778 resultados para Numerical Evaluation


Relevância:

20.00% 20.00%

Publicador:

Resumo:

Determined the effectiveness of a psychosocial intervention, provided to expectant couples in routine antenatal classes, on the postpartum psychosocial adjustment of women and men. Preparation for Parenthood programs were randomly allocated to one of three conditions: usual service ('control'), experimental ('empathy'), or non-specific control ('baby-play'). The latter condition controlled for the non-specific effects of the intervention, these being: the provision of an extra class; asking couples to consider the early postpartum weeks; and receiving booster information after the antenatal class, and again shortly after the birth. Women and men were categorised into three levels of self-esteem, as measured antenatally: low, medium and high. 268 participants were recruited antenatally. Interview data and self-report information was collected from 202 of these women at 6 weeks postpartum, and 180 women at 6 months postpartum. The intervention consisted of a session focusing on psychosocial issues related to becoming first-time parents. Participants discussed possible postpartum concerns in separate gender groups for part of the session, and then discussed these issues with their partners

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The host specificity of the five published sewage-associated Bacteroides markers (i.e., HF183, BacHum, HuBac, BacH and Human-Bac) was evaluated in Southeast Queensland, Australia by testing fecal DNA samples (n = 186) from 11 animal species including human fecal samples collected via influent to a sewage treatment plant (STP). All human fecal samples (n = 50) were positive for all five markers indicating 100% sensitivity of these markers. The overall specificity of the HF183 markers to differentiate between humans and animals was 99%. The specificities of the BacHum and BacH markers were > 94%, suggesting that these markers are suitable for sewage pollution in environmental waters in Australia. The BacHum (i.e., 63% specificity) and Human-Bac (i.e., 79% specificity) markers performed poorly in distinguishing between the sources of human and animal fecal samples. It is recommended that the specificity of the sewage-associated markers must be rigorously tested prior to its application to identify the sources of fecal pollution in environmental waters.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Effective focusing of electromagnetic (EM) energy to nanoscale regions is one of the major challenges in nano-photonics and plasmonics. The strong localization of the optical energy into regions much smaller than allowed by the diffraction limit, also called nanofocusing, offers promising applications in nano-sensor technology, nanofabrication, near-field optics or spectroscopy. One of the most promising solutions to the problem of efficient nanofocusing is related to surface plasmon propagation in metallic structures. Metallic tapered rods, commonly used as probes in near field microscopy and spectroscopy, are of a particular interest. They can provide very strong EM field enhancement at the tip due to surface plasmons (SP’s) propagating towards the tip of the tapered metal rod. A large number of studies have been devoted to the manufacturing process of tapered rods or tapered fibers coated by a metal film. On the other hand, structures such as metallic V-grooves or metal wedges can also provide strong electric field enhancements but manufacturing of these structures is still a challenge. It has been shown, however, that the attainable electric field enhancement at the apex in the V-groove is higher than at the tip of a metal tapered rod when the dissipation level in the metal is strong. Metallic V-grooves also have very promising characteristics as plasmonic waveguides. This thesis will present a thorough theoretical and numerical investigation of nanofocusing during plasmon propagation along a metal tapered rod and into a metallic V-groove. Optimal structural parameters including optimal taper angle, taper length and shape of the taper are determined in order to achieve maximum field enhancement factors at the tip of the nanofocusing structure. An analytical investigation of plasmon nanofocusing by metal tapered rods is carried out by means of the geometric optics approximation (GOA), which is also called adiabatic nanofocusing. However, GOA is applicable only for analysing tapered structures with small taper angles and without considering a terminating tip structure in order to neglect reflections. Rigorous numerical methods are employed for analysing non-adiabatic nanofocusing, by tapered rod and V-grooves with larger taper angles and with a rounded tip. These structures cannot be studied by analytical methods due to the presence of reflected waves from the taper section, the tip and also from (artificial) computational boundaries. A new method is introduced to combine the advantages of GOA and rigorous numerical methods in order to reduce significantly the use of computational resources and yet achieve accurate results for the analysis of large tapered structures, within reasonable calculation time. Detailed comparison between GOA and rigorous numerical methods will be carried out in order to find the critical taper angle of the tapered structures at which GOA is still applicable. It will be demonstrated that optimal taper angles, at which maximum field enhancements occur, coincide with the critical angles, at which GOA is still applicable. It will be shown that the applicability of GOA can be substantially expanded to include structures which could be analysed previously by numerical methods only. The influence of the rounded tip, the taper angle and the role of dissipation onto the plasmon field distribution along the tapered rod and near the tip will be analysed analytically and numerically in detail. It will be demonstrated that electric field enhancement factors of up to ~ 2500 within nanoscale regions are predicted. These are sufficient, for instance, to detect single molecules using surface enhanced Raman spectroscopy (SERS) with the tip of a tapered rod, an approach also known as tip enhanced Raman spectroscopy or TERS. The results obtained in this project will be important for applications for which strong local field enhancement factors are crucial for the performance of devices such as near field microscopes or spectroscopy. The optimal design of nanofocusing structures, at which the delivery of electromagnetic energy to the nanometer region is most efficient, will lead to new applications in near field sensors, near field measuring technology, or generation of nanometer sized energy sources. This includes: applications in tip enhanced Raman spectroscopy (TERS); manipulation of nanoparticles and molecules; efficient coupling of optical energy into and out of plasmonic circuits; second harmonic generation in non-linear optics; or delivery of energy to quantum dots, for instance, for quantum computations.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

26 tinnitus patients received either electromyogram (EMG) biofeedback with counterdemand instructions, EMG biofeedback with neutral demand instructions, or no treatment. Assessment was conducted on self-report measures of the distress associated with tinnitus, the loudness, annoyance and awareness of tinnitus, sleep-onset difficulties, depression, and anxiety. Audiological assessment of tinnitus was also conducted and EMG levels were measured (the latter only in the 2 treatment groups). No significant treatment effects were found on any of the measures. There was a significant decrease in the ratings of tinnitus awareness over the assessment occasions, but the degree of change was equivalent for treated and untreated groups. Results do not support the assertion that EMG biofeedback is an effective treatment for tinnitus.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The role of the evaluation for Official Development Assistance (ODA) enterprises including educational development has become critical after increasing “aid fatigue” experienced by the international community in the 1990s. To date, however, monitoring and evaluating outcomes of the projects has been limited to the project life. Consequently these have been mainly through the international aid agencies. Furthermore, the monitoring and evaluation led by international aid agencies have paid little attention to aspects of the sustainability of technical cooperation in educational development. To sustain the impact of technical cooperation, the reinforcement of evaluation has drawn increasing attention in light of the emerging modalities in international development. Therefore this research was inspired to investigate alternative evaluation frameworks for an educational reform project for teacher quality improvement that may increase possibilities for long term sustainability. Importantly, the new modalities in international development and educational issues provide new options. In addition, the research reviewed theoretical and practical issues surrounding evaluation in general, and highlighted the evaluation of education reform projects. The research reported explored via case studies, the evaluation processes employed by the Egyptian education reform projects implemented by the Japan International Cooperation Agency (JICA) and the United Nations Children’s Fund (UNICEF). The case studies used three data sources (archival and relevant documents, a survey questionnaire and interviews) to illuminate the contextually-embedded evaluation processes. The research found that process evaluation is a potential alternative method since it is likely to be locally institutionalised, which may yield long-term sustainability of the projects.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This study considers the solution of a class of linear systems related with the fractional Poisson equation (FPE) (−∇2)α/2φ=g(x,y) with nonhomogeneous boundary conditions on a bounded domain. A numerical approximation to FPE is derived using a matrix representation of the Laplacian to generate a linear system of equations with its matrix A raised to the fractional power α/2. The solution of the linear system then requires the action of the matrix function f(A)=A−α/2 on a vector b. For large, sparse, and symmetric positive definite matrices, the Lanczos approximation generates f(A)b≈β0Vmf(Tm)e1. This method works well when both the analytic grade of A with respect to b and the residual for the linear system are sufficiently small. Memory constraints often require restarting the Lanczos decomposition; however this is not straightforward in the context of matrix function approximation. In this paper, we use the idea of thick-restart and adaptive preconditioning for solving linear systems to improve convergence of the Lanczos approximation. We give an error bound for the new method and illustrate its role in solving FPE. Numerical results are provided to gauge the performance of the proposed method relative to exact analytic solutions.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The evolution of property education to adapt to the changing business environment requires changes to course content, methods of delivery and assessment. Many universities have a special interest in understanding how successfully students transition in and transition out of property programs. This study sought the views of final year students engaged in professional employment, employer representatives and representatives from professional associations to assess the preparedness of students to commence professional employment. The study showed that generally students possessed an appropriate level of technical and ‘soft skills’ to enter the professional realm with development required in some areas. All stakeholders agreed that the transition out of university was made more seamless through greater engagement with industry through field work and work experience from the intermediate stages of the property course.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Public private partnerships (PPP) have been widely used as a method for public infrastructure project delivery not only locally and internationally, however the adoption of PPPs in social infrastructure procurement has still been very limited. The objective of this paper is to investigate the potential of implementation of current PPP framework in social affordable housing projects in South East Queensland. Data were collected from 22 interviewees with rich experiences in the industry. The findings of this study show that affordable housing investment have been considered by the industry practitioners as a risky business in comparison to other private rental housing investment. The main determents of the adoption of PPPs in social infrastructure project are the tenant-related factors, such as the inability of paying rent and the inability of caring the property. The study also suggests the importance of seeking strategic partnership with community-based organisation that has experiences in managing similar tenants’ profiles. Current PPP guideline is also viewed as inappropriate for the affordable housing projects, but the principle of VFM framework and risk allocation in PPPs still be applied to the affordable housing projects. This study helps to understand the viability of PPP in social housing procurement projects, and point out the importance of developing guideline for multi-stakeholder partnership and the expansion of the current VFM and PPPs guidelines.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Service-orientation has gained widespread acceptance and is increasingly being employed as a paradigm for structuring both business and IT architectures. An earlier study of extant service analysis and design methodologies discovered a need for holistic approaches that equally account for both business and software services, which motivated the design of a new, consolidated service analysis and design methodology. A challenge in design-oriented research is to evaluate the utility of the newly created artefacts (here: the methodology), as they are often intended to become part of complex socio-technical systems. Therefore, after presenting a brief overview of the consolidated methodology, the paper discusses possible approaches for the “evaluate” phase of this design-science research process and presents the results of an empirical evaluation conducted in an Action Research study at one of Australia’s largest financial services providers.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

In this paper, we consider a modified anomalous subdiffusion equation with a nonlinear source term for describing processes that become less anomalous as time progresses by the inclusion of a second fractional time derivative acting on the diffusion term. A new implicit difference method is constructed. The stability and convergence are discussed using a new energy method. Finally, some numerical examples are given. The numerical results demonstrate the effectiveness of theoretical analysis

Relevância:

20.00% 20.00%

Publicador:

Resumo:

In this paper, we consider a variable-order fractional advection-diffusion equation with a nonlinear source term on a finite domain. Explicit and implicit Euler approximations for the equation are proposed. Stability and convergence of the methods are discussed. Moreover, we also present a fractional method of lines, a matrix transfer technique, and an extrapolation method for the equation. Some numerical examples are given, and the results demonstrate the effectiveness of theoretical analysis.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Anomalous dynamics in complex systems have gained much interest in recent years. In this paper, a two-dimensional anomalous subdiffusion equation (2D-ASDE) is considered. Two numerical methods for solving the 2D-ASDE are presented. Their stability, convergence and solvability are discussed. A new multivariate extrapolation is introduced to improve the accuracy. Finally, numerical examples are given to demonstrate the effectiveness of the schemes and confirm the theoretical analysis.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

In this paper, the numerical simulation of the 3D seepage flow with fractional derivatives in porous media is considered under two special cases: non-continued seepage flow in uniform media (NCSFUM) and continued seepage flow in non-uniform media (CSF-NUM). A fractional alternating direction implicit scheme (FADIS) for the NCSF-UM and a modified Douglas scheme (MDS) for the CSF-NUM are proposed. The stability, consistency and convergence of both FADIS and MDS in a bounded domain are discussed. A method for improving the speed of convergence by Richardson extrapolation for the MDS is also presented. Finally, numerical results are presented to support our theoretical analysis.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

In this paper, we consider the following non-linear fractional reaction–subdiffusion process (NFR-SubDP): Formula where f(u, x, t) is a linear function of u, the function g(u, x, t) satisfies the Lipschitz condition and 0Dt1–{gamma} is the Riemann–Liouville time fractional partial derivative of order 1 – {gamma}. We propose a new computationally efficient numerical technique to simulate the process. Firstly, the NFR-SubDP is decoupled, which is equivalent to solving a non-linear fractional reaction–subdiffusion equation (NFR-SubDE). Secondly, we propose an implicit numerical method to approximate the NFR-SubDE. Thirdly, the stability and convergence of the method are discussed using a new energy method. Finally, some numerical examples are presented to show the application of the present technique. This method and supporting theoretical results can also be applied to fractional integrodifferential equations.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

In this paper, we consider the numerical solution of a fractional partial differential equation with Riesz space fractional derivatives (FPDE-RSFD) on a finite domain. Two types of FPDE-RSFD are considered: the Riesz fractional diffusion equation (RFDE) and the Riesz fractional advection–dispersion equation (RFADE). The RFDE is obtained from the standard diffusion equation by replacing the second-order space derivative with the Riesz fractional derivative of order αset membership, variant(1,2]. The RFADE is obtained from the standard advection–dispersion equation by replacing the first-order and second-order space derivatives with the Riesz fractional derivatives of order βset membership, variant(0,1) and of order αset membership, variant(1,2], respectively. Firstly, analytic solutions of both the RFDE and RFADE are derived. Secondly, three numerical methods are provided to deal with the Riesz space fractional derivatives, namely, the L1/L2-approximation method, the standard/shifted Grünwald method, and the matrix transform method (MTM). Thirdly, the RFDE and RFADE are transformed into a system of ordinary differential equations, which is then solved by the method of lines. Finally, numerical results are given, which demonstrate the effectiveness and convergence of the three numerical methods.