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Lee-ra Cho - One of the best experts on this subject based on the ideXlab platform.
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Effect of materials on Axial Displacement and internal discrepancy of cement-retained implant-supported prostheses.
The Journal of prosthetic dentistry, 2020Co-Authors: Yoon-hyuk Huh, Chan-jin Park, Lee-ra ChoAbstract:How Axial Displacement may be affected by the mechanical properties and internal discrepancy of a cement-retained implant-supported prosthesis is unclear. The purpose of this in vitro study was to assess the difference in internal discrepancy and Axial Displacement according to the prosthesis material in cement-retained prostheses splinting nonparallel implants. Computer-aided design and computer-aided manufacture (CAD-CAM) titanium abutments were fabricated for a vertically placed implant and a 15-degree tilted implant. Three types of prostheses, in zirconia, cobalt-chromium (Co-Cr) alloy, and polymethylmethacrylate resin (PMMA), were fabricated (n=10). The internal discrepancy between the CAD-CAM titanium abutment and the prosthesis was measured by using the replica technique. After luting with an interim cement, they were mounted in Type IV gypsum. The specimens were cyclic loaded, and Axial Displacement of the prosthesis was measured after 3, 10, 100, and 106 cycles. The internal discrepancy and cumulative Axial Displacement were assessed by using a 3-way analysis of variance and repeated measures analysis of variance (α=.05). The internal discrepancy of the prosthesis did not differ based on the prosthesis material (P=.869); however, it was significantly different based on the measurement location, with the occlusal discrepancy (224 ±29 μm) being greater than the Axial discrepancy (21 ±10 μm) (P<.05). Implants with an angled placement exhibited less Axial Displacement than implants with vertical placement (P<.05). The PMMA prosthesis demonstrated significantly greater Axial Displacement than the zirconia or Co-Cr prostheses (P<.05), which were similar (P=.623). Prostheses made with high-elastic moduli materials exhibited less Axial Displacement than PMMA prostheses, even though the internal discrepancy was not different. Moreover, vertically placed implants presented a greater Axial Displacement of the prosthesis than implants with angled placement. Copyright © 2020 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.
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Effect of materials on Axial Displacement and internal discrepancy of cement-retained implant-supported prostheses.
The Journal of prosthetic dentistry, 2020Co-Authors: Yoon-hyuk Huh, Chan-jin Park, Lee-ra ChoAbstract:Abstract Statement of problem How Axial Displacement may be affected by the mechanical properties and internal discrepancy of a cement-retained implant-supported prosthesis is unclear. Purpose The purpose of this in vitro study was to assess the difference in internal discrepancy and Axial Displacement according to the prosthesis material in cement-retained prostheses splinting nonparallel implants. Material and methods Computer-aided design and computer-aided manufacture (CAD-CAM) titanium abutments were fabricated for a vertically placed implant and a 15-degree tilted implant. Three types of prostheses, in zirconia, cobalt-chromium (Co-Cr) alloy, and polymethylmethacrylate resin (PMMA), were fabricated (n=10). The internal discrepancy between the CAD-CAM titanium abutment and the prosthesis was measured by using the replica technique. After luting with an interim cement, they were mounted in Type IV gypsum. The specimens were cyclic loaded, and Axial Displacement of the prosthesis was measured after 3, 10, 100, and 106 cycles. The internal discrepancy and cumulative Axial Displacement were assessed by using a 3-way analysis of variance and repeated measures analysis of variance (α=.05). Results The internal discrepancy of the prosthesis did not differ based on the prosthesis material (P=.869); however, it was significantly different based on the measurement location, with the occlusal discrepancy (224 ±29 μm) being greater than the Axial discrepancy (21 ±10 μm) (P Conclusions Prostheses made with high-elastic moduli materials exhibited less Axial Displacement than PMMA prostheses, even though the internal discrepancy was not different. Moreover, vertically placed implants presented a greater Axial Displacement of the prosthesis than implants with angled placement.
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Axial Displacement in cement-retained prostheses with different implant-abutment connections.
The International journal of oral & maxillofacial implants, 2019Co-Authors: Yoon-hyuk Huh, Chan-jin Park, Lee-ra ChoAbstract:Purpose The purpose of this study was to evaluate Axial Displacement in cement-retained prostheses using computer-aided design/computer-aided manufacturing (CAD/CAM) abutments with three different types of implant-abutment connections. Materials and methods CAD/CAM abutments made with two types of titanium blocks (made by the same manufacturer as the implant manufacturer and by a manufacturer with a patent for CAD/CAM abutment fabrication) were connected with three types of implant connections: external, internal butt, and internal conical connection. Titanium custom abutments and zirconia prostheses were fabricated using the CAD/CAM system for each specimen. The geometries and surface morphologies of CAD/CAM abutments and ready-made abutments were comparatively evaluated using scanning electron microscopy. Cemented prostheses on abutments were mounted on a universal testing machine and subjected to 250-N sine wave cyclic loads. Cumulative Axial Displacement was measured at loading cycles of 3, 10, 100, and 106 and analyzed by repeated measures analysis of variance (ANOVA). Results Surface geometries and morphologies of CAD/CAM abutments varied according to the implant-abutment connection and manufacturers of the titanium block. The internal conical connection exhibited the greatest Axial Displacement, while the external connection showed the lowest Axial Displacement. The CAD/CAM abutment made with a compatible titanium block exhibited a greater Axial Displacement than that exhibited by the abutment fabricated using a titanium block made by the implant manufacturer. Conclusion In implant connections with a vertical stop, Axial Displacement occurred primarily in the early loading period and was self-limited. However, long-term Axial Displacement can occur with internal conical connection implants. Therefore, in internal conical connection implants, Axial Displacement should be managed more carefully using a provisional restoration, with consideration of the abutment fabrication method.
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Axial Displacements in external and internal implant abutment connection
Clinical Oral Implants Research, 2014Co-Authors: Jihye Lee, Chan-jin Park, Daegon Kim, Lee-ra ChoAbstract:Objectives The purpose of this study was to evaluate the Axial Displacement of the abutments during clinical procedures by the tightening torque and cyclic loading. Materials and methods Two different implant-abutment connection systems were used (external butt joint connection [EXT]; internal tapered conical connection [INT]). The master casts with two implant replicas, angulated 10° from each other, were fabricated for each implant connection system. Four types of impression copings were assembled and tightened with the corresponding implants (hex transfer impression coping, non-hex transfer impression coping, hex pick-up impression coping, non-hex pick-up impression coping). Resin splinted abutments and final prosthesis were assembled. The Axial Displacement was measured from the length of each assembly, which was evaluated repeatedly, after 30 Ncm torque tightening. After 250 N cyclic loading of final prosthesis for 1,000,000 cycles, additional Axial Displacement was recorded. The mean Axial Displacement was statistically analyzed (repeated measured ANOVA). Results There was more Axial Displacement in the INT group than that of the EXT group in impression copings, resin splinted abutments, and final prosthesis. Less Axial Displacement was found at 1-piece non-hex transfer type impression coping than other type of impression copings in the INT group. There was more Axial Displacement at the final prosthesis than resin splinted abutments in the INT and the EXT groups. After 250 N cyclic loading of final prosthesis, the INT group showed more Axial Displacement than that of the EXT group. Conclusion Internal tapered conical connection demonstrated a varying amount of Axial Displacement with tightening torque and cyclic loading.
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Axial Displacements in external and internal implant‐abutment connection
Clinical oral implants research, 2012Co-Authors: Jihye Lee, Chan-jin Park, Daegon Kim, Lee-ra ChoAbstract:Objectives The purpose of this study was to evaluate the Axial Displacement of the abutments during clinical procedures by the tightening torque and cyclic loading. Materials and methods Two different implant-abutment connection systems were used (external butt joint connection [EXT]; internal tapered conical connection [INT]). The master casts with two implant replicas, angulated 10° from each other, were fabricated for each implant connection system. Four types of impression copings were assembled and tightened with the corresponding implants (hex transfer impression coping, non-hex transfer impression coping, hex pick-up impression coping, non-hex pick-up impression coping). Resin splinted abutments and final prosthesis were assembled. The Axial Displacement was measured from the length of each assembly, which was evaluated repeatedly, after 30 Ncm torque tightening. After 250 N cyclic loading of final prosthesis for 1,000,000 cycles, additional Axial Displacement was recorded. The mean Axial Displacement was statistically analyzed (repeated measured ANOVA). Results There was more Axial Displacement in the INT group than that of the EXT group in impression copings, resin splinted abutments, and final prosthesis. Less Axial Displacement was found at 1-piece non-hex transfer type impression coping than other type of impression copings in the INT group. There was more Axial Displacement at the final prosthesis than resin splinted abutments in the INT and the EXT groups. After 250 N cyclic loading of final prosthesis, the INT group showed more Axial Displacement than that of the EXT group. Conclusion Internal tapered conical connection demonstrated a varying amount of Axial Displacement with tightening torque and cyclic loading.
Chan-jin Park - One of the best experts on this subject based on the ideXlab platform.
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Effect of materials on Axial Displacement and internal discrepancy of cement-retained implant-supported prostheses.
The Journal of prosthetic dentistry, 2020Co-Authors: Yoon-hyuk Huh, Chan-jin Park, Lee-ra ChoAbstract:How Axial Displacement may be affected by the mechanical properties and internal discrepancy of a cement-retained implant-supported prosthesis is unclear. The purpose of this in vitro study was to assess the difference in internal discrepancy and Axial Displacement according to the prosthesis material in cement-retained prostheses splinting nonparallel implants. Computer-aided design and computer-aided manufacture (CAD-CAM) titanium abutments were fabricated for a vertically placed implant and a 15-degree tilted implant. Three types of prostheses, in zirconia, cobalt-chromium (Co-Cr) alloy, and polymethylmethacrylate resin (PMMA), were fabricated (n=10). The internal discrepancy between the CAD-CAM titanium abutment and the prosthesis was measured by using the replica technique. After luting with an interim cement, they were mounted in Type IV gypsum. The specimens were cyclic loaded, and Axial Displacement of the prosthesis was measured after 3, 10, 100, and 106 cycles. The internal discrepancy and cumulative Axial Displacement were assessed by using a 3-way analysis of variance and repeated measures analysis of variance (α=.05). The internal discrepancy of the prosthesis did not differ based on the prosthesis material (P=.869); however, it was significantly different based on the measurement location, with the occlusal discrepancy (224 ±29 μm) being greater than the Axial discrepancy (21 ±10 μm) (P<.05). Implants with an angled placement exhibited less Axial Displacement than implants with vertical placement (P<.05). The PMMA prosthesis demonstrated significantly greater Axial Displacement than the zirconia or Co-Cr prostheses (P<.05), which were similar (P=.623). Prostheses made with high-elastic moduli materials exhibited less Axial Displacement than PMMA prostheses, even though the internal discrepancy was not different. Moreover, vertically placed implants presented a greater Axial Displacement of the prosthesis than implants with angled placement. Copyright © 2020 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.
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Effect of materials on Axial Displacement and internal discrepancy of cement-retained implant-supported prostheses.
The Journal of prosthetic dentistry, 2020Co-Authors: Yoon-hyuk Huh, Chan-jin Park, Lee-ra ChoAbstract:Abstract Statement of problem How Axial Displacement may be affected by the mechanical properties and internal discrepancy of a cement-retained implant-supported prosthesis is unclear. Purpose The purpose of this in vitro study was to assess the difference in internal discrepancy and Axial Displacement according to the prosthesis material in cement-retained prostheses splinting nonparallel implants. Material and methods Computer-aided design and computer-aided manufacture (CAD-CAM) titanium abutments were fabricated for a vertically placed implant and a 15-degree tilted implant. Three types of prostheses, in zirconia, cobalt-chromium (Co-Cr) alloy, and polymethylmethacrylate resin (PMMA), were fabricated (n=10). The internal discrepancy between the CAD-CAM titanium abutment and the prosthesis was measured by using the replica technique. After luting with an interim cement, they were mounted in Type IV gypsum. The specimens were cyclic loaded, and Axial Displacement of the prosthesis was measured after 3, 10, 100, and 106 cycles. The internal discrepancy and cumulative Axial Displacement were assessed by using a 3-way analysis of variance and repeated measures analysis of variance (α=.05). Results The internal discrepancy of the prosthesis did not differ based on the prosthesis material (P=.869); however, it was significantly different based on the measurement location, with the occlusal discrepancy (224 ±29 μm) being greater than the Axial discrepancy (21 ±10 μm) (P Conclusions Prostheses made with high-elastic moduli materials exhibited less Axial Displacement than PMMA prostheses, even though the internal discrepancy was not different. Moreover, vertically placed implants presented a greater Axial Displacement of the prosthesis than implants with angled placement.
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Axial Displacement in cement-retained prostheses with different implant-abutment connections.
The International journal of oral & maxillofacial implants, 2019Co-Authors: Yoon-hyuk Huh, Chan-jin Park, Lee-ra ChoAbstract:Purpose The purpose of this study was to evaluate Axial Displacement in cement-retained prostheses using computer-aided design/computer-aided manufacturing (CAD/CAM) abutments with three different types of implant-abutment connections. Materials and methods CAD/CAM abutments made with two types of titanium blocks (made by the same manufacturer as the implant manufacturer and by a manufacturer with a patent for CAD/CAM abutment fabrication) were connected with three types of implant connections: external, internal butt, and internal conical connection. Titanium custom abutments and zirconia prostheses were fabricated using the CAD/CAM system for each specimen. The geometries and surface morphologies of CAD/CAM abutments and ready-made abutments were comparatively evaluated using scanning electron microscopy. Cemented prostheses on abutments were mounted on a universal testing machine and subjected to 250-N sine wave cyclic loads. Cumulative Axial Displacement was measured at loading cycles of 3, 10, 100, and 106 and analyzed by repeated measures analysis of variance (ANOVA). Results Surface geometries and morphologies of CAD/CAM abutments varied according to the implant-abutment connection and manufacturers of the titanium block. The internal conical connection exhibited the greatest Axial Displacement, while the external connection showed the lowest Axial Displacement. The CAD/CAM abutment made with a compatible titanium block exhibited a greater Axial Displacement than that exhibited by the abutment fabricated using a titanium block made by the implant manufacturer. Conclusion In implant connections with a vertical stop, Axial Displacement occurred primarily in the early loading period and was self-limited. However, long-term Axial Displacement can occur with internal conical connection implants. Therefore, in internal conical connection implants, Axial Displacement should be managed more carefully using a provisional restoration, with consideration of the abutment fabrication method.
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Axial Displacements in external and internal implant abutment connection
Clinical Oral Implants Research, 2014Co-Authors: Jihye Lee, Chan-jin Park, Daegon Kim, Lee-ra ChoAbstract:Objectives The purpose of this study was to evaluate the Axial Displacement of the abutments during clinical procedures by the tightening torque and cyclic loading. Materials and methods Two different implant-abutment connection systems were used (external butt joint connection [EXT]; internal tapered conical connection [INT]). The master casts with two implant replicas, angulated 10° from each other, were fabricated for each implant connection system. Four types of impression copings were assembled and tightened with the corresponding implants (hex transfer impression coping, non-hex transfer impression coping, hex pick-up impression coping, non-hex pick-up impression coping). Resin splinted abutments and final prosthesis were assembled. The Axial Displacement was measured from the length of each assembly, which was evaluated repeatedly, after 30 Ncm torque tightening. After 250 N cyclic loading of final prosthesis for 1,000,000 cycles, additional Axial Displacement was recorded. The mean Axial Displacement was statistically analyzed (repeated measured ANOVA). Results There was more Axial Displacement in the INT group than that of the EXT group in impression copings, resin splinted abutments, and final prosthesis. Less Axial Displacement was found at 1-piece non-hex transfer type impression coping than other type of impression copings in the INT group. There was more Axial Displacement at the final prosthesis than resin splinted abutments in the INT and the EXT groups. After 250 N cyclic loading of final prosthesis, the INT group showed more Axial Displacement than that of the EXT group. Conclusion Internal tapered conical connection demonstrated a varying amount of Axial Displacement with tightening torque and cyclic loading.
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Axial Displacements in external and internal implant‐abutment connection
Clinical oral implants research, 2012Co-Authors: Jihye Lee, Chan-jin Park, Daegon Kim, Lee-ra ChoAbstract:Objectives The purpose of this study was to evaluate the Axial Displacement of the abutments during clinical procedures by the tightening torque and cyclic loading. Materials and methods Two different implant-abutment connection systems were used (external butt joint connection [EXT]; internal tapered conical connection [INT]). The master casts with two implant replicas, angulated 10° from each other, were fabricated for each implant connection system. Four types of impression copings were assembled and tightened with the corresponding implants (hex transfer impression coping, non-hex transfer impression coping, hex pick-up impression coping, non-hex pick-up impression coping). Resin splinted abutments and final prosthesis were assembled. The Axial Displacement was measured from the length of each assembly, which was evaluated repeatedly, after 30 Ncm torque tightening. After 250 N cyclic loading of final prosthesis for 1,000,000 cycles, additional Axial Displacement was recorded. The mean Axial Displacement was statistically analyzed (repeated measured ANOVA). Results There was more Axial Displacement in the INT group than that of the EXT group in impression copings, resin splinted abutments, and final prosthesis. Less Axial Displacement was found at 1-piece non-hex transfer type impression coping than other type of impression copings in the INT group. There was more Axial Displacement at the final prosthesis than resin splinted abutments in the INT and the EXT groups. After 250 N cyclic loading of final prosthesis, the INT group showed more Axial Displacement than that of the EXT group. Conclusion Internal tapered conical connection demonstrated a varying amount of Axial Displacement with tightening torque and cyclic loading.
Maryam A. Hejazi - One of the best experts on this subject based on the ideXlab platform.
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Feasibility Study on Simultaneous Detection of Partial Discharge and Axial Displacement of HV Transformer Winding Using Electromagnetic Waves
IEEE Transactions on Industrial Informatics, 2020Co-Authors: H Karami, Gevork B. Gharehpetian, Hamidreza Tabarsa, Yaser Norouzi, Maryam A. HejaziAbstract:Recently, Axial Displacement detection of transformer winding has been performed using synthetic-aperture radar (SAR) imaging, as an online method, in ultra-wideband frequency band. Another important problem in power transformers is partial discharge (PD), which emits signal in the ultra-high-frequency (UHF) frequency band. If detection of Axial Displacement using SAR imaging can be applied to the UHF band, both defects can be detected using only one set of antennas and application of these methods can be more economic. However, as shown in this paper, using the same frequency band for detection of both defects leads to wrong conclusions about winding conditions, if PD is occurred during the application of SAR imaging. As a solution, UHF stepped-frequency imaging method and generalized likelihood ratio test method are proposed for detection of Axial Displacement. Finally, on a three-phase real transformer both defects are simultaneously detected using designed monitoring system.
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online monitoring of transformer winding Axial Displacement and its extent using scattering parameters and k nearest neighbour method
Iet Generation Transmission & Distribution, 2011Co-Authors: Maryam A. Hejazi, G B Gharehpetian, Gholamreza Moradi, H A Alehosseini, Mohammad MohammadiAbstract:The online monitoring of the transformer winding using scattering parameters fingerprint is presented. As a test object, a simplified model of transformer is used. The winding Axial Displacement is modelled on this test object. The scattering parameters of the test object are calculated using the high-frequency simulation software and measured using a network analyser. Two indices are defined based on the magnitude and phase of scattering parameters for the detection of the Axial Displacement. A new algorithm for the estimation of the Axial Displacement extent is presented using the proposed indices and high-frequency modelling of the transformer. To detect this mechanical defect and its extent, the k-nearest neighbour (k-NN) regression is suggested.
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Application of Classifiers for On-line Monitoring of Transformer Winding Axial Displacement by Electromagnetic Non-destructive Testing
Electric Power Components and Systems, 2011Co-Authors: Maryam A. Hejazi, Gevork B. Gharehpetian, Gholamreza Moradi, Mohammad Mohammadi, Hasan A. AlehoseiniAbstract:Abstract Transformer winding on-line monitoring using electromagnetic non-destructive testing has been suggested in this article. As a test object, a simplified model of transformer has been used. The winding Axial Displacement can be modeled on the test object. The scattering parameters of the test object can be measured and stored in a database. To detect the Axial Displacement, two indices have been defined using the magnitude and phase of scattering parameters. The k-nearest neighbor and decision tree classifiers have been used for the detection of the winding Axial Displacement and its value. The accuracy of the k-nearest neighbor method to find the Axial Displacement value has been improved by using a proposed k-nearest neighbor regression algorithm. The comparison of the average error of two classifiers shows the superiority of the k-nearest neighbor regression over the decision tree classifier.
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Simulation of on-line monitoring of transformer winding Axial Displacement
The XIX International Conference on Electrical Machines - ICEM 2010, 2010Co-Authors: Ghassem Mokhtari, Gevork B. Gharehpetian, Maryam A. Hejazi, J. EbrahimiAbstract:Mechanical or electromechanical forces can cause Axial Displacement of transformer winding. In this paper a new monitoring method based on Ultra Wide Band (UWB) waves to detect the Axial Displacement of the high voltage and low voltage winding of large power transformers is proposed. The proposed experimental set-up for this method has been modelled using CST (Computer Simulation Technology) software. The simulation results show that the upward and downward Axial Displacement of windings can be detected by the on-line monitoring of UWB wave.
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Detection of transformer winding Axial Displacement using scattering parameter and ANN
2010 IEEE International Conference on Power and Energy, 2010Co-Authors: Maryam A. Hejazi, Hasan A. Alehoseini, Gevork B. GharehpetianAbstract:The method of the on-line monitoring of transformer winding Axial Displacements using scattering parameters has been presented in this paper. In this method, the signature of the transformer is the scattering parameters, which are calculated using high frequency simulation software and saved for further analysis as a base case. The new simulations can be compared with this case, to detect the Axial Displacement of transformer winding. Based on simulations on the simplified model of the transformer winding, it is shown that the proposed method can discriminate between the displaced and intact windings. The Displacement extent can be determined using Artificial Neural Network.
Xiaoqin Gao - One of the best experts on this subject based on the ideXlab platform.
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Axial Displacement calibration and tracking of optically trapped beads
Optics and Lasers in Engineering, 2020Co-Authors: Ma Guoteng, Xiaoqin GaoAbstract:Abstract High-precision Axial Displacement tracking of trapped beads is an indispensable feature of optical tweezers in advanced single-molecule studies. Here, we demonstrate an alternative method that enables Axial calibration and tracking to be carried out on the same sample to avoid unnecessary errors. This method works by applying a dynamic force balance on a bead trapped between a piezoelectrically driven glass slide and an optical trap; in this configuration, the bead can be stopped precisely in different positions and imaged by a camera. A simple gradient algorithm is used to process the images into calibration data. After optimization of the calibration method and samples, our method exhibited better than 5 nm experimental Axial resolution, with a measurement range of +/-500 nm around the objective focus at video speed. Moreover, for the first time, the deviation of the focusing plane in dual-trap optical tweezers was measured. We confirmed the Axial deviation between two optical traps in our setup to be ~10 nm, corresponding to a force spectroscopy gage error of ~1 pN. This approach offers a favorable solution for in-use setup updating, as it can be seamlessly integrated into any optical tweezers system without requiring new hardware updates.
Hasan A. Alehoseini - One of the best experts on this subject based on the ideXlab platform.
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a new on line monitoring method of transformer winding Axial Displacement based on measurement of scattering parameters and decision tree
Expert Systems With Applications, 2011Co-Authors: M Akhavanhejazi, G B Gharehpetian, Gholamreza Moradi, Mohammad Mohammadi, Reza Farajidana, Hasan A. AlehoseiniAbstract:In this paper the scattering parameter of a simplified model of transformer has been measured in different Axial Displacement of the winding using a Network Analyzer. Two indices have been suggested to detect the Axial Displacement. The measurement results show the effectiveness of these indices. A new method of the detection of the Axial Displacement extent based on decision tree (DT) has been proposed, too. It has been shown that this method has a good accuracy to determine the Displacement of the winding and its extent.
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Application of Classifiers for On-line Monitoring of Transformer Winding Axial Displacement by Electromagnetic Non-destructive Testing
Electric Power Components and Systems, 2011Co-Authors: Maryam A. Hejazi, Gevork B. Gharehpetian, Gholamreza Moradi, Mohammad Mohammadi, Hasan A. AlehoseiniAbstract:Abstract Transformer winding on-line monitoring using electromagnetic non-destructive testing has been suggested in this article. As a test object, a simplified model of transformer has been used. The winding Axial Displacement can be modeled on the test object. The scattering parameters of the test object can be measured and stored in a database. To detect the Axial Displacement, two indices have been defined using the magnitude and phase of scattering parameters. The k-nearest neighbor and decision tree classifiers have been used for the detection of the winding Axial Displacement and its value. The accuracy of the k-nearest neighbor method to find the Axial Displacement value has been improved by using a proposed k-nearest neighbor regression algorithm. The comparison of the average error of two classifiers shows the superiority of the k-nearest neighbor regression over the decision tree classifier.
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Detection of transformer winding Axial Displacement using scattering parameter and ANN
2010 IEEE International Conference on Power and Energy, 2010Co-Authors: Maryam A. Hejazi, Hasan A. Alehoseini, Gevork B. GharehpetianAbstract:The method of the on-line monitoring of transformer winding Axial Displacements using scattering parameters has been presented in this paper. In this method, the signature of the transformer is the scattering parameters, which are calculated using high frequency simulation software and saved for further analysis as a base case. The new simulations can be compared with this case, to detect the Axial Displacement of transformer winding. Based on simulations on the simplified model of the transformer winding, it is shown that the proposed method can discriminate between the displaced and intact windings. The Displacement extent can be determined using Artificial Neural Network.
