Publications related to Light meter

Light-Intensity Switching of Graphene/WSe2 Synaptic Devices

Giulia Tagliabue, Tarique Anwar, Hongyu Tang

2D van der Waals heterojunctions (vdWH) have emerged as an attractive platform for the realization of optoelectronic synaptic devices, which are critical for energy-efficient computing systems. Photogating induced by charge traps at the interfaces indeed r ...

Wiley2024

Towards learning-based denoising of light fields

Touradj Ebrahimi, Michela Testolina, Tomás Soares De Carvalho Feith

In recent years, new emerging immersive imaging modalities, e.g. light fields, have been receiving growing attention, becoming increasingly widespread over the years. Light fields are often captured through multi-camera arrays or plenoptic cameras, with th ...

2023

Optimized office lighting advances melatonin phase and peripheral heat loss prior bedtime

Jean-Louis Scartezzini, Mirjam Münch, Marta Benedetti, Lenka Maierova

Improving indoor lighting conditions at the workplace has the potential to support proper circadian entrainment of hormonal rhythms, sleep, and well-being. We tested the effects of optimized dynamic daylight and electric lighting on circadian phase of mela ...

Nature Research2022

Continuous Simulation Data Stream: A dynamical timescale-dependent output scheme for simulations

Loïc Hausammann, Matthieu Schaller

Exa-scale simulations are on the horizon but almost no new design for the output has been proposed in recent years. In simulations using individual time steps, the traditional snapshots are over resolving particles/cells with large time steps and are under ...

ELSEVIER2022

Validation of spectral simulation tools in the context of ipRGC-influenced light responses of building occupants

Marilyne Andersen, Clotilde Marie A Pierson

With the growing awareness about ipRGC-influenced light (IIL) responses, design applications related to these responses are flourishing. To compare design options and optimize lighting conditions for building occupants, lighting simulations are typically u ...

2023

Effects of illuminance intensity on the green channel of remote photoplethysmography (rPPG) signals

Ata Jedari Golparvar

Point-of-care remote photoplethysmography (rPPG) devices that utilize low-cost RGB cameras have drawn considerable attention due to their convenience in contactless and non-invasive vital signs monitoring. In rPPG, sufficient lighting conditions are essent ...

SPRINGER2022

Influence of Light Soaking on Silicon Heterojunction Solar Cells With Various Architectures

Christophe Ballif, Bertrand Yves Paul Paviet-Salomon, Matthieu Despeisse, Laurie-Lou Senaud, Mathieu Gérard Boccard, Jan Haschke, Jean Cattin

In this article, we investigate the effect of prolonged light exposure on silicon heterojunction solar cells. We show that, although light exposure systematically improves solar cell efficiency in the case of devices using intrinsic and p-type layers with ...

2021

Exploring light exposure of hospital nurses working rapidly rotating shifts in relation to sleepiness and sleep

Steffen Lutz Hartmeyer

Nightshift work can negatively impact sleep, performance, and health. Careful manipulation of light exposure patterns can help reduce these negative effects but is challenging in conditions of rapidly rotating shiftwork and due to individual differences. A ...

IOP PUBLISHING LTD2021

A conceptual simulation workflow to guide design decisions regarding the effects of daylight on occupants' alertness

Marilyne Andersen, Clotilde Marie A Pierson, Victoria Eugenia Soto Magán

Recent developments in the lighting research field have demonstrated the importance of a proper exposure to light to mediate several of our behavioral and physiological responses. However, we spend nowadays around 90% of our time indoors with an often quit ...

IOP PUBLISHING LTD2021

Towards a wearable sensor for spectrally-resolved personal light monitoring

Marilyne Andersen, Forrest Simon Webler, Giorgia Chinazzo

Given the large impact that the spectrum and intensity of light can have on people's health and well-being, it is of fundamental importance to understand the properties of light received under normal living conditions. Historically, as research into the bi ...

2021

Estimating Nonplanar Flow from 2D Motion-blurred Widefield Microscopy Images via Deep Learning

Michael Stefan Daniel Liebling, Adrian Shajkofci

Optical flow is a method aimed at predicting the movement velocity of any pixel in the image and is used in medicine and biology to estimate flow of particles in organs or organelles. However, a precise optical flow measurement requires images taken at hig ...

IEEE2021

Integrating non-visual effects of light in the automated daylight-responsive control of blinds and electric lighting

Marta Benedetti

The use of daylight in buildings is important because it contributes to energy savings by reducing the use of electric lighting and space heating. It also impacts on biological functions and on well-being. Indeed, light not only allows vision, but has non- ...

EPFL2021

Phase calibration of a basic bright-field microscope for 3D metrology of transparent samples at the nanoscale

Martinus Gijs, Daniel Migliozzi, Bingying Zhao

Optical retrieval of the structure of transparent objects at the nano-scale requires adapted methods capable of probing their interaction with suitable light. Scattering events, for instance, depend on the content and the arrangement of the medium encounte ...

SPIE-INT SOC OPTICAL ENGINEERING2021

Precise and accurate image-based measurements of optical material properties

Marjan Shahpaski

The appearance of objects is governed by how they reflect, transmit and absorb the light they receive. That, in turn, depends on the material's internal structure, surface structure, and viewing and illumination directions. Changes in those characteristics ...

EPFL2020

Large field of view multi-camera endoscopic apparatus with omni-directional illumination

Yusuf Leblebici, Ömer Cogal

A multi-camera hemispherical very wide field of view imaging apparatus with omnidirectional illumination capability comprises a cylindrical body (4, 4.a, 4.b), a hemispherical mechanical frame (2) arranged on one end of the cylindrical body (4, 4.a, 4.b), ...

2020

Graph-based regularization of inverse problems in imaging

Mattia Rossi

As of today, the extension of the human visual capabilities to machines remains both a cornerstone and an open challenge in the attempt to develop intelligent systems. On the one hand, the development of more and more sophisticated imaging devices, capable ...

EPFL2020

Towards Light-Activated Ruthenium-Arene (RAPTA-Type) Prodrug Candidates

Paul Joseph Dyson, Rosario Scopelliti, Felix Daniel Bobbink, Patrycja Nowak-Sliwinska, Anna Katherine Renfrew

Cancer is currently one of the deadliest diseases worldwide. Based on the high incidence of this disease, the side effects associated with current chemotherapies and the appearance of drug resistance, considerable efforts have been directed towards the dev ...

WILEY-V C H VERLAG GMBH2019

Impact of dynamic lighting control on light exposure, visual comfort and alertness in office users

Jean-Louis Scartezzini, Mirjam Münch, Ali Motamed, Marta Benedetti, Lenka Maierova

The lighting environment at indoor workplaces is important not only to provide vision and visual comfort, but also for light's direct influence on human physiology, cognitive performance and mood. The purpose of this ongoing study is to investigate the imp ...

IOP Science2019

Cognitive performance evaluation under controlled daylight levels at different indoor temperatures

Marilyne Andersen, Jan Wienold, Giorgia Chinazzo

This paper details the results of an experimental study investigating the influence of daylight illuminance levels and indoor temperatures on objective and subjective performance evaluations, investigated through paper-based tasks and questionnaires, respe ...

2019

How to assess alerting effects of daylight at the workplace? Learnings from semi-controlled studies

Marilyne Andersen, Victoria Eugenia Soto Magán

Daylight, in which we evolved, is naturally rich in the blue component of the spectrum and has key properties when it comes to impacts on body functioning. Current lifestyles are driving the emergence of a 24-hour society that spends most of the time indoo ...

2019