12,507 research outputs found
Energy translation and Proper-Time Eigenstates
The usual quantum mechanics describes the mass eigenstates. To describe the
proper-time eigenstates, a duality theory of the usual quantum mechanics was
developed. The time interval is treated as an operator on an equal footing with
the space interval, and the quantization of the space-time intervals between
events is obtained. As a result, one can show that there exists a zero-point
time interval.Comment: 15 pages, No figur
Design for safety: theoretical framework of the safety aspect of BIM system to determine the safety index
Despite the safety improvement drive that has been implemented in the construction industry in Singapore for many years, the industry continues to report the highest number of workplace fatalities, compared to other industries. The purpose of this paper is to discuss the theoretical framework of the safety aspect of a proposed BIM System to determine a Safety Index. An online questionnaire survey was conducted to ascertain the current workplace safety and health situation in the construction industry and explore how BIM can be used to improve safety performance in the industry. A safety hazard library was developed based on the main contributors to fatal accidents in the construction industry, determined from the formal records and existing literature, and a series of discussions with representatives from the Workplace Safety and Health Institute (WSH Institute) in Singapore. The results from the survey suggested that the majority of the firms have implemented the necessary policies, programmes and procedures on Workplace Safety and Health (WSH) practices. However, BIM is still not widely applied or explored beyond the mandatory requirement that building plans should be submitted to the authorities for approval in BIM format. This paper presents a discussion of the safety aspect of the Intelligent Productivity and Safety System (IPASS) developed in the study. IPASS is an intelligent system incorporating the buildable design concept, theory on the detection, prevention and control of hazards, and the Construction Safety Audit Scoring System (ConSASS). The system is based on the premise that safety should be considered at the design stage, and BIM can be an effective tool to facilitate the efforts to enhance safety performance. IPASS allows users to analyse and monitor key aspects of the safety performance of the project before the project starts and as the project progresses
Guest Editorial
This section contains upgraded papers originally published at The CIB W099 International Conference on "Modelling and Building Health and Safety”, which was organised and hosted by the Department of Building, National University of Singapore (NUS). It was held on 10 -11 September 2012 at the Marina Bay Sands Expo and Convention Center, Singapore.  The focal objectives of this section are to explore the integration and application of new techniques, technologies and strategies towards attaining verifiable improvements in occupational safety and health in construction
Novel Genetic Causes of Cerebral and Systemic Vasculopathies
Vasculopathies are a varied group of disorders that affect the vascular tree resulting in arterial stenosis or dilatation causing multi-organ ischaemia and significant cardiac and cerebral circulation complications. Commonly, vasculopathies present in infancy and segregate within families so a genetic cause is often suspected but not always identified by the current routinely available genetic tests in the UK National Health Service (NHS). Due to the overlapping phenotypes of these disorders genetic sequencing is required for accurate diagnosis and appropriate clinical intervention. In this thesis, a cohort of children with cerebral and systemic vasculopathies was subject to next-generation genetic sequencing. Several discoveries were made and various families are discussed herein. Firstly, a novel heterozygous mutation in MYH11, a gene affecting smooth muscle myosin heavy chain, was identified in a child with a moyamoya-like cerebrovascular disease and renal artery stenosis. This expanded the vasculopathic phenotype associated with MYH11, which previously was associated with familial aortopathy. Secondly, multiple members of three families diagnosed with a moyamoya arteriopathy were studied and were all found to have heterozygous mutations in c-CBL, an E3 ubiquitin ligase that down regulates various receptor tyrosine kinases. Detailed in vitro functional expression studies were undertaken in the patients with mutations in c-CBL showing impaired CBL-mediated degradation of cell-surface receptors in a dominant negative fashion. These results were compatible with dysregulated intracellular signaling through RAS. Lastly, three families with systemic vasculopathies associated with heterozygous mutations in RNF213 were also studied. This protein possesses both ubiquitin ligase and ATPase activity and adversely affects endothelial cell function. For the first time I showed that heterozygous mutations in RNF213 cause a vasculopathy that is not confined to the cerebral circulation
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