Sensitivity Analysis and Optimal Shape Design for Bone-Prosthesis Interfaces in a Femoral Head Surface Replacement

A numerical optimization procedure has been applied for the shape optimal design of a femoral head surface replacement. The failure modes of the prosthesis that were considered in the formulation of the objective functions concerned the interface stress magnitude and the bone remodelling activity beneath the implant. In order to find a compromising solution between different requirements demanded by the two objective functions, a two step optimization procedure has been developed. Through step 1 the minimization of interface stress was achieved, through step 2 the minimization of bone remodelling was achieved with constraints on interface stresses. The results obtained provided an optimal design that generates limited bone remodelling activity with controlled interface stress distribution. The computational procedure was based on the application of the finite element method, linked to a mathematical programming package and a design sensitivity analysis package.     

Sensitivity Analysis and Optimal Shape Design for Bone-Prosthesis Interfaces in a Femoral Head Surface Replacement

Abstract

A numerical optimization procedure has been applied for the shape optimal design of a femoral head surface replacement. The failure modes of the prosthesis that were considered in the formulation of the objective functions concerned the interface stress magnitude and the bone remodelling activity beneath the implant. In order to find a compromising solution between different requirements demanded by the two objective functions, a two step optimization procedure has been developed. Through step I the minimization of interface stress was achieved, through step 2 the minimization of bone remodelling was achieved with constraints on interface stresses.

The results obtained provided an optimal design that generates limited bone remodelling activity with controlled interface stress distribution.

The computational procedure was based on the application of the finite element method, linked to a mathematical programming package and a design sensitivity analysis package.     

区域生态安全灾变态势分析方法——以辽河流域为例

在实际生产生活中人们关注的不仅是基于P-S-R（压力-状态-响应）框架的生态安全状态评价,而是未来生态安全灾变态势问题。灾变是由风险演变而来。存在生态安全隐患,就存在生态安全灾变的风险,生态安全隐患是生态安全灾变的风险源。生态安全灾变风险是指在一定区域内,由于各种隐患因素对人与自然环境复合生态系统可能产生的危害作用,从而使生态安全状态所承受的恶化和灾变的可能性,是人们不能确切把握且不愿接受的安全状态恶化的一种态势。以区域突发型生态安全隐患和缓发型生态安全隐患的危害作用为研究对象,采用生态风险评价和地理信息系统（GIS）分析技术相结合的方法,以辽河流域为实例探讨了生态安全灾变态势的理论与方法。     

基于韧性原则——以天津梅江地区某社区规划为例的社区步行景观设计策略

随着城市生态环境危机和自然灾害日益严重,提升城市韧性、促进城市生态系统的完善已成为当前学界的共识。社区作为城市的基本组成单元,是实现这一目标的基础;而步行景观系统的友好性应更加强调发挥其应对扰动、减轻灾害影响的能力。基于韧性原则的社区步行景观设计策略从灾害发生的时序及韧性的作用方式2方面,提出社区在生态韧性、防灾韧性、空间韧性3方面的相关策略,从而提升社区韧性,促进城市的可持续发展。     

基于PSR模型的国家公园综合灾害风险评估指标体系构建

灾害会对社会-生态系统产生严重影响,造成重大的社会、经济、环境等方面的损失,科学地对灾害风险进行评估是进行防灾减灾的基础工作。自然保护地是区域灾害风险管理热点地区,在国家公园体制试点建设与自然保护地体系改革中,国家公园作为保护重要生态系统并保障全民公益性的重要的自然保护地类型之一,管理目标的多样性,决定了其具有多风险源-多受体的灾害风险特征,因此,进行全面有效的灾害风险评估是支持国家公园生态系统管理、游客管理、社区管理等具体管理目标的必要环节。在明确国家公园灾害风险的特征与内涵的基础上,以国际减灾署灾害风险定量评估框架为依据,细分灾害风险源和风险受体,然后针对国家公园不同类型的灾害风险受体,以灾害风险源的危险性与灾害风险受体的脆弱性(包含敏感性、暴露性和适应性)衡量灾害风险度,结合压力-状态-响应(Pressure-State-Response, PSR)模型,构建了适用于国家公园综合灾害风险管理的评估指标体系,旨在为国家公园的灾害风险管理提供理论基础和科学依据,服务于国家公园多元化管理目标。     

弹性概念下适应台风灾害风险的开放空间设计思考

在全球气候变化背景之下,台风灾害对沿海城乡地区有着长久且深远的影响。弹性概念的引入使得适应台风灾害风险的规划设计有了与常规不同的角度。本文综述了弹性与城市规划、台风灾害风险的相关研究,探讨了当前沿海地区的台风灾害风险与开放空间现状,将开放空间划分为社会型、生产型、生态型3类,与弹性概念相结合展开设计思考,以期为相关的设计实践与研究提供新的思路与可能。     

北疆牧区雪灾预警与风险评估方法

在分析北疆牧区畜牧业生产与雪灾分布特征的基础上,利用RS、GIS和地面监测资料,从草地抗灾力、家畜承灾体和积雪致灾力3个子系统中选择9个因素作为预警参评因子,用家畜死亡率作为风险评估因子,构建了一个在完全放牧状态下的牧区雪灾预警与风险评估体系和模式.采用多层次综合法和目标线性加权函数法,建立了雪灾预警分级模型、判别模型和风险评估模型,据此可对草地和家畜抵御雪灾的强度和雪灾的风险期望损失进行动态预警与评估.北疆牧区雪灾预警与风险评估模型的精度分别达85%和72%.     

Flood Risk Analysis Based on Information Diffusion Theory

Due to the fact that the flood data series of small drainage basins is relatively short, available data are often not sufficient for flood risk analysis. This presents the problem of risk analysis using very small data samples. One method that can be applied is to regard the available small samples as fuzzy information and optimize them using information diffusion technology to yield analytical results with greater reliability. In this article a risk analysis method based on information diffusion theory is applied to create a new flood risk analysis model. Application of the model is illustrated taking the Jinhuajiang and Qujiang drainage basins as examples. This is a new attempt at applying information diffusion theory in flood risk analysis. Computations based on this analytical flood risk model can yield an estimated flood damage value that is relatively accurate. This study indicates that the aforementioned model exhibits fairly stable analytical results, even when using a small set of sample data. The results also indicate that information diffusion technology is highly capable of extracting useful information and therefore improves system recognition accuracy. This method can be easily applied and the analytical results produced are easy to understand. Results are accurate enough to act as a guide in disaster situations.     

灾难及突发事件住院信息管理系统的开发与实现

本文从系统设计目标、功能设计、结构设计等几个方面论述了灾难及突发事件住院信息管理系统的开发与实现。该系统由六大模块构成,实现了从预约管理、住院信息管理、床位管理、伤情评分、感染监测、查询统计到打印输出的灾害及突发时间住院伤病员信息全过程管理。应用本系统可规范灾害及突发事件医疗救援保障流程,大大提高了住院伤病员信息管理水平和工作效率。     

Frequency Spectrum Method-Based Stress Analysis for Oil Pipelines in Earthquake Disaster Areas

When a long distance oil pipeline crosses an earthquake disaster area, inertial force and strong ground motion can cause the pipeline stress to exceed the failure limit, resulting in bending and deformation failure. To date, researchers have performed limited safety analyses of oil pipelines in earthquake disaster areas that include stress analysis. Therefore, using the spectrum method and theory of one-dimensional beam units, CAESAR II is used to perform a dynamic earthquake analysis for an oil pipeline in the XX earthquake disaster area. This software is used to determine if the displacement and stress of the pipeline meet the standards when subjected to a strong earthquake. After performing the numerical analysis, the primary seismic action axial, longitudinal and horizontal displacement directions and the critical section of the pipeline can be located. Feasible project enhancement suggestions based on the analysis results are proposed. The designer is able to utilize this stress analysis method to perform an ultimate design for an oil pipeline in earthquake disaster areas; therefore, improving the safe operation of the pipeline.     

灾难及突发事件住院信息管理系统的开发与实现

本文从系统设计目标、功能设计、结构设计等几个方面论述了灾难及突发事件住院信息管理系统的开发与实现。该系统由六大模块构成,实现了从预约管理、住院信息管理、床位管理、伤情评分、感染监测、查询统计到打印输出的灾害及突发时间住院伤病员信息全过程管理。应用本系统可规范灾害及突发事件医疗救援保障流程,大大提高了住院伤病员信息管理水平和工作效率。     

城市滑坡灾害生态风险不确定性分析及风险管理——以深圳市为例

城市化的快速推进加剧了建设活动强度,强烈改变自然地表,破环原本稳定的地质环境,导致滑坡灾害日益频繁。本研究以深圳市为研究区,基于"危险性-脆弱性-潜在损失"三维评价框架评价深圳市街道尺度滑坡灾害生态风险、运用"三基色"原理可视化风险结构,并采用蒙特卡洛模拟进行不确定性分析,进而提出生态风险管理措施。结果表明:(1)不确定性与街道面积呈显著的负相关关系,随着街道面积增加,生态风险源不确定性减少;(2)以风险源为不确定性主体的生态风险评价中,不确定性由生态风险源不确定性和"源外"因子大小共同主导,"源外"因子大小是生态风险评价不确定的敏感因素;(3)深圳市滑坡灾害生态风险从西到东呈现"低-高-低-高"交错结构,风险结构主要为"高脆弱-高潜在损失"型和"高危险-高潜在损失"型。分析生态风险结构,建立滑坡灾害生态风险管理体系,制定明确风险管理目标,有利于高效地进行生态风险管理。     

面向国家公园管理目标的综合灾害风险管理:一个概念模型

减小阻碍国家公园管理目标实现的灾害风险,实现管理有效性,是保证国家公园体制建设建立的重要途径。研究提出,面向国家公园多元管理目标,保障社会-生态系统稳定性和恢复力,国家公园灾害风险管理具有综合性。这种综合性体现在国家公园内致灾因子与承灾体的多样性、相对性与转化性,需要集成分别侧重社会与生态系统的传统自然灾害风险管理与生态风险管理,让灾害风险管理贯穿国家公园具体管理。为实现集成应对这种综合性,研究首先总结国内外多类型自然保护地灾害风险管理特点与经验,辨析国家公园灾害风险管理在国家公园管理职责和管理规划中的定位,从3个方面提出对我国国家公园灾害风险管理的启示：1）需要与国家公园宏观管理目标紧密相连;2）以维持社会-生态系统理想状态为目标;3）要具有管理空间、时间与运行的整体性。在此基础上提出一个面向国家公园管理目标的综合灾害风险管理框架,其主要特点是：1）具有"层级式"管理目标;2）以社会-生态系统服务为评价终点开展以理想状态为目标的风险管理;3）联结研究与管理、协调科学与价值观进行适应性管理。     

Changes in Cognitive Functions in the Elderly Living in Temporary Housing after the Great East Japan Earthquake

On March 11, 2011, Japan experienced an earthquake of magnitude 9.0 and subsequent enormous tsunamis. This disaster destroyed many coastal cities and caused nearly 20,000 casualties. In the aftermath of the disaster, many tsunami survivors who lost their homes were forced to live in small temporary apartments. Although all tsunami survivors were at risk of deteriorating health, the elderly people were particularly at a great risk with regard to not only their physical health but also their mental health. In the present study, we performed a longitudinal cohort study to investigate and analyze health conditions and cognitive functions at 28, 32, and 42 months after the disaster in the elderly people who were forced to reside in temporary apartments in Kesennuma, a city severely damaged by the tsunamis. The ratio of people considered to be cognitively impaired significantly increased during the research period. On the other hand, the mean scores of the Kessler Psychological Distress Scale-6 and Athens Insomnia Scale improved based on the comparison between the data at 24 and 42 months. The multiple logistic regression analysis revealed that frequency of “out-of-home activities” and “walking duration” were independently associated with an increase in the ratio of people with cognitive impairment. We concluded that the elderly people living in temporary apartments were at a high risk of cognitive impairment and “out-of-home activities” and “walking” could possibly maintain the stability of cognitive functions.     

Performance Analysis of Auction-Based Distributed Shop-Floor Control Schemes from the Perspective of the Communication System

A growing level of interest in academia and industry centers on the paradigm of distributed shop-floor control in which task and resource allocation in the manufacturing system is accomplished in a distributed manner through message passing and auction-based decision making among autonomous entities. Due to the prominent role played by the communication system in this paradigm, it is important to consider the requirements and performance characteristics of the communication system during the design and evaluation of distributed shop-floor control schemes. In this paper, we propose a two-phase methodology for analyzing auction-based shop-floor control schemes from the perspective of the communication system. In the first phase, the control scheme is modeled as a closed queueing network and performance measures related to the auctioning process and the communication system are obtained rapidly using asymptotic bounding analysis and mean value analysis. Control schemes identified as attractive in the first phase are then evaluated in greater detail during the second phase, using a discrete event simulation model. We illustrate this methodology using two-class and four-class control schemes and discuss insights learned about the impact of various control-scheme-related factors on the performance of the auctioning process and the communication system.     

Development of a Composite Index with Quantitative Indicators for Drought Disaster Risk Analysis at the Micro Level

It is the aim of this study to provide non-state as well as state actors with an effective tool to assess the drought risk of households. The developed methodology introduces a technique for comparative measuring in the context of drought disaster risk management. This approach is designed to contribute to the effectiveness and accuracy of drought risk analyses at the micro level. In a process of qualitative and quantitative empirical research in East India, 10 single indicators for drought risk at the household level have been developed and validated. Based on this, methods of combining these single indicators within a composite index are introduced. Within the study area in Orissa, this instrument can be used for drought risk analysis in order to prioritize preventive measures. Outside the study area, the developed methodology can be adopted to gain suitable risk indicators and composite index weighting criteria. This study tackles the desire of disaster risk management projects for comparative risk analysis at the micro level and demonstrates how certain characteristics of households’ can be quantified. Thus the developed instrument facilitates prioritizing preventive actions for the most vulnerable households.     

功能约束条件下的钱江源国家公园体制试点区游憩利用适宜性评价研究

国家公园功能分区根据生态系统和文化资源的保护要求划定不同的区域,并通过对区域内活动开展的范围和强度进行管控,实现生态保护、游憩利用等目标。从功能约束条件出发,以钱江源国家公园体制试点区(简称"钱江源国家公园")为例,采用德尔菲法和层次分析法,选取自然游憩资源、景观美景度、人文游憩资源、游憩利用能力、生态环境承载力、社会条件等6个因子构建了国家公园游憩利用适宜性评价体系。运用GIS空间分析工具对其进行单因子分级评价和综合评价,定量评估了钱江源国家公园游憩利用的适宜性,并将其适宜性从低到高依次划分为I—IV的4个等级。结果表明,钱江源国家公园游憩利用适宜性4个等级的面积呈"橄榄"型分布格局。在游憩利用适宜性分析结果及国家公园功能分区管理要求的基础上,本文进一步将钱江源国家公园游憩利用划分为6大游憩利用类型,并提出不同游憩利用类型的主导服务功能与管理措施。研究结果可为国家公园功能分区管理和游憩利用提供规划与管理指导。     

Applications of cell-free protein synthesis in synthetic biology: Interfacing bio-machinery with synthetic environments

Synthetic biology is built on the synthesis, engineering, and assembly of biological parts. Proteins are the first components considered for the construction of systems with designed biological functions because proteins carry out most of the biological functions and chemical reactions inside cells. Protein synthesis is considered to comprise the most basic levels of the hierarchical structure of synthetic biology. Cell-free protein synthesis has emerged as a powerful technology that can potentially transform the concept of bioprocesses. With the ability to harness the synthetic power of biology without many of the constraints of cell-based systems, cell-free protein synthesis enables the rapid creation of protein molecules from diverse sources of genetic information. Cell-free protein synthesis is virtually free from the intrinsic constraints of cell-based methods and offers greater flexibility in system design and manipulability of biological synthetic machinery. Among its potential applications, cell-free protein synthesis can be combined with various man-made devices for rapid functional analysis of genomic sequences. This review covers recent efforts to integrate cell-free protein synthesis with various reaction devices and analytical platforms.     

Risk Assessment and Safety Evaluation Using Probabilistic Fault Tree Analysis

Risk assessment is an essential prelude to the development of accident prevention strategies in any chemical or petrochemical industry. Many techniques and methodologies such as HAZOP, failure mode effect analysis, fault tree analysis, preliminary hazard analysis, quantitative risk assessment and probabilistic safety analysis are available to conduct qualitative, quantitative, and probabilistic risk assessment. However, these methodologies are limited by: extensive data requirements, the length of study, results are not directly interpretable for decision making, simulation is often difficult, and they are applicable only at the operation or late design stage. Khan et al. (2001a) recently proposed a detailed methodology for risk assessment and safety evaluation. This methodology is simple, yet it is effective in safety and design-related decision making, and it has been applied successfully to many case studies. It is named SCAP, where S stands for safety, C and A stand for credible accident respectively, and P stands for probabilistic fault tree analysis. This paper recapitulates the SCAP methodology and demonstrates its application to a petrochemical plant.     

Questioning the Ubiquity of Neofunctionalization

Gene duplication provides much of the raw material from which functional diversity evolves. Two evolutionary mechanisms have been proposed that generate functional diversity: neofunctionalization, the de novo acquisition of function by one duplicate, and subfunctionalization, the partitioning of ancestral functions between gene duplicates. With protein interactions as a surrogate for protein functions, evidence of prodigious neofunctionalization and subfunctionalization has been identified in analyses of empirical protein interactions and evolutionary models of protein interactions. However, we have identified three phenomena that have contributed to neofunctionalization being erroneously identified as a significant factor in protein interaction network evolution. First, self-interacting proteins are underreported in interaction data due to biological artifacts and design limitations in the two most common high-throughput protein interaction assays. Second, evolutionary inferences have been drawn from paralog analysis without consideration for concurrent and subsequent duplication events. Third, the theoretical model of prodigious neofunctionalization is unable to reproduce empirical network clustering and relies on untenable parameter requirements. In light of these findings, we believe that protein interaction evolution is more persuasively characterized by subfunctionalization and self-interactions.