New Hyperspectral Procedure to Discriminate Intertidal Macroalgae

The recent development and miniaturization of hyperspectral sensors embedded in drones has allowed the acquisition of hyperspectral images with high spectral and spatial resolution. The characteristics of both the embedded sensors and drones (viewing angle, flying altitude, resolution) create opportunities to consider the use of hyperspectral imagery to map and monitor macroalgae communities. In general, the overflight of the areas to be mapped is conconmittently associated accompanied with measurements carried out in the field to acquire the spectra of previously identified objects. An alternative to these simultaneous acquisitions is to use a hyperspectral library made up of pure spectra of the different species in place, that would spare field acquisition of spectra during each flight. However, the use of such a technique requires developed appropriate procedure for testing the level of species classification that can be achieved, as well as the reproducibility of the classification over time. This study presents a novel classification approach based on the use of reflectance spectra of macroalgae acquired in controlled conditions. This overall approach developed is based on both the use of the spectral angle mapper (SAM) algorithm applied on first derivative hyperspectral data. The efficiency of this approach has been tested on a hyperspectral library composed of 16 macroalgae species, and its temporal reproducibility has been tested on a monthly survey of the spectral response of different macro-algae species. In addition, the classification results obtained with this new approach were also compared to the results obtained through the use of the most recent and robust procedure published. The classification obtained shows that the developed approach allows to perfectly discriminate the different phyla, whatever the period. At the species level, the classification approach is less effective when the individuals studied belong to phylogenetically close species (i.e., Fucus spiralis and Fucus serratus).

ІНТЕЛЕКТУАЛЬНА СИСТЕМА УПРАВЛІННЯ В ОСВІТЛЕННІ ПІШОХІДНИХ ПЕРЕХОДІВ ДЛЯ ПІДВИЩЕННЯ ЕНЕРГОЕФЕКТИВНОСТІ

Purpose. Development of the concept of an intelligent control system for implementation in the scheme of pedestrian crossing lighting and design of a street lamp to reduces electricity costs and increases the service life of street lights, using technical devices such as dimmers and special motion sensors.Method. The research methods of theoretical analysis, modeling of appearance and creation of the scheme of intellectual control complex, basic provisions on lighting of pedestrian crossings and design of street lighting, analysis of possibilities of motion sensors and dimming at use in lighting are used.Results. Technologies of application of dimers and various motion sensors in lighting are analyzed and modern technological advantages of their use are allocated. Having identified a problem in the payment for electricity for street lighting for many local budgets, an intelligent control system for pedestrian crossing lighting was developed. The system allows obtaining of significant economic effect, reducing electricity consumption by a maximum of 70%. This saving is achieved by using dimming lamps and special narrow motion sensors, which have a viewing angle of 6 ° horizontally. At rest, the system keeps the lamp power at 50% until the person falls within the range of the sensor and the illumination rises to 100% for the set time. Specially selected sensors and their correct placement allow the system to work only when a person approaches a pedestrian crossing, and to remove accidental unpredictable inclusions. After analyzing the modern street lighting market, the design of a street lamp was created and proposed.Scientific novelty. It is proposed to use an intelligent control system in the lighting of pedestrian crossings, because now it is widely used only as part of the complex "smart home". Application in the scheme of lighting of pedestrian crossings of dimming and special narrowly directed motion sensors with a viewing angle of 6° horizontally that will allow to exclude accidental operation, both from people and cars, and from dogs and cats. A new design of the road lamp has been developed, based on the analyzed provisions on the correct lighting of pedestrian crossings.Practical significance. Lighting of pedestrian crossings is currently a problem in our country, because there are many accidents, and for good lighting you need to spend a lot of money on electricity from local budgets. This intelligent pedestrian crossing lighting control system is specially designed so that the use of electricity can be reduced by 70% and the service life of lamps can be significantly increased, for example by 1.5 times, but a more accurate value can be obtained only after the introduction of the first experimental sample. The use of such a system is possible throughout Ukraine at each crossing, unlike many other projects for lighting road crossings.

THROUGHPUT INCREASE IN THE OFFICE LI-FI SYSTEM

Background. Wi-Fi has many disadvantages, such as how the maximum bandwidth is limited by the frequency of the range. The work uses Li-Fi technology, which uses visible light for data transmission. The frequency range of Li-Fi is 1000 times greater than the entire radio range. Feedback is used to increase the throughput. But the feedback decreases the bandwidth of the downstream signal. Objective. The purpose of the paper is to analyse what parameters are advisable to change to increase the throughput of the Li-Fi system. Methods. Study of the simulated dependence of the optimal interval change for using the feedback, and using this interval plot the dependence of the throughput on the change in the parameters of the Li-Fi system with a mobile user. Results. With an increase in the area of the photodiode and its refractive index, the throughput increases. As the receiver speed increases, the throughput decreases slightly <0.1%. Reducing the angle of the photodiode field of view and the half-angle of radiation significantly increases the throughput (by 50%) only when decreasing to small angles (<10 °). Conclusions. It is advisable to make photodiode from a material with a high refractive index, with a big area. Since mobile devices are often used in the office Li-Fi network, it is not advisable to reduce the receiver's viewing angle, as well as to reduce the half-angle of radiation. It may also be beneficial to give mobile users more download throughput than upload throughput.

Naturalistic Face Learning in Infants and Adults

Everyday face recognition presents a difficult challenge because faces vary naturally in appearance as a result of changes in lighting, expression, viewing angle, and hairstyle. We know little about how humans develop the ability to learn faces despite natural facial variability. In the current study, we provide the first examination of attentional mechanisms underlying adults’ and infants’ learning of naturally varying faces. Adults ( n = 48) and 6- to 12-month-old infants ( n = 48) viewed videos of models reading a storybook; the facial appearance of these models was either high or low in variability. Participants then viewed the learned face paired with a novel face. Infants showed adultlike prioritization of face over nonface regions; both age groups fixated the face region more in the high- than low-variability condition. Overall, however, infants showed less ability to resist contextual distractions during learning, which potentially contributed to their lack of discrimination between the learned and novel faces. Mechanisms underlying face learning across natural variability are discussed.

The Relationship Between Shape Perception Accuracy and Drawing Ability.

Accurate shape perception is critical for object perception, identification, manipulation, and recreation. Humans are capable of making judgements of both objective (physical) and projective (retinal) shape. Objective judgements benefit from a global approach by incorporating context to overcome the effects of viewing angle on an object’s shape, whereas projective judgements benefit from a local approach to filter out contextual information. Realistic drawing skill requires projective judgements of 3D targets to accurately depict 3D shape on a 2D surface, thus benefiting from a local approach. The current study used a shape perception task that comprehensively tests the effects of context on shape perception, in conjunction with a drawing task and several measures of local processing bias, to show that the perceptual basis of drawing skill in neurotypical adults is not due to a local processing bias but to perceptual flexibility, the ability to process local or global information as needed.

Accurate flux calibration of GW170817: is the X-ray counterpart on the rise?

X-ray emission from the gravitational wave transient GW170817 is well described as non-thermal afterglow radiation produced by a structured relativistic jet viewed off-axis. We show that the X-ray counterpart continues to be detected at 3.3 years after the merger. Such long-lasting signal is not a prediction of the earlier jet models characterized by a narrow jet core and a viewing angle ≈20 deg, and is spurring a renewed interest in the origin of the X-ray emission. We present a comprehensive analysis of the X-ray dataset aimed at clarifying existing discrepancies in the literature, and in particular the presence of an X-ray rebrightening at late times. Our analysis does not find evidence for an increase in the X-ray flux, but confirms a growing tension between the observations and the jet model. Further observations at radio and X-ray wavelengths would be critical to break the degeneracy between models.

Effect of nanocoating morphology on the signal of X-ray Photoelectron Spectroscopy

The paper considers the application of the traditional X-ray photoelectron spectroscopy (XPS) methodology: the Overlayer Thickness Determination for the analysis of coating parameters. In particular situations considered in this work, it is energetically favorable for the atoms of the coating to form clusters, but not be evenly distributed on the surface of the substrate material. The change in the XPS signal is analyzed in situations when the coating is not a plane-parallel homogeneous layer, but an island (cluster) structure. The mathematical model of the XPS signal formation is considered for the case of the cluster covering in the form of parallelepipeds. Photoelectron path distributions (in the coating material) analysis indicated a strong dependence of the signal on the viewing angle. For the purpose of analysis, experimental spectra were obtained for several samples: gold depositions of various thicknesses on a silicon substrate. The spectra were measured for different viewing angles of photoelectrons and interpreted within the Straight Line Approximation (SLA). It is shown that proposed simplest model of an island coating allows to describe the effect of a decrease in the value of the effective average coating thickness, determined in plane-parallel geometry, with an increase in the viewing angle, observed in XPS experiments with angular resolution.

The implementation and evaluation of the field of view in 3D PC game

This research developed a 3D third-person game, made open and closed scenes, through experiments to investigate the field of view suitable for different scenes. Playing 3D games can sometimes cause 3D discomfort or motion sickness. There are many people who have this kind of 3D discomfort. In the research on this issue, the authenticity of the game or the physiological impact of the observer was discussed in detail; however, the impact of the design of the game itself was less discussed. The field of view in the game scene is likely to cause motion sickness. This experimental method uses the adjustment method in psychophysics to test whether the player is comfortable with different scenes. According to the test of different scenarios, the average and standard deviation of the most comfortable visual field are obtained. The viewing angles of different scenes are significantly different, and the best viewing angle of a closed scene is larger than that of an open scene.

Spin and Accretion Rate Dependence of Black Hole X-Ray Spectra

We present a survey of how the spectral features of black hole X-ray binary systems depend on spin, accretion rate, viewing angle, and Fe abundance when predicted on the basis of first-principles physical calculations. The power-law component hardens with increasing spin. The thermal component strengthens with increasing accretion rate. The Compton bump is enhanced by higher accretion rate and lower spin. The Fe Kα equivalent width grows sublinearly with Fe abundance. Strikingly, the Kα profile is more sensitive to accretion rate than to spin because its radial surface brightness profile is relatively flat, and higher accretion rate extends the production region to smaller radii. The overall radiative efficiency is at least 30%–100% greater than as predicted by the Novikov–Thorne model.