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  • 1.
    Alisic, Rijad
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Decision and Control Systems (Automatic Control).
    Molinari, Marco
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Pare, P. E.
    Sandberg, Henrik
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Decision and Control Systems (Automatic Control).
    Maximizing Privacy in MIMO Cyber-Physical Systems Using the Chapman-Robbins Bound2020In: Proceedings of the IEEE Conference on Decision and Control, Institute of Electrical and Electronics Engineers Inc. , 2020, p. 6272-6277Conference paper (Refereed)
    Abstract [en]

    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. 

  • 2.
    Alisic, Rijad
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Decision and Control Systems (Automatic Control). KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Molinari, Marco
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration. KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Decision and Control Systems (Automatic Control).
    Pare, Philip E.
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration. KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Decision and Control Systems (Automatic Control).
    Sandberg, Henrik
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration. KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Decision and Control Systems (Automatic Control).
    Ensuring privacy of occupancy changes in smart buildings2020In: CCTA 2020 - 4th IEEE Conference on Control Technology and Applications, Institute of Electrical and Electronics Engineers Inc. , 2020, p. 871-876Conference paper (Refereed)
    Abstract [en]

    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.

  • 3.
    Björk, Folke
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Technology.
    Kilkis, Siir
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Technology.
    Molinari, Marco
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Technology.
    Energy quality management and low energy architecture2012In: World Renewable Energy Forum, WREF 2012, Including World Renewable Energy Congress XII and Colorado Renewable Energy Society (CRES) Annual Conference, American Solar Energy Society , 2012, p. 4558-4564Conference paper (Refereed)
    Abstract [en]

    This paper puts forth energy quality management as the stepwise process of taking care of the quality of energy better. Energy quality can also be expressed as exergy, which measures the useful work potential of a given amount or flow of energy. Energy quality management is particularly useful to reduce the primary energy use in the built environment. This is achieved by reducing the heating and cooling demand, making use of passive building techniques, exploiting local renewable sources, and utilizing efficiently non-renewable energy. The application of the Rational Exergy Management Model further indicates how the integration of the building in the broader perspective of the community level is crucial to curb the building-related CO2 emissions. The paper concludes that exergy is a vital aspect for low energy and low CO2 emissions architecture.

  • 4.
    Björk, Folke
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Technology.
    Molinari, Marco
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Technology.
    Exergi - en kvalitetsfråga2009In: Bygg och Teknik, ISSN 0281-658X, E-ISSN 2002-8350, no 5, p. 17-20Article in journal (Other (popular science, discussion, etc.))
  • 5.
    Brown, Nils
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Environmental Strategies.
    Bai, Wei
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Environmental Strategies.
    Björk, Folke
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Technology.
    Malmqvist, Tove
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Environmental Strategies.
    Molinari, Marco
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Technology.
    Sustainability assessment of Renovation for Increased End-use Energy Efficiency for Multi-family Buildings in Sweden2011In: Proceedings of 6th World Sustainable Building Conference, SB11, 2011Conference paper (Refereed)
  • 6.
    Brown, Nils W. O.
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Environmental Strategies.
    Malmqvist, Tove
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Environmental Strategies.
    Bai, Wei
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Environmental Strategies.
    Molinari, Marco
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Technology.
    Sustainability assessment of renovation packages for increased energy efficiency for multi-family buildings in Sweden2012In: Building and Environment, ISSN 0360-1323, E-ISSN 1873-684X, Vol. 61, p. 140-148Article in journal (Refereed)
    Abstract [en]

    In this paper, we propose a method for assessing renovation packages drawn up with the goal of increasing energy efficiency. The method includes calculation of bought energy demand, life-cycle cost (LCC) analysis and assessment of the building according to the Swedish environmental rating tool Miljöbyggnad (MB). In this way the methodology assesses economic, indoor environmental quality (IEQ) and specifically environmental aspects associated with energy demand of such packages from a sustainability point-of-view. Through MB, energy efficiency packages are placed in context with other necessary measures required to improve environmental performance in buildings, providing a consistent and systematic basis other than simply financial performance by which to compare capital improvements. The method is further explained and analyzed by applying it in three case studies. In each case study a multi-family building representing a typologically significant class in the Swedish building stock is considered, and for each building a base case and two renovation packages with higher initial investment requirement and higher energy efficiency are defined. It is shown that higher efficiency packages can impact IEQ indicators both positively and negatively and that packages reducing energy demand by approx. 50% have somewhat higher LCC. Identified positive IEQ impacts point to added value for packages that may not otherwise be communicated, while negative impacts identify areas where packages need to be improved, or where MB indicators may be referred to as specifications in procurement procedures.

  • 7.
    Bäcklund, Katarina
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Lundqvist, Per
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Molinari, Marco
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Showcasing a Digital Twin for Higher Educational Buildings: Developing the Concept Towards Human Centricity2024In: Frontiers in Built Environment, E-ISSN 2297-3362, Vol. 10, article id 1347451Article in journal (Refereed)
    Abstract [en]

    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: 

  • 8.
    Bäcklund, Katarina
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Molinari, Marco
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Lundqvist, Per
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    In Search for Untapped Energy-Saving Potential in Green and Smart Higher Educational Buildings—An Empirical Case Study Involving the Building Occupants2023In: Buildings, E-ISSN 2075-5309, Vol. 13, no 12, article id 3103Article in journal (Refereed)
    Abstract [en]

    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.

  • 9.
    Bäcklund, Katarina
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology.
    Molinari, Marco
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Lundqvist, Per
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Karlsson, Peter
    Akademisk Hus AB.
    Showcasing the First Steps Towards a Digital Twin for Campus Environments2022In: 2022 BuildSim Nordic, 2022Conference paper (Refereed)
    Abstract [en]

    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.  

    Download full text (pdf)
    BSN20221010
  • 10.
    Bäcklund, Katarina
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Molinari, Marco
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Lundqvist, Per
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Palm, Björn
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Building Occupants, Their Behavior and the Resulting Impact on Energy Use in Campus Buildings: A Literature Review with Focus on Smart Building Systems2023In: Energies, E-ISSN 1996-1073, Vol. 16, no 17, p. 6104-6104Article in journal (Refereed)
    Abstract [en]

    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.

  • 11.
    Ebadat, Afrooz
    et al.
    KTH, School of Electrical Engineering (EES), Automatic Control.
    Bottegal, Giulio
    KTH, School of Electrical Engineering (EES), Automatic Control.
    Molinari, Marco
    KTH, School of Electrical Engineering (EES), Automatic Control.
    Varagnolo, Damiano
    Division of Signals and Systems, Department of Computer Science, Electrical and Space Engineering, Luleå University of Innovation and Technology.
    Wahlberg, Bo
    KTH, School of Electrical Engineering (EES), Automatic Control.
    Hjalmarsson, Håkan
    KTH, School of Electrical Engineering (EES), Automatic Control.
    Johansson, Karl Henrik
    KTH, School of Electrical Engineering (EES), Automatic Control. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Multi-room occupancy estimation through adaptive gray-box models2015In: Decision and Control (CDC), 2015 IEEE 54th Annual Conference on, IEEE conference proceedings, 2015, p. 3705-3711Conference paper (Other academic)
    Abstract [en]

    We consider the problem of estimating the occupancylevel in buildings using indirect information such as CO2 concentrations and ventilation levels. We assume that oneof the rooms is temporarily equipped with a device measuringthe occupancy. Using the collected data, we identify a gray-boxmodel whose parameters carry information about the structuralcharacteristics of the room. Exploiting the knowledge of thesame type of structural characteristics of the other rooms inthe building, we adjust the gray-box model to capture the CO2dynamics of the other rooms. Then the occupancy estimatorsare designed using a regularized deconvolution approach whichaims at estimating the occupancy pattern that best explainsthe observed CO2 dynamics. We evaluate the proposed schemethrough extensive simulation using a commercial software tool,IDA-ICE, for dynamic building simulation.

    Download full text (pdf)
    fulltext
  • 12.
    Farjadnia, Mahsa
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Alanwar, Amr
    Jacobs University Bremen, Bremen, Germany.
    Niazi, Muhammad Umar B.
    Laboratory for Information and Decision Systems, Massachusetts Institute of Technology, Cambridge, USA.
    Molinari, Marco
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Johansson, Karl H.
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Decision and Control Systems (Automatic Control).
    Robust Data-Driven Predictive Control of Unknown Nonlinear Systems Using Reachability Analysis2023Conference paper (Refereed)
    Abstract [en]

    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 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 through the effective use of 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.

  • 13.
    Farjadnia, Mahsa
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Alanwar, Amr
    Niazi, Muhammad Umar B.
    Molinari, Marco
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Johansson, Karl H.
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Decision and Control Systems (Automatic Control).
    Robust data-driven predictive control of unknown nonlinear systems using reachability analysis2023In: European Journal of Control, ISSN 09473580Article in journal (Refereed)
    Abstract [en]

    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.

  • 14.
    Farjadnia, Mahsa
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Fontan, Angela
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Decision and Control Systems (Automatic Control).
    Russo, Alessio
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Decision and Control Systems (Automatic Control).
    Johansson, Karl H.
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Decision and Control Systems (Automatic Control).
    Molinari, Marco
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    What influences occupants' behavior in residential buildings: An experimental study on window operation in the KTH Live-In Lab2023In: 2023 IEEE Conference on Control Technology and Applications, CCTA 2023, 2023, p. 752-758Conference paper (Refereed)
    Abstract [en]

     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. 

  • 15.
    Fontan, Angela
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Decision and Control Systems (Automatic Control).
    Farjadnia, Mahsa
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration. KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Decision and Control Systems (Automatic Control).
    Llewellyn, Joseph
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Strategic Sustainability Studies.
    Katzeff, Cecilia
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Strategic Sustainability Studies.
    Molinari, Marco
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Cvetkovic, Vladimir
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Resources, Energy and Infrastructure.
    Johansson, Karl H.
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Decision and Control Systems (Automatic Control).
    Social interactions for a sustainable lifestyle: The design of an experimental case study2023Conference paper (Refereed)
    Abstract [en]

    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.

  • 16.
    Gullström, Charlie
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Architecture.
    Kordas, Olga
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering.
    Molinari, Marco
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology.
    Sharing Spaces in the Sharing Economy - to save energy, increasewell-being or boost inn vation? How do new initiatives align with energy transition?2017In: BIWAES - Biennial International Workshop Advances in Energy Studies, Graz, 2017Conference paper (Other academic)
    Abstract [en]

    Our paper is informed by the recent interest in how the sharing economy and related initiatives mayact as drivers for energy transition and increase well-being and social sustainability in smart sustainable city contexts. We take the example of temporary buildings that for a limited time period offer shared public spaces for public events in the city. Such initiatives are often linked to quadruple helix initiatives in which a local city council, industry and academia join forces to engage citizens in the energy and climate debate, with a temporary building structure as the focal point. The paper argues that such energy initiatives are valuable in terms of social sustainability since they create additional public space for the benefit of citizen debate; contribute scalable solutions and effective infrastructure that can promote energy awareness among citizens. However, there is limited scientific evidence, and a lacking awareness, of the energy efficiency and climate comfort relating to temporary buildings for public use. Our preliminary results show that such factors risk to obscure the well-intended objectives of quadruple helix initiatives to support energy transition. The revealed problems of a Stockholm use case suggest that in spite of significant social and economic impact resulting from curated public events which attracted an unprecedented number of visitors, energy consumption, climate comfort and indoor air quality are nevertheless important factors that also must be considered in the design and implementation of temporary building structures. The paper concludes that better climate controlshared economy thinking is necessary at theearliest stage of a planning process, for temporary buildings to be successful.

  • 17. Holm, Cyril
    et al.
    Anund Vogel, Jonas
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Molinari, Marco
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    GDPR och Smarta Byggnader - En undersökning av teknik, individ och samhälle i framtidens smarta byggnader2019Report (Other academic)
    Abstract [sv]

    Denna rapports huvudfokus är att undersöka balansen, beskriven ovan, utifrån det rättsliga ramverk som GDPR utgör, samt att ge vägledning för hur kommersiella fastighetsägare rent praktiskt kan arbeta med smarta byggnader. Den pågående trenden att genom sensorer och hantering av data påverka byggnaders resursanvändning och möjligheten till ökad tjänsteleverans kommer med all sannolikhet att fortsätta och öka. Digitaliseringen av samhällsbyggnadssektorn är enbart i sin linda och vinsterna på individ, företags och samhällsnivå, dels ekonomiskt och miljömässigt, bedöms som mycket stora. För att möjliggöra potentialen av digitaliseringen, en minimering av klimatpåverkan kopplat till drift av byggnader, och samtidigt värna om individens integritet måste framtida byggnaders system för insamling och hantering av data designas varsamt. För att möjliggöra optimering av en byggnads tekniska system, samt en minimering av klimatpåverkan kopplat till drift av byggnaden, kan en fastighetsägare behöva samla in och lagra information som faller inom ramen för GDPR. För att säkerställa att fastighetsägaren följer GDPR beskrivet ovan bör följande rutiner och åtgärder genomföras.

    • Rättslig strategi
    • Minimera uppgifter som går att koppla till fysisk person
    • Hur kan man optimera med aggregerade uppgifter som inte kopplas till person
    • Problematisera samtycken, resultatet av det är en rättslig osäker het som leder till att använda anonyma data. Det är inte kopplingen till person som är intressant, utan optimeringen.
    • Problematisera anonymisering, hur gör man rent tekniskt eller sam man utgå ifrån att det är en praktisk variant av anonymisering som gäller eftersom GDPR förslår det?

    I den här rapporten vill vi visa hur man kan göra det enkelt att följa GDPR, och enkelt att bygga kommersiella smarta hus i relation till GDPR. Vårt förslag innehåller följande punkter som vi sedan utvecklar nedan.

    Data:

    • Minimera lagring av data och maximera momentant utnyttjande av sensordata
    • Höj och förfina optimeringsgraden Minimera uppgifter som går att koppla till fysisk person Pseudonymisera data som måste lagras

    Organisation:

    • Ha tydlig organisation och ansvarsfördelning runt hanteringen av data och personuppgifter i relation till GDPR.
    • Alltid ha en aktuell lista på sensorer.
    • Använd opt-out5GDPR OCH SMARTA BYGGNADER.
    • Utarbeta genomarbetade skriftliga samtycken. 
    Download full text (pdf)
    fulltext
  • 18.
    Jóhannesson, Gudni
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering.
    Molinari, Marco
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering.
    Exergy analysis of single and multistep thermal processes2011Conference paper (Refereed)
    Abstract [en]

    The present paper introduces the concepts of exergy and treats it applications to analysis of the gain in exergy efficiency between one step and multi-step thermal processes. The analysis, which is carried out with the Excel based SEPE program, is exemplified with the comparison between single step and two-steps heat pump setup for providing heat to a heat floor system and a domestic hot water. The paper discusses the use of the concept of exergy efficiency as a measure of success for design of a heat pump application and how the use of information on exergy destruction and temperature levels in different parts of the system add a new perspective to the analysis and the evaluation of the system performance. The paper shows how this information can be used to improve the system configuration and also the operation of the system for given boundary conditions. This is especially useful when the energy from the low temperature sources is can be utilized at different temperature or quality levels such as for space heating and domestic hot water.

  • 19. Jóhannesson, Gudni
    et al.
    Molinari, Marco
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Technology.
    Exergy Analysis of Single and Multi-Step Thermal Processes2012In: Journal of Civil Engineering and Architecture, ISSN 1934-7359, Vol. 6, no 10, p. 1384-1391Article in journal (Refereed)
    Abstract [en]

    The present paper introduces the concepts of exergy and treats it applications to analysis of the gain in exergy efficiency between one-step and multi-step thermal processes. The analysis, which is carried out with the Excel-based SEPE program, is exemplified with the comparison between single-step and two-steps heat pump setup for providing heat to a floor heating system and for domestic hot water. The paper discusses the use of the concept of exergy efficiency as a measure of success for design of a heat pump application and how the use of information on exergy destruction and temperature levels in different parts of the system add a new perspective to the analysis and the evaluation of the system performance. The paper shows how this information can be used to improve the system configuration and also the operation of the system for given boundary conditions. This is especially useful when the energy from the low temperature sources can be utilized at different temperature or quality levels such as for space heating and domestic hot water.

  • 20.
    Karvonen, Andrew
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering.
    Cvetkovic, Vladimir
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Resources, Energy and Infrastructure.
    Herman, Pawel
    KTH, School of Electrical Engineering and Computer Science (EECS), Computer Science, Computational Science and Technology (CST).
    Johansson, Karl H.
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Decision and Control Systems (Automatic Control).
    Kjellström, Hedvig
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Robotics, Perception and Learning, RPL.
    Molinari, Marco
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Skoglund, Mikael
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Information Science and Engineering.
    The ‘New Urban Science’: towards the interdisciplinary and transdisciplinary pursuit of sustainable transformations2021In: Urban Transformations, E-ISSN 2524-8162, Vol. 3, no 1Article in journal (Refereed)
    Abstract [en]

    Digitalisation is an increasingly important driver of urban development. The ‘New Urban Science’ is one particular approach to urban digitalisation that promises new ways of knowing and managing cities more effectively. Proponents of the New Urban Science emphasise urban data analytics and modelling as a means to develop novel insights on how cities function. However, there are multiple opportunities to broaden and deepen these practices through collaborations between the natural and social sciences as well as with public authorities, private companies, and civil society. In this article, we summarise the history and critiques of urban science and then call for a New Urban Science that embraces interdisciplinary and transdisciplinary approaches to scientific knowledge production and application. We argue that such an expanded version of the New Urban Science can be used to develop urban transformative capacity and achieve ecologically resilient, economically prosperous, and socially robust cities of the twenty-first century.

  • 21.
    Molinari, Marco
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering.
    A pressure and thermal exergy analysis of a waterborne and an airborne system2009In: Proceedings of the 15th International Conference on Building Services, Mechanical and Building Industry Days, 2009, p. 73-80Conference paper (Refereed)
    Abstract [en]

    The exergetic performances of two different heating systems, a full air system with a gas boiler and a floor heating with a heat pump, have been analyzed from the generation to the emission system. Exergy thermal and pressure losses have been evaluated to illustrate which potential exists for improving the energy use. Simulations have been performed by means of SEPE, a steady state tool that makes use of the iterative cycles in Excel.

  • 22.
    Molinari, Marco
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering.
    Energy management in buildings: matching supply and demand by means of exergyManuscript (preprint) (Other academic)
  • 23.
    Molinari, Marco
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering.
    Exergy Analysis in Buildings: A complementary approach to energy analysis2009Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    Though mandatory to be pursued, improved energy efficiency is not the only target to reach. The quality of energy has to be assessed as well. Most of the overall energy use in residential building is for low temperature heat, i.e. temperatures relatively close to the outdoor conditions. From a thermodynamic point of view, this is a degraded form of energy with low potential to be converted into work. On the other hand energy demand is mostly met with high quality energy, such as electricity and natural gas. There is a mismatch between supply and demand, which is not clearly shown by the sole energy analysis. Target of this thesis is to analyze the energy use in buildings from the point of view of its quality, to provide effective theoretical and calculation tools to investigate this mismatch, to assess its magnitudo and to propose improvements aiming at a more rational use of the energy. The idea behind the quality is clarified with the concept of exergy.

    The potential for improvement in space heating is shown. In no heating system the overall exergy efficiency is above 20%, with fossil fuels. Using direct electricity heating results in exergy efficiency below 7%. Most of the household appliances processes have low-exergy factors but still are supplied with electricity. This results in poor exergy efficiencies and large exergy losses.

    Systems are poorly performing because little consideration is explicitly given to energy quality. Policies to lower the energy demand, though vital as first step towards an improved use of energy, should not neglect the exergy content.

    The problem is then shifted to find suitable supplies. Electricity can be exploited with low exergy losses with high-COP heat pumps. Use of fossil fuels for heating purposes should be avoided. District heating from cogeneration and geothermal proves to be a suitable solution at the building level. The issues connected to its exploitation forces to shift the boundary layers of the analysis from the building level to the community level. A rational use of energy should address the community level. The system boundaries have to be enlarged to a dimension where both the energy conversion and use take place with reduced energy transportation losses. This is a cost-effective way to avoid the waste of the exergy potential of the sources with exergy cascade and to make it possible the integration of with renewable sources. Exergy efficiency of the buildings is a prerequisite for a better of energy in this field.

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  • 24.
    Molinari, Marco
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Technology.
    Exergy and Parametric Analysis: Methods and Concepts for a Sustainable Built Environment2012Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Energy use in the world is continuously increasing. In the last 30 years the use of primary energy worldwide has more than doubled and it is mainly supplied with fossil fuels. A more efficient use of energy in the built environment has to be pursued if a more sustainable development is to be attained.

    The housing sector accounts for a major share of the energy use. Both in residential and commercial buildings, energy is mainly used for heating. Heat is energy with low quality. Traditional energy analysis methods, by failing to consider the energy quality, cannot give a holistic insight of the potential for reducing the energy used in the built environment. Exergy, instead, provides a tool to quantify the energy quality based on thermodynamic grounds.

    In this thesis a methodology based on both the reduction of the energy demand and exergy demand in buildings is proposed to mitigate the problems related to the energy use in buildings through a reduced and more efficient use of energy.

    The complex relations between building parameters to reduce the energy demand are managed with parametric analysis tools. The potential for energy demand reduction is investigated by means of screening analyses, local sensitivity analyses and global methods. A method for assessing the potential reduction of the energy demand in existing buildings and to evaluate the cost-efficiency of renovation measures based on the screening analysis is introduced and tested on two building typologies. In parallel, a program tool for parametric energy simulations, Consolis Parametric, has been developed on the core of an existing dynamic software, Consolis Energy +.

    Factorial analysis has been used to investigate the relations between the reduction of the energy demand and of the energy supply when ground source heat pumps are used for heating and cooling. Optimal configurations- dependent on the insulation of the building- of number of boreholes and spacing were identified for minimum electricity consumption.

    In the second part of this thesis exergy is used as tool for the definition of the efficient energy use in the built environment. The analysis of a multi-step heat pump to supply energy at two temperature levels, for space heating and domestic hot water production, exemplified how the reduction of the exergy loss can lead to a more efficient use of energy. The analysis was performed by means of SEPE, a modular software program developed in this work for exergy analysis in buildings.

    For the systematic reduction of the exergy losses in the built environment, an important prerequisite is the reduction of the exergy required by the building. Systems like floor heating and cooling, based on low difference emission temperature, are examples of low-exergy systems. Buildings with reduced need of exergy input increase the efficiency of systems like heat pumps and enhance the use of low quality energy, like waste heat and energy from low temperature renewable sources.

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  • 25.
    Molinari, Marco
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering.
    Exergy efficient space heating systems: analysis of different solutionsManuscript (preprint) (Other academic)
  • 26.
    Molinari, Marco
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering.
    SEPE: an Excel calculation tool for exergy-based optimizations2009In: Annex 49 Newsletter, Vol. September, no 6, p. 3-3Article in journal (Other academic)
    Abstract [en]

    SEPE is an acronym that stands for Software for Exergy Performance Evaluation developed at KTH, the Royal Institute for Technology, in Stockholm: it is an excel-based software that utilizes the iteration features of Excel to perform steady-state exergy evaluations and optimization of different cooling and heating systems.

  • 27.
    Molinari, Marco
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration. Digital futures KTH.
    Anund Vogel, Jonas
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Rolando, Davide
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration. Digital futures KTH.
    Using Living Labs to tackle innovation bottlenecks: the KTH Live-In Lab case study2021In: Technology Innovation to Accelerate Energy Transitions, 2021Conference paper (Refereed)
    Abstract [en]

    The adoption of innovation in the buildingsector is currently too low for the ambitious sustainability goals that our societies have agreed upon. The concept of smart building, for instance, is being implemented too slowly. One of the main reasons for this is that technologies have to be proven effective and reliable before being introduced at large scale in buildings. Testbeds and demonstrators are seen as a crucial infrastructure to test and demonstrate the impact of solutions in the building sector and hence facilitate their adoption in buildings. The KTHLive-In Lab is a platform of building testbeds designed to this scope. This work describes the Live-In Lab vision,approach, technical features,provides an overview on the multidisciplinary projects that it has enabled and discusses its replicability.

    Download full text (pdf)
    Using Living Labs to tackle innovation bottlenecks: the KTH Live-In Lab case study
  • 28.
    Molinari, Marco
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Anund Vogel, Jonas
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Rolando, Davide
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Lundqvist, Per
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Using living labs to tackle innovation bottlenecks: the KTH Live-In Lab case study2023In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 338, p. 120877-120877, article id 120877Article in journal (Refereed)
    Abstract [en]

    The adoption of innovation in the building sector is currently too slow for the ambitious sustainability goals thatour societies have agreed upon. Living labs are open innovation ecosystems in real-life environments usingiterative feedback processes throughout a lifecycle approach of an innovation to create sustainable impact. In thecontext of the built environment, such co-creative innovation and demonstration platforms are needed tofacilitate the adoption of innovative technologies and concepts for more energy-efficient and sustainablebuildings. However, their feasibility is not extensively proven. This paper illustrates the implementation anddemonstrates the feasibility of the Living Labs Triangle Framework for buildings living labs. This conceptualframework has been used to conceive the KTH Live-In Lab, a living lab for buildings. The goal of the Live-In Labwas to create a co-creative open platform for research and education bridging the gap between industry andacademia, featuring smart building demonstrators. The Living Lab Triangle Framework has been deployed tomeet the goals of the Live-in Lab, and the resulting concept is described. This paper then analyses the meth-odological and operational results introducing performance metrics to measure the economic sustainability, thepromotion of multidisciplinary research and development projects, dissemination and impact. The results arecompleted with a SWOT analysis identifying its current strengths and weaknesses. The results collected in thiswork fill a missing gap in the scientific literature on the performance of living labs and provide empirical evi-dence on the sustainability and impact of living labs.

  • 29.
    Molinari, Marco
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering.
    Broström, T.
    Exergy analysis of different solutions for humidity control in heritage buildings2011Conference paper (Refereed)
    Abstract [en]

    Energy use in the building stock represents a major contribution to the total energy use in developed countries. Increasing limitations to the energy demand of the new buildings have been imposed by the building codes in the last decades, which resulted in improved building envelopes.

    Yet, in many cases it is not either technically or economically feasible to improve the existing building shells. A typical example is represented by historical buildings, such churches and old buildings, which often may not be improved for aesthetical or economic reasons. Often poorly insulated, such buildings would require a high energy demand to keep them at the preferable hygro-thermal conditions. As a consequence they are often left unheated, which also affects the usability of these buildings. However, the risk of moisture damage often requires them to be slightly heated to a certain temperature.

    As the energy demand is linked to the possibility of improving the building shell, the exergy approach gives interesting insights on the problem. Exergy analysis emphasizes the thermodynamic valuable part of the energy demand in the building and straightforwardly defines the minimum energy demand for a certain process. The energy demand being equal, it is still possible to lower the exergy demand and consumption. A lower exergy demand paves the way to the exploitation of renewable sources, such as solar power.

    Often the main task is to keep the RH humidity within a certain range. Aim of this paper is to perform a theoretical exergy analysis of three different solutions for lowering the RH in the building. The basic approach keeps the temperature of the indoor space at a constant level. A second approach-the so-called conservation heating- consists in letting the temperature vary according to the maximum allowed indoor relative humidity. In the third case the target is reached by means of a dehumidification process. Advantages and disadvantages of the different approaches are shown under the energy and exergy points of view.

    The present research is done within the framework of the "Spara och bevara" project, which targets cost-efficient solutions for the conservation and the use of heritage buildings in Sweden and the IEA Annex49 and ESF COSTexergy projects, which aim at energy-efficient buildings and communities through the application of the low-exergy approach.

  • 30.
    Molinari, Marco
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Technology.
    Gudmundsson, Kjartan
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Technology.
    An Application of the Screening Analysis to Rank the Potential for the Reduction of the Energy Demand in RenovationArticle in journal (Other academic)
  • 31.
    Molinari, Marco
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Technology.
    Jóhannesson, Gudni
    Exergy As A Decision Tool For The Choice Of Heating And Cooling Emission Systems2011In: Proceedings of the 2nd International Exergy, Life Cycle Assessment, and Sustainability Workshop & Symposium (ELCAS2), 2011Conference paper (Other academic)
    Abstract [en]

    Buildings have low exergy demand compared to their energy demand. In spite of this,heating and cooling are mostly supplied with high quality energy sources, resulting inhigh thermodynamic losses. Heat pumps give an example how this potential can bebetter exploited, since their energy performance is dependent on the exergy demandof the building. The energy performance of heat pumps is highly dependent onemission temperature in the building and source temperature in the environment.Given certain environmental conditions, the exergy optimization of the emissionsystems has a direct consequence on the performance of the HPs, and hence on theelectricity consumed. In residential buildings, waterborne systems such as floorheating/cooling have large emission surfaces and allow lower input temperatures.However, a certain amount of fresh air has to be supplied for hygienic reasons, whichmight make airborne systems advantageous. In the present paper an exergy analysisof a waterborne and a hollow-core slab emission system is performed to show underwhat conditions each system has the lowest exergy demand. The analysis is based onthe results from SEPE, a specific tool for exergy analysis. It is believed that theresults indicate rational building solutions to the designers

  • 32.
    Molinari, Marco
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering.
    Jóhannesson, Gudni A
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering.
    An Exergetic Analysis and Potential for Improving the Rational Energy Use in Dwellings2008In: Proceedings of the 8th Symposium on Building Physics in the Nordic Countries / [ed] C. Rode, Danish Society of Engineers, IDA , 2008, p. 613-620Conference paper (Refereed)
    Abstract [en]

    The quality of a certain amount of energy is defined as the relative exergy content of this energy. Most of our buildings with their heating and cooling systems today are built for conversion of high quality energy sources to low quality use with destruction of the available exergy as a result. Globally we have a huge potential for transforming our processes to more efficient use of the exergy and also for feeding our processes directly from renewable energy sources without the use of high quality energy sources. Exergy analysis is also important as an innovation driver in buildings and building systems. This work is carried out within the frame of IEA Annex 49 Low Exergy Systems for High-Performance Buildings and Communities. The scope of the annex is to improve, on a community and building level, the design of energy use strategies, taking into account the different qualities of energy sources, from generation and distribution to consumption within in the built environment. In particular, this is carried our by the method of exergy analyses to provide assessment of the thermodynamic features of any process and to achieve a clear, quantitative indication of both the irreversibilities and potential for matchmaking between the resources used and the end-use energy flows. The paper contains a systematic survey of the exergy consuming processes for building and building appliances, their role in exergy balance, the level of energy quality needed in primary process and the potential for developing processes towards improved exergy efficiency. The work presented here gives a listing of the important processes in buildings with a discussion of their nature from an exergy point of view. The methodology for analysis is exemplified for a limited number of processes, dealing with the energy use and exergy destruction in processes, the potential for exergy  saving and the discussion on the technical and economical feasibility.

  • 33.
    Molinari, Marco
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering.
    Karlström, Petra
    Exergy analysis of cooling systems and strategies2011In: NSB 2011 - 9th Nordic Symposium on Building Physics, 2011, p. 1153-1160Conference paper (Refereed)
    Abstract [en]

    Energy use in the building stock represents a major share of the total energy use in developed countries. Ventilation and cooling of buildings constitute a constantly increasing part of the total energy use in buildings. One of the reasons for the increase of the energy use is increasing user demands. In combination with increasing ambient air temperatures, cooling of buildings will become a necessity. To minimise costs and energy demand, available cooling solutions must be optimised and innovative approaches encouraged.

    The growing awareness of climate change in combination with rising prices on fossil fuels have boosted the demand for energy efficient and even plus-energy buildings. By minimising the losses of energy used for conditioning the indoor environment, heating and cooling systems with a low temperature difference to the room can be used. Floor heating or cooling are common examples. Using distribution of heating and cooling at temperatures close to the room temperature opens the possibility to utilise low quality energy sources, for instance cooling with ambient heat sinks or heating with waste energy.

    Exergy analysis is a powerful tool for allocating the most relevant energy losses and suggesting technical solutions for improving cooling and heating systems. Aim of this paper is to illustrate the methodological issues with exergy analysis and to show what potential exists for improving the cooling systems by means of the exergy analysis.

    A program for exergy performance assessment has been developed for analyzing cooling systems. Different cooling systems have been analyzed from the generation to the heat emission system to the room environment. The analyzed systems comprise a chiller with high temperature lift, a hybrid cooling tower and floor cooling, a chiller with low temperature lift, hybrid cooling tower and floor cooling and a chiller with high temperature lift, hybrid cooling and air cooling. The results from simulations illustrate that the overall exergy efficiency of such systems is low and can be further improved by a more rational energy management.

  • 34.
    Molinari, Marco
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology.
    Kordas, Olga
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Resources, Energy and Infrastructure.
    ICT in the built environment: drivers, barriers and uncertainties2017In: Biennial International Workshop Advances in Energy Studies: BIWAES, Graz, 2017Conference paper (Other academic)
    Abstract [en]

    Buildings are major contributors to energy use and environmental impact in developed societies. If theambitious sustainability targets of modern societies are to be met, energy use in the built environmentmust be addressed as a central issue.New momentum on achieving energy efficiency in the building sector has been triggered by informationand communication technology (ICT). New opportunities bringing the concept of smart building closerto reality are offered e.g. by innovative sensing techniques, extensive and cost-efficient data collectionand analysis, advanced controls and artificial intelligence.However, these opportunities are associated with cost and uncertainties regarding whether theinvestment costs are paid back in terms of energy savings, whether indoor comfort and air quality andimproved, the drawbacks in term of increased maintenance effort, complexity, reliability and resilience,the effects in terms of user interaction, how data security is affected and the long-term effects on society.This paper critically analyses recent research findings and reviews the pros and cons of some promisingICT techniques being applied in the building sector. It exemplifies drivers and barriers to implementationof advanced controls and artificial intelligence in buildings, based on findings from two test-beds inStockholm, and discusses the implications of these findings for future research.

  • 35.
    Molinari, Marco
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Technology.
    Lazzarotto, Alberto
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Technology.
    Dynamic exergy analysis of ground-coupled heat pumps for residential buildings2011Conference paper (Refereed)
    Abstract [en]

    Buildings have lower exergy demand than their energy demand. Heat pumps can exploit this potential. Their COP greatly increases for a reduced temperature difference between evaporator and condenser. Given a low-temperature heating emission system, the performance of the heat pumps can be maintained high throughout the year, even in cold climates, if a ground storage system or a ground heat source is present. The interactions between building, heat pump, circulation pumps and source systems are complex. The performance of ground-coupled heat pumps is commonly measured in terms of COP, but the mere energy analysis might be misleading in finding potential for further optimization. Instead, the concept of exergy has been chosen since it yields the thermodynamic value of its associated energy flow.

    In this paper exergy has been applied to practical study cases, involving ground-coupled heat pumps, to give a better understanding on such systems and explore the potential for improving them. Dynamic simulations of the buildings have been done with IDA and the storage has been modeled by means of MATLAB.

  • 36.
    Molinari, Marco
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Technology.
    Lazzarotto, Alberto
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Technology.
    Björk, Folke
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Technology.
    The application of the parametric analysis for improved energy design of a ground source heat pump for residential buildings2013In: Energy and Buildings, ISSN 0378-7788, E-ISSN 1872-6178, Vol. 63, p. 119-128Article in journal (Refereed)
    Abstract [en]

    Energy use in buildings represents a major share of the overall energy used in developed countries. The reduction of the energy demand and the efficient energy use are often seen as feasible ways for a more sustainable energy use in the built environment. Ground source heat pumps (GSHPs) are efficient systems to supply heating and cooling energy to buildings but their design is critical for their performance. Furthermore, their performance depends on the cooling and heating demand and on the environmental conditions. The need for the end-use energy for a building supplied with GSHP has been studied with regard to four parameters in two different locations. The effect of two building performance parameters, roof and external walls insulation, and of two parameters affecting the performance of GSHP, boreholes spacing and number of boreholes, have been investigated by means of factorial analysis. Results show that from an energy point of view the optimal configurations of the boreholes change depending on the variation of building parameters such as insulation. The methodology proposed allows to quantify the impact of different design configurations on the need for end-use energy.

  • 37.
    Molinari, Marco
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Rolando, Davide
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Digital twin of the Live-In Lab Testbed KTH: development and calibration2020In: BuildSIM-Nordic 2020 / [ed] Laurent Georges, Matthias Haase, Vojislav Novakovic and Peter G. Schild, Oslo: sintef akademisk forlag, 2020Conference paper (Refereed)
    Abstract [en]

    In the last decade, the development of Information and Communication Technology (ICT) has enabled unprecedented possibilities to tackle worldwide ambitious sustainability targets. Demonstration facilities like the KTH Live-In Lab are fundamental for the adoption of ICT solutions for energy efficiency and sustainability in buildings. The Live-In Lab monitoring infrastructure enables the creation of a digital-twin, which facilitates a cost effective development, testing and implementation of advanced control and fault detection strategies.The paper proposes a calibration methodology for the thermal model (energy and comfort) of the Live-In Lab, developed in IDA-ICE, to be deployed as a digital twin. The methodology first screens the parameters with most impact on energy use and then calibrates the model minimizing the error in both indoor comfort and energy use with a weighting parameter β. Calibration results are then validated against the measured data.The results of this paper will be instrumental to the improvement of control systems and it will facilitate the study of behavioral aspects of the energy use.

  • 38. Müller, A.
    et al.
    Kranzl, L.
    Tuominen, P.
    Boelman, E.
    Molinari, Marco
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Technology.
    Entrop, A.G.
    Estimating exergy prices for energy carriers in heating systems: Country analyses of exergy substitution with capital expenditures2011In: Energy and Buildings, ISSN 0378-7788, E-ISSN 1872-6178, Vol. 43, no 12, p. 3609-3617Article in journal (Refereed)
    Abstract [en]

    Exergy represents the ability of an energy carrier to perform work and can be seen as a core indicator for measuring its quality. In this article we postulate that energy prices reflect the exergy content of the underlying energy carrier and that capital expenditures can substitute for exergy to some degree. We draw our line of argumentation from cost and technology data for heating systems of four European countries: Austria, Finland, The Netherlands, and Sweden. Firstly, this paper shows that the overall consumer costs for different heating options, widely installed in those countries, are in the same range. In this analysis we derived an overall standard deviation of about 8%. Secondly, additional analysis demonstrates that the share of capital costs on total heating cost increases with lower exergy input. Based on the data used in this analysis, we conclude that for the case of modern cost effective heating systems the substitution rate between exergy and capital is in the vicinity of 2/3. This means that by reducing the average specific exergy input of the applied energy carriers by one unit, the share of capital costs on the total costs increases by 2/3 of a unit.

  • 39. Parisio, A.
    et al.
    Molinari, Marco
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Varagnolo, D.
    Johansson, Karl H.
    KTH, School of Electrical Engineering (EES), Automatic Control. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Energy management systems for intelligent buildings in smart grids2018In: Intelligent Building Control Systems: A Survey of Modern Building Control and Sensing Strategies, Springer, 2018, no 9783319684611, p. 253-291Chapter in book (Refereed)
    Abstract [en]

    The next-generation electric grid needs to be smart and sustainable to simultaneously deal with the ever-growing global energy demand and achieve environmental goals. In this context, the role of residential and commercial buildings is crucial, due to their large share of primary energy usage worldwide. In this chapter, we describe energy management frameworks for buildings in a smart grid scenario. An Energy Management System (EMS) is responsible for optimally scheduling end-user smart appliances, heating systems, ventilation units, and local generation devices. We discuss the performance and the practical implementation of novel stochastic MPC schemes for HVAC systems, and illustrate how these schemes take into account several sources of uncertainties, e.g., occupancy and weather conditions. Furthermore, we show how to integrate local generation capabilities and storage systems into a holistic building energy management framework.

  • 40.
    Parisio, Alessandra
    et al.
    KTH, School of Electrical Engineering (EES), Automatic Control. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Fabietti, Luca
    KTH, School of Electrical Engineering (EES), Automatic Control. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Varagnolo, Damiano
    Technical University of Luleå, Sweden.
    Molinari, Marco
    KTH, School of Electrical Engineering (EES), Automatic Control. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Johansson, Karl Henrik
    KTH, School of Electrical Engineering (EES), Automatic Control. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Control of HVAC systems via scenario-based explicit MPC2014In: 2014 IEEE 53rd Annual Conference on Decision and Control (CDC), Institute of Electrical and Electronics Engineers (IEEE), 2014, p. 5201-5207, article id 7040202Conference paper (Refereed)
    Abstract [en]

    Improving energy efficiency of Heating, Ventilation and Air Conditioning (HVAC) systems is a primary objective for the society. Model Predictive Control (MPC) techniques for HVAC systems have recently received particular attention, since they can naturally account for several factors, such as weather and occupancy forecasts, comfort ranges and actuation constraints. Developing effective MPC based control strategies for HVAC systems is nontrivial, since buildings dynamics are nonlinear and affected by various uncertainties. Further, the complexity of the MPC problem and the burden of on-line computations can lead to difficulties in integrating this scheme into a building management system.

  • 41.
    Parisio, Alessandra
    et al.
    KTH, School of Electrical Engineering (EES), Automatic Control. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Molinari, Marco
    KTH, School of Electrical Engineering (EES), Automatic Control. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Varagnolo, Damiano
    KTH, School of Electrical Engineering (EES), Automatic Control. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Johansson, Karl Henrik
    KTH, School of Electrical Engineering (EES), Automatic Control. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    A Scenario-based Predictive Control Approach to Building HVAC Management Systems2013In: IEEE International Conference on Automation Science and Engineering, 2013, p. -435Conference paper (Refereed)
    Abstract [en]

    We present a Stochastic Model Predictive Control (SMPC) algorithm that maintains predefined comfort levels in building Heating, Ventilation and Air Conditioning (HVAC) systems while minimizing the overall energy use. The strategy uses the knowledge of the statistics of the building occupancy and ambient conditions forecasts errors and determines the optimal control inputs by solving a scenario-based stochastic optimization problem. Peculiarities of this strategy are that it does not make assumptions on the distribution of the uncertain variables, and that it allows dynamical learning of these statistics from true data through the use of copulas, i.e., opportune probabilistic description of random vectors. The scheme, investigated on a prototypical student laboratory, shows good performance and computational tractability.

  • 42.
    Parisio, Alessandra
    et al.
    KTH, School of Electrical Engineering (EES), Automatic Control.
    Varagnolo, Damianno
    Technical University of Luleå.
    Molinari, Marco
    KTH, School of Electrical Engineering (EES), Automatic Control.
    Pattarello, Giorgio
    KTH, School of Electrical Engineering (EES), Automatic Control.
    Fabietti, Luca
    University of Padova.
    Johansson, Karl Henrik
    KTH, School of Electrical Engineering (EES), Automatic Control.
    Implementation of a Scenario-based MPC for HVAC Systems: an Experimental Case Study2014In: Proceedings of the 19th IFAC World Congress, 2014, Elsevier BV , 2014, Vol. 47, p. 599-605Conference paper (Refereed)
    Abstract [en]

    Heating, Ventilation and Air Conditioning (HVAC) systems play a fundamental role in maintaining acceptable thermal comfort and air quality levels. Model Predictive Control (MPC) techniques are known to bring significant energy savings potential. Developing effective MPC-based control strategies for HVAC systems is nontrivial since buildings dynamics are nonlinear and influenced by various uncertainties. This complicates the use of MPC techniques in practice. We propose to address this issue by designing a stochastic MPC strategy that dynamically learns the statistics of the building occupancy patterns and weather conditions. The main advantage of this method is the absence of a-priori assumptions on the distributions of the uncertain variables, and that it can be applied to any type of building. We investigate the practical implementation of the proposed MPC controller on a student laboratory, showing its effectiveness and computational tractability.

  • 43.
    Parisio, Alessandra
    et al.
    KTH, School of Electrical Engineering (EES), Automatic Control. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Varagnolo, Damiano
    KTH, School of Electrical Engineering (EES), Automatic Control. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Risberg, Daniel
    KTH, School of Electrical Engineering (EES), Automatic Control. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Pattarello, Giorgio
    KTH, School of Electrical Engineering (EES), Automatic Control. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Molinari, Marco
    KTH, School of Electrical Engineering (EES), Automatic Control. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Johansson, Karl Henrik
    KTH, School of Electrical Engineering (EES), Automatic Control. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Randomized Model Predictive Control for HVAC Systems2013In: BuildSys'13 Proceedings of the 5th ACM Workshop on Embedded Systems For Energy-Efficient Buildings, 2013Conference paper (Refereed)
    Abstract [en]

    Heating, Ventilation and Air Conditioning (HVAC) systems play a fundamental role in maintaining acceptable thermal comfort and Indoor Air Quality (IAQ) levels, essentials for occupants well-being. Since performing this task implies high energy requirements, there is a need for improving the energetic efficiency of existing buildings. A possible solution is to develop effective control strategies for HVAC systems, but this is complicated by the inherent uncertainty of the to-be-controlled system. To cope with this problem, we design a stochastic Model Predictive Control (MPC) strategy that dynamically learns the statistics of the building occupancy and weather conditions and uses them to build probabilistic constraints on the indoor temperature and CO2 concentration levels. More specifically, we propose a randomization technique that finds suboptimal solutions to the generally non-convex stochastic MPC problem. The main advantage of this method is the absence of apriori assumptions on the distributions of the uncertain variables, and that it can be applied to any type of building. We investigate the proposed approach by means of numerical simulations and real tests on a student laboratory, and show its practical effectiveness and computational tractability.

  • 44.
    Pourghazian, Hanif
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Technology.
    Molinari, Marco
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Technology.
    Energy efficient design of buildings: building envelope performance and thermal stability2008In: Journal of Building Physics, ISSN 1744-2591, E-ISSN 1744-2583Article in journal (Other academic)
  • 45.
    Risuleo, Riccardo Sven
    et al.
    KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Molinari, Marco
    KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Bottegal, Giulio
    KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Hjalmarsson, Håkan
    KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Johansson, Karl H.
    KTH, School of Electrical Engineering (EES), Automatic Control.
    A benchmark for data-based office modeling: challenges related to CO2 dynamics2015In: IFAC-PapersOnLine / [ed] IFAC, IFAC Papers Online, 2015, Vol. 48, p. 1256-1261Conference paper (Refereed)
    Abstract [en]

    This paper describes a benchmark consisting of a set of synthetic measurements relative to an office environment simulated with the software IDA-ICE. The simulated environment reproduces a laboratory at the KTH-EES Smart Building, equipped with a building management system. The data set contains measurement records collected over a period of several days. The signals correspond to CO2 concentration, mechanical ventilation airows, air infiltrations and occupancy. Information on door and window opening is also available. This benchmark is intended for testing data-based modeling techniques. The ultimate goal is the development of models to improve the forecast and control of environmental variables. Among the numerous challenges related to this framework, we focus on the problem of occupancy estimation using information on CO2 concentration, which we treat as a blind identification problem. For benchmarking purposes, we present two different identification approaches: a baseline overparameterization method and a kernel-based method.

  • 46.
    Rolando, Davide
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Mazzotti, Willem
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Molinari, Marco
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Long-Term Evaluation of Comfort, Indoor Air Quality and Energy Performance in Buildings: The Case of the KTH Live-In Lab Testbeds2022In: Energies, E-ISSN 1996-1073, ISSN 1996-1073, Vol. 15, no 14, p. 4955-Article in journal (Refereed)
    Abstract [en]

    Digitalization offers new, unprecedented possibilities to increase the energy efficiencyand improve the indoor conditions in buildings in a cost-efficient way. Smart buildings are seen bymany stakeholders as the way forward. Smart buildings feature advanced monitoring and controlsystems that allow a better control of the buildings’ indoor spaces, but it is becoming evident that themassive amount of data produced in smart buildings is rarely used. This work presents a long-termevaluation of a smart building testbed for one year; the building features state-of-the-art monitoringcapability and local energy generation (PV). The analysis shows room for improving energy efficiencyand indoor comfort due to non-optimal control settings; for instance, average indoor temperaturesin all winter months were above 24 ◦C. The analysis of electricity and domestic hot water use hasshown a relevant spread in average use, with single users consuming approximately four times morethan the average users. The combination of CO2 and temperature sensor was sufficient to pinpointthe anomalous operation of windows in wintertime, which has an impact on energy use for spaceheating. Although the quantification of the impact of users on the overall energy performance ofthe building was beyond the scope of this paper, this study showcases that modern commercialmonitoring systems for buildings have the potential to identify anomalies. The evidence collectedin the paper suggests that this data could be used to promote energy-efficient behaviors amongbuilding occupants and shows that cost-effective actions could be carried out if data generated by themonitoring and control systems were used more extensively.

  • 47.
    Rolando, Davide
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration. Live-In Lab.
    Molinari, Marco
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration. Live-In Lab.
    Development of a comfort platform for user feedback: the experience of the KTH Live-In Lab2020In: Proceedings of 12th International Conference on Applied Energy, Part 3, 2020 (ICAE2020), Thailand/Virtual, 2020, Vol. 11, article id 385Conference paper (Refereed)
    Abstract [en]

    This paper presents the comfort platform created within a research project carried out at KTH Live-In Lab in Stockholm, Sweden. The KTH Live-In Lab is a platform of buildings to test and promote innovation into the built environment. The Live-In Lab includes several buildings with state-of-the-art and expandable sensor infrastructure.The comfort platform has been created to manage user feedbacks in buildings. The comfort platform includes a user-friendly web application and a cost efficient sensor device that allow to exchange feedbacks with the building users.The comfort platform is proposed as a possible solution to bridge the gap between modern smart buildings and existing buildings with limited sensor capability.This paper describes the comfort platform and the environment where it has been tested. The paper also summarizes the preliminary findings and the potential large-scale implementation.

  • 48.
    Russo, Alessio
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Decision and Control Systems (Automatic Control).
    Molinari, Marco
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Proutiere, Alexandre
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Decision and Control Systems (Automatic Control).
    Data-Driven Control and Data-Poisoning attacks in Buildings: the KTH Live-In Lab case study2021In: 2021 29th Mediterranean Conference on Control and Automation (MED), Institute of Electrical and Electronics Engineers (IEEE) , 2021, p. 53-58, article id 9480238Conference paper (Refereed)
    Abstract [en]

    This work investigates the feasibility of using input-output data-driven control techniques for building control and their susceptibility to data-poisoning techniques. The analysis is performed on a digital replica of the KTH Live- in Lab, a non-linear validated model representing one of the KTH Live-in Lab building testbeds. This work is motivated by recent trends showing a surge of interest in using data- based techniques to control cyber-physical systems. We also analyze the susceptibility of these controllers to data poisoning methods, a particular type of machine learning threat geared towards finding imperceptible attacks that can undermine the performance of the system under consideration. We consider the Virtual Reference Feedback Tuning (VRFT), a popular data- driven control technique, and show its performance on the KTH Live-In Lab digital replica. We then demonstrate how poisoning attacks can be crafted and illustrate the impact of such attacks. Numerical experiments reveal the feasibility of using data-driven control methods for finding efficient control laws. However, a subtle change in the datasets can significantly deteriorate the performance of VRFT.

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  • 49.
    Walther, Karl
    et al.
    University of Wuppertal, Wuppertal, Germany.
    Molinari, Marco
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Voss, Karsten
    University of Wuppertal, Wuppertal, Germany.
    The role of HVAC controls in building Digital Twins: lessons learned from demonstration buildings with an application to air handling units2023In: BS 2023 - Proceedings of Building Simulation 2023: 18th Conference of IBPSA, International Building Performance Simulation Association , 2023, p. 2005-2012Conference paper (Refereed)
    Abstract [en]

    This study investigates how information about the controls of heating, ventilation and air-conditioning (HVAC) systems can be gathered from building automation systems for the creation of Digital Twins in Building Performance Simulation (BPS). The concept of Digital Twins in BPS environments is commonly used for Fault Detection and Diagnosis or performance gap analysis during operation. In the creation, often emphasis is put on building physics or user behavior. In modern buildings, automation systems play an important role to guarantee user comfort requirements as well as an energy efficient operation. To replicate the behavior of real HVAC systems in Building Performance Simulations, the underlying control logic has to be known. To gather this information in operation we have investigated three sources: firstly, documentation from the design phase including already existing simulation models, secondly, the control code on automation systems and thirdly, reverse engineering from measured data. The study focuses on air handling units and is based on experiences in state-of-the-art building demonstrators from research projects in Sweden and Germany.

  • 50.
    Wei, Jieqiang
    et al.
    KTH, School of Electrical Engineering (EES), Automatic Control. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Wu, Junfeng
    KTH, School of Electrical Engineering (EES), Automatic Control. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Molinari, Marco
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Cvetkovic, Vladimir
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Resources, Energy and Infrastructure.
    Johansson, Karl Henrik
    KTH, School of Electrical Engineering (EES), Automatic Control. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    On the modeling of neural cognition for social network applications2017In: 2017 IEEE Conference on Control Technology and Applications (CCTA), Institute of Electrical and Electronics Engineers (IEEE), 2017Conference paper (Refereed)
    Abstract [en]

    In this paper, we study neural cognition in social network. A stochastic model is introduced and shown to incorporate two well-known models in Pavlovian conditioning and social networks as special case, namely Rescorla-Wagner model and Friedkin-Johnsen model. The interpretation and comparison of these model are discussed. We consider two cases when the disturbance is independent identically distributed for all time and when the distribution of the random variable evolves according to a Markov chain. We show that the systems for both cases are mean square stable and the expectation of the states converges to consensus.

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