| 1. |
- Alisic, Rijad, et al.
(författare)
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Ensuring privacy of occupancy changes in smart buildings
- 2020
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Ingår i: CCTA 2020 - 4th IEEE Conference on Control Technology and Applications. - : Institute of Electrical and Electronics Engineers Inc.. ; , s. 871-876
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Konferensbidrag (refereegranskat)abstract
- Smart building management systems rely on sensors to optimize the operation of buildings. If an unauthorized user gains access to these sensors, a privacy leak may occur. This paper considers such a potential leak of privacy in a smart residential building, and how it may be mitigated by corrupting the measurements with additive Gaussian noise. This corruption is done in order to hide when the occupancy changes in an apartment. A lower bound on the variance of any estimator that estimates the change time is derived. The bound is then used to analyze how different model parameters affect the variance. It is shown that the signal to noise ratio and the system dynamics are the main factors that affect the bound. These results are then verified on a simulator of the KTH Live-In Lab Testbed, showing good correspondence with theoretical results.
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| 2. |
- Alisic, Rijad, et al.
(författare)
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Maximizing Privacy in MIMO Cyber-Physical Systems Using the Chapman-Robbins Bound
- 2020
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Ingår i: Proceedings of the IEEE Conference on Decision and Control. - : Institute of Electrical and Electronics Engineers Inc.. ; , s. 6272-6277
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Konferensbidrag (refereegranskat)abstract
- Privacy breaches of cyber-physical systems could expose vulnerabilities to an adversary. Here, privacy leaks of step inputs to linear time-invariant systems are mitigated through additive Gaussian noise. Fundamental lower bounds on the privacy are derived, which are based on the variance of any estimator that seeks to recreate the input. Fully private inputs are investigated and related to transmission zeros. Thereafter, a method to increase the privacy of optimal step inputs is presented and a privacy-utility trade-off bound is derived. Finally, these results are verified on data from the KTH Live-In Lab Testbed, showing good correspondence with theoretical results.
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| 3. |
- Bäcklund, Katarina, 1982-, et al.
(författare)
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Building Occupants, Their Behavior and the Resulting Impact on Energy Use in Campus Buildings : A Literature Review with Focus on Smart Building Systems
- 2023
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Ingår i: Energies. - : MDPI AG. - 1996-1073. ; 16:17, s. 6104-6104
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Tidskriftsartikel (refereegranskat)abstract
- In the light of global climate change and the current energy crisis, it is crucial to target sustainable energy use in all sectors. Buildings still remain one of the most energy-demanding sectors. Campus buildings and higher educational buildings are important to target due to their high and increasing energy demand. This building segment also represents a research gap, as mostly office or domestic buildings have been studied previously. In the quest for thermal comfort, a key stakeholder in building energy demand is the building occupant. It is therefore crucial to promote energy-aware behaviors. The building systems are another key factor to consider. As conventional building systems are replaced with smart building systems, the entire scenario is redrawn for how building occupants interact with the building and its systems. This study argues that behavior is evolving with the smartness of building systems. By means of a semi-systematic literature review, this study presents key findings from peer-reviewed research that deal with building occupant behavior, building systems and energy use in campus buildings. The literature review was an iterative process based on six predefined research questions. Two key results are presented: a graph of reported energy-saving potentials and a conceptual framework to evaluate building occupants impact on building energy use. Furthermore, based on the identified research gaps in the selected literature, areas for future research are proposed.
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| 4. |
- Bäcklund, Katarina, 1982-
(författare)
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Human-Centric Operations of Smarter Higher Educational Buildings in Sweden
- 2024
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This PhD thesis is based on four articles, each focused on distinct research areas: building occupants, smarter higher educational buildings, smart building systems and the digital transformation of real estate organizations. Rather than concentrating on one specific research area, the objective was to provide a comprehensive view of the broader system and delve into these four key research areas. Thus, they are all interdependent and require equal attention to facilitate the digital transformation within the commercial real estate industry. This transformation aims to create a more climate neutral built environment while ensuring good quality indoor comfort. The findings reveal a paradox within smart building systems, where building occupants are often treated as passive agents and interactions are intentionally reduced. However, it can be argued that some interactions will be beneficial, as building occupants considered as active agents could contribute to a more sustainable building operation. This study also concludes that current smart buildings are not yet smart enough and that all data is not smart data. Furthermore, the investigation into what constitutes a smart building has led to the identification of key features of smarter higher educational buildings. Finally, the concluding part of this study delved into the organizational challenges associated with digital transformation, proposing potential solutions to enhance innovation processes. Based on these findings, a framework for human-centric digital transformation was proposed.
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| 5. |
- Bäcklund, Katarina, 1982-, et al.
(författare)
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In Search for Untapped Energy-Saving Potential in Green and Smart Higher Educational Buildings—An Empirical Case Study Involving the Building Occupants
- 2023
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Ingår i: Buildings. - : MDPI AG. - 2075-5309. ; 13:12
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Tidskriftsartikel (refereegranskat)abstract
- Energy-intense activities and the unpredictable and complex behavior of building occupants lead to an increase in building energy demand. It is, therefore, crucial to study underlying factors for building energy demand related to the users. Higher educational buildings are relevant to study for several reasons: they host the future workforce and citizens, they are predicted to increase in numbers, and they represent a building type less studied. Furthermore, green-rated buildings equipped with smart building systems also represent a research gap that is relevant to address since such a building design involves IoT-functionalities and digital features for the building occupants to interact with. There is also a conceivable risk that if the users know that the building is green-rated and technologically advanced, this may alter their perception of the building operation and thus their behavior. To study the relationship between building occupants and such green and smart educational structure, a survey was conducted in a Swedish higher educational building; as a result, 300 responses were collected and analyzed. The responses revealed that the building occupants act with energy awareness, and they are conscious about energy-saving behaviors. One building feature in particular was studied: the Digital Room Panels (DRPs). The DRP allows the building occupants to modify the indoor temperature and is, therefore, essential for thermal comfort. One key finding from the survey revealed that 70% of the building occupants did not know how the DRPs operate. This study argues that this result can be explained with a lack of communication and user friendliness. Inadequate interactions with building systems could also result in opportunities for energy saving might not be realized. The findings of this case study led to valuable recommendations and suggestions for future research endeavors.
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| 6. |
- Bäcklund, Katarina, 1982-, et al.
(författare)
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Showcasing a Digital Twin for Higher Educational Buildings : Developing the Concept Towards Human Centricity
- 2024
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Ingår i: Frontiers in Built Environment. - : Frontiers Media SA. - 2297-3362. ; 10
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Tidskriftsartikel (refereegranskat)abstract
- Digital twin technology is an emerging technology within the built environment. There are yet many unexplored opportunities to utilize digital twins for facilitating the transformation towards a climate neutral building stock while also meeting the expectations from the building occupants. This article presents a case study of a digital twin, developed for an existing commercial building stock of campus areas in Sweden. The overarching purpose of the digital twin is to support both building occupants and building operators. This twofold human-centric approach represents a novel approach for building digital twins. The digital twin is based on 3D scanning and together with geospatial data, a real-like navigational indoor environment is created. Three innovative features are presented; the building analysis module, the digital twin mobile application and the building operations module. The results show that the digital twin improves the building occupant’s experience by supporting navigation and providing access to room booking system via this dedicated interface. Building management is also benefited by the digital twin through easier access to building data aggregated into one platform and a state-of-the-art analysis tool for optimizing the use of indoor space. The digital twin holds future potential to achieve operational excellence by incorporating feedback mechanisms and utilizing Artificial Intelligence to enable intelligent fault detection and prevention. Keywords:
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| 7. |
- Bäcklund, Katarina, 1982-, et al.
(författare)
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Showcasing the First Steps Towards a Digital Twin for Campus Environments
- 2022
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Ingår i: 2022 BuildSim Nordic. - : EDP Sciences.
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Konferensbidrag (refereegranskat)abstract
- This paper presents a path towards the implementation of a Digital Twin for campus environments. The main purpose of the Digital Twin is to accomplish an advanced analytical tool, which supports building owners, building operators and building users to reach an improved performance of the building. Digital Twins is new to the building and the real estate industry, hence research within this field is scarce. This paper contributes to the research by providing a methodology to implement a Digital Twin of an existing building stock of campus areas in Sweden. The main results obtained so far are presented. They indicate that the potential of a Digital Twin expands beyond the aspects of a navigational digital 3D model, including a state-of-the-art app that is developed from the Digital Twin platform.
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| 8. |
- Farjadnia, Mahsa, et al.
(författare)
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Robust data-driven predictive control of unknown nonlinear systems using reachability analysis
- 2023
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Ingår i: European Journal of Control. - : Elsevier BV. - 0947-3580.
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Tidskriftsartikel (refereegranskat)abstract
- This work proposes a robust data-driven predictive control approach for unknown nonlinear systems in the presence of bounded process and measurement noise. Data-driven reachable sets are employed for the controller design instead of using an explicit nonlinear system model. Although the process and measurement noise are bounded, the statistical properties of the noise are not required to be known. By using the past noisy input-output data in the learning phase, we propose a novel method to over-approximate exact reachable sets of an unknown nonlinear system. Then, we propose a data-driven predictive control approach to compute safe and robust control policies from noisy online data. The constraints are guaranteed in the control phase with robust safety margins by effectively using the predicted output reachable set obtained in the learning phase. Finally, a numerical example validates the efficacy of the proposed approach and demonstrates comparable performance with a model-based predictive control approach.
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| 9. |
- Farjadnia, Mahsa, et al.
(författare)
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What influences occupants' behavior in residential buildings : An experimental study on window operation in the KTH Live-In Lab
- 2023
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Ingår i: 2023 IEEE Conference on Control Technology and Applications, CCTA 2023. ; , s. 752-758
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Konferensbidrag (refereegranskat)abstract
- Window-opening and window-closing behaviors play an important role in indoor environmental conditions and therefore have an impact on building energy efficiency. On the other hand, the same environmental conditions drive occupants to interact with windows. Understanding this mutual relationship of interaction between occupants and the residential building is thus crucial to improve energy efficiency without disregarding occupants' comfort. This paper investigates the influence of physical environmental variables (i.e., indoor and outside climate parameters) and categorical variables (i.e., time of the day) on occupants' behavior patterns related to window operation, utilizing a multivariate logistic regression analysis. The data considered in this study are collected during winter months, when the effect on the energy consumption of the window operation is the highest, at a Swedish residential building, the KTH Live-In Lab, accommodating four occupants in separate studio apartments. Although all the occupants seem to share a sensitivity to some common factors, such as air quality and time of the day, we can also observe individual variability with respect to the most significant drivers influencing window operation behaviors.
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| 10. |
- Fontan, Angela, 1991-, et al.
(författare)
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Social interactions for a sustainable lifestyle : The design of an experimental case study
- 2023
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Konferensbidrag (refereegranskat)abstract
- Every day we face numerous lifestyle decisions, some dictated by habits and somemore conscious, which may or may not promote sustainable living. Aided by digital technology,sustainable behaviors can diffuse within social groups and inclusive communities. This paperoutlines a longitudinal experimental study of social influence in behavioral changes towardsustainability, in the context of smart residential homes. Participants are students residing inthe housing on campus referred to as KTH Live-In Lab, whose behaviors will be observedw.r.t. key lifestyle choices, such as food, resources, mobility, consumption, and environmentalcitizenship. The focus is on the preparatory phase of the case study and the challengesand limitations encountered during its setup. In particular, this work proposes a definitionof sustainability indicators for environmentally significant behaviors, and hypothesizes that,through digitalization of a household into a social network of interacting tenants, sustainableliving can be promoted.
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