高压配电网如何选择中性点接地方式

分析高压配电网中性点各种接地方式的特点,影响其选择的因素,及实际工程应用中应注意的问题。     

碳中和目标导向的省域消费端碳排放减排模式研究——基于多区域投入产出模型

文章以多区域投入产出模型为基础,研究了中国省级和行业层面基于消费端的碳排放及碳转移,并解析了碳中和导向下的碳减排模式。结果表明:23个省份本地消费碳排放大于外地输入碳排放;资本形成是碳排放最大贡献者;能源生产和供应业以及非金属和金属业是碳转移的主要行业,能源生产和供应业输出碳排放量最大的内蒙古主要输出给北方地区,非金属和金属业输出碳排放量最大的河北主要输出给江苏等省份;中国30个省份可以根据消费端碳排放的来源特征和净碳转移方向分为四类。在碳中和目标导向下,本研究有助于倒逼各省份绿色发展和绿色低碳产品的输出,绿色低碳也将是未来贸易市场趋向。     

供应链中甄别契约设计与信息共享激励

针对供应链中上下游企业的委托-代理问题,委托人可以设计出某种甄别契约以区分不同类型的代理人在不同的市场需求状况下的努力程度。在完全信息的条件下,委托人采取固定佣金方案及承担全部风险为最优选择。在信息不完全的条件下,若代理人为风险规避者则委托人只承担部分销售风险但需付出额外的风险补偿成本,若代理人为风险中性者则委托人不需付出额外的风险补偿成本。     

Retrieving the implicit risk neutral density of WTI options with a semi-nonparametric approach

This paper contributes to the literature on the estimation of the Risk Neutral Density (RND) function by proposing a log-semi-nonparametric (log-SNP) distribution as the implicit RND when the Gram-Charlier model is used for option pricing. The performance of the model is compared to the lognormal (Black Scholes) benchmark for a sample of option prices for West Texas Intermediate (WTI) crude oil that were traded in the period between January 2016 and December 2017. Results show that the lognormal specification tends to systematically undervalue option prices and that the proposed log-SNP distribution, which explicitly adjusts for negative skewness and excess kurtosis, results in markedly improved accuracy, especially in periods of market instability. As a result, the implied skewness and excess kurtosis are relevant sources of information on market expectations that should be used for hedging and risk management purposes.     

Neutral agents and social tolerance: a dynamic perspective based on economic interaction model with local social cost functions

The influence of neutral agents on the evolutionary dynamics of social tolerance is discussed based on a recently proposed economic interaction model with local social cost functions. We show that the dynamical structure of social tolerance is completely changed even if a few neutral agents are introduced into the society. Especially, the full intolerance steady state, which is stable in previous works, becomes unstable and avoidable due to the economic incentive introduced by the neutral agents. The necessary condition of achieving full tolerance is also reduced compared to previous works without neutral agents.     

Semi‐efficient valuations and put‐call parity

We propose an approach to the valuation of payoffs in general semimartingale models of financial markets where prices are nonnegative. Each asset price can hit 0; we only exclude that this ever happens simultaneously for all assets. We start from two simple, economically motivated axioms, namely, absence of arbitrage (in the sense of NUPBR) and absence of relative arbitrage among all buy‐and‐hold strategies (called static efficiency). A valuation process for a payoff is then called semi‐efficient consistent if the financial market enlarged by that process still satisfies this combination of properties. It turns out that this approach lies in the middle between the extremes of valuing by risk‐neutral expectation and valuing by absence of arbitrage alone. We show that this always yields put‐call parity, although put and call values themselves can be nonunique, even for complete markets. We provide general formulas for put and call values in complete markets and show that these are symmetric and that both contain three terms in general. We also show that our approach recovers all the put‐call parity respecting valuation formulas in the classic theory as special cases, and we explain when and how the different terms in the put and call valuation formulas disappear or simplify. Along the way, we also define and characterize completeness for general semimartingale financial markets and connect this to the classic theory.     

浅谈四极开关的选用

针对不同的接地形式,依据现行规范,介绍了四极开关的选择:1.IT系统有中性线引出时,应采用四极开关;2.TT系统应在隔离相线的同时隔离中性线;3.在TN-C系统中必须选用三极开关;4.TN-S系统可选用四极开关,但是开关的N极只能接N线,而不能接PEN或PE线,在有总等电位联结的TN-S系统中建筑物内不必为电气检修安全而隔离中性线;5.在TN-C-S系统的建筑物内不必为电气检修安全而装设四极开关。     

浅谈电力系统中的接地和接零

随着当代科学技术的迅速发展,各种电器、电子设备全面进入社会生活各个领域,成为社会文明进步的重要标志。在我国,人民生活水平不断提高,对家用电器的需求量越来越大。各类电器、电子设备在全国城乡和到迅速普及,给生产带来极大方便。但各类电器、电子设备的广泛使用,由此带来的人身事故也大为增加。在电力系统中,为避免事故的发生,通常采取保护接地和保护接零的防范措施。下面就谈谈有关保护接地和保护接零的问题。     

多变时滞中立型系统稳定性研究

本文研究了一类多时变时滞中立型系统的渐近稳定性问题。基于Lyapunov第二方法,推导出新的时滞依赖稳定性判据。所给得判据可以保证多变时滞中立型系统渐进稳定,结论以线性矩阵不等式(LMI)形式表示,便于应用。仿真结果表明本文稳定性判定准则具有较小的保守性。