Energy Efficiency Concerns and Trends in Future 5G Network Infrastructures

Energy efficiency is a huge opportunity for both the developed and the developing world, and ICT will be the key enabler towards realising this challenge, in a huge variety of ways across the full range of industries. In the telecommunications space in particular, power consumption and the resulting energy-related pollution are becoming major operational and economical concerns. The exponential increases in network traffic and the number of connected devices both make energy efficiency an increasingly important concern for the mobile networks of the (near) future. More specifically, as 5G is being deployed at a time when energy efficiency appears as a significant matter for the network ability to take into account and to serve societal and environmental issues, this can play a major role in helping industries to achieve sustainability goals. Within this scope, energy efficiency has recently gained its own role as a performance measure and design constraint for 5G communication networks and this has identified new challenges for the future. In particular, the inclusion of AI/ML techniques will further enhance 5G’s capabilities to achieve lower power consumption and, most importantly, dynamic adaption of the network elements to any sort of energy requirements, to ensure effective functioning.

Global feedforward active noise control using a linearly constrained loudspeaker beamformer and a sensor interpolation approach

The key issue of three-dimensional active noise control (3D ANC) problems is that global control is generally difficult, given limited number of discrete sensors. In this paper, feedforward multi-channel ANC approach is proposed to circumvent this difficulty. In view of the model-matching principle and multiple secondary sources, an underdetermined multi-channel inverse filtering (UMIF) system is formulated. With this UMIF system as a design constraint, a cost function is introduced to minimize the noise energy at a large number of control points. This linearly constrained minimum variance (LCMV) proves effective in broadening the controlled area in a 3D space. Optimal deployment of control points and the regularization terms of LCMV approach are also examined. To implement the proposed ANC system in a non-freefield environment, sensor interpolation can be used to find the frequency response between control points and loudspeakers, with plane wave decomposition and some room response measurements. The proposed ANC system has been implemented on a six-element linear loudspeaker array. Simulation and experiment results have demonstrated that the propose approach has yielded significant noise reduction performance in a large control area.

Macro and Micro-Geometric Robust Design of Cylindrical Roller Bearings Using Fatigue and Wear Considerations

Cylindrical roller bearings have been chosen for the optimization using a robust design because tolerances are always provided during manufacturing. For rolling element bearings, a measure of satisfactory performance is a long life, lubrication and thermal characteristics. Hence, the first two objectives have been optimized simultaneously using the robust design. For bearing design, variables chosen include four basic internal dimensions and five design constraint factors. Genetic algorithm is implemented for solving the problem by considering both the objective functions, simultaneously. The lives of the bearing are found to be improved at least two times that of the standard bearings. It has been found that during manufacturing, designer should have more attention on the roller diameter compared to others dimensions.

AIMED CONTROL OF THE FREQUENCY SPECTRUM OF EIGENVIBRATIONS OF ELASTIC PLATES WITH A FINITE NUMBER OF DEGREES OF FREEDOM OF MASSES BY SUPERIMPOSING ADDITIONAL CONSTRAINTS

As is known, for some elastic systems with a finite number of degrees of freedom of masses, for which thedirections of motion of the masses are parallel and lie in the same plane, methods have been developed for creatingadditional constraints that purposefully change the spectrum of natural frequencies. In particular, theory and algorithm forthe formation of aimed additional constraints have been developed for the rods, the introduction of each of which doesnot change any of the modes of natural vibrations, but only increases the value of only one frequency, without changingthe values of the remaining frequencies. The distinctive paper is devoted to the method of forming a matrix of additionalstiffness coefficients corresponding to such aimed constraint in the problem of natural vibrations of rods. This method canalso be applied to solving a similar problem for elastic systems with a finite number of degrees of freedom, in which thedirections of motion of the masses are parallel, but not lie in the same plane. In particular, such systems include plates.However, the algorithms for the formation of aimed additional constraints, developed for rods and based on the propertiesof rope polygons, cannot be used without significant changes in a similar problem for plates. The method for the formationof design constraint schemes that purposefully change the spectrum of frequencies of natural vibrations of elastic plateswith a finite number of degrees of freedom of masses, will be considered in the next work.

Measuring the Power Efficiency Of Subthreshold FPGAs For Implementing Portable Biomedical Applications

Power is a significant design constraint for implementing portable applications. Operating transistors in the subthreshold region can significantly reduce power consumption while reducing performance. The low frequency nature of biosignals makes a FPGA operating subthreshold region a good candidate. In this work, I investigate the feasibility of desinging such a device and the trade-off between power consumpation and performance for FPGA routing resources operating in the subthreshold region. For the 32nm Predictive Technology Model studied in this work, it was observed a power reduction of 197.7 times (or power-delay-product reduction of 3.3 times) for operating under a supply voltage of 0.4 volts (as compared to normal operation in the saturation region using a 0.9V). Under a supply voltage of 0,4 volts, FPGA can operate at 2.0 MHz while allowing signals to propagate unregistered through 20 routing tracks which meets the real-time requirement for processing 20000 samples per second.

Measuring the Power Efficiency Of Subthreshold FPGAs For Implementing Portable Biomedical Applications

Power is a significant design constraint for implementing portable applications. Operating transistors in the subthreshold region can significantly reduce power consumption while reducing performance. The low frequency nature of biosignals makes a FPGA operating subthreshold region a good candidate. In this work, I investigate the feasibility of desinging such a device and the trade-off between power consumpation and performance for FPGA routing resources operating in the subthreshold region. For the 32nm Predictive Technology Model studied in this work, it was observed a power reduction of 197.7 times (or power-delay-product reduction of 3.3 times) for operating under a supply voltage of 0.4 volts (as compared to normal operation in the saturation region using a 0.9V). Under a supply voltage of 0,4 volts, FPGA can operate at 2.0 MHz while allowing signals to propagate unregistered through 20 routing tracks which meets the real-time requirement for processing 20000 samples per second.

Steam Turbine Overspeed Scenarios: Comparison Between API Energy Method and Dynamic Simulation

In turbomachinery applications the possibility to reduce size and costs of main flow-path components, by increasing shaft rotating speed, has always been appealing. The technological challenge in increasing this power density capability is typically related to performance prediction, to operating stress in blades and shafts, as well as to the need for a more accurate rotor-dynamic analysis. Yet another aspect, often reduced to standard assessments in less demanding applications, is related to the analysis of overspeed scenarios where, following a sudden loss of load and/or driven inertia, the turbomachine shall maintain its mechanical integrity. Especially in steam turbines applications, where the behavior of the machine is strongly affected by the plant conditions, valves intervention time and connected volumes, the reduction of the rotor inertia, against comparable power, may produce overspeed scenarios that can become a primary design constraint and, if overlooked, may have both availability and safety implications. In this paper several approaches to the analysis of overspeed scenarios are discussed, with increasing level of detail. The energy-based overspeed analysis method, as required by API612, is first discussed against practical design cases. A more accurate dynamic model is then presented, and its results compared with those of the energy-based approach. Finally, the sensitivity analysis of the overspeed peak value with respect to critical design parameters is discussed. With respect to previous works, mostly based on load rejection scenarios, the main focus is on the scenario of sudden coupling loss.

Research on the application of 3D reconstruction technology in traditional handicraft design

The use of computer technology for three-dimensional (3 D) reconstruction is one of the important development directions of social production. The purpose is to find a new method that can be used in traditional handicraft design, and to explore the application of 3 D reconstruction technology in it. Based on the description and analysis of 3 D reconstruction technology, the 3 D reconstruction algorithm based on Poisson equation is analyzed, and the key steps and problems of the method are clarified. Then, by introducing the shielding design constraint, a 3 D reconstruction algorithm based on shielded Poisson equation is proposed. Finally, the performance of two algorithms is compared by reconstructing the 3 D image of rabbit. The results show that: when the depth value of the algorithm is 11, the surface of the rabbit image obtained by the proposed optimization algorithm is smoother, and the details are more delicate and fluent; under different depth values, with the increase of the depth value, the number of vertices and faces of the two algorithms increase, and the optimal depth values of 3 D reconstruction are more than 8. However, the proposed optimization algorithm has more vertices, and performs better in the reconstruction process; the larger the depth value is, the more time and memory are consumed in 3 D reconstruction, so it is necessary to select the appropriate depth value; the shielding parameters of the algorithm have a great impact on the fineness of the reconstruction model. The larger the parameter is, the higher the fineness is. In a word, the proposed 3 D reconstruction algorithm based on shielded Poisson equation has better practicability and superiority.

Practical Considerations of Wastewater–Seawater Integrated Reverse Osmosis: Design Constraint by Boron Removal

The wastewater–seawater (WW-SW) integrated reverse osmosis (RO) process has gained much attention in and out of academia due to its energy saving capability, economic benefits, and sustainability. The other advantage of this process is to reduce boron concentration in the RO permeate that can exclude the post-treatment process. However, there are multiple design constraints regarding boron removal that restrict process design in the WW-SW integrated system. In this study, uncertainties in design factors of the WW-SW integrated system in consideration of boron removal have been explored. In comprehensive consideration of the blending ratio of between WW and SW, regulatory water quality standard, specific energy consumption (SEC), specific water cost, and RO recovery rate, a range of 15,000~20,000 mg/L feed turned out to be the most appropriate. Furthermore, boron rejection tests with SWRO (seawater reverse osmosis) and BWRO (brackish water reverse osmosis) membranes under actual WW-SW integration found a critical reduction in boron rejection at less than 20 bar of operating pressure. These findings emphasize the importance of caution in the use of BWRO membranes in the WW-SW integrated RO system.