ALBERT

Description: Ozone (O3) pollution has become one of the most challenging problems in China, and high O3 concentrations have been a major air quality issue in Changchun. Based on continuous observation data of surface ozone concentrations from ten automatic air monitoring stations and meteorological data from the meteorological bureau in Changchun, the temporal and spatial variations of the O3 concentration and its relationships with meteorological factors were analyzed by correlation analysis during the period of 2013–2017. The results showed the following: A single apex model of the annual mean O3 concentrations of the daily maximum 8 h average (MDA8) was found from the data for 2013 to 2017 in Changchun, with the highest MDA8 O3 concentrations in 2015 and a slight decline from then until 2017. The O3 concentrations in the suburban areas and the south of Changchun were higher than those downtown and north of the city. The seasonal variation of O3 concentrations was obvious, following the order summer 〉 spring 〉 autumn 〉 winter, which was similar to the results of neighboring cities and provinces in Changchun. The days on which O3 concentrations exceeded the standard were concentrated in summer and spring, and the total number of ozone excess days was 91 days; the maximum number of ozone excess days was in 2015. The O3 concentration exceeded the standard in Changchun mainly in March–August, and its monthly mean value curve showed a bimodal type in which the highest values appeared in May and July, while the lowest values appeared in December. The diurnal pattern of ozone showed a single peak mode, and the peak value usually appeared at 14:00–16:00 while the minimum value appeared at 07:00–08:00. O3 concentrations in Changchun and the six selected pollutants CO, NO, NO2, NOx, PM10, and PM2.5 were negatively correlated. Higher temperature is a necessary synoptic condition for ozone pollution in Changchun: when the temperature rose, O3 concentrations increased significantly; further, O3 concentrations were negatively correlated with relative humidity and atmospheric pressure and were positively correlated with temperature and solar radiation. The O3 concentrations were highest when the wind scale approached 14~20 km/h and the wind direction was S. Combined with the research results in the surrounding areas of Changchun, it is indicated that there may be an ozone contribution from south of Changchun through long-range pollution transport and tropospheric subsidence.

Description: FlexRay is a next-generation in-vehicle communication protocol which works in real time with flexibility. The most common applications in FlexRay are high bandwidth. X-by-wire applications, such as brake by wire and throttle by wire. However, there is no mechanism which can prevent transient faults in the application layer of FlexRay. If a transient fault occurs during driving, this would be very dangerous; therefore, we propose a fast reliability scheduling algorithm (FRSA) to improve the communication reliability of FlexRay. The proposed method reduces the probability of transient faults in one clock cycle by using a retransmission mechanism to recover the transient errors, and further improves computational complexity using the lookup table method to ensure system reliability. In this paper, we analyze a related literature to establish the system reliability constraints needed to evaluate the necessary time and slot usage, and the proposed cost function is used to evaluate the performance and efficiency when the number of messages is increased. Experimental results show that the proposed FRSA reduces execution time by an average 70.76% and cost by an average 13.33% more than the other existing methods. This method can be useful to others, especially regarding research about periodic time-triggered communication systems.