园区多能互补供能系统设计方法研究

为提高园区多能互补工程的能源综合利用效率及整体效益，对供能系统设计中的负荷统计、逐时负荷匹配、供能系统、设备选型、容量配置及运行策略等问题进行了分析和总结，提出园区多能互补供能系统设计的基本流程与方法，可为园区多能互补供能系统的设计提供参考。     

双碳目标下的钢铁节能理念创新与能源结构重塑探讨

在“碳达峰”“碳中和”背景下,中国钢铁必须走脱碳化发展道路,提高能效是当前最为行之有效的举措之一。通过分析钢铁行业存在的较大节能潜力及拥有丰富二次能源的用能特点,在热力学定律、系统最小外部损失、最佳推动力、能源梯级利用等几项基本原则的基础上,提出钢铁行业多能互补与储能相结合的创新理念,包括钢铁二次能源与可再生能源的互补、钢铁不同高低品位能源的互补、储能系统的创新应用等。从中长期看,需以更高的站位,走能源资源环境、高效清洁低碳一体化协同创新道路,构建化工-能源-生态一体化用能系统,进行合理优化与集成,实现能效提升及协同碳减排。     

基于多能互补的综合能源系统多场景规划案例分析

综合能源系统存在冷热电气多种能源形式、多方利益主体、差异化用能需求等特点,如何统筹协调多种能源互补特性,通过源-网-荷-储等各环节灵活配置,实现可再生能源就地消纳,提升系统综合能效,是综合能源规划所面临的关键问题。结合北方某园区综合能源系统规划实例,对多场景规划理念进行了探讨,分别对能源需求预测分析、综合能源站子系统规划场景设计、建设时序及多能互补协同效益等规划环节进行了深入的分析,可为相关区域综合能源系统规划项目提供参考。     

求解对称锥互补问题的一种非精确光滑牛顿方法(英文)

本文给出了一种求解对称锥互补问题的非精确光滑牛顿方法,所采用的互补函数是含一个参数且以FB和CHKS为特例的光滑函数.新方法的每步迭代中,都采用非精确牛顿方法求解由原问题产生的子问题.在一定条件下,新算法具有全局收敛和局部超线性收敛的性质.数值试验表明算法对于求解大规模对称锥互补问题是非常有效的.     

高速率通信网络下时变系统的有限时域H∞控制

针对高速率通信网络和Round-Robin（RR）协议影响下网络化时变系统的有限时域[H∞]控制问题，考虑到系统中存在乘性噪声、随机时滞和量化效应，提出了一种基于观测器的有限时域[H∞]控制器的设计方法。利用李雅普诺夫稳定性理论和线性矩阵不等式（Linear Matrix Inequality，LMI）技术得到有限时域[H∞]控制器存在的充分条件。基于锥补线性化（Cone Complementarity Linearization，CCL）方法通过求解一组递归矩阵不等式得到观测器和控制器参数。所设计的控制器保证闭环网络化时变系统在给定的时域内稳定，且满足预定的[H∞]性能指标。数值仿真验证了所提方法的有效性。     

A direct complementarity approach for the elastoplastic analysis of plane stress and plane strain structures

This paper presents a direct complementarity approach for carrying out the elastoplastic analysis of plane stress and plane strain structures. Founded on a traditional finite‐step formulation, our approach, however, avoids the typically cumbersome implementation of iterative predictor–corrector procedures associated with the ubiquitous return mapping algorithm. Instead, at each predefined step, the governing formulation—cast in its most natural mathematical programming format known as a mixed complementarity problem—is directly solved by using a complementarity solver run from within a mathematical modeling system. We have chosen the industry‐standard General Algebraic Modeling System/PATH mixed complementarity problem solver that is called from within the General Algebraic Modeling System environment. We consider both von Mises and Tresca materials, with perfect or hardening (kinematic and isotropic) behaviors. Our numerical tests, five (benchmark) examples of which are presented in this paper, have been carried out using models constructed from the mixed finite element of Capsoni and Corradi (Comput. Methods Appl. Mech. Eng. 1997; 141 :67–93), which beneficially offers a locking‐free behavior and coarse‐mesh accuracy. The results indicate, in addition to an isochoric locking‐free behavior, good accuracy and the ability to circumvent the difficult singularity problem associated with the corners of Tresca yield surfaces. Copyright © 2012 John Wiley & Sons, Ltd.     

Some iterative algorithms for the obstacle problems

In this paper we propose some iterative algorithms for the obstacle problems discretized by the finite difference method. We rewrite the obstacle problem to an equivalent complementarity problem. We use the regularization trick to non-smooth absolute function. Then we apply the Newton's method to obtain an iterative algorithm. Some other two algorithms based on this algorithm are derived. Numerical experiments show the effective of the algorithm.     

High-accuracy finite-difference methods for the valuation of options

A finite-difference scheme often employed for the valuation of options from the Black–Scholes equation is the Crank–Nicolson (CN) scheme. The CN scheme is second order in both time and asset. For a rapid valuation with a reasonable resolution of the option price curve, it requires extremely small steps in both time and asset. In this paper, we present high-accuracy finite-difference methods for the Black–Scholes equation in which we employ the fourth-order L-stable Simpson-type (LSIMP) time integration schemes developed earlier and the well-known Numerov method for discretization in the asset direction. The resulting schemes, called LSIMP–NUM, are fourth order in both time and asset. The LSIMP–NUM schemes obtained can provide a rapid, stable and accurate resolution of option prices, allowing for relatively large steps in both time and asset. We compare the computational efficiency of the LSIMP–NUM schemes with the CN and Douglas schemes by considering valuation of European options and American options via the linear complementarity approach.     

Understanding compulsive social media use: The premise of complementing self-conceptions mismatch with technology

Some anecdotal accounts and research reports have suggested that obsessive social media involvement could turn into a compulsive behavior among university students. Unfortunately, the research that sheds light on the possible conditional nature of that relationship is scarce at best. Therefore, this study tries to address this issue by developing a contingency-based model and tests it using data gathered from a sample of university students. The model postulates that compulsive social media use arises due to self-awareness factors, and together they in turn predict problematic learning outcomes. It also postulates that these relationships are moderated by the influence of technological factors. The results indicate that self-esteem has a significant negative influence on compulsive social media use and that interaction anxiousness has a significant positive influence on the same. The results also reveal that only compulsive social media use has a significant direct influence on problematic learning outcomes; and that social media complementarity plays a moderating role in the model. We discuss the implications of these findings for research and practice.