The Perception of Time in Scale Model Environments

Perception ◽  
1987 ◽  
Vol 16 (1) ◽  
pp. 5-16 ◽  
Author(s):  
C Thomas Mitchell ◽  
Roy Davis
Keyword(s):  
Individual Variability ◽  
Scale Model ◽  
Subjective Time ◽  
Similar Model ◽  
Clock Time ◽  
Scaled Model ◽  
Time Compression ◽  
Series Of Experiments ◽  
Standard Clock ◽  
Perception Of Time

It has been claimed that when subjects observe differently-scaled model environments their experience of temporal duration is compressed relative to standard clock time in the same proportion as the scale of the model being observed. A series of experiments is reported in which subjects made judgements of duration while observing model environments of different scale. In each experiment, two similar model environments of different scale were presented. Three different kinds of model were used: scale model railways, sitting-room models, and abstract nonrepresentional models. Despite considerable individual variability, significant effects were obtained. Smaller scale was, up to a point, related to a compression of subjective time relative to clock time, although the effect was nowhere near as great as that previously reported. Also, when scale was reduced beyond a certain point the effect on judgements of duration was eliminated, or even reversed. It is suggested that the effect of time compression is related to differences in the density of the information to be processed in environments of different scale, and that there may be an optimum value for information density related both to the scale and to the type of environment.

Validation of mathematical model of electrothermal calculation of DC catenary on the basis of scale model

2018 ◽  
Vol 77 (4) ◽  
pp. 222-229 ◽  
Author(s):  
A. V. Paranin ◽  
A. B. Batrashov
Keyword(s):  
Mathematical Model ◽  
Operating Conditions ◽  
Scale Model ◽  
Contact Network ◽  
Scaled Model ◽  
Cross Sectional ◽  
Current Collection ◽  
Topological Features ◽  
Study Results ◽  
Real Physical Process

The article compares the results of calculation of the finite element simulation of current and temperature distribution in the scale model of the DC catenary with the data of laboratory tests. Researches were carried on various versions of the structural design of catenary model, reflecting the topological features of the wire connection, characteristic of the DC contact network. The proportions of the cross-sectional area of the scaled model wires are comparable to each other with the corresponding values for real DC catenary. The article deals with the operating conditions of the catenary model in the modes of transit and current collection. When studying the operation of the scale catenary model in the transit mode, the effect of the structural elements on the current distribution and heating of the wires was obtained. Within the framework of the scale model, theoretical assumptions about the current overload of the supporting cable near the middle anchoring have been confirmed. In the current collection mode, the experimental dependences of the current in the transverse wires of the scale model are obtained from the coordinate of the current collection point. Using the model it was experimentally confirmed that in the section of the contact wire with local wear, not only the temperature rise occurs but also the current redistribution due to the smaller cross section. Thus, the current share in other longitudinal wires of the scale model increases and their temperature rises. Scale and mathematical models are constructed with allowance for laboratory clamps and supporting elements that participate in the removal of heat from the investigated wires. Obtained study results of the scale model allow to draw a conclusion about the adequacy of the mathematical model and its correspondence to the real physical process. These conclusions indicate the possibility of applying mathematical model for calculating real catenary, taking into account the uneven contact wear wire and the armature of the contact network.

Working Time on Mars

KronoScope ◽  
2009 ◽  
Vol 8 (2) ◽  
pp. 159-178 ◽  
Author(s):  
Zara Mirmalek
Keyword(s):  
Natural Phenomenon ◽  
Clock Time ◽  
Effective Work ◽  
Work Support ◽  
Organizational Infrastructure ◽  
Industrial Organizations ◽  
Time Work ◽  
Standard Clock ◽  
Temporal Rhythm ◽  
Post Industrial

AbstractThe constancy of clock time as an effective work support technology has made it almost impossible to imagine a modern organization where time, specifically standard clock time, is not a component of the organizational infrastructure. Demonstrating the degree to which clock time has become embedded within the organizational sphere are the ways in which clock time operates as though it were a natural phenomenon, rather than a human-built technology (Adam, 1990; Anderson, 1964; Bluedorn, 2002; de Grazia, 1964; Zerubavel, 1981). The naturalization of clock time within organizations is evidenced by the reified assumption technology of clock time is fixed and cannot be modified to support contextually based temporal rhythms of work. The opportunity to challenge particular notions about the relationship between time and work is found in the organization of NASA's Mars Exploration Rovers mission (MER). In addition to standard clock time, the MER mission employed an extra-terrestrial version of standard clock time, known as “Mars time,” to track the presence and absence of sunlight on Mars. Drawing on empirical data, I foreground the inadequacies of the time support technologies that led me to question the use of standard clock time as a way of ordering the experience of time on Mars. I argue that the naturalization of clock time within post-industrial organizations contributed to this occasion in which the scientific exploration of Mars was conducted according to an agrarian era temporal rhythm but for which work support was organized around an industrial era time/work relationship.

How Self-Motion in Virtual Reality Affects the Subjective Perception of Time

2020 ◽  
Vol 8 (2) ◽  
pp. 119-136
Author(s):  
Stefan Weber ◽  
David Weibel ◽  
Fred W. Mast
Keyword(s):  
Virtual Reality ◽  
Positive Association ◽  
Subjective Perception ◽  
Subjective Time ◽  
Time Loss ◽  
Stimulus Motion ◽  
Subjective Duration ◽  
Perception Of Time ◽  
Virtual Experiences ◽  
Self Motion

The velocity of moving stimuli has been linked to their experienced duration. This effect was extended to instances of self-motion, where one’s own movement affects the subjective length of time. However, the experimental evidence for this extension is scarce and the effect of self-motion has not been investigated using a reproduction paradigm. Therefore, we designed a virtual reality scenario that controls for attention and eliminates the confounding effect of velocity and acceleration. The scenario consisted of a virtual road on which participants (n = 26) moved along in a car for six different durations and with six different velocities. We measured the subjective duration of the movement with reproduction and direct numerical estimation. We also assessed levels of presence in the virtual world. Our results show that higher velocity was connected to longer subjective time for both forms of measurement. However, the effect showed deviations from linearity. Presence was not associated with subjective time and did not improve performance on the task. We interpreted the effect of velocity as corroborating previous work using stimulus motion, which showed the same positive association between velocity of movement and subjective time. The absence of an effect of presence was explained in terms of a lacking dependency of time on characteristics of the virtual environment. We suggest applying our findings to the design of virtual experiences intended for inducing time loss.

Age Effects in Perception of Time

2005 ◽  
Vol 97 (3) ◽  
pp. 921-935 ◽  
Author(s):  
Marc Wittmann ◽  
Sandra Lehnhoff
Keyword(s):  
Time Perception ◽  
Nonlinear Regression ◽  
Age Effects ◽  
Chronological Age ◽  
Subjective Time ◽  
Regression Analyses ◽  
Empirical Results ◽  
Widespread Belief ◽  
Perception Of Time ◽  
Pearson Correlations

Despite the widespread belief that the subjective speed of the passage of time increases with age, empirical results are controversial. In this study, a combination of questionnaires was employed to assess subjective time perception by 499 subjects, ages 14 to 94 years. Pearson correlations and nonlinear regression analyses on a variety of questionnaires and the age of the participants show that the momentary perception of the passage of time and the retrospective judgment of past periods of time are a function of chronological age; however, small-to-moderate effects accounted for at most 10% of the variance. Results generally support the widespread perception that the passage of time speeds up with age. These results are discussed in the context of models of prospective and retrospective time judgment, but interpretations have to be treated with caution given methodological limitations.

Stability and Drag Analysis of Wheeled Amphibious Vehicle Using CFD and Model Testing Techniques

2014 ◽  
Vol 592-594 ◽  
pp. 1210-1219 ◽  
Author(s):  
R. R. More ◽  
Piyush Adhav ◽  
K. Senthilkumar ◽  
M.W. Trikande
Keyword(s):  
Cfd Simulation ◽  
Scale Model ◽  
Cfd Analysis ◽  
Scaled Model ◽  
Towing Tank ◽  
Weapon Systems ◽  
Viable Solution ◽  
Present Generation ◽  
Combat Vehicle ◽  
Gross Vehicle Weight

Amphibious design of combat vehicle has become a challenging task in the context of increase in Gross Vehicle weight (GVW) of present generation combat vehicles due to demand for high protection levels and higher capacity engine and transmission, incorporation of multiple weapon systems, increased ammunition storage and larger addition of electrical and electronic items. Development of combat vehicles is complex and very expensive, and normally limited with less number of prototypes. The scale modeling and CFD analysis offers a viable solution to accomplish the amphibian design of a combat vehicle with adequate confidence before manufacturing the actual prototype. In the present work, an approach involving experimental towing test using scaled model and CFD simulation has been used to carry out the amphibious design of an 8X8, wheeled, combat vehicle with GVW of 22 ton. In this work, a 1/5thscaled model of the vehicle was manufactured and tested in the towing tank at different test speeds for drag and stability analysis. CFD analysis was carried out on the full scale model to gain adequate details about the dynamics of vehicle in the water in addition to drag estimation. Good correlation has been found in drag values and the flow patterns obtained from towing tank tests and CFD simulations.

Children’s Perception of Time-Compressed Speech on Two Measures of Speech Discrimination

1976 ◽  
Vol 41 (2) ◽  
pp. 216-225 ◽  
Author(s):  
Daniel S. Beasley ◽  
Jean E. Maki ◽  
Daniel J. Orchik
Keyword(s):  
Auditory Processing ◽  
Age Groups ◽  
Central Auditory Processing ◽  
Speech Discrimination ◽  
Sensation Level ◽  
Time Compression ◽  
Compressed Speech ◽  
Two Measures ◽  
Perception Of Time ◽  
Open Versus

Time-compressed versions of the WIPI and PB-K 50 speech discrimination measures were presented at two sensation levels to 60 children divided into three age-groups of 20 each. Results showed that average intelligibility scores increased as a function of increasing age and sensation level and decreased with increasing amounts of time compression. The PB-K 50 measure was found to be more difficult than the WIPI for each age-group under each condition of time compression and sensation level. The several factors under study were found to interact. The results are discussed relative to open- versus closed-message set response tasks and the implications for audiological diagnoses of children with central auditory processing problems.

scholarly journals Monitoring accumulation sediment characteristics in full scale sewer physical model with urban wastewater

2017 ◽  
Vol 76 (1) ◽  
pp. 115-123 ◽  
Author(s):  
Manuel Regueiro-Picallo ◽  
Juan Naves ◽  
Jose Anta ◽  
Joaquín Suárez ◽  
Jerónimo Puertas
Keyword(s):  
Accumulation Rate ◽  
Sediment Accumulation ◽  
Treatment Plant ◽  
Organic Content ◽  
Full Scale ◽  
Scale Model ◽  
Experimental Conditions ◽  
Sediment Distribution ◽  
Wastewater Quality ◽  
Series Of Experiments

A series of experiments were carried out with real wastewater in a pilot flume located at A Coruña wastewater treatment plant (WWTP) (Spain). A full scale model was developed to test a circular (300 mm inner diameter) and an equivalent area egg-shaped plastic pipe under controlled experimental conditions (pipe slope 2–5‰, averaged discharge Q = 4 L/s). Velocity profiles and sediment accumulation in the pipe invert was daily measured. Within the 7–11 days, the average sediment accumulation rate found in the circular pipe was between 1.4 and 3.8 mm/d. The sediment height depended on the input wastewater sediment distribution and organic content. The egg-shaped pipe presented no sediment deposit for the same downstream boundary conditions, although biofilms were attached to the walls of both pipes. Besides, wastewater quality was monitored continuously and sediment composition was studied at the end of experiments. Two types of sediment were recorded: a granular bed deposit (ρ = 1,460 kg/m3, d50 = 202 μm) and wall biofilms (ρ = 1,190 kg/m3, d50 = 76 μm).

Experimental Study on Hydrodynamics of a FPSO in Deepwater Gulf of Mexico

2015 ◽  
Author(s):  
Jaime Torres Lopez ◽  
Longbin Tao ◽  
Longfei Xiao ◽  
Zhiqiang Hu
Keyword(s):  
Environmental Conditions ◽  
Loading Condition ◽  
Nonlinear Effects ◽  
Plane Motion ◽  
Experimental Methodology ◽  
Scale Model ◽  
Mooring Lines ◽  
Scaled Model ◽  
Hydrodynamic Behaviour ◽  
Floating System

The scaled model testing of a FPSO with its mooring lines and risers for deepwater and ultra-deepwater installation sites is considered to be the most reliable methodology to study the complex hydrodynamic behaviour of the complete system, since it can represent the nearest real environmental conditions and the comprehensive hydrodynamic interactions of the waves, current and wind with the total floating production system. The best technical option, at the present time, is a combination of an appropriate scale model of the FPSO and a suitable level of truncation obtained using a hybrid passive truncated experimental methodology for the mooring lines and risers. This is in order to minimize the various uncertainties in model behaviour and to study the hydrodynamic behaviour of the complete floating system and thus to validate numerical design of prototype systems for installation in deepwater and ultra-deepwater locations. This paper investigates the global response of a specific FPSO to prevailing environmental conditions, based on a hybrid passive truncated experimental methodology for the mooring lines and risers in a specific deepwater location with a water depth of 1000m in the GOM. The main objective of the experiment is to examine the nonlinear effects of the FPSO vessel and its mooring lines and to provide reliable experimental data for subsequent extrapolation to a full scale prototype design. Several case studies were carried out. The FPSO global responses for Full load and Ballast Load conditions with static and dynamic load tension components of the truncated mooring lines were studied for both collinear and non-collinear extreme storm environmental conditions. The experiments revealed that the main horizontal plane motion response of the FPSO (surge) under non-collinear loading condition is almost two-times that of the collinear loading condition.

scholarly journals Hydrodynamic Response of the Deep Turbine Installation-Floating Concept

2019 ◽  
Author(s):  
Jordi Serret ◽  
Tim Stratford ◽  
Philipp R. Thies ◽  
Vengatesan Venugopal ◽  
Tahsin Tezdogan
Keyword(s):  
Numerical Simulations ◽  
Numerical Study ◽  
Offshore Wind ◽  
Scale Model ◽  
Offshore Wind Turbine ◽  
Mooring Lines ◽  
Scaled Model ◽  
Irregular Wave ◽  
Floating System ◽  
Turbine Installation

Abstract Floating offshore wind turbine (FOWT) installations are progressing from the R&D stage to commercial installation projects. The prospective sites are situated in increasingly deeper water and further away from the shore. This paper presents the Deep Turbine Installation-Floating (DTI-F) concept, an innovative hybrid spar buoy-based FOWT capable of being able to raise and lower the tower and nacelle, which simplifies construction, installation, maintenance and decommissioning. The study is focused on the hydrodynamics of the moored floating system, and it is based on experimental and numerical modelling work. A 1:45 Froude scaled model of the DTI-F wind concept was tested using three different mooring configurations: i) three mooring lines, ii) four mooring lines, and iii) three mooring lines with a delta connection. Free decay and stiffness decay tests were carried out together with regular and irregular wave tests. The numerical study comprises diffraction (ANSYS AQWA) and time-domain modelling (OrcaFlex). The experimental hydrostatic and hydrodynamic results are compared with the numerical simulations based on the as-built scale model. Considering the natural frequencies results obtained for the three mooring configurations, the three lines configuration without delta connection was selected as the most suitable design. The obtained results for the three mooring lines configuration show good agreement between the experiment and numerical simulations. The presented analysis of the design concept indicates a high degree of technical feasibility.

Investigation of Mean and Turbulent Flow Behaviour Over an Escarpment

2016 ◽  
Author(s):  
R. Kilpatrick ◽  
K. Siddiqui ◽  
H. Hangan ◽  
D. Parvu
Keyword(s):  
Reynolds Number ◽  
Turbulent Flow ◽  
Flow Behaviour ◽  
Scale Model ◽  
Mean Flow ◽  
Scaled Model ◽  
Energy And Environment ◽  
Flow Parameters ◽  
Image Velocimetry ◽  
Bolund Hill

Mean and turbulent flow behaviour over a 1:25 scale model of Bolund hill was investigated at Western University’s Wind Engineering, Energy, and Environment Research Institute (WindEEE) using Particle Image Velocimetry (PIV). A range of upstream flow and surface conditions were considered. Results showed almost no Reynolds dependency on the mean flow and weak dependency of Reynolds number on the upstream surface roughness conditions. However, a strong Reynolds number and upstream surface rough dependency is observed on the turbulent flow particularly in the shear layer formed in the immediate downstream region of the escarpment. It is concluded that the consideration of Reynolds number independency must be cautiously used when extrapolating the flow parameters from scaled model testing to full scale in the field.

Sign in / Sign up

Export Citation Format

Share Document