Dual‐band multifunctional metasurface for absorption and polarization conversion

In this paper, a multifunctional metasurface capable of switching between an absorber and a polarization converter is presented. The active metasurface comprises diamond‐shaped unit cells embedded with PIN diodes. The characteristic of the design lies in its capability of exhibiting multifunctionality at the same frequency of operation. The structure behaves as an absorber and linear polarization converter around 15 and 17 GHz when the PIN diode is switched ON and OFF, respectively. The working principle is demonstrated with the help of simulated results. Finally, the design is fabricated and measured, and it is seen that the results are in accordance with that of the simulated ones, establishing the concept behind switchability of absorber and polarization converter.     

基于改进差分算法的变桨ADRC参数优化

自抗扰控制器是一类不依赖被控对象数学模型且具有较强鲁棒性及抗干扰能力的非线性控制器,已成功应用于风力发电机变桨距控制这一多变量、强耦合的非线性系统中,但自抗扰控制器也存在参数众多整定难度大这一明显缺点。现提出了通过智能算法来实现参数的自动整定。分析了改进差分进化算法的原理及步骤,并将改进差分进化算法应用到ADRC的整定过程中,实现参数的自动整定。仿真结果验证了通过改进差分进化算法自动整定ADRC参数的可行性,与传统PID控制器相比,改进差分进化算法整定后的ADRC能较好的满足风力发电机变桨控制要求,有效维持了风力发电机组输出功率的稳定性。     

A secondary decomposition based hybrid structure with meteorological analysis for deterministic and probabilistic wind speed forecasting

Accurate wind speed forecasting could ensure the reliability and controllability for the wind power system. In this paper, a new hybrid structure based on meteorological analysis is proposed for the wind speed vector (wind speed and direction) deterministic and probabilistic forecasting. Twelve kinds of secondary decomposition methods are employed to decrease the interference existing in the data. To improve the training efficiency and accelerate the sample selection process, active learning is employed. Four different wind speed datasets collected from Ontario Province, Canada, are utilized as case studies to evaluate the forecasting performance of the proposed structure. Experimental results show that the proposed structure based on meteorological analysis is suitable for wind speed vector forecasting and could obtain better forecasting performance. Furthermore, except accurate deterministic forecasts, the proposed structure also provides more probabilistic forecasting information.     

Ear Field Adaptive Noise Control for Snoring: An Real-time Experimental Approach

In this paper, an active noise control (ANC) system is developed to provide an effective and non-intrusive solution for reducing loud snoring to provide a quiet environment for a snorer's bed partner. An adaptive least mean square (LMS) algorithm optimized for different kinds of snore signals is introduced and theoretically analyzed. Also, a residual noise masking approach is proposed to further reduce the effect of the snore noise without interfering with the LMS algorithm. Computer simulations followed by real-time experiments are conducted to demonstrate the feasibility of the snore ANC systems based on a pillow setup. For the optimum effect based on the characteristics of human hearing, the performance of the proposed approach is evaluated by using the multi-channel feedforward ANC systems based on the filtered-X least mean square (FXLMS) algorithm. Compared with a traditional headboard setup for snoring noise control, the proposed snore ANC systems optimized for ear field operation yield much higher noise reduction around the ears of the snorer's bed partner.      

Guaranteed-cost active disturbance rejection control for uncertain systems with an integral controller

Guaranteed-cost active disturbance rejection control (ADRC) for uncertain systems is investigated in this study. Firstly, an integral action is introduced in the framework of ADRC to measure and reduce the tracking error. Then, a robust stability condition is presented, and a quadratic cost function where the tracking error is appearing explicitly is used for ADRC performance assessment. The cost bound is formulated by linear matrix inequality and optimised to obtain controller parameters. Full-dimension extended state observer is used, and thus, the proposed strategy is applicable to an uncertain system that allows relative-degree varying or right-half-plane zero. Finally, the validity of the proposed method and its advantages is demonstrated through the simulations of comparative examples and experiments on a motor speed control system.     

Information and Communication Technology in Active and Healthy Ageing: Exploring Risks from Multi-generation Perspective

ABSTRACT

This study investigates risks associated with using information and communication technology (ICT) in elderly care. A qualitative analysis based on grounded theory has been performed using data gathered from various generations of Polish adults (adult children, their parents, and grandparents). The main risks include deterioration of family relationships, inadequate skills needed for software and equipment operation, and unreliability of solutions. The consequences for various stakeholders, such as potential end-users, caregivers, and organizations, have been discussed.     

Effects of mutations on active site conformation and dynamics of RNA-dependent RNA polymerase from Coxsackievirus B3

Recent crystal structures of RNA-dependent RNA polymerase (3D^pol) from Coxsackievirus B3 (CVB3) revealed that a tyrosine mutation at Phe364 (F364Y) resulted in structures with open active site whereas a hydrophobic mutation at Phe364 (F364A) led to conformations with closed active site. Besides, the crystal structures showed that the F364W mutation had no preference between the open and closed active sites, similar to wild-type. In this paper, we present a molecular dynamics (MD) study on CVB3 3D^pol in order to address some important questions raised by experiments. First, MD simulations of F364Y and F364A were carried out to explore how these mutations at Phe364 influence active site dynamics and conformations. Second, MD simulations of wild-type and mutants were performed to discover the connection between active site dynamics and polymerase function. MD simulations reveal that the effect of mutations on active site dynamics is associated with the interaction between the structural motifs A and D in CVB3 3D^pol. Interestingly, we discover that the active site state is influenced by the formation of a hydrogen bond between backbone atoms of Ala231 (in motif A) and Ala358 (in motif D), which has never been revealed before.     

Gaussian Process models for ubiquitous user comfort preference sampling; global priors,active sampling and outlier rejection

This paper presents a ubiquitous thermal comfort preference learning study in a noisy environment. We introduce Gaussian Process models into this field and show they are ideal, allowing rejection of outliers, deadband samples, and produce excellent estimates of a users preference function. In addition, informative combinations of users preferences becomes possible, some of which demonstrate well defined maxima ideal for control signals. Interestingly, while those users studied have differing preferences, their hyperparameters are concentrated allowing priors for new users. In addition, we present an active learning algorithm which estimates when to poll users to maximise the information returned.     

采用调制晶体管和双反馈回路的有源电感

在共源共栅-共漏有源电感的基础上,联合采用调制晶体管和双反馈回路,提出了一种可在不同频率下获得高的品质因子(Q)峰值,且分别可在大、小范围内粗调和细调电感值的新型宽频带可调谐有源电感。基于TSMC 0.18 μm CMOS工艺,利用ADS设计软件进行验证。结果表明,该有源电感在0~8.15 GHz的工作频率范围内,调节主回路的偏置电压,在频率为4.0,4.85,5.95 GHz时,分别获得1 154,6和1 293的高Q峰值。当Q值大于20时,其频率带宽均大于1.5 GHz,可以在43~132 nH之间粗调电感值的峰值。调节从回路的偏置电压,在5.95 GHz固定频率下,获得418~3 517的高Q峰值,且可以在10%比例范围内细调电感值的峰值。     

一种有源零点补偿的片上LDO设计

提出了一种新颖的有源零点补偿LDO结构,实现了LDO在全负载范围内的稳定,1~10 MHz范围内的电源抑制比提高了10 dB。采用欠冲电压减小技术,显著减小了输出欠冲电压,提高了瞬态响应性能。基于SMIC 65 nm CMOS工艺,设计了输出电压为1 V、压差电压为200 mV、最大输出电流为100mA的无片外电容LDO。仿真结果显示,空载时LDO的相位裕度为64.3°,最大过冲和欠冲电压分别为52 mV和47 mV,满载时LDO的电源抑制比为－66 dB@10 kHz。