Fuzzy risk assessment of oil and gas offshore wells

Risk evaluation of offshore wells is a challenging task, given that much of the available data is highly uncertain and vague, and many of the mechanisms are complex and difficult to understand. Consequently, a systematic approach is required to handle both quantitative and qualitative data as well as means to update existing information when new knowledge and data become available. Each Basic Risk Item (BRI) in a hierarchical framework is expressed as a fuzzy number, which is a combination of the likelihood of a failure event and the associated failure consequence. Analytical Hierarchy Process (AHP) is used to estimate weights required for grouping non-commensurate risk sources. Evidential Reasoning (ER) is employed to incorporate new data for updating existing risk estimates. It is envisaged that the proposed approach could serve as a basis for benchmarking acceptable risks in offshore wells.     

蚊香燃烧产物中多环芳烃的分布规律及相关性研究

对蚊香燃烧后的烟气和灰烬样品进行采集,利用GC-MS方法分析其中16种优控多环芳烃(PAHs)的含量,并对烟气和灰烬中各PAHs组分及总量间的相关关系进行探讨.结果表明:蚊香烟气中16种PAHs均有检出,排放量较大的组分主要有萘、苊、二氢苊、菲和荧蒽,并以2～3环PAHs为主;灰烬中PAHs也以2～3环化合物为主,但排放总量仅为烟气中的4.7%～21.8%.通过与其他室内燃烧源PAHs排放量的对比发现,蚊香灰烬中总PAHs排放量低于卫生香源和木柴源,但比香烟源高一个数量级以上;烟气中总PAHs排放量低于燃煤源、木柴源和卫生香源,但明显高于烹调源.回归分析结果表明,烟气中总PAHs排放量与灰烬中的排放量表现出明显的线性关系(R2=0.9054).     

Integrated resource management systems: Coupling expert systems with data-base management and geographic information systems

Decision making in natural resource management is becoming increasingly information-intensive because of the rising public concerns about resource conservation and environmental quality. The volume of information that must be analyzed and the complexity of the decision-making process demands that computerized systems be developed to provide decision support services. An integrated systems approach that couples data-base management, geographic information systems, and expert systems is needed. We refer to such an approach as integrated resource management automation (IRMA) and describe a prototype system that is currently being tested in the Nicolet National Forest. This type of information system is likely to play an increasingly important role in the management of natural resources in the future.     

Boomerangs versus Javelins: How Polarization Constrains Communication on Climate Change

Political communicators work under the assumption that information provision, such as framing, may influence audiences and elicit some desired attitudinal or behavioral shift. However, some political issues, such as climate change, have become polarized along party lines, with partisans seemingly impervious to disconfirming information. On these highly polarized issues, can framing sway partisans to moderate their positions, or are partisans so motivated in their issue stances that framing fails? Using a variety of vignettes, and Republican climate change skepticism as a case, this article reports an experiment of how partisans respond to counter-attitudinal framing on a sharply polarized issue. Results indicate that Republicans are resistant to frames that encourage support of governmental action or personal engagement against climate change. There is strong evidence of motivated skepticism, given widespread backfire (or ‘boomerang’) effects and decreased attitudinal ambivalence following exposure to framing, suggesting that issue polarization may severely constrain attempts at communication.     

A lagrangian dispersion model for calculating concentration distribution within a built-up domain

A Lagrangian model to study the dispersion of pollutants between urban buildings is described. The flow field is supplied by an objective analysis (Rockle (1990) Ph.D. thesis, Vom Fachbereich Mechanik, der Technischen Hochschule Darmstadt, Germany) and is adjusted to satisfy the continuity equation. From the resulting; mass consistent field the Lagrangian diffusion parameters are eliminated. A 3-D Lagrangian diffusion model in a nonhomogeneous field is applied to calculate the pollutant distribution between the buildings. Several examples are studied and compared to wind tunnel measurements.     

城市自然灾害风险评价的二级模型

利用模糊集方法建立了城市自然灾害风险评价的二级模型。二级模型适用于单一致灾因子的分析。结合文[1]提出的一级模型,即可构成完整的城市自然灾害风险评价体系。     

退化生态系统的诊断特征及其评价指标体系

退化生态系统具有结构和功能简化、生产力和抗逆力低、生物多样性下降等基本诊断特征,由于区域背景和人类活动干扰的差异,生态系统退化具有不同的类型、过程和阶段。为了定量地研究退化生态系统,文中分别建立了土壤、植被、大气、水体,以及农业生态系统、区域自然－人类复合生态系统退化的评价指标体系,其中,土壤退化指标包括物理退化、化学退化、生物退化和土壤污染四类指标;植被退化则从数量、结构、功能与生产力、品质四个