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Task-Oriented Semantic Communication with Foundation Models
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作者 Chen Mingkai Liu Minghao +2 位作者 Zhang Zhe Xu Zhiping Wang Lei 《China Communications》 SCIE CSCD 2024年第7期65-77,共13页
In the future development direction of the sixth generation(6G)mobile communication,several communication models are proposed to face the growing challenges of the task.The rapid development of artificial intelligence... In the future development direction of the sixth generation(6G)mobile communication,several communication models are proposed to face the growing challenges of the task.The rapid development of artificial intelligence(AI)foundation models provides significant support for efficient and intelligent communication interactions.In this paper,we propose an innovative semantic communication paradigm called task-oriented semantic communication system with foundation models.First,we segment the image by using task prompts based on the segment anything model(SAM)and contrastive language-image pretraining(CLIP).Meanwhile,we adopt Bezier curve to enhance the mask to improve the segmentation accuracy.Second,we have differentiated semantic compression and transmission approaches for segmented content.Third,we fuse different semantic information based on the conditional diffusion model to generate high-quality images that satisfy the users'specific task requirements.Finally,the experimental results show that the proposed system compresses the semantic information effectively and improves the robustness of semantic communication. 展开更多
关键词 diffusion model foundation model joint source-channel coding task-oriented semantic communication
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Novel Sum-of-Sinusoids Simulation Channel Modeling for 6G Multiple-Input Multiple-Output Vehicle-to-Everything Communications
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作者 Hao Jiang Hongming Zhang Ting Liu 《China Communications》 SCIE CSCD 2024年第1期242-259,共18页
In this paper,a statistical cluster-based simulation channel model with a finite number of sinusoids is proposed for depicting the multiple-input multiple-output(MIMO)communications in vehicleto-everything(V2X)environ... In this paper,a statistical cluster-based simulation channel model with a finite number of sinusoids is proposed for depicting the multiple-input multiple-output(MIMO)communications in vehicleto-everything(V2X)environments.In the proposed sum-of-sinusoids(SoS)channel model,the waves that emerge from the transmitter undergo line-of-sight(LoS)and non-line-of-sight(NLoS)propagation to the receiver,which makes the model suitable for describing numerous V2X wireless communication scenarios for sixth-generation(6G).We derive expressions for the real and imaginary parts of the complex channel impulse response(CIR),which characterize the physical propagation characteristics of V2X wireless channels.The statistical properties of the real and imaginary parts of the complex CIRs,i.e.,autocorrelation functions(ACFs),Doppler power spectral densities(PSDs),cross-correlation functions(CCFs),and variances of ACFs and CCFs,are derived and discussed.Simulation results are generated and match those predicted by the underlying theory,demonstrating the accuracy of our derivation and analysis.The proposed framework and underlying theory arise as an efficient tool to investigate the statistical properties of 6G MIMO V2X communication systems. 展开更多
关键词 complex CIRs LoS and NLoS propagation components MIMO V2X communication environments SoS simulation channel model statistical properties
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CRB:A new rumor blocking algorithm in online social networks based on competitive spreading model and influence maximization
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作者 董晨 徐桂琼 孟蕾 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第8期588-604,共17页
The virtuality and openness of online social platforms make networks a hotbed for the rapid propagation of various rumors.In order to block the outbreak of rumor,one of the most effective containment measures is sprea... The virtuality and openness of online social platforms make networks a hotbed for the rapid propagation of various rumors.In order to block the outbreak of rumor,one of the most effective containment measures is spreading positive information to counterbalance the diffusion of rumor.The spreading mechanism of rumors and effective suppression strategies are significant and challenging research issues.Firstly,in order to simulate the dissemination of multiple types of information,we propose a competitive linear threshold model with state transition(CLTST)to describe the spreading process of rumor and anti-rumor in the same network.Subsequently,we put forward a community-based rumor blocking(CRB)algorithm based on influence maximization theory in social networks.Its crucial step is to identify a set of influential seeds that propagate anti-rumor information to other nodes,which includes community detection,selection of candidate anti-rumor seeds and generation of anti-rumor seed set.Under the CLTST model,the CRB algorithm has been compared with six state-of-the-art algorithms on nine online social networks to verify the performance.Experimental results show that the proposed model can better reflect the process of rumor propagation,and review the propagation mechanism of rumor and anti-rumor in online social networks.Moreover,the proposed CRB algorithm has better performance in weakening the rumor dissemination ability,which can select anti-rumor seeds in networks more accurately and achieve better performance in influence spread,sensitivity analysis,seeds distribution and running time. 展开更多
关键词 online social networks rumor blocking competitive linear threshold model influence maximization
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Intellicise Model Transmission for Semantic Communication in Intelligence-Native 6G Networks
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作者 Wang Yining Han Shujun +4 位作者 Xu Xiaodong Meng Rui Liang Haotai Dong Chen Zhang Ping 《China Communications》 SCIE CSCD 2024年第7期95-112,共18页
To facilitate emerging applications and demands of edge intelligence(EI)-empowered 6G networks,model-driven semantic communications have been proposed to reduce transmission volume by deploying artificial intelligence... To facilitate emerging applications and demands of edge intelligence(EI)-empowered 6G networks,model-driven semantic communications have been proposed to reduce transmission volume by deploying artificial intelligence(AI)models that provide abilities of semantic extraction and recovery.Nevertheless,it is not feasible to preload all AI models on resource-constrained terminals.Thus,in-time model transmission becomes a crucial problem.This paper proposes an intellicise model transmission architecture to guarantee the reliable transmission of models for semantic communication.The mathematical relationship between model size and performance is formulated by employing a recognition error function supported with experimental data.We consider the characteristics of wireless channels and derive the closed-form expression of model transmission outage probability(MTOP)over the Rayleigh channel.Besides,we define the effective model accuracy(EMA)to evaluate the model transmission performance of both communication and intelligence.Then we propose a joint model selection and resource allocation(JMSRA)algorithm to maximize the average EMA of all users.Simulation results demonstrate that the average EMA of the JMSRA algorithm outperforms baseline algorithms by about 22%. 展开更多
关键词 edge intelligence(EI) model transmission outage probability and accuracy resource allocation semantic communication
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Innovative Practice of Intelligent Business Models in the Field of Communication
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作者 Yi Yin Chenggang Li 《Intelligent Information Management》 2024年第4期147-156,共10页
As a service format to meet spiritual needs, fashion culture industry is often synchronized in its creation, production, dissemination, display and consumption. In order to explore how artificial intelligence provides... As a service format to meet spiritual needs, fashion culture industry is often synchronized in its creation, production, dissemination, display and consumption. In order to explore how artificial intelligence provides technical means, platforms, channels and space for intelligent formats in the field of communication, and how to provide intelligent services for cultural creation, communication, display and consumption. This paper discusses the application and innovation of artificial intelligence in all aspects of communication field, analyzes the problems and puts forward corresponding countermeasures and suggestions. 展开更多
关键词 communication Field Intelligent Business Format model Innovation
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Coupled multiphysical model for investigation of influence factors in the application of microbially induced calcite precipitation 被引量:1
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作者 Xuerui Wang Pavan Kumar Bhukya +1 位作者 Dali Naidu Arnepalli Shuang Chen 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第6期2232-2249,共18页
The study presents a comprehensive coupled thermo-bio-chemo-hydraulic(T-BCH)modeling framework for stabilizing soils using microbially induced calcite precipitation(MICP).The numerical model considers relevant multiph... The study presents a comprehensive coupled thermo-bio-chemo-hydraulic(T-BCH)modeling framework for stabilizing soils using microbially induced calcite precipitation(MICP).The numerical model considers relevant multiphysics involved in MICP,such as bacterial ureolytic activities,biochemical reactions,multiphase and multicomponent transport,and alteration of the porosity and permeability.The model incorporates multiphysical coupling effects through well-established constitutive relations that connect parameters and variables from different physical fields.It was implemented in the open-source finite element code OpenGeoSys(OGS),and a semi-staggered solution strategy was designed to solve the couplings,allowing for flexible model settings.Therefore,the developed model can be easily adapted to simulate MICP applications in different scenarios.The numerical model was employed to analyze the effect of various factors,including temperature,injection strategies,and application scales.Besides,a TBCH modeling study was conducted on the laboratory-scale domain to analyze the effects of temperature on urease activity and precipitated calcium carbonate.To understand the scale dependency of MICP treatment,a large-scale heterogeneous domain was subjected to variable biochemical injection strategies.The simulations conducted at the field-scale guided the selection of an injection strategy to achieve the desired type and amount of precipitation.Additionally,the study emphasized the potential of numerical models as reliable tools for optimizing future developments in field-scale MICP treatment.The present study demonstrates the potential of this numerical framework for designing and optimizing the MICP applications in laboratory-,prototype-,and field-scale scenarios. 展开更多
关键词 MULTIPHYSICS Microbially induced calcite precipitation(MICP) Coupled thermo-bio-chemo-hydraulic(TBCH) model OpenGeoSys(OGS) influence factors
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Generative Adversarial Networks Based Digital Twin Channel Modeling for Intelligent Communication Networks 被引量:2
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作者 Yuxin Zhang Ruisi He +5 位作者 Bo Ai Mi Yang Ruifeng Chen Chenlong Wang Zhengyu Zhang Zhangdui Zhong 《China Communications》 SCIE CSCD 2023年第8期32-43,共12页
Integration of digital twin(DT)and wireless channel provides new solution of channel modeling and simulation,and can assist to design,optimize and evaluate intelligent wireless communication system and networks.With D... Integration of digital twin(DT)and wireless channel provides new solution of channel modeling and simulation,and can assist to design,optimize and evaluate intelligent wireless communication system and networks.With DT channel modeling,the generated channel data can be closer to realistic channel measurements without requiring a prior channel model,and amount of channel data can be significantly increased.Artificial intelligence(AI)based modeling approach shows outstanding performance to solve such problems.In this work,a channel modeling method based on generative adversarial networks is proposed for DT channel,which can generate identical statistical distribution with measured channel.Model validation is conducted by comparing DT channel characteristics with measurements,and results show that DT channel leads to fairly good agreement with measured channel.Finally,a link-layer simulation is implemented based on DT channel.It is found that the proposed DT channel model can be well used to conduct link-layer simulation and its performance is comparable to using measurement data.The observations and results can facilitate the development of DT channel modeling and provide new thoughts for DT channel applications,as well as improving the performance and reliability of intelligent communication networking. 展开更多
关键词 digital twin channel modeling generative adversarial networks intelligent communication networking
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Practical Progress of SBAR Communication Model-Related Teaching in Clinical Teaching
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作者 Xu Liu Meili Ma +2 位作者 Chenfei Qu Chunlin Liu Yan Yin 《Journal of Clinical and Nursing Research》 2023年第1期7-14,共8页
This paper elaborates the core and essence of situation,background,assessment,recommendation(SBAR)communication model,clarify the application status of SBAR communication model in the clinical teaching of nursing stud... This paper elaborates the core and essence of situation,background,assessment,recommendation(SBAR)communication model,clarify the application status of SBAR communication model in the clinical teaching of nursing students,and describe its effectiveness and limitations,so as to provide reference for improving clinical nursing teaching ability. 展开更多
关键词 SBAR communication model Clinical teaching Nursing education PROGRESS
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Influence Factors Concept Model for Public Participation in Nanotechnology Risk Communication
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作者 刘中梅 王续琨 +2 位作者 罗晨阳 黄福 侯海燕 《Journal of Donghua University(English Edition)》 EI CAS 2016年第2期327-331,共5页
Based on risk social cognition theory and planned behavior theory, the influence factors of the public participation in the nanotechnology risk communication are analyzed,and the concept model is presented to analyze ... Based on risk social cognition theory and planned behavior theory, the influence factors of the public participation in the nanotechnology risk communication are analyzed,and the concept model is presented to analyze their relationships and functional mechanism. In the model,the risk communication behaviors are divided into two variables of the public opinion expression and information acquisition,and the subjective norm divided into the internal and external social networks. Then the questionnaire is designed so as to verify the proposed model and analyze their relationships. The survey data are analyzed using SMART PLS software. The validity analysis shows that the questionnaire has a high convergence and discriminant validity. In addition, the Cronbach'a coefficient of each item is more than 0. 70,which shows the questionnaire has a high credibility. Based on the statistical data analysis, relationships of the influence factors are obtained.Further,the influence path model of the public attitude,intention,self regulation and behavior control in the risk communication is established. According to the Bootstrap algorithm in SMART,the path coefficient and its explanation variance of each influence factor are obtained. The calculation results show that the explanation variance values are all bigger than 10% and the path is reliable.Based on the path model, the influence path and function relationships of the participation attitude, subjective norm and behavior control on the participation intention and behavior are obtained. This will provide theoretical and data supports for the risk management and strategy making of the public participation in nanotechnology risk communication. 展开更多
关键词 NANOTECHNOLOGY risk communication public participation influence path model
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MIMO-Terahertz in 6G Nano-Communications:Channel Modeling and Analysis 被引量:6
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作者 Shahid Bashir Mohammed H.Alsharif +4 位作者 Imran Khan Mahmoud A.Albreem Aduwati Sali Borhanuddin Mohd Ali Wonjong Noh 《Computers, Materials & Continua》 SCIE EI 2021年第1期263-274,共12页
With the development of wireless mobile communication technology,the demand for wireless communication rate and frequency increases year by year.Existing wireless mobile communication frequency tends to be saturated,w... With the development of wireless mobile communication technology,the demand for wireless communication rate and frequency increases year by year.Existing wireless mobile communication frequency tends to be saturated,which demands for new solutions.Terahertz(THz)communication has great potential for the future mobile communications(Beyond 5G),and is also an important technique for the high data rate transmission in spatial information network.THz communication has great application prospects in military-civilian integration and coordinated development.In China,important breakthroughs have been achieved for the key techniques of THz high data rate communications,which is practically keeping up with the most advanced technological level in the world.Therefore,further intensifying efforts on the development of THz communication have the strategic importance for China in leading the development of future wireless communication techniques and the standardization process of Beyond 5G.This paper analyzes the performance of the MIMO channel in the Terahertz(THz)band and a discrete mathematical method is used to propose a novel channel model.Then,a channel capacity model is proposed by the combination of path loss and molecular absorption in the THz band based on the CSI at the receiver.Simulation results show that the integration of MIMO in the THz band gives better data rate and channel capacity as compared with a single channel. 展开更多
关键词 Wireless communication 6G mobile communication terahertz communication MIMO channel modeling
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On Communication Models
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作者 蒋娜 谢有琪 《潍坊教育学院学报》 2012年第6期105-108,共4页
With the development of human society,the social hub enlarges beyond one community to the extent that the world is deemed as a community as a whole.Communication,therefore,plays an increasingly important role in our d... With the development of human society,the social hub enlarges beyond one community to the extent that the world is deemed as a community as a whole.Communication,therefore,plays an increasingly important role in our daily life.As a consequence,communication model or the definition of which is not so much a definition as a guide in communication.However,some existed communication models are not as practical as it was.This paper tries to make an overall contrast among three communication models——Coded Model,Gable's Communication Model and Ostensive Inferential Model,to see how they assist people to comprehend verbal and non-verbal communication. 展开更多
关键词 Coded model Gable’s communication model Ostensive Inferential model
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Short-term inbound rail transit passenger flow prediction based on BILSTM model and influence factor analysis
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作者 Qianru Qi Rongjun Cheng Hongxia Ge 《Digital Transportation and Safety》 2023年第1期12-22,共11页
Accurate and real-time passenger flow prediction of rail transit is an important part of intelligent transportation systems(ITS).According to previous studies,it is found that the prediction effect of a single model i... Accurate and real-time passenger flow prediction of rail transit is an important part of intelligent transportation systems(ITS).According to previous studies,it is found that the prediction effect of a single model is not good for datasets with large changes in passenger flow characteristics and the deep learning model with added influencing factors has better prediction accuracy.In order to provide persuasive passenger flow forecast data for ITS,a deep learning model considering the influencing factors is proposed in this paper.In view of the lack of objective analysis on the selection of influencing factors by predecessors,this paper uses analytic hierarchy processes(AHP)and one-way ANOVA analysis to scientifically select the factor of time characteristics,which classifies and gives weight to the hourly passenger flow through Duncan test.Then,combining the time weight,BILSTM based model considering the hourly travel characteristics factors is proposed.The model performance is verified through the inbound passenger flow of Ningbo rail transit.The proposed model is compared with many current mainstream deep learning algorithms,the effectiveness of the BILSTM model considering influencing factors is validated.Through comparison and analysis with various evaluation indicators and other deep learning models,the results show that the R2 score of the BILSTM model considering influencing factors reaches 0.968,and the MAE value of the BILSTM model without adding influencing factors decreases by 45.61%. 展开更多
关键词 Rail transit passenger flow predict Time travel characteristics BILSTM influence factor Deep learning model
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Investigation and Comparison of Two Models in Galvanic Coupling Intra-body Communications 被引量:3
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作者 PUN Siohang GAO Yueming +3 位作者 WONG Kuokkit MAK Pengun VAI Mangi DU min 《China Communications》 SCIE CSCD 2010年第4期35-40,共6页
Intra-body communication (IBC) is a new,emerging,short-range and human body based communication methodology.It is a technique to network various devices on human body,by utilizing the conducting properties of human ti... Intra-body communication (IBC) is a new,emerging,short-range and human body based communication methodology.It is a technique to network various devices on human body,by utilizing the conducting properties of human tissues,suitable for currently fast developing Body area network (BAN)/Body sensor network (BSN).IBC is believed to have advantages in power consumption,electromagnetic radiation,interference from external electromagnetic noise,security,and restriction in spectrum resource.In this article,the authors develop two models,which are analytical and empirical approaches,for comparing the performance and accuracy of IBC on a human limb.Through in vivo experiment of five volunteers,both models basically match with the experimental result with equivalent circuit model superior than electromagnetic model in term of maximum error. 展开更多
关键词 Intra-body communication Analytical model Empirical circuit model
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Acquisition performance analysis for intersatellite optical communications with vibration influence
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作者 Jing Ma Gaoyuan Lu +3 位作者 Siyuan Yu Liying Tan Yulong Fu Fajun Li 《Chinese Physics B》 SCIE EI CAS CSCD 2020年第1期280-286,共7页
A stable and accurate pointing,acquisition system is an important part of initially building intersatellite optical communication links.Satellite platform vibration can cause the system instability and reduce the syst... A stable and accurate pointing,acquisition system is an important part of initially building intersatellite optical communication links.Satellite platform vibration can cause the system instability and reduce the system precision in building and maintenance of a satellite optical communication system.In this paper,vibration influence is consciously discussed by acquisition time for intersatellite optical communications.Analytical expression of acquisition possibility is derived,taking the scan parameters and platform vibration into account,and vibration influence on the multi-scan acquisition time is also presented.The theoretical result calculated by the proposed analytical expression is approximate to the result by the Monte Carlo simulation. 展开更多
关键词 optical communication systems optical communications acquisition time vibration influence
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Observed communication between oncologists and patients:A causal model of communication competence
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作者 Katie LaPlant Turkiewicz Mike Allen +1 位作者 Maria K Venetis Jeffrey D Robinson 《World Journal of Meta-Analysis》 2014年第4期186-193,共8页
AIM: To investigate and test a causal model derivedfrom previous meta-analytic data of health provider be-haviors and patient satisfaction.METHODS: A literature search was conducted forrelevant manuscripts that met ... AIM: To investigate and test a causal model derivedfrom previous meta-analytic data of health provider be-haviors and patient satisfaction.METHODS: A literature search was conducted forrelevant manuscripts that met the following criteria:Reported an analysis of provider-patient interaction inthe context of an oncology interview; the study hadto measure at least two of the variables of interest tothe model (provider activity, provider patient-centeredcommunication, provider facilitative communication,patient activity, patient involvement, and patient satis-faction or reduced anxiety); and the information had tobe reported in a manner that permitted the calculationof a zero-order correlation between at least two of thevariables under consideration. Data were transformedinto correlation coefficients and compiled to producethe correlation matrix used for data analysis. The test of the causal model is a comparison of the expected correlation matrix generated using an Ordinary Least Squares method of estimation. The expected matrix iscompared to the actual matrix of zero order correlation coeffcients. A model is considered a possible ft if the level of deviation is less than expected due to random sampling error as measured by a chi-square statistic. The signifcance of the path coeffcients was tested us-ing a z test. Lastly, the Sobel test provides a test of the level of mediation provided by a variable and provides an estimate of the level of mediation for each connec-tion. Such a test is warranted in models with multiple paths.RESULTS: A test of the original model indicated a lack of ft with the summary data. The largest discrepancy in the model was between the patient satisfaction and the provider patient-centered utterances. The observed correlation was far larger than expected given a medi-ated relationship. The test of a modifed model was un-dertaken to determine possible ft. The corrected model provides a fit to within tolerance as evaluated by the test statistic, χ2 (8, average n = 342) = 10.22. Each of the path coefficients for the model reveals that each one can be considered signifcant, P 〈 0.05. The Sobel test examining the impact of the mediating variables demonstrated that patient involvement is a signifcantmediator in the model, Sobel statistic = 3.56, P 〈 0.05. Patient active was also demonstrated to be a signifcant mediator in the model, Sobel statistic = 4.21, P 〈 0.05. The statistics indicate that patient behavior mediates the relationship between provider behavior and patient satisfaction with the interaction.CONCLUSION: The results demonstrate empirical support for the importance of patient-centered care and satisfy the need for empirical casual support of provider-patient behaviors on health outcomes. 展开更多
关键词 Provider-patient communication communication competence ONCOLOGIST Cancer Causal model META-ANALYSIS
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An Interactive Model for Analyzing the Development of the Communication Discipline: Israel as a Case Study
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作者 Anat First Hanna Adoni 《Journalism and Mass Communication》 2015年第7期324-340,共17页
Our paper presents an interactive four-dimensional model for studying the long- and short-term development of the communication discipline with Israel serving as a case study: institutional-contextual, institutional-... Our paper presents an interactive four-dimensional model for studying the long- and short-term development of the communication discipline with Israel serving as a case study: institutional-contextual, institutional-in-field, intellectual-contextual, and intellectual-in-field. Our empirical analysis utilized personal interviews, archive documents, and statistical data. Four main processes were discerned: transition from integration to alienation between institutions of higher learning and the larger political and ideological context; a shift from Hebrew University Institute of Communication's institutional monopoly to a multiplicity of increasingly competitive communication schools/departments; transition from intellectual hegemony to limited intellectual diversity; and gradually improving status for the communication field among social science disciplines. Our case-study analysis validated the interactive relationship among the model's conceptual dimensions, calling for future cross-national comparisons. 展开更多
关键词 development of communication discipline interactive model conceptual dimensions limited intellectual diversity communication field in Israel
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A Study on Doctor-patient Communication under Defler Interaction Process Model
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作者 XIAO Fu 《Journal of Literature and Art Studies》 2022年第4期405-409,共5页
At present,doctor-patient relationship has become a sensitive topic in society,and frequent doctor-patient communication problems have become an important factor affecting the tension of the relationship.From the pers... At present,doctor-patient relationship has become a sensitive topic in society,and frequent doctor-patient communication problems have become an important factor affecting the tension of the relationship.From the perspective of communication,this paper analyzes the causes of doctor-patient communication barriers based on the communication mode of interaction process proposed by Deffler and puts forward relevant solutions. 展开更多
关键词 Defler interaction process model doctor-patient communication communication barrier
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A General Channel Model for Visible Light Communications in Underground Mines 被引量:7
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作者 Jia Wang Ahmed Al-Kinani +2 位作者 Wensheng Zhang Cheng-Xiang Wang Li Zhou 《China Communications》 SCIE CSCD 2018年第9期95-105,共11页
In underground mines, visible light communication(VLC) system is a promising method to realize effective communication,which supports communication and illumination at the same time. Therefore, adequate research of un... In underground mines, visible light communication(VLC) system is a promising method to realize effective communication,which supports communication and illumination at the same time. Therefore, adequate research of underlying physical propagation phenomenon should be carried out to realize VLC system in underground mines. To design VLC system and evaluate its performance, accurate and efficient channel models, including large-scale fading and scattering characteristics, are needed to be established. However,the characteristics of the underlying VLC channels about fading and scattering have not been sufficiently investigated yet. In this paper, a path loss channel model, based on the recursive model, is proposed precisely. Its path loss exponent is determined by three different trajectories, which is studied in the mining roadway and working face environment. Besides, the shadowing effect for VLC has been modelled by a Bimodal Gaussian distribution in underground mines. Considering the number of transmitters in line-of-sight(Lo S) as well as non-line-of-sight(NLo S) scenarios,our simulation illustrates the fact that, as the curve fitting technique is employed, the path loss displays a linear behavior in log-domain.The path loss expression is derived, it is related to the distance. Finally, root mean square(RMS) delay spread and Mie scattering in underground mines are analyzed. 展开更多
关键词 underground mines visible light communications channel modeling path loss SHADOWING delay spread.
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Energy Model for UAV Communications:Experimental Validation and Model Generalization 被引量:3
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作者 Ning Gao Yong Zeng +5 位作者 Jian Wang Di Wu Chaoyue Zhang Qingheng Song Jachen Qian Shi Jin 《China Communications》 SCIE CSCD 2021年第7期253-264,共12页
Wireless communication involving unmanned aerial vehicles(UAVs)is expected to play an important role in future wireless networks.However,different from conventional terrestrial communication systems,UAVs typically hav... Wireless communication involving unmanned aerial vehicles(UAVs)is expected to play an important role in future wireless networks.However,different from conventional terrestrial communication systems,UAVs typically have rather limited onboard energy on one hand,and require additional flying energy consumption on the other hand.This renders energy-efficient UAV communication with smart energy expenditure of paramount importance.In this paper,via extensive flight experiments,we aim to firstly validate the recently derived theoretical energy model for rotary-wing UAVs,and then develop a general model for those complicated flight scenarios where rigorous theoretical model derivation is quite challenging,if not impossible.Specifically,we first investigate how UAV power consumption varies with its flying speed for the simplest straight-and-level flight.With about 12,000 valid power-speed data points collected,we first apply the model-based curve fitting to obtain the modelling parameters based on the theoretical closed-form energy model in the existing literature.In addition,in order to exclude the potential bias caused by the theoretical energy model,the obtained measurement data is also trained using a model-free deep neural network.It is found that the obtained curve from both methods can match quite well with the theoretical energy model.Next,we further extend the study to arbitrary 2-dimensional(2-D)flight,where,to our best knowledge,no rigorous theoretical derivation is available for the closed-form energy model as a function of its flying speed,direction,and acceleration.To fill the gap,we first propose a heuristic energy model for these more complicated cases,and then provide experimental validation based on the measurement results for circular level flight. 展开更多
关键词 UAV communications energy model energy consumption flight experiments model generalization
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System-Level EMC Assessment for Military Vehicular Communication Systems Based on a Modified Four-Level Assessment Model 被引量:5
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作者 Ping Zhou Yinghua Lv +1 位作者 Zhihong Chen Hongping Xu 《China Communications》 SCIE CSCD 2018年第8期39-53,共15页
With the development of EMC technology, EMC assessment has become increasingly important in EMC design. Although numerous EMC assessment models are available today, few of them can provide a tradeoff between efficienc... With the development of EMC technology, EMC assessment has become increasingly important in EMC design. Although numerous EMC assessment models are available today, few of them can provide a tradeoff between efficiency and accuracy for the specific case of military vehicular communication systems. Face to this situation, a modified four-level assessment model is proposed in the paper. First, the development of EMC assessment technology is briefly reviewed, and the theoretical mechanism of EMI environment is introduced. Then, the architecture of the proposed model is outlined, and the assessment methods are explored. To demonstrate the application of it, an example involving a communication system in a military vehicle is presented. From the physical layer to the signal layer, a hierarchical assessment on the entire system is successfully performed based on the proposed model, and we can make a qualitative EMC assessment on the EMC performance of the system. Based on a comparison with the traditional model, we conclude that the proposed model is more accurate, more efficient and less time-consuming, which is suitable for the EMC assessment on militaryvehicular communication systems. We hope that the proposed model will serve as a useful reference for system-level EMC assessments for other systems. 展开更多
关键词 military vehicular communication system system-level electromagnetic compatibility (EMC) assessment four-level assessment model
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