Mathematical Apparatus for Selection of Optimal Parameters of Technical, Technological Systems and Materials Based on Vector Optimization

We presented Mathematical apparatus of the choice of optimum parameters of technical, technological systems and materials on the basis of vector optimization. We have considered the formulation and solution of three types of tasks presented below. First, the problem of selecting the optimal parameters of technical systems depending on the functional characteristics of the system. Secondly, the problem of selecting the optimal parameters of the process depending on the technological characteristics of the process. Third, the problem of choosing the optimal structure of the material depending on the functional characteristics of this material. The statement of all problems is made in the form of vector problems of mathematical (nonlinear) programming. The theory and the principle of optimality of the solution of vector tasks it is explained in work of https://rdcu.be/bhZ8i. The implementation of the methodology is shown on a numerical example of the choice of optimum parameters of the technical, technological systems and materials. On the basis of mathematical methods of solution of vector problems we developed the software in the MATLAB system. The numerical example includes: input data (requirement specification) for modeling;transformation of mathematical models with uncertainty to the model under certainty;acceptance of an optimal solution with equivalent criteria (the solution of numerical model);acceptance of an optimal solution with the given priority of criterion.

Production base of annual 3000 tons sintered NdFeB of SinoMagnetics Technology goes into operation

Sino magnetics technology is a high-tech enterprise specializing in R&D and production of rare earth permanent magnet materials.It is reported that the enterprise has accelerated the construction of annual3000 tons of high performance sintered NdFeB production base,and the construction of the base has been completed and put into use.

Key technologies for medium and low voltage DC distribution system

Development of the medium and low voltage DC distribution system is of great significance to a regional transmission of electric energy,increasing a penetration rate of new energy,and enhancing a safety of the operation of the AC/DC interconnected grid.This paper first summarizes the medium and low voltage DC distribution system schemes and plans put forward by many countries,and then elaborate status of under-construction medium and low voltage DC distribution system project cases in China.Based on these project cases,this paper analyzes key issues involved in the medium and low voltage DC distribution system topologies,equipment,operation control technologies and DC fault protections,in order to provide theoretical and technical reference for future medium and low voltage DC distribution system-related projects.Finally,this paper combines a current China research status to summarize and give a prediction about the future research direction of medium and low voltage DC distribution system,which can provide reference for the research of medium and low voltage DC distribution system.

Countermeasures for dealing with the change of blast furnace raw materials

Following the dramatic increase of iron and steel output ,iron ore is increasingly in short supply ,and the quality of blast furnace （BF） raw materials is increasingly inferior. All these factors have a strong impact on the BF operation. According to the analysis of the raw material properties at Baosteel and the combination of the BF smelting mechanism and its operational practice, this study probes into the operational countermeasures for dealing with the change of raw materials and puts forward optimized BF control technology to ensure the operation of BFs is stable and smooth.

Resilience at the Core: Critical Infrastructure Protection Challenges, Priorities and Cybersecurity Assessment Strategies

The importance of a nation’s infrastructure is a vital core for economic growth, development, and innovation. Health, wealth, access to education, public safety, and helping prepare for global crises like pandemics are all dependent on functioning and reliable infrastructures. In decades, the substantial threats affecting infrastructures globally whether in the form of extreme weather, Covid-19 pandemic, or the threats of state and non-state actors’ hackers, demanded urgency in building resilience infrastructures both during crises and in more stable conditions. At the same time, the adoption of emerging and innovative technologies boosts the development of the infrastructures using information, communication, and technology (ICT) platform. This shift accelerated its evolution toward digitization where interdependent and interconnected cyberspace demands collaborative and holistic strategies in protecting critical and high risks infrastructure assets from a growing number of disruptive cyberattacks. These ever-evolving cyber threats are creating increasingly dangerous and targeted cyberattacks to damage or disrupt the critical infrastructures delivering vital services to government, energy, healthcare, transportation, telecommunication, and other critical sectors. The infrastructure’s high risks assets present serious challenges and are crucial to safety, efficiency, and reliability. Any nation must recognize and determine how to cope with any type of threats to their critical infrastructure as well as the strategies to remain resilient. This article first describes the challenges and the need for critical infrastructure protection including the related global risks challenges. It then reviews the United Nations, the European Union, and the United States’ strategies, priorities, and urgencies of critical infrastructure protection. Subsequently, it surveys the critical infrastructure protection resilience strategies including ISO, IEC, ISA, NIST, CAF and CMM frameworks.

A low-noise widely tunable Gm-C filter with frequency calibration

A fourth-order Gm-C Chebyshev low-pass filter is presented as channel selection filter for reconfigurable multi-mode wireless receivers. Low-noise technologies are proposed in optimizing the noise characteristics of both the Gm cells and the filter topology. A frequency tuning strategy is used by tuning both the transconductance of the Gm cells and the capacitance of the capacitor banks. To achieve accurate cut-off frequencies, an on-chip calibration circuit is presented to compensate for the frequency inaccuracy introduced by process variation. The filter is fabricated in a 0.13 m CMOS process. It exhibits a wide programmable bandwidth from 322.5 k Hz to20 MHz. Measured results show that the filter has low input referred noise of 5.9 n V/（Hz）^（1/2） and high out-of-band IIP3 of 16.2 d Bm. It consumes 4.2 and 9.5 m W from a 1 V power supply at its lowest and highest cut-off frequencies respectively.