The Internet of Things(IoT)has witnessed a significant surge in adoption,particularly through the utilization of Wireless Sensor Networks(WSNs),which comprise small internet-connected devices.These deployments span va...The Internet of Things(IoT)has witnessed a significant surge in adoption,particularly through the utilization of Wireless Sensor Networks(WSNs),which comprise small internet-connected devices.These deployments span various environments and offer a multitude of benefits.However,the widespread use of battery-powered devices introduces challenges due to their limited hardware resources and communication capabilities.In response to this,the Internet Engineering Task Force(IETF)has developed the IPv6 Routing Protocol for Low-power and Lossy Networks(RPL)to address the unique requirements of such networks.Recognizing the critical role of RPL in maintaining high performance,this paper proposes a novel approach to optimizing power consumption.Specifically,it introduces a developed sensor motes topology integrated with a Radio Duty Cycling(RDC)mechanism aimed at minimizing power usage.Through rigorous analysis,the paper evaluates the power efficiency of this approach through several simulations conducted across different network topologies,including random,linear,tree,and elliptical topologies.Additionally,three distinct RDC mechanisms—CXMAC,ContikiMAC,and NullRDC—are investigated to assess their impact on power consumption.The findings of the study,based on a comprehensive and deep analysis of the simulated results,highlight the efficiency of ContikiMAC in power conservation.This research contributes valuable insights into enhancing the energy efficiency of RPL-based IoT networks,ultimately facilitating their widespread deployment and usability in diverse environments.展开更多
In view of the large current peak and torque ripple in the actual current chopping control of switched reluctance motor,a segmented PWM duty cycle analysis method of switched reluctance motor based on current chopping...In view of the large current peak and torque ripple in the actual current chopping control of switched reluctance motor,a segmented PWM duty cycle analysis method of switched reluctance motor based on current chopping control is proposed in this paper.The method realizes the control of the winding current by adjusting the average voltage of the two ends of the winding in one cycle through the PWM duty cycle.At the same time,according to the inductance linear model,the conduction phase is divided into a small inductance region and an inductance rising region,and the analytical formulas of PWM duty cycle in the two regions are deduced respectively.Finally,through matlab/simulink simulation and motor platform experiment,the current chopping control is compared with the segmented PWM duty cycle analysis method in this paper.Simulation and experimental results show that the segmented PWM duty cycle analysis method can effectively reduce the current peak and torque ripple,and has high practical application value.展开更多
This work is geared to carry out epistemic analysis of Kantian ethics of duty call vis-à-vis paranormal in Nigerian society among clergymen.The recent changes in Nigerian and other African countries like colonial...This work is geared to carry out epistemic analysis of Kantian ethics of duty call vis-à-vis paranormal in Nigerian society among clergymen.The recent changes in Nigerian and other African countries like colonialism that brought Western education,globalization,urbanization,and new religion(Islam and Christianity)have made it that divination in traditional African religion is no longer in vogue in this contemporary period.Divination and fortune telling have taken a new dimension in form of faith healing and miracles by some prophets and so called men of God like pastors,priests,and imam.The quest for materialism among the ministers and clerics of Islamic,Christian and traditional religion has made them abuse their religious calling for their selfish interests.This work makes use of analytic and critical methods of data analysis.This work postulates that Immanuel Kant’s ethics of duty call serves to provide a guiding principle to Nigeria clergymen of different religions on the need for them to carry out their religious duties out of good will.On the other hand,twisting or distorting the teachings of their religion to serve their various selfish interests contravenes Immanuel Kant’s ethics of duty call.Finally,they have to contribute positively to nation building by propagating or fostering the positive ideology,theories,or doctrines that will promote love and national unity in a multicultural country like Nigeria.展开更多
This study looked at the impact of the Nigerian stamp duty tax on the growth of the economy.Time series data were employed spanning the years 1999-2020.For various years,related data were extracted from the Central Ba...This study looked at the impact of the Nigerian stamp duty tax on the growth of the economy.Time series data were employed spanning the years 1999-2020.For various years,related data were extracted from the Central Bank of Nigeria Statistical Bulletin,the Bureau of National Statistics,and Federal Inland Revenue Service reports.E-view 9.0 was used to test the hypothesis using the ordinary least square.The study outcome revealed that stamp duty has an insignificant and positive impact on Nigeria’s economic growth.It was recommended that the government improve public entities and provide strong government investment as a source of domestic revenue generated from various business activities.展开更多
The heavy-duty vehicle fleet involved in delivering water and sand makes noticeable issues of exhaust emissions and fuel consumption in the process of shale gas development. To examine the possibility of converting th...The heavy-duty vehicle fleet involved in delivering water and sand makes noticeable issues of exhaust emissions and fuel consumption in the process of shale gas development. To examine the possibility of converting these heavy-duty diesel engines to run on natural gas-diesel dual-fuel, a transient engine duty cycle representing the real-world engine working conditions is necessary. In this paper, a methodology is proposed, and a target engine duty cycle comprising of 2231 seconds is developed from on-road data collected from 11 on-road sand and water hauling trucks. The similarity of inherent characteristics of the developed cycle and the base trip observed is evidenced by the 2.05% error of standard deviation and average values for normalized engine speed and engine torque. Our results show that the proposed approach is expected to produce a representative cycle of in-use heavy-duty engine behavior.展开更多
With the expansion of the application range and network scale of wireless sensor networks in recent years,WSNs often generate data surges and delay queues during the transmission process,causing network paralysis,even...With the expansion of the application range and network scale of wireless sensor networks in recent years,WSNs often generate data surges and delay queues during the transmission process,causing network paralysis,even resulting in local or global congestion.In this paper,a dynamically Adjusted Duty Cycle for Optimized Congestion based on a real-time Queue Length(ADCOC)scheme is proposed.In order to improve the resource utilization rate of network nodes,we carried out optimization analysis based on the theory and applied it to the adjustment of the node’s duty cycle strategy.Using this strategy to ensure that the network lifetime remains the same,can minimize system delay and maximize energy efficiency.Firstly,the problems of the existing RED algorithm are analyzed.We introduce the improved SIG-RED algorithm into the ADCOC mechanism.As the data traffic changes,the RED protocol cannot automatically adjust the duty cycle.A scheduler is added to the buffer area manager,referring to a weighted index of network congestion,which can quickly determine the status of network congestion.The value of the weighting coefficient W is adjusted by the Bayesian method.The scheduler preferably transmits severely urgent data,alleviating the memory load.Then we combined improved data fusion technology and information gain methods to adjust the duty cycle dynamically.By simulating the algorithm,it shows that it has faster convergence speed and smaller queue jitter.Finally,we combine the adjusted congestion weight and the duty cycle growth value to adjust the data processing rate capability in the real-time network by dynamically adjusting it to adapt to bursts of data streams.Thus,the frequency of congestion is reduced to ensure that the system has higher processing efficiency and good adaptability.展开更多
Duty-cycle modulation alternately blowing from two opposite-facing plasma actu- ators on the leeward surface near the apex of a cone with a 10° semi-apex angle is adopted to control mean lateral force and moment,...Duty-cycle modulation alternately blowing from two opposite-facing plasma actu- ators on the leeward surface near the apex of a cone with a 10° semi-apex angle is adopted to control mean lateral force and moment, and the flow control mechanisms are presented. Pressure distributions over the forebody of the cone are measured by steady pressure tappings. The experiments are performed in a 3.0×1.6 m open-circuit wind tunnel at a wind speed of 20 m/s, a 45° angle of attack and a Reynolds number of 2×10^5, based on the diameter of the base of the cone. Almost linearly proportional control of the lateral forces and moments over a slender conical forebody at a high angle of attack has been demonstrated by employing a pair of single dielectric barrier discharge plasma actuators near the apex of the cone, combined with a duty-cycle tech- nique. The pressure distribution measurements indicate that the hi-stable vortex pattern appears to be shifted in the opposite direction when the port or starboard actuator is activated, while the other is kept off during the test. It is shown that the reduced pulse-repetition frequency based on the local diameter at the plasma actuator equal to one yields the highest effectiveness among the cases considered.展开更多
We report the transient effects in Erbium Doped Fiber Amplifier (EDFA) systems for pulsed signals with different duty-cycles. The work includes the analysis using three different duty-cycles, 10%, 20% and 50%. A curve...We report the transient effects in Erbium Doped Fiber Amplifier (EDFA) systems for pulsed signals with different duty-cycles. The work includes the analysis using three different duty-cycles, 10%, 20% and 50%. A curve fitting technique is also proposed to predict the transients of any lesser duty-cycled pulse, once the transients of a larger duty-cycled pulse is known. Mathematical evaluation confirms the double exponential shape of transient distorted signal. Further, EDFA transient effect is experimentally verified on a Wavelength Division Multiplexed (WDM) link by multiplexing high and low bitrate modulated optical signals. We conclude the paper by proposing a transient suppression technique for variable dutycycle signals and analyzing its effectiveness with different wavelength spacing.展开更多
Driving style,traffic and weather conditions have a significant impact on vehicle fuel consumption and in particular,the road freight traffic significantly contributes to the CO2 increase in atmosphere.This paper prop...Driving style,traffic and weather conditions have a significant impact on vehicle fuel consumption and in particular,the road freight traffic significantly contributes to the CO2 increase in atmosphere.This paper proposes an Eco-Route Planner devoted to determine and communicate to the drivers of Heavy-Duty Vehicles(HDVs)the eco-route that guarantees the minimum fuel consumption by respecting the travel time established by the freight companies.The proposed eco-route is the optimal route from origin to destination and includes the optimized speed and gear profiles.To this aim,the Cloud Computing System architecture is composed of two main components:the Data Management System that collects,fuses and integrates the raw external sources data and the Cloud Optimizer that builds the route network,selects the eco-route and determines the optimal speed and gear profiles.Finally,a real case study is discussed by showing the benefit of the proposed Eco-Route planner.展开更多
SnS∶Ag thin films were deposited on ITO glasses by pulse electro-deposition. By studying the effect of duty cycle on the properties of SnS∶Ag thin films, the optimum off-time(toff) is obtained to be 5 s, namely, the...SnS∶Ag thin films were deposited on ITO glasses by pulse electro-deposition. By studying the effect of duty cycle on the properties of SnS∶Ag thin films, the optimum off-time(toff) is obtained to be 5 s, namely, the optimal duty cycle is about 67%. The primary phase of SnS∶Ag films deposited on optimum parameters condition is SnS compound with good crystallization, and the films prefer to grow towards (111) plane. The films are dense, smooth and uniform with good microstructure, and the grains in the films are densely packed together, and their direct bandgap is about 1.40 eV. In addition, the bandgap of the films first rises and then drops with the increase of the duty cycle.展开更多
文摘The Internet of Things(IoT)has witnessed a significant surge in adoption,particularly through the utilization of Wireless Sensor Networks(WSNs),which comprise small internet-connected devices.These deployments span various environments and offer a multitude of benefits.However,the widespread use of battery-powered devices introduces challenges due to their limited hardware resources and communication capabilities.In response to this,the Internet Engineering Task Force(IETF)has developed the IPv6 Routing Protocol for Low-power and Lossy Networks(RPL)to address the unique requirements of such networks.Recognizing the critical role of RPL in maintaining high performance,this paper proposes a novel approach to optimizing power consumption.Specifically,it introduces a developed sensor motes topology integrated with a Radio Duty Cycling(RDC)mechanism aimed at minimizing power usage.Through rigorous analysis,the paper evaluates the power efficiency of this approach through several simulations conducted across different network topologies,including random,linear,tree,and elliptical topologies.Additionally,three distinct RDC mechanisms—CXMAC,ContikiMAC,and NullRDC—are investigated to assess their impact on power consumption.The findings of the study,based on a comprehensive and deep analysis of the simulated results,highlight the efficiency of ContikiMAC in power conservation.This research contributes valuable insights into enhancing the energy efficiency of RPL-based IoT networks,ultimately facilitating their widespread deployment and usability in diverse environments.
基金supported by National Natural Science Foundation of China under Grant 52167005Science and Technology Research Project of Jiangxi Provincial Department of Education under Grant GJJ200826。
文摘In view of the large current peak and torque ripple in the actual current chopping control of switched reluctance motor,a segmented PWM duty cycle analysis method of switched reluctance motor based on current chopping control is proposed in this paper.The method realizes the control of the winding current by adjusting the average voltage of the two ends of the winding in one cycle through the PWM duty cycle.At the same time,according to the inductance linear model,the conduction phase is divided into a small inductance region and an inductance rising region,and the analytical formulas of PWM duty cycle in the two regions are deduced respectively.Finally,through matlab/simulink simulation and motor platform experiment,the current chopping control is compared with the segmented PWM duty cycle analysis method in this paper.Simulation and experimental results show that the segmented PWM duty cycle analysis method can effectively reduce the current peak and torque ripple,and has high practical application value.
文摘This work is geared to carry out epistemic analysis of Kantian ethics of duty call vis-à-vis paranormal in Nigerian society among clergymen.The recent changes in Nigerian and other African countries like colonialism that brought Western education,globalization,urbanization,and new religion(Islam and Christianity)have made it that divination in traditional African religion is no longer in vogue in this contemporary period.Divination and fortune telling have taken a new dimension in form of faith healing and miracles by some prophets and so called men of God like pastors,priests,and imam.The quest for materialism among the ministers and clerics of Islamic,Christian and traditional religion has made them abuse their religious calling for their selfish interests.This work makes use of analytic and critical methods of data analysis.This work postulates that Immanuel Kant’s ethics of duty call serves to provide a guiding principle to Nigeria clergymen of different religions on the need for them to carry out their religious duties out of good will.On the other hand,twisting or distorting the teachings of their religion to serve their various selfish interests contravenes Immanuel Kant’s ethics of duty call.Finally,they have to contribute positively to nation building by propagating or fostering the positive ideology,theories,or doctrines that will promote love and national unity in a multicultural country like Nigeria.
文摘This study looked at the impact of the Nigerian stamp duty tax on the growth of the economy.Time series data were employed spanning the years 1999-2020.For various years,related data were extracted from the Central Bank of Nigeria Statistical Bulletin,the Bureau of National Statistics,and Federal Inland Revenue Service reports.E-view 9.0 was used to test the hypothesis using the ordinary least square.The study outcome revealed that stamp duty has an insignificant and positive impact on Nigeria’s economic growth.It was recommended that the government improve public entities and provide strong government investment as a source of domestic revenue generated from various business activities.
文摘The heavy-duty vehicle fleet involved in delivering water and sand makes noticeable issues of exhaust emissions and fuel consumption in the process of shale gas development. To examine the possibility of converting these heavy-duty diesel engines to run on natural gas-diesel dual-fuel, a transient engine duty cycle representing the real-world engine working conditions is necessary. In this paper, a methodology is proposed, and a target engine duty cycle comprising of 2231 seconds is developed from on-road data collected from 11 on-road sand and water hauling trucks. The similarity of inherent characteristics of the developed cycle and the base trip observed is evidenced by the 2.05% error of standard deviation and average values for normalized engine speed and engine torque. Our results show that the proposed approach is expected to produce a representative cycle of in-use heavy-duty engine behavior.
基金This work is supported by“National Science Foundation of Hunan Province,China”under Grant 2020JJ4757.
文摘With the expansion of the application range and network scale of wireless sensor networks in recent years,WSNs often generate data surges and delay queues during the transmission process,causing network paralysis,even resulting in local or global congestion.In this paper,a dynamically Adjusted Duty Cycle for Optimized Congestion based on a real-time Queue Length(ADCOC)scheme is proposed.In order to improve the resource utilization rate of network nodes,we carried out optimization analysis based on the theory and applied it to the adjustment of the node’s duty cycle strategy.Using this strategy to ensure that the network lifetime remains the same,can minimize system delay and maximize energy efficiency.Firstly,the problems of the existing RED algorithm are analyzed.We introduce the improved SIG-RED algorithm into the ADCOC mechanism.As the data traffic changes,the RED protocol cannot automatically adjust the duty cycle.A scheduler is added to the buffer area manager,referring to a weighted index of network congestion,which can quickly determine the status of network congestion.The value of the weighting coefficient W is adjusted by the Bayesian method.The scheduler preferably transmits severely urgent data,alleviating the memory load.Then we combined improved data fusion technology and information gain methods to adjust the duty cycle dynamically.By simulating the algorithm,it shows that it has faster convergence speed and smaller queue jitter.Finally,we combine the adjusted congestion weight and the duty cycle growth value to adjust the data processing rate capability in the real-time network by dynamically adjusting it to adapt to bursts of data streams.Thus,the frequency of congestion is reduced to ensure that the system has higher processing efficiency and good adaptability.
基金supported by the Specialized Research Fund for Doctoral Program of Higher Education,SPFDP-200806990003the Foundation for Fundamental Research of the Northwestern Polytechnical University,NPU-FFR-W018102
文摘Duty-cycle modulation alternately blowing from two opposite-facing plasma actu- ators on the leeward surface near the apex of a cone with a 10° semi-apex angle is adopted to control mean lateral force and moment, and the flow control mechanisms are presented. Pressure distributions over the forebody of the cone are measured by steady pressure tappings. The experiments are performed in a 3.0×1.6 m open-circuit wind tunnel at a wind speed of 20 m/s, a 45° angle of attack and a Reynolds number of 2×10^5, based on the diameter of the base of the cone. Almost linearly proportional control of the lateral forces and moments over a slender conical forebody at a high angle of attack has been demonstrated by employing a pair of single dielectric barrier discharge plasma actuators near the apex of the cone, combined with a duty-cycle tech- nique. The pressure distribution measurements indicate that the hi-stable vortex pattern appears to be shifted in the opposite direction when the port or starboard actuator is activated, while the other is kept off during the test. It is shown that the reduced pulse-repetition frequency based on the local diameter at the plasma actuator equal to one yields the highest effectiveness among the cases considered.
文摘We report the transient effects in Erbium Doped Fiber Amplifier (EDFA) systems for pulsed signals with different duty-cycles. The work includes the analysis using three different duty-cycles, 10%, 20% and 50%. A curve fitting technique is also proposed to predict the transients of any lesser duty-cycled pulse, once the transients of a larger duty-cycled pulse is known. Mathematical evaluation confirms the double exponential shape of transient distorted signal. Further, EDFA transient effect is experimentally verified on a Wavelength Division Multiplexed (WDM) link by multiplexing high and low bitrate modulated optical signals. We conclude the paper by proposing a transient suppression technique for variable dutycycle signals and analyzing its effectiveness with different wavelength spacing.
基金the European Project opti Truck(optimal fuel consumption with predictive power train control and calibration for intelligent Truck)of the H2020 innovation programme。
文摘Driving style,traffic and weather conditions have a significant impact on vehicle fuel consumption and in particular,the road freight traffic significantly contributes to the CO2 increase in atmosphere.This paper proposes an Eco-Route Planner devoted to determine and communicate to the drivers of Heavy-Duty Vehicles(HDVs)the eco-route that guarantees the minimum fuel consumption by respecting the travel time established by the freight companies.The proposed eco-route is the optimal route from origin to destination and includes the optimized speed and gear profiles.To this aim,the Cloud Computing System architecture is composed of two main components:the Data Management System that collects,fuses and integrates the raw external sources data and the Cloud Optimizer that builds the route network,selects the eco-route and determines the optimal speed and gear profiles.Finally,a real case study is discussed by showing the benefit of the proposed Eco-Route planner.
基金National Nature Sciences Funding of China(61076063)Key Project of Fujian Provincial Department of Science &Technology(2008I0019)Fujian Provincial Natural Science Foundation of China(2009J01285)
文摘SnS∶Ag thin films were deposited on ITO glasses by pulse electro-deposition. By studying the effect of duty cycle on the properties of SnS∶Ag thin films, the optimum off-time(toff) is obtained to be 5 s, namely, the optimal duty cycle is about 67%. The primary phase of SnS∶Ag films deposited on optimum parameters condition is SnS compound with good crystallization, and the films prefer to grow towards (111) plane. The films are dense, smooth and uniform with good microstructure, and the grains in the films are densely packed together, and their direct bandgap is about 1.40 eV. In addition, the bandgap of the films first rises and then drops with the increase of the duty cycle.
