A New Device for Gas-Liquid Flow Measurements Relying on Forced Annular Flow

A new measurement device,consisting of swirling blades and capsule-shaped throttling elements,is proposed in this study to eliminate typical measurement errors caused by complex flow patterns in gas-liquid flow.The swirling blades are used to transform the complex flow pattern into a forced annular flow.Drawing on the research of existing blockage flow meters and also exploiting the single-phase flow measurement theory,a formula is introduced to measure the phase-separated flow of gas and liquid.The formula requires the pressure ratio,Lockhart-Martinelli number(L-M number),and the gas phase Froude number.The unknown parameters appearing in the formula are fitted through numerical simulation using computational fluid dynamics(CFD),which involves a comprehensive analysis of the flow field inside the device from multiple perspectives,and takes into account the influence of pressure fluctuations.Finally,the measurement model is validated through an experimental error analysis.The results demonstrate that the measurement error can be maintained within±8%for various flow patterns,including stratified flow,bubble flow,and wave flow.

Impact of Migrant Populations on Tuberculosis Rates in Saudi Arabia: Assessing How Migration Patterns Affect TB Incidence and Control Measures: A Narrative Review

This research focuses on the effects of migration on the TB infection rate and its prevention in Saudi Arabia, which has a large number of expatriates from TB-affected countries. Despite, based on the current global statistics of TB occurrence, it is evident that the national incidence of TB has reduced from 10.55 per 100,000 in 2015 to 8.36 per 100,000 in 2019;despite this, there are still some difficulties because migrants bring new strains of Mycobacterium tuberculosis. Hindrances, including language barriers and perceived immigration status, hinder patients from seeking medical attention or doctors from diagnosing diseases. Each patient and each cultural group need special attention to public health, enhancing living circumstances, and health care support. Community participation, inclusion of TB control programs into functional healthcare facilities, and the functioning of TB programs need to be stressed to address TB issues. Considering the focus on social, economic, and cultural approaches, the country can make severe advancements in TB control and population protection. This holistic analysis is critical for a long-term effective strategy to combat TB in the Kingdom.

RESEARCH ON MECHANICAL MEASUREMENT-ORIENTED INTELLIGENT VIRTUAL CONTROLS

Intelligent virtual control (IVC) is an intelligent measurement instrumentunit with the function of actual measurement instruments, and the unit can be used as basic buildingblock for a variety of more complex virtual measurement instruments on a PC. IVC is a furtheradvancement from virtual instrument (VI), and it fuses the function modules and the controls modulesso that the relationship between the functions and controls of an instrument is imbedded in one ormore units. The design, implementation and optimization methods of IVCs are introduced. The computersoftware representation of IVCs is discussed. An example of an actual VI constructed with thebuilding blocks of IVCs is given.

Behavior Measurement Model Based on Prediction and Control of Trusted Network

In order to construct the trusted network and realize the trust of network behavior,a new multi-dimensional behavior measurement model based on prediction and control is presented.By using behavior predictive equation,individual similarity function,group similarity function,direct trust assessment function,and generalized predictive control,this model can guarantee the trust of an end user and users in its network.Compared with traditional measurement model,the model considers different characteristics of various networks.The trusted measurement policies established according to different network environments have better adaptability.By constructing trusted group,the threats to trusted group will be reduced greatly.Utilizing trusted group to restrict individuals in network can ensure the fault tolerance of trustworthiness of trusted individuals and group.The simulation shows that this scheme can support behavior measurement more efficiently than traditional ones and the model resists viruses and Trojans more efficiently than older ones.

Controlled teleportation of high-dimension quantumstates with generalized Bell-state measurement

In this paper a scheme for controlled teleportation of arbitrary high-dimensional unknown quantum states is proposed by using the generalized Bell-basis measurement and the generalized Hadamard transformation. As two special cases, two schemes of controlled teleportation of an unknown single-qutrit state and an unknown two-qutrit state are investigated in detail. In the first scheme, a maximally entangled three-qutrit state is used as the quantum channel, while in the second scheme, an entangled two-qutrit state and an entangled three-qutrit state are employed as the quantum channels. In these schemes, an unknown qutrit state can be teleported to either one of two receivers, but only one of them can reconstruct the qutrit state with the help of the other. Based on the case of qutrits, a scheme of controlled teleportation of an unknown qudit state is presented.

H-infinity measurement-feedback control for discrete-time systems with a single measurement delay

H-infinity control problem for linear discrete-time systems with instantaneous and delayed measurements is studied. A necessary and sufficient condition for the existence of the H-infinity controller is derived by applying reorganized innovation analysis approach in Krein space. The measurement-feedback controller is designed by performing two Riccati equations. The presented approach does not require the state augmentation.

PRECISE INTEGRATION METHOD FOR LQG OPTIMAL MEASUREMENT FEEDBACK CONTROL PROBLEM

By using the precise integration method, the numerical solution of linear quadratic Gaussian (LQG) optimal control problem was discussed. Based on the separation principle, the LQG central problem decomposes, or separates, into an optimal state-feedback control problem and an optimal state estimation problem. That is the off-line solution of two sets of Riccati differential equations and the on-line integration solution of the state vector from a set of time-variant differential equations. The present algorithms are not only appropriate to solve the two-point boundary-value problem and the corresponding Riccati differential equation, but also can be used to solve the estimated state from the time-variant differential equations. The high precision of precise integration is of advantage for the control and estimation. Numerical examples demonstrate the high precision and effectiveness of the algorithm.

Active Disturbance Rejection Control for Uncertain Nonlinear Systems With Sporadic Measurements

This paper deals with the problem of active disturbance rejection control(ADRC)design for a class of uncertain nonlinear systems with sporadic measurements.A novel extended state observer(ESO)is designed in a cascade form consisting of a continuous time estimator,a continuous observation error predictor,and a reset compensator.The proposed ESO estimates not only the system state but also the total uncertainty,which may include the effects of the external perturbation,the parametric uncertainty,and the unknown nonlinear dynamics.Such a reset compensator,whose state is reset to zero whenever a new measurement arrives,is used to calibrate the predictor.Due to the cascade structure,the resulting error dynamics system is presented in a non-hybrid form,and accordingly,analyzed in a general sampled-data system framework.Based on the output of the ESO,a continuous ADRC law is then developed.The convergence of the resulting closed-loop system is proved under given conditions.Two numerical simulations demonstrate the effectiveness of the proposed control method.

Study on DeviceNet communication mechanism and its application in protection measurement and control system

To fit in with the developing requirement of int and communication of protective relays, a protection egrated functions of protection measurement, control measurement and control system based on DeviceNet fieldbus is designed. The communication mechanism of DeviceNet is studied and data trigger modes, communication connection, message types and other key technologies are analyzed. The object modeling and device description of the device are realized too. Results of network test, dynamic simulation and test in the field indicate that this system can accomplish all the communication tasks in real time and can make precise response to every kind of faults of the motor, transformer, line and capacitor. Moreover, this system has higher measurement precision and better control capability.

A review on stress determination and control in metal-based additive manufacturing

Metal additive manufacturing(MAM)is an emerging and disruptive technology that builds three-dimensional(3D)components by adding layer-upon-layer of metallic materials.The complex cyclic thermal history and highly localized energy can produce large temperature gradients,which will,in turn,lead to compressive and tensile stress during the MAM process and eventually result in residual stress.Being an issue of great concern,residual stress,which can cause distortion,delamination,cracking,etc.,is considered a key mechanical quantity that affects the manufacturing quality and service performance of MAM parts.In this review paper,the ongoing work in the field of residual stress determination and control for MAM is described with a particular emphasis on the experimental measurement/control methods and numerical models.We also provide insight on what still requires to be achieved and the research opportunities and challenges.

Dynamics of super-quantum discord and direct control with weak measurement in open quantum system

Super-quantum discord（SQD） with weak measurement is regarded as a kind of quantum correlation in quantum information processing. We compare and analyze the dynamical evolutions of SQD, quantum discord（QD）, and quantum entanglement（QE） between two qubits in the correlated dephasing environmental model. The results indicate that（i） owing to the much smaller influence of weak measurement on the coherence of the system than that of von Neumann projection measurement, SQD with weak measurement is larger than QD, and（ii） dynamical evolution of QD or QE monotonically goes to zero with time, while SQD monotonically tends to a stable value and a freezing phenomenon occurs. The stable value after freezing mainly depends on the measurement strength and the purity of the initial quantum state.

The Measurement and Control of Diameter in Large-Scale Part Processing

Based on laser-scanned measuring technology, a met ho d of on-line dynamic non-contact measurement and feedback control of processin g dimension, i.e. the double edges laser-scanned large diameter on-line dynami c measurement and control system is presented, which can be used to measure diam eter in large-scale machine part processing. In this paper, the working princip le, overall structure and microcomputer real-time control and data processing s ystem of the system are discussed in detail, the method of double edges scanned large diameter dimension measurement and control is theoretically analyzed, its possibility has been verified by experiments of lathing large diameters machine parts by a vertical lathe. The system adopts the measuring scheme of double edge s laser-scanned combined with grating displacement measurement. The two edges c haracteristic information of the measured diameter is given by the double edges laser-scanned measuring system, the non-contact measurement of large diameter dimension is realized to combine with the grating displacement measuring systems . The main controller gives out feedback control signal by means of measured res ults, and controls advance and retreat of lathe tool by the servo-control syste m of a vertical lathe to realize on-line dynamic non-contact measurement and c ontrol in processing.

Software Development for Digital Control of WDW Series Testing Machine and Measurement of K_(IC)

Software has been developed for digital control of WDW series testing machine and the measurement of fracture toughness by modularized design. Development of the software makes use of multi-thread and serial communication techniques, which can accurately control the testing machine and measure the fracture toughness in real-time. Three-point bending specimens were used in the measurement. The software operates stably and reliably, expanding the function of WDW series testing machine.

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.

A Study of Model for Distributed Measurement and Control System

This paper is concerned with a method for forming distributed measurement and control system.A three-layer structure model based on network,physical node layer and func-tion node layer is discussed.It is designed on object-oriented software method.The model has a fine application prospect.

Design of a Modularized Automatic Measurement and Control System for LaserInduced Breakdown Spectrometer

In order to improve the compatibility of laser-induced breakdown spectroscopy( LIBS) instrument for different types of parts and optimize the analysis and testing processes,a modularized automatic measurement and control system was developed. Based on the characteristics of each LIBS component, the following development steps have been performed:( 1) a summary of characteristic parameters of the component are established;( 2) the integration mechanism of multiple electrical interfaces is designed;( 3) the component control instruction library is developed. The experimental results indicate that the measurement and control system is compatible with most LIBS parts in the market.Spectrometer and laser can be compatible with at least three different types of parts. In addition,a multilayer iterative testing process is designed to improve the efficiency of optimization process of LIBS parameters. The experimental results have shown that the automatic optimization of the delay time compared to the manual testing provides significant gain in testing efficiency. The range of delay time in the experiments is 1. 28 to 10. 28 μs and the step value is 1,0. 5,0. 2 and 0. 1 μs. The gain in testing efficiency has been found to be increased by 73. 76%,75. 93%,78. 81% and 80. 42%,respectively.

Problems in Water Environmental Control—Sense and Nonsense in Measurement of Water Protection

Water environmental control and process refinement inside a wastewater treatment plant (WWTP) is fundamentally based on sampling, analysis and on-line measurements on water and sludge streams. The problems related to an accurate and reliable control and thus an efficient water protection are addressed in the following. Four different crucial points whenever a sampling and control scheme is planned: 1) Where should a sampling and on-line measurement take place? 2) When should sampling take place? 3) How should the sampling and on-line measurement take place? 4) Which variables should be controlled? Examples are given from different plants demonstrating ways to address the questions. Especially the relevance of the adopted parameter BOD (Biochemical Oxygen Demand) is discussed. It is finally suggested to even abandon the use of BOD as consent variable in favor of on-line measurement of Suspended Solids, Nitrogen and Phosphorous.

Markov Quantum Feedback Control Based on Homodyne Measurement of a Two-Qubit System

We consider the system consisting of two qubits collectively damped, with the output being unit-efficiency measured and subsequently fed back to control the system state. Our primary goal in this paper is （i） to solve the feedback-modified master equation, （ii） to demonstrate the ability of feedback control based on the solutions, and （iii） to pick out different steady states by choosing different driving strengths and feedback strengths to counteract the effects of both damping and the measurement back-action on the system. We further investigate some properties of the equilibrium steady state, its distribution probability and entanglement vs. the driving and feedback amplitudes. We find that in our feedback model feedback plays a negative role in producing entanglement.

Study of measurement and control of free loop of hot steel strip in twin-roll strip casting

In the twin-roll strip casting process, hot cast strips can be broken or tom if the casting speed does not match the rolling speed. Usually, a certain length of hot steel strip is hung freely between the caster and rolling mill to deal with the effect of this speed difference. In this paper,the freely hanging hot steel strip is referred to as the free loop of hot steel strip. Accurately measuring and controlling the height of this free loop is the key factor in maintaining a stable casting operation. Several methods for measuring the loop height of a steel strip are discussed and a method for accurately measuring and controlling the free loop height of hot steel strip is presented. Based on the results of the casting loop quantity change curve, this control method is confirmed to be effective and able to meet the requirements of continuous casting strip production.

MEASUREMENT AND CONTROL OF THE JET FLOTATION COLUMN

According to the new structure of the jet flotation column, a system which can measure and control the parameters of the column flotation system is successfully designed.