Multiresolution Approximation of a Bayesian Inverse Problem using Second-Generation Wavelets

Bayesian approaches are one of the primary methodologies to tackle an inverse problem in high dimensions. Such an inverse problem arises in hydrology to infer the permeability field given flow data in a porous media. It is common practice to decompose the unknown field into some basis and infer the decomposition parameters instead of directly inferring the unknown. Given the multiscale nature of permeability fields, wavelets are a natural choice for parameterizing them. This study uses a Bayesian approach to incorporate the statistical sparsity that characterizes discrete wavelet coefficients. First, we impose a prior distribution incorporating the hierarchical structure of the wavelet coefficient and smoothness of reconstruction via scale-dependent hyperparameters. Then, Sequential Monte Carlo (SMC) method adaptively explores the posterior density on different scales, followed by model selection based on Bayes Factors. Finally, the permeability field is reconstructed from the coefficients using a multiresolution approach based on second-generation wavelets. Here, observations from the pressure sensor grid network are computed via Multilevel Adaptive Wavelet Collocation Method (AWCM). Results highlight the importance of prior modeling on parameter estimation in the inverse problem

Dynamics of a Vapour Bubble inside a Vertical Rigid Cylinder

In this Paper dynamics of a vapour bubble generated due to a local energy input inside a vertical rigid cylinder and in the absence of buoyancy forces is investigated. Different ratios of the rigid cylinder to the maximum radius of the bubble are considered. The Boundary Integral Equation Method is employed for numerical simulation of the problem. Results show that during the collapse phase of the bubble inside a vertical rigid cylinder, two liquid micro jets are developed on the top and bottom sides of the vapour bubble and are directed inward. Results also show that existence of a deposit rib inside the vertical rigid cylinder slightly increases the life time of the bubble. It is found that by increasing the ratio of the cylinder diameter to the maximum radius of the bubble, the rate of the growth and collapse phases of the bubble increases and the life time of the bubble decreases

The readiness of schools in Zimbabwe for the implementation of early childhood education

This qualitative study focuses on primary schools’ state of readiness for the introduction of early childhood education. Adopting a multiple case study design, the article explores, through semi-structured interviews and documentation, school heads, teachers-in-charge and classroom teachers’ perceptions of their respective schools’ state of readiness for the installation and implementation of early childhood education. The study established that, while classroom teachers were adequately qualified to implement early childhood education, teachers-in-charge were not. Secondly, school heads received limited induction for the introduction and implementation of early childhood education. Additionally, inadequate teaching-learning resources and lack of on-going teacher support contributed to schools’ lack of readiness for the introduction of early childhood education. The study recommends interventions that curriculum planners and implementers can utilise in order to create conditions that enable primary schools to be ready for introducing and implementing early childhood education.Keywords: early childhood education; implementation; primary school; school readines

Dynamics of a vapour bubble near a thin elastic plate

Numerical and experimental results show that during the collapse phase of a vapor bubble near a rigid boundary, in the absence of strong buoyancy forces, a liquid micro jet is developed on the side of the bubble far from the rigid surface and directed towards it. Numerical and experimental results also show that, in the case of a bubble near a free surface, during the collapse phase of the bubble and in the absence of strong buoyancy forces, the vapor bubble is repelled by the free surface. In this case a liquid micro jet is developed on the closest side of the bubble to the free surface and is directed away from it. The dynamic behavior of a vapor bubble near a free surface leads to the idea that a vapor bubble during its growth and collapse phases near a deformable diaphragm may have a behavior similar to its behavior near a free surface. In this paper dynamics of a vapor bubble during its growth and collapse phases near a thin elastic plate is investigated. It has been shown that the growth and collapse of a vapor bubble generated due to a high local energy input causes considerable deformation on the nearby thin elastic plate. Different thin elastic plates with different thicknesses and different flexural rigidities are assumed and the dynamic behavior of a vapor bubble near each of these plates is investigated. Results show that during the growth and collapse of a vapor bubble near a thin elastic plate with a proper thickness and flexural rigidity, in the absence of strong buoyancy forces, a liquid micro jet may develop on the closest side of the bubble to the thin elastic plate and directed away from it.http://deepblue.lib.umich.edu/bitstream/2027.42/84307/1/CAV2009-final132.pd

Clinical and official users’ readiness for hospital information system implementation in Valiyasr Hospital of Boroujen

زمینه و هدف: سنجش میزان آگاهی و دانش کاربران هنگام پیاده سازی یک سیستم اطلاعات مبتنی بر فناوری روز دنیا از ضروریات است؛ بنابراین این پژوهش با قصد ارزیابی آمادگی و بررسی میزان آگاهی کاربران درمانی و اداری از سیستم اطلاعات بیمارستانی در هنگام پیاده سازی این سیستم انجام شده است. روش بررسی: این پژوهش یک مطالعه توصیفی –تحلیلی است که جامعه آن را کاربران درمانی و اداری بیمارستان ولی عصر(عج) بروجن تشکیل داده است. نمونه گیری به روش سرشماری و شامل 60 نفر از کاربران بود. برای جمع آوری داده ها از پرسشنامه ای محقق ساخته مبتنی بر ارزیابی دانش رایانه ای کاربران (10 مولفه)، امکان آموزش مطلوب (10مولفه)، خود توصیف کننده بودن سیستم (12 مولفه) و مطابقت سیستم با نیازهای کاربران (19مولفه) براساس استاندارد ایزو 10/9241 استفاده شد. یافته ها: میانگین نمره دانش رایانه ای کاربران 5/17±27/44، میانگین نمره آموزش مطلوب کاربران 38/8±36/45، میانگین نمره خود توصیف کننده بودن سیستم 57/15±34/47 و میانگین نمره مطابقت سیستم با نیازهای کاربران 00/15± 45/39 بود. همچنین بین دانش رایانه‌ای کاربران و امکان آموزش مطلوب آنان رابطه معنی داری وجود داشت (0/04=P) و بین دانش رایانه ای و خودتوصیف کننده بودن سیستم و نیز مطابقت با نیازهای کاربران رابطه معنی داری مشاهده شد (0/008=P). نتیجه گیری: با توجه به نتایج این پژوهش، مدیران و سیاستگذاران اجرایی در هنگام پیاده سازی خدمات فناوری در نظام سلامت باید به ارزیابی سطح دانش کاربر، شناسایی سیستم و رفع نیازهای کاربر از طریق سیستم توجه داشته تا در جهت افزایش بهره وری آن موثر باشند

Design of a utility-scale wind farm in Newfoundland and Labrador

The Muskrat falls hydroelectric project in Newfoundland and Labrador has faced many issues (economic, temporal and ecological). In this article, a study of a wind project of similar generation capacity (4.9 TWh) is conducted. The wind farm is able to generate the same annual energy output as muskrat falls for a fraction of the cost. St. john’s international airport was chosen as the test location to introduce the methodology and to provide preliminary evaluation of a large-scale wind project in the province with the results being favorable (823 million USD profit). Using a comprehensive multifactorial wind farm sitting approach, four sites for possible wind energy deployment were selected which are: Portugal Cove, Bonavista, Grand Banks and Saint Bride’s. Through a review of the most prominent wind farms inside and outside Canada, five types of wind turbines (from different manufacturers) were selected for the study which areGE-2.5 XL, Vestas 164, Enercon E-126, GE 1.5s and Siemens SWT 3.6 120. A parametric study of 36 systems was then conducted to test each turbine type at each location at different hub heights. The study included both financial (LCOE, Profit) and area (Energy density, Profit/Area) considerations. The results of the study showed that different systems performed better at one category or another. After careful comparison of the 36-systems, Bonavista wind site with Enercon-126 wind turbine at 135m hub height was justifiably the best system. The study is then finalized by adding ACS880 inverter from ABB and reporting on the final system values (4.83 TWh energy production, 884 million USD profit and 3.06 million tons of CO2 emissions curtailed per year