At the invitation of Union Youth Federation of Cambodia and the International Department of the Lao People’s Revolutionary Party’s Central Committee,a Chinese NGO Delegation headed by Mr.Ni Jian,Secretary-General of...At the invitation of Union Youth Federation of Cambodia and the International Department of the Lao People’s Revolutionary Party’s Central Committee,a Chinese NGO Delegation headed by Mr.Ni Jian,Secretary-General of the Chinese Association for International Understanding paid visit to Cambodia and Laos from October 21 to 28.As a member of the delegation,I set my feet on展开更多
Since the launch in 1950,Science China Series and Science Bulletin have published numerous significant scientific achievements,witnessing the development of science and technology in China and serving as a bridge conn...Since the launch in 1950,Science China Series and Science Bulletin have published numerous significant scientific achievements,witnessing the development of science and technology in China and serving as a bridge connecting Chinese scientists with their counterparts in the international scientific community.展开更多
China textile and apparel exports to Japan was witnessing a downturn in all statistics of China Customs and Japan METI in the Jan.-Apr. 2010 period. Exports to Japan this year later will face more pressure as gains in...China textile and apparel exports to Japan was witnessing a downturn in all statistics of China Customs and Japan METI in the Jan.-Apr. 2010 period. Exports to Japan this year later will face more pressure as gains in Japan’s consumption could moderate due to a lackluster jobs market and debt crisis.展开更多
Wireless Power Transfer(WPT)technology can provide real-time power for many terminal devices in Internet of Things(IoT)through millimeterWave(mmWave)to support applications with large capacity and low latency.Although...Wireless Power Transfer(WPT)technology can provide real-time power for many terminal devices in Internet of Things(IoT)through millimeterWave(mmWave)to support applications with large capacity and low latency.Although the intelligent reflecting surface(IRS)can be adopted to create effective virtual links to address the mmWave blockage problem,the conventional solutions only adopt IRS in the downlink from the Base Station(BS)to the users to enhance the received signal strength.In practice,the reflection of IRS is also applicable to the uplink to improve the spectral efficiency.It is a challenging to jointly optimize IRS beamforming and system resource allocation for wireless energy acquisition and information transmission.In this paper,we first design a Low-Energy Adaptive Clustering Hierarchy(LEACH)clustering protocol for clustering and data collection.Then,the problem of maximizing the minimum system spectral efficiency is constructed by jointly optimizing the transmit power of sensor devices,the uplink and downlink transmission times,the active beamforming at the BS,and the IRS dynamic beamforming.To solve this non-convex optimization problem,we propose an alternating optimization(AO)-based joint solution algorithm.Simulation results show that the use of IRS dynamic beamforming can significantly improve the spectral efficiency of the system,and ensure the reliability of equipment communication and the sustainability of energy supply under NLOS link.展开更多
The year 2023 witnessed frequent conflicts in South Asia, Africa, and the Middle East, fueling the existing security crises and paving the way for the expansion of international terrorism. The United States(US) is now...The year 2023 witnessed frequent conflicts in South Asia, Africa, and the Middle East, fueling the existing security crises and paving the way for the expansion of international terrorism. The United States(US) is now pursuing a “counterterrorism light” strategy, reducing investments in the fight against terrorism, and focusing on so-called great power competition. In such a context, security turbulence has severely affected counterterrorism in many world regions, pushing international counterterrorism efforts into a tight corner.展开更多
针对物流云服务模式中调度任务多、信息量大、需求广的特点,提出了一种改进蝙蝠算法求解物流云服务调度问题的方案,其优化目标为最小化调度时间和最大化资源利用率。根据设计的算法流程,首先基于工件升序排列(ranked order value,ROV)...针对物流云服务模式中调度任务多、信息量大、需求广的特点,提出了一种改进蝙蝠算法求解物流云服务调度问题的方案,其优化目标为最小化调度时间和最大化资源利用率。根据设计的算法流程,首先基于工件升序排列(ranked order value,ROV)规则对蝙蝠个体进行重新编码;然后调整初始化数据范围来减少分配任务超载和资源闲置现象,并在迭代过程中增加约束条件来均衡任务量,最终实现了资源与任务的智能调度。通过和遗传、粒子群以及基本蝙蝠算法的对比分析,体现了改进算法的优越性。最后利用Witness对方案进行仿真,证明了改进蝙蝠算法在解决物流云服务任务调度中的有效性,同时扩展了蝙蝠算法的应用领域。展开更多
文摘At the invitation of Union Youth Federation of Cambodia and the International Department of the Lao People’s Revolutionary Party’s Central Committee,a Chinese NGO Delegation headed by Mr.Ni Jian,Secretary-General of the Chinese Association for International Understanding paid visit to Cambodia and Laos from October 21 to 28.As a member of the delegation,I set my feet on
文摘Since the launch in 1950,Science China Series and Science Bulletin have published numerous significant scientific achievements,witnessing the development of science and technology in China and serving as a bridge connecting Chinese scientists with their counterparts in the international scientific community.
文摘China textile and apparel exports to Japan was witnessing a downturn in all statistics of China Customs and Japan METI in the Jan.-Apr. 2010 period. Exports to Japan this year later will face more pressure as gains in Japan’s consumption could moderate due to a lackluster jobs market and debt crisis.
基金supported by the National Natural Science Foundation of China 62001051.
文摘Wireless Power Transfer(WPT)technology can provide real-time power for many terminal devices in Internet of Things(IoT)through millimeterWave(mmWave)to support applications with large capacity and low latency.Although the intelligent reflecting surface(IRS)can be adopted to create effective virtual links to address the mmWave blockage problem,the conventional solutions only adopt IRS in the downlink from the Base Station(BS)to the users to enhance the received signal strength.In practice,the reflection of IRS is also applicable to the uplink to improve the spectral efficiency.It is a challenging to jointly optimize IRS beamforming and system resource allocation for wireless energy acquisition and information transmission.In this paper,we first design a Low-Energy Adaptive Clustering Hierarchy(LEACH)clustering protocol for clustering and data collection.Then,the problem of maximizing the minimum system spectral efficiency is constructed by jointly optimizing the transmit power of sensor devices,the uplink and downlink transmission times,the active beamforming at the BS,and the IRS dynamic beamforming.To solve this non-convex optimization problem,we propose an alternating optimization(AO)-based joint solution algorithm.Simulation results show that the use of IRS dynamic beamforming can significantly improve the spectral efficiency of the system,and ensure the reliability of equipment communication and the sustainability of energy supply under NLOS link.
文摘The year 2023 witnessed frequent conflicts in South Asia, Africa, and the Middle East, fueling the existing security crises and paving the way for the expansion of international terrorism. The United States(US) is now pursuing a “counterterrorism light” strategy, reducing investments in the fight against terrorism, and focusing on so-called great power competition. In such a context, security turbulence has severely affected counterterrorism in many world regions, pushing international counterterrorism efforts into a tight corner.
文摘针对物流云服务模式中调度任务多、信息量大、需求广的特点,提出了一种改进蝙蝠算法求解物流云服务调度问题的方案,其优化目标为最小化调度时间和最大化资源利用率。根据设计的算法流程,首先基于工件升序排列(ranked order value,ROV)规则对蝙蝠个体进行重新编码;然后调整初始化数据范围来减少分配任务超载和资源闲置现象,并在迭代过程中增加约束条件来均衡任务量,最终实现了资源与任务的智能调度。通过和遗传、粒子群以及基本蝙蝠算法的对比分析,体现了改进算法的优越性。最后利用Witness对方案进行仿真,证明了改进蝙蝠算法在解决物流云服务任务调度中的有效性,同时扩展了蝙蝠算法的应用领域。
