This paper analyses of the outage probability and the achievable rate of massive multi-input-multi-output(MIMO) systems, in which the base station(BS) is equipped with digital-to-analog-converters(DACs) of mixed-level...This paper analyses of the outage probability and the achievable rate of massive multi-input-multi-output(MIMO) systems, in which the base station(BS) is equipped with digital-to-analog-converters(DACs) of mixed-level resolution. And the matched-filter(MF) precoding is used on the BS. Closedform expressions are derived by the distribution of user-interference power and other statistical properties in the signal-to-interference-plus-noise-ratio. Then, the combination of mixed-DACs resolution profile is chosen about outage probability and achievable rate with the BS energy consumption. And the resolution configurations between the outage probability and the achievable rate and the BS energy consumption are given. Meanwhile, Effects of related parameters and channel errors are analysed about outage probability and achievable rate. The numerical results show that the correctness of the formula derivations. As the number of users increases the system's achievable rate increases and the outage probability decreases. The selected resolution configuration system has better comprehensive performance.展开更多
Achievable rate (AR) is significant to communications. As to multi-input multi-output (MIMO) digital transmissions with finite alphabets inputs, which greatly improve the performance of communications, it seems rather...Achievable rate (AR) is significant to communications. As to multi-input multi-output (MIMO) digital transmissions with finite alphabets inputs, which greatly improve the performance of communications, it seems rather difficult to calculate accurate AR. Here we propose an estimation of con-siderable accuracy and low complexity, based on Euclidean measure matrix for given channel states and constellations. The main contribution is explicit expression, non-constraints to MIMO schemes and channel states and constellations, and controllable estimating gap. Numerical results show that the proposition is able to achieve enough accurate AR computation. In addition the estimating gap given by theoretical deduction is well agreed.展开更多
This paper presents a theoretical comparison of a single carrier system and a multi-carrier system through an analysis of the achievable rate under frequency selective fading with channel state information at the rece...This paper presents a theoretical comparison of a single carrier system and a multi-carrier system through an analysis of the achievable rate under frequency selective fading with channel state information at the receiver. A scheme was designed to compare the achievable rates of a single carrier system and an Or- thogonal Frequency Division Multiplexing （OFDM） system. A thorough theoretical analysis of the two-path channel was conducted, and simulations were also used to analyze practical stochastic channels. Analysis and simulation results show that the achievable rates of the two approaches are comparable when the channel is flat fading. However, when the channel is frequency selective fading, the single carrier system outperforms the OFDM system. The achievable rate of the OFDM system is about 10% lower than that of the single carrier system at higher SNRs.展开更多
An achievable rate region for the asynchronous multiple access channel with feedback is established through the use of superposition coding, list decoding and time sharing. The calculation results demonstrate that lac...An achievable rate region for the asynchronous multiple access channel with feedback is established through the use of superposition coding, list decoding and time sharing. The calculation results demonstrate that lack of synchronization does not affect the achievable rate region when the code block length tends to infinity, and that if the length of the code word is finite, especially not sufficiently larger than a fixed maximal delay, the asynchronization will cause a loss of the rate region. The amount of such a loss with its explanation for the reason is given, and the difference between the losses for the asynchronous multiple access channel with and without feedback is also discussed in this paper.展开更多
This paper studies the achievable rate for three-node discrete memoryless relay channel. Specifically in this mode, we explore two generalized feedbacks simultaneously： the source node actively collects feedback sign...This paper studies the achievable rate for three-node discrete memoryless relay channel. Specifically in this mode, we explore two generalized feedbacks simultaneously： the source node actively collects feedback signals from the channel; and at the same time, the destination node actively transmits feedback signals to the relay node. These two feedback signals, which are called generalized feedback overheard from the channel that is likely to be noisy, induce that all the three nodes are in full duplex mode. The basic coding strategies of Cover and El Gamal are applied to the relay-source feedback transmission by the source forwarding the compressions of the channel output sequences at the relay node to the destination, and are also applied to the destination-relay feedback transmission to improve the decoding ability at the relay. Based on Cover and El Gamal coding, a new coding scheme adopting rate splitting and four-block Markov superposition encoding is proposed and the corresponding achievable rate is achieved. The proposed scheme is able to exploit two feedbacks simultaneously which can effectively eliminate underlying transmission bottlenecks for the channels. The derived achievable rate result generalizes several previously known results by including them as special cases.展开更多
Optical fber communication networks play an important role in the global telecommunication network.However,nonlinear efects in the optical fber and transceiver noise greatly limit the performance of fber communication...Optical fber communication networks play an important role in the global telecommunication network.However,nonlinear efects in the optical fber and transceiver noise greatly limit the performance of fber communication systems.In this paper,the product of mutual information(MI)and communication bandwidth is used as the metric of the achievable information rate(AIR).The MI loss caused by the transceiver is also considered in this work,and the bit-wise MI,generalized mutual information(GMI),is used to calculate the AIR.This loss is more signifcant in the use of higher-order modulation formats.The AIR analysis is carried out in the QPSK,16QAM,64QAM and 256QAM modulation formats for the communication systems with diferent communication bandwidths and transmission distances based on the enhanced Gaussian noise(EGN)model.The paper provides suggestions for the selection of the optimal modulation format in diferent transmission scenarios.展开更多
Prepared with concrete and pragmatic questions,members of a media delegation from the Republic of the Congo toured the cities of Yunfu and Zhaoqing in Guangdong Province from 16 to 22 November 2025.They visited produc...Prepared with concrete and pragmatic questions,members of a media delegation from the Republic of the Congo toured the cities of Yunfu and Zhaoqing in Guangdong Province from 16 to 22 November 2025.They visited production workshops,explored research institutes,toured beautiful villages and discovered archaeological sites,searching for the keys to Chinese modernisation in its many dimensions.展开更多
One important MN-puzzle problem is to find a sequence of up-down and right-left movements of the empty-cell so that a goal-pattern can be achieved from a given initial-pattern.The second problem is to characterize the...One important MN-puzzle problem is to find a sequence of up-down and right-left movements of the empty-cell so that a goal-pattern can be achieved from a given initial-pattern.The second problem is to characterize the totality of the goal-pattern from a given initial-pattern.The third problem is finding the fewest movements to achieve it.In this paper,these problems will be completely solved.展开更多
This paper proposes a hybrid wireless communication framework that integrates an active intelligent reflecting surface(IRS)with a decode-andforward(DF)relay to enhance spectral efficiency in extended-range scenarios.B...This paper proposes a hybrid wireless communication framework that integrates an active intelligent reflecting surface(IRS)with a decode-andforward(DF)relay to enhance spectral efficiency in extended-range scenarios.By combining the amplification capability of the active IRS and the signal regeneration function of the DF relay,the proposed system effectively mitigates path loss and fading.We derive closed-form upper bounds on the achievable rate and develop an optimal power allocation strategy under a total power constraint.Numerical results demonstrate that the hybrid scheme significantly outperforms conventional passive IRS-assisted or active IRS-only configurations,particularly under conditions of limited reflecting elements or moderate signal-to-noise ratios.展开更多
Objective This study aimed to investigate the level of knowledge among urologists of usage of fluoroscopy during percutaneous nephrolithotomy.MethodsWe conducted an anonymous internet-based survey addressed to the EAU...Objective This study aimed to investigate the level of knowledge among urologists of usage of fluoroscopy during percutaneous nephrolithotomy.MethodsWe conducted an anonymous internet-based survey addressed to the EAU Section of Uro-Technology and the International Alliance of Urolithiasis members with particular interest in the stone treatment at all levels of expertise.The final version of the questionnaire included 31 questions,evaluated the level of knowledge on X-ray utilization and exposure,and identified correlations between geographic areas,levels of seniority,surgical volumes,and awareness on radiation protection.ResultsIn total,586 respondents were included.Knowledge of fluoroscopy settings appeared low,particularly among trainees(up to 87.5%were uninformed,p=0.008).Precautions to reduce exposure appeared poorly followed as up to 25.4%of respondents used regularly continuous fluoroscopy,and up to 20.5%used regularly high-frequency setting and this trend was more obvious among senior specialists(6.2%of trainees used high-frequency settings vs.21.3%of consultants,p<0.05).Additionally,only 24.9%of respondents would provide X-ray protection to patients too.ConclusionAlthough high and routinary utilization of X-rays,the level of awareness and adhesion to“as low as reasonably achievable”principles among endourologists seems suboptimal in 65.0%of all respondents.Highest volume surgeons,inevitably at higher risk,do not seem to adopt more precautions.More efforts should be addressed to improve these results,reducing the risk related to excessive radiation exposure for both surgical staff and patients in order to minimize health related issues.展开更多
Teacher–student relationships play a vital role in improving college students’academic performance and the quality of higher education.However,empirical studies with substantial data-driven insights remain limited.T...Teacher–student relationships play a vital role in improving college students’academic performance and the quality of higher education.However,empirical studies with substantial data-driven insights remain limited.To address this gap,this study collected 3278 questionnaires from seven universities across four provinces in China to analyze the key factors affecting college students’academic performance.A machine learning framework,CQFOA-KELM,was developed by enhancing the Fruit Fly Optimization Algorithm(FOA)with Covariance Matrix Adaptation Evolution Strategy(CMAES)and Quadratic Approximation(QA).CQFOA significantly improved population diversity and was validated on the IEEE CEC2017 benchmark functions.The CQFOA-KELM model achieved an accuracy of 98.15%and a sensitivity of 98.53%in predicting college students’academic performance.Additionally,it effectively identified the key factors influencing academic performance through the feature selection process.展开更多
Mingalarpar!On behalf of the Consulate-General of the Republic of the Union of Myanmar in Nanning,I would like to express my sincerest congratulations to CAEXPO on reaching the remarkable milestone of over 20 years—a...Mingalarpar!On behalf of the Consulate-General of the Republic of the Union of Myanmar in Nanning,I would like to express my sincerest congratulations to CAEXPO on reaching the remarkable milestone of over 20 years—an incredible journey filled with numerous achievements.展开更多
Mental healthcare in Ethiopia is underutilized due to a lack of resources and skilled practitioners.Psychological counselling offers unique intervention possibilities because of its focus on a wide range of mental hea...Mental healthcare in Ethiopia is underutilized due to a lack of resources and skilled practitioners.Psychological counselling offers unique intervention possibilities because of its focus on a wide range of mental health and social justice issues.This literature review tracks the historical development of the profession of psychological counselling in Ethiopia to establish what has been achieved to date and the development challenges.Key achievements include recognition of the profession by the Ministry of Education,growing public awareness,and increasing capacity of practitioners skilled in psychological counselling.Challenges include limited contextually relevant training,poor representation of the profession within Ministry of Health policies,poor public and government mental health literacy,and a lack of regulatory frameworks.Postgraduate training would benefit from more culturally,contextually,and linguistically appropriate evidence-based,indigenous psychology practices.The profession would benefit from engagement in government policy development that promotes mental health,and professional regulatory bodies to hold practitioners accountable to professional standards and ethical practice.展开更多
In every society,there are individuals who stand out with great achievements.These people are often seen as leaders and innovators,paving the way for others to follow.They are pioneers in their fields,who use their in...In every society,there are individuals who stand out with great achievements.These people are often seen as leaders and innovators,paving the way for others to follow.They are pioneers in their fields,who use their influential and inspiring personalities to motivate those around them.Their ability to drive change is due to not only their skills but also their characters.展开更多
基金supported by the National Natural Science Foundation of China(No.61961018)the Jiangxi Province Foundation for Distinguished Young Scholar(No.20192BCB23013)the Jiangxi Province Natural Science Foundation of China(20192ACB21003)。
文摘This paper analyses of the outage probability and the achievable rate of massive multi-input-multi-output(MIMO) systems, in which the base station(BS) is equipped with digital-to-analog-converters(DACs) of mixed-level resolution. And the matched-filter(MF) precoding is used on the BS. Closedform expressions are derived by the distribution of user-interference power and other statistical properties in the signal-to-interference-plus-noise-ratio. Then, the combination of mixed-DACs resolution profile is chosen about outage probability and achievable rate with the BS energy consumption. And the resolution configurations between the outage probability and the achievable rate and the BS energy consumption are given. Meanwhile, Effects of related parameters and channel errors are analysed about outage probability and achievable rate. The numerical results show that the correctness of the formula derivations. As the number of users increases the system's achievable rate increases and the outage probability decreases. The selected resolution configuration system has better comprehensive performance.
文摘Achievable rate (AR) is significant to communications. As to multi-input multi-output (MIMO) digital transmissions with finite alphabets inputs, which greatly improve the performance of communications, it seems rather difficult to calculate accurate AR. Here we propose an estimation of con-siderable accuracy and low complexity, based on Euclidean measure matrix for given channel states and constellations. The main contribution is explicit expression, non-constraints to MIMO schemes and channel states and constellations, and controllable estimating gap. Numerical results show that the proposition is able to achieve enough accurate AR computation. In addition the estimating gap given by theoretical deduction is well agreed.
基金Supported by the National Key Technology Research and Devel-opment Program (No. 2009ZX03006-007-02)the National Natural Science Foundation of China (Nos. 60972019, 61021001,and 60928001)
文摘This paper presents a theoretical comparison of a single carrier system and a multi-carrier system through an analysis of the achievable rate under frequency selective fading with channel state information at the receiver. A scheme was designed to compare the achievable rates of a single carrier system and an Or- thogonal Frequency Division Multiplexing （OFDM） system. A thorough theoretical analysis of the two-path channel was conducted, and simulations were also used to analyze practical stochastic channels. Analysis and simulation results show that the achievable rates of the two approaches are comparable when the channel is flat fading. However, when the channel is frequency selective fading, the single carrier system outperforms the OFDM system. The achievable rate of the OFDM system is about 10% lower than that of the single carrier system at higher SNRs.
文摘An achievable rate region for the asynchronous multiple access channel with feedback is established through the use of superposition coding, list decoding and time sharing. The calculation results demonstrate that lack of synchronization does not affect the achievable rate region when the code block length tends to infinity, and that if the length of the code word is finite, especially not sufficiently larger than a fixed maximal delay, the asynchronization will cause a loss of the rate region. The amount of such a loss with its explanation for the reason is given, and the difference between the losses for the asynchronous multiple access channel with and without feedback is also discussed in this paper.
基金supported by the National Natural Science Foundation of China (60972045)the Cultivation and Innovation Project for Jiangsu Provincial Postgraduate (CX10B_192Z)
文摘This paper studies the achievable rate for three-node discrete memoryless relay channel. Specifically in this mode, we explore two generalized feedbacks simultaneously： the source node actively collects feedback signals from the channel; and at the same time, the destination node actively transmits feedback signals to the relay node. These two feedback signals, which are called generalized feedback overheard from the channel that is likely to be noisy, induce that all the three nodes are in full duplex mode. The basic coding strategies of Cover and El Gamal are applied to the relay-source feedback transmission by the source forwarding the compressions of the channel output sequences at the relay node to the destination, and are also applied to the destination-relay feedback transmission to improve the decoding ability at the relay. Based on Cover and El Gamal coding, a new coding scheme adopting rate splitting and four-block Markov superposition encoding is proposed and the corresponding achievable rate is achieved. The proposed scheme is able to exploit two feedbacks simultaneously which can effectively eliminate underlying transmission bottlenecks for the channels. The derived achievable rate result generalizes several previously known results by including them as special cases.
基金supported by the National Key Research and Development Program of China(No.2022YFE0202100)EU Horizon 2020 MSCA Grant 101008280 and UK Royal Society Grant(IES\R3\223068).
文摘Optical fber communication networks play an important role in the global telecommunication network.However,nonlinear efects in the optical fber and transceiver noise greatly limit the performance of fber communication systems.In this paper,the product of mutual information(MI)and communication bandwidth is used as the metric of the achievable information rate(AIR).The MI loss caused by the transceiver is also considered in this work,and the bit-wise MI,generalized mutual information(GMI),is used to calculate the AIR.This loss is more signifcant in the use of higher-order modulation formats.The AIR analysis is carried out in the QPSK,16QAM,64QAM and 256QAM modulation formats for the communication systems with diferent communication bandwidths and transmission distances based on the enhanced Gaussian noise(EGN)model.The paper provides suggestions for the selection of the optimal modulation format in diferent transmission scenarios.
文摘Prepared with concrete and pragmatic questions,members of a media delegation from the Republic of the Congo toured the cities of Yunfu and Zhaoqing in Guangdong Province from 16 to 22 November 2025.They visited production workshops,explored research institutes,toured beautiful villages and discovered archaeological sites,searching for the keys to Chinese modernisation in its many dimensions.
文摘One important MN-puzzle problem is to find a sequence of up-down and right-left movements of the empty-cell so that a goal-pattern can be achieved from a given initial-pattern.The second problem is to characterize the totality of the goal-pattern from a given initial-pattern.The third problem is finding the fewest movements to achieve it.In this paper,these problems will be completely solved.
基金supported in part by National Key R&D Program of China(2022YFB2903500)NSFC Grant 62331022,Grant 62371289+4 种基金Grant 624B2094in part by the Shanghai Jiao Tong University 2030 Initiative,and the Guangdong Science and Technology program under grant 2022A0505050011in part by the Outstanding Doctoral Graduates Development Scholarship of Shanghai Jiao Tong Universityin part by Shanghai Kewei under Grant 22JC1404000Grant 24DP1500500.
文摘This paper proposes a hybrid wireless communication framework that integrates an active intelligent reflecting surface(IRS)with a decode-andforward(DF)relay to enhance spectral efficiency in extended-range scenarios.By combining the amplification capability of the active IRS and the signal regeneration function of the DF relay,the proposed system effectively mitigates path loss and fading.We derive closed-form upper bounds on the achievable rate and develop an optimal power allocation strategy under a total power constraint.Numerical results demonstrate that the hybrid scheme significantly outperforms conventional passive IRS-assisted or active IRS-only configurations,particularly under conditions of limited reflecting elements or moderate signal-to-noise ratios.
文摘Objective This study aimed to investigate the level of knowledge among urologists of usage of fluoroscopy during percutaneous nephrolithotomy.MethodsWe conducted an anonymous internet-based survey addressed to the EAU Section of Uro-Technology and the International Alliance of Urolithiasis members with particular interest in the stone treatment at all levels of expertise.The final version of the questionnaire included 31 questions,evaluated the level of knowledge on X-ray utilization and exposure,and identified correlations between geographic areas,levels of seniority,surgical volumes,and awareness on radiation protection.ResultsIn total,586 respondents were included.Knowledge of fluoroscopy settings appeared low,particularly among trainees(up to 87.5%were uninformed,p=0.008).Precautions to reduce exposure appeared poorly followed as up to 25.4%of respondents used regularly continuous fluoroscopy,and up to 20.5%used regularly high-frequency setting and this trend was more obvious among senior specialists(6.2%of trainees used high-frequency settings vs.21.3%of consultants,p<0.05).Additionally,only 24.9%of respondents would provide X-ray protection to patients too.ConclusionAlthough high and routinary utilization of X-rays,the level of awareness and adhesion to“as low as reasonably achievable”principles among endourologists seems suboptimal in 65.0%of all respondents.Highest volume surgeons,inevitably at higher risk,do not seem to adopt more precautions.More efforts should be addressed to improve these results,reducing the risk related to excessive radiation exposure for both surgical staff and patients in order to minimize health related issues.
文摘Teacher–student relationships play a vital role in improving college students’academic performance and the quality of higher education.However,empirical studies with substantial data-driven insights remain limited.To address this gap,this study collected 3278 questionnaires from seven universities across four provinces in China to analyze the key factors affecting college students’academic performance.A machine learning framework,CQFOA-KELM,was developed by enhancing the Fruit Fly Optimization Algorithm(FOA)with Covariance Matrix Adaptation Evolution Strategy(CMAES)and Quadratic Approximation(QA).CQFOA significantly improved population diversity and was validated on the IEEE CEC2017 benchmark functions.The CQFOA-KELM model achieved an accuracy of 98.15%and a sensitivity of 98.53%in predicting college students’academic performance.Additionally,it effectively identified the key factors influencing academic performance through the feature selection process.
文摘Mingalarpar!On behalf of the Consulate-General of the Republic of the Union of Myanmar in Nanning,I would like to express my sincerest congratulations to CAEXPO on reaching the remarkable milestone of over 20 years—an incredible journey filled with numerous achievements.
文摘Mental healthcare in Ethiopia is underutilized due to a lack of resources and skilled practitioners.Psychological counselling offers unique intervention possibilities because of its focus on a wide range of mental health and social justice issues.This literature review tracks the historical development of the profession of psychological counselling in Ethiopia to establish what has been achieved to date and the development challenges.Key achievements include recognition of the profession by the Ministry of Education,growing public awareness,and increasing capacity of practitioners skilled in psychological counselling.Challenges include limited contextually relevant training,poor representation of the profession within Ministry of Health policies,poor public and government mental health literacy,and a lack of regulatory frameworks.Postgraduate training would benefit from more culturally,contextually,and linguistically appropriate evidence-based,indigenous psychology practices.The profession would benefit from engagement in government policy development that promotes mental health,and professional regulatory bodies to hold practitioners accountable to professional standards and ethical practice.
文摘In every society,there are individuals who stand out with great achievements.These people are often seen as leaders and innovators,paving the way for others to follow.They are pioneers in their fields,who use their influential and inspiring personalities to motivate those around them.Their ability to drive change is due to not only their skills but also their characters.
