Ambient hues and audible cues: An approach to automotive user interface design using multi-modal feedback

The use of touchscreen interfaces for in-vehicle information, entertainment, and for the control of comfort settings is proliferating. Moreover, using these interfaces requires the same visual and manual resources needed for safe driving. Guided by much of the prevalent research in the areas of the human visual system, attention, and multimodal redundancy the Hues and Cues design paradigm was developed to make touchscreen automotive user interfaces more suitable to use while driving. This paradigm was applied to a prototype of an automotive user interface and evaluated with respects to driver performance using the dual-task, Lane Change Test (LCT). Each level of the design paradigm was evaluated in light of possible gender differences. The results of the repeated measures experiment suggests that when compared to interfaces without both the Hues and the Cues paradigm applied, the Hues and Cues interface requires less mental effort to operate, is more usable, and is more preferred. However, the results differ in the degradation in driver performance with interfaces that only have visual feedback resulting in better task times and significant gender differences in the driving task with interfaces that only have auditory feedback. Overall, the results reported show that the presentation of multimodal feedback can be useful in design automotive interfaces, but must be flexible enough to account for individual differences

Studies in ambient intelligent lighting

The revolution in lighting we are arguably experiencing is led by technical developments in the area of solid state lighting technology. The improved lifetime, efficiency and environmentally friendly raw materials make LEDs the main contender for the light source of the future. The core of the change is, however, not in the basic technology, but in the way users interact with it and the way the quality of the produced effect on the environment is judged. With the new found freedom the users can switch their focus from the confines of the technology to the expression of their needs, regardless of the details of the lighting system. Identifying the user needs, creating an effective language to communicate them to the system, and translating them to control signals that fulfill them, as well as defining the means to measure the quality of the produced result are the topic of study of a new multidisciplinary area of study, Ambient Intelligent Lighting. This thesis describes a series of studies in the field of Ambient Intelligent Lighting, divided in two parts. The first part of the thesis demonstrates how, by adopting a user centric design philosophy, the traditional control paradigms can be superseded by novel, so-called effect driven controls. Chapter 3 describes an algorithm that, using statistical methods and image processing, generates a set of colors based on a term or set of terms. The algorithm uses Internet image search engines (Google Images, Flickr) to acquire a set of images that represent a term and subsequently extracts representative colors from the set. Additionally, an estimate of the quality of the extracted set of colors is computed. Based on the algorithm, a system that automatically enriches music with lyrics based images and lighting was built and is described. Chapter 4 proposes a novel effect driven control algorithm, enabling users easy, natural and system agnostic means to create a spatial light distribution. By using an emerging technology, visible light communication, and an intuitive effect definition, a real time interactive light design system was developed. Usability studies on a virtual prototype of the system demonstrated the perceived ease of use and increased efficiency of an effect driven approach. In chapter 5, using stochastic models, natural temporal light transitions are modeled and reproduced. Based on an example video of a natural light effect, a Markov model of the transitions between colors of a single light source representing the effect is learned. The model is a compact, easy to reproduce, and as the user studies show, recognizable representation of the original light effect. The second part of the thesis studies the perceived quality of one of the unique capabilities of LEDs, chromatic temporal transitions. Using psychophysical methods, existing spatial models of human color vision were found to be unsuitable for predicting the visibility of temporal artifacts caused by the digital controls. The chapters in this part demonstrate new perceptual effects and make the first steps towards building a temporal model of human color vision. In chapter 6 the perception of smoothness of digital light transitions is studied. The studies presented demonstrate the dependence of the visibility of digital steps in a temporal transition on the frequency of change, chromaticity, intensity and direction of change of the transition. Furthermore, a clear link between the visibility of digital steps and flicker visibility is demonstrated. Finally, a new, exponential law for the dependence of the threshold speed of smooth transitions on the changing frequency is hypothesized and proven in subsequent experiments. Chapter 7 studies the discrimination and preference of different color transitions between two colors. Due to memory effects, the discrimination threshold for complete transitions was shown to be larger than the discrimination threshold for two single colors. Two linear transitions in different color spaces were shown to be significantly preferred over a set of other, curved, transitions. Chapter 8 studies chromatic and achromatic flicker visibility in the periphery. A complex change of both the absolute visibility thresholds for different frequencies, as well as the critical flicker frequency is observed. Finally, an increase in the absolute visibility thresholds caused by an addition of a mental task in central vision is demonstrated

Remote Assessment of the Cardiovascular Function Using Camera-Based Photoplethysmography

Camera-based photoplethysmography (cbPPG) is a novel measurement technique that allows the continuous monitoring of vital signs by using common video cameras. In the last decade, the technology has attracted a lot of attention as it is easy to set up, operates remotely, and offers new diagnostic opportunities. Despite the growing interest, cbPPG is not completely established yet and is still primarily the object of research. There are a variety of reasons for this lack of development including that reliable and autonomous hardware setups are missing, that robust processing algorithms are needed, that application fields are still limited, and that it is not completely understood which physiological factors impact the captured signal. In this thesis, these issues will be addressed. A new and innovative measuring system for cbPPG was developed. In the course of three large studies conducted in clinical and non-clinical environments, the system’s great flexibility, autonomy, user-friendliness, and integrability could be successfully proven. Furthermore, it was investigated what value optical polarization filtration adds to cbPPG. The results show that a perpendicular filter setting can significantly enhance the signal quality. In addition, the performed analyses were used to draw conclusions about the origin of cbPPG signals: Blood volume changes are most likely the defining element for the signal's modulation. Besides the hardware-related topics, the software topic was addressed. A new method for the selection of regions of interest (ROIs) in cbPPG videos was developed. Choosing valid ROIs is one of the most important steps in the processing chain of cbPPG software. The new method has the advantage of being fully automated, more independent, and universally applicable. Moreover, it suppresses ballistocardiographic artifacts by utilizing a level-set-based approach. The suitability of the ROI selection method was demonstrated on a large and challenging data set. In the last part of the work, a potentially new application field for cbPPG was explored. It was investigated how cbPPG can be used to assess autonomic reactions of the nervous system at the cutaneous vasculature. The results show that changes in the vasomotor tone, i.e. vasodilation and vasoconstriction, reflect in the pulsation strength of cbPPG signals. These characteristics also shed more light on the origin problem. Similar to the polarization analyses, they support the classic blood volume theory. In conclusion, this thesis tackles relevant issues regarding the application of cbPPG. The proposed solutions pave the way for cbPPG to become an established and widely accepted technology

User-centered design of a dynamic-autonomy remote interaction concept for manipulation-capable robots to assist elderly people in the home

In this article, we describe the development of a human-robot interaction concept for service robots to assist elderly people in the home with physical tasks. Our approach is based on the insight that robots are not yet able to handle all tasks autonomously with sufficient reliability in the complex and heterogeneous environments of private homes. We therefore employ remote human operators to assist on tasks a robot cannot handle completely autonomously. Our development methodology was user-centric and iterative, with six user studies carried out at various stages involving a total of 241 participants. The concept is under implementation on the Care-O-bot 3 robotic platform. The main contributions of this article are (1) the results of a survey in form of a ranking of the demands of elderly people and informal caregivers for a range of 25 robot services, (2) the results of an ethnography investigating the suitability of emergency teleassistance and telemedical centers for incorporating robotic teleassistance, and (3) a user-validated human-robot interaction concept with three user roles and corresponding three user interfaces designed as a solution to the problem of engineering reliable service robots for home environments

Dark Mode Preferences: Exploring User Motivations in Interface Theme Selection

In a world that is increasingly digital, the interfaces through which we interact with our technology play a critical role in our daily experiences. One important aspect of interface design is theming, which allows users to personalize their visual interaction with software applications and websites. Theming itself is a varied concept, but it enables users to tailor their digital environments according to their preferences, thereby enhancing usability and user satisfaction. Among various theming options, ’Dark mode’ has risen to prominence as a notable design trend in recent years. The adoption of Dark mode by major software platforms and applications signifies its impact and growing relevance. However, the key factors that lead to its adoption are highly debated among end users. In addition, many websites and applications have yet to incorporate a Dark mode feature. For this reason, understanding what leads to these preferences has practical implications for web developers and designers as well. To better understand and evaluate the motivations behind users’ Dark mode theme selection, a survey was conducted. The survey employed a questionnaire where the questions were rooted in a set of background hypotheses that are believed to be influential in determining why users opt for Dark or Light mode. These background hypotheses were formed using the literature existing in the field. The results of the survey suggest that there is no single driver for Dark mode selection, rather, users might be weighing Dark mode’s visual appeal against functional benefits like reduced eye strain, focus, power savings, and select a theme based on these assumptions. A subset of users also tailor their own interfaces more than others, where the implications of application specificity rises to question. In addition, age also plays a factor in the selection, but only to a degree.Digitaalisessa vuorovaikutuksessa käyttöliittymät ovat keskiössä. Yksi tärkeä käyttöliittymäsuunnittelun näkökulma ovat teemat, joiden avulla käyttäjät voivat yksilöidä oman kokemuksensa sovelluksissa ja verkkosivustoilla. Teemojen käyttö on monipuolinen ilmiö, mutta viime kädessä ne sallivat käyttäjien mukauttaa digitaalista ympäristöään heidän mieltymystensä mukaisesti parantaen näin käytettävyyttä ja käyttäjätyytyväisyyttä. Yksi suosituimmista teemavaihtoehdoista on ’Tumma tila’ eli ’Dark Mode’. Se on noussut merkittäväksi trendiksi viime vuosina erityisesti suurten ohjelmistoyritysten ja suosittujen sovellusten vauhdittamana. Kuitenkin ne avaintekijät, jotka johtavat sen käyttöönottoon, ovat kiistanalaisia. Näistä tekijöistä myös käydään kiivaita keskusteluja loppukäyttäjien joukossa. Lisäksi monet verkkosivustot ja sovellukset eivät ole vielä sisällyttäneet Dark Mode -ominaisuutta alustalleen. Tästä syystä teemamieltymysten ymmärtäminen on tärkeää myös web-kehittäjille ja sovellusten suunnittelijoille. Käyttäjien teeman valintaperusteiden ymmärtämisen ja arvioinnin parantamiseksi suoritettiin kattava kyselytutkimus. Kyselyssä käytettiin kyselylomaketta, jonka kysymykset perustuivat taustaoletuksiin, joiden uskotaan vaikuttavan käyttäjien päätöksiin valita joko tumma tai vaalea teema. Nämä taustaoletukset muodostettiin olemassa olevan alan kirjallisuuden perusteella. Kyselytutkimuksen tulokset viittaavat siihen, että tumman teeman valintaan ei ole yksittäistä merkittävää tekijää. Sen sijaan käyttäjät saattavat punnita tumman teeman visuaalista viehätysvoimaa toiminnallisiin hyötyihin, kuten esimerkiksi silmien rasituksen vähentämiseen, keskittymiseen, virrankulutukseen ja valita näiden olettamusten perusteella oman teemansa. Osa käyttäjistä myös mukauttaa omia käyttöliittymiään enemmän kuin toiset, jolloin sovelluskohtaiset valinnat tulevat ilmi. Lisäksi ikä vaikuttaa valintaan, mutta ainoastaan tietyssä määrin