Evaluating the objective and subjective physical environments of residential care facilities

The aim of this research was to explore the objective and subjective physical environments of residential care facilities (RCFs) by studying 34 facilities in Harbin, Changchun, Shenyang and Dalian. A study that combines questionnaires and instrumental testing. Pearson’s correlation and regression analysis were used to analyse the correlation between the measured value and the evaluation result and the impact on the results of the participants’ personal background evaluations. The results showed that the brightness intensity ranged from 100 to 450 cd/m2, illuminance 200–550 lx and sound pressure level (SPL) 40–58 dBA. In reconstructed RCFs (RCFs converted from other buildings), the odour and other factors were significantly positively correlated with the satisfaction of participants. Seasonal changes had a significant impact on the level of different physical environments, particularly in the assessment of the thermal environment. Temperatures were highest in bedrooms, reaching 27°C. The correlation between the measured value and the evaluated satisfaction was high. The education level of participants was related to their satisfaction with the overall Indoor environmental quality (IEQ). Participants in the study were satisfied with the overall IEQ of the RCFs. These results can provide data-based support and act as a reference for IEQ research on RCFs

Acoustic comfort in large railway stations

Large railway stations attract a wide range of passengers and citizens, and these buildings are likely to have a complex acoustic environment. Previous studies have focused on reducing people’s exposure to excessive sound levels caused by transportation, but more research is needed to assess people’s preferences and ensure their psychophysical wellbeing. The aim of this study was to explore the complex aspects of the sound environment in large railway stations that contribute to acoustic comfort. On-site measurements and an acoustic comfort survey were performed at a case study site in Harbin, China. The results showed a significant positive correlation between the subjective comfort evaluations and objective measurements of the sound pressure level and reverberation time. Differences in dominant sound sources in different spaces lead to different evaluations of acoustic comfort. People prefer broadcast sound, but its intelligibility needs to be improved. When the density of people increases, the preference for speech sounds and activity sounds decline rapidly. With regard to demographic and social factors, older people and people with higher incomes and education levels are more tolerant of the environment. As railway transportation has become modernized, large railway stations now play an important role in civic architecture. The aim of this study was to explore the effects of sound sources on the sound environment and acoustic comfort in such an extra-large space. Based on subjective and objective measurements of a typical railway station in China that has an extra-large space and multiple sound sources, the effects of sound sources in different functional zones were studied. The overall acoustic comfort and sound pressure levels were related to the sonic composition of the sound sources. The roles of various individual sound sources were investigated, including the speech sounds of other passengers in the seating area, the speech sounds of staff, the sounds of placing luggage in the security scan machine in the security check area, the sounds of a ticket machine in the ticket lobby, and the speech sounds of restaurant workers. The sound sources that have dominant impacts on the survey participants' evaluations of acoustic comfort were determined. In terms of acoustic comfort, broadcast sound was the most preferable, whereas mechanical noise and luggage noise were the least preferable. The sound levels of speech, the intelligibility of both broadcast and speech sounds, and the loudness of the three dominant sound sources exhibited a linear correlation with the sound pressure level. In terms of the effect of the sound characteristics on acoustic comfort, the sound level of speech was the dominant factor. Overall, acoustic comfort can be effectively improved by better planning of the combination and arrangement of sound sources

Effects of raster angle and material components on mechanical properties of polyether-ether-ketone/calcium silicate scaffolds

Polyetheretherketone (PEEK) was widely used in the fabrication of bone substitutes for its excellent chemical resistance, thermal stability and mechanical properties that were similar to those of natural bone tissue. However, the biological inertness restricted the osseointegration with surrounding bone tissue. In this study, calcium silicate (CS) was introduced to improve the bioactivity of PEEK. The PEEK/CS composites scaffolds with CS contents in gradient were fabricated with different raster angles via fused filament fabrication (FFF). With the CS content ranging from 0 to 40% wt, the crystallinity degree (from 16% to 30%) and surface roughness (from 0.13 ± 0.04 to 0.48 ± 0.062 µm) of PEEK/CS scaffolds was enhanced. Mechanical testing showed that the compressive modulus of the PEEK/CS scaffolds could be tuned in the range of 23.3–541.5 MPa. Under the same printing raster angle, the compressive strength reached the maximum with CS content of 20% wt. The deformation process and failure modes could be adjusted by changing the raster angle. Furthermore, the mapping relationships among the modulus, strength, raster angle and CS content were derived, providing guidance for the selection of printing parameters and the control of mechanical properties

Image-Image Domain Adaptation with Preserved Self-Similarity and Domain-Dissimilarity for Person Re-identification

© 2018 IEEE. Person re-identification (re-ID) models trained on one domain often fail to generalize well to another. In our attempt, we present a 'learning via translation' framework. In the baseline, we translate the labeled images from source to target domain in an unsupervised manner. We then train re-ID models with the translated images by supervised methods. Yet, being an essential part of this framework, unsupervised image-image translation suffers from the information loss of source-domain labels during translation. Our motivation is two-fold. First, for each image, the discriminative cues contained in its ID label should be maintained after translation. Second, given the fact that two domains have entirely different persons, a translated image should be dissimilar to any of the target IDs. To this end, we propose to preserve two types of unsupervised similarities, 1) self-similarity of an image before and after translation, and 2) domain-dissimilarity of a translated source image and a target image. Both constraints are implemented in the similarity preserving generative adversarial network (SPGAN) which consists of an Siamese network and a CycleGAN. Through domain adaptation experiment, we show that images generated by SPGAN are more suitable for domain adaptation and yield consistent and competitive re-ID accuracy on two large-scale datasets

Expected Signature For the Lorentz Invariance Violation Effects on γ−γ\gamma-\gamma Absorption

There are still some {significant and} unanswered questions about the {incredible} {very high energy (VHE)} $\gamma$-ray signatures. To help understand the mechanism, focusing on the linear and quadratic perturbation mode for the subluminal regime, the present paper revisited the expected signature for the Lorentz invariance violation effects on $\gamma-\gamma$ absorption in TeV spectra of Gamma-ray bursts (GRBs). We note that there is {a critical energy} for the pair production process, which is sensitive to the assumed quantum gravity energy scale. We suggest that a {reemergence of the energy spectrum of $\gamma$-rays} at the several tens of TeV is a rough observational diagnostic for the Lorentz invariance violation (LIV) effects. The expected spectra characteristics are applied to a GRB 221009A. The results show that the cosmic opacity with LIV effects considered here {can} roughly reproduce the observed $\gamma$-ray spectra for the source, which enabled us to constrain the upper limit of the values of energy scale at $E_{\rm QG,~1}\leq3.35\times10^{20}$ GeV for the linear perturbation and $E_{\rm QG,~2}\leq9.19\times10^{12}$ GeV for the quadratic perturbation. {These scenarios would update the bound of the LIV coefficient with $\xi_{\rm 1}^{\prime}\geq 3.62\times10^{-2}$ for the linear perturbation, and $\xi_{\rm 2}^{\prime}\geq 1.33\times10^{6}$ for the quadratic perturbation in the standard model extension (SME) framework, respectively. }Comment: Accepted for publication in PRD, 8 pages, 5 figure

Acoustic environment research of railway station in China

One characteristic of railway stations in China is that the entrance hall, ticket office, integrated waiting hall and auxiliary space are all concentrated in a large span of space, forming a unified whole space. However, the multi-function fusion in such a large space results in a series of acoustic problems, such as long reverberation time, high environmental noise and poor language articulation. Therefore, it is necessary to study the acoustic environment of railway stations in China. In this study, the sound field characteristics of the typical railway station are studied to reveal its law of sound propagation. Next, subjective evaluation and objective experiments are carried out to study the acoustic environment and comfort in the waiting hall. Finally, based on the comparative analysis of various influential factors, such as sound source and sound field, this paper advances some suggestions for the acoustical design of high-speed railway stations