Critical Asset and Portfolio Risk Analysis: An All-Hazards Framework

This article develops a quantitative all-hazards framework for critical asset and portfolio risk analysis (CAPRA) that considers both natural and human-caused hazards. Following a discussion on the nature of security threats, the need for actionable risk assessments, and the distinction between asset and portfolio-level analysis, a general formula for all-hazards risk analysis is obtained that resembles the traditional model based on the notional product of consequence, vulnerability, and threat, though with clear meanings assigned to each parameter. Furthermore, a simple portfolio consequence model is presented that yields first-order estimates of interdependency effects following a successful attack on an asset. Moreover, depending on the needs of the decisions being made and available analytical resources, values for the parameters in this model can be obtained at a high level or through detailed systems analysis. Several illustrative examples of the CAPRA methodology are provided.     

正确理解和把握科学发展观

一个国家坚持什么样的发展观,对这个国家的发展会产生重大影响。在新的历史发展时期,我们坚持的科学发展就是对过去不够科学的发展观的变革。科学发展不再是“抓革命,促生产”的连续不断的政治运动,而是长期的改革开放;不再是脱离实际的“大跃进”,而是符合人类社会发展规律的可持续发展;不再是“以钢为纲”的生产资料优先增长,而是全面协调发展。     

A corrected likelihood method for the proportional hazards model with covariates subject to measurement error

There has been extensive interest in discussing inference methods for survival data when some covariates are subject to measurement error. It is known that standard inferential procedures produce biased estimation if measurement error is not taken into account. With the Cox proportional hazards model a number of methods have been proposed to correct bias induced by measurement error, where the attention centers on utilizing the partial likelihood function. It is also of interest to understand the impact on estimation of the baseline hazard function in settings with mismeasured covariates. In this paper we employ a weakly parametric form for the baseline hazard function and propose simple unbiased estimating functions for estimation of parameters. The proposed method is easy to implement and it reveals the connection between the naive method ignoring measurement error and the corrected method with measurement error accounted for. Simulation studies are carried out to evaluate the performance of the estimators as well as the impact of ignoring measurement error in covariates. As an illustration we apply the proposed methods to analyze a data set arising from the Busselton Health Study [Knuiman, M.W., Cullent, K.J., Bulsara, M.K., Welborn, T.A., Hobbs, M.S.T., 1994. Mortality trends, 1965 to 1989, in Busselton, the site of repeated health surveys and interventions. Austral. J. Public Health 18, 129–135].     

Governance,credit access and clean cooking technologies in Sub-Saharan Africa: Implications for energy transition

There is a global effort toward reducing or eliminating dirty fuels and technologies for cooking due to their severe health, environmental and economic implications. Reducing dirty energy usage requires an effective transition toward clean fuels and technologies for cooking. Effective governance and financial systems are needed to hasten the transition toward clean fuels and technologies for cooking. However, not much is known empirically about the role of access to credit and governance in the transition towards clean cooking technologies, especially in sub-Saharan Africa (SSA). This study, therefore, utilizes the two-step-dynamic system generalized method of moment estimator to investigate the effect of access to credit and governance on the adoption of clean cooking technologies in SSA. The findings indicate that access to credit and governance variables do not facilitate clean cooking technologies usage. The conditional analysis also reveals that the governance variables moderate the effect of access to credit to impede the adoption of clean fuels and technologies for cooking. The findings indicate that economic growth, education, and rural population drive the adoption of clean cooking technologies. Sensitivity checks show that the effect of access to credit and governance on clean fuels and cooking technologies usage differs among income and regional groups within SSA. We, therefore, argue that better financial and governance systems are required to hasten the transition toward clean fuels and technologies for cooking in SSA.     

对防治家庭暴力的思考

家庭暴力是由封建文化的影响、社会变革引起的失衡、夫妻感情不和,以及社会控制乏力等原因引起的,不仅严重危害妇女的身心健康和社会稳定,而且可能给孩童起到不良示范作用,助长其暴力倾向.必须加大制裁力度,加强社会控制,增加家庭暴力的实施成本.此外,应通过广泛的宣传教育,消除家庭暴力的文化土壤;提高妇女的自身素质,培养其拒绝家庭暴力的能力.     

商业银行经营缺乏创新的危害及原因分析

商业银行的同质化倾向是其经营缺乏创新的反映,这对信贷资金供给、商业银行发展、宏观经济调控都产生了危害。创新不足的外部原因是缺少引导与激励商业银行创新的环境,内部原因是商业银行自身缺乏创新动力与创新能力,这需要从监管设计、行业促进、银行变革三方面突破,提升商业银行系统的活力,提高资源配置效率。     

聚氨酯泡沫塑料火灾危险性分析及其防火措施

聚氨酯泡沫塑料是一种高分子合成材料 ,应用范围十分广泛 ,但聚氨酯泡沫塑料在火灾时能放出使人窒息死亡的毒气 ,特别是近年来已在一些场所造成重大的人员伤亡事故。文章通过对聚氨酯泡沫塑料的燃烧过程及燃烧产物的毒性分析 ,探讨聚氨酯泡沫塑料的防火措施 ,并提出聚氨酯泡沫塑料在火灾初期对人体的伤害以及如何在一些场所有效、安全、合理地使用这一材料。     

A class of tests of proportional hazards assumption for left-truncated and right-censored data

In this paper, we proposed a class of tests of proportional hazards assumption for left-truncated and right-censored data based on a pair of estimators of the hazard ratio constant. Using counting process and martingale theory, the asymptotically normal distribution of the test statistic is derived and a family of consistent estimators of variance are also provided. Extensive simulation studies were conducted to evaluate the performance of the proposed test statistics under finite sample situations. Two real data sets are analyzed to illustrate our method.     

Do Legacy Industrial Sites Produce Legacy Effects in Ethnic and Racial Residential Settlement? Environmental Inequality Formation in Rhode Island’s Industrial Core1

This study advances understanding of environmental inequality by examining its production through the interaction of two ubiquitous and ongoing urban-ecological processes: industrial land-use changes and changing patterns of residential segregation. We employ longitudinal data from the Rhode Island Directory of Manufacturers (1953–2012) and tract-level US Census data measured at four panel-years (1980, 1990, 2000, and 2010) to study the effects of these interactions in Rhode Island’s historical industrial cities of Providence, Pawtucket, and Central Falls. Spatial patterning analysis and hybrid spatial panel modeling of residential exposure to active and legacy industrial sites in relation to ongoing racial and industrial change reveal two novel findings. First, we find a “legacy effect,” suggesting that the spatial organization of industrial activities prior to the study period has measurable impacts on patterns of residential segregation in later decades. Our results also indicate that over the study period Latinx and African-American residents have become increasingly less likely to bear disproportionate impacts of active manufacturing sites, despite very different spatial patterns of population growth. This is strong evidence that environmental inequality formation is a variable process in which historically distinct pathways can lead to similarly disproportionate exposure to environmental risk.     

Restricted mean survival time as a summary measure of time‐to‐event outcome

Many clinical research studies evaluate a time‐to‐event outcome, illustrate survival functions, and conventionally report estimated hazard ratios to express the magnitude of the treatment effect when comparing between groups. However, it may not be straightforward to interpret the hazard ratio clinically and statistically when the proportional hazards assumption is invalid. In some recent papers published in clinical journals, the use of restricted mean survival time (RMST) or τ ‐year mean survival time is discussed as one of the alternative summary measures for the time‐to‐event outcome. The RMST is defined as the expected value of time to event limited to a specific time point corresponding to the area under the survival curve up to the specific time point. This article summarizes the necessary information to conduct statistical analysis using the RMST, including the definition and statistical properties of the RMST, adjusted analysis methods, sample size calculation, information fraction for the RMST difference, and clinical and statistical meaning and interpretation. Additionally, we discuss how to set the specific time point to define the RMST from two main points of view. We also provide developed SAS codes to determine the sample size required to detect an expected RMST difference with appropriate power and reconstruct individual survival data to estimate an RMST reference value from a reported survival curve.