Contractors Perspective on the Selection of Innovative Sustainable Technologies for Achieving Zero Carbon Retail Buildings

The use of innovative sustainable technologies (IST) has been regarded as an effective approach to enhancing energy efficiency and reducing carbon emissions of buildings. However, contractors face significant challenges in the selection of IST. The reported challenges in the literature include: lack of skills and knowledge, uncertainties, risks and the rapid development of a large number of technological alternatives and decision criteria. The selection process emerges as a multi-attribute, value-based task that includes both qualitative and quantitative factors, which are often assessed with imprecise data and human judgments. This paper aims to establish the decision criteria for the selection of IST for achieving low carbon existing retail buildings with a focus on the main contractor’s perspective. The arguments are informed by the combination of literature review and an in-depth case study with a UK leading contractor. Five broad decision criteria are identified systematically drawing on the contractor’s practice. The established criteria are weighted and ranked using the analytic hierarchy process and expert opinions; with ‘margin opportunity’ being the most important, followed by ‘repeat business’, ‘investment costs’, ‘differentiation’ and then ‘transferability’. The findings should facilitate the integration of various facets of the selection process and stimulate contractors to use IST

Quantum oscillations of self-dual Abrikosov-Nielsen-Olesen vortices

The mass shift induced by one-loop quantum fluctuations on self-dual ANO vortices is computed using heat kernel/generalized zeta function regularization methods. The quantum masses of super-imposed multi-vortices with vorticity lower than five are given. The case of two separate vortices with a quantum of magnetic flux is also discussed.Comment: RevTex, 13 pages, 4 figures, 7 tables. Minor corrections. Version to appear in Physical Review

User-Interface Modelling for Blind Users

The design of a user interface usable by blind people sets specific usability requirements that are unnecessary for sighted users. These requirements focus on task adequacy, dimensional trade-off, behaviour equivalence, semantic loss avoidance and device-independency. Consequently, the development of human-computer interfaces (HCI) that are based on task, domain, dialog, presentation, platform and user models has to be modified to take into account these requirements. This paper presents a user interface model for blind people, which incorporates these usability requirements into the above HCI models. A frame-work implementing the model has been developed and implemented in an electronic speaking bilingual software environment for blind or visually impaired people and in an educational system for children with special educational needs

Cu(In,Ga)Se2 absorber thinning and the homo-interface model: Influence of Mo back contact and 3-stage process on device characteristics

Thinning the absorber layer is one of the possibilities envisaged to further decrease the production costs of Cu(In,Ga)Se2 (CIGSe) thin films solar cell technology. In the present study, the electronic transport in submicron CIGSe-based devices has been investigated and compared to that of standard devices. It is observed that when the absorber is around 0.5 μm-thick, tunnelling enhanced interface recombination dominates, which harms cells energy conversion efficiency. It is also shown that by varying either the properties of the Mo back contact or the characteristics of 3-stage growth processing, one can shift the dominating recombination mechanism from interface to space charge region and thereby improve the cells efficiency. Discussions on these experimental facts led to the conclusions that 3-stage process implies the formation of a CIGSe/CIGSe homo-interface, whose location as well as properties rule the device operation; its influence is enhanced in submicron CIGSe based solar cells

Building and exploiting a Digital Twin for the management of drinking water distribution networks

[EN] Digital Twins (DTs) are starting to be exploited to improve the management of water distribution systems (WDSs) and, in the future, they will be crucial for decision making. In this paper, the authors propose several requirements that a DT of a water distribution system should accomplish. Developing a DT is a challenge, and a continuous process of adjustments and learning is required. Due to the advantages of having a DT of the WDS always available, during the last years a strategy to build and maintain a DT of the water distribution network of Valencia (Spain) and its Metropolitan Area (1.6 million inhabitants) was developed. This is one of the first DTs built of a water utility, being currently in operation. The great benefits of their use in the daily operation of the system ensure that they will begin to be usual in the most advanced smart cities.Conejos Fuertes, P.; Martínez Alzamora, F.; Hervás-Carot, M.; Alonso Campos, JC. (2020). Building and exploiting a Digital Twin for the management of drinking water distribution networks. Urban Water Journal. 17(8):704-713. https://doi.org/10.1080/1573062X.2020.1771382S704713178Chacón Ramírez, E., Albarrán, J. C., & Cruz Salazar, L. A. (2019). The Control of Water Distribution Systems as a Holonic System. Studies in Computational Intelligence, 352-365. doi:10.1007/978-3-030-27477-1_27Grieves, M., et al. 2015. Virtually Intelligent Product Systems: Digital and Physical Twins. In Complex Systems Engineering: Theory and Practice, edited by S. Flumerfelt, et al., 175–200. American Institute of Aeronautics and Astronautics.Hatchett, S., J. Uber, D. Boccelli, T. Haxton, R. Janke, A. Kramer, A. Matracia, and S. Panguluri. 2011. “Real-Time Distribution System Modeling: Development, Application, and Insights.” Urban Water Management: Challenges and Oppurtunities - 11thInternational Conference on Computing and Control for the Water Industry, CCWI 2011 July.Kartakis, S., Abraham, E., & McCann, J. A. (2015). WaterBox. Proceedings of the 1st ACM International Workshop on Cyber-Physical Systems for Smart Water Networks. doi:10.1145/2738935.2738939Lin, J., Sedigh, S., & Miller, A. (2009). Towards Integrated Simulation of Cyber-Physical Systems: A Case Study on Intelligent Water Distribution. 2009 Eighth IEEE International Conference on Dependable, Autonomic and Secure Computing. doi:10.1109/dasc.2009.140Qi, Q., & Tao, F. (2018). Digital Twin and Big Data Towards Smart Manufacturing and Industry 4.0: 360 Degree Comparison. IEEE Access, 6, 3585-3593. doi:10.1109/access.2018.2793265Alac, M. (2008). Working with Brain Scans. Social Studies of Science, 38(4), 483-508. doi:10.1177/0306312708089715Shi, Y., Xu, J., & Du, W. (2019). Discussion on the New Operation Management Mode of Hydraulic Engineering Based on the Digital Twin Technique. Journal of Physics: Conference Series, 1168, 022044. doi:10.1088/1742-6596/1168/2/022044Tao, F., Zhang, H., Liu, A., & Nee, A. Y. C. (2019). Digital Twin in Industry: State-of-the-Art. IEEE Transactions on Industrial Informatics, 15(4), 2405-2415. doi:10.1109/tii.2018.2873186Tao, F., Cheng, J., Qi, Q., Zhang, M., Zhang, H., & Sui, F. (2017). Digital twin-driven product design, manufacturing and service with big data. The International Journal of Advanced Manufacturing Technology, 94(9-12), 3563-3576. doi:10.1007/s00170-017-0233-1Tao, F., & Qi, Q. (2019). Make more digital twins. Nature, 573(7775), 490-491. doi:10.1038/d41586-019-02849-1Uber, J., S. Hatchett, S. Hooper, D. Boccelli, H. Woo, and R. Janke. 2014. Water Utility Case Study of Real-Time Network Hydaulic and Water Qualilty Modeling Using EPANET-RTX Libraries. EPA 6007R-14/350 Report. Cincinnati, Ohio: Environmental Protection Agency.Wang, Z., Song, H., Watkins, D. W., Ong, K. G., Xue, P., Yang, Q., & Shi, X. (2015). Cyber-physical systems for water sustainability: challenges and opportunities. IEEE Communications Magazine, 53(5), 216-222. doi:10.1109/mcom.2015.710566

Patio as a Structural Invariant. Buildings with Patio Facing Adaptive Reuse in Barcelona

Certain architectural structures have the ability to persist over time when a building undergoes a change of use. This is the case of patios, according to the conclusions of a study focused on the reused buildings of Barcelona recently developed. The survey of this architectural element should enable us to better understand the behaviour of these buildings. If we define the open-air inner courtyard of a building as a patio, this study is especially interested in those who have the capacity to organize spaces, systematize circulations — along with stairs and corridors — and configure the building as a whole. This set of structuring patios particularly applies in a dense city like Barcelona because their position and size also provide liveability to interior rooms. In light of these qualities, such patios can be regarded as an essential piece of both the formal and the bearing structure of a building. The location and attributes of these patios can be associated with the potential for adaptive reuse: they can help achieve a lower impact on the architectural and formal structure of a renovated building, when used appropriately. Hence the patio can be seen as an indicator of how a new programme adapts to the existing support. 171 out of 565 buildings documented and analysed in Barcelona — a thirty percent of the overall — have at least one patio of a kind whose characteristics have outlived one or more renovation processes. The percentage rises to 50% in Ciutat Vella and Eixample districts, where density and architectural typology make them particularly relevant. Buildings with patios match different uses and periods from the 11th to the 20th century. In spite of the expected differences, the studio draws conclusions on the understanding of material transformations and changes of use they have undergone. In short, with regard to buildings included in this category — both heritage and common ones — this paper helps verify the hypothesis that the very existence of a patio is responsible for the persistence of the internal arrangement and structure and must be carefully considered in future interventions when addressed to extend the life-cycle of a building

Implied Filtering Densities on Volatility's Hidden State

We formulate and analyze an inverse problem using derivatives prices to obtain an implied filtering density on volatility's hidden state. Stochastic volatility is the unobserved state in a hidden Markov model (HMM) and can be tracked using Bayesian filtering. However, derivative data can be considered as conditional expectations that are already observed in the market, and which can be used as input to an inverse problem whose solution is an implied conditional density on volatility. Our analysis relies on a specification of the martingale change of measure, which we refer to as \textit{separability}. This specification has a multiplicative component that behaves like a risk premium on volatility uncertainty in the market. When applied to SPX options data, the estimated model and implied densities produce variance-swap rates that are consistent with the VIX volatility index. The implied densities are relatively stable over time and pick up some of the monthly effects that occur due to the options' expiration, indicating that the volatility-uncertainty premium could experience cyclic effects due to the maturity date of the options