• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 725
  • 442
  • 115
  • 90
  • 47
  • 44
  • 35
  • 25
  • 11
  • 9
  • 6
  • 5
  • 4
  • 4
  • 3
  • Tagged with
  • 1787
  • 432
  • 371
  • 344
  • 309
  • 287
  • 238
  • 191
  • 177
  • 177
  • 169
  • 169
  • 168
  • 167
  • 167
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

Permeability degradation and wear of dental composites

Mair, Lawrence January 1989 (has links)
No description available.
42

An investigation of tool stresses caused by unsteady chip formations in machining

Brown, Charles Jeremy January 1986 (has links)
No description available.
43

Intelligent drill wear condition monitoring using self organising feature maps

Ashar, Jesal January 2009 (has links)
The rising demand for exacting performances from manufacturing systems has led to new challenges for the development of complex tool condition monitoring techniques. Although a wide range of monitoring methods have been investigated and developed, there has been very little migration of these innovations into industrial practice. The principal factor behind this phenomenon is the stochastic nature of the environment in which the system must function. A truly universal application has yet to be developed. The work presented here centres around the application of an unsupervised neural network model to the said problem. These networks learn without the aid of a human teacher or supervisor and learn to organise and re-organise themselves in accordance to the input data. This leads to the network structure reflecting the given input distribution more precisely than a predefined model, which generally follows a decay schedule. The dynamic nature of the process provides an evaluation of the underlying connectivity and topology in the original data space. This makes the network far more capable of capturing details in the target space. These networks have been successfully used in speech recognition applications and various pattern recognition tasks involving very noisy signals. Work is in progress on their application to robotics, process control and telecommunications. The procedure followed here has been to conduct experimental drilling trials using solid carbide drills on a Duplex Stainless Steel workpiece. Duplex Stainless Steel was chosen as a preferred metal for drilling experiments because of this high strength, good resistance to corrosion, low thermal expansion and good fatigue resistance. During the drilling trials, forces on the workpiece along the x, y and z axes were captured in real time and moments of the forces were calculated using these values. These three axial forces, along with their power spectral densities and moments were used as input parameters to the Artificial Neural Network model which followed the Self-Organising Map algorithm to classify this data. After the network was able to adapt itself to classify this real world data, the generated model was tested against a different set of data values captured during the drilling trials. The network was able to correctly identify a worn out drill from a new drill from this previously unseen set of data. This autonomous classification of the drill wear state by the neural network is a step towards creating a “universal” application that will eventually be able to predict tool wear in any machining operation without prior training.
44

Intelligent drill wear condition monitoring using self organising feature maps

Ashar, Jesal January 2009 (has links)
The rising demand for exacting performances from manufacturing systems has led to new challenges for the development of complex tool condition monitoring techniques. Although a wide range of monitoring methods have been investigated and developed, there has been very little migration of these innovations into industrial practice. The principal factor behind this phenomenon is the stochastic nature of the environment in which the system must function. A truly universal application has yet to be developed. The work presented here centres around the application of an unsupervised neural network model to the said problem. These networks learn without the aid of a human teacher or supervisor and learn to organise and re-organise themselves in accordance to the input data. This leads to the network structure reflecting the given input distribution more precisely than a predefined model, which generally follows a decay schedule. The dynamic nature of the process provides an evaluation of the underlying connectivity and topology in the original data space. This makes the network far more capable of capturing details in the target space. These networks have been successfully used in speech recognition applications and various pattern recognition tasks involving very noisy signals. Work is in progress on their application to robotics, process control and telecommunications. The procedure followed here has been to conduct experimental drilling trials using solid carbide drills on a Duplex Stainless Steel workpiece. Duplex Stainless Steel was chosen as a preferred metal for drilling experiments because of this high strength, good resistance to corrosion, low thermal expansion and good fatigue resistance. During the drilling trials, forces on the workpiece along the x, y and z axes were captured in real time and moments of the forces were calculated using these values. These three axial forces, along with their power spectral densities and moments were used as input parameters to the Artificial Neural Network model which followed the Self-Organising Map algorithm to classify this data. After the network was able to adapt itself to classify this real world data, the generated model was tested against a different set of data values captured during the drilling trials. The network was able to correctly identify a worn out drill from a new drill from this previously unseen set of data. This autonomous classification of the drill wear state by the neural network is a step towards creating a “universal” application that will eventually be able to predict tool wear in any machining operation without prior training.
45

Intelligent drill wear condition monitoring using self organising feature maps

Ashar, Jesal January 2009 (has links)
The rising demand for exacting performances from manufacturing systems has led to new challenges for the development of complex tool condition monitoring techniques. Although a wide range of monitoring methods have been investigated and developed, there has been very little migration of these innovations into industrial practice. The principal factor behind this phenomenon is the stochastic nature of the environment in which the system must function. A truly universal application has yet to be developed. The work presented here centres around the application of an unsupervised neural network model to the said problem. These networks learn without the aid of a human teacher or supervisor and learn to organise and re-organise themselves in accordance to the input data. This leads to the network structure reflecting the given input distribution more precisely than a predefined model, which generally follows a decay schedule. The dynamic nature of the process provides an evaluation of the underlying connectivity and topology in the original data space. This makes the network far more capable of capturing details in the target space. These networks have been successfully used in speech recognition applications and various pattern recognition tasks involving very noisy signals. Work is in progress on their application to robotics, process control and telecommunications. The procedure followed here has been to conduct experimental drilling trials using solid carbide drills on a Duplex Stainless Steel workpiece. Duplex Stainless Steel was chosen as a preferred metal for drilling experiments because of this high strength, good resistance to corrosion, low thermal expansion and good fatigue resistance. During the drilling trials, forces on the workpiece along the x, y and z axes were captured in real time and moments of the forces were calculated using these values. These three axial forces, along with their power spectral densities and moments were used as input parameters to the Artificial Neural Network model which followed the Self-Organising Map algorithm to classify this data. After the network was able to adapt itself to classify this real world data, the generated model was tested against a different set of data values captured during the drilling trials. The network was able to correctly identify a worn out drill from a new drill from this previously unseen set of data. This autonomous classification of the drill wear state by the neural network is a step towards creating a “universal” application that will eventually be able to predict tool wear in any machining operation without prior training.
46

Wear mechanisms in sheet metal forming : effects of tool microstructure, adhersion and temperature /

Gåård, Anders, January 2008 (has links)
Diss. (sammanfattning) Karlstad : Karlstads universitet, 2008. / Härtill 8 uppsatser.
47

Wear in sheet metal forming /

Gåård, Anders, January 2008 (has links)
Licentiatavhandling (sammanfattning) Karlstad : Karlstads universitet, 2008. / Härtill 5 uppsatser.
48

Tool life criteria and effect of wear on related variables

Wang, Kuo-King, January 1962 (has links)
Thesis (M.S.)--University of Wisconsin--Madison, 1962. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 74-76).
49

An analysis of the structure and wear of grinding wheels by autoregressive-moving average models

Deutsch, Stuart Jay, January 1970 (has links)
Thesis (Ph. D.)--University of Wisconsin--Madison, 1970. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.
50

Abrasive wear properties of ceramic particulates (Al₄C₃) reinforced al-based composites

Tam, Anlam Chi Lam. January 2002 (has links) (PDF)
Thesis (M.Sc.)--City University of Hong Kong, 2002. / At head of title: City University of Hong Kong, Department of Physics and Materials Science, Master of Science in materials technology and management dissertation. Title from title screen (viewed on Sept. 4, 2006) Includes bibliographical references.

Page generated in 0.033 seconds