In this paper, we discuss the effects of error feedback on the output of a nonlinear bistable system with stochastic resonance. The bit error rate is employed to quantify the performance of the system. The theoretical...In this paper, we discuss the effects of error feedback on the output of a nonlinear bistable system with stochastic resonance. The bit error rate is employed to quantify the performance of the system. The theoretical analysis and the numerical simulation are presented. By investigating the performances of the nonlinear systems with different strengths of error feedback, we argue that the presented system may provide guidance for practical nonlinear signal processing.展开更多
Time-interleaved structure can promote the equivalent processing speed of a digital signal processing system. An improved time-interleaved error feedback delta sigma modulator( TI-EF-DSM)for digital transmitter applic...Time-interleaved structure can promote the equivalent processing speed of a digital signal processing system. An improved time-interleaved error feedback delta sigma modulator( TI-EF-DSM)for digital transmitter application is presented in this paper. Two TI-EF-DSMs are compared,one is a conventional directly implemented and the other is the improved. The processing speed of the proposed two-channel improved time-interleaved error feedback delta sigma modulator( ITI-EF-DSM) is higher than the conventional directly implemented TI-EF-DSM for shortened critical path. A digital transmitter based on the ITI-EF-DSM is implemented on field progrmmable gate array( FPGA). The long term evolution( LTE) signals with different bandwidths of 5 MHz,10 MHz and 20 MHz are used as the signal source to evaluate the transmitter. The achieved SNR is 41 dB for the 20 MHz LTE signal with the processing clock of only 184 MHz.展开更多
Vehicle tracking plays a crucial role in intelligent transportation, autonomous driving, and video surveillance. However, challenges such as occlusion, multi-target interference, and nonlinear motion in dynamic scenar...Vehicle tracking plays a crucial role in intelligent transportation, autonomous driving, and video surveillance. However, challenges such as occlusion, multi-target interference, and nonlinear motion in dynamic scenarios make tracking accuracy and stability a focus of ongoing research. This paper proposes an integrated method combining YOLOv8 object detection with adaptive Kalman filtering. The approach employs a support vector machine (SVM) to dynamically select the optimal filter (including standard Kalman filter, extended Kalman filter, and unscented Kalman filter), enhancing the system’s adaptability to different motion patterns. Additionally, an error feedback mechanism is incorporated to dynamically adjust filter parameters, further improving responsiveness to sudden events. Experimental results on the KITTI and UA-DETRAC datasets demonstrate that the proposed method significantly improves detection accuracy (mAP@0.5 increased by approximately 3%), tracking accuracy (MOTA improved by 5%), and system robustness, providing an efficient solution for vehicle tracking in complex environments.展开更多
This study explores how error feedback is practiced by Chinese tertiary EFL teachers with its focus on the extent and modes of error feedback, types of focused errors, feedback strategies, and perceptions and attitude...This study explores how error feedback is practiced by Chinese tertiary EFL teachers with its focus on the extent and modes of error feedback, types of focused errors, feedback strategies, and perceptions and attitudes of concern. Analysis of the data from questionnaires, interviews and sample writings indicates that error feedback was extensively practiced in both comprehensive and selective modes. When providing feedback, teachers tended to focus on diction problems and ill-formed sentences, and mainly used the strategies of ＂direct feedback＂ and ＂hinting at the location of errors＂. Despite their expectations on students to locate and correct errors, teachers were found more concerned with the immediate goal of helping students avoid making the same errors than helping them learn on their own. As for the students, they expected teachers to provide comprehensive error feedback and make frequent use of error codes. This paper finally points out that for more effective error feedback, various feedback strategies should be used by teachers and self-correction and peer review should be conducted by students.展开更多
As the number of Chinese international students studying in the U.S. has grown dramatically in recent years, there has been increasing attention to how English Composition instructors approach these students＇ writing...As the number of Chinese international students studying in the U.S. has grown dramatically in recent years, there has been increasing attention to how English Composition instructors approach these students＇ writings. Using a dialogue format representing ＂narratives of classroom life＂ （Nelson, 2011a）, this paper demonstrates two polemic views held by teachers and researchers： one view sees students＇ language use as problematic as it differs from the expected standards required for academic success in the U.S., while the other calls for more tolerance of the students＇ linguistic and cultural diversity and accordingly, more strategic ways to give ＂error feedback.＂ By opening up the debate, the paper explores possibilities for teachers in the U.S. and around the world to help their students address the gap between academic expectations, and what they are currently capable of.展开更多
This paper is aimed at investigating the different ways of English teachers correcting errors in second language acquisition in classroom and offering constructive pedagogical proposal on error correction in oral Engl...This paper is aimed at investigating the different ways of English teachers correcting errors in second language acquisition in classroom and offering constructive pedagogical proposal on error correction in oral English class. Transcripts totaling450 minutes of classroom interaction taken from 5 non-native English classes of different types(reading, writing, speaking, and integrated English learning) were analyzed on error correction and feedback in second language acquisition. Results include the frequency and distribution of the six different feedback types used by five teachers. The findings here illustrate an overwhelming tendency for teachers to use recasts in class. Four other feedback types-elicitation, metalinguistic feedback, clarification request,and repetition—lead to student-generated repair more successfully and are thus able to initiate what the authors characterize as the negotiation of form.展开更多
Feedbacks given by teachers is possibly a common instruction in second language writing classes, to help students makeprogress in writing. At one time, feedback was almost entirely at a superficial level--identifying ...Feedbacks given by teachers is possibly a common instruction in second language writing classes, to help students makeprogress in writing. At one time, feedback was almost entirely at a superficial level--identifying the grammatical errors and givingthe correct form. However, recently, this type of feedback has begun to be challenged by some researchers(eg.,Krashen, 1984, Trus-cott, 1996),who argue that teachers should be more concerned with the content of essay instead of grammatical errors. This essaywill discuss some research surrounding feedback to students' writing and will try to find the answer to the question whether the er-ror corrective feedback should be abandoned. In order to find the answer, the essay will elaborate on two parts: some literary reviewabout the issue and some suggested solutions to the issue.展开更多
To enhance encoding efficiency, an unequal error protection （UEP） broadcast scheme based on one additional feedback is proposed. Different from the equal probability selection for source packets in traditional fount...To enhance encoding efficiency, an unequal error protection （UEP） broadcast scheme based on one additional feedback is proposed. Different from the equal probability selection for source packets in traditional fountain encoding, the proposed scheme calculates the packet loss ratio （PLR） according to the feedback results in systematic broadcast phase （SBP） and then optimizes the selection probability for source packets to guarantee higher level error protection for those source packets with larger PLRs. Thus the amount of unnecessarily redundant encoded packets during encoding broadcast phase （EBP） is decreased significantly. Numerical results show that the proposed scheme can recover 60% more packets than the traditional non-feedback broadcast scheme at the ex- pense of tolerably only one feedback procedure.展开更多
Radar leveling system is the key equipment for improving the radar mobility and survival capability. A combined quantitative feedback theory (QFT) controller is designed for the radar truck leveling simulator in this ...Radar leveling system is the key equipment for improving the radar mobility and survival capability. A combined quantitative feedback theory (QFT) controller is designed for the radar truck leveling simulator in this paper, which suffers from strong nonlinearities and system parameter uncertainties. QFT can reduce the plant uncertainties and stabilize the system, but it fails to obtain high-precision tracking. This drawback can be solved by a robust QFT control scheme based on zero phase error tracking control (ZPETC) compensation. The combined controller not only possesses high robustness, but greatly improves the system performance. To verify the effiectiveness and the potential of the proposed controller, a series of experiments have been carried out. Experimental results have demonstrated its robustness against a large range of parameters variation and high tracking precision performance, as well as its capability of restraining the load coupling among channels. The combined QFT controller can drive the radar truck leveling platform accurately, quickly and stably.展开更多
Since the satellite communication goes in the trend of high-frequency and fast speed, the coefficients updating and the precision of the traditional pre-distortion feedback methods need to be further improved. On this...Since the satellite communication goes in the trend of high-frequency and fast speed, the coefficients updating and the precision of the traditional pre-distortion feedback methods need to be further improved. On this basis, this paper proposes dual loop feedback pre-distortion, which uses two first-order Volterra filter models to reduce the computing complexity and a dynamic error adjustment model to construct a revised feedback to ensure a better pre-distortion performance. The computation complexity, iterative convergence speed and precision of the proposed method are theoretically analyzed. Simulation results show that this dual loop feedback pre-distortion can speed the updating of coefficients and ensure the linearity of the amplifier output.展开更多
Analyses the errors of new parallel machine tools and presents a structural scheme for feedback compensation of machine tools to eliminate these errors, the theory behind and the relation between direction consine of ...Analyses the errors of new parallel machine tools and presents a structural scheme for feedback compensation of machine tools to eliminate these errors, the theory behind and the relation between direction consine of normal vector of the workpiece surface and the rotation angles α,β,γ of the cutter head.展开更多
To improve the robustness of high-precision servo systems, quantitative feedback theory （QFT） which aims to achieve a desired robust design over a specified region of plant uncertainty is proposed. The robust design...To improve the robustness of high-precision servo systems, quantitative feedback theory （QFT） which aims to achieve a desired robust design over a specified region of plant uncertainty is proposed. The robust design problem can be solved using QFT but it fails to guarantee a high precision tracking. This problem is solved by a robust digital QFT control scheme based on zero phase error （ZPE） feed forward compensation. This scheme consists of two parts： a QFT controller in the closed-loop system and a ZPE feed-forward compensator. Digital QFT controller is designed to overcome the uncertainties in the system. Digital ZPE feed forward controller is used to improve the tracking precision. Simulation and real-time examples for flight simulator servo system indicate that this control scheme can guarantee both high robust performance and high position tracking precision.展开更多
In this paper, we consider a multi-relay cooperative communication network that consists of a source node transmitting to its destination with the help of multiple decode-and- forward (DF) relays. Specifically, the DF...In this paper, we consider a multi-relay cooperative communication network that consists of a source node transmitting to its destination with the help of multiple decode-and- forward (DF) relays. Specifically, the DF relays that succeed in decoding the source signal are allowed to re-transmit their decoded results simultaneously to the destination in a cooperative beamforming manner. In order to carry out the cooperative beamforming, the destination needs to send the quantized channel state information (CSI) to the relays through a limited feedback channel in the face of channel quantization errors (CQE). We propose a CQE oriented multi-relay beamforming (MRB) scheme, denoted CQE-MRB for short, for the sake of improving the throughput of relay-destination transmissions. An effective throughput defined as the difference between the transmission rate and the feedback rate is used to measure an outage probability of the source-destination transmission. Simulation results demonstrate that the outage performance of proposed CQEMRB scheme is improved substantially with an increasing number of relays. Moreover, it is shown that the number of channel quantization bits can be further optimized to minimize the outage probability of proposed CQE-MRB scheme.展开更多
This paper evaluates the effect of decision feedback equalizer( DFE) error propagation for400 Gb/s Ethernet( 400 GbE) electrical link in order to propose some effective methods to improve bit error rate( BER). First,a...This paper evaluates the effect of decision feedback equalizer( DFE) error propagation for400 Gb/s Ethernet( 400 GbE) electrical link in order to propose some effective methods to improve bit error rate( BER). First,an analytical model for DFE burst error length distribution is proposed and simulated based on a NRZ electrical link in which a 5-tap DFE combined with a multiple-tap feed forward equalizer( FFE) is included. Then,a detailed derivation for BER considering DFE error propagation is given based on the distribution of burst error run length and the BER performance with and without forward error correction( FEC) is simulated too. After that,this paper investigates several MUX-based FEC interleaving methods including their complexity and latency in order to improve BER further. At last,three FEC interleaving schemes are compared not only in interleaving gain,but also in hardware complexities and latencies. Simulation results show that pre-interleave bit muxing can obtain good tradeoff between BER and complexity for 400 Gb E electrical link.展开更多
Error correction in writing is effective in an English as a foreign language (EFL) learning context, as error correction is an essential means of accuracy improvement in EFL writing. Studies of error correction show t...Error correction in writing is effective in an English as a foreign language (EFL) learning context, as error correction is an essential means of accuracy improvement in EFL writing. Studies of error correction show that error correction is benefitial for EFL writers not only in the short term but also in the long run.展开更多
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 61171147 and 60702022)
文摘In this paper, we discuss the effects of error feedback on the output of a nonlinear bistable system with stochastic resonance. The bit error rate is employed to quantify the performance of the system. The theoretical analysis and the numerical simulation are presented. By investigating the performances of the nonlinear systems with different strengths of error feedback, we argue that the presented system may provide guidance for practical nonlinear signal processing.
基金Supported by the National Natural Science Foundation of China(No.61674037)the National Key Research and Development Program of China(No.2016YFC0800400)+2 种基金the Priority Academic Program Development of Jiangsu Higher Education Institutionsthe National Power Grid Corp Science and Technology Project(No.SGTYHT/16-JS-198)the State Grid Nanjing Power Supply Company Project(No.1701052)
文摘Time-interleaved structure can promote the equivalent processing speed of a digital signal processing system. An improved time-interleaved error feedback delta sigma modulator( TI-EF-DSM)for digital transmitter application is presented in this paper. Two TI-EF-DSMs are compared,one is a conventional directly implemented and the other is the improved. The processing speed of the proposed two-channel improved time-interleaved error feedback delta sigma modulator( ITI-EF-DSM) is higher than the conventional directly implemented TI-EF-DSM for shortened critical path. A digital transmitter based on the ITI-EF-DSM is implemented on field progrmmable gate array( FPGA). The long term evolution( LTE) signals with different bandwidths of 5 MHz,10 MHz and 20 MHz are used as the signal source to evaluate the transmitter. The achieved SNR is 41 dB for the 20 MHz LTE signal with the processing clock of only 184 MHz.
文摘Vehicle tracking plays a crucial role in intelligent transportation, autonomous driving, and video surveillance. However, challenges such as occlusion, multi-target interference, and nonlinear motion in dynamic scenarios make tracking accuracy and stability a focus of ongoing research. This paper proposes an integrated method combining YOLOv8 object detection with adaptive Kalman filtering. The approach employs a support vector machine (SVM) to dynamically select the optimal filter (including standard Kalman filter, extended Kalman filter, and unscented Kalman filter), enhancing the system’s adaptability to different motion patterns. Additionally, an error feedback mechanism is incorporated to dynamically adjust filter parameters, further improving responsiveness to sudden events. Experimental results on the KITTI and UA-DETRAC datasets demonstrate that the proposed method significantly improves detection accuracy (mAP@0.5 increased by approximately 3%), tracking accuracy (MOTA improved by 5%), and system robustness, providing an efficient solution for vehicle tracking in complex environments.
基金supported by Shandong Provincial Planning Project of Education Science (2010GZ079)China National Social Sciences Foundation (10BYY026)
文摘This study explores how error feedback is practiced by Chinese tertiary EFL teachers with its focus on the extent and modes of error feedback, types of focused errors, feedback strategies, and perceptions and attitudes of concern. Analysis of the data from questionnaires, interviews and sample writings indicates that error feedback was extensively practiced in both comprehensive and selective modes. When providing feedback, teachers tended to focus on diction problems and ill-formed sentences, and mainly used the strategies of ＂direct feedback＂ and ＂hinting at the location of errors＂. Despite their expectations on students to locate and correct errors, teachers were found more concerned with the immediate goal of helping students avoid making the same errors than helping them learn on their own. As for the students, they expected teachers to provide comprehensive error feedback and make frequent use of error codes. This paper finally points out that for more effective error feedback, various feedback strategies should be used by teachers and self-correction and peer review should be conducted by students.
文摘As the number of Chinese international students studying in the U.S. has grown dramatically in recent years, there has been increasing attention to how English Composition instructors approach these students＇ writings. Using a dialogue format representing ＂narratives of classroom life＂ （Nelson, 2011a）, this paper demonstrates two polemic views held by teachers and researchers： one view sees students＇ language use as problematic as it differs from the expected standards required for academic success in the U.S., while the other calls for more tolerance of the students＇ linguistic and cultural diversity and accordingly, more strategic ways to give ＂error feedback.＂ By opening up the debate, the paper explores possibilities for teachers in the U.S. and around the world to help their students address the gap between academic expectations, and what they are currently capable of.
文摘This paper is aimed at investigating the different ways of English teachers correcting errors in second language acquisition in classroom and offering constructive pedagogical proposal on error correction in oral English class. Transcripts totaling450 minutes of classroom interaction taken from 5 non-native English classes of different types(reading, writing, speaking, and integrated English learning) were analyzed on error correction and feedback in second language acquisition. Results include the frequency and distribution of the six different feedback types used by five teachers. The findings here illustrate an overwhelming tendency for teachers to use recasts in class. Four other feedback types-elicitation, metalinguistic feedback, clarification request,and repetition—lead to student-generated repair more successfully and are thus able to initiate what the authors characterize as the negotiation of form.
文摘Feedbacks given by teachers is possibly a common instruction in second language writing classes, to help students makeprogress in writing. At one time, feedback was almost entirely at a superficial level--identifying the grammatical errors and givingthe correct form. However, recently, this type of feedback has begun to be challenged by some researchers(eg.,Krashen, 1984, Trus-cott, 1996),who argue that teachers should be more concerned with the content of essay instead of grammatical errors. This essaywill discuss some research surrounding feedback to students' writing and will try to find the answer to the question whether the er-ror corrective feedback should be abandoned. In order to find the answer, the essay will elaborate on two parts: some literary reviewabout the issue and some suggested solutions to the issue.
基金Supported by China National S&T Major Project(2013ZX03003002003)the National Natural Science Foundation of China(61371075)"111"Project of China(B14010)
文摘To enhance encoding efficiency, an unequal error protection （UEP） broadcast scheme based on one additional feedback is proposed. Different from the equal probability selection for source packets in traditional fountain encoding, the proposed scheme calculates the packet loss ratio （PLR） according to the feedback results in systematic broadcast phase （SBP） and then optimizes the selection probability for source packets to guarantee higher level error protection for those source packets with larger PLRs. Thus the amount of unnecessarily redundant encoded packets during encoding broadcast phase （EBP） is decreased significantly. Numerical results show that the proposed scheme can recover 60% more packets than the traditional non-feedback broadcast scheme at the ex- pense of tolerably only one feedback procedure.
文摘Radar leveling system is the key equipment for improving the radar mobility and survival capability. A combined quantitative feedback theory (QFT) controller is designed for the radar truck leveling simulator in this paper, which suffers from strong nonlinearities and system parameter uncertainties. QFT can reduce the plant uncertainties and stabilize the system, but it fails to obtain high-precision tracking. This drawback can be solved by a robust QFT control scheme based on zero phase error tracking control (ZPETC) compensation. The combined controller not only possesses high robustness, but greatly improves the system performance. To verify the effiectiveness and the potential of the proposed controller, a series of experiments have been carried out. Experimental results have demonstrated its robustness against a large range of parameters variation and high tracking precision performance, as well as its capability of restraining the load coupling among channels. The combined QFT controller can drive the radar truck leveling platform accurately, quickly and stably.
文摘Since the satellite communication goes in the trend of high-frequency and fast speed, the coefficients updating and the precision of the traditional pre-distortion feedback methods need to be further improved. On this basis, this paper proposes dual loop feedback pre-distortion, which uses two first-order Volterra filter models to reduce the computing complexity and a dynamic error adjustment model to construct a revised feedback to ensure a better pre-distortion performance. The computation complexity, iterative convergence speed and precision of the proposed method are theoretically analyzed. Simulation results show that this dual loop feedback pre-distortion can speed the updating of coefficients and ensure the linearity of the amplifier output.
文摘Analyses the errors of new parallel machine tools and presents a structural scheme for feedback compensation of machine tools to eliminate these errors, the theory behind and the relation between direction consine of normal vector of the workpiece surface and the rotation angles α,β,γ of the cutter head.
基金This project was supported by the Aeronautics Foundation of China (00E51022).
文摘To improve the robustness of high-precision servo systems, quantitative feedback theory （QFT） which aims to achieve a desired robust design over a specified region of plant uncertainty is proposed. The robust design problem can be solved using QFT but it fails to guarantee a high precision tracking. This problem is solved by a robust digital QFT control scheme based on zero phase error （ZPE） feed forward compensation. This scheme consists of two parts： a QFT controller in the closed-loop system and a ZPE feed-forward compensator. Digital QFT controller is designed to overcome the uncertainties in the system. Digital ZPE feed forward controller is used to improve the tracking precision. Simulation and real-time examples for flight simulator servo system indicate that this control scheme can guarantee both high robust performance and high position tracking precision.
基金supported by the National Natural Science Foundation of China (Grant Nos. 61522109, 61631020, 61671253 and 91738201)the Natural Science Foundation of Jiangsu Province (Grant Nos. BK20150040, BK20171446 and BRA2018043)
文摘In this paper, we consider a multi-relay cooperative communication network that consists of a source node transmitting to its destination with the help of multiple decode-and- forward (DF) relays. Specifically, the DF relays that succeed in decoding the source signal are allowed to re-transmit their decoded results simultaneously to the destination in a cooperative beamforming manner. In order to carry out the cooperative beamforming, the destination needs to send the quantized channel state information (CSI) to the relays through a limited feedback channel in the face of channel quantization errors (CQE). We propose a CQE oriented multi-relay beamforming (MRB) scheme, denoted CQE-MRB for short, for the sake of improving the throughput of relay-destination transmissions. An effective throughput defined as the difference between the transmission rate and the feedback rate is used to measure an outage probability of the source-destination transmission. Simulation results demonstrate that the outage performance of proposed CQEMRB scheme is improved substantially with an increasing number of relays. Moreover, it is shown that the number of channel quantization bits can be further optimized to minimize the outage probability of proposed CQE-MRB scheme.
基金Supported by the National Natural Science Foundation of China(No.61471119)
文摘This paper evaluates the effect of decision feedback equalizer( DFE) error propagation for400 Gb/s Ethernet( 400 GbE) electrical link in order to propose some effective methods to improve bit error rate( BER). First,an analytical model for DFE burst error length distribution is proposed and simulated based on a NRZ electrical link in which a 5-tap DFE combined with a multiple-tap feed forward equalizer( FFE) is included. Then,a detailed derivation for BER considering DFE error propagation is given based on the distribution of burst error run length and the BER performance with and without forward error correction( FEC) is simulated too. After that,this paper investigates several MUX-based FEC interleaving methods including their complexity and latency in order to improve BER further. At last,three FEC interleaving schemes are compared not only in interleaving gain,but also in hardware complexities and latencies. Simulation results show that pre-interleave bit muxing can obtain good tradeoff between BER and complexity for 400 Gb E electrical link.
文摘Error correction in writing is effective in an English as a foreign language (EFL) learning context, as error correction is an essential means of accuracy improvement in EFL writing. Studies of error correction show that error correction is benefitial for EFL writers not only in the short term but also in the long run.
