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

Continuous Monitoring of Distributed Data Streams over a Time-based Sliding Window

The past decade has witnessed many interesting algorithms for maintaining statistics over a data stream. This paper initiates a theoretical study of algorithms for monitoring distributed data streams over a time-based sliding window (which contains a variable number of items and possibly out-of-order items). The concern is how to minimize the communication between individual streams and the root, while allowing the root, at any time, to be able to report the global statistics of all streams within a given error bound. This paper presents communication-efficient algorithms for three classical statistics, namely, basic counting, frequent items and quantiles. The worst-case communication cost over a window is $O(\frac{k} {\epsilon} \log \frac{\epsilon N}{k})$ bits for basic counting and $O(\frac{k}{\epsilon} \log \frac{N}{k})$ words for the remainings, where $k$ is the number of distributed data streams, $N$ is the total number of items in the streams that arrive or expire in the window, and $\epsilon < 1$ is the desired error bound. Matching and nearly matching lower bounds are also obtained.Comment: 12 pages, to appear in the 27th International Symposium on Theoretical Aspects of Computer Science (STACS), 201

Functional characterisation of a novel nucleoporin gene NUP98 in zebrafish embryo.

Oral PresentationINTRODUCTION: The nucleoporin gene nup98 is important for the regulation of cytoplasmic-nuclear trafficking. Frequent disruptions of NUP98 during chromosomal translocation in acute myeloid leukaemia suggest that it may play a role in normal haematopoiesis. nup98-knockout mice has resulted in early embryonic lethality. Therefore, its role in embryonic haematopoiesis remains unclear. In this study, we have cloned a zebrafish nup98 gene and examined its role in embryonic development, with particular reference to haematopoiesis. METHODS: Two expressed sequence tags with translated sequence homologous to human NUP98 were identified. The gene was cloned by PCR from cDNA of zebrafish embryos. Expression of nup98 in zebrafish embryos was investigated spatially by whole-mount in-situ hybridisation and temporally by RT-PCR. The functions of nup98 were examined by morpholino knockdown and the effects on embryonic development evaluated by gene expression studies and confocal microscopy. Cellular functions of zebrafish nup98 were investigated in HeLa cells. RESULTS: Zebrafish nup98 gene shared 65% identity to human NUP98 homolog in protein sequence. The gene was expressed during early embryonic development since 1-cell stage and diffusely in eyes and the developing brain since 18 hpf. About 30% nup98-knockdown embryos developed intracranial haemorrhage at 48 hpf, resulting from disrupted blood vessels. nup98-knockdown upregulated pu.1 and scl as evaluated by quantitative RT-PCR. Moreover, ectopic expression of zebrafish nup98 rescued the defective mRNA export due to NUP98 knockdown in HeLa cells. CONCLUSION: A novel zebrafish nup98 gene was shown to exhibit conserved function in mRNA trafficking. Its role in embryonic development should be further evaluated.published_or_final_versio

Would Older Adults with Mild Cognitive Impairment Adhere to and Benefit from a Structured Lifestyle Activity Intervention to Enhance Cognition?: A Cluster Randomized Controlled Trial

Background Epidemiologic evidence suggests that cognitive and physical activities are associated with better cognition in late life. The present study was conducted to examine the possible benefits of four structured lifestyle activity interventions and compare their effectiveness in optimizing cognition for older adults with mild cognitive impairment (MCI). Method and Findings This was a 12-month cluster randomized controlled trial. 555 community-dwelling Chinese older adults with MCI (295 with multiple-domain deficits (mdMCI), 260 with single-domain deficit (sdMCI)) were recruited. Participants were randomized into physical exercise (P), cognitive activity (C), integrated cognitive and physical exercise (CP), and social activity (S, active control) groups. Interventions comprised of one-hour structured activities three times per week. Primary outcome was Clinical Dementia Rating sum of boxes (CDR-SOB) scores. Secondary outcomes included Chinese versions of Alzheimer's Disease Assessment Scale Cognitive subscale (ADAS-Cog), delayed recall, Mini-Mental State Examination, Category Verbal Fluency Test (CVFT) and Disability Assessment for Dementia - Instrumental Activities of Daily Living (DAD-IADL). Percentage adherence to programs and factors affecting adherence were also examined. At 12th month, 423 (76.2%) completed final assessment. There was no change in CDR-SOB and DAD-IADL scores across time and intervention groups. Multilevel normal model and linear link function showed improvement in ADAS-Cog, delayed recall and CVFT with time (p<0.05). Post-hoc subgroup analyses showed that the CP group, compared with other intervention groups, had more significant improvements of ADAS-Cog, delayed recall and CVFT performance with sdMCI participants (p<0.05). Overall adherence rate was 73.3%. Improvements in ADAS-Cog and delayed recall scores were associated with adherence after controlling for age, education, and intervention groups (univariate analyses). Conclusions Structured lifestyle activity interventions were not associated with changes in everyday functioning, albeit with some improvements in cognitive scores across time. Higher adherence was associated with greater improvement in cognitive scores. Factors to enhance adherence should be specially considered in the design of psychosocial interventions for older adults with cognitive decline.published_or_final_versio

Hedonic pricing models for metropolitan bus services

Conventional studies on the pricing of bus services use the cost structure to explain bus fares. In this paper, a hedonic pricing model for bus services in Hong Kong is estimated. The contributions of cost and market factors are uncovered. It is found that the cost factors dominate the determination of bus fares. In contrast to our expectation, bus fares do not react to competition faced by bus companies. Moreover, except the three cross-harbour tunnels, the bus fare has no direct relationship with the tolls of other tunnels. Our model serves well as a reference tool for bus companies to set market-acceptable bus fares.Hedonic Pricing Model, Bus Fares, Kowloon Motor Bus.

Gene selection in microarray data analysis for brain cancer classification

Cancer classification has been one of the most challenging tasks in clinical diagnosis. At present cancer classification is done mainly by looking through the cells' morphological differences, which do not always give a clear distinction of cancer subtypes. Unfortunately, this may have a significant impact on the final outcome of whether a patient could be cured effectively. Microarray technology can play an important role on diagnosing which type of disease one is carrying. The gene selection process is critical for developing gene markers for faster and more accurate diagnosis. In this paper, we develop a method using pairwise data comparisons instead of the one-over-the-rest approach used nowadays. Results are evaluated using available clustering techniques including hierarchical clustering and k-means clustering. Using pairwise comparison, the best accuracy achieved is 95% while it is only 83% when using one-over-the-rest approach. ©2006 IEEE.published_or_final_versio

Modelling the sound absorption of panels with tapered elliptic micro-perforations

A theoretical model is developed in the present study to predict the spectral characteristics of the sound absorption of solid panels with tapered elliptic micro-perforations backed by a rigid wall cavity. In the model, plane wave propagation is assumed along the length of the perforation in the presence of a viscous boundary layer at the internal wall of the perforation. End impedances are approximated using results in existing literature. Validation is done using impedance tube measurements. It is confirmed that the present tapered elliptic perforation model can give much better agreement with experimental results than the conventional cylindrical perforation model for all micro-perforation configurations tested. Results also suggest the importance of perforation density in controlling the variation of sound absorption of the panel absorbers upon changes in perforation configurations

Sound transmission across a rectangular duct section with a thin micro-perforated wall backed by a sidebranch cavity

An experimental investigation was carried out in the present study for deeper understanding on the sound transmission across a rectangular duct section installed with a thin micro-perforated panel (as a duct wall) backed by a sidebranch cavity. The contributions of the panel configuration and the cavity depth on reducing sound transmission are examined in detail. Results indicate a complicated relationship between sound power transmission, micro-perforation configuration and backing cavity depth. For panels with strong sound absorption capacity, sound power transmission efficiency is reduced as the panels become less absorptive, but there exists a frequency or frequency band above which the opposite is observed. It appears that there is also a certain level of panel sound absorption below which the sound transmission is strengthened over the whole frequency range of present study when the panel becomes less absorptive to sound