Changing the Culture of Building Simulation with Emergent Modelling

Ljubomir Jankovic, ‘Changing the Culture of Building Simulation with Emergent Modelling’, in Charles S. Barnaby and Michael Wetter, eds., Building Simulation 2017 Proceedings. Paper presented at the IBPSA Conference 2017, San Francisco, August 2017. Content in the UH Research Archive is made available for personal research, educational, and non-commercial purposes only. Unless otherwise stated, all content is protected by copyright, and in the absence of an open license, permissions for further re-use should be sought from the publisher, the author, or other copyright holder.Dynamic simulation models of buildings have been predominantly based on a top-down approach, which defines the system as a whole with equations, simplifies the representation to make the solutions computable at the expense of accuracy, and then seeks solutions to the system using numerical methods. This traditional approach, evolved as result of the development of traditional mathematics over the past 300 years, differs considerably from the way building physics operates. Building materials do not solve systems of complex equations. Instead, heat transfer occurs as result of neighbour to neighbour interaction of molecules. That leads to a much faster process than the one calculated by equations. This paper investigates an approach that replaces the system of equations with neighbour to neighbour interaction between autonomous components representing groups of molecules, giving rise to spontaneous emergence of the system behaviour

Development and Analysis of a Predictive Control Algorithm for Embedding in a Microprocessor Controller

Ljubomir Jankovic, ‘Development and Analysis of a Predictive Control Algorithm for Embedding in a Microprocessor Controller’, in BSO 2016 Proceedings. Paper presented at the 3rd IBPSA England Conference, Newcastle, September 2016. Content in the UH Research Archive is made available for personal research, educational, and non-commercial purposes only. Unless otherwise stated, all content is protected by copyright, and in the absence of an open license, permissions for further re-use should be sought from the publisher, the author, or other copyright holder.The aim of this paper is to develop a predictive control algorithm and compare it with thermostat based control. The approach is based on modelling thermostat based control in EnergyPlus, and creating a predictive model using Fast Fourier Transform (FFT). Thermostat based control was modelled in EnergyPlus using a simple single zone building with 42% of south glazing. Predictive model was developed as an FFT response function to heat input, thus obtaining an inverse model and applying it several time steps ahead. The heating load and predictive percentage of dissatisfied of thermostat based control and of the predictive control cases were compared. The results show that in this particular study the predictive control approach leads to just over 20% reduction of energy consumption whilst keeping similar level of thermal comfort. In addition to investigating the modelling of predictive control using Fourier series, the aim of the research is to assess the feasibility of embedding this type of control algorithm in a microprocessor controller

Performance comparison between KNN and NSGA-II algorithms as calibration approaches for building simulation models

Shadi Basurra , and Ljubomir Jankovic, ‘Performance comparison between KNN and NSGA-II algorithms as calibration approaches for building simulation models’, in BSO 2016 Proceedings. Paper presented at the 3rd IBPSA England Conference, Newcastle, September 2016. Content in the UH Research Archive is made available for personal research, educational, and non-commercial purposes only. Unless otherwise stated, all content is protected by copyright, and in the absence of an open license, permissions for further re-use should be sought from the publisher, the author, or other copyright holder.In this paper, a study of calibration methods for a thermal performance model of a building is presented. Two calibration approaches are evaluated and compared in terms of accuracy and computation speed. These approaches are the 푘 Nearest Neighbour (KNN) algorithm and NSGA-II algorithm. The comparison of these two approaches was based on the simulation model of the Birmingham Zero Carbon House, which has been under continuous monitoring over the past five years. Data from architectural drawings and site measurements were used to build the geometry of the house. All building systems, fabric, lighting and equipment were specified to closely correspond to the actual house. The preliminary results suggest that the predictive performance of simulation models can be calibrated quickly and accurately using the monitored performance data of the real building. Automating such process increases its efficiency and consistency of the results while reducing the time and effort required for calibration. The results show that both NSGA-II and KNN provide similar degree of accuracy in terms of the results closeness to measured data, but whilst the former outperforms the latter in terms of computational speed, the latter outperforms the former in terms of results wide coverage of solutions around the reference point, which is essential for calibration.Final Published versio

Opportunities for financing sustainable development using complementary local currencies

Financing building retrofit projects that contribute to climate change mitigation has always represented a significant barrier. With 28% of global emissions coming from existing buildings, it is of paramount importance to carry out retrofit measures that lead to significant reduction of these emissions. Whilst this is perfectly possible to achieve with current methods and current technology, there is no sufficient conventional finance to carry out zero carbon retrofit at scale required for climate change mitigation. The article introduces an alternative and sustainable business model that creates new opportunities for financing zero carbon retrofit of buildings. It demonstrates that the value of solar energy falling on roofs of buildings can become a driver for new local economic systems, and discusses the requirements for practical application.Peer reviewedFinal Published versio

The Google Car: Driving Toward A Better Future?

Google’s dramatic ascent and subsequent domination in the past fifteen years of the technology and information industries has financially enabled Google to explore seemingly unrelated projects ranging from Google Mail to the Google Car. In particular, Google has invested a significant amount of resources in the Google Car, an integrated system that allows for the driverless operation of a vehicle. While initial reports indicate that the Google Car driverless automobile will be more safe and efficient than current vehicles, the Google Car is not without its critics. In particular, the existential threat that the car presents to several large industries, including the insurance, health care and construction industries, creates an additional challenge to the success of the Google Car well beyond the standard competitive threats from other established car manufacturers in the automobile industry, which begs the question, “Can the Google Car be successful?” With so many challenges above and beyond the competitive forces typically threatening long-term profitability, will the Google Car be able to create and sustain a competitive advantage for Google in the driverless car space

General Motors: The Electric Revolution

The recent explosion in demand for electric vehicles, fueled by both increasing gas prices and rising awareness of consumers to environmental concerns, has challenged traditional car manufacturers to explore alternatives to gas-powered automobiles. Of the new models presenting alternatives to traditional gas-powered cars, the award-winning Tesla Model S and Nissan Leaf have commanded the majority of the attention and sales in the electric car market. General Motors’ Volt, on the other hand, has seen lukewarm sales after missing its high production and consumption expectations. As the inevitable pursuit of sustainable solutions for energy use continues, GM is placed in a precarious situation. On the one hand, their attempts at entering the electric car market have been unsuccessful thus far. On the other hand, retreating from the emerging industry may be detrimental if gas-powered cars become vestigial in the future. Should GM simply continue to manufacture standard automobiles? Or should they invest further in electric vehicles, acquiring the necessary technology to compete with market leaders

Second harmonic generation, beam dynamics and spatial soliton generation in periodically poled KTiOPO4

Spatial solitons were investigated in periodically poled KTiOPO4 under conditions of second harmonic generation and many new features associated with soliton generation in quasi-phase-matched samples were observed. The effects on the second harmonic generation tuning curves of the beam narrowing mechanisms responsible for soliton generation were found to be dramatic. It was demonstrated experimentally that the mutual collapse of the fundamental and harmonic beams is a complex phenomenon

London's weather and the everyday: two centuries of newspaper reports

This study surveys 200 years of London’s weather and its public reporting in newspapers to reveal some of the recurring modes of reporting and linguistic styles that are used to describe and make sense of the human experience of weather. These modes include: the cultural anxieties prompted by ‘unusual weather’; the visual dramas of ‘great storms’; the weather as culpable; and bench-marking extreme weather. Even as the broader processes and patterns of our climate are changing, at the level of the everyday the human and cultural experience of weather remains remarkably familiar