Two-phase Switching Optimization Strategy in LSTM Model For Predictive Maintenance

Author(s):  
Zim Chen Chia ◽  
King Hann Lim ◽  
Terence Peng Lian Tan
Processes ◽  
2020 ◽  
Vol 8 (10) ◽  
pp. 1324
Author(s):  
Cheng Gong ◽  
Chao Guo ◽  
Haitao Xu ◽  
Chengcheng Zhou ◽  
Xiaotao Yuan

Wireless Sensor Networks (WSNs) have the characteristics of large-scale deployment, flexible networking, and many applications. They are important parts of wireless communication networks. However, due to limited energy supply, the development of WSNs is greatly restricted. Wireless rechargeable sensor networks (WRSNs) transform the distributed energy around the environment into usable electricity through energy collection technology. In this work, a two-phase scheme is proposed to improve the energy management efficiency for WRSNs. In the first phase, we designed an annulus virtual force based particle swarm optimization (AVFPSO) algorithm for area coverage. It adopts the multi-parameter joint optimization method to improve the efficiency of the algorithm. In the second phase, a queuing game-based energy supply (QGES) algorithm was designed. It converts energy supply and consumption into network service. By solving the game equilibrium of the model, the optimal energy distribution strategy can be obtained. The simulation results show that our scheme improves the efficiency of coverage and energy supply, and then extends the lifetime of WSN.


2012 ◽  
Vol 562-564 ◽  
pp. 1155-1158
Author(s):  
Hong Ling Ye ◽  
Pin Wen ◽  
Xiao Long Zheng

The natural frequency at lower orders for hydrostatic supported worktable system may easily give rise to vibration as in resonance with excitation frequency. This paper is concerned with the geometrical optimum design and dynamic modal analysis for system with hydrostatic oil fluid and worktable simultaneously. The variations of eigenfrequency, respect to oil film thickness, outer radius of worktable, recess shape and number, were discussed. The results show that, under linear increment/decrement of geometry dimension, frequency increase/decrease but in nonlinear regularity. Therefore there exists an optimum dimension resulting the optimum frequency that deviate from the rotary frequency at work and its multiple ones. Then two-phase optimization strategy was effectively programmed to get involved with finite element analysis software. It is theoretically critical to get the optimum parameter of hydrostatic supported worktable on how and practically important to guide the design in engineering.


2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Selvaraj Raja ◽  
Vytla Ramachandra Murty

Aqueous two-phase system (ATPS) composed of polyethylene glycol 6000 (PEG 6000) and sodium citrate (SC) has been proposed to recover the valuable soluble proteins from tannery wastewater. A sequential optimization strategy which included fractional factorial design (fFD) and central composite design (CCD) was employed to enhance the recovery. From this strategy, a second-order polynomial model was obtained for the protein recovery and it was validated. The optimum recovery was found as 93.46% when pH, NaCl concentration, and temperature were kept at 7.5, 0.1 M, and 33°C, respectively, for a phase system composed of 20% (w/w) PEG 6000-15% (w/w) SC. Thus the proposed ATPS can serve as an alternative to the conventional precipitation method to recover the soluble proteins from tannery wastewater.


2013 ◽  
Vol 299 ◽  
pp. 8-11
Author(s):  
Hong Ling Ye ◽  
Pin Wen ◽  
Xiao Long Zheng

In this paper, optimal parameters in hydrostatic supported worktable system with circular oil recess are calculated. The optimal model is established in which the objective is to make natural frequency deviate from speeds of the rotary work axis, and the design variables are recess number, initial oil film thickness and recess radius. As the design variable vector includes both discrete and continuous components, two-phase optimization strategy is developed. Furthermore Fibonacci method is applied to deal with the problem of discrete variable, and response surface methodology is used to form an explicit expression between the objective expression and continuous variables. Then the optimal model is solved by gradient projection method and simplex method. As a result, numerical calculation of dynamic optimization with hydrostatic worktable system with circular recess shows that two-strategy optimization algorithm is stable and effectively.


Sensors ◽  
2019 ◽  
Vol 19 (19) ◽  
pp. 4099 ◽  
Author(s):  
Ren ◽  
Song ◽  
Chu

In industrial production, soft sensors play very important roles in ensuring product quality and production safety. Traditionally, global modeling methods, which use historical data to construct models offline, are often used to develop soft sensors. However, because of various complex and unknown changes in industrial production processes, the performance of global models deteriorates over time, and frequent model maintenance is difficult. In this study, locally weighted partial least squares (LWPLS) is adopted as a just-in-time learning method for industrial soft sensor modeling. In LWPLS, the bandwidth parameter h has an important impact on the performance of the algorithm, since it decides the range of the neighborhood and affects how the weight changes. Therefore, we propose a two-phase bandwidth optimization strategy that combines particle swarm optimization (PSO) and LWPLS. A numerical simulation example and an industrial application case were studied to estimate the performance of the proposed PSO–LWPLS method. The results show that, compared to the traditional global methods and the LWPLS with a fixed bandwidth, the proposed PSO–LWPLS can achieve a better prediction performance. The results also prove that the proposed method has apparent advantages over other methods in the case of data density changes.


2013 ◽  
Vol 64 (5) ◽  
pp. 334-336 ◽  
Author(s):  
Bohumil Brtník

Abstract This paper deals with the symbolic solution of the switched current circuits. As is described, the full graph method of the solution can be used for finding relationships expressing current transfer, too. The summa MC-graph is constructed using two-graphs method in two-phase switching. By comparing the matrix form with results of the Mason’s formula are derived relations for current transfers in all phases. There are discussed various options described transistor memory cells - with loss and lossless transistors and normal transistor current mirror. Evaluation of the graph is simplified if we consider the lossless transistors or if the y21 -parameter of one transistor is alpha multiple of second ones.


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