Experimental and optimization of material synthesis process parameters for improving capacity of lithium‐ion battery

New methods for synthesis of active materials have been developed to improve capacity and cycle life performance of lithium‐ion batteries. Past studies have focused on routes of development of materials and new processes, which might not be economical for large‐scale production. In this regard, this study examines a widely employed carbothermal reduction technology for the synthesis of lithium‐iron phosphate (LiFePO₄/C) and investigates effects of process conditions during this synthesis on final battery performance. An experimental combined genetic programming approach is used to model the effects of crucial process conditions (sintering time, the carbon content, and the sintering temperature) on the discharge capacity of the assembled battery. Experiments are conducted to collect the discharge capacity data based on varying LiFePO₄/C synthesis conditions, and genetic programming is employed to develop a suitable functional relationship between them. The results show that the battery discharge capacity is controlled significantly by adjusting sintering temperature and carbon content, while the effect of sintering time is found to be insignificant. Further, the interaction effect of the sintering time and carbon content is much more obvious than that of the sintering time and the sintering temperature. The findings from the study pave the way for the optimum design of the synthesis process of LiFePO₄/C for a higher battery performance.     

Efficient 3D point clouds classification for face detection using linear programming and data mining

Most of the applications related to security and biometric rely on skin region detection such as face detection, adult 3D objects filtering, and gesture recognition. In this paper, we propose a robust method for skin detection on 3D coloured point clouds. Then, we extend this method to solve the problem of 3D face detection. To do so, we construct a weighted graph from initial coloured 3D point clouds. Then, we present a linear programming algorithm using a predictive model based on a data mining approach to classify and label graph vertices as skin and non-skin regions. Moreover, we apply some refinement rules on skin regions to confirm the presence of a face. Furthermore, we demonstrate the robustness of our method by showing and analysing some experimental results. Finally, we show that our method deals with many data that can be represented by a weighted graph such as 2D images and 3D models.     

Optimal load rating-based inspection planning of corroded steel girders using Markov decision process

Steel girder bridges are vulnerable to corrosion. To maintain their safety above a predefined target level, the load rating can be computed from the inspection results and guide the following maintenance actions. Optimizing inspection and maintenance based on load ratings has substantial practical and economic relevance. Load rating-based strategies can be categorized based on whether the inspection interval and replacement criteria are fixed or flexible. Existing studies focus on fixed inspection intervals throughout the service life. In general, their results are not optimal for inspection planning. To reduce life-cycle cost, aged steel girders may be inspected and repaired in an adaptive manner. To this end, a method based on Markov decision process (MDP) is proposed to compare the life-cycle cost of four load rating-based policies (i.e. uniform or adaptive non-uniform inspection interval, and fixed or adaptive replacement threshold). Load rating-based inspection planning is formulated as MDP and the optimal plans are obtained using dynamic programming. The conventional approach to discretize states cannot accurately approximate the non-stationary deterioration process, while state augmentation is successful in doing this but will increase computational cost. A comparison of two approaches is made to investigate their effects on life-cycle cost. A bridge girder under corrosion attack is used as an illustrative example. The results show that the load rating-based plan with an adaptive non-uniform inspection interval and fixed replacement threshold obtained using the state augmentation technique can be near-optimal.     

数控加工编程及修改的注意事项

对数控加工编程中容易出现的一些问题进行具体分析,并提出了相应的对策。强调数控编程并不是单一的纯编程,还应结合实际加工的具体情况进行考虑,才能真正发挥数控加工的高效率和高精度等特点。     

A robust mixed integer linear programming framework for underground cut-and-fill mining production scheduling

ABSTRACT

A review of general optimization studies that have been proposed for underground mining shows that previous works lack flexibility, operability and practicality in relation to cut-and-fill mining production scheduling. This paper presents a robust mixed integer linear programming (MILP) formulation for underground cut-and-fill mining. The objective function of the model is to maximize the net present value (NPV) of the operation while meeting all mining and processing operational and technical constraints. The MILP model features stope development and extraction sequencing constraints, mining and processing tonnage fluctuation constraints, and extraction duration and active levels control constraints. These features make the model more practical and expandable. The MILP model is verified and validated with two case studies from an existing mine and the results are compared with the actual mining strategy. The comparison shows a 9% to 17% improved NPV in both case studies resulting from mining higher grades and processing less tonnes thereby generating a better cash flow.     

道路工程的控制桩测设及fx-4500P编程

通过对道路工程复曲线特征分析,提出复杂线形可简化为直线、圆曲线和完全缓和曲线三种线形,以及道路工程施工控制桩可采用中、边桩的办法进行测设的两种观点,并用fx-4500P计算器编写测设计算程序。     

0—1多目标规划优化法在矿业投资方向决策中的应用

鉴于矿山采、选、冶联合企业投资方向的决策尚欠科学论证与算法,本文提出按二进制迭加为序的投资状态穷举法,配以严密的0—1多目标规划优化法的数学模型,求解多目标、多属性、多方案、多因素的矿业的投资“瓶颈”问题。借助于计算机,文中给出了理论上和算法上的可行性,提供了开发决策科学化的决策环境。     

非线性规划法在矿井综采工作面长度优化中的应用研究

根据矿井综采工作面 ,用非线性规划法对矿井综采工作面长度进行优化 ,建立有关工作面长度的目标函数和约束条件 ,经不同经济指标参数的计算 ,其理论与实际结论吻合 ,有十分明显的经济效果     

遗传算法和遗传规划及其在矿业中的应用

本文介绍一种新兴的搜索寻优技术——遗传算法和遗传规划，并论述它们在矿业中的应用。