The enhancement of spatial microsimulation models using geodemographics

The generation of synthetic population estimates through spatial microsimulation has been a popular technique in recent years, with applications to research and policy problems in many areas of social science. Estimation techniques typically involve cloning or matching households in surveys with small-area census data. When model estimates are benchmarked against real-world data, the models are typically well behaved and very robust, but they can struggle to capture the diversity of spatial variations shown by observed data. We argue in this paper that this is the result of 3 potential problems in spatial microsimulation estimation techniques. The first issue results from the matching process in the estimation techniques, and the second problem relates to the variations of household types in the surveys being reweighted. Third, similar household types may show different behaviours or have different attributes depending on geographical factors not contained in surveys (such as the proximity of service or job locations). The aim of this paper is to demonstrate and measure the loss of accuracy and intensity induced by spatial microsimulation in the context of real individual data. It will be argued in particular that while the first two problems have begun to be addressed in the literature, the third issue is still largely unreported. The paper will thus suggest a solution framework which involves linking spatial microsimulation models with geodemographics and demonstrates the promise of this technique with real numerical experiments.     

Elaboration of energy saving renovation measures for urban existing residential buildings in north China based on simulation and site investigations

It is necessary to determine whether to implement a retrofit measure or not based on its energy saving and economic benefits, when conducting a retrofit project. The common way to do that is to set up a building simulation model and calculate its energy saving and economic benefits. Because of the great discrepancy between the actuality and the building simulation model, it is very important to use the factual energy use to calibrate the model, so as to accurately predict the benefits of retrofit measures. Although the energy efficiency retrofit of residential buildings in north China is implemented in a large scale, it seldom knows whether the commonly used retrofit packages are optimized. Therefore, a typical residential building is selected in Beijing, and the energy saving and economic benefits of different retrofit measures are analyzed using a simulation model calibrated with its actual space heating energy use, and the optimized retrofit packages are put forward. Results shows the retrofit of space heating system is a very attractive measure due to its relatively low investment but good energy saving benefit, and roof retrofit is also cost effective, while window retrofit and wall retrofit are not economic to conduct separately. Four optimized retrofit packages are figured out to realize the 50% and 65% reductions of space heating intensity required in the energy efficiency standards, which have less investment costs compared with currently widely used packages, and the retrofit packages for the 65% reduction is more cost-effective than the packages for the 50% reduction.     

用信息取代规制：寻找塑造城市设计的另一种方式

本文的写作目的既不是为了展示研究成果，也不是为了批评（或表扬）规制（regulation）。我的目的是提出两个问题．有没有替代规制的可行方法？如果有，我们能在哪里找到模型7我建议通过关注一个领域来完成这个任务。     

Spatial time-dependent reliability analysis of reinforced concrete slab bridges subject to realistic traffic loading

Resistance and loads are often correlated in time and space. The paper assesses the influence of these correlations on structural reliability/probability of failure for a typical two-lane reinforced concrete (RC) slab bridge under realistic traffic loading. Spatial variables for structural resistance are cover and concrete compressive strength, which in turn affect the strength and chloride-induced corrosion of RC elements. Random variables include pit depth and model error. Correlation of weights between trucks in adjacent lanes and inter-vehicle gaps are also included and are calibrated against weigh-in-motion data. Reliability analysis of deteriorating bridges needs to incorporate uncertainties associated with parameters governing the deterioration process and loading. One of the major unanswered questions in the work carried out to date is the influence of spatial variability of load and resistance on failure probability. Spatial variability research carried out to date has been mainly focused on predicting the remaining lifetime of a corroding structure and spatial variability of material, dimensional and environmental properties. A major shortcoming in the work carried out to date is the lack of an allowance for the spatial variability of applied traffic loads. In this article, a two-dimensional (2D) random field is developed where load effects and time-dependent structural resistance are calculated for each segment in the field. The 2D spatial time-dependent reliability analysis of an RC slab bridge found that a spatially correlated resistance results in only a small increase in probability of failure. Despite the fact that load effect at points along the length of a bridge is strongly correlated, the combined influence of correlation in load and resistance on probability of failure is small.     

Demand Profiling for Dynamic Traffic Assignment by Integrating Departure Time Choice and Trip Distribution

One challenge in dynamic traffic assignment (DTA) modeling is estimating the finely disaggregated trip matrix required by such models. In previous work, an exogenous time distribution profile for trip departure rates is applied uniformly across all origin‐destination (O‐D) pairs. This article develops an endogenous departure time choice model based on an arrival time penalty function incorporated into trip distribution, which results in distinct demand profiles by O‐D pair. This yields a simultaneous departure time and trip choice making use of the time‐varying travel times in DTA. The required input is arrival time preferences, which can be disaggregated by O‐D pair and may be easier to collect through surveys than the demand profile. This model is integrated into the four‐step planning process with feedback, creating an extension of previous frameworks which aggregate over time. Empirical results from a network representing Austin, Texas indicate variation in departure time choice appropriate to the arrival time penalties and travel times. Our model also appears to converge faster to a dynamic trip table prediction than a time‐aggregated coupling of DTA and planning, potentially reducing the substantial computation time of combined planning models that solve DTA as a subproblem of a feedback process.     

Antoni Gaudí and Frei Otto: Essential Precursors to the Parametricism Manifesto

As Senior Architect to the Basilica of the Sagrada Família in Barcelona, Mark Burry has been ‘thinking parametrically’ for almost his entire career. Here he describes how his longstanding role overseeing the completion of Antoni Gaudí's masterpiece has afforded unique insights into the work of a great geometer and parametric thinker. Burry places the contribution of Gaudí alongside that of Frei Otto – the other eminent 20th-century Proto-Parametricist.     

Architectural Patents and Open-Source Architectures: The Globalisation of Spatial Design Innovations (or Learning from ‘E99’)

Patents are the strongest form of intellectual property rights available internationally, so far unbeaten by open source as a body of innovation and know-how. Mark Garcia , senior lecturer in the Department of Architecture & Landscape at the University of Greenwich, London, here considers the pros and cons of the patent system for architects in the digital age: from issues over patent categorisation by type, to possibilities of micro-royalties through the capacity of design software to track every stage of input from multiple contributors.     

Predicting faecal indicator fluxes using digital land use data in the UK's sentinel Water Framework Directive catchment: the Ribble study

The Ribble drainage basin is the single UK sentinel study area chosen for examining the implementation of the EU Water Framework Directive (WFD 20/60/EC). The study which has generated the data for this paper was initiated to quantify 'catchment-derived' fluxes of faecal indicators originating from both point and diffuse sources to inform the competent authorities on the potential for, and prioritization of, further options for reducing the faecal indicator loadings to this crucial coastal environment. It represents the first UK drainage basin-scale 'profile' of faecal indicator sources as recommended by WHO [1999. Health Based Monitoring of Recreational Waters: The Feasibility of a New Approach; the "Annapolis Protocol". World Health Organisation Geneva, Switzerland; 2003. Guidelines for Safe Recreational-Water Environments Volume 1: Coastal and Fresh-Waters. World Health Organisation Geneva, Switzerland] and incorporated into current drafts of the revised Bathing Water Directive [Anon, 2004. Council of the European Communities Amended proposal for a Directive of the European Parliament and of the Council concerning the management of bathing water quality. Brussels 23rd June]. This paper focuses on the relationships between land use and faecal indicator organism concentrations in surface waters within this very large drainage basin (1583 km2) containing some extensive urban areas. A geographical information system comprising readily available digital elevation, remotely sensed land cover and digital map data was used to generate the land use variables for subcatchments draining to 41 locations across the study area. Presumptive concentrations of coliforms, Escherichia coli and enterococci (colony forming unit (cfu) 100 ml(-1)) were measured at each location on at least 20 occasions over a 44-day period within the 2002 bathing season. The sampling programme targeted hydrograph events. Hydrometric records were used to allocate results as either base flow or high flow. At each site, geometric mean faecal indicator organism concentrations were significantly elevated at high flow compared to base flow. Stepwise regression modelling produced statistically significant models predicting geometric mean base and high-flow faecal indicator organism concentrations from land use variables (r2: 49.5-68.1%). The dominant predictor variable in each case was the proportion of built-up land in subcatchments, suggesting that this land use type, with associated sewage-related inputs, is a critical source of faecal indicator organisms in this drainage basin.