Early exiting has shown significant potential in accelerating the inference of pre-trained language models(PLMs)by allowing easy samples to exit from shallow layers.However,existing early exiting methods primarily rel...Early exiting has shown significant potential in accelerating the inference of pre-trained language models(PLMs)by allowing easy samples to exit from shallow layers.However,existing early exiting methods primarily rely on local information from individual samples to estimate prediction uncertainty for making exiting decisions,overlooking the global information provided by the sample population.This impacts the estimation of prediction uncertainty,compromising the reliability of exiting de-cisions.To remedy this,inspired by principal component analysis(PCA),the authors define a residual score to capture the deviation of features from the principal space of the sample population,providing a global perspective for estimating prediction uncertainty.Building on this,a two-stage exiting strategy is proposed that integrates global information from residual scores with local information from energy scores at both the decision and feature levels.This strategy incorporates three-way decisions to enable more reliable exiting decisions for boundary region samples by delaying judgement.Extensive experiments on the GLUE benchmark validate that the method achieves an average speed-up ratio of 2.17×across all tasks with minimal per-formance degradation.Additionally,it surpasses the state-of-the-art E-LANG by 11%in model acceleration,along with a performance improvement of 0.6 points,demonstrating a better performance-efficiency trade-off.展开更多
Given the explosive growth in video content generation,there is a rising demand for efficient and scalable video recognition.Deep learning has shown its remarkable performance in video analytics,by applying 2D or 3D C...Given the explosive growth in video content generation,there is a rising demand for efficient and scalable video recognition.Deep learning has shown its remarkable performance in video analytics,by applying 2D or 3D Convolutional Neural Networks(CNNs)across multiple video frames.However,high data quantities,intensive computational costs,and various performance requirements restrict the deployment and application of these video-oriented models on resource-constrained edge devices,e.g.,Internet-of-Things(IoT)and mobile devices.To tackle this issue,we propose a joint optimization system RSEE by adaptive Resolution Selection(RS)and conditional Early Exiting(EE)to facilitate efficient video recognition based on 2D CNN backbones.Given a video frame,RSEE firstly determines what input resolution is to be used for processing by the dynamic resolution selector,then sends the resolution-adjusted frame into the backbone network to extract features,and finally determines whether to stop further processing based on the accumulated features of current video at the early-exiting gate.Extensive experiments conducted on benchmark datasets indicate that RSEE remarkably outperforms current state-of-the-art solutions in terms of computational cost(by up to 84.72%on UCF101 and 78.93%on HMDB51)and inference speed(up to 3.18×on UCF101 and 3.50×on HMDB51),while still preserving competitive recognition accuracy(up to 7.81%on UCF1017.21%on HMDB51).Furthermore,the superiority of RSEE on resource-constrained edge devices is validated on the NVIDIA Jetson Nano,with processing speeds controlled by hyperparameters ranging from about 12 to 60 Frame-Per-Second(FPS)that well enable real-time analysis.展开更多
Roundabouts are becoming a preferred form of intersection control type due to their safety and capacity benefits. Yield control at roundabout entries inherently reduces fuel consumption and emissions when compared to ...Roundabouts are becoming a preferred form of intersection control type due to their safety and capacity benefits. Yield control at roundabout entries inherently reduces fuel consumption and emissions when compared to other conventional intersection types. However, these benefits can be limited by poor driver behavior and judgment when entering the roundabout. This research addresses the nature of gap distributions and use of turn indicators by exiting vehicles at three single-lane roundabouts in Vermont, New York, and Alaska. Presented here is a comparison of vehicle headways measured at two different locations in each roundabout. Rejected headways are analyzed in the context of priority abstaining events when entering drivers yield to vehicles exiting on the same leg of the roundabout suggesting that ＂true＂ critical gaps are being overestimated. Results indicate that exiting vehicles, particularly those that do not use their turn indicators when departing from the major-stream of traffic have an influence on the entry decision of drivers on the same approach. This behavior is of particular concern for intersection efficiency （i.e., delay） and sustainability （i.e., excess fuel consumption and emissions）. Results prompt the consideration of more consistent guidance on and enforcement of turn indicator use during roundabout negotiations.展开更多
In order to better predict the traffic states on freeways and make management decisions,a hybrid model of support vector machine(SVM)and K-nearest neighbor(KNN)is proposed for shortterm freeway exiting volume predicti...In order to better predict the traffic states on freeways and make management decisions,a hybrid model of support vector machine(SVM)and K-nearest neighbor(KNN)is proposed for shortterm freeway exiting volume prediction.First,a historical data set is built by using the freeway toll data.The abnormal toll records,such as records that have same entry and exit station,illogical time record and abnormal travel speed,are excluded by data quality control.Based on the historical dataset,it is found that the exiting volume has periodical variation over time which provides the basis of the short-term prediction.Then,the historical data set is cross-classified into twelves groups based on the day of week and time of day.The prediction has been done for each group.Finally,the prediction is accomplished by the hybrid-model of SVM and KNN.The exiting volumes of previous time periods are used as the feature vector for KNN and SVM.Besides,a dynamic weight is adopted for the prediction of current time period based on the latest prediction accuracy of KNN and SVM.The model results indicate that the proposed algorithm is feasible and accurate.The Mean Absolute Percentage Error is under 10%.When comparing with the results of single KNN or SVM method,the results show that the combination of KNN and SVM can improve the reliability of the prediction significantly.The proposed method can be implemented in the on-line application of exiting volume prediction,which is able to consider different vehicle types.展开更多
Using the approach of D. Landriault et al. and B. Li and X. Zhou, for a one-dimensional time-homogeneous diffusion process X and constants c 〈 a 〈 b 〈 d, we find expressions of double Laplace transforms of the form...Using the approach of D. Landriault et al. and B. Li and X. Zhou, for a one-dimensional time-homogeneous diffusion process X and constants c 〈 a 〈 b 〈 d, we find expressions of double Laplace transforms of the form Ex[e--θTd--λ∫o Td1a 〈Xs〈b ds; Td 〈 Tc], where Tx denotes the first passage time of level x. As applications, we find explicit Laplace transforms of the corresponding occupation time and occupation density for the Brownian motion with two-valued drift and that of occupation time for the skew Ornstein- Uhlenbeck process, respectively. Some known results are also recovered.展开更多
This study investigates the hydrodynamic process of a cylinder ejected from the water’s surface through high-speed camera experiments.Using digital image processing methods,the images obtained through experiments are...This study investigates the hydrodynamic process of a cylinder ejected from the water’s surface through high-speed camera experiments.Using digital image processing methods,the images obtained through experiments are processed and analyzed.Although the dynamics of rising buoyant cylinders have been thoroughly investigated,the pop-up height of the cylinders has not been extensively explored.Statistical analysis of the kinematic and dynamic data of cylinders is conducted.Research has shown that after the cylinder rises,it pops out of the water’s surface.Within the experimental range,the pop-up height of the cylinder is related to the release depth.Furthermore,the pop-up height and release depth of the cylinder vary linearly under vertical release conditions.Under horizontal release conditions,the relationship between pop-up height and release depth shows irregular changes mainly because of the unstable shedding of the wake vortex.展开更多
The paper addresses the impacts of political exits on capital structure policies,through studying the impact of the Brexit deal on the UK's companies listed at FTSE 100 as a practical case.The study is divided int...The paper addresses the impacts of political exits on capital structure policies,through studying the impact of the Brexit deal on the UK's companies listed at FTSE 100 as a practical case.The study is divided into two periods:the first before the Brexit deal(2010-2015)and the second after the referendum until Brexit(2016-2021).Data were collected from the annual reports of the UK companies and the FTSE 100 database.Moreover,capital structure policies were studied by analyzing the determinants such as long-term debt over total equity,profitability,tangibility,liquidity,propensity to pay dividends,size,and political factor-Brexit.The results show that there is a direct relationship between political exits and capital structure.Also,the results show that the financial ratios are different between the two periods(before and after Brexit),where it seems that the capital structure variables were affected starting from the referendum period,political negotiations between the two parties,and then Brexit(2016-2021).In addition,the correlation matrix shows that long-term debt over total equity has a negative correlation with profitability,liquidity,and political factors,where it seems that long-term debt over total equity has a positive correlation with tangibility,size,and paying dividends.Moreover,the results show that political shocks were affecting the FTSE 100 performance starting from 2016 until 2021.The study could be useful for financial and economic academics.Moreover,the study could be helpful for EU members and the UK government,taking into consideration the interests of the UK and EU where any future policies or laws will affect the financial and economic sectors of the two parties.展开更多
Understanding the evolution mechanisms of water-exit cavities and flow fields evolve during highintensity interactions between vehicles and floating ice is critical for advancing the application of submarine-launched ...Understanding the evolution mechanisms of water-exit cavities and flow fields evolve during highintensity interactions between vehicles and floating ice is critical for advancing the application of submarine-launched marine equipment in low-temperature ice-prone waters.A computational fluid dynamics-finite element method(CFD-FEM) coupled framework was established to simulate bidirectional fluid-structure interactions during the water-exit process of a ventilated vehicle impacting ice in brash environments.Distinct evolution characteristics were revealed by comparatively analyzing the cavity,flow fields,hydrodynamic loading,structural deformation,and trajectory stability across three scenarios:ice-free,single-ice,and multi-ice.Furthermore,the position-dependent impact effects were characterized.The findings reveal that the impact,friction,and compression effects of ice induce bending and wrinkling of the shoulder cavity,aggravating its collapse and increasing the wetting of the vehicle,resulting in a substantial expansion of the high-velocity and vortex-dominated regions within the flow field,accompanied by more obvious water splashes.The impact of ice notably increases the kinetic energy dissipation of the vehicle during the cross-water stage and diminishes its motion stability.In the center-symmetric layout,the vehicle collides with ice only once,with high stress confined to the head.Conversely,the radial-offset layout causes secondary or even multiple collisions,resulting in high-stress areas on the shoulder of the vehicle,making it deflect and ultimately causing the tail cavity to tilt and become destabilized.The design of new vehicles suitable for ice-prone environments should focus on enhancing the impact toughness of the head structure and optimizing the surface shape design to improve the adaptability to low-temperature complex environments.展开更多
This invited commentary discusses the recent study by Atay et al,which investigated relapse rates following the spontaneous withdrawal of maintenance 5-aminosalicylates in ulcerative colitis.The discussion focuses,in ...This invited commentary discusses the recent study by Atay et al,which investigated relapse rates following the spontaneous withdrawal of maintenance 5-aminosalicylates in ulcerative colitis.The discussion focuses,in this patient setting,on the possible reasons that might prompt clinicians to pursue such exit strategies,and on the importance of exercising caution in these decisions,given the extremely narrow subsets of patients for whom international guidelines allow any degree of leeway.展开更多
EXIT(EXtrinsic Information Transfer)图分析方法可以看作密度进化技术的一种简化,具有实现简单的优点,并且在不同的信道、调制方案以及检测器中都可以使用。在详细阐述了EXIT图分析方法的基础上,给出了基于EXIT图的正则LDPC码的门限...EXIT(EXtrinsic Information Transfer)图分析方法可以看作密度进化技术的一种简化,具有实现简单的优点,并且在不同的信道、调制方案以及检测器中都可以使用。在详细阐述了EXIT图分析方法的基础上,给出了基于EXIT图的正则LDPC码的门限判决算法,进一步通过计算机仿真分别给出了变量节点译码器和校验节点译码器的EXIT曲线,以及不同的信道信噪比下(3,6)正则LDPC码EXIT图的变化规律,直观地对迭代译码过程中的互信息变化进行了描述分析。展开更多
Poverty incidence is the key index that needs to be measured in the poverty exit examination and evaluation of 832 poverty-stricken counties and 128 000 poverty-stricken villages. In this paper, based on the statement...Poverty incidence is the key index that needs to be measured in the poverty exit examination and evaluation of 832 poverty-stricken counties and 128 000 poverty-stricken villages. In this paper, based on the statement of general concept and conventional calculation method of the poverty incidence, the calculation method of poverty incidence in the exit evaluation of poverty-stricken counties （also including poverty-stricken township and poverty-stricken villages） was investigated through the view of the third-party evaluation. In addition to considering the previous ＂number of planned poverty remaining population＂, the method also needed to give consideration to the exiting mistaken population, evaluation missing population. Based on the case in Yuanyang County, Honghe Hani and Yi Autonomous Prefecture, Yunnan Province, the poverty incidences of 10 exit planning villages by the end of 2017 in Yuanyang County were investigated and estimated, and suggestions were proposed to promote the precise poverty alleviation and poverty relief of the county.展开更多
星座映射方式在BICM系统的设计中非常重要。将外信息传递函数(Extrinsic Information Transfer Function)曲线用于星座映射的设计,用Monte Carlo仿真给出了16QAM星座的几种星座映射方式的外信息传递函数曲线,结合EXIT曲线分析了星座映...星座映射方式在BICM系统的设计中非常重要。将外信息传递函数(Extrinsic Information Transfer Function)曲线用于星座映射的设计,用Monte Carlo仿真给出了16QAM星座的几种星座映射方式的外信息传递函数曲线,结合EXIT曲线分析了星座映射方式对系统性能的影响。仿真结果证实了EXIT曲线在星座映射设计中的有效性。展开更多
基金supported by the National Natural Science Foundation of China(No.62376198)the National Key Research and Development Program of China(No.2022YFB3104700)the Shanghai Baiyulan Pujiang Project(No.08002360429).
文摘Early exiting has shown significant potential in accelerating the inference of pre-trained language models(PLMs)by allowing easy samples to exit from shallow layers.However,existing early exiting methods primarily rely on local information from individual samples to estimate prediction uncertainty for making exiting decisions,overlooking the global information provided by the sample population.This impacts the estimation of prediction uncertainty,compromising the reliability of exiting de-cisions.To remedy this,inspired by principal component analysis(PCA),the authors define a residual score to capture the deviation of features from the principal space of the sample population,providing a global perspective for estimating prediction uncertainty.Building on this,a two-stage exiting strategy is proposed that integrates global information from residual scores with local information from energy scores at both the decision and feature levels.This strategy incorporates three-way decisions to enable more reliable exiting decisions for boundary region samples by delaying judgement.Extensive experiments on the GLUE benchmark validate that the method achieves an average speed-up ratio of 2.17×across all tasks with minimal per-formance degradation.Additionally,it surpasses the state-of-the-art E-LANG by 11%in model acceleration,along with a performance improvement of 0.6 points,demonstrating a better performance-efficiency trade-off.
基金supported by the National Science Foundation of China(No.62172031)the Beijing Municipal Natural Science Foundation(No.L191019).
文摘Given the explosive growth in video content generation,there is a rising demand for efficient and scalable video recognition.Deep learning has shown its remarkable performance in video analytics,by applying 2D or 3D Convolutional Neural Networks(CNNs)across multiple video frames.However,high data quantities,intensive computational costs,and various performance requirements restrict the deployment and application of these video-oriented models on resource-constrained edge devices,e.g.,Internet-of-Things(IoT)and mobile devices.To tackle this issue,we propose a joint optimization system RSEE by adaptive Resolution Selection(RS)and conditional Early Exiting(EE)to facilitate efficient video recognition based on 2D CNN backbones.Given a video frame,RSEE firstly determines what input resolution is to be used for processing by the dynamic resolution selector,then sends the resolution-adjusted frame into the backbone network to extract features,and finally determines whether to stop further processing based on the accumulated features of current video at the early-exiting gate.Extensive experiments conducted on benchmark datasets indicate that RSEE remarkably outperforms current state-of-the-art solutions in terms of computational cost(by up to 84.72%on UCF101 and 78.93%on HMDB51)and inference speed(up to 3.18×on UCF101 and 3.50×on HMDB51),while still preserving competitive recognition accuracy(up to 7.81%on UCF1017.21%on HMDB51).Furthermore,the superiority of RSEE on resource-constrained edge devices is validated on the NVIDIA Jetson Nano,with processing speeds controlled by hyperparameters ranging from about 12 to 60 Frame-Per-Second(FPS)that well enable real-time analysis.
文摘Roundabouts are becoming a preferred form of intersection control type due to their safety and capacity benefits. Yield control at roundabout entries inherently reduces fuel consumption and emissions when compared to other conventional intersection types. However, these benefits can be limited by poor driver behavior and judgment when entering the roundabout. This research addresses the nature of gap distributions and use of turn indicators by exiting vehicles at three single-lane roundabouts in Vermont, New York, and Alaska. Presented here is a comparison of vehicle headways measured at two different locations in each roundabout. Rejected headways are analyzed in the context of priority abstaining events when entering drivers yield to vehicles exiting on the same leg of the roundabout suggesting that ＂true＂ critical gaps are being overestimated. Results indicate that exiting vehicles, particularly those that do not use their turn indicators when departing from the major-stream of traffic have an influence on the entry decision of drivers on the same approach. This behavior is of particular concern for intersection efficiency （i.e., delay） and sustainability （i.e., excess fuel consumption and emissions）. Results prompt the consideration of more consistent guidance on and enforcement of turn indicator use during roundabout negotiations.
文摘In order to better predict the traffic states on freeways and make management decisions,a hybrid model of support vector machine(SVM)and K-nearest neighbor(KNN)is proposed for shortterm freeway exiting volume prediction.First,a historical data set is built by using the freeway toll data.The abnormal toll records,such as records that have same entry and exit station,illogical time record and abnormal travel speed,are excluded by data quality control.Based on the historical dataset,it is found that the exiting volume has periodical variation over time which provides the basis of the short-term prediction.Then,the historical data set is cross-classified into twelves groups based on the day of week and time of day.The prediction has been done for each group.Finally,the prediction is accomplished by the hybrid-model of SVM and KNN.The exiting volumes of previous time periods are used as the feature vector for KNN and SVM.Besides,a dynamic weight is adopted for the prediction of current time period based on the latest prediction accuracy of KNN and SVM.The model results indicate that the proposed algorithm is feasible and accurate.The Mean Absolute Percentage Error is under 10%.When comparing with the results of single KNN or SVM method,the results show that the combination of KNN and SVM can improve the reliability of the prediction significantly.The proposed method can be implemented in the on-line application of exiting volume prediction,which is able to consider different vehicle types.
基金Acknowledgements The authors thank the anonymous referees for helpful comments. Yingqiu Li＇s work was supported by the National Natural Science Foundation of China （Grant No. 11171044） und the Natural Science Foundation of Hunan Province （Grant No. llJ32001） Suxin Wang＇s work was supported by the Natural Sciences and Engineering Research Council of Canada.
文摘Using the approach of D. Landriault et al. and B. Li and X. Zhou, for a one-dimensional time-homogeneous diffusion process X and constants c 〈 a 〈 b 〈 d, we find expressions of double Laplace transforms of the form Ex[e--θTd--λ∫o Td1a 〈Xs〈b ds; Td 〈 Tc], where Tx denotes the first passage time of level x. As applications, we find explicit Laplace transforms of the corresponding occupation time and occupation density for the Brownian motion with two-valued drift and that of occupation time for the skew Ornstein- Uhlenbeck process, respectively. Some known results are also recovered.
基金supported in part by the National Natural Science Foundation of China under Grant No.41706108the Science and Technology Commission of Shanghai Municipality Project 20dz1206600+2 种基金the Natural Science Foundation of Shanghai under Grant No.20ZR1424800the Oceanic Interdisciplinary Program of Shanghai Jiao Tong University under Grant No.SL2022ZD106the Natural Science Foundation of Chongqing under Grant No.cstc2021jcyj-msxmX0650.
文摘This study investigates the hydrodynamic process of a cylinder ejected from the water’s surface through high-speed camera experiments.Using digital image processing methods,the images obtained through experiments are processed and analyzed.Although the dynamics of rising buoyant cylinders have been thoroughly investigated,the pop-up height of the cylinders has not been extensively explored.Statistical analysis of the kinematic and dynamic data of cylinders is conducted.Research has shown that after the cylinder rises,it pops out of the water’s surface.Within the experimental range,the pop-up height of the cylinder is related to the release depth.Furthermore,the pop-up height and release depth of the cylinder vary linearly under vertical release conditions.Under horizontal release conditions,the relationship between pop-up height and release depth shows irregular changes mainly because of the unstable shedding of the wake vortex.
文摘The paper addresses the impacts of political exits on capital structure policies,through studying the impact of the Brexit deal on the UK's companies listed at FTSE 100 as a practical case.The study is divided into two periods:the first before the Brexit deal(2010-2015)and the second after the referendum until Brexit(2016-2021).Data were collected from the annual reports of the UK companies and the FTSE 100 database.Moreover,capital structure policies were studied by analyzing the determinants such as long-term debt over total equity,profitability,tangibility,liquidity,propensity to pay dividends,size,and political factor-Brexit.The results show that there is a direct relationship between political exits and capital structure.Also,the results show that the financial ratios are different between the two periods(before and after Brexit),where it seems that the capital structure variables were affected starting from the referendum period,political negotiations between the two parties,and then Brexit(2016-2021).In addition,the correlation matrix shows that long-term debt over total equity has a negative correlation with profitability,liquidity,and political factors,where it seems that long-term debt over total equity has a positive correlation with tangibility,size,and paying dividends.Moreover,the results show that political shocks were affecting the FTSE 100 performance starting from 2016 until 2021.The study could be useful for financial and economic academics.Moreover,the study could be helpful for EU members and the UK government,taking into consideration the interests of the UK and EU where any future policies or laws will affect the financial and economic sectors of the two parties.
文摘Understanding the evolution mechanisms of water-exit cavities and flow fields evolve during highintensity interactions between vehicles and floating ice is critical for advancing the application of submarine-launched marine equipment in low-temperature ice-prone waters.A computational fluid dynamics-finite element method(CFD-FEM) coupled framework was established to simulate bidirectional fluid-structure interactions during the water-exit process of a ventilated vehicle impacting ice in brash environments.Distinct evolution characteristics were revealed by comparatively analyzing the cavity,flow fields,hydrodynamic loading,structural deformation,and trajectory stability across three scenarios:ice-free,single-ice,and multi-ice.Furthermore,the position-dependent impact effects were characterized.The findings reveal that the impact,friction,and compression effects of ice induce bending and wrinkling of the shoulder cavity,aggravating its collapse and increasing the wetting of the vehicle,resulting in a substantial expansion of the high-velocity and vortex-dominated regions within the flow field,accompanied by more obvious water splashes.The impact of ice notably increases the kinetic energy dissipation of the vehicle during the cross-water stage and diminishes its motion stability.In the center-symmetric layout,the vehicle collides with ice only once,with high stress confined to the head.Conversely,the radial-offset layout causes secondary or even multiple collisions,resulting in high-stress areas on the shoulder of the vehicle,making it deflect and ultimately causing the tail cavity to tilt and become destabilized.The design of new vehicles suitable for ice-prone environments should focus on enhancing the impact toughness of the head structure and optimizing the surface shape design to improve the adaptability to low-temperature complex environments.
文摘This invited commentary discusses the recent study by Atay et al,which investigated relapse rates following the spontaneous withdrawal of maintenance 5-aminosalicylates in ulcerative colitis.The discussion focuses,in this patient setting,on the possible reasons that might prompt clinicians to pursue such exit strategies,and on the importance of exercising caution in these decisions,given the extremely narrow subsets of patients for whom international guidelines allow any degree of leeway.
文摘EXIT(EXtrinsic Information Transfer)图分析方法可以看作密度进化技术的一种简化,具有实现简单的优点,并且在不同的信道、调制方案以及检测器中都可以使用。在详细阐述了EXIT图分析方法的基础上,给出了基于EXIT图的正则LDPC码的门限判决算法,进一步通过计算机仿真分别给出了变量节点译码器和校验节点译码器的EXIT曲线,以及不同的信道信噪比下(3,6)正则LDPC码EXIT图的变化规律,直观地对迭代译码过程中的互信息变化进行了描述分析。
文摘Poverty incidence is the key index that needs to be measured in the poverty exit examination and evaluation of 832 poverty-stricken counties and 128 000 poverty-stricken villages. In this paper, based on the statement of general concept and conventional calculation method of the poverty incidence, the calculation method of poverty incidence in the exit evaluation of poverty-stricken counties （also including poverty-stricken township and poverty-stricken villages） was investigated through the view of the third-party evaluation. In addition to considering the previous ＂number of planned poverty remaining population＂, the method also needed to give consideration to the exiting mistaken population, evaluation missing population. Based on the case in Yuanyang County, Honghe Hani and Yi Autonomous Prefecture, Yunnan Province, the poverty incidences of 10 exit planning villages by the end of 2017 in Yuanyang County were investigated and estimated, and suggestions were proposed to promote the precise poverty alleviation and poverty relief of the county.
文摘星座映射方式在BICM系统的设计中非常重要。将外信息传递函数(Extrinsic Information Transfer Function)曲线用于星座映射的设计,用Monte Carlo仿真给出了16QAM星座的几种星座映射方式的外信息传递函数曲线,结合EXIT曲线分析了星座映射方式对系统性能的影响。仿真结果证实了EXIT曲线在星座映射设计中的有效性。
