In the coexisted world of 3G,4G,5G and many other specialized wireless communication systems,billions of connections could be existing for various information transmission types.Unluckily,data show that the increase o...In the coexisted world of 3G,4G,5G and many other specialized wireless communication systems,billions of connections could be existing for various information transmission types.Unluckily,data show that the increase of network capacity is heavily more than the increase of the network energy efficiency in recent years,which could lead to more energy consumption per transmitted bit in the future network.As basic units in mobile communication systems,microwave/RF components and modules play key roles展开更多
In this paper,a statistical cluster-based simulation channel model with a finite number of sinusoids is proposed for depicting the multiple-input multiple-output(MIMO)communications in vehicleto-everything(V2X)environ...In this paper,a statistical cluster-based simulation channel model with a finite number of sinusoids is proposed for depicting the multiple-input multiple-output(MIMO)communications in vehicleto-everything(V2X)environments.In the proposed sum-of-sinusoids(SoS)channel model,the waves that emerge from the transmitter undergo line-of-sight(LoS)and non-line-of-sight(NLoS)propagation to the receiver,which makes the model suitable for describing numerous V2X wireless communication scenarios for sixth-generation(6G).We derive expressions for the real and imaginary parts of the complex channel impulse response(CIR),which characterize the physical propagation characteristics of V2X wireless channels.The statistical properties of the real and imaginary parts of the complex CIRs,i.e.,autocorrelation functions(ACFs),Doppler power spectral densities(PSDs),cross-correlation functions(CCFs),and variances of ACFs and CCFs,are derived and discussed.Simulation results are generated and match those predicted by the underlying theory,demonstrating the accuracy of our derivation and analysis.The proposed framework and underlying theory arise as an efficient tool to investigate the statistical properties of 6G MIMO V2X communication systems.展开更多
Since the theory of communicative competence was put forward by Canale and Swain,there have been teaching professionals developing it to different models,three of which are reviewed in this essay.
This paper attempts to give an interpretation of communicative competence by a comparative approach,internally and externally.It first examines the internal components of communication competence as formulated by Hyme...This paper attempts to give an interpretation of communicative competence by a comparative approach,internally and externally.It first examines the internal components of communication competence as formulated by Hymes and Canale & Swain,and then explores the possible relationship between linguistic competence and communication competence by comparing and constrasting the two.Our conclusion is that linguistic competence is the foundation for communicative competence and the latter is a further development of the former.展开更多
The Android operating system provides a rich Inter-Component Communication(ICC) method that brings enormous convenience. However, the Android ICC also increases security risks. To address this problem, a formal method...The Android operating system provides a rich Inter-Component Communication(ICC) method that brings enormous convenience. However, the Android ICC also increases security risks. To address this problem, a formal method is proposed to model and detect inter-component communication behavior in Android applications. Firstly,we generate data flow graphs and data facts for each component through component-level data flow analysis.Secondly, our approach treats ICC just like method calls. After analyzing the fields and data dependencies of the intent, we identify the ICC caller and callee, track the data flow between them, and construct the ICC model. Thirdly,the behavior model of Android applications is constructed by a formal mapping method for component data flow graph based on Pi calculus. The runtime sensitive path trigger detection algorithm is then given. Communicationbased attacks are detected by analyzing intent abnormity. Finally, we analyze the modeling and detection efficiency,and compare it with relevant methods. Analysis of 57 real-world applications partly verifies the effectiveness of the proposed method.展开更多
Modern vessels are designed to collect,store and communicate large quantities of ship performance and navigation information through complex onboard data handling processes.That data should be transferred to shore bas...Modern vessels are designed to collect,store and communicate large quantities of ship performance and navigation information through complex onboard data handling processes.That data should be transferred to shore based data centers for further analysis and storage.However,the associated transfer cost in large-scale data sets is a major challenge for the shipping industry,today.The same cost relates to the amount of data that are transferring through various communication networks(i.e.satellites and wireless networks),i.e.between vessels and shore based data centers.Hence,this study proposes to use an autoencoder system architecture(i.e.a deep learning approach)to compress ship performance and navigation parameters(i.e.reduce the number of parameters)and transfer through the respective communication networks as reduced data sets.The data compression is done under the linear version of an autoencoder that consists of principal component analysis(PCA),where the respective principal components(PCs)represent the structure of the data set.The compressed data set is expanded by the same data structure(i.e.an autoencoder system architecture)at the respective data center requiring further analyses and storage.A data set of ship performance and navigation parameters in a selected vessel is analyzed(i.e.data compression and expansion)through an autoencoder system architecture and the results are presented in this study.Furthermore,the respective input and output values of the autoencoder are also compared as statistical distributions and sample number series to evaluate its performance.展开更多
Spatial modedivision multiplexing is emerging as a potential solution to further increasing optical fiber capacity and spectral efficiency. We report a dualmode, dualpolarization transmission method based on modeselec...Spatial modedivision multiplexing is emerging as a potential solution to further increasing optical fiber capacity and spectral efficiency. We report a dualmode, dualpolarization transmission method based on modeselective excitation and detection over a twomode fiber. In particular, we present 107 Gbit/s coherent optical OFDM （COOFDM） transmission over a 4.5 km twomode fiber using LP and LP. modes in which mode separation is performed optically.展开更多
With the rapid development of global information highway,multimedia communication technology plays a more and more important role in national economic and social development.However,the multimedia communication sy... With the rapid development of global information highway,multimedia communication technology plays a more and more important role in national economic and social development.However,the multimedia communication system is a complicated real time distributed system and its software is difficult to develop.In order to improve the rapid development and application of the multimedia communication technology,there is an urgent need to carry out the basic research work of software development platform in this field.……展开更多
This paper presents an analysis and validation by advanced system simulation of compact and low-cost six-port transceivers for future wireless local area networks （WLANs） operating at millimeter-wave frequencies. To...This paper presents an analysis and validation by advanced system simulation of compact and low-cost six-port transceivers for future wireless local area networks （WLANs） operating at millimeter-wave frequencies. To obtain realistic simulation results, a six-port model based on the measurement results of a fabricated V-band hybrid coupler, the core component, is used. A frequency-division multiplexing scheme is used by introducing four quadrature phase-shift keying （QPSK） channels in the wireless communication link. The data rate achieved is about 4 Gbit/s. The operating frequency is in the 60-64 GHz unlicensed band. Bit error rate （BER） results are presented, and a comparison is made between single-carrier and multicarrier architectures. The proposed wireless system can be considered an efficient candidate for millimeter-wave communication systems operating at quasi-optical data rates.展开更多
In recent years,quantum computing has made significant strides,particularly in light-based technology.The introduction of quantum photonic chips has ushered in an era marked by scalability,stability,and cost-effective...In recent years,quantum computing has made significant strides,particularly in light-based technology.The introduction of quantum photonic chips has ushered in an era marked by scalability,stability,and cost-effectiveness,paving the way for innovative possibilities within compact footprints.This article provides a comprehensive exploration of photonic quantum computing,covering key aspects such as encoding information in photons,the merits of photonic qubits,and essential photonic device components including light squeezers,quantum light sources,interferometers,photodetectors,and wave-guides.The article also examines photonic quantum communication and internet,and its implications for secure systems,detailing implementations such as quantum key distribution and long-distance communication.Emerging trends in quantum communication and essential reconfigurable elements for advancing photonic quantum internet are discussed.The review further navigates the path towards establishing scalable and fault-tolerant photonic quantum computers,highlighting quantum computational advantages achieved using photons.Additionally,the discussion extends to programmable photonic circuits,integrated photonics and transformative applications.Lastly,the review addresses prospects,implications,and challenges in photonic quantum computing,offering valuable insights into current advancements and promising future directions in this technology.展开更多
Interface automata are one of the prominent formalisms for specifying interface behaviors of componentbased systems. However, only one-to-one communication is allowed in the composition of interface automata. This pap...Interface automata are one of the prominent formalisms for specifying interface behaviors of componentbased systems. However, only one-to-one communication is allowed in the composition of interface automata. This paper presents multicast interface automata which generalize the classic interface automata and accommodate multicast communication mechanism. The multicast interface automata endorse both bottom-up and top-down design methodologies. Theoretical results on compatibility and refinement are established for incremental design and independent implementability.展开更多
Fiber Bragg grating has been successfully fabricated in the silica microfiber by the use of femtosecond laser point-by-point inscription.Temporal thermal response of the fabricated silica microfiber Bragg grating has ...Fiber Bragg grating has been successfully fabricated in the silica microfiber by the use of femtosecond laser point-by-point inscription.Temporal thermal response of the fabricated silica microfiber Bragg grating has been measured by the use of the CO_(2) laser thermal excitation method,and the result shows that the time constant of the microfiber Bragg grating is reduced by an order of magnitude compared with the traditional single-mode fiber Bragg grating and the measured time constant is〜21 ms.展开更多
文摘In the coexisted world of 3G,4G,5G and many other specialized wireless communication systems,billions of connections could be existing for various information transmission types.Unluckily,data show that the increase of network capacity is heavily more than the increase of the network energy efficiency in recent years,which could lead to more energy consumption per transmitted bit in the future network.As basic units in mobile communication systems,microwave/RF components and modules play key roles
基金supported by National Natural Science Foundation of China(NSFC)(No.62101274 and 62101275)Natural Science Foundation of Jiangsu Province(BK20210640)Open Research Fund of National Mobile Communications Research Laboratory Southeast University under Grant 2021D03。
文摘In this paper,a statistical cluster-based simulation channel model with a finite number of sinusoids is proposed for depicting the multiple-input multiple-output(MIMO)communications in vehicleto-everything(V2X)environments.In the proposed sum-of-sinusoids(SoS)channel model,the waves that emerge from the transmitter undergo line-of-sight(LoS)and non-line-of-sight(NLoS)propagation to the receiver,which makes the model suitable for describing numerous V2X wireless communication scenarios for sixth-generation(6G).We derive expressions for the real and imaginary parts of the complex channel impulse response(CIR),which characterize the physical propagation characteristics of V2X wireless channels.The statistical properties of the real and imaginary parts of the complex CIRs,i.e.,autocorrelation functions(ACFs),Doppler power spectral densities(PSDs),cross-correlation functions(CCFs),and variances of ACFs and CCFs,are derived and discussed.Simulation results are generated and match those predicted by the underlying theory,demonstrating the accuracy of our derivation and analysis.The proposed framework and underlying theory arise as an efficient tool to investigate the statistical properties of 6G MIMO V2X communication systems.
文摘Since the theory of communicative competence was put forward by Canale and Swain,there have been teaching professionals developing it to different models,three of which are reviewed in this essay.
文摘This paper attempts to give an interpretation of communicative competence by a comparative approach,internally and externally.It first examines the internal components of communication competence as formulated by Hymes and Canale & Swain,and then explores the possible relationship between linguistic competence and communication competence by comparing and constrasting the two.Our conclusion is that linguistic competence is the foundation for communicative competence and the latter is a further development of the former.
基金supported by the Hebei Provincial Natural Science Foundation(Nos.F2016203290 and F2017203307)the National Natural Science Foundation of China(No.61772450)+3 种基金the Doctoral Foundation of Yanshan University(Nos.BL18011 and B906)the Hebei Normal University of Science and Technology Scientific Research Foundation(No.2018YB019)the China Postdoctoral Science Foundation(No.2018M631764)the Hebei Province Science and Technology Planning Project(No.17210701D)
文摘The Android operating system provides a rich Inter-Component Communication(ICC) method that brings enormous convenience. However, the Android ICC also increases security risks. To address this problem, a formal method is proposed to model and detect inter-component communication behavior in Android applications. Firstly,we generate data flow graphs and data facts for each component through component-level data flow analysis.Secondly, our approach treats ICC just like method calls. After analyzing the fields and data dependencies of the intent, we identify the ICC caller and callee, track the data flow between them, and construct the ICC model. Thirdly,the behavior model of Android applications is constructed by a formal mapping method for component data flow graph based on Pi calculus. The runtime sensitive path trigger detection algorithm is then given. Communicationbased attacks are detected by analyzing intent abnormity. Finally, we analyze the modeling and detection efficiency,and compare it with relevant methods. Analysis of 57 real-world applications partly verifies the effectiveness of the proposed method.
基金This work has been conducted under the project of“SFI Smart Maritime(237917/O30)-Norwegian Centre for im-proved energy-efficiency and reduced emissions from the mar-itime sector”that is partly funded by the Research Council of NorwayAn initial version of this paper is presented at the 35th International Conference on Ocean,Offshore and Arc-tic Engineering(OMAE 2016),Busan,Korea,June,2016,(OMAE2016-54093).
文摘Modern vessels are designed to collect,store and communicate large quantities of ship performance and navigation information through complex onboard data handling processes.That data should be transferred to shore based data centers for further analysis and storage.However,the associated transfer cost in large-scale data sets is a major challenge for the shipping industry,today.The same cost relates to the amount of data that are transferring through various communication networks(i.e.satellites and wireless networks),i.e.between vessels and shore based data centers.Hence,this study proposes to use an autoencoder system architecture(i.e.a deep learning approach)to compress ship performance and navigation parameters(i.e.reduce the number of parameters)and transfer through the respective communication networks as reduced data sets.The data compression is done under the linear version of an autoencoder that consists of principal component analysis(PCA),where the respective principal components(PCs)represent the structure of the data set.The compressed data set is expanded by the same data structure(i.e.an autoencoder system architecture)at the respective data center requiring further analyses and storage.A data set of ship performance and navigation parameters in a selected vessel is analyzed(i.e.data compression and expansion)through an autoencoder system architecture and the results are presented in this study.Furthermore,the respective input and output values of the autoencoder are also compared as statistical distributions and sample number series to evaluate its performance.
文摘Spatial modedivision multiplexing is emerging as a potential solution to further increasing optical fiber capacity and spectral efficiency. We report a dualmode, dualpolarization transmission method based on modeselective excitation and detection over a twomode fiber. In particular, we present 107 Gbit/s coherent optical OFDM （COOFDM） transmission over a 4.5 km twomode fiber using LP and LP. modes in which mode separation is performed optically.
文摘 With the rapid development of global information highway,multimedia communication technology plays a more and more important role in national economic and social development.However,the multimedia communication system is a complicated real time distributed system and its software is difficult to develop.In order to improve the rapid development and application of the multimedia communication technology,there is an urgent need to carry out the basic research work of software development platform in this field.……
文摘This paper presents an analysis and validation by advanced system simulation of compact and low-cost six-port transceivers for future wireless local area networks （WLANs） operating at millimeter-wave frequencies. To obtain realistic simulation results, a six-port model based on the measurement results of a fabricated V-band hybrid coupler, the core component, is used. A frequency-division multiplexing scheme is used by introducing four quadrature phase-shift keying （QPSK） channels in the wireless communication link. The data rate achieved is about 4 Gbit/s. The operating frequency is in the 60-64 GHz unlicensed band. Bit error rate （BER） results are presented, and a comparison is made between single-carrier and multicarrier architectures. The proposed wireless system can be considered an efficient candidate for millimeter-wave communication systems operating at quasi-optical data rates.
文摘In recent years,quantum computing has made significant strides,particularly in light-based technology.The introduction of quantum photonic chips has ushered in an era marked by scalability,stability,and cost-effectiveness,paving the way for innovative possibilities within compact footprints.This article provides a comprehensive exploration of photonic quantum computing,covering key aspects such as encoding information in photons,the merits of photonic qubits,and essential photonic device components including light squeezers,quantum light sources,interferometers,photodetectors,and wave-guides.The article also examines photonic quantum communication and internet,and its implications for secure systems,detailing implementations such as quantum key distribution and long-distance communication.Emerging trends in quantum communication and essential reconfigurable elements for advancing photonic quantum internet are discussed.The review further navigates the path towards establishing scalable and fault-tolerant photonic quantum computers,highlighting quantum computational advantages achieved using photons.Additionally,the discussion extends to programmable photonic circuits,integrated photonics and transformative applications.Lastly,the review addresses prospects,implications,and challenges in photonic quantum computing,offering valuable insights into current advancements and promising future directions in this technology.
基金This work was supported by the Chinese National 973 Plan （2010CB328003）, the National Natural Science Foundation of China （Grant Nos. 61272001, 60903030, 91218302）, the Chinese National Key Technology R＆D Program （SQ2012BAJY4052）, the Importation and Development of High-Caliber Talents Project of Beijing Municipal Institutions （YETP0167）, and the Tsinghua University Initiative Scientific Research Program.
文摘Interface automata are one of the prominent formalisms for specifying interface behaviors of componentbased systems. However, only one-to-one communication is allowed in the composition of interface automata. This paper presents multicast interface automata which generalize the classic interface automata and accommodate multicast communication mechanism. The multicast interface automata endorse both bottom-up and top-down design methodologies. Theoretical results on compatibility and refinement are established for incremental design and independent implementability.
文摘Fiber Bragg grating has been successfully fabricated in the silica microfiber by the use of femtosecond laser point-by-point inscription.Temporal thermal response of the fabricated silica microfiber Bragg grating has been measured by the use of the CO_(2) laser thermal excitation method,and the result shows that the time constant of the microfiber Bragg grating is reduced by an order of magnitude compared with the traditional single-mode fiber Bragg grating and the measured time constant is〜21 ms.
