In Beyond the Fifth Generation(B5G)heterogeneous edge networks,numerous users are multiplexed on a channel or served on the same frequency resource block,in which case the transmitter applies coding and the receiver u...In Beyond the Fifth Generation(B5G)heterogeneous edge networks,numerous users are multiplexed on a channel or served on the same frequency resource block,in which case the transmitter applies coding and the receiver uses interference cancellation.Unfortunately,uncoordinated radio resource allocation can reduce system throughput and lead to user inequity,for this reason,in this paper,channel allocation and power allocation problems are formulated to maximize the system sum rate and minimum user achievable rate.Since the construction model is non-convex and the response variables are high-dimensional,a distributed Deep Reinforcement Learning(DRL)framework called distributed Proximal Policy Optimization(PPO)is proposed to allocate or assign resources.Specifically,several simulated agents are trained in a heterogeneous environment to find robust behaviors that perform well in channel assignment and power allocation.Moreover,agents in the collection stage slow down,which hinders the learning of other agents.Therefore,a preemption strategy is further proposed in this paper to optimize the distributed PPO,form DP-PPO and successfully mitigate the straggler problem.The experimental results show that our mechanism named DP-PPO improves the performance over other DRL methods.展开更多
Single atomic catalysts(SACs),especially metal-nitrogen doped carbon(M-NC)catalysts,have been extensively explored for the electrochemical oxygen reduction reaction(ORR),owing to their high activity and atomic utiliza...Single atomic catalysts(SACs),especially metal-nitrogen doped carbon(M-NC)catalysts,have been extensively explored for the electrochemical oxygen reduction reaction(ORR),owing to their high activity and atomic utilization efficiency.However,there is still a lack of systematic screening and optimization of local structures surrounding active centers of SACs for ORR as the local coordination has an essential impact on their electronic structures and catalytic performance.Herein,we systematic study the ORR catalytic performance of M-NC SACs with different central metals and environmental atoms in the first and second coordination sphere by using density functional theory(DFT)calculation and machine learning(ML).The geometric and electronic informed overpotential model(GEIOM)based on random forest algorithm showed the highest accuracy,and its R^(2) and root mean square errors(RMSE)were 0.96 and 0.21,respectively.30 potential high-performance catalysts were screened out by GEIOM,and the RMSE of the predicted result was only 0.12 V.This work not only helps us fast screen high-performance catalysts,but also provides a low-cost way to improve the accuracy of ML models.展开更多
The minimum energy per bit(EPB)as the energy efficiency(EE)metric in an automatic retransmission request(ARQ)based multi-hop system is analyzed under power and throughput constraints.Two ARQ protocols including type-I...The minimum energy per bit(EPB)as the energy efficiency(EE)metric in an automatic retransmission request(ARQ)based multi-hop system is analyzed under power and throughput constraints.Two ARQ protocols including type-I(ARQ-I)and repetition redundancy(ARQ-RR)are considered and expressions for the optimal power allocation(PA)are obtained.Using the obtained optimal powers,the EE-throughput tradeoff(EETT)is analyzed and the EETT closed-form expressions for both ARQ protocols and in arbitrary average channel gain values are obtained.It is shown that how different throughput requirements,especially the high levels,affect the EE performance.Additionally,asymptotic analysis is made in the feasible high throughput values and lower and upper EETT bounds are derived for ARQ-I protocol.To evaluate the EE a distributed PA scenario,as a benchmark,is presented and the energy savinggain obtained from the optimal PA in comparison with the distributed PA for ARQ-I and ARQ-RR protocols is discussed in different throughput values and node locations.展开更多
The simultaneous wireless information and power transfer(SWIPT)relay system is one of the emerging technologies.Xiaomi Corporation and Motorola Inc.recently launched indoor wireless power transfer equipment is one of ...The simultaneous wireless information and power transfer(SWIPT)relay system is one of the emerging technologies.Xiaomi Corporation and Motorola Inc.recently launched indoor wireless power transfer equipment is one of the most promising applications.To tap the potential of the system,hybrid automatic repeat request(HARQ)is introduced into the SWIPT relay system.Firstly,the time slot structure of HARQ scheme based on full duplex two-way amplify and forward(AF)SWIPT relay is given,and its retransmission status is analyzed.Secondly,the equivalent signal-to-noise ratio and outage probability of various states are calculated by approximate simplification.Thirdly,the energy harvesting power in each state is calculated.Finally,the energy harvested-throughput sum function is constructed to characterize the performance of energy harvesting and data transmission.Simulation results show that the proposed HARQ scheme has better energy harvestedthroughput sum function than the traditional HARQ scheme.When P_(2)=22 dB,the maximum sum function is 54.86%(the proposed HARQ scheme)and 52.307%(the traditional HARQ scheme),respectively.展开更多
Chemical vapor deposition is considered as the most hopeful method for the synthesis of large-area high-quality hexagonal boron nitride on the substrate of catalytic metal. However, the size the hexagonal boron nitrid...Chemical vapor deposition is considered as the most hopeful method for the synthesis of large-area high-quality hexagonal boron nitride on the substrate of catalytic metal. However, the size the hexagonal boron nitride films are limited to the size of growth chamber, which indicates a lower production efficiency. In this paper, the utilization efficiency of growth chamber is highly improved by alternately stacking multiple pieces of Cu foils and carbon fiber surface felt with porous structure. Uniform and continuous hexagonal boron nitride films are prepared on Cu foils through chemical vapor deposition utilizing ammonia borane as the precursor. This work develops a simple and practicable method for high-throughput preparation of hexagonal boron nitride films, which could contribute to the industrial application of hexagonal boron nitride. .展开更多
In the process of food testing,human operation is an important variable affecting the experimental results.In order to reasonably avoid the influence of human subjective operation behavior on the accuracy of detection...In the process of food testing,human operation is an important variable affecting the experimental results.In order to reasonably avoid the influence of human subjective operation behavior on the accuracy of detection results,the laboratory information management system was used as the information platform to design a high-throughput laboratory automation pre-treatment system based on the deep integration of mechanical principles,visual analysis,high-speed conduction,intelligent storage and other technical systems.The experimental results showed that the system could shorten the sample circulation cycle,effectively improve the laboratory biosafety,and meet the requirements of high-throughput processing of samples.展开更多
This paper proposes a raptor-like low-density parity-check(RL-LDPC)code design together with the corresponding decoder hardware architecture aiming at next-generation mobile communication.A new kind of protograph diff...This paper proposes a raptor-like low-density parity-check(RL-LDPC)code design together with the corresponding decoder hardware architecture aiming at next-generation mobile communication.A new kind of protograph different from the 5G new radio(NR)LDPC basic matrix is presented,and a code construction algorithm is proposed to improve the error-correcting performance.A multi-core layered decoder architecture that supports up to 100 Gbit/s throughput is designed based on the special protograph structure.展开更多
目的了解极早产儿生后1个月肠道菌群的动态变化及分布特征,为益生菌早期干预提供理论依据。方法采取前瞻性研究方法,选取2022年9月至2023年3月本院收治的极早产儿为研究对象,收集生后第7、14、21、28天的粪便标本行16 S rRNA高通量测序...目的了解极早产儿生后1个月肠道菌群的动态变化及分布特征,为益生菌早期干预提供理论依据。方法采取前瞻性研究方法,选取2022年9月至2023年3月本院收治的极早产儿为研究对象,收集生后第7、14、21、28天的粪便标本行16 S rRNA高通量测序及生物信息分析。结果共纳入极早产儿35例,男22例,女13例,出生胎龄210±11天,出生体重1419±339 g,收集粪便样本140份。在门水平上检测到的优势菌群包括厚壁菌门、变形菌门,占80%以上;属水平上检测到的优势菌群主要以条件致病菌为主,包括埃希菌属、梭菌属、葡萄球菌属、不动杆菌属和克雷伯杆菌属,而双歧杆菌属相对丰度均<5%。关键菌群差异分析发现,门及属水平的差异菌群主要为拟杆菌门(P=0.029)、蓝藻菌门(P=0.011)及葡萄球菌属(P=0.010)、罗氏菌属(P=0.040)。肠道菌群的多样性分析发现,四个时间点Alpla多样性指数Ace值及Shannon值比较差异无统计学差异(P>0.05),而Chao值呈逐渐下降趋势(P=0.001);四个时间点的Beta多样性分析Weighted-unifrac值分别为0.412(0.281~0.493)、0.498(0.214~0.526)、0.428(0.289~0.490)、0.143(0.077~0.423),差异有统计学意义(P<0.001)。结论极早产儿生后7~28天肠道优势菌群从厚壁菌门逐渐转变为变形菌门,并以条件致病菌为主,而双歧杆菌属定植数量少,肠道菌群多样性呈下降趋势。展开更多
基金supported by the Key Research and Development Program of China(No.2022YFC3005401)Key Research and Development Program of China,Yunnan Province(No.202203AA080009,202202AF080003)Postgraduate Research&Practice Innovation Program of Jiangsu Province(No.KYCX21_0482).
文摘In Beyond the Fifth Generation(B5G)heterogeneous edge networks,numerous users are multiplexed on a channel or served on the same frequency resource block,in which case the transmitter applies coding and the receiver uses interference cancellation.Unfortunately,uncoordinated radio resource allocation can reduce system throughput and lead to user inequity,for this reason,in this paper,channel allocation and power allocation problems are formulated to maximize the system sum rate and minimum user achievable rate.Since the construction model is non-convex and the response variables are high-dimensional,a distributed Deep Reinforcement Learning(DRL)framework called distributed Proximal Policy Optimization(PPO)is proposed to allocate or assign resources.Specifically,several simulated agents are trained in a heterogeneous environment to find robust behaviors that perform well in channel assignment and power allocation.Moreover,agents in the collection stage slow down,which hinders the learning of other agents.Therefore,a preemption strategy is further proposed in this paper to optimize the distributed PPO,form DP-PPO and successfully mitigate the straggler problem.The experimental results show that our mechanism named DP-PPO improves the performance over other DRL methods.
基金financially supported by the National Key Research and Development Program of China (2018YFA0702002)the Beijing Natural Science Foundation (Z210016)the National Natural Science Foundation of China (21935001)。
文摘Single atomic catalysts(SACs),especially metal-nitrogen doped carbon(M-NC)catalysts,have been extensively explored for the electrochemical oxygen reduction reaction(ORR),owing to their high activity and atomic utilization efficiency.However,there is still a lack of systematic screening and optimization of local structures surrounding active centers of SACs for ORR as the local coordination has an essential impact on their electronic structures and catalytic performance.Herein,we systematic study the ORR catalytic performance of M-NC SACs with different central metals and environmental atoms in the first and second coordination sphere by using density functional theory(DFT)calculation and machine learning(ML).The geometric and electronic informed overpotential model(GEIOM)based on random forest algorithm showed the highest accuracy,and its R^(2) and root mean square errors(RMSE)were 0.96 and 0.21,respectively.30 potential high-performance catalysts were screened out by GEIOM,and the RMSE of the predicted result was only 0.12 V.This work not only helps us fast screen high-performance catalysts,but also provides a low-cost way to improve the accuracy of ML models.
文摘The minimum energy per bit(EPB)as the energy efficiency(EE)metric in an automatic retransmission request(ARQ)based multi-hop system is analyzed under power and throughput constraints.Two ARQ protocols including type-I(ARQ-I)and repetition redundancy(ARQ-RR)are considered and expressions for the optimal power allocation(PA)are obtained.Using the obtained optimal powers,the EE-throughput tradeoff(EETT)is analyzed and the EETT closed-form expressions for both ARQ protocols and in arbitrary average channel gain values are obtained.It is shown that how different throughput requirements,especially the high levels,affect the EE performance.Additionally,asymptotic analysis is made in the feasible high throughput values and lower and upper EETT bounds are derived for ARQ-I protocol.To evaluate the EE a distributed PA scenario,as a benchmark,is presented and the energy savinggain obtained from the optimal PA in comparison with the distributed PA for ARQ-I and ARQ-RR protocols is discussed in different throughput values and node locations.
基金This work was supported by the National Natural Science Foundation of China(Grants No.61701251,62071244,62071249,61872423,61801236 and 61806100)Open Fund of Key Laboratory of Icing and Anti/De-icing(Grant No.IADL20190105)the Natural Science Foundation of Jiangsu Province(Grants No.BK20160903).
文摘The simultaneous wireless information and power transfer(SWIPT)relay system is one of the emerging technologies.Xiaomi Corporation and Motorola Inc.recently launched indoor wireless power transfer equipment is one of the most promising applications.To tap the potential of the system,hybrid automatic repeat request(HARQ)is introduced into the SWIPT relay system.Firstly,the time slot structure of HARQ scheme based on full duplex two-way amplify and forward(AF)SWIPT relay is given,and its retransmission status is analyzed.Secondly,the equivalent signal-to-noise ratio and outage probability of various states are calculated by approximate simplification.Thirdly,the energy harvesting power in each state is calculated.Finally,the energy harvested-throughput sum function is constructed to characterize the performance of energy harvesting and data transmission.Simulation results show that the proposed HARQ scheme has better energy harvestedthroughput sum function than the traditional HARQ scheme.When P_(2)=22 dB,the maximum sum function is 54.86%(the proposed HARQ scheme)and 52.307%(the traditional HARQ scheme),respectively.
文摘Chemical vapor deposition is considered as the most hopeful method for the synthesis of large-area high-quality hexagonal boron nitride on the substrate of catalytic metal. However, the size the hexagonal boron nitride films are limited to the size of growth chamber, which indicates a lower production efficiency. In this paper, the utilization efficiency of growth chamber is highly improved by alternately stacking multiple pieces of Cu foils and carbon fiber surface felt with porous structure. Uniform and continuous hexagonal boron nitride films are prepared on Cu foils through chemical vapor deposition utilizing ammonia borane as the precursor. This work develops a simple and practicable method for high-throughput preparation of hexagonal boron nitride films, which could contribute to the industrial application of hexagonal boron nitride. .
文摘In the process of food testing,human operation is an important variable affecting the experimental results.In order to reasonably avoid the influence of human subjective operation behavior on the accuracy of detection results,the laboratory information management system was used as the information platform to design a high-throughput laboratory automation pre-treatment system based on the deep integration of mechanical principles,visual analysis,high-speed conduction,intelligent storage and other technical systems.The experimental results showed that the system could shorten the sample circulation cycle,effectively improve the laboratory biosafety,and meet the requirements of high-throughput processing of samples.
基金supported in part by ZTE Industry-University-Institute Coop⁃eration funds under Grant No.2020ZTE01-03.
文摘This paper proposes a raptor-like low-density parity-check(RL-LDPC)code design together with the corresponding decoder hardware architecture aiming at next-generation mobile communication.A new kind of protograph different from the 5G new radio(NR)LDPC basic matrix is presented,and a code construction algorithm is proposed to improve the error-correcting performance.A multi-core layered decoder architecture that supports up to 100 Gbit/s throughput is designed based on the special protograph structure.
文摘目的了解极早产儿生后1个月肠道菌群的动态变化及分布特征,为益生菌早期干预提供理论依据。方法采取前瞻性研究方法,选取2022年9月至2023年3月本院收治的极早产儿为研究对象,收集生后第7、14、21、28天的粪便标本行16 S rRNA高通量测序及生物信息分析。结果共纳入极早产儿35例,男22例,女13例,出生胎龄210±11天,出生体重1419±339 g,收集粪便样本140份。在门水平上检测到的优势菌群包括厚壁菌门、变形菌门,占80%以上;属水平上检测到的优势菌群主要以条件致病菌为主,包括埃希菌属、梭菌属、葡萄球菌属、不动杆菌属和克雷伯杆菌属,而双歧杆菌属相对丰度均<5%。关键菌群差异分析发现,门及属水平的差异菌群主要为拟杆菌门(P=0.029)、蓝藻菌门(P=0.011)及葡萄球菌属(P=0.010)、罗氏菌属(P=0.040)。肠道菌群的多样性分析发现,四个时间点Alpla多样性指数Ace值及Shannon值比较差异无统计学差异(P>0.05),而Chao值呈逐渐下降趋势(P=0.001);四个时间点的Beta多样性分析Weighted-unifrac值分别为0.412(0.281~0.493)、0.498(0.214~0.526)、0.428(0.289~0.490)、0.143(0.077~0.423),差异有统计学意义(P<0.001)。结论极早产儿生后7~28天肠道优势菌群从厚壁菌门逐渐转变为变形菌门,并以条件致病菌为主,而双歧杆菌属定植数量少,肠道菌群多样性呈下降趋势。
