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Thinking- Skins: Cyber-physical systems as foundation for intelligent adaptive façades
Get PDFUnder the guiding concept of a thinking skin, the research project examines the transferability of cyber-physical systems to the application field of façades. It thereby opens up potential increases in the performance of automated and adaptive façade systems and provides a conceptual framework for further research and development of intelligent building envelopes in the current age of digital transformation.
The project is characterized by the influence of digital architectural design methods and the associated computational processing of information in the design process. The possible establishment of relationships and dependencies in an architecture understood as a system, in particular, are the starting point for the conducted investigation. With the available automation technologies, the possibility of movable building constructions, and existing computer-based control systems, the technical preconditions for the realisation of complex and active buildings exist today. Against this background, dynamic and responsive constructions that allow adaptations in the operation of the building are a current topic in architecture. In the application field of the building envelope, the need for such designs is evident, particularly with regards to the concrete field of adaptive façades. In its mediating role, the façade is confronted with the dynamic influences of the external microclimate of a building and the changing comfort demands of the indoor climate. The objective in the application of adaptive façades is to increase building efficiency by balancing dynamic influencing factors and requirements. Façade features are diverse and with the increasing integration of building services, both the scope of fulfilled façade functions and the complexity of today’s façades increase. One challenge is the coordination of adaptive functions to ensure effective reactions of the façade as a complete system. The ThinkingSkins research project identifies cyber-physical systems as a possible solution to this challenge. This involves the close integration of physical systems with their digital control. Important features are the decentralized organization of individual system constituents and their cooperation via an exchange of information. Developments in recent decades, such as the miniaturisation of computer technology and the availability of the Internet, have established the technical basis required for these developments. Cyber-physical systems are already employed in many fields of application. Examples are decentralized energy supply, or transportation systems with autonomous vehicles. The influence is particularly evident in the transformation of the industrial sector to Industry 4.0, where formerly mechatronic production plants are networked into intelligent technical systems with the aim of achieving higher and more flexible productivity.
In the ThinkingSkins research project it is assumed that the implementation of cyber-physical systems based on the role model of cooperating production plants in IIndustry 4.0 can contribute to an increase in the performance of façades. Accordingly, the research work investigates a possible transfer of cyber-physical systems to the application field of building envelopes along the research question:
How can cyber-physical systems be applied to façades, in order to enable coordinated adaptations of networked individual façade functions?
To answer this question, four partial studies are carried out, which build upon each other. The first study is based on a literature review, in which the understanding and the state-of-the-art development of intelligent façade systems is examined in comparison to the exemplary field of application of cyber-physical systems in the manufacturing industry. In the following partial study, a second literature search identifies façade functions that can be considered as components of a cyber-physical façade due to their adaptive feasibility and their effect on the façade performance. For the evaluation of the adaptive capabilities, characteristics of their automated and adaptive implementation are assigned to the identified façade functions. The resulting superposition matrix serves as an organizational tool for the third investigation of the actual conditions in construction practice. In a multiple case study, realized façade projects in Germany are examined with regard to their degree of automation and adaptivity. The investigation includes interviews with experts involved in the projects as well as field studies on site. Finally, an experimental examination of the technical feasibility of cyber-physical façade systems is carried out through the development of a prototype. In the sense of an internet of façade functions, the automated adaptive façade functions ventilation, sun protection as well as heating and cooling are implemented in decentrally organized modules. They are connected to a digital twin and can exchange data with each other via a communication protocol.
The research project shows that the application field of façades has not yet been exploited for the implementation of cyber-physical systems. With the automation technologies used in building practice, however, many technical preconditions for the development of cyber-physical façade systems already exist. Many features of such a system are successfully implemented within the study by the development of a prototype. The research project therefore comes to the conclusion that the application of cyber-physical systems to the façade is possible and offers a promising potential for the effective use of automation technologies. Due to the lack of artificial intelligence and machine learning strategies, the project does not achieve the goal of developing a façade in the sense of a true ThinkingSkin as the title indicates. A milestone is achieved by the close integration of the physical façade system with a decentralized and integrated control system. In this sense, the researched cyber-physical implementation of façades represents a conceptual framework for the realisation of corresponding systems in building practice, and a pioneer for further research of ThinkingSkins
Energy-Efficient Office Renovation: Developing design principles based on user-focused evaluation
Get PDFThis research aims to develop user-focused design principles for energy-efficient office renovations. The goal of this is to improve the quality and comfort of workspaces without compromising on energy-saving goals. Due to increasing sustainability requirements, new ways of working and changing office user preferences, there is a growing need for office renovations that not only deal with the energy performance and the replacement of building facilities, but also the occupants’ health and well-being. The renovation of office buildings can substantially reduce energy demand and improve building performance. For this reason, most studies regarding office renovations have focused on achieving better energy performance and indoor environmental quality. Also, several studies have investigated employee satisfaction in the work environment. However, the users are only considered after the buildings have been built and taken into use (e.g., postoccupancy evaluation), but not in the early stage of the design phase. Although there are building regulations and norms regarding indoor comfort, no clear design principles or guidelines considering users have been developed for office renovations. Therefore, it is necessary to explore how office users can be included in the early design stage of office renovations to improve their comfort and satisfaction. This led to the following main research question to be answered in this thesis:
How can design principles for energy efficient office renovation be developed, based on the evaluation of user satisfaction?
To answer to this question, field studies were conducted in 5 office buildings in the Netherlands. The cases consist of four renovated offices and one non-renovated office, originally built in 1960s to 70s. Before conducting empirical studies, a literature was conducted that is implemented in the theoretical framework. Ten parameters for satisfaction, such as thermal comfort, air quality, light, noise, personal control, privacy, concentration, communication, social contact, and territoriality, were defined and were classified based on the findings from 124 items of studies focussing on physical and psychological satisfaction in the work environment. Each chapter and several sub-research questions address these parameters. Based on the findings, a classification of user satisfaction parameters is proposed, including a discussion about an hierarchy of ten parameters. This hierarchy is structured based on theoretical definitions of parameters and its physical, functional, and psychological influences.
For the empirical studies, a multidisciplinary methodology was applied to prioritise the important aspects of office renovations. The various methods for data collection and analyses included examining energy use and the quality of indoor climate after renovation, and investigating the impact of design factors on user satisfaction with thermal, visual, and psychological comfort. The design factors in this research are influential design factors on user satisfaction. These are office layout, orientation, window-to-wall ratio, and desk location. The empirical studies are structured in four parts.
Energy consumption
As a preliminary study, architects and facility managers were interviewed to identify the building characteristics of renovated offices and energy consumption. Henceforth, the five case studies were conducted. A cross-case-analysis was used to compare the building characteristics of the five case studies. The energy consumption of renovated and non-renovated offices were compared by different energy matrix. In addition, the limitations that hinder the achievement of better energy performance, were described.
Indoor climate and users’ thermal comfort
Indoor temperature and humidity were measured by using data loggers to identify the condition of the indoor climate for users’ thermal comfort after renovation. A questionnaire, including thermal sensation, preference, and satisfaction, was distributed among the building users. The monitored climate data of the thermal conditions were evaluated based on the Dutch building norms and users’ responses.
Personal control
This part aims to identify the relationship between the degree of personal control over indoor environmental conditions (e.g., temperature, ventilation, light) and user satisfaction with thermal and visual comfort. This study investigated the impact of personal control on user satisfaction through user surveys and statistical analyses. The results present that higher controllability leads to more satisfaction in terms of thermal and visual comfort. It also reveals the psychological impact of personal control on user satisfaction by showing differences in perceived satisfaction according to ‘no control’ and ‘do not have’. These findings provide support to workplace management and the design of personal environmental control systems.
User satisfaction with thermal, visual, and psychological comfort
Together with the indoor climate conditions of workspaces, 579 office users from the five cases were studied. The responses of the users were collected and analysed through statistical analyses. This study phase demonstrates the results of the impact of influential office design factors on user satisfaction with thermal, visual, and psychological comfort. It also contributes to predicting which design variables may bring better user satisfaction.
After the empirical studies, the conceptual study was conducted through energy simulation to evaluate the impact of the combination of design factors on the energy demand. Twenty-four office model variants were created based on the combination of design factors, which are consisted of 3 or 4 variables. The energy demand is predicted according to the office model variants. As a next step, the design principles were developed by incorporating the previous findings and various perspectives of energy-efficient office renovation. An overview of the predicted user satisfaction and energy demand is graphically provided in this research.
Based hereupon, a flow chart is created for applying the principles to the renovation process. First, the most influential design factors on thermal, visual, and psychological satisfaction are suggested in the design principles. Next, the values of predicted user satisfaction and energy demand can be evaluated by following the flow chart, to find the optimal renovation plan. In this step renovation alternatives are suggested in terms of office variants to create a balance between user satisfaction and energy efficiency. Last, if design limitations occur, the degree of personal control should be included to increase user satisfaction. The comprehensive design principles can help architects, designers, and facility managers to make design decisions in an early stage of office renovations.
To summarise, this research demonstrates the relationship between design factors, indoor climate and user satisfaction, without neglecting the fundamental goal of office renovation: reducing the energy demand, upgrading facilities, and improving building performance. It also contributes to developing design principles for office renovations with integrated user perspectives, that improve users’ satisfaction and comfort, as well as energy efficiency. Although users’ individual control over the indoor environment has a significant impact on satisfaction, it needs to be explored further. In addition, it is important to mention that other variables such as building elements and various façade configurations need to be included in further research. In conclusion, design principles considering both energy efficiency and user satisfaction will not only contribute to an increase in the value of a building, but also serve as a stepping stone for user-focused office designs or user-related aspects of the built environment
Histoire Croisée: A Relational Process-based Approach
Get PDFGlobalization makes understanding worldmaking processes a crucial issue. During the Cold War the social sciences mainly addressed this issue through comparative studies which mirrored the logic of the world-historical confrontation. In this respect 1989 fostered not only a political turn but an epistemological one. The new political situation fueled the development of approaches dedicated to the study of relations and interdependencies between different parts of the world.
Like entangled, shared or connected histories, Histoire croisée takes a cross-border approach.Their common feature is shifting the analysis from comparative approaches centered on territorial entities to the relationships that flow through and the interactions which constitute them, as well as moving away from approaches solely focused on state relationships. Dedicated to the study of intersecting processes in various settings, Histoire croisée is driven by an empirical, methodological and epistemological shift that involves redefining the object of research.
 
Performance Gaps in Energy Consumption: Household Groups and Building Characteristics
Get PDFThe difference between actual and calculated energy is called the ‘energy performance gap’. Possible explanations for this gap are: construction mistakes, improper adjusting of equipment, excessive simplification in simulation models and, occupant behaviour. Many researchers and governmental institutions think this gap is mainly caused by the occupant. However, only limited evidence exists. Therefore, an analysis is presented of actual and theoretical energy consumption, based on specific household types and building characteristics. Using a large dataset (1.4 million social housing households), the average actual and theoretical energy consumption (gas and electricity) of different household types and characteristics (income level, type of income, number of occupants and their age) were compared for each energy label. Additionally, the 10% highest and lowest energy consuming groups were analysed. It is shown that taking combinations of occupant characteristics into account instead of individual occupant characteristics provides new insights in the influence of the occupant on residential energy consumption. For example: In contradiction to previous studies, low-income households consume more gas per m2 (space heating and hot water) than households with a high income for all types of housing. Furthermore, the performance gap is not only caused by the occupant, but also by the assumed building characteristics
Individually controlled noise reducing devices to improve IEQ in classrooms of primary schools
Get PDFIn recent decades, many indoor environmental quality (IEQ) related problems (such as noise, odour, overheating, glare…) in classrooms have been identified. The impact of IEQ in classrooms on school children has been thoroughly researched. Consequently, many studies have been carried out to attempt to improve the IEQ in classrooms. However, most of the IEQ-improvements were developed based on general requirements and ignored individual differences. No matter how advanced these improvements are, always some children keep being unsatisfied with the IEQ in their classrooms. Given the fact that different children have different IEQ perceptions, preferences, and needs, it makes more sense to control the IEQ in classrooms on the level of the individual rather than of the room. Only by doing this can the comfort, health, and ultimately performance of school children be improved. For this reason, this research explored the possibility of customizing IEQ in classrooms of primary schools in the Netherlands. This thesis addressed the following topics:
–Current ways of controlling IEQ in classrooms and their effect on school children’s IEQ perception;
– Individual preferences and needs of primary school children related to IEQ in classrooms;
– Impact of the main IEQ problem on school children’s perception and performance;
– Use of individually controlled devices to cope with the main IEQ problem in classrooms;
– Children’s feedback on an individually controlled noise-reducing device.
Several approaches were used to address these topics, including a field study, lab studies, computer simulations and a prototype study.
In the spring of 2017, the indoor environment group conducted the field study in 54 classrooms of 21 primary schools in the Netherlands. 54 teachers’ questionnaire and 1145 children’s questionnaire were collected and analysed. The results of the field study provided insight into the current ways to control IEQ in classrooms, as well as the preferences and needs of children with respect to IEQ in their classrooms.
Through a series of correlation analyses, the current ways to control IEQ, namely teachers’ IEQ-improving actions, were shown to be inefficient in improving children’s IEQ perceptions in classrooms, even though these actions were conducted based on children’s requests. Two possible explanations can be put forward. First, a teacher could only take one action to respond to one child at a time, therefore, another child’s request might have been ignored. Second, the options that teachers had to change the IEQ in classrooms were quite limited (for example, in most classrooms, opening windows was the only thing the teacher could do if children felt too hot in summer). It was, therefore, concluded that a more effective method to control the IEQ in classrooms is needed.
To create a good learning environment for school children, it is important to know their perceptions, preferences, and needs concerning IEQ in their classrooms. The analyses of the 1145 children’s responses showed that different children within the same classroom could have different IEQ perceptions, preferences, and needs. Based on their IEQ perceptions, preferences, and needs and with the use of a twostep cluster analysis method, the children were grouped into six clusters (‘Sound concerned’, ‘Smell and Sound concerned’, ‘Thermal and Draught concerned’, ‘Light concerned’, ‘All concerned’ and ‘Nothing concerned’), with each a different profile was established.
The analysis of the children’s responses also showed that 87% of the children were bothered by noise (mainly caused by themselves) in their classrooms. Therefore, noise was identified as the main problem in the classrooms studied. To get more insight in this main problem, a lab study was conducted in the spring of 2018 in which children were invited to participate in a listening task with different background sounds. The experiment was conducted in two chambers (acoustically treated chamber and untreated chamber) with different reverberation times (RTs) at the same time. Results of the two-way ANOVA analysis showed a significant interaction between the impact of sound type and sound pressure level (SPL) on children’s performance in the untreated chamber (RT = 0.3 s). Additionally, the t-test results showed that children performed significantly better in the untreated chamber than in the treated chamber (RT = 0.07 s). This indicated that a shorter RT is not always better, and it was recommended to also introduce a lower limit for the RT in classrooms to prevent over-damping.
After the establishment of the main IEQ problem, namely noise, the next step of this research was searching for an effective way to address this problem. Because the use of individually controlled devices in offices has shown to be able to improve both the IEQ and the workers’ satisfaction rates, it was assumed that these devices can have a similar effect on children in classrooms. To get a preliminary understanding of this assumption, a series of computer simulations was therefore conducted to test the effect of an individually controlled device on noise reduction. By comparing the simulation results of these individually controlled devices with the conventional ways to reduce noise (namely acoustic ceiling tiles), it was seen that the individually controlled devices have the ability to provide better acoustics in terms of providing shorter RTs and higher speech transmission indices.
Subsequently, a real individually controlled noise-reducing device (ICND) was prototyped and tested in a lab study during the summer and autumn vacation of 2019. This prototype was similar to the stimulated device. It looks like a large umbrella that hung above every child’s head. In this research, two identical prototypes were tested with more than 200 school children, whose feedback was collected through questionnaires. Children could control the device using a remote controller. The descriptive analysis of children’s answers indicated that most of them liked this device and wanted to have one in their classrooms. The content analysis elucidated the reasons for their choices: children liked this device mainly because of its appearance (they thought it looked funny/cool/nice), and they wanted to have it mainly because of its functionality (they thought it worked/helped/reduced noise). Additionally, the device’s noise reducing effect was confirmed by simulations and measurements. This study showed the potential of the ICND to create better acoustics for every school child, and resulted in clear recommendations to improve the prototype.
To sum up, this research showed that school children differ in their IEQ preferences and needs and, based on that, classified them into six clusters. It also indicated that teachers’ actions could not effectively improve IEQ in classrooms, which paves the way for the need for individual control of IEQ in classrooms of primary schools. Then, an ICND was designed and tested to address the main IEQ problem in classrooms, namely noise. The results obtained from the simulations, measurements, and children’s feedback on the prototype of the ICND, indicated the feasibility of such devices in classrooms at primary schools. More research in real classrooms, however, is needed
Mapping Landscape Spaces: Understanding, interpretation, and the use of spatial-visual landscape characteristics in landscape design
Get PDFLandscape design focuses on the construction and articulation of outdoor space and results in landscape architectonic compositions. In order to communicate about three-dimensional forms and functions, vocabulary, representations, and tools (in terms of spatial-visual characteristics) are of fundamental importance for landscape architects to describe, interpret, and manipulate landscape spaces. While combining design vocabulary and landscape indicators, qualitative and quantitative mapping approaches, visual representation and interpretation methods, this research aims to provide a framework for describing, understanding, and communicating about spatial-visual characteristics in landscape design. A pilot study is used to explore the potential of specific mapping approaches, such as compartment analysis, 3D landscapes, grid-cell analysis, landscape metrics, visibility analysis, and eye-tracking analysis, which are employed to address spatial-visual phenomena like sequence, orientation, continuity, and complexity. Hypothetical design experiments are conducted to evaluate the feasibility and effectiveness of spatial-visual mapping in the design process. Interviews with designers are carried out to reflect on techniques for mapping spatial-visual characteristics in the daily practice of landscape architecture. This research opens a way in which to apply visual landscape research in the process of landscape design and supports the development of multidisciplinary approaches. By expanding the spatial-visual mapping toolbox, designers can engage in issues of landscape development, transformation, and preservation while providing realistic and instrumental clues for interventions in urban landscapes
Visibility as a conceptual tool for the design and planning of democratic streets
No full textDemocratic public spaces are open spaces - such as streets, parks, playgrounds and marketplaces - which are accessible to all and allow different cultural expressions for individuals and groups. They can be characterized by their vivid and active public life. This paper focuses on the visual features of public spaces at street level and understanding visibility as the condition of seeing and being seen in public space. It analyses how visibility can be useful to assess and promote democratic public spaces. This paper considers the visibility of immigrant amenities, such as shops, restaurants and communal places with distinctive signs, languages, and spatial practices. Describing the main features of democratic public spaces and democratic streets, this paper explains how the concept of visibility is associated with observable features of democratic streets. It claims that visibility can be used as a tool to analyse the democratic character of public space. This suggests that planners and designers need to be aware of the usefulness of taking into account visibility issues to promote inclusive public spaces and cities
Supply chain management and management science: A successful marriage
Get PDFThe last century has witnessed extant studies on the applications of Management Science (MS) to a diverse set of Supply Chain Management (SCM) issues. This paper provides an overview of the contribution of MS within SCM. A framework is developed in this paper with a sampling of MS contributions to major SCM dimensions. Future research directions are presented
Erratum to: Annual climate impact and primary energy use of Swedish transport infrastructure
Get PDFIn the original version of this paper, some figures and units in Table 5 (in the main text) and Table A1, A2, A6, and A7 (in the Appendix) were found to be incorrect. The corrected tables are presented below. These changes only concern the presentation of data. They do not concern any of the calculations made; hence, they do not affect any of the results or conclusions in the paper.
(the original paper was published in volume 19(2))
 
A structural equations approach for modeling the endogeneity of lane-mean speeds considering the downstream speeds
Get PDFLike other transportation data, lane-mean speeds are also best modeled by a system of structural equations. Several studies omit the interrelation between adjacent lane speeds, which may produce biased and inconsistent results if models are solved by ordinary least squares. The uncorrelatedness of regressors and disturbances assumption of ordinary least squares is violated since one or more independent variables are endogenous in the system. This study attempts to propose a structural equations approach to model the lane-mean speeds in multi-lane traffic, in which the endogeneity of adjacent lane speeds and the downstream speeds are being considered. Additionally, the equations system can serve as a prediction model for lane-mean speeds. Several empirical analyses using the data collected from multi-lane freeways with different lengths and different numbers of lanes are conducted to observe the performance of the equations system in different conditions. The study further compares the prediction accuracy between the underlying approach and the model established by Shankar and Mannering (1998) for assessing the impact of introducing downstream speeds within the model. The findings show that more precise results are obtained generally after downstream speeds are included, emphasizing the improvements and superiority of this approach
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