Articles de revues : « Bottom-up bias effect »

1

Intaitė, M., A. Šoliūnas, O. Gurčinienė, and O. Rukšėnas. "EFFECT OF BIAS ON THE PERCEPTION OF TWO SIMULTANEOUSLY PRESENTED AMBIGUOUS FIGURES." Psichologija 47 (January 1, 2013): 91–101. http://dx.doi.org/10.15388/psichol.2013.47.1403.

Texte intégral

Résumé :

Ambiguous figures are pictures which reverse their appearance during prolonged viewing and can be perceived in two (or more) available interpretations. Explanations for this phenomenon favour either early bottom-up processes or higher-level top-down processes. This study aimed to investigate the perception of simultaneously presented neutral and biased (i.e. with a slight modification towards one or another of the available interpretations) ambiguous figures. Our results have indicated that observers tend to perceive two adjacent identical figures as reversing simultaneously, and the same percepts dominated both in the reversal rate and the duration of perception. In the case of biased and neutral figures presented in pairs, modifications of interpretation either increased or decreased the frequency of a biased percept. The results show that both bottom-up and top-down perceptual processes influence the perception of ambiguous figures.Key words: ambiguous figure, adaptation, multiple-figure presentation, bias, visual perceptionTENDENCIJOS ĮTAKA DVIEJŲ DVIPRASMIŲ FIGŪRŲ SUVOKIMUIMonika Intaitė, Alvydas Šoliūnas, Ona Gurčinienė, Osvaldas Rukšėnas SantraukaDviprasmės figūros yra vaizdai, kuriuos stebint ilgesnį laiką keičiasi jų suvokimas – galimos dvi (ar daugiau) jo interpretacijos. Šis fenomenas aiškinamas arba ankstyvesniais vadinamaisiais bottom-up procesais, arba aukštesnio lygio vadinamaisiais top-down procesais. Šiame straipsnyje tiriama, kaip vyksta vienu metu pateikiamų dviejų figūrų – vienos dviprasmės, kitos dviprasmės modifikuotos taip, kad viena interpretacijų yra išryškinta, suvokimas. Rezultatai parodė, kad dviejų šalia esančių nemodifikuotų dviprasmių figūrų suvokiamos interpretacijos keičiasi kartu, o viena interpretacijų dominuoja tiek pagal trukmę, tiek pagal dažnį. Figūros modifikavimas dažniausiai sumažindavo priešingos nei išryškinta interpretacijos suvokimą. Stipriausias efektas buvo stebint Bugelskio piešinį žmogus-žiurkė, mažiausias – Rubino piešinį vaza-veidai. Dažnesnį ir ilgesnį išryškintos interpretacijos suvokimą galbūt maskavo faktas, kad figūros modifikavimas dažnais atvejais padidindavo skirtingų interpretacijų suvokimą vienu metu, kai viena figūra suvokiama vienokia prasme, kita – kitokia. Rezultatai gali būti aiškinami tuo, kad tiek bottom-up, tiek top-down procesai turi įtakos dviprasmių figūrų suvokimui.

Styles APA, Harvard, Vancouver, ISO, etc.

2

Zeljko, Mick, and Philip M. Grove. "Low-Level Motion Characteristics Do Not Account for Perceptions of Stream-Bounce Stimuli." Perception 46, no. 1 (2016): 31–49. http://dx.doi.org/10.1177/0301006616672483.

Texte intégral

Résumé :

The stream-bounce effect refers to a bistable motion stimulus that is interpreted as two targets either “streaming” past or “bouncing” off one another, and the manipulations that bias responses. Directional bias, according to Bertenthal et al., is an account of the effect proposing that low-level motion integration promotes streaming, and its disruption leads to bouncing, and it is sometimes cited either directly in a bottom-up fashion or indirectly under top-down control despite Sekuler and Sekuler finding evidence inconsistent with it. We tested two key aspects of the hypothesis: (a) comparable changes in speed should produce comparable disruptions and lead to similar effects; and (b) speed changes alone should disrupt integration without the need for additional more complex changes of motion. We found that target motion influences stream-bounce perception, but not as directional bias predicts. Our results support Sekuler and Sekuler and argue against the low-level motion signals driving perceptual outcomes in stream-bounce displays (directly or indirectly) and point to higher level inferential processes involving perceptual history and expectation. Directional bias as a mechanism should be abandoned and either another specific bottom-up process must be proposed and tested or consideration should be given to top-down factors alone driving the effect.

Styles APA, Harvard, Vancouver, ISO, etc.

3

Amici, David R., Jasen M. Jackson, Mihai I. Truica, Roger S. Smith, Sarki A. Abdulkadir, and Marc L. Mendillo. "FIREWORKS: a bottom-up approach to integrative coessentiality network analysis." Life Science Alliance 4, no. 2 (2020): e202000882. http://dx.doi.org/10.26508/lsa.202000882.

Texte intégral

Résumé :

Genetic coessentiality analysis, a computational approach which identifies genes sharing a common effect on cell fitness across large-scale screening datasets, has emerged as a powerful tool to identify functional relationships between human genes. However, widespread implementation of coessentiality to study individual genes and pathways is limited by systematic biases in existing coessentiality approaches and accessibility barriers for investigators without computational expertise. We created FIREWORKS, a method and interactive tool for the construction and statistical analysis of coessentiality networks centered around gene(s) provided by the user. FIREWORKS incorporates a novel bias reduction approach to reduce false discoveries, enables restriction of coessentiality analyses to custom subsets of cell lines, and integrates multiomic and drug–gene interaction datasets to investigate and target contextual gene essentiality. We demonstrate the broad utility of FIREWORKS through case vignettes investigating gene function and specialization, indirect therapeutic targeting of “undruggable” proteins, and context-specific rewiring of genetic networks.

Styles APA, Harvard, Vancouver, ISO, etc.

4

Bermundo, Juan Paolo, Yasuaki Ishikawa, Haruka Yamazaki, Toshiaki Nonaka, and Yukiharu Uraoka. "Highly reliable passivation layer for a-InGaZnO thin-film transistors fabricated using polysilsesquioxane." MRS Proceedings 1633 (2014): 139–44. http://dx.doi.org/10.1557/opl.2014.118.

Texte intégral

Résumé :

ABSTRACTPolysilsesquioxane passivation layers were used to passivate bottom gate a-InGaZnO (a-IGZO) thin film transistors (TFT). The a-IGZO TFTs passivated with polysilsesquioxane showed highly stable behavior during positive bias stress, negative bias stress, and negative bias illumination stress. A voltage threshold shift of up to 0.1 V, less than -0.1 V and -2.3 V for positive bias stress, negative bias stress, and negative bias illumination stress, respectively. We also report the effect of reactive ion etching (RIE) on the electrical characteristics of a-InGaZnO (a-IGZO) thin-film transistors (TFT) passivated with the polysilsesquioxane-based passivation layers. We show how post-annealing treatment using two different atmosphere conditions: under O2 ambient and combination of N2 and O2 ambient (20% O2), can be performed to recover the initial characteristics. Furthermore, we present a highly stable novel polysilsesquioxane photosensitive passivation material that can be used to completely circumvent the reactive ion etching effects.

Styles APA, Harvard, Vancouver, ISO, etc.

5

Park, Jihye, and Yoon Jin Ma. "Number-location bias: do consumers correctly process the number on the product package?" Journal of Product & Brand Management 28, no. 1 (2019): 80–94. http://dx.doi.org/10.1108/jpbm-12-2017-1711.

Texte intégral

Résumé :

Purpose This study aims to investigate the following three issues: whether consumers process numeric information with locational cues, which locations (horizontal vs vertical) are more influential in processing numbers and whether a number-location association is weakened or strengthened when a visual reference frame moves up or down. Design/methodology/approach A field study and a series of three lab experiments were conducted to examine the location effect of numeric information on the package façade on the perceived magnitude of a number. Findings The authors found that a number at the right was perceived as larger than one at the left only when the number is located at the bottom. Also, placing numeric information at the bottom rather than the top of a product package façade was more powerful in processing the numeric information, but this is true only when the visual frame is set lower. Practical implications This study provides practical insights for product managers in placing core numeric information on product packaging to effectively communicate product value to consumers. Optimal locations can be deliberately considered along with types of numeric information and product categories. For healthy products that promote fewer calories, the top area of the package façade may be a better position for placing information on calories per serving to make the product more appealing to those who follow a healthy diet. Heavier, more voluminous products (e.g., refrigerator) better position their volume/weight information at the bottom than at the top or at the right of the bottom than at the left of the bottom on the product facade. Either the left side or right side of the top position may be beneficial for thinner, lightweight products (e.g., television). Originality/value The present work adds valuable empirical findings; inconsistent with past research, left-right location-number associations are not always true. People tend to associate smaller numbers with left-side locations and larger numbers with right-side locations only when the number is located at the bottom. Also, the study reported that top-small, bottom-large associations are not always true. The difference in perceived magnitude of the number between a number at the top and one at the bottom within the visual frame is significant only when the visual frame is set close to the ground.

Styles APA, Harvard, Vancouver, ISO, etc.

6

Bertleff, Sabine, Gereon R. Fink, and Ralph Weidner. "The Role of Top–Down Focused Spatial Attention in Preattentive Salience Coding and Salience-based Attentional Capture." Journal of Cognitive Neuroscience 28, no. 8 (2016): 1152–65. http://dx.doi.org/10.1162/jocn_a_00964.

Texte intégral

Résumé :

Selective visual attention requires an efficient coordination between top–down and bottom–up attention control mechanisms. This study investigated the behavioral and neural effects of top–down focused spatial attention on the coding of highly salient distractors and their tendency to capture attention. Combining spatial cueing with an irrelevant distractor paradigm revealed bottom–up based attentional capture only when attention was distributed across the whole search display, including the distractor location. Top–down focusing spatial attention on the target location abolished attentional capture of a salient distractor outside the current attentional focus. Functional data indicated that the missing capture effect was not based on diminished bottom–up salience signals at unattended distractor locations. Irrespectively of whether salient distractors occurred at attended or unattended locations, their presence enhanced BOLD signals at their respective spatial representation in early visual areas as well as in inferior frontal, superior parietal, and medial parietal cortex. Importantly, activity in these regions reflected the presence of a salient distractor rather than attentional capture per se. Moreover, successfully inhibiting attentional capture of a salient distractor at an unattended location further increased neural responses in medial parietal regions known to be involved in controlling spatial attentional shifts. Consequently, data provide evidence that top–down focused spatial attention prevents automatic attentional capture by supporting attentional control processes counteracting a spatial bias toward a salient distractor.

Styles APA, Harvard, Vancouver, ISO, etc.

7

Capron, Daniel W., Aaron M. Norr, Nicholas P. Allan, and Norman B. Schmidt. "Combined “top-down” and “bottom-up” intervention for anxiety sensitivity: Pilot randomized trial testing the additive effect of interpretation bias modification." Journal of Psychiatric Research 85 (February 2017): 75–82. http://dx.doi.org/10.1016/j.jpsychires.2016.11.003.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

8

Varalta, Munari, Pertile, et al. "Effects of Neck Taping in the Treatment of Hemispatial Neglect in Chronic Stroke Patients: A Pilot, Single Blind, Randomized Controlled Trial." Medicina 55, no. 4 (2019): 108. http://dx.doi.org/10.3390/medicina55040108.

Texte intégral

Résumé :

Background and objectives: Hemispatial neglect is a common consequence of stroke, with an estimated incidence of 23%. Interventions for treating hemispatial neglect may be categorized as either top-down or bottom-up processing. The aim of top-down approaches is to train the person to voluntarily compensate for their neglect. Such approaches require awareness of the disorder and a high level of active participation by the patient. Differently, bottom-up approaches are based on manipulation of a patient’s sensory environment and so require less awareness of behavioral bias. In line with the latter, it is conceivable that elastic therapeutic taping applied to the left neck surface may provide bottom-up inputs that reduce hemispatial neglect symptoms. The aim of this study was to assess the effect of therapeutic neck taping on visuo-spatial abilities, neck motion, and kinesthetic sensibility in chronic stroke patients with hemispatial neglect. Materials and Methods: After randomization, 12 chronic stroke patients with hemispatial neglect received 30 consecutive days of real (treatment group) or sham (control group) neck taping. The outcomes were as follows: Stars Cancellation Test; neck active range of motion; Letter Cancellation Test; Comb and Razor Test; Cervical Joint Position Error Test evaluated before and after one month of taping. Results: Between-group comparison showed significant differences only for the Cervical Joint Position Error Test after treatment (p = 0.009). Conclusions: Our preliminary findings support the hypothesis that neck taping might improve cervicocephalic kinesthetic sensibility in chronic stroke patients with hemispatial neglect. Further studies are needed to strengthen our results and better investigate the effects of elastic therapeutic taping on visuo-spatial abilities in stroke patients with hemispatial neglect.

Styles APA, Harvard, Vancouver, ISO, etc.

9

Luo, Xi, Li-Ting Tseng, Sean Li, and Jiabao Yi. "The magnetism of BiFeO3 powders." Functional Materials Letters 08, no. 02 (2015): 1550027. http://dx.doi.org/10.1142/s1793604715500277.

Texte intégral

Résumé :

Conventional sintering and direct ball milling of Bi 2 O 3 + Fe 2 O 3 mixture were used for the fabrication of BiFeO 3 powders. The fabricated powders were performed annealing or high energy ball milling to vary the grain size from bottom-up or top-down. It was found that the magnetization of the powders synthesized by both methods plotted with the reciprocal of the grain size could be linearly fitted, indicating that the magnetism is from the finite size effect. Exchange bias phenomenon was observed after field cooling (FC) of the powders, confirming the magnetization is due to the uncompensated or canted surface spins. No spin glass behavior was found in these powders.

Styles APA, Harvard, Vancouver, ISO, etc.

10

Yang, Yang, Yu Zhao, Lei Zhang, et al. "Improvement of the satellite-derived NOx emissions on air quality modeling and its effect on ozone and secondary inorganic aerosol formation in the Yangtze River Delta, China." Atmospheric Chemistry and Physics 21, no. 2 (2021): 1191–209. http://dx.doi.org/10.5194/acp-21-1191-2021.

Texte intégral

Résumé :

Abstract. We developed a top-down methodology combining the inversed chemistry transport modeling and satellite-derived tropospheric vertical column of NO2 and estimated the NOx emissions of the Yangtze River Delta (YRD) region at a horizontal resolution of 9 km for January, April, July, and October 2016. The effect of the top-down emission estimation on air quality modeling and the response of ambient ozone (O3) and inorganic aerosols (SO42-, NO3-, and NH4+, SNA) to the changed precursor emissions were evaluated with the Community Multi-scale Air Quality (CMAQ) system. The top-down estimates of NOx emissions were smaller than those (i.e., the bottom-up estimates) in a national emission inventory, Multi-resolution Emission Inventory for China (MEIC), for all the 4 months, and the monthly mean was calculated to be 260.0 Gg/month, 24 % less than the bottom-up one. The NO2 concentrations simulated with the bottom-up estimate of NOx emissions were clearly higher than the ground observations, indicating the possible overestimation in the current emission inventory, attributed to its insufficient consideration of recent emission control in the region. The model performance based on top-down estimate was much better, and the biggest change was found for July, with the normalized mean bias (NMB) and normalized mean error (NME) reduced from 111 % to −0.4 % and from 111 % to 33 %, respectively. The results demonstrate the improvement of NOx emission estimation with the nonlinear inversed modeling and satellite observation constraint. With the smaller NOx emissions in the top-down estimate than the bottom-up one, the elevated concentrations of ambient O3 were simulated for most of the YRD, and they were closer to observations except for July, implying the VOC (volatile organic compound)-limited regime of O3 formation. With available ground observations of SNA in the YRD, moreover, better model performance of NO3- and NH4+ was achieved for most seasons, implying the effectiveness of precursor emission estimation on the simulation of secondary inorganic aerosols. Through the sensitivity analysis of O3 formation for April 2016, the decreased O3 concentrations were found for most of the YRD region when only VOC emissions were reduced or the reduced rate of VOC emissions was 2 times of that of NOx, implying the crucial role of VOC control in O3 pollution abatement. The SNA level for January 2016 was simulated to decline 12 % when 30 % of NH3 emissions were reduced, while the change was much smaller with the same reduced rate for SO2 or NOx. The result suggests that reducing NH3 emissions was the most effective way to alleviate SNA pollution of the YRD in winter.

Styles APA, Harvard, Vancouver, ISO, etc.

11

Zaw, Amayar, Rebecca Nguyen, Leon Lam, Anthony Kaplan, and Claudia C. Dobler. "The Effect of Limiting the Scan Range of Computed Tomography Pulmonary Angiography (to Reduce Radiation Exposure) on the Detection of Pulmonary Embolism: A Systematic Review." Diagnostics 11, no. 12 (2021): 2179. http://dx.doi.org/10.3390/diagnostics11122179.

Texte intégral

Résumé :

(1) Background: Computed tomography pulmonary angiography (CTPA) is the standard imaging test for the evaluation of acute pulmonary embolism (PE), but it is associated with patients’ exposure to radiation. Studies have suggested that radiation exposure can be reduced without compromising PE detection by limiting the scan range (the z-axis, going from up to down); (2) Methods: A literature search was conducted in MEDLINE and EMBASE on 17 July 2021. Studies were included if they enrolled patients who had undergone a CTPA and described the yield of PE diagnoses, number of missed filling defects and/or other diagnoses using a reduced z-axis in comparison to a full-length scan. To assess risk of bias, we modified an existing risk of bias tools for observational studies, the Newcastle-Ottawa Scale. Results were synthesized in a narrative review. Primary outcomes were the number of missed PE diagnoses (based on at least one filling defect) and filling defects; the secondary outcome was the number of other missed findings; (3) Results: Eleven cohort studies and one case-control study were included reporting on a total of 3955 scans including 1025 scans with a diagnosis of PE. Six different reduced scan ranges were assessed; the most studied was from the top of the aortic arch to below the heart, in which no PEs were missed (seven studies). One sub-segmental PE was missed when the scan coverage was 10 cm starting from the bottom of the aortic arch and 14.7 cm starting from the top of the arch. Five studies that reported on other findings all found that other diagnoses were missed with a reduced z-axis. Most of the included studies had a high risk of bias; (4) Conclusions: CTPA scan coverage reduction from the top of aortic arch to below the heart reduced radiation exposure without affecting PE diagnoses, but studies were generally at high risk of bias.

Styles APA, Harvard, Vancouver, ISO, etc.

12

Loebiantoro, Ika Yanuarti, H. C. Eaw, and Nursyamilah Annuar. "The Existence of Behavioral Biases and Personality Traits in Explaining the Effect of Fundamental and Technical Analysis to Investment Performance in Indonesia Stock Exchange." Jurnal Intelek 16, no. 1 (2021): 190–99. http://dx.doi.org/10.24191/ji.v16i1.380.

Texte intégral

Résumé :

Rational investors focus on the fundamental and technical analysis in their investment decisions. In fundamental analysis, they consider economic conditions, industry analysis, and company analysis if they use a top-down approach, and vice versa if they use a bottom-up approach. Technical analysis focuses on the historical movement of stock price to predict the future price by using the pattern of a chart. However, in modern finance, investors are not fully rational as they are also affected by the psychological factors when making their investment decisions. These psychological factors then create behavioral biases, which becomes the basic assumption of behavioral finance This research is aimed at investigating the role of availability bias and disposition effect as behavioral biases that make investors irrational in their behaviors and whether it is supported by the Big Five Personality Traits, which include openness, conscientiousness, extraversion, agreeableness, and neuroticism (OCEAN). It needs to explore the influence of fundamental analysis and technical analysis on investment performance with the existence of behavioral biases as mediating variable and personality traits as a moderating variable between fundamental analysis and behavioral biases.

Styles APA, Harvard, Vancouver, ISO, etc.

13

Tonet Maciel, Francieli, and Ana Maria Hermeto C. Oliveira. "Women’s formal and informal labour in Brazil: an inequality decomposition (2000-2010)." International Journal of Social Economics 45, no. 4 (2018): 700–726. http://dx.doi.org/10.1108/ijse-02-2017-0056.

Texte intégral

Résumé :

Purpose The purpose of this paper is to examine the effects of changes in the relative composition and in the segmentation between formal and informal labour on earnings differentials among women over the last decade in Brazil. Design/methodology/approach The authors follow Machado and Mata’s method to decompose the changes along the earnings distribution, with correction for sample selection and using microdata from the Demographic Census of 2000 and 2010. Informal labour was divided into informal salaried labour and self-employment, and both groups were compared with the formal labour separately. Findings The results indicate that, in both cases, an increase in earnings differentials in the bottom of the earnings distribution due to segmentation, suggesting that the returns to formal labour have grown relatively to informal labour during the period. On the other hand, earnings differentials decrease as one moves up the earnings distribution due to the composition effect, which is stronger on the top of the distribution relatively to the bottom. Furthermore, there are compensating differentials for self-employed women above the 30th quantile, which contributed to reduce the inequality between this group and formal workers. Originality/value The paper contributes to a better understanding of the changes taking place in female labour, shedding some light on how they affect different points along the earnings distribution. Furthermore, the adopted approach proposes a new application for the correction of sample bias in the context of quantile regression by employing a logit multinomial, and using the Demographic Census data.

Styles APA, Harvard, Vancouver, ISO, etc.

14

Mirpour, Koorosh, Wei Song Ong, and James W. Bisley. "Microstimulation of Posterior Parietal Cortex Biases the Selection of Eye Movement Goals During Search." Journal of Neurophysiology 104, no. 6 (2010): 3021–28. http://dx.doi.org/10.1152/jn.00397.2010.

Texte intégral

Résumé :

People can find objects in a visual scene fast and effortlessly. It is thought that this may be accomplished by creating a map of the outside world that incorporates bottom-up sensory and top-down cognitive inputs—a priority map. Eye movements are made toward the location represented by the highest activity on the priority map. We hypothesized that the lateral intraparietal area (LIP) of posterior parietal cortex acts as such a map. To test this, we performed low current microstimulation on animals trained to perform a foraging task and asked whether we could bias the animals to make a saccade to a particular stimulus, by creating an artificial peak of activity at the location representing that stimulus on the map. We found that microstimulation slightly biased the animals to make saccades to visual stimuli at the stimulated location, without actively generating saccades. The magnitude of this effect was small, but it appeared to be similar for all visual stimuli. We interpret these results to mean that microstimulation slightly biased saccade goal selection to the object represented at the stimulated location in LIP.

Styles APA, Harvard, Vancouver, ISO, etc.

15

Elferjani, Raed, Lahcen Benomar, Mina Momayyezi, et al. "A meta-analysis of mesophyll conductance to CO2 in relation to major abiotic stresses in poplar species." Journal of Experimental Botany 72, no. 12 (2021): 4384–400. http://dx.doi.org/10.1093/jxb/erab127.

Texte intégral

Résumé :

Abstract Mesophyll conductance (gm) determines the diffusion of CO2 from the substomatal cavities to the site of carboxylation in the chloroplasts and represents a critical component of the diffusive limitation of photosynthesis. In this study, we evaluated the average effect sizes of different environmental constraints on gm in Populus spp., a forest tree model. We collected raw data of 815 A–Ci response curves from 26 datasets to estimate gm, using a single curve-fitting method to alleviate method-related bias. We performed a meta-analysis to assess the effects of different abiotic stresses on gm. We found a significant increase in gm from the bottom to the top of the canopy that was concomitant with the increase of maximum rate of carboxylation and light-saturated photosynthetic rate (Amax). gm was positively associated with increases in soil moisture and nutrient availability, but was insensitive to increasing soil copper concentration and did not vary with atmospheric CO2 concentration. Our results showed that gm was strongly related to Amax and to a lesser extent to stomatal conductance (gs). Moreover, a negative exponential relationship was obtained between gm and specific leaf area, which may be used to scale-up gm within the canopy.

Styles APA, Harvard, Vancouver, ISO, etc.

16

Markakis, K., M. Valari, O. Perrussel, O. Sanchez, and C. Honore. "Climate forced air-quality modeling at urban scale: sensitivity to model resolution, emissions and meteorology." Atmospheric Chemistry and Physics Discussions 15, no. 4 (2015): 4767–821. http://dx.doi.org/10.5194/acpd-15-4767-2015.

Texte intégral

Résumé :

Abstract. While previous research helped to identify and prioritize the sources of error in air-quality modeling due to anthropogenic emissions and spatial scale effects our knowledge is limited on how these uncertainties affect climate forced air-quality assessments. Using as reference a 10 yr model simulation over the greater Paris (France) area at 4 km resolution and anthropogenic emissions from a 1 km resolution bottom-up inventory, through several tests we estimate the sensitivity of modeled ozone and PM2.5 concentrations to different potentially influential factors with a particular interest over the urban areas. These factors include the model horizontal and vertical resolution, the meteorological input from a climate model and its resolution, the use of a top-down emission inventory, the resolution of the emissions input and the post-processing coefficients used to derive the temporal, vertical and chemical split of emissions. We show that urban ozone displays moderate sensitivity to the resolution of emissions (~8%), the post-processing method (6.5%) and model resolution (~5) while annual PM2.5 levels are particularly sensitive to changes in their primary emissions (~32%) and the resolution of the emission inventory (~24%) while model horizontal and vertical resolution are of little effect. In addition we use the results of these sensitivities to explain and quantify the discrepancy between a coarse (~50 km) and a fine (4 km) resolution simulation over the urban area. We show that the ozone bias of the coarse run (+9 ppb) is reduced by ~40% by adopting a higher resolution emission inventory, by 25% by using a post-processing technique based on the local inventory (same improvement is obtained by increasing model horizontal resolution) and by 10% by adopting the annual emission totals of the local inventory. The bias on PM2.5 follows a more complex pattern with the positive bias associated to the coarse run (+3.6 μg m3) increasing or decreasing depending on the type of the refinement. We conclude that in the case of fine particles the coarse simulation cannot selectively incorporate local scale features in order to reduce model error.

Styles APA, Harvard, Vancouver, ISO, etc.

17

Stanley, Nicholas, Tara Davis, and Julie Estis. "The Effect of Signal-to-Noise Ratio on Linguistic Processing in a Semantic Judgment Task: An Aging Study." Journal of the American Academy of Audiology 28, no. 03 (2017): 209–21. http://dx.doi.org/10.3766/jaaa.16025.

Texte intégral

Résumé :

AbstractAging effects on speech understanding in noise have primarily been assessed through speech recognition tasks. Recognition tasks, which focus on bottom-up, perceptual aspects of speech understanding, intentionally limit linguistic and cognitive factors by asking participants to only repeat what they have heard. On the other hand, linguistic processing tasks require bottom-up and top-down (linguistic, cognitive) processing skills and are, therefore, more reflective of speech understanding abilities used in everyday communication. The effect of signal-to-noise ratio (SNR) on linguistic processing ability is relatively unknown for either young (YAs) or older adults (OAs).To determine if reduced SNRs would be more deleterious to the linguistic processing of OAs than YAs, as measured by accuracy and reaction time in a semantic judgment task in competing speech.In the semantic judgment task, participants indicated via button press whether word pairs were a semantic Match or No Match. This task was performed in quiet, as well as, +3, 0, −3, and −6 dB SNR with two-talker speech competition.Seventeen YAs (20–30 yr) with normal hearing sensitivity and 17 OAs (60–68 yr) with normal hearing sensitivity or mild-to-moderate sensorineural hearing loss within age-appropriate norms.Accuracy, reaction time, and false alarm rate were measured and analyzed using a mixed design analysis of variance.A decrease in SNR level significantly reduced accuracy and increased reaction time in both YAs and OAs. However, poor SNRs affected accuracy and reaction time of Match and No Match word pairs differently. Accuracy for Match pairs declined at a steeper rate than No Match pairs in both groups as SNR decreased. In addition, reaction time for No Match pairs increased at a greater rate than Match pairs in more difficult SNRs, particularly at −3 and −6 dB SNR. False-alarm rates indicated that participants had a response bias to No Match pairs as the SNR decreased. Age-related differences were limited to No Match pair accuracies at −6 dB SNR.The ability to correctly identify semantically matched word pairs was more susceptible to disruption by a poor SNR than semantically unrelated words in both YAs and OAs. The effect of SNR on this semantic judgment task implies that speech competition differentially affected the facilitation of semantically related words and the inhibition of semantically incompatible words, although processing speed, as measured by reaction time, remained faster for semantically matched pairs. Overall, the semantic judgment task in competing speech elucidated the effect of a poor listening environment on the higher order processing of words.

Styles APA, Harvard, Vancouver, ISO, etc.

18

Fang, Xinding, Yingcai Zheng, and Michael C. Fehler. "Fracture clustering effect on amplitude variation with offset and azimuth analyses." GEOPHYSICS 82, no. 1 (2017): N13—N25. http://dx.doi.org/10.1190/geo2016-0045.1.

Texte intégral

Résumé :

Traditional amplitude variation with offset and azimuth (AVOAz) analysis for fracture characterization extracts fracture properties through analysis of reflection AVOAz to determine anisotropic parameters (e.g., Thomsen’s parameters) that are then related to fracture properties. The validity of this method relies on the basic assumption that a fractured unit can be viewed as an equivalent anisotropic medium. As a rule of thumb, this assumption is taken to be valid when the fracture spacing is less than [Formula: see text]. Under the effective medium assumption, diffractions from individual fractures destructively interfere and only specular reflections from boundaries of a fractured layer can be observed in seismic data. The effective medium theory has been widely used in fracture characterization, and its applicability has been validated through many field applications. However, through numerical simulations, we find that diffractions from fracture clusters can significantly distort the AVOAz signatures when a fracture system has irregular spacing even though the average fracture spacing is much smaller than a wavelength (e.g., [Formula: see text]). Contamination by diffractions from irregularly spaced fractures on reflections can substantially bias the fracture properties estimated from AVOAz analysis and may possibly lead to incorrect estimates of fracture properties. Additionally, through Monte Carlo simulations, we find that fracture spacing uncertainty inverted from amplitude variation with offset (AVO) analysis can be up to 10%–20% when fractures are not uniformly distributed, which should be the realistic state of fractures present in the earth. Also, AVOAz and AVO analysis gives more reliable estimates of fracture properties when reflections at the top of the fractured layer are used compared with those from the bottom of the layer.

Styles APA, Harvard, Vancouver, ISO, etc.

19

Boisot, Max. "Generating knowledge in a connected world: The case of the ATLAS experiment at CERN." Management Learning 42, no. 4 (2011): 447–57. http://dx.doi.org/10.1177/1350507611408676.

Texte intégral

Résumé :

The spatial challenges posed by the dynamics of globalization together with the availability of new information and communication technologies (ICTs) have fostered the development of virtual collaboration. Driven by organizational authority systems, however, much of this activity remains of a top-down, hierarchical nature. Although the proportion of bottom-up activity has increased, it has not displaced the top-down bias in the governance structures of firms and the formal processes that give them effect. Yet recent developments are challenging the organizational assumptions that underpin such structures and processes. In what follows, we first offer a theoretical perspective on the above questions and then illustrate it with a look at the way that the ATLAS experiment at CERN—one of the four experiments that are using the Large Hadron Collider (LHC)— is organized and managed. The ATLAS Collaboration—the team of physicists responsible for the experiment— consists of a culturally heterogeneous and loosely coupled population of agents, each operating in a different institutional setting. We shall use our theoretical perspective to interpret some of the issues raised by this kind of ‘big science’ experiment and discuss their implications for a broader class of organizations.

Styles APA, Harvard, Vancouver, ISO, etc.

20

Hikosaka, Okihide, Satoru Miyauchi, and Shinsuke Shimojo. "Voluntary and Stimulus-Induced Attention Detected as Motion Sensation." Perception 22, no. 5 (1993): 517–26. http://dx.doi.org/10.1068/p220517.

Texte intégral

Résumé :

Attention may be drawn passively to a visually salient object. We may also actively direct attention to an object of interest. Do the two kinds of attention, passive and active, interact and jointly influence visual information processing at some neural level? What happens if the passive and active attentions come into conflict? These questions were addressed with the aid of a novel psychophysical technique which reveals an attentional gradient as a sensation of motion in a line which is presented instantaneously. The subjects were asked to direct attention with voluntary effort: to the side opposite to a stimulus change, to an object with a predetermined colour, and to an object moving smoothly. In every case the same motion sensation was induced in the line from the attended side to the unattended side. This voluntary attention, however, can easily and quickly be distracted by a change in the periphery, though it can be regained within a period of 200 to 500 ms. The results suggest that the line motion can be induced in voluntary (top-down) as well as stimulus-driven (bottom-up) situations, thus indicating the truly attentional nature of the effect, rather than it being some kind of retinotopic sensory artifact or response bias. The results also suggest that these two kinds of attention have facilitatory effects acting together on a relatively early stage of visual information processing.

Styles APA, Harvard, Vancouver, ISO, etc.

21

Pay, M. T., F. Martínez, M. Guevara, and J. M. Baldasano. "Air quality forecasts at kilometer scale grid over Spanish complex terrains." Geoscientific Model Development Discussions 7, no. 2 (2014): 2293–334. http://dx.doi.org/10.5194/gmdd-7-2293-2014.

Texte intégral

Résumé :

Abstract. CALIOPE-AQFS represents the current state-of-the-art in air quality forecasting systems running at high resolution over high performance computing platforms. It provides 48 h forecast of main pollutants over Spain at 4 km horizontal resolution, and over the most populated areas with complex terrains in Spain (Barcelona, Madrid and Andalucia domains) at 1 km. Increased horizontal resolution from 4 km to 1 km over the aforementioned domains leads to finer texture and more realistic concentration maps, justified by the increase of NO2/O3 spatial correlation coefficients from 0.79/0.69 (4 km) to 0.81/0.73 (1 km). High resolution emissions using the bottom-up HERMESv2.0 model are essential to improve the model performance when increasing resolution at urban scale, but it is not sufficient. Decreasing grid spacing does not reveal the expected improvement on hourly statistics, decreasing NO2 bias only in ~ 2 μg m−3 and increasing O3 bias in ~ 1 μg m−3. The grid effect is less pronounced for PM10 because part of its mass consists of secondary aerosols which are less affected by a decreasing grid size in contrast to the locally emitted primary components. The resolution increase has the highest impact over Barcelona, where air flow is mainly controlled by mesoscale phenomena and a lower PBL. Despite the merits and potential uses of the 1 km simulation, the limitations of current model formulations do not allow confirming their expected superiority close to highly urbanized areas and large sources. Future work should combine high grid resolution with techniques that decrease subgrid variability and models that consider urban morphology and thermal parameters.

Styles APA, Harvard, Vancouver, ISO, etc.

22

Pay, M. T., F. Martínez, M. Guevara, and J. M. Baldasano. "Air quality forecasts on a kilometer-scale grid over complex Spanish terrains." Geoscientific Model Development 7, no. 5 (2014): 1979–99. http://dx.doi.org/10.5194/gmd-7-1979-2014.

Texte intégral

Résumé :

Abstract. The CALIOPE Air Quality Forecast System (CALIOPE-AQFS) represents the current state of the art in air quality forecasting systems of high-resolution running on high-performance computing platforms. It provides a 48 h forecast of NO2, O3, SO2, PM10, PM2.5, CO, and C6H6 at a 4 km horizontal resolution over all of Spain, and at a 1 km horizontal resolution over the most populated areas in Spain with complex terrains (the Barcelona (BCN), Madrid (MAD) and Andalusia (AND) domains). Increased horizontal resolution from 4 to 1 km over the aforementioned domains leads to finer textures and more realistic concentration maps, which is justified by the increase in NO2/O3 spatial correlation coefficients from 0.79/0.69 (4 km) to 0.81/0.73 (1 km). High-resolution emissions using the bottom-up HERMESv2.0 model are essential for improving model performance when increasing resolution on an urban scale, but it is still insufficient. Decreasing grid spacing does not reveal the expected improvement in hourly statistics, i.e., decreasing NO2 bias by only ~ 2 μg m−3 and increasing O3 bias by ~ 1 μg m−3. The grid effect is less pronounced for PM10, because part of its mass consists of secondary aerosols, which are less affected than the locally emitted primary components by a decreasing grid size. The resolution increase has the highest impact over Barcelona, where air flow is controlled mainly by mesoscale phenomena and a lower planetary boundary layer (PBL). Despite the merits and potential uses of the 1-km simulation, the limitations of current model formulations do not allow confirmation of their expected superiority close to highly urbanized areas and large emissions sources. Future work should combine high grid resolutions with techniques that decrease subgrid variability (e.g., stochastic field methods), and also include models that consider urban morphology and thermal parameters.

Styles APA, Harvard, Vancouver, ISO, etc.

23

Markakis, K., M. Valari, O. Perrussel, O. Sanchez, and C. Honore. "Climate-forced air-quality modeling at the urban scale: sensitivity to model resolution, emissions and meteorology." Atmospheric Chemistry and Physics 15, no. 13 (2015): 7703–23. http://dx.doi.org/10.5194/acp-15-7703-2015.

Texte intégral

Résumé :

Abstract. While previous research helped to identify and prioritize the sources of error in air-quality modeling due to anthropogenic emissions and spatial scale effects, our knowledge is limited on how these uncertainties affect climate-forced air-quality assessments. Using as reference a 10-year model simulation over the greater Paris (France) area at 4 km resolution and anthropogenic emissions from a 1 km resolution bottom-up inventory, through several tests we estimate the sensitivity of modeled ozone and PM2.5 concentrations to different potentially influential factors with a particular interest over the urban areas. These factors include the model horizontal and vertical resolution, the meteorological input from a climate model and its resolution, the use of a top-down emission inventory, the resolution of the emissions input and the post-processing coefficients used to derive the temporal, vertical and chemical split of emissions. We show that urban ozone displays moderate sensitivity to the resolution of emissions (~ 8 %), the post-processing method (6.5 %) and the horizontal resolution of the air-quality model (~ 5 %), while annual PM2.5 levels are particularly sensitive to changes in their primary emissions (~ 32 %) and the resolution of the emission inventory (~ 24 %). The air-quality model horizontal and vertical resolution have little effect on model predictions for the specific study domain. In the case of modeled ozone concentrations, the implementation of refined input data results in a consistent decrease (from 2.5 up to 8.3 %), mainly due to inhibition of the titration rate by nitrogen oxides. Such consistency is not observed for PM2.5. In contrast this consistency is not observed for PM2.5. In addition we use the results of these sensitivities to explain and quantify the discrepancy between a coarse (~ 50 km) and a fine (4 km) resolution simulation over the urban area. We show that the ozone bias of the coarse run (+9 ppb) is reduced by ~ 40 % by adopting a higher resolution emission inventory, by 25 % by using a post-processing technique based on the local inventory (same improvement is obtained by increasing model horizontal resolution) and by 10 % by adopting the annual emission totals of the local inventory. The bias of PM2.5 concentrations follows a more complex pattern, with the positive values associated with the coarse run (+3.6 μg m−3), increasing or decreasing depending on the type of the refinement. We conclude that in the case of fine particles, the coarse simulation cannot selectively incorporate local-scale features in order to reduce its error.

Styles APA, Harvard, Vancouver, ISO, etc.

24

Soet, M., R. J. Ronda, J. N. M. Stricker, and A. J. Dolman. "Land surface scheme conceptualisation and parameter values for three sites with contrasting soils and climate." Hydrology and Earth System Sciences 4, no. 2 (2000): 283–94. http://dx.doi.org/10.5194/hess-4-283-2000.

Texte intégral

Résumé :

Abstract. The objective of the present study is to test the performance of the ECMWF land surface module (LSM) developed by Viterbo and Beljaars (1995) and to identify primary future adjustments, focusing on the hydrological components. This was achieved by comparing off-line simulations against observations and a detailed state-of-the-art model over a range of experimental conditions. Results showed that the standard LSM, which uses fixed vegetation and soil parameter values, systematically underestimated evapotranspiration, partly due to underestimating bare soil evaporation, which appeared to be a conceptual problem. In dry summer conditions, transpiration was seriously underestimated. The bias in surface runoff and percolation was not of the same sign for all three locations. A sensitivity analysis, set up to explore the impact of using standard parameter values, found that implementing specific soil hydraulic properties had a significant effect on runoff and percolation at all three sites. Evapotranspiration, however affected only slightly at the temperate humid climate sites. Under semi-arid conditions, introducing site specific soil hydraulic properties plus a realistic rooting depth improved simulation results considerably. Future adjustments to the standard LSM should focus on parameter values of soil hydraulic functions and rooting depths and, conceptually, on the bare soil evaporation parameterisation and the soil bottom boundary condition. Implications of changing soil hydraulic properties for future large-simulations were explored briefly. For Europe, soil data requirements can be fulfilled partly by the recent data base HYPRES. Sandy and loamy sand soils will then cover about 65% of Europe, whereas in the present model 100% of the area is loam. Keywords: land surface model; soil hydraulic properties; water balance simulation

Styles APA, Harvard, Vancouver, ISO, etc.

25

Giadrossich, F., M. Niedda, D. Cohen, and M. Pirastru. "Evaporation in a Mediterranean environment by energy budget and Penman methods, Lake Baratz, Sardinia, Italy." Hydrology and Earth System Sciences 19, no. 5 (2015): 2451–68. http://dx.doi.org/10.5194/hess-19-2451-2015.

Texte intégral

Résumé :

Abstract. In Mediterranean environments, evaporation is a key component of lake water budgets. This applies to Lake Baratz in Sardinia, Italy, a closed lake that almost dried up in 2008 after a succession of years with low seasonal rainfall. We used the energy budget method and Penman's equation to estimate evaporation over Lake Baratz. We measured, using a raft station, water temperature at the surface, at 1, 2, 4, 6 m depth and at the bottom of the lake, as well as air temperature, relative humidity, wind speed, and net radiation over a period of 3 years. We also compared Penman's equation and the energy budget method in two other climatic zones using published data. Our results indicate that mean yearly evaporation over Lake Baratz was 950 mm. On an annual scale, evaporation estimated by Penman's method omitting heat storage as is usually done was 18% higher than by the energy budget method that included heat storage, with monthly differences ranging between −38 and +60%. Including the heat storage term in Penman's equation changed the monthly values but did not change the yearly value significantly. Solar radiation and heat storage were found to be the most important energy fluxes to and from the lake and had the greatest effect on evaporation rates for the energy budget method. The bias between the two methods has a seasonal cycle due to the storage and release of energy from the lake. Energy advected to and from the lake by precipitation, surface water and ground water had minor effect on evaporation rates. Lake Baratz, like other lakes in a Mediterranean environment, is particularly sensitive to the summer hot and dry climate. In contrast, we found that rates of evaporation estimated from Penman and the energy budget methods over tropical African lakes were nearly constant over the entire year and the difference between the two methods smaller. Difference between the two methods for North American lakes is also smaller probably owing to the ice-cover season and to lower radiation and lower temperatures during summer.

Styles APA, Harvard, Vancouver, ISO, etc.

26

Kingston, John. "Most but not all bottom-up interactions between signal properties improve categorization." Behavioral and Brain Sciences 23, no. 3 (2000): 335–36. http://dx.doi.org/10.1017/s0140525x00333246.

Texte intégral

Résumé :

The massive acoustic redundancy of minimally contrasting speech sounds, coupled with the auditory integration of psychoacoustically similar acoustic properties produces a highly invariant percept, which cannot be improved by top-down feedback from the lexicon. Contextual effects are also bottom-up but not all entirely auditory and may thus differ in whether they affect sensitivity or only response bias.

Styles APA, Harvard, Vancouver, ISO, etc.

27

Scalf, Paige E., JeeWon Ahn, Diane M. Beck, and Alejandro Lleras. "Trial History Effects in the Ventral Attentional Network." Journal of Cognitive Neuroscience 26, no. 12 (2014): 2789–97. http://dx.doi.org/10.1162/jocn_a_00678.

Texte intégral

Résumé :

The ventral attentional network (VAN) is thought to drive “stimulus driven attention” [e.g., Asplund, C. L., Todd, J. J., Snyder, A. P., & Marois, R. A central role for the lateral prefrontal cortex in goal-directed and stimulus-driven attention. Nature Neuroscience, 13, 507–512, 2010; Shulman, G. L., McAvoy, M. P., Cowan, M. C., Astafiev, S. V., Tansy, A. P., D' Avossa, G., et al. Quantitative analysis of attention and detection signals during visual search. Journal of Neurophysiology, 90, 3384–3397, 2003]; in other words, it instantiates within the current stimulus environment the top–down attentional biases maintained by the dorsal attention network [e.g., Kincade, J. M., Abrams, R. A., Astafiev, S. V., Shulman, G. L., & Corbetta, M. An event-related functional magnetic resonance imaging study of voluntary and stimulus-driven orienting of attention. The Journal of Neuroscience: The Official Journal of the Society for Neuroscience, 25, 4593–4604, 2005]. Previous work has shown that the dorsal attentional network is sensitive to trial history, such that it is challenged by changes in task goals and facilitated by repetition thereof [e.g., Kristjánsson, A., Vuilleumier, P., Schwartz, S., Macaluso, E., & Driver, J. Neural basis for priming of pop-out during visual search revealed with fMRI. Cerebral Cortex, 17, 1612–1624, 2007]. Here, we investigate whether the VAN also preserves information across trials such that it is challenged when previously rejected stimuli become task relevant. We used fMRI to investigate the sensitivity of the ventral attentional system to prior history effects as measured by the distractor preview effect. This behavioral phenomenon reflects a bias against stimuli that have historically not supported task performance. We found regions traditionally considered to be part of the VAN (right middle frontal gyrus, inferior frontal gyrus and right supramarginal gyrus) [Shulman, G. L., McAvoy, M. P., Cowan, M. C., Astafiev, S. V., Tansy, A. P., D' Avossa, G., et al. Quantitative analysis of attention and detection signals during visual search. Journal of Neurophysiology, 90, 3384–3397, 2003] to be more active when task-relevant stimuli had not supported task performance in a previous trial than when they had. Investigations of the ventral visual system suggest that this effect is more reliably driven by trial history preserved within the VAN than that preserved within the visual system per se. We conclude that VAN maintains its interactions with top–down stimulus biases and bottom–up stimulation across time, allowing previous experience with the stimulus environment to influence attentional biases under current circumstances.

Styles APA, Harvard, Vancouver, ISO, etc.

28

Skavronskaya, Liubov, Noel Scott, Brent Moyle, et al. "Cognitive psychology and tourism research: state of the art." Tourism Review 72, no. 2 (2017): 221–37. http://dx.doi.org/10.1108/tr-03-2017-0041.

Texte intégral

Résumé :

PurposeThis review aims to discuss concepts and theories from cognitive psychology, identifies tourism studies applying them and discusses key areas for future research. The paper aims to demonstrate the usefulness of cognitive psychology for understanding why tourists and particularly pleasure travellers demonstrate the behaviour they exhibit. Design/methodology/approachThe paper reviews 165 papers from the cognitive psychology and literature regarding pleasure travel related to consciousness, mindfulness, flow, retrospection, prospection, attention, schema and memory, feelings and emotions. The papers are chosen to demonstrate the state of the art of the literature and provide guidance on how these concepts are vital for further research. FindingsThe paper demonstrates that research has favoured a behaviourist rather than cognitive approach to the study of hedonic travel. Cognitive psychology can help to understand the mental processes connecting perception of stimuli with behaviour. Numerous examples are provided: top-down and bottom-up attention processes help to understand advertising effectiveness, theories of consciousness and memory processes help to distinguish between lived and recalled experience, cognitive appraisal theory predicts the emotion elicited based on a small number of appraisal dimensions such as surprise and goals, knowledge of the mental organisation of autobiographical memory and schema support understanding of destination image formation and change and the effect of storytelling on decision-making, reconstructive bias in prospection or retrospection about a holiday inform the study of pleasurable experience. These findings indicate need for further cognitive psychology research in tourism generally and studies of holiday travel experiences. Research limitations/implicationsThis review is limited to cognitive psychology and excludes psychoanalytic studies. Practical implicationsCognitive psychology provides insight into key areas of practical importance. In general, the use of a cognitive approach allows further understanding of leisure tourists’ behaviour. The concept of attention is vital to understand destination advertising effectiveness, biases in memory process help to understand visitor satisfaction and experience design and so on. Use of cognitive psychology theory will lead to better practical outcomes for tourists seeking pleasurable experiences and destination managers. Originality valueThis is the first review that examines the application of concepts from cognitive psychology to the study of leisure tourism in particular. The concepts studied are also applicable to study of travellers generally.

Styles APA, Harvard, Vancouver, ISO, etc.

29

Well, Reinhard, Martin Maier, Dominika Lewicka-Szczebak, Jan-Reent Köster, and Nicolas Ruoss. "Underestimation of denitrification rates from field application of the 15N gas flux method and its correction by gas diffusion modelling." Biogeosciences 16, no. 10 (2019): 2233–46. http://dx.doi.org/10.5194/bg-16-2233-2019.

Texte intégral

Résumé :

Abstract. Common methods for measuring soil denitrification in situ include monitoring the accumulation of 15N-labelled N2 and N2O evolved from 15N-labelled soil nitrate pool in closed chambers that are placed on the soil surface. Gas diffusion is considered to be the main transport process in the soil. Because accumulation of gases within the chamber decreases concentration gradients between soil and the chamber over time, the surface efflux of gases decreases as well, and gas production rates are underestimated if calculated from chamber concentrations without consideration of this mechanism. Moreover, concentration gradients to the non-labelled subsoil exist, inevitably causing downward diffusion of 15N-labelled denitrification products. A numerical 3-D model for simulating gas diffusion in soil was used in order to determine the significance of this source of error. Results show that subsoil diffusion of 15N-labelled N2 and N2O – and thus potential underestimation of denitrification derived from chamber fluxes – increases with chamber deployment time as well as with increasing soil gas diffusivity. Simulations based on the range of typical soil gas diffusivities of unsaturated soils showed that the fraction of N2 and N2O evolved from 15N-labelled NO3- that is not emitted at the soil surface during 1 h chamber closing is always significant, with values up to >50 % of total production. This is due to accumulation in the pore space of the 15N-labelled soil and diffusive flux to the unlabelled subsoil. Empirical coefficients to calculate denitrification from surface fluxes were derived by modelling multiple scenarios with varying soil water content. Modelling several theoretical experimental set-ups showed that the fraction of produced gases that are retained in soil can be lowered by lowering the depth of 15N labelling and/or increasing the length of the confining cylinder. Field experiments with arable silt loam soil for measuring denitrification with the 15N gas flux method were conducted to obtain direct evidence for the incomplete surface emission of gaseous denitrification products. We compared surface fluxes of 15N2 and 15N2O from 15N-labelled micro-plots confined by cylinders using the closed-chamber method with cylinders open or closed at the bottom, finding 37 % higher surface fluxes with the bottom closed. Modelling fluxes of this experiment confirmed this effect, however with a higher increase in surface flux of 89 %. From our model and experimental results we conclude that field surface fluxes of 15N-labelled N2 and N2O severely underestimate denitrification rates if calculated from chamber accumulation only. The extent of this underestimation increases with closure time. Underestimation also occurs during laboratory incubations in closed systems due to pore space accumulation of 15N-labelled N2 and N2O. Due to this bias in past denitrification measurements, denitrification in soils might be more relevant than assumed to date. Corrected denitrification rates can be obtained by estimating subsurface flux and storage with our model. The observed deviation between experimental and modelled subsurface flux revealed the need for refined model evaluation, which must include assessment of the spatial variability in diffusivity and production and the spatial dimension of the chamber.

Styles APA, Harvard, Vancouver, ISO, etc.

30

Chang, Yonghwan, and Yong Jae Ko. "The effects of association strength on attention and product evaluation." European Journal of Marketing 52, no. 5/6 (2018): 1257–79. http://dx.doi.org/10.1108/ejm-05-2016-0261.

Texte intégral

Résumé :

Purpose The purpose of this study was to test whether endorsements that show a low strength of association (bottom-up bias) benefit from increased attention and processing efforts. The current study also tested whether consumer involvement level (top-down bias) dynamically interacts with the bottom-up attention phenomena. Design/methodology/approach Through a series of pretests, 36 potential celebrity-product matches were identified using real athletes and product brands. Two experiments were conducted: 330 individual responses (110 participants × three conditions) were obtained in a within-subjects lab experiment, and 868 participants were recruited for a between-subjects online experiment. Linear mixed modeling and moderated mediation analysis were performed. Findings The relationships between the strength of image associations and attention time to endorsements and recall and choice consideration of endorsed brands were U-shaped and curvilinear. Attention largely mediated the relationship between the strength of association and recall/choice. Involvement effects were diluted by the strength of association effects, rejecting top-down attentional control. Practical implications Brand managers for both products and celebrities are recommended to search for corresponding not only image-matched partners but also endorsement partners with dissonant pre-existing images. Originality/value The majority of the existing endorsement literature has conventionally suggested that congruence between the endorser and the endorsed property, rather than incongruence, induces consumers’ positive endorsement evaluation. This study constructs important theoretical advancements to the existing literature by empirically proving that through an attentional process, an endorsement contract, conventionally perceived as mismatched, can also generate positive outcomes.

Styles APA, Harvard, Vancouver, ISO, etc.

31

Chen, Tzu-Ting, Linus Y. S. Chiu, and Ying-Tsong Lin. "Effects of nonlinear internal gravity waves on normal-incident reflection measurements of seafloor sediments." Journal of the Acoustical Society of America 153, no. 1 (2023): 328–37. http://dx.doi.org/10.1121/10.0016858.

Texte intégral

Résumé :

Sonar data acquired by sub-bottom profilers and echosounder systems are widely used to estimate geoacoustic properties of marine sediments. However, the uncertainty of the seabed property estimates caused by water-column variability may limit the application. In this paper, the acoustic focusing and defocusing effects of nonlinear internal gravity waves on normal-incident acoustic reflection measurements are studied. The experiment data were collected in the South China Sea from two transceiver moorings located at two different sites, one of which contained strong nonlinear internal waves (NIWs), while another site did not. The observed reflection intensity variation at the internal wave site varied up to 10 dB. On the other hand, the bottom reflections at the other site without internal waves were stable, and a seafloor sediment sample collected there was analyzed to validate the sediment type inferred from bottom loss. Numerical simulations using ray-tracing and parabolic equation models confirmed the cause of this intensity fluctuation by the acoustic focusing and defocusing of NIWs. This study eventually showed that NIWs may induce a significant bias for geoacoustic property estimates from seabed reflection coefficients.

Styles APA, Harvard, Vancouver, ISO, etc.

32

Lin, Peng, Yan Jin, Fu Yang, et al. "A Simulation and Optimization Study of the Swirling Nozzle for Eccentric Flow Fields of Round Molds." Metals 10, no. 5 (2020): 691. http://dx.doi.org/10.3390/met10050691.

Texte intégral

Résumé :

In continuous casting, the nozzle position may deviate from the center under actual operating conditions, which may cause periodic fluctuation of the steel-slag interface and easily lead to slag entrapment and gas absorption. Swirling nozzles can reduce these negative effects. A mathematical simulation method based on a round mold of steel components with a 600 mm diameter is applied to study the flow field of molten steel in a mold. The swirling nozzle is optimized through the establishment of a fluid dynamics model. Meanwhile, a 1:2 hydraulic model is established for validation experiments. The results show that, when the submerged entry nozzle (SEN) is eccentric in the mold, it results in serious bias flow, increasing the drift index in the mold up to 0.46 at the eccentric distance of 50 mm. The impact depth of liquid steel and turbulent kinetic energy can be decreased by increasing the rotation angle of the nozzle. The nozzle with one bottom hole, which significantly decreases the bottom pressure and turbulent kinetic energy, greatly weakens the scour on nozzle and surface fluctuation. In the eccentric casting condition, using the optimized swirling nozzle that employs a 5-fractional structure, in which the rotation angle of 4 side holes is 30° and there is one bottom outlet, can effectively restrain bias flow and reduce the drift index to 0.28, a decline of more than 39%.

Styles APA, Harvard, Vancouver, ISO, etc.

33

Munneke, Jaap, İlker Duymaz, and Jennifer E. Corbett. "Value-driven effects on perceptual averaging." Attention, Perception, & Psychophysics 84, no. 3 (2022): 781–94. http://dx.doi.org/10.3758/s13414-022-02446-x.

Texte intégral

Résumé :

AbstractPerceptual averaging refers to a strategy of encoding the statistical properties of entire sets of objects rather than encoding individual object properties, potentially circumventing the visual system’s strict capacity limitations. Prior work has shown that such average representations of set properties, such as its mean size, can be modulated by top-down and bottom-up attention. However, it is unclear to what extent attentional biases through selection history, in the form of value-driven attentional capture, influences this type of summary statistical representation. To investigate, we conducted two experiments in which participants estimated the mean size of a set of heterogeneously sized circles while a previously rewarded color singleton was part of the set. In Experiment 1, all circles were gray, except either the smallest or the largest circle, which was presented in a color previously associated with a reward. When the largest circle in the set was associated with the highest value (as a proxy of selection history), we observed the largest biases, such that perceived mean size scaled linearly with the increasing value of the attended color singleton. In Experiment 2, we introduced a dual-task component in the form of an attentional search task to ensure that the observed bias of reward on perceptual averaging was not fully explained by focusing attention solely on the reward-signaling color singleton. Collectively, findings support the proposal that selection history, like bottom-up and top-down attention, influences perceptual averaging, and that this happens in a flexible manner proportional to the extent to which attention is captured.

Styles APA, Harvard, Vancouver, ISO, etc.

34

Javadi, Amir-Homayoun, Angeliki Beyko, Vincent Walsh, and Ryota Kanai. "Transcranial Direct Current Stimulation of the Motor Cortex Biases Action Choice in a Perceptual Decision Task." Journal of Cognitive Neuroscience 27, no. 11 (2015): 2174–85. http://dx.doi.org/10.1162/jocn_a_00848.

Texte intégral

Résumé :

One of the multiple interacting systems involved in the selection and execution of voluntary actions is the primary motor cortex (PMC). We aimed to investigate whether the transcranial direct current stimulation (tDCS) of this area can modulate hand choice. A perceptual decision-making task was administered. Participants were asked to classify rectangles with different height-to-width ratios into horizontal and vertical rectangles using their right and left index fingers while their PMC was stimulated either bilaterally or unilaterally. Two experiments were conducted with different stimulation conditions: the first experiment (n = 12) had only one stimulation condition (bilateral stimulation), and the second experiment (n = 45) had three stimulation conditions (bilateral, anodal unilateral, and cathodal unilateral stimulations). The second experiment was designed to confirm the results of the first experiment and to further investigate the effects of anodal and cathodal stimulations alone in the observed effects. Each participant took part in two sessions. The laterality of stimulation was reversed over the two sessions. Our results showed that anodal stimulation of the PMC biases participants' responses toward using the contralateral hand whereas cathodal stimulation biases responses toward the ipsilateral hand. Brain stimulation also modulated the RT of the left hand in all stimulation conditions: Responses were faster when the response bias was in favor of the left hand and slower when the response bias was against it. We propose two possible explanations for these findings: the perceptual bias account (bottom–up effects of stimulation on perception) and the motor-choice bias account (top–down modulation of the decision-making system by facilitation of response in one hand over the other). We conclude that motor responses and the choice of hand can be modulated using tDCS.

Styles APA, Harvard, Vancouver, ISO, etc.

35

Leppanen, Jenni, Olivia Patsalos, Sophie Surguladze, Jess Kerr-Gaffney, Steven Williams, and Ketevan Tchanturia. "Evaluation of film stimuli for the assessment of social-emotional processing: a pilot study." PeerJ 10 (November 23, 2022): e14160. http://dx.doi.org/10.7717/peerj.14160.

Texte intégral

Résumé :

Background Difficulties in top-down and bottom-up emotion generation have been proposed to play a key role in the progression of psychiatric disorders. The aim of the current study was to develop more ecologically valid measures of top-down interpretation biases and bottom-up evoked emotional responses. Methods A total of 124 healthy female participants aged 18–25 took part in the study. We evaluated two sets of 18 brief film clips. The first set of film clips presented ambiguous social situations designed to examine interpretation biases. Participants provided written interpretations of each ambiguous film clip which were subjected to sentiment analysis. We compared the films in terms of the valence of participants interpretations. The second set of film clips presented neutral and emotionally provoking social scenarios designed to elicit subjective and facial emotional responses. While viewing these film clips participants mood ratings and facial affect were recorded and analysed using exploratory factor analyses. Results Most of the 18 ambiguous film clips were interpreted in the expected manner while still retaining some ambiguity. However, participants were more attuned to the negative cues in the ambiguous film clips and three film clips were identified as unambiguous. These films clips were deemed unsuitable for assessing interpretation bias. The exploratory factor analyses of participants’ mood ratings and evoked facial affect showed that the positive and negative emotionally provoking film clips formed their own factors as expected. However, there was substantial cross-loading of the neutral film clips when participants’ facial expression data was analysed. Discussion A subset of the film clips from the two tasks could be used to assess top-down interpretation biases and bottom-up evoked emotional responses. Ambiguous negatively valenced film clips should have more subtle negative cues to avoid ceiling effects and to ensure there is enough room for interpretation.

Styles APA, Harvard, Vancouver, ISO, etc.

36

Susilowati, Rini. "Listening Anxiety and The Solutions To Inhibit Its Negative Effects." Edukasi Lingua Sastra 17, no. 2 (2019): 13–26. http://dx.doi.org/10.47637/elsa.v17i2.36.

Texte intégral

Résumé :

Kemampuan menyimak dalam bahasa Inggris adalah kemampuan yang tidak mudah dikuasai oleh semua siswa yang bukan penutur asli bahasa tersebut. Kemampuan ini harus didukung oleh penguasaan kosakata bahasa Iggris yang baik, mengaitkan makna kata dan frase bahasa Inggris dengan konteks topik pembicaran sehingga dapat menyimpulkan dengan benar isi pembicaraan yang disimak, mengikuti kecepatan berbicara penutur asing dan aksen berbicara yang berbeda-beda, memahami konteks struktur tata bahasa yang biasa dipergunakan dalam bentuk lisan percakapan bahasa Inggris, serta pengetahuan dasar yand dimiliki terkait topik pembicaraan materi yang disimak. Jika semua hal tersebut tidak dikuasai oleh siswa, salah satu dampak yang akan muncul adalah rasa cemas, takut dan khawatir atau dikenal dengan istilah listening anxiety. Listening anxiety harus diantisipasi dan diatasi dengan strategi yang tepat salah satunya dengan menerapkan teknik bottom-up pada proses pengajaran sehingga efek negatif dari listening anxiety dapat diminimalisir secara sifnifikan.

Styles APA, Harvard, Vancouver, ISO, etc.

37

Sahabuddin, Farhah Nadhirah Aiman, Nazatul Izzati Jamaludin, Nurul Hidayah Amir, and Shazlin Shaharudin. "The effects of hip- and ankle-focused exercise intervention on dynamic knee valgus: a systematic review." PeerJ 9 (July 5, 2021): e11731. http://dx.doi.org/10.7717/peerj.11731.

Texte intégral

Résumé :

Background A range of non-contact injuries such as anterior cruciate ligament tear, and patellofemoral pain syndrome are caused by disordered knee joint loading from excessive dynamic knee valgus (DKV). Previous systematic reviews showed that DKV could be modified through the influence of hip strength and ankle range of motion. Therefore, the purpose of this systematic review was to examine the effects of exercise intervention which involved either top-down or bottom-up kinetic chains on minimizing DKV in male and female adults and adolescents, with and without existing knee pain. Methodology Electronic searches were conducted in SAGE, Science Direct, SCOPUS, and Pubmed. The search strategy consisted of medical subject headings and free-text search keywords, synonyms and variations of ‘exercise intervention,’ ‘knee alignment,’ ‘dynamic knee valgus’, ‘knee abduction’ that were merged via the Boolean operator ‘AND’ and ‘OR’. The search was conducted on full-text journals that documented the impact of the exercise intervention program involving either the bottom-up or top-down DKV mechanism on the knee kinematics. Furthermore, exercise intervention in this review should last at least one week which included two or three sessions per week. This review also considered both men and women of all ages with a healthy or symptomatic knee problem. The risk of bias of the included studies was assessed by Cochrane risk assessment tool. The protocol of this review was registered at PROSPERO (registration number: CRD42021219121). Results Ten studies with a total of 423 participants (male = 22.7%, female = 77.3%; adults = 249, adolescents = 123; pre-adolescent = 51) met the inclusion criteria of this review. Seven studies showed the significant effects of the exercise intervention program (range from two weeks to ten weeks) on reducing DKV. The exercise training in these seven studies focused on muscle groups directly attached to the knee joint such as hamstrings and gastrocnemius. The remaining three studies did not show significant improvement in DKV after the exercise intervention (range between eight weeks to twelve weeks) probably because they focused on trunk and back muscles instead of muscles crossing the knee joint. Conclusion Exercises targeting specific knee-joint muscles, either from top-down or bottom-up kinetic chain, are likely to reduce DKV formation. These results may assist athletes and coaches to develop effective exercise program that could minimize DKV and ultimately prevent lower limb injuries.

Styles APA, Harvard, Vancouver, ISO, etc.

38

Fairfield, Beth, Caterina Padulo, Alessandro Bortolotti, Bernardo Perfetti, Nicola Mammarella, and Michela Balsamo. "Do Older and Younger Adults Prefer the Positive or Avoid the Negative?" Brain Sciences 12, no. 3 (2022): 393. http://dx.doi.org/10.3390/brainsci12030393.

Texte intégral

Résumé :

Affective information is processed in different ways across one’s lifespan. Explanations for this pattern of performance are multiple and range from top-down motivational shifts and cognitive control to faster bottom-up and implicit processes. In this study, we aimed to investigate implicit affective information processing and positivity effects by examining performance in a modified version of the dot-probe task across three image-pair conditions (positive/neutral; negative/neutral; and positive/negative). We examined data from 50 older adults and 50 younger adults. The results showed that affective information processing varies with age and valence and that age effects in affective processing may occur early during information processing. Positivity biases emerge in both younger and older adults. However, while younger adults seem to prioritize positive information independently of context, older adults showed this prioritization only when presented in an emotional (i.e., negative) context. Moreover, older adults showed a tendency to avoid negative information whereas younger adults showed a general bias for affective content modulated by image-pair context.

Styles APA, Harvard, Vancouver, ISO, etc.

39

Trubnikova, Victoriya Yu. "Pragmatic (In)appropriateness of Diminutives in Russian Language." RUDN Journal of Language Studies, Semiotics and Semantics 12, no. 4 (2021): 1160–74. http://dx.doi.org/10.22363/2313-2299-2021-12-4-1160-1174.

Texte intégral

Résumé :

The article discusses the issue of pragmatic meanings of diminutive forms in the Russian language from the point of view of politeness and speech act theories. The impact of diminutives on the illocutionary force and perlocutionary effects of speech acts raises the question of their appropriateness in various communicative situations. Since there is a negative bias towards diminutives among lay native speakers, it was decided to analyse their opinions, beliefs and feelings in order to define 1) the speakers illocutionary intentions; 2) contexts of use and 3) perlocutionary effects. The online articles, forums, posts on social networks and comments of Internet users were collected, with a total amount of 23 sources and 714 user comments. The emic and bottom-up approach referred to speakers intuition reveal 1) negative attitude towards diminutives in hierarchical relationships, 2) perception of diminutives as a positive politeness tool in low distance relationships, 3) perception of diminutives as a manipulative tool in unequal relationships. Thus, the appropriate use of diminutives calls for pragmatic skills to assess a communicative situation in terms of social variables, such as social distance and power, mutual costs and benefits, rights and obligations of interlocutors.

Styles APA, Harvard, Vancouver, ISO, etc.

40

Yuan, Xian-Xun, and Iliya Nemtsov. "Local Calibration of the MEPDG Distress and Performance Models for Ontario’s Flexible Roads: Overview, Impacts, and Reflection." Transportation Research Record: Journal of the Transportation Research Board 2672, no. 40 (2018): 207–16. http://dx.doi.org/10.1177/0361198118759013.

Texte intégral

Résumé :

Built upon a seven-year local calibration study of Ontario’s flexible pavements, this paper provides a summary of the calibration results and design impact and, more importantly, shares the experience and lessons learned from the process. The best results have been achieved on the local calibration of the rutting, bottom-up fatigue cracking, and international roughness index (IRI) distress models minimizing the residual sum of squares (RSS) while maintaining the average bias at zero. Significant efforts have been made to calibrate the other distress models with limited success. A design impact study found that local calibration of the rutting models was very important, whereas the alligator fatigue cracking did not usually govern the design in Ontario, although the global model was found to under-predict the cracking damage. The performance of the calibrated IRI model in the design of heavy traffic freeways for both reconstructed and rehabilitated sections was unsatisfactory and needs further study. The paper also presents several open questions for future research. These include the handling of section-length effects of observed cracking data, the determination of initial IRI, the updating of standard deviation functions and the overall reliability models, and the prioritization of pavement research under the new paradigm of the Mechanistic–Empirical Pavement Design Guide (MEPDG).

Styles APA, Harvard, Vancouver, ISO, etc.

41

Hu, Yiwen, Zengliang Zang, Dan Chen, et al. "Optimization and Evaluation of SO2 Emissions Based on WRF-Chem and 3DVAR Data Assimilation." Remote Sensing 14, no. 1 (2022): 220. http://dx.doi.org/10.3390/rs14010220.

Texte intégral

Résumé :

Emission inventories are important for modeling studies and policy-making, but the traditional “bottom-up” emission inventories are often outdated with a time lag, mainly due to the lack of accurate and timely statistics. In this study, we developed a “top-down” approach to optimize the emission inventory of sulfur dioxide (SO2) using the Weather Research and Forecasting model coupled with Chemistry (WRF-Chem) and a three-dimensional variational (3DVAR) system. The observed hourly surface SO2 concentrations from the China National Environmental Monitoring Center were assimilated and used to estimate the gridded concentration forecast errors of WRF-Chem. The concentration forecast errors were then converted to the emission errors by assuming a linear response from SO2 emission to concentration by grids. To eliminate the effects of modelling errors from aspects other than emissions, a strict data-screening process was conducted. Using the Multi-Resolution Emission Inventory for China (MEIC) 2010 as the a priori emission, the emission inventory for October 2015 over Mainland China was optimized. Two forecast experiments were conducted to evaluate the performance of the SO2 forecast by using the a priori (control experiment) and optimized emissions (optimized emission experiment). The results showed that the forecasts with optimized emissions typically outperformed the forecasts with 2010 a priori emissions in terms of the accuracy of the spatial and temporal distributions. Compared with the control experiment, the bias and root-mean-squared error (RMSE) of the optimized emission experiment decreased by 71.2% and 25.9%, and the correlation coefficients increased by 50.0%. The improvements in Southern China were more significant than those in Northern China. For the Sichuan Basin, Yangtze River Delta, and Pearl River Delta, the bias and RMSEs decreased by 76.4–94.2% and 29.0–45.7%, respectively, and the correlation coefficients increased by 23.5–53.4%. This SO2 emission optimization methodology is computationally cost-effective.

Styles APA, Harvard, Vancouver, ISO, etc.

42

Hahnloser, Richard H. R., Rodney J. Douglas, and Klaus Hepp. "Attentional Recruitment of Inter-Areal Recurrent Networks for Selective Gain Control." Neural Computation 14, no. 7 (2002): 1669–89. http://dx.doi.org/10.1162/08997660260028665.

Texte intégral

Résumé :

There is strong anatomical and physiological evidence that neurons with large receptive fields located in higher visual areas are recurrently connected to neurons with smaller receptive fields in lower areas. We have previously described a minimal neuronal network architecture in which top-down attentional signals to large receptive field neurons can bias and selectively read out the bottom-up sensory information to small receptive field neurons (Hahnloser, Douglas, Mahowald, & Hepp, 1999). Here we study an enhanced model, where the role of attention is to recruit specific inter-areal feedback loops (e.g., drive neurons above firing threshold). We first illustrate the operation of recruitment on a simple example of visual stimulus selection. In the subsequent analysis, we find that attentional recruitment operates by dynamical modulation of signal amplification and response multistability. In particular, we find that attentional stimulus selection necessitates increased recruitment when the stimulus to be selected is of small contrast and of small distance away from distractor stimuli. The selectability of a low-contrast stimulus is dependent on the gain of attentional effects; for example, low-contrast stimuli can be selected only when attention enhances neural responses. However, the dependence of attentional selection on stimulus-distractor distance is not contingent on whether attention enhances or suppresses responses. The computational implications of attentional recruitment are that cortical circuits can behave as winner-take-all mechanisms of variable strength and can achieve close to optimal signal discrimination in the presence of external noise.

Styles APA, Harvard, Vancouver, ISO, etc.

43

Kumar, Dipankar, and Satoshi Takewaka. "Automatic Shoreline Position and Intertidal Foreshore Slope Detection from X-Band Radar Images using Modified Temporal Waterline Method with Corrected Wave Run-up." Journal of Marine Science and Engineering 7, no. 2 (2019): 45. http://dx.doi.org/10.3390/jmse7020045.

Texte intégral

Résumé :

Automatic and accurate shoreline position and intertidal foreshore slope detection are challenging and significantly important for coastal dynamics. In the present study, a time series shoreline position and intertidal foreshore slope have been automatically detected using modified Temporal Waterline Method (mTWM) from time-averaged X-band radar images captured throughout the course of two-week tidal cycle variation over an area spanning 5.6 km on the Hasaki coast between 12 April 2005 and 31 December 2008. The methodology is based on the correlation map between the pixel intensity variation of the time-averaged X-band radar images and the binary signal of the tide level ranging from −0.8 m to 0.8 m. In order to ensure the binary signal represented each of the water levels in the intertidal shore profile, determining the water level direction-wise bottom elevation is considered as the modification. Random gaps were detected in the captured images owing to the unclear or oversaturation of the waterline signal. A horizontal shift in the detected shoreline positions was observed compared to the survey data previously collected at Hasaki Oceanographical Research Station (HORS). This horizontal shift can be attributed to wave breaking and high wave conditions. Wave set-up and run-up are the effects of wave breaking and high wave conditions, respectively. The correction of the wave set-up and run-up is considered to allow the upward shift of the water level position, as well as shoreline position, to the landward direction. The findings indicate that the shoreline positions derived by mTWM with the corrected wave run-up reasonably agree with the survey data. The mean absolute bias (MAB) between the survey data and the shoreline positions detected using mTWM with the corrected wave run-up is approximately 5.9 m, which is theoretically smaller than the spatial resolution of the radar measurements. The random gaps in the mTWM-derived shoreline positions are filled by Garcia’s data filling algorithm which is a Penalized Least Squares regression method by means of the Discrete Cosine Transform (PLS-DCT). The MAB between survey data and the gap filled shoreline positions detected using TWM with corrected wave run-up is approximately 5.9 m. The obtained results indicate the accuracy of the mTWM with corrected wave run-up integrated with Garcia’s method compared to the survey observations. The executed approach in this study is considered as an efficient and robust tool to automatically detect shoreline positions and intertidal foreshore slopes extracted from X-band radar images with the consideration of wave run-up correction.

Styles APA, Harvard, Vancouver, ISO, etc.

44

Ghosh, Sanhita, Shubha Verma, Jayanarayanan Kuttippurath, and Laurent Menut. "Wintertime direct radiative effects due to black carbon (BC) over the Indo-Gangetic Plain as modelled with new BC emission inventories in CHIMERE." Atmospheric Chemistry and Physics 21, no. 10 (2021): 7671–94. http://dx.doi.org/10.5194/acp-21-7671-2021.

Texte intégral

Résumé :

Abstract. To reduce the uncertainty in climatic impacts induced by black carbon (BC) from global and regional aerosol–climate model simulations, it is a foremost requirement to improve the prediction of modelled BC distribution, specifically over the regions where the atmosphere is loaded with a large amount of BC, e.g. the Indo-Gangetic Plain (IGP) in the Indian subcontinent. Here we examine the wintertime direct radiative perturbation due to BC with an efficiently modelled BC distribution over the IGP in a high-resolution (0.1∘ × 0.1∘) chemical transport model, CHIMERE, implementing new BC emission inventories. The model efficiency in simulating the observed BC distribution was assessed by executing five simulations: Constrained and bottomup (bottomup includes Smog, Cmip, Edgar, and Pku). These simulations respectively implement the recently estimated India-based observationally constrained BC emissions (Constrainedemiss) and the latest bottom-up BC emissions (India-based: Smog-India; global: Coupled Model Intercomparison Project phase 6 – CMIP6, Emission Database for Global Atmospheric Research-V4 – EDGAR-V4, and Peking University BC Inventory – PKU). The mean BC emission flux from the five BC emission inventory databases was found to be considerably high (450–1000 kg km−2 yr−1) over most of the IGP, with this being the highest (> 2500 kg km−2 yr−1) over megacities (Kolkata and Delhi). A low estimated value of the normalised mean bias (NMB) and root mean square error (RMSE) from the Constrained estimated BC concentration (NMB: < 17 %) and aerosol optical depth due to BC (BC-AOD) (NMB: 11 %) indicated that simulations with Constrainedemiss BC emissions in CHIMERE could simulate the distribution of BC pollution over the IGP more efficiently than with bottom-up emissions. The high BC pollution covering the IGP region comprised a wintertime all-day (daytime) mean BC concentration and BC-AOD respectively in the range 14–25 µg m−3 (6–8 µg m−3) and 0.04–0.08 from the Constrained simulation. The simulated BC concentration and BC-AOD were inferred to be primarily sensitive to the change in BC emission strength over most of the IGP (including the megacity of Kolkata), but also to the transport of BC aerosols over megacity Delhi. Five main hotspot locations were identified in and around Delhi (northern IGP), Prayagraj–Allahabad–Varanasi (central IGP), Patna–Palamu (mideastern IGP), and Kolkata (eastern IGP). The wintertime direct radiative perturbation due to BC aerosols from the Constrained simulation estimated the atmospheric radiative warming (+30 to +50 W m−2) to be about 50 %–70 % larger than the surface cooling. A widespread enhancement in atmospheric radiative warming due to BC by 2–3 times and a reduction in surface cooling by 10 %–20 %, with net warming at the top of the atmosphere (TOA) of 10–15 W m−2, were noticed compared to the atmosphere without BC, for which a net cooling at the TOA was exhibited. These perturbations were the strongest around megacities (Kolkata and Delhi), extended to the eastern coast, and were inferred to be 30 %–50% lower from the bottomup than the Constrained simulation.

Styles APA, Harvard, Vancouver, ISO, etc.

45

Cairney, Paul, and Sean Kippin. "The future of education equity policy in a COVID-19 world: a qualitative systematic review of lessons from education policymaking." Open Research Europe 1 (July 8, 2021): 78. http://dx.doi.org/10.12688/openreseurope.13834.1.

Texte intégral

Résumé :

Background: COVID-19 had a major global impact on education, prompting concerns about its unequal effects and some impetus to reboot equity strategies. Yet, policy processes exhibit major gaps between expectations and outcomes, and inequalities endured for decades before the pandemic. Our objective is to establish, from education research, how policymakers seek equitable outcomes. Our study emulates its partner review of ‘Health in All Policies’ (HiAP) to ask: How does education equity research use policy theory to understand policymaking? Methods: A qualitative systematic review (from 2020-21), to identify peer reviewed research and commentary articles on education, equity, and policymaking, in specialist and general databases (ERIC, Web of Science, Scopus, Cochrane/ Social Systems Evidence). We did not apply additional quality measures. We used an inductive approach to identify key themes. We use these texts to produce a general narrative and explore how relatively theory-informed articles enhance it. Results: 140 texts (109 articles included; 31 texts snowballed) provide a non-trivial reference to policymaking. Limiting inclusion to English-language produced a bias towards Global North articles. The comparison with HIAP highlights distinctive elements of education research. First, educational equity is ambiguous and contested, with no settled global definition or agenda (although countries like the US, and organisations like the World Bank, have disproportionate influence). Second, researchers critique the narrow equity definitions – focusing on performance – that dominate policymaking. Third, more studies provide ‘bottom-up’ analysis of ‘implementation gaps’. Fourth, more studies relate inequity to ineffective policymaking to address marginalised groups. Conclusions: Few studies use policy theories to explain policymaking, but there is an education-specific literature performing a similar task. Compared to HIAP research, there is more use of critical policy analysis to reflect on power and less focus on delivering top-down aims. Most studies criticise current educational equity aims and expect them to fail.

Styles APA, Harvard, Vancouver, ISO, etc.

46

Cairney, Paul, and Sean Kippin. "The future of education equity policy in a COVID-19 world: a qualitative systematic review of lessons from education policymaking." Open Research Europe 1 (January 13, 2022): 78. http://dx.doi.org/10.12688/openreseurope.13834.2.

Texte intégral

Résumé :

Background: COVID-19 had a major global impact on education, prompting concerns about its unequal effects and some impetus to reboot equity strategies. Yet, policy processes exhibit major gaps between such expectations and outcomes, and similar inequalities endured for decades before the pandemic. Our objective is to establish how education researchers, drawing on policy concepts and theories, explain and seek to address this problem. Methods: A qualitative systematic review (2020-21), to identify peer reviewed research and commentary articles on education, equity, and policymaking, in specialist and general databases (ERIC, Web of Science, Scopus, Cochrane/ Social Systems Evidence). We did not apply additional quality measures. We used an immersive and inductive approach to identify key themes. We use these texts to produce a general narrative and explore how policy theory articles inform it. Results: 140 texts (109 articles included; 31 texts snowballed) provide a non-trivial reference to policymaking. Limiting inclusion to English-language produced a bias towards Global North articles. Our comparison with a review of health equity research highlights distinctive elements in education. First, education equity is ambiguous and contested, with no settled global definition or agenda (although some countries and international organisations have disproportionate influence). Second, researchers critique ‘neoliberal’ approaches that dominate policymaking at the expense of ‘social justice’. Third, more studies provide ‘bottom-up’ analysis of ‘implementation gaps’. Fourth, more studies relate inequity to ineffective policymaking to address marginalised groups. Conclusions: Few studies use policy theories to explain policymaking, but there is an education-specific literature performing a similar role. Compared to health research, there is more use of critical policy analysis to reflect on power and less focus on technical design issues. There is high certainty that current neoliberal policies are failing, but low certainty about how to challenge them successfully.

Styles APA, Harvard, Vancouver, ISO, etc.

47

Hopfinger, Joseph B., and Anthony J. Ries. "Automatic Versus Contingent Mechanisms of Sensory-Driven Neural Biasing and Reflexive Attention." Journal of Cognitive Neuroscience 17, no. 8 (2005): 1341–52. http://dx.doi.org/10.1162/0898929055002445.

Texte intégral

Résumé :

Recent studies have generated debate regarding whether reflexive attention mechanisms are triggered in a purely automatic stimulus-driven manner. Behavioral studies have found that a nonpredictive “cue” stimulus will speed manual responses to subsequent targets at the same location, but only if that cue is congruent with actively maintained top-down settings for target detection. When a cue is incongruent with top-down settings, response times are unaffected, and this has been taken as evidence that reflexive attention mechanisms were never engaged in those conditions. However, manual response times may mask effects on earlier stages of processing. Here, we used event-related potentials to investigate the interaction of bottom-up sensory-driven mechanisms and top-down control settings at multiple stages of processing in the brain. Our results dissociate sensory-driven mechanisms that automatically bias early stages of visual processing from later mechanisms that are contingent on top-down control. An early enhancement of target processing in the extrastriate visual cortex (i.e., the P1 component) was triggered by the appearance of a unique bright cue, regardless of top-down settings. The enhancement of visual processing was prolonged, however, when the cue was congruent with top-down settings. Later processing in posterior temporal-parietal regions (i.e., the ipsilateral invalid negativity) was triggered automatically when the cue consisted of the abrupt appearance of a single new object. However, in cases where more than a single object appeared during the cue display, this stage of processing was contingent on top-down control. These findings provide evidence that visual information processing is biased at multiple levels in the brain, and the results distinguish automatically triggered sensory-driven mechanisms from those that are contingent on top-down control settings.

Styles APA, Harvard, Vancouver, ISO, etc.

48

Sánchez-González, Diego, Fermina Rojo-Pérez, Vicente Rodríguez-Rodríguez, and Gloria Fernández-Mayoralas. "Environmental and Psychosocial Interventions in Age-Friendly Communities and Active Ageing: A Systematic Review." International Journal of Environmental Research and Public Health 17, no. 22 (2020): 8305. http://dx.doi.org/10.3390/ijerph17228305.

Texte intégral

Résumé :

Background: The academic literature contains little information regarding the interventions that create age-friendly cities and communities in order to promote active ageing. Objectives: A systematic review was carried out to determine the available empirical evidence in relation to the characteristics, content and effectiveness of interventions aimed at improving environmental and psychosocial risk factors for older people, from the perspective of age-friendly communities and the promotion of active ageing. Methods: Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, the studies retained in this review were identified through a systematic search of the academic literature in selected electronic databases including Web of Science and Scopus. Independent critical appraisal and data extraction were conducted by two reviewers. The checklist was used to assess the quality of the articles. Findings: The search identified 1020 potentially eligible documents, of which 11 satisfied the established criteria. Non-exhaustive practices prevailed over rigorous investigations, with a high proportion of studies observed to be of low methodological quality and at high risk of bias. This reflected the predominance of uncontrolled interventions. Environmental interventions were focused on reducing risk and adapting the everyday environmental setting, while psychosocial interventions prioritised social strategies (behavioural changes, promotion of participation) and training. Interventions were more effective in certain domains of age-friendly cities and communities such as transportation and housing, followed by increased participation as a lifestyle-related behavioural change. The inferred changes were associated with providing information and enhancing skills; modifying access, barriers, exposures, and opportunities; enhancing services and support; continuity and effectiveness of changes over time; and modifying policies based on the bottom-up approach of age-friendly cities and communities (AFCC). Discussion and conclusion: Interventions focused on personal and organisational aspects might have positive effects in the longer term. However, fewer changes would be observed in interventions revolving around changing lifestyles owing to the impact of complex multi-causal factors. The relative effectiveness in terms of health calls into question the design of interventions and the supposed “friendliness” of certain communities. There is a need to encourage sound longitudinal research aimed at providing key knowledge for the implementation and evaluation of public policies, and to encourage age-friendly community programmes to promote active ageing.

Styles APA, Harvard, Vancouver, ISO, etc.

49

Olver, Ian N., Kate M. Gunn, Vikki E. Knott, Alwin Chong, Kristiaan Spronk, and Joan Cunningham. "Communicating cancer and its treatment to Australian Aboriginal patients with cancer: A qualitative study." Journal of Clinical Oncology 38, no. 15_suppl (2020): e24188-e24188. http://dx.doi.org/10.1200/jco.2020.38.15_suppl.e24188.

Texte intégral

Résumé :

e24188 Background: To enable clinicians to effectively communicate about cancer and its treatment to Aboriginal and Torres Strait (Aboriginal) people with cancer who need to make informed choices about the Western medicine offered, we sought strategies from health professionals with experience in that field. Methods: Semi-structured interviews were conducted face-to face or via telephone with the experienced health professionals and audio-recorded. Thematic analysis using a bottom up, essentialist/realist approach was employed to analyse the data, when data saturation was reached. Results: The 23 health professionals interviewed were medical and radiation oncologists, oncology nurses and Aboriginal health workers. Twelve were female, 11 were male with 5 identifying as Aboriginal. Six themes emerged. (1) Create a safe environment, engender trust and build rapport. This involves avoiding assumptions, allowing time, considering the physical environment, asking about home and family, being aware of gender issues and noting non-verbals. (2) Employ specific strategies to explain cancer, treatment and its side effects by using simple language, employing visual aids such as drawings, metaphors and relatable analogies such as trees with roots, weeds, abandoned rusty cars and blocked pipes. Use repetition and ensure alignment with patient needs. Warning about upcoming sensitive issues minimised the chance of disengagement. (3) Obtain support from those who can assist in communication. This includes interpreters, aboriginal liaison officers and health workers, and patient escorts. (4) Consider the culture which involves collective decision-making, strong connection to country and community, with cultural obligations and unique understanding of cancer which can involve curses, shame and utilise bush medicine. (5) Develop personal qualities of good communicators, including showing respect, patience, empathy, honesty, being person centred and embracing personal reflection. (6) Understand the contextual complexity of multiple languages, possible disengagement with treatment, difficulty maintaining contact with patients, conflicts between Western medicine and Aboriginal culture and late stage presentations. Be aware of practitioner bias. Conclusions: These insights will help foster more positive interactions with the health system and promote optimal outcomes for Aboriginal people with cancer and enable the creation of educational modules for inexperienced clinicians.

Styles APA, Harvard, Vancouver, ISO, etc.

50

Derawi, Hadeer, Eva Reinisch, and Yafit Gabay. "Increased reliance on top-down information to compensate for reduced bottom-up use of acoustic cues in dyslexia." Psychonomic Bulletin & Review, September 24, 2021. http://dx.doi.org/10.3758/s13423-021-01996-9.

Texte intégral

Résumé :

AbstractSpeech recognition is a complex human behavior in the course of which listeners must integrate the detailed phonetic information present in the acoustic signal with their general linguistic knowledge. It is commonly assumed that this process occurs effortlessly for most people, but it is still unclear whether this also holds true in the case of developmental dyslexia (DD), a condition characterized by perceptual deficits. In the present study, we used a dual-task setting to test the assumption that speech recognition is effortful for people with DD. In particular, we tested the Ganong effect (i.e., lexical bias on phoneme identification) while participants performed a secondary task of either low or high cognitive demand. We presumed that reduced efficiency in perceptual processing in DD would manifest in greater modulation in the performance of primary task by cognitive load. Results revealed that this was indeed the case. We found a larger Ganong effect in the DD group under high than under low cognitive load, and this modulation was larger than it was for typically developed (TD) readers. Furthermore, phoneme categorization was less precise in the DD group than in the TD group. These findings suggest that individuals with DD show increased reliance on top-down lexically mediated perception processes, possibly as a compensatory mechanism for reduced efficiency in bottom-up use of acoustic cues. This indicates an imbalance between bottom-up and top-down processes in speech recognition of individuals with DD.

Styles APA, Harvard, Vancouver, ISO, etc.

Articles de revues sur le sujet « Bottom-up bias effect »

Créez une référence correcte selon les styles APA, MLA, Chicago, Harvard et plusieurs autres