Search Time as a Function of Context Letter Frequency

Perception ◽  
1972 ◽  
Vol 1 (1) ◽  
pp. 57-71 ◽  
Author(s):  
C R Latimer
Keyword(s):  
Pattern Recognition ◽  
Reaction Time ◽  
High Frequency ◽  
Relative Frequency ◽  
Search Time ◽  
Low Frequency ◽  
Frequency Of Occurrence ◽  
Template Model ◽  
Letter Frequency ◽  
Feature Frequency

Neisser (1967) posits the operation of purely feature analytic processes in the scanning of context letters in search lists. This contention was tested by varying the relative frequency of occurrence in English of the context letters in alphanumeric search lists, while holding their feature content constant. It was hypothesized that faster search time on lists of high-frequency context letters would indicate letter-level processing. Equality of search time would indicate the purely feature-level processing required by Neisser's theory. Context letters were segregated into high- and low-frequency sets and their features defined and held constant according to two feature analyses. This yielded a 2 × 2 design with 22 subjects per condition. Attention was given to the control of feature frequency, size of the context-letter set, and approximation of English at the level of bigram, trigram, and word. Results supported a letter level or template model of processing but were shown also to be explainable in terms of some feature-testing models of pattern recognition. Apparatus which allowed for the removal of reaction time in search lists is described.

Intelligent Control Circuit Integral with Pattern Recognition Techniques for High-Pressure Sodium Lamps

2017 ◽  
Vol 26 (07) ◽  
pp. 1750108
Author(s):  
Yuzhuo Pan ◽  
Chen Lv ◽  
Shanhe Su ◽  
Jincan Chen
Keyword(s):  
Pattern Recognition ◽  
High Pressure ◽  
Intelligent Control ◽  
High Frequency ◽  
Pulse Width Modulation ◽  
Smart Cities ◽  
Control Strategies ◽  
Low Frequency ◽  
Acoustic Resonance ◽  
Working Device

The paper presents the analysis, simulation, and experimental methods to eliminate acoustic resonance in high-frequency high-pressure sodium (HPS) lamps and integrate intelligent control strategies in the working device. Based on the pulse-width modulation (PWM) output generated by the microcontroller, the acoustic resonance in the high-frequency lamp can be successfully eliminated by modulating the high-frequency driving current via a low-frequency signal. Particularly, by implementing the pattern recognition, the control system enables the lamp to have the abilities of accurate timing, gradient dimming, automatic protection, and intellisense. The proposed model will provide useful information for designing intelligent lighting system towards smart cities.

Disynaptic Pyramidal Excitation in Forelimb Motoneurons Mediated Via C3–C4 Propriospinal Neurons in theMacaca fuscata

1999 ◽  
Vol 82 (6) ◽  
pp. 3580-3585 ◽  
Author(s):  
B. Alstermark ◽  
T. Isa ◽  
Y. Ohki ◽  
Y. Saito
Keyword(s):  
Inhibitory Control ◽  
High Frequency ◽  
Macaca Fuscata ◽  
Low Frequency ◽  
Macaque Monkey ◽  
Special Focus ◽  
Frequency Of Occurrence ◽  
Macaque Monkeys ◽  
Monosynaptic Connection ◽  
Propriospinal Neurons

In contrast to findings in the cat, it recently has been shown that disynaptic pyramidal EPSPs only rarely are observed in forelimb motoneurons of the macaque monkey in the intact spinal cord or after a corticospinal transection in C5. This finding has been taken to indicate that the disynaptic pyramidal excitatory pathway via C3–C4 propriospinal neurons (PNs) is weakened through phylogeny when the monosynaptic cortico-motoneuronal connection has been strengthened. We reinvestigate this issue with special focus on the possibility that the inhibitory control of the C3–C4 PNs may be stronger in the macaque monkey than in the cat. The effect in forelimb motoneurons of electrical stimulation in the contralateral pyramid was investigated in anesthetized macaque monkeys ( Macaca fuscata). We confirmed the low frequency of disynaptic pyramidal EPSPs in forelimb motoneurons. However, after intravenous injection of strychnine, disynaptic EPSPs could be evoked in 39 of 41 forelimb motoneurons recorded after lesion of the corticospinal fibers in C5. After a corresponding lesion in C2, disynaptic pyramidal EPSPs were observed in 2 of 25 motoneurons. In contrast to previous reports, we conclude that C3–C4 PNs can mediate disynaptic pyramidal excitation in high frequency of occurrence to forelimb motoneurons in the C6–C8 segments and that this transmission is under a stronger inhibitory control than in the cat. Thus, the hypothesis that the disynaptic excitatory cortico-motoneuronal pathway via the C3–C4 PNs is weakened in parallel with the strengthened monosynaptic connection through phylogeny is not supported by the present findings.

Frequency of Pairs of Items and Associative Probability in Learning

1971 ◽  
Vol 29 (1) ◽  
pp. 127-133
Author(s):  
Charles S. Berdiansky
Keyword(s):  
Associative Learning ◽  
Word Pair ◽  
High Frequency ◽  
Paired Associate ◽  
Low Frequency ◽  
Similar Rate ◽  
Frequency Of Occurrence ◽  
Control Pair ◽  
Zero Frequency

The study was designed to compare Underwood and Schulz's associative probability hypothesis and the paired frequency of two words in performance on a paired-associate task. After being presented a list, 16 Ss matched responses with their stimuli. Each list contained a word pair or item, of (a) high frequency of occurrence, (b) low frequency, (c) zero frequency plus a mediator, and (d) zero frequency (the control pair). While the high-frequency items were learned more rapidly than the low-frequency items, the mediator did not affect the zero-frequency items which were learned at a similar rate to that for the control. This result was interpreted as showing the superiority of paired frequency in associative learning.

Frequency of Occurrence and Identification of Ambiguous Perceptual Forms

1964 ◽  
Vol 19 (1) ◽  
pp. 119-129
Author(s):  
James H. Brown
Keyword(s):  
Test Stimulus ◽  
High Frequency ◽  
Training Session ◽  
Low Frequency ◽  
Stimulus Presentation ◽  
Test Session ◽  
Frequency Of Occurrence ◽  
Knowledge Of Results ◽  
Test Task ◽  
Nonsense Form

Differential frequency of stimulus presentation was manipulated in a training session during which 144 Ss identified nonsense form prototypes. Knowledge of results was given. In a test session Ss attempted to identify variations of the eight prototypes seen during training. The test task was to decide as to which of two prototypes a given variation was most similar, under some conditions a neither response being allowed. The results showed that the manipulation of differential frequency during a training session can lead to low-frequency responding to one type of test stimulus and high-frequency responding to another. These results were interpreted as supporting a perceptual set rather than a response bias explanation of the influence of frequency of stimulus occurrence.

scholarly journals Performance Analysis of Different Filters for Digital Image Processing

2021 ◽  
Vol 12 (2) ◽  
pp. 2572-2576
Author(s):  
Ch. Kavya , Et. al.
Keyword(s):  
Remote Sensing ◽  
Image Processing ◽  
Pattern Recognition ◽  
Digital Image Processing ◽  
Digital Image ◽  
High Frequency ◽  
Satellite Remote Sensing ◽  
Low Frequency ◽  
Linear Filters

Digital image processing is one of the drastically growing areas used in various real- time industries like medical, satellite, remote sensing, and pattern recognition. The output of the image processing depends on the quality of the image. Filters are used to modify the images, such as removing the noise and smoothing the images. It is essential to suppress the high- frequency values in the image for smoothening and improving the low-frequency values to enhance the image of strengthening else it doesn't provide good output. This paper discussed various filters and their functionalities concerning digital image processing. Here linear, as well as non-linear filters, are presented. It is easy to decide about the better filter for improving the image processing output from the discussion.

scholarly journals Hybrid Pattern Recognition and Multi-resolution Analysis (MRA) Based Fault Location in Power Transmission Lines

2019 ◽  
pp. 1-14
Author(s):  
Jude I. Aneke ◽  
O. A. Ezechukwu ◽  
P. I. Tagboh
Keyword(s):  
Neural Network ◽  
Pattern Recognition ◽  
Transmission Lines ◽  
High Frequency ◽  
Fault Location ◽  
Power Transmission ◽  
Low Frequency ◽  
Power Transmission Lines ◽  
Multi Resolution Analysis ◽  
Resolution Analysis

This paper proposes a fault (line-to-line) location on Ikeja West – Benin 330kV electric power transmission lines using wavelet multi-resolution analysis and neural networks pattern recognition abilities. Three-phase line-to-line current and voltage waveforms measured during the occurrence of a fault in the power transmission-line were pre-processed first and then decomposed using wavelet multi-resolution analysis to obtain the high-frequency details and low-frequency approximations. The patterns formed based on high-frequency signal components were arranged as inputs of the neural network, whose task is to indicate the occurrence of a fault on the lines. The patterns formed using low-frequency approximations were arranged as inputs of the second neural network, whose task is to indicate the exact fault type. The new method uses both low and high-frequency information of the fault signal to achieve an exact location of the fault. The neural network was trained to recognize patterns, classify data and forecast future events. Feed forward networks have been employed along with back propagation algorithm for each of the three phases in the Fault location process. An analysis of the learning and generalization characteristics of elements in power system was carried using Neural Network toolbox in MATLAB/SIMULINK environment. Simulation results obtained demonstrate that neural network pattern recognition and wavelet multi-resolution analysis approach are efficient in identifying and locating faults on transmission lines as the average percentage error in fault location was just 0.1386%. This showed that satisfactory performance was achieved especially when compared to the conventional methods such as impedance and travelling wave methods.

Some Determinants of Word-Frequency Estimates

1975 ◽  
Vol 40 (3) ◽  
pp. 923-929 ◽  
Author(s):  
Margaret W. Matlin ◽  
David J. Stang
Keyword(s):  
Word Frequency ◽  
High Frequency ◽  
Low Frequency ◽  
Frequency Of Occurrence ◽  
True Frequency

Subjects saw Turkish nonsense words and estimated their frequency of occurrence (72 subjects, 12 words, Exp. I; 33 subjects, 16 words, Exp. II). Results indicated that: (a) low-frequency stimuli were overestimated while high-frequency stimuli were underestimated; (b) stimuli were judged more frequent when they were positively evaluated than when they were negatively evaluated; (c) stimuli were judged more frequent in a distributed presentation than in a massed presentation; (d) stimuli were judged more frequent when they were rated after a 2-wk. delay than when they were rated immediately; (e) a 2-wk. delay enhanced the interaction between true frequency and judged frequency; (f) stimuli were judged more frequent when they appeared at the beginning or end of the presentation period rather than in the middle.

scholarly journals Analysis of SARS-CoV-2 mutations reveals three types of temporal dynamics and one is correlated with international travels

2021 ◽  
Author(s):  
Santiago Justo Arevalo ◽  
Daniela Zapata Sifuentes ◽  
Cesar J. Huallpa ◽  
Gianfranco Landa Bianchi ◽  
Adriana Castillo Chavez ◽  
...  
Keyword(s):  
High Frequency ◽  
Relative Frequency ◽  
Temporal Dynamics ◽  
Low Frequency ◽  
Frequency Change ◽  
Medium Frequency ◽  
Human Behaviors ◽  
Viral Adaptation ◽  
Mutation Dynamics

Coronavirus disease 2019 (COVID-19) is a contagious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). This disease has spread globally, causing more than 161.5 million cases and 3.3 million deaths. Keeping on the identification, surveillance and the study of the temporal dynamics of mutations with significant representation is central to understand the adaptation of SARS-CoV-2. Furthermore, how lockdown policies influence the dynamics of SARS-CoV-2 mutations is poorly understood. Here, using 1 058 020 SARS-CoV-2 genomes and COVID-19 cases from 714 country-month combinations representing 98 countries, we performed a normalization by COVID-19 cases calculation of relative frequency of SARS-CoV-2 mutations. We found 115 mutations estimated to be present in more than 3 % of global COVID-19 cases and determined three types of mutation dynamics: High-Frequency, Medium-Frequency, and Low-Frequency. Classification of mutations based on temporal dynamics helps to study viral adaptation and can be used to evaluate the effects of human behaviors in the pandemic. For instance, we report a negative and positive correlation of the frequency change of High-Frequency mutations with the level of international movement controls and the number of flight departures, respectively.

Vowel Formant Structure Predicts Metric Position in Hip-hop Lyrics

2019 ◽  
Vol 36 (5) ◽  
pp. 480-487
Author(s):  
Paolo Ammirante ◽  
Fran Copelli
Keyword(s):  
Hip Hop ◽  
High Frequency ◽  
Rap Music ◽  
Low Frequency ◽  
Population Estimates ◽  
Frequency Of Occurrence ◽  
Vowel Formant ◽  
Singer's Formant ◽  
Second Formant ◽  
Opera Singers

In order to be heard over the low-frequency energy of a loud orchestra, opera singers adjust their vocal tracts to increase high-frequency energy around 3,000 Hz (known as a “singer's formant”). In rap music, rhymes often coincide with the beat and thus may be masked by loud, low-frequency percussion events. How do emcees (i.e., rappers) avoid masking of on-beat rhymes? If emcees exploit formant structure, this may be reflected in the distribution of on- and off-beat vowels. To test this prediction, we used a sample of words from the MCFlow rap lyric corpus (Condit-Schultz, 2016). Frequency of occurrence of on- and off-beat words was compared. Each word contained one of eight vowel nuclei; population estimates of each vowel's first and second formant (F1 and F2) frequencies were obtained from an existing source. A bias was observed: vowels with higher F2, which are less likely to be masked by percussion, were favored for on-beat words. Words with lower F2 vowels, which may be masked, were more likely to deviate from the beat. Bias was most evident among rhyming words but persisted for nonrhyming words. These findings imply that emcees use formant structure to implicitly or explicitly target the intelligibility of salient lyric events.

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