How can BIM support construction safety management? Development of SIM

BIM is continuously changing the way construction can be approached, from design, scheduling, costing to facilities management. However, even though construction safety is a worldwide issue, and though previous, yet limited, studies have proven its great potential, BIM has not been extended to include automated construction safety management functions, i.e., hazard identification, assessment and control for construction works. In fact, as many as 71% of safety incidents can be prevented by safety considerations at design stage. Automation via BIM is the key to enhance effectiveness and efficiency of safety management, but development of Safety Information Modelling (SIM) is the key pre-requisite. This paper aims to outline a research project for developing both information and technical requirements for SIM via questionnaire survey, focus group, and real case studies. The project results, to be validated by real projects, will act as solid platform for developing:- i) Practical guidance to construction and safety professionals on the types of safety management a SIM can conduct, and the ways of utilizing the safety information in a SIM model [based on the systematic SIM information requirements (e.g., object identification, geometry attributes, safety rules)]; and ii) Overall guidance to software developers to develop appropriate SIM tools for different scenarios [based on the systematic SIM technical requirements (e.g., model information exchange, visualization, conflict analysis process for risk assessment, reliability)].published_or_final_versio

THE IMPACTS OF CLIMATE AND THE ENVIRONMENT ON HUMAN SKELETAL MORPHOLOGY DURING THE HOLOCENE IN NORTH CHINA A

This dissertation investigates the temporal and regional variation in human skeletal morphology in relation to climate and the environment in Holocene China. Linking skeletal morphology to the changes in climate, subsistence strategy and socio-political development has been well-documented in various geographical areas. Although a general pattern has been observed among different populations, it is evident that local factors have played an equally important role in human morphological variation. China was chosen in this dissertation because its diverse geographical, historical and cultural background provides an ideal setting in which to elucidate human biological responses to a variety different external forces and stimuli. A total sample of 533 adult skeletons, spanning from the mid-Neolithic to the twentieth century, was examined. These skeletons represent the ancient agriculturalists, nomadic pastoralists and agropastoralists inhabiting in contemporary Northeast China and modern humans from South China. This dissertation uses body size and shape, entheseal expression and biomechanical properties of long bones to investigate: 1.) temporal patterns in postcranial dimensions, stature and body mass; 2.) regional differences between the northern and southern Chinese in body size and body/limb proportions; and 3.) variation in skeletal biomechanics and entheses in relation to subsistence strategy. The findings in this dissertation indicated that while the human skeletons studied were morphologically varied throughout Holocene China, they were, to some extent, correlated with climatic and environmental factors. Body size and shape and body/limb proportions corresponded with variation in temperature. Additionally, stature, body mass and entheseal expression were correlated with socio-political and cultural development. Nevertheless, entheseal expression unexpectedly did not show a straightforward relationship with subsistence strategy, in which is inconsistent with the findings of previous studies. Although the comparisons of biomechanical properties were not unequivocal, they suggest differences in mobility and mechanical loading between different populations and subsistence strategies. On the whole, the results suggested that variation in skeletal morphology of the Holocene Chinese follows the universal patterns on the one hand, while on the other, they were influenced by local environmental and behavioural factors.Cambridge Commonwealth Trust; the Wenner Gren Foundation (8186

Long-term trends in human body size track regional variation in subsistence transitions and growth acceleration linked to dairying

Evidence for a reduction in stature between Mesolithic foragers and Neolithic farmers has been interpreted as reflective of declines in health, however, our current understanding of this trend fails to account for the complexity of cultural and dietary transitions or the possible causes of phenotypic change. The agricultural transition was extended in primary centers of domestication and abrupt in regions characterized by demic diffusion. In regions such as Northern Europe where foreign domesticates were difficult to establish, there is strong evidence for natural selection for lactase persistence in relation to dairying. We employ broad-scale analyses of diachronic variation in stature and body mass in the Levant, Europe, the Nile Valley, South Asia, and China, to test three hypotheses about the timing of subsistence shifts and human body size, that: 1) the adoption of agriculture led to a decrease in stature, 2) there were different trajectories in regions of in situ domestication or cultural diffusion of agriculture; and 3) increases in stature and body mass are observed in regions with evidence for selection for lactase persistence. Our results demonstrate that 1) decreases in stature preceded the origins of agriculture in some regions; 2) the Levant and China, regions of in situ domestication of species and an extended period of mixed foraging and agricultural subsistence, had stable stature and body mass over time; and 3) stature and body mass increases in Central and Northern Europe coincide with the timing of selective sweeps for lactase persistence, providing support for the "Lactase Growth Hypothesis.

Bias in mean velocities and noise in variances and covariances measured using a multistatic acoustic profiler: The Nortek Vectrino Profiler

This paper compiles the technical characteristics and operating principles of the Nortek Vectrino Profiler and reviews previously reported user experiences. A series of experiments are then presented that investigate instrument behaviour and performance, with a particular focus on variations within the profile. First, controlled tests investigate the sensitivity of acoustic amplitude (and Signal-to-Noise Ratio, SNR) and pulse-to-pulse correlation coefficient, R2, to seeding concentration and cell geometry. Second, a novel methodology that systematically shifts profiling cells through a single absolute vertical position investigates the sensitivity of mean velocities, SNR and noise to: (a). emitted sound intensity and the presence (or absence) of acoustic seeding; and (b). varying flow rates under ideal acoustic seeding conditions. A new solution is derived to quantify the noise affecting the two orthogonal tristatic systems of the Vectrino Profiler and its contribution to components of the Reynolds stress tensor. Results suggest that for the Vectrino Profiler: 1. optimum acoustic seeding concentrations are ~3,000 to 6,000 mg L-1; 2. mean velocity magnitudes are biased by variable amounts in proximal cells but are consistently underestimated in distal cells; 3. noise varies parabolically with a minimum around the "sweet spot", 50 mm below the transceiver; 4. the receiver beams only intersect at the sweet spot and diverge nearer to and further from the transceiver. This divergence significantly reduces the size of the sampled area away from the sweet spot, reducing data quality; 5. the most reliable velocity data will normally be collected in the region between approximately 43 and 61 mm below the transceiver

Seasonally-managed wetland footprint delineation using Landsat ETM+ satellite imagery

One major challenge in water resource management is the estimation of evapotranspiration losses from seasonally managed wetlands. Quantifying these losses is complicated by the dynamic nature of the wetlands' areal footprint during the periods of flood-up and drawdown. We present a data-lean solution to this problem using an example application in the San Joaquin Basin, California. Through analysis of high-resolution Landsat Enhanced Thematic Mapper Plus (ETM+) satellite imagery, we develop a metric to better capture the extent of total flooded wetland area. The procedure is validated using year-long, continuously-logged field datasets for two wetlands within the study area. The proposed classification which uses a Landsat ETM+Band 5 (mid-IR wavelength) to Band 2 (visible green wavelength) ratio improves estimates by 30-50% relative to previous wetland delineation studies. Requiring modest ancillary data, the study results provide a practical and efficient option for wetland management in data-sparse regions or un-gauged watersheds. © 2013 Elsevier Ltd

Critical role of the learning transfer climate in fostering innovation in construction

Because learning is a key antecedent to innovative activities, more attention needs to be paid to the climate, within the organization or project settings, that supports learning. The objectives of this paper are (1) to empirically examine the influences of the learning transfer climate on innovation and (2) to investigate how the between-group variability in the learning transfer climates of clients, contractors, and consultants affects innovation. The learning transfer climates are assessed in terms of the task-support and motivational elements adopted from the well-tested questionnaire of the Learning Transfer System Inventory. Based on the 147 survey returns collected from construction participants, factor analysis, correlation analysis, and regression analysis are conducted (the latter two using the total sample and the subsamples of client developers, contractors, and consultants). It is found from the total sample that openness to change (task-support element), performance-outcome expectations, and performance self-efficacy (motivational elements) are significant predictors of innovation. Whereas a successful construction project requires the interaction of multiple waves of innovation, contributed by various construction participants throughout the project, it is important to acknowledge the heterogeneity of these participants in considering the innovation process. The results also indicate that, with regard to their innovations, the different groups are influenced by different learning transfer climate factors: clients are affected by openness to change and performance self-efficacy; contractors are affected by openness to change; and consultants are affected by performance-outcome expectations. Analysis of these findings leads to a conceptual model of learning transfer climate and interactions between the clients, contractors, and consultants. From the theoretical perspective, the findings of this study lay ground for an interorganizational framework for further innovation-learning transfer studies. From the managerial perspective, this study provides empirical confirmation of the importance of measuring the learning transfer climate in construction organizations and of developing strategies for facilitating an innovation-conducive climate that fits each particular organization