Fire is one of the most common accidents in daily life. In the process of fire accident prevention, monitoring and management, attention should be paid not only to the timeliness of automatic fire alarm equipment, but...Fire is one of the most common accidents in daily life. In the process of fire accident prevention, monitoring and management, attention should be paid not only to the timeliness of automatic fire alarm equipment, but also to the danger of fire caused by building power distribution facilities. Therefore, in the process of design and construction of building electrical systems, We should not only pay attention to the design and installation of the automatic fire alarm system, but also pay attention to the fire protection power distribution system, so that the building electrical system can give full play to its functions, improve the utilization rate of building electrical facilities, and enable the building electrical system to play a good role in the process of fire accident prevention and alarm. This paper will focus on the topic of fire protection power distribution system design and automatic fire alarm system design in the building electrical system.展开更多
A large number of automatic weather stations with different observation elements and gradient configurations are connected for operation,in order to meet the meteorological service needs of different scenes.The statio...A large number of automatic weather stations with different observation elements and gradient configurations are connected for operation,in order to meet the meteorological service needs of different scenes.The station density and observation frequency are encrypted to obtain observation data with higher spatial and temporal resolution.The original message with fixed element data location is the data combination of all observation elements and the maximum observation gradient of each element,which not only has higher invalid data redundancy,but also restricts the efficiency of data collection and processing,and also increases communication costs.An adaptive coding design method for the original message of automatic weather station is proposed.The embedded software coding algorithm of the weather station collector is optimized according to"plug and output"to realize intelligent networking,intelligent identification of observation elements and gradients,and dynamic flexible output of messages with variable length.The intelligent networking and business application of nearly 4000 automatic weather stations across the province show that the networking data acquisition and processing are efficient and stable.展开更多
A cross-layer design which combines adaptive modulation and coding (AMC) at the physical layer with a hybrid automatic repeat request (HARQ) protocol at the data link layer (LL) is presented, in cooperative relay syst...A cross-layer design which combines adaptive modulation and coding (AMC) at the physical layer with a hybrid automatic repeat request (HARQ) protocol at the data link layer (LL) is presented, in cooperative relay system over Nakagami-m fading channels with perfect and imperfect channel state information (CSI). In order to maximize spectral efficiency (SE) under delay and packet error rate (PER) performance constraints, a state transition model and an optimization framework with perfect CSI are presented. Then the framework is extended to cooperative relay system with imperfect CSI. The numerical results show that the scheme can achieve maximum SE while satisfying transmitting delay requirements. Compared with the imperfect CSI, the average PER with perfect CSI is much lower and the spectral efficiency is much higher.展开更多
文摘Fire is one of the most common accidents in daily life. In the process of fire accident prevention, monitoring and management, attention should be paid not only to the timeliness of automatic fire alarm equipment, but also to the danger of fire caused by building power distribution facilities. Therefore, in the process of design and construction of building electrical systems, We should not only pay attention to the design and installation of the automatic fire alarm system, but also pay attention to the fire protection power distribution system, so that the building electrical system can give full play to its functions, improve the utilization rate of building electrical facilities, and enable the building electrical system to play a good role in the process of fire accident prevention and alarm. This paper will focus on the topic of fire protection power distribution system design and automatic fire alarm system design in the building electrical system.
基金Supported by Technical Innovation Team Project of Collaborative Observation and Multi-source Live Data Fusion Analysis of Guangdong Meteorological Bu-reau(GRMCTD202103)R&D Plan Projects of Key Fields in Guangdong Province(2020B1111200001).
文摘A large number of automatic weather stations with different observation elements and gradient configurations are connected for operation,in order to meet the meteorological service needs of different scenes.The station density and observation frequency are encrypted to obtain observation data with higher spatial and temporal resolution.The original message with fixed element data location is the data combination of all observation elements and the maximum observation gradient of each element,which not only has higher invalid data redundancy,but also restricts the efficiency of data collection and processing,and also increases communication costs.An adaptive coding design method for the original message of automatic weather station is proposed.The embedded software coding algorithm of the weather station collector is optimized according to"plug and output"to realize intelligent networking,intelligent identification of observation elements and gradients,and dynamic flexible output of messages with variable length.The intelligent networking and business application of nearly 4000 automatic weather stations across the province show that the networking data acquisition and processing are efficient and stable.
基金Sponsored by the National Science and Technology Major Special Project of China (Grant No.2011ZX03003-003-02)the Natural Science Foundation of China (Grant No. 60972070)+2 种基金the Natural Science Foundation of Chongqing (Grant No. CSTC2009BA2090)the Foundation of Chongqing Educational Committee ( Grant No. KJ100514)the Special Fund of Chongqing Key Laboratory
文摘A cross-layer design which combines adaptive modulation and coding (AMC) at the physical layer with a hybrid automatic repeat request (HARQ) protocol at the data link layer (LL) is presented, in cooperative relay system over Nakagami-m fading channels with perfect and imperfect channel state information (CSI). In order to maximize spectral efficiency (SE) under delay and packet error rate (PER) performance constraints, a state transition model and an optimization framework with perfect CSI are presented. Then the framework is extended to cooperative relay system with imperfect CSI. The numerical results show that the scheme can achieve maximum SE while satisfying transmitting delay requirements. Compared with the imperfect CSI, the average PER with perfect CSI is much lower and the spectral efficiency is much higher.
