Integrated importance measure for multi-state coherent systems of k level

To verify the effectiveness of the integrated importance measure （IIM） for multi-state coherent systems of k level, the definition and physical meaning of IIM are demonstrated. Then, the improvement potential and Δ-importance measures are generalized to multi-state coherent systems based on the system performance level, and the relationships between IIM and traditional importance measures are discussed. The characteristics of IIM are demonstrated in both series and parallel systems. Also, an application to an oil transportation system is given. The comparison results show that： （i） IIM has some useful properties that are not possessed by traditional importance measures; （ii） IIM is effective in evaluating the component role in multi-state systems when the component reliability and the failure rate are simultaneously considered.

Integrated On-line Instrumentation System of Magnetic Properties Measurement

A portable microcomputer-controlled inspection system has been developed for detection of magnetic properties of soft magnetic materials. It incorporates custom designed software for control of the magnetic field during operation such as demagnetization, field sweeping, and for data logging and analysis. Results are recorded using a 12-bit analog to digital converter and are then stored on disk. The magnetic hysteresis loop and Barkhausen noise data can be converted into important magnetic parameters: coecivity, remanence, and hysteresis loss, Barkhausen amplitude, and Barkhausen noise energy. This system incorporated with the magnetostriction, and magnetoacoustic emission, is then related with the nondestructive detection of material degradation.

BBACIMA:A Trustworthy Integrity Measurement Architecture through Behavior-Based TPM Access Control

Two limitations of current integrity measurement architectures are pointed out： （1） a reference value is required for every measured entity to verify the system states, as is impractical however; （2） malicious user can forge proof of inexistent system states. This paper proposes a trustworthy integrity measurement architecture, BBACIMA, through enforcing behavior-based access control for trusted platform module （TPM）. BBACIMA introduces a TPM reference monitor （TPMRM） to ensure the trustworthiness of integrity measurement. TPMRM enforces behavior-based access control for the TPM and is isolated from other entities which may be malicious. TPMRM is the only entity manipulating TPM directly and all PCR （platform configuration register） operation requests must pass through the security check of it so that only trusted processes can do measurement and produce the proof of system states. Through these mechanisms malicious user can not enforce attack which is feasible in current measurement architectures.

Position and attitude determination by integrated GPS/SINS/TS for feed support system of FAST

This paper presents a new measurement system based on integration method that can provide all-weather dependability and higher precision for the measurement of FAST's feed support system.The measurement system consists of three types of measuring equipments,and a processing software with the core data fusion algorithm.The Strapdown Inertial Navigation System(SINS)can autonomously measure the position,speed and attitude of the carrier.Its own shortcoming is that the measurement data diverge rapidly over time.SINS must combine the Global Positioning System(GPS)and the Total Station(TS)to obtain high-precision measurement data.The Kalman filtering algorithm is adopted for the integration measurement system,which is an optimal algorithm to estimate the measurement errors.A series of tests are carried out to evaluate the performance.For the feed cabin,the maximum RMS of the position is 14.56 mm,the maximum RMS of the attitude is 0.095,these values are less than 15 mm and 0.1°as the precision for measuring the feed cabin.For the Stewart manipulator,the maximum RMS of the position is 2.99 mm,the maximum RMS of the attitude is 0.093°,these values are less than 3 mm and 0.1°as the precision for measuring the Stewart manipulator.As a result,the new measurement meets the requirement of measurement precision for FAST's feed support system.

FOURIER TRANSFORMATION AND SINGULAR INTEGRALS ON SELF-SIMILAR MEASURE

This paper serves two purposes. One is to modify Strichartz's results with respect to the asymptotic averages of the Fourier transform of μ on , self-similar measure defined by Hutchinson. Another purpose is to consider a singular integral operator on μ and show that this op- erator is of type (p,p)(1<p<∞).

THE INTEGRAL FORMULA FOR CALCULATINGTHE HAUSDORFF MEASURE OF SOME FRACTAL SETS

It is important to calculate the Hausdorff dimension and the Hausdorff mesure respect to this dimension for some fractal sets. By using the usual method of “Mass Distribution”, we can only calculate the Hausdorff dimension. In this paper, we will construct an integral formula by using lower inverse s-density and then use it to calculate the Hausdorff measures for some fractional dimensional sets.

APPROXIMATION OF SPHERICAL MEANS OF MULTIPLE FOURIER INTEGRALS AND FOURIER SERIES ON SET OF FULL MEASURE

In this paper we consider the approximation for functions in some subspaces of L^2 by spherical means of their Fourier integrals and Fourier series on set of full measure. Two main theorems are obtained.

Particle Filter and Its Application in the Integrated Train Speed Measurement

Particle filter(PF) can solve the problem of state estimation under strong non-linear non-Gaussian noise condition with respect to traditional Kalman filter(KF) and those improved KFs such as extended KF(EKF) and unscented KF(UKF). However, problems such as particle depletion and particle degradation affect the performance of PF. Optimizing the particle set to high likelihood region with intelligent optimization algorithm results in a more reasonable distribution of the sampling particles and more accurate state estimation. In this paper, a novel bird swarm algorithm based PF(BSAPF) is presented. Firstly, different behavior models are established by emulating the predation, flight, vigilance and follower behavior of the birds. Then, the observation information is introduced into the optimization process of the proposal distribution with the design of fitness function. In order to prevent particles from getting premature(being stuck into local optimum) and increase the diversity of particles, Lévy flight is designed to increase the randomness of particle's movement. Finally,the proposed algorithm is applied to estimate the speed of the train under the condition that the measurement noise of the wheel sensor is non-Gaussian distribution. Simulation study and experimental results both show that BSAPF is more accurate and has more effective particle number as compared with PF and UKF, demonstrating the promising performance of the method.

MGCPN:An Efficient Deep Learning Model for Tibetan Plateau Precipitation Nowcasting Based on the IMERG Data

The sparse and uneven placement of rain gauges across the Tibetan Plateau(TP) impedes the acquisition of precise,high-resolution precipitation measurements,thus challenging the reliability of forecast data.To address such a challenge,we introduce a model called Multisource Generative Adversarial Network-Convolutional Long Short-Term Memory(GAN-ConvLSTM) for Precipitation Nowcasting(MGCPN),which utilizes data products from the Integrated Multi-satellite Retrievals for global precipitation measurement(IMERG) data,offering high spatiotemporal resolution precipitation forecasts for upcoming periods ranging from 30 to 300 min.The results of our study confirm that the implementation of the MGCPN model successfully addresses the problem of underestimating and blurring precipitation results that often arise with increasing forecast time.This issue is a common challenge in precipitation forecasting models.Furthermore,we have used multisource spatiotemporal datasets with integrated geographic elements for training and prediction to improve model accuracy.The model demonstrates its competence in generating precise precipitation nowcasting with IMERG data,offering valuable support for precipitation research and forecasting in the TP region.The metrics results obtained from our study further emphasize the notable advantages of the MGCPN model;it outperforms the other considered models in the probability of detection(POD),critical success index,Heidke Skill Score,and mean absolute error,especially showing improvements in POD by approximately 33%,19%,and 8% compared to Convolutional Gated Recurrent Unit(ConvGRU),ConvLSTM,and small Attention-UNet(SmaAt-UNet) models.

High-accuracy stretched-wire measurement system for cryogenic permanent magnet undulator(CPMU)in High Energy Photon Source(HEPS)

A new stretched-wire system is built for a cryogenic permanent magnet undulator in High Energy Photon Source Testing Facility.The system has two functions:integral field measurement and magnet gap measurement.Integral field measurement and gap measurement are important for evaluation and optimization of the magnetic performance of the undulator in cryogenic-vacuum environment.Two high-precision,high-load motion stages are used for accurate positioning.A special fix structure of stretched wire is adopted for vacuum environment.To reduce the deflection of the 3-meter-long wire,constant tension is maintained along the wire.The measurement repeatability of field integral and magnetic gap is the key performance which depends on the stability of wire and suppression of the electric noise.Strategy of improving the measurement accuracy and stability is presented.

An Overview of Passive and Active Dust Detection Methods Using Satellite Measurements

In this paper,the methods to detect dust based on passive and active measurements from satellites have been summarized.These include the visible and infrared（VIR） method,thermal infrared（TIR） method,microwave polarized index（MPI） method,active lidar-based method,and combined lidar and infrared measurement（CLIM） method.The VIR method can identify dust during daytime.Using measurements at wavelengths of 8.5,11.0,and 12.0 fan,the TIR method can distinguish dust from other types of aerosols and cloud,and identify the occurrence of dust over bright surfaces and during night.Since neither the VIR nor the TIR method can penetrate ice clouds,they cannot detect dust beneath ice clouds.The MPI method,however,can identify about 85%of the dust beneath ice clouds.Meanwhile,the active lidar-based method,which uses the Cloud-Aerosol Lidar with Orthogonal Polarization（CALIOP） data and five-dimensional probability distribution functions,can provide very high-resolution vertical profiles of dust aerosols.Nonetheless,as the signals from dense dust and thin clouds are similar in the CALIOP measurements,the lidar-based method may fail to distinguish between them,especially over dust source regions.To address this issue,the CLIM method was developed,which takes the advantages of both TIR measurements（to discriminate between ice cloud and dense dust layers） and lidar measurements（to detect thin dust and water cloud layers）.The results obtained by using the new CLIM method show that the ratio of dust misclassification has been significantly reduced.Finally,a concept module for an integrated multi-satellites dust detection system was proposed to overcome some of the weaknesses inherent in the single-sensor dust detection.

Pulsed-wire system for undulator measurement

Purpose More undulators are required of HEPS in future.The efficiency of traditional Hall-probe measurement method is relatively low,which is difficult to meet the measurement needs of large quantities of undulators.In order to improve debugging efficiency,the pulsed-wire method is required further improvement.Methods A pulsed-wire method is an effective method to achieve magnetic field distribution through narrow aperture of undulator.The pulsed-wire method works by sending a square current pulse through the wire,which will induce an interaction with the magnetic field due to the Lorentz force.This force causes the wire to be displaced,and this displacement travels along the wire in both directions as an acoustic wave.Measurement of the displacement in the wire over time using a motion detector yields the first or second integrals of the magnetic field.Results The accuracy and repeatability are the important requirements.The repeatability of the first field integral of the pulsed-wire system is better than 1‰which meets the design requirements.Conclusions This paper illustrates the effectiveness of pulsed-wire system by test results.Through comparison,the accuracy of the system is proved.It provides a new important measurement system for undulators in future.

Quasi-Homeomorphisms and Measures of Finite Energy Integrals of Generalized Dirichlet Forms

We introduce the quasi-homeomorphisms of generalized Dirichlet forms and prove that any quasi-regular generalized Dirichlet form is quasi-homeomorphic to a semi-regular generalized Dirichlet form. Moreover. we apply this quasi-homeomorphism method to study the measures of finite energy integrals of generalized Dirichlet forms. We show that any 1-coexcessive function which is dominated by a function in is associated with a measure of finite energy integral. Consequently, we prove that a Borel set B is-exceptional if and only if μ(B)=0 for any measure μ of finite energy integral.

Refined Spatialization of 10-Day Precipitation in China Based on GPM IMERG Data and Terrain Decomposition Using the BEMD Algorithm

Continuous high spatial-resolution 10-day precipitation data are essential for crop growth services and phenological research.In this study,we first use the bidimensional empirical mode decomposition(BEMD)algorithm to decompose the digital elevation model(DEM)data and obtain high-frequency(OR3),intermediate-frequency(OR5),and low-frequency(OR8)margin terrains.Then,we propose a refined precipitation spatialization model,which uses ground-based meteorological observation data,integrated multi-satellite retrievals for global precipitation measurement(GPM IMERG)satellite precipitation products,DEM data,terrain decomposition data,prevailing precipitation direction(PPD)data,and other multisource data,to construct China's high-resolution 10-day precipitation data from2001 to 2018.The decomposition results show mountainous terrain from fine to coarse scales;and the influences of altitude,slope,and aspect on precipitation are better represented in the model after topography is decomposed.Moreover,terrain decomposition data can be added to the model simulation to improve the quality of the simulation product;the simulation quality of the model in summer is better than that in spring and autumn,and is relatively poor in winter;and OR5 and OR8 can be improved in the simulation,with better OR5 and OR8 dynamically selected.In addition,preprocessing the data before precipitation spatialization is particularly important.For example,adding 0.01to the 0 value of precipitation,multiplying the small value of precipitation less than 1 by 10,and performing the normal distributions transform(e.g.,Yeo–Johnson)on the data can improve the simulation quality.

A pilot survey on indoor radon concentration in Beijing

Objective:To explore the level of indoor radon concentration especially after recent 3 decades’great economic development in metropolis Beijing,so as to describe the outline of indoor radon level in Beijing.Methods:A one-year integrated measurement on 800 dwellings was carried out from September 2018 to August 2019.Passive integrated radon cup monitor with CR-39 as an alpha-track detector was adopted for the survey.As a pilot study,measurement scheme was designed in detail.For measurement quality control,the background track density of CR-39 was strictly defined and controlled throughout the operation of the survey.Results:The annual geometric and arithmetic mean of radon concentration of the surveyed are(39.3±12.9)and(42.0±13.7)Bq/m^(3),respectively,varying from(12.1±2.5)to(119.0±7.8)Bq/m^(3).Radon concentration of the ground floor dwellings is obviously higher than that of other floors.No difference of radon level is found among the dwellings of other floors.Higher radon concentration in buildings built after 2010 is obtained compared with buildings built in 1980s,1990s,and 2000s.Conclusions:There is no big change of radon concentration level in dwellings in Beijing area observed in general compared with a previous survey performed more than ten years ago.For high-rise buildings,building materials are suggested to be the main source of indoor radon.For higher radon concentration in buildings built in latest ten years,the change on building materials and indoor ventilation rate are thought to be the causes,further study in detail is needed to clarify.

A new steering approach for VSCMGs with high precision

A new variable speed control moment gyro(VSCMG) steering law is proposed in order to achieve higher torque precision. The dynamics of VSCMGs is established, and two work modes are then designed according to command torque: control momentum gyro(CMG)/reaction wheel(RW) hybrid mode for the large torque case and RW single mode for the small. When working in the CMG/RW hybrid mode, the steering law deals with the gimbal dead-zone nonlinearity through compensation by RW sub-mode. This is in contrast to the conventional CMG singularity avoidance and wheel speed equalization, as well as the proof of definitely hyperbolic singular property of the CMG sub-mode. When working in the RW single mode, the motion of gimbals will be locked. Both the transition from CMG/RW hybrid mode to RW single mode and the reverse are studied. During the transition, wheel speed equalization and singularity avoidance of both the CMG and RW submodes are considered. A steering law for the RWs with locked gimbals is presented. It is shown by simulations that the VSCMGs with this new steering law could reach a better torque precision than the normal CMGs in the case of both large and small torques.

An attack-immune trusted architecture for supervisory aircraft hardware

With the wide application of electronic hardware in aircraft such as air-to-ground communication,satellite communication,positioning system and so on,aircraft hardware is facing great secure pressure.Focusing on the secure problem of aircraft hardware,this paper proposes a supervisory control architecture based on secure System-on-a-Chip(So C)system.The proposed architecture is attack-immune and trustworthy,which can support trusted escrow application and Dynamic Integrity Measurement(DIM)without interference.This architecture is characterized by a Trusted Monitoring System(TMS)hardware isolated from the Main Processor System(MPS),a secure access channel from TMS to the running memory of the MPS,and the channel is unidirectional.Based on this architecture,the DIM program running on TMS is used to measure and call the Lightweight Measurement Agent(LMA)program running on MPS.By this method,the Operating System(OS)kernel,key software and data of the MPS can be dynamically measured without disturbance,which makes it difficult for adversaries to attack through software.Besides,this architecture has been fully verified on FPGA prototype system.Compared with the existing systems,our architecture achieves higher security and is more efficient on DIM,which can fully supervise the running of application and aircraft hardware OS.

Geometry and Hardy spaces on spaces of homogeneous type in the sense of Coifman and Weiss

It is known that the space of homogeneous type introduced by Coifman and Weiss(1971) provides a very natural setting for establishing a theory of Hardy spaces. This paper concentrates on how the geometrical conditions of the space of homogeneous type play a crucial role in building a theory of Hardy spaces via the Littlewood-Paley functions.

A lattice measuring method based on integral imaging technology

Aiming at the problem that the lattice feature exceeds the view field of the scanning electron microscope(SEM)measuring system,a new lattice measuring method is proposed based on integral imaging technology.When the system works,the SEM measuring system is equivalent to an integral image acquisition system.Firstly,a lattice measuring method is researched based on integral imaging theory.Secondly,the system parameters are calibrated by the VLSI lattice standard.Finally,the value of the lattice standard to be tested is determined based on the calibration parameters and the lattice measuring algorithm.The experimental results show that,compared with the traditional electron microscope measurement method,the relative error of the measured value of the algorithm is maintained within 0.2%,with the same level of measurement accuracy,but it expands the field of view of the electron microscope measurement system,which is suitable for the measurement of samples under high magnification.