27 resultados para design-based survey sampling

em Aston University Research Archive


Relevância:

100.00% 100.00%

Publicador:

Resumo:

This paper reports the results of a web-based perception study of the ranking of peer reviewed accounting journals by UK academics. The design of the survey instrument allows an interactive selection of journals to be scored. The webbased format is unique in that it also includes a step in which respondents classify the journals according to methodological perspective (paradigm). This is depicted graphically in the paper in a bubble diagram that shows the "positioning" of journals according to perceptions of both paradigm and quality.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

This paper reports the results of a web-based study of the perceptions of accounting journals in Australasia. Journal ranking studies have generally adopted citation techniques or used academics’ perceptions as the basis for assessing journal quality. Our research contributes to the existing literature by conducting a survey of academics in Australasia using a web-based instrument. The analysis indicates that the perceptions of the so-called “elite” accounting journals have become unsettled. The research highlights the emergence of more recent, alternative paradigm journals (CPA and AAAJ) as both highly ranking.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

As a new medium for questionnaire delivery, the internet has the potential to revolutionize the survey process. Online (web-based) questionnaires provide several advantages over traditional survey methods in terms of cost, speed, appearance, flexibility, functionality, and usability. Designers of online-questionnaires are faced with a plethora of design tools to assist in the development of their electronic questionnaires. Little, if any, support is incorporated, however, within these tools to guide online-questionnaire designers according to best practice. In essence, an online-questionnaire combines questionnaire-based survey functionality with that of a webpage/site. As such, the design of an online-questionnaire should incorporate principles from both contributing fields. Drawing on existing guidelines for paper-based questionnaire design, website design (paying particular attention to issues of accessibility and usability), and existing but scarce guidelines for electronic surveys, we have derived a comprehensive set of guidelines for the design of online-questionnaires. This article introduces this comprehensive set of guidelines – as a practical reference guide – for the design of online-questionnaires.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Most pavement design procedures incorporate reliability to account for design inputs-associated uncertainty and variability effect on predicted performance. The load and resistance factor design (LRFD) procedure, which delivers economical section while considering design inputs variability separately, has been recognised as an effective tool to incorporate reliability into design procedures. This paper presents a new reliability-based calibration in LRFD format for a mechanics-based fatigue cracking analysis framework. This paper employs a two-component reliability analysis methodology that utilises a central composite design-based response surface approach and a first-order reliability method. The reliability calibration was achieved based on a number of field pavement sections that have well-documented performance history and high-quality field and laboratory data. The effectiveness of the developed LRFD procedure was evaluated by performing pavement designs of various target reliabilities and design conditions. The result shows an excellent agreement between the target and actual reliabilities. Furthermore, it is clear from the results that more design features need to be included in the reliability calibration to minimise the deviation of the actual reliability from the target reliability.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

This thesis deals with the problem of Information Systems design for Corporate Management. It shows that the results of applying current approaches to Management Information Systems and Corporate Modelling fully justify a fresh look to the problem. The thesis develops an approach to design based on Cybernetic principles and theories. It looks at Management as an informational process and discusses the relevance of regulation theory to its practice. The work proceeds around the concept of change and its effects on the organization's stability and survival. The idea of looking at organizations as viable systems is discussed and a design to enhance survival capacity is developed. It takes Ashby's theory of adaptation and developments on ultra-stability as a theoretical framework and considering conditions for learning and foresight deduces that a design should include three basic components: A dynamic model of the organization- environment relationships; a method to spot significant changes in the value of the essential variables and in a certain set of parameters; and a Controller able to conceive and change the other two elements and to make choices among alternative policies. Further considerations of the conditions for rapid adaptation in organisms composed of many parts, and the law of Requisite Variety determine that successful adaptive behaviour requires certain functional organization. Beer's model of viable organizations is put in relation to Ashby's theory of adaptation and regulation. The use of the Ultra-stable system as abstract unit of analysis permits developing a rigorous taxonomy of change; it starts distinguishing between change with in behaviour and change of behaviour to complete the classification with organizational change. It relates these changes to the logical categories of learning connecting the topic of Information System design with that of organizational learning.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Purpose – This paper reports the study of key success factors (KSFs) in the project management of the implementation of strategic manufacturing initiatives (SMIs). Design/methodology/approach – In order to gather the experience and knowledge of many industries, from different geographic locations, in a broad range of types and sizes of SMIs, a questionnaire-based survey of practitioners worldwide was selected as the most appropriate research method among those available. Findings – The identification of those tasks and activities that must be done well in order to succeed in the implementation of a SMI in practice. Practical implications – Practitioners focusing their attention on the KSFs identified are more likely to succeed. Once these factors have been identified, the value of benchmarking project management methodologies then comes from drawing attention to those tasks that are key to the success of the implementation of SMIs. Originality/value – The paper presents new thinking by bringing project management into the operations strategy implementation literature as an important mediating factor for success. In this context the factors that are required for successful implementation are identified.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Breakfast skipping is a health concern that has well-known negative consequences physically and psychologically. It is therefore important to understand why children skip breakfast. The purpose of this study was to establish whether the experience of bullying and cyberbullying impacts upon breakfast skipping and to further evaluate whether the inability for youths to cope with bullying victimization affects their mental health (depression), and in turn predicts breakfast skipping. Data were obtained from the Eastern Ontario 2011 Youth Risk Behaviour Survey, a cross-sectional regional school-based survey of middle and high school students (11-20 years old) across the five counties of Eastern Ontario, Canada (N = 3035). Self-reported data about children's experiences of bullying victimization, breakfast eating habits, socio-economical status, depression, and other risk behaviours were analysed. Approximately half of the participants (50.4%) reported not eating breakfast on a regular basis: 26.3% and 24.1% reported often (usually eat breakfast three times or more per week) and frequent (usually eat breakfast twice a week or less) breakfast skipping behaviour, respectively. Victims of both cyberbullying and school bullying presented greater likelihood of often (adjusted relative risk ratio (RR) = 1.55; 95% confidence interval (CI) = 1.17-2.06) and frequent (RR = 1.97; 95% CI = 1.28-3.03) breakfast skipping. Mediation analysis further showed that depression fully mediated the relationship between school bullying victimization and frequent breakfast skipping. Moreover, depression partially mediated the associations between both cyberbullying and school bullying with frequent breakfast skipping. These findings highlight the potential interrelationships between cyberbullying, school bullying and depression in predicting unhealthy breakfast skipping behaviour in children. © 2014 Elsevier Ltd.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

A novel method of fiber Bragg grating design based on tailored group delay is presented. The method leads to designs that are superior to the previously reported results. © OSA 2012.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

This article reports the results of a web-based survey of real estate portfolio managers in the pension fund industry. The study focused on ascertaining the real estate research interests of the respondents as well as whether or not research funding should be allocated to various research topics. Performance measures of real estate assets and portfolios, microeconomic factors affecting real estate and the role of real estate in a mixed-asset portfolio were the top three real estate research interests. There was some variation by the type and size of fund providing evidence that segmentation is important within the money management industry. Respondents were also queried on more focused research subtopics and additional questions in the survey focused on satisfaction with existing real estate benchmarks, and perceptions of the usefulness of published research. Findings should be used to guide research practitioners and academics as to the most important research interests of plan sponsor real estate investment managers.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The article discusses various reports published within the issue, including one by Movando et al. concerning marketing measures and constructs, and an article by Grandcolas et al. concerning research methodologies and the future of web-based survey research.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

This thesis presents a detailed, experiment-based study of generation of ultrashort optical pulses from diode lasers. Simple and cost-effective techniques were used to generate high power, high quality optical short pulses at various wavelength windows. The major achievements presented in the thesis is summarised as follows. High power pulses generation is one of the major topics discussed in the thesis. Although gain switching is the simplest way for ultrashort pulse generation, it proves to be quite effective to deliver high energy pulses on condition that the pumping pulses with extremely fast rising time and high enough amplitude are applied on specially designed pulse generators. In the experiment on a grating-coupled surface emitting laser (GCSEL), peak power as high as 1W was achieved even when its spectral bandwidth was controlled within 0.2nm. Another experiment shows violet picosecond pulses with peak power as high as 7W was achieved when the intensive electrical pulses were applied on optimised DC bias to pump on InGaN violet diode laser. The physical mechanism of this phenomenon, as we considered, may attributed to the self-organised quantum dots structure in the laser. Control of pulse quality, including spectral quality and temporal profile, is an important issue for high power pulse generation. The ways to control pulse quality described in the thesis are also based on simple and effective techniques. For instance, GCSEL used in our experiment has a specially designed air-grating structure for out-coupling of optical signals; hence, a tiny flat aluminium mirror was placed closed to the grating section and resulted in a wavelength tuning range over 100nm and the best side band suppression ratio of 40dB. Self-seeding, as an effective technique for spectral control of pulsed lasers, was demonstrated for the first time in a violet diode laser. In addition, control of temporal profile of the pulse is demonstrated in an overdriven DFB laser. Wavelength tuneable fibre Bragg gratings were used to tailor the huge energy tail of the high power pulse. The whole system was compact and robust. The ultimate purpose of our study is to design a new family of compact ultrafast diode lasers. Some practical ideas of laser design based on gain-switched and Q-switched devices are also provided in the end.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

In this paper we develop set of novel Markov chain Monte Carlo algorithms for Bayesian smoothing of partially observed non-linear diffusion processes. The sampling algorithms developed herein use a deterministic approximation to the posterior distribution over paths as the proposal distribution for a mixture of an independence and a random walk sampler. The approximating distribution is sampled by simulating an optimized time-dependent linear diffusion process derived from the recently developed variational Gaussian process approximation method. Flexible blocking strategies are introduced to further improve mixing, and thus the efficiency, of the sampling algorithms. The algorithms are tested on two diffusion processes: one with double-well potential drift and another with SINE drift. The new algorithm's accuracy and efficiency is compared with state-of-the-art hybrid Monte Carlo based path sampling. It is shown that in practical, finite sample, applications the algorithm is accurate except in the presence of large observation errors and low observation densities, which lead to a multi-modal structure in the posterior distribution over paths. More importantly, the variational approximation assisted sampling algorithm outperforms hybrid Monte Carlo in terms of computational efficiency, except when the diffusion process is densely observed with small errors in which case both algorithms are equally efficient.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Not withstanding the high demand of metal powder for automotive and High Tech applications, there are still many unclear aspects of the production process. Only recentlyhas supercomputer performance made possible numerical investigation of such phenomena. This thesis focuses on the modelling aspects of primary and secondary atomization. Initially two-dimensional analysis is carried out to investigate the influence of flow parameters (reservoir pressure and gas temperature principally) and nozzle geometry on final powder yielding. Among the different types, close coupled atomizers have the best performance in terms of cost and narrow size distribution. An isentropic contoured nozzle is introduced to minimize the gas flow losses through shock cells: the results demonstrate that it outperformed the standard converging-diverging slit nozzle. Furthermore the utilization of hot gas gave a promising outcome: the powder size distribution is narrowed and the gas consumption reduced. In the second part of the thesis, the interaction of liquid metal and high speed gas near the feeding tube exit was studied. Both axisymmetric andnon-axisymmetric geometries were simulated using a 3D approach. The filming mechanism was detected only for very small metal flow rates (typically obtained in laboratory scale atomizers). When the melt flow increased, the liquid core overtook the adverse gas flow and entered in the high speed wake directly: in this case the disruption isdriven by sinusoidal surface waves. The process is characterized by fluctuating values of liquid volumes entering the domain that are monitored only as a time average rate: it is far from industrial robustness and capability concept. The non-axisymmetric geometry promoted the splitting of the initial stream into four cores, smaller in diameter and easier to atomize. Finally a new atomization design based on the lesson learned from previous cases simulation is presented.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The aim of this research is to assess the acquisition and absorption technology capabilities of the public sector in developing countries, with specific focus on the State of Kuwait. The assessment process of these two capabilities was conducted using a model originally designed for the private sector. In addition, the research aims to propose a framework to enhance the technological capability of developing countries, as well as the performance of the public sector. To achieve these aims, an investigation of the technology process to three public ministries in Kuwait was conducted. The prime interest of this investigation was to evaluate the role of the transferred technology in enhancing the indigenous technological capability of the public sector. The research is based on a case study approach, comprising a main case study (Ministry of Electricity and Water) and three minor case studies. Based on the outcomes from an extensive literature review and the preliminary sectoral visits, the research question and four hypotheses were formulated. These hypotheses were then tested using interview-based survey and documentation. The findings of the research revealed the weakness of the acquisition and absorption technological capabilities of the public sector. Consequently, the public sector relies extensively on foreign contractors and expatriates to compensate for this weakness. Also, it was found that Kuwait Government has not taken the necessary measures to develop its technological capability. This research has proposed a framework which could lead, if properly managed, to the enhancement of indigenous capability. It has also proposed how to improve performance and productivity in the public sector. Finally, the findings suggest that the assessment model, with minor adjustment, is applicable to the public sector.