The Internet of things(IoT)has become a key infrastructure providing up-to-date and fresh information for policy analysis and decision-making of upper-layer applications.However,there are limited sensing and communica...The Internet of things(IoT)has become a key infrastructure providing up-to-date and fresh information for policy analysis and decision-making of upper-layer applications.However,there are limited sensing and communication resources in IoT devices,which significantly affects the timeliness and freshness of the updated status.This work proposes two schemes,namely,the generation rate control and service rate reservation schemes,to improve the overall information freshness of multiple status update streams at the receiver.Specifically,using the recently proposed Age of Information(AoI)as the metric for evaluating information freshness,we characterized the overall information freshness,i.e.,the overall average AoI at the receiver for both schemes,by considering the urgency difference of status update and streams.Both schemes for status updates and streams,respectively,were formulated as two optimization problems.We proved that both problems are convex and the optimal generation and service rates for different streams are found by the standard convex optimization algorithm.Moreover,we proposed both approximate optimal generation and approximate optimal service rate for fast deployment in heavy and light load cases.Numerical results verify the theoretical findings and accuracy of the proposed approximate solutions,guiding the design and deployment of IoT.展开更多
To discover new lead compounds for M1 agonists. Ten typical M1 agonists were superimposed to build a M1 agonists 3D-pharmacophore model using distance-comparisons （DISCO） method without the previous knowledge of the...To discover new lead compounds for M1 agonists. Ten typical M1 agonists were superimposed to build a M1 agonists 3D-pharmacophore model using distance-comparisons （DISCO） method without the previous knowledge of the three-dimensional structure of M1 receptor. Virtual screening strategy was used to analyze the Available Chemicals Directory-Screening Compounds （ACD-SC） to identify possible new hits. Twenty-two compounds which fit the pharmacophore model well and are not similar with known M1 agonists were purchased in order to evaluate their M1 receptor agonist activity. One of them shows M1 receptor agonist activity with EC50 of 4.90 μmol/L and maximum response. Multiple of 10.0 which shows it worthy of further study as a new lead compound for M1 agonists.展开更多
The Sèmè oilfield is located in Benin’s offshore coastal sedimentary basin, near the Benin-Nigeria border, and contains two important oil bearing structures called “Sèmè North” and “Sèm...The Sèmè oilfield is located in Benin’s offshore coastal sedimentary basin, near the Benin-Nigeria border, and contains two important oil bearing structures called “Sèmè North” and “Sèmè South”. In this coastal basin, Turonian sandstones of Abeokuta formation (Cenomanian-Turonian to Early Senonian age) form two reservoir units differentiated by two seismic horizons H6 and H6.5. The H6 seismic horizon represents the upper reservoir unit and is the main reservoir from which, more than 22 million barrels of crude oil had previously been produced in Sèmè oilfield. In order to improve knowledge of field petroleum geology, the present study presents the structural features of this upper reservoir unit. The use of Petrel software modules for the integration of 15 wells data, allowed presenting a structural model and illustrative cross sections that precise the geometry and specifying the structural characteristics of this reservoir unit within Sèmè field. The displayed structural architecture shows that the upper Turonian sandstones unit is composed of 11 layers including 7 reservoir layers (A, B, C1, C2, D1, D2, E) and 4 intra-reservoir layers (1, 2, 3 and 4) controlled by faults systems. The model provides basic framework necessary for geological characterization of the reservoir through a static model. The results of this study can be used for petrophysical modeling, Gross Rock Volume (GRV) determination and technical redevelopment of the field.展开更多
研究部署与任务期间导弹武器系统可用性建模方法与仿真实验设计。阐述了可用性概念,明确了量化指标,构建建模与仿真(modeling and simulation,M&S)一体化框架,利用分层组合的思想,提出了基于体系-实体-行为-状态(system-of-system,e...研究部署与任务期间导弹武器系统可用性建模方法与仿真实验设计。阐述了可用性概念,明确了量化指标,构建建模与仿真(modeling and simulation,M&S)一体化框架,利用分层组合的思想,提出了基于体系-实体-行为-状态(system-of-system,entity,behavior,state,SEBS)的可用性建模方法,即以体系组织集成建模为框架,以变结构实体建模为主体,以可用性为中心的行为建模为支撑,以基于故障与战损的可用状态建模为核心,并对模型的形式化描述展开研究。探讨了仿真实验设计的关键技术,提出基于测试-使用-维修-保障(test,operation,maintain,support,TOMS)的实验空间串联分割方法,并对随机变量建模、仿真优化设计、仿真系统可信度评估进行阐述。仿真结果表明,该分层组合评估方法快捷有效,仿真实验设计合理可行,极大地提高了可用性评估和分析的效率,为精确保障奠定了基础。展开更多
基金sponsored by the National Natural Science Foundation of China under Grant 61901066,Grant 61971077sponsored by Natural Science Foundation of Chongqing,China under Grant cstc2019jcyjmsxmX0575,Grant cstc2021jcyj-msxmX0458+2 种基金in part by the Entrepreneurship and Innovation Support Plan of Chongqing for Returned Overseas Scholars under Grant cx2021092supported by the open research fund of National Mobile Communications Research Laboratory,Southeast University(No.2021D13,No.2022D06)the Industrial Internet innovation and development project(No.TC200A00M).
文摘The Internet of things(IoT)has become a key infrastructure providing up-to-date and fresh information for policy analysis and decision-making of upper-layer applications.However,there are limited sensing and communication resources in IoT devices,which significantly affects the timeliness and freshness of the updated status.This work proposes two schemes,namely,the generation rate control and service rate reservation schemes,to improve the overall information freshness of multiple status update streams at the receiver.Specifically,using the recently proposed Age of Information(AoI)as the metric for evaluating information freshness,we characterized the overall information freshness,i.e.,the overall average AoI at the receiver for both schemes,by considering the urgency difference of status update and streams.Both schemes for status updates and streams,respectively,were formulated as two optimization problems.We proved that both problems are convex and the optimal generation and service rates for different streams are found by the standard convex optimization algorithm.Moreover,we proposed both approximate optimal generation and approximate optimal service rate for fast deployment in heavy and light load cases.Numerical results verify the theoretical findings and accuracy of the proposed approximate solutions,guiding the design and deployment of IoT.
基金National Natural Science Foundation of China (Grant No. 30271538)985 program,Ministry of Education of China
文摘To discover new lead compounds for M1 agonists. Ten typical M1 agonists were superimposed to build a M1 agonists 3D-pharmacophore model using distance-comparisons （DISCO） method without the previous knowledge of the three-dimensional structure of M1 receptor. Virtual screening strategy was used to analyze the Available Chemicals Directory-Screening Compounds （ACD-SC） to identify possible new hits. Twenty-two compounds which fit the pharmacophore model well and are not similar with known M1 agonists were purchased in order to evaluate their M1 receptor agonist activity. One of them shows M1 receptor agonist activity with EC50 of 4.90 μmol/L and maximum response. Multiple of 10.0 which shows it worthy of further study as a new lead compound for M1 agonists.
文摘The Sèmè oilfield is located in Benin’s offshore coastal sedimentary basin, near the Benin-Nigeria border, and contains two important oil bearing structures called “Sèmè North” and “Sèmè South”. In this coastal basin, Turonian sandstones of Abeokuta formation (Cenomanian-Turonian to Early Senonian age) form two reservoir units differentiated by two seismic horizons H6 and H6.5. The H6 seismic horizon represents the upper reservoir unit and is the main reservoir from which, more than 22 million barrels of crude oil had previously been produced in Sèmè oilfield. In order to improve knowledge of field petroleum geology, the present study presents the structural features of this upper reservoir unit. The use of Petrel software modules for the integration of 15 wells data, allowed presenting a structural model and illustrative cross sections that precise the geometry and specifying the structural characteristics of this reservoir unit within Sèmè field. The displayed structural architecture shows that the upper Turonian sandstones unit is composed of 11 layers including 7 reservoir layers (A, B, C1, C2, D1, D2, E) and 4 intra-reservoir layers (1, 2, 3 and 4) controlled by faults systems. The model provides basic framework necessary for geological characterization of the reservoir through a static model. The results of this study can be used for petrophysical modeling, Gross Rock Volume (GRV) determination and technical redevelopment of the field.
文摘为减少电力线信道时变性对自动抄表系统(automaticmeter-reading system,AMRS)计量数据传输效率的不利影响,提出了中继路由与分组队列相结合的方法。中继路由将整条通信链路分割成若干子链路,可以有效提高传输效率,但传输效率仍受制于信噪比(signal to noise ratio,SNR)最低的子链路。为充分利用每条子链路的最大传输效率,在中继路由的基础上,引入了分组队列机制。该方法根据接收和发送子链路的信道状况,动态调整分组队列长度,实现了发送子链路和接收子链路独立传输。由基于SNR的3状态Markov信道模型得到分组的平均发送次数,以该次数表示中继路由的分组接收速率和分组发送速率,建立了基于OPNET的M/M/1/K的AMRS分组排队模型。通过分析不同排队强度时的分组队列长度与队列延时等参数,验证了该方法能够提高传输效率。
文摘研究部署与任务期间导弹武器系统可用性建模方法与仿真实验设计。阐述了可用性概念,明确了量化指标,构建建模与仿真(modeling and simulation,M&S)一体化框架,利用分层组合的思想,提出了基于体系-实体-行为-状态(system-of-system,entity,behavior,state,SEBS)的可用性建模方法,即以体系组织集成建模为框架,以变结构实体建模为主体,以可用性为中心的行为建模为支撑,以基于故障与战损的可用状态建模为核心,并对模型的形式化描述展开研究。探讨了仿真实验设计的关键技术,提出基于测试-使用-维修-保障(test,operation,maintain,support,TOMS)的实验空间串联分割方法,并对随机变量建模、仿真优化设计、仿真系统可信度评估进行阐述。仿真结果表明,该分层组合评估方法快捷有效,仿真实验设计合理可行,极大地提高了可用性评估和分析的效率,为精确保障奠定了基础。
