Pub Date : 2010-10-01DOI: 10.1109/ISOT.2010.5687316
Michael T. C. Chow, A. Hafiz, O. R. Tutunea-Fatan, G. Knopf, E. Bordatchev
Laser micropolishing (LµP) is a new advanced m aterial microprocessing technology that attempts to smooth the original surface geometry through laser-material interactions such as melting or material ablation. Despite the significant advantages of LµP micro features, surfaces, parts, moulds and dies with complex 3D geometries from a wide range of materials, LµP is a complicated dynamic process that requires very fine tuning of a number of process parameters related to laser, optics, laser beam motions, and material properties. This paper describes a new approach for statistical analysis of LµP, where LµP is considered as a single-input (original surface) / singleoutput (polished surface) dynamic system. Original and polished cross-sections were obtained experimentally and their statistical characteristics, such as, surface roughness, material ratio function and autospectrums were calculated and analysed. In addition, LµP process was experimentally investigated as a dy namic operator represented by a transfer function and it was analysed using a coherence function. Analysis of these ch aracteristics allowed finding specific characteristics of the LµP process when surface roughness was improved by 21.3 %, lo wering averaged Ra value from 577 nm to 452 nm, and significantly reducing Ra non-uniformity from 132 nm to 44 nm for a Ti6Al4V sample.
{"title":"Experimental statistical analysis of laser micropolishing process","authors":"Michael T. C. Chow, A. Hafiz, O. R. Tutunea-Fatan, G. Knopf, E. Bordatchev","doi":"10.1109/ISOT.2010.5687316","DOIUrl":"https://doi.org/10.1109/ISOT.2010.5687316","url":null,"abstract":"Laser micropolishing (LµP) is a new advanced m aterial microprocessing technology that attempts to smooth the original surface geometry through laser-material interactions such as melting or material ablation. Despite the significant advantages of LµP micro features, surfaces, parts, moulds and dies with complex 3D geometries from a wide range of materials, LµP is a complicated dynamic process that requires very fine tuning of a number of process parameters related to laser, optics, laser beam motions, and material properties. This paper describes a new approach for statistical analysis of LµP, where LµP is considered as a single-input (original surface) / singleoutput (polished surface) dynamic system. Original and polished cross-sections were obtained experimentally and their statistical characteristics, such as, surface roughness, material ratio function and autospectrums were calculated and analysed. In addition, LµP process was experimentally investigated as a dy namic operator represented by a transfer function and it was analysed using a coherence function. Analysis of these ch aracteristics allowed finding specific characteristics of the LµP process when surface roughness was improved by 21.3 %, lo wering averaged Ra value from 577 nm to 452 nm, and significantly reducing Ra non-uniformity from 132 nm to 44 nm for a Ti6Al4V sample.","PeriodicalId":91154,"journal":{"name":"Optomechatronic Technologies (ISOT), 2010 International Symposium on : 25-27 Oct. 2010 : [Toronto, ON]. International Symposium on Optomechatronic Technologies (2010 : Toronto, Ont.)","volume":"41 1","pages":"1-6"},"PeriodicalIF":0.0,"publicationDate":"2010-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75497381","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2010-10-01DOI: 10.1109/ISOT.2010.5687354
S. Cho, Hyuk-Hoon Shim, Chun-Sam Song, Jong-Hyeong Kim
We have performed a single X-ray image extract of three-dimensional shape information (edges and vertex) by using characteristics of a specific material with a specific size (thickness). We have used that fact that the intensity distribution X-ray images decreases around edge areas in the form of exponential function and used the least square method and the coefficient of determination value to extract edges. Here we could infer the effect of the penetration rate of X-ray on the coefficient of determination value according to the kind of material (Zn, Ti, A, and Si) and that the penetration rate and the coefficient of determination value are inversely proportional. We could also conclude the effect of the penetration rate of X-ray on the coefficient of determination value according to the size of the material (5, 10, 15mm) differs and the size and the coefficient of determination value are proportional.
我们利用具有特定尺寸(厚度)的特定材料的特征，对三维形状信息(边缘和顶点)进行了单个x射线图像提取。我们利用x射线图像在边缘区域周围的强度分布以指数函数的形式递减的事实，利用最小二乘法和确定值系数对边缘进行提取。根据材料种类(Zn, Ti, A, Si)，我们可以推断出x射线的穿透率对测定值系数的影响，穿透率与测定值系数成反比。我们还可以得出x射线穿透率对测定值系数的影响根据材料的尺寸(5、10、15mm)不同而不同，尺寸与测定值系数成正比。
{"title":"Edge extraction in X-ray image based on COD of materials","authors":"S. Cho, Hyuk-Hoon Shim, Chun-Sam Song, Jong-Hyeong Kim","doi":"10.1109/ISOT.2010.5687354","DOIUrl":"https://doi.org/10.1109/ISOT.2010.5687354","url":null,"abstract":"We have performed a single X-ray image extract of three-dimensional shape information (edges and vertex) by using characteristics of a specific material with a specific size (thickness). We have used that fact that the intensity distribution X-ray images decreases around edge areas in the form of exponential function and used the least square method and the coefficient of determination value to extract edges. Here we could infer the effect of the penetration rate of X-ray on the coefficient of determination value according to the kind of material (Zn, Ti, A, and Si) and that the penetration rate and the coefficient of determination value are inversely proportional. We could also conclude the effect of the penetration rate of X-ray on the coefficient of determination value according to the size of the material (5, 10, 15mm) differs and the size and the coefficient of determination value are proportional.","PeriodicalId":91154,"journal":{"name":"Optomechatronic Technologies (ISOT), 2010 International Symposium on : 25-27 Oct. 2010 : [Toronto, ON]. International Symposium on Optomechatronic Technologies (2010 : Toronto, Ont.)","volume":"15 1","pages":"1-7"},"PeriodicalIF":0.0,"publicationDate":"2010-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75030532","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Optically driven actuators do not require contact and thus can be used to generate movement remotely. In this paper, we propose a new method for optically driving a magnetic levitation system that consists of a diamagnetic material as the moving object, a neodymium magnet, and a temperature-sensitive ferrite for varying the potential energy of the diamagnetic object. The diamagnetic object is levitated by the magnetic force between it and the neodymium magnet. Laser irradiation of the temperature-sensitive ferrite reduces its magnetic susceptibility due to the photothermal effect. In this study, the conditions for levitation are derived using a numerical approach. The results reveal that movement can be controlled in a three-dimensional r egion.
{"title":"Optically driven method for magnetically levitating a diamagnetic material using the photothermal effect","authors":"Y. Mizutani, T. Iwata, A. Tsutsumi, Y. Otani","doi":"10.1063/1.3675182","DOIUrl":"https://doi.org/10.1063/1.3675182","url":null,"abstract":"Optically driven actuators do not require contact and thus can be used to generate movement remotely. In this paper, we propose a new method for optically driving a magnetic levitation system that consists of a diamagnetic material as the moving object, a neodymium magnet, and a temperature-sensitive ferrite for varying the potential energy of the diamagnetic object. The diamagnetic object is levitated by the magnetic force between it and the neodymium magnet. Laser irradiation of the temperature-sensitive ferrite reduces its magnetic susceptibility due to the photothermal effect. In this study, the conditions for levitation are derived using a numerical approach. The results reveal that movement can be controlled in a three-dimensional r egion.","PeriodicalId":91154,"journal":{"name":"Optomechatronic Technologies (ISOT), 2010 International Symposium on : 25-27 Oct. 2010 : [Toronto, ON]. International Symposium on Optomechatronic Technologies (2010 : Toronto, Ont.)","volume":"33 1","pages":"1-4"},"PeriodicalIF":0.0,"publicationDate":"2010-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75094880","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2010-10-01DOI: 10.1109/ISOT.2010.5687357
Charles Tremblay, Joscelyn Jean, L. Marchand, Ali Turki, Philippe Chouinard-Gaouette, Mathieu Brousseau, M. Mohammadi, S. Martel
In this paper we present a hardware architecture with software implementation able to track free swimming single 2µm in diameter MC-1 bacterium. The computer vision system operates at up to 77 fps at full speed and up to 24 fps when recording full 512×512 pixels frame from coupled-charge device (CCD) array. Closed-loop control with lock-in tracking is achieved using the Otsu Segmentation Method (OSM) with a cubic spline model-based predictive algorithm. Using the system, speed distribution of MC-1 cells has been recorded showing a m ean speed of 200µm/s. Tracking is demonstrated over a range of a few millimeters during 30 sec.
{"title":"Robotic platform for real-time tracking of a single fast swimming bacterium","authors":"Charles Tremblay, Joscelyn Jean, L. Marchand, Ali Turki, Philippe Chouinard-Gaouette, Mathieu Brousseau, M. Mohammadi, S. Martel","doi":"10.1109/ISOT.2010.5687357","DOIUrl":"https://doi.org/10.1109/ISOT.2010.5687357","url":null,"abstract":"In this paper we present a hardware architecture with software implementation able to track free swimming single 2µm in diameter MC-1 bacterium. The computer vision system operates at up to 77 fps at full speed and up to 24 fps when recording full 512×512 pixels frame from coupled-charge device (CCD) array. Closed-loop control with lock-in tracking is achieved using the Otsu Segmentation Method (OSM) with a cubic spline model-based predictive algorithm. Using the system, speed distribution of MC-1 cells has been recorded showing a m ean speed of 200µm/s. Tracking is demonstrated over a range of a few millimeters during 30 sec.","PeriodicalId":91154,"journal":{"name":"Optomechatronic Technologies (ISOT), 2010 International Symposium on : 25-27 Oct. 2010 : [Toronto, ON]. International Symposium on Optomechatronic Technologies (2010 : Toronto, Ont.)","volume":"144 1","pages":"1-5"},"PeriodicalIF":0.0,"publicationDate":"2010-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82269406","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2010-10-01DOI: 10.1109/ISOT.2010.5687392
Hua Lu, Cuiru Sun
The paper presents a new study on the method of Projection Speckle Digital Correlation (PSDC) for surface out-of-plane displacement and tilt measurement. Considering that perspective and parallel devices differ substantially in the nature of pattern projection and imaging, four different camera-projector setups are modeled by optical triangulation. The different W-u relationships that the models give indicate the impact of the device properties on raw measurement. In assessing overall error sources and error structure in the PSDC measurement, sources and magnitudes of the error in relation to Digital Speckle Correlation (DSC) are evaluated since DSC is a core technique embedded in the P SDC for image in-plane motion extraction. Another category of the errors inherent to the PSDC is analyzed, which is due to the misuse of the field equations. For a particular PSDC setup, such systematic error is correctable by a calibration test using a planar sample with known rigid-body motion. A case application serves as a demonstration of the potential of the low cost system, in which DSC and PSDC are combined to resolve 3D deformation in a 1 mm2 area in a notched tensile sample.
{"title":"Projection speckle digital correlation for surface out-of-plane deformation measurement","authors":"Hua Lu, Cuiru Sun","doi":"10.1109/ISOT.2010.5687392","DOIUrl":"https://doi.org/10.1109/ISOT.2010.5687392","url":null,"abstract":"The paper presents a new study on the method of Projection Speckle Digital Correlation (PSDC) for surface out-of-plane displacement and tilt measurement. Considering that perspective and parallel devices differ substantially in the nature of pattern projection and imaging, four different camera-projector setups are modeled by optical triangulation. The different W-u relationships that the models give indicate the impact of the device properties on raw measurement. In assessing overall error sources and error structure in the PSDC measurement, sources and magnitudes of the error in relation to Digital Speckle Correlation (DSC) are evaluated since DSC is a core technique embedded in the P SDC for image in-plane motion extraction. Another category of the errors inherent to the PSDC is analyzed, which is due to the misuse of the field equations. For a particular PSDC setup, such systematic error is correctable by a calibration test using a planar sample with known rigid-body motion. A case application serves as a demonstration of the potential of the low cost system, in which DSC and PSDC are combined to resolve 3D deformation in a 1 mm2 area in a notched tensile sample.","PeriodicalId":91154,"journal":{"name":"Optomechatronic Technologies (ISOT), 2010 International Symposium on : 25-27 Oct. 2010 : [Toronto, ON]. International Symposium on Optomechatronic Technologies (2010 : Toronto, Ont.)","volume":"53 1","pages":"1-6"},"PeriodicalIF":0.0,"publicationDate":"2010-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77742145","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2010-10-01DOI: 10.1109/ISOT.2010.5687311
S. Hung, Y. H. Huang, L. Liu
Microelectronic devices and components require hermetic packaging for mechanical protection and thermal dissipation. A hermetic packaging also prevents the intrusion of atmospheric contaminants such as moisture and airborne particles, thereby mitigating their attack on the enclosed delicate electronic components. Imperfect hermetic sealing, however, allows moisture and other impurities to migrate into the package and cause microcircuit malfunctions. This malfunction is often experienced in automobiles where the microchips and microelectronic devices are exposed to hostile environments. To date, testing of hermetic seals of microelectronic packages is achieved primarily through fluorocarbon fluid, helium and even radioisotope leak detection, which are cumbersome and risky in operation, therefore unemployable on production lines. In this paper, a laser based optical system is presented for rapid evaluation of hermetic seals. The proposed system is composed of a partial vacuum chamber and a shearographic camera. During testing, the electronic packages are placed inside the chamber and the shearographic camera is used to monitor the packages through a transparent glass window. The package under test is then stressed by an air pressure change. With the pressure change maintained, the lid of a perfectly sealed package will remain deformed while a leaky package will not hold the deformation and recover gradually, which can be monitored by shearography. Hence, by measuring the deformation of the packages' surface as a function of time, package leaks and the extent of leakage can be revealed in seconds. This leak testing is fast and practical and can be extended for testing of pharmaceutical packages, food packages, etc.
{"title":"Optical system for fast inspection of hermetic seals in electronic packages","authors":"S. Hung, Y. H. Huang, L. Liu","doi":"10.1109/ISOT.2010.5687311","DOIUrl":"https://doi.org/10.1109/ISOT.2010.5687311","url":null,"abstract":"Microelectronic devices and components require hermetic packaging for mechanical protection and thermal dissipation. A hermetic packaging also prevents the intrusion of atmospheric contaminants such as moisture and airborne particles, thereby mitigating their attack on the enclosed delicate electronic components. Imperfect hermetic sealing, however, allows moisture and other impurities to migrate into the package and cause microcircuit malfunctions. This malfunction is often experienced in automobiles where the microchips and microelectronic devices are exposed to hostile environments. To date, testing of hermetic seals of microelectronic packages is achieved primarily through fluorocarbon fluid, helium and even radioisotope leak detection, which are cumbersome and risky in operation, therefore unemployable on production lines. In this paper, a laser based optical system is presented for rapid evaluation of hermetic seals. The proposed system is composed of a partial vacuum chamber and a shearographic camera. During testing, the electronic packages are placed inside the chamber and the shearographic camera is used to monitor the packages through a transparent glass window. The package under test is then stressed by an air pressure change. With the pressure change maintained, the lid of a perfectly sealed package will remain deformed while a leaky package will not hold the deformation and recover gradually, which can be monitored by shearography. Hence, by measuring the deformation of the packages' surface as a function of time, package leaks and the extent of leakage can be revealed in seconds. This leak testing is fast and practical and can be extended for testing of pharmaceutical packages, food packages, etc.","PeriodicalId":91154,"journal":{"name":"Optomechatronic Technologies (ISOT), 2010 International Symposium on : 25-27 Oct. 2010 : [Toronto, ON]. International Symposium on Optomechatronic Technologies (2010 : Toronto, Ont.)","volume":"20 1","pages":"1-4"},"PeriodicalIF":0.0,"publicationDate":"2010-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89871513","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2010-10-01DOI: 10.1109/ISOT.2010.5687345
Kieran J. O' Callaghan, M. J. O. Mahony
In the majority of cases blindness is caused by retinal degenerative conditions such as Age-Related Macular Degeneration (AMD) and Retinitis Pigmentosa (RP). However, blind individuals still retain central visual pathways and processing mechanisms. Recent advances in Time of Flight (TOF) imaging technology have presented new opportunities to develop improved sensory substitution systems for compensation of visual sensory loss. In sensory substitution information from an artificial receptor/sensor is coupled to the brain via a Human Machine Interface (HMI). The brain is able to utilise this information in place of what is usually transmitted from an intact sense organ such as the eye. The human brain has an adaptive capacity called plasticity. Research has shown that inputs from sensory substitution devices can reach numerous brain structures including those anatomically and physiologically related to the lost sensory modality. This is provided that the information from the HMI/artificial receptors is appropriate to restore function. The authors segmentation and classification system (VisionRE) aims at improving the shortcomings of the current state of the art by accurately segmenting and classifying 3D objects/obstacles in real-time and presenting the 3D information to the user in a more intuitive manner via a multimodal electro-tactile and audio HMI.
{"title":"An obstacle segmentation and classification system for the visually impaired","authors":"Kieran J. O' Callaghan, M. J. O. Mahony","doi":"10.1109/ISOT.2010.5687345","DOIUrl":"https://doi.org/10.1109/ISOT.2010.5687345","url":null,"abstract":"In the majority of cases blindness is caused by retinal degenerative conditions such as Age-Related Macular Degeneration (AMD) and Retinitis Pigmentosa (RP). However, blind individuals still retain central visual pathways and processing mechanisms. Recent advances in Time of Flight (TOF) imaging technology have presented new opportunities to develop improved sensory substitution systems for compensation of visual sensory loss. In sensory substitution information from an artificial receptor/sensor is coupled to the brain via a Human Machine Interface (HMI). The brain is able to utilise this information in place of what is usually transmitted from an intact sense organ such as the eye. The human brain has an adaptive capacity called plasticity. Research has shown that inputs from sensory substitution devices can reach numerous brain structures including those anatomically and physiologically related to the lost sensory modality. This is provided that the information from the HMI/artificial receptors is appropriate to restore function. The authors segmentation and classification system (VisionRE) aims at improving the shortcomings of the current state of the art by accurately segmenting and classifying 3D objects/obstacles in real-time and presenting the 3D information to the user in a more intuitive manner via a multimodal electro-tactile and audio HMI.","PeriodicalId":91154,"journal":{"name":"Optomechatronic Technologies (ISOT), 2010 International Symposium on : 25-27 Oct. 2010 : [Toronto, ON]. International Symposium on Optomechatronic Technologies (2010 : Toronto, Ont.)","volume":"53 1","pages":"1-6"},"PeriodicalIF":0.0,"publicationDate":"2010-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87476515","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2010-10-01DOI: 10.1109/ISOT.2010.5687309
Hyunki Lee, J. Y. Jeon, K. Ko, Hyungsuck Cho, M. Y. Kim
The ball grid array (BGA) has become one of the most popular packaging alternatives for high I/O devices in the industry with many advantages: high interconnection density and less packaging space and so on. In these days, the size of chip becomes small and the size of ball grid also becomes small, so the process of BGA alignment becomes more important and difficult. In this paper, the BGA alignment system before the oven process step is managed. The main difficult of inspecting the BGA alignment is that the substrate is always tilted due to irregular carrier size and in-line process. In this paper, to overcome this problem, tilt angle of substrate is measured by phase measuring profilometry (PMP), and then the compensated alignment offset calc ulation algorithm is suggested. The performance of our system is checked by a series of real experiments.
{"title":"Development of alignment inspection system for ball grid array packaging","authors":"Hyunki Lee, J. Y. Jeon, K. Ko, Hyungsuck Cho, M. Y. Kim","doi":"10.1109/ISOT.2010.5687309","DOIUrl":"https://doi.org/10.1109/ISOT.2010.5687309","url":null,"abstract":"The ball grid array (BGA) has become one of the most popular packaging alternatives for high I/O devices in the industry with many advantages: high interconnection density and less packaging space and so on. In these days, the size of chip becomes small and the size of ball grid also becomes small, so the process of BGA alignment becomes more important and difficult. In this paper, the BGA alignment system before the oven process step is managed. The main difficult of inspecting the BGA alignment is that the substrate is always tilted due to irregular carrier size and in-line process. In this paper, to overcome this problem, tilt angle of substrate is measured by phase measuring profilometry (PMP), and then the compensated alignment offset calc ulation algorithm is suggested. The performance of our system is checked by a series of real experiments.","PeriodicalId":91154,"journal":{"name":"Optomechatronic Technologies (ISOT), 2010 International Symposium on : 25-27 Oct. 2010 : [Toronto, ON]. International Symposium on Optomechatronic Technologies (2010 : Toronto, Ont.)","volume":"8 1","pages":"1-6"},"PeriodicalIF":0.0,"publicationDate":"2010-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79272582","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2010-10-01DOI: 10.1109/ISOT.2010.5687352
Masahito Takahashi, K. Irie, Kenji Terabayashi, K. Umeda
In this paper, we propose a method to recognize periodic gestures from images. The proposed method uses a amplitude spectrum and a phase spectrum that are obtained by applying Fast Fourier Transform (FFT) to a time series of intensity images. FFT is applied to each pixel of low-resolution images. The method consists of 2 steps. First, the method detects p eriodic motion regions from the amplitude spectrum. Secondly, the method uses the phase spectrum in the detected periodic motion region to classify the gestures. The proposed method is robust to lighting conditions and individual differences in skin color because it does not rely on color information. Several experiments are performed to demonstrate the effectiveness of the proposed method.
{"title":"Gesture recognition based on the detection of periodic motion","authors":"Masahito Takahashi, K. Irie, Kenji Terabayashi, K. Umeda","doi":"10.1109/ISOT.2010.5687352","DOIUrl":"https://doi.org/10.1109/ISOT.2010.5687352","url":null,"abstract":"In this paper, we propose a method to recognize periodic gestures from images. The proposed method uses a amplitude spectrum and a phase spectrum that are obtained by applying Fast Fourier Transform (FFT) to a time series of intensity images. FFT is applied to each pixel of low-resolution images. The method consists of 2 steps. First, the method detects p eriodic motion regions from the amplitude spectrum. Secondly, the method uses the phase spectrum in the detected periodic motion region to classify the gestures. The proposed method is robust to lighting conditions and individual differences in skin color because it does not rely on color information. Several experiments are performed to demonstrate the effectiveness of the proposed method.","PeriodicalId":91154,"journal":{"name":"Optomechatronic Technologies (ISOT), 2010 International Symposium on : 25-27 Oct. 2010 : [Toronto, ON]. International Symposium on Optomechatronic Technologies (2010 : Toronto, Ont.)","volume":"8 1","pages":"1-6"},"PeriodicalIF":0.0,"publicationDate":"2010-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82926332","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2010-10-01DOI: 10.1109/ISOT.2010.5687318
M. Hadinia, R. Jafari
Diffuse optical tomography (DOT) is a non-invasive imaging modality for visualizing and continuously monitoring tissue and blood oxygenation levels in brain and breast. DOT includes an ill-posed inverse problem. The image reconstruction algorithm in the inverse problem involves generating images by means of forward modeling results and the boundary measurements. A for ward model describes the dependence of the photon intensity data on the distribution of absorbing and scattering coefficients. The ability of the forward model to generate the corresponding data efficiently plays an important issue in DOT image reconstruction. Small measurement or forward modeling errors can lead to unbounded fluctuations in the image reconstruction algorithm. Using a first-order finite element method for forward modeling, the discretization error is reduced by increasing the number of elements. However, increasing the number of elements may cause a critical issue in the ill-posed inverse problem. This paper focuses on applying the high-order finite element method for forward modeling. In this method, the polynomial degree of shape functions is increased and the mesh size is kept fixed. Numerical results are compared with an analytical solution.
{"title":"A high-order finite element method for forward problem in diffuse optical tomography","authors":"M. Hadinia, R. Jafari","doi":"10.1109/ISOT.2010.5687318","DOIUrl":"https://doi.org/10.1109/ISOT.2010.5687318","url":null,"abstract":"Diffuse optical tomography (DOT) is a non-invasive imaging modality for visualizing and continuously monitoring tissue and blood oxygenation levels in brain and breast. DOT includes an ill-posed inverse problem. The image reconstruction algorithm in the inverse problem involves generating images by means of forward modeling results and the boundary measurements. A for ward model describes the dependence of the photon intensity data on the distribution of absorbing and scattering coefficients. The ability of the forward model to generate the corresponding data efficiently plays an important issue in DOT image reconstruction. Small measurement or forward modeling errors can lead to unbounded fluctuations in the image reconstruction algorithm. Using a first-order finite element method for forward modeling, the discretization error is reduced by increasing the number of elements. However, increasing the number of elements may cause a critical issue in the ill-posed inverse problem. This paper focuses on applying the high-order finite element method for forward modeling. In this method, the polynomial degree of shape functions is increased and the mesh size is kept fixed. Numerical results are compared with an analytical solution.","PeriodicalId":91154,"journal":{"name":"Optomechatronic Technologies (ISOT), 2010 International Symposium on : 25-27 Oct. 2010 : [Toronto, ON]. International Symposium on Optomechatronic Technologies (2010 : Toronto, Ont.)","volume":"3 1","pages":"1-6"},"PeriodicalIF":0.0,"publicationDate":"2010-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83438381","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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