Design issues of using prefabrication in Hong Kong building construction

Prefabrication techniques have been adopted for the last two decades in public housing projects in Hong Kong, but the use of prefabrication in the private sector was encouraged only after the implementation of the Joint Practices Notes which promote its use. Although previous studies acknowledge the environmental benefits of using prefabrication, only a few studies have addressed sustainable design concepts (closed‐loop) in the adoption of precast construction. A questionnaire survey was administered to experienced Hong Kong construction professionals, and case studies of recently completed building projects were compiled to ascertain the use of prefabrication with reference to life cycle approach. The findings revealed that prefabrication, combined with modular design and standard components, saved time and construction/design costs, as buildings systems were used across projects. However, in some projects, specific site conditions restricted the use of similar prefabricated building systems across projects. Surprisingly only a few participants addressed life cycle design concepts such as design for deconstruction when adopting precast construction. Also, although it is common knowledge that flexible and demountable prefabricated building systems would result in efficient use of resources, their use is seldom practised in Hong Kong.Hong Kong, life cycle design, prefabrication, precast concrete, sustainable construction,

Study of multiscale global optimization based on parameter space partition

Inverse problem, Multiscale parameter space partition, Multi-grid seed growth, Deterministic global optimization,

International collaboration to assess the risk of Guillain Barre Syndrome following Influenza A (H1N1) 2009 monovalent vaccines

<p>Background: The global spread of the 2009 novel pandemic influenza A (H1N1) virus led to the accelerated production and distribution of monovalent 2009 Influenza A (H1N1) vaccines (pH1N1). This pandemic provided the opportunity to evaluate the risk of Guillain-Barre syndrome (GBS), which has been an influenza vaccine safety concern since the swine flu pandemic of 1976, using a common protocol among high and middle-income countries. The primary objective of this project was to demonstrate the feasibility and utility of global collaboration in the assessment of vaccine safety, including countries both with and without an established infrastructure for vaccine active safety surveillance. A second objective, included a priori, was to assess the risk of GBS following pH1N1 vaccination.</p><p>Methods: The primary analysis used the self-controlled case series (SCCS) design to estimate the relative incidence (RI) of GBS in the 42 days following vaccination with pH1N1 vaccine in a pooled analysis across databases and in analysis using a meta-analytic approach.</p><p>Results: We found a relative incidence of GBS of 2.42(95% CI 1.58-3.72) in the 42 days following exposure to pH1N1 vaccine in analysis of pooled data and 2.09(95% CI 1.28-3.42) using the meta-analytic approach.</p><p>Conclusions: This study demonstrates that international collaboration to evaluate serious outcomes using a common protocol is feasible. The significance and consistency of our findings support a conclusion of an association between 2009 H1N1 vaccination and GBS. Given the rarity of the event the relative incidence found does not provide evidence in contradiction to international recommendations for the continued use of influenza vaccines. (C) 2013 Elsevier Ltd. All rights reserved.</p>