"When I was a youngster," complained the frustrated father, shaking his head, "I wasdisciplined by being sent to my room without supper, But our son has his own color TV,phone, computer and CD player.&q..."When I was a youngster," complained the frustrated father, shaking his head, "I wasdisciplined by being sent to my room without supper, But our son has his own color TV,phone, computer and CD player." "So what do you do when your son misbehaves?" asked his friend. "I send him to our room."展开更多
Adverse weather has serious implications for flight timeliness, as well as passenger and aircraft safety. This often implies that alternative flight paths have to be used by aircraft to avoid adverse weather. To reduc...Adverse weather has serious implications for flight timeliness, as well as passenger and aircraft safety. This often implies that alternative flight paths have to be used by aircraft to avoid adverse weather. To reduce the impact of such path re-routes, exact techniques such as artificial potential field model and Dijkstra’s algorithms have been proposed. However, such approaches are often unsuitable for real time scenarios involving large number of waypoints and constraints. This has led to the use of metaheuristic techniques that give sub-optimal solutions in good time. In this work, an improved genetic algorithm-based technique has been proposed. The algorithm used an improved mutation operator, reduced passenger inconvenience and considered the schedules of aircraft.展开更多
In developing countries like South Africa,users experienced more than 1030 hours of load shedding outages in just the first half of 2023 due to inadequate power supply from the national grid.Residential homes that can...In developing countries like South Africa,users experienced more than 1030 hours of load shedding outages in just the first half of 2023 due to inadequate power supply from the national grid.Residential homes that cannot afford to take actions to mitigate the challenges of load shedding are severely inconvenienced as they have to reschedule their demand involuntarily.This study presents optimal strategies to guide households in determining suitable scheduling and sizing solutions for solar home systems to mitigate the inconvenience experienced by residents due to load shedding.To start with,we predict the load shedding stages that are used as input for the optimal strategies by using the K-Nearest Neighbour(KNN)algorithm.Based on an accurate forecast of the future load shedding patterns,we formulate the residents’inconvenience and the loss of power supply probability during load shedding as the objective function.When solving the multi-objective optimisation problem,four different strategies to fight against load shedding are identified,namely(1)optimal home appliance scheduling(HAS)under load shedding;(2)optimal HAS supported by solar panels;(3)optimal HAS supported by batteries,and(4)optimal HAS supported by the solar home system with both solar panels and batteries.Among these strategies,appliance scheduling with an optimally sized 9.6 kWh battery and a 2.74 kWp panel array of five 550 Wp panels,eliminates the loss of power supply probability and reduces the inconvenience by 92%when tested under the South African load shedding cases in 2023.展开更多
The development of cloud computing has accel-erated the worldwide growth of internet data centers(IDCs).While a large portion of the energy consumption generated by intense computation introduces greater operation exp...The development of cloud computing has accel-erated the worldwide growth of internet data centers(IDCs).While a large portion of the energy consumption generated by intense computation introduces greater operation expenditures to the IDC enterprises.To manage the overall costs and utilize resources to their fullest extent,this paper introduces the concept of spatio-temporal workload allocation among the geographically distributed IDCs within a cloud,with the guarantee of the workload completion time and the consideration of computing service delay penalties by introducing the cost of inconvenience.Apart from the effort of the workload migration,the spatio-temporal variance of the renewable energies in the data center microgrids(DMGs)is fully considered in this paper.What's more,as the power consumed by the IDCs are primarily converted into heat,the waste heat recovery process is embedded in each IDC to demonstrate the effectiveness of the repurposed heat,which can be used by the residential heating demand in the thermal system,for total cost reduction and energy usage efficiency in the whole operating system.Applying real-life data traces of the electricity price,renewable energies and heating demand,these extensive evaluations demonstrate that both spatial and temporal complementary attempts on the supply side and demand side,along with power and thermal complementary efforts,can significantly reduce the overall cost for the IDC enterprise.展开更多
When it comes to carbon tariffs, China shouldn’t buy what the United States is selling The current cap-and-trade debate is generating a lot of noise in the United States. Much of that noise is coming from the halls o...When it comes to carbon tariffs, China shouldn’t buy what the United States is selling The current cap-and-trade debate is generating a lot of noise in the United States. Much of that noise is coming from the halls of Congress, where phone lines are ringing off the hook from citizens expressing展开更多
文摘"When I was a youngster," complained the frustrated father, shaking his head, "I wasdisciplined by being sent to my room without supper, But our son has his own color TV,phone, computer and CD player." "So what do you do when your son misbehaves?" asked his friend. "I send him to our room."
文摘Adverse weather has serious implications for flight timeliness, as well as passenger and aircraft safety. This often implies that alternative flight paths have to be used by aircraft to avoid adverse weather. To reduce the impact of such path re-routes, exact techniques such as artificial potential field model and Dijkstra’s algorithms have been proposed. However, such approaches are often unsuitable for real time scenarios involving large number of waypoints and constraints. This has led to the use of metaheuristic techniques that give sub-optimal solutions in good time. In this work, an improved genetic algorithm-based technique has been proposed. The algorithm used an improved mutation operator, reduced passenger inconvenience and considered the schedules of aircraft.
基金supported by National Key R&D Program of China(Grant No.2021YFE0199000)National Natural Science Foundation of China(Grant No.62133015)+1 种基金National Research Foundation China/South Africa Research Cooperation Programme with Grant No.148762Royal Academy of Engineering Transforming Systems through Partnership grant scheme with reference No.TSP2021\100016.
文摘In developing countries like South Africa,users experienced more than 1030 hours of load shedding outages in just the first half of 2023 due to inadequate power supply from the national grid.Residential homes that cannot afford to take actions to mitigate the challenges of load shedding are severely inconvenienced as they have to reschedule their demand involuntarily.This study presents optimal strategies to guide households in determining suitable scheduling and sizing solutions for solar home systems to mitigate the inconvenience experienced by residents due to load shedding.To start with,we predict the load shedding stages that are used as input for the optimal strategies by using the K-Nearest Neighbour(KNN)algorithm.Based on an accurate forecast of the future load shedding patterns,we formulate the residents’inconvenience and the loss of power supply probability during load shedding as the objective function.When solving the multi-objective optimisation problem,four different strategies to fight against load shedding are identified,namely(1)optimal home appliance scheduling(HAS)under load shedding;(2)optimal HAS supported by solar panels;(3)optimal HAS supported by batteries,and(4)optimal HAS supported by the solar home system with both solar panels and batteries.Among these strategies,appliance scheduling with an optimally sized 9.6 kWh battery and a 2.74 kWp panel array of five 550 Wp panels,eliminates the loss of power supply probability and reduces the inconvenience by 92%when tested under the South African load shedding cases in 2023.
基金This work was supported in part by the Support Project by the Ministry of Science and Technology of State Grid Corporation of China under Grant SGBJDK00KJJS1900085the World Bank China Renewable Energy Development Project Management Office.
文摘The development of cloud computing has accel-erated the worldwide growth of internet data centers(IDCs).While a large portion of the energy consumption generated by intense computation introduces greater operation expenditures to the IDC enterprises.To manage the overall costs and utilize resources to their fullest extent,this paper introduces the concept of spatio-temporal workload allocation among the geographically distributed IDCs within a cloud,with the guarantee of the workload completion time and the consideration of computing service delay penalties by introducing the cost of inconvenience.Apart from the effort of the workload migration,the spatio-temporal variance of the renewable energies in the data center microgrids(DMGs)is fully considered in this paper.What's more,as the power consumed by the IDCs are primarily converted into heat,the waste heat recovery process is embedded in each IDC to demonstrate the effectiveness of the repurposed heat,which can be used by the residential heating demand in the thermal system,for total cost reduction and energy usage efficiency in the whole operating system.Applying real-life data traces of the electricity price,renewable energies and heating demand,these extensive evaluations demonstrate that both spatial and temporal complementary attempts on the supply side and demand side,along with power and thermal complementary efforts,can significantly reduce the overall cost for the IDC enterprise.
文摘When it comes to carbon tariffs, China shouldn’t buy what the United States is selling The current cap-and-trade debate is generating a lot of noise in the United States. Much of that noise is coming from the halls of Congress, where phone lines are ringing off the hook from citizens expressing
