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Aiming at the problem of large amount of work in the matching stage of traditional visible light fingerprint positioning methods, an indoor high-precision visible light positioning method combining TDOA and fingerprints is proposed. This method first builds a visible light fingerprint library in the positioning area, and then uses the TDOA algorithm to determine the application range of fingerprint positioning. Finally, the weighted K-nearest neighbor algorithm is used to determine the position coordinates of the point to be located within the specified range. The simulation results show that the positioning method proposed in this paper greatly reduces the number of matching in the fingerprint matching stage compared with the traditional fingerprint positioning method, and has a higher positioning accuracy.

Bridges are the lifelines of disasters in earthquake areas. Therefore, it is very necessary to ensure the safety and traffic function after earthquake. Seismic isolation refers to install external energy dissipation devices or external energy input devices in specific parts of engineering structures. There are certain differences in longitudinal and transverse seismic responses of multi-span continuous beam bridges by changing the seismic dynamic characteristics or dynamic effects of structures. It is difficult to achieve the purpose of seismic isolation in both horizontal directions using isolation devices alone. The rubber deformation ability of lead rubber bearings can effectively insulate, and the yield energy consumption ability of its lead core can effectively consume the seismic energy for damping. The horizontal resistance is very small under the creep load, and the stiffness decreases rapidly after yielding under the strong dynamic earthquake load; meanwhile, the seismic energy is dissipated by the hysteresis of bearing. Fluid viscous damper is a velocity-dependent energy dissipation device, which produces viscous damping force, provides strong restoring force for components, and has a good limit function. This process will also dissipate the seismic energy, so as to reduce the structural earthquake response. Using these two methods together, the horizontal seismic responses of multi-span continuous beam bridges can be effectively controlled at the same time. Based on this idea, this article takes a high-speed multi-span continuous beam bridge with equal section as the engineering background, and uses dynamic time history analysis method to discuss the seismic isolation effect of lead rubber bearings and fluid viscous dampers.

Three issues should be addressed in ubiquitous power Internet of things (IoT) terminals, such as lack of terminal standardization, high business coupling and weak local intelligent processing ability. The application of operating system in power IoT terminals provides the possibility to solve the above problems, but needs to address the real-time and security problems. In this paper, TrustZone based virtualization architecture is used to tackle the above real-time and security problems, which adopts the dual system architecture of real-time operating system (FreeRTOS) to run real-time tasks, such as power parameter acquisition and control on the real-time operating system, to solve the real-time problem; And non real-time tasks are run on the general operating system(Linux) to solve the expansibility problem of power terminals with hardware assisted virtualization technology achieving the isolation of resources, ensuring the safety of power related applications. The scheme is verified on the physical platform. The results show that the dual operating system power IoT terminal scheme based on ARM TrustZone meets the security requirements and has better real-time performance, with unifying terminal standards, business decoupling and enhancing local processing capacity.

Anomaly detection is the primary method of detecting intrusion. Unsupervised models, such as auto-encoders network, auto-encoder, and GMM, are currently the most widely used anomaly detection techniques. In reality, the samples used to train the unsupervised model may not be pure enough and may include some abnormal samples. However, the classification effect is poor since these approaches do not completely understand the association between reconstruction errors, reconstruction characteristics, and irregular sample density distribution. This paper proposes a novel intrusion detection system architecture that includes data collection, processing, and feature extraction by integrating data reconstruction features, reconstruction errors, auto-encoder parameters, and GMM. Our system outperforms other unsupervised learning-based detection approaches in terms of accuracy, recall, F1-score, and other assessment metrics after training and testing on multiple intrusion detection data sets.

For the scene of high real-time requirement in power system, a multi-core asymmetric software and hardware architecture is designed. In the hardware, the CCI architecture is removed to ensure a high degree of decoupling between asymmetric architectures. At the same time, a dedicated RIPC is used to interlock the shared resources between CPU. The CPU software can complete the shared resources application, idle query, interrupt notification and other operations by simply reading and writing RIPC. In the software, Linux and baremetal run at the same time to meet the requirements of real-time and non real-time collaborative processing ability of application scenarios. A multi-core management framework supporting remoteproc API is customized and developed, and the communication between Linux and baremetal is realized through rpmsg protocol.

In recent years, the microkernel architecture has become an increasingly popular kernel architecture. Since most of the system services of the microkernel run as user-mode process, the user process needs to access system services through the kernel’s communication mechanism to request other usermode service process to provide services. Therefore, the frequency and amount of inter-process communication in the microkernel is much larger than that in the monolithic kernel, causing the poor performance of the microkernel. In this paper, two exchange-based IPC communication algorithms are proposed to optimize the communication algorithm based on replication mode, which is commonly used in the microkernel. One is based on the algorithm of exchange of physical page of MMU, and the other is based on the algorithm of exchange of segment base address of MMU. These two exchange algorithms can achieve efficient transmission while using the independent address space to ensure the correctness of the transmitted data, greatly improving the efficiency of communication in the microkernel, thereby improving the performance of the microkernel.

For the scene of high real-time requirement in industrial field, the homogeneous multi-core asymmetric software system architecture is designed. This architecture meets the requirements of real-time and non real-time collaborative processing ability in application scenarios, and realizes multi-core remote management. In FPGA verification stage or production stage, porting remoteproc management structure in a typical operating system (Linux), at the same time, the bare metal software and RTOS porting openamp source project. We customized and developed a multi-core management framework, supporting remoteproc API. Based on the implemented SGI interrupt, rpmsg protocol is implemented with the help of hardware IPC mechanism and shared memory, and cross processor communication between Linux and bare metal software is realized through rpmsg protocol.

A novel UHF RFID communication link rate adjustment strategy based on the coprime factor algorithm was proposed, and chip-level physical implementation was performed using 0.18um CMOS process. The test result shows that the new reverse link bit rate adjustment scheme not only controls the BLF violation within 5%, effectively avoids electromagnetic interference. The implementation reduces the design complexity of the chip baseband circuit where reverse link realization clock is 640KHz, jitter is 0.8ns and power consumption is 140nA.

The design of an MCU chip Bootloader program is introduced, and a UVM-based verification environment for interactive communication between the UART VIP and the Bootloader is built. The Bootloader design is simple and convenient, and has a strong security. The designed Bootloader can realize the import of interactive applications to the MCU chip through the interconnection of the UART interface and the computer RS232 interface, which is convenient for upgrading and maintaining the embedded programs in practical applications. Before the tape-out process, the UART VIP is used to simulate the host computer operation to pre-test whether the Bootloader meets the design expectations, thus reducing the risk of tape-out failure. The application of the UVM verification methodology makes the Bootloader’s verification environment more portable, and make it more convenient to construct complex verification scenarios.

Now the requirements for chip security are getting higher, the bootrom is a small mask ROM or write-protected flash memory embedded in a processor chip, It contains the first code that the processor executes when it is energized or reset. This design adds AES/SHA/ECC security algorithm in the chip bootrom and check the loaded image for security, providing personalized key management for chips to prevent attacks.

The joint roughness coefficient (JRC) is an index defined by geometrical characteristics and correlated to mechanical shear strength. It is empirical and subjective to evaluate JRC by visual comparison. The existing quantitative evaluations of joint roughness are based on statistical parameters (i.e., the root mean square Z2, the structure function SF, and the textural parameter RP ), which fail to describe the spatial variability of joint profiles. This paper presents a novel roughness descriptor, semivariogram parameter CA , to quantify roughness characteristics. Based on the theory of geostatistics , a semivariogram function is established. Furthermore, a Gaussian fitting model is applied to obtain the semivariogram parameter CA and its empirical equation, which can be used to evaluate the joint roughness coefficient. Finally, to verify the feasibility of this method, a comparison has been conducted between statistical parameters and the semivariogram parameter for the analysis of Barton's ten standard JRC profiles and 102 additional rock joint profiles.

An ultra-low-power and low-area complementary metal oxide semiconductor (CMOS) bandgap voltage reference, without resistor and substrate bipolar, is presented and verified in the TSMC 0.18 μm CMOS process in this paper. By adopting PMOS transistor with N+ doped gate and a new temperature compensation technique, the proposed bandgap demonstrates a power consumption of around 50 nA for a supply voltage of 1.5 V and a temperature coefficient of 75 ppm without trimming. The chip can operate with a supply voltage from 1.2 V to 1.8 V and small area of the bandgap is around 0.001 mm2. The characteristic of the proposed voltage bandgap reference makes it suitable for ultralow-power low-area applications.

With the rapid construction of the ubiquitous power internet of things, the increasing demand of embedded hardware usage and the complex usage scenario of the embedded platform hardware in intelligent terminal. A more efficient vitalization solution was demanded. With the analysis of traditional virtualization solutions and the armv8 architecture embedded platform hardware support for virtualization, the implementation details of arm embedded platform supporting containerization technology are described. In particular, the specific steps of application containerization are introduced. In the end, we analyze the performance that application run in container and discuss future research directions.

This paper introduces a performance test method for dual ethernet interface of ubiquitous power IoT MCU chip. The method is based on the RFC2544 ethernet performance test standard which is benchmarking methodology for Network Interconnect Devices. With the characteristics of the ubiquitous power IoT integrated communication network, we developed embedded software for the MCU chip to realize the data flow between the physical layer, data link layer and network interface layer. Network test instrument of Spirent's N11U is used to test and evaluate performance items such as throughput, latency, frame loss rate and back-to-back frames performance of the dual ethernet interface. This method is of great significance for the network performance testing of device terminals in the field of power IoT which our MCU chip is applied in.

Collecting morphological characteristics of rock joint surfaces and building a digital rock joint library with abundant sample types and sufficient sample numbers is important for fractured rock mass analysis. To solve the “inflexible field operation” problem in existing contact type and non-contact type data collection procedures, this work presents a photogrammetric workflow in the field for the construction of a 3D rock joint surface database. Innovations in some steps make it practical for field scenarios: image collection procedures in the field and post-processing steps of the SfM-MVS-derived dense point cloud. The performance is considered as good as that of white light scanning, and sub-millimetre accuracy is achieved during batch processing. Two rock joint databases containing 310 samples are established, and two application examples show very good potential of the proposed photogrammetric workflow in the evaluation of rock joint roughness and rock joint anisotropy.

This paper presents a particle shape characterization and reconstruction method to describe the geometrical information of granular railway ballast. The outline of a real granular particle is segmented and transformed as discrete time domain signals based on Fourier transform method. Then, the discrete Fourier transform algorithm is developed and applied to convert discrete time domain signals into a discrete Fourier spectrum. Meanwhile, the normalized amplitudes are defined as Fourier descriptors, which is found to be applicable to characterize and reconstruct particle contour. Further, the proposed method is validated by comparing the contours of the real particle with that of reconstructed particle. Moreover, the shape indexes of particles Fourier descriptors and reconstruction of ballasted gravel are illustrated and the the results show that the geometrical parameters can be classified as three levels which can represent the geometrical characteristics in terms of macroscopical and microscopic structure. The inverse discrete Fourier transform can quantitatively control the shape of reconstructed particles by controlling the value and distribution of Fourier descriptors, which matchs the three levels of shape indexes. Furthermore, it can be found that a large number of virtual particles with similar geometrical features can be reconstructed using the proposed Fourier descriptors in a rapid and convenient manner, which is beneficial for providing a virtual test sample for the numerical modeling of realistic granular materials.

Hydrophilic characteristics of rocks are affected by their microscopic pore structures, which clearly change after water absorption. Water absorption tests and scanning electron microscopic (SEM) experiments on rock samples, located at a site in Tibet, China, were carried out. Changes of rock pore structures before and after water absorption were studied with the distribution of pore sizes and fractal characteristics of pores. The results show that surface porosities, fractal dimensions of pores and the complexity of pore structures increased because the number of new small pores produced increased or the original macropore flow channels were expanded after rocks absorbed water. There were points of inflection on their water absorption curves. After water absorption of other rocks, surface porosities and fractal dimensions of pores and complexity of pore structures decreased as the original pore flow channels became filled. Water absorption curves did not change. Surface porosity and the pore fractal dimensions of rocks have good linear relationships before and after water absorption.

In order to capture the mechanism of roadway instability in deep mines, a new approach of Physically Finite Elemental Slab Assemblage (PFESA) is proposed in order to construct a large-scale physical model simulating the geologically horizontal strata. We carried out physical modeling on the deformation and failure processes of roadways subjected to a plane loading scheme. Our laboratory tests were based on work which incorporated infrared (IR) detection, IR radiation temperature (IRT) statistics, image feature extraction and 2D Fourier transformation, from resulting thermographies. The IRT characterizes the mechanical responses from the roadway after loading with two stages, i.e., IRT evolving at higher levels corresponded to shallow mining (fl500 m) during which the roadway deformed gradually (referred to as the “steady deformation stage”); IRT evolving in a quasi-cyclical manner with multiple peaks corresponded to deep mining (800–2600 m), in which the failure mode for the roadway are dominated by breakage and collapse (called the “unsteady deformation stage”). The IR images and 2D Fourier spectra illustrate detailed information in terms of initiation, nucleation and coalescence of the damage to rock masses and the eventual failure of roadways subject to external loading.

Taking Shihezi single tower cable-stayed bridge as the engineering background to establish finite element seismic model, using the nonlinear dynamic time history to get seismic analysis of the bridge under strong earthquake. In order to study the effect of damping constrained system on single tower cable-stayed bridge's seismic performance, this paper makes a contrastive analysis about the longitudinal, lateral different constrained system. In the longitudinal direction, we make a seismic calculation under the rare earthquake action while the single tower cable-stayed bridge respectively use different constrained system, such as rigid system, floating system, vertical supporting system, vertical support and elastic cable system, vertical support and viscous damper (FVD), etc, drawing the following conclusion: When using the movable support as the vertical bearing, friction resistance of the bearing can greatly improved the seismic performance of the structure, so its influence should be considered while calculating, the system that includes vertical support and the FVD is the optimal longitudinal seismic constrained system correspondingly. In the lateral direction, we respectively make a seismic calculation under the rare earthquake action while the pylons respectively use rigid system, floating system, transverse hinged, transverse free, vertical support and elastic cable, vertical support and viscous dampers (FVD) etc different constrained forms, transition pier respectively use transverse hinged, transverse free, lead rubber bearing, vertical support and viscous dampers (FVD) etc different constrained forms, drawing the following conclusions: If the force of transition pier stress has no conclusive effect on the design, the main tower with vertical support and viscous dampers while the transition pier with transverse hinged is the relatively optimal constrained system, If the force of transition pier stress has conclusive effect on the design, the main tower with vertical support and elastic cable while the transition pier with lead rubber bearings is the relatively optimal constrained system.

Defect review is a time consuming job. Human error makes result inconsistent. The defects located on don’t care area would not hurt the yield and no need to review them such as defects on dark area. However, critical area defects can impact yield dramatically and need more attention to review them such as defects on clear area. With decrease in integrated circuit dimensions, mask defects are always thousands detected during inspection even more. Traditional manual or simple classification approaches are unable to meet efficient and accuracy requirement. This paper focuses on automatic defect management and classification solution using image output of Lasertec inspection equipment and Anchor pattern centric image process technology. The number of mask defect found during an inspection is always in the range of thousands or even more. This system can handle large number defects with quick and accurate defect classification result. Our experiment includes Die to Die and Single Die modes. The classification accuracy can reach 87.4% and 93.3%. No critical or printable defects are missing in our test cases. The missing classification defects are 0.25% and 0.24% in Die to Die mode and Single Die mode. This kind of missing rate is encouraging and acceptable to apply on production line. The result can be output and reloaded back to inspection machine to have further review. This step helps users to validate some unsure defects with clear and magnification images when captured images can’t provide enough information to make judgment. This system effectively reduces expensive inline defect review time. As a fully inline automated defect management solution, the system could be compatible with current inspection approach and integrated with optical simulation even scoring function and guide wafer level defect inspection.

An either simple or stylish lifting device was designed according to the engineering requirement for steel billet moving equipment by rolling mills. And equivalent moment of inertia and equivalent of the torque are worked out, using matlab. Finally, it is a feasible mechanism showed by the computational results and provides a basis for the subsequent structural design and optimal design.

The concept of the antiseismic energy dissipation safety factor of the reinforced concrete bridge pier is put forward based on the dynamic energy equation of multi-degree structures and the inverse deduction of the Park-Ang damage model under given displacement and damage controlling conditions. In addition, a real concrete pier is analyzed in practical to show the feasibility of the theory, where the popular finite element software is utilized. The results show that the real ability of energy dissipation of the reinforced concrete bridge pier can be calculated under given displacement and damage controlling conditions and then the safety factor can be obtained subsequently in varied earthquake waves. This method may provide an effective means for the antiseismic assessment of the existing concrete bridge piers.

This article is based on the basic principle of the calculation of friction losses of prestressed tendon in post-tensioning, and it also put forward a new method which can measure effectively coefficient of friction (μ), wobble factor (k) and the friction loss rate of anchorage zone. With the measured actual elongation of prestressed tendon and the known jacking force, the method can get the unknown parameters by solving nonlinear equations. This method does not need to use stress sensor, and the test can be done with the only need of common measuring tools and equipment, and the process is simple. It has important reference value to construction and detection of post-tensioning system.

Embedded block coding with optimized truncation (EBCOT) algorithm plays a basic and crucial part in JPEG2000 still image compression system. This paper proposes VLSI architecture of EBCOT, in which a dynamic memory control (DMC) strategy is used to reduce 60% of the on-chip wavelet coefficients storage. A parallel architecture is proposed to speed-up the coding process. This architecture can be used as a compact and efficient IP core for JPEG2000 VLSI implementation and various real-time image and video applications.