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Phase shift full bridge DC/DC converter gains growing attention as the rapid development of electric vehicles, battery energy storage systems and microgrids. Comparing to conventional power converters, modern power converters are requested to meet dynamic load demands, high power conversion, efficiency and, simultaneously, to achieve a wide range voltage output. The co-design of modern converter with wide range voltage output capability and voltage controller for the converter is technically challenging and still vacant in existing literatures. This paper provides a practical design demonstration to bridge the gap. After validations using IsSpice and MATLAB, a 750 watts phase shift full bridge DC/DC converter is implemented and a digital voltage controller is realized on a field-programmable gate array (FPGA) chip alongside. This commercially ready prototype can provide a wide voltage output ranging from 0 to 50 V with excellent transient response, rendering 1% overshoot, less than 4.2 ms rise time and a maximum of 93.4% conversion efficiency.

This paper presents an advanced nonlinear control design for the servo layer in typical EP printers, which complements our previous work focusing on control of supervisory layer. A control centric modeling and reduction approach for the main motor in the servo layer (i.e., a PWM three-phase permanent magnet brushless dc motor) is conducted. The set of differential equations and the corresponding state variable model are established for each operation interval. The subsystem model from each interval is combined to form a comprehensive model. Model reduction is performed to reduce the complexity but preserve crucial dynamics of the model. Finally, a robust adaptive fuzzy controller is designed and its feasibility and effectiveness is verified on the comprehensive model.

This paper presents a novel visual servo tracking method for a wheeled mobile robot based on target features and depth of scenery. The robot is equipped with an RGBD sensor to provide both color and depth information of the scene. The proposed method comprises two phases. The first phase utilizes feature matching to ensure that the target moves into the field of vision such that the robot may enter the second phase. The second phase implements visual servo aiming at object tacking accuracy. The depth information is employed in the proposed approach, which reduces the computational complexity required as in conventional approaches based on feature extraction. In addition, the second phase has built-in mechanism for detecting and exiting local minimum when the robot speed converges. The method is also capable of sequentially tracking multiple objects. Experimental results demonstrate the feasibility and effectiveness of the proposed two-phase method.

This paper proposes a new method for vehicle license plate recognition on the basis of Extreme Learning Machine. ELM is a new category of neural networks which possesses compelling characteristics essential for license plate recognition, such as low computational complexity, fast training, and good generalization (as opposed to traditional neural networks). The proposed method studies incorporation of three ELMs (i.e., basic ELM, incremental ELM, and enhanced incremental ELM) into a typical pipeline for automatic license plate recognition. In the preliminary study (under Windows PC with MATLAB), the success rate of recognition is 87.5% with execution time of 0.3s. A comparative study also shows that the proposed method outperforms conventional approaches (template matching, edge statistics, RBF, and SVM) in terms of accuracy and speed.

In most scenes, images captured by digital devices are greatly influenced by environmental illuminant. Because there are different illuminants in the scene, the color from objects even change and be similar to the illuminant color. It results that the objects cannot reflect the true color and this phenomenon is called color cast. In this thesis, by utilizing basic color science and experimental results, a dataset of color sample under different illuminants is constructed. Using the existing method of illuminant estimation to calculate plural color temperatures of the input image, called the initial estimated color temperature. Furthermore, utilizing clustering algorithm to execute illuminant classification to initial plural color temperatures, and calculating the multi-determined color temperatures of image. This study takes the lead in utilizing the spatial fuzzy c-means (SFCM) clustering algorithm to execute the illuminant classification. In traditional white balance, the correction configuration focuses on single illuminant scene, which is fixed correction value, whereas there are multi-illuminant scenes mostly in real scene, the performance of white balance is not good. In this thesis, the adopted SFCM algorithm revises the main illuminant individually and solves the color cast successfully.

The dependence of the L10 ordering, magnetic properties and microstructure on film thickness of the Fe51Pd49 nanoparticle films deposited at 800 °C was investigated. The L10 ordered phase and hard magnetic properties were found for the samples with the thickness less than 30 nm. As the thickness was increased to 45 nm and thicker, the samples exhibited the A1 disordered phase and soft magnetic properties. The lack of heterogeneous nucleation sites is responsible for the A1 disordered phase in the thicker FePd samples, which was confirmed by the results of microstructural and crystallographic analyses. The long term re-annealing at a lower temperature (600 °C for 8 h) can induce the L10 ordering of the large size FePd nanoparticles originally composed of the A1 phase, which also supports the statement that the heterogeneous nucleation sites play an important role on L10 ordering of the FePd films.

Objective The detailed characteristics and prognosis of nonsurgery-related unilateral vocal fold paralysis (NSUVFP) are currently unclear. This study evaluated the extent of laryngeal nerve lesions and the individual characteristics for patients with NSUVFP. Study Design Retrospective, case series. Methods Patients with unilateral vocal fold paralysis (UVFP) were evaluated using videolaryngostroboscopy and quantitative laryngeal electromyography. The side of nerve lesions, involvement of the external branch of the superior laryngeal nerve (eSLN), and complete vocal fold motion recovery were evaluated after ≥ 6 month follow-up. Results A total of 207 UVFP patients were recruited, including 153 surgery-related UVFP and 54 NSUVFP patients. Thirty-four (63%) and 20 (37%) NSUVFP patients were further assigned to idiopathic and nonsurgery-related–nonidiopathic (NSNI) groups, respectively. In the idiopathic group, eSLN lesions occurred in all six (100%) patients with right-side paralysis, but in only six of 28 (21%) patients with left-side paralysis (P 0.05). Conclusion Idiopathic and NSNI UVFP have different clinical presentations defined by laryngeal electromyography. NSNI UVFP had more severe denervation changes compared with idiopathic UVFP. These results may support two pathogenic mechanisms for idiopathic UVFP: 1) neuropathy specifically involving left recurrent laryngeal nerve (RLN), and 2) neuropathy affecting nerves proximal to the RLN. Level of Evidence 4. Laryngoscope, 2016

Effect of rapid thermal annealing (RTA) on the crystallographic orientation and magnetic properties in single-layered FePt and FePd films has been characterized. A huge biaxial tensile stress of ∼2 GPa was induced in the L 1 0 -FePt thin films after an RTA of 800 °C, which resulted in a significant orientation transition from (111) to (001) texture. On the other hand, in case of the FePd films, only a small in-plane tensile stress (∼0.5 GPa) was accumulated, which caused that the orientation barely changed from a (111) texture to isotropic state. These results suggest that the high ordering temperature and low tensile stress were the likely reasons why RTA has no effect on texture formation of the FePd films.

This paper presents a control centric modeling and analysis approach along with a nonlinear control design for a class of switching power converters. A comprehensive model combining the respective state variable models of the interval subsystems is established. Comparison with PSpice simulation justifies the credibility of the model. Based on this model, internal/BIBO stability can be studied for each interval subsystem. Moreover, controllability and observability can also be analyzed to help determining subsequent control configuration. The established model is further investigated for advanced control design, i.e., robust adaptive fuzzy control.

This paper presents FPGA hardware implementation of a type-2 TSK fuzzy neural system for illuminant estimation, i.e., color temperature, based only on the contents of the image along with performing white balance for the image. The implementation is conducted on an FPGA development platform with Xilinx artix-7 XC7A200 chip. Experiments and comparative study are performed. It is shown that the proposed FPGA design can operate in real-time. For generic 1080p image, it can reach the frame rate of 51.598 frames per second at maximal operation frequency for illuminant estimation and white balance. This resolves the slow execution speed of the proposed algorithm on software platform. The results demonstrate major advancements of the proposed approach over previous and existing methods.

The LiMn 2 O 4 thin film electrode modified by hyperbranched oligomer has been prepared and studied. The hyperbranched oligomer can be self-polymerized for reducing the thermal-runaway hazard by the internal short protection mechanism in lithium ion batteries. The influence of the oligomer coating on cathode has been studied with the binder/carbon-free thin film. In the various C-rate charged-discharged tests, there are no significant differences between the cells with/without the oligomer coating. In this research, the hyperbranched oligomer additive acts as a protection to improve the thermal stability of LiMn 2 O 4 . Therefore, the property of thermal stability and its function in safety may benefit the future development of electric vehicles.

This paper presents an output feedback LPV gain-scheduling control design for a class of PSPWM full-bridge power converters. The design starts with an averaged model of the converter with adequate complexity. One main contribution of this work is to demonstrate how to reformulate the averaged model into an LPV one. A gain-scheduling controller can then be synthesized taking advantage of the design framework of LPV-based H-infinity control. Forming the open-loop LPV system and synthesizing the controller, a repetitive control module and an anti-windup scheme are incorporated into the design. The proposed design is further justified with a numerical simulation.

A low temperature direct current pulsed plasma technique has been applied on laminated composite lithium manganese oxide powder cathodes containing the polyvinylidene fluoride binder and carbon black additive. The plasma treatment results in mass transport on the surface of the particles due to an ion bombardment induced atomic peening process. A thin layer is induced on the particle surface. This plasma induced surface layer acts as a protection coating, which improves the cycling and structural stability of the treated cathodes even at high discharge rates, high temperature (60 °C) and low cut-off potential (2.0 V). The X-ray photo electron spectra of Mn3p for the treated and untreated samples after high temperature (60 °C) cycling reveal binding energy shift on the surface of the untreated sample, whereas a stable molecular structure is preserved in the pulsed plasma treated cathode.

This book chapter reviews and summarizes the recent progress in the design of spatial‐ based robust adaptive repetitive and iterative learning control. In particular, the collection of methods aims at rotary systems that are subject to spatially periodic uncertainties and based on nonlinear control paradigm, e.g., adaptive feedback linearization and adaptive backstepping. We will elaborate on the design procedure (applicable to generic nth‐ order systems) of each method and the corresponding stability and convergence theorems.

A study of oxygen dc pulsed plasma irradiation treatment has been carried out on LiMn2O4 powder cathodes to enhance the electrochemical performances of lithium ion batteries. The samples have been characterized by X-ray diffraction, scanning electron microscope, energy dispersion spectroscope and electrochemical measurements. It is found that after undergoing the plasma treatments, the sharp facets of LiMn2O4 particles become smooth due to plasma ion bombardment. The treated electrodes are partially covered by layers with high atomic percent of element F, indicating the reflow of binders. The electrochemical measurements are carried out under harsh conditions, including deep-discharge at low cut-off potential of 2 V and cycling at elevated temperature of 60 °C. The results reveal that moderate oxygen dc pulsed plasma treatment can improve the cycling stability of LiMn2O4 powder electrodes in the above mentioned conditions. The enhanced electrochemical performances are attributed to the dense protection layers on electrode surface, which reduce the capacity fading due to the Mn+2 ions dissolution.

We have investigated the effect of polymer molecular weight (MW) on the morphology and efficiency of bulk heterojunction (BHJ) solar cells comprised of poly[(4,4′-bis(2-ethylhexyl)dithieno[3,2-b:2′,3′-d]silole)-2,6-diyl- alt -(5,5′-thienyl-4,4′-dihexyl-2,2′-bithiazole)-2,6-diyl] (Si-PCPDTTBT) and [6,6]-phenyl C 61 butyric acid methyl ester (PCBM). Striking morphological changes are observed in BHJ films upon the change of the polymer MW. Atomic force microscopy and transmission electron microscopy studies suggest that high MW polymer generated high degree of phase separation, leading to formation of an interpenetrating network for carrier transport. The X-ray diffraction investigation indicated that increased π–π stacking in Si-PCPDTTBT with increasing polymer MWs results in an increase in hole mobility of Si-PCPDTTBT and electron mobility of PCBM as well as the red shift absorption spectrum in BHJ films. The solar cells based on PCBM with high-MW Si-PCPDTTBT deliver power conversion efficiencies of 3.33%.

Nano-crystalline TiO2 thin films have been fabricated by direct-current sputter deposition. The crystalline TiO2 films are deposited without thermal annealing. The crystal structures, morphologies and electrochemical performances of the fabricated TiO2 electrodes toward lithium have been systematically investigated. By controlling the total deposition pressures and O2 partial pressures, anatase-phase TiO2 electrodes with granular grains and spindle-like grains can be fabricated. The TiO2 electrode exhibits with granular morphology shows short discharge plateau and lower capacity, whereas the spindle-like TiO2 electrode shows a long flat plateau at ~1.7 V with a reversible capacity around 400 mAhg-1 (3.0-0.0 V v.s. Li/Li+ at 0.2 C). The results have demonstrated that the nano-structured spindle-like TiO2 can be used as safe and high capacity electrodes for lithium ion thin film batteries.

In this study, the bilayers of the lithium phosphorus oxynitride (LiPON) film on LiCoO2 cathode have been deposited using radio frequency (RF) magnetron sputtering with in-situ substrate bias, followed by post-anneal. For the purpose of decreasing charge transfer resistances, the solid-state interfaces between the LiPON solid-state electrolyte and the LiCoO2 cathode have been modified. By controlling different in-situ substrate bias voltages and anneal times, the properties of both LiPON electrolyte thin films and LiPON/LiCoO2 interface have been altered, as characterized by scanning electron microscopy, X-ray diffraction, impedance spectroscopy, and electron spectroscopy for chemical analysis. It is found that the electrolyte/cathode interfaces are modified in terms of contact structures and interface resistances. After anneal of 30 min. at 200 oC in nitrogen environment, the seams and voids at the interface are eliminated. The charge transfer resistance at the interface has been greatly reduced. As a result, one order of reduction in both interfacial resistance and total cell resistance has been achieved.

This article proposes a systematic approach to conduct system level optimal parameter design for electrophotographic systems. A conventional monochrome laser printer serves as the platform for verification of the proposed optimal design approach. Besides performance, we incorporate two other practical indices, i.e., cost and energy consumption, into design objectives and formulate a multi-objective optimization problem. Fuzzy logics are employed to provide the nonlinear or linguistic mapping between the decision variables and the design objectives. For comparison, the problem is solved using both single-objective and multi-objective optimization algorithms. Note that the proposed approach is also applicable to other complex systems.

This paper presents a two-dimensional Wiener model in spatial domain for a class of laser electrophotographic printers, and embeds it into a framework of model-based digital halftoning. The Wiener model comprises an FIR filter followed by a nonlinear static mapping. The nonlinear static mapping is synthesized using a fuzzy system to maximize its capability to approximate nonlinearity of high degree. A set of systematic steps for parametric optimization and evaluation of the Wiener printer model is proposed. Due to the parameters being determined off-line, the Wiener model demands much less computation and memory when executing on-line. Another advantage is that the structure complexity of the Wiener model is adjustable via altering the order of the FIR filter and the number of membership functions in the fuzzy system. Experimental results as well as a comparative study show that the proposed model-based halftoning approach is superior (in terms of image quality) to conventional ones and comparable to the one with a comprehensive printer model.

All solid-state thin film batteries (TFBs) consisting of amorphous lithium phosphorus oxynitride (LiPON) solid electrolyte, crystalline LiMn2O4 cathode and crystalline SnO2 anode have been fabricated and characterized. All of the thin films are prepared by RF magnetron sputtering. By fabricating under different pressures and applying low temperature post-annealing (200 °C), the performances of the LiPON electrolytes and SnO2/LiPON/LiMn2O4 TFBs are improved. Suitable working pressures results in pinhole-free amorphous LiPON films with smooth surface and dense micro-structure. The TFBs post-annealed at 200 °C show smooth interface contacts between electrode and electrolyte thin films. The low pressure deposited and post-annealed TFBs exhibits lower impedance and higher cycling stability. Initial open-circuit voltage of 3.8 V and initial capacity of 12 μAh/cm2 are obtained.

This paper proposes new insights and methodologies that complement existing techniques for characterizing and modeling halftone banding, an artifact of periodic light and dark bands across a printed image perpendicular to the print direction, for a class of electrophotographic (EP) systems, which is commercially known as laser printers. For characterizing banding based on transmission error measurement, specific frequency-domain signal processing, i.e., order analysis, was applied to help identify possible disturbance sources with certain gear components. For characterizing banding based on absorptance measurement on printed images, it was pointed out that a good metric should incorporate appropriate nonlinear operator that characterizes the human visual system. This proposition was supported by simulation results obtained from a three-stage visual model. For modeling banding, a more comprehensive EP model was developed to include transmission parameters such as laser scanning frequency, gear dimension, and angular velocity. Simulation study was performed on the simplified version of the derived model, which demonstrated close correlation between halftone banding and transmission quality. This motivates control of the motor/gear transmission system for reducing banding artifact in EP processes.

A new control configuration for laser printing process was proposed, which constructs a feedback controller for regulation of the motor/gear transmission subsystem using direct velocity measurement from the imaging component. Causal connection between banding artifact and transmission errors has been demonstrated previously. Two controller design approaches were suggested for reducing banding artifact. The proposed designs were based on the internal model principle and H ∞ robust control theories, both have two degree of freedom control structure. The controllers were implemented on a monochrome laser printer, for which latent images are formed on a cylindrical photoconductor drum. Experimental results showed significant reduction in the measured velocity error for the photoconductor drum as well as noticeable banding reduction on the printed images.

In this paper, we propose a new design of spatial-based repetitive control for a class of rotary motion systems operating at variable speeds. The open-loop system in spatial domain is obtained by reformulating a nonlinear time-invariant system with respect to angular displacement. A two-degree-of-freedom control structure (comprising two control modules) is then proposed to robustly stabilize the open-loop system and improve the tracking performance. The first control module applies adaptive feedback linearization with projected parametric update and concentrates on robust stabilization of the closed-loop system. The second control module introduces a spatial-based repetitive controller cascaded with a loop-shaping filter, which not only further reduces the tracking error, but also improves parametric adaptation. The overall control system is robust to model uncertainties of the system and capable of rejecting position-dependent disturbances under varying process speeds. Stability proof for the overall system is given. A design example with simulation is provided to demonstrate the applicability of the proposed design. Copyright © 2008 John Wiley & Sons, Ltd.

In this paper, we propose a new design of spatial-based repetitive control for rotational motion systems required to operate at varying speeds and subject to spatially periodic disturbances. The system has known model structure with uncertain parameters. To synthesize a repetitive controller in spatial domain, a linear time-invariant system is reformulated with respect to a spatial coordinate (e.g., angular displacement), which results in a nonlinear system. A nonlinear state observer is then established for the system. Adaptive feedback linearization is applied to the system with the state observer so as to minimize the tacking error. Moreover, a spatial-based repetitive controller is added and operates in parallel with the adaptively feedback linearized system, which not only further reduces the tracking error but also improves parameter adaptation. The overall output feedback adaptive feedback linearization repetitive control system is robust to structured parameter uncertainty, capable of rejecting spatially periodic disturbances under varying process speeds, and can be proved to be stable and produce bounded tracking error. Finally, feasibility and effectiveness of the proposed scheme is verified by simulation.

Statins have been reported to induce tendinopathy and even tendon rupture. The present study was designed to investigate the potential molecular mechanism underlying the adverse effect of simvastatin on tendon cells. An in vitro tendon healing model was performed using tendon cells isolated from rat Achilles tendons. The viability of tendon cells and cell cycle progression were examined by the MTT assay and flow cytometric analysis, respectively. Immunofluorescent staining for Ki-67 was used to assess the proliferation activity of tendon cells. Western blot analysis and coimmunoprecipitation was used to determine the protein expression of cell cycle-related proteins. To investigate the potential mechanism underlying the effect of statins on tendon cells, mevalonate, farnesyl pyrophosphate (FPP), or geranylgeranyl pyrophosphate (GGPP) was added to simvastatin-treated tendon cells. Simvastatin inhibited the in vitro tendon healing model and tendon cell proliferation in a dose-dependent manner. Immunofluorescent staining demonstrated reduced ki-67 expression in simvastatin-treated tendon cells. Furthermore, simvastatin induced cell cycle arrest at the G1 phase. The expression levels of cdk1, cdk2, cyclin A, and cyclin E were downregulated by simvastatin in a dose-dependent manner. The inhibitory effect of simvastatin was proved to mediate the reduction of mevalonate, and the addition of exogenous GGPP completely prevented the inhibitory effect of simvastatin on tendon cells. The present study demonstrated, for the first time, the molecular mechanism underlying simvastatin-induced tendinopathy or tendon rupture. GGPP was shown to prevent the adverse effect of simvastatin in tendon cells without interfering with its cholesterol-reducing efficacy.

This paper presents a fuzzy neural approach to establish a model for estimation of unknown illuminant, i.e., color temperature, of a digitally captured image based only on the contents of the image. The estimated temperature may be further utilized to perform white balance for the image. The results demonstrate strong improvement of the proposed approach over a previous work. The comparative study also suggests that the proposed method is more adaptable to generic images and varieties of illuminants and scenes than other existing methods do. Hardware implementation of the algorithm based on FPGA is also presented in this work.

An improved controller design and implementation technique for electrophotographic process (EP) was proposed. The new controller aimed at solving two additional issues for generic EP platforms, i.e., reducing position-dependent or spatially periodic disturbances, and reducing system sensitivity to manufacturing variations in EP engine and consumables. To handle spatially periodic disturbances, a digital repetitive controller was synthesized and implemented using a spatial-sampling scheme. The result is a control algorithm that takes into account the variation of the nominal operating speed. Second, system variations due to manufacturing variations as well as consumable changes were incorporated into the design of a two degree of freedom robust controller. The controller is optimal in the sense that it minimizes the size of the sensitivity function from a set of disturbance signals to a set of measurable signals critical to print quality, e.g., photoconductor drum velocity or scan line spacing. A suitable trade-off between system performance and robustness to system modeling uncertainties was considered in the synthesis and optimization formulation. The effectiveness of the proposed controller design and implementation technique was numerically and experimentally verified. Significant reduction in visible banding was seen in printed images and was verified by reflectance measurement.