Annoyance evaluation of noise emitted by urban substation

In China, noise pollution from substations in urban areas is becoming more and more serious. An annoyance evaluation of the noise emitted by urban substations is presented. First, the subjective evaluation is conducted on the noise samples from urban substations via the semantic differential method. Subsequently, according to the typical characteristics of urban substation noise, 14 acoustical metrics are used to describe the noise samples for objective evaluation. Then the correlation analysis and regression analysis between the objective and subjective evaluation results are carried out. Finally, a regression model for urban substation noise evaluation is established. Practical application shows that the regression model can correctly predict the subjective annoyance of urban substation noise.

Objective and subjective evaluation of a new airplane seat with an optimally pre-shaped foam support

BACKGROUND: Aircraft seat manufacturers are making efforts to reduce seat weight while continuously increasing seating comfort. OBJECTIVES: To verify if seats with an optimally pre-shaped foam support could improve seating comfort while reducing seat weight. METHODS: The optimally pre-shaped surface was obtained from a synthesis of 95% of individually optimized compressed seat pan surfaces of a target population. Two new seats were proposed with two different cushions, one slightly softer and the other harder. Nineteen differently sized volunteers tested the two new seats and an existing seat randomly. After an assessment of initial discomfort, participants were instructed to watch a TV series for 50 minutes. A same questionnaire was used to assess both initial and longer-term discomfort. Contact forces and pressure distribution were analysed as well in-chair movements (ICM) during sitting. RESULTS: The two new seats exhibited lower shear, lower peak pressure and larger contact area on the seat pan as well lower number of ICM during the 50 minutes sitting. They also had lower initial overall discomfort, though significant differences between the seats were not found after the long sitting. CONCLUSIONS: Properly pre-shaped surface could be used as foam support to reduce the amount of foam while reducing seating discomfort.

Study on the influence of underwear on local thermal and moisture comfort of human body

In order to study the influence of underwear on human thermal and moisture comfort in different sports conditions, the objective and subjective evaluation of underwear (including undershirt and underpants) made of three kinds of fabrics were carried out, and the underwear comfort model was established by computational fluid dynamics, and the application prospect of computational fluid dynamics technology in the field of clothing comfort research was prospected. The results show: 1. the underwear combination of different fabrics has certain influence on the thermal and moisture comfort of human body, and the thermal and moisture of fabric of composite fiber is better than that of fabric of single fiber; 2. the temperature and humidity of chest, back, hip and thighs of the human body in different motion states change, and the temperature and humidity of the chest and back change greatly; 3. computational fluid dynamics can accurately predict human skin temperature.