Sebastian Babilon

Verified

Sebastian verified their affiliation via an institutional email.

Learn more

Verified

Sebastian verified their affiliation via an institutional email.

Learn more

• Dr.-Ing.
• PostDoc Position at Technical University of Darmstadt

Provoking high user acceptance in lighting can be a very challenging task and demands suitable tools for properly modelling and predicting the users’ perception of the lit environment. Recently, a new model formalism based on the perceptually relevant attributes of perceived brightness, visual clarity, and color preference has been introduced and s...

Featured Application Accurate practical measurements of the circadian effectiveness of daylight and artificial light sources using RGB color sensors for future human-centered lighting control. Abstract The three main tasks of modern lighting design are to support the visual performance, satisfy color emotion (color quality), and promote positive n...

Cortisol secretion has a fundamental role in human circadian regulation. The cortisol awakening response (CAR) can be observed as a daily recurring sharp increase in cortisol concentration within the first hour after awakening and is influenced by environmental light conditions. The current work provides the study protocol for an ongoing research p...

This paper explores human observer preferences for various sky-like interior lighting scenarios realized by a combination of a blue-enriched indirect uplight component with a correlated color temperature (CCT) of 6,500 K up to 30,000 K and a 4,000 K or 5,500 K direct downlight component. Variations in the natural sky were mimicked by the indirect u...

Lighting is not only a key mediator for the perception of the architectural space but also plays a crucial role regarding the long-term well-being of its human occupants. Future lighting solutions must therefore be capable of monitoring lighting parameters to allow for a dynamic compensation of temporal changes from the optimal or intended conditio...

This study explores a novel approach to monitor the spectral emission of LEDs by estimating the spectral power distribution from the spectral sensor responses during an accelerated ageing experiment. Two methods for reconstructing the actual LED spectra from sensor responses are presented and tested, one solely requires sensor datasheet information...

Multi-channel LED luminaires are fundamental components of smart-lighting systems for a dynamical adjustment of the room and ambient light conditions. The lighting preference of an individual user can vary due to the variations of the environment and the physiological and psychological state of the user. Modeling these dynamic preferences and ranki...

Vertical farming is considered to play a crucial role in future food supply. Until today, the high amount of electrical energy required for artificial lighting has been problematic in this context. Various possibilities for increasing efficiency through adapted lighting conditions have been and are being investigated. However, comparably little att...

The purpose of this work is to determine as a function of velocity the minimal roadway luminance that is required to be judged as being bright enough for a driver to perform a nighttime driving task with an adequate feeling of safety. In this context, it shall also be evaluated which areas of the vehicle forefield are most crucial for the driver’s...

Residents of nursing homes often have a very limited access to natural daylight, which is the main environmental cue for circadian entrainment that usually cannot be compensated by standard indoor lighting. For the development of adequate modernization strategies with regard to a more human-centred lighting approach, reliable field measurements of...

LICHT - Fachzeitschrift für Lichttechnik und Lichtplanung, Ausgabe 8/2021, pp. 62–70: Die richtige Beleuchtung spielt in Büroumgebungen eine immer größere Rolle. Welche Auswirkungen räumlich variable, ungleichmäßige Lichtverteilungen auf die Beleuchtungspräferenzen des Menschen bei der Erfüllung bestimmter Aufgaben haben, während die übrige Raumlic...

Featured Application Selection of most diverse light spectra from a larger set of possible candidates to be used in subject studies or for machine learning to find correlations between photometric and other parameters such as psychological, physiological, or preference-based outcome measures. Abstract Current subject studies and data-driven approa...

Die Optimierung human-zentrierter Beleuchtungssysteme darf nicht ausschließlich unter biodynamischen Aspekten stattfinden, sondern es müssen dabei auch emotionale und visuelle Gesichtspunkte berücksichtigt werden, um, insbesondere im Kontext der Büroinnenraumbeleuchtung, ein zu jederzeit konzentriertes und effizientes Arbeiten zu ermöglichen. Um de...

Light Emitting Diodes are an integral part of modern illumination systems. While their long-term stability in terms of lumen maintenance used to be in the focus leading to drastically increased nominal lifetimes over the past decade, the color shift or respectively chromaticity shift is lately attracting more and more attention especially in lighti...

Featured Application In-field spatially resolved light measurements for the characterization of non-visual effects and proper prediction of the circadian effectiveness for human-centric lighting design. Abstract As one factor among others, circadian effectiveness depends on the spatial light distribution of the prevalent lighting conditions. In a...

Due to their potential use as an internal reference, memory colors may provide an excellent approach for the color rendition evaluation of white light sources in terms of predicting visual appreciation. Because of certain limitations in the design of existing memory-related color quality measures, a new metric based on the outcome of a series of re...

The Sternberg task is a widely used tool for assessing the working memory performance in vision and cognitive science. It is possible to apply a visual or auditory variant of the Sternberg task to query the memory load. However, previous studies have shown that the subjects’ corresponding reaction times differ dependent on the used variant. In this...

Intelligent systems for interior lighting strive to balance economical, ecological, and health-related needs. For this purpose, they rely on sensors to assess and respond to the current room conditions. With an augmented demand for more dedicated control, the number of sensors used in parallel increases considerably. In this context, the present wo...

Cortisol secretion has a fundamental role in human circadian regulation. The cortisol awakening response (CAR) can be observed as a daily recurring sharp increase in cortisol concentration within the first hour after awakening and is influenced by environmental light conditions. However, so far, the spectral dependencies of this process are still l...

For the design of modern office environments, lighting is a central aspect. With regard to current practice, uniform illumination is most often applied in interiors. In this paper, however, further aspects of a more individual approach are investigated, that deliberately violate the usual demands for uniformity by explicitly considering task-relate...

Fully digital microscopes are becoming more and more common in surgical applications. In addition to high-resolution stereoscopic images of the operating field, which can be transmitted over long distances or stored directly, these systems offer further potentials by supporting the surgical workflow based on their fully digital image processing cha...

With their inherent ability of serving as an internal reference, memory colors provide a very powerful concept in the evaluation of color rendering properties of white light sources with respect to visual appreciation. Recent results for example suggest fairly good correlations between memory‐based color quality metrics and the observers' general c...

Due to their potential use as an internal reference, memory colours have proven to provide an excellent conceptional approach for the colour rendition evaluation of white light sources in terms of predicting visual appreciation. However, there are still some major drawbacks that can be identified in the principal design of existing memory-based or...

With video-assisted surgery devices becoming more common in all fields of diagnostics and therapy, the question of how well such systems are able to reproduce surface colors of organic tissue arises, especially in cases where a proper distinction of different kinds of tissue-not only through their texture but also through their color-might be cruci...

Due to their potential use as an internal reference, memory colors have proven to provide an excellent conceptional approach for the color rendition evaluation of white light sources in terms of predicting visual appreciation. However, there are still some major drawbacks that can be identified in the principal design of existing memory-based or me...

Subjects assessed white tone preference and tint percentage perception (e.g., a faint greenish tint perceived in the white tone) in a viewing booth containing small colored objects at the illuminance level of 1000 lx for cool white, neutral white and warm white spectra. White points with the lowest perceived tint percentage were most preferred. Whi...

With the concept of memory colors being considered to play a crucial role for many imaging and lighting applications, the questions how people assess the color appearance of familiar objects and what kind of fundamental characteristics can be derived from these assessments have extensively been studied in the past. However, all of the previous stud...

In this follow-up paper, a display-based experiment on inter-cultural image quality assessment should be presented. In the course of preparing the experiment, four different functional colour image transforms were adopted and applied to eight different test images. The processed images were subsequently presented to Chinese and German observers in...

Subjects rated the colour preference of a colourful object scene illuminated to 2000 lx by 28 different spectra from a four-channel LED light engine at different object saturation levels and different white points (3200 K, 4200 K, 5000 K and 5600 K). Mean colour preference ratings had a maximum at a moderate saturation level. The lowest correlated...

Memory colors generated continuous interest in the color community. Previous studies focused on reflecting color chips and color samples in real scenes or on monitors. The cognitive effect of culture was rarely considered. In this paper, we performed a comprehensive investigation of the long-term memory colors of 26 familiar objects using the asymm...

Digital color imaging technology has become omnipresent in today's modern life. Digital image capturing and reproduction devices such as smartphones, digital still and video cameras, displays , printers, and color scanners can be found in every home, offering extremely high functionality and flexibility. In order to guarantee qualitatively good res...

Investigation of image quality on preference and naturalness using 1-dimensional and 2-dimensional colour attributes was performed. Each colour attribute varied in two directions, and each direction had two levels, i.e. large and small. In the present study, paired comparison was employed for image preference and categorical judgement for image nat...

Digital color imaging technology has become omnipresent in today's modern life. Digital image capturing and reproduction devices such as smartphones, digital still and video cameras, displays, printers, and color scanners can be found in every home, offering extremely high functionality and flexibility. In order to guarantee qualitatively good resu...

Investigation of image quality on preference and naturalness using 1- dimensional and 2- dimensional colour attributes was performed. Each colour attribute varied in two directions, and each direction had two levels, i.e. large and small. In the present study, paired comparison was employed for image preference and categorical judgement for image n...

A deep understanding of how humans assess memory colors is extremely important for various lighting and imaging applications, such as color and image reproduction as well as image enhancement (e.g., in film and TV-studios, in professional and home cinema applications , in shop and museum lighting). Potentially occurring cultural differences have to...

A deep understanding of how humans assess memory colors is extremely important for various lighting and imaging applications, such as color and image reproduction as well as image enhancement (e.g., in film and TV-studios, in professional and home cinema appli-cations, in shop and museum lighting). Potentially occurring cultural differences have to...

Heutzutage sind digitale Bildaufnahme- und Wiedergabegeräte wie Smartphones, Foto- oder Video-Kameras, Bildschirme, Fernseher und Drucker in nahezu jedem Haushalt zu finden. Damit solche Geräte jedoch eine möglichst hohe Nutzerakkzeptanz erzielen, ist eine wahrnehmungsgetreue Farbreproduktion ausschlaggebend, wobei es beobachterspezifische Präferen...

The use of LED spotlights has become more and more common in today’s digital film and television production. In this context, the flexibility that comes along with the new LED technology offers a unique possibility to optimize the color reproduction of digital camera systems. In the following paper, an appropriate evaluation model should be propose...

Memory colours have been extensively investigated. They are important for different image applications, such as colour image reproduction. However, it is possible memory colours vary according to different cultures. The present experiments were conducted to investigate 22 memory colours, which are divided into three types: 12 common colours such as...

The use of LED spotlights has become more and more common in today's digital film and television production. In this context, the flexibility that comes along with the new LED technology offers a unique possibility to optimize the color reproduction of digital camera systems. In the following paper, an appropriate evaluation model should be propose...

There has been significant recent progress in solving the long-standing problems of how nuclear shell structure and collective motion emerge from underlying microscopic inter-nucleon interactions. We review a selection of recent significant results within the ab initio No Core Shell Model (NCSM) closely tied to three major factors enabling this pro...

We report ab initio calculations for neutron drops in a 10 MeV external harmonic-oscillator trap using chiral nucleon-nucleon plus three-nucleon interactions. We present total binding energies, internal energies, radii and odd-even energy differences for neutron numbers N = 2 - 18 using the no-core shell model with and without importance truncation...

Neutron drops provide a simple test system for neutron-rich matter. Hence, ab initio calculations of these pure neutron systems may be used to constrain the large-isospin properties of energy-density functionals and equations of state that are used for the description of very neutron-rich systems as they occur in astrophysical environments, e.g., n...

A generalized kinetic model equation which takes into account the frequency depence of the thermal conductivity is used to analyze the problem of sound propagation in dilute polyatomic gases. By comparing the theoretical results with some available experimental data we infer that our model equation provides a precise transition between low and high...

In this work we analyze the time-dependent problem of sound propagation in dilute polyatomic gases with classical internal degrees of freedom. The sound wave is assumed to be a plane harmonic wave of small amplitude propagating along the x -axis through the gas. Hydrodynamic as well as kinetic approaches to the problem of sound propagation in dilut...

Bisherige Messmethoden der Wassertemperatur im Meer basieren auf sogenannten in-situ Techniken. Mit Hilfe von Messbojen, Einwegsensoren oder Unterwasserglidern werden entsprechende Datensätze aufgenommen. Diese Techniken dringen zwar in große Meerestiefen vor und erreichen eine Genauigkeit von typischerweise ∆T = 0, 01 K, sie sind jedoch örtlich nu...