I type system model of CCCAM(Contention-Collision Cancellation Access Mode)is studied through mathematical modelling and simulation. There are two innovations: (1) in the account; (2) the time at which customers depar...I type system model of CCCAM(Contention-Collision Cancellation Access Mode)is studied through mathematical modelling and simulation. There are two innovations: (1) in the account; (2) the time at which customers depart after having been served successfully are chosen to be the embedded point, thereby "free period" is introduced reasonably. So the mathematical modelling and analysis result in this paper are significant for application of wire star LAN and wireless star LAN.展开更多
The sleep mode which works upon low arrival traffic is introduced in IEEE802.16e standard to reduce the power consumption of the mobile access terminal. Due to the rapid growth in the sleep interval in the exponential...The sleep mode which works upon low arrival traffic is introduced in IEEE802.16e standard to reduce the power consumption of the mobile access terminal. Due to the rapid growth in the sleep interval in the exponential growth algorithm prescribed in IEEE802.16e, the power saving efficiency of the mobile access terminal is limited and the average delay time of receiving data frames is prolonged when the arrival rate of data frames is low. To obtain lower power consumption and shorter average delay time, the logarithmic growth algorithm is proposed. Theoretical analysis and simulation results show that the proposed algorithm has lower average power consumption and shorter average delay time than the exponential growth algorithm, and it can meet the requirements of low traffic and real-time applications.展开更多
目的探讨Donabedian质量理论干预模式对行血管通路术的血液透析患者血管通路并发症发生率的影响。方法选取福建医科大学附属第二医院2021年12月—2022年12月收治的160例血液透析患者作为研究对象,按照随机数字表法分为对照组(n=80,予以...目的探讨Donabedian质量理论干预模式对行血管通路术的血液透析患者血管通路并发症发生率的影响。方法选取福建医科大学附属第二医院2021年12月—2022年12月收治的160例血液透析患者作为研究对象,按照随机数字表法分为对照组(n=80,予以常规护理干预)与观察组(n=80,在对照组的基础上予以Donabedian质量理论干预)。比较2组血液透析患者的日常生活能力评定量表(activity of daily living scale,ADL)及血管通路并发症的发生率。结果在对行血管通路术的血液透析患者进行质量理论干预后,观察组ADL评分[(40.48±3.97)分]明显低于对照组[(44.07±2.51)分](P<0.05);观察组血管通路并发症的总发生率(2.50%)明显低于对照组(11.25%),差异有统计学意义(P<0.05)。结论行血管通路术的血液透析患者使用Donabedian质量理论的干预模式可改善日常生活能力,减少血管通路并发症。展开更多
In the metropolises of China, the metro plays an increasingly important role in commuting because of its efficiency, affordability, and cleanliness. This paper attempts to explore the relationship between walking acce...In the metropolises of China, the metro plays an increasingly important role in commuting because of its efficiency, affordability, and cleanliness. This paper attempts to explore the relationship between walking access distance to metro stations and the demographic characteristics of passengers, such as age, monthly income, travel frequency, gender, and travel purpose, as well as the influence of the urban context. Nanjing Metro Line 2 is selected as the case study. By using different methods such as a questionnaire survey, spatial decay function, analysis of covariance(ANOVA), network analysis of routes, and K-means cluster analysis, it is suggested that demographic characteristics have a significant impact on the pedestrian walking distance, with the exception of gender. Furthermore, the paper finds a spatial decay effect in walking access distance, the decay rate of which, however, varies across stations. Terminal stations have a larger pedestrian catchment area than in regular and exchange stations. Moreover, the passengers of Nanjing Metro Line 2 can be classified into six groups according to their demographic characteristics, among which education and occupation are vital indicators in determining their willingness to walk to the stations. Middle-class passengers have a higher dependence on the metro and tend to walk longer than other groups do. This study provides an important reference for planners and transport sectors to optimize land-use and transport infrastructures.展开更多
Functional failure mode of commercial deep sub-micron static random access memory（SRAM） induced by total dose irradiation is experimentally analyzed and verified by circuit simulation. We extensively characterize th...Functional failure mode of commercial deep sub-micron static random access memory（SRAM） induced by total dose irradiation is experimentally analyzed and verified by circuit simulation. We extensively characterize the functional failure mode of the device by testing its electrical parameters and function with test patterns covering different functional failure modes. Experimental results reveal that the functional failure mode of the device is a temporary function interruption caused by peripheral circuits being sensitive to the standby current rising. By including radiation-induced threshold shift and off-state leakage current in memory cell transistors, we simulate the influence of radiation on the functionality of the memory cell. Simulation results reveal that the memory cell is tolerant to irradiation due to its high stability, which agrees with our experimental result.展开更多
老年人公园绿地可达性的评价,能够有效衡量老年人出行需求与公园绿地供给之间的关系,提高城市公共设施服务水平并增大老年人生活的幸福指数。以老年人出行方式选择行为和公园绿地固有属性确定的出行选择概率,得到基于选择概率的两步移...老年人公园绿地可达性的评价,能够有效衡量老年人出行需求与公园绿地供给之间的关系,提高城市公共设施服务水平并增大老年人生活的幸福指数。以老年人出行方式选择行为和公园绿地固有属性确定的出行选择概率,得到基于选择概率的两步移动搜索法(two-step floating catchment area method based on selection probability,SP2SFCA),用于评估老年人公园绿地的可达性。以重庆市渝北区为例,用ArcGIS进行插值分析与叠加分析,确定公园绿地可达性的分布差异与重点改善区域,计算老年人公园绿地的空间可达性。结果表明:与两步移动搜索法相比,SP2SFCA更具合理性与适配性,尤其是在评价高可达性区域内部差异和边界区域的可达性计算中具有更高的敏感性。由SP2SFCA计算得到的可达性,增长率最高达到3 127.17%,降低率最高达到97.03%;可达性极差的区域由0.48%提高至6.27%,极好的区域由48.92%降低至35.42%;低人口密度高可达性区域占比约14%,高人口密度低可达性区域占比约21%。SP2SFCA能够分析城市公园绿地资源的供给分布,为保障老年人生活与城市公园绿地分布格局提供了优化建议。展开更多
基金Supported by Natural Science Foundation of Qingdao University
文摘I type system model of CCCAM(Contention-Collision Cancellation Access Mode)is studied through mathematical modelling and simulation. There are two innovations: (1) in the account; (2) the time at which customers depart after having been served successfully are chosen to be the embedded point, thereby "free period" is introduced reasonably. So the mathematical modelling and analysis result in this paper are significant for application of wire star LAN and wireless star LAN.
基金Supported by the Major National Science and Technology Special Project (No. 2010ZX03004-002)
文摘The sleep mode which works upon low arrival traffic is introduced in IEEE802.16e standard to reduce the power consumption of the mobile access terminal. Due to the rapid growth in the sleep interval in the exponential growth algorithm prescribed in IEEE802.16e, the power saving efficiency of the mobile access terminal is limited and the average delay time of receiving data frames is prolonged when the arrival rate of data frames is low. To obtain lower power consumption and shorter average delay time, the logarithmic growth algorithm is proposed. Theoretical analysis and simulation results show that the proposed algorithm has lower average power consumption and shorter average delay time than the exponential growth algorithm, and it can meet the requirements of low traffic and real-time applications.
文摘目的探讨Donabedian质量理论干预模式对行血管通路术的血液透析患者血管通路并发症发生率的影响。方法选取福建医科大学附属第二医院2021年12月—2022年12月收治的160例血液透析患者作为研究对象,按照随机数字表法分为对照组(n=80,予以常规护理干预)与观察组(n=80,在对照组的基础上予以Donabedian质量理论干预)。比较2组血液透析患者的日常生活能力评定量表(activity of daily living scale,ADL)及血管通路并发症的发生率。结果在对行血管通路术的血液透析患者进行质量理论干预后,观察组ADL评分[(40.48±3.97)分]明显低于对照组[(44.07±2.51)分](P<0.05);观察组血管通路并发症的总发生率(2.50%)明显低于对照组(11.25%),差异有统计学意义(P<0.05)。结论行血管通路术的血液透析患者使用Donabedian质量理论的干预模式可改善日常生活能力,减少血管通路并发症。
基金Under the auspices of National Nature Science Foundation of China(No.41701180)
文摘In the metropolises of China, the metro plays an increasingly important role in commuting because of its efficiency, affordability, and cleanliness. This paper attempts to explore the relationship between walking access distance to metro stations and the demographic characteristics of passengers, such as age, monthly income, travel frequency, gender, and travel purpose, as well as the influence of the urban context. Nanjing Metro Line 2 is selected as the case study. By using different methods such as a questionnaire survey, spatial decay function, analysis of covariance(ANOVA), network analysis of routes, and K-means cluster analysis, it is suggested that demographic characteristics have a significant impact on the pedestrian walking distance, with the exception of gender. Furthermore, the paper finds a spatial decay effect in walking access distance, the decay rate of which, however, varies across stations. Terminal stations have a larger pedestrian catchment area than in regular and exchange stations. Moreover, the passengers of Nanjing Metro Line 2 can be classified into six groups according to their demographic characteristics, among which education and occupation are vital indicators in determining their willingness to walk to the stations. Middle-class passengers have a higher dependence on the metro and tend to walk longer than other groups do. This study provides an important reference for planners and transport sectors to optimize land-use and transport infrastructures.
文摘Functional failure mode of commercial deep sub-micron static random access memory（SRAM） induced by total dose irradiation is experimentally analyzed and verified by circuit simulation. We extensively characterize the functional failure mode of the device by testing its electrical parameters and function with test patterns covering different functional failure modes. Experimental results reveal that the functional failure mode of the device is a temporary function interruption caused by peripheral circuits being sensitive to the standby current rising. By including radiation-induced threshold shift and off-state leakage current in memory cell transistors, we simulate the influence of radiation on the functionality of the memory cell. Simulation results reveal that the memory cell is tolerant to irradiation due to its high stability, which agrees with our experimental result.
文摘老年人公园绿地可达性的评价,能够有效衡量老年人出行需求与公园绿地供给之间的关系,提高城市公共设施服务水平并增大老年人生活的幸福指数。以老年人出行方式选择行为和公园绿地固有属性确定的出行选择概率,得到基于选择概率的两步移动搜索法(two-step floating catchment area method based on selection probability,SP2SFCA),用于评估老年人公园绿地的可达性。以重庆市渝北区为例,用ArcGIS进行插值分析与叠加分析,确定公园绿地可达性的分布差异与重点改善区域,计算老年人公园绿地的空间可达性。结果表明:与两步移动搜索法相比,SP2SFCA更具合理性与适配性,尤其是在评价高可达性区域内部差异和边界区域的可达性计算中具有更高的敏感性。由SP2SFCA计算得到的可达性,增长率最高达到3 127.17%,降低率最高达到97.03%;可达性极差的区域由0.48%提高至6.27%,极好的区域由48.92%降低至35.42%;低人口密度高可达性区域占比约14%,高人口密度低可达性区域占比约21%。SP2SFCA能够分析城市公园绿地资源的供给分布,为保障老年人生活与城市公园绿地分布格局提供了优化建议。
