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Grasping possibilities for action: Influence of object function and action capabilities

HUMAN MOVEMENT SCIENCE 2011年第6期30卷 1102-1114页

作者： Ranganathan, Rajiv Lee, Mei-Hua Brown, Amber J. Newell, Karl M. Penn State Univ Dept Kinesiol Philadelphia PA USA

The purpose of this study was to investigate the influence of object function and the observer's action capabilities on grasp facilitation. We used a stimulus-response compatibility (SRC) protocol in which participants were asked to reach and grasp a drinking glass using one of two grasps - the thumb-up or the thumb-down grasp. The reaction time (RT) was used as the index of grasp facilitation. In Experiment 1, we found evidence for the facilitation of "functionally relevant" grasps - where the type of grasp facilitated depended on the location of opening but not the shape of the object. However, this effect was found only when attention was directed toward the location of the opening. In Experiments 2 and 3, we found that this facilitation was also affected by whether participants had the ability to functionally interact with the object. These results show that S-R compatibilities are influenced both by the object's function and the actor's action capabilities, and are interpreted in Gibson's (1979) framework of affordances. (C) 2011 Elsevier B.V. All rights reserved.

关键词： Grasping Affordances Stimulus-response compatibility object function Action capabilities

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Study on object function of Milling Insert Impact Disrepair Based on Stress Field Analysis

Study on Object Function of Milling Insert Impact Disrepair ...

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2nd International Conference on functional Manufacturing Technologies

作者： Cheng Yaonan Wang Liquan Wu Mingyang Li Zhenjia Harbin Engn Univ Harbin 150001 Peoples R China Harbin Univ Sci & Technol Harbin 150080 Peoples R China

ISBN: (纸本)9780878492367

This article takes the waved-edge milling insert (the rake face is curve plane) developed by Harbin University of Science and Technology as an example, as the goal of minimal impact disrepair, the optimization object function of the milling insert grooves is studied. Based on the force density function of the 3D complex groove milling insert, we have the finite element analysis on the stress fields of different Gutting parameters, and have fuzzy synthetical judgement on the stress fields with fuzzy mathematic theory. We build the object function relation between the fuzzy synthetical judgement results and cutting parameters of the impact disrepair, so to have groove design optimization. All these studies provide the theoretic basis for the groove exploitation and the cutter disrepair which is :he key problem in the automatization production and groove optimization.

关键词： Milling insert Stress field Impact disrepair object function

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Concurrent Cortical Representations of function- and Size-Related object Affordances: An fMRI Study

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COGNITIVE AFFECTIVE & BEHAVIORAL NEUROSCIENCE 2018年第6期18卷 1221-1232页

作者： Kourtis, Dimitrios Vandemaele, Pieter Vingerhoets, Guy Univ Stirling Fac Nat Sci Psychol Stirling FK9 4LA Scotland Univ Ghent Dept Expt Psychol Ghent Belgium Univ Ghent Dept Radiol Ghent Belgium

Previous work has shown that the perception of a graspable object may automatically potentiate actions that are tailored to specific action-related features of the object (e.g., its size) and may be related to its immediate grasping as well as to its long-term, functional use. We investigated the neural correlates of function- and size-related object affordances that may be concurrently potentiated by a graspable object. Participants were lying in a MR scanner holding a large switch in one hand and a small switch in the other hand. They passively attended a large or a small object with clearly separated functional and graspable end that was displayed centrally at an average angle of 45 degrees. Participants responded to the direction of an arrow that was overlaid on the object after a mean period of 1,000 ms after object onset and was pointing to the left or to the right with equal probability. Response times were shorter when the arrow pointed to the functional end of the object and when the responses were made with the switch that was congruent to the size of the perceived object. A clear distinction was found in the representation of function- and size-related affordances;the former was represented in the posterior parietal cortex and the latter in prefrontal, premotor, and primary sensorimotor cortices. We conclude that different aspects of object-directed actions may be automatically potentiated by individual object features and are represented in distinct brain areas.

关键词： object affordances object size object function Dorsal stream Posterior parietal cortex fMRI

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Color-function categories that prime infants to use color information in an object individuation task

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COGNITIVE PSYCHOLOGY 2008年第3期57卷 220-261页

作者： Wilcox, Teresa Woods, Rebecca Chapa, Catherine Texas A&M Univ Dept Psychol College Stn TX 77843 USA Palo Alto Coll Inst Res Planning & Effectiveness San Antonio TX 78224 USA

There is evidence for developmental hierarchies in the type of information to which infants attend when reasoning about objects. Investigators have questioned the origin of these hierarchies and how infants come to identify new sources of information when reasoning about objects. The goal of the present experiments was to shed light oil this debate by identifying conditions under which infants' sensitivity to color information, which is slow to emerge, could be enhanced in all object individuation task. The outcome of Experiment I confirmed and extended previous reports that 9.5-month-olds call be primed, through exposure to events in which the color of an object predicts its function, to attend to color differences in a subsequent individuation task. The outcomes of Experiments 2-4 revealed age-related changes in the nature of the representations that Support color priming. This is exemplified by three main findings. First, the representations that are formed during the color-function events are relatively specific. That is, infants are primed to use the color difference seen in the color-function events to individuate objects in the test events. but riot other color differences. Second, 9.5-month-olds can be led to form more abstract event representations, and then generalize to other colors in the test events if they, are shown Multiple pairs of colors in the color-function events. Third. Slightly younger 9-month-olds also call be led to form more inclusive categories with multiple color pairs, but only when they are allowed to directly compare the exemplars in each color pair during the present events. These results shed light oil the development of categorization abilities, cognitive mechanisms that Support color-function priming, and the kinds of experiences that call increase infants' sensitivity to color information. (C) 2008 Elsevier Inc. All rights reserved.

关键词： object individuation Categorization Color Infants object function object knowledge

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Identification of Parameters of Short-Time Creep of Plexiglas By Means of Studying Decaying Flexural Vibrations of Test Samples

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JOURNAL OF APPLIED MECHANICS AND TECHNICAL PHYSICS 2018年第3期59卷 519-530页

作者： Paimushin, V. N. Firsov, V. A. Shishkin, V. M. Kazan Natl Res Tech Univ Kazan 420111 Russia Kazan Fed Univ Kazan 420008 Russia Vyatka State Univ Kirov 610000 Russia

A technique for identification of hereditary properties under conditions of short-time creep of Plexiglas is developed. The technique is based on experimental determination of shifting of the center of decaying flexural vibrations of vertically aligned test samples after their preliminary maintaining in a static bent state. Mathematically, the technique is based on using the finite element method and integral equations of the theory of hereditary viscoelasticity with the Koltunov-Rzhanitsyn hereditary kernel. An object function is constructed for identification of rheological parameters of this kernel. The minimum of this function is found by the direct search method, which does not require the function gradient to be known. The hereditary kernel of Plexiglas averaged on the basis of data for several test samples is obtained as a function of time.

关键词： viscoelastic material hereditary kernel finite element direct search method object function

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Three-dimensional imaging of an object behind an anisotropic wall

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IET SCIENCE MEASUREMENT & TECHNOLOGY 2019年第1期13卷 53-59页

作者： Jafarpourjalali, Mohammad Tavakoli, Ahad Dehkhoda, Parisa Amirkabir Univ Technol Dept Elect Engn Tehran Iran

Based on the well-known diffraction tomography (DT) method, a three-dimensional (3D) inverse scattering algorithm is proposed to identify a hidden object behind an anisotropic wall. The spatial spectral expansion of the dyadic Green's function of the multi-layered structure with anisotropic material is employed in the DT formulation of the scattered field. Born approximation is utilised for weak scatterers that model the scattered field as a linear function of the object function. The proposed method is very efficient and suitable for real-time applications due to its easy and fast implementation.

关键词： Green's function methods image reconstruction tomography electromagnetic wave scattering stereo image processing approximation theory anisotropic wall diffraction tomography method three-dimensional inverse scattering algorithm hidden object spatial spectral expansion multilayered structure anisotropic material DT formulation born approximation linear function object function three-dimensional imaging dyadic Green function

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Deformation mechanism of polyethylene spherulites estimated by crystal orientation distribution function and small angle light scattering under Hv polarization condition

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POLYMER 1997年第17期38卷 4311-4318页

作者： Matsuo, M Xu, CY Department of Textile and Apparel Science Faculty of Human Life and Environment Nara Women's University Nara 630 Japan

The deformation mechanism of polyethylene spherulites was studied by using melt films of high density polyethylene with a 78% crystallinity in terms of crystallite orientation distribution estimated by X-ray diffraction technique and small angle light scattering under Hv polarization condition. In doing so, a model relating crystal orientation to the deformation of polyethylene spherulite was proposed. The distribution function of crystallites within a spherulite was assumed to be a function of crystal lamella. The distribution functions of reciprocal lattice vectors of given crystal planes were derived from two functions of the crystallites and lamellae with several parameters. The best values of each parameter were determined by the simplex method associated with direct research method to obtain the object function on the basis of trial and error. As a result, it was found that at an initial elongation ratio of 1.5, the most important factor in fitting the model to experimental results, was the preferred orientation of lamellar axis but most of the crystallites within the lamella were maintained without taking characteristic orientation. The Hv scattering from a deformed three-dimensional spherulite was formulated on the basis of the proposed model. The scattered intensity distribution in an undeformed state showed the typical four-leaf clover pattern and the lobes extending in the horizontal direction indicated the deformation of spherical to ellipsoid structure with a draw ratio of 1.5. The calculated patterns were in good agreement with those observed. (C) 1997 Elsevier Science Ltd.

关键词： polyethylene spherulite crystallite orientation distribution small angle light scattering reciprocal lattice vector object function

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DPD with IPF and GD method

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IET SIGNAL PROCESSING 2019年第8期13卷 718-725页

作者： Song, Kekang Yang, Yuxiang Feng, Wentao Peng, Huafeng Natl Key Lab Sci & Technol Blind Signal Proc Chengdu Sichuan Peoples R China

The localisation of a stationary emitter with several separated sensors is studied. At low signal-to-noise ratio, the direct position determination (DPD) approach is more precise than the two-step method which estimates the time difference of arrival (TDOA) first and locates the emitter by the TDOAs. However, the exhaustive search is usually employed to find the global maximum since the object function of DPD is non-convex. After analysing the characteristics of the object function, a DPD with improved particle filter and gradient descent method (GDIPF-DPD) is proposed. The initial and fine estimations are provided by the IPF and GD methods, successively, as the object function has single peak around the expected position and is differentiable. The IPF decreases the times of resampling through mapping the particle weights before normalisation into 0-1. The GD method improves the accuracy by seeking within the single peak. Furthermore, the position Cramer-Rao lower bound of DPD with attenuation coefficient is derived and proved to be consistent with the two-step method of TDOA. Simulation results indicate that the position accuracy of the proposed algorithm is equivalent with grad search method and its computation cost is less by two orders of magnitude.

关键词： direction-of-arrival estimation time-of-arrival estimation particle swarm optimisation particle filtering (numerical methods) gradient methods IPF GD method stationary emitter low signal-to-noise ratio direct position determination approach two-step method time difference TDOA object function improved particle filter gradient descent method GDIPF-DPD initial estimations fine estimations single peak expected position position Cramer-Rao lower bound position accuracy grad search method

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Testing the accuracy of the two-dimensional object model in HAADF STEM

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MICRON 2014年 63卷 47-51页

作者： Jones, Lewys Nellist, Peter D. Univ Oxford Dept Mat Oxford OX1 3PH England

In high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) the two-dimensional (2D) object-function approximation and image convolution model is often used to describe the recorded image data from on-axis crystalline samples. In this model the sample, represented by an object function with sharp peaks at the atomic column positions, is convolved with the 2D point spread function (PSF) of the focussed STEM illumination. In this work the validity of the assumption that the object can be considered as 2D is evaluated experimentally through the use of HAADF-STEM focal-series from MgO smoke cubes. The intensity of laterally resolved image-information is evaluated using Fourier transforms and is tracked with respect to defocus. The experimental results are compared with the expected depth resolution capabilities of simulated STEM probes to yield the normalised or 'apparent thickness' of the samples. The 2D object-function and image convolution models are found to hold for sample thicknesses of up to 250 nm. As the 2D object model holds true for each individual frame in a recorded focal series, we can hence express the focal-series as a whole as the convolution of a 2D object function with a 3D probe function with implications for both the diagnosis of remnant aberrations and also image reconstruction. (C) 2014 Elsevier Ltd. All rights reserved.

关键词： HAADF STEM Depth resolution Focal series object function Point spread function

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NEW APPROACH FOR REAL POWER LOSS MINIMIZATION

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IEE PROCEEDINGS-C GENERATION TRANSMISSION AND DISTRIBUTION 1983年第6期130卷 295-299页

作者： ELANGOVAN, S Department of Electrical Engineering National University of Singapore Singapore Singapore

The paper presents a new approach to the minimisation of line losses in a given power-system network by means of certain sensitivity coefficients. These coefficients are used to see how sensitive is the line loss for small changes in the control variables, i.e. voltage magnitudes of the generators, reactive-power injections by VAR sources and transformer tap ratios. These sensitivity coefficients are derived using an eigenvector of the transposed Jacobian matrix. After establishing the objective function for minimising the system losses with the help of linearised sensitivity relationships of control variables, a dual linear programming (LP) technique is used to determine the optimum adjustments to the control variables, simultaneoulsy satisfying the constraints like reactive-power limits of the generators, limits on the load busbar voltages and the operating limits of the control variables.

关键词： eigenvalues and eigenfunctions Power system management, operation and economics minimisation power systems dual linear programming real power loss minimisation Jacobian matrix object function sensitivity Algebra matrix algebra losses eigenvector power-system network line losses Network and transmission line calculations sensitivity coefficients

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