Decision modeling and acceptance criteria

This paper is partly tutorial by presenting well known classical decision theory in a slightly untraditional form, but it does also present thinking and results that have not been published in the engineering literature before. The paper introduces the mathematical modeling basis for rational formulation of decision criteria and public acceptance criteria connected to risk analysis of technical operations that may endanger human life and property. Public restrictions on the decisions concerning the design, construction and managing of the technical operation have in the past been imposed on the basis of the frequency and severity of experienced adverse events. No clear rationale to decide how restrictive the public should be in setting a boundary for allowable risk seems to have been applied. To clarify this problem, focus is on the difficulty of simultaneously having two decision makers, the owner that tries to optimize the net gain of the operation, and the public that has somewhat different preferences than the owner, but also strong interests in the success of the owner. The principles of rational decision are needed for appreciation of the problem. Recognizing that there is an insurance compensation value of a human life and a public money equivalent of a human life, where the last value usually is considerably larger than the first value, it is possible from the decision analysis to determine an upper limit that the public should impose on the ratio of the owner's expected loss rate to the expected gain rate. The public money equivalent of a human life is assessed by use of a recently in (Nathwani JS, Lind NC, Pandey MD. Affordable safety by choice: the life quality method. Waterloo, Ontario, Canada: Institute for risk Research, University of Waterloo, 1997) suggested Life Quality Index (LQI) that combines wealth in terms of Gross Domestic Product per person, life expectancy at birth, and yearly work time into a single number. The philosophy behind the published evaluations is that the prevention of a loss of a life is counteracted by a cost such that the LQI remains unchanged (Skjong R, Ronold K. Societal indicators and risk acceptance. In: 17th International Conference on Offshore Mechanics and Arctic Engineering, number OMAE98-1488. ASME; 1998; Rackwitz R. Optimization and risk acceptability based on the Life Quality Index. Structural Safety 2002;24:297–331.).     

Life quality index revisited

The derivation of the life quality index (LQI) is revisited for a revision. This revision takes into account the unpaid but necessary work time needed to stay alive in clean and healthy conditions to be fit for effective wealth producing work and to enjoyable free time. Dimension analysis consistency problems with the standard power function expression of the LQI are pointed out. It is emphasized that the combination coefficient in the convex differential combination between the relative differential of the gross domestic product per capita and the relative differential of the expected life at birth should not vary between countries. Finally the distributional assumptions are relaxed as compared to the assumptions made in an earlier work by the author. These assumptions concern the calculation of the life expectancy change due to the removal of an accident source. Moreover a simple public acceptance criterion is compared to the LQI criterion.     

基于LQI的隧道工程人员安全风险控制决策模型

在社会指数LQI理论的基础上分析得到最优安全成本ICAF,针对我国隧道工程特点提出隧道工程安全风险增强系数,依据ALARP原则建立了基于LQI的隧道工程人员安全风险控制决策模型,并以英国Jubilee线工程为例阐述了基于该模型的隧道工程人员安全风险控制决策流程.     

The derivation and calibration of the life-quality index (LQI) from economic principles

The life-quality index (LQI) is a versatile tool to support the effective implementation of programs and practices for managing risk to life safety. The LQI allows a transparent and consistent basis for determination of the net benefit arising from projects, programs, standards and policies undertaken at some cost to improve safety or enhance the quality of life. The paper shows that the LQI model is in harmony with well-established principles of economics, utility theory and recent developments to quantify the progress of nations through indicators of human development. The initial calibration of the LQI was based on a simplifying assumption of a linear relation between the GDP and work time. In this paper, we modify the calibration using empirical data for GDP and work time and link the LQI model to well-established economic principles and theory of production. The proposed improvements to the model eliminate a systematic bias associated with estimation of societal willingness to pay for safety. In addition, it provides a rigorous basis for program evaluation to assist decision-makers in directing expenditures where they may most effective.     

Life quality time allocation index – an equilibrium economy consistent version of the current life quality index

The definition the life quality index for a country as originally suggested by Nathwani, Lind and Pandey is based on the gross domestic product (GDP), the expected life in good health at birth, and the fraction of life time the anonymous citizen of the country is occupied with money making work. The LQI is invented to serve as a mean to evaluate how much money that reasonably can be allocated to safety improving investments by simply requiring constancy of the LQI. By choosing that the importance of increments in the two first variables should be measured relative to the current values of the variables themselves, the relative increment of the LQI becomes defined as a convex combination of the two relative increments. The combination parameter is obtained by an optimality argument about the anonymous citizen’s distribution of his or her time between free time and work time. In the original definition this equilibrium economy principle is applied under the assumption that the GDP is directly proportional to the work time fraction. This direct proportionality has been relaxed by the first author in two earlier papers with an essential effect on the combination parameter. The present paper presents a further development casting the definition into dimensionless quantities that make the index get a pure unit of time and not the somewhat obscure unit as a power product of a money unit and a time unit. To avoid confusion, this new variant of the LQI is called the life quality time allocation index (LQTAI). Moreover, the Danish data from the period from 1948 to 2003 show good agreement with the relation between the productivity and the work time as obtained from the optimality argument. The data fitting leads to an estimate of the combination coefficient of c = 0.092 together with a reduction factor of r = 0.92 to be applied to the total life expectation at birth to obtain the expected life in good health. Among other infinitely many choices of (c, r) there are (0.085, 1.0) and (0.1, 0.85).     

建筑工程项目的环境扰动度研究

建筑工程项目的市场环境从来没有像今天这样复杂、多样和存在着更多的市场风险以及经营的不确定性;对于建筑工程项目环境的定量分析,有助于提高工程项目资源的配置效率。对建筑工程项目环境进行了定性分析,给出了工程项目环境扰动函数;对网络经济环境下的建筑工程项目环境扰动函数进行了比较研究;构建了项目的环境扰动度测度模型,并运用所构建的预测模型对环境扰动因素值进行了预测,并运用工程项目环境扰动度模型对工程项目的环境扰动度进行了测度。     

建设震不倒的学校

孩子是祖国的未来和民族的希望,又是一个弱势群体。幼儿园，中小学校聚集了成百上千的孩子，保护他们的生命，提高这些建筑的安全度？建设震不垮的学校，是国家、集体、全民的责任。     

An LCA-based environmental impact assessment model for construction processes

A quantitative assessment of the environmental impact of construction activities can help decision-makers identify major environmental impact factors and make environmentally friendly construction plans in the early stages of construction. This paper presents an integrated life cycle environmental impact assessment model that is applicable to construction phase studies, where impact factors are examined according to two aspects of a typical construction process: construction equipment and ancillary materials. Environmental impacts are categorized into three safeguard subjects: ecosystems, natural resources and human health. A disability adjusted life year (DALY) model for assessing human health damage due to construction dust is developed. In addition, the environmental impact of earthwork construction is assessed as a case study to demonstrate the application of the proposed model. Results indicate that the proposed model can effectively quantify the environmental impacts of construction processes, and can potentially be used as a tool for contractors to select environmentally friendly construction plans.     

Quality adjusted life years (QALYs) and dose-response models in environmental health policy analysis -- methodological considerations.

Analyses of competing risks are currently limited by the lack of empirically well-founded and generalizable quantitative methods. Specifically, quantitative methods for comparative risk analysis require the consideration of the population impacted, the duration of impact, the health endpoints at risk, and the impact on individual quality of life. Whereas risk analysis can be used to provide quantitative estimates of disease incidence, environmental health policy analyses do not often account for differences in health impact from alternative disease states. We discuss the methodological issues related to the use of quality adjusted life years (QALY) as a metric for normalizing expected disease incidence to account for health impact. Through a case study of the risks and benefits of fish consumption, we demonstrate the use of QALY weights with dose-response models for environmental health policy decision making. We suggest that, although this approach can be generalized for use in comparative risk and health policy analysis, it is informationally intensive and requires additional assumptions to those used in traditional safety/risk assessment.     

空中多层公寓 献给未来新城的住宅原型

文章就当代中国新城建设中高层住宅小区普遍存在的公共空间质与量两方面的缺失提出批判,从20世纪50-80年代多层住宅小区充满生气的社区生活中汲取变革的动力和养分,提出"空中多层公寓"这一新的住宅建筑原型,尝试把多层小区在公共空间上的优点移植到高层小区,从而在保持高容积率的同时,大幅提高"公共空间率",在每个城市人的家门口营造触手可及的、容量充足的、尺度宜人的、多元化的空中公共空间,为未来高密度居住模式的公共生活提供建筑学的回应。     

城市公共安全规划研究——以成都市中心城公共安全规划为例

城市公共安全是城市规划研究的一项重要课题.城市公共安全规划应从综合防灾减灾的角度出发,实现资源共享、设施共用,达到消除隐患,降低风险,有效减灾避灾,保证居民的生命、财产安全的目的.成都市中心城公共安全规划将城市公共环境、公共安全保障设施的布局及建设标准作为规划的重点.     

Life cycle performance goals for civil infrastructure: intergenerational risk-informed decisions

Civil infrastructure facilities play a central role in the economic, social and political health of modern society. Such facilities are susceptible to ageing, which is stochastic in nature and makes their reliabilities time dependent. Life-cycle engineering analysis and risk-informed decision tools have advanced in recent years for managing public investments in performance assurance and risk mitigation of civil infrastructure. However, certain civil infrastructure projects may be designed for service periods that are substantially longer than what has been typically expected of buildings, bridges and similar facilities, extending the potential consequences of life-cycle engineering decisions far beyond the limits for which there is practical experience. Current assessment procedures will require modification to evaluate performance of civil infrastructure facilities over extended time frames and to support sustainable and equitable decisions affecting long-term public safety. This paper considers a number of key issues that must be addressed in life-cycle reliability assessment of civil infrastructure facilities that must remain functional for service periods of several generations, and introduces perspectives on risk that are germane to ensure sustainability and intergenerational equity in risk-informed decision-making.     

Optimization of Structures Subject to Stochastic Dynamic Loading

Structural optimization has progressed substantially over the last half century. However, the literature on optimization of structures under random excitation is limited. This study provides a framework for structural optimization subject to stochastic dynamic loading. Illustrative examples of structures under nonstationary seismic and stationary wind loads are presented to demonstrate the procedure. Both safety and serviceability are considered concurrently. The objective function for safety is given in terms of both harmful interstory drift and harmful interstory drift angle; whereas for serviceability, the objective function is defined in terms of floor acceleration. Safety and serviceability are shown to be competing objectives under both seismic and wind excitation; however, the contrast is less under wind excitation. The proposed optimization framework provides a rational manner in which engineering design tradeoffs can be made between the two competing objectives.     

电梯安全评价中的公共安全风险评估

将安全系统工程、风险管理理论和公共安全风险评估全面引入电梯安全评估工作。简要讨论了公共安全风险和电梯监察安全评价中的公共安全风险评估,构建了梯度模型作为电梯公共安全风险的影响指标,对电梯公共安全风险评估的基本流程中各主要环节进行了全面、系统的分析。     

生化及放射性威胁下地下工程安全评估与决策

本文分析了世界恐怖主义发展趋势，我国地下工程的现有防护思想及可能遭受的恐怖袭击。论述了地下工程遭受生化及放射性恐怖袭击时的灾害特点。指出通过识别并评估各种已知和潜在的威胁，采取有效措施降低灾害或减轻灾害后果，使地下工程的安全性提高到可接受水平，是增强地下工程反恐能力，维护公共安全，经济而有效的方法。建立了地下工程的安全评估与决策平台，为地下依据和技术措施。     

A framework for reliability-based system assessment based on structural health monitoring

The safety and usability of transport infrastructures is of great importance for the entire society, because disturbances of traffic networks can have significant consequences for the economy and the environment. Especially today, when bad news about deteriorated structures and shortened public budgets are omnipresent, this must not be forgotten. Structural health monitoring (SHM) can help to ensure the safety of deteriorated structures. SHM is expensive and therefore the investigation of optimized inspection and monitoring strategies is an active field of research. The Collaborative Research Centre (CRC) 477 at the Braunschweig University of Technology investigates innovative methods for SHM. In project field A1, a framework for the probabilistic safety assessment of structures has been developed using data from SHM. The current paper describes and explains the methodology of the framework and shows its application using a substitute structure, which was built for the CRC 477.     

Decision support tool on investments in life safety based on sampling theory

For decisions related to investments in societal safety and health, it is often difficult to balance the discretionary competence of decision-makers with theoretical optimum levels of investment. While removing day-to-day decisions about risk from the political arena would arguably result in better decisions, a full depoliticisation is not desirable since public and private risk preferences cannot simply be neglected without negatively affecting the perception of risk and inducing a democratic deficit. Therefore, a decision-making tool has been developed which allows for narrowing the scope of possible decisions for the decision-maker, based on predetermined maximum acceptable deviations from the theoretic optimum investment level. These maximum acceptable deviations should be established upfront on a general basis and may subsequently be applied on a case-by-case basis. In this paper, the basic calculation concepts are explained and a detailed example study is presented in which limits for the target safety level of concrete slabs are determined under some specific considerations.     

From Comprehensive Defense to Resilient City: Strategic Conception of Shanghai's City Security in the New Normal

The trend of climate warming and deeper globalization is adding new content to urban risks in Shanghai, resulting in the adaption of traditional comprehensive defense planning to the new environment. Based on the resilient city theory, this paper proposes a transition for Shanghai from an original comprehensive defense to a resilient city vision through strategic framework and approaches from the three aspects of engineering technology, spatial defense, and social governance in the New Normal age. Meanwhile, it suggests that Shanghai should use information technology to enhance the level of risk monitoring and to improve engineering design standards; strengthen the resilience from the scales of "life circle-urban circle-municipal administrative area"; and innovate as well as improve the social safety governance.     

武汉疾病控制中心空调通风设计

该工程是武汉公共卫生安全保障体系的一个组成部分。本文介绍了空调通风的设计和负压通风方面的特点,并就传染病医院的空调通风设计进行了讨论。     

基于全寿命周期的变电站设计集成研究

作为重要的公共设施,变电站的设计不仅要考虑其全寿命周期,也应当体现科学发展、可持续发展、保护环境的理念和工程对社会、历史负责的精神。文章提出了这样的设计集成模型,即用工程系统结构维和设计目标结构维的映射构成变电站全寿命周期设计集成技术系统的模型和框架。作为国家电网资产全寿命周期管理研究的子课题,文章研究应当能对变电站等重要公共设施的设计管理工作起到一定的指导和借鉴作用。