171 research outputs found
Islamic da\u27wa in Korea: a study of Koreans\u27 religious conversion to Islam taking place in the twenty-first century
https://place.asburyseminary.edu/ecommonsatsdissertations/1719/thumbnail.jp
Adaptive Control of a Vibratory Angle Measuring Gyroscope
This paper presents an adaptive control algorithm for realizing a vibratory angle measuring gyroscope so that rotation angle can be directly measured without integration of angular rate, thus eliminating the accumulation of numerical integration errors. The proposed control algorithm uses a trajectory following approach and the reference trajectory is generated by an ideal angle measuring gyroscope driven by the estimate of angular rate and the auxiliary sinusoidal input so that the persistent excitation condition is satisfied. The developed control algorithm can compensate for all types of fabrication imperfections such as coupled damping and stiffness, and mismatched stiffness and un-equal damping term in an on-line fashion. The simulation results show the feasibility and effectiveness of the developed control algorithm that is capable of directly measuring rotation angle without the integration of angular rate
Phenotypic assay for cytotoxicity assessment of Balamuthia mandrillaris against human neurospheroids
IntroductionThe phenotypic screening of drugs against Balamuthia mandrillaris, a neuropathogenic amoeba, involves two simultaneous phases: an initial step to test amoebicidal activity followed by an assay for cytotoxicity to host cells. The emergence of three-dimensional (3D) cell cultures has provided a more physiologically relevant model than traditional 2D cell culture for studying the pathogenicity of B. mandrillaris. However, the measurement of ATP, a critical indicator of cell viability, is complicated by the overgrowth of B. mandrillaris in coculture with host cells during drug screening, making it challenging to differentiate between amoebicidal activity and drug toxicity to human cells.MethodsTo address this limitation, we introduce a novel assay that utilizes three-dimensional hanging spheroid plates (3DHSPs) to evaluate both activities simultaneously on a single platform.Results and discussionOur study showed that the incubation of neurospheroids with clinically isolated B. mandrillaris trophozoites resulted in a loss of neurospheroid integrity, while the ATP levels in the neurospheroids decreased over time, indicating decreased host cell viability. Conversely, ATP levels in isolated trophozoites increased, indicating active parasite metabolism. Our findings suggest that the 3DHSP-based assay can serve as an endpoint for the phenotypic screening of drugs against B. mandrillaris, providing a more efficient and accurate approach for evaluating both parasite cytotoxicity and viability
Nano-Floating Gate Memory Devices Composed of ZnO Thin-Film Transistors on Flexible Plastics
Nano-floating gate memory devices were fabricated on a flexible plastic substrate by a low-temperature fabrication process. The memory characteristics of ZnO-based thin-film transistors with Al nanoparticles embedded in the gate oxides were investigated in this study. Their electron mobility was found to be 0.18 cm2/V·s and their on/off ratio was in the range of 104–105. The threshold voltages of the programmed and erased states were negligibly changed up to 103 cycles. The flexibility, memory properties, and low-temperature fabrication of the nano-floating gate memory devices described herein suggest that they have potential applications for future flexible integrated electronics
Oscillation Control Algorithms for Resonant Sensors with Applications to Vibratory Gyroscopes
We present two oscillation control algorithms for resonant sensors such as vibratory gyroscopes. One control algorithm tracks the resonant frequency of the resonator and the other algorithm tunes it to the specified resonant frequency by altering the resonator dynamics. Both algorithms maintain the specified amplitude of oscillations. The stability of each of the control systems is analyzed using the averaging method, and quantitative guidelines are given for selecting the control gains needed to achieve stability. The effects of displacement measurement noise on the accuracy of tracking and estimation of the resonant frequency are also analyzed. The proposed control algorithms are applied to two important problems in a vibratory gyroscope. The first is the leading-following resonator problem in the drive axis of MEMS dual-mass vibratory gyroscope where there is no mechanical linkage between the two proof-masses and the second is the on-line modal frequency matching problem in a general vibratory gyroscope. Simulation results demonstrate that the proposed control algorithms are effective. They ensure the proof-masses to oscillate in an anti-phase manner with the same resonant frequency and oscillation amplitude in a dual-mass gyroscope, and two modal frequencies to match in a general vibratory gyroscope
Characterization of Curli A Production on Living Bacterial Surfaces by Scanning Probe Microscopy
AbstractCurli are adhesive surface fibers produced by many Enterobacteriaceae, such as Escherichia coli and Salmonella enterica. They are implicated in bacterial attachment and invasion to epithelial cells. In this study, atomic force microscopy was used to determine the effects of curli on topology and mechanical properties of live E. coli cells. Young's moduli of both curli-deficient and curli-overproducing mutants were significantly lower than that of their wild-type (WT) strain, while decay lengths of the former strains were higher than that of the latter strain. Surprisingly, topological images showed that, unlike the WT and curli-overproducing mutant, the curli-deficient mutant produced a large number of flagella-like fibers, which may explain why the strain had a lower Young's modulus than the WT. These results suggest that the mechanical properties of bacterial surfaces are greatly affected by the presence of filamentous structures such as curli and flagella
Angular Rate Estimation Using a Distributed Set of Accelerometers
A distributed set of accelerometers based on the minimum number of 12 accelerometers allows for computation of the magnitude of angular rate without using the integration operation. However, it is not easy to extract the magnitude of angular rate in the presence of the accelerometer noises, and even worse, it is difficult to determine the direction of a rotation because the angular rate is present in its quadratic form within the inertial measurement system equations. In this paper, an extended Kalman filter scheme to correctly estimate both the direction and magnitude of the angular rate through fusion of the angular acceleration and quadratic form of the angular rate is proposed. We also provide observability analysis for the general distributed accelerometers-based inertial measurement unit, and show that the angular rate can be correctly estimated by general nonlinear state estimators such as an extended Kalman filter, except under certain extreme conditions
Gain-Scheduled Complementary Filter Design for a MEMS Based Attitude and Heading Reference System
This paper describes a robust and simple algorithm for an attitude and heading reference system (AHRS) based on low-cost MEMS inertial and magnetic sensors. The proposed approach relies on a gain-scheduled complementary filter, augmented by an acceleration-based switching architecture to yield robust performance, even when the vehicle is subject to strong accelerations. Experimental results are provided for a road captive test during which the vehicle dynamics are in high-acceleration mode and the performance of the proposed filter is evaluated against the output from a conventional linear complementary filter
A Unified Compression Framework for Efficient Speech-Driven Talking-Face Generation
Virtual humans have gained considerable attention in numerous industries,
e.g., entertainment and e-commerce. As a core technology, synthesizing
photorealistic face frames from target speech and facial identity has been
actively studied with generative adversarial networks. Despite remarkable
results of modern talking-face generation models, they often entail high
computational burdens, which limit their efficient deployment. This study aims
to develop a lightweight model for speech-driven talking-face synthesis. We
build a compact generator by removing the residual blocks and reducing the
channel width from Wav2Lip, a popular talking-face generator. We also present a
knowledge distillation scheme to stably yet effectively train the
small-capacity generator without adversarial learning. We reduce the number of
parameters and MACs by 28 while retaining the performance of the
original model. Moreover, to alleviate a severe performance drop when
converting the whole generator to INT8 precision, we adopt a selective
quantization method that uses FP16 for the quantization-sensitive layers and
INT8 for the other layers. Using this mixed precision, we achieve up to a
19 speedup on edge GPUs without noticeably compromising the generation
quality.Comment: MLSys Workshop on On-Device Intelligence, 2023; Demo:
https://huggingface.co/spaces/nota-ai/compressed_wav2li
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