Hùng Hoàng - Academia.edu (original) (raw)

Papers by Hùng Hoàng

An electronic imaging system incorporating a hand-held fundus camera was used to collect images o... more An electronic imaging system incorporating a hand-held fundus camera was used to collect images of the canine ocular fundus. The electronic imaging system comprised a hand-held fundus camera, an IBM personal computer (PC 350), Microsoft Windows NT 4.0, Adobe Photoshop, and a color printer (Tektronix Phaser 550) and was used to store, edit, and print the images captured by the fundus camera. Hand-held fundus cameras are essential for use in canine ophthalmology. The Nidek NM-100 hand-held fundus camera digitalizes images, enabling their direct transfer into reports and their storage on writeable CDs.

IEEE Transactions on Signal Processing, 2009

Analog filters constitute indispensable components of analog circuits. Inspired by recent advance... more Analog filters constitute indispensable components of analog circuits. Inspired by recent advances in digital filter design, this paper provides a flexible design for analog filters. All-pole filters have maximally flat passband, so our design minimizes their passband distortion. Analogously, maximally flat filters have maximally flat passband, so our design maximizes their stopband attenuation. Its particular cases provide flexible alternatives to the classical counterparts. Semidefinite program (SDP) formulations for the posed filter design problems are presented, which are efficiently solved by existing optimization software. Several examples and comparisons are provided to validate the viability of our design.

Pancreas, 1988

Plasma levels of neurotensin are increased by ingestion of fat, making this peptide a candidate f... more Plasma levels of neurotensin are increased by ingestion of fat, making this peptide a candidate for mediation of pancreatic adaptation to dietary fat. We examined the effects of doses of neurotensin on pancreatic secretion and growth to determine whether doses stimulating secretion also increased pancreatic growth and lipase content in rats. Because neurotensin inhibits gastric secretion in other species, we also measured its effects on gastric secretion and growth. In conscious rats, neurotensin (33, 100, and 300 micrograms kg-1 subcutaneously in gelatin) produced dose-related increases in pancreatic amylase output and decreases in basal gastric secretion. Duration of acid inhibition by neurotensin was longer than stimulation of amylase secretion. Chronic administration of the same doses of neurotensin to groups of rats every 8 h for 5 days produced small but statistically significant trophic effects on the pancreas. The highest dose of neurotensin significantly increased pancreatic weight (16%) and content of DNA (12%), protein (17%), and chymotrypsinogen (60%) but did not affect amylase or lipase content. There were no effects of neurotensin on any measurement of oxyntic or pyloric gland area growth. We conclude that although neurotensin stimulates both pancreatic secretion and growth, it is not the mediator of fat-induced pancreatic adaptation.

Magnetic encoders are widely used for speed or position measurement. This research presents a sui... more Magnetic encoders are widely used for speed or position measurement. This research presents a suitable method to correct the quadratic signal from a magnetic sensor. A new quadrature all digital phased-locked loop (QADPLL) method is presented. The method minimizes the effect of amplitude imbalance, noise, phase shift, and signal offsets. It also can solve waveform distortion and time-lag problems. Moreover, this paper proposes an interpolation technique to improve the accuracy of position information. By deriving the high-order signal from a sinusoidal signal, a high-resolution position can be obtained from a low-resolution encoder. Simulation and experiment on a linear motor were conducted. The results verify the performance of the proposed methods.

IEEE Transactions on Signal Processing, 2009

For a transfer function ( ) of order , Kalman-Yakubovich-Popov (KYP) lemma characterizes a genera... more For a transfer function ( ) of order , Kalman-Yakubovich-Popov (KYP) lemma characterizes a general intractable semi-infinite programming (SIP) condition by a tractable semidefinite programming (SDP) for the entire frequency range. Some recent results generalize this lemma for a certain frequency interval. All these SDP characterizations are given at the expense of the introduced Lyapunov matrix variable of dimension . Consequently, formulation and design of high dimensional problem is challenging. Moreover, existing SDP characterizations for frequency-selective SIP (FS-SIP) do not allow to formulate synthesis problems as SDPs. In this paper, we propose a completely new SDP characterization of general FS-SIP involving SDPs of moderate size and free from Lyapunov variables. Furthermore, a systematic IIR filter and filter bank design is developed in a similar vein, with several simulations provided to validate the effectiveness of our SDP formulation. Index Terms-Filter and filter bank, Kalman-Yakubovich-Popov (KYP) lemma, semidefinite programming.

Spectrochimica Acta Part A-molecular and Biomolecular Spectroscopy, 2011

Polypyrrole (PPy) and poly(pyrrole-2,6-dimethyl-␤-cyclodextrin) [P(Py-␤-DMCD)] films prepared by ... more Polypyrrole (PPy) and poly(pyrrole-2,6-dimethyl-␤-cyclodextrin) [P(Py-␤-DMCD)] films prepared by potential cycling in aqueous acidic solutions on indium tin oxide (ITO)-coated glass and gold electrodes were studied by in situ UV-vis and Raman spectroscopy. Characteristic UV-vis and Raman bands were identified and their dependencies on the electrode potential have been discussed. Spectroelectrochemical results reveal differences both in the position of the spectral bands and their potential dependence for PPy and P(Py-␤-DMCD) films indicating interactions between polymer chains and CDs during electropolymerization process. The films were also characterized by cyclic voltammetry and FT-IR spectroscopy.

IEEE Transactions on Automatic Control, 2008

This paper proposes a novel frequency-selective Kalman-Yakubovich-Popov (FS-KYP) lemma for analys... more This paper proposes a novel frequency-selective Kalman-Yakubovich-Popov (FS-KYP) lemma for analysis of single-input single-output (SISO) continuous systems. In contrast to existing approaches, the proposed method only uses a minimal number of variables due to the absence of Lyapunov variables in semidefinite programming (SDP) formulation. The SDP formulation is extended to polytopic uncertain systems also without any additional variable and yields an efficient method for computation of the H ∞ gain for polytopic systems. The viability of the proposed method are demonstrated through several numerical examples.

Journal of Oral Rehabilitation, 2009

Summary Previous in vitro permeability and scanning electron microscopic studies have demonstrat... more Summary Previous in vitro permeability and scanning electron microscopic studies have demonstrated the effectiveness of a new natural based-resin varnish (Shellac F) in dentin permeability reduction and effective tubule occlusion. The aim of this randomized double-blind, controlled, split mouth 8-week clinical study was to evaluate the efficiency of Shellac F in reducing dentin hypersensitivity. Ten patients (eight women: two men) completed the study. A quadrant including at least one hypersensitive tooth (Visual Analog Scale – VAS = 15 mm to air blast) was considered as a unit and randomly assigned to different groups for Shellac F, Duraphat®, Isodan®. Three applications of each material were completed at days 0, 1 and 7. The subjective response was assessed by tactile and thermal/evaporative methods. Data were collected at baseline and after the first application, at 15 min, 1, 7, 14, 28 and 56 days. Analysis was based on Kruskall–Wallis test, Wilcoxon signed rank test and the method of the least square means. No statistically significant difference was noted between Shellac F and the two control materials. Regardless of the type of stimulus, Shellac F showed significant immediate and progressive continuous efficiency in reducing dentin hypersensitivity until 56 days (VAS of 14 ± 12 mm and provoking pain force of 89 ± 12 cN, respectively, compared with 38 ± 23 mm and 41 ± 10 cN at baseline), corresponding to a highly effective relief dentin hypersensitivity. Shellac F reduced dentin hypersensitivity and did not differ from the two desensitizing agents used as controls.

IEEE Transactions on Antennas and Propagation, 2007

Abstract Bounding the sidelobe and mainlobe levels of an array with complex weights is attractive... more Abstract Bounding the sidelobe and mainlobe levels of an array with complex weights is attractive in that it allows direct control of the radiation pattern. In this paper we propose an efficient beamforming technique for synthesizing the patterns of large arrays with bound constraints on the sidelobe and mainlobe levels. It is shown that the pattern synthesis problem can be posed as a convex semi-infinite program (SIP) which is then turned into a semi-definite program (SDP) via a novel linear matrix inequality (LMI) characterization of ...

IEEE Transactions on Signal Processing, 2009

For a transfer function ( ) of order , Kalman-Yakubovich-Popov (KYP) lemma characterizes a genera... more For a transfer function ( ) of order , Kalman-Yakubovich-Popov (KYP) lemma characterizes a general intractable semi-infinite programming (SIP) condition by a tractable semidefinite programming (SDP) for the entire frequency range. Some recent results generalize this lemma for a certain frequency interval. All these SDP characterizations are given at the expense of the introduced Lyapunov matrix variable of dimension . Consequently, formulation and design of high dimensional problem is challenging. Moreover, existing SDP characterizations for frequency-selective SIP (FS-SIP) do not allow to formulate synthesis problems as SDPs. In this paper, we propose a completely new SDP characterization of general FS-SIP involving SDPs of moderate size and free from Lyapunov variables. Furthermore, a systematic IIR filter and filter bank design is developed in a similar vein, with several simulations provided to validate the effectiveness of our SDP formulation. Index Terms-Filter and filter bank, Kalman-Yakubovich-Popov (KYP) lemma, semidefinite programming.

Position sensors using magnetic effects, such as magnetic encoders (MEs), are increasingly used i... more Position sensors using magnetic effects, such as magnetic encoders (MEs), are increasingly used in many industrial applications. These include motor control, electro-mechanical braking systems, and precision measurement systems. The magnetic encoders generally provide a pair of sinusoidal signals dephasing 90deg to each other. Unfortunately, the signals obtained are not ideal, in that they always exist with the DC offsets, different amplitudes, phase-shifts and waveform distortions. These are further compromised by noise and changes in operating conditions. This paper proposes an approach for real-time correcting and tracking ME signals based on the Advanced Adaptive Digital Phase-Locked Loop (AADPLL) technique. AADPLL provides a robust filtering characteristic as well as a wideband of input frequency. It can effectively filter noise and improve the accuracy of ME signals. AADPLL also takes advantage of tracking high-speed input signals without time-lag, unlike traditional filters. A quadrature pulse interpolator is introduced to obtain high resolution. This interpolator uses look-up tables (LUTs) to store pulse-out values in one period of MEs signals. These LUTs are reduced in size for easy implementation in Digital Signal Processor (DSP) hardware platforms. Experimental results demonstrate the effectiveness of the proposed method.

Confocal laser-scanning microscopes (CLMs) are such versatile platforms that they are routinely u... more Confocal laser-scanning microscopes (CLMs) are such versatile platforms that they are routinely used now in a broad range of disciplines for multi-colour three-dimensional imaging of sub-micron features. In addition to imaging, many CLMs have built-in software for directing the laser beams to purposely photobleach regions of a specimen, such as for FRAP experiments, or for optically writing information into photosensitive materials. The regions are usually regularly shaped, such as rectangles or circles; or if they are irregularly shaped then they are relatively simple, hand-drawn regions. Here, we demonstrate the photobleaching of arbitrarily complex patterns, including full-colour RGB photos, into polymer nanostructured materials using a commercially-available Zeiss LSM510 confocal microscope. The three-dye material is specially designed to prevent resonant energy transfer between the different dyes, allowing us to photobleach in three colour channels without crosstalk between them [1]. A Visual Basic for Applications (VBA) macro was written that accepts as input any binary, grayscale, or colour image and directs the LSM510 mirrors to position the focused beam from the LSM510 laser(s) to corresponding coordinates in the specimen. Naturally, the photobleached patterns or images can be viewed immediately upon their completion by simply acquiring normal confocal fluorescence images of the same region. We applied the technique to the writing of security information, including a binary fingerprint and signature, a grayscale photo, and full-colour RGB photos . . The three colour channels of an RGB image were independently photobleached into three spatially and spectrally distinct dyes in our polymer nanocomposite material, and subsequently imaged using laser lines a) 458nm, b) 364nm, and c) 633nm. d) Colour composite reproduces the original photo (scalebar 50µm). e) At higher magnification the composite nature of the material is apparent, making it difficult to counterfeit (scalebar 10µm). [1] H. H. Pham, I Gourevich, J.E.N. Jonkman, and E. Kumacheva, "Polymer nanostructured material for the recording of biometric features," J. Mater. Chem.

Abstract: MEs (magnetic encoders) are widely used in industrial control systems because of its si... more Abstract: MEs (magnetic encoders) are widely used in industrial control systems because of its significant advantages, such as high resolution, high speed, operation in harsh environments, and low cost. This paper describes a method to extract the position ...

Ultramicroscopy, 2008

Keywords: Scanning electron microscope Electron energy spectrometers Auger electron spectroscopy ... more Keywords: Scanning electron microscope Electron energy spectrometers Auger electron spectroscopy a b s t r a c t This paper presents a toroidal electron energy spectrometer designed to capture electrons in the full 2p azimuthal angular direction while at the same time having second-order focusing optics. Simulation results based upon direct ray tracing predict that the relative energy resolution of the spectrometer will be 0.146% and 0.0188% at input angular spreads of 761 and 731, respectively, comparable to the theoretically best resolution of the cylindrical mirror analyzer (CMA), and an order of magnitude better than existing toroidal spectrometers. Also predicted for the spectrometer is a parallel energy acquisition mode of operation, where the energy bandwidth is expected to be 4710% (20% total) of the pass energy. The spectrometer is designed to allow for retardation of the pass energy without the need to incorporate auxiliary lenses.

Chemistry of Materials, 2006

A novel approach to the synthesis of polyaniline−montmorillonite (PANI−MMT) nanocomposites by in ... more A novel approach to the synthesis of polyaniline−montmorillonite (PANI−MMT) nanocomposites by in situ electropolymerization of anilinium−montmorillonite in 0.3 M sulfuric acid on a gold substrate is reported. The nanocomposites were characterized by elemental analysis, cyclic ...

Journal of The Electrochemical Society, 2007

Corrosion protection performance of a completely soluble polyaniline-dodecylbenzenesulfonic acid ... more Corrosion protection performance of a completely soluble polyaniline-dodecylbenzenesulfonic acid salt (PANI-DBSA) on C45 steel has been studied with electrochemical impedance and potentiodynamic measurements. Chloroform is the most suitable solvent to process the pristine PANI-DBSA because of negligible interaction of the solvent with the polyaniline (PANI) backbone. An anodic shift in the corrosion potential (E = ~70 mV), a decrease in the corrosion current and a significant increase in the charge transfer resistance indicate a significant anti-corrosion performance of the soluble PANI deposited on the protected steel surface.

Ultramicroscopy, 2009

This article describes preliminary experiments to test the concept of scanning electron microscop... more This article describes preliminary experiments to test the concept of scanning electron microscope (SEM) using a round magnetic beam separator to perform energy spectroscopy. Two experiments with an add-on attachment inside a conventional SEM were performed, one to estimate the sector image aberrations and the other to capture an energy spectrum of scattered electrons. The experiments show that the sector image aberrations lie well below 2 nm and that it is possible to capture the energy spectrum of secondary electrons.

Dental Materials, 2008

Natural resin-based desensitizing agent Cytotoxicity Dentin hydraulic conductance a b s t r a c t

In this paper, we present a new generating method for the velocity profile to increase productivi... more In this paper, we present a new generating method for the velocity profile to increase productivity and stability for industrial hydraulic systems. Most industrial hydraulic systems repeat a single motion plan that consists of several velocity profiles to produce products. It has deceleration and acceleration terms between each velocity profiles. These terms cause delay to finish a one-motion plan. Useless delay time in the industrial field will be directly connected to low-productivity. Motion planning using high-speed can cause noise, vibration and safety problems. Therefore, we propose a new method to generate the velocity profile with non-delay time. The new method can connect the velocity profiles in one motion plan after eliminating useless acceleration or deceleration terms. Eliminating these terms can reduce motion moving time and physical shock with inertia. The motion moving time is related with productivity and the shock is related with safety probability. Especially, the shock that is even small can generate another big shock and effect to human. Thus, the industrial systems consider these two issues very carefully. The proposed velocity profile can increase performance from these angles. A pressure machine based on a hydraulic system will operate with the new velocity profile using the proposed implementation method and be proved by two result of motion plan.

An electronic imaging system incorporating a hand-held fundus camera was used to collect images o... more An electronic imaging system incorporating a hand-held fundus camera was used to collect images of the canine ocular fundus. The electronic imaging system comprised a hand-held fundus camera, an IBM personal computer (PC 350), Microsoft Windows NT 4.0, Adobe Photoshop, and a color printer (Tektronix Phaser 550) and was used to store, edit, and print the images captured by the fundus camera. Hand-held fundus cameras are essential for use in canine ophthalmology. The Nidek NM-100 hand-held fundus camera digitalizes images, enabling their direct transfer into reports and their storage on writeable CDs.

IEEE Transactions on Signal Processing, 2009

Analog filters constitute indispensable components of analog circuits. Inspired by recent advance... more Analog filters constitute indispensable components of analog circuits. Inspired by recent advances in digital filter design, this paper provides a flexible design for analog filters. All-pole filters have maximally flat passband, so our design minimizes their passband distortion. Analogously, maximally flat filters have maximally flat passband, so our design maximizes their stopband attenuation. Its particular cases provide flexible alternatives to the classical counterparts. Semidefinite program (SDP) formulations for the posed filter design problems are presented, which are efficiently solved by existing optimization software. Several examples and comparisons are provided to validate the viability of our design.

Pancreas, 1988

Plasma levels of neurotensin are increased by ingestion of fat, making this peptide a candidate f... more Plasma levels of neurotensin are increased by ingestion of fat, making this peptide a candidate for mediation of pancreatic adaptation to dietary fat. We examined the effects of doses of neurotensin on pancreatic secretion and growth to determine whether doses stimulating secretion also increased pancreatic growth and lipase content in rats. Because neurotensin inhibits gastric secretion in other species, we also measured its effects on gastric secretion and growth. In conscious rats, neurotensin (33, 100, and 300 micrograms kg-1 subcutaneously in gelatin) produced dose-related increases in pancreatic amylase output and decreases in basal gastric secretion. Duration of acid inhibition by neurotensin was longer than stimulation of amylase secretion. Chronic administration of the same doses of neurotensin to groups of rats every 8 h for 5 days produced small but statistically significant trophic effects on the pancreas. The highest dose of neurotensin significantly increased pancreatic weight (16%) and content of DNA (12%), protein (17%), and chymotrypsinogen (60%) but did not affect amylase or lipase content. There were no effects of neurotensin on any measurement of oxyntic or pyloric gland area growth. We conclude that although neurotensin stimulates both pancreatic secretion and growth, it is not the mediator of fat-induced pancreatic adaptation.

Magnetic encoders are widely used for speed or position measurement. This research presents a sui... more Magnetic encoders are widely used for speed or position measurement. This research presents a suitable method to correct the quadratic signal from a magnetic sensor. A new quadrature all digital phased-locked loop (QADPLL) method is presented. The method minimizes the effect of amplitude imbalance, noise, phase shift, and signal offsets. It also can solve waveform distortion and time-lag problems. Moreover, this paper proposes an interpolation technique to improve the accuracy of position information. By deriving the high-order signal from a sinusoidal signal, a high-resolution position can be obtained from a low-resolution encoder. Simulation and experiment on a linear motor were conducted. The results verify the performance of the proposed methods.

IEEE Transactions on Signal Processing, 2009

For a transfer function ( ) of order , Kalman-Yakubovich-Popov (KYP) lemma characterizes a genera... more For a transfer function ( ) of order , Kalman-Yakubovich-Popov (KYP) lemma characterizes a general intractable semi-infinite programming (SIP) condition by a tractable semidefinite programming (SDP) for the entire frequency range. Some recent results generalize this lemma for a certain frequency interval. All these SDP characterizations are given at the expense of the introduced Lyapunov matrix variable of dimension . Consequently, formulation and design of high dimensional problem is challenging. Moreover, existing SDP characterizations for frequency-selective SIP (FS-SIP) do not allow to formulate synthesis problems as SDPs. In this paper, we propose a completely new SDP characterization of general FS-SIP involving SDPs of moderate size and free from Lyapunov variables. Furthermore, a systematic IIR filter and filter bank design is developed in a similar vein, with several simulations provided to validate the effectiveness of our SDP formulation. Index Terms-Filter and filter bank, Kalman-Yakubovich-Popov (KYP) lemma, semidefinite programming.

Spectrochimica Acta Part A-molecular and Biomolecular Spectroscopy, 2011

Polypyrrole (PPy) and poly(pyrrole-2,6-dimethyl-␤-cyclodextrin) [P(Py-␤-DMCD)] films prepared by ... more Polypyrrole (PPy) and poly(pyrrole-2,6-dimethyl-␤-cyclodextrin) [P(Py-␤-DMCD)] films prepared by potential cycling in aqueous acidic solutions on indium tin oxide (ITO)-coated glass and gold electrodes were studied by in situ UV-vis and Raman spectroscopy. Characteristic UV-vis and Raman bands were identified and their dependencies on the electrode potential have been discussed. Spectroelectrochemical results reveal differences both in the position of the spectral bands and their potential dependence for PPy and P(Py-␤-DMCD) films indicating interactions between polymer chains and CDs during electropolymerization process. The films were also characterized by cyclic voltammetry and FT-IR spectroscopy.

IEEE Transactions on Automatic Control, 2008

This paper proposes a novel frequency-selective Kalman-Yakubovich-Popov (FS-KYP) lemma for analys... more This paper proposes a novel frequency-selective Kalman-Yakubovich-Popov (FS-KYP) lemma for analysis of single-input single-output (SISO) continuous systems. In contrast to existing approaches, the proposed method only uses a minimal number of variables due to the absence of Lyapunov variables in semidefinite programming (SDP) formulation. The SDP formulation is extended to polytopic uncertain systems also without any additional variable and yields an efficient method for computation of the H ∞ gain for polytopic systems. The viability of the proposed method are demonstrated through several numerical examples.

Journal of Oral Rehabilitation, 2009

Summary Previous in vitro permeability and scanning electron microscopic studies have demonstrat... more Summary Previous in vitro permeability and scanning electron microscopic studies have demonstrated the effectiveness of a new natural based-resin varnish (Shellac F) in dentin permeability reduction and effective tubule occlusion. The aim of this randomized double-blind, controlled, split mouth 8-week clinical study was to evaluate the efficiency of Shellac F in reducing dentin hypersensitivity. Ten patients (eight women: two men) completed the study. A quadrant including at least one hypersensitive tooth (Visual Analog Scale – VAS = 15 mm to air blast) was considered as a unit and randomly assigned to different groups for Shellac F, Duraphat®, Isodan®. Three applications of each material were completed at days 0, 1 and 7. The subjective response was assessed by tactile and thermal/evaporative methods. Data were collected at baseline and after the first application, at 15 min, 1, 7, 14, 28 and 56 days. Analysis was based on Kruskall–Wallis test, Wilcoxon signed rank test and the method of the least square means. No statistically significant difference was noted between Shellac F and the two control materials. Regardless of the type of stimulus, Shellac F showed significant immediate and progressive continuous efficiency in reducing dentin hypersensitivity until 56 days (VAS of 14 ± 12 mm and provoking pain force of 89 ± 12 cN, respectively, compared with 38 ± 23 mm and 41 ± 10 cN at baseline), corresponding to a highly effective relief dentin hypersensitivity. Shellac F reduced dentin hypersensitivity and did not differ from the two desensitizing agents used as controls.

IEEE Transactions on Antennas and Propagation, 2007

Abstract Bounding the sidelobe and mainlobe levels of an array with complex weights is attractive... more Abstract Bounding the sidelobe and mainlobe levels of an array with complex weights is attractive in that it allows direct control of the radiation pattern. In this paper we propose an efficient beamforming technique for synthesizing the patterns of large arrays with bound constraints on the sidelobe and mainlobe levels. It is shown that the pattern synthesis problem can be posed as a convex semi-infinite program (SIP) which is then turned into a semi-definite program (SDP) via a novel linear matrix inequality (LMI) characterization of ...

IEEE Transactions on Signal Processing, 2009

For a transfer function ( ) of order , Kalman-Yakubovich-Popov (KYP) lemma characterizes a genera... more For a transfer function ( ) of order , Kalman-Yakubovich-Popov (KYP) lemma characterizes a general intractable semi-infinite programming (SIP) condition by a tractable semidefinite programming (SDP) for the entire frequency range. Some recent results generalize this lemma for a certain frequency interval. All these SDP characterizations are given at the expense of the introduced Lyapunov matrix variable of dimension . Consequently, formulation and design of high dimensional problem is challenging. Moreover, existing SDP characterizations for frequency-selective SIP (FS-SIP) do not allow to formulate synthesis problems as SDPs. In this paper, we propose a completely new SDP characterization of general FS-SIP involving SDPs of moderate size and free from Lyapunov variables. Furthermore, a systematic IIR filter and filter bank design is developed in a similar vein, with several simulations provided to validate the effectiveness of our SDP formulation. Index Terms-Filter and filter bank, Kalman-Yakubovich-Popov (KYP) lemma, semidefinite programming.

Position sensors using magnetic effects, such as magnetic encoders (MEs), are increasingly used i... more Position sensors using magnetic effects, such as magnetic encoders (MEs), are increasingly used in many industrial applications. These include motor control, electro-mechanical braking systems, and precision measurement systems. The magnetic encoders generally provide a pair of sinusoidal signals dephasing 90deg to each other. Unfortunately, the signals obtained are not ideal, in that they always exist with the DC offsets, different amplitudes, phase-shifts and waveform distortions. These are further compromised by noise and changes in operating conditions. This paper proposes an approach for real-time correcting and tracking ME signals based on the Advanced Adaptive Digital Phase-Locked Loop (AADPLL) technique. AADPLL provides a robust filtering characteristic as well as a wideband of input frequency. It can effectively filter noise and improve the accuracy of ME signals. AADPLL also takes advantage of tracking high-speed input signals without time-lag, unlike traditional filters. A quadrature pulse interpolator is introduced to obtain high resolution. This interpolator uses look-up tables (LUTs) to store pulse-out values in one period of MEs signals. These LUTs are reduced in size for easy implementation in Digital Signal Processor (DSP) hardware platforms. Experimental results demonstrate the effectiveness of the proposed method.

Confocal laser-scanning microscopes (CLMs) are such versatile platforms that they are routinely u... more Confocal laser-scanning microscopes (CLMs) are such versatile platforms that they are routinely used now in a broad range of disciplines for multi-colour three-dimensional imaging of sub-micron features. In addition to imaging, many CLMs have built-in software for directing the laser beams to purposely photobleach regions of a specimen, such as for FRAP experiments, or for optically writing information into photosensitive materials. The regions are usually regularly shaped, such as rectangles or circles; or if they are irregularly shaped then they are relatively simple, hand-drawn regions. Here, we demonstrate the photobleaching of arbitrarily complex patterns, including full-colour RGB photos, into polymer nanostructured materials using a commercially-available Zeiss LSM510 confocal microscope. The three-dye material is specially designed to prevent resonant energy transfer between the different dyes, allowing us to photobleach in three colour channels without crosstalk between them [1]. A Visual Basic for Applications (VBA) macro was written that accepts as input any binary, grayscale, or colour image and directs the LSM510 mirrors to position the focused beam from the LSM510 laser(s) to corresponding coordinates in the specimen. Naturally, the photobleached patterns or images can be viewed immediately upon their completion by simply acquiring normal confocal fluorescence images of the same region. We applied the technique to the writing of security information, including a binary fingerprint and signature, a grayscale photo, and full-colour RGB photos . . The three colour channels of an RGB image were independently photobleached into three spatially and spectrally distinct dyes in our polymer nanocomposite material, and subsequently imaged using laser lines a) 458nm, b) 364nm, and c) 633nm. d) Colour composite reproduces the original photo (scalebar 50µm). e) At higher magnification the composite nature of the material is apparent, making it difficult to counterfeit (scalebar 10µm). [1] H. H. Pham, I Gourevich, J.E.N. Jonkman, and E. Kumacheva, "Polymer nanostructured material for the recording of biometric features," J. Mater. Chem.

Abstract: MEs (magnetic encoders) are widely used in industrial control systems because of its si... more Abstract: MEs (magnetic encoders) are widely used in industrial control systems because of its significant advantages, such as high resolution, high speed, operation in harsh environments, and low cost. This paper describes a method to extract the position ...

Ultramicroscopy, 2008

Keywords: Scanning electron microscope Electron energy spectrometers Auger electron spectroscopy ... more Keywords: Scanning electron microscope Electron energy spectrometers Auger electron spectroscopy a b s t r a c t This paper presents a toroidal electron energy spectrometer designed to capture electrons in the full 2p azimuthal angular direction while at the same time having second-order focusing optics. Simulation results based upon direct ray tracing predict that the relative energy resolution of the spectrometer will be 0.146% and 0.0188% at input angular spreads of 761 and 731, respectively, comparable to the theoretically best resolution of the cylindrical mirror analyzer (CMA), and an order of magnitude better than existing toroidal spectrometers. Also predicted for the spectrometer is a parallel energy acquisition mode of operation, where the energy bandwidth is expected to be 4710% (20% total) of the pass energy. The spectrometer is designed to allow for retardation of the pass energy without the need to incorporate auxiliary lenses.

Chemistry of Materials, 2006

A novel approach to the synthesis of polyaniline−montmorillonite (PANI−MMT) nanocomposites by in ... more A novel approach to the synthesis of polyaniline−montmorillonite (PANI−MMT) nanocomposites by in situ electropolymerization of anilinium−montmorillonite in 0.3 M sulfuric acid on a gold substrate is reported. The nanocomposites were characterized by elemental analysis, cyclic ...

Journal of The Electrochemical Society, 2007

Corrosion protection performance of a completely soluble polyaniline-dodecylbenzenesulfonic acid ... more Corrosion protection performance of a completely soluble polyaniline-dodecylbenzenesulfonic acid salt (PANI-DBSA) on C45 steel has been studied with electrochemical impedance and potentiodynamic measurements. Chloroform is the most suitable solvent to process the pristine PANI-DBSA because of negligible interaction of the solvent with the polyaniline (PANI) backbone. An anodic shift in the corrosion potential (E = ~70 mV), a decrease in the corrosion current and a significant increase in the charge transfer resistance indicate a significant anti-corrosion performance of the soluble PANI deposited on the protected steel surface.

Ultramicroscopy, 2009

This article describes preliminary experiments to test the concept of scanning electron microscop... more This article describes preliminary experiments to test the concept of scanning electron microscope (SEM) using a round magnetic beam separator to perform energy spectroscopy. Two experiments with an add-on attachment inside a conventional SEM were performed, one to estimate the sector image aberrations and the other to capture an energy spectrum of scattered electrons. The experiments show that the sector image aberrations lie well below 2 nm and that it is possible to capture the energy spectrum of secondary electrons.

Dental Materials, 2008

Natural resin-based desensitizing agent Cytotoxicity Dentin hydraulic conductance a b s t r a c t

In this paper, we present a new generating method for the velocity profile to increase productivi... more In this paper, we present a new generating method for the velocity profile to increase productivity and stability for industrial hydraulic systems. Most industrial hydraulic systems repeat a single motion plan that consists of several velocity profiles to produce products. It has deceleration and acceleration terms between each velocity profiles. These terms cause delay to finish a one-motion plan. Useless delay time in the industrial field will be directly connected to low-productivity. Motion planning using high-speed can cause noise, vibration and safety problems. Therefore, we propose a new method to generate the velocity profile with non-delay time. The new method can connect the velocity profiles in one motion plan after eliminating useless acceleration or deceleration terms. Eliminating these terms can reduce motion moving time and physical shock with inertia. The motion moving time is related with productivity and the shock is related with safety probability. Especially, the shock that is even small can generate another big shock and effect to human. Thus, the industrial systems consider these two issues very carefully. The proposed velocity profile can increase performance from these angles. A pressure machine based on a hydraulic system will operate with the new velocity profile using the proposed implementation method and be proved by two result of motion plan.