781 resultados para design-based survey sampling


Relevância:

100.00% 100.00%

Publicador:

Resumo:

Objective-To estimate disease prevalence among dogs and cats in the United States and Australia and proportions of dogs and cats that receive therapeutic diets or dietary supplements. Design-Telephone survey. Sample Population-Dog and cat owners located in 5 geographic areas. Procedures-A telephone survey was administered to dog and cat owners. Results-Of 18,194 telephone calls that were made, 1,104 (6%) were to individuals who owned at least I dog or cat and agreed to participate. Information was collected for 635 dogs and 469 cats. Only 14 (1%) respondents indicated that their pet was unhealthy, but 176 (16%) indicated that their pets had 1 or more diseases. The most common diseases were musculoskeletal, dental, and gastrointestinal tract or hepatic disease. Many owners (n = 356) reported their pets were overweight or obese, but only 3 reported obesity as a health problem in their pets. Owners of 28 (2.5%) animals reported that they were feeding a therapeutic diet, with the most common being diets for animals with renal disease (n = 5), reduced-calorie diets (5), and reduced-fat diets (4). Owners of 107 of 1,076 (9.9%) animals reported administering dietary supplements to their pets. Multivitamins (n = 53 animals), chondroprotective agents (22), and fatty acids (13) were the most common dietary supplements used. Conclusions and Clinical Relevance-Results suggest that most dogs and cats reported by their owners to have a health problem were not being fed a therapeutic diet. In addition, the rate of dietary supplement use was lower than that reported for people.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Introductory courses covering modem physics sometimes introduce some elementary ideas from general relativity, though the idea of a geodesic is generally limited to shortest Euclidean length on a curved surface of two spatial dimensions rather than extremal aging in spacetime. It is shown that Epstein charts provide a simple geometric picture of geodesics in one space and one time dimension and that for a hypothetical uniform gravitational field, geodesics are straight lines on a planar diagram. This means that the properties of geodesics in a uniform field can be calculated with only a knowledge of elementary geometry and trigonometry, thus making the calculation of some basic results of general relativity accessible to students even in an algebra-based survey course on physics.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The integrated chemical-biological degradation combining advanced oxidation by UV/H2O2 followed by aerobic biodegradation was used to degrade C.I. Reactive Azo Red 195A, commonly used in the textile industry in Australia. An experimental design based on the response surface method was applied to evaluate the interactive effects of influencing factors (UV irradiation time, initial hydrogen peroxide dosage and recirculation ratio of the system) on decolourisation efficiency and optimizing the operating conditions of the treatment process. The effects were determined by the measurement of dye concentration and soluble chemical oxygen demand (S-COD). The results showed that the dye and S-COD removal were affected by all factors individually and interactively. Maximal colour degradation performance was predicted, and experimentally validated, with no recirculation, 30 min UV irradiation and 500 mg H2O2/L. The model predictions for colour removal, based on a three-factor/five-level Box-Wilson central composite design and the response surface method analysis, were found to be very close to additional experimental results obtained under near optimal conditions. This demonstrates the benefits of this approach in achieving good predictions while minimising the number of experiments required. (c) 2006 Elsevier B.V. All rights reserved.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Objective: To describe the demographics of solarium users and the correlates of solarium use in Queensland. Methods: A cross-sectional survey of 9,419 Queensland residents was conducted via an anonymous computer-assisted telephone interview. Results: Overall, 8.8% of the respondents had ever used a solarium and less than 1% had used a solarium in the previous year. Results indicated that users were more likely to be female and younger than non-users, and less than half of the users signed a consent form, suggesting that they had not been made aware of the associated risks by operators. Conclusions: The Queensland Cancer Risk Study was one of the first population-based studies to address solarium use in this State and highlights that the use of solariums in Queensland is low in comparison to other countries. Implications: There is no regulation of compliance with guidelines. It may become necessary to make compliance with the guidelines mandatory to effectively communicate the associated risks.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Data are taken from a representative sample of the Australian population to determine the qualities that are desired in a sexual partner. These qualities are considered in three categories: those reflecting the perceived reproductive value of the partner (evolutionary imperative), the emotional attachment to a partner and the pure pleasure associated with having sex. Subjects completed a telephone-based survey 876 males; 908 females; aged 18-59). The qualities respondents report they most desire in a sexual partner are that the person is someone who cares about them, and whom they love. They also rank highly the criterion that their partner should enjoy sex, and much less highly that they themselves should enjoy the sex. Evolutionary imperatives are ranked fairly low as criteria sought in a sexual partner. Males and females generally expressed similar preferences in a sexual partner, as do persons in different age groups, and persons in different marital status categories. Heterosexual males appear to place a higher emphasis on the physical appearance of a partner when compared with non-heterosexuals. [PUBLICATION ABSTRACT]

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Objective: To describe the population prevalence of key cancer risk behaviours in Queensland. Methods: The Queensland Cancer Risk Study was a population-based survey of 9,419 Queensland residents aged 20-75 years. Information was collected through an anonymous, computer-assisted telephone interview between February and November 2004. Outcome measures included tobacco smoking, alcohol consumption, sun-tanning and sunburn, obesity physical inactivity and poor diet, weighted by age, gender and geographic region. Results: Prevalence of current smoking was 25.2% for males and 20.8% for females and was highest in the 20-39 year age group and in rural/remote areas. Two-thirds of participants regularly drank alcohol; of these, 63% consumed excessive amounts of alcohol. Excessive sun exposure is still a problem; 70% of Queenslanders reported an episode of sunburn and 12% reported attempting to get a suntan in the past year. More than half of the respondents (53.9%) were above the healthy weight range, and 17.1% of males and 18.4% of females were obese. Just over 40% of Queensland adults reported having insufficient levels of physical activity. Fewer than half of the participants met recommended levels of fruit or vegetable consumption. Conclusions and implications: The majority of Queensland adults exhibit known, modifiable cancer risk behaviours. These results suggest that continuing efforts to reduce the prevalence of these risk factors are warranted. Specifically, significant gains could be made by targeting behaviour change programs at younger Queenslanders (aged 20-39 years), men, and those living in remote/ very remote areas of Queensland.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The successful restructuring of Chinese industries is of immense importance not only for the continued development of China but also to the stability of the world economy. The transformation of the Chinese wool textile industry illustrates well the many problems and pressures currently facing most Chinese industries. The Chinese wool textile industry has undergone major upheaval and restructuring in its drive to modernize and take advantage of developments in world textile markets. Macro level ownership and administrative reforms are well advanced as is the uptake of new technology and equipment. However, the changing market and institutional environment also demands an increasing level of sophistication in mill management decisions including product selection, input procurement, product pricing, investment appraisal, cost analysis and proactive identification of new market and growth opportunities. This paper outlines a series of analyses that have been integrated into a decision-making model designed to assist mill managers with these decisions. Features of the model include a whole-of-mill approach, a design based on existing mill structures and information systems, and the capacity for the model to be tailored to individual mills. All of these features facilitate the adoption of the model by time and resource constrained managers seeking to maintain the viability of their enterprises in the face of extremely dynamic market conditions.

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.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

This study is primarily concerned with the problem of break-squeal in disc brakes, using moulded organic disc pads. Moulded organic friction materials are complex composites and due to this complexity it was thought that they are unlikely to be of uniform composition. Variation in composition would under certain conditions of the braking system, cause slight changes in its vibrational characteristics thus causing resonance in the high audio-frequency range. Dynamic mechanical propertes appear the most likely parameters to be related to a given composition's tendency to promote squeal. Since it was necessary to test under service conditions a review was made of all the available commercial test instruments but as none were suitable it was necessary to design and develop a new instrument. The final instrument design, based on longitudinal resonance, enabled modulus and damping to be determined over a wide range of temperatures and frequencies. This apparatus has commercial value since it is not restricted to friction material testing. Both used and unused pads were tested and although the cause of brake squeal was not definitely established, the results enabled formulation of a tentative theory of the possible conditions for brake squeal. The presence of a temperature of minimum damping was indicated which may be of use to braking design engineers. Some auxilIary testing was also performed to establish the effect of water, oil and brake fluid and also to determine the effect of the various components of friction materials.