Reliability-based life-cycle cost seismic design optimization of coastal bridge piers with nonuniform corrosion using different materials

Reinforcement corrosion is the main cause of performance deterioration of reinforced concrete(RC)structures.Limited research has been performed to investigate the life-cycle cost(LCC)of coastal bridge piers with nonuniform corrosion using different materials.In this study,a reliability-based design optimization(RBDO)procedure is improved for the design of coastal bridge piers using six groups of commonly used materials,i.e.,normal performance concrete(NPC)with black steel(BS)rebar,high strength steel(HSS)rebar,epoxy coated(EC)rebar,and stainless steel(SS)rebar(named NPC-BS,NPC-HSS,NPC-EC,and NPC-SS,respectively),NPC with BS with silane soakage on the pier surface(named NPC-Silane),and high-performance concrete(HPC)with BS rebar(named HPC-BS).First,the RBDO procedure is improved for the design optimization of coastal bridge piers,and a bridge is selected to illustrate the procedure.Then,reliability analysis of the pier designed with each group of materials is carried out to obtain the time-dependent reliability in terms of the ultimate and serviceability performances.Next,the repair time of the pier is predicted based on the time-dependent reliability indices.Finally,the time-dependent LCCs for the pier are obtained for the selection of the optimal design.

Application of Grey System Theory in Design For Cost (DFC)

Design For Cost (DFC) is a branch of Design For X (DFX). In this paper, wedefined DFC as a design method that analyzed and evaluated the product's life cycle cost (LCC), thenmodified the design to reduce the LCC. Nowadays it is a very difficult thing to obtain LCC data inChina or in developing countries. Statistical methods can not be used because available LCC data arefew. In order to solve this problem, we used grey system theory. Then relations of cost factorswere analyzed in LCC using grey relevant methods, and a GM(1,1) model between design parameters andLCC was established. Using this model, we can estimate and control LCC by changing design parametersat the beginning of the design stage.

Optimization for performance-based design under seismic demands, including social costs

Performance-based design in earthquake engineering is a structural optimization problem that has, as the objective, the determination of design parameters for the minimization of total costs, while at the same time satisfying minimum reliability levels for the specifi ed performance criteria. Total costs include those for construction and structural damage repairs, those associated with non-structural components and the social costs of economic losses, injuries and fatalities. This paper presents a general framework to approach this problem, using a numerical optimization strategy and incorporating the use of neural networks for the evaluation of dynamic responses and the reliability levels achieved for a given set of design parameters. The strategy is applied to an example of a three-story offi ce building. The results show the importance of considering the social costs, and the optimum failure probabilities when minimum reliability constraints are not taken into account.

Structural Design of Asphalt Pavement for Low Cost Rural Roads

On the basis of the equivalent axle load action frequency, the traffic classifications of rural roads as well as their corresponding types are classified. The asphalt pavement structure, road surface types and thickness of the rural roads are suggested for the various action frequency of the equivalent axle load. Furthermore, the roadbase thickness graphs are provided according to different equivalent axle load action frequency with different roadbed modulus and road surface modulus taken into account.

The Design of Stall-Regulated Wind Turbine Blade for a Maximum Annual Energy Output and Minimum Cost of Energy Based on a Specific Wind Statistic

The design of a stall-regulated wind turbine to achieve a maximum annual energy output is still a formidable task for engineers. The design could be carried out using an average wind speed together with a standard statistical distribution such as a Weibull with k = 2.0. In this study a more elaborated design will be attempted by also considering the statistical bias as a design criterion. The wind data used in this study were collected from three areas of the Lamtakong weather station in Nakhonratchasima Provice, the Khaokoh weather station in Phetchaboon and the Sirindhorn dam weather station in Ubonratchathani, Thailand. The objective is to design a best aerodynamic configurations for the blade (chord, twist and pitch) using the same airfoil as that of NREL Phase VI wind turbine. Such design is carried out at a design wind speed point. Wind turbine blades were optimized for both maximum annual energy production and minimum cost of energy using a method that take into account aerodynamic and structural considerations. The work will be carried out by the program “SuWiTStat” which was developed by the authors and based on BEM Theory (Blade Element Momentum). Another side issue is the credibility of the Weibull statistic in representing the real wind measurement. This study uses a regression analysis to determine this issue.

Study on Influencing Factors and Control Points of Design Estimate of Landscaping Engineering

In recent years,China’s landscaping projects have developed vigorously,and the growth rate of urban garden green space areas has been maintained at about 5%.Overall,with the development of the national economy and the support of macro policies,people’s demand for close to nature and beautify the environment is gradually increasing,which has brought new growth momentum for the development of the landscaping industry.Simultaneously,from the perspective of future economic development and urban development,the landscaping industry still has a lot of room for development.However,with the rapid development of landscape engineering,the problem of cost control of landscape engineering is becoming more prominent,the phenomenon of budget overestimation is common,and there are many factors affecting the cost of landscape engineering,which brings difficulties and challenges to the analysis of its influencing factors and cost management.How to scientifically analyze the influencing factors and control the cost has become an important link in the landscaping project.To solve the above problems,this paper takes the design stage of landscaping engineering as the background,takes the design estimate of landscaping engineering as the research object,through literature research and data collection,fully excavates the main influencing factors of the design estimate stage of landscaping engineering,analyzes the key points of cost control,and provides reference ideas and directions for the later cost management and control.

Low-cost Plant Landscape Design of Small-scale Residential Area——A Case Study of Huayu Residential Area on Baoping Road in Baoji City of Shaanxi Province

Modern landscape emphasizes the resource conservation and sustainable development.Simple and fine residential green areas should be the development trend.Taking the landscape design of Huayu residential area on Baoping Road in Baoji City of Shaanxi Province as an example,the way how to create a fine view and a good ecological environment for the people living in the bustling city with less investment and simple maintenance was analyzed.

An estimation method for direct maintenance cost of aircraft components based on particle swarm optimization with immunity algorithm

A particle swarm optimization (PSO) algorithm improved by immunity algorithm (IA) was presented. Memory and self-regulation mechanisms of IA were used to avoid PSO plunging into local optima. Vaccination and immune selection mechanisms were used to prevent the undulate phenomenon during the evolutionary process. The algorithm was introduced through an application in the direct maintenance cost (DMC) estimation of aircraft components. Experiments results show that the algorithm can compute simply and run quickly. It resolves the combinatorial optimization problem of component DMC estimation with simple and available parameters. And it has higher accuracy than individual methods, such as PLS, BP and v-SVM, and also has better performance than other combined methods, such as basic PSO and BP neural network.

External Landscape Design of Affordable Housing in Yuxing Homeland of Shanghai City

Approaches of external landscape design for affordable housing were discussed through analyzing the landscape designs of Yuxing Homeland in Shanghai City. By adopting simple landscape elements, following the design principle of 'natural, simple and comfortable', proceeding from the overall concept, a space for neighbors’ communication with pleasant environment and outstanding functions was created, a harmonious living environment was built, and the optimal landscape benefits were obtained.

Reliability-Based Full-Life Cycle Optimum Design of Offshore Jacket Platform

Based on the consideration of operation environment and structural property, an optimum design model of offshore jacket platform is developed in this paper, namely, the reliability-based full-life cycle optimum design model. In this model, the time-dependent reliability assessment method for structural members is established by combination of the decrease of sectional size and performance deterioration of material. The initial investment, maintenance cost and failure loss cost are assembled into the model. The total cost of the platform structure system in its full service period is chosen as the objective function, and the initial reliabilities of the layer elements partitioned in advance are taken as the design variables. Different models are obtained, depending on whether the system reliability constraint is considered or not. This optimum design model can result in the lowest full-life cost and the optimal initial layer reliability of an offshore jacket platform in the design of marine structures. The feasibility of this model is illustrated with an actual jacket platform in the Liaodong Gulf as an example.

A Wireless Sensor Network Ad-Hoc Designed as Anti-Theft Alarm System for Photovoltaic Panels

Photovoltaic (PV) systems have attracted increasing attention in last years as well as Wireless Sensor Networks (WSNs), which have been used in many application fields. In PV plants, especially in ground installations, a lot of thefts and damages occur due to the still high cost of the modules. A new experimental WSN ad-hoc has been designed to be an anti-theft alarm system. Each node of the network is directly installed under each PV string and it is equipped with an accelerometer sensor capable to detect a minimum displacement of the panel from its steady position. The WSN presents a star topology: a master node cyclically interrogates the slave nodes through RF link. It collects all the nodes responses and communicates though a RS-232 interface with a control PC checking the network status. When a slave node detects an alarm, continuous messages are sent to the control PC which turns on all the alarm signaling systems. The control PC is equipped with an open source operative system and software and provides for SMS, e-mail and sound-light signaling in case of alarm. It also communicates with a remote server where all the WSN information is stored. A first low cost experimental WSN has been already installed and it is working properly.

Constraints Based Decision Support for Site-Specific Preliminary Design of Wind Turbines

This study presents a decision-support tool for preliminary design of a horizontal wind turbine system. The function of this tool is to assist the various actors in making decisions about choices inherent to their activities in the field of wind energy. Wind turbine cost and site characteristics are taken into account in the used models which are mainly based on the engineering knowledge. The present tool uses a constraint-modelling technique in combination with a CSP solver (numerical CSPs which are based on an arithmetic interval). In this way, it generates solutions and automatically performs the concept selection and costing of a given wind turbine. The data generated by the tool and required for decision making are: the quality index of solution (wind turbine), the amount of energy produced, the total cost of the wind turbine and the design variables which define the architecture of the wind turbine system. When applied to redesign a standard wind turbine in adequacy with a given site, the present tool proved both its ability to implement constraint modelling and its usefulness in conducting an appraisal.

决策树和Design to Cost在纺织品开发中的应用

采用决策树分析的方法,并应用Design to Cost的概念,对某服装公司产品成本进行了分析,找出了影响产品成本的关键因素,进而降低产品的成本,使产品在市场上更加具有竞争力。

决策树和design to cost在纺织品开发中的应用

本文采用决策树分析的方法，应用Design to cost的概念。对某服装公司产品成本进行了分析．从而找出影响产品成本的关键因素，进而降低产品的成本，使得产品在市场上更加具有竞争力。 决策树是用二叉树形图来表示处理逻辑的一种工具。决策树有一个决策图和可能的结果（包括资源成本和风险）组成，用来创建到达目标的规则。决策树建立并用来辅助决策，是一种特殊的树结构。 Design to cost理念使得人们认识在纺织品的开发中，上游的产品的设计与开发在对产品成本或者最终价格的影响最为重要，而不完全是后期物流、管理方面的花费。 本文巧妙的将这两种分析法结合运用在纺织品开发这样一个复杂的环节中，从而清晰了产品开发的思路，简化复杂的开发过程，最终提高产品的竞争力。

Reliability-Based Optimal Design for Very Large Floating Structure

Costs and losses induced by possible future extreme environmental conditions and difficulties in repairing post yielding damage strongly suggest the need for proper consideration in design rather than just life loss prevention. This can be addressed through the development of design methodology that balances the initial cost of the very large floating structure (VLFS) against the expected potential losses resulting from future extreme wave induced structural damage. Here, the development of a methodology for determining optimal, cost effective design will be presented and applied to a VLFS located in the Tokyo bay. Optimal design criteria are determined based on the total expected life cycle cost and acceptable damage probability and curvature of the structure, and a set of sizes of the structure are obtained. The methodology and applications require expressions of the initial cost and the expected life cycle damage cost as functions of the optimal design variables. This study includes the methodology, total life cycle cost function, structural damage modeling, and reliability analysis.

Highway Planning and Design in the Qinghai–Tibet Plateau of China: A Cost–Safety Balance Perspective

Engineering designs for mountainous highways emphasize compliance checking to ensure safety. However, relying solely on compliance checking may lead designers to minimize costs at the expense of high risk indicators, since the overall risk level of the highway design is unknown to the designers. This paper describes a method for the simultaneous consideration of traffic safety risks and the associated cost burden related to the appropriate planning and design of a mountainous highway. The method can be carried out in four steps: First, the highway design is represented by a new parametric framework to extract the key design variables that affect not only the life-cycle cost but also the operational safety. Second, the relationship between the life-cycle cost and the operational safety risk factors is established in the cost-estimation functions. Third, a fault tree analysis (FTA) is introduced to identify the traffic risk factors from the design variables. The safety performance of the design solutions is also assessed by the generalized linear-regression model. Fourth, a theory of acceptable risk analysis is introduced to the traffic safety assessment, and a computing algorithm is proposed to solve for a cost-efficient optimal solution within the range of acceptable risk, in order to help decision-makers. This approach was applied and examined in the Sichuan–Tibet Highway engineering project, which is located in a complex area with a large elevation gradient and a wide range of mountains. The experimental results show that the proposed approach significantly improved both the safety and cost performance of the project in the study area.

决策树和design to cost在纺织品开发中的应用

本文采用决策树分析的方法，应用Design to cost的概念，对某服装公司产品成本进行了分析，从而找出影响产品成本的关键因素，进而降低产品的成本，使得产品在市场上更加具有竞争力。决策树是用二叉树形图来表示处理逻辑的一种工具。决策树由一个决策图和可能的结果（包括资源成本和风险）组成，用来创建到达目标的规则。决策树建立并用来辅助决策，是一种特殊的树结构。Design to cost理念使得人们认识到在纺织品的开发中，上游的产品的设计与开发对产品成本或者最终价格的影响最为重要，而不完全是后期生产、物流、管理方面的花费。本文巧妙的将这两种分析法结合运用在纺织品开发这样一个复杂的环节中，从而清晰化产品开发的思路，简化复杂的开发过程，最终提高产品的竞争力。

Area-time associated test cost model for SoC and lower bound of test time

A novel test access mechanism （TAM） architecture with multi test-channel （TC） based on IEEE Standard 1500 is proposed instead of the traditional sub-TAM structure. The cost model of an area-time associated test and the corresponding lower bound of system-on-chip （SoC） test time are established based on this TAM architecture. The model provides a more reliable method to control the SoC scheduling and reduces the complexity in related algorithm research. The result based on the area time associated test cost model has been validated using the ITC02 test benchmark.

决策树和Design to Cost在纺织品开发中的应用

本文采用决策树分析的方法,应用Design to cost的概念,对某服装公司产品成本进行了分析,从而找出影响产品成本的关键因素,进而降低产品的成本,使得产品在市场上更加具有竞争力。决策树是用二叉树形图来表示处理逻辑的一种工具。决策树有一个决策图和可能的结果(包括资源成本和风险)组成,用来创建到达目标的规则。决策树建立并用来辅助决策,是一种特殊的树结构。Design to cost理念使得人们认识到在纺织品的开发中,上游的产品设计与开发不仅影响后期物流、管理方面的花费,且对产品成本或者最终价格有着极为重要的影响。本文将这两种分析法结合运用在纺织品开发环节中,从而清晰了产品开发的思路,简化了复杂的开发过程,最终提高产品的竞争力。

CO_(2)and Cost-Based Optimum Design of Sustainable Metakaolin-Modified Concrete

Metakaolin is a highly reactive pozzolanic material that is widely utilized for enhancing the performance of concrete.This study offers a framework for the mixture design of sustainable metakaolin-modified concrete with low CO_(2)emissions and low costs.Different design strengths after 28 days are first formulated,with values such as 30,40,50,and 60 MPa.A genetic algorithm is then used to determine the optimal mixtures.Minimized CO_(2)and cost are set as the aims of the genetic algorithm.The strength of the concrete,its workability(slump),and carbonation service life with climate change are set as constraints of the genetic algorithm.Five design cases are considered:1)low-CO_(2)concrete with no carbonation,2)low-CO_(2)concrete with carbonation,3)low-material cost concrete with carbonation,4)low-total cost concrete with carbonation,and 5)low-total cost concrete with climate change.Based on the analysis,the following results are found:1)When the design’s strength is 30 MPa,to satisfy the requirement of carbonation durability,the concrete real strength should exceed 30 MPa.Moreover,after considering climate change,the concrete real strength should be further improved.2)When the design strength is 40,50,or 60 MPa for low-total-cost concrete,climate change has no impact on the optimal design because the concrete has sufficient carbonation resistance.3)Low-material-cost concrete has the same mixture as low-total-cost concrete because compared with the material cost,the CO_(2)emission cost is much lower.Moreover,for low-material-cost or low-total-cost concrete,the metakaolin content is at the lower limit because the price of metakaolin is much higher than that of cement.Summarily,the proposed model covered different aspects of sustainable concrete,such as cost and CO_(2)emissions,clarified various decisive factors of mix design,such as strength and carbon durability,and considered different conditions of climate change,such as no climate change and Representative Concentration Pathways(RCP)8.5.The proposed method is valuable for designing sustainable metakaolin-modified concrete with low CO_(2)emissions and costs.