To address the shortcomings of single-step decision making in the existing deep reinforcement learning based unmanned aerial vehicle(UAV)real-time path planning problem,a real-time UAV path planning algorithm based on...To address the shortcomings of single-step decision making in the existing deep reinforcement learning based unmanned aerial vehicle(UAV)real-time path planning problem,a real-time UAV path planning algorithm based on long shortterm memory(RPP-LSTM)network is proposed,which combines the memory characteristics of recurrent neural network(RNN)and the deep reinforcement learning algorithm.LSTM networks are used in this algorithm as Q-value networks for the deep Q network(DQN)algorithm,which makes the decision of the Q-value network has some memory.Thanks to LSTM network,the Q-value network can use the previous environmental information and action information which effectively avoids the problem of single-step decision considering only the current environment.Besides,the algorithm proposes a hierarchical reward and punishment function for the specific problem of UAV real-time path planning,so that the UAV can more reasonably perform path planning.Simulation verification shows that compared with the traditional feed-forward neural network(FNN)based UAV autonomous path planning algorithm,the RPP-LSTM proposed in this paper can adapt to more complex environments and has significantly improved robustness and accuracy when performing UAV real-time path planning.展开更多
Background: Long-acting and reversible contraceptive methods hold great potential as solutions to address the unmet need for contraception and the significant discontinuation rates, especially in sub-Saharan Africa. A...Background: Long-acting and reversible contraceptive methods hold great potential as solutions to address the unmet need for contraception and the significant discontinuation rates, especially in sub-Saharan Africa. Among these methods, the Implant has gained popularity in sub-Saharan Africa, whereas the utilization of Intrauterine Devices (IUDs) has remained comparatively low, particularly in Burkina Faso. This study aims to evaluate the shifts in IUD and Implant usage from 2010 to 2020 and to pinpoint the factors influencing the choice of IUDs among LARCs users in Burkina Faso. Data and Methods: We conducted an analysis using data from Burkina Faso, drawn from the 2010 Demographic and Health Survey (DHS) and the 2020 PMA Phase 1 data. The 2010 DHS garnered responses from 17,087 women aged 15 - 49, achieving a response rate of 98.4%. The 2020 PMA data collected responses from 6590 women aged 15 - 49, with a response rate of 95.8%. The final sample of Long-Acting Reversible Contraceptives (LARCs) users consisted of 1502 women, including 576 women from the 2010 survey and 926 women from the 2020 survey. Results: The study demonstrates an expansion of IUD usage to include socioeconomically disadvantaged segments among LARC users. However, higher levels of education, older age, and decisions influenced by healthcare providers are correlated with the preference for IUDs over Implants. The choice of IUDs is also connected to a comprehensive understanding of contraceptive methods, suggesting potential biases in the counseling process. Conclusion: Facilitating the broader adoption of IUDs among disadvantaged groups could be achieved by improving the accessibility of IUD products and services in rural areas. Nevertheless, there should be focused initiatives to enhance access to removal services, as this factor could dissuade specific users. Further efforts are required to train healthcare providers, aiming to mitigate biases in delivering Long-Acting Reversible Contraceptives (LARCs). Providers should provide impartial counseling, irrespective of the selected type of LARC.展开更多
Medium-term air quality assessment,benchmarking it to recent past data can usefully complement short-term air quality index data for monitoring purposes.By using daily and monthly averaged data,medium-term air quality...Medium-term air quality assessment,benchmarking it to recent past data can usefully complement short-term air quality index data for monitoring purposes.By using daily and monthly averaged data,medium-term air quality benchmarking provides a distinctive perspective with which to monitor air quality for sustainability planning and ecosystem perspectives.By normalizing the data for individual air pollutants to a standard scale they can be more easily integrated to generate a daily combined local area benchmark(CLAB).The objectives of the study are to demonstrate that medium-term air quality benchmarking can be tailored to reflect local conditions by selecting the most relevant pollutants to incorporate in the CLAB indicator.Such a benchmark can provide an overall air quality assessment for areas of interest.A case study is presented for Dallas County(U.S.A.)applying the proposed method by benchmarking 2020 data for air pollutants to their trends established for 2015 to 2019.Six air pollutants considered are:ozone,carbon monoxide,nitrogen dioxide,sulfur dioxide,benzene and particulate matter less than 2.5 micrometres.These pollutants are assessed individually and in terms of CLAB,and their 2020 variations for Dallas County compared to daily trends established for years 2015 to 2019.Reductions in benzene and carbon monoxide during much of 2020 are clearly discernible compared to preceding years.The CLAB indicator shows clear seasonal trends for air quality for 2015 to 2019 with high pollution in winter and spring compared to other seasons that is strongly influenced by climatic variations with some anthropogenic inputs.Conducting CLAB analysis on an ongoing basis,using a relevant near-past time interval for benchmarking that covers several years,can reveal useful monthly,seasonal and annual trends in overall air quality.This type of medium-term,benchmarked air quality data analysis is well suited for ecosystem monitoring.展开更多
受高比例新能源并网带来的波动性和间歇性影响,新型电力系统的长周期供需不平衡矛盾日益突出。该文将电力系统的长周期供需不平衡风险分为两部分:连续多日无风无光的极端天气场景和月电量供需不平衡风险。首先,选取连续多日无风无光的...受高比例新能源并网带来的波动性和间歇性影响,新型电力系统的长周期供需不平衡矛盾日益突出。该文将电力系统的长周期供需不平衡风险分为两部分:连续多日无风无光的极端天气场景和月电量供需不平衡风险。首先,选取连续多日无风无光的极端天气场景,提出基于条件风险价值理论(conditional value at risk,CvaR)的月电量不平衡风险评估模型。在此基础上,提出考虑长周期供需不平衡风险的新型电力系统规划方法,通过季节性储能等灵活性资源的优化配置,可有效提升电力系统的长周期平衡能力。最后,基于IEEE RTS-79算例分析论证了所提方法的有效性,并初步讨论季节性储能在平抑长周期供需不平衡风险方面的作用。展开更多
Objective: The aim of the current study was to assess the impact of operative interventions for misplaced device among women who opted for PPIIUCD and the evaluation of reasons for PPIUCD removal within the follow up ...Objective: The aim of the current study was to assess the impact of operative interventions for misplaced device among women who opted for PPIIUCD and the evaluation of reasons for PPIUCD removal within the follow up period of two years. Design: A descriptive exploratory study was conducted over three months among fourteen PPIUCD acceptors at a tertiary care health facility in Delhi, India. Face-to-face & telephonic in-depth interviews were conducted with a selected sample of PPIUCD acceptors who had later opted for its removal. Results: Participants (n = 14) aged 24 – 40 exhibited generally positive attitudes towards PPIUCDs indicating an indicate an understanding of the importance of PPIUCD in preventing unintended pregnancies. Menstrual disturbance and misplaced IUCD were major reasons for removal. despite their own experience necessitating the removal of IUCD, positive experience by other family members (mothers in law) in this study helped to keep the confidence on the contraceptive. Themes included (a) general experience of PPIUCD use (b) Health Facility accessed for removal of IUCD (c) Would she recommend it to others? (d) preferred contraceptive after removal of IUCD. Conclusion: Misplaced IUCD, missing thread, menstrual irregularities, and pain are all associated with PPIUCD and are important reasons for dissatisfaction. Appropriate, timely and supportive individualized care that address knowledge gaps, societal perceptions, and healthcare system challenges would certainly help in reducing dissatisfaction due to PPIUCD and thereby the removal rates.展开更多
基金supported by the Natural Science Basic Research Prog ram of Shaanxi(2022JQ-593)。
文摘To address the shortcomings of single-step decision making in the existing deep reinforcement learning based unmanned aerial vehicle(UAV)real-time path planning problem,a real-time UAV path planning algorithm based on long shortterm memory(RPP-LSTM)network is proposed,which combines the memory characteristics of recurrent neural network(RNN)and the deep reinforcement learning algorithm.LSTM networks are used in this algorithm as Q-value networks for the deep Q network(DQN)algorithm,which makes the decision of the Q-value network has some memory.Thanks to LSTM network,the Q-value network can use the previous environmental information and action information which effectively avoids the problem of single-step decision considering only the current environment.Besides,the algorithm proposes a hierarchical reward and punishment function for the specific problem of UAV real-time path planning,so that the UAV can more reasonably perform path planning.Simulation verification shows that compared with the traditional feed-forward neural network(FNN)based UAV autonomous path planning algorithm,the RPP-LSTM proposed in this paper can adapt to more complex environments and has significantly improved robustness and accuracy when performing UAV real-time path planning.
文摘Background: Long-acting and reversible contraceptive methods hold great potential as solutions to address the unmet need for contraception and the significant discontinuation rates, especially in sub-Saharan Africa. Among these methods, the Implant has gained popularity in sub-Saharan Africa, whereas the utilization of Intrauterine Devices (IUDs) has remained comparatively low, particularly in Burkina Faso. This study aims to evaluate the shifts in IUD and Implant usage from 2010 to 2020 and to pinpoint the factors influencing the choice of IUDs among LARCs users in Burkina Faso. Data and Methods: We conducted an analysis using data from Burkina Faso, drawn from the 2010 Demographic and Health Survey (DHS) and the 2020 PMA Phase 1 data. The 2010 DHS garnered responses from 17,087 women aged 15 - 49, achieving a response rate of 98.4%. The 2020 PMA data collected responses from 6590 women aged 15 - 49, with a response rate of 95.8%. The final sample of Long-Acting Reversible Contraceptives (LARCs) users consisted of 1502 women, including 576 women from the 2010 survey and 926 women from the 2020 survey. Results: The study demonstrates an expansion of IUD usage to include socioeconomically disadvantaged segments among LARC users. However, higher levels of education, older age, and decisions influenced by healthcare providers are correlated with the preference for IUDs over Implants. The choice of IUDs is also connected to a comprehensive understanding of contraceptive methods, suggesting potential biases in the counseling process. Conclusion: Facilitating the broader adoption of IUDs among disadvantaged groups could be achieved by improving the accessibility of IUD products and services in rural areas. Nevertheless, there should be focused initiatives to enhance access to removal services, as this factor could dissuade specific users. Further efforts are required to train healthcare providers, aiming to mitigate biases in delivering Long-Acting Reversible Contraceptives (LARCs). Providers should provide impartial counseling, irrespective of the selected type of LARC.
文摘Medium-term air quality assessment,benchmarking it to recent past data can usefully complement short-term air quality index data for monitoring purposes.By using daily and monthly averaged data,medium-term air quality benchmarking provides a distinctive perspective with which to monitor air quality for sustainability planning and ecosystem perspectives.By normalizing the data for individual air pollutants to a standard scale they can be more easily integrated to generate a daily combined local area benchmark(CLAB).The objectives of the study are to demonstrate that medium-term air quality benchmarking can be tailored to reflect local conditions by selecting the most relevant pollutants to incorporate in the CLAB indicator.Such a benchmark can provide an overall air quality assessment for areas of interest.A case study is presented for Dallas County(U.S.A.)applying the proposed method by benchmarking 2020 data for air pollutants to their trends established for 2015 to 2019.Six air pollutants considered are:ozone,carbon monoxide,nitrogen dioxide,sulfur dioxide,benzene and particulate matter less than 2.5 micrometres.These pollutants are assessed individually and in terms of CLAB,and their 2020 variations for Dallas County compared to daily trends established for years 2015 to 2019.Reductions in benzene and carbon monoxide during much of 2020 are clearly discernible compared to preceding years.The CLAB indicator shows clear seasonal trends for air quality for 2015 to 2019 with high pollution in winter and spring compared to other seasons that is strongly influenced by climatic variations with some anthropogenic inputs.Conducting CLAB analysis on an ongoing basis,using a relevant near-past time interval for benchmarking that covers several years,can reveal useful monthly,seasonal and annual trends in overall air quality.This type of medium-term,benchmarked air quality data analysis is well suited for ecosystem monitoring.
文摘受高比例新能源并网带来的波动性和间歇性影响,新型电力系统的长周期供需不平衡矛盾日益突出。该文将电力系统的长周期供需不平衡风险分为两部分:连续多日无风无光的极端天气场景和月电量供需不平衡风险。首先,选取连续多日无风无光的极端天气场景,提出基于条件风险价值理论(conditional value at risk,CvaR)的月电量不平衡风险评估模型。在此基础上,提出考虑长周期供需不平衡风险的新型电力系统规划方法,通过季节性储能等灵活性资源的优化配置,可有效提升电力系统的长周期平衡能力。最后,基于IEEE RTS-79算例分析论证了所提方法的有效性,并初步讨论季节性储能在平抑长周期供需不平衡风险方面的作用。
文摘Objective: The aim of the current study was to assess the impact of operative interventions for misplaced device among women who opted for PPIIUCD and the evaluation of reasons for PPIUCD removal within the follow up period of two years. Design: A descriptive exploratory study was conducted over three months among fourteen PPIUCD acceptors at a tertiary care health facility in Delhi, India. Face-to-face & telephonic in-depth interviews were conducted with a selected sample of PPIUCD acceptors who had later opted for its removal. Results: Participants (n = 14) aged 24 – 40 exhibited generally positive attitudes towards PPIUCDs indicating an indicate an understanding of the importance of PPIUCD in preventing unintended pregnancies. Menstrual disturbance and misplaced IUCD were major reasons for removal. despite their own experience necessitating the removal of IUCD, positive experience by other family members (mothers in law) in this study helped to keep the confidence on the contraceptive. Themes included (a) general experience of PPIUCD use (b) Health Facility accessed for removal of IUCD (c) Would she recommend it to others? (d) preferred contraceptive after removal of IUCD. Conclusion: Misplaced IUCD, missing thread, menstrual irregularities, and pain are all associated with PPIUCD and are important reasons for dissatisfaction. Appropriate, timely and supportive individualized care that address knowledge gaps, societal perceptions, and healthcare system challenges would certainly help in reducing dissatisfaction due to PPIUCD and thereby the removal rates.
