遗传算法优化天然气管网输配运行方案

前言目前,天然气管网系统的规模越来越大,其构造与设施也越来越复杂。这样就使调度管理趋于复杂,经验调度的管理方法已经不能适应发展的需要,因而实现管理现代化、决策科学化的要求也就越来越成为一个迫切需要解决的课题。管网优化输配是调度管理的一个重要内容,对其进行研究具有重要意义[1～3]。文献4建立了无压缩机的优化模型,这是一个非线性规划问题,用约束变尺度进行求解。文献5建立了带压气站的管网输配气运行方案优化模型,模型的求解分为两阶段进行。本文利用一种新型的优化方法——遗传算法,结合管网稳态分析模型,对管网输配优化模型…     

中国电力行业融资问题研究

电力行业的融资方式与过程是与其在国民经济中的地位、作用以及自身的经济技术特征密切联系的,作为资金密集型行业,电力行业的发展,主要靠扩大投入来实现。我国目前电力融资仍然没有脱离计划经济的融资特征,还存在一系列阻碍电力产业资金融通的问题,这在很大程度上影响了整个行业特别是电网经营企业的发展。因此,必须积极寻求符合电力行业发展客观要求的融资方式。     

如何理解运用国标对管道取样起止时段的规定

输油管道采取试样时间的确定，是关系着油品运销中贸易结算的关键环节，国标为此特作了专门规定。针对目前在实际引用标准的过程中产生的两种不同的认识和操作对生产的影响，通过对标准的学习和理解，根据国标制定的基本原则和目地，对管道取样的开始和结束两个时间加以分析和论证，使计量交接双方达到对国标理论认识上的统一，从而达到执行上的统一，最终完成好油品计量交接工作。     

关于石油企业标准化工作的思考

结合石油工业的特点，阐述了开展石油企业标准化体系研究的必要性，以及石油企业标准化研究中的发现的问题。对今后石油企业标准化工作的几点建议指出，要加大对强制性标准的实施力度，提高行业标准质量，做好产品质量认证工作。     

竹纤维小荷才露尖尖角

深受喜爱的竹子能够做成服饰用品,这本身就是一个很大的诱惑,无论对商家还是消费者,这种诱惑都因为渊源深厚的"竹文化"而更加强烈.继天丝之后,竹纤维的推出曾激动人心一两年.但是技术层面难以获得突破,也使竹纤维沉寂多时.竹纤维产品究竟怎么个好法?技术突破如何?市场前景如何?     

关于无形资产评估中折现率确定方法的探讨

折现率的预测和确定是无形资产评估中的难点问题之一。由于折现率是影响评估结果准确度的重要参数,所以在当前对高质量资产评估结果的需求日益迫切的背景下,有必要再度探讨无形资产折现率确定方法的相关问题。本文提出应根据引起无形资产评估的具体情况来选择合理的折现率确定方法;同时也提出了无形资产折现率确定方法运用和发展的几点建议:科学性和合理性相结合、静态分析与动态分析相结合、因素分析与模型分析相结合。     

What Moves the Mortgage‐Backed Securities Market?

Using a vector autoregressive model with monthly data from 1988 through 2001, this study investigates the factors that drive the excess returns on a widely followed mortgage-backed securities (MBS) index. We find that eight important economic variables (industrial productions, new home sales, bond horizon premium, bond quality premium, mortgage rate, refinancing proxy, general stock market index and world bond market index) appear to move the excess returns on MBS. Impulse response analysis and variance decomposition further indicate a strong dynamic relationship between MBS excess returns and changes in these economic variables. Additional analysis of Freddie Mac and Fannie Mae MBS also indicates that the risk of the MBS guarantor is an important determinant of the MBS return dynamics after the creation of the Office of Federal Housing Enterprise Oversight.     

Trust‐Preferred Securities and Insurer Financing Decisions

We analyze insurance holding company (IHC) issuance of trust‐preferred securities (TPS) from 1994 to 2013. We find that larger and more financially levered IHCs issued TPS in 1996 and 1997, as well as those that obtained financial strength ratings from A.M. Best. Abnormal stock price returns are positively related to financial distress costs, growth opportunities, and tax burden, but negatively related to size. Consistent with the pecking order theory, intent to use TPS proceeds to retire debt is positively related to abnormal stock returns, whereas intent to use proceeds to retire preferred equity is negatively related to abnormal stock returns.     

Enterprise Risk Management and the Cost of Capital

Enterprise risk management (ERM) is a process that manages all risks in an integrated, holistic fashion by controlling and coordinating any offsetting risks across the enterprise. This research investigates whether the adoption of the ERM approach affects firms' cost of equity capital. We restrict our analysis to the U.S. insurance industry to control for unobservable differences in business models and risk exposures across industries. We simultaneously model firms' adoption of ERM and the effect of ERM on the cost of capital. We find that ERM adoption significantly reduces firm's cost of capital. Our results suggest that cost of capital benefits are one answer to the question how ERM can create value.     

Leading the herd: evidence from mutual funds’ buy and sell decisions

This article investigates whether a mutual fund’s performance is related to its herding behavior. Using the methodology of Sias (Rev Finance Stud 17:165–206, 2004), we develop a measure to capture the magnitude that a fund’s buy (sell) decisions are leading other funds’ buys (sells), and find that a fund’s performance is positively (negatively) related to its “buy leading” (“sell leading”). We interpret these findings as evidence that “buy leaders” (“sell leaders”)’ performance benefits (suffers) from the positive (negative) price effect associated with buy (sell) herds. Additionally, we find a positive relationship between fund performance and valuation-motivated “buy leading”, while we find weak evidence on the relationship between performance and valuation-motivated “sell leading”. We interpret these results as evidence that leading funds’ outperformance is due, in part, to their ability to value stocks.