液晶显示器(LCD)用基板玻璃浅析

网络与无线通信技术的发展及其产品的迅速普及,全球数字化进程的快速推进,促成了信息技术(IT)与产业的蓬勃兴起,也为映像和显示技术创造了广阔的市场和良好的发展机遇。各种信息显示技术成为众多研究开发和产业投资的热点。其中,液晶显示器(LCD:Liquid Crystal     

求解带有等式约束的混合整数非线性规划问题的粒子群算法

针对带有等式约束的混合整数非线性规划(MINLP)问题,建立了一种改进的粒子群优化(PSO)算法--简约空间法.利用等式约束将问题的维数降低,使带有等式约束的优化问题转化为无等式约束优化问题.通过测试函数和过程综合的实例对该算法进行了测试并与其他算法所得的结果进行了比较,结果表明,PSO算法在使用的普遍性、求解的准确性等方面都优于一般的算法,尤其对于非凸的MINLP问题,PSO算法是一种有效的求解方法.     

Use of sequential x-ray fluorescence analysis for solving analytical problems in the glass industry

The capabilities of x-ray spectral instruments for fast analysis of raw materials and glass and ceramics were demonstrated. The range of the content of determinable elements in a sample ranges from 1 ppm to 100%. The measurement time is 10–15 sec.     

基于GPU加速求解MINLP问题的SQP并行算法

针对确定性算法求解大型复杂混合整数非线性规划的时间不可接受问题,通过对序贯二次规划算法(SQP)和图形处理器(GPU)的架构特点分析,提出了基于GPU加速策略的并行化SQP算法。算法的主要思想是通过枚举法确定二元变量的取值,在保证取值完整的基础上,使用CPU+GPU的并行策略,同时运用大量线程进行非线性规划子问题的求解。算例的数值实验结果表明:本文所提出的算法较之传统串行计算具有较好的加速效果,特别适合求解二元变量较多,约束条件相对少的MINLP问题。     

LCD和TFT-LCD用玻璃基片

液晶显示器(LCD)由于具有低功耗、高画质和轻巧等诸多优势,已成为平板显示领域的主导技术。市场上应用的LCD主要有TN-LCD(扭曲向列型液晶显示器)、STN-LCD(超扭曲向列型液晶显示器)及TFT-LCD(薄膜晶体管液晶显示器)三种。     

Exergy as an objective function to MINLP problems in process synthesis

The optimal layout of a chemical plant is determined by both economic and environmental aspects. The mathematical approach to this problem is given by representing the process through a superstructure, including any foreseeable process topology. It is described by integer variables, whereas real variables arise from the unit models and the thermodynamic calculations. By including process constraints and an objective function, a Mixed Integer Nonlinear Programming (MINLP) optimization problem is postulated. In this paper MINLP algorithms are combined with a technique for the exergy analysis of chemical processes for the preliminary screening of process alternatives. The exergy analysis as a screening technique is advantageous due to a significantly smaller amount of required data and computing time, compared with true optimization, including cost estimation at an earlier stage of process synthesis and analysis. Thus, a broader solution space can be examined. The subsequent cost analysis has then only to be focused on a reduced set of parameters.     

Criterion for employing bivariate formulations in collision-coalescence problems

A constant kernel collision and coalescence model in bivariate moment form is used to develop a criterion for when a bivariate formulation of the collision-coalescence problem is necessary. This analysis springs from a previous publication in which the more complex problem of simultaneous collision, coalescence and breakage is considered.     

Using redundancy to strengthen the relaxation for the global optimization of MINLP problems

In this paper we present a strategy to improve the relaxation for the global optimization of non-convex MINLPs. The main idea consists in recognizing that each constraint or set of constraints has a meaning that comes from the physical interpretation of the problem. When these constraints are relaxed part of this meaning is lost. Adding redundant constraints that recover that physical meaning strengthens the relaxation. We propose a methodology to find such redundant constraints based on engineering knowledge and physical insight.     

Novel bound contraction procedure for global optimization of bilinear MINLP problems with applications to water management problems

We propose a new method to obtain the global optimum of MINLP problems containing bilinearities. Our special method that contracts the bounds of one variable at a time allows reducing the gap between a linear lower bound and an upper bound obtained solving the original problem. Unlike some methods based on variable partitioning, our bound contraction procedure does not introduce new integers or intervals. We illustrate the method by applying it to water management problems.     

A chrome-corundum refractory in the packing for a glass furnace regenerator

Translated from Steklo i Keramika, No. 1, pp. 11–14, January, 1991.     

Symmetry breaking in MILP formulations for Unit Commitment problems

This paper addresses the study of symmetry in Unit Commitment (UC) problems solved by Mixed Integer Linear Programming (MILP) formulations, and using Linear Programming based Branch & Bound MILP solvers. We propose three sets of symmetry breaking constraints for UC MILP formulations exhibiting symmetry, and its impact on three UC MILP models are studied. The case studies involve the solution of 24 instances by three widely used models in the literature, with and without symmetry breaking constraints. The results show that problems that could not be solved to optimality within hours can be solved with a relatively small computational burden if the symmetry breaking constraints are assumed. The proposed symmetry breaking constraints are also compared with the symmetry breaking methods included in two MILP solvers, and the symmetry breaking constraints derived in this work have a distinct advantage over the methods in the MILP solvers.