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We study optical transmission and reflection of graphene flakes suspended in liquid with external magnetic fields in both experiment and simulation. We show that graphene flakes controlled by magnetic fields can be used for display.
Networked control is now widely used in engineering systems. We have studied networked supervisory control of discrete event systems in several previous papers. In this paper, we investigate the issue of blocking in networked supervisory control. Due to randomness in communication delays, the issue of blocking is much more complex in networked systems. More conditions need to be satisfied in order...
Jump random noises exist widely in control systems. In this paper, the guaranteed cost control problem for uncertain systems perturbed by jump random noises is considered. By adopting Poisson process to describe jump random noises, this paper utilize martingale theory to design a controller, which can stabilize such stochastic systems and guarantee the specified cost function has an upper bound.
A power-on-reset (POR) circuit, which is an important block in mixed-signal integrated circuits, is used for the correct initialization of critical logic states in digital blocks of mixed-signal circuits. A POR circuit with precisely triggered threshold voltages is proposed. The circuit is designed in a 0.18 μm CMOS technology with a maximum 4 μA quiescent current. The output signal of the proposed...
A 27.6 MHz 297 μW relaxation oscillator is presented in this paper by using an 180-nm CMOS technology. The proposed oscillator employs an adjustable temperature compensation feedforward scheme, in which the charging current can be set steady by a four-bit digital trimming signal. We have demonstrated a frequency variation lower than 33.5 ppm/°C which could be close to 0 ppm/°C in theory if the precision...
We have designed, implemented and evaluated the novel single array acoustic localization system SAILoc. The SAILoc system can interact with the commercial-off-the-shelf (COTS) smart phone and it is easier to deploy than multiple sensors' system. We also propose a robust time delay estimation (TDE) algorithm which is based on frequency domain (FD-TDE) and has an advantage over generalized cross-correlation...
In this paper, we investigate the state estimation problem for timed discrete event systems with communication delays. The problem is how to estimate the current state under the uncertainties caused by partial observations and random observation delays. We construct an augmented automaton after analyzing the influence mechanism of random observation delays existed between the supervisor and the timed...
Melasma is a widely spread skin pigmentation disease and accurate assessments of the disease severity is crucial during its treatment. Recently, several computerized methods have been developed to overcome the shortcomings of the conventional clinical assessment method. As a key step in algorithm, image segmentation has extensive impacts on the accuracy of the assessment. Currently, the optimal hybrid...
Radio vortex carries orbit angular momentums which can multiplex many communications channels without additional frequency and time resources. In this paper, radio vortex antennas based on time modulated arrays are described. The generation and detection of radio vortex using time modulated arrays is analyzed. Comparing to methods based on conventional phased arrays, time modulated arrays use simple...
Windmill clutter mitigation using active meta-surfaces is introduced. The active meta-surfaces are smart metamaterial whose elements are loaded with tunable lumped elements. Using the Gaussian white noise as the control signal, the reflecting signal of the meta-surface would act like noise which makes the radar receiver very hard to detect. The concept and simple simulation are shown to show that...
MM (Machine Model) is an ESD test method used to test for robustness of the device against the ESD event which is induced by the running equipment in fabrication or testing procedure [1]. Due to zero resistance in the equivalent circuit, MM is difficult to simulate. In most cases, MM capability can be calculated from HBM (Human Body Model) result (MM ∼10∼20∗HBM) [2]. But in this study HBM can reach...
The large difference between TLP (Transmission Line Pulse) and HBM (Human Body Model) test results of a power NMOS have been analysed using experimental tests as well as physical FA (Failure Analysis). A phenomenological explanation has been provided to account for the negative (positive) voltage surge that occurs during HBM positive (negative) zap on drain due to inductance of the bonding wire. Finally,...
The underactuation of the standard quadrotor(four independent control input versus six output) is a serious problem which can be solved by tilting four rotors. The steering wheel is installed on each axle of the original quadrotor so that the quadrotor turns into an actuation system(eight-input versus six-output). In this paper, the dynamic model of the tilt-quadrotor is established, and the validity...
Identifying fall risk can prevent injuries in the elderly as well as reduce the related financial burden. A balance assessment, Timed Up and Go (TUG), has been widely applied to estimate fall risk. However, the standardized TUG usually excludes complex factors (e.g. slopes and obstacles) falling short of representing challenges in environments that many older adults navigate. Having information on...
Many researches have proved the significance of gait analysis since it strongly relates to several urgent health issues. As a response, we develop an unobtrusive sensor device, named SennoGait, which provides comprehensive gait information. In this paper, we verify the robustness and reliability of the device's hardware components, including a 16 pressure sensors array and a 9-axis inertial measurement...
A nonlinear model of a flapping-wing micro aerial vehicle (MAV) is built in which the load acceleration and equivalent moment are formulated linearly in the body frame. The aerodynamic force and moment are not considered directly because the mass and moment of inertia of the flapping-wing MAV are too tiny. The visual measurement system (VMS) is taken to measure the flight data such as the position...
In recent times, unmanned aerial vehicles (UAVs) are popular for several applications like rescue, surveillance, mapping, and so on. However, slow flight motion of Quadrotor UAVs is still a challenging issue to overcome. Although there exist several algorithms for the motion estimation and path planning of UAVs, most of them cannot be applied for fast flight in cluttered urban and forest environments...
This paper presents a novel hand-grip system for evaluation and rehabilitation of individuals with stroke. This system contains a pair of hand dynamometers, which are sensors for the input of grip force, and LabVIEW VI software to translate the grip force into meaningful data. The hand-grip system requires the subjects to move a small ball on a computer screen toward a target, using the hand grip...
Fuzzy discrete event systems are useful models for solving complex practical problems in biomedical and other fields. The theory of detectabilities in conventional crisp discrete event systems investigates state determination or estimation based on event observation. The theory is also important to fuzzy discrete event systems (e.g., disease diagnosis and treatment effectiveness evaluation). In this...
This paper presents a 40nm 9.5Mb embedded flash (eflash) macro which can be partitioned as code storage and data storage in a single macro with enhanced read margin by using two design schemes: temperature adaptive reference scheme and flexible array partitioned scheme. By way of these design features, code storage memory achieves 140MHz read speed at the junction temperature of 160°C and data storage...
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