Performance Evaluation of Three Virtual Metering Methods to Estimate Zone-level Perimeter Heater Energy Requirement

Virtual metering provides a cost-effective alternative to physical meters to monitor building energy performance and capture unmetered energy flows at the zone-level. Virtual metering accuracy depends on the modelling method and its ability to represent the heating and cooling processes at a building thermal zone. This paper employs three virtual metering methods to estimate the heating energy of zone-level perimeter heaters: a steady-state modelling method, a transient modelling method, and a load disaggregation modelling method. Inverse models representing these three virtual metering methods are trained using data obtained from seven perimeter offices in an academic building in Ottawa, Canada. Model parameters are identified using the genetic algorithm and used for creating virtual meters that estimate the energy requirement of zone-level perimeter heaters. The virtual meters\u27 accuracy is assessed by comparing the results to measured heating energy obtained from physical meters installed in the seven offices. The three virtual metering methods\u27 performance is evaluated through illustrative examples in terms of modelling assumptions, data requirements, and virtual metering accuracy. The results indicate that the three virtual metering methods can estimate the daily heating energy supplied by perimeter heaters at a normalized root-mean-square error between 13% and 23%

Performance Modelling of Consolidated Virtual Machines

With rapid and flexible resource provisioning of virtualization in data centers, problems of determining optimal virtual machine (VM) placements and dealing with virtualization overheads have emerged due to workload fluctuations and changing needs. These challenges have impacts on system performance.In this work, a performance model based on queuing theory, statistical methods and basic theories on system performance is proposed in which the researcher models the response time distribution of an application performance metric conditioned on variables that can be measured or controlled, such as system resource utilization and allocation metrics. The research also examined the relationships between virtualized CPU allocation, CPU contention, and application response time to identify the influence of CPU allocation and how it affects system performance.Comparing estimated values with measured values, empirical result shows that the proposed model validated for all the CPU allocations in the experiments conducted. The response time increases as workload increases; it is also observed from the analysis that the response time increases with low CPU. Thus by varying the CPU allocation base on business needs, am optimal point can be reached such that the CPU can be efficiently managed

Group emotion modelling and the use of middleware for virtual crowds in video-games

In this paper we discuss the use of crowd simulation in video-games to augment their realism. Using previous works on emotion modelling and virtual crowds we define a game world in an urban context. To achieve that, we explore a biologically inspired human emotion model, investigate the formation of groups in crowds, and examine the use of physics middleware for crowds. Furthermore, we assess the realism and computational performance of the proposed approach. Our system runs at interactive frame-rate and can generate large crowds which demonstrate complex behaviour

Integrated Thermal Systems and Controls Modelling for AUTO Mode Simulation and Optimization

Virtual product development has become the preferred approach for vehicle A/C system development. The advantages provided by virtual modelling compared to traditional approach are accelerated development pace and reduced cost. The thesis focuses on virtual modelling of the A/C system on a SUV vehicle based on experimental data. A virtual model of the A/C system is constructed and calibrated in Simcenter Amesim. The model includes a vapour-compression refrigeration cycle and a cabin air model. The components are modelled and calibrated based on supplier data. The two thermal systems interact thermally at the evaporator level. The cabin air blower unit with a PI controller and a small DC motor is also modelled in MATLAB/Simulink. The virtual thermal model is able to simulate the cabin air temperature development during High Ambient AUTO mode drive cycle. The controlled DC motor system tracks reference speed to provide adequate air flow for the cabin. The virtual models can be used for A/C system and components performance analysis and optimization. The modelling process provides deeper understanding on thermal and control systems design

Internet-driven customer centric : an exploratory analysis

Firm’s are becoming everyday more focus on customer orientation, leading to the need use of new techniques or combine use of existent ones. Both Customer Relationship Management and Knowledge Management are increasingly relevant in the corporate agendas as well as been broadly studied by academic researchers and with the development of the digital economy it’s necessary to have a larger understanding of their role in e-business performance. Thus, our aims are to determine whether the implementation of virtual CRM and KM is linked to e-business performance and to identify the nature of the relationship existing in the combine use of these tools. Thus, this paper establishes a new model of the practices and results of the both tools which has been tested in European companies. For that purpose, we used a structural equation modelling analysis. The results show that both virtual CRM and KM have a positive impact on the maximization of e-business performance and that their combine use has also a positive impact on e-business performance. As limitations of the study we consider the need for more research into this field and the inclusion of news elements such as technological readiness and management support. This paper contributes to the research on this topic with new evidence in a broad sample.info:eu-repo/semantics/publishedVersio

The Impact of Virtuality and Shared Leadership on Virtual Team Performance

Previous studies show divergent views of shared leadership in the team performance of virtual teams. In this study, we seek to understand the mediating and moderating roles of trust, commitment, and virtuality among virtual team members on performance within the context of shared leadership. We conducted a questionnaire-based survey to gather perspectives on shared leadership and performance and analysed responses through structural equation modelling. We find that there is a significant positive effect between the two and that virtuality plays a significant moderating role for virtual team performance. In addition, we find that when virtuality increases, the mediating effect of trust and commitment is not significant, which challenges previous findings

Unravelling the dynamics of learning design within and between disciplines in higher education using learning analytics

Designing effective learning experience in virtual learning environment (VLE) can be supported by learning analytics (LA) through explicit feedback on how learning design (LD) influences students’ engagement, satisfaction and performance. Marrying LA with LD not only puts existing pedagogical theories in instructional design to the test with actual learning data, but also provides the context of learning which helps educators translate established LA findings to direct interventions. My dissertation aims at unpacking the complexity of LD and its impact on students’ engagement, satisfaction and performance on VLE using LA. The context of this study is 400+ online and blended learning modules at the Open University (OU) UK. This research combines multiple sources of data from the OU Learning Design Initiative (OULDI), system log data, self-reported surveys, and performance data. Given the scope of this study, a wide range of visualization techniques, social network analysis, multi-level modelling, and machine learning will be used

Development and validation of detailed building, plant and controller modelling to demonstrate interactive behaviour of system components

As plant modelling becomes capable of more complexity and detailed resolution, new opportunities arise for the virtual evaluation of discrete plant components such as flow control and energy conversion devices, and controllers. Such objects are conventionally developed and tested at the prototype stage in a laboratory environment. Designers now seek to use modelling technology to extend their understanding from limited laboratory test results to full building and plant system analysis. This paper describes the development of a modelling system, using ESP-r, for typical United Kingdom domestic house types with hydronic gas or oil fired central heating including radiator and underfloor heating systems, and with a variety of conventional or advanced control types. It demonstrates the ability of detailed building and plant modelling to reveal unexpected insights into how real control systems perform in combination with other plant items and in different building types, including estimation of their influence on annual energy consumption. Comparisons with measurements taken in test rooms confirm that the observed behaviour of controls is realised in practice. The authors conclude that the complex dynamic interactions that take place between the various elements that make up a real building energy system have an important influence on its overall energy performance, revealing causes of variance that cannot be identified by laboratory testing alone, or by simplistic energy assessment tools