Single Photon Detection Technology in Underwater Wireless Optical Communication:Modulation Modes and Error Correction Coding Analysis

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.

An ISGW Filtering Antenna with Spurious Modes and Surface Wave Suppression for Millimeter Wave Communications

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.

Spatial Models in Thinking and Communication

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.

Cross-Ice Acoustic Communication:Cascade Acoustic Channel Model and Experimental Results

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.

Robust control for a class of nonlinear networked systems with stochastic communication delays via sliding mode conception

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.

Application and effect evaluation on Acknowledge-Introduce-Duration-Explanation-Thank you(AIDET)communication mode in cataract daytime operation nursing

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.

Threshold Characteristics Enhancement of a Single Mode 1.55 µm InGaAsP Photonic Crystal VCSEL for Optical Communication Systems

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.

DUAL MODE WIDEBAND BAND-PASS FILTER WITH NOTCHED BAND FOR COMMUNICATION SYSTEM

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.

Robust Finite-time Synchronization of Non-identical Fractional-order Hyperchaotic Systems and Its Application in Secure Communication

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.

Relay Selection Strategy in the Secure Cooperative Communications System

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.

The Process-based Approach in English Writing Class

English writing is gaining high attention and emphasis in our college syllabus. It is a complicated process of written communication. In the process, the four basic skills—speaking, reading, listening and writing are organically integrated together. This paper is about the process-based approach in English writing class and its aim to emphasize the importance of process-based approach to writing. There are four parts in this paper. I start with a brief introduction to the importance of writing. Next, I will introduce my practice in English writing class. Then I will comment on the process approach and then make a little revision.

Exploration of French-Chinese Translation Methods of Electrical Engineering Terminology Using Online Image-Text Retrieval Mode

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.

Application of sensory and motor training in AIDET communication mode in patients after knee arthroplasty

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.

Cultivation of Translators for Multimodal Translation in the New Media Age

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.

Demonstration of fully-connected quantum communication network exploiting entangled sideband modes

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.

Design of Photonic Crystal Fiber Capable of Carrying Multiple Orbital Angular Momentum Modes Transmission

For the traditional photonic crystal fibers with circular air holes, rectangular air holes are added to the fiber cladding. The periodic arrangement of the inner rectangular air holes allows the fiber structure to better match the annular mode field distribution of the vortex beam. The fiber structure was analyzed and calculated by COMSOL Multiphysics 5.4 finite element software, and the characteristics of fiber were analyzed, such as the dispersion, confinement loss, effective mode area and nonlinear coefficient. The results reveal that the photonic crystal fiber structure capable of carrying 50 orbital angular momentum (OAM) modes at the wavelength of 1.15 to 2.0 μm (850 nm). The effective refractive index difference Δneff between vector modes can reach 1 × 10-3, and larger difference can effectively separate the vector modes and improve the transmission performance of OAM modes. Moreover, the fiber has good performance, such as flat dispersion distribution of the low-order modes, low confinement loss below 10-9 dB·m-1, large effective mode field area and small nonlinear coefficient in the 850 nm wavelength range. Therefore, this fiber structure can be applied to the high-capacity communication system of fiber multiplexing OAM. In addition, the good characteristics of this fiber structure are of great significance for the transmission of vortex beam in fiber.

Spatial Mode-Division Multiplexing for High-Speed Optical Coherent Detection Systems

Spatial modedivision multiplexing is emerging as a potential solution to further increasing optical fiber capacity and spectral efficiency. We report a dualmode, dualpolarization transmission method based on modeselective excitation and detection over a twomode fiber. In particular, we present 107 Gbit/s coherent optical OFDM （COOFDM） transmission over a 4.5 km twomode fiber using LP and LP. modes in which mode separation is performed optically.

Finite-time sliding mode synchronization of chaotic systems

A new finite-time sliding mode control approach is presented for synchronizing two different topological structure chaotic systems. With the help of the Lyapunov method, the convergence property of the proposed control strategy is discussed in a rigorous manner. Furthermore, it is mathematically proved that our control strategy has a faster convergence speed than the conventional finite-time sliding mode control scheme. In addition, the proposed control strategy can ensure the finite-time synchronization between the master and the slave chaotic systems under internal uncertainties and external disturbances. Simulation results are provided to show the speediness and robustness of the proposed scheme. It is worth noticing that the proposed control scheme is applicable for secure communications.

An Analysis of the Cultural Differences Between China and the West from the Perspective of Mode of Thinking

People with various cultural backgrounds and habits have different modes of thinking,making it difficult to communicate between different cultures. Based on culture,thinking and their relationship,this paper analyzes the differences between Chinese and the Western cultures to find the solutions to the problem of how to use the differences to establish international mind and global vision to achieve"cultural confidence".

ERROR COUNTER-BASED NEGATIVE ACKNOWLEDGEMENT MODE IN CCSDS FILE DELIVERY PROTOCOL

Deep space communication has its own features such as long propagation delays,heavy noise,asymmetric link rates,and intermittent connectivity in space,therefore TCP/IP protocol cannot perform as well as it does in terrestrial communications.Accordingly,the Consultative Committee for Space Data Systems(CCSDS) developed CCSDS File Delivery Protocol(CFDP),which sets standards of efficient file delivery service capable of transferring files to and from mass memory located in the space segment.In CFDP,four optional acknowledge modes are supported to make the communication more reliable.In this paper,we gave a general introduction of typical communication process in CFDP and analysis of its four Negative Acknowledgement(NAK) modes on the respect of file delivery delay and times of retransmission.We found out that despite the shortest file delivery delay,immediate NAK mode suffers from the problem that frequent retransmission may probably lead to network congestion.Thus,we proposed a new mode,the error counter-based NAK mode.By simulation of the case focused on the link between a deep space probe on Mars and a ter-restrial station on Earth,we concluded that error counter-based NAK mode has successfully reduced the retransmission times at negligible cost of certain amount of file delivery delay.