Modelling the robustness properties of HVAC plant under feedback control

Most existing building simulation programs fail to capture sufficient of the underlying dynamics of nonlinear HVAC plant and some have restricted room space modelling capabilities for low-time-horizon analyses. In this work, a simplified model of a room space with hot water heating and a chilled ceiling system is developed for the main purpose of analysing control system response. The room model is based on a new approach to lumped capacitance modelling and the heating and chilled ceiling emitters are modelled using third-order descriptions. Control system components are treated in detail and both controllers are ‘tuned’ at a nominal region of plant operation using a gradient-descent-based optimization procedure. Robustness qualities of the controllers are analysed with reference to extremes in plant operating conditions. A key feature of the work is the transparency of the modelling procedure, designed to have appeal to researchers as well as practitioners involved with HVAC control system design problems

Thermal comfort based fuzzy logic control

Most heating, ventilation and air conditioning (HVAC) control systems are considered as temperature control problems. In this work, the predicted mean vote (PMV) is used to control the indoor temperature of a space by setting it at a point where the PMV index becomes zero and the predicted percentage of persons dissatisfied (PPD) achieves a maximum threshold of 5%. This is achieved through the use of a fuzzy logic controller that takes into account a range of human comfort criteria in the formulation of the control action that should be applied to the heating system to bring the space to comfort conditions. The resulting controller is free of the set up and tuning problems that hinder conventional HVAC controllers. Simulation results show that the proposed control strategy makes it possible to maximize the indoor thermal comfort and, correspondingly, a reduction in energy use of 20% was obtained for a typical 7-day winter period when compared with conventional control

Constructs for quality in on-line learning

© 2016 WIETE. To develop a culture of quality and self-improvement in on-line learning, researchers argue that responsibility should be situated close to those people directly involved. The research project described here is concerned with developing a method of assessing quality that is close to faculty and students. The method is applicable to a broad range of tertiary level on-line courses, and is quick and easy to administer. In this article, the identification of the constructs that make up the model is presented. This was done by a literature research of a very large number of publications to determine the important features of on-line learning. Subsequently, the Nominal Group Technique was utilised with a group of experts during the analysis of the information in order to determine the constructs that make up the model. After a number of rounds of discussion using the technique seven constructs emerged that are considered essential in a quality on-line course

The role of course development and design in an itinerant schooling program: the perceptions of staff members of the School of Distance Education in Brisbane, Queensland

This paper examines the perceptions of teachers associated with the Brisbane School of Distance Education (Queensland, Australia), concerning their role in the establishment and implementation of a primary education program for children of the Showmen's Guild of Australasia. Interviews with five itinerant teachers revealed that their responsibilities include assessing correspondence papers from students and maintaining telephone contact with students, home tutors, and parents, as well as working in selected towns on a short-term basis to teach 'face-to-face' lessons to itinerant students. Each teacher worked with between 15 and 20 children, usually in family groups across grade levels. Teachers expressed concerns about the show children's lifestyle and how this has affected their educational and social development. However, all teachers felt that the distance education program had improved the children's educational opportunities and adequately addressed their educational needs. Disadvantages of the children's itinerant lifestyle that the program was unable to address were lack of routine, lack of continuity, dependence on the support of the home tutor, role conflicts of local teachers, and insufficient program funding. Implications for other itinerant education projects include recognizing the importance of teacher attitudes when implementing an educational program for a marginalized group. Contains 20 references. (LP

Assessing students\u27 foundation skills prior to the STEM majors

To increase the employability of STEM graduates and their readiness as scientific and technical knowledge workers for the 21st Century knowledge economies, higher education must emphasise what are known as foundation skills, such as critical thinking, quantitative reasoning, communication and teamwork, to name a few. Quality assurance organisations, such as ABET (the international accrediting body for technical fields) and national higher education accrediting bodies require programmes to show evidence of student attainment of foundation skills. Such skills, however, are recognised as difficult to both teach and assess. In earlier articles, the authors have described and presented preliminary results and findings from an assessment framework - The General Education Foundation Skills Assessment (GEFSA) - used to measure and assess the attainment of foundation skills for non-native English speaking students in a general education programme (i.e. pre-major students) at Zayed University in the United Arab Emirates. This article focuses on recent GEFSA testing with students in their first and last semesters of the general education programme

Measuring attainment of foundation skills in general education at a public university in the United Arab Emirates

© 2016 WIETE. To increase the employability of graduates, tertiary education must emphasise what are known as foundational skills, such as critical thinking, teamwork and information literacy, to name a few. These skills, however, are recognised as difficult to both teach and assess. In this article, the authors describe a novel performance assessment - the General Education Foundational Skills Assessment (GEFSA) - that can be used to teach and measure attainment of foundational skills for non-native English speaking students in a General Education programme, and the results of a pilot study conducted at Zayed University in the United Arab Emirates. The GEFSA is comprised of a scenario of an unresolved contemporary issue, prompts to engage students in an on-line discussion, and a task-specific analytic rubric to assess the extent to which students attain the targeted skills. This article focuses on the GEFSA Rubric development and the supporting instruments. The pilot study results indicated that the method could be used to both teach and measure the foundation skills, as well as to be used for programme assessment reporting purposes

Exact Hybrid Covariance Thresholding for Joint Graphical Lasso

This paper considers the problem of estimating multiple related Gaussian graphical models from a $p$-dimensional dataset consisting of different classes. Our work is based upon the formulation of this problem as group graphical lasso. This paper proposes a novel hybrid covariance thresholding algorithm that can effectively identify zero entries in the precision matrices and split a large joint graphical lasso problem into small subproblems. Our hybrid covariance thresholding method is superior to existing uniform thresholding methods in that our method can split the precision matrix of each individual class using different partition schemes and thus split group graphical lasso into much smaller subproblems, each of which can be solved very fast. In addition, this paper establishes necessary and sufficient conditions for our hybrid covariance thresholding algorithm. The superior performance of our thresholding method is thoroughly analyzed and illustrated by a few experiments on simulated data and real gene expression data

Efficacy and mechanistic insights into endocrine disruptor degradation using atmospheric air plasma

Endocrine disruptors are a class of contaminants found in water and process effluents at low concentrations. They are of concern due to their high estrogenic potency. Their presence in the environment has led to the search for effective techniques for their removal in wastewater. For this purpose, an atmospheric air plasma reactor was employed for the study of the degradation of three endocrine disruptor chemicals (EDC) namely; bisphenol A (BPA), estrone (E1) and 17β-estradiol (E2) within a model dairy effluent. Identification of the plasma induced active species both in the gas and liquid phases were performed. Also studied was the influence of an inhibitor, namely tertiary butanol, on the degradation of the EDCs. The results demonstrate that air plasma could successfully degrade the tested EDCs, achieving efficacies of 93% (k=0.189min−1) for BPA, 83% (k=0.132min−1) for E1 and 86% (k=0.149min−1) for E2, with the process following first order kinetics. The removal efficacy was reduced in the presence of a radical scavenger confirming the key role of oxygen radicals such as OH in the degradation process. The intermediate and final products generated in the degradation process were identified using UHPLC-MS and LC-MS. Based on the intermediates identified a proposed degradation pathway is presented

Construction and Assembly of the Wire Planes for the MicroBooNE Time Projection Chamber

In this paper we describe how the readout planes for the MicroBooNE Time Projection Chamber were constructed, assembled and installed. We present the individual wire preparation using semi-automatic winding machines and the assembly of wire carrier boards. The details of the wire installation on the detector frame and the tensioning of the wires are given. A strict quality assurance plan ensured the integrity of the readout planes. The different tests performed at all stages of construction and installation provided crucial information to achieve the successful realisation of the MicroBooNE wire planes.Comment: 24 pages, 22 figures, accepted for publication as Technical Report in JINS