EFFECT OF LIGHT SOURCE DISTANCE ON THE DISCRIMINATION AND GLOSS PERCEPTION OF PAPER

Gloss is an essential visual property of objects. It is still controversial how well gloss constancy works under different light distributions. In this paper, we conducted three experiments of different light distributions to investigate whether the stable discrimination and gloss constancy of paper occurred with different glossiness levels at the different light source distances and illuminances. The results suggest instability of paper discrimination and gloss perception when both light source distance and illuminance change. Then we tested two additional conditions. One is setting the distance the same and manipulating the illumination. The other is setting the illuminance constant and manipulating the distance, respectively. We further verify that illuminance and specular reflection can affect material and gloss perception, regardless of the width of the highlight region changed by light source distance.

Partial visual loss disrupts the relationship between judged room size and sound source distance

Visual spatial information plays an important role in calibrating auditory space. Blindness results in deficits in a number of auditory abilities, which have been explained in terms of the hypothesis that visual information is needed to calibrate audition. When judging the size of a novel room when only auditory cues are available, normally sighted participants may use the location of the farthest sound source to infer the nearest possible distance of the far wall. However, for people with partial visual loss (distinct from blindness in that some vision is present), such a strategy may not be reliable if vision is needed to calibrate auditory cues for distance. In the current study, participants were presented with sounds at different distances (ranging from 1.2 to 13.8 m) in a simulated reverberant (T60 = 700 ms) or anechoic room. Farthest distance judgments and room size judgments (volume and area) were obtained from blindfolded participants (18 normally sighted, 38 partially sighted) for speech, music, and noise stimuli. With sighted participants, the judged room volume and farthest sound source distance estimates were positively correlated (p < 0.05) for all conditions. Participants with visual losses showed no significant correlations for any of the conditions tested. A similar pattern of results was observed for the correlations between farthest distance and room floor area estimates. Results demonstrate that partial visual loss disrupts the relationship between judged room size and sound source distance that is shown by sighted participants.

The distribution and behavioral characteristics of plateau pikas (Ochotona curzoniae)

Plateau pikas (Ochotona curzoniae) are regarded as one of the main causes of the degradation of alpine meadows in the Qinghai-Tibet Plateau (QTP). The population density of plateau pikas is directly related to the degree of grassland damage. In this study, field observation was conducted for one week in the southeastern QTP in August 2019. A random encounter model (REM) was used to estimate the population density of plateau pikas from photographs and videos, and the frequencies of different behaviors were calculated. In addition, the effects of water-source distance and terrain on the distribution of plateau pikas and the frequencies of different pika behaviors under different population densities were explored. The observations and knowledge derived from this study provide a reference for the population control of plateau pikas.

Assessment of Sound Source Tracking Using Multiple Drones Equipped with Multiple Microphone Arrays

Drone audition techniques are helpful for listening to target sound sources from the sky, which can be used for human searching tasks in disaster sites. Among many techniques required for drone audition, sound source tracking is an essential technique, and thus several tracking methods have been proposed. Authors have also proposed a sound source tracking method that utilizes multiple microphone arrays to obtain the likelihood distribution of the sound source locations. These methods have been demonstrated in benchmark experiments. However, the performance against various sound sources with different distances and signal-to-noise ratios (SNRs) has been less evaluated. Since drone audition often needs to listen to distant sound sources and the input acoustic signal generally has a low SNR due to drone noise, making a performance assessment against source distance and SNR is essential. Therefore, this paper presents a concrete evaluation of sound source tracking methods using numerical simulation, focusing on various source distances and SNRs. The simulated results captured how the tracking performance will change when the sound source distance and SNR change. The proposed approach based on location distribution estimation tended to be more robust against distance increase, while existing approaches based on directional estimation tended to be more robust against decreasing SNR.

Measurement and Calculation of Electron Contamination for Radiotherapy Photon Mode

Context: This study was done to review the electron contamination sources and measurement based on dosimetry and simulation techniques for radiotherapy and also investigate factors affecting electron contamination reduction. Methods: We systematically searched five major indexing databases, including PubMed, Scopus, Embase, ISI web of science, and Cochrane central, using keywords of electron contamination, electron contamination AND measurement, electron contamination AND simulation, and electron contamination AND reduction until Dec 2020. Results: Overall, 35 studies were reviewed, including articles reporting the theory of electron contamination, papers on dosimetry methods to measure electron contamination, studies about simulation methods to assess electron contamination, and articles about reducing electron contamination. The results indicated an increase in electron contamination using a flattering filter, an increase in field size, the presence of prosthesis in the patient's body, and a rise in photon energy. Conclusions: It can be concluded that the excessive delivered doses by electron contamination can cause skin complications, such as erythema, desquamation, and telangiectasia inside or outside the photon field. The amount of electron contamination depends on factors, such as radiation field size, beam energy, and materials placed in the photon path. Electron contamination can be decreased by increasing the source distance to the point of measurement by the dosimeter, applying a lead foil, magnetic deflector, or replacing a portion of air column between patient and radiotherapy system head by helium gas, and also limiting the treatment field.

NICER observations of the black hole candidate MAXI J0637–430 during the 2019-2020 Outburst

We present detailed timing and spectral studies of the black hole candidate MAXI J0637–430 during its 2019-2020 outburst using observations with the Neutron Star Interior Composition Explorer (NICER) and the Neil Gehrels Swift Observatory. We find that the source evolves through the soft-intermediate, high-soft, hard-intermediate and low-hard states during the outburst. No evidence of quasi-periodic oscillations is found in the power density spectra of the source. Weak variability with fractional rms amplitude $&lt;5{{\ \rm per\ cent}}$ is found in the softer spectral states. In the hard-intermediate and hard states, high variability with the fractional rms amplitude of $&gt;20{{\ \rm per\ cent}}$ is observed. The 0.7 − 10 keV spectra with NICER are studied with a combined disk-blackbody and nthcomp model along with the interstellar absorption. The temperature of the disc is estimated to be 0.6 keV in the rising phase and decreased slowly to 0.1 keV in the declining phase. The disc component was not detectable or absent during the low hard state. From the state-transition luminosity and the inner edge of the accretion flow, we estimate the mass of the black hole to be in the range of 5–12 M⊙, assuming the source distance of d &lt; 10 kpc.

The distribution and behavioral characteristics of plateau pika (Ochotona curzoniae)

Plateau pikas (Ochotona curzoniae) are regarded as one of the main reasons for the degradation of alpine meadows in the Qinghai-Tibet Plateau (QTP). The population density of plateau pikas is directly related to the degree of grassland damage. In this study, a one-week field observation was conducted in the southeastern QTP in August 2019. Based on the photos and videos, the random encounter model (REM) was used to estimate the population density of plateau pikas, and the frequency of different behaviors was counted. The effects of water source distance and terrain on the distribution of plateau pikas were also investigated. In addition, the frequency of different behaviors of plateau pikas under different population densities was also explored. The observations and knowledge derived from this study provide a reference for the population control of plateau pikas.