油田井下作业事故分析及应对措施探讨

石油行业是我国工业发展的命脉,能够为国家创造更高的经济价值。但是,这个行业也同样伴随着较高的安全风险。石油井下作业过程往往复杂多变,具有极高的危险性。本文首先列举了石油井下作业事故的类型,接着详细分析了安全事故的发生原因,最后针对发现的问题,提出了相应的应对措施,希望可以对油田井下作业安全防治问题有所帮助。     

A unified approach to systemic risk measures via acceptance sets

We specify a general methodological framework for systemic risk measures via multidimensional acceptance sets and aggregation functions. Existing systemic risk measures can usually be interpreted as the minimal amount of cash needed to secure the system after aggregating individual risks. In contrast, our approach also includes systemic risk measures that can be interpreted as the minimal amount of cash that secures the aggregated system by allocating capital to the single institutions before aggregating the individual risks. An important feature of our approach is the possibility of allocating cash according to the future state of the system (scenario‐dependent allocation). We also provide conditions that ensure monotonicity, convexity, or quasi‐convexity of our systemic risk measures.     

Conditional risk measures in a bipartite market structure

In this paper, we study the effect of network structure between agents and objects on measures for systemic risk. We model the influence of sharing large exogeneous losses to the financial or (re)insurance market by a bipartite graph. Using Pareto-tailed losses and multivariate regular variation, we obtain asymptotic results for conditional risk measures based on the Value-at-Risk and the Conditional Tail Expectation. These results allow us to assess the influence of an individual institution on the systemic or market risk and vice versa through a collection of conditional risk measures. For large markets, Poisson approximations of the relevant constants are provided. Differences of the conditional risk measures for an underlying homogeneous and inhomogeneous random graph are illustrated by simulations.     

Threats to the Validity of Logistics and Supply Chain Management Research

To increase the relevance of logistics and supply chain academic research, this paper recommends the development and testing of middle‐range theory and practice‐level theory. Yet, there are a number of research issues that arise when academic researchers test middle‐range and practice‐level theory, both in measuring constructs and in testing theoretical relationships between constructs. Concerning the measurement of constructs, this paper recommends that academic researchers pay more attention to content validity and undertake rigorous processes to ensure content validity. In addition, academic researchers need to more explicitly define constructs as either reflective or formative. If the construct is defined as formative, then the traditional statistical approaches to validate these measurement scales are not recommended. The appropriate use of employing single‐item measures for concrete constructs is discussed. In regard to conducting hypothesis tests, research issues associated with multicollinearity and omitted variable bias are discussed. Relative weight analysis is ideal for testing theoretical models and research hypotheses when survey data are obtained, multicollinearity is present, and there are a large number of independent variables predicting a dependent variable. Thus, relative weight analysis is ideal for testing research hypotheses in logistics and supply chain management.     

The failure of agri-environment measures to promote and conserve grassland biodiversity in Slovenia

The effectiveness of four grassland-specific agri-environment measures (AEM), implemented in the frame of the European Agricultural Fund for Rural Development (EAFRD) in the period 2007–2013 in Slovenia was studied. We questioned whether the measures – “extensive grassland maintenance”; “preservation of special grassland habitats”; “preservation of grassland habitats for butterflies” and “bird conservation in humid extensive meadows in Natura 2000 sites” did genuinely support the conservation (maintenance or improvement) of high nature value (HNV) grasslands in Slovenia. The HNV grasslands were defined on the basis of national fine-resolution field mapping of habitat types. Two main outcomes emerged: AEM did not reach the vast majority of HNV grasslands in Slovenia (only 3%); the proportion of HNV grassland area included in AEM was negligibly low (1). Moreover, even this very limited interest in AEM did not target only grasslands of HNV, but any permanent grasslands regardless of their conservation value: forty-one percent (41%) of the grassland areas included in the AEM were actually non-HNV grasslands (2). The absence of pre-selection criteria for grasslands along with an absence of monitoring of the effectiveness and efficiency of the measures and low interest in the subsidies among farmers, led to almost complete failure of the AEM to promote and conserve species-rich extensive grasslands in Slovenia between 2007 and 2013. Even with some minor differences, the same concept was maintained for the currently running EAFRD 2014–2020, which raises serious concern.     

浅谈城中村用电困局及解决措施

随着城市的迅猛发展,大量外来人口迁入各地城中村,导致城中村用电负荷暴增,残旧的城中村电网以及各种违法用电行为使得城中村用电陷入频繁停电的困局。该文通过对城中村用电现状的描述,分析造成用电困局的原因,并在此基础上提出破解城中村用电困局的若干建议。     

浅谈建设工程资料的管理与常见问题

建设工程资料是建设工程的重要组成部分,工程资料的管理不仅对建设工程而且对工程后期的使用、维修、改扩建工程有着重要的意义。因此,有必要对工程资料的规范管理及常见问题进行阐述。     

浅析西安地铁项目工程变更管理

地铁项目工程在施工过程易受地形地貌以及水文等自然条件的制约,因此会经常出现工程变更的情况,会直接影响工程造价的变迁。基于这种情况,结合地铁三号线的相关做法和经验,分析地铁项目工程变更管理中存在的问题与相应的完善措施。希望对地铁项目工程的变更管理起到一些借鉴。     

服务质量的要素、测量及关系研究

服务质量概念是由对产品质量的定义逐渐延伸到服务中而产生的.基于对服务质量的相关研究文献的回顾,从服务质量要素、服务质量测量及服务质量与顾客满意、顾客忠诚、企业绩效之间的关系研究角度来展开论述,对服务质量的国内外相关研究做了一些总结与展望.服务质量的研究经历了一个由概念界定、测量维度的探索向服务质量与其他服务要素之间的关系及在不同行业的适用性逐步扩展的过程,对于服务行业及服务质量标准的制定都是一个不可缺少的参考要素.     

A new approach to measuring riskiness in the equity market: Implications for the risk premium

We introduce a new approach to measuring riskiness in the equity market. We propose option implied and physical measures of riskiness and investigate their performance in predicting future market returns. The predictive regressions indicate a positive and significant relation between time-varying riskiness and expected market returns. The significantly positive link between aggregate riskiness and market risk premium remains intact after controlling for the S&P 500 index option implied volatility (VIX), aggregate idiosyncratic volatility, and a large set of macroeconomic variables. We also provide alternative explanations for the positive relation by showing that aggregate riskiness is higher during economic downturns characterized by high aggregate risk aversion and high expected returns.