Albeit the widespread application of recommender systems (RecSys) in our daily lives, rather limited research has been done on quantifying unfairness and biases present in such systems. Prior work largely focuses on determining whether a RecSys is discriminating or not but does not compute the amount of bias present in these systems. Biased recommendations may lead to decisions that can potentially have adverse effects on individuals, sensitive user groups, and society. Hence, it is important to quantify these biases for fair and safe commercial applications of these systems. This paper focuses on quantifying popularity bias that stems directly from the output of RecSys models, leading to over recommendation of popular items that are likely to be misaligned with user preferences. Four metrics to quantify popularity bias in RescSys over time in dynamic setting across different sensitive user groups have been proposed. These metrics have been demonstrated for four collaborative filteri ng based RecSys algorithms trained on two commonly used benchmark datasets in the literature. Results obtained show that the metrics proposed provide a comprehensive understanding of growing disparities in treatment between sensitive groups over time when used conjointly.
DOCUMENT
Usually the whole is the sum of its parts (added linearly): someone is happy and travelling, so happy travelling. Someone walks across a motionless and stable bridge and thus moves forward. But when hundreds of people walk together, the bridge may start to wobble quite suddenly. Both systems - the pedestrian and the bridge - are coupled into one new pattern, in which the whole is more than the sum of its parts. Such discontinuous shifts can be observed everywhere: in horses, the shift from walk to trot to canter (3 patterns); from ice to water to steam. Psychological measures - IQ, emotional stability, planning skills are marginal at best. It is argued that our behaviour is often determined by such dynamic systems.
MULTIFILE
Long-term care facilities are currently installing dynamic lighting systems with the aim to improve the well-being and behaviour of residents with dementia. The aim of this study was to investigate the implementation of dynamic lighting systems from the perspective of stakeholders and the performance of the technology. Therefore, a questionnaire survey was conducted with the management and care professionals of six care facilities. Moreover, light measurements were conducted in order to describe the exposure of residents to lighting. The results showed that the main reason for purchasing dynamic lighting systems lied in the assumption that the well-being and day/night rhythmicity of residents could be improved. The majority of care professionals were not aware of the reasons why dynamic lighting systems were installed. Despite positive subjective ratings of the dynamic lighting systems, no data were collected by the organizations to evaluate the effectiveness of the lighting. Although the care professionals stated that they did not see any large positive effects of the dynamic lighting systems on the residents and their own work situation, the majority appreciated the dynamic lighting systems more than the old situation. The light values measured in the care facilities did not exceed the minimum threshold values reported in the literature. Therefore, it seems illogical that the dynamic lighting systems installed in the researched care facilities will have any positive health effects.
DOCUMENT
Physical rehabilitation programs revolve around the repetitive execution of exercises since it has been proven to lead to better rehabilitation results. Although beginning the motor (re)learning process early is paramount to obtain good recovery outcomes, patients do not normally see/experience any short-term improvement, which has a toll on their motivation. Therefore, patients find it difficult to stay engaged in seemingly mundane exercises, not only in terms of adhering to the rehabilitation program, but also in terms of proper execution of the movements. One way in which this motivation problem has been tackled is to employ games in the rehabilitation process. These games are designed to reward patients for performing the exercises correctly or regularly. The rewards can take many forms, for instance providing an experience that is engaging (fun), one that is aesthetically pleasing (appealing visual and aural feedback), or one that employs gamification elements such as points, badges, or achievements. However, even though some of these serious game systems are designed together with physiotherapists and with the patients’ needs in mind, many of them end up not being used consistently during physical rehabilitation past the first few sessions (i.e. novelty effect). Thus, in this project, we aim to 1) Identify, by means of literature reviews, focus groups, and interviews with the involved stakeholders, why this is happening, 2) Develop a set of guidelines for the successful deployment of serious games for rehabilitation, and 3) Develop an initial implementation process and ideas for potential serious games. In a follow-up application, we intend to build on this knowledge and apply it in the design of a (set of) serious game for rehabilitation to be deployed at one of the partners centers and conduct a longitudinal evaluation to measure the success of the application of the deployment guidelines.
Climate change is one of the most critical global challenges nowadays. Increasing atmospheric CO2 concentration brought by anthropogenic emissions has been recognized as the primary driver of global warming. Therefore, currently, there is a strong demand within the chemical and chemical technology industry for systems that can covert, capture and reuse/recover CO2. Few examples can be seen in the literature: Hamelers et al (2013) presented systems that can use CO2 aqueous solutions to produce energy using electrochemical cells with porous electrodes; Legrand et al (2018) has proven that CDI can be used to capture CO2 without solvents; Shu et al (2020) have used electrochemical systems to desorb (recover) CO2 from an alkaline absorbent with low energy demand. Even though many efforts have been done, there is still demand for efficient and market-ready systems, especially related to solvent-free CO2 capturing systems. This project intends to assess a relatively efficient technology, with low-energy costs which can change the CO2 capturing market. This technology is called whorlpipe. The whorlpipe, developed by Viktor Schauberger, has shown already promising results in reducing the energy and CO2 emissions for water pumping. Recently, studies conducted by Wetsus and NHL Stenden (under submission), in combination with different companies (also members in this proposal) have shown that vortices like systems, like the Schauberger funnel, and thus “whorlpipe”, can be fluid dynamically represented using Taylor-Couette flows. This means that such systems have a strong tendency to form vortices like fluid-patterns close to their air-water interface. Such flow system drastically increase advection. Combined with their higher area to volume ratio, which increases diffusion, these systems can greatly enhance gas capturing (in liquids), and are, thus, a unique opportunity for CO2 uptake from the air, i.e. competing with systems like conventional scrubbers or bubble-based aeration.
Wat is de mogelijke rol van lokale duurzame energiesystemen en –initiatieven in de overgang naar een duurzame samenleving? En hoe kunnen op lokale toepassing gerichte innovaties worden ontwikkeld en toegepast op een zodanige manier dat deze bij lokale systemen en initiatieven aansluiten?Deze vragen staan centraal in dit onderzoeksproject dat zich richt op innovaties die rekening houden met een grotere rol van burgers bij een duurzame energievoorziening. Het project behelst echter meer dan het verrichten van onderzoek. Het beoogt bouwstenen te leveren voor een duurzame samenleving waarin meer ruimte is voor lokale (burger)initiatieven. We stellen drie deelprojecten voor:1. een vergelijkende studie naar energiecoöperaties en vergelijkbare innovatieve initiatieven, binnen en buiten Nederland, in heden en verleden. Daarbij hopen we lering te kunnen trekken uit de succesvolle ervaringen in Denemarken en Oostenrijk en van innovaties door coöperatiesen collectieven in het verleden.2. een analyse van energie-innovaties die beogen aan te sluiten bij lokale energiesystemen. Concreet zal het onderzoek zich richten op speciale batterijen, ontwikkeld dor het bedrijf Dr.Ten, en een soort slimme grote zoneboiler, ontwikkeld door het gelijknamige bedrijf Ecovat.3. De ontwikkeling van drie scenario’s, gebaseerd op inzichten uit studies 1 en 2. De scenario’s zullen bijvoorbeeld inhoudelijk verschillen in de mate waarin deze geïntegreerd zijn in bestaande energiesystemen. Deze zullen worden ontwikkeld en besproken met relevante stakeholders.Het onderzoek moet leiden tot een nauwkeurig overzicht van de mate van interesse en betrokkenheid van stakeholders en van de beperkingen en mogelijkheden van lokale energiesystemen en daarbij betrokken technologie. Ook leidt het tot een routemap voor duurzame energiesystemen op lokaal niveau. Het project heeft een technisch aspect, onderzoek naar verfijning en ontwikkeling van de technologie en een sociaal en normatief aspect, studies naar aansluitingsmogelijkheden bij de wensen en mogelijkheden van burgers, instanties en bedrijven in Noord-Nederland. Bovenal is het integratief en ontwerpend van karakter.This research proposal will explore new socio- technical configurations of local community-based sustainable energy systems. Energy collectives successfully combine technological and societal innovations, developing new business and organization models. A better understanding of their dynamics and needs will contribute to their continued success and thereby contribute to fulfilling the Top Sector’s Agenda. This work will also enhance the knowledge position of the Netherlands on this topic. Currently, over 500 local energy collectives are active in The Netherlands, many of them aim to produce their own sustainable energy, with thousands more in Europe. These collectives search for a new more local-based ways of organizing a sustainable society, including more direct democratic decision-making and influence on local living environment. The development of the collectives is enabled by openings in policy but –evenly important - by innovations in local energy production technologies (solar panels, windmills, biogas installations). Their future role in the sustainable energy transition can be strengthened by careful aligning new organizational and technological innovations in local energy production, storage and smart micro-grids.