In this paper, we study D2D (Device-to-Device) communication underlying LTE-Advanced uplink system. Since D2D communication reuses uplink resources with cellular communication in this scenario, it’s hard to avoid the...In this paper, we study D2D (Device-to-Device) communication underlying LTE-Advanced uplink system. Since D2D communication reuses uplink resources with cellular communication in this scenario, it’s hard to avoid the inference between D2D users and cellular users. If there is no restriction for D2D communication on using the whole uplink frequency band, it will have a strong negative impact on cellular communication. In order to overcome this shortage, we propose a resource allocation method that D2D users and cellular users use orthogonal frequency resources. This method will effectively reduce the inference between both kinds of communication. However, an obvious disadvantage of this method is no effective use of uplink resources. Based on this, we propose an optimized resource allocation method that a specific cellular user will be chosen to reuse the RBs (Resource Block) of D2D users. These ideas will be taken into system-level simulation, and from the results of simulation we can see that the optimized method has the ability to improve overall system performance and limit inference for cell-edge users.展开更多
RLS and LMS blind adaptive multi-user detection algorithm and multi-user detector was proposed to solve the problem of multi-user signal detection problem encountered in underwater acoustic communication networks.In s...RLS and LMS blind adaptive multi-user detection algorithm and multi-user detector was proposed to solve the problem of multi-user signal detection problem encountered in underwater acoustic communication networks.In simulation analysis,RLS and the LMS blind adaptive multi-user detector were designed and tested for synchronous and asynchronous multi-user communication process.The results of SIR comparison and MMSE comparison show that,both of the two methods can realize blind adaptive detection when any user change in multi-user communication,during this process,the training communication sequences are not needed.The RLS algorithm has about 5 dB higher in SIR compared with LMS algorithm,and the convergence velocity of RLS algorithm is also higher than LMS algorithm when the communication users change.RLS algorithm has better ability in multi-user detection than that of LMS algorithm,and it has great attraction and guiding significance for solving the problem of multiple access interference(MAI) in multi-user communication.展开更多
With the deepening of economic globalization,international exchanges and cooperation have become increasingly frequent,making cross-cultural collisions and integration a common phenomenon.As a vital pathway for cultiv...With the deepening of economic globalization,international exchanges and cooperation have become increasingly frequent,making cross-cultural collisions and integration a common phenomenon.As a vital pathway for cultivating applied talents,higher vocational education bears the responsibility of delivering high-quality professionals with intercultural communication competence to society.English,as the universal language of international communication,holds a pivotal position in higher vocational education.However,traditional English teaching in vocational colleges often focuses on language knowledge transmission while neglecting the cultivation of students’intercultural communication skills,leading to misunderstandings and conflicts caused by cultural differences in practical interactions.Therefore,enhancing the development of intercultural communication competence in vocational English education has become an urgent issue requiring resolution.This paper aims to explore the current status,challenges,and countermeasures for cultivating intercultural communication competence in vocational English education under globalization,providing references for teaching reform in vocational English education.展开更多
This paper develops a new transmit beamforming for an integrated mechanical and electrical scanning dual-function radar-communication(DFRC)system.Differing from the related some works using beampattern sidelobe level ...This paper develops a new transmit beamforming for an integrated mechanical and electrical scanning dual-function radar-communication(DFRC)system.Differing from the related some works using beampattern sidelobe level to communication,we exploit the fact that transmit beamforming weight vector u k in directionθand weight vector u*k in direction-θcan achieve the same spatial power distribution,and formulate a new transmit beamforming vector design problem accounting for some extra sidelobe level constraints.By doing so,the number of the transmit beamforming weight vectors and the computing demand in the multi-user communication(MUC)scenario can be reduced.Finally,the numerical examples are designed to verify the effectiveness of the proposed design strategy in comparison with the existing method.展开更多
Efficient communication is important to every parallel algorithm. A parallel communication optimization is introduced into lattice Boltzmann method （LBM）. It relies on a simplified communication strategy which is im...Efficient communication is important to every parallel algorithm. A parallel communication optimization is introduced into lattice Boltzmann method （LBM）. It relies on a simplified communication strategy which is implemented by least square method. After testing the improved algorithm on parallel platform, the experimental results show that compared with normal parallel lattice Boltzmann algorithm, it provides better stability, higher performance while maintaining the same accuracy.展开更多
Since communication protocol deals with complex issues related to distribution such as communication, concurrency and synchronization, their development needs to be traced by using sophisticated formal description met...Since communication protocol deals with complex issues related to distribution such as communication, concurrency and synchronization, their development needs to be traced by using sophisticated formal description methods. This paper presents a new hybrid formal method for communication protocol specification. In this method, finite state machine (FSM), communication sequential process (CSP) and abstract data type (ADT) are mixed and the best features of these approaches are offered. In this paper, the main formal description techniques (FDT) for protocol engineering are brieny introduced and a hybrid formal description method based on the FSM, CSP and ADT for communication protocol is described. Finally, this paper presents the formal specification of an example protocol for LAN by using the proposed hybrid formal method. The results of studies show that the hybrid formal description method for communication protocol is an available and effective approach.展开更多
Zhiba culture is a profound culture with a long history,but there are still many problems in the C-E translation of it,such as low popularity,few recipients,and so on,which hinder its communication and development.The...Zhiba culture is a profound culture with a long history,but there are still many problems in the C-E translation of it,such as low popularity,few recipients,and so on,which hinder its communication and development.Therefore,it’s necessary to improve the quality of C-E translation of Zhiba culture.Based on the perspective of communication studies,combining with the principle of“Information First”,the principle of“The Audience First”,the paper explores the existing problems of Zhiba culture C-E translation and hopes to help to improve the present situation,to truly show the charm of Zhiba culture,to make it better accepted by the international community and optimize the global communication effect.展开更多
This paper is divided into two cases to study the communication transmission equipment reliability in the state of the ice storm, according to the huge losses of power system communication caused by the ice storm. For...This paper is divided into two cases to study the communication transmission equipment reliability in the state of the ice storm, according to the huge losses of power system communication caused by the ice storm. For the nodes or links which are not affected by the ice storm, we use the calculation with “the mean time between failures (MTBF)” and “the mean time to repair” (MTTR) to put forward the calculation methods;for the OPGW cable which influenced greater in ice storm, we use the fiber excess length and the elongation of fiber optic cable. It obtains all the paths of the network through improved adjacency matrix method, and then it uses binary decision diagram to obtain the overall reliability of the network. By testing the network nodes and links using “N-1” inspection, the key nodes and key links can be obtained. Finally, considering the importance degree of network transmission business, the reliability evaluation method of power system communication network based on the risk theory in the case of the ice storm has been put forward, and the example to verify that the method can provide the basis for the reliability assessment of the power system communication in the case of the ice storm has been given.展开更多
Aims and objectives: To explore any changes in nurses’ skills at communicating with residents with dementia disease when using the validation method, as observed in one-to-one videotaped conversations. Background: Co...Aims and objectives: To explore any changes in nurses’ skills at communicating with residents with dementia disease when using the validation method, as observed in one-to-one videotaped conversations. Background: Communication difficulties due to cognitive impairment among residents with dementia disease may complicate care situations. Training can improve nurses’ communication skills and increase care quality. The validation method aims to facilitate communication with residents with dementia disease through empathic and confirmatory approaches. Evaluations of the validation method have primarily focused on the residents’ perspective, and reports on nurses’ experiences are sparse. Improved communication and relationships with residents after validation method training have been described previously. Videotaped data could provide additional information about these earlier results. Design: A descriptive qualitative design. Methods: Eight nurses participated in a year of validation method training, including videotaped conversations with eleven residents. Videotapes with at least five months between the first and last recording were analysed and compared qualitatively. Results: The analysis revealed an overall pattern: nurses’ movements within and between various paths when improving their communication skills. This was based on three sub-patterns: from controlling communication towards developing attentiveness in communication, from ambiguous communication towards developing coherence in communication, and from being open and attentive towards having a refined attuned communication. Conclusions: All nurses developed their communication skills during the programme, albeit to different degrees. The findings are in congruence with the experiences described by nurses, and so it is reasonable to believe that the programme helped to improve the nurses’ skills in communicating with residents with dementia disease. Relevance to clinical practice: A validation method training programme could give nurses the possibility to develop their skills in communicating with residents with dementia disease.展开更多
With the rural concealed communication cable as the study object, the shielding effectiveness of different slot shapes was analyzed by using LBEM （linear boundary element method）. The engineering example results sho...With the rural concealed communication cable as the study object, the shielding effectiveness of different slot shapes was analyzed by using LBEM （linear boundary element method）. The engineering example results showed that for twocore shielded cable, the coupling capacitance of trapezoid slots （asymmetric and symmetric） changed the most, followed by rectangular slots （asymmetric and symmetric）, and the changes of wedge slots were the smallest, but the change tenden- cies were consistent. In addition, with the increase of slot width of different slots, the coupling capacitance of tow-cored shielded cable showed small change.展开更多
Comprehensive English is a very basic and important course for English majors,according to the features of the text-book A New English Course,teachers should adopt the integration of grammar translation method and com...Comprehensive English is a very basic and important course for English majors,according to the features of the text-book A New English Course,teachers should adopt the integration of grammar translation method and communicative approach to improve students' linguistic competence and communicative competence.展开更多
Channel estimation is a key technology in indoor wireless visible light communications(VLCs).Using the training sequence(TS),this paper investigates the channel estimation in indoor wireless visible light communicatio...Channel estimation is a key technology in indoor wireless visible light communications(VLCs).Using the training sequence(TS),this paper investigates the channel estimation in indoor wireless visible light communications.Based on the propagation and signal modulation characteristics of visible light,a link model for the indoor wireless visible light communications is established.Using the model,three channel estimation methods,i.e.,the correlation method,the least square(LS) method and the minimum mean square error(MMSE) method,are proposed.Moreover,the performances of the proposed three methods are evaluated by computer simulation.The results show that the performance of the correlation method is the worst,the LS method is suitable for higher signal to noise ratio(SNR),and the MMSE method obtains the best performance at the expense of highest complexity.展开更多
To improve the efficiency and fairness of the spectrum allocation for ground communication assisted by unmanned aerial vehicles(UAVs),a joint optimization method for on-demand deployment and spectrum allocation of UAV...To improve the efficiency and fairness of the spectrum allocation for ground communication assisted by unmanned aerial vehicles(UAVs),a joint optimization method for on-demand deployment and spectrum allocation of UAVs is proposed,which is modeled as a mixed-integer non-convex optimization problem(MINCOP).An algorithm to estimate the minimum number of required UAVs is firstly proposed based on the pre-estimation and simulated annealing.The MINCOP is then decomposed into three sub-problems based on the block coordinate descent method,including the spectrum allocation of UAVs,the association between UAVs and ground users,and the deployment of UAVs.Specifically,the optimal spectrum allocation is derived based on the interference mitigation and channel reuse.The association between UAVs and ground users is optimized based on local iterated optimization.A particle-based optimization algorithm is proposed to resolve the subproblem of the UAVs deployment.Simulation results show that the proposed method could effectively improve the minimum transmission rate of UAVs as well as user fairness of spectrum allocation.展开更多
Objective: To explore the effect of video combined with the teach-back method on respiratory function exercise in patients undergoing tumor thoracotomy. Methods: Eligible patients undergoing thoracotomy for tumor were...Objective: To explore the effect of video combined with the teach-back method on respiratory function exercise in patients undergoing tumor thoracotomy. Methods: Eligible patients undergoing thoracotomy for tumor were selected from the thoracic surgery at a level-A tertiary hospital between August 2021 and December 2021 and included in the control group and the observation group (40 patients in each group). To prevent two groups of patients from interacting with each other, the thoracic surgery ward I was distinguished as the control group, which was adopted by the routine instruction. Based on routine instruction, the thoracic surgery ward II conducted respiratory function exercise instruction by video combined with the teach-back method to compare the two groups’ compliance with respiratory function exercise, complication rates, and patient satisfaction. Results: The patient compliance with respiratory function exercise in the observation group was significantly higher (P < 0.05) and the rate of pulmonary complications in the observation group was lower (P < 0.05) than that in the control group, while the observation group had a high level of satisfaction (P Conclusion: Taking video combined with the teach-back method, an effective health education method, can improve the compliance of the respiratory function exercise of patients undergoing thoracotomy for tumor and promote the recovery of pulmonary function to reduce the incidence of postoperative pulmonary complications so as to improve patient satisfaction.展开更多
With the continuous development of national‘reforms and opening-up’policy and development of economic globalization,learning and application of foreign languages are becoming increasingly important.Society needs a l...With the continuous development of national‘reforms and opening-up’policy and development of economic globalization,learning and application of foreign languages are becoming increasingly important.Society needs a large number of professional linguistic workers.Therefore,there are higher requirements for new era higher learning institutes which serve as training base for cultivating linguistic talents.Linguistic talents must possess very strong overall quality and skill to meet these requirements.In this context,this study carried out an in-depth analysis and research on translation method commonly used in German language teaching,and communicative method which is increasingly popular in recent years,to contribute to cultivation of German linguistic talents in higher learning institutes of China.展开更多
To increase the efficiency of teaching and improve the quality of teaching, it is necessary to learn the English teaching methodology and put the theory into practice. Audio-lingual Method and Communicative Language T...To increase the efficiency of teaching and improve the quality of teaching, it is necessary to learn the English teaching methodology and put the theory into practice. Audio-lingual Method and Communicative Language Teaching are very important methods in English language teaching. In this essay, I made a comparison and analysis based on their theories and practices. It is beneficial for us to proceed from the reality and use these methods appropriately.展开更多
Synchronization of fractional-order chaotic systems is receiving significant attention in the literature due to its applications in a variety of fields,including cryptography,optics,and secure communications.In this p...Synchronization of fractional-order chaotic systems is receiving significant attention in the literature due to its applications in a variety of fields,including cryptography,optics,and secure communications.In this paper,a three-dimensional fractional-order chaotic Lorenz model of chemical reactions is discussed.Some basic dynamical properties,such as stability of equilibria,Lyapunov exponents,bifurcation diagrams,Poincarémap,and sensitivity to initial conditions,are studied.By adopting the Adomian decomposition algorithm(ADM),the numerical solution of the fractional-order system is obtained.It is found that the lowest derivative order in which the proposed system exhibits chaos is q=0.694 by applying ADM.The result has been validated by the existence of one positive Lyapunov exponent and by employing some phase diagrams.In addition,the richer dynamics of the system are confirmed by using powerful tools in nonlinear dynamic analysis,such as the 0-1 test and C_(0)complexity.Moreover,modified projective synchronization has been implemented based on the stability theory of fractional-order systems.This paper presents the application of the modified projective synchronization in secure communication,where the information signal can be transmitted and recovered successfully through the channel.MATLAB simulations are provided to show the validity of the constructed secure communication scheme.展开更多
For further exploring the confidentiality of optical communication,exponential synchronization for the delayed nonlinear Schrodinger equation is studied.It is possible for time-delay systems to generate multiple posit...For further exploring the confidentiality of optical communication,exponential synchronization for the delayed nonlinear Schrodinger equation is studied.It is possible for time-delay systems to generate multiple positive Lyapunov exponents without the limitation of system dimension.Firstly,the homoclinic orbit analysis is carried out by using the bifurcation theory,and it is found that there are two homoclinic orbits in the system.According to the corresponding relationship,solitary waves also exist in the system.Secondly,the Melnikov method is used to prove that homoclinic orbits can evolve into chaos under arbitrary perturbations,and then chaotic signals are used as the carriers of information transmission.The Lyapunov exponent spectrum,phase diagram and time series of the system also prove the existence of chaos.Thirdly,an exponential synchronization controller is designed to achieve the chaotic synchronization between the driving system and the response system,and it is proved by the Lyapunov stability theory.Finally,the error system is simulated by using MATLAB,and it is found that the error tends to zero in a very short time.Numerical simulation results demonstrate that the proposed exponential synchronization scheme can effectively guarantee the chaotic synchronization within 1 s.展开更多
Individuals exchange information,experience and strategy based on communication.Communication is the basis for individuals to form swarms and the bridge of swarms to realize cooperative control.In this paper,the multi...Individuals exchange information,experience and strategy based on communication.Communication is the basis for individuals to form swarms and the bridge of swarms to realize cooperative control.In this paper,the multirobot swarm and its cooperative control and communication methods are reviewed,and we summarize these methods from the task,control,and perception levels.Based on the research,the cooperative control and communication methods of intelligent swarms are divided into the following four categories:task assignment based methods(divided into market-based methods and alliance based methods),bio-inspired methods(divided into biochemical information inspired methods,vision based methods and self-organization based methods),distributed sensor fusion and reinforcement learning based methods,and we briefly define each method and introduce its basic ideas.Based on WOS database,we divide the development of each method into several stages according to the time distribution of the literature,and outline the main research content of each stage.Finally,we discuss the communication problems of intelligent swarms and the key issues,challenges and future work of each method.展开更多
文摘In this paper, we study D2D (Device-to-Device) communication underlying LTE-Advanced uplink system. Since D2D communication reuses uplink resources with cellular communication in this scenario, it’s hard to avoid the inference between D2D users and cellular users. If there is no restriction for D2D communication on using the whole uplink frequency band, it will have a strong negative impact on cellular communication. In order to overcome this shortage, we propose a resource allocation method that D2D users and cellular users use orthogonal frequency resources. This method will effectively reduce the inference between both kinds of communication. However, an obvious disadvantage of this method is no effective use of uplink resources. Based on this, we propose an optimized resource allocation method that a specific cellular user will be chosen to reuse the RBs (Resource Block) of D2D users. These ideas will be taken into system-level simulation, and from the results of simulation we can see that the optimized method has the ability to improve overall system performance and limit inference for cell-edge users.
基金financially supported by Key Technologies R&D Program of Shandong Province(2015GSF115018)Natural Science Foundation of Shandong Province(ZR2013FL027+1 种基金ZR2013DM 014)Youth Foundation of Shandong Academy of Science(2013QN030)
文摘RLS and LMS blind adaptive multi-user detection algorithm and multi-user detector was proposed to solve the problem of multi-user signal detection problem encountered in underwater acoustic communication networks.In simulation analysis,RLS and the LMS blind adaptive multi-user detector were designed and tested for synchronous and asynchronous multi-user communication process.The results of SIR comparison and MMSE comparison show that,both of the two methods can realize blind adaptive detection when any user change in multi-user communication,during this process,the training communication sequences are not needed.The RLS algorithm has about 5 dB higher in SIR compared with LMS algorithm,and the convergence velocity of RLS algorithm is also higher than LMS algorithm when the communication users change.RLS algorithm has better ability in multi-user detection than that of LMS algorithm,and it has great attraction and guiding significance for solving the problem of multiple access interference(MAI) in multi-user communication.
文摘With the deepening of economic globalization,international exchanges and cooperation have become increasingly frequent,making cross-cultural collisions and integration a common phenomenon.As a vital pathway for cultivating applied talents,higher vocational education bears the responsibility of delivering high-quality professionals with intercultural communication competence to society.English,as the universal language of international communication,holds a pivotal position in higher vocational education.However,traditional English teaching in vocational colleges often focuses on language knowledge transmission while neglecting the cultivation of students’intercultural communication skills,leading to misunderstandings and conflicts caused by cultural differences in practical interactions.Therefore,enhancing the development of intercultural communication competence in vocational English education has become an urgent issue requiring resolution.This paper aims to explore the current status,challenges,and countermeasures for cultivating intercultural communication competence in vocational English education under globalization,providing references for teaching reform in vocational English education.
基金This work was supported by Chongqing Key Laboratory of Geological Environment Monitoring and Disaster Early-warning in Three Gorges Reservoir Area(No.MP2020B0101)Natural Science Foundation of Chongqing(No.cstc2019jcyj-msxm1328)。
文摘This paper develops a new transmit beamforming for an integrated mechanical and electrical scanning dual-function radar-communication(DFRC)system.Differing from the related some works using beampattern sidelobe level to communication,we exploit the fact that transmit beamforming weight vector u k in directionθand weight vector u*k in direction-θcan achieve the same spatial power distribution,and formulate a new transmit beamforming vector design problem accounting for some extra sidelobe level constraints.By doing so,the number of the transmit beamforming weight vectors and the computing demand in the multi-user communication(MUC)scenario can be reduced.Finally,the numerical examples are designed to verify the effectiveness of the proposed design strategy in comparison with the existing method.
基金Project supported by the National Natural Science Foundation of China(Grant No.11002086)the Shanghai Leading Academic Discipline Project(Grant No.J50103)
文摘Efficient communication is important to every parallel algorithm. A parallel communication optimization is introduced into lattice Boltzmann method （LBM）. It relies on a simplified communication strategy which is implemented by least square method. After testing the improved algorithm on parallel platform, the experimental results show that compared with normal parallel lattice Boltzmann algorithm, it provides better stability, higher performance while maintaining the same accuracy.
文摘Since communication protocol deals with complex issues related to distribution such as communication, concurrency and synchronization, their development needs to be traced by using sophisticated formal description methods. This paper presents a new hybrid formal method for communication protocol specification. In this method, finite state machine (FSM), communication sequential process (CSP) and abstract data type (ADT) are mixed and the best features of these approaches are offered. In this paper, the main formal description techniques (FDT) for protocol engineering are brieny introduced and a hybrid formal description method based on the FSM, CSP and ADT for communication protocol is described. Finally, this paper presents the formal specification of an example protocol for LAN by using the proposed hybrid formal method. The results of studies show that the hybrid formal description method for communication protocol is an available and effective approach.
基金This research was financially supported by the National College Students Innovation and Entrepreneurship Project(Grant NO.S202010647018).
文摘Zhiba culture is a profound culture with a long history,but there are still many problems in the C-E translation of it,such as low popularity,few recipients,and so on,which hinder its communication and development.Therefore,it’s necessary to improve the quality of C-E translation of Zhiba culture.Based on the perspective of communication studies,combining with the principle of“Information First”,the principle of“The Audience First”,the paper explores the existing problems of Zhiba culture C-E translation and hopes to help to improve the present situation,to truly show the charm of Zhiba culture,to make it better accepted by the international community and optimize the global communication effect.
文摘This paper is divided into two cases to study the communication transmission equipment reliability in the state of the ice storm, according to the huge losses of power system communication caused by the ice storm. For the nodes or links which are not affected by the ice storm, we use the calculation with “the mean time between failures (MTBF)” and “the mean time to repair” (MTTR) to put forward the calculation methods;for the OPGW cable which influenced greater in ice storm, we use the fiber excess length and the elongation of fiber optic cable. It obtains all the paths of the network through improved adjacency matrix method, and then it uses binary decision diagram to obtain the overall reliability of the network. By testing the network nodes and links using “N-1” inspection, the key nodes and key links can be obtained. Finally, considering the importance degree of network transmission business, the reliability evaluation method of power system communication network based on the risk theory in the case of the ice storm has been put forward, and the example to verify that the method can provide the basis for the reliability assessment of the power system communication in the case of the ice storm has been given.
基金Ersta Skondal University College financed by grants from AFA Insurance
文摘Aims and objectives: To explore any changes in nurses’ skills at communicating with residents with dementia disease when using the validation method, as observed in one-to-one videotaped conversations. Background: Communication difficulties due to cognitive impairment among residents with dementia disease may complicate care situations. Training can improve nurses’ communication skills and increase care quality. The validation method aims to facilitate communication with residents with dementia disease through empathic and confirmatory approaches. Evaluations of the validation method have primarily focused on the residents’ perspective, and reports on nurses’ experiences are sparse. Improved communication and relationships with residents after validation method training have been described previously. Videotaped data could provide additional information about these earlier results. Design: A descriptive qualitative design. Methods: Eight nurses participated in a year of validation method training, including videotaped conversations with eleven residents. Videotapes with at least five months between the first and last recording were analysed and compared qualitatively. Results: The analysis revealed an overall pattern: nurses’ movements within and between various paths when improving their communication skills. This was based on three sub-patterns: from controlling communication towards developing attentiveness in communication, from ambiguous communication towards developing coherence in communication, and from being open and attentive towards having a refined attuned communication. Conclusions: All nurses developed their communication skills during the programme, albeit to different degrees. The findings are in congruence with the experiences described by nurses, and so it is reasonable to believe that the programme helped to improve the nurses’ skills in communicating with residents with dementia disease. Relevance to clinical practice: A validation method training programme could give nurses the possibility to develop their skills in communicating with residents with dementia disease.
基金Supported by the Science and Technology Program of the Education Department of Shaanxi Provincial Government(09JK378)the Key Scientific Research Fund of Shaanxi University of Technology(SLGKY12-02)~~
文摘With the rural concealed communication cable as the study object, the shielding effectiveness of different slot shapes was analyzed by using LBEM （linear boundary element method）. The engineering example results showed that for twocore shielded cable, the coupling capacitance of trapezoid slots （asymmetric and symmetric） changed the most, followed by rectangular slots （asymmetric and symmetric）, and the changes of wedge slots were the smallest, but the change tenden- cies were consistent. In addition, with the increase of slot width of different slots, the coupling capacitance of tow-cored shielded cable showed small change.
文摘Comprehensive English is a very basic and important course for English majors,according to the features of the text-book A New English Course,teachers should adopt the integration of grammar translation method and communicative approach to improve students' linguistic competence and communicative competence.
基金supported by the National Natural Science Foundation of China(No.60972023)the National Science and Technology Important Special Project(Nos.2010ZX03003-002 and 2010ZX03003-004)+4 种基金the Open Research Fund of National Mobile Communication Research Laboratory,Southeast University(No.2010D01)the Open Research Fund of State Key Laboratory of Advanced Optical Communication Systems and Networks,China(No.2008SH06)the Startup Fund of Nanjing University of Aeronautics and Astronautics(NUAA)the NUAA Research Funding(No.NS2010091)the Fundation of Graduate Innovation Center in NUAA
文摘Channel estimation is a key technology in indoor wireless visible light communications(VLCs).Using the training sequence(TS),this paper investigates the channel estimation in indoor wireless visible light communications.Based on the propagation and signal modulation characteristics of visible light,a link model for the indoor wireless visible light communications is established.Using the model,three channel estimation methods,i.e.,the correlation method,the least square(LS) method and the minimum mean square error(MMSE) method,are proposed.Moreover,the performances of the proposed three methods are evaluated by computer simulation.The results show that the performance of the correlation method is the worst,the LS method is suitable for higher signal to noise ratio(SNR),and the MMSE method obtains the best performance at the expense of highest complexity.
基金supported by Project funded by China Postdoctoral Science Foundation(No.2021MD703980)。
文摘To improve the efficiency and fairness of the spectrum allocation for ground communication assisted by unmanned aerial vehicles(UAVs),a joint optimization method for on-demand deployment and spectrum allocation of UAVs is proposed,which is modeled as a mixed-integer non-convex optimization problem(MINCOP).An algorithm to estimate the minimum number of required UAVs is firstly proposed based on the pre-estimation and simulated annealing.The MINCOP is then decomposed into three sub-problems based on the block coordinate descent method,including the spectrum allocation of UAVs,the association between UAVs and ground users,and the deployment of UAVs.Specifically,the optimal spectrum allocation is derived based on the interference mitigation and channel reuse.The association between UAVs and ground users is optimized based on local iterated optimization.A particle-based optimization algorithm is proposed to resolve the subproblem of the UAVs deployment.Simulation results show that the proposed method could effectively improve the minimum transmission rate of UAVs as well as user fairness of spectrum allocation.
文摘Objective: To explore the effect of video combined with the teach-back method on respiratory function exercise in patients undergoing tumor thoracotomy. Methods: Eligible patients undergoing thoracotomy for tumor were selected from the thoracic surgery at a level-A tertiary hospital between August 2021 and December 2021 and included in the control group and the observation group (40 patients in each group). To prevent two groups of patients from interacting with each other, the thoracic surgery ward I was distinguished as the control group, which was adopted by the routine instruction. Based on routine instruction, the thoracic surgery ward II conducted respiratory function exercise instruction by video combined with the teach-back method to compare the two groups’ compliance with respiratory function exercise, complication rates, and patient satisfaction. Results: The patient compliance with respiratory function exercise in the observation group was significantly higher (P < 0.05) and the rate of pulmonary complications in the observation group was lower (P < 0.05) than that in the control group, while the observation group had a high level of satisfaction (P Conclusion: Taking video combined with the teach-back method, an effective health education method, can improve the compliance of the respiratory function exercise of patients undergoing thoracotomy for tumor and promote the recovery of pulmonary function to reduce the incidence of postoperative pulmonary complications so as to improve patient satisfaction.
文摘With the continuous development of national‘reforms and opening-up’policy and development of economic globalization,learning and application of foreign languages are becoming increasingly important.Society needs a large number of professional linguistic workers.Therefore,there are higher requirements for new era higher learning institutes which serve as training base for cultivating linguistic talents.Linguistic talents must possess very strong overall quality and skill to meet these requirements.In this context,this study carried out an in-depth analysis and research on translation method commonly used in German language teaching,and communicative method which is increasingly popular in recent years,to contribute to cultivation of German linguistic talents in higher learning institutes of China.
文摘To increase the efficiency of teaching and improve the quality of teaching, it is necessary to learn the English teaching methodology and put the theory into practice. Audio-lingual Method and Communicative Language Teaching are very important methods in English language teaching. In this essay, I made a comparison and analysis based on their theories and practices. It is beneficial for us to proceed from the reality and use these methods appropriately.
文摘Synchronization of fractional-order chaotic systems is receiving significant attention in the literature due to its applications in a variety of fields,including cryptography,optics,and secure communications.In this paper,a three-dimensional fractional-order chaotic Lorenz model of chemical reactions is discussed.Some basic dynamical properties,such as stability of equilibria,Lyapunov exponents,bifurcation diagrams,Poincarémap,and sensitivity to initial conditions,are studied.By adopting the Adomian decomposition algorithm(ADM),the numerical solution of the fractional-order system is obtained.It is found that the lowest derivative order in which the proposed system exhibits chaos is q=0.694 by applying ADM.The result has been validated by the existence of one positive Lyapunov exponent and by employing some phase diagrams.In addition,the richer dynamics of the system are confirmed by using powerful tools in nonlinear dynamic analysis,such as the 0-1 test and C_(0)complexity.Moreover,modified projective synchronization has been implemented based on the stability theory of fractional-order systems.This paper presents the application of the modified projective synchronization in secure communication,where the information signal can be transmitted and recovered successfully through the channel.MATLAB simulations are provided to show the validity of the constructed secure communication scheme.
基金The National Natural Science Foundation of China(No.71673116,71690242)the Humanistic and Social Science Foundation from M inistry of Education of China(No.16YJAZH007)the Natural Science Foundation of Jiangsu Province(No.SBK2015021674)
文摘For further exploring the confidentiality of optical communication,exponential synchronization for the delayed nonlinear Schrodinger equation is studied.It is possible for time-delay systems to generate multiple positive Lyapunov exponents without the limitation of system dimension.Firstly,the homoclinic orbit analysis is carried out by using the bifurcation theory,and it is found that there are two homoclinic orbits in the system.According to the corresponding relationship,solitary waves also exist in the system.Secondly,the Melnikov method is used to prove that homoclinic orbits can evolve into chaos under arbitrary perturbations,and then chaotic signals are used as the carriers of information transmission.The Lyapunov exponent spectrum,phase diagram and time series of the system also prove the existence of chaos.Thirdly,an exponential synchronization controller is designed to achieve the chaotic synchronization between the driving system and the response system,and it is proved by the Lyapunov stability theory.Finally,the error system is simulated by using MATLAB,and it is found that the error tends to zero in a very short time.Numerical simulation results demonstrate that the proposed exponential synchronization scheme can effectively guarantee the chaotic synchronization within 1 s.
基金supported by National Natural Science Foundation of China(No.61803383).
文摘Individuals exchange information,experience and strategy based on communication.Communication is the basis for individuals to form swarms and the bridge of swarms to realize cooperative control.In this paper,the multirobot swarm and its cooperative control and communication methods are reviewed,and we summarize these methods from the task,control,and perception levels.Based on the research,the cooperative control and communication methods of intelligent swarms are divided into the following four categories:task assignment based methods(divided into market-based methods and alliance based methods),bio-inspired methods(divided into biochemical information inspired methods,vision based methods and self-organization based methods),distributed sensor fusion and reinforcement learning based methods,and we briefly define each method and introduce its basic ideas.Based on WOS database,we divide the development of each method into several stages according to the time distribution of the literature,and outline the main research content of each stage.Finally,we discuss the communication problems of intelligent swarms and the key issues,challenges and future work of each method.
