提示:这是后非典时期新加坡传来的一则消息,新加坡在SARS肆虐时,标题中的Ferris Wheel,俗称“费里斯大转轮;大观览车”。所谓“费里斯转轮”,即一种在垂直转动的巨轮上挂有旋转时保持水平的座位的娱乐设施。其命名中的“费里斯”,即首...提示:这是后非典时期新加坡传来的一则消息,新加坡在SARS肆虐时,标题中的Ferris Wheel,俗称“费里斯大转轮;大观览车”。所谓“费里斯转轮”,即一种在垂直转动的巨轮上挂有旋转时保持水平的座位的娱乐设施。其命名中的“费里斯”,即首创这种设计的美国工程师George Washington Gale Ferris/乔治·华盛顿·盖尔·费里斯(1859-1896年)展开更多
This paper posits that a low-speed wind turbine design is suitable for harnessing wind energy in Africa.Conventional wind turbines consisting of propeller designs are commonly used across the world.A major hurdle to u...This paper posits that a low-speed wind turbine design is suitable for harnessing wind energy in Africa.Conventional wind turbines consisting of propeller designs are commonly used across the world.A major hurdle to utilizing wind energy in Africa is that conventional commercial wind turbines are designed to operate at wind speeds greater than those prevalent in most of the continent,especially in sub-Sahara Africa(SSA).They are heavy and expensive to purchase,install,and maintain.As a result,only a few countries in Africa have been able to include wind energy in their energy mix.In this paper,the feasibility of a novel low-speed wind turbine based on a Ferris wheel is demonstrated for low wind speed applications in Africa.The performance of Ferris wheel wind turbines(FWT)with 61m(200 ft),73m(240 ft)and 104m(341 ft)diameter rims and an 800kW generator are evaluated for selected African cities.The research also compares the Weibull wind distribution of the African cities of interest.A comparison between the FWT and the conventional commercial wind turbines in terms of efficiency,rated wind speed,cost,performance,and power to weight is included.Results show that the FWT has the potential for economic power generation at rated wind speeds of 6.74m/s,which are lower than the average of 12 m/s for conventional wind turbines and have lower power to weight ratios of 5.2 kW/tonne as compared to 6.0-9.2 kW/tonne for conventional wind turbines.展开更多
In this feasibility study, we investigate the viability of using Liquefied Natural Gas （LNG） fuel in an open type Ro-Ro passenger ferry and the associated potential challenges with regard to the vessel safety system...In this feasibility study, we investigate the viability of using Liquefied Natural Gas （LNG） fuel in an open type Ro-Ro passenger ferry and the associated potential challenges with regard to the vessel safety systems. We recommend an appropriate methodology for converting existing ships to run on LNG fuel, discuss all the necessary modifications to the ship’s safety systems, and also evaluate the relevant ship evacuation procedures. We outline the basic requirements with which the ship already complies for each safety system and analyze the additional restrictions that must be taken into consideration for the use of LNG fuel. Appropriate actions are recommended. Furthermore, we carry out a hazard identification study. Overall, we clearly demonstrate the technical feasibility of the investigated scenario. Minimal modifications to the ship’s safety systems are required to comply with existing safety rules for this specific type of ship.展开更多
In recent years,using message ferries as mechanical carriers of data has been shown to be an effective way to collect information in sparse wireless sensor networks.As the sensors are far away from each other in such ...In recent years,using message ferries as mechanical carriers of data has been shown to be an effective way to collect information in sparse wireless sensor networks.As the sensors are far away from each other in such highly partitioned scenario,a message ferry needs to travel a long route to access all the sensors and carry the data collected from the sensors to the sink.Typically,practical constraints(e.g.,the energy)preclude a ferry from visiting all sensors in a single tour.In such case,the ferry can only access part of the sensors in each tour and move back to the sink to get the energy refilled.So,the energy-constrained ferry route design(ECFRD)problem is discussed,which leads to the optimization problem of minimizing the total route length of the ferry,while keeping the route length of each tour below a given constraint.The ECFRD problem is proved to be NP-hard problem,and the integer linear programming(ILP)formulation is given.After that,efficient heuristic algorithms are proposed to solve this problem.The experimental results show that the performances of the proposed algorithms are effective in practice compared to the optimal solution.展开更多
Ferry accidents often occur the result of ship handling difficulty which interfacing human, machine and environment. Therefore, a decision tool model as a comprehensive information system, based on the ship handling d...Ferry accidents often occur the result of ship handling difficulty which interfacing human, machine and environment. Therefore, a decision tool model as a comprehensive information system, based on the ship handling difficulty, needs to be developed through the combination of Analytic Hierarchy Process (AHP) and Fuzzy Logic System. The Fuzzy Logic System part consists of ship condition, ship handling facility condition, navigation condition and weather condition. The output of decision tool is the ship handling difficulty level in linguistic form. The simulation of model is conducted at several straits in Indonesia water. The decision tool model could be used as management information system by port authority to monitor the ferry/ship movement in real time regarding the ship handling difficulty. Further, it would be used to take some useful safety operation strategies and safety policies to improve ferry transportation safety at port water and strait water.展开更多
文摘提示:这是后非典时期新加坡传来的一则消息,新加坡在SARS肆虐时,标题中的Ferris Wheel,俗称“费里斯大转轮;大观览车”。所谓“费里斯转轮”,即一种在垂直转动的巨轮上挂有旋转时保持水平的座位的娱乐设施。其命名中的“费里斯”,即首创这种设计的美国工程师George Washington Gale Ferris/乔治·华盛顿·盖尔·费里斯(1859-1896年)
基金This research is funded by the African Centre of Excellence,Energy for Sustainable Development,University of Rwanda,through the World Bank ACE II Program.
文摘This paper posits that a low-speed wind turbine design is suitable for harnessing wind energy in Africa.Conventional wind turbines consisting of propeller designs are commonly used across the world.A major hurdle to utilizing wind energy in Africa is that conventional commercial wind turbines are designed to operate at wind speeds greater than those prevalent in most of the continent,especially in sub-Sahara Africa(SSA).They are heavy and expensive to purchase,install,and maintain.As a result,only a few countries in Africa have been able to include wind energy in their energy mix.In this paper,the feasibility of a novel low-speed wind turbine based on a Ferris wheel is demonstrated for low wind speed applications in Africa.The performance of Ferris wheel wind turbines(FWT)with 61m(200 ft),73m(240 ft)and 104m(341 ft)diameter rims and an 800kW generator are evaluated for selected African cities.The research also compares the Weibull wind distribution of the African cities of interest.A comparison between the FWT and the conventional commercial wind turbines in terms of efficiency,rated wind speed,cost,performance,and power to weight is included.Results show that the FWT has the potential for economic power generation at rated wind speeds of 6.74m/s,which are lower than the average of 12 m/s for conventional wind turbines and have lower power to weight ratios of 5.2 kW/tonne as compared to 6.0-9.2 kW/tonne for conventional wind turbines.
基金conducted within the framework of the project LNG-COMSHIP,Greek General Secretariat of Research and Technology Code:12CHN400,and was funded by the European Regional Development Fund(ERDF) and National Resources
文摘In this feasibility study, we investigate the viability of using Liquefied Natural Gas （LNG） fuel in an open type Ro-Ro passenger ferry and the associated potential challenges with regard to the vessel safety systems. We recommend an appropriate methodology for converting existing ships to run on LNG fuel, discuss all the necessary modifications to the ship’s safety systems, and also evaluate the relevant ship evacuation procedures. We outline the basic requirements with which the ship already complies for each safety system and analyze the additional restrictions that must be taken into consideration for the use of LNG fuel. Appropriate actions are recommended. Furthermore, we carry out a hazard identification study. Overall, we clearly demonstrate the technical feasibility of the investigated scenario. Minimal modifications to the ship’s safety systems are required to comply with existing safety rules for this specific type of ship.
基金Projects(61272139,61070199,61103182)supported by the National Natural Science Foundation of ChinaProject(2013ZX01028001-002)supported by the National Science and Technology Major Projects of China+1 种基金Project(2011AA01A103)supported by theNational High-Tech Research and Development Plan of ChinaProject(11JJ7003)supported by Hunan Provincial Natural ScienceFoundation of China
文摘In recent years,using message ferries as mechanical carriers of data has been shown to be an effective way to collect information in sparse wireless sensor networks.As the sensors are far away from each other in such highly partitioned scenario,a message ferry needs to travel a long route to access all the sensors and carry the data collected from the sensors to the sink.Typically,practical constraints(e.g.,the energy)preclude a ferry from visiting all sensors in a single tour.In such case,the ferry can only access part of the sensors in each tour and move back to the sink to get the energy refilled.So,the energy-constrained ferry route design(ECFRD)problem is discussed,which leads to the optimization problem of minimizing the total route length of the ferry,while keeping the route length of each tour below a given constraint.The ECFRD problem is proved to be NP-hard problem,and the integer linear programming(ILP)formulation is given.After that,efficient heuristic algorithms are proposed to solve this problem.The experimental results show that the performances of the proposed algorithms are effective in practice compared to the optimal solution.
文摘Ferry accidents often occur the result of ship handling difficulty which interfacing human, machine and environment. Therefore, a decision tool model as a comprehensive information system, based on the ship handling difficulty, needs to be developed through the combination of Analytic Hierarchy Process (AHP) and Fuzzy Logic System. The Fuzzy Logic System part consists of ship condition, ship handling facility condition, navigation condition and weather condition. The output of decision tool is the ship handling difficulty level in linguistic form. The simulation of model is conducted at several straits in Indonesia water. The decision tool model could be used as management information system by port authority to monitor the ferry/ship movement in real time regarding the ship handling difficulty. Further, it would be used to take some useful safety operation strategies and safety policies to improve ferry transportation safety at port water and strait water.
