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Pflug, Justin M., Yiwen Fang, Steven A. Margulis i Ben Livneh. "Interactions between thresholds and spatial discretizations of snow: insights from estimates of wolverine denning habitat in the Colorado Rocky Mountains". Hydrology and Earth System Sciences 27, nr 14 (24.07.2023): 2747–62. http://dx.doi.org/10.5194/hess-27-2747-2023.
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Abstract. Thresholds can be used to interpret environmental data in a way that is easily communicated and useful for decision-making purposes. However, thresholds are often developed for specific data products and time periods, changing findings when the same threshold is applied to datasets or periods with different characteristics. Here, we test the impact of different spatial discretizations of snow on annual estimates of wolverine denning opportunities in the Colorado Rocky Mountains, defined using a snow water equivalent (SWE) threshold (0.20 m) and threshold date (15 May) from previous habitat assessments. Annual potential wolverine denning area (PWDA) was thresholded from a 36-year (1985–2020) snow reanalysis model with three different spatial discretizations: (1) 480 m grid cells (D480), (2) 90 m grid cells (D90), and (3) 480 m grid cells with implicit representations of subgrid snow spatial heterogeneity (S480). Relative to the D480 and S480 discretizations, D90 resolved shallower snow deposits on slopes between 3050 and 3350 m elevation, decreasing PWDA by 10 %, on average. In years with warmer and/or drier winters, S480 discretizations with subgrid representations of snow heterogeneity increased PWDA, even within grid cells where mean 15 May SWE was less than the SWE threshold. These simulations increased PWDA by upwards of 30 % in low-snow years, as compared to the D480 and D90 simulations without subgrid snow heterogeneity. Despite PWDA sensitivity to different snow spatial discretizations, PWDA was controlled more by annual variations in winter precipitation and temperature. However, small changes to the SWE threshold (±0.07 m) and threshold date (±2 weeks) also affected PWDA by as much as 82 %. Across these threshold ranges, PWDA was approximately 18 % more sensitive to the SWE threshold than the threshold date. However, the sensitivity to the threshold date was larger in years with late spring snowfall, when PWDA depended on whether modeled SWE was thresholded before, during, or after spring snow accumulation. Our results demonstrate that snow thresholds are useful but may not always provide a complete picture of the annual variability in snow-adapted wildlife denning opportunities. Studies thresholding spatiotemporal datasets could be improved by including (1) information about the fidelity of thresholds across multiple spatial discretizations and (2) uncertainties related to ranges of realistic thresholds.
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Perry, Trevor T., i Douglas S. Brungart. "Monte Carlo simulation of pure tone audiometry reveals threshold-dependent differences in error". Journal of the Acoustical Society of America 153, nr 3_supplement (1.03.2023): A47. http://dx.doi.org/10.1121/10.0018108.
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This study used a Monte Carlo simulation to evaluate the reliability of pure tone audiometry while incorporating information about the population distribution of thresholds. Results confirm that audiometric error (outcome threshold minus modeled threshold) is symmetric when simulated data are binned by modeled threshold. However, when data are binned by outcome threshold, the error depends on the relative distribution of modeled thresholds. When a realistic distribution is used, outcome thresholds of 0 dB HL show the lowest error rate. Bins with outcome thresholds <0 dB HL show a negative median error (outcome threshold < modeled threshold) and bins >0 dB HL show a positive median error (outcome threshold > modeled threshold). These results suggest that a substantial proportion of individuals who obtain a very good threshold during audiometric testing (−5 or −10 dB HL) are individuals who actually have higher thresholds, which are being underestimated. These findings are relevant for hearing conservation programs, which monitor for upward shifts from baseline thresholds. [The views expressed in this abstract are those of the authors and do not reflect the official policy of the Department of Army/Navy/Air Force, Department of Defense, or U.S. Government.]
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Hather Ibraheem Abed. "Image segmentation with a multilevel threshold using backtracking search optimization algorithm". Tikrit Journal of Pure Science 25, nr 2 (17.03.2020): 102–9. http://dx.doi.org/10.25130/tjps.v25i2.241.
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Image segmentation is an important process in image processing. Though, there are many applications are affected by the segmentation methods and algorithms, unfortunately, not one technique, but the threshold is the popular one. Threshold technique can be categorized into two ways either simple threshold which has one threshold or multi- thresholds separated which has more than two thresholds . In this paper, image segmentation is used simple threshold method which is a simple and effective technique. Therefore, to calculate the value of threshold solution which is led to increase exponentially threshold that gives multi-thresholds image segmentation present a huge challenge. This paper is considered the multi-thresholds segmentation model for the optimization problem in order to overcome the problem of excessive calculation. The objective of this paper proposed an slgorithmto solve the optimization problem and realize multi-thresholds image segmentation. The proposed multi-thresholds segmentation algorithm should be segmented the raw image into pieces, and compared with other algorithms results. The experimental results that show multi-thresholds image segmentation based on backtracking search optimization algorithm are feasible and have a good segmentation.
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Lima Filho, Tarcísio, Valéria Paula Rodrigues Minim, Rita de Cássia dos Santos Navarro da Silva, Suzana Maria Della Lucia i Luis Antônio Minim. "Methodology for determination of two new sensory thresholds: Compromised acceptance threshold and rejection threshold". Food Research International 76 (październik 2015): 561–66. http://dx.doi.org/10.1016/j.foodres.2015.07.037.
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Jukna, Stasys. "Computing threshold functions by depth-3 threshold circuits with smaller thresholds of their gates". Information Processing Letters 56, nr 3 (listopad 1995): 147–50. http://dx.doi.org/10.1016/0020-0190(95)00137-2.
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Abed, Hather Ibraheem. "Image segmentation with a multilevel threshold using backtracking search optimization algorithm". Tikrit Journal of Pure Science 25, nr 2 (17.03.2020): 102. http://dx.doi.org/10.25130/j.v25i2.964.
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Image segmentation is an important process in image processing. Though, there are many applications are affected by the segmentation methods and algorithms, unfortunately, not one technique, but the threshold is the popular one. Threshold technique can be categorized into two ways either simple threshold which has one threshold or multi- thresholds separated which has more than two thresholds . In this paper, image segmentation is used simple threshold method which is a simple and effective technique. Therefore, to calculate the value of threshold solution which is led to increase exponentially threshold that gives multi-thresholds image segmentation present a huge challenge. This paper is considered the multi-thresholds segmentation model for the optimization problem in order to overcome the problem of excessive calculation. The objective of this paper proposed an slgorithmto solve the optimization problem and realize multi-thresholds image segmentation. The proposed multi-thresholds segmentation algorithm should be segmented the raw image into pieces, and compared with other algorithms results. The experimental results that show multi-thresholds image segmentation based on backtracking search optimization algorithm are feasible and have a good segmentation.
http://dx.doi.org/10.25130/tjps.25.2020.036
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Meyer, N. K., A. V. Dyrrdal, R. Frauenfelder, B. Etzelmüller i F. Nadim. "Hydrometeorological threshold conditions for debris flow initiation in Norway". Natural Hazards and Earth System Sciences 12, nr 10 (11.10.2012): 3059–73. http://dx.doi.org/10.5194/nhess-12-3059-2012.
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Abstract. Debris flows, triggered by extreme precipitation events and rapid snow melt, cause considerable damage to the Norwegian infrastructure every year. To define intensity-duration (ID) thresholds for debris flow initiation critical water supply conditions arising from intensive rainfall or snow melt were assessed on the basis of daily hydro-meteorological information for 502 documented debris flow events. Two threshold types were computed: one based on absolute ID relationships and one using ID relationships normalized by the local precipitation day normal (PDN). For each threshold type, minimum, medium and maximum threshold values were defined by fitting power law curves along the 10th, 50th and 90th percentiles of the data population. Depending on the duration of the event, the absolute threshold intensities needed for debris flow initiation vary between 15 and 107 mm day−1. Since the PDN changes locally, the normalized thresholds show spatial variations. Depending on location, duration and threshold level, the normalized threshold intensities vary between 6 and 250 mm day−1. The thresholds obtained were used for a frequency analysis of over-threshold events giving an estimation of the exceedance probability and thus potential for debris flow events in different parts of Norway. The absolute thresholds are most often exceeded along the west coast, while the normalized thresholds are most frequently exceeded on the west-facing slopes of the Norwegian mountain ranges. The minimum thresholds derived in this study are in the range of other thresholds obtained for regions with a climate comparable to Norway. Statistics reveal that the normalized threshold is more reliable than the absolute threshold as the former shows no spatial clustering of debris flows related to water supply events captured by the threshold.
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Richter, Chris, Kevin McGuinness, Noel E. O’Connor i Kieran Moran. "The Variance Needed to Accurately Describe Jump Height from Vertical Ground Reaction Force Data". Journal of Applied Biomechanics 30, nr 6 (grudzień 2014): 732–36. http://dx.doi.org/10.1123/jab.2013-0313.
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In functional principal component analysis (fPCA) a threshold is chosen to define the number of retained principal components, which corresponds to the amount of preserved information. A variety of thresholds have been used in previous studies and the chosen threshold is often not evaluated. The aim of this study is to identify the optimal threshold that preserves the information needed to describe a jump height accurately utilizing vertical ground reaction force (vGRF) curves. To find an optimal threshold, a neural network was used to predict jump height from vGRF curve measures generated using different fPCA thresholds. The findings indicate that a threshold from 99% to 99.9% (6–11 principal components) is optimal for describing jump height, as these thresholds generated significantly lower jump height prediction errors than other thresholds.
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Stejskal, Vaclav, Tomas Vendl, Zhihong Li i Radek Aulicky. "Minimal Thermal Requirements for Development and Activity of Stored Product and Food Industry Pests (Acari, Coleoptera, Lepidoptera, Psocoptera, Diptera and Blattodea): A Review". Insects 10, nr 5 (23.05.2019): 149. http://dx.doi.org/10.3390/insects10050149.
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Low temperatures play an important role in arthropods because they affect both the individual and population development of all physiological and behavioural activities. Manipulation with low temperatures is a primary nonchemical pest control method. For stored product and food industry practitioners, a knowledge of pest thermal requirements, in particular threshold temperatures at which development and other activities of a particular pest species cease, is of crucial importance. This review presents summary data regarding the lower temperature thresholds of 121 species of stored product and food industry pests from six arthropod taxa (Acari, Coleoptera, Lepidoptera, Psocoptera, Diptera, and Blattodea). In particular, this review collected and summarized information regarding the lower development thresholds, lower population thresholds, lower acoustic or respiratory thresholds, lower walking and flying thresholds and lower trap capture thresholds for flying and walking arthropods. The average lower development threshold (LDT) differed among orders: the lowest was reported for Acari (6.8 °C) and Diptera (8.1 °C), followed by Lepidoptera (11.3 °C) and Psocoptera (13.8 °C), and the highest was reported for Coleoptera (14 °C) and Blattodea (15 °C). An exclusion-function was established showing the percentage of pest species (n = 112) that were developmentally suppressed (excluded) due to temperatures reaching the LDT in the range of decreasing temperatures from 25 °C to 0 °C. We scaled various temperature thresholds from the lowest to highest temperature as follows: the walking threshold, the trap capture threshold for walking insects, the lower development threshold, lower population threshold, lower flying threshold and the lower trap capture threshold for flying pests. Important pest species were identified for which information regarding the lower temperature threshold is missing, or for which the information is too variable and should be refined in future research.
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Pauker, Stephen G., Susan P. Pauker i John B. Wong. "The Utility of Thresholds and the Threshold Utility". Medical Decision Making 7, nr 4 (grudzień 1987): 201–2. http://dx.doi.org/10.1177/0272989x8700700401.
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LOOP, MICHAEL S., i DAVID K. CROSSMAN. "High color-vision sensitivity in macaque and humans". Visual Neuroscience 17, nr 1 (styczeń 2000): 119–25. http://dx.doi.org/10.1017/s0952523800171123.
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Psychophysical (behavioral) detection thresholds and color-discrimination thresholds were determined in a macaque using a two-alternative forced-choice procedure. On a white background, detection thresholds were determined for a white increment and three spectral increments: 618, 516, and 456 nm. Intermixed with detection threshold determinations, color-discrimination thresholds were determined by presenting the white increment, and one of the spectral increments, at 1.0 log units above their respective detection thresholds and dimming both until discrimination performance fell to threshold. The monkey could discriminate the color of the increments at detection threshold because the average color-discrimination threshold was 0.98 ± 0.14 log attenuation. Because the monkey was much more sensitive to the spectral increments than the white increment, we performed an unconventional experiment. We determined the monkey's detection threshold for the white increment alone, and with broadband color filters in the white light path without adjusting the light's intensity. Insertion of several color filters in the light path lowered detection thresholds of both the macaque and six human trichromats. We believe that this improvement in detection thresholds produced by simply inserting color filters in a white light path is a threshold manifestation of the Helmholtz-Kohlrausch effect and suggests that one of color vision's important evolutionary advantages may be improved detection sensitivity.
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Pierce, John D., Richard L. Doty i John E. Amoore. "Analysis of Position of Trial Sequence and Type of Diluent on the Detection Threshold for Phenyl Ethyl Alcohol Using a Single Staircase Method". Perceptual and Motor Skills 82, nr 2 (kwiecień 1996): 451–58. http://dx.doi.org/10.2466/pms.1996.82.2.451.
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Although detection thresholds for odors are commonly measured in academic and medical settings, the influences of procedural factors on threshold values are poorly understood. The present study evaluated the influences of (i) trial sequence position and (ii) diluent type on the threshold value for the rose-like odorant phenyl ethyl alcohol. In Exp. 1, detection thresholds were measured in 24 subjects on two occasions in which different diluents were used in the concentration series, propylene glycol and light mineral oil. The thresholds were estimated using a 7-reversal initially ascending single-staircase procedure. Threshold values were significantly influenced by the type of diluent (lower for mineral oil) and trial sequence (lower for later threshold reversals). In Exp. 2, 24 subjects were administered a staircase threshold test which continued through 15 staircase reversals. Continued testing resulted in a significant lowering of the threshold measure. These findings demonstrate the importance of both diluent and test length on detection threshold values measured by a single staircase procedure and emphasize the need for standardization of procedures for threshold testing.
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Mehta, Gunjan, Anuj Kumar Neupane, Abhishek Mistri, Hiral Joshi i Nirmit Shah. "Comparative Study on Method of Threshold Estimation: Distortion Product Threshold Test versus Pure Tone Threshold Test". Annals of Otology and Neurotology 3, nr 02 (wrzesień 2020): 077–81. http://dx.doi.org/10.1055/s-0041-1724218.
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Abstract Introduction Distortion product otoacoustic emissions (DPOAEs) can be helpful in estimating the hearing thresholds by extrapolating the DPOAE input/output function with the help of scissor paradigm, and thus the following study aims at assessing its reliability by comparing DPOAE thresholds with those obtained by behavioral responses at pure tones on various frequencies. Materials and Methods Fifty participants having normal hearing sensitivity were included in the study. Pure tone (PT) audiometry was carried out on all participants to determine PT thresholds in both ears. DPOAE threshold test was administered and thresholds at 1, 2, 4, and 8 kHz were compared accordingly. Results The result indicated significant difference between the two methods of threshold estimation where the mean difference was found to be 3 decibel (dB) and 4 dB for left and right ears, respectively. Shapiro-Wilk test revealed normal distribution (p > 0.05) of the data. Hence, parametric paired t-test was performed, which revealed significant difference between PT and distortion product thresholds. Conclusion Study concludes as having good clinical applicability in assessing neonates and infants.
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Deng, Rilang, Huifen Liu, Xianchang Zheng, Qinghua Zhang, Wei Liu i Lingwei Chen. "Towards Establishing Empirical Rainfall Thresholds for Shallow Landslides in Guangzhou, Guangdong Province, China". Water 14, nr 23 (1.12.2022): 3914. http://dx.doi.org/10.3390/w14233914.
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Empirical rainfall thresholds for predicting rainfall-triggered shallow landslides are proposed for Guangzhou city, which is prone to widespread geological hazards during the annual flood season due to the subtropical monsoon climate and frequent tropical storms and typhoons. In this study, the cumulated event rainfall (E, in mm), the duration of rainfall event (D, in day) (E–D) thresholds, normalized cumulated event rainfall, and the duration of rainfall event (EMAP–D) thresholds were defined. Thresholds based on five lithological units were obtained at 5%, 20%, and 50% probability levels using quantile regression methods. More than two-thirds of the landslides occurred within units of intrusive rock. The 20-day cumulative rainfall of 97 mm integrating cumulative event rainfall and the duration of rainfall events (CED) is introduced into the three-dimensional spatial threshold. The areas under the receiver operating characteristic curves for the CED threshold and E–D threshold were 0.944 and 0.914, respectively, and the true-positive rate of the CED threshold with the same probability level was slightly lower than that of the E–D threshold, but the CED threshold false-positive rate was much better than the E–D threshold, which can significantly reduce false alarm rate since many non-triggering rainfalls were filtered out.
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EDGECOMB, ROBERT S., LARRY L. MURDOCK, ANDRÉ B. SMITH i MARGARET D. STEPHEN. "Regulation of Tarsal Taste Threshold in the Blowfly, Phormia Regina". Journal of Experimental Biology 127, nr 1 (1.01.1987): 79–94. http://dx.doi.org/10.1242/jeb.127.1.79.
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The nutritional condition of adult blowflies (Phormia regina Meigen) affects their readiness to respond with proboscis extension when their tarsi contact food stimuli. Thresholds are high in sated flies (100–1000 mmol−1 sucrose) and low in starved flies (1–10 mmoll−1 sucrose). Two feeding regimes employing aqueous sucrose were used to reveal factors regulating tarsal taste threshold in this insect: long-term feeding (ad libitum) and single meals administered to starved flies. A positive logarithmic relationship was found between crop weight and tarsal taste threshold, expressed as mean acceptance threshold, in flies fed aqueous sucrose ad libitum for 4 days. Threshold changes after a single meal were positively correlated to both concentration and volume of the sugar solution fed. Thresholds observed in flies fed a single meal were not as high as those in ad libitum-ied flies having the same crop volume. Nerve-transection experiments demonstrated that the median abdominal nerve plays no direct role in threshold regulation in either single-meal-fed or ad libitum-fed flies. Transection of the recurrent nerve (RN), however, significantly attenuated the post-feeding rise in tarsal threshold in starved flies fed a single meal and markedly reduced threshold in sated flies fed ad libitum. Thresholds for RN-transected flies subjected to either feeding regime were still significantly higher than thresholds for starved flies. Haemocoel-injected D-glucose did not significantly elevate threshold in starved flies. These observations establish that the RN plays an important role in the regulation of tarsal taste threshold in blowflies. The effect of the RN on threshold depends largely on the prior feeding activity of the flies. It appears, however, that other factors, in addition to the recurrent nerve, affect taste threshold after feeding.
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Long, S. H., G. Q. Zhou, H. Y. Wang, X. Zhou, J. L. Chen i J. Gao. "DENOISING OF LIDAR ECHO SIGNAL BASED ON WAVELET ADAPTIVE THRESHOLD METHOD". ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLII-3/W10 (7.02.2020): 215–20. http://dx.doi.org/10.5194/isprs-archives-xlii-3-w10-215-2020.
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Abstract. The wavelet threshold method is widely used in signal denoising. However, traditional hard threshold method or soft threshold method is deficient for depending on fixed threshold and instability. In order to achieve efficient denoising of echo signals, an adaptive wavelet threshold denoising method, absorbing the advantages of the hard threshold and the soft threshold, is proposed. Based on the advantages of traditional threshold method, new threshold function is continuous, steerable and flexibly changeable by adjusting two parameters. The threshold function is flexibly changed between the hard threshold and the soft threshold function by two parameter adjustments. According to the Stein unbiased risk estimate (SURE), this new method can determine thresholds adaptively. Adopting different thresholds adaptively at different scales, this method can automatically track noise, which can effectively remove the noise on each scale. Therefore, the problems of noise misjudgement and incomplete denoising can be solved, to some extent, in the process of signal processing. The simulation results of MATLAB show that compared with hard threshold method and soft threshold method, the signal-to-noise ratio (SNR) of the proposed de-noising method is increased by nearly 2dB, and 4dB respectively. It is safely to conclude that, when background noise eliminated, the new wavelet adaptive threshold method preserves signal details effectively and enhances the separability of signal characteristics.
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Oliver, Lawrence R. "Principles of Weed Threshold Research". Weed Technology 2, nr 4 (październik 1988): 398–403. http://dx.doi.org/10.1017/s0890037x00032152.
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Competitive and economic thresholds are distinctive and important concepts to weed scientists. The producer is most concerned about the economic threshold because of its importance in production decisions. The three additive research techniques to determine competitive weed thresholds are removal or plant-back, paired plot, and area of influence. Each method has advantages and disadvantages and must be conducted in a specific manner in the field. The area of influence technique is the most accurate for determining the influence of a single weed. Data must be reported in a usable form such as percent yield reduction. An example calculation for determining the two weed thresholds is illustrated with common cocklebur in soybeans. Generally, the economic threshold is one-half to one-third the competitive threshold.
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Segoni, S., A. Rosi, G. Rossi, F. Catani i N. Casagli. "Analysing the relationship between rainfalls and landslides to define a mosaic of triggering thresholds for regional-scale warning systems". Natural Hazards and Earth System Sciences 14, nr 9 (29.09.2014): 2637–48. http://dx.doi.org/10.5194/nhess-14-2637-2014.
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Abstract. We propose an original approach to develop rainfall thresholds to be used in civil protection warning systems for the occurrence of landslides at regional scale (i.e. tens of thousands of kilometres), and we apply it to Tuscany, Italy (23 000 km2). Purpose-developed software is used to define statistical intensity–duration rainfall thresholds by means of an automated and standardized analysis of rainfall data. The automation and standardization of the analysis brings several advantages that in turn have a positive impact on the applicability of the thresholds to operational warning systems. Moreover, the possibility of defining a threshold in very short times compared to traditional analyses allowed us to subdivide the study area into several alert zones to be analysed independently, with the aim of setting up a specific threshold for each of them. As a consequence, a mosaic of several local rainfall thresholds is set up in place of a single regional threshold. Even if pertaining to the same region, the local thresholds vary substantially and can have very different equations. We subsequently analysed how the physical features of the test area influence the parameters and the equations of the local thresholds, and found that some threshold parameters can be put in relation with the prevailing lithology. In addition, we investigated the possible relations between effectiveness of the threshold and number of landslides used for the calibration. A validation procedure and a quantitative comparison with some literature thresholds showed that the performance of a threshold can be increased if the areal extent of its test area is reduced, as long as a statistically significant landslide sample is present. In particular, we demonstrated that the effectiveness of a warning system can be significantly enhanced if a mosaic of site-specific thresholds is used instead of a single regional threshold.
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Guieu, R., J. C. Samuélian i H. Coulouvrat. "Objective Evaluation of Pain Perception in Patients with Schizophrenia". British Journal of Psychiatry 164, nr 2 (luty 1994): 253–55. http://dx.doi.org/10.1192/bjp.164.2.253.
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The pain thresholds of patients with schizophrenia often seem to differ from those of healthy subjects. In the present study we assessed the pain thresholds of ten patients with schizophrenia, and of ten controls, by measuring the leg flexion nociceptive reflex threshold: the stimulation threshold at which this reflex is triggered, is known to be correlated with the pain threshold. Our conclusion is that, in most cases, the increase in pain threshold is the result of ‘attitude’ and not of alterations in brain function.
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Hoover, Eric C., i Katherine N. Palandrani. "Simulated audiometry reveals multiple asymptotic thresholds for the same listener depending on the number of presentations at threshold". Journal of the Acoustical Society of America 150, nr 4 (październik 2021): A340—A341. http://dx.doi.org/10.1121/10.0008517.
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Changes in audiometric thresholds are used to detect auditory insult resulting from exposure to hazardous noise, blasts, and ototoxicity. Stimuli presented during audiometry reflect a stochastic process driven by listener responses, and thus a threshold can be reported after a different number of presentations, e.g., two hits and zero, one, or two misses. We interpret thresholds as equivalent despite large differences in the proportion of hits observed. To test for systematic bias in thresholds obtained after a different number of presentations, a continuous distribution of audiometric threshold as a function of stimulus level was numerically approximated for a fixed listener model tested using 2 and 5 dB ascending steps. Results were sorted by the number of presentations at threshold and summary statistics were calculated directly from the proportion of Monte Carlo simulations reporting each stimulus level as threshold. Thresholds differed systematically as a function of the number of times the threshold stimulus level was presented, consistent with a model combining the probability of meeting the stopping criteria with the asymptotic distribution of ascending trials. The implication is that recording the number of presentations at threshold on the audiogram will improve our ability to detect changes in hearing. [R01DC015051.]
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YAMAMOTO, YORIKO, YORIKO ATOMI i HIDEO HATTA. "VENTILATION THRESHOLD AND LACTATE THRESHOLD OF 9-12 YEAR-OLD BOYS AND GIRLS". Japanese Journal of Physical Fitness and Sports Medicine 34, nr 4 (1985): 211–17. http://dx.doi.org/10.7600/jspfsm1949.34.211.
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Petersen, Karin Lottrup, Jannick Brennum i Jes Olesen. "Evaluation of Pericranial Myofascial Nociception by Pressure Algometry. Reproducibility and Factors of Variation". Cephalalgia 12, nr 1 (luty 1992): 33–37. http://dx.doi.org/10.1046/j.1468-2982.1992.1201033.x.
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Pressure pain detection threshold and pressure pain tolerance threshold were measured in the temples and on the fingers in 40 healthy volunteers, equally distributed as to sex and handedness. Lower pressure pain thresholds were found over the temporal muscle than in a neighbouring temporal location without interposed myofascial tissue ( p < 0.001), indicating that nociception from myofascial tissue contributes to the pressure pain threshold. Pressure pain tolerance was more reproducible within the individual subject but differed more between subjects than pressure pain detection. Pressure pain thresholds were higher on the fingers than in the temples ( p < 10-5) and, in general, thresholds were higher in males than in females ( p = 0.02 – 0.09). Finally, pressure pain thresholds were lateralized in dextrals but not in sinistrals. The information that can be obtained from pressure pain detection and tolerance thresholds is discussed and examination of both threshold types is recommended in future studies.
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Tang, Hui, Zeng Li Liu, Lin Chen i Zai Yu Chen. "Wavelet Image Denoising Based on the New Threshold Function". Applied Mechanics and Materials 347-350 (sierpień 2013): 2231–35. http://dx.doi.org/10.4028/www.scientific.net/amm.347-350.2231.
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A new threshold function was proposed to overcome that hard threshold function is not continuous, soft threshold function has constant deviation and derivative discontinuity defects. It will be applied to using different thresholds denoising method with different decomposition level based on the D.J global threshold. Experimental results shows that the denoising result of new threshold function is superior to the traditional soft and hard threshold function in minimum mean square error (MSE) and peak signal to noise ratio (PSNR).
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Beranic, Tina, i Marjan Hericko. "Comparison of systematically derived software metrics thresholds for object-oriented programming languages". Computer Science and Information Systems 17, nr 1 (2020): 181–203. http://dx.doi.org/10.2298/csis181012035b.
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Without reliable software metrics threshold values, the efficient quality evaluation of software could not be done. In order to derive reliable thresholds, we have to address several challenges, which impact the final result. For instance, software metrics implementations vary in various software metrics tools, including varying threshold values that result from different threshold derivation approaches. In addition, the programming language is also another important aspect. In this paper, we present the results of an empirical study aimed at comparing systematically obtained threshold values for nine software metrics in four object-oriented programming languages (i.e., Java, C++, C#, and Python).We addressed challenges in the threshold derivation domain within introduced adjustments of the benchmarkbased threshold derivation approach. The data set was selected in a uniform way, allowing derivation repeatability, while input values were collected using a single software metric tool, enabling the comparison of derived thresholds among the chosen object-oriented programming languages.Within the performed empirical study, the comparison reveals that threshold values differ between different programming languages.
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Farooq, Muhammad Umar, Alexandre Graell i Amat i Michael Lentmaier. "Threshold Computation for Spatially Coupled Turbo-Like Codes on the AWGN Channel". Entropy 23, nr 2 (19.02.2021): 240. http://dx.doi.org/10.3390/e23020240.
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In this paper, we perform a belief propagation (BP) decoding threshold analysis of spatially coupled (SC) turbo-like codes (TCs) (SC-TCs) on the additive white Gaussian noise (AWGN) channel. We review Monte-Carlo density evolution (MC-DE) and efficient prediction methods, which determine the BP thresholds of SC-TCs over the AWGN channel. We demonstrate that instead of performing time-consuming MC-DE computations, the BP threshold of SC-TCs over the AWGN channel can be predicted very efficiently from their binary erasure channel (BEC) thresholds. From threshold results, we conjecture that the similarity of MC-DE and predicted thresholds is related to the threshold saturation capability as well as capacity-approaching maximum a posteriori (MAP) performance of an SC-TC ensemble.
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Shock, C. C., E. B. G. Feibert i L. D. Saunders. "Onion Yield and Quality Affected by Soil Water Potential as Irrigation Threshold". HortScience 33, nr 7 (grudzień 1998): 1188–91. http://dx.doi.org/10.21273/hortsci.33.7.1188.
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Onion (Allium cepa L., `Great Scott') was grown on silt loam soils and submitted to four irrigation thresholds (-25, -50, -75, and -100 kPa) in 1992 and six irrigation thresholds (-12.5, -25, -37.5, -50, -75, and -100 kPa) in 1993 and 1994. Irrigation thresholds (soil water potential measured at 0.2-m depth) were used as criteria to initiate furrow irrigations. Onions were evaluated for yield and grade after 70 days of storage. In 1992 and 1994, total yield, marketable yield, and profit increased with increasing irrigation threshold. In 1993, total yield increased with increasing irrigation threshold, but marketable yield and profit were maximized by a calculated threshold of -27 kPa due to a substantial increase of decomposition during storage with increasing threshold.
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Zhu, Xiao Li, i Ze Zhang. "Research of Filtering Algorithm for Echo of Ultrasonic Wave Based on Wavelet Transformation". Applied Mechanics and Materials 52-54 (marzec 2011): 1212–17. http://dx.doi.org/10.4028/www.scientific.net/amm.52-54.1212.
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This paper proposes an improved wavelet threshold denoising method, threshold function by selecting different thresholds to filter out the noisy signal. Firstly, do the wavelet transformation for noisy signal, and then use soft threshold, hard threshold and the improved threshold algorithm to denoising the signal, finally realized by Matlab simulation of wavelet thresholding. Threshold denoising via different methods of simulation experiments show that the improved threshold denoising algorithm can effectively filter plate bonding ultrasonic echo signal in the noise detection and can be a good feature to retain the original signal.
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McCreery, Ryan, Elizabeth Walker, Meredith Spratford, Benjamin Kirby, Jacob Oleson i Marc Brennan. "Stability of Audiometric Thresholds for Children with Hearing Aids Applying the American Academy of Audiology Pediatric Amplification Guideline: Implications for Safety". Journal of the American Academy of Audiology 27, nr 03 (marzec 2016): 252–63. http://dx.doi.org/10.3766/jaaa.15049.
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Background: Children who wear hearing aids may be at risk for further damage to their hearing from overamplification. Previous research on amplification-induced hearing loss has included children using linear amplification or simulations of predicted threshold shifts based on nonlinear amplification formulae. A relationship between threshold shifts and the use of nonlinear hearing aids in children has not been empirically verified. Purpose: The purpose of the study was to compare predicted threshold shifts from amplification to longitudinal behavioral thresholds in a large group of children who wear hearing aids to determine the likelihood of amplification-induced hearing loss. Research Design: An accelerated longitudinal design was used to collect behavioral threshold and amplification data prospectively. Study Sample: Two-hundred and thirteen children with mild-to-profound hearing loss who wore hearing aids were included in the analysis. Data Collection and Analysis: Behavioral audiometric thresholds, hearing aid outputs, and hearing aid use data were collected for each participant across four study visits. Individual ear- and frequency-specific safety limits were derived based on the Modified Power Law to determine the level at which increased amplification could result in permanent threshold shifts. Behavioral thresholds were used to estimate which children would be above the safety limit at 500, 1000, 2000, and 4000 Hz using thresholds in dB HL and then in dB SPL in the ear canal. Changes in thresholds across visits were compared for children who were above and below the safety limits. Results: Behavioral thresholds decreased across study visits for all children, regardless of whether their amplification was above the safety limits. The magnitude of threshold change across time corresponded with changes in ear canal acoustics as measured by the real-ear-to-coupler difference. Conclusions: Predictions of threshold changes due to amplification for children with hearing loss did not correspond with observed changes in threshold over across 2–4 yr of monitoring amplification. Use of dB HL thresholds and predictions of hearing aid output to set the safety limit resulted in a larger number of children being classified as above the safety limit than when safety limits were based on dB SPL thresholds and measured hearing aid output. Children above the safety limit for the dB SPL criteria tended to be fit above prescriptive targets. Additional research should seek to explain how the Modified Power Law predictions of threshold shift overestimated risk for children who wear hearing aids.
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Strzalkowski, Nicholas D. J., Robyn L. Mildren i Leah R. Bent. "Thresholds of cutaneous afferents related to perceptual threshold across the human foot sole". Journal of Neurophysiology 114, nr 4 (październik 2015): 2144–51. http://dx.doi.org/10.1152/jn.00524.2015.
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Perceptual thresholds are known to vary across the foot sole, despite a reported even distribution in cutaneous afferents. Skin mechanical properties have been proposed to account for these differences; however, a direct relationship between foot sole afferent firing, perceptual threshold, and skin mechanical properties has not been previously investigated. Using the technique of microneurography, we recorded the monofilament firing thresholds of cutaneous afferents and associated perceptual thresholds across the foot sole. In addition, receptive field hardness measurements were taken to investigate the influence of skin hardness on these threshold measures. Afferents were identified as fast adapting [FAI ( n = 48) or FAII ( n = 13)] or slowly adapting [SAI ( n = 21) or SAII ( n = 20)], and were grouped based on receptive field location (heel, arch, metatarsals, toes). Overall, perceptual thresholds were found to most closely align with firing thresholds of FA afferents. In contrast, SAI and SAII afferent firing thresholds were found to be significantly higher than perceptual thresholds and are not thought to mediate monofilament perceptual threshold across the foot sole. Perceptual thresholds and FAI afferent firing thresholds were significantly lower in the arch compared with other regions, and skin hardness was found to positively correlate with both FAI and FAII afferent firing and perceptual thresholds. These data support a perceptual influence of skin hardness, which is likely the result of elevated FA afferent firing threshold at harder foot sole sites. The close coupling between FA afferent firing and perceptual threshold across foot sole indicates that small changes in FA afferent firing can influence perceptual thresholds.
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Raggio, Marcia W., i Christoph E. Schreiner. "Neuronal Responses in Cat Primary Auditory Cortex to Electrical Cochlear Stimulation: IV. Activation Pattern for Sinusoidal Stimulation". Journal of Neurophysiology 89, nr 6 (czerwiec 2003): 3190–204. http://dx.doi.org/10.1152/jn.00341.2002.
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Patterns of threshold distributions for single-cycle sinusoidal electrical stimulation and single pulse electrical stimulation were compared in primary auditory cortex of the adult cat. Furthermore, the effects of auditory deprivation on these distributions were evaluated and compared across three groups of adult cats. Threshold distributions for single and multiple unit responses from the middle cortical layers were obtained on the ectosylvian gyrus in an acutely implanted animal; 2 wk after deafening and implantation (short-term group); and neonatally deafened animals implanted following 2–5 yr of deafness (long-term group). For all three cases, we observed similar patterns of circumscribed regions of low response thresholds in the region of primary auditory cortex (AI). A dorsal and a ventral region of low response thresholds were found separated by a narrow, anterior-posterior strip of elevated thresholds. The ventral low-threshold regions in the short-term group were cochleotopically arranged. By contrast, the dorsal region in the short-term animals and both low-threshold regions in long-term deafened animals maintained only weak cochleotopicity. Analysis of the spatial extent of the low-threshold regions revealed that the activated area for sinusoidal stimulation was smaller and more circumscribed than for pulsatile stimulation for both dorsal and ventral AI. The width of the high-threshold ridge that separated the dorsal and ventral low-threshold regions was greater for sinusoidal stimulation. Sinusoidal and pulsatile threshold behavior differed significantly for electrode configurations with low and high minimum thresholds. Differences in threshold behavior and cortical response distributions between the sinusoidal and pulsatile stimulation suggest that stimulus shape plays a significant role in the activation of cortical activity. Differences in the activation pattern for short-term and long-term deafness reflect deafness-induced reorganizational changes based on factors such as differences in excitatory and inhibitory balance that are affected by the stimulation parameters.
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Prasher, Deepak, Mohamed Mula i Linda Luxon. "Cortical evoked potential criteria in the objective assessment of auditory threshold: a comparison of noise induced hearing loss with Ménière's disease". Journal of Laryngology & Otology 107, nr 9 (wrzesień 1993): 780–86. http://dx.doi.org/10.1017/s0022215100124429.
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AbstractAmplitude of the Nl component of the cortical response was used to objectively determine threshold of hearing at 1 kHz and 4 kHz in a series of consecutively referred medicolegal cases with alleged occupational noise induced hearing loss and a control group of patients with Ménière's disease who were not seeking compensation for their hearing loss. The cortical response thresholds were compared with the subjective pure tone audiometric (PTA) thresholds at the same frequencies. The cortical and PTA thresholds were ‘;within 10 dB’; for 84 and 92 per cent of the cases of noise induced hearing loss (NIHL) and Ménière's disease respectively, confirming the validity of CERA as a means of denning accurately the frequency specific thresholds and the audiometric configuration. Of the remaining 16 per cent of NIHL, 13 per cent exaggerated their PTA thresholds at 1 kHz and 10 per cent at 4 kHz whilst the error in cortical threshold estimation was beyond the 10 dB level for three and six per cent of cases at those frequencies respectively. The median exaggeration of threshold was 25 dB. For eight per cent of the Ménière's patients, thresholds exceeded 10 dB at both 1 and 4 kHz, four per cent of whom exaggerated their PTA thresholds and four per cent had a test error greater than 10 dB. A similar percentage (four per cent) of both groups revealed a cortical test error greater than 10 dB whereas three times as many cases of noise induced hearing loss (13 per cent) revealed exaggeration of their subjective audiometric thresholds compared with the Ménière's group (four per cent).The value of latency criteria in the assessment of cortical threshold was established. The latency of Nl close to threshold was invariably greater than 150 ms and at 30 dB above threshold, irrespective of absolute levels, it was within 10 ms of 100 ms, thereby providing another criterion for the improved measurement of threshold.
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Ferreira, Guilherme A., Romulo Bertuzzi, Adriano E. Lima-Silva, Carlos Malfatti, Fernando R. De-Oliveira i Raul Osiecki. "Identification of training status differences using perceived exertion threshold". Applied Physiology, Nutrition, and Metabolism 41, nr 4 (kwiecień 2016): 456–59. http://dx.doi.org/10.1139/apnm-2015-0478.
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We investigated if the rate of perceived exertion (RPE) threshold is as sensitive as the lactate threshold to detect training differences. Lactate and RPE thresholds were identified in well-trained cyclists and physically active males. Power output was higher in well-trained cyclists than in physically active individuals for both thresholds (p < 0.05). Our results suggest that RPE threshold is successful in discriminating differences between well-trained cyclists and physically active individuals.
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Lin, Yang, i Jin Liang. "The relationship between two kinds of structural credit migration models". AIMS Mathematics 9, nr 2 (2024): 4551–61. http://dx.doi.org/10.3934/math.2024219.
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<abstract><p>In this paper, we presented an asymptotic relationship between the single threshold model and the model with different upgrade and downgrade thresholds for credit migration problems with fixed boundaries. By partial differential equation (PDE) techniques, we proved that the solution of the asymmetric threshold problem converges to that of a single threshold problem uniformly as one of the asymmetric thresholds approaches the other.</p></abstract>
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Corbin, J. C., T. B. Towles, W. D. Crow, A. L. Catchot, D. R. Cook, D. M. Dodds i J. Gore. "Evaluation of Current Tarnished Plant Bug (Hemiptera: Miridae) Thresholds in Transgenic MON 88702 Cotton Expressing the Bt Cry51Aa2.834_16 Trait". Journal of Economic Entomology 113, nr 4 (25.04.2020): 1816–22. http://dx.doi.org/10.1093/jee/toaa075.
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Abstract The tarnished plant bug, Lygus lineolaris (Palisot de Beauvois), is an important pest of cotton in many areas of the southern United States. An experiment was conducted at two locations in Mississippi during 2016 and 2017 to evaluate action thresholds for tarnished plant bug on a novel Bacillus thuringiensis cotton that expresses the Cry51Aa2.834_16 toxin. Treatments included the current action threshold, a 2× threshold, and treatments where insecticides were only applied during the early season (preflower) or only during late season (during flowering) based on the current action thresholds. These were compared to an untreated control and a weekly insecticide use regime that received weekly insecticide sprays. All treatments were imposed on both Bt Cry1Aa2.834_16 cotton and a nontraited cotton. The Bt Cry1Aa2.834_16 trait reduced the number of tarnished plant bugs and injury, and improved yields compared to nontraited cotton. For all spray treatments except the weekly insecticide use regime, yields were greater for the Bt Cry51Aa2.834_16 cotton than the nontraited cotton. In terms of thresholds, Bt Cry1Aa2.834_16 cotton sprayed based on current action thresholds resulted in similar yields to the weekly insecticide use regime of both cotton types. In contrast, the 2× threshold resulted in lower yields than the current threshold for both cotton types. Though thresholds intermediate to the currently recommended action threshold and the 2× threshold were not tested, these data suggest that currently recommended action thresholds appear appropriate for Bt Cry51Aa2.834_16 cotton. These results suggest that this trait will be an important component of current IPM programs in cotton where tarnished plant bug is an important pest.
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Das, Aparna, Arun Alexander, Anuprasad Sreenivasan i Sivaraman Ganesan. "Electrically evoked compound action potential in children following cochlear implantation and its correlation with cochlear nerve diameter". International Journal of Otorhinolaryngology and Head and Neck Surgery 9, nr 11 (25.10.2023): 860–66. http://dx.doi.org/10.18203/issn.2454-5929.ijohns20233215.
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Background: The study evaluated changes in the threshold of ECAP recorded during cochlear implantation, at switch on, after three months and six months following cochlear implantation. It further assessed the correlation between the ECAP threshold with T and C levels and the cochlear nerve diameter measured preoperatively. Methods: A prospective study of 42 prelingually deaf children who underwent cochlear implantation was conducted. The ECAP threshold values intra-operatively, at switch on, three months and six months were recorded and analysed. The T and C levels were assessed six months postoperatively, and correlation with the ECAP threshold was analysed. The diameter of the cochlear nerve was recorded, and its correlation with the ECAP threshold was determined. Results: Over six months, the basal, central and apical electrodes showed a statistically significant reduction in ECAP threshold of 11.64%, 4.67% and 25.81%, respectively, in candidates implanted with Advanced Bionics implant and 18.89%, 12.78% and 14.08%, respectively in candidates implanted with Nucleus implant. The ECAP thresholds were lower for the apical electrodes. No correlation was found between the ECAP threshold and T and C levels. A correlation between the cochlear nerve diameter and ECAP was not statistically significant. Conclusions: There was a statistically significant change in the ECAP threshold over six months. There was no statistically significant correlation between the ECAP thresholds and T and C levels. The value of ECAP thresholds to measure C and T values need to be relooked. There was no correlation between the cochlear nerve diameter and the ECAP threshold.
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Tran, Christopher, i Elena Zheleva. "Heterogeneous Peer Effects in the Linear Threshold Model". Proceedings of the AAAI Conference on Artificial Intelligence 36, nr 4 (28.06.2022): 4175–83. http://dx.doi.org/10.1609/aaai.v36i4.20336.
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The Linear Threshold Model is a widely used model that describes how information diffuses through a social network. According to this model, an individual adopts an idea or product after the proportion of their neighbors who have adopted it reaches a certain threshold. Typical applications of the Linear Threshold Model assume that thresholds are either the same for all network nodes or randomly distributed, even though some people may be more susceptible to peer pressure than others. To address individual-level differences, we propose causal inference methods for estimating individual thresholds that can more accurately predict whether and when individuals will be affected by their peers. We introduce the concept of heterogeneous peer effects and develop a Structural Causal Model which corresponds to the Linear Threshold Model and supports heterogeneous peer effect identification and estimation. We develop two algorithms for individual threshold estimation, one based on causal trees and one based on causal meta-learners. Our experimental results on synthetic and real- world datasets show that our proposed models can better predict individual-level thresholds in the Linear Threshold Model and thus more precisely predict which nodes will get activated over time.
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Zhang, Haiguang, i Wenjun Bu. "Exploring Large-Scale Patterns of Genetic Variation in the COI Gene among Insecta: Implications for DNA Barcoding and Threshold-Based Species Delimitation Studies". Insects 13, nr 5 (30.04.2022): 425. http://dx.doi.org/10.3390/insects13050425.
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The genetic variation in the COI gene has had a great effect on the final results of species delimitation studies. However, little research has comprehensively investigated the genetic divergence in COI among Insecta. The fast-growing COI data in BOLD provide an opportunity for the comprehensive appraisal of the genetic variation in COI among Insecta. We calculated the K2P distance of 64,414 insect species downloaded from BOLD. The match ratios of the clustering analysis, based on different thresholds, were also compared among 4288 genera (35,068 species). The results indicate that approximately one-quarter of the species of Insecta showed high intraspecific genetic variation (>3%), and a conservative estimate of this proportion ranges from 12.05% to 22.58%. The application of empirical thresholds (e.g., 2% and 3%) in the clustering analysis may result in the overestimation of the species diversity. If the minimum interspecific genetic distance of the congeneric species is greater than or equal to 2%, it is possible to avoid overestimating the species diversity on the basis of the empirical thresholds. In comparison to the fixed thresholds, the “threshOpt” and “localMinima” algorithms are recommended for the provision of a reference threshold for threshold-based species-delimitation studies.
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Segoni, S., A. Rosi, G. Rossi, F. Catani i N. Casagli. "Analysing the relationship between rainfalls and landslides to define a mosaic of triggering thresholds for regional scale warning systems". Natural Hazards and Earth System Sciences Discussions 2, nr 3 (25.03.2014): 2185–213. http://dx.doi.org/10.5194/nhessd-2-2185-2014.
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Abstract. We propose an original approach to develop rainfall thresholds to be used in civil protection warning systems for the occurrence of landslides at regional scale (i.e. tens of thousands kilometres). A purposely developed software is used to define statistical intensity-duration rainfall thresholds by means of an automated and standardized analysis of rainfall data. The automation and standardization of the analysis brings several advantages that in turn have a positive impact on the applicability of the thresholds to operational warning systems. Moreover, the possibility of defining a threshold in very short times compared to traditional analyses allowed us subdividing the study area in several alert zones to be analyzed independently with the aim of setting up a specific threshold for each of them. As a consequence, a mosaic of several local rainfall thresholds is set up in place of a single regional threshold. We subsequently analyzed how the physical features of the test area influence the parameters and the equations of the local thresholds, founding a significant correlation with the prevailing lithology. A validation procedure and a quantitative comparison with some literature thresholds showed that the performance of a threshold can be increased if the areal extent of its test area is reduced, as long as a statistically significant landslide sample is present. In particular, we demonstrated that the effectiveness of a warning system can be significantly enhanced if a mosaic of site specific thresholds is used instead of a single regional threshold.
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Charansiriphaisan, Kanjana, Sirapat Chiewchanwattana i Khamron Sunat. "A Global Multilevel Thresholding Using Differential Evolution Approach". Mathematical Problems in Engineering 2014 (2014): 1–23. http://dx.doi.org/10.1155/2014/974024.
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Otsu’s function measures the properness of threshold values in multilevel image thresholding. Optimal threshold values are necessary for some applications and a global search algorithm is required. Differential evolution (DE) is an algorithm that has been used successfully for solving this problem. Because the difficulty of a problem grows exponentially when the number of thresholds increases, the ordinary DE fails when the number of thresholds is greater than 12. An improved DE, using a new mutation strategy, is proposed to overcome this problem. Experiments were conducted on 20 real images and the number of thresholds varied from 2 to 16. Existing global optimization algorithms were compared with the proposed algorithms, that is, DE, rank-DE, artificial bee colony (ABC), particle swarm optimization (PSO), DPSO, and FODPSO. The experimental results show that the proposed algorithm not only achieves a more successful rate but also yields a lower threshold value distortion than its competitors in the search for optimal threshold values, especially when the number of thresholds is large.
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Nikitinskaya, Oksana A., i Natalya V. Toroptsova. "Progress of osteoporosis: stratification of fracture risk". Osteoporosis and Bone Diseases 21, nr 1 (25.04.2018): 4–9. http://dx.doi.org/10.14341/osteo9620.
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Background: There are two approaches to identify candidates for the prescription of osteoporosis treatment: identification of patients with low bone mineral density using DEXA of the axial skeleton and calculation of the 10-year probability of major osteoporotic fractures using FRAX®.
Aims: to assess the diagnostic accuracy of different FRAX® thresholds in the Russian population.
Materials and methods: the value of individual 10-year probability of osteoporotic fracture by FRAX® at the time of inclusion in the study was retrospectively estimated in 224 postmenopausal women, whom the major osteoporotic fractures were recorded over 10 years of prospective observation. The diagnostic accuracy of different thresholds were compared: "European" and Russian age-dependent thresholds, fixed 20% threshold, the average FRAX® of patients who had a major osteoporotic fracture during follow-up (16%), FRAX® value corresponding to the "cut-off point" (12,5%).
Results: The Russian FRAX model showed the acceptable diagnostic accuracy of the method (AUC=0.665±0.036; 95% CI 0.595; 0.736). The "European" threshold of therapeutic intervention demonstrated 72% sensitivity and 38% specificity, 20% threshold – 27% and 87%, the Russian threshold – 41% and 77%, 12.5% threshold – 68% and 58%, 16% threshold – 57% and 73%, respectively. The diagnostic precision of the specified thresholds was 54%, 58%, 60%, 63% and 65%, respectively.
Conclusions: the Russian age-dependent threshold remains the optimal way to decide whether to initiate anti-osteoporotic therapy based on an assessment of the 10-year probability of fracture by the Russian model for FRAX®.
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Werner, Lynne A., Richard C. Folsom, Lisa R. Mancl i Connie L. Syapin. "Human Auditory Brainstem Response to Temporal Gaps in Noise". Journal of Speech, Language, and Hearing Research 44, nr 4 (sierpień 2001): 737–50. http://dx.doi.org/10.1044/1092-4388(2001/058).
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Gap detection is a commonly used measure of temporal resolution, although the mechanisms underlying gap detection are not well understood. To the extent that gap detection depends on processes within, or peripheral to, the auditory brainstem, one would predict that a measure of gap threshold based on the auditory brainstem response (ABR) would be similar to the psychophysical gap detection threshold. Three experiments were performed to examine the relationship between ABR gap threshold and gap detection. Thresholds for gaps in a broadband noise were measured in young adults with normal hearing, using both psychophysical techniques and electrophysiological techniques that use the ABR. The mean gap thresholds obtained with the two methods were very similar, although ABR gap thresholds tended to be lower than psychophysical gap thresholds. There was a modest correlation between psychophysical and ABR gap thresholds across participants. ABR and psychophysical thresholds for noise masked by temporally continuous, high-pass, or spectrally notched noise were measured in adults with normal hearing. Restricting the frequency range with masking led to poorer gap thresholds on both measures. High-pass maskers affected the ABR and psychophysical gap thresholds similarly. Notched-noise-masked ABR and psychophysical gap thresholds were very similar except that low-frequency, notched-noise-masked ABR gap threshold was much poorer at low levels. The ABR gap threshold was more sensitive to changes in signal-to-masker ratio than was the psychophysical gap detection threshold. ABR and psychophysical thresholds for gaps in broadband noise were measured in listeners with sensorineural hearing loss and in infants. On average, both ABR gap thresholds and psychophysical gap detection thresholds of listeners with hearing loss were worse than those of listeners with normal hearing, although individual differences were observed. Psychophysical gap detection thresholds of 3- and 6-month-old infants were an order of magnitude worse than those of adults with normal hearing, as previously reported; however, ABR gap thresholds of 3-month-old infants were no different from those of adults with normal hearing. These results suggest that ABR gap thresholds and psychophysical gap detection depend on at least some of the same mechanisms within the auditory system.
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Dawood, Akram A. "A Contourlet-Based Image Denoising Technique with Coefficient Threshold Level Estimation". Tikrit Journal of Engineering Sciences 20, nr 4 (31.12.2013): 11–22. http://dx.doi.org/10.25130/tjes.20.4.02.
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In this paper, a new image denoising technique is proposed based on contourlet transform. Many random images are generated simulating the standard deviation level of the original noisy image and the contourlet threshold level is then calculated based on such simulations. Different contourlet coefficients are thresholded by such precalculated contourlet thresholds indicating a nonlinear thresholding manner. The resulting denoised images posses the superiority of the proposed technique over three other recents. Subjective and objective measurements of the proposed technique support such superiority.
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Kelly, Ryan P., Ashley L. Erickson, Lindley A. Mease, Willow Battista, John N. Kittinger i Rod Fujita. "Embracing thresholds for better environmental management". Philosophical Transactions of the Royal Society B: Biological Sciences 370, nr 1659 (5.01.2015): 20130276. http://dx.doi.org/10.1098/rstb.2013.0276.
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Three decades of study have revealed dozens of examples in which natural systems have crossed biophysical thresholds (‘tipping points’)—nonlinear changes in ecosystem structure and function—as a result of human-induced stressors, dramatically altering ecosystem function and services. Environmental management that avoids such thresholds could prevent severe social, economic and environmental impacts. Here, we review management measures implemented in ecological systems that have thresholds. Using Ostrom's social–ecological systems framework, we analysed key biophysical and institutional factors associated with 51 social–ecological systems and associated management regimes, and related these to management success defined by ecological outcomes. We categorized cases as instances of prospective or retrospective management, based upon whether management aimed to avoid a threshold or to restore systems that have crossed a threshold. We find that smaller systems are more amenable to threshold-based management, that routine monitoring is associated with successful avoidance of thresholds and recovery after thresholds have been crossed, and that success is associated with the explicit threshold-based management. These findings are powerful evidence for the policy relevance of information on ecological thresholds across a wide range of ecosystems.
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Nilsson-Örtman, Viktor, i Locke Rowe. "The evolution of developmental thresholds and reaction norms for age and size at maturity". Proceedings of the National Academy of Sciences 118, nr 7 (8.02.2021): e2017185118. http://dx.doi.org/10.1073/pnas.2017185118.
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Developing organisms typically mature earlier and at larger sizes in favorable growth conditions, while in rarer cases, maturity is delayed. The rarer reaction norm is easily accommodated by general life history models, whereas the common pattern is not. Theory suggests that a solution to this paradox lies in the existence of critical size thresholds at which maturation or metamorphosis can commence, and in the evolution of these threshold sizes in response to environmental variation. For example, ephemeral environments might favor the evolution of smaller thresholds, enabling earlier maturation. The threshold model makes two unique and untested predictions. First, reaction norms for age and size should steepen, and even change sign, with decreases in threshold size; second, food reductions at sizes below the threshold should delay maturation, while those occurring after the threshold should accelerate maturation. We test these predictions through food manipulations in five damselfly species that theory suggests should differ in threshold size. The results provide strong support for the threshold model’s predictions. In all species, early food reductions delayed maturation, while late reductions accelerated maturation. Reaction norms were steeper, and the effect of food reductions changed from decelerating to accelerating at a much smaller size in species from ephemeral habitats. These results support the view that developmental thresholds can account for the widespread observation of negative correlations between age and size at maturity. Moreover, evolution of the threshold appears to be both predictable and central to the observed diversity of reaction norms for age and size at maturity.
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Rosen, D. "Threshold". Canadian Medical Association Journal 185, nr 3 (21.01.2013): 272. http://dx.doi.org/10.1503/cmaj.121197.
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Sacks, Peter. "Threshold". Yale Review 90, nr 1 (styczeń 2002): 106–7. http://dx.doi.org/10.1111/0044-0124.00581.
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Thurston, Bonnie. "Threshold". Spiritus: A Journal of Christian Spirituality 12, nr 2 (2012): 293. http://dx.doi.org/10.1353/scs.2012.0027.
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Zernecke, R., B. Vollmer, J. Albrecht, A. M. Kleemann, K. Haegler, J. Linn, G. Fesl, H. Bruckmann i M. Wiesmann. "Comparison of two different odorants in an olfactory detection threshold test of the Sniffin’ Sticks". Rhinology journal 48, nr 3 (1.09.2010): 368–73. http://dx.doi.org/10.4193/rhino09.212.
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The olfactory test battery Sniffin’ Sticks is a test of nasal chemosensory function that is based on pen-like devices for odour presentation. It consists of three olfactory subtests: threshold, discrimination, and identification. The detection threshold can be measured using two different odorants--n-butanol or PEA (phenylethyl alcohol). Both tasks are commonly applied in published studies, but little is known about the formal comparison of values obtained using them. Unlike the Sniffin’ Sticks with n-butanol as odorant, there is poor validation for the threshold subtest with the odorant PEA. The purpose of this study was to compare these two different odorants. Both odorants were applied to 100 normosmic, healthy subjects (50 females). The experiment was divided into two sessions performed on two different days. After each threshold test the discrimination and identification subtests were conducted. We obtained significant differences in detection thresholds of PEA and n-butanol. The mean score of PEA threshold and PEA TDI (sum of threshold, discrimination, identification) was significantly higher compared to n-butanol. No significant correlation between individual PEA and n-butanol thresholds was observed. The differences between both odorants indicate that a formal validation of the Sniffin’ Sticks with PEA as odorant for probing olfactory thresholds may be required.
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Sharma, K., P. Sharma, A. Sharma i G. Singh. "Phenylthiocarbamide taste perception and susceptibility to motion sickness: linking higher susceptibility with higher phenylthiocarbamide taste acuity". Journal of Laryngology & Otology 122, nr 10 (5.02.2008): 1064–73. http://dx.doi.org/10.1017/s0022215107001442.
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AbstractObjective:This study is the first attempt to link quantified phenylthiocarbamide bitter taste recognition threshold with susceptibility to motion sickness.Subjects:The study was conducted on a sample of 291 teenage Rajput children (146 males and 145 females; age range 13–19 years) from the Sirmour district of Himachal Pradesh, India. Phenylthiocarbamide taste sensitivity was measured by administering a serial dilution of a freshly prepared phenylthiocarbamide solution, following the method of Harris and Kalmus. Motion sickness susceptibility was assessed retrospectively via interview.Results:About 40 per cent of the subjects had experienced motion sickness in the past. The mean and standard deviation of phenylthiocarbamide taste thresholds in non-tasters and tasters were 0.83 ± 0.87 and 7.98 ± 1.86, respectively. A bimodal distribution test (D/S) index of 5.24 confirmed bimodality of phenylthiocarbamide taste threshold distribution. The Mann–Whitney U test rejected the null hypothesis of μ1 = μ2 and thus confirmed the existence of differences in the distributions of phenylthiocarbamide taste threshold between individuals susceptible and not susceptible to motion sickness. Individuals susceptible to motion sickness had lower mean and median taste thresholds, indicating higher phenylthiocarbamide taste sensitivity, compared with non-susceptible individuals. The frequency of non-tasters was about 10 per cent in both motion sickness susceptible and non-susceptible individuals. The simple division of phenylthiocarbamide tasting ability into tasters and non-tasters was a less sensitive criterion with which to measure the association of this ability with motion sickness susceptibility. However, further differentiation of tasters into weak threshold, medium threshold and super threshold (‘supersensitive’) tasters clearly revealed a highly significantly increased risk of motion sickness in super threshold tasters (i.e. threshold solution number ≥12). The ratio of motion sickness susceptible individuals to non-susceptible individuals was 1:1.7 for non-tasters (threshold solution numbers zero to three) and weak and medium tasters (threshold solution numbers four to 11), but the trend was reversed for super threshold tasters (threshold solution numbers 12 and 13), in whom the ratio was 2:1.Conclusion:Individuals exhibiting greater phenylthiocarbamide taste acuity (i.e. supersensitive tasters) had a higher susceptibility to motion sickness than did non-, weak and medium phenylthiocarbamide tasters, as measured in terms of their taste thresholds (i.e. threshold solution numbers zero to 11).
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Fadhli, Harun, Sarip Sarip i Nur Rahman. "DAMPAK PRESIDENTIAL THRESHOLD TERHADAP REGENT THRESHOLD". Jurnal De Jure Muhammadiyah Cirebon 5, nr 1 (2.06.2021): 19–41. http://dx.doi.org/10.32534/djmc.v5i1.3173.
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The election of the President and Vice President of Indonesia has experienced many dynamics from time to time. The beginning of independence, precisely on August 18, 1945, was carried out by the Preparatory Committee for Indonesian Independence (PPKI). the second replaces Sukarno. The minimum threshold (presidential threshold) became known in Indonesia in 2004, along with the issuance of Law no. 23/2003 concerning General Elections (Pemilu). The stipulation is that Political Parties (Parpol) must reach a minimum of 15% of the DPR seats and 20% of the national valid votes to be able to carry the president and vice president. Efforts to restore democracy to prevent the arbitrariness of the rulers through the presidential threshold have their own obstacles. The function of research is to seek the truth, truth is intended with regard to the nature, source, and scope of knowledge. Setting the Presidential Threshold in the presidential and vice presidential elections in Indonesia has had many impacts. So with the high Presidential Threshold, the public and political parties then submitted a judicial review to the Constitutional Court and in the Constitutional Court's decision Number 53/PUU-XV/2017 regarding the judicial review of Law No. 7/2017 article 222 which discusses the Presidential Threshold, the Constitutional Court refused. The refusal of judicial review of Article 222 of Law No. 7/2017 of the Constitutional Court resulted in setting the threshold for regional head elections still referring to Law No. 10/2016 on regional government.
Keywords: threshold, political parties, local government, democracy.