大数据分析视角下的俄罗斯陀学(1844-2020)

随着信息技术的发展,"数字人文"逐渐成为人文研究领域的新热点。将数据分析和人文研究结合起来,对研究对象进行数据化的思考和呈现,是学术史研究的新路径。自1844年陀思妥耶夫斯基的作品首次发表至今,俄苏陀学呈现出历史悠久、方法多样、成果颇丰的面貌,积累了数万条研究文献。本文尝试使用数据技术对俄苏陀学的发展轨迹、研究热点和代表学者的研究进行可视化呈现,以期勾勒俄苏陀学发展的历程和面貌、特点和规律,并对陀学大数据分析的方法与成果进行整理与分析。

新世纪英美斯拉夫学界陀思妥耶夫斯基研究成果述评

进入新世纪后,英美斯拉夫学界对陀思妥耶夫斯基的研究在广度和深度上都取得了很大的进展。陀学研究者将陀思妥耶夫斯基还原入十九世纪俄罗斯社会激烈转型时期,对作家的宗教思想进行了深入的研究。跨学科批评持续升温下,陀学研究者从政治学、伦理学、性别研究等多重角度探讨陀思妥耶夫斯基的作品。同时,英美陀学界也产生了一批从文本细读的角度对陀思妥耶夫斯基作品进行分析的专著。

MATHEMATICAL MODEL OF ~4He QUANTUM INTERFEROMETER GYROSCOPE

The mathematical model of 4He quantum interferometer gyroscope is presented. The model includes the driven equation, the current equation and the position equation. Therefore, it can sufficiently describe the gyro- scope system. The driven equation shows the thermally driven gyroscope can work for a long time but the pres- sure driven one cannot. From the current equation, the superfluid currents passing through the weak link contain the AC currents which show the rotation flux, and other currents caused by drive. As shown in the position equa- tion, the displacement of diaphragm is the only detectable parameter in the gyroscope system. The model is tested by the simulations based on experimental parameters, and can be used to research performance of the gyroscope and analyse the gyroscope error.

An Open-Loop Test of a Resonator Fiber Optic Gyro

The resonator fiber optic gyro （R-FOG） ,which utilizes a resonance frequency change due to the Sagnac effect,is a promising candidate for the next generation inertial rotation sensor. In this study, an open-loop R-FOG is set up using phase modulation spectroscopy. First,the demodulation curve is obtained using a lock-in amplifier. From the demodulation signal,a gyro dynamic range of ± 4.2rad/s is obtained. Then,using different phase modulation frequencies,the open-loop gyro output signal is measured when the gyro is rotated clockwise or counterclockwise. The bias drift as a function of time is also measured. The fluctuation of the output over 5s is about 0.02rad/s. The drift can be reduced by taking countermeasures against system noise.

The research on signal-obtaining pattern for a new type of gyroscope

In this paper, a photoelectric signal obtained scheme via equator triangle pattern engraved on rotor is discussed and the mathematic model is deduced in the case which is deflexion between rotor axis and the coordinate frame of case. The deflexion error and coupling error under the situation are analyzed. Finally, three methods of engraving based on the spherical triangle pattern are presented. The error models of various methods are built up and the simulation curves are provided respectively. We have done the primary experiments on the surface of rotor using this method. It can be seen from the enlarged figures that the rim of the pattern is smooth and the demand of sensor resolution is satisfied by and large. The results of study supply reference for signal obtaining.

Data⁃Based Feedback Relearning Algorithm for Robust Control of SGCMG Gimbal Servo System with Multi⁃source Disturbance

Single gimbal control moment gyroscope(SGCMG)with high precision and fast response is an important attitude control system for high precision docking,rapid maneuvering navigation and guidance system in the aerospace field.In this paper,considering the influence of multi-source disturbance,a data-based feedback relearning(FR)algorithm is designed for the robust control of SGCMG gimbal servo system.Based on adaptive dynamic programming and least-square principle,the FR algorithm is used to obtain the servo control strategy by collecting the online operation data of SGCMG system.This is a model-free learning strategy in which no prior knowledge of the SGCMG model is required.Then,combining the reinforcement learning mechanism,the servo control strategy is interacted with system dynamic of SGCMG.The adaptive evaluation and improvement of servo control strategy against the multi-source disturbance are realized.Meanwhile,a data redistribution method based on experience replay is designed to reduce data correlation to improve algorithm stability and data utilization efficiency.Finally,by comparing with other methods on the simulation model of SGCMG,the effectiveness of the proposed servo control strategy is verified.

Analysis of mathematical model for micromechanical vibratory wheel gyroscope

By the sketch of structure of MVWG,the working laws of this kind of gyroscope we re explained.To the aid of Euler′s Dynamics Equation,a mathematical model of the gyroscope was constructed,and then by the basic working laws of MVWG the model was simplified.Under the conditions of the three axial direction rotations and general rotation,the mathematical model was resolved.And finally by the solutions, the working laws of the gyroscope, the working disparity among all sorts of gyrations and the influences from the gyrations in the axial directions were analysed.

Research and implementation of digital detection method on closed loop FOG

In the strapdown inertial navigation system, the Fiber Optical Gyro(FOG) must have high precision to give accurate navigation information. In this paper, a digital closed loop detection method based on the ramp wave modulating technigue is introduced. DSP and FPGA have many advantages in digital signal proeessing. In the design, by using DSP, a complex arithmetic operation is completed to meet the needs of closed loop control of FOG within a short time. All kinds of control signals are produced easily by FPGA, under which DSP could work properly. Combining the DSP and FPGA,the detecting method is implemented successfully. In the end, the result of test and performance is given. From the result we can conclude that the precision of FOG is improved and the noises are limited to a low level.

Mathematical Modelling of a Two Degree of Freedom Platform Using Accelerometers and Gyro Sensors

This paper demonstrates the assembly of a servo-controlled platform with two degrees of freedom, empirical methods and a developed closed-loop control found in the system mathematical model. This control aims to stabilize and hold small objects on the platform. We parsed the step response in X and Y axes, hence we found the first and second-order models for each one. We did some further analyses to decide which one would better represent the behavior of the system. The MATLAB software provided step response for the model empirically obtained and latter compared it to experimental data acquired in the trials. Accelerometers and gyro sensors from the MPU-6050 sensor measured the angular position of platform on X and Y axes. In order to improve measurements accuracy and eliminate noise effects, we implemented the complementary filter to the firmware system. We used Arduino to control servomotors through PWM pulses and perform data acquisition.

Reduction of nonreciprocal errors in a differential interferometric fiber optical gyroscope using optically differential processing

The bias stability of differential interferometric fiber optical gyroscope is analyzed.Thermal error causing long-term bias drift are reduced by putting the 90°splice in the middle of the fiber coil and applying a wide spectrum light source.Also,a kind of novel optical differential processing,which is much more precise than the electronic differential processing,is proposed for reducing the residual nonreciprocal error in the final differential output.An experimental setup based on optical differential processing was built.An^100 fold reduction in the long-term bias drift is demonstrated experimentally compared with the primary differential interferometric fiber optical gyroscope.

Comparative study of static and dynamic parameters of rock for the Xishan Rock Cliff Statue

Ultrasonic wave testing was applied to investigate the quality and weathering status of rock specimens obtained in two borings situated in the Xishan Buddha rock slope in Taiyuan, China. This paper pays special attention to the distribution of bulk density, dynamic parameters and static parameters of rock specimens as well as the relationship between static and dynamic parameters. The results illustrate that the distribution of both parameters is identical along the depth of two drilled holes in the rock slope. When the hole depth increases, the density of rock mass, saturated compression strength and static elastic modulus, dynamic elastic modulus and wave velocity also show increase tendency. The weathering degree in the rock mass ranging from the surface of cliff to the depth of 2.5 m is the highest while the rock mass is unsalted and more rigid when the depth is larger than 3.0 m. The relationship between dynamic elastic modulus, sonic wave velocity and horizontal depth indicates that dynamic elastic modulus is more sensitive than sonic wave velocity. Conversely, by comparing quantity relationship between static elastic modulus and sonic wave velocity, it is found that the composition of rock has a great influence on the relationship between static and dynamic parameters, that is, inequality of rock composition will lead to dispersion and abnormality of the distribution of static and dynamic parameters.

Nonlinear dynamics of MEMS turning fork gyroscope

Accuracy improvement of MEMS gyros requires not only microelectronic development but also the investigations of th mathematical model of sensitive element dynamics. In the present paper, we study the errors of the vibrating microgyroscop which arise because of nonlinear dynamics of a sensitive element. A MEMS tuning fork gyroscope with elastic rods is consid ered. Nonlinear differential equations of bending vibrations of sensitive element on the moving basis are derived. Free nonlin ear vibrations of gyroscopes as the flexible rod are studied. Nonlinear dynamics of gyroscope on the moving basis are investi gated by asymptotic two scales method. Sensitive element frequencies split on two frequencies resulted from slowly changin angular velocity are taken into account in the equations of zero approximation. The differential equations for slowly changin amplitudes and phases of two normal waves of the oscillations measured by capacitor gauges and an electronic contour of th device are obtained from the equations of the first approximation.