Development and validation of regression models to predict monthly heating demand for residential buildings

The present research work concerns development of regression models to predict the monthly heating demand for single-family residential sector in temperate climates, with the aim to be used by architects or design engineers as support tools in the very first stage of their projects in finding efficiently energetic solutions. Another interest to use such simplified models is to make it possible a very quick parametric study in order to optimize the building structure versus environmental or economic criteria. All the energy prediction models were based on an extended database obtained by dynamic simulations for 16 major cities of France. The inputs for the regression models are the building shape factor, the building envelope U-value, the window to floor area ratio, the building time constant and the climate which is defined as function of the sol-air temperature and heating set-point. If the neural network (NN) methods could give precise representations in predicting energy use, with the advantage that they are capable of adjusting themselves to unexpected pattern changes in the incoming data, the multiple regression analysis was also found to be an efficient method, nevertheless with the requirement that an extended database should be used for the regression. The validation is probably the most important level when trying to find prediction models, so 270 different scenarios are analysed in this research work for different inputs of the models. It has been established that the energy equations obtained can do predictions quite well, a maximum deviation between the predicted and the simulated is noticed to be 5.1% for Nice climate, with an average error of 2%. In this paper, we also show that is possible to predict the building heating demand even for more complex scenarios, when the construction is adjacent to non-heated spaces, basements or roof attics.     

火灾下梁柱端板式节点研究进展

回顾总结了近年来高温下梁柱端板式连接节点力学性能相关的研究成果。针对三类常用的端板连接形式:外伸式端板、齐平式端板以及内缩式端板连接进行了细致讨论。同时,从试验研究、有限元分析以及组件法的高温运用等方面着手归纳了相应研究成果。首先,对近年来为数不多的端板式节点高温试验进行了回顾,包括针对孤立节点的高温试验以及针对子结构的高温试验。随后,对有限元方法和推广应用的组件法这两种理论研究方法进行了详细的归纳总结,细致讨论了各组件模型实际运用中的优势以及存在的不足。最后,根据已有的研究成果,指出了梁柱端板式连接节点性能分析时还存在的诸多问题,并在此基础上提出了一些研究建议。     

摩擦摆隔震支座在网壳结构中多尺度模型分析

为研究摩擦摆隔震支座在网壳中的隔震特性和局部受力特性,利用ABAQUS有限元软件建立摩擦摆支座的实体模型,并将其应用于网壳结构,建立网壳结构的多尺度模型,并对该多尺度模型进行动力分析。分析表明摩擦摆隔震支座的加入可以有效的延长结构低阶振型的自振周期,而对结构的高阶振型的自振周期影响很小。通过对网壳结构输入单向地震波,探讨不同地震动输入强度下摩擦摆支座水平刚度变化对网壳节点加速度峰值、节点位移峰值及杆件轴力的影响。研究表明随着地震强度增加,摩擦摆隔震支座的水平刚度变化对网壳隔震响应影响越显著。在强震作用下摩擦摆隔震支座发生局部破坏,但不影响整体模型的多尺度分析。     

Seismic gravelly soil liquefaction assessment based on dynamic penetration test using expanded case history dataset

The seismic liquefaction has been observed in gravelly soils, in addition to sandy soils. Despite sandy soils, there is still a shortage of an extended case history database for developing empirical, semi-empirical, and probabilistic models to predict this phenomenon in gravelly soils. This study examines the documentations of several case histories of gravelly soil liquefaction all around the world to create a database, and then to develop probabilistic models to consider uncertainties of the models as well as the parameters for evaluating gravelly soil liquefaction triggering caused by earthquakes. The logistic regression and Bayesian mapping function, both of which are based on the maximizing likelihood estimation, were applied to present classifier curves to predict the occurrence of liquefaction. Additionally, a sensitivity analysis on the bias sampling weighting factor was performed to assess its effect on the model’s prediction accuracy. The results point to the effect of extended database and sampling bias on the developed models. Meanwhile, this study highlights the importance of developing probabilistic models rather than deterministic ones to consider uncertainties.

     

The role of proximity to universities for corporate patenting: provincial evidence from China

This paper investigates whether proximity to universities matters for corporate patenting in Chinese provinces. The investigation is based on estimating regional knowledge production functions using a Chinese provincial data set for the years from 2000 to 2008. Geographic proximity of companies to universities is taken as a key element to measure firms’ accessibility to university research. In addition, quality-adjusted accessibility measures are considered in extended models to take into account quality difference in university research. The results suggest the existence of spatial academic effects on corporate patenting activities in China as found in the previous literature for Western economies. In China, however, these effects are especially strong for realising technologically less demanding non-invention corporate patents than for invention corporate patents. Moreover, companies’ geographic proximity to universities dominates over university research quality difference for determining the relevance of universities as knowledge sources for companies. Extended models are estimated for robustness checks which ascertain the main results.     

AN EXTENDED INPUT-OUTPUT MODEL INCORPORATING EMPLOYED, UNEMPLOYED, AND IN-MIGRANT HOUSEHOLDS

ABSTRACT Household disaggregation is an important, yet relatively neglected, factor in the construction of regional input-output models. This paper shows how a simple input-output model can he progressively extended to provide a more realistic representation or the relationship between industrial sectors anti demographic characteristics of a local labor market. An extended, model including employed, unemployed, and in-migrant households is proposed and its analytical properties examined. A detailed sensitivity analysis of this model is conducted, using data for Strathelyde in Scotland. Particular attention is given to establishing the range of parameter values that must be adhered in in order that economically feasible solutions may he obtained.     

博弈论在建设工程投标报价中的应用研究

建立了投标报价一般静态贝叶斯博弈模型。运用这一模型及其扩展形式，对常用的几种评标方法下的报价决策进行了相关分析。以一般静态贝叶斯博弈模型为核心，通过对其进行简化或扩展，初步构建了投标报价博弈分析的理论框架。     

关于一起火灾延伸调查责任追究的思考

文章结合一起火灾事故案例,对火灾延伸调查现状展开定性分析,就具体追责情形、如何落实责任追究及后续整改问题进行初步探讨,对进一步落实火灾延伸调查,优化调查中的各项流程,切实深入推进火灾“一案三查”,将调查结果转化为提高社会火灾防控能力具有一定的现实意义。     

面向数字城市规划的城市规划模型研究

作为面向数字城市规划的关键技术,地理信息系统技术、遥感技术支撑下的城市规划模型的研究已经成为城市规划领域的热点问题之一。根据规划模型研究的对象和目的的不同,提出将城市规划模型分为综合规划模型和工程专项规划模型,按照这种分类方式这两种模型的研究进展进行了简要的介绍,并对其研究趋势与研究对策进行了分析。     

Modeling regional innovativeness and innovation

Advanced means of communication are necessary ingredients in the process of the dissemination of information and knowledge over space. Thus the spatial diffusion of innovation is contingent upon rapid, accurate transmission of knowledge and the ability to interact frequently and efficiently among different locations. This paper presents an extended empirical model for evaluating innovativeness and the innovation potential of various regions. The extended model is based on two basic models: the LOGIT model, a behavioral logistic model that is used to describe the diffusion process, and Bayesian statistical decision theory. A simplified example with synthetic data is presented to demonstrate the three steps involved in evaluating the probabilities of technology innovation in various regions with the extended model. Finally, the example is used to present possible way of employing the model to evaluate the effectiveness of public policy to attract firms to different regions.This paper was partially supported by a research grant No. 021-619 from the office of the Vice-President for Research at the Technion — Israel Institute of Technology, Haifa, Israel.     

群桩基础桥梁抗震分析简化模型

首先回顾了桩-土-结构共同作用的分析方法和我国大跨度桥梁抗震分析中对于桩基础的处理方法,然后在分析已有的桩基础简化模型的基础上,建议了一种更加合理有效的桩基础简化模型。采用各种简化模型对一座大跨度桥梁进行抗震分析,计算结果表明本文建议桩基础简化模型具有更高的精度。     

基于IFC标准结构工程产品模型构造和扩展

根据结构分析所涵盖的信息,构造和设计了结构产品模型信息基本框架,并对结构几何信息模型、荷载信息模型、分析信息模型的基本组成进行定义和表达。在基于IFC的EXPRESS-G图表达规范基础上,分别从几何信息模型、荷载信息模型、分析信息模型三个方面对IFC标准的结构产品模型缺失信息进行扩展,从而全面完善IFC标准的结构信息模型基本框架,以促进建筑结构设计过程中信息的有效交换。     

Modelling algal behaviour in the river thames

Forecasting the movement and growth of algae in river systems as particularly important for operational managers responsible for the distribution and supply of potable water. Algae affect the taste and smell of water and pose considerable filtration problems at water treatment plants. In a collaborative study with the Thames Water Authority, algal models have been developed for the River Thames. The non-linear processes controlling algal growth are examined using a generalized sensitivity analysis technique and the dominant parameters controlling system behaviour are identified. The extended Kalman filter (EKF) is then used to estimate these important parameters. The technique of using generalized sensitivity analysis prior to EKF estimation is suggested as a pragmatic approach to the problem of identifying the subset of physically, chemically or biologically meaningful parameters controlling system behaviour in mechanistic models.     

Numerical simulation of concrete filled steel tube columns against BLAST loads

Concrete filled steel tubes (CFST) have been widely used in constructing high-rise buildings, arch bridges and factories for the past few decades. In this research, numerical studies were carried out to investigate the flexural behaviour of CFST columns under both static and dynamic loads. The numerical models were calibrated and validated against a number of experimental data where the proposed models showed very good agreement with the test results. The results indicated that CFST columns showed good resistance against flexural loads under both static and dynamic loading conditions and therefore it has the potential to be widely used in these areas where potential blast attacks or frequent earthquakes are expected. The verified numerical model can also be extended to predict performances of concrete-infilled steel tubes under different loading conditions.     

A discrete method of limit analysis and its application to plastic stability problems of structural members

A method of discrete limit analysis which was proposed by Kawai in 1976 is extended to study structural behaviour of a set of solid blocks at the ultimate state of loading where the effect of finite rotation of these blocks should be taken into account. It is shown that Shanley's theory of plastic buckling can be simply demonstrated by using the present discrete models.     

Differential Quadrature Element Method Analysis of In-Plane Deflection of Vertically Curved Beam Structures

Abstract:   The development of the differential quadrature element method (DQEM) in-plane deflection analysis model of arbitrarily curved beam structures was carried out. The DQEM uses the extended differential quadrature to discretize the differential equation defined on each element, the transition conditions defined on the interelement boundary of two adjacent elements, and the boundary conditions of the beam. Numerical results obtained from solving two structural models using a numerical algorithm are presented. The convergence of the developed DQEM analysis model is efficient.     

Mathematical programming models for construction site layout problems

We address the construction site layout problem that determines the locations of temporary facilities. Mathematical programming models for the site layout problem are proposed, which can be solved by state-of-the-art solvers to optimality. A number of safety, health and environmental concerns, such as falling objects, dusts, and noise, are incorporated in the extensions of the mathematical models. We demonstrate, using numerical experiments, the superiority of our proposed mathematical programming model over existing heuristics in terms of solution optimality and the wide applicability in terms of handling practical considerations. Based on the results of conducted experiments, the proposed method achieved a 3–19% improvement on optimality over those of the existing heuristics methods. The contribution of this research work includes the advanced development of a mathematical programming model incorporating extended concerns and solving site layout problems within reasonable time.     

钢筋砼杆系结构的非线性全过程分析

本文以能量原理为基础提出了一种结构非线性全过程分析的数学方法。此方法适用于包括桁架、连续桨及框架在内的各类钢筋砼杆系结构。结构的本构关系可以考虑强度的强化作用和变形超过极限状态后的强度下降,而把理想弹塑性假定做为一种特殊情况来处理。此方法物理意义明确,使用简便,当结构形式复杂或使用计算机做分析时,优点更为突出。本文对Gibson单分量和Clough双分量杆单元模型进行了扩展,并利用扩展后的新模型做了包括下降段在内的钢筋砼框架的非线性全过程分析的计算例题。最后,做了框架结构的试验结果与计算结果的比较,两者符合较好。