Tolerance-Maps Applied to a Point-Line Cluster of Features

2005 ◽  
Author(s):  
Gaurav Ameta ◽  
Joseph K. Davidson ◽  
Jami J. Shah
Keyword(s):  
Dimensional Space ◽  
Local Level ◽  
Relative Location ◽  
Global Level ◽  
Tolerance Zone ◽  
Geometric Tolerances ◽  
Level Model ◽  
Cluster A ◽  
Point Line ◽  
Picture Frame

In this paper, groups of individual features, i.e. a point, a line, and a plane, are called clusters and are used to constrain sufficiently the relative location of adjacent parts. A new mathematical model for representing geometric tolerances is applied to a point-line cluster of features that is used to align adjacent parts in two-dimensional space. First, tolerance-zones are described for the point-line cluster. Then, a Tolerance-Map®, a hypothetical volume of points, is established which is the range of a mapping from all possible locations for the features in the cluster. A picture frame assembly of four parts is used to illustrate the accumulations of manufacturing variations, and the T-Maps provide stackup relations that can be used to allocate size and orientational tolerances. This model is one part of a bi-level model that we are developing for geometric tolerances. At the local level the model deals with the permitted variations in a tolerance zone, while at the global level it interrelates all the frames of reference on a part or assembly.

Tolerance-Maps Applied to a Point-Line Cluster of Features

2006 ◽  
Vol 129 (8) ◽  
pp. 782-792 ◽  
Author(s):  
Gaurav Ameta ◽  
Joseph K. Davidson ◽  
Jami J. Shah
Keyword(s):  
Dimensional Space ◽  
Local Level ◽  
Two Dimensional ◽  
Relative Location ◽  
Global Level ◽  
Tolerance Zone ◽  
Geometric Tolerances ◽  
Cluster A ◽  
Point Line ◽  
Picture Frame

In this paper, groups of individual features, i.e., a point, a line, and a plane, are called clusters and are used to constrain sufficiently the relative location of adjacent parts. A new mathematical model for representing size and geometric tolerances is applied to a point-line cluster of features that is used to align adjacent parts in two-dimensional space. First, tolerance-zones are described for the point-line cluster. A Tolerance-Map® (Patent no. 69638242), a hypothetical volume of points, is then established which is the range of a mapping from all possible locations for the features in the cluster. A picture frame assembly of four parts is used to illustrate the accumulations of manufacturing variations, and the T-Maps® provide stackup relations that can be used to allocate size and orientational tolerances. This model is one part of a bilevel model that we are developing for size and geometric tolerances. At the local level the model deals with the permitted variations in a tolerance zone, while at the global level it interrelates all the frames of reference on a part or assembly.

Do You Want to See the Tree? Ignore the Forest

2014 ◽  
Vol 61 (3) ◽  
pp. 205-214 ◽  
Author(s):  
Nicolas Poirel ◽  
Claire Sara Krakowski ◽  
Sabrina Sayah ◽  
Arlette Pineau ◽  
Olivier Houdé ◽  
...  
Keyword(s):  
Visual Recognition ◽  
Local Level ◽  
Local Information ◽  
Visual Environment ◽  
Global Information ◽  
Focus Attention ◽  
Global Level ◽  
Hierarchical Stimuli ◽  
Priming Paradigm ◽  
The One

The visual environment consists of global structures (e.g., a forest) made up of local parts (e.g., trees). When compound stimuli are presented (e.g., large global letters composed of arrangements of small local letters), the global unattended information slows responses to local targets. Using a negative priming paradigm, we investigated whether inhibition is required to process hierarchical stimuli when information at the local level is in conflict with the one at the global level. The results show that when local and global information is in conflict, global information must be inhibited to process local information, but that the reverse is not true. This finding has potential direct implications for brain models of visual recognition, by suggesting that when local information is conflicting with global information, inhibitory control reduces feedback activity from global information (e.g., inhibits the forest) which allows the visual system to process local information (e.g., to focus attention on a particular tree).

Formation of Geometric Tolerance Zones for Polyhedral Objects

1997 ◽  
Author(s):  
Utpal Roy ◽  
Bing Li
Keyword(s):  
Variational Model ◽  
Tolerance Zone ◽  
Geometric Tolerance ◽  
Geometric Tolerances ◽  
Polyhedral Objects ◽  
Different Types ◽  
Tolerance Zones ◽  
Algebraic Constraints ◽  
Size Tolerance ◽  
Part Model

Abstract This paper presents a scheme for establishing geometric tolerance zones for polyhedral objects in solid modelers. The proposed scheme is based on a surface-based variational model. Variations are applied to a part model by varying each surface’s model variables. Those model variables are constrained by some algebraic relations derived from the specified geometric tolerances. For size tolerance, two types of tolerance zones are considered in order to reflect two different types of size tolerances. For any other geometric tolerance (form, orientation or positional), the resultant tolerance zone is defined by the combination of size tolerance and that particular geometric tolerance specifications. Appropriate algebraic constraints (on the model variables) are finally used to establish the tolerance zone boundaries in the surface-based variational model.

A comparison of methods for bootstrapping in the local level model

2001 ◽  
Vol 21 (1) ◽  
pp. 27-38 ◽  
Author(s):  
Glaura C. Franco ◽  
Reinaldo C. Souza
Keyword(s):  
Local Level ◽  
Comparison Of Methods ◽  
Level Model

Diagnosis of embankment dam distresses using Bayesian networks. Part I. Global-level characteristics based on a dam distress database

2011 ◽  
Vol 48 (11) ◽  
pp. 1630-1644 ◽  
Author(s):  
L.M. Zhang ◽  
Y. Xu ◽  
J.S. Jia ◽  
C. Zhao
Keyword(s):  
Bayesian Networks ◽  
Local Level ◽  
Companion Paper ◽  
General Information ◽  
Dam Safety ◽  
Global Level ◽  
Embankment Dam ◽  
The Public ◽  
Embankment Dams ◽  
Level Performance

Dam safety has drawn increasing attention from the public. To ensure dam safety, it is essential to diagnose any dam distresses and their causes properly. The main objective of this paper is to develop a robust probability-based tool using Bayesian networks for the diagnosis of embankment dam distresses at the global level based on past dam distress data. A database of 993 distressed in-service embankment dams in China has been compiled, including general information on the dams, distresses, and causes. Based on the database, general characteristics of embankment dam distresses are studied using Bayesian networks, which can tackle not only the multiplicity of dam distresses and causes, but also the complex interrelations among them. Common patterns and causes of distresses are identified. The interrelations among the dam distresses and their causes are quantified using conditional probabilities determined based on the historical frequencies from the dam distress database. A sensitivity analysis is also conducted to identify and rank the most important factors that cause the distresses. With the prior information of common characteristics extracted from the database, Bayesian networks are further used to diagnose a specific distressed dam at the local level by combining global-level performance records and project-specific evidence in a systematic structure, which is presented in a companion paper.

Local-Level and Global-Level Form Characteristics in Apparent-Motion Correspondence

Perception ◽  
1995 ◽  
Vol 24 (11) ◽  
pp. 1233-1245 ◽  
Author(s):  
Terry Palmer ◽  
Ovid J L Tzeng ◽  
Sheng He
Keyword(s):  
Apparent Motion ◽  
Motion Detection ◽  
Local Level ◽  
The Other ◽  
Correspondence Problem ◽  
Global Level ◽  
Global Precedence ◽  
Detection Mechanism ◽  
Motion Display ◽  
Motion Correspondence

This study addressed the ‘correspondence’ problem of apparent-motion (AM) perception in which parts of a scene must be matched with counterparts separated in time and space. Given evidence that AM correspondence can be mediated by two distinct processes—one based on a low-level motion-detection mechanism (the Reichardt process), the other involving the tracking of objects by visual attention (the attention-based process)—the present study explored how these processes interact in the perception of apparent motion between hierarchically structured figures. In three experiments, hierarchical figures were presented in a competition motion display so that, across frames, figures were identical at either the local or the global level. In experiment 1 it was shown that AM occurred between locally identical figures. Furthermore, with the Reichardt AM component eliminated in experiments 3 and 4, no preference was obtained for either level. While evidence from previous studies suggests that form extraction for hierarchically structured figures proceeds from the global to the local level, the present results indicate the irrelevance of such a global precedence in AM correspondence. In addition, it is suggested that Reichardt AM correspondence between local elements constrains attention-based AM correspondence between global figures so that both components move in the same direction. It is argued that this constraining process represents an elegant means of achieving AM correspondence between objects undergoing complex transformations.

scholarly journals A Global-Level Model of the Potential Impacts of Climate Change on Child Stunting via Income and Food Price in 2030

2018 ◽  
Vol 126 (9) ◽  
pp. 097007 ◽  
Author(s):  
Simon J. Lloyd ◽  
Mook Bangalore ◽  
Zaid Chalabi ◽  
R. Sari Kovats ◽  
Stèphane Hallegatte ◽  
...  
Keyword(s):  
Climate Change ◽  
Food Price ◽  
Global Level ◽  
Child Stunting ◽  
Level Model ◽  
Impacts Of Climate Change

Evaluation of Actual Geometric Tolerances Using Coordinate Measuring Machine Data

1989 ◽  
Author(s):  
W. H. ElMaraghy ◽  
Z. Wu ◽  
H. A. ElMaraghy
Keyword(s):  
Three Dimensional ◽  
Measurement Data ◽  
Simulated Data ◽  
Coordinate Measuring Machine ◽  
Optimization Techniques ◽  
Test Cases ◽  
Tolerance Zone ◽  
Geometric Tolerances ◽  
Measuring Machine

Abstract This paper focuses on the development of a procedure and algorithms for the systematic comparison of geometric variations of measured features with their specified geometric tolerances. To automate the inspection of mechanical parts, it is necessary to analyze the measurement data captured by coordinate measuring machines (CMM) in order to detect out-of-tolerance conditions. A procedure for determining the geometric tolerances from the measured three dimensional coordinates on the surface of a cylindrical feature is presented. This procedure follows the definitions of the geometric tolerances used in the current Standards, and is capable of determining the value of each geometric tolerance from the composite 3-D data. The developed algorithms adopt the minimum tolerance zone criterion. Nonlinear numerical optimization techniques are used to fit the data to the minimum tolerance zone. Two test cases are given in the paper which demonstrate the successful determination of geometric tolerances from given simulated data.

scholarly journals Combat as an Interpersonal Synergy: An Ecological Dynamics Approach to Combat Sports

2019 ◽  
Vol 49 (12) ◽  
pp. 1825-1836 ◽  
Author(s):  
Kai Krabben ◽  
Dominic Orth ◽  
John van der Kamp
Keyword(s):  
Dynamic Systems ◽  
Local Level ◽  
Control Parameters ◽  
Combat Sports ◽  
Global Level ◽  
Interactive Approach ◽  
Ecological Dynamics ◽  
Skilled Performance ◽  
Initial Support ◽  
And Control

Abstract In combat sports, athletes continuously co-adapt their behavior to that of the opponent. We consider this interactive aspect of combat to be at the heart of skilled performance, yet combat sports research often neglects or limits interaction between combatants. To promote a more interactive approach, the aim of this paper is to understand combat sports from the combined perspective of ecological psychology and dynamic systems. Accordingly, combat athletes are driven by perception of affordances to attack and defend. Two combatants in a fight self-organize into one interpersonal synergy, where the perceptions and actions of both athletes are coupled. To be successful in combat, performers need to manipulate and take advantage of the (in)stability of the system. Skilled performance in combat sports therefore requires brinkmanship: combatants need to be aware of their action boundaries and purposefully act in meta-stable regions on the limits of their capabilities. We review the experimental literature to provide initial support for a synergetic approach to combat sports. Expert combatants seem able to accurately perceive action boundaries for themselves and their opponent. Local-level behavior of individual combatants has been found to lead to spatiotemporal synchronization at the global level of a fight. Yet, a formal understanding of combat as a dynamic system starting with the identification of order and control parameters is still lacking. We conclude that the ecological dynamics perspective offers a promising approach to further our understanding of skilled performance in combat sports, as well as to assist coaches and athletes to promote optimal training and learning.

Manufacturing Social Responsibility Benchmarks in the Competitive Intelligence Age

2011 ◽  
pp. 173-188
Author(s):  
James Douglas Orton
Keyword(s):  
Information Technology ◽  
Social Responsibility ◽  
Competitive Strategy ◽  
Local Level ◽  
Economic Security ◽  
Competitive Intelligence ◽  
Global Level ◽  
The Us ◽  
Economic Warfare ◽  
Rational Standard

The themes explored elsewhere in this volume, on the intersection between information technology and social responsibility, take on new shapes when considered in the context of competitive intelligence. Using the (probably) apocryphal Thomson-Raytheon story as a launching point, this chapter will explore the emergence of social responsibility benchmarks in the competitive intelligence age. This analysis is heavily flavored by my own experiences trying to understand the French approach to competitive intelligence. The paper reviews attempts by competitive intelligence agents in the US and France to manufacture Social Responsibility benchmarks in the contexts of covert operations, competitive strategy, corporate intelligence, economic security, economic intelligence, and economic warfare. The conclusion of the paper will argue that the construction of social responsibility is a local-level human accomplishment, not a global-level rational standard. Furthermore, the paper implies that the burden of social responsibility lies more heavily on the successful economic oppressor than the unsuccessful economic resistance.

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