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The mechanism of the banded structure of drifting macroalgae in the Yellow Sea

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Acta Oceanologica Sinica 2021年第7期40卷 31-41页

作者： Yan Li Fangli Qiao Hongyu Ma Qiuli Shao Zhixin Zhang Guansuo Wang First Institute of Oceanography Ministry of Natural ResourcesQingdao 266061China Key laboratory of Marine Sciences and Numerical modeling Ministry of Natural ResourcesQingdao 266061China laboratory for Regional Oceanography and Numerical modeling Pilot National Laboratory for Marine Science and Technology(Qingdao)Qingdao 266037China Institute of Oceanographic instrumentation Shandong Academy of SciencesQilu University of Technology(Shandong Academy of Sciences)Qingdao 266100China

At the end of May 2008,a massive bloom of macroalgae occurred in the western Yellow Sea off China and lasted for nearly two months,and annual blooms have occurred since then on. During bloom period,the surface-drifting macroalgae have showed an interesting pattern dominated by a banded structure,and the distance between neighboring bands ranged from hundreds of meters to about 6 km with a peak at 1–1.5 km,which is an order of higher than the scale of Langmuir circulation of 50–100 m. In order to explain this new phenomenon,ocean current data obtained from a Doppler current profiler off Qingdao was used to implement stability analysis. By numerically solving the resulting differential Orr-Sommerfeld equation,the secondary circulation induced from the instability of the Emkan current was found to fit well with the observed spatial scale of the surface-drifting macroalgae’s banded structure. As the wind driven Emkan current exist universally in the global ocean,it is reasonable to conclude that the banded structure with kilometers distance between adjoining bands is ubiquitous. We found a new circulation in the upper ocean which is important for exchange of energy,materials and gas between the upper ocean and subsurface layer.

关键词： banded structure stability analysis secondary circulation

Deep Learning-Based Speech Emotion Recognition: Leveraging Diverse Datasets and Augmentation Techniques for Robust modeling

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Journal of Harbin Institute of Technology(New series) 2024年

作者： Ayush Porwal Praveen Kumar Tyagi Ajay Sharma Dheeraj Kumar Agarwal Department of Electronics and instrumentation Engineering， Shri G.S.Institute of Technology and Science Department of Electronics and Communication Engineering， Maulana Azad National Institute of Technology School of Computing Science and Engineering， VIT Bhopal University

In recent years， Speech Emotion Recognition (SER) has developed into an essential instrument for interpreting human emotions from auditory data. The proposed research focused on the development of a SER system employing deep learning and multiple datasets containing samples of emotive speech. The primary objective of this research endeavor is to investigate the utilization of Convolutional Neural Networks (CNNs) in the process of sound feature extraction. Stretching， pitch manipulation， and noise injection are a few of the techniques utilized in this study to improve the data quality. The investigation includes coverage of these methods. Feature extraction methods including Zero Crossing Rate， Chroma＿stft， MFCC， RMS， and MelSpectogram are used to train a model. By using these techniques， audio signals can be transformed into recognized features that can be utilized to train the model. Ultimately， the study will produce a thorough evaluation of the model’s performance. When this method was applied， the model achieved an impressive accuracy of 94.57% on the test dataset. Proposed work also validated on EMO-BD and IEMOCAP dataset. These consist of further data augmentation， feature engineering， and hyperparameter optimization. By following these development paths， SER systems will be able to be implemented in real-world scenarios with greater accuracy and resilience.

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Design,modeling,and Control of Biomimetic Fish Robot:A Review

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Journal of Bionic Engineering 2019年第6期16卷 967-993页

作者： Palmani Duraisamy Rakesh Kumar Sidharthan Manigandan Nagarajan Santhanakrishnan Robotics laboratory Department of Electronics and Instrumentation EngineeringSASTRA Deemed UniversityThanjavurTamil Nadu-613401India

A comprehensive review on bio-inspired fish robots has been done in this article with an enhanced focus on swimming styles,actuators,hydrodynamics,kinematic-dynamic modeling,and *** styles such as body and/or caudal fin and median and/or paired fin and their variants are discussed in *** shows that most fish robots adapt carangiform in body and/or caudal fin type swimming as it gives significant thrust with a maximum speed of 3.7 ms 1 in *** of smart or soft actuators to enhance real-time dynamics was studied from literature,and it was found that the robot built with polymer fiber composite material could reach a speed of 0.6 m s However,dynamic modeling is relatively complex,and material selection needs to be *** numerical and analytical methods in dynamic modeling have been investigated highlighting merits and *** parameter estimation through the data-driven model is widely used in offline,however online estimation of the same need to be *** controllers are frequently used tor navigation and stabilization,which often encounters the linearization problem and hence,can be replaced with the state-of-the-art adaptive and intelligent *** article also summarizes the potential research gaps and future scopes.

关键词： biomimetic fish robot swimming modes hydrodynamic modeling motion control smart actuators

Development of a novel accelerometer based on an overlay detection bridge

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Journal of Semiconductors 2013年第2期34卷 52-59页

作者：杜春晖何常德葛晓洋张永平于佳琪宋小鹏张文栋 Key laboratory of instrumentation Science & Dynamic Measurement Ministry of EducationNorth University of China Key laboratory of Science and Technology on Electronic Test & Measurement North University of China

This paper describes the design, simulation, processing and test result of a high sensitivity accelerometer based on the piezoresistive effect which uses an overlay bridge detection method. The structure of this accelerometer is supersymmetric ＂mass-beams＂. This accelerometer has 8 beams, where two varistors are put in the two ends. Four varistors compose a Wheatstone bridge and the output voltages of the 4 Wheatstone bridges have been superimposed as the final output voltage. The sensitivity of the accelerometer can be improved effectively by these clever methods. A simplified mathematical model has been created to analyze the mechanical properties of the sensor, then the finite element modeling and simulation have been used to verify the feasibility of the accelerometer. The results show that the sensitivity of the accelerometer is 1.1381 mV/g, which is about four times larger than that of the single bridge accelerometers and series bridge sensor. The bandwidth is 0-1000 Hz which is equal to that of the single bridge accelerometers and the series bridge sensor. The comparison reveals that the new overlay detection bridge method can improve the sensitivity of the sensor in the same bandwidth. Meanwhile, this method provides an effective method to improve the sensitivity of piezoresistive sensors.

关键词： accelerometer MEMS piezoresistive overlay detection bridge

The dual cycle bridge detection of piezoresistive triaxial accelerometer based on MEMS technology

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Journal of Semiconductors 2014年第6期35卷 80-89页

作者：张娟婷何常德张慧李玉平张永平杜春晖张文栋 Key laboratory of instrumentation Science & Dynamic Measurement Ministry of EducationNorth University of China Key laboratory of Science and Technology on Electronic Test & Measurement North University of China

A cycle bridge detection method, which uses a piezoresistive triaxial accelerometer, has been described innovatively. This method just uses eight resistors to form a cycle detection bridge, which can detect the signal of the three directions for real time. It breaks the law of the ordinary independent Wheatstone bridge detection method, which uses at least 12 resistors and each four resistors connected as a Wheatstone bridge to detect the output signal from a specific direction. In order to verify the feasibility of this method, the modeling and simulating of the sensor structure have been conducted by ANSYS, then the dual cycle bridge detection method and independent Wheatstone bridge detection method are compared, the result shows that the former method can improve the sensitivity of the sensor effectively. The sensitivity of the x, y-axis used in the former method is two times that of the sensor used in the latter method, and the sensitivity of the z-axis is four times. At the same time, it can also reduce the cross-axis coupling degree of the sensor used in the dual cycle bridge detection method. In addition, a signal amplifier circuit and adder circuit have been provided, Finally, the test result of the ＂eight-beams/mass＂ triaxial accelerometer, which is based on the dual cycle bridge detection method and the related circuits, have been provided. The results of the test and the theoretical analysis are consistent, on the whole.

关键词： piezoresistive triaxial accelerometer cycle detection bridge MEMS

Future Precipitation Extremes in China under Climate Change and Their Physical Quantification Based on a Regional Climate Model and CMIP5 Model Simulations

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Advances in Atmospheric Sciences 2021年第3期38卷 460-479页

作者： Peihua QIN Zhenghui XIE Jing ZOU Shuang LIU Si CHEN State Key laboratory of Numerical modeling for Atmospheric Sciences and Geophysical Fluid Dynamics Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China Institute of Oceanographic instrumentation Qilu University of Technology(Shandong Academy of Sciences)Qingdao 266001China Key laboratory of Mountain Hazards and Earth Surface Processes Institute of Mountain Hazards and EnvironmentChinese Academy of SciencesChengdu 610041China

The atmospheric water holding capacity will increase with temperature according to Clausius-Clapeyron scaling and affects *** rates of change in future precipitation extremes are quantified with changes in surface air *** extremes in China are determined for the 21st century in six simulations using a regional climate model,RegCM4,and 17 global climate models that participated in ***,we assess the performance of the CMIP5 models and RCM runs in their simulation of extreme precipitation for the current period(RF:1982-2001).The CMIP5 models and RCM results can capture the spatial variations of precipitation extremes,as well as those based on observations:OBS and *** extremes over four subregions in China are predicted to increase in the mid-future(MF:2039-58)and far-future(FF:2079-98)relative to those for the RF period based on both the CMIP5 ensemble mean and RCM ensemble *** secular trends in the extremes of the CMIP5 models are predicted to increase from 2008 to 2058,and the RCM results show higher interannual variability relative to that of the CMIP5 ***,we quantify the increasing rates of change in precipitation extremes in the MF and FF periods in the subregions of China with the changes in surface air ***,based on the water vapor equation,changes in precipitation extremes in China for the MF and FF periods are found to correlate positively with changes in the atmospheric vertical wind multiplied by changes in surface specific humidity(significant at the p<0.1 level).

关键词： precipitation extremes regional climate model CMIP5 models

modeling light propagation through taper-microfiber structures integrated on substrates

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Chinese Optics Letters 2010年第6期8卷 560-563页

作者：寇煦丰范固廉王光辉 State Key laboratory of Modern Optical instrumentation Department of Optical EngineeringZhejiang University School of Electrical and Electronic Engineering Nanyang Technological University

We use the three-dimensional finite-difference time-domain（3D-FDTD） method to model silica taper-microfiber structures integrated on *** dependence of the transmission on the length of the microfiber is investigated for two different *** of the geometric parameters is provided and two substrate materials,namely MgF2 and fluorosilicate glass,are *** also investigate the case where the structure is covered with a dielectric material.

关键词： Dielectric materials Silica Structural optimization Substrates Three dimensional Time domain analysis

Electron beam modeling and analyses of the electric field distribution and space charge effect

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Chinese Physics B 2022年第5期31卷 288-293页

作者： Yueling Jiang Quanlin Dong School of instrumentation and Optoelectronic Engineering Beihang UniversityBeijingChina

In electron beam technology, one of the critical focuses of research and development efforts is on improving the measurement of electron beam parameters. The parameters are closely related to the generation, emission, operation environment, and role of the electron beam and the corresponding medium. In this study, a field calculation method is proposed, and the electric field intensity distribution on the electron beam’s cross-section is analyzed. The characteristics of beam diffusion caused by the space charge effect are investigated in simulation, and the obtained data are compared with the experiment. The simulation demonstrated that the cross-sectional electric field distribution is primarily affected by the electron beam current, current density distribution, and electron beam propagation speed.

关键词： electron beam electric field distribution space charge effect

New rapid transfer alignment method for SINS of airborne weapon systems

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Journal of Systems Engineering and Electronics 2014年第2期25卷 281-287页

作者： Yu Chen Yan Zhao School of instrumentation Science and Opto-electronics Engineering Beihang University

Transfer alignment is an effective alignment method for the strapdown inertial navigation system （SINS） of airborne weapon systems. The traditional transfer alignment methods for large misalignment angles alignment use nonlinear transfer align- ment models and incorporate nonlinear filtering. A rapid transfer alignment method with linear models and linear filtering for ar- bitrary misalignment angles is presented. Through the attitude quaternion decomposition, the purpose of transfer alignment is converted to estimate a constant quaternion. Employing special manipulations on measurement equation, velocity and attitude linear measurement equations are derived. Then the linear trans- fer alignment model for arbitrary misalignment angles is built. An adaptive Kalman filter is developed to handle modeling errors of the measurement noise statistics. Simulation results show feasibili- ty and effectiveness of the proposed method, which provides an alternative rapid transfer alignment method for airborne weapons.

关键词： strapdown inertial navigation system (SINS) transferalignment Kalman filter quaternion.