The compressibility properties of systems consisting of generic rotating rigid triangles are analyzed and discussed. It is shown that these systems which are usually associated with auxeticity can exhibit strongly ani...The compressibility properties of systems consisting of generic rotating rigid triangles are analyzed and discussed. It is shown that these systems which are usually associated with auxeticity can exhibit strongly anisotropic properties for certain conformations, which may give rise to the anomalous property of negative linear compressibility （NLC）, that is, the system with particular geometry will expand along one direction when loaded hydrostatically. It is also shown that through carefully choosing the geometric features （i.e. the dimensions and the alignment of the rotating triangles as well as the angles between them） and the direction along which the linear compressibility is measured, one may control the magnitude and range of the NLC. All this provides a novel but effective method of manufacturing the systems which can be tailored to achieve particular values of NLC to fit particular practical applications.展开更多
Smillie and Weiss proved that the set of the areas of the minimal triangles of Veech surfaces with area 1 can be arranged as a strictly decreasing sequence{an}.And each an in the sequence corresponds to finitely many ...Smillie and Weiss proved that the set of the areas of the minimal triangles of Veech surfaces with area 1 can be arranged as a strictly decreasing sequence{an}.And each an in the sequence corresponds to finitely many affine equivalent classes of Veech surfaces with area 1.In this article,we give an algorithm for calculating the area of the minimal triangles in a Veech surface and prove that the first element of{an}which corresponds to non arithmetic Veech surfaces is(5-√5)/20,which is uniquely realized by the area of the minimal triangles of the normalized golden L-shaped translation surface up to affine equivalence.展开更多
Quasiconformal mappings between hyperbolic triangles are considered.We give an explicit estimate of the dilation of the quasiconformal mappings,which generalizes Bishop's results.
With the development of the Internet of Things(IoT),it requires better performance from wireless sensor networks(WSNs),such as larger coverage,longer lifetime,and lower latency.However,a large amount of data generated...With the development of the Internet of Things(IoT),it requires better performance from wireless sensor networks(WSNs),such as larger coverage,longer lifetime,and lower latency.However,a large amount of data generated from monitoring and long-distance transmission places a heavy burden on sensor nodes with the limited battery power.For this,we investigate an unmanned aerial vehicles assisted mobile wireless sensor network(UAV-assisted WSN)to prolong the network lifetime in this paper.Specifically,we use UAVs to assist the WSN in collecting data.In the current UAV-assisted WSN,the clustering and routing schemes are determined sequentially.However,such a separate consideration might not maximize the lifetime of the whole WSN due to the mutual coupling of clustering and routing.To efficiently prolong the lifetime of the WSN,we propose an integrated clustering and routing scheme that jointly optimizes the clustering and routing together.In the whole network space,it is intractable to efficiently obtain the optimal integrated clustering and routing scheme.Therefore,we propose the Monte-Las search strategy based on Monte Carlo and Las Vegas ideas,which can generate the chain matrix to guide the algorithm to find the solution faster.Unnecessary point-to-point collection leads to long collection paths,so a triangle optimization strategy is then proposed that finds a compromise path to shorten the collection path based on the geometric distribution and energy of sensor nodes.To avoid the coverage hole caused by the death of sensor nodes,the deployment of mobile sensor nodes and the preventive mechanism design are indispensable.An emergency data transmission mechanism is further proposed to reduce the latency of collecting the latency-sensitive data due to the absence of UAVs.Compared with the existing schemes,the proposed scheme can prolong the lifetime of the UAVassisted WSN at least by 360%,and shorten the collection path of UAVs by 56.24%.展开更多
Considering the demands,situations and trends in respect to global climate change,carbon neutrality and energy transition,the achievements and significance of the global green energy transition and the new energy revo...Considering the demands,situations and trends in respect to global climate change,carbon neutrality and energy transition,the achievements and significance of the global green energy transition and the new energy revolution of China are summarized,and the“Energy Triangle”theory is proposed.The research indicates that the energy technology revolution is driving a dual transformation in global energy:the black“shale oil and gas revolution”in North America and the green“new energy revolution”in China.The green energy revolution of China has achieved significant milestones in wind-solar-hydrogen-energy storage technologies,leading the world in photovoltaic and wind power.The country has developed the world's largest,most comprehensive,and competitive new energy innovation,industrial and value chains,along with the largest clean power supply system globally.New quality productive forces represent the green productive forces.The green“new energy revolution”of China has accelerated the transformation of its energy structure and the global shift towards clean energy,promoting a new win-win model for the global green and low-carbon transition.Under the backdrop of a carbon-neutral goal-driven energy transition,the“Energy Triangle”theory within the framework of new quality productive forces explains the correlation and development of energy security,economic growth,and environmental sustainability throughout the evolution from fossil fuels to new energy systems,culminating in an energy revolution.Compared to the global energy resource endowment,the energy resources of China are characterized by abundant coal,limited oil and gas,and unlimited wind and photovoltaic energy.Moving forward,the energy strategies of China will focus on the advancement of technologies to clean coal for carbon emission reduction,increase gas output while stabilizing oil production,increase green energy while enhancing new energy,and achieve intelligent integration.Vigorously developing new energy is an essential step in maintaining the energy security of China,and establishing a carbon-neutral“super energy system”is a necessary choice.It is crucial to enhance the international competitiveness of China in new energy development,promote high-quality energy productive forces,support the country's transition to an“energy power”,and strive for“energy independence”.展开更多
In this paper, a photoelectric signal obtained scheme via equator triangle pattern engraved on rotor is discussed and the mathematic model is deduced in the case which is deflexion between rotor axis and the coordinat...In this paper, a photoelectric signal obtained scheme via equator triangle pattern engraved on rotor is discussed and the mathematic model is deduced in the case which is deflexion between rotor axis and the coordinate frame of case. The deflexion error and coupling error under the situation are analyzed. Finally, three methods of engraving based on the spherical triangle pattern are presented. The error models of various methods are built up and the simulation curves are provided respectively. We have done the primary experiments on the surface of rotor using this method. It can be seen from the enlarged figures that the rim of the pattern is smooth and the demand of sensor resolution is satisfied by and large. The results of study supply reference for signal obtaining.展开更多
the routing protocol for low-power and lossy networks(RPL) has been used in advanced metering infrastructure(AMI)which could provide two-way communication between smart meters and city utilities.To improve the network...the routing protocol for low-power and lossy networks(RPL) has been used in advanced metering infrastructure(AMI)which could provide two-way communication between smart meters and city utilities.To improve the network performance of AMI networks, this paper proposed an improved algorithm of RPL based on triangle module operator(IAR-TMO). IAR-TMO proposes membership functions of the following five typical routing metrics: end-to-end delay, number of hops, expected transmission count(ETX),node remaining energy, and child node count.Moreover, IAR-TMO uses triangle module operator to fuse membership functions of these routing metrics. Then, IAR-TMO selects preferred parents(the next hop) based on the triangle module operator. Theoretical analysis and simulation results show that IAR-TMO has a great improvement when compared with two recent representative algorithms: ETXOF(ETX Objective Function) and OF-FL(Objective Function based on Fuzzy Logic), in terms of network lifetime, average end-to-end delay,etc. Consequently, the network performances of AMI networks can be improved effectively.展开更多
Resonator micro-optic gyro (R-MOG) sensing rotation angular-velocity is based on Sagnac effect.We present a frequency modulation (FM) induced by the analog triangle-waveform phase modulation (ATAW-PM) technique in an ...Resonator micro-optic gyro (R-MOG) sensing rotation angular-velocity is based on Sagnac effect.We present a frequency modulation (FM) induced by the analog triangle-waveform phase modulation (ATAW-PM) technique in an R-MOG.Compared with the traditional serrodyne phase modulation or digital phase modulation methods,the proposed modulation technique has the intrinsic advantage in free of sweeping-back or step-effect induced pulse noise.The influence on dynamic range and resolution of the R-MOG by the parameters of analog trianglewaveform is theoretically analyzed.Experiments are carried out on an R-MOG composed of an integrated optic resonator with a free spectral range (FSR) and a fitness (F) of 1.6GHz and 61,respectively.Dynamic range of ±500 deg/s and bias drift of 0.6 deg/s over 1 h and 0.05 deg/s for 60 s are reliably obtained.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant No.51475208)
文摘The compressibility properties of systems consisting of generic rotating rigid triangles are analyzed and discussed. It is shown that these systems which are usually associated with auxeticity can exhibit strongly anisotropic properties for certain conformations, which may give rise to the anomalous property of negative linear compressibility （NLC）, that is, the system with particular geometry will expand along one direction when loaded hydrostatically. It is also shown that through carefully choosing the geometric features （i.e. the dimensions and the alignment of the rotating triangles as well as the angles between them） and the direction along which the linear compressibility is measured, one may control the magnitude and range of the NLC. All this provides a novel but effective method of manufacturing the systems which can be tailored to achieve particular values of NLC to fit particular practical applications.
基金Supported by National Natural Science Foundation of China(11701039)Youth and Research and Innovation Program of BUPT(2017RC18)。
文摘Smillie and Weiss proved that the set of the areas of the minimal triangles of Veech surfaces with area 1 can be arranged as a strictly decreasing sequence{an}.And each an in the sequence corresponds to finitely many affine equivalent classes of Veech surfaces with area 1.In this article,we give an algorithm for calculating the area of the minimal triangles in a Veech surface and prove that the first element of{an}which corresponds to non arithmetic Veech surfaces is(5-√5)/20,which is uniquely realized by the area of the minimal triangles of the normalized golden L-shaped translation surface up to affine equivalence.
基金Partially Supported by NSFC(Grant No.12071047)Fundamental Research Funds for the Central Universities(Grant No.500421126).
文摘Quasiconformal mappings between hyperbolic triangles are considered.We give an explicit estimate of the dilation of the quasiconformal mappings,which generalizes Bishop's results.
基金supported in part by National Natural Science Foundation of China under Grants 62122069, 62071431, 62072490 and 62301490in part by Science and Technology Development Fund of Macao SAR, China under Grant 0158/2022/A+2 种基金in part by the Guangdong Basic and Applied Basic Research Foundation (2022A1515011287)in part by MYRG202000107-IOTSCin part by FDCT SKL-IOTSC (UM)-2021-2023
文摘With the development of the Internet of Things(IoT),it requires better performance from wireless sensor networks(WSNs),such as larger coverage,longer lifetime,and lower latency.However,a large amount of data generated from monitoring and long-distance transmission places a heavy burden on sensor nodes with the limited battery power.For this,we investigate an unmanned aerial vehicles assisted mobile wireless sensor network(UAV-assisted WSN)to prolong the network lifetime in this paper.Specifically,we use UAVs to assist the WSN in collecting data.In the current UAV-assisted WSN,the clustering and routing schemes are determined sequentially.However,such a separate consideration might not maximize the lifetime of the whole WSN due to the mutual coupling of clustering and routing.To efficiently prolong the lifetime of the WSN,we propose an integrated clustering and routing scheme that jointly optimizes the clustering and routing together.In the whole network space,it is intractable to efficiently obtain the optimal integrated clustering and routing scheme.Therefore,we propose the Monte-Las search strategy based on Monte Carlo and Las Vegas ideas,which can generate the chain matrix to guide the algorithm to find the solution faster.Unnecessary point-to-point collection leads to long collection paths,so a triangle optimization strategy is then proposed that finds a compromise path to shorten the collection path based on the geometric distribution and energy of sensor nodes.To avoid the coverage hole caused by the death of sensor nodes,the deployment of mobile sensor nodes and the preventive mechanism design are indispensable.An emergency data transmission mechanism is further proposed to reduce the latency of collecting the latency-sensitive data due to the absence of UAVs.Compared with the existing schemes,the proposed scheme can prolong the lifetime of the UAVassisted WSN at least by 360%,and shorten the collection path of UAVs by 56.24%.
基金Supported by the National Science and Technology Major Special Project Secretariat(2022-5596510-000064)Petro China Science and Technology Special Project(2021ZZ01-05)。
文摘Considering the demands,situations and trends in respect to global climate change,carbon neutrality and energy transition,the achievements and significance of the global green energy transition and the new energy revolution of China are summarized,and the“Energy Triangle”theory is proposed.The research indicates that the energy technology revolution is driving a dual transformation in global energy:the black“shale oil and gas revolution”in North America and the green“new energy revolution”in China.The green energy revolution of China has achieved significant milestones in wind-solar-hydrogen-energy storage technologies,leading the world in photovoltaic and wind power.The country has developed the world's largest,most comprehensive,and competitive new energy innovation,industrial and value chains,along with the largest clean power supply system globally.New quality productive forces represent the green productive forces.The green“new energy revolution”of China has accelerated the transformation of its energy structure and the global shift towards clean energy,promoting a new win-win model for the global green and low-carbon transition.Under the backdrop of a carbon-neutral goal-driven energy transition,the“Energy Triangle”theory within the framework of new quality productive forces explains the correlation and development of energy security,economic growth,and environmental sustainability throughout the evolution from fossil fuels to new energy systems,culminating in an energy revolution.Compared to the global energy resource endowment,the energy resources of China are characterized by abundant coal,limited oil and gas,and unlimited wind and photovoltaic energy.Moving forward,the energy strategies of China will focus on the advancement of technologies to clean coal for carbon emission reduction,increase gas output while stabilizing oil production,increase green energy while enhancing new energy,and achieve intelligent integration.Vigorously developing new energy is an essential step in maintaining the energy security of China,and establishing a carbon-neutral“super energy system”is a necessary choice.It is crucial to enhance the international competitiveness of China in new energy development,promote high-quality energy productive forces,support the country's transition to an“energy power”,and strive for“energy independence”.
文摘In this paper, a photoelectric signal obtained scheme via equator triangle pattern engraved on rotor is discussed and the mathematic model is deduced in the case which is deflexion between rotor axis and the coordinate frame of case. The deflexion error and coupling error under the situation are analyzed. Finally, three methods of engraving based on the spherical triangle pattern are presented. The error models of various methods are built up and the simulation curves are provided respectively. We have done the primary experiments on the surface of rotor using this method. It can be seen from the enlarged figures that the rim of the pattern is smooth and the demand of sensor resolution is satisfied by and large. The results of study supply reference for signal obtaining.
基金supported by the Beijing Laboratory of Advanced Information Networks
文摘the routing protocol for low-power and lossy networks(RPL) has been used in advanced metering infrastructure(AMI)which could provide two-way communication between smart meters and city utilities.To improve the network performance of AMI networks, this paper proposed an improved algorithm of RPL based on triangle module operator(IAR-TMO). IAR-TMO proposes membership functions of the following five typical routing metrics: end-to-end delay, number of hops, expected transmission count(ETX),node remaining energy, and child node count.Moreover, IAR-TMO uses triangle module operator to fuse membership functions of these routing metrics. Then, IAR-TMO selects preferred parents(the next hop) based on the triangle module operator. Theoretical analysis and simulation results show that IAR-TMO has a great improvement when compared with two recent representative algorithms: ETXOF(ETX Objective Function) and OF-FL(Objective Function based on Fuzzy Logic), in terms of network lifetime, average end-to-end delay,etc. Consequently, the network performances of AMI networks can be improved effectively.
基金Supported by the National Natural Science Foundation of China under Grant No 50875015.
文摘Resonator micro-optic gyro (R-MOG) sensing rotation angular-velocity is based on Sagnac effect.We present a frequency modulation (FM) induced by the analog triangle-waveform phase modulation (ATAW-PM) technique in an R-MOG.Compared with the traditional serrodyne phase modulation or digital phase modulation methods,the proposed modulation technique has the intrinsic advantage in free of sweeping-back or step-effect induced pulse noise.The influence on dynamic range and resolution of the R-MOG by the parameters of analog trianglewaveform is theoretically analyzed.Experiments are carried out on an R-MOG composed of an integrated optic resonator with a free spectral range (FSR) and a fitness (F) of 1.6GHz and 61,respectively.Dynamic range of ±500 deg/s and bias drift of 0.6 deg/s over 1 h and 0.05 deg/s for 60 s are reliably obtained.
