This study explores the application of single photon detection(SPD)technology in underwater wireless optical communication(UWOC)and analyzes the influence of different modulation modes and error correction coding type...This study explores the application of single photon detection(SPD)technology in underwater wireless optical communication(UWOC)and analyzes the influence of different modulation modes and error correction coding types on communication performance.The study investigates the impact of on-off keying(OOK)and 2-pulse-position modulation(2-PPM)on the bit error rate(BER)in single-channel intensity and polarization multiplexing.Furthermore,it compares the error correction performance of low-density parity check(LDPC)and Reed-Solomon(RS)codes across different error correction coding types.The effects of unscattered photon ratio and depolarization ratio on BER are also verified.Finally,a UWOC system based on SPD is constructed,achieving 14.58 Mbps with polarization OOK multiplexing modulation and 4.37 Mbps with polarization 2-PPM multiplexing modulation using LDPC code error correction.展开更多
BACKGROUND Patients with knee arthroplasty often have problems such as slow recovery of knee function,which may cause negative emotions and affect their postoperative rehabilitation.The application of sensory and moto...BACKGROUND Patients with knee arthroplasty often have problems such as slow recovery of knee function,which may cause negative emotions and affect their postoperative rehabilitation.The application of sensory and motor training in the Acknowledge,Introduce,Duration,Evaluation,Thank You(AIDET)communication mode in patients after knee arthroplasty can provide reference for the selection of postoperative rehabilitation training measures.AIM To explore the sensory and motor training effects in AIDET communication mode on knee function recovery and resilience of patients after knee arthroplasty.METHODS One hundred patients who underwent knee arthroplasty at our hospital between January 2022 and January 2024 were randomly divided into two groups.The control group(n=50)received routine rehabilitation training.In the observation group(n=50),the AIDET communication mode was used to perform sensory and motor training,in addition to routine rehabilitation training.The rehabilitation training was administered for 8 weeks.After surgery,knee function,balance ability,walking ability,proprioception,and resilience were compared between the two groups.RESULTS The New York Hospital for Special Surgery knee scores of the observation group at the time of discharge and 8 weeks after intervention were(65.23±6.84,84.53±5.27),which was higher than those of the control group(61.03±7.15,74.92±6.52)(P<0.05).The balance ability of the observation group at the time of discharge and 8 weeks after the intervention was higher than that of the control group,the time of time up to go test was shorter than that of the control group,and proprioceptive function was higher than that of the control group(P<0.05).The resilience level in the observation group after the intervention was higher than that in the control group(P<0.05).CONCLUSION Sensory and motor training in AIDET communication mode promotes knee function recovery of patients after knee arthroplasty,improves their limb walking ability and balance function,and increases their resilience level.展开更多
In this paper,an integrated substrate gap waveguide(ISGW)filtering antenna is proposed at millimeter wave band,whose surface wave and spurious modes are simultaneously suppressed.A secondorder filtering response is ob...In this paper,an integrated substrate gap waveguide(ISGW)filtering antenna is proposed at millimeter wave band,whose surface wave and spurious modes are simultaneously suppressed.A secondorder filtering response is obtained through a coupling feeding scheme using one uniform impedance resonator(UIR)and two stepped-impedance resonators(SIRs).To increase the stopband width of the antenna,the spurious modes are suppressed by selecting the appropriate sizes of the ISGW unit cell.Furthermore,the ISGW is implemented to improve the radiation performance of the antenna by alleviating the propagation of surface wave.And an equivalent circuit is investigated to reveal the working principle of ISGW.To demonstrate this methodology,an ISGW filtering antenna operating at a center frequency of 25 GHz is designed,fabricated,and measured.The results show that the antenna achieves a stopband width of 1.6f0(center frequency),an out-of-band suppression level of 21 dB,and a peak realized gain of 8.5 dBi.展开更多
Spatial models joint external and internal aspects of human activity,mental schemas of thinking,and spatial structures of things.These models represent objects of knowledge,valuation,and transformation due to similari...Spatial models joint external and internal aspects of human activity,mental schemas of thinking,and spatial structures of things.These models represent objects of knowledge,valuation,and transformation due to similarity with them in various relations,and they participate in inter-subject communication using schemata common for many people.The spatial models can reproduce a modelled object or be productive regarding it.These models are created in cognitive modus of comprehension as images of objects known at various mental levels;in projective modus,they appear as projects of object’s transformation and planes of subject’s actions;in communicative modus,they are interpreted as spatial texts expressing certain senses.All of them interact in spatial thinking,which deals with the relationship of parts and the whole,unlike logical thinking operating with genus-species relations.Both practical and theoretical thinking use common spatial schemas as means of internal modelling,which are elaborated in collective and individual experience.Due to their simplicity and unification,these schemas can serve also as units of spatial codes mediating the objects representation and inter-subject communication through spatial texts created in the semiotized space.展开更多
The teaching objective of vocational business English is not only to improve students' English language competence, but also to develop their intercultural communication competence. Based on an analysis of the outcom...The teaching objective of vocational business English is not only to improve students' English language competence, but also to develop their intercultural communication competence. Based on an analysis of the outcome of a survey on cultivation of English majors' intercultural competence among vocational colleges in Guangxi, the paper aims at exploring the framework and cultivating modes of intercultural communication competence for business English majors in vocational colleges.展开更多
To meet the increasing demand of wireless broadband applications in future 5G cellular networks, Device-to-Device(D2D) communications serve as a candidate paradigm to improve spectrum efficiency. Considering the chall...To meet the increasing demand of wireless broadband applications in future 5G cellular networks, Device-to-Device(D2D) communications serve as a candidate paradigm to improve spectrum efficiency. Considering the challenges after D2 D transmission is introduced for future cellular networks, this paper deals with mode selection and resource allocation issues related with D2 D communications. First, we propose a mode selection scheme which aims at guaranteeing the transmission of cellular users and also considering the potential interference. We analyze the condition under which D2 D underlay mode should be used. Second, we answer the question of "how to effectively reuse cellular resource once underlaying mode is adopted". We further present a resource allocation scheme that focuses on minimizing overall interference as well as a power control method to improve the performance of D2 D systems. Simulation results demonstrate that system parameters greatly affect the switching condition of mode selection and probability of choosing underlay mode. Furthermore, for D2 D underlaying scenario, the proposed resource allocation algorithm guarantees the transmission of cellular users with consideration of transmission requirements of D2 D users. Hence, the proposed scheme can achieve better user experience.展开更多
Device-to-device(D2D) communications can be underlaid with a cellular infrastructure to increase resource utilization, improve user throughput and save battery energy. In such networks, power allocation and mode selec...Device-to-device(D2D) communications can be underlaid with a cellular infrastructure to increase resource utilization, improve user throughput and save battery energy. In such networks, power allocation and mode selection are crucial problems. To address the joint optimization of power and mode selection under imperfect CSI, we propose an optimal, energy-aware joint power allocation and mode selection(JPAMS) scheme. First, we derive the closed-form solution for the power minimization for both D2 D and cellular links while satisfying different quality of service(Qo S) constraints. Second, we address the mode selection problem in presence of imperfect CSI, based on the derived power allocation. Moreover, the theoretical analysis and simulation results are presented to evaluate the proposed scheme for the D2 D communications.展开更多
Cross-ice acoustic information transmission is an effective means of communication in polar sea areas covered by ice.However,the channel is extremely complicated because of the combined influence of water,ice,and air....Cross-ice acoustic information transmission is an effective means of communication in polar sea areas covered by ice.However,the channel is extremely complicated because of the combined influence of water,ice,and air.Based on the normalmode theory,this paper establishes a cascade acoustic channel(CAC)model for the transmission of underwater acoustic waves across ice layer.The model can calculate the displacement response of the ice layer’s upper surface by separating the upward waves from normal modes in the water and multiplying it by a transmission coefficient matrix.The relationship between the displacement response of the upper surface of ice layer and the acoustic frequency is calculated by the finite-element method,and the calculation result was consistent with that of the CAC model.To verify the applicability of the model,a cross-ice acoustic communication experiment was conducted in Songhua River in January 2019.Experimental results show the energy of the acoustic signals received by geophones is closely related to sound frequency and crossice acoustic communication is feasible.The result of present research is important for understanding crossice acoustic channel characteristics and developing future cross-ice acoustic communication in polar sea areas.展开更多
This paper deals with the robust control problem for a class of uncertain nonlinear networked systems with stochastic communication delays via sliding mode conception (SMC). A sequence of variables obeying Bernoulli...This paper deals with the robust control problem for a class of uncertain nonlinear networked systems with stochastic communication delays via sliding mode conception (SMC). A sequence of variables obeying Bernoulli distribution are employed to model the randomly occurring communication delays which could be different for different state variables. A discrete switching function that is different from those in the existing literature is first proposed. Then, expressed as the feasibility of a linear matrix inequality (LMI) with an equality constraint, sufficient conditions are derived in order to ensure the globally mean-square asymptotic stability of the system dynamics on the sliding surface. A discrete-time SMC controller is then synthesized to guarantee the discrete-time sliding mode reaching condition with the specified sliding surface. Finally, a simulation example is given to show the effectiveness of the proposed method.展开更多
Joint mode selection and link allocation are crucial to achieve the advantage of Device-to-Device(D2 D) communications in improving spectral efficiency. In practice, cellular users tend to not be totally altruistic or...Joint mode selection and link allocation are crucial to achieve the advantage of Device-to-Device(D2 D) communications in improving spectral efficiency. In practice, cellular users tend to not be totally altruistic or absolutely selfish. How to stimulate them to devote their links and how to allocate their links to D2 D pair candidates efficiently are two main challenges. In this paper, we encourage cellular users through the variable payment with regard to the social tie strength between cellular users and D2 D pair candidates. In particular, the social tie strength is inferred through a graph inference model and its impact on the payment is quantified as a negative exponential function. Then, we propose a resource scheduling optimization model based on the non-transferable utility coalition formation game, and a distributed coalition formation algorithm based on the Pareto preference and merge-and-split rule. From them, the final coalition structure is obtained, which reflects the strategy of mode selection and link allocation. Numerical results are presented to verify the effectiveness of our proposed scheme.展开更多
For the multipath fading on electromagnetic waves of wireless communication in the confined areas,the rectangular tunnel cooperative communication system was established based on the multimode channel model and the ch...For the multipath fading on electromagnetic waves of wireless communication in the confined areas,the rectangular tunnel cooperative communication system was established based on the multimode channel model and the channel capacity formula derivation was obtained.On the optimal criterion of the channel capacity,the power allocation methods of both amplifying and forwarding(AF) and decoding and forwarding(DF) cooperative communication systems were proposed in the limitation of the total power to maximize the channel capacity.The mode selection methods of single input single output(SISO) and single input multiple output(SIMO) models in the rectangular tunnel,through which the higher channel capacity can be obtained,were put forward as well.The theoretical analysis and simulation comparison show that,channel capacity of the wireless communication system in the rectangular tunnel can be effectively enhanced through the cooperative technology;channel capacity of the rectangular tunnel under complicated conditions is maximized through the proposed power allocation methods,and the optimal cooperative mode of the channel capacity can be chosen according to the cooperative mode selection methods given in the paper.展开更多
Background:To explore the application effect of Acknowledge-Introduce-Duration-Explanation-Thank you(AIDET)communication mode in reducing anxiety and improving the care services satisfaction of the patients.Methods:Th...Background:To explore the application effect of Acknowledge-Introduce-Duration-Explanation-Thank you(AIDET)communication mode in reducing anxiety and improving the care services satisfaction of the patients.Methods:The 100 cases undergoing cataract daytime operation from February to July 2019 were divided into test group and control group.The test group conducted health education and nursing care for patients during admission,pre-operation,post-operation,and discharge according to the AIDET communication mode.And the control group was given health education and nursing care to the patients according to the traditional way of communication.Results:The difference of the socioeconomic information between these two groups showed no statistical significance.The care services satisfaction score in the test group was statistically higher than that in the control group(P<0.05).The Self-Rating Anxiety Scale(SAS)score in the test group was significantly lower than that in the control group(P<0.01).This result indicated that the patients suffered less anxiety with the AIDET mode of communication.Conclusions:The application of AIDET communication mode to the nursing service of cataract daytime operation can reduce the tension and anxiety of the patients from the treatment and improve their satisfaction to care services.展开更多
In the present work, we investigate threshold characteristics of a single mode 1.55 μm InGaAsP vertical cavity surface emitting laser (VCSEL) with two different optical confinement structures. The device employs InGa...In the present work, we investigate threshold characteristics of a single mode 1.55 μm InGaAsP vertical cavity surface emitting laser (VCSEL) with two different optical confinement structures. The device employs InGaAsP active region, which is sandwiched between GaAs/AlGaAs and GaAs/AlAs distributed Bragg reflectors (DBRs). The optical confinement introduced by the oxide aperture or a single defect photonic crystal design with holes etched throughout the whole structure, is compared with previous work. Photonic crystal VCSEL shows 30.86% and 57.02% lower threshold current than that of the similar oxide confined VCSEL and previous results, respectively. This paper provides key results of the threshold characteristics, including the threshold current and the threshold power. Results suggest that, the 1.55 μm InGaAsP photonic crystal VCSEL seems to be the most optimal one for light sources in high performance optical communication systems.展开更多
This paper presents a planar microstrip wideband dual mode Band-Pass Filter(BPF) from 2 GHz to 3.4 GHz with a notched band at 2.62 GHz.The dual mode band-pass filter consists of a ring resonator with two quarter-wavel...This paper presents a planar microstrip wideband dual mode Band-Pass Filter(BPF) from 2 GHz to 3.4 GHz with a notched band at 2.62 GHz.The dual mode band-pass filter consists of a ring resonator with two quarter-wavelength open-circuited stubs at =90o and =0o,respectively.A square perturbation stub has been put at the corner of the ring resonator to increase the narrow stopbands and improve the performance of selectivity.By using a parallel-coupled feed line,a narrow notched band is introduced at the required frequency and its Fractional BandWidth(FBW) is about 5%.The proposed filter has a narrow notched band and a wide pass-band with a sharp cutoff frequency characteristic,the attenuation rate for the sharp cutoff frequency responses is 297.17 dB/GHz(cal-culated from 1.959 GHz with-34.43 dB to 2.065 GHz with-2.93 dB) and 228.10 dB/GHz(calculated from 3.395 GHz with-2.873 dB to 3.507 GHz with-28.42 dB).This filter has the advantages of good insertion loss in both operating bands and two rejections of greater than 16 dB in the range of 1.59 GHz to 1.99 GHz and 3.49 GHz to 3.98 GHz.Having been presented in this article,the measurement results agree well with the simulation results,which validates our idea.展开更多
This paper proposes a novel adaptive sliding mode control(SMC) method for synchronization of non-identical fractional-order(FO) chaotic and hyper-chaotic systems. Under the existence of system uncertainties and extern...This paper proposes a novel adaptive sliding mode control(SMC) method for synchronization of non-identical fractional-order(FO) chaotic and hyper-chaotic systems. Under the existence of system uncertainties and external disturbances,finite-time synchronization between two FO chaotic and hyperchaotic systems is achieved by introducing a novel adaptive sliding mode controller(ASMC). Here in this paper, a fractional sliding surface is proposed. A stability criterion for FO nonlinear dynamic systems is introduced. Sufficient conditions to guarantee stable synchronization are given in the sense of the Lyapunov stability theorem. To tackle the uncertainties and external disturbances, appropriate adaptation laws are introduced. Particle swarm optimization(PSO) is used for estimating the controller parameters. Finally, finite-time synchronization of the FO chaotic and hyper-chaotic systems is applied to secure communication.展开更多
With the low cost and low hardware complex considerations,cooperative systems are a tendency in the future communications.This work considers the secure cooperative communications systems.For a practical situation in ...With the low cost and low hardware complex considerations,cooperative systems are a tendency in the future communications.This work considers the secure cooperative communications systems.For a practical situation in the system,the scenario includes multiple source stations,multiple relay stations,multiple destination stations,and eavesdroppers.To analyze the optimal relay selection in the system,we begin with the performance analysis for a single source station and a single destination station.By applying two cooperative models,the amplify-andforward(AF) mode and decode-and-forward(DF)mode,the secrecy capacity is derived.Then,we apply the derived results to the considered environment to find the optimal relay assignment.By the way,the relay selection can be obtained by the exhaustive search algorithm.However,there are a lot of steps needed if the number of source stations is large.Hence,applying the characters of the cooperative modes in the relay selection,the pre-selection step is proposed with a mathematical derivation.It could be used for the practical situation without a long-time calculation.展开更多
With the incessant propulsion of the Open Door Policy,which is related to the consolidation of international collaborative partnerships,an increasing number of Chinese companies are moving toward cooperating countries...With the incessant propulsion of the Open Door Policy,which is related to the consolidation of international collaborative partnerships,an increasing number of Chinese companies are moving toward cooperating countries to participate in infrastructure construction,employing a win-win strategy in favor of the people and governments of both countries.Among the cooperation domains,our country’s electrical companies have achieved a series of remarkable results in the international Engineering,Procurement,and Construction(EPC)project market with their outstanding business capabilities and technical advantages.Nevertheless,some shortcomings cannot be overlooked,the most notable of which appears to be the impediment associated with engineering translation,which has always been an obsession among translators of Chinese companies.Taking the transmission line project in the Republic of Madagascar as an example,an analysis of French-Chinese translation methods of electrical engineering terminology in the field of the transmission line is carried out.展开更多
In the 21st century,the development of digital and new media technologies has ushered in an age of pervasive multimodal communication,which has significantly amplified the role of multimodal translation in facilitatin...In the 21st century,the development of digital and new media technologies has ushered in an age of pervasive multimodal communication,which has significantly amplified the role of multimodal translation in facilitating crosscultural exchanges.Despite the profound impact of these developments,the prevailing translation pedagogy remains predominantly focused on the enhancement of linguistic translation skills,with noticeable neglect of the imperative to cultivate students’competencies in multimodal translation.Based on the distinctive characteristics and challenges that multimodal translation presents in the context of new media,this study delves into the formulation of educational objectives and curriculum design for the training of multimodal translators.The intent is to propose a framework that can guide the preparation of translators who are adept and equipped to navigate the complexities and demands of the contemporary age.展开更多
Quantum communication network scales point-to-point quantum communication protocols to more than two detached parties,which would permit a wide variety of quantum communication applications.Here,we demonstrate a fully...Quantum communication network scales point-to-point quantum communication protocols to more than two detached parties,which would permit a wide variety of quantum communication applications.Here,we demonstrate a fully-connected quantum communication network,exploiting three pairs of Einstein–Podolsky–Rosen(EPR)entangled sideband modes,with high degree entanglement of 8.0 dB,7.6 dB,and 7.2 dB.Each sideband modes from a squeezed field are spatially separated by demultiplexing operation,then recombining into new group according to network requirement.Each group of sideband modes are distributed to one of the parties via a single physical path,making sure each pair of parties build their own private communication links with high channel capacity better than any classical scheme.展开更多
This paper deals with the synchronization of chaotic systems with structure or parameters difference. Nonlinear differential geometry theory was applied to transform the chaotic discrepancy system into canonical form....This paper deals with the synchronization of chaotic systems with structure or parameters difference. Nonlinear differential geometry theory was applied to transform the chaotic discrepancy system into canonical form. A feedback control for synchronizing two chaotic systems is proposed based on sliding mode control design. To make this controller physically realizable, an extended state observer is used to estimate the error between the transmitter and receiver. Two illustrative examples were carried out: (1) The Chua oscillator was used to show that synchronization was achieved and the message signal was recovered in spite of parametric variations; (2) Two second-order driven oscillators were presented to show that the synchronization can be achieved and that the message can be recovered in spite of the strictly different model.展开更多
基金supported in part by the National Natural Science Foundation of China(Nos.62071441 and 61701464)in part by the Fundamental Research Funds for the Central Universities(No.202151006).
文摘This study explores the application of single photon detection(SPD)technology in underwater wireless optical communication(UWOC)and analyzes the influence of different modulation modes and error correction coding types on communication performance.The study investigates the impact of on-off keying(OOK)and 2-pulse-position modulation(2-PPM)on the bit error rate(BER)in single-channel intensity and polarization multiplexing.Furthermore,it compares the error correction performance of low-density parity check(LDPC)and Reed-Solomon(RS)codes across different error correction coding types.The effects of unscattered photon ratio and depolarization ratio on BER are also verified.Finally,a UWOC system based on SPD is constructed,achieving 14.58 Mbps with polarization OOK multiplexing modulation and 4.37 Mbps with polarization 2-PPM multiplexing modulation using LDPC code error correction.
文摘BACKGROUND Patients with knee arthroplasty often have problems such as slow recovery of knee function,which may cause negative emotions and affect their postoperative rehabilitation.The application of sensory and motor training in the Acknowledge,Introduce,Duration,Evaluation,Thank You(AIDET)communication mode in patients after knee arthroplasty can provide reference for the selection of postoperative rehabilitation training measures.AIM To explore the sensory and motor training effects in AIDET communication mode on knee function recovery and resilience of patients after knee arthroplasty.METHODS One hundred patients who underwent knee arthroplasty at our hospital between January 2022 and January 2024 were randomly divided into two groups.The control group(n=50)received routine rehabilitation training.In the observation group(n=50),the AIDET communication mode was used to perform sensory and motor training,in addition to routine rehabilitation training.The rehabilitation training was administered for 8 weeks.After surgery,knee function,balance ability,walking ability,proprioception,and resilience were compared between the two groups.RESULTS The New York Hospital for Special Surgery knee scores of the observation group at the time of discharge and 8 weeks after intervention were(65.23±6.84,84.53±5.27),which was higher than those of the control group(61.03±7.15,74.92±6.52)(P<0.05).The balance ability of the observation group at the time of discharge and 8 weeks after the intervention was higher than that of the control group,the time of time up to go test was shorter than that of the control group,and proprioceptive function was higher than that of the control group(P<0.05).The resilience level in the observation group after the intervention was higher than that in the control group(P<0.05).CONCLUSION Sensory and motor training in AIDET communication mode promotes knee function recovery of patients after knee arthroplasty,improves their limb walking ability and balance function,and increases their resilience level.
基金This work was supported by the National Key research and development program of China(No.2021YFB 2900401)the national natural science foundation of China(No.62361057,No.61861046)+1 种基金the key natural science foundation of Shenzhen(No.JCYJ20220818102209020)the key research and development program of Shenzhen(No.ZDSYS20210623091807023).
文摘In this paper,an integrated substrate gap waveguide(ISGW)filtering antenna is proposed at millimeter wave band,whose surface wave and spurious modes are simultaneously suppressed.A secondorder filtering response is obtained through a coupling feeding scheme using one uniform impedance resonator(UIR)and two stepped-impedance resonators(SIRs).To increase the stopband width of the antenna,the spurious modes are suppressed by selecting the appropriate sizes of the ISGW unit cell.Furthermore,the ISGW is implemented to improve the radiation performance of the antenna by alleviating the propagation of surface wave.And an equivalent circuit is investigated to reveal the working principle of ISGW.To demonstrate this methodology,an ISGW filtering antenna operating at a center frequency of 25 GHz is designed,fabricated,and measured.The results show that the antenna achieves a stopband width of 1.6f0(center frequency),an out-of-band suppression level of 21 dB,and a peak realized gain of 8.5 dBi.
文摘Spatial models joint external and internal aspects of human activity,mental schemas of thinking,and spatial structures of things.These models represent objects of knowledge,valuation,and transformation due to similarity with them in various relations,and they participate in inter-subject communication using schemata common for many people.The spatial models can reproduce a modelled object or be productive regarding it.These models are created in cognitive modus of comprehension as images of objects known at various mental levels;in projective modus,they appear as projects of object’s transformation and planes of subject’s actions;in communicative modus,they are interpreted as spatial texts expressing certain senses.All of them interact in spatial thinking,which deals with the relationship of parts and the whole,unlike logical thinking operating with genus-species relations.Both practical and theoretical thinking use common spatial schemas as means of internal modelling,which are elaborated in collective and individual experience.Due to their simplicity and unification,these schemas can serve also as units of spatial codes mediating the objects representation and inter-subject communication through spatial texts created in the semiotized space.
文摘The teaching objective of vocational business English is not only to improve students' English language competence, but also to develop their intercultural communication competence. Based on an analysis of the outcome of a survey on cultivation of English majors' intercultural competence among vocational colleges in Guangxi, the paper aims at exploring the framework and cultivating modes of intercultural communication competence for business English majors in vocational colleges.
基金supported by the National Natural Science Foundation of China(No.61501371)National 863 High Tech R&D Program of China(project number:2014AA01A703)+1 种基金National Science and Technology Major Project of the Ministry of Science and Technology of China(project number:2014ZX03001025-006)The international Exchange and Cooperation Projects of Shaanxi Province(project number:2016KW-046)
文摘To meet the increasing demand of wireless broadband applications in future 5G cellular networks, Device-to-Device(D2D) communications serve as a candidate paradigm to improve spectrum efficiency. Considering the challenges after D2 D transmission is introduced for future cellular networks, this paper deals with mode selection and resource allocation issues related with D2 D communications. First, we propose a mode selection scheme which aims at guaranteeing the transmission of cellular users and also considering the potential interference. We analyze the condition under which D2 D underlay mode should be used. Second, we answer the question of "how to effectively reuse cellular resource once underlaying mode is adopted". We further present a resource allocation scheme that focuses on minimizing overall interference as well as a power control method to improve the performance of D2 D systems. Simulation results demonstrate that system parameters greatly affect the switching condition of mode selection and probability of choosing underlay mode. Furthermore, for D2 D underlaying scenario, the proposed resource allocation algorithm guarantees the transmission of cellular users with consideration of transmission requirements of D2 D users. Hence, the proposed scheme can achieve better user experience.
基金supported in part by Important National Science and Technology Specific Projects (Grants Nos. 2011 ZX 0300300104, 2012ZX03003012)Fundamental Research Funds for Central Universities (Grant Nos. 72125377)
文摘Device-to-device(D2D) communications can be underlaid with a cellular infrastructure to increase resource utilization, improve user throughput and save battery energy. In such networks, power allocation and mode selection are crucial problems. To address the joint optimization of power and mode selection under imperfect CSI, we propose an optimal, energy-aware joint power allocation and mode selection(JPAMS) scheme. First, we derive the closed-form solution for the power minimization for both D2 D and cellular links while satisfying different quality of service(Qo S) constraints. Second, we address the mode selection problem in presence of imperfect CSI, based on the derived power allocation. Moreover, the theoretical analysis and simulation results are presented to evaluate the proposed scheme for the D2 D communications.
基金This research was funded by the National Key R&D Program of China(2018YFC1405900)The National Natural Science Foundation of China(Grant No.61631008 and No.51779061)+2 种基金the Fok Ying-Tong Education Foundation,China(Grant,No.151007)The Heilongjiang Province Outstanding Youth Science Fund(JC2017017)and the Innovation Special Zone of National Defense Science and Technology.
文摘Cross-ice acoustic information transmission is an effective means of communication in polar sea areas covered by ice.However,the channel is extremely complicated because of the combined influence of water,ice,and air.Based on the normalmode theory,this paper establishes a cascade acoustic channel(CAC)model for the transmission of underwater acoustic waves across ice layer.The model can calculate the displacement response of the ice layer’s upper surface by separating the upward waves from normal modes in the water and multiplying it by a transmission coefficient matrix.The relationship between the displacement response of the upper surface of ice layer and the acoustic frequency is calculated by the finite-element method,and the calculation result was consistent with that of the CAC model.To verify the applicability of the model,a cross-ice acoustic communication experiment was conducted in Songhua River in January 2019.Experimental results show the energy of the acoustic signals received by geophones is closely related to sound frequency and crossice acoustic communication is feasible.The result of present research is important for understanding crossice acoustic channel characteristics and developing future cross-ice acoustic communication in polar sea areas.
基金supported by the Engineering and Physical Sciences Research Council(EPSRC)of the UK(No.GR/S27658/01)the Royal Society of the UK and the Alexander von Humboldt Foundation of Germany
文摘This paper deals with the robust control problem for a class of uncertain nonlinear networked systems with stochastic communication delays via sliding mode conception (SMC). A sequence of variables obeying Bernoulli distribution are employed to model the randomly occurring communication delays which could be different for different state variables. A discrete switching function that is different from those in the existing literature is first proposed. Then, expressed as the feasibility of a linear matrix inequality (LMI) with an equality constraint, sufficient conditions are derived in order to ensure the globally mean-square asymptotic stability of the system dynamics on the sliding surface. A discrete-time SMC controller is then synthesized to guarantee the discrete-time sliding mode reaching condition with the specified sliding surface. Finally, a simulation example is given to show the effectiveness of the proposed method.
基金supported by Natural Science Foundations of China (No. 61671474)Jiangsu Provincial Natural Science Foundation for Excellent Young Scholars (No. BK20170089)
文摘Joint mode selection and link allocation are crucial to achieve the advantage of Device-to-Device(D2 D) communications in improving spectral efficiency. In practice, cellular users tend to not be totally altruistic or absolutely selfish. How to stimulate them to devote their links and how to allocate their links to D2 D pair candidates efficiently are two main challenges. In this paper, we encourage cellular users through the variable payment with regard to the social tie strength between cellular users and D2 D pair candidates. In particular, the social tie strength is inferred through a graph inference model and its impact on the payment is quantified as a negative exponential function. Then, we propose a resource scheduling optimization model based on the non-transferable utility coalition formation game, and a distributed coalition formation algorithm based on the Pareto preference and merge-and-split rule. From them, the final coalition structure is obtained, which reflects the strategy of mode selection and link allocation. Numerical results are presented to verify the effectiveness of our proposed scheme.
基金financial supports provided by the National Natural Science Foundation of China (No.51274202)the Fundamental Research Funds for the Central Universities (No.2013RC11)+3 种基金the Science and Technology Achievements Transformation Project of Jiangsu Province (No.BA2012068)the Natural Science Foundation of Jiangsu Province (Nos.BK20130199 and BK20131124)Ceeusro Prospective Joint Research Project of Jiangsu Province (No.BY2014028-01)Great Cultivating Special Project at China University of Mining and Technology (No.2014ZDPY16)
文摘For the multipath fading on electromagnetic waves of wireless communication in the confined areas,the rectangular tunnel cooperative communication system was established based on the multimode channel model and the channel capacity formula derivation was obtained.On the optimal criterion of the channel capacity,the power allocation methods of both amplifying and forwarding(AF) and decoding and forwarding(DF) cooperative communication systems were proposed in the limitation of the total power to maximize the channel capacity.The mode selection methods of single input single output(SISO) and single input multiple output(SIMO) models in the rectangular tunnel,through which the higher channel capacity can be obtained,were put forward as well.The theoretical analysis and simulation comparison show that,channel capacity of the wireless communication system in the rectangular tunnel can be effectively enhanced through the cooperative technology;channel capacity of the rectangular tunnel under complicated conditions is maximized through the proposed power allocation methods,and the optimal cooperative mode of the channel capacity can be chosen according to the cooperative mode selection methods given in the paper.
文摘Background:To explore the application effect of Acknowledge-Introduce-Duration-Explanation-Thank you(AIDET)communication mode in reducing anxiety and improving the care services satisfaction of the patients.Methods:The 100 cases undergoing cataract daytime operation from February to July 2019 were divided into test group and control group.The test group conducted health education and nursing care for patients during admission,pre-operation,post-operation,and discharge according to the AIDET communication mode.And the control group was given health education and nursing care to the patients according to the traditional way of communication.Results:The difference of the socioeconomic information between these two groups showed no statistical significance.The care services satisfaction score in the test group was statistically higher than that in the control group(P<0.05).The Self-Rating Anxiety Scale(SAS)score in the test group was significantly lower than that in the control group(P<0.01).This result indicated that the patients suffered less anxiety with the AIDET mode of communication.Conclusions:The application of AIDET communication mode to the nursing service of cataract daytime operation can reduce the tension and anxiety of the patients from the treatment and improve their satisfaction to care services.
文摘In the present work, we investigate threshold characteristics of a single mode 1.55 μm InGaAsP vertical cavity surface emitting laser (VCSEL) with two different optical confinement structures. The device employs InGaAsP active region, which is sandwiched between GaAs/AlGaAs and GaAs/AlAs distributed Bragg reflectors (DBRs). The optical confinement introduced by the oxide aperture or a single defect photonic crystal design with holes etched throughout the whole structure, is compared with previous work. Photonic crystal VCSEL shows 30.86% and 57.02% lower threshold current than that of the similar oxide confined VCSEL and previous results, respectively. This paper provides key results of the threshold characteristics, including the threshold current and the threshold power. Results suggest that, the 1.55 μm InGaAsP photonic crystal VCSEL seems to be the most optimal one for light sources in high performance optical communication systems.
基金Supported by the National Natural Science Foundation of China (No. 51007040)
文摘This paper presents a planar microstrip wideband dual mode Band-Pass Filter(BPF) from 2 GHz to 3.4 GHz with a notched band at 2.62 GHz.The dual mode band-pass filter consists of a ring resonator with two quarter-wavelength open-circuited stubs at =90o and =0o,respectively.A square perturbation stub has been put at the corner of the ring resonator to increase the narrow stopbands and improve the performance of selectivity.By using a parallel-coupled feed line,a narrow notched band is introduced at the required frequency and its Fractional BandWidth(FBW) is about 5%.The proposed filter has a narrow notched band and a wide pass-band with a sharp cutoff frequency characteristic,the attenuation rate for the sharp cutoff frequency responses is 297.17 dB/GHz(cal-culated from 1.959 GHz with-34.43 dB to 2.065 GHz with-2.93 dB) and 228.10 dB/GHz(calculated from 3.395 GHz with-2.873 dB to 3.507 GHz with-28.42 dB).This filter has the advantages of good insertion loss in both operating bands and two rejections of greater than 16 dB in the range of 1.59 GHz to 1.99 GHz and 3.49 GHz to 3.98 GHz.Having been presented in this article,the measurement results agree well with the simulation results,which validates our idea.
文摘This paper proposes a novel adaptive sliding mode control(SMC) method for synchronization of non-identical fractional-order(FO) chaotic and hyper-chaotic systems. Under the existence of system uncertainties and external disturbances,finite-time synchronization between two FO chaotic and hyperchaotic systems is achieved by introducing a novel adaptive sliding mode controller(ASMC). Here in this paper, a fractional sliding surface is proposed. A stability criterion for FO nonlinear dynamic systems is introduced. Sufficient conditions to guarantee stable synchronization are given in the sense of the Lyapunov stability theorem. To tackle the uncertainties and external disturbances, appropriate adaptation laws are introduced. Particle swarm optimization(PSO) is used for estimating the controller parameters. Finally, finite-time synchronization of the FO chaotic and hyper-chaotic systems is applied to secure communication.
文摘With the low cost and low hardware complex considerations,cooperative systems are a tendency in the future communications.This work considers the secure cooperative communications systems.For a practical situation in the system,the scenario includes multiple source stations,multiple relay stations,multiple destination stations,and eavesdroppers.To analyze the optimal relay selection in the system,we begin with the performance analysis for a single source station and a single destination station.By applying two cooperative models,the amplify-andforward(AF) mode and decode-and-forward(DF)mode,the secrecy capacity is derived.Then,we apply the derived results to the considered environment to find the optimal relay assignment.By the way,the relay selection can be obtained by the exhaustive search algorithm.However,there are a lot of steps needed if the number of source stations is large.Hence,applying the characters of the cooperative modes in the relay selection,the pre-selection step is proposed with a mathematical derivation.It could be used for the practical situation without a long-time calculation.
文摘With the incessant propulsion of the Open Door Policy,which is related to the consolidation of international collaborative partnerships,an increasing number of Chinese companies are moving toward cooperating countries to participate in infrastructure construction,employing a win-win strategy in favor of the people and governments of both countries.Among the cooperation domains,our country’s electrical companies have achieved a series of remarkable results in the international Engineering,Procurement,and Construction(EPC)project market with their outstanding business capabilities and technical advantages.Nevertheless,some shortcomings cannot be overlooked,the most notable of which appears to be the impediment associated with engineering translation,which has always been an obsession among translators of Chinese companies.Taking the transmission line project in the Republic of Madagascar as an example,an analysis of French-Chinese translation methods of electrical engineering terminology in the field of the transmission line is carried out.
基金2020 Chongqing Municipal Education Planning Project“Research on the Cultivation of Multimodal Translation Talent in the Digital Age”(2020-GX-278)Chongqing Higher Education Teaching Reform Research Project“Research on the Cultivation Model of Compound Application-Oriented Foreign Language Talent Based on the Integration of Classrooms One,Two,and Three Under the Background of the New Liberal Arts”(233177)。
文摘In the 21st century,the development of digital and new media technologies has ushered in an age of pervasive multimodal communication,which has significantly amplified the role of multimodal translation in facilitating crosscultural exchanges.Despite the profound impact of these developments,the prevailing translation pedagogy remains predominantly focused on the enhancement of linguistic translation skills,with noticeable neglect of the imperative to cultivate students’competencies in multimodal translation.Based on the distinctive characteristics and challenges that multimodal translation presents in the context of new media,this study delves into the formulation of educational objectives and curriculum design for the training of multimodal translators.The intent is to propose a framework that can guide the preparation of translators who are adept and equipped to navigate the complexities and demands of the contemporary age.
基金the National Natural Science Foundation of China(NSFC)(Grant Nos.62225504,62027821,62035015,U22A6003,and 12174234)the National Key R&D Program of China(Grant No.2020YFC2200402)the Program for Sanjin Scholar of Shanxi Province.
文摘Quantum communication network scales point-to-point quantum communication protocols to more than two detached parties,which would permit a wide variety of quantum communication applications.Here,we demonstrate a fully-connected quantum communication network,exploiting three pairs of Einstein–Podolsky–Rosen(EPR)entangled sideband modes,with high degree entanglement of 8.0 dB,7.6 dB,and 7.2 dB.Each sideband modes from a squeezed field are spatially separated by demultiplexing operation,then recombining into new group according to network requirement.Each group of sideband modes are distributed to one of the parties via a single physical path,making sure each pair of parties build their own private communication links with high channel capacity better than any classical scheme.
基金Project (No. 20040146) supported by Zhejiang Provincial Edu-cation Department Foundation, China
文摘This paper deals with the synchronization of chaotic systems with structure or parameters difference. Nonlinear differential geometry theory was applied to transform the chaotic discrepancy system into canonical form. A feedback control for synchronizing two chaotic systems is proposed based on sliding mode control design. To make this controller physically realizable, an extended state observer is used to estimate the error between the transmitter and receiver. Two illustrative examples were carried out: (1) The Chua oscillator was used to show that synchronization was achieved and the message signal was recovered in spite of parametric variations; (2) Two second-order driven oscillators were presented to show that the synchronization can be achieved and that the message can be recovered in spite of the strictly different model.