scholarly journals Colour Perception and Visitor Experiences of Urban Parks as Influenced by an Intense Colourful Urban Artefact: An In-situ Quasi-experiment

2021 ◽  
Vol 9 (2) ◽  
pp. 485-505
Author(s):  
Petra Thorpert ◽  
Jan-Eric Englund
Keyword(s):  
Urban Parks ◽  
Colour Perception ◽  
Visitor Experiences ◽  
Quasi Experiment

scholarly journals Spectrum projection with a bandgap-gradient perovskite cell for colour perception

2020 ◽  
Vol 9 (1) ◽  
Author(s):  
Mei-Na Zhang ◽  
Xiaohan Wu ◽  
Antoine Riaud ◽  
Xiao-Lin Wang ◽  
Fengxian Xie ◽  
...  
Keyword(s):  
High Efficiency ◽  
Optoelectronic Devices ◽  
Photon Flux ◽  
Spectral Information ◽  
In Situ Characterization ◽  
Colour Perception ◽  
Spectral Signal ◽  
Wide Range ◽  
Good Agreement

Abstract Optoelectronic devices for light or spectral signal detection are desired for use in a wide range of applications, including sensing, imaging, optical communications, and in situ characterization. However, existing photodetectors indicate only light intensities, whereas multiphotosensor spectrometers require at least a chip-level assembly and can generate redundant signals for applications that do not need detailed spectral information. Inspired by human visual and psychological light perceptions, the compression of spectral information into representative intensities and colours may simplify spectrum processing at the device level. Here, we propose a concept of spectrum projection using a bandgap-gradient semiconductor cell for intensity and colour perception. Bandgap-gradient perovskites, prepared by a halide-exchanging method via dipping in a solution, are developed as the photoactive layer of the cell. The fabricated cell produces two output signals: one shows linear responses to both photon energy and flux, while the other depends on only photon flux. Thus, by combining the two signals, the single device can project the monochromatic and broadband spectra into the total photon fluxes and average photon energies (i.e., intensities and hues), which are in good agreement with those obtained from a commercial photodetector and spectrometer. Under changing illumination in real time, the prepared device can instantaneously provide intensity and hue results. In addition, the flexibility and chemical/bio-sensing of the device via colour comparison are demonstrated. Therefore, this work shows a human visual-like method of spectrum projection and colour perception based on a single device, providing a paradigm for high-efficiency spectrum-processing applications.

scholarly journals Assessing soundscape: Comparison between in situ and laboratory methodologies

Noise Mapping ◽  
2017 ◽  
Vol 4 (1) ◽  
pp. 57-66 ◽  
Author(s):  
Luis Fernando Hermida Cadena ◽  
Antonio Carlos Lobo Soares ◽  
Ignacio Pavón ◽  
Luis Bento Coelho
Keyword(s):  
Laboratory Tests ◽  
Subjective Evaluation ◽  
Interdisciplinary Approach ◽  
Urban Parks ◽  
In Situ Tests ◽  
Sound Recordings ◽  
Targeted Analysis ◽  
The City ◽  
Binaural Sound

AbstractThe assessment of soundscape implies an interdisciplinary approach, where objective and subjective aspects are considered. For the subjective evaluation, in situ and laboratory methodologies are usually followed. Local observations allow the collection of information on the influence of different stimuli present in the environment, whereas laboratory tests present a determined quantity of controlled stimuli to the evaluator. The purpose of this work is to compare results from the different methodologies in order to understand their strengths and their weaknesses. Three urban parks in the city of Lisbon, Portugal, were evaluated. Fragments of binaural sound recordings collected in the parks were used in laboratory tests to compare with the responses in situ and of expert and nonexpert listeners. Statistically significant differences were found in several of the perceptual attributes under observation, which led to variation in the results of the main model’s components. The sound environments were found to be more pleasant and uneventful in situ than in the laboratory, a phenomenon possibly due to the influence of other stimuli such as visual in the process of assessment. The in situ tests allow a systemic and holistic evaluation of the environment under study,whereas the laboratory tests allow a specific and tightly targeted analysis of different component sound events. Therefore, the two methodologies can be useful in soundscape assessment depending on the specific application and needs. No differences were found in the assessment made by either experts or nonexperts.

scholarly journals Multiple ancestral duplications of the red-sensitive opsin gene (LWS) in teleost fishes and convergent spectral shifts to green vision in gobies

2021 ◽  
Author(s):  
Fabio Cortesi ◽  
Daniel Escobar Camacho ◽  
Martin Luehrmann ◽  
Gina Maria Sommer ◽  
Zuzana Musilova
Keyword(s):  
Genome Duplication ◽  
In Situ Hybridisation ◽  
Bright Light ◽  
Opsin Gene ◽  
Colour Perception ◽  
Long Wavelength ◽  
Cone Opsin ◽  
Spectral Shifts ◽  
Functional Replacement

Photopigments, consisting of an opsin protein bound to a light-sensitive chromophore, are at the centre of vertebrate vision. The vertebrate ancestor already possessed four cone opsin classes involved in colour perception during bright-light conditions, which are sensitive from the ultraviolet to the red-wavelengths of light. Teleosts experienced an extra round of whole genome duplication (3R) at their origin, and while most teleosts maintained only one long-wavelength-sensitive opsin gene (LWS1), the second ancestral copy (LWS2) persisted in characins and osteoglossomorphs. Following 3R, teleost opsins have continued to expand and diversify, which is thought to be a consequence of the different light environment fishes inhabit, from clear streams to the relative darkness of the deep-sea. Although many recent and a few ancestral opsin duplicates can be found, none predating the 3R were thought to exist. In this study we report on a second, previously unnoticed ancestral duplication of the red-sensitive opsin (LWS3), which predates the teleost-specific genome duplication and only persists in gobiid fishes. This is surprising, since it implies that LWS3 has been lost at least 19-20 times independently along the teleost phylogeny. Mining 109 teleost genomes we also uncover a third lineage, the elopomorphs, that maintained the LWS2 copy. We identify convergent amino acid changes that green-shift ancestral and recent LWS copies, leading to adaptive differentiation and the functional replacement of the original green-sensitive RH2 opsin. Retinal transcriptomes and in-situ hybridisation show that LWS3 is expressed to various extents in gobies and in the case of the whitebarred goby, Amblygobius phalaena, it occurs in a separate photoreceptor to LWS1. Our study highlights the importance of comparative studies to comprehend evolution of gene function.

scholarly journals In-vacuum active colour sensor and wireless communication across a vacuum-air interface

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Osamu Sakai ◽  
Takayuki Kitagawa ◽  
Keiji Sakurai ◽  
Go Itami ◽  
Shigeyuki Miyagi ◽  
...  
Keyword(s):  
Wireless Communication ◽  
Vacuum Chamber ◽  
Low Pressure ◽  
Ambient Atmosphere ◽  
Colour Perception ◽  
Processing Scheme ◽  
Pressure Plasma ◽  
Low Pressure Plasma ◽  
Light Signals

AbstractIn situ sensing with wireless digital-data transfer is a potential processing scheme that works very closely to the location of an event monitored by a sensor and converts the sensor’s raw output into digitized and informative small-volume bits, as suggested by recent proposals for edge computing and the Internet of Things (IoT). Colour perception may be a target of in situ sensor data acquisition; however, in contrast to from other sensing devices, colour sensors that detect visible light signals are usually located away from light-emitting sources, collecting light transmitting through the space and attenuating it in some manner. For example, in a vacuum chamber whose gas pressure is much less than the ambient atmosphere in which the sensors usually work, there are many veiled light sources, such as discharge plasma, for various industrial purposes including nanoscale manufacturing. In this study, we designed an in-vacuum colour sensor that can work with analogue-to-digital conversion and transfer data by wireless communication; this sensor is active in a low-pressure plasma chamber, detecting light signals and transferring them to a personal computer located outside the vacuum chamber. In addition to detecting lights with controlled spectra from outside successfully, we achieved complete operation of our in-vacuum active sensor for plasma emissions generated at 100 Pa. Comparing the signals with data from simultaneous monitoring by a monochromator, we established that the recorded signals arose from the plasma, confirming successful direct detection of low-pressure plasma emissions without any filtering effects between the sensor and the target object.

Rendez vous with Saturn's rings

1984 ◽  
Vol 75 ◽  
pp. 743-759 ◽  
Author(s):  
Kerry T. Nock
Keyword(s):  
Solar Energy ◽  
Electric Propulsion ◽  
Power Source ◽  
Propulsion System ◽  
Low Thrust ◽  
Ring Plane ◽  
The Earth ◽  
Total Impulse ◽  
Saturn's Rings

ABSTRACTA mission to rendezvous with the rings of Saturn is studied with regard to science rationale and instrumentation and engineering feasibility and design. Future detailedin situexploration of the rings of Saturn will require spacecraft systems with enormous propulsive capability. NASA is currently studying the critical technologies for just such a system, called Nuclear Electric Propulsion (NEP). Electric propulsion is the only technology which can effectively provide the required total impulse for this demanding mission. Furthermore, the power source must be nuclear because the solar energy reaching Saturn is only 1% of that at the Earth. An important aspect of this mission is the ability of the low thrust propulsion system to continuously boost the spacecraft above the ring plane as it spirals in toward Saturn, thus enabling scientific measurements of ring particles from only a few kilometers.

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