煤矿井巷工程质量控制的系统特性分析

我国煤矿的工程质量一直是社会关注的焦点,因为最近几年我国煤矿频频发生重大的安全事故,这就使得许多的矿井作业安全问题日益的暴露了出来。而且在煤矿开采过程中其本身就是一个高危作业,再加之许多的人为操作的失误,很容易造成重大的安全事故,所以安全作业系数根本就不好控制。文章主要从煤矿的安全生产和维护工程质量方面分析。     

煤矿工程造价竞标的高效研究

本文在分析和研究煤矿工程造价的基础上,介绍了其含义与职能,并进一步探讨了煤矿工程造价竞标的意义和作用。     

浅析软煤层中顶层综采工作面回采初期技术管理

目前正处于煤炭行业的寒潮时期,各地煤炭企业亏损严重。为了响应国家的安全生产方针,煤炭企业在该时期生产过程中安全方面更不敢出一丝的问题。由于综采工艺相比其他采煤工艺而言大大提高了施工人员的安全系数。所以,综采工艺往往是工作面回采的首选。河南能源化工集团焦煤公司中马村矿同样采用了综采工艺对211021工作面进行回采。211021综采工作面为顶层工作面,并且所采煤层煤质较软,初采初放期间遇到了三条断层。下面就211021综采工作面回采初期的技术管理进行简要的分析总结。     

Fire sales by euro area banks and funds: What is their asset price impact?

The assets under management of investment funds have soared in recent years, triggering a debate on their possible implications for financial stability. We contribute to this debate assessing the asset price impact of fire sales in a novel partial equilibrium model of euro area funds and banks calibrated over the period between 2008 and 2017. An initial shock to yields causes funds to sell assets to address investor redemptions, while both banks and funds sell assets to keep their leverage constant. These fire sales generate second-round price effects. We find that the potential losses due to the price impact of fire sales have decreased over time for the system. The contribution of funds to this impact is lower than that of banks. However, funds’ relative contribution has risen due to their increased assets under management and banks’ lower leverage and rebalancing towards loans. Should this trend continue, funds will become an increasingly important source of systemic risk.     

Live streaming commerce from the sellers’ perspective: implications for online relationship marketing

ABSTRACT

Live streaming has recently become a popular direct selling channel which offers small, self-employed sellers unseen levels of consumer interaction and engagement. While the extant research focused on consumer motivation and intention to shop via live streaming, little is known from the seller’s perspective. Indeed, the potential advantages of live streaming commerce are accessible to everyone, but sellers experience different levels of success with this medium. Using a mixed quantitative and qualitative approach, this study analyses Facebook data of live streaming sellers to assess the nature and extent of engagement metrics, and delineate the dynamic, interactive live streaming sales process. We identify four sales approaches and twelve strategies adopted in acquiring and retaining customers. This typology of sales approach representing seller-focused antecedents is mapped against the relationship process and outcomes to provide a framework for understanding relationship mechanisms in live streaming commerce.     

Policy responses to an overheated housing market: Credit tightening versus transaction taxes

Among Asian economies, Hong Kong has experienced the highest real growth in house prices since the 2010s. Two macroprudential measures, namely credit tightening (loan-to-value ratio cap) and transaction taxes (stamp duty), were introduced to cool down the overheated housing market. This study examines and compares their effectiveness based on a set of constant-quality house price indices. Through an error correction model, we find that credit tightening was able to curb house price growth in the high-price segment, while transaction taxes could not. An explanation is that the exemptions from transaction taxes for those with genuine housing needs could be abused by other market participants. It is easier for buyers to exploit the exemptions to get around the stamp duty than to manipulate the property valuation for mortgage lending. The implication is that the effectiveness of macroprudential measures hinges on whether compliance or exemption can be easily monitored and enforced.     

以煤为原料的甲醇制备工艺研究

本文对以煤为原料的甲醇制备工艺研究,有利于指导煤制甲醇生产工艺实践,有助于煤制甲醇生产工艺的改进和提高。     

工业锅炉煤改气客户细分模型及其应用——基于层次分析和熵权修正的模糊综合评价理论

煤改气是加快调整工业锅炉能源结构、改善大气环境质量的重要措施之一。燃气运营商欲开拓工业锅炉煤改气市场，应正确辨别终端市场客户的类别。从行业特性、企业特性、锅炉状况和客户开发潜力4个方面构建工业锅炉煤改气客户细分评价指标体系，用AHP－修正熵组合赋权方法确定评价指标权重，建立工业锅炉煤改气客户细分模型并开展应用。评价结果兼顾客观属性与主观偏好，符合客观实际，可为燃气运营商开展差异化管理，采取多元化营销模式提供决策依据。     

FIRE SALES FORENSICS: MEASURING ENDOGENOUS RISK

We propose a tractable framework for quantifying the impact of loss‐triggered fire sales on portfolio risk, in a multi‐asset setting. We derive analytical expressions for the impact of fire sales on the realized volatility and correlations of asset returns in a fire sales scenario and show that our results provide a quantitative explanation for the spikes in volatility and correlations observed during such deleveraging episodes. These results are then used to develop an econometric framework for the forensic analysis of fire sales episodes, using observations of market prices. We give conditions for the identifiability of model parameters from time series of asset prices, propose a statistical test for the presence of fire sales, and an estimator for the magnitude of fire sales in each asset class. Pathwise consistency and large sample properties of the estimator are studied in the high‐frequency asymptotic regime. We illustrate our methodology by applying it to the forensic analysis of two recent deleveraging episodes: the Quant Crash of August 2007 and the Great Deleveraging following the default of Lehman Brothers in Fall 2008.     

The managerial flash sales dash: Is there advantage or disadvantage at the finish line?

The central intent of this qualitative inquiry is to investigate the benefits, drawbacks, and performance measures of hotel room inventory distribution via flash sales websites. Key advantages and disadvantages of using such a distribution channel fall within the categories of inventory management, revenue management, brand marketing, customer relationships, and operational challenges. The significance of the study is in providing a comprehensive review of the flash sales phenomenon in the lodging industry that may assist hotel managers with the performance evaluation of this distribution channel. Using grounded theory methodology, a flash sales evaluation framework was developed based on 46 phone interviews with hotel managers from different segments of the American hotel industry.