The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
We demonstrate an attosecond synchronization of mode-locked lasers using optical heterodyne technique. The measured RMS timing fluctuation between two mode-locked Er:fiber lasers with same color was about 800 attosecond within 60 s.
Fano resonance of high order WGMs with Lorentzian peak lineshape is generated and utilized for bulk RI sensor in optofluidic microcapillary resonator. And both high sensitivity (∼800nm/RIU) and FoM (∼4100) can be achieved simultaneously.
This paper presents a digital repetitive control design on the basis of attracting law (AL). A control law, together with the disturbance compensation, can be derived by applying the AL which includes a measure of disturbance-rejection. Chattering is alleviated by a sign-function continuous approximation technique. To characterize the closed-loop performance, the steady-state error band, absolute...
Scattering performance of a reflectarray using a log-periodic dipole array (LPDA) element is demonstrated numerically and experimentally. The LPDA element and the reflectarray are designed using method of moments (MoM). The designed 10 × 1 reflectarray was fabricated using a 3D printing technology. A bistatic radar cross section (BRCS) of the designed reflectarray was measured in a radio anechoic...
To design antennas for underwater communication systems using LF band, the transmission factor of dipole antennas with the sheath immersed in seawater are investigated by numerical study. Comparison of antenna characteristics between dipole antennas with different sheath structure is presented.
Parsing urban scene images benefits many applications, especially self-driving. Most of the current solutions employ generic image parsing models that treat all scales and locations in the images equally and do not consider the geometry property of car-captured urban scene images. Thus, they suffer from heterogeneous object scales caused by perspective projection of cameras on actual scenes and inevitably...
The transmission factor of a dipole to dipole and a loop to loop through homogenous human muscle equivalent material is investigated using the FDTD analysis. The transmission factors of the dipole system and the loop system are compared and the optimization of antenna type and the optimal frequency is also discussed. In the case of dipole system, a local maximum of transmission factor is observed...
In this paper, a composite integral terminal sliding mode surface is developed, and an adaptive synchronization control scheme is proposed accordingly for multiple robotic manipulators with actuator saturation. By combining the terminal sliding mode with integral terms, the presented scheme is able to reduce the static tracking errors and improve the synchronization performance. Moreover, the system...
Introducing dummy slots is often applied to reduce cogging torque in permanent magnet synchronous machines. Although this solution always helps for smooth operation, its influence on noise and vibration (NV) performance needs more focused analysis. This paper employs two surface-mounted machines to investigate the effect of dummy slots, one of which is a 10-pole/12-slot machine (M1) with few magnetic-field...
High-precision attribute prediction is a challenging issue due to the complex object and scene variations. Targeting on enhancing attribute prediction precision, we propose an Enhanced Attribute Prediction-Latent Dirichlet Allocation (EAP-LDA) model to address this issue. EAP-LDA model enhances the attribute prediction precision in two steps: classification adaptation and prediction enhancement. In...
A new method to design frequency selective surface (FSS) structure with absorptive/ transmissive property is presented in this paper. It is characterized by a wideband transmission at high frequency and a wideband absorption performance over lower band. The FSS structure is composed of a resistive sheet and a metallic bandpass FSS layer. The resistive element is realized by inserting a strip-type...
This paper demonstrates the performance of a novel interpolation technique for computing the impedance matrix with a layered media Green's function (LMGF). The interpolation technique is based on a recursive Taylor expansion of a Bessel function of arbitrary order. Numerical simulation of microstrip array antennas embedded in a multi-layer medium is performed and the performance of the interpolation...
Modeling is the basis work of the analysis and design of a control system, and models obtained by different modeling methods have different characteristics. In the maglev system, current is generally used as a state to model. Through analysis and comparison in this paper, compared with modeling with current state, using magnetic flux density as a state to model the maglev system, the model is much...
This paper deals with the control of simple process models where multiple time-delays appear. These delays can be input, output or state delays. For the case of input/output time-delays, a general solution is retrieved from the literature. For state time-delays, the scalar case is considered and a pre-compensator is used to cancel the delay. The proposed algorithms are applied to the control of a...
We demonstrated an atmospheric radio-frequency transfer over a 50 m outdoor free-space link using a compact diode laser with an electronic phase compensation technique. With transferring a 1 GHz microwave signal in 5000 seconds, the total root-mean-square (RMS) timing fluctuation was measured to be about 560 fs, with fractional frequency instability on the order of 4 × 10−13 at 1 s, and order of 4...
In the control of maglev systems, decentralized control structure is widely used due to its simplicity. Due to the existence of mechanical coupling, the performance of decentralized control is limited. This paper focuses on designing a centralized controller for a small maglev platform that already has a decentralized control structure. A distributed reduced-order observer is first proposed for one...
In this paper, precise tracking control of a class of high-order hydraulic servo systems is studied, where the dynamics of the electrohydraulic actuator are considered. Different to available results, a new control method is proposed without using the backstepping scheme and any function approximators. The model of the hydraulic servo system is transformed into a Brunovsky form, so that the tracking...
In this paper, an adaptive optimal integral sliding mode controller is presented to realize the load position tracking for a multi-motor driving servo system (MDSS). By reformulating the MDSS in a strict feedback form, a neural network state observer is designed to estimate both immeasurable states and unknown nonlinearities. Based on this state observer, two adaptive optimal integral sliding mode...
Multiservice delivery is an important research issue in wireless sensor networks (WSNs) integrated with cloud computing, especially for heterogeneous applications which require reliable, timely and fair data delivery in adversarial environments. Therefore, both reliability requirements and delay constraints should be taken into account. Moreover, the delivery protocol should be designed to cater for...
In 1998, JAMSTEC started the development project of the first prototype of a long-range cruising AUV (LCAUV) to evaluate fundamental technologies needed to travel through under the ice covered area of the Arctic. In 2005, The LCAUV, Urashima, achieved 317 km continuous cruising powered by a deep sea fuel cell developed in JAMSTEC [1]. We then moved to next stage and have conducted to design the second...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.