查看更多>>摘要：In this study, a System Dynamics based model, FML Model, was used to simulate city level CO{sub}2 emission data, based on the case study of Iskandar Development Region (IDR) of Malaysia, in order to promote data accessibility, synthesis and analysis for evaluating emissions, as CO{sub}2 emissions related database in developing countries is generally either unavailable or not yet mature. This paper firstly gives an outline of the construction of the developed FML Model. Subsequently, simulation results of energy consumptions and CO{sub}2 emissions for IDR up to 2050 are presented. The results showed that, if the current 'Business as Usual' trend of socioeconomic development continues to prevail, emissions from IDR is possible to increase to about 44 million tons by 2050, over seven times of 2005 level of 5.6 million tons. This paper also gives an overview of the possible functions of FML Model, including its capabilities to simulate city level energy consumption and CO{sub}2 emission trends, and to serve as a decision making tool in urban planning process by providing a quantitative evaluation on various urban policies.
查看更多>>摘要：Condition monitoring on rails and train wheels is vitally important to the railway asset management and the rail-wheel interactions provide the crucial information of the health state of both rails and wheels. Continuous and remote monitoring is always a preference for operators. With a new generation of strain sensing devices in Fibre Bragg Grating (FBG) sensors, this study explores the possibility of continuous monitoring of the health state of the rails; and investigates the required signal processing techniques and their limitations.
查看更多>>摘要：Hong Kong, a city on hilly natural terrain, with a total area of 1,000 square kilometres, has a population of 7 million. Its developments mainly concentrate in 20% of the flat land in the coastal area, mostly formed by reclamation from the sea. The rapid economic growth in the last 20 years demands new infrastructure and upgrading of existing facilities. The crowded spaghettilike complex of existing utilities and services underground in the limited road space, and the busy traffic, make such upgrading and construction of new features, by the conventional open-trench method, difficult. The use of tunnelling and pipejacking techniques could however resolve most of the problems associated therewith, such as disturbance to traffic, major diversions of existing utilities, earth moving, and effect of inclement weather. This would also minimise public complaints due to inconvenience and loss of business in the nearby shops as temporary traffic management schemes are only required at the jacking and receiving shaft locations. This paper discusses the various types of tunnelling and pipejacking techniques adopted in Hong Kong for drainage pipeline construction under different site constraints and ground conditions, their performance, the problems encountered and the recommendations made.
查看更多>>摘要：Coal-bed gas has been considered an attractive alternative fuel for combustion engines. In the present study, a special spark-ignition combustion system with a swirl chamber is used to operate the engine with coal-bed gas and a 2-zone combustion model has been developed and employed to study the characteristics of combustion and emissions of the engine. The combustion model includes two sub-models, with the first calculating the turbulence intensity history and the second modelling the jet flow through the orifice of the swirl chamber. Emissions of NO{sub}x, HC and CO have been predicted using the numerical model based on an extended Zeldovich mechanism, wall quenching and incomplete oxidation theory. The effects of various chemical components in coal-bed gas on the engine combustion process and emissions have been investigated, with a satisfactory agreement between the simulation and experimental data achieved.
查看更多>>摘要：Building Information Modelling (BIM) is a promising tool for facilitating automation in the construction industry. Since its inception in the early 80s, assisted by advancement in computing technologies, BIM is slowly replacing conventional 2-dimensional CAD technologies in a few countries. Also, standards and guidelines are being developed by various organisations for its unified use on architectural, engineering and construction projects. The attributes of BIM derived from its various definitions are discussed in this paper along with its utilisation trend in Hong Kong. A qualitative consideration of BIM is provided by the item analysis of BIM definitions. Evolution of the perceptions of architectural professionals about BIM in Hong Kong has been investigated by reviewing past studies and by use of a questionnaire survey. The major stakeholders driving the implementation of BIM in Hong Kong are identified. Finally, the studies of five selected cases of BIM implementation in Hong Kong are presented and the lessons learned from these cases are examined.
查看更多>>摘要：The vehicles being operated without tire pressure monitoring system (TPMS) is posing a significant safety problem. To solve the problems, number researches have been widely investigated. However, factors of limitation described in introduction are still the major concern. Hence, the appropriate systems of TPMS are still being investigated. This paper deals with development of TPMS that contributes significantly towards the enhancement of the intelligent vehicle safety application. A detailed overview on tire pressure monitor (TPM) and receiver modules development such as data acquisition, communication protocol, Manchester encoding algorithm and interface programme are demonstrated. The performance evaluation of the experimental results of the TPMS shows that data acquisition, complete messages of pressure and temperature and real-time monitoring are unique and advance. Thus, the experimental result is therefore ensures the data monitoring and provides warning to validate the usefulness of the TPMS system in maintaining and enhancing vehicle performance.
查看更多>>摘要：In recent years, as a common practice in Hong Kong, reinforced concrete plate structures including pile caps, footings and transfer plates are often analysed by the finite element method using plate bending elements. Structural designs are then based on the analytical results by the finite element method. Though this has been a common local practice in the past decades, the authors, as practicing engineers, have identified some problems in relation to reinforced concrete design of the plate structures against shear and bending affecting accuracy and structural adequacy which they wish to share with the readers. The problem that will be discussed in the paper include practical design approaches based on 'node force' and 'stress', both of which are analytical results given by the finite element method. The authors have pointed out in the paper that 'node force' is not true a representation of the behaviour of the plate bending structure. The approach based on 'node force' is therefore without sound ground. With the adopted methods of design by some current softwares, the 'node force approach' may even lead to under-design. The author further discuss the appropriate approaches in design based on 'stress' against flexure and shear, with reference to the true behaviour of the plate bending structure. Finally, some practical considerations in the use of design approach based on 'stress' are also discussed by which practical and adequate design can be achieved.
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