煤矿上山掘进轨道双提升系统的设计及应用

本文介绍了煤矿长斜巷正头掘进与斜巷中段联巷掘进同时施工的新型运输方式。     

Time-changed Lévy LIBOR market model: Pricing and joint estimation of the cap surface and swaption cube

We propose a novel time-changed Lévy LIBOR (London Interbank Offered Rate) market model for jointly pricing of caps and swaptions. The time changes are split into three components. The first component allows matching the volatility term structure, the second generates stochastic volatility, and the third accommodates for stochastic skew. The parsimonious model is flexible enough to accommodate the behavior of both caps and swaptions. For the joint estimation we use a comprehensive data set spanning the financial crisis of 2007–2010. We find that, even during this period, neither market is as fragmented as suggested by the previous literature.     

基于JIT思想对汽车玻璃生产线WIP的控制策略

本文分析了汽车玻璃加工生产线的生产流程,生产车间不同种类的在制品(WIP)数量很庞大,为此研究生产线的瓶颈工序,得到瓶颈工序生产线的切换时间对WIP库存的影响,研究生产线的切换时间、工序之间的生产节拍比和WIP库存数三者之间的关系,结合JIT和WIP库存控制策略来保证生产线的流畅生产,归纳出关键的工序节拍比下所需的WIP库存数的动态变化情况,从而动态地控制WIP库存的变化并最大程度地降低车间的WIP库存。     

VB6.0中变量的作用域及参数传递

本文主要阐述了变量的生存期和作用域的问题,因为它们是程序中引用变量的依据。同时对同名变量的处理进行了讨论,并结合实例进行了分析,旨在程序设计时,能正确的定义和引用变量。     

Stochastic volatility: A tale of co-jumps,non-normality,GMM and high frequency data

In this article we introduce a linear–quadratic volatility model with co-jumps and show how to calibrate this model to a rich dataset. We apply GMM and more specifically match the moments of realized power and multi-power variations, which are obtained from high-frequency stock market data. Our model incorporates two salient features: the setting of simultaneous jumps in both return process and volatility process and the superposition structure of a continuous linear–quadratic volatility process and a Lévy-driven Ornstein–Uhlenbeck process. We compare the quality of fit for several models, and show that our model outperforms the conventional jump diffusion or Bates model. Besides that, we find evidence that the jump sizes are not normally distributed and that our model performs best when the distribution of jump-sizes is only specified through certain (co-) moment conditions. Monte Carlo experiments are employed to confirm this.     

Opportunities and pitfalls for researchers to contribute to the design of evidence-based agricultural policies: lessons from Uganda

Agricultural policies in sub-Saharan Africa have paid insufficient attention to sustainable intensification. In Uganda, agricultural productivity has stagnated with aggregate increases in crop production being attributed to expansion of cultivated land area. To enhance sustainable crop intensification, the Ugandan Government collaborated with stakeholders to develop agricultural policies using an evidence-based approach. Previously, evidence-based decision-making tended to focus on the evidence base rather than evidence and its interactions within the broader policy context. We identify opportunities and pitfalls to strengthen science engagement in agricultural policy design by analysing the types of evidence required, and how it was shared and used during policy development. Qualitative tools captured stakeholders' perspectives of agricultural policies and their status in the policy cycle. Subsequent multi-level studies identified crop growth constraints and quantified yield gaps which were used to compute the economic analyses of policy options that subsequently contributed to sub-national program planning. The study identified a need to generate relevant evidence within a short time 'window' to influence policy design, power influence by different stakeholders and quality of stakeholder interaction. Opportunities for evidence integration surfaced at random phases of policy development due to researchers’ ’embededness’ within co-management and coordination structures.     

浅谈三轴搅拌桩施工技术

三轴水泥土搅拌桩是多轴搅拌机就地钻进切削土体,同时在钻头端部将水泥浆液注入土体,经充分搅拌混合后,再将H型钢或其他型材插入搅拌桩体内,形成地下连续墙体的一种施工工艺。特点是构造简单,挡土止水性能好,材料还可循环利用。     

如何进一步优化“哑铃式”生产工艺

煤炭科研院所转制后的企业大多采用"哑铃式"生产模式,即设计、组装(生产的两头)由自身控制,中间加工环节放在各外委厂家加工,以避免科研院所自身加工生产条件不足的缺陷,在转制起始阶段能迅速组织生产,形成较为快速的经济增长。但随着产品品种逐渐增多、产品生产数量日益增加,采用本模式的生产工艺逐步暴露出一定的缺陷,如:产品质量的不稳定、产品库存的积压、产品成本的增加等等一系列问题。因此本文将通过对多种新产生问题的分析,提出进一步优化"哑铃式"生产工艺的方法。     

高酸值原油脱酸装置腐蚀防护措施及改进建议

本文根据高酸值原油腐蚀机理,分析了加工高酸值原油对常减压(高酸值原油脱酸装置)装置的腐蚀特点和重点腐蚀部位,并在此基础上提出了具体的防护措施:电脱盐、塔顶"三注"、高温缓蚀剂、腐蚀监测等,并重点介绍了本公司50万吨/年常减压装置的具体防腐措施,实践证明这些措施取得了较好的防腐效果,最后根据实践提出了可行的改进建议。     

河北省着力改善两个环境面临的问题与对策建议

着力改善发展环境和生态环境具有十分重要的意义作用,目前河北省在着力改善两个环境的过程中存在一定的问题,需要采取措施积极解决。