490 resultados para Critical commentary
Resumo:
A qualitative analysis of the expected dilatation strain field in the vicinity of an array of grain-boundary (GB) dislocations is presented. The analysis provides a basis for the prediction of the critical current densities (jc) across low-angle YBa2Cu3O7- (YBCO) GBs as a function of their energy. The introduction of the GB energy allows the extension of the analysis to high-angle GBs using established models which predict the GB energy as a function of misorientation angle. The results are compared to published data for jc across [001]-tilt YBCO GBs for the full range of misorientations, showing a good fit. Since the GB energy is directly related to the GB structure, the analysis may allow a generalization of the scaling behavior of jc with the GB energy. © 1995 The American Physical Society.
Resumo:
Defence projects are typically undertaken within a multi-project-management environment where a common agenda of project managers is to achieve higher project efficiency. This study adopted a multi-facet qualitative approach to investigate factors contributing to or impeding project efficiency in the Defence sector. Semi-structured interviews were undertaken to identify additional factors to those compiled from the literature survey. This was followed by a three-round Delphi study to examine the perceived critical factors of project efficiency. The results showed that project efficiency in the Defence sector went beyond its traditional internally focused scope to one that is externally focused. As a result, efforts are needed on not only those factors related to individual projects but also those factors related to project inter-dependencies and external customers. The management of these factors will help to enhance the efficiency of a project within the Defence sector.
Resumo:
Railway Bridges deteriorate over time due to different critical factors including, flood, wind, earthquake, collision, and environment factors, such as corrosion, wear, termite attack, etc. In current practice, the contributions of the critical factors, towards the deterioration of railway bridges, which show their criticalities, are not appropriately taken into account. In this paper, a new method for quantifying the criticality of these factors will be introduced. The available knowledge as well as risk analyses conducted in different Australian standards and developed for bridge-design will be adopted. The analytic hierarchy process (AHP) is utilized for prioritising the factors. The method is used for synthetic rating of railway bridges developed by the authors of this paper. Enhancing the reliability of predicting the vulnerability of railway bridges to the critical factors, will be the significant achievement of this research.
Resumo:
In response to a growing interest in art and science interactions and transdisciplinary research strategies, this research project examines the critical and conceptual affordances of ArtScience practice and outlines a new experiential methodology for practice-lead research using a framework of creative becoming. In doing so, the study contributes to the field of ArtScience and transdisciplinary practice, by providing new strategies for creative development and critical enquiry across art and science.
Resumo:
This paper investigates how Enterprise Architecture (EA) evolves due to emerging trends. It specifically explores how EA integrates the Service-oriented Architecture (SOA). Archer’s Morphogenetic theory is used as an analytical approach to distinguish the architectural conditions under which SOA is introduced, to study the relationships between these conditions and SOA introduction, and to reflect on EA evolution (elaborations) that then take place. The paper focuses on reasons for why EA evolution could take place, or not and what architectural changes could happen due to SOA integration. The research builds on sound theoretical foundations to discuss EA evolution in a field that often lacks a solid theoretical groundwork. Specifically, it proposes that critical realism, using the morphogenetic theory, can provide a useful theoretical foundation to study enterprise architecture (EA) evolution. The initial results of a literature review (a-priori model) were extended using explorative interviews. The findings of this study are threefold. First, there are five different levels of EA-SOA integration outcomes. Second, a mature EA, flexible and well-defined EA framework and comprehensive objectives of EA improve the integration outcomes. Third, the analytical separation using Archer’s theory is helpful in order to understand how these different integration outcomes are generated.
Resumo:
This paper presents a strategy to predict the lifetime of rails subjected to large rolling contact loads that induce ratchetting strains in the rail head. A critical element concept is used to calculate the number of loading cycles needed for crack initiation to occur in the rail head surface. In this technique the finite element method (FEM) is used to determine the maximum equivalent ratchetting strain per load cycle, which is calculated by combining longitudinal and shear stains in the critical element. This technique builds on a previously developed critical plane concept that has been used to calculate the number of cycles to crack initiation in rolling contact fatigue under ratchetting failure conditions. The critical element concept simplifies the analytical difficulties of critical plane analysis. Finite element analysis (FEA) is used to identify the critical element in the mesh, and then the strain values of the critical element are used to calculate the ratchetting rate analytically. Finally, a ratchetting criterion is used to calculate the number of cycles to crack initiation from the ratchetting rate calculated.
Resumo:
The interaction between head contractor and subcontractor in modern construction often contributes to the degree of success or failure of any large-scale construction project. In this paper, previous research on the relationship and interaction between head contractor and subcontractor is examined in order to establish how these relationships will affect the overall performance of a project. Based on the review, research questions on how to best manage the interaction and relationship between these two vital project participants are proposed and future research direction discussed.
Resumo:
By using information collected from numerous American Economic Review publications from the last 100 years, Torgler and Piatti examine the top publishing institutions to determine their most renowned AER papers based on citation success. Areas of interest include how often an individual can publish in the AER, how equally successful citations are distributed and who the top AER publishing authors are. The book explores what the level of cooperation is among authors and what drives systems such as the alphabetical name ordering. Torgler and Piatti critically examine the individual characteristics of AER authors, editors, editorial board members and referees and even tackle more intricate details such as the frequency of female publications in the AER. The authors observe and analyse the relationship between academic age and publication performance to see if there is any pattern on these factors and citation success. The book then goes on to analyse data concerning awards, and whether awards can increase the probability of publishing in the AER at a later stage
Resumo:
Indigenous Australians are the most socially and economically disadvantaged population group in Australia and have the poorest health status. The statistics describe and highlight the degree of sicknesses and disadvantage along with lower life expectancy, elevated mortality rate and increased risk of cardiovascular disease, cancer, diabetes, respiratory disease and kidney disease. While these statistics reflect poor health status and a high level of illness within Indigenous communities, it is known that individual, family and community behaviours play a key role in Indigenous health and wellbeing outcomes. These behavioural issues include use of tobacco, alcohol and other substances along with lack of physical activity and poor nutrition. The paper Nutrition and older Indigenous Australians: Service delivery implications in remote communities. A narrative view explores some of the issues specific to nutrition. Bronwyn Fredericks was invited to provide this commentary by the Editor of the Australasian Journal on Aging.
Resumo:
Dementia is an irreversible and incurable syndrome that leads to progressive impairment of cognitive functions and behavioural and psychological symptoms such as agitation, depression and psychosis. Appropriate environmental conditions can help delay its onset and progression, and indoor environmental (IE) factors have a major impact. However, there is no firm understanding of the full range of relevant IE factors and their impact levels. This paper describes a preliminary study to investigate the effects of IE on Hong Kong residential care homes (RCH) dementia residents. This involved six purposively selected focus groups, each comprising the main stakeholders of the dementia residents’ caregivers, RCH staff and/or registered nurses, and architects. Using the Critical Incident Technique, the main context and experiences of behavioural problems of dementia residents caused by IE were explored and the key causal RCH IE quality factors identified, together with the associated responses and stress levels involved. The findings indicate that the acoustic environment, lighting and thermal environment are the most important influencing factors. Many of the remedies provided by the focus groups are quite simple to carry out and are summarised in the form of recommendations to current RCHs providers and users. The knowledge acquired in this initial study will help enrich the knowledge of IE design for dementiaspecific residential facilities. It also provides some preliminary insights for healthcare policymakers and practitioners in the building design/facilities management and dementia-care sectors into the IE factors contributing to a more comfortable, healthy and sustainable RCH living environment in Hong Kong.