Mobile devices as a popular computing platform for enterprise systems have enabled certain tasks to be executed out of office.However,the work may be interrupted due to the server shutdown or network disconnection whe...Mobile devices as a popular computing platform for enterprise systems have enabled certain tasks to be executed out of office.However,the work may be interrupted due to the server shutdown or network disconnection when employees access traditional single-engine Business Process Management System.To overcome this defect,we present a lightweight twin-engine architecture based on Service Oriented Architecture(SOA).In this paper,we discuss in detail the design and implementation of the architecture,and present a trigger mechanism to activate engines according to the states of hybrid environments since it is critical for the two types of engines to cooperate closely in hybrid environments with fixed and mobile computing resources.The experimental results validate the usability of the architecture.展开更多
The Boeing 747 and Airbus A380 passenger jets used to control long-distance traveling,a symbol of safety,distance,and status.However,advances in high-bypass turbofan engines,rising fuel prices,and growing environmenta...The Boeing 747 and Airbus A380 passenger jets used to control long-distance traveling,a symbol of safety,distance,and status.However,advances in high-bypass turbofan engines,rising fuel prices,and growing environmental pressures have made this configuration increasingly uneconomic.This project investigates three questions:why four-engine airliners have been discontinued,and what engine improvements have enabled twin-engine aircraft to replace them while still leaving essential challenges for the future.Drawing on technical textbooks,academic articles,industry reports,and historical case studies,the dissertation explains the working principles of turbofan engines,traces the development of quadjets,and compares the performance,fuel efficiency,maintenance demands,and regulatory constraints of four-and twoengine layouts.The analysis shows that modern twin-engine wide-bodies can match or exceed the range and payload of classic quadjets with much lower fuel burn and maintenance cost,especially after the relaxation of Extended-range Twin-engine Operational Performance Standards(ETOPS)rules and the shift towards pointtopoint networks.At the same time,gas-turbine technology is approaching limits in bypass ratio,temperature,and materials,while climate policy highlights unresolved CO₂and non-CO₂impacts.Future propulsion concepts such as open-rotor engines,hybrid-electric systems,and sustainable aviation fuels offer potential benefits but introduce new technical and economic trade-offs.展开更多
基金supported by the National 973 Programs(2013CB329102)the National Natural Science Foundation of China(61501048)+3 种基金China Postdoctoral Science Foundation funded project(2016T90067,2015M570060)the Key Project of National Natural Science Foundation of China(61132001)the National Key Technology Research and Development Program of China(2012BAH94F02)the Fundamental Research Funds for the Central Universities(2015RC22)
文摘Mobile devices as a popular computing platform for enterprise systems have enabled certain tasks to be executed out of office.However,the work may be interrupted due to the server shutdown or network disconnection when employees access traditional single-engine Business Process Management System.To overcome this defect,we present a lightweight twin-engine architecture based on Service Oriented Architecture(SOA).In this paper,we discuss in detail the design and implementation of the architecture,and present a trigger mechanism to activate engines according to the states of hybrid environments since it is critical for the two types of engines to cooperate closely in hybrid environments with fixed and mobile computing resources.The experimental results validate the usability of the architecture.
文摘The Boeing 747 and Airbus A380 passenger jets used to control long-distance traveling,a symbol of safety,distance,and status.However,advances in high-bypass turbofan engines,rising fuel prices,and growing environmental pressures have made this configuration increasingly uneconomic.This project investigates three questions:why four-engine airliners have been discontinued,and what engine improvements have enabled twin-engine aircraft to replace them while still leaving essential challenges for the future.Drawing on technical textbooks,academic articles,industry reports,and historical case studies,the dissertation explains the working principles of turbofan engines,traces the development of quadjets,and compares the performance,fuel efficiency,maintenance demands,and regulatory constraints of four-and twoengine layouts.The analysis shows that modern twin-engine wide-bodies can match or exceed the range and payload of classic quadjets with much lower fuel burn and maintenance cost,especially after the relaxation of Extended-range Twin-engine Operational Performance Standards(ETOPS)rules and the shift towards pointtopoint networks.At the same time,gas-turbine technology is approaching limits in bypass ratio,temperature,and materials,while climate policy highlights unresolved CO₂and non-CO₂impacts.Future propulsion concepts such as open-rotor engines,hybrid-electric systems,and sustainable aviation fuels offer potential benefits but introduce new technical and economic trade-offs.
