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Journal articles on the topic 'HVS masking'
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Bhateja, Vikrant, Mukul Misra, and Shabana Urooj. "Unsharp masking approaches for HVS based enhancement of mammographic masses: A comparative evaluation." Future Generation Computer Systems 82 (May 2018): 176–89. http://dx.doi.org/10.1016/j.future.2017.12.006.
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Zhu, Yu Hua. "Design of a Digital Watermarking Scheme Based on Logistic Mapping." Advanced Materials Research 271-273 (July 2011): 1334–38. http://dx.doi.org/10.4028/www.scientific.net/amr.271-273.1334.
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A chaotic digital watermarking scheme based on logistic mapping was introduced. In the frequency domain, the chaos sequence embedded in DC component DC through using discrete cosine transform (DCT). Being of human visual system(HVS) masking properties, the watermarking adapt itself into the image, which ensure the watermark is invisible.
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Zhu, Yu Hua. "Test of a Digital Watermarking Scheme Based on Logistic Mapping." Advanced Materials Research 271-273 (July 2011): 1339–42. http://dx.doi.org/10.4028/www.scientific.net/amr.271-273.1339.
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A chaotic digital watermarking scheme based on logistic mapping is tested by experiments. Being of human visual system(HVS) masking properties, the watermarking adapt itself into the image, which ensure the watermark is invisible. Experimental results show that the proposed algorithm has good robustness for the common signal distortion (adding salt & pepper noise, median filtering, etc.) and geometric distortion (lossy compression, shear, etc).
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Liu, Xing Yu, Mei Yu, Tao Tian, and Chao Zheng Hu. "New just-Noticeable-Distortion Model Based on the Depth Information and its Application in Multiview Video Coding." Applied Mechanics and Materials 423-426 (September 2013): 2512–17. http://dx.doi.org/10.4028/www.scientific.net/amm.423-426.2512.
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To reach higher compression ratios without perceptually degrading the reconstructed signal, the properties of the human visual system (HVS) need to be better exploited. Research simulated the sensitivity of HVS with the just-noticeable-distortion (JND) model, which describes the perception redundancy quantitatively. This paper proposed a new JND model in multiview video coding (MVC) which explored the property of HVS to stereoscopic masking effect. The proposed model contained the spatial JND, temporal JND and the JND in depth. A novel asymmetric stereoscopic video coding method was proposed based on the new JND model. For each macroblock (MB), the quantization parameters (QPs) were optimized adaptively based on the new JND. Compared with the original JMVC scheme without JND, our method gets remain perceptual quality and save bits averagely 24.18%~36.24%.
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HE, LIHUO, WEN LU, XINBO GAO, DACHENG TAO, and XUELONG LI. "A NOVEL METRIC BASED ON MCA FOR IMAGE QUALITY." International Journal of Wavelets, Multiresolution and Information Processing 09, no. 05 (September 2011): 743–57. http://dx.doi.org/10.1142/s0219691311004298.
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Considering that the Human Visual System (HVS) has different perceptual characteristics for different morphological components, a novel image quality metric is proposed by incorporating Morphological Component Analysis (MCA) and HVS, which is capable of assessing the image with different kinds of distortion. Firstly, reference and distorted images are decomposed into linearly combined texture and cartoon components by MCA respectively. Then these components are turned into perceptual features by Just Noticeable Difference (JND) which integrates masking features, luminance adaptation and Contrast Sensitive Function (CSF). Finally, the discrimination between reference and distorted images perceptual features is quantified using a pooling strategy before the final image quality is obtained. Experimental results demonstrate that the performance of the proposed prevails over some existing methods on LIVE database II.
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Niu, Yaqing, Sridhar Krishnan, and Qin Zhang. "Spatio-Temporal Just Noticeable Distortion Model Guided Video Watermarking." International Journal of Digital Crime and Forensics 2, no. 4 (October 2010): 16–36. http://dx.doi.org/10.4018/jdcf.2010100102.
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Perceptual Watermarking should take full advantage of the results from human visual system (HVS) studies. Just noticeable distortion (JND), which refers to the maximum distortion that the HVS does not perceive, gives a way to model the HVS accurately. An effective Spatio-Temporal JND model guided video watermarking scheme in DCT domain is proposed in this paper. The watermarking scheme is based on the design of an additional accurate JND visual model which incorporates spatial Contrast Sensitivity Function (CSF), temporal modulation factor, retinal velocity, luminance adaptation and contrast masking. The proposed watermarking scheme, where the JND model is fully used to determine scene-adaptive upper bounds on watermark insertion, allows providing the maximum strength transparent watermark. Experimental results confirm the improved performance of the Spatio-Temporal JND model. The authors’ Spatio-Temporal JND model is capable of yielding higher injected-watermark energy without introducing noticeable distortion to the original video sequences and outperforms the relevant existing visual models. Simulation results show that the proposed Spatio-Temporal JND model guided video watermarking scheme is more robust than other algorithms based on the relevant existing perceptual models while retaining the watermark transparency.
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Escalante-Ramírez, Boris, and S. L. Gomez-Coronel. "A Perceptive Approach to Digital Image Watermarking Using a Brightness Model and the Hermite Transform." Mathematical Problems in Engineering 2018 (2018): 1–19. http://dx.doi.org/10.1155/2018/5463632.
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This work presents a watermarking technique in digital images using a brightness model and the Hermite Transform (HT). The HT is an image representation model that incorporates important properties of the Human Vision System (HVS), such as the analysis of local orientation, and the model of Gaussian derivatives of early vision. The proposed watermarking scheme is based on a perceptive model that takes advantage of the masking characteristics of the HVS, thus allowing the generation of a watermark that cannot be detected by a human observer. The mask is constructed using a brightness model that exploits the limited sensibility of the human visual system for noise detection in areas of high or low brightness. Experimental results show the imperceptibility of the watermark and the fact that the proposed algorithm is robust to most common processing attacks. For the case of geometric distortions, an image normalization stage is carried out prior to the watermarking.
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Paunwala, Mita, and S. Patnaik. "DCT Watermarking Approach for Security Enhancement of Multimodal System." ISRN Signal Processing 2012 (December 18, 2012): 1–11. http://dx.doi.org/10.5402/2012/781940.
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We have addressed a novel watermarking algorithm to support the capacity demanded by the multimodal biometric templates. Proposed technique embeds watermark in low frequency AC coefficients of selected 8 × 8 DCT blocks. Selection of blocks accomplishes perceptual transparency by exploiting the masking effects of human visual system (HVS). Embedding is done by modulating the coefficient magnitude as a function of its estimated value. Neighborhood estimation is used for the weighted DC coefficients from eight neighboring DCT blocks. The weights of the DC coefficients are calculated from local image intrinsic property. For our experimentation we have used iris and finger prints as the two templates which are watermarked into standard test images. The robustness of the proposed algorithm is compared with the few state-of-the-art literature when watermarked image is subjected to common channel attacks.
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Wang, Chunxing, Xiaoyue Han, Wenbo Wan, Jing Li, Jiande Sun, and Meiling Xu. "Visual Saliency Based Just Noticeable Difference Estimation in DWT Domain." Information 9, no. 7 (July 20, 2018): 178. http://dx.doi.org/10.3390/info9070178.
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It has been known that human visual systems (HVSs) can be applied to describe the underlying masking properties for the image processing. In general, HVS can only perceive small changes in a scene when they are greater than the just noticeable distortion (JND) threshold. Recently, the cognitive resources of huma visual attention mechanisms are limited, which can not concentrate on all stimuli. To be specific, only more important stimuli will react from the mechanisms. When it comes to visual attention mechanisms, we need to introduce the visual saliency to model the human perception more accurately. In this paper, we presents a new wavelet-based JND estimation method that takes into account the interrelationship between visual saliency and JND threshold. In the experimental part, we verify it from both subjective and objective aspects. In addition, the experimental results show that extracting the saliency map of the image in the discrete wavelet transform (DWT) domain and then modulating its JND threshold is better than the non-modulated JND effect.
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Shah, Raj, Simon Tung, Rui Chen, and Roger Miller. "Grease Performance Requirements and Future Perspectives for Electric and Hybrid Vehicle Applications." Lubricants 9, no. 4 (April 6, 2021): 40. http://dx.doi.org/10.3390/lubricants9040040.
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Electric vehicle sales are growing globally in response to the move towards a greener environment and a reduction in greenhouse gas emissions. As in any machine, grease lubricants will play a significant role in the component life of these new power plants and drivetrains. In this paper, the role of grease lubrication in electric vehicles (EVs) and hybrid vehicles (HVs) will be discussed in terms of performance requirements. Comparisons of grease lubrication in EVs and HVs for performance requirements to current internal combustion engines (ICEs) will be reviewed to contrast the major differences under different operating conditions. The operating conditions for grease lubrication in these EVs and HVs are demanding. Greases formulated and manufactured to meet specific performance specifications in EVs and HVs, which will operate within these specific electrification components, will be reviewed. Specifically, the thermal and electrified effects from the higher operating temperatures and electromagnetic fields on lubricant degradation, rheology, elastomer compatibility, and corrosion protection of the grease need to be evaluated to accurately meet the performance requirements for EVs and HV. The major differences between EVs and conventional ICEVs can be grouped into the following technical areas: energy efficiency, noise, vibration, and harshness (NVH), the presence of electrical current and electromagnetic fields from electric modules, sensors and circuits, and bearing lubrication. Additional considerations include thermal heat transfer, seals, corrosion protection, and materials’ compatibility. The authors will review the future development trends of EVs/HVs on driveline lubrication and thermal management requirements. The future development of electric vehicles will globally influence the selection and development of gear oils, coolants, and greases as they will be in contact with electric modules, sensors, and circuits and will be affected by electrical current and electromagnetic fields. The increasing presence of electrical parts in EVs/HVs will demand the corrosion protection of bearings and other remaining mechanical components. Thus, it is imperative that specialized greases should be explored for specific applications in EVs/HVs to ensure maximum protection from friction, wear, and corrosion to guarantee the longevity of the operating automobile. Low-viscosity lubricants and greases will be used in EVs to achieve improvements in energy efficiency. However, low-viscosity fluids reduce the film thickness in the driveline application. This reduced film thickness increases the operating temperature and reduces the calculated fatigue life of the bearings. Bearing components for EVs/HVs will be even more crucial as original equipment manufacturers (OEMs) specify these low-viscosity fluids. The application of premium bearing components using low-viscosity grease will leverage materials, bearing geometries, and surface topography to combat the impact of low-viscosity lubricants. In addition, EVs and HVs will create their own NVH challenges. Wind and road noise are more prominent, with no masking noise from the ICE. Increasing comfort, quality, and reliability issues will be more complicated with the introduction of new electrified powertrain and E-driveline subsystems. This paper elaborates on the current development trends and industrial test standard for the specified grease used for electrical/hybrid driveline lubrication.
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Krivenko, Sergey, Vladimir Lukin, Olha Krylova, Liudmyla Kryvenko, and Karen Egiazarian. "A Fast Method of Visually Lossless Compression of Dental Images." Applied Sciences 11, no. 1 (December 25, 2020): 135. http://dx.doi.org/10.3390/app11010135.
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A noniterative approach to the problem of visually lossless compression of dental images is proposed for an image coder based on the discrete cosine transform (DCT) and partition scheme optimization. This approach considers the following peculiarities of the problem. It is necessary to carry out lossy compression of dental images to achieve large compression ratios (CRs). Since dental images are viewed and analyzed by specialists, it is important to preserve useful diagnostic information preventing appearance of any visible artifacts due to lossy compression. At last, dental images may contain noise having complex statistical and spectral properties. In this paper, we have analyzed and utilized dependences of three quality metrics (Peak signal-to-noise ratio, PSNR; eak Signal-to-Noise Ratio using Human Visual System and Masking (PSNR-HVS-M); and feature similarity, FSIM) on the quantization step (QS), which controls a compression ratio for the so-called advanced DCT coder (ADCTC). The threshold values of distortion visibility for these metrics have been considered. Finally, the recent results on detectable changes in noise intensity have been incorporated in the QS setting. A visual comparison of original and compressed images allows to conclude that the introduced distortions are practically undetectable for the proposed approach; meanwhile, the provided CR lies within the interval.
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Inns, Daniel, Patrick Campbell, and Kylie Catchpole. "Wafer Surface Charge Reversal as a Method of Simplifying Nanosphere Lithography for Reactive Ion Etch Texturing of Solar Cells." Advances in OptoElectronics 2007 (July 31, 2007): 1–4. http://dx.doi.org/10.1155/2007/32707.
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A simplified nanosphere lithography process has been developed which allows fast and low-waste maskings of Si surfaces for subsequent reactive ion etching (RIE) texturing. Initially, a positive surface charge is applied to a wafer surface by dipping in a solution of aluminum nitrate. Dipping the positive-coated wafer into a solution of negatively charged silica beads (nanospheres) results in the spheres becoming electrostatically attracted to the wafer surface. These nanospheres form an etch mask for RIE. After RIE texturing, the reflection of the surface is reduced as effectively as any other nanosphere lithography method, while this batch process used for masking is much faster, making it more industrially relevant.
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Mueller, Benjamin Johannes, Mariella Laubengeiger, Noemi Martin, and Philip Leistner. "Creating a sound-designed sound masking signal for open-plan offices that is both pleasant and has a positive impact on cognitive performance." INTER-NOISE and NOISE-CON Congress and Conference Proceedings 263, no. 2 (August 1, 2021): 4471–82. http://dx.doi.org/10.3397/in-2021-2713.
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In open-plan offices, sound masking is often used to lower speech intelligibility and raise cognitive performance of the employees by reducing the irrelevant speech effect. Classic sound masking methods use speakers built into the ceiling of the office to increase the overall background noise level in the office and reduce speech intelligibility. However, the emergence of activity based offices is increasing the need for personalized sound masking methods that are no longer used globally in the office, but can be controlled by each employee individually depending on their activity and, for example, played back through headphones during activities that require particularly intense concentration. The playback of a classical sound-masking noise (e.g. a simple pink noise filtered by -5 dB per octave) via headphones is effective, but not pleasant. For this reason, a new sound-designed masking signal was developed in the present study, which consists of slowly fluctuating binaural harmonic components, as well as atmospheric sounds like water sounds and masking noise. A listening test with a cognitive task and a survey after each test condition showed that the developed signal had a similar positive effect on cognitive performance as a classical masking noise, but was rated as significantly more pleasant.
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Petrosino, Linda, Donald Fucci, Daniel Harris, and Lee Ellis. "Effect of Auditory Masking on Lingual Vibrotactile Thresholds and Magnitude Estimation Scaling Responses." Perceptual and Motor Skills 67, no. 2 (October 1988): 491–94. http://dx.doi.org/10.2466/pms.1988.67.2.491.
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Auditory masking has become a frequently employed part of the procedure used in vibrotactile research. Research investigating the effect of auditory masking on lingual vibrotactile thresholds of sensitivity has shown that there is little difference between lingual vibrotactile thresholds under masking and no masking conditions. The purpose of the present study was to extend the investigation of the effect of auditory masking to include lingual vibrotactile suprathreshold scaling responses. 20 young adult subjects of mean age 19 yr. completed lingual vibrotactile-threshold and magnitude-estimation scaling tasks under conditions of bilateral auditory masking and no masking. Similar lingual vibrotactile-threshold values and magnitude-estimation power-function exponents for the conditions of masking and no masking were noted.
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Kim, Chang Hyo, Chae-Bong Lim, Kyu-Sung Kim, and Hoseok Choi. "Diagnostic Value of Cochlear Hydrops Analysis Masking Procedure in Meniere's Disease." Korean Journal of Otorhinolaryngology-Head and Neck Surgery 52, no. 12 (2009): 956. http://dx.doi.org/10.3342/kjorl-hns.2009.52.12.956.
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Weidner, R., N. J. Shah, and G. R. Fink. "The Neural Basis of Perceptual Hypothesis Generation and Testing." Journal of Cognitive Neuroscience 18, no. 2 (February 1, 2006): 258–66. http://dx.doi.org/10.1162/jocn.2006.18.2.258.
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Four-dot masking is a new form of visual masking that does not involve local contour interactions or spatial superimposition of the target stimulus and the mask (as, e.g., in pattern or metacontrast masking). Rather, the effective masking mechanism is based on object substitution. Object substitution masking occurs when low-level visual information representations are altered before target identification through iterative interaction with high-level visual processing stages has been completed. Interestingly, object substitution interacts with attention processes: Strong masking effects are observed when attentional orientation toward the target location is delayed. In contrast, no masking occurs when attention can be rapidly shifted to and engaged onto the target location. We investigated the neural basis of object substitution masking by studying the interaction of spatial attention and masking processes using functional magnetic resonance imaging. Behavioral data indicated a two-way interaction between the factors Spatial Attention (valid vs. invalid cueing) and Masking (four-dot vs. pattern masking). As expected, spatial attention improved performance more strongly during object substitution masking. Functional correlates of this interaction were found in the primary visual cortex, higher visual areas, and left intraparietal sulcus. A region-of-interest analysis in these areas revealed that the largest blood oxygenation level-dependent signal changes occurred during effective four-dot masking. In contrast, the weakest signal changes in these areas were observed when target visibility was highest. The data suggest that these areas represent an object substitution network dedicated to the generation and testing of a perceptual hypotheses as described by the object substitution theory of masking of Di-Lollo et al. [Competition for consciousness among visual events: The psychophysics of reentrant visual processes. Journal of Experimental Psychology: General, 129, 481–507, 2000].
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Shang, Wei-Min, Fu-Lin Zhang, Jie Zhou, Hui-Xian Meng, and Jing-Ling Chen. "Qubit masking in multipartite qubit system." Modern Physics Letters A 36, no. 21 (July 10, 2021): 2150156. http://dx.doi.org/10.1142/s021773232150156x.
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The no-masking theories show that it is impossible to mask the set of all qubit states into the quantum correlation of bipartite qubit system or tripartite qubit system. In this paper, we give a new proof of the no-masking situation of the tripartite qubit system. Recent work has shown that there exists a universal masker which can mask an arbitrary set of qubit states in four-qubit systems perfectly by means of the maximum entangled states. Here we show that there exist more than one masking scheme even for the same multipartite qubit system. Basing on the maximum entangled states we give the deterministic masking scenario for N-qubit system. In practice, decoherence hinders us from obtaining the maximum entangled states. From this viewpoint, the masking scenario based on non-maximum entangled states becomes more universal. Furthermore, we provide an approximate quantum masking scenario and investigate the relation between approximate masking and quantum entanglement.
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Jansen, Jan. "Masking Sunjata: A Hermeneutical Critique." History in Africa 27 (January 2000): 131–41. http://dx.doi.org/10.2307/3172110.
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Among the rich legacy of African oral traditions, the Sunjata epic is still one of the most complex phenonema, because it undoubtedly goes back to the times of Ibn Battuta, because of the limited variety between the available text editions, and because of its present-day popularity in sub-Saharan West Africa among people of all kinds of social background. In scholarly discussion, the epic has challenged many academics since Delafosse used the Sunjata epic as evidence for his reconstruction of the Mali empire as a thirteenth-century vast centralized polity. Although his views have been criticized since then, they have become part of history lessons at primary schools in Mali, the Gambia, Senegal, and Guinea. All these countries belong to the so-called “Mande,” an area inhabited by various ethnic groups that have close similarities in language, oral tradition, and social organization.In the last decade History in Africa has given room to discuss the Sunjata epic, in particular in order to explore how data from the epic can be used as historical sources, and as what history for whom. Articles by David Conrad, Tim Geysbeek, Stephan Bühnen, Stephen Bulman, Kathryn Green, George Brooks, Ralph Austen, and myself come my mind. All these authors have treated the Sunjata epic as a text. This seems to be a logical and inevitable choice for the historian.However, this approach implies a choice that limits the range of interpretations which can be made about the Sunjata traditions as a source for African history.
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Madhavaraj, Lavanya, Ho-Dong Lim, Kong-Min Kim, Dae-Hyuk Kim, and Gui Hwan Han. "Influence of Sargassum horneri Mitigating Odorous Gas Emissions from Swine Manure Storage Facilities." Sustainability 12, no. 18 (September 15, 2020): 7587. http://dx.doi.org/10.3390/su12187587.
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Manures from livestock industries and farmyards should be managed for land application. Currently, a deep pit or barn system is adopted by many swine farms for manure management, therefore releasing harmful gases and rising the total global emissions of GHGs. This research focuses on the effectiveness of the brown seaweed Sargassum horneri as a masking agent to mitigate odor-generating gaseous pollutants and reduce the emissions of volatile fatty acids (VFAs) from swine manure storage facilities. Using an optimized procedure, we compared the gaseous emissions from two manure storage barns, one containing swine manure masked with S. horneri and the other without masking as a control, over a 30-day period. The results showed that, compared to the control, seaweed masking significantly reduced the sulfide and VFA contents. Furthermore, reductions of 99.48% in H2S, 60 ± 5.21% in NH3 and 74.28 ± 2.14% in gaseous amine emissions were observed within the experimental period. Intriguingly, seaweed masking had beneficial effects, decreasing the total odor content by 97.78 ± 3.15% and increasing the nutrient quality of the manure. S. horneri has great potential as a masking agent in swine manure management to control environmental pollution.
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Naeim, Mahdi, Ali Rezaeisharif, and Aziz Kamran. "COVID-19 Has Made the Elderly Lonelier." Dementia and Geriatric Cognitive Disorders Extra 11, no. 1 (February 16, 2021): 26–28. http://dx.doi.org/10.1159/000514181.
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Loneliness is a major risk factor for the elderly and can double their problems. When COVID-19 started, things became more difficult for the elderly. The news that the elderly are at a higher risk for severe COVID-19 than others made the elderly lonelier. This is a library type study that was conducted over 2 months using valid scientific sources and books. Based on the findings of this study, we believe that focusing on education and reminding people of the necessary dos and don’ts of illness, modifying their diet, emphasizing masking, and even familiarizing the elderly with social media and virtual activities will prevent them from suffering loneliness.
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Kludt, Eugen, Waldo Nogueira, Thomas Lenarz, and Andreas Buechner. "A sound coding strategy based on a temporal masking model for cochlear implants." PLOS ONE 16, no. 1 (January 8, 2021): e0244433. http://dx.doi.org/10.1371/journal.pone.0244433.
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Auditory masking occurs when one sound is perceptually altered by the presence of another sound. Auditory masking in the frequency domain is known as simultaneous masking and in the time domain is known as temporal masking or non-simultaneous masking. This works presents a sound coding strategy that incorporates a temporal masking model to select the most relevant channels for stimulation in a cochlear implant (CI). A previous version of the strategy, termed psychoacoustic advanced combination encoder (PACE), only used a simultaneous masking model for the same purpose, for this reason the new strategy has been termed temporal-PACE (TPACE). We hypothesized that a sound coding strategy that focuses on stimulating the auditory nerve with pulses that are as masked as possible can improve speech intelligibility for CI users. The temporal masking model used within TPACE attenuates the simultaneous masking thresholds estimated by PACE over time. The attenuation is designed to fall exponentially with a strength determined by a single parameter, the temporal masking half-life T½. This parameter gives the time interval at which the simultaneous masking threshold is halved. The study group consisted of 24 postlingually deaf subjects with a minimum of six months experience after CI activation. A crossover design was used to compare four variants of the new temporal masking strategy TPACE (T½ ranging between 0.4 and 1.1 ms) with respect to the clinical MP3000 strategy, a commercial implementation of the PACE strategy, in two prospective, within-subject, repeated-measure experiments. The outcome measure was speech intelligibility in noise at 15 to 5 dB SNR. In two consecutive experiments, the TPACE with T½ of 0.5 ms obtained a speech performance increase of 11% and 10% with respect to the MP3000 (T½ = 0 ms), respectively. The improved speech test scores correlated with the clinical performance of the subjects: CI users with above-average outcome in their routine speech tests showed higher benefit with TPACE. It seems that the consideration of short-acting temporal masking can improve speech intelligibility in CI users. The half-live with the highest average speech perception benefit (0.5 ms) corresponds to time scales that are typical for neuronal refractory behavior.
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Kludt, Eugen, Waldo Nogueira, Thomas Lenarz, and Andreas Buechner. "A sound coding strategy based on a temporal masking model for cochlear implants." PLOS ONE 16, no. 1 (January 8, 2021): e0244433. http://dx.doi.org/10.1371/journal.pone.0244433.
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Auditory masking occurs when one sound is perceptually altered by the presence of another sound. Auditory masking in the frequency domain is known as simultaneous masking and in the time domain is known as temporal masking or non-simultaneous masking. This works presents a sound coding strategy that incorporates a temporal masking model to select the most relevant channels for stimulation in a cochlear implant (CI). A previous version of the strategy, termed psychoacoustic advanced combination encoder (PACE), only used a simultaneous masking model for the same purpose, for this reason the new strategy has been termed temporal-PACE (TPACE). We hypothesized that a sound coding strategy that focuses on stimulating the auditory nerve with pulses that are as masked as possible can improve speech intelligibility for CI users. The temporal masking model used within TPACE attenuates the simultaneous masking thresholds estimated by PACE over time. The attenuation is designed to fall exponentially with a strength determined by a single parameter, the temporal masking half-life T½. This parameter gives the time interval at which the simultaneous masking threshold is halved. The study group consisted of 24 postlingually deaf subjects with a minimum of six months experience after CI activation. A crossover design was used to compare four variants of the new temporal masking strategy TPACE (T½ ranging between 0.4 and 1.1 ms) with respect to the clinical MP3000 strategy, a commercial implementation of the PACE strategy, in two prospective, within-subject, repeated-measure experiments. The outcome measure was speech intelligibility in noise at 15 to 5 dB SNR. In two consecutive experiments, the TPACE with T½ of 0.5 ms obtained a speech performance increase of 11% and 10% with respect to the MP3000 (T½ = 0 ms), respectively. The improved speech test scores correlated with the clinical performance of the subjects: CI users with above-average outcome in their routine speech tests showed higher benefit with TPACE. It seems that the consideration of short-acting temporal masking can improve speech intelligibility in CI users. The half-live with the highest average speech perception benefit (0.5 ms) corresponds to time scales that are typical for neuronal refractory behavior.
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Ghosh, Arijit, Pragya Sharma, Shephali Dansana, and Vasu Sheeba. "Evidence for Co-Evolution of Masking With Circadian Phase in Drosophila Melanogaster." Journal of Biological Rhythms 36, no. 3 (March 22, 2021): 254–70. http://dx.doi.org/10.1177/0748730421997262.
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Heritable variation in the timing of rhythmic events with respect to daily time cues gives rise to chronotypes. Despite its importance, the mechanisms (clock or non-clock) regulating chronotypes remain elusive. Using artificial laboratory selection for divergent phasing of emergence of adults from pupae, our group has derived populations of Drosophila melanogaster which are early and late chronotypes for eclosion rhythm. Several circadian rhythm characteristics of these populations have since been described. We hypothesized that our selection protocol has inadvertently resulted in selection for masking, a non-clock phenomenon, in the early chronotype due to the placement of our selection window (which includes the lights-ON transition). We designed experiments to discriminate between enhanced masking to light versus circadian clock mediated changes in determining enhanced emergence in the morning window in our early chronotypes. Using a series of phase-shift protocols, LD-DD transition, and T-cycle experiments, we find that our early chronotypes have evolved positive masking, and their apparent entrained phases are largely contributed by masking. Through skeleton T-cycle experiments, we find that in addition to the evolution of greater masking, our early chronotypes have also evolved advanced phase of entrainment. Furthermore, our study systematically outlines experimental approaches to examine relative contributions of clock versus non-clock control of an entrained behavior. Although it has previously been suggested that masking may confer an adaptive advantage to organisms, here we provide experimental evidence for the evolution of masking as a means of phasing that can complement clock control of an entrained behavior.
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Bolton, Matthew L., Xi Zheng, Meng Li, Judy Reed Edworthy, and Andrew D. Boyd. "An Experimental Validation of Masking in IEC 60601-1-8:2006-Compliant Alarm Sounds." Human Factors: The Journal of the Human Factors and Ergonomics Society 62, no. 6 (August 14, 2019): 954–72. http://dx.doi.org/10.1177/0018720819862911.
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Objective This research investigated whether the psychoacoustics of simultaneous masking, which are integral to a model-checking-based method, previously developed for detecting perceivability problems in alarm configurations, could predict when IEC 60601-1-8-compliant medical alarm sounds are audible. Background The tonal nature of sounds prescribed by IEC 60601-1-8 makes them potentially susceptible to simultaneous masking: where concurrent sounds render one or more inaudible due to human sensory limitations. No work has experimentally assessed whether the psychoacoustics of simultaneous masking accurately predict IEC 60601-1-8 alarm perceivability. Method In two signal detection experiments, 28 nursing students judged whether alarm sounds were present in collections of concurrently sounding standard-compliant tones. The first experiment used alarm sounds with single-frequency (primary harmonic) tones. The second experiment’s sounds included the additional, standard-required frequencies (often called subharmonics). T tests compared miss, false alarm, sensitivity, and bias measures between masking and nonmasking conditions and between the two experiments. Results Miss rates were significantly higher and sensitivity was significantly lower for the masking condition than for the nonmasking one. There were no significant differences between the measures of the two experiments. Conclusion These results validate the predictions of the psychoacoustics of simultaneous masking for medical alarms and the masking detection capabilities of our method that relies on them. The results also show that masking of an alarm’s primary harmonic is sufficient to make an alarm sound indistinguishable. Application Findings have profound implications for medical alarm design, the international standard, and masking detection methods.
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Badcock, David R., and Elizabeth Sevdalis. "Masking by Uniform Field Flicker: Some Practical Problems." Perception 16, no. 5 (October 1987): 641–47. http://dx.doi.org/10.1068/p160641.
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The technique of uniform field flicker (UFF) masking has frequently been used to address issues concerning the relative performance of sustained and transient neural channels in the human visual system. Unfortunately there has been an artifact in the implementation of this method in most published experiments which has meant that the contrast of the target has been flickered in synchrony with the mean luminance. A study is reported in which the artifact was corrected and the effects of UFF masking on the contrast sensitivity function then examined. With this correction, masking was still restricted to low spatial frequencies but it was much weaker than reported originally. It is argued that the original evidence suggesting that UFF masking can be used to examine the functioning of transient and sustained channels has not been interpreted correctly and that the basis for such a claim is weak.
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Petrosino, Linda, Donald Fucci, Lee Ellis, and Daniel Harris. "Effects of Auditory Masking on Lingual Vibrotactile Magnitude-Estimation Scaling Responses of Young Children." Perceptual and Motor Skills 68, no. 2 (April 1989): 523–29. http://dx.doi.org/10.2466/pms.1989.68.2.523.
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Studies of lingual vibrotactile magnitude-estimation scaling have focused primarily on the responses of normal young adults. Little is known about the scaling responses of young children to suprathreshold vibratory stimulation because of the complexities of the experimental procedure. Binaural auditory masking is one aspect of the procedure that has recently been studied in adults. The purpose of this study was to investigate the effects of binaural auditory masking on lingual vibrotactile magnitude-estimation responses of young children. Four children whose mean age was 4.6 yr. completed magnitude-estimation scaling tasks for eight lingual vibrotactile suprathreshold intensity levels (6, 10, 16, 20, 26, 30, 36, 40 dB SL) under masking and no masking conditions. Results suggest possible effects of auditory masking on the lingual vibrotactile magnitude-estimation scaling responses of these young children that have not been found for such responses of adults.
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Zandbergen, Paul A. "Ensuring Confidentiality of Geocoded Health Data: Assessing Geographic Masking Strategies for Individual-Level Data." Advances in Medicine 2014 (2014): 1–14. http://dx.doi.org/10.1155/2014/567049.
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Public health datasets increasingly use geographic identifiers such as an individual’s address. Geocoding these addresses often provides new insights since it becomes possible to examine spatial patterns and associations. Address information is typically considered confidential and is therefore not released or shared with others. Publishing maps with the locations of individuals, however, may also breach confidentiality since addresses and associated identities can be discovered through reverse geocoding. One commonly used technique to protect confidentiality when releasing individual-level geocoded data is geographic masking. This typically consists of applying a certain amount of random perturbation in a systematic manner to reduce the risk of reidentification. A number of geographic masking techniques have been developed as well as methods to quantity the risk of reidentification associated with a particular masking method. This paper presents a review of the current state-of-the-art in geographic masking, summarizing the various methods and their strengths and weaknesses. Despite recent progress, no universally accepted or endorsed geographic masking technique has emerged. Researchers on the other hand are publishing maps using geographic masking of confidential locations. Any researcher publishing such maps is advised to become familiar with the different masking techniques available and their associated reidentification risks.
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Berthet, Vincent, and Sid Kouider. "The Role of Spatial Switching in the Attentional Blink." Spanish journal of psychology 15, no. 1 (March 2012): 3–9. http://dx.doi.org/10.5209/rev_sjop.2012.v15.n1.37278.
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The attentional blink (AB) is a well-established paradigm in which identification of a target T2 is reduced shortly after presentation of an earlier target T1. An important question concerns the importance of backward masking during the AB. While task switching has been found to be a strong modulator mediating the AB without any masking of T2, the present study investigated whether spatial switching could similarly produce an AB without masking. Using a spatial AB paradigm in which items appeared at different locations; we found (a) a significant AB without backward masking of T2 but no AB when no distractors followed T2, (b) no evidence for Lag 1 sparing. These findings show that when there is a spatial switch between the targets, presenting the distractor following T2 at the same location than T2 (backward masking) is not a necessary condition for the AB to occur, but T2 has to be followed by surrounding distractors (appearing at different locations than T2). This pattern of data confirms that spatial switching is a robust modulator of the AB, but to a less extent than task switching.
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Lu, Shiming, Mingjun He, Shuangyan He, Shuo He, Yunhe Pan, Wenbin Yin, and Peiliang Li. "An Improved Cloud Masking Method for GOCI Data over Turbid Coastal Waters." Remote Sensing 13, no. 14 (July 10, 2021): 2722. http://dx.doi.org/10.3390/rs13142722.
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Clouds severely hinder the radiative transmission of visible light; thus, correctly masking cloudy and non-cloudy pixels is a preliminary step in processing ocean color remote sensing data. However, cloud masking over turbid waters is prone to misjudgment, leading to loss of non-cloudy pixel data. This research proposes an improved cloud masking method over turbid water to classify cloudy and non-cloudy pixels based on spectral variability of Rayleigh-corrected reflectance acquired by the Geostationary Ocean Color Imager (GOCI). Compared with other existing cloud masking methods, we demonstrated that this improved method can identify the spatial positions and shapes of clouds more realistically, and more accurate pixels of turbid waters were retained. This improved method can be effectively applied in typical turbid coastal waters. It has potential to be used in cloud masking procedures of spaceborne ocean color sensors without short-wave infrared bands.
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Dhar, Pintu, Himangshu Sarma, and Hemanta Kumar Sharma. "Fixed Dose Oral Dispersible Tablet of Bitter Drug Using Okra Mucilage: Formulation and Evaluation." Journal of Drug Delivery and Therapeutics 10, no. 5 (September 15, 2020): 149–58. http://dx.doi.org/10.22270/jddt.v10i5.4393.
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Background: The solid oral dosage forms containing bitter drugs need improved palatability for administration. Formulation scientists have given attention to the improvement of taste masking technologies and utilised various strategies.
Objective: The present work aimed to mask the bitter taste of Promethazine Hydrochloride by formulating Oral Dispersible Tablets using Okra mucilage as a taste-masking agent.
Methods: The Okra mucilage was extracted from Okra by the aqueous extraction process. An emulsion solvent diffusion technique was used for masking the bitter taste of Promethazine Hydrochloride by using Okra mucilage. The Oral Dispersible Tablet was prepared by the wet granulation method. The mucilage and the formulation were characterized and evaluated by standard methods and protocols.
Results: Taste masking of the bitter drug was successfully achieved by Okra mucilage. The DSC and FTIR study revealed that the drug molecule was compatible with okra mucilage and drug entrapment efficacy was found to be 94.76%. The palatability test asserted that masking of the bitter taste of the drug. The In vitro drug release study showed that the F7 tablet batch has a better drug release rate and followed non- fickian mechanism of drug release.
Conclusion: Thus, taste masking with Okra mucilage was successful and this opens opportunities for application of common edible substances in formulation development.
Keywords: Fast disintegrating tablet; Natural polymer; Mouth dissolving tablet; Promethazine Hydrochloride; Taste masking
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Asaoka, Riku, and Jiro Gyoba. "The time compression effect induced by visual masking has a spatial selectivity." Proceedings of the Annual Convention of the Japanese Psychological Association 81 (September 20, 2017): 1C—047–1C—047. http://dx.doi.org/10.4992/pacjpa.81.0_1c-047.
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Altun, Gulay Durmus, Armagan Altun, Mustafa Yildiz, Mehmet F. Frat, Sevim Hacimahmutoglu, and Sakir Berkarda. "Irbesartan has a masking effect on dipyridamole stress induced myocardial perfusion defects." Nuclear Medicine Communications 25, no. 2 (February 2004): 195–99. http://dx.doi.org/10.1097/00006231-200402000-00017.
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Mackenzie, Roderick, Farideh Zarei, Vincent Le Men, and Joonhee Lee. "Spatial uniformity tolerances for sound masking systems in open-plan offices." INTER-NOISE and NOISE-CON Congress and Conference Proceedings 263, no. 1 (August 1, 2021): 5643–49. http://dx.doi.org/10.3397/in-2021-3199.
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Electronic sound masking systems raise the ambient sound level in offices to a controlled minimum sound level in order to increase speech privacy and reduce distractions. Sound masking systems are calibrated to provide the most uniform sound field achievable, as a spatially non-uniform masking sound field could result in occupant perception and uneven speech privacy conditions. Tolerances for acceptable spatial uniformity vary between specifiers, and may be based on different evaluation methods using only a few discrete measurement points to represent an entire office space. However, the actual uniformity of a masking sound field across an office, and the parameters influencing it, has not been widely investigated. Thus, this study aims to investigate the masking sound uniformity in a typical open-plan office space using fine-grid measurements conforming to measurement method of ASTM E1573-18. Percentages of measured locations where the sound pressure levels were within specified tolerances (with increments of 0.5 dB) were calculated using the measured 1/3 octave band levels. The research also utilized geometric acoustical simulations to investigate how physical office parameters (number of loudspeakers, partition heights, ceiling absorption, and diffusion characteristics) affect the sound field uniformity of the sound masking system.
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Kachinthaya, Anish, Yi Ding, and Tobias Hollerer. "Exploring the Benefits of Depth Information in Object Pixel Masking (Student Abstract)." Proceedings of the AAAI Conference on Artificial Intelligence 34, no. 10 (April 3, 2020): 13833–34. http://dx.doi.org/10.1609/aaai.v34i10.7189.
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In this paper, we look at how depth data can benefit existing object masking methods applied in occluded scenes. Masking the pixel locations of objects within scenes helps computers get a spatial awareness of where objects are within images. The current state-of-the-art algorithm for masking objects in images is Mask R-CNN, which builds on the Faster R-CNN network to mask object pixels rather than just detecting their bounding boxes. This paper examines the weaknesses Mask R-CNN has in masking people when they are occluded in a frame. It then looks at how depth data gathered from an RGB-D sensor can be used. We provide a case study to show how simply applying thresholding methods on the depth information can aid in distinguishing occluded persons. The intention of our research is to examine how features from depth data can benefit object pixel masking methods in an explainable manner, especially in complex scenes with multiple objects.
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Lewis, H. Donell, Vernon A. Benignus, Keith E. Muller, Carolin M. Malott, and Curtis N. Barton. "Babble and Random-Noise Masking of Speech in High and Low Context Cue Conditions." Journal of Speech, Language, and Hearing Research 31, no. 1 (March 1988): 108–14. http://dx.doi.org/10.1044/jshr.3101.108.
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"Perceptual" masking of speech by multitalker speech (babble) has been widely reported but poorly quantified. Furthermore, the validity of the construct of perceptual masking is questionable. This report describes an experiment using a newly standardized test of speech perception in noise (SPIN) with both babble and spectrally matched random-noise maskers. Classical psychophysieal ogive curves were used to model speech recognition as a function of signal-to-noise ratio (S/N). The two maskers yielded speech recognition functions of the same steepness but different locations on the S/N axis. The high-context items of SPIN yielded speech recognition curves with steeper slope and different locations on the S/N axis than the low-context items. These data are used to argue that perceptual masking was not documented (under certain assumptions) and that the superior masking of babble may be explained in purely acoustical terms. Speculations are offered about the possible acoustical differences that could be responsible for the differences in masking effect.
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SKOTTUN, BERNT C., and JOHN R. SKOYLES. "Metacontrast, target recovery, and the magno- and parvocellular systems: A perspective." Visual Neuroscience 24, no. 2 (March 2007): 177–81. http://dx.doi.org/10.1017/s0952523807070228.
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In metacontrast a masking stimulus reduces the visibility of an adjacent target stimulus. This effect has been interpreted in terms of magno-/parvocellular interactions. It has also been found that a second masking stimulus, which precedes the primary mask by about 90 ms reduces the masking effect. This reduction, which is termed “target recovery,” has been hypothesized to reflect parvocellular inhibition of the magnocellular system. However, this is problematic because the time course of this effect is much larger than would be expected from magno-/parvocellular interactions. For this and other reasons, it is difficult to understand metacontrast in terms of magno- and parvocellular mechanisms.
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Cogan, Alexander I. "Anatomy of a Flash. 2. The ‘Width’ of a Temporal Edge." Perception 21, no. 2 (April 1992): 167–76. http://dx.doi.org/10.1068/p210167.
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In a previous study it has been found by using the Crawford masking paradigm with spatially coextensive stimuli that the end points of even a weak flash have a strong masking effect on the probe pulse, but no threshold elevation was observed when the probe was 100 ms or longer from flash onset and offset. The relationship between the strength of a temporal edge (eg the amplitude of a sudden increase in field luminance) and the duration of masking has not been systematically investigated. In the present experiments the duration of masking produced by a step of luminance as a function of step size was measured. With steps whose amplitude was between ten and five hundred times detection threshold, the duration of masking was about constant, ie 70 and 50 ms for on-responses and off-responses, respectively. This refractory period defined the ‘width’ of a temporal edge. Unless two suprathreshold unidirectional luminance changes are separated by an interval exceeding the width of a temporal edge, they are perceived as a single change in brightness. A linear systems analysis led to predictions for ramp stimuli that were confirmed by experiment.
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Di Lollo, Vincent, Walter F. Bischof, and Peter Dixon. "Stimulus-Onset Asynchrony Is Not Necessary for Motion Perception or Metacontrast Masking." Psychological Science 4, no. 4 (July 1993): 260–63. http://dx.doi.org/10.1111/j.1467-9280.1993.tb00272.x.
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Coherent directional motion is seen if a translated image is displayed in two sequential frames (F1 and F2). In a related paradigm—metacontrast masking—the mask (F2) reduces the visibility of the target (F1). Although strict temporal succession has been considered essential in both paradigms, we obtained both coherent motion and metacontrast masking with simultaneous onsets of F1 and F2, provided that F2 outlasted F1. Computational models of motion sensors are inherently capable of explaining these results, but inhibitory theories of metacontrast masking are disconfirmed.
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Calford, M. B., and M. N. Semple. "Monaural inhibition in cat auditory cortex." Journal of Neurophysiology 73, no. 5 (May 1, 1995): 1876–91. http://dx.doi.org/10.1152/jn.1995.73.5.1876.
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1. Several studies of auditory cortex have examined the competitive inhibition that can occur when appropriate sounds are presented to each ear. However, most cortical neurons also show both excitation and inhibition in response to presentation of stimuli at one ear alone. The extent of such inhibition has not been described. Forward masking, in which a variable masking stimulus was followed by a fixed probe stimulus (within the excitatory response area), was used to examine the extent of monaural inhibition for neurons in primary auditory cortex of anesthetized cats (barbiturate or barbiturate-ketamine). Both the masking and probe stimuli were 50-ms tone pips presented to the contralateral ear. Most cortical neurons showed significant forward masking at delays beyond which masking effects in the auditory nerve are relatively small compared with those seen in cortical neurons. Analysis was primarily concerned with such components. Standard rate-level functions were also obtained and were examined for nonmonotonicity, an indication of level-dependent monaural inhibition. 2. Consistent with previous reports, a wide range of frequency tuning properties (excitatory response area shapes) was found in cortical neurons. This was matched by a wide range of forward-masking-derived inhibitory response areas. At the most basic level of analysis, these were classified according to the presence of lateral inhibition, i.e., where a probe tone at a neuron's characteristic frequency was masked by tones outside the limits of the excitatory response area. Lateral inhibition was a property of 38% of the sampled neurons. Such neurons represented 77% of those with nonmonotonic rate-level functions, indicating a strong correlation between the two indexes of monaural inhibition; however, the shapes of forward masking inhibitory response areas did not usually correspond with those required to account for the "tuning" of a neuron. In addition, it was found that level-dependent inhibition was not added to by forward masking inhibition. 3. Analysis of the discharges to individual stimulus pair presentations, under conditions of partial masking, revealed that discharges to the probe occurred independently of discharges to the preceding masker. This indicates that even when the masker is within a neuron's excitatory response area, forward masking is not a postdischarge habituation phenomenon. However, for most neurons the degree of masking summed over multiple stimulus presentations appears determined by the same stimulus parameters that determine the probability of response to the masker.(ABSTRACT TRUNCATED AT 400 WORDS)
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Rouby, Catherine, and André Holley. "Temporal Competition between Odorants: Effect of Different Time Intervals on the Perception of Monorhinic and Dichorhinic Binary Mixtures." Perception 24, no. 9 (September 1995): 1083–97. http://dx.doi.org/10.1068/p241083.
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Backward masking and its possible connection with the perception of odour mixtures has been investigated. Temporal competition between odorants in a binary mixture was tested by artificially creating a delay between one odour (the target) and a second, stronger, odour (the mask) during a single natural sniff. To test the influence of central versus peripheral competition, the same mixture was presented either monorhinically or dichorhinically. The delay (100 to 400 ms) did not influence intensity perception, indicating that intensities are integrated during the sniff irrespective of the temporal arrangement. In contrast, the number of qualities perceived was influenced by the delay: delays of 200 to 400 ms gave significant increases in the frequency of detection of a mixture, whereas synchronous mixtures favoured the perception of a single odour. Masking was also significantly stronger in dichorhinic mixtures. These effects are discussed in terms of retroactive masking which seems to be enhanced by dichorhinic mixtures, suggesting that masking has an important central component.
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Gray, Lesley, Carol MacDonald, Natasha Tassell-Matamua, James Stanley, Amanda Kvalsvig, Jane Zhang, Samantha Murton, et al. "Wearing one for the team: views and attitudes to face covering in New Zealand/Aotearoa during COVID-19 Alert Level 4 lockdown." Journal of Primary Health Care 12, no. 3 (2020): 199. http://dx.doi.org/10.1071/hc20089.
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ABSTRACT INTRODUCTIONMass masking is emerging as a key non-pharmaceutical intervention for reducing community spread of COVID-19. However, although hand washing, social distancing and bubble living have been widely adopted by the ‘team of 5 million’, mass masking has not been socialised to the general population. AIMTo identify factors associated with face masking in New Zealand during COVID-19 Alert Level 4 lockdown to inform strategies to socialise and support mass masking. METHODSA quantitative online survey conducted in New Zealand during April 2020 invited residents aged ≥18 years to complete a questionnaire. Questions about face masking were included in the survey. The sample was drawn from a commissioned research panel survey, with boosted sampling for Māori and Pacific participants. Responses were weighted to reflect the New Zealand population for all analyses. RESULTSA total of 1015 individuals participated. Self-reported beliefs were strongly related to behaviours, with respondents viewing face masking measures as ‘somewhat’ or ‘very’ effective in preventing them from contracting COVID-19 more likely to report having worn a face mask than respondents who viewed them as ‘not at all’ effective. The strongest barriers to face mask use included beliefs that there was a mask shortage and that the needs of others were greater than their own. DISCUSSIONHighlighting the efficacy of and dispelling myths about the relative efficacy of mask types and socialising people to the purpose of mass masking will contribute to community protective actions of mask wearing in the New Zealand response to COVID-19.
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Ryu, Semin, Dongbum Pyo, Soo-Chul Lim, and Dong-Soo Kwon. "Rendering Strategy to Counter Mutual Masking Effect in Multiple Tactile Feedback." Applied Sciences 10, no. 14 (July 20, 2020): 4990. http://dx.doi.org/10.3390/app10144990.
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Recently, methods and devices that simultaneously utilize two or more tactile feedback types have been proposed for more immersive interaction with virtual objects. However, the masking effect, which makes us less sensitive to various stimuli presented at the same time, has scarcely been explored. In this study, we propose a novel tactile rendering algorithm that can eliminate the mutual masking effect at the user’s sensation level, when mechanical vibration and electrovibration are applied simultaneously. First, the masking functions of the two stimuli were investigated for various stimulus combinations. Based on these, a generalized form of the masking function was derived. We then tested and confirmed that the proposed algorithm, which calculates the required stimulus intensity to compensate for the mutual masking effect, could render the arbitrary stimulus intensity desired to be perceived by the users. The results of the user test revealed that the proposed rendering algorithm significantly improved the virtual object recognition rate by approximately 23% when geometry and texture were presented jointly. This finding suggests principal guidelines for the combined use of mechanical vibration and electrovibration, as well as for other combinations of different tactile feedback types.
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Nelson, David A., and Rosemary Pavlov. "Auditory Time Constants for Off-Frequency Forward Masking in Normal-Hearing and Hearing-Impaired Listeners." Journal of Speech, Language, and Hearing Research 32, no. 2 (June 1989): 298–306. http://dx.doi.org/10.1044/jshr.3202.298.
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Previous research has shown that frequency-specific estimates of auditory time constants for recovery from short-term adaptation can be made using a fixed-probe forward-masking procedure (Nelson & Freyman, 1987) if the masker and the probe stimuli are at the same frequency. This study examines the validity of time-constant estimates for off-frequency forward-masking conditions in which the masker frequency is below (900 Hz) or above (1100 Hz) the probe frequency (1000 Hz). Fixed-probe-level temporal masking functions were obtained from four normal-hearing and four hearing-impaired listeners. Auditory time constants were estimated with iterative least-squares procedures to derive parameter values for an exponential model of recovery from forward masking. After appropriate corrections were made for attenuation to the maskers provided by the auditory filter centered at the probe frequency, recovery from forward masking produced by either off-frequency or on-frequency maskers could be described by a single time constant. That time constant was around 50 ms in normal-hearing listeners and was larger in those hearing-impaired listeners who demonstrated moderate hearing loss at the probe frequency.
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Griz, Silvana Maria Sobral, Denise Costa Menezes, Leonardo Gleygson Angelo Venâncio, Nathália Holanda da Fonsêca, Thaís Ohanny do Nascimento, Anne Karoline Lima de Araújo, Kelly Cristina Lira de Andrade, and Pedro de Lemos Menezes. "Effect of Forward Masking on Frequency Following Response as a Function of Age." Journal of the American Academy of Audiology 31, no. 05 (May 2020): 317–23. http://dx.doi.org/10.3766/jaaa.18104.
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Abstract Background Forward masking occurs when noise is presented before the target signal, making the latter difficult to be perceived. It is related to temporal auditory processing and consequently to speech recognition in noisy environments, which may decline with age. Interest in forward masking has grown in the last years. Studies investigate psychoacoustic and electrophysiological recordings in different age- groups. Purpose The purpose of the study was to investigate the effect of forward masking on frequency following response (FFR) as a function of age. Research Design Cross-sectional analytical observational study. Study Sample We assessed 69 normal-hearing participants of both genders assigned to three groups: 40 young individuals (aged 18-25 years, mean age = 22 years 8 months), 21 middle-age individuals (aged 25-55 years, mean age = 37 years 2 months), and 8 seniors (aged <55 years, mean age = 65 years 3 months). Intervention FFRs were recorded using the /da/ syllable with and without noise. Data Collection and Analysis The /da/ syllable and speech-shaped noise were monaurally presented to the participants' right ears through ER-3a insert earphones. Electrodes were placed in M1 and M2 (-), Fz (+), and Fpz (ground). Acquisition occurred under two conditions: (1) the/da/ syllable presented without the noise and (2) the /da/ syllable presented 4 msec after the noise. Results Data show that (1) considering the mean values of all participants, there was a significant latency delay of all waves (PV, A, PW, PX, PY, PZ, and O) when the /da/ syllable was presented 4 msec after the masking noise as compared with the condition without noise, that is, forward masking occurred in all components of the FFR responses, and (2) for the youngest group and the middle-age group, forward masking was seen for all waves, except PX in the latter one; for the senior group, an irregular pattern was observed (presence of forward masking in PA, PY, PZ, and O). This pattern may be due to an aging effect on FFR responses even without noise presence, which makes it more difficult to identify forward masking effect in this population. Although it is well documented in the literature that forward masking increases with age, this is less evident on FFR recordings in the senior population. Conclusions An aging effect was identified in FFR responses. Forward masking was identified in FFR responses of all groups but less evident in senior population.
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Hyeok Lee, Dong, and Nam Je. Park. "ROI-based efficient video data processing for large-scale cloud storage in intelligent CCTV environment." International Journal of Engineering & Technology 7, no. 3.3 (June 8, 2018): 151. http://dx.doi.org/10.14419/ijet.v7i2.33.13873.
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Background/Objectives: Big data environment is being realized. Recently, intelligent public safety environment on the foundation of the image processing technique based on big data is being introduced, and accordingly, processing CCTV images is becoming more important day by day.Methods/Statistical analysis: In this paper, an efficient technique to send image information for mass cloud storage environment was proposed. With the offered method, only the ROI area is extracted and partial object images are transmitted, and it has the strengths of higher efficiency and protected privacy with the application of a masking technique.Findings: it is general to apply the masking technique partially to face information, and in this study, the privacy of the image data registered in the cloud storage was to be protected based on this masking technique, and an efficient data transmission structure grounded on ROI area extraction was proposed.Improvements/Applications: With the offered method, only the ROI area is extracted and partial object images are transmitted, and it has the strengths of higher efficiency and protected privacy with the application of a masking technique.
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Filippini, Renata, and Eliane Schochat. "A new paradigm for temporal masking assessment: pilot study." CoDAS 26, no. 4 (July 2014): 302–7. http://dx.doi.org/10.1590/2317-1782/201420130044.
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PURPOSE: To determine the feasibility and applicability of a clinical backward masking test, focusing on the analysis of inter-stimuli interval, and not on the intensity thresholds as it has been traditionally done, thus proposing a new paradigm for temporal masking assessment.METHOD: The test consisted of the presentation of a target tone of 1.000 Hz followed by a broadband masking noise (950-1.050 Hz), with inter-stimuli interval of 0, 10, 20, 50 and 100 ms. The stimuli were presented monaurally to both ears, with intensity ratio between masker and target tone varying between -10, -20, -30 and -40 dB. Twenty undergraduate students, without hearing or auditory processing complaints, participated in this study.RESULTS: Regardless of the signal-to-noise ratio, we observed decrease of average performance according to the decrease of the interval between stimuli. We also observed the indication that little or no masking occurs at the 100 ms interval, suggesting this interval is unsuitable for temporal masking assessment. The average interval threshold was below 27 ms for all investigated intensities, and increased 9 ms with every increase of 10 dB at signal-to-noise ratio. The signal-to-noise ratios of -20 and -30 were the best ratios for the test application.CONCLUSION: The paradigm proposed in this pilot study proved to be feasible, easy to apply, and trustworthy, being compatible with other researches which are the foundation for the study of temporal masking. This theme deserves further studies, continuing the analysis initiated here.
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Ogura, Katsuo. "A Large Number of Herbig-Haro Candidates Found by the Contrast Enhancement and Unsharp Masking Technique." International Astronomical Union Colloquium 148 (1995): 331–36. http://dx.doi.org/10.1017/s0252921100022132.
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AbstractAbout 1300, 60 and 70 Herbig-Haro candidates have been picked up in the Ori A/L1641, Ori B/L1630 and NGC 2264/Mon OBI regions, respectively, on deep Schmidt plates. The contrast enhancement and unsharp masking technique has been applied simultaneously. Unsharp masking applied to an objective-prism Schmidt plate for the Carina Nebula region has yielded the detection of 38 Hα emission stars, of which 13 are new findings.
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Amelian, Aleksandra, Marta Szekalska, Patrycja Ciosek, Anna Basa, and Katarzyna Winnicka. "Characterization and taste masking evaluation of microparticles with cetirizine dihydrochloride and methacrylate-based copolymer obtained by spray drying." Acta Pharmaceutica 67, no. 1 (March 1, 2017): 113–24. http://dx.doi.org/10.1515/acph-2017-0002.
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Abstract Taste of a pharmaceutical formulation is an important parameter for the effectiveness of pharmacotherapy. Cetirizine dihydrochloride (CET) is a second-generation antihistamine that is commonly administered in allergy treatment. CET is characterized by extremely bitter taste and it is a great challenge to successfully mask its taste; therefore the goal of this work was to formulate and characterize the microparticles obtained by the spray drying method with CET and poly(butyl methacrylate-co-(2-dimethylaminoethyl) methacrylate-co-methyl methacrylate 1:2:1 copolymer (Eudragit E PO) as a barrier coating. Assessment of taste masking by the electronic tongue has revealed that designed formulations created an effective taste masking barrier. Taste masking effect was also confirmed by the in vivo model and the in vitro release profile of CET. Obtained data have shown that microparticles with a drug/polymer ratio (0.5:1) are promising CET carriers with efficient taste masking potential and might be further used in designing orodispersible dosage forms with CET.
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Liu, Chunlei, Longbiao Wang, and Jianwu Dang. "Deep Learning-Based Amplitude Fusion for Speech Dereverberation." Discrete Dynamics in Nature and Society 2020 (July 14, 2020): 1–14. http://dx.doi.org/10.1155/2020/4618317.
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Mapping and masking are two important speech enhancement methods based on deep learning that aim to recover the original clean speech from corrupted speech. In practice, too large recovery errors severely restrict the improvement in speech quality. In our preliminary experiment, we demonstrated that mapping and masking methods had different conversion mechanisms and thus assumed that their recovery errors are highly likely to be complementary. Also, the complementarity was validated accordingly. Based on the principle of error minimization, we propose the fusion between mapping and masking for speech dereverberation. Specifically, we take the weighted mean of the amplitudes recovered by the two methods as the estimated amplitude of the fusion method. Experiments verify that the recovery error of the fusion method is further controlled. Compared with the existing geometric mean method, the weighted mean method we proposed has achieved better results. Speech dereverberation experiments manifest that the weighted mean method improves PESQ and SNR by 5.8% and 25.0%, respectively, compared with the traditional masking method.
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Candra, Danang Surya, Stuart Phinn, and Peter Scarth. "Automated Cloud and Cloud-Shadow Masking for Landsat 8 Using Multitemporal Images in a Variety of Environments." Remote Sensing 11, no. 17 (September 2, 2019): 2060. http://dx.doi.org/10.3390/rs11172060.
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Landsat 8 images have been widely used for many applications, but cloud and cloud-shadow cover issues remain. In this study, multitemporal cloud masking (MCM), designed to detect cloud and cloud-shadow for Landsat 8 in tropical environments, was improved for application in sub-tropical environments, with the greatest improvement in cloud masking. We added a haze optimized transformation (HOT) test and thermal band in the previous MCM algorithm to improve the algorithm in the detection of haze, thin-cirrus cloud, and thick cloud. We also improved the previous MCM in the detection of cloud-shadow by adding a blue band. In the visual assessment, the algorithm can detect a thick cloud, haze, thin-cirrus cloud, and cloud-shadow accurately. In the statistical assessment, the average user’s accuracy and producer’s accuracy of cloud masking results across the different land cover in the selected area was 98.03% and 98.98%, respectively. On the other hand, the average user’s accuracy and producer’s accuracy of cloud-shadow masking results was 97.97% and 96.66%, respectively. Compared to the Landsat 8 cloud cover assessment (L8 CCA) algorithm, MCM has better accuracies, especially in cloud-shadow masking. Our preliminary tests showed that the new MCM algorithm can detect cloud and cloud-shadow for Landsat 8 in a variety of environments.