550 resultados para Concrete construction
Resumo:
We propose two public-key schemes to achieve “deniable authentication” for the Internet Key Exchange (IKE). Our protocols can be implemented using different concrete mechanisms and we discuss different options; in particular we suggest solutions based on elliptic curve pairings. The protocol designs use the modular construction method of Canetti and Krawczyk which provides the basis for a proof of security. Our schemes can, in some situations, be more efficient than existing IKE protocols as well as having stronger deniability properties.
Resumo:
Abstract Maintaining the health of a construction project can help to achieve the desired outcomes of the project. An analogy is drawn to the medical process of a human health check where it is possible to broadly diagnose health in terms of a number of key areas such as blood pressure or cholesterol level. Similarly it appears possible to diagnose the current health of a construction project in terms of a number of Critical Success Factors (CSFs) and key performance indicators (KPIs). The medical analogy continues into the detailed investigation phase where a number of contributing factors are evaluated to identify possible causes of ill health and through the identification of potential remedies to return the project to the desired level of health. This paper presents the development of a model that diagnoses the immediate health of a construction project, investigates the factors which appear to be causing the ill health and proposes a remedy to return the project to good health. The proposed model uses the well-established continuous improvement management model (Deming, 1986) to adapt the process of human physical health checking to construction project health.
Resumo:
Bomb attacks carried out by terrorists, targeting high occupancy buildings, have become increasingly common in recent times. Large numbers of casualties and property damage result from overpressure of the blast followed by failing of structural elements. Understanding the blast response of multi-storey buildings and evaluating their remaining life have therefore become important. Response and damage analysis of single structural components, such as columns or slabs, to explosive loads have been examined in the literature, but the studies on blast response and damage analysis of structural frames in multi-storey buildings is limited and this is necessary for assessing the vulnerability of them. This paper investigates the blast response and damage evaluation of reinforced concrete (RC) frames, designed for normal gravity loads, in order to evaluate their remaining life. Numerical modelling and analysis were carried out using the explicit finite element software, LS DYNA. The modelling and analysis takes into consideration reinforcement details together and material performance under higher strain rates. Damage indices for columns are calculated based on their residual and original capacities. Numerical results generated in the can be used to identify relationships between the blast load parameters and the column damage. Damage index curve will provide a simple means for assessing the damage to a typical multi-storey building RC frame under an external bomb circumstance.
Resumo:
The Digital Practice Ecosystem is a network of professional architectural, engineering and contracting firms, government agencies and professional bodies, academic, educational, and research institutions that have the shared goal of fostering changes in the construction industry through applications of digital practice. Changing the process of designing and constructing buildings using digital models will improve quality and efficiency and reduce costs allowing completion on time and on budget.
Resumo:
Research and innovation in the built environment is increasingly taking on an inter-disciplinary nature. The built environment industry and professional practice have long adopted multi and inter-disciplinary practices. The application of IT in Construction is moving beyond the automation and replication of discrete mono and multi-disciplinary tasks to replicate and model the improved inter-disciplinary processes of modern design and construction practice. A major long-term research project underway at the University of Salford seeks to develop IT modelling capability to support the design of buildings and facilities that are buildable, maintainable, operable, sustainable, accessible, and have properties of acoustic, thermal and business support performance that are of a high standard. Such an IT modelling tool has been the dream of the research community for a long time. Recent advances in technology are beginning to make such a modelling tool feasible.----- Some of the key problems with its further research and development, and with its ultimate implementation, will be the challenges of multiple research and built environment stakeholders sharing a common vision, language and sense of trust. This paper explores these challenges as a set of research issues that underpin the development of appropriate technology to support realisable advances in construction process improvements.
Resumo:
The construction industry is dynamic in nature. The concept of project success has remained ambiguously defined in the construction industry. Project success is almost the ultimate goal for every project. However, it means different things to different people. While some writers consider time, cost and quality as predominant criteria, others suggest that success is something more complex. The aim of this paper is to develop a framework for measuring success of construction projects. In this paper, a set of key performance indicators (KPIs), measured both objectively and subjectively are developed through a comprehensive literature review. The validity of the proposed KPIs is also tested by three case studies. Then, the limitations of the suggested KPIs are discussed. With the development of KPIs, a benchmark for measuring the performance of a construction project can be set. It also provides significant insights into developing a general and comprehensive base for further research.
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This paper focuses on the development and delivery of a core construction management (CM) unit, which forms the capstone of a four-unit CM stream in an undergraduate programme in the Faculty of Built Environment and Engineering at the Queensland University of Technology. UDB410 (Construction Management) is a final year unit that consolidates skills students have learned throughout their degree, hopefully graduating them as work-ready construction managers. It was developed in consultation with the Queensland Chapter of the Australian Institute of Building (AIB) and is a final year unit in the undergraduate Bachelor of Urban Development (CM) course. The unit uses various tools such as the OSIRIS business database (Bureau van Dijk Electronic Publishing, 2009), the AROUSAL (UK Version) construction business simulation (Lansley, 2009) and the Denison Organisational Culture Survey (Denison, 2000) to facilitate the development of skills in managing a construction company. The objectives of the paper are: • To track the rationale and development of the UDB410 unit sand describe the way in which this final year unit integrates learning from other parts of the course within which it is located as well as capping-off the CM stream of core units; • To highlight the difficulties of blending a balance of technology and management in a single unit; and • To explain how partnering with the construction industry benefited the learning quality of the unit.
Resumo:
Indonesia’s construction industry is important to the national economy. However, its competitiveness is considered low due to the lack of success of its development strategy and policy. A new approach known as the cluster approach is being used to make strategy and policy in order to develop a stronger, and more competitive industry. This paper discusses the layout of the Indonesian construction cluster and its competitiveness. The archival analysis research approach was used to identify the construction cluster. The analysis was based on the input-output (I/O) tables of the years 1995 and 2000, which were published by the Indonesian Central Bureau of Statistics. The results suggest that the Indonesian construction cluster consists of the industries directly involved in construction as the core, with the other related and supporting industries as the balance. The anatomy of the Indonesian construction cluster permits structural changes to happen within it. These changes depend on policies that regulate the cluster’s constituents
Resumo:
Purpose – Virtual prototyping technologies linked to building information models are commonplace within the aeronautical and automotive industries. Their use within the construction industry is now emerging. The purpose of this paper is to show how these technologies have been adopted on the pre-tender planning for a typical construction project. Design/methodology/approach – The research methodology taken was an “action research” approach where the researchers and developers were actively involved in the production of the virtual prototypes on behalf of the contractor thereby gaining consistent access to the decisions of the planning staff. The experiences from the case study were considered together with similar research on other construction projects. Findings – The findings from the case studies identify the role of virtual prototyping in components modelling, site modelling, construction equipment modelling, temporary works modelling, construction method visualization and method verification processes. Originality/value – The paper presents a state-of-the-art review and discusses the implications for the tendering process as these technologies are adopted. The adoption of the technologies will lead to new protocols and changes in the procurement of buildings and infrastructure.
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This study investigates the existence of intercultural adjustment in the multicultural construction workplaces by examining the leadership orientations (task-/people-orientation), communication and conflict resolution skills (high/low-context culture), and power relationship styles (high/low power distance) of local Chinese and the British expatriate project managers in the multinational construction companies in Hong Kong. A sample of project managers (N = 40) and their subordinates (N = 61) were surveyed using the structured questionnaires. Statistical techniques (independent-samples t-test, and Pearson correlation analysis) were employed to evaluate the data. The results revealed a number of interesting findings. First, it was found that both project manager groups equally considered the importance of task performance and interpersonal relationship. The results of correlations analysis provide support for the linkages of the length of working abroad with the change in task/people orientation for Chinese and expatriate managers. The analysis revealed that those Chinese managers who have the longest length of time living or working in Western countries tended to measure higher on task-orientation. Similarly, those British expatriate managers who have the longest period of working in Hong Kong tended to be less task-orientated. Second, local Chinese managers were found to be more confrontational when they strongly disagree with their team members than their British expatriate counterparts. It would appear that stress from project deadline which increase the directness and terseness in communication acts, and retain the composure of project managers in dealing with the subordinates. Finally, our findings show that there is significant difference between local Chinese and British expatriate managers in their power relationship with subordinates. This implies that although the intercultural adjustment might influence perceptions of local and expatriate managers, some dominant deep-rooted cultural values and beliefs are still not easily altered. Conclusions are presented along with suggestions for future studies.