Recent evidence suggests that SARS-CoV-2, which is the virus causing a global pandemic in 2020, is predominantly transmitted via airborne aerosols in indoor environments. This calls for novel strategies when assessing and controlling a building's indoor air quality (IAQ). IAQ can generally be controlled by ventilation and/or policies to regulate human-building-interaction. However, in a building, occupants use rooms in different ways, and it may not be obvious which measure or combination of measures leads to a cost-and energy-effective solution ensuring good IAQ across the entire building. Therefore, in this article, we introduce a novel agent-based simulator, ArchABM, designed to assist in creating new or adapt existing buildings by estimating adequate room sizes, ventilation parameters and testing the effect of policies while taking into account IAQ as a result of complex human-building interaction patterns. A recently published aerosol model was adapted to calculate time-dependent carbon dioxide (CO2) and virus quanta concentrations in each room and inhaled CO2 and virus quanta for each occupant over a day as a measure of physiological response. ArchABM is flexible regarding the aerosol model and the building layout due to its modular architecture, which allows implementing further models, any number and size of rooms, agents, and actions reflecting human-building interaction patterns. We present a use case based on a real floor plan and working schedules adopted in our research center. This study demonstrates how advanced simulation tools can contribute to improving IAQ across a building, thereby ensuring a healthy indoor environment.

The aim of this study was to develop an artificial intelligence-based tool that is able to predict wind power density. Wind power density is volatile in nature, and this creates certain challenges, such as grid controlling problems or obstacles to guaranteeing power generation capacity. In order to ensure the proper control of the traditional network, energy generation and demand must be balanced, yet the variability of wind power density poses difficulties for fulfilling this requirement. This study addresses the complex control in systems based on wind energies by proposing a tool that is able to predict future wind power density in the near future, specifically, the next 10 min, allowing microgrid's control to be optimized. The tool is validated by examining the root mean square error value of the prediction. The deviation between the actual and forecasted wind power density was less than 6% for 81% of the examined days in the validation step, from January 2017 to August 2017. In addition, the obtained average deviation for the same period was 3.75%. After analysing the results, it was determined that the forecaster is accurate enough to be installed in systems that have wind turbines in order to improve their control strategy.

Electric motorcycles use a battery storage system and a controlled inverter (motor drive) to drive the wheels. Given that the sale of electric motorcycles is expected to grow significantly over the next decade, the aim of this research is to add a supercapacitor storage system to this simple network in order to extend the autonomy of the motorcycle. This paper analyzes and demonstrates the benefits of two different structures for adding a supercapacitor bank to a lithium-ion battery pack: a passive filter and a buffer for the battery. The advantages of each structure are presented and design guidelines are provided. In addition, we propose a synthetic inductor filter typology based on the two analyzed structures in order to increase the autonomy of the motorcycle. Simulations and experimental results using real data validate the analysis. This paper then uses real data extracted from an electric motorcycle to compare the four topologies: batteries only, the passive filter, the buffer, and the synthetic inductor semi-active hybrid storage system. The comparison shows that battery capacity is extended up to 7.8% with a smoother current profile. However, due to the losses from the added converter in cascade, the net capacity of the whole system is extended only up to 3.7%. Therefore, improvements in the dc/dc converter can further increase the entire system capacity.

Purpose Late deformity/indentation is well-recognised following fronto-orbital remodelling (FOR) for metopic synostosis. We hypothesise that if damage to temporalis muscle were a contributor, the thickness of soft tissue and bone in the affected area would be reduced. Materials and methods Soft tissues and bone were separately segmented and reconstructed three-dimensionally from computed tomograms of 8 patients 1.5¿18 years post-FOR performed at 16 ± 2 months for metopic synostosis and from 8 age-matched controls. Soft tissue (taken as proxy for temporalis muscle) and bone thickness overall and in the indented areas were computed. Results Post-FOR, three-dimensional soft tissue thickness maps demonstrated temporalis extending upwards but falling short of the indented area. Overall skull thickness increased with age post-FOR (logarithmic fit R2 = 0.71) and for controls (R2 = 0.90). Although immediately post-FOR the future indented area had a thickness of 98% of control, it decreased linearly to 64% 16 years later (Pearson's r = 0.84). Conclusion These findings suggest that late post-FOR deformity/indentation is enhanced by limited upward extension (or retraction downwards) of temporalis muscle, while bone thickness in the affected area gradually decreases. This supports the hypothesis that aberrant re-attachment of the temporalis muscle makes a material contribution to late deformity following FOR for metopic synostosis.

This paper characterizes the bidirectional feature of the transformer-based quasi-Z-source inverter (trans-qZSI) obtained by adding a controllable power device to the input of the circuit. Different arising operation modes and states are analysed and an AC small signal model is proposed accordingly. A controller was designed using the proposed model, and an experimental validation platform was implemented. After the computational and experimental model validation, it was analysed how and when bidirectional Z topology benefits from bidirectional feature, apart from obvious inverse power conversion operation. Robustness increase and fault tolerance of the bidirectional trans-qZSI topology were characterized and validated experimentally for different current demand decrease case studies: when an open circuit is produced in one output phase or when the current demand decreases due to normal operation requirements. The paper characterizes and demonstrates, computationally and experimentally, that it is the bidirectional feature that provides the system with the robustness needed to protect against these kind of failures or operation modes. Not having the additional IGBT could cause the system to enter the discontinuous conduction mode (DCM) zone and destabilize the system¿s currents and voltages. In that case the voltage is not able to follow the control reference, which could ultimately lead to the destruction of the components.

This paper proposes, analyses and validates, both computationally and experimentally, an AC small signal model for a Trans quasi-Z-source inverter working in continuous conduction mode (CCM). For the implementation of the small-signal model, the dynamics of the particular Trans-gZSI network components have been considered. The presented AC small signal model is used for a detailed analysis of the performance of the Trans-gZSI topology, involving various aspects; a parametric study of the influence of the passive components on the dynamic response of the Z network, as well as the influence of their associated losses. Duty cycle and load variations are studied too, for Z topology operating point performance analysis. The AC small-signal model is then used to design a compensator for a closed -loop control scheme. Computer simulation results are presented to validate the model and the control method, comparing PSIM TransqZSI detailed simulations to the MATLAB derived results. Finally, experimental validation is achieved for the AC model in a low-medium power Trans-gZSI design, both in time and frequency domain. According to experimental results analysis, a snubber circuit is designed too, for the converter.

This paper presents a transient analysis of the trans quasi-Z-source inverter (trans-qZSI) topology operating in discontinuous conduction mode (DCM). Usually only the continuous conduction mode (CCM) is considered and high current operating points are assumed in the literature. Thus the main contributions of this article are a clear definition of the limits of the DCM and the development of a small-signal model that takes into account the dynamics introduced by the particular Z network contained in the trans-qZSI converter, which allows the behaviour of the system working in DCM to be analysed under different current demand circumstances. Moreover, the obtained small-signal model allows the expressions of the control-to-capacitor transfer function to be derived and used together with any inverter control strategy. For trans-qZSI topology performance analysis and model validation, computer simulation results are presented, including frequency domain analysis and small-signal/PSIM comparisons. Lastly, experimental validation is presented for the time and frequency domains.