The Effects on Bilateral-Symmetry Detection of Multiple Symmetry, near Symmetry, and Axis Orientation

Perception ◽  
1997 ◽  
Vol 26 (7) ◽  
pp. 891-904 ◽  
Author(s):  
Peter Wenderoth
Keyword(s):  
Response Bias ◽  
Human Perception ◽  
Negative Stimulus ◽  
Bilateral Symmetry ◽  
Symmetry Detection ◽  
Axis Orientation ◽  
Second Stage ◽  
Asymmetrical Pattern ◽  
Stage Process ◽  
Axes Of Symmetry

Palmer and Hemenway (1978 Journal of Experimental Psychology: Human Perception and Performance4 691–702) reported that shapes with multiple axes of symmetry are processed faster than those with single symmetry even when trials are blocked so that the subject knows that any symmetry axis will be vertical. Because their model of symmetry detection postulated a two-stage process in which all orientations are searched crudely at first, in no particular order, followed by second-stage scrutiny, the continued salience of multiple over single symmetry with blocking could not be explained. They claimed that stimuli with multiple axes of symmetry have an additional ‘goodness’. Four experiments are reported in which it is demonstrated that both sensitivity ( d′) and response bias ( β) vary considerably in symmetry detection, not just as a function of the positive (symmetrical) stimuli used but also as a function of the negative or conjugate instances selected. Although stimuli with multiple axes of symmetry may well have extra salience due to pattern ‘goodness’, this factor may have been confounded with response bias in Palmer and Hemenway's experiments. It is suggested that several of their—as well as other researchers—results could be due to some combination of the effects of type of positive stimulus, type of negative stimulus, and response bias directed towards responding positively to highly symmetrical stimuli in a mix of less symmetrical stimuli. Palmer and Hemenway appear to have been correct in suggesting that subjects are more sensitive to quadruple than single symmetry, but the experiments indicate that subjects are also more willing to respond “symmetrical” to stimuli with quadruple symmetry when trials are not blocked, as in Palmer and Hemenway's experiment 1. However, it is demonstrated that the latter effect can be removed by blocking trials so that only one class of symmetrical pattern and one class of asymmetrical pattern occur in any block.

The Differential Effects of Simultaneous and Successive Cueing on the Detection of Bilateral Symmetry in Dot Patterns

2000 ◽  
Vol 53 (1) ◽  
pp. 165-190 ◽  
Author(s):  
Peter Wenderoth
Keyword(s):  
Visual Processing ◽  
Processing Time ◽  
Reaction Times ◽  
Vertical Axis ◽  
Bilateral Symmetry ◽  
Frame Of Reference ◽  
Symmetry Detection ◽  
Axis Orientation ◽  
Differential Effects ◽  
Orientation Ordering

Corballis and Roldan (1975) obtained speeded judgements of whether dot patterns were bilaterally symmetrical about, or translated across, a line. Reaction times (RTs) were ordered V (vertical) > D (diagonal) > H (horizontal) where “>” means faster than. Similar results occurred with blocked axis orientations, suggesting subjects cannot prepare by rotating a mental frame of reference. Blocking trials may have been ineffective because blocking cannot provide incremental benefits over those already provided by axis lines. Four experiments show that the usual axis orientation ordering of V > H > D is markedly attentuated by simultaneous but not successive axis lines. Also, axis cue lines and axis blocking are not equivalent treatments. Instead, unblocked line cues require finite processing time whereas, under blocking, subjects can prepare for the expected orientation. There was no suggestion anywhere of the V > D > H axis ordering that Corballis and Roldan reported. Successive axis line cues may only direct attention to the orientation being cued, but simultaneous line cues may change the stimulus itself, thus providing an additional means of visual processing that facilitates symmetry detection at non-vertical axis orientations.

The Role of ON- and OFF-Channel Processing in the Detection of Bilateral Symmetry

Perception ◽  
10.1068/p3387 ◽  
2002 ◽  
Vol 31 (9) ◽  
pp. 1061-1072 ◽  
Author(s):  
Anna Brooks ◽  
Rick van der Zwan
Keyword(s):  
Bilateral Symmetry ◽  
Limited Range ◽  
Visual Scene ◽  
Performance Decrement ◽  
Symmetry Detection ◽  
Axis Orientation ◽  
Present Evidence ◽  
Detection Mechanisms

We present evidence that grouping for luminance does not take precedence over the detection of bilaterally symmetrical patterns. Using single-axis and double-axis images, we found that element pairs within which luminance is held constant drive symmetry-detection mechanisms more effectively than pairs within which luminance varies. Moreover, the performance decrement observed for patterns defined by element pairs within which luminance varies is not specific to interchannel variation. Luminance variation within the ON and OFF channels has the same effect as variation between the channels on the performance of axis-orientation identification tasks. It is argued that this constitutes possible evidence for subchannels within the ON and OFF channels. One of the characteristics of the subchannels is that each processes only a limited range of luminance steps. The implications of this type of luminance processing for the detection of symmetry in the visual scene are discussed.

scholarly journals A new methodology for polyvalent intravenous immunoglobulin solution production with a two-stage process of viral inactivation

2010 ◽  
Vol 46 (4) ◽  
pp. 777-783
Author(s):  
Antônio Edson de Souza Lucena ◽  
Divaldo de Almeida Sampaio ◽  
Ednaldo Rosas da Silva ◽  
Virgínia Florêncio de Paiva ◽  
Ana Cláudia Santiago ◽  
...  
Keyword(s):  
Intravenous Immunoglobulin ◽  
Immunoglobulin G ◽  
Cation Exchanger ◽  
Product Analysis ◽  
Viral Inactivation ◽  
Two Stage ◽  
Second Stage ◽  
Neutralizing Capacity ◽  
Stage Process ◽  
Sodium Caprylate

Highly purified intravenous immunoglobulin G concentrate (IV IgG) was produced with the use of polyethylene glycol associated to a single-stage precipitation by ethanol, instead of the classic Cohn-Oncley process, which employs cold alcohol as the precipitating agent, in a three-stage process. Precipitation of crude fraction containing more than 95% of immunoglobulin G was performed by liquid chromatography with a cation exchanger, CM-Sepharose, as a stationary phase. During the process, the product was subjected to two-stage viral inactivation. The first stage was performed by the action of sodium caprylate, 30 mM at pH 5.1+/- 0.1, and the second stage was performed by the action of a solvent-detergent mixture. The finished product was formulated at 5% with 10% sucralose as the stabilizing agent. The process yields 3.3g of IgG/liter of plasma. The finished product analysis showed an anti-complementary activity lower than 1CH50. Polymer and aggregate percent levels were lower than 3% in the five batches studied. The analysis of neutralizing capacity showed the presence of antibacterial and antiviral antibodies in at least three times higher concentrations than the levels found in source plasma. The finished product fulfilled all purity requirements stated in the 4th edition of the European pharmacopeia.

scholarly journals Two-Stage Discrete Mechanical Modelin Three-Dimensional Space for Garment Simulation

2019 ◽  
Vol 19 (1) ◽  
pp. 26-35 ◽  
Author(s):  
Xuan Luo ◽  
Gaoming Jiang ◽  
Honglian Cong
Keyword(s):  
Mechanical Model ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Mathematical Expression ◽  
Two Stage ◽  
Second Stage ◽  
Simulation Speed ◽  
Optimal Value ◽  
Variable Distance ◽  
Stage Process

Abstract This paper focuses on the better performance between the garment simulation result and the simulation speed. For simplicity and clarity, a notation “PART” is defined to indicate the areas between the garment and the human body satisfying some constraints. The discrete mechanical model can be achieved by the two-stage process. In the first stage, the garment can be divided into several PARTs constrained by the distance. In the second stage, the mechanical model of each PART is formulated with a mathematical expression. Thus, the mechanical model of the garment can be obtained. Through changing the constrained distance, the simulation result and the simulation speed can be observed. From the variable distance, a desired value can be chosen for an optimal value. The results of simulations and experiments demonstrate that the better performance can be achieved at a higher speed by saving runtime with the acceptable simulation results and the efficiency of the proposed scheme can be verified as well.

An Anaerobic Process for Treatment of CTMP Effluent

1988 ◽  
Vol 20 (1) ◽  
pp. 143-147 ◽  
Author(s):  
T. Welander
Keyword(s):  
Volatile Fatty Acids ◽  
Anaerobic Bacteria ◽  
Methanogenic Bacteria ◽  
Second Stage ◽  
The Third ◽  
Multi Stage ◽  
Third Stage ◽  
Aluminum Iron ◽  
Stage Process ◽  
Iron And Calcium

A multi-stage process for treatment of CTMP effluent has been developed. It comprises primary settling and four biological stages. The concentration of hydrogen peroxide, a compound which is toxic to anaerobic bacteria, is reduced in the first biological stage by means of the biocatalytic action of biomass that is recycled from the following acidogenic and/or aerobic stages. The second stage is an acidogenic stage, in which volatile fatty acids are formed and remaining peroxide is decomposed. A mixture of aluminum, iron and calcium salts is added to the effluent in order to detoxify compounds which are toxic to methanogenic bacteria. The main part of the COD and BOD removal takes place in the third stage, the methanogenic stage, after which follows an aerobic stage for polishing and removal of bad-smelling compounds. The COD and BOD7 removals in the anaerobic part of the process are 60 and 90 %, respectively, and the methane yield is 0.20-0.25 Nm3/kg COD removed.

scholarly journals Tequila Still Distillation Fractioned Residual Streams for Use in Biorefinery

Energies ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 6222
Author(s):  
Edgardo Martinez-Orozco ◽  
Pablo Gortares-Moroyoqui ◽  
Norberto Santiago-Olivares ◽  
Juan Napoles-Armenta ◽  
Ruth Gabriela Ulloa-Mercado ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Gas Chromatography ◽  
Energy Analysis ◽  
Oxygen Demand ◽  
Solid Content ◽  
Co2 Production ◽  
Second Stage ◽  
Stage Process ◽  
Very High ◽  
Tequila Vinasses

Tequila vinasses is a mixture made from up to six still distillation two-stage process residual effluents. First stage fractions: residual must (60%), heads (0.9%) and tails (20.0%); second stage fractions: non-evaporated (8.0%), heads (0.1%) and tails (1.0%); the result is a more complex effluent for its treatment or biorefining. The objectives of this study were to: (a) characterize the five still distillation volatile streams in the Tequila 100% Agave processing; compounds: methanol, ethanol, acetaldehyde, ethyl acetate, sec-butanol, n-propanol, iso-butanol, n-butanol, iso-amyl, n-amyl, and ethyl lactate were detected by gas chromatography; calculated chemical oxygen demand from chemical composition had very high values (53,760–1,239,220 mg/L); measurement of pH (3.24–4.80), color (38.6 UC Pt-Co max), turbidity (46.1 max), electrical conductivity (3.30–172.20 μS/cm), and solid content (0 mg/L) was also made; (b) report an energy analysis (2.02 × 109 KWh) and CO2 production (429 × 106 kg) in the Tequila industry during 2019; (c) up to date residues (365.2 × 106 kg agave bagasse, 1146.1 × 106 kg agave leaves and 3300.0 × 106 L agave vinasse) in 2019; (d) economic analysis, current tequila vinasses treatment price is 16.00 USD/m3 but could reach a considerable fraction value if is bio-refined, a break down component analysis reach for five volatile streams $51.23–$140.00 USD/m3.

A THREE-STEP COMBINED GENETIC PROGRAMMING AND NEURAL NETWORKS METHOD OF FORECASTING THE S&P/CASE-SHILLER HOME PRICE INDEX

2013 ◽  
Vol 12 (01) ◽  
pp. 1350001 ◽  
Author(s):  
MAK KABOUDAN ◽  
MARK CONOVER
Keyword(s):  
Neural Networks ◽  
Genetic Programming ◽  
San Francisco ◽  
Price Index ◽  
Combined Method ◽  
Second Stage ◽  
Third Stage ◽  
Multi Agent ◽  
Stage Process ◽  
Two Stages

Forecasts of the San Diego and San Francisco S&P/Case-Shiller Home Price Indices through December 2012 are obtained using a multi-agent system that utilizes January, 2002–June, 2011 data. Agents employ genetic programming (GP) and neural networks (NN) in a three-stage process to produce fits and forecasts. First, GP and NN compete to provide independent predictions. In the second stage, they cooperate by fitting the first-stage competitor's residuals. Outputs from the first two stages then become inputs to produce two final GP and NN outputs. The NN output from the third stage using the combined method produces improved forecasts over the 3-stage GP method as well as those produced by either method alone. The proposed methodology serves as an example of how combining more than one estimation/forecasting technique may lead to more accurate forecasts.

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