scholarly journals Prey selection by thaidid gastropods: some observational and experimental field tests of foraging models

Oecologia ◽  
1984 ◽  
Vol 62 (2) ◽  
pp. 162-172 ◽  
Author(s):  
A. Richard Palmer
Keyword(s):  
Prey Selection ◽  
Field Tests ◽  
Experimental Field ◽  
Foraging Models

scholarly journals Biased belief updating and suboptimal choice in foraging decisions

2019 ◽  
Author(s):  
Neil Garrett ◽  
Nathaniel D. Daw
Keyword(s):  
Prey Selection ◽  
Learning Rule ◽  
Belief Updating ◽  
Reward Rate ◽  
Mate Search ◽  
Learning Rates ◽  
Foraging Decisions ◽  
Foraging Models ◽  
Choice Setting

AbstractIn many choice scenarios, including prey, employment, and mate search, options are not encountered simultaneously and so cannot be directly compared. Deciding which ones optimally to engage, and which to forego, requires developing accurate beliefs about the overall distribution of prospects. However, the role of learning in this process – and how biases due to learning may affect choice – are poorly understood. In three experiments, we adapted a classic prey selection task from foraging theory to examine how individuals kept track of an environment’s reward rate and adjusted their choices in response to its fluctuations. In accord with qualitative predictions from optimal foraging models, participants adjusted their selectivity to the richness of the environment: becoming less selective in poorer environments and increasing acceptance of less profitable options. These preference shifts were observed not just in response to global (between block) manipulations of the offer distributions, but also to local, trial-by-trial offer variation within a block, suggesting an incremental learning rule. Further offering evidence into the learning process, these preference changes were more pronounced when the environment improved compared to when it deteriorated. All these observations were best explained by a trial-by-trial learning model in which participants estimate the overall reward rate, but with upward vs. downward changes controlled by separate learning rates. A failure to adjust expectations sufficiently when an environment becomes worse leads to suboptimal choices: options that are valuable given the environmental conditions are rejected in the false expectation that better options will materialize. These findings offer a previously unappreciated parallel in the serial choice setting of observations of asymmetric updating and resulting biased (often overoptimistic) estimates in other domains.

scholarly journals Experimental field tests of Batesian mimicry in the swallowtail butterfly Papilio polytes

2018 ◽  
Vol 8 (15) ◽  
pp. 7657-7666 ◽  
Author(s):  
Daniela H. Palmer ◽  
Yue Qian Tan ◽  
Susan D. Finkbeiner ◽  
Adriana D. Briscoe ◽  
Antónia Monteiro ◽  
...  
Keyword(s):  
Field Tests ◽  
Batesian Mimicry ◽  
Swallowtail Butterfly ◽  
Experimental Field ◽  
Papilio Polytes

scholarly journals Experimental Field Tests and Finite Element Analyses for Rock Cracking Using the Expansion of Vermiculite Materials

2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Chi-hyung Ahn ◽  
Jong Wan Hu
Keyword(s):  
Finite Element ◽  
Field Tests ◽  
Experimental Tests ◽  
Heating Time ◽  
Test Results ◽  
Experimental Field ◽  
Expansion Pressure ◽  
Circular Holes ◽  
Granite Rocks ◽  
Good Agreement

In the previous research, laboratory tests were performed in order to measure the expansion of vermiculite upon heating and to convert it into expansion pressure. Based on these test results, this study mainly focuses on experimental field tests conducted to verify that expansion pressure obtained by heating vermiculite materials is enough to break massive and hard granite rock with an intention to excavate the tunnel. Hexahedral granite specimens with a circular hole perforated in the center were constructed for the experimental tests. The circular holes were filled with vermiculite plus thermal conduction and then heated using the cartridge heater. As a result, all of hexahedral granite specimens had cracks in the surface after 700-second thermal heating and were finally spilt into two pieces completely. The specimen of larger size only requires more heating time and expansion pressure. The material properties of granite rocks, which were obtained from the experimental tests, were utilized to produce finite element models used for numerical analyses. The analysis results show good agreement with the experimental results in terms of initial cracking, propagation direction, and expansion pressure.

scholarly journals Destruction mechanisms and methods of laboratory autoclave tests of internal coatings of oil pipes

2019 ◽  
Vol 121 ◽  
pp. 01009
Author(s):  
Pavel Yudin ◽  
Sergei Petrov ◽  
Andrey Maximuk ◽  
Zhanna Knyazeva
Keyword(s):  
Critical Analysis ◽  
Natural Aging ◽  
Field Tests ◽  
Polymer Coatings ◽  
Experimental Field ◽  
Anticorrosive Coatings ◽  
Inner Surface ◽  
Selection Of

The main mechanisms of destruction of internal anticorrosive polymer coatings (IACPC) of the inner surface of tubing and fielding pipes are review in the article. They are divide into decompression peeling, substrate destruction under the corrosion of and natural aging of the polymeric basis. A critical analysis of the existing standards for the testing of internal anticorrosive coatings was made. The carrying out test on these documents does not allow obtaining the destructions identical to those found during the exploitation of pipelines. Investigations on the selection of optimal regimes of autoclave tests and the methodology for conduct research are describe. A comparison for the results of laboratory and experimental field tests of the coatings presented.

scholarly journals Model for predicting the vibrations of historical timber buildings due to traffic loads and its experimental validation

2019 ◽  
Vol 38 (2) ◽  
pp. 328-340 ◽  
Author(s):  
Yunshi Zhang ◽  
Nan Zhang
Keyword(s):  
Experimental Validation ◽  
Prediction Method ◽  
Field Tests ◽  
Structural Vibration ◽  
Test Results ◽  
Harmonic Loading ◽  
Measurement Point ◽  
Experimental Field ◽  
Traffic Loads ◽  
Vibration Responses

This study established the transfer laws of vibration waves in a linear system under simple harmonic loading. Then, a method based on multipoint delivery in the frequency domain was proposed to predict the vibrations of historical timber buildings induced by traffic loads, in which the transfer function between two delivery points of different single frequencies is obtained. Finally, the vibration responses of the Feiyun pavilion induced by traffic loads were predicted and compared with experimental field test results. The results indicate that the predicted vibration responses and experimental field tests at the measurement point in the Feiyun pavilion correspond well in the concerned frequency bands and that the proposed prediction method can be used to predict the structural vibration responses under the influence of complex traffic loads.

scholarly journals Prototyping, Testing, and Redesign of a Three-Wheel Trekking Wheelchair for Accessible Tourism Applications

2021 ◽  
Vol 11 (20) ◽  
pp. 9641
Author(s):  
Gabriele Baronio ◽  
Ileana Bodini ◽  
Barbara Motyl ◽  
Stefano Uberti
Keyword(s):  
Initial Phase ◽  
Field Tests ◽  
Experimental Results ◽  
Kinematics And Dynamics ◽  
Physical Effort ◽  
Passenger Comfort ◽  
Impaired Mobility ◽  
Testing Phase ◽  
Experimental Field

This work is part of the project called “Gölem project”, started in 2017, about special devices developed to enable the so-called Accessible Tourism. This project aims to design and develop a trekking wheelchair for people with impaired mobility. After an initial phase of design and prototyping, the testing phase has now begun. The objective is to validate several aspects of the design, concerning basic kinematics and dynamics, passenger comfort and physical effort of the carriers. This paper describes the development of qualitative tests for drivability and balance validation of this first prototype. At this stage, a list of features to be investigated was made, suitable trekking paths were chosen, and qualitative experimental field tests were performed. Then, the design of the prototype was modified according to these first experimental results, to improve the wheelchair characteristics. The prototype is now undergoing the modification phase, then further testing will be performed with the use of specific instrumental devices to evaluate the wheelchair itself and to perform the kinematic, dynamical, and comfort characterization.

Experimental field test of proposed pedestrian safety messages: Volume II: Child messages

1983 ◽  
Author(s):  
Richard D. Blomberg ◽  
David F. Preusser ◽  
Allen Hale ◽  
William A. Leaf
Keyword(s):  
Field Test ◽  
Pedestrian Safety ◽  
Experimental Field
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