipole strength. TLM at 100 Hz was associated with larger pupil sizes and greater ERP dipole strength during 100 Hz exposure than no TLM, particularly in the right hemisphere. Cognitive interference was lower for 500 Hz TLM than 100 Hz. State anxiety was unaffected. The addition of TLM to the light source signal increased arousal and altered brain activity; at the highest frequency tested here this reduced cognitive interference. Arousal theory and stochastic facilitation can provide possible explanations. [ABSTRACT FROM AUTHOR]

Voltage flickers and harmonics are power quality (PQ) problems in the electric system during a variation and arc furnace (AF) adaptability. AF creations must determine a harmonic and flicker. This article evaluates complex AF systems. This article presents a newly established time domain (TD) static become to on an AF's V-I attributes (VIA). Static arc configurations are useful for harmonic analyses, but dynamic methods are needed for PQ studies, especially voltage flicker analysis. The MATLABbased dynamic AF configuration is simulated for four different configurations. A response with configurations 1 and 4 varies from the real AF outcomes. The simulation results and numerical finding shows that configurations 2 and 3 are much more appropriate and produce better results for minimum 3rd harmonics for arc current, arc voltage, and point of common coupling (PCC) voltage. The novelty of this configuration is that the energy transferred to the load by the AF during the cycle of operation has been identified, making the developed scheme more reliable and dependent on the load's operational conditions. After that, effective applications of these configurations and other configurations' accuracy should be clarified. [ABSTRACT FROM AUTHOR]

This paper proposes a novel pixel circuit and driving scheme that adopts low-temperature polycrystalline silicon and oxide thin-film transistors (LTPO TFTs) for mobile devices using active-matrix organic light-emitting diode (AMOLED) displays. The proposed pixel circuit and driving scheme provide uniform luminance and render flicker invisible at variable refresh rates (VRRs) from 1 to 120 Hz. Using the proposed pixel circuit with extended compensation time (tCOMP) improves the luminance uniformity at a high-frame rate. The proposed driving scheme applies a voltage to the driving TFTs (D-TFTs) higher than the programmed data voltage during the skip frame. This reduces the flicker caused by the hysteresis of D-TFTs during low-frame rate driving. A 6.0-inch quad high-definition (QHD) LTPO-based AMOLED display was fabricated using the new pixel circuit and driving scheme. Experimental results of the proposed pixel circuit show that the standard deviation of luminance was reduced from 0.056 to 0.008 by extending tCOMP from 2 to 8 µs. The flicker level was −51 dB, so there was no visual artifact during 1 Hz driving. A flicker-free LTPO-based AMOLED display with low power consumption is possible; driving can proceed in 1–120 Hz range. [ABSTRACT FROM AUTHOR]

This paper proposes a novel pixel circuit and driving scheme that adopts low-temperature polycrystalline silicon and oxide thin-film transistors (LTPO TFTs) for mobile devices using active-matrix organic light-emitting diode (AMOLED) displays. The proposed pixel circuit and driving scheme provide uniform luminance and render flicker invisible at variable refresh rates (VRRs) from 1 to 120 Hz. Using the proposed pixel circuit with extended compensation time (tCOMP) improves the luminance uniformity at a high-frame rate. The proposed driving scheme applies a voltage to the driving TFTs (D-TFTs) higher than the programmed data voltage during the skip frame. This reduces the flicker caused by the hysteresis of D-TFTs during low-frame rate driving. A 6.0-inch quad high-definition (QHD) LTPO-based AMOLED display was fabricated using the new pixel circuit and driving scheme. Experimental results of the proposed pixel circuit show that the standard deviation of luminance was reduced from 0.056 to 0.008 by extending tCOMP from 2 to 8 µs. The flicker level was −51 dB, so there was no visual artifact during 1 Hz driving. A flicker-free LTPO-based AMOLED display with low power consumption is possible; driving can proceed in 1–120 Hz range.

We investigated the impact of micro‐LED backplane structures on the light leakage by optical simulation. A transparent micro‐LED display with low light leakage, high transparency, and low reflectivity can be achieved by using metal layers and black materials with specific structures on the transparent backplane. [ABSTRACT FROM AUTHOR]

For LCD low‐frequency display products, study the influence of factors such as Ioff, frequency, and capacitance on grayscale Flicker, to meet the specification of low‐frequency products display quality. [ABSTRACT FROM AUTHOR]

To address the high power consumption associated with image refresh operations in EPDs, this paper proposes a low-power driving waveform that reduces the refresh power of EPDs by lowering the system’s peak power. Compared to traditional waveforms, this waveform first activates the particles before erasing them, thus reducing voltage polarity changes. Additionally, it introduces a specific duration of 0 V voltage during the activation phase based on the physical characteristics of the electrophoretic particles to reduce the voltage span. Finally, a particular duration of 0 V voltage is introduced during the erasure phase to minimize the voltage span while ensuring the stability and consistency of the reference gray scale. The experimental results demonstrate that, in standard power tests, the new driving waveform reduces the power fluctuation value by 1.33% and the energy fluctuation value by 37.24% compared to the traditional driving waveform. This reduction in refresh power also mitigates screen flicker and ghosting phenomena.

This article proposes several solutions for the use of novel AC voltage regulators as electrical energy quality conditioners and for the use of a half-bridge voltage inverter circuit as an active filter. This study was carried out with a real object, and more attention was paid to it. Structural models of electrical energy quality assurance systems, the calculation of control system elements and experimental results are presented. In particular, the use of a half-bridge voltage inverter circuit was considered as a replacement for the passive filter of the battery charger and rectifier device. AC voltage regulators are also used as compensators for higher-current harmonics, namely active filters and reactive power, voltage drop, voltage unbalance and flicker effect compensators. Block diagrams of power quality conditioners are presented, control algorithms are developed and the results of the current high-frequency harmonics compensation, reactive power and signal balancing are presented. The results of an active filter experiment based on the NRT 160.220 charge-rectifier device circuit showed a reduction in ripple of up to 1% with smaller dimensions compared to a passive filter. The control characteristics and external characteristics of the regulators are removed. The dependences of the current THD factor and the power factor are presented depending on the modulation depth for AC voltage regulator circuits used as power quality conditioners. [ABSTRACT FROM AUTHOR]

Alternating current can result in flickering—or pulsing—in the brightness of light emitted by luminaires. Lighting flicker typically occurs in the range of 100 to 140 cycles per second (Hz), which is too fast for visual perception by most organisms. However, evidence indicates that many organisms perceive flicker with non-visual photoreceptors present on the retinas. Exposure to flickering lights at night disrupts the circadian rhythm of organisms, leading to symptoms similar to blue light exposure at night. The traditional method for detecting flickering is with a flickermeter held near a single light. In this paper, we explore the use of high-speed camera data in the collection of temporal profiles for groups of luminaires simultaneously at distances ranging from several meters to several kilometers. Temporal profiles are extracted for individual lighting features and the full scene. The identification of luminaire types is based on their spectral signatures. With the camera data, it is possible to identify flickering and non-flickering lights, to determine the flicker frequency, to calculate percent flicker and the flicker index, and to identify groups of lights whose flickers are synchronized. Both flickering and non-flickering luminaires can be found for LED, metal halide, fluorescent, and compact fluorescent lights. To date, flickering has been detected in all of the incandescent, high-pressure sodium, and low-pressure sodium luminaires that we measured. We found that flicker synchronization is often present for lights installed within a single facility and also for strings of streetlights. We also found that flicker exposure can come from the light reflected off of the earth’s surface. Luminaires designed to illuminate large areas often saturate high-speed camera data collection. This saturation can be reduced or eliminated using neutral density filters on the camera. Published experimental data on the impacts of flicker on organisms remains sparse. Many studies have drawn inferences on the impacts of spectral and lighting brightness on organisms without controlling for flicker. Our conclusion is that lighting flicker is a type of light pollution. The use of high-speed camera data makes it easier to include flicker as a variable in studies regarding the impacts of lighting on organisms.

The present study aims to connect the psychophysical research on the human visual perception of flicker with the neurophysiological research on steady-state visual evoked potentials (SSVEPs) in the context of their application needs and current technological developments. In four experiments, we investigated whether a temporal contrast sensitivity model could be established based on the electrophysiological responses to repetitive visual stimulation and, if so, how this model compares to the psychophysical models of flicker visibility. We used data from 62 observers viewing periodic flicker at a range of frequencies and modulation depths sampled around the perceptual visibility thresholds. The resulting temporal contrast sensitivity curve (TCSC) was similar in shape to its psychophysical counterpart, confirming that the human visual system is most sensitive to repetitive visual stimulation at frequencies between 10 and 20 Hz. The electrophysiological TCSC, however, was below the psychophysical TCSC measured in our experiments for lower frequencies (1-50 Hz), crossed it when the frequency was 50 Hz, and stayed above while decreasing at a slower rate for frequencies in the gamma range (40-60 Hz). This finding provides evidence that SSVEPs could be measured even without the conscious perception of flicker, particularly at frequencies above 50 Hz. The cortical and perceptual mechanisms that apply at higher temporal frequencies, however, do not seem to directly translate to lower frequencies. The presence of harmonics, which show better response for many frequencies, suggests non-linear processing in the visual system. These findings are important for the potential applications of SSVEPs in studying, assisting, or augmenting human cognitive and sensorimotor functions. [ABSTRACT FROM AUTHOR]

Interphotoreceptor retinoid-binding protein (IRBP) is an abundant glycoprotein in the subretinal space bound by the photoreceptor (PR) outer segments and the processes of the retinal pigmented epithelium (RPE). IRBP binds retinoids, including 11-cis-retinal and all-trans-retinol. In this study, visual function for demanding visual tasks was assessed in IRBP knock-out (KO) mice. Surprisingly, IRBP KO mice showed no differences in scotopic critical flicker frequency (CFF) compared to wildtype (WT). However, they did have lower photopic CFF than WT. IRBP KO mice had reduced scotopic and photopic acuity and contrast sensitivity compared to WT. IRBP KO mice had a significant reduction in outer nuclear layer (ONL) thickness, PR outer and inner segment, and full retinal thickness (FRT) compared to WT. There were fewer cones in IRBP KO mice. Overall, these results confirm substantial loss of rods and significant loss of cones within 30 days. Absence of IRBP resulted in cone circuit damage, reducing photopic flicker, contrast sensitivity, and spatial frequency sensitivity. The c-wave was reduced and accelerated in response to bright steps of light. This result also suggests altered retinal pigment epithelium activity. There appears to be a compensatory mechanism such as higher synaptic gain between PRs and bipolar cells since the loss of the b-wave did not linearly follow the loss of rods, or the a-wave. Scotopic CFF is normal despite thinning of ONL and reduced scotopic electroretinogram (ERG) in IRBP KO mice, suggesting either a redundancy or plasticity in circuits detecting (encoding) scotopic flicker at threshold even with substantial rod loss. [ABSTRACT FROM AUTHOR]

Here, we demonstrate world's first 1 Hz driving fringe‐field switching (FFS) LCD via development of low flexoelectric coefficient LCs with high voltage holding ratio (VHR). The evaluation of the 1 Hz driving 13.4‐inch FFS LCD laptop panel shows no flicker, and the power consumption is reduced by 83% compared to the 60 Hz driving. We believe this result opens a new chapter of FFS LCDs for low‐power consumption. [ABSTRACT FROM AUTHOR]

The flickering of low‐temperature polycrystalline silicon and metal‐oxide (LTPO) active‐matrix organic light‐emitting diode (AMOLED) display under low‐refresh‐rate driving condition can be detected even though there is no critical leakage current path from the storage capacitor. The flickering is mainly due to the brightness increase during data holding period. The effective channel length of driving thin‐film transistor (DTFT) would be reduced by electron trapping into the gate insulator of DTFT which operates under saturation mode. This study presents not only the physical model of electron trapping but also a novel driving method to release the trapped electrons. The experimental results show that that the brightness variation can be reduced from 3.7 % to 1.4 % at the 63rd gray level by the novel driving method. [ABSTRACT FROM AUTHOR]

Time-varying nature of wind farms is one of their major obstacles in providing a constant and reliable power output. They can be considered as a time-varying source of power considering different timeframes, from long to extremely short time periods. The focus of this study is modeling the wind farms for power quality studies by focusing on voltage flicker caused by the extremely fast wind farm output power variations. Despite there being several models developed for modeling the variations over longer time periods, there are few models that consider the extremely short time power variation, i.e., those in the range of 5–15 milliseconds. Our research started with the acquisition of a large data set of actual instantaneous voltage and current signals, recorded at a wind farm under different weather and operating conditions. The data set is utilized to develop practical models for the individual wind turbines and for the whole wind farm suitable for the mentioned extremely short time variations for the case of wind farms with the wound rotor induction generators (WRIG). The proposed model can be used for voltage flicker studies in power systems with WRIGs. The equivalent model of the WRIG is represented by a current source which its magnitude and phase change every half-cycle. It is observed that the variations of active and reactive powers follow a non-stationary seasonal time series where the seasonal part is not a simple single frequency. The seasonal term contains several frequencies which are modeled by 10 frequency components between 0.1 Hz to 1 Hz plus a DC component. The remaining component is modeled by autoregressive moving average (ARMA) models. The accuracy of the proposed equivalent model is assessed by several tests based on actual data and their corresponding simulated time series.

Individuals with migraine tend to experience discomfort when viewing flickering stimuli. It has been suggested that one of the characteristics of migraine is a lack of habituation to repetitive visual stimuli, although findings can be mixed. Previous work has typically used similar visual stimuli (chequerboard) and only one temporal frequency. This study systematically varied the spatial and temporal characteristics of the visual stimulus, using steady‐state visual evoked potentials to assess the differences in amplitude between migraine and control group over consecutive blocks of stimulation. Twenty individuals with migraine and 18 control observers were asked to rate their visual discomfort after viewing sequences of flickering Gabor patches with a frequency of either 3 or 9 Hz across three different spatial frequencies (low 0.5 cpd; mid‐range 3 cpd; high 12 cpd). Compared to the control group, the migraine group showed a reduction in SSVEP responses with increased exposure, suggesting habituation processes are intact at 3‐Hz stimulation. However, at 9‐Hz stimulation, there was evidence of increased responses with increasing exposure in the migraine group in particular, which might suggest a build‐up of the response over repetitive presentations. Visual discomfort varied with spatial frequency, for both 3‐ and 9‐Hz stimuli, the highest spatial frequencies were the least uncomfortable compared to the low‐ and mid‐range spatial frequencies in both groups. This difference in SSVEP response behaviour, dependent on temporal frequency, is important to consider when researching the effects of repetitive visual stimulation in migraine and could give some indication of build‐up of effects leading to aversion to visual stimuli. [ABSTRACT FROM AUTHOR]

Realize 20~240Hz wide refresh rate display on 16.0 WUXGA Oxide platform, while meeting intel LPDT4.0 test standard, adding dynamic VCOM solution to optimize low frequency flicker. The experimental countermeasures are mainly to verify different panel parameters, dynamic VCOM, and different K‐value LCDs, which have been tested pass on the 16.0 WU platform. [ABSTRACT FROM AUTHOR]

This paper studies the influence of dimming frequency of Organic Light‐Emitting Diode (OLED) smartphone displays on the viewer's visual fatigue. Results show that, after a short period of viewing (about 35min) in the dark environment, no statistically significant difference occurs in the effect of tested dimming frequencies, ranging from 360Hz to 1920Hz together with a direct‐current mode, on neither subjective ratings nor objective measurements of visual fatigue. [ABSTRACT FROM AUTHOR]

This paper study the impact of pixel voltage leakage and liquid crystal flexoelectric effect on flicker with simulation and measurement method. The impact rule of pixel architecture, TFT voltage, electrode design, liquid crystal material, driving signal and other factors is obtained, and the key factors under different conditions are identified. The pixel design and liquid crystal scheme under different conditions are proposed, and a strategy of data voltage modulation at the blanking stage combined with frequency‐wise ACC brightness compensation is established to reduce flicker. Based on the proposed complete flicker optimization strategy, flicker lower than ‐50dB is achieved on 55/65/75 inch 4K gaming products when switching back and forth at 48/120Hz every 200ms, meeting the G‐Sync flicker standard. [ABSTRACT FROM AUTHOR]

We proposed a novel 6T1C pixel circuit as well as its driving scheme based on amorphous InGaZnO thin‐film transistors (a‐IGZO TFTs) for micro‐LED displays. Compared with the conventional 7T1C pixel circuit, the new design not only simplified the circuit structure but also exhibited apparently better threshold voltage compensation effect as well as much lower flicker value. [ABSTRACT FROM AUTHOR]

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Human primary visual cortex (V1) responds more strongly, or resonates, when exposed to ∼10, ∼15–20, and ∼40–50 Hz rhythmic flickering light. Full-field flicker also evokes the perception of hallucinatory geometric patterns, which mathematical models explain as standing-wave formations emerging from periodic forcing at resonant frequencies of the simulated neural network. However, empirical evidence for such flicker-induced standing waves in the visual cortex was missing. We recorded cortical responses to flicker in awake mice using high-spatial-resolution widefield imaging in combination with high-temporal-resolution glutamate-sensing fluorescent reporter (iGluSnFR). The temporal frequency tuning curves in the mouse V1 were similar to those observed in humans, showing a banded structure with multiple resonance peaks (8, 15, and 33 Hz). Spatially, all flicker frequencies evoked responses in V1 corresponding to retinotopic stimulus location, but some evoked additional peaks. These flicker-induced cortical patterns displayed standing-wave characteristics and matched linear wave equation solutions in an area restricted to the visual cortex. Taken together, the interaction of periodic traveling waves with cortical area boundaries leads to spatiotemporal activity patterns that may affect perception. [Display omitted] • Widefield imaging of spatiotemporal responses to visual flicker in iGluSnFR mice • Mouse V1—just like human—resonates in response to specific flicker frequencies • Flicker-induced cortical patterns form standing waves confined to the visual cortex • These patterns correspond to standing-wave solutions of the linear wave equation Gulbinaite et al. report that a flickering spotlight evokes both retinotopic and non-retinotopic responses in the mouse visual cortex. They demonstrate that these flicker-induced cortical patterns are standing waves, resembling the eigenmodes of a nearly circular vibrating membrane, with spatial scale varying by temporal flicker frequency. [ABSTRACT FROM AUTHOR]

Background: Visual phenomena like brightness illusions impressively demonstrate the highly constructive nature of perception. In addition to physical illumination, the subjective experience of brightness is related to temporal neural dynamics in visual cortex. Objective: Here, we asked whether biasing the temporal pattern of neural excitability in visual cortex by transcranial alternating current stimulation (tACS) modulates brightness perception of concurrent rhythmic visual stimuli. Methods: Participants performed a brightness discrimination task of two flickering lights, one of which was targeted by same-frequency electrical stimulation at varying phase shifts. tACS was applied with an occipital and a periorbital active control montage, based on simulations of electrical currents using finite element head models. Results: Experimental results reveal that flicker brightness perception is modulated dependent on the phase shift between sensory and electrical stimulation, solely under occipital tACS. Phase-specific modulatory effects by tACS were dependent on flicker-evoked neural phase stability at the tACS-targeted frequency, recorded prior to electrical stimulation. Further, the optimal timing of tACS application leading to enhanced brightness perception was correlated with the neural phase delay of the cortical flicker response. Conclusions: Our results corroborate the role of temporally coordinated neural activity in visual cortex for brightness perception of rhythmic visual input in humans. Phase-specific behavioral modulations by tACS emphasize its efficacy to transfer perceptually relevant temporal information to the cortex. These findings provide an important step towards understanding the basis of visual perception and further confirm electrical stimulation as a tool for advancing controlled modulations of neural activity and related behavior.

The brightness of low-temperature polycrystalline silicon and metal-oxide (LTPO) active-matrix organic light-emitting diode (AMOLED) display under low-refresh-rate driving condition tends to increase during pixel voltage holding time of each frame even though there is no critical leakage current path from the storage capacitor. We have found that the main cause of the brightness increase is electron trapping into the gate insulator of driving thin-film transistor (DTFT) which operates in the saturation mode prone to hot carrier injection. We propose a novel driving method to suppress the brightness variation by applying a high voltage to the source and drain of the DTFT during the non-emitting time which is inserted periodically for dimming the organic light-emitting diode (OLED) display. Our experimental results show that the brightness variation can be reduced from 3.7 % to 1.4 % at the 63rd gray level by the proposed DTFT reset scheme.

THE PURPOSE. To consider issues related to the study of methods for determining the sources of violations of the quality of electrical energy in power supply systems, in particular consumers which create rapid voltage changes or voltage fluctuations that create rapid changes in the luminous flux in electric lighting installations. Show that electrical receivers with a sharply variable operating mode are sources of fluctuations in the consumed current and voltage in the electrical network of power supply systems, which in turn manifests itself in the form of unacceptable values of one of the indicators of the quality of electricity - flicker, defined as the subjective perception of fluctuations in the luminous flux of lighting devices. To study the possibilities of determining the places of occurrence of significant voltage fluctuations without the use of expensive and complex instruments for measuring flicker values in the electrical network. To develop a simplified method for determining the locations of electricity consumers that negatively affect the operation of electric lighting systems and, ultimately, the vision of personnel. Conduct a check on a computer model of a simplified method for determining the places of occurrence of voltage fluctuations that are inadmissible in their magnitude, which are expressed in the appearance of significant doses of flicker that exceed the standard values.METHODS. Solving the problem, a computer model was used, created in the Simulink extension package of the Matlab scientific and technical calculation system.RESULTS. The article describes the relevance of the problem, discusses the quality of electricity in power supply systems. It has been shown using experimental data that in electrical networks there is an excess of the standard values of flicker doses. The possibility of using interharmonic components of the mains voltage to determine the sources of unacceptable doses of flicker is considered. A simplified method for finding flicker sources based on obtaining the values of the derivatives of currents at various points of the electrical network is presented. Computer simulation of an electrical network diagram with electrical receivers, which have both calm and sharply variable nature of work, has been performed. It is shown that the use of the values of the derivatives of the current at various points of the electrical network makes it possible to identify the sources of the occurrence of unacceptable doses of flicker.CONCLUSION. The occurrence of significant rapid voltage changes in the electrical network negatively affects vision, which is inevitably accompanied by increased personnel fatigue and can lead to industrial injuries. The results obtained by the authors of the article show that it is possible to use it to determine the places of occurrence of large voltage fluctuations, which are manifested in unacceptable doses of flicker of the derivatives of currents. It should be taken into account when conducting surveys of power supply systems in order to use fairly simple hardware to identify sources of disturbance in the quality of electrical energy.

Harmonics, inter-harmonics, and low-frequency (below the fundamental frequency) components produced by nonlinear loads and renewables may cause undesired effects on electric power equipment including overheating, resonance, and voltage flickers. This paper presents a hybrid method for the detection of frequency components of the measured waveform that is nonstationary (time-varying) in a holistic manner. In the proposed method, the multi-syncrosqueezing transform (MSST) is firstly applied to determine time-frequency ridges for the low-frequency, fundamental, harmonic, and interharmonic components. Next, the algorithm of density-based spatial clustering of applications with noise (DBSCAN) is adopted to precisely identify the prominent frequency components (i.e., intrinsic modes) using the MSST results. The time-domain waveforms corresponding to each detected frequency component and the original signal are then reconstructed via the inverse operation of MSST to assess the rms, and total harmonic and interharmonic distortion (THD and ITHD) trends of the recovered waveforms. The proposed method is validated by simulations and actual measurements to show its usefulness. Results are also compared with different time-frequency analysis methods to show the superiority of the proposed method. [ABSTRACT FROM AUTHOR]