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Operation Mode on Pulse Modulation in Atmospheric Radio Frequency Glow Discharges 被引量:1
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作者 张杰 郭颖 +2 位作者 黄晓江 张菁 石建军 《Plasma Science and Technology》 SCIE EI CAS CSCD 2016年第10期974-977,共4页
The discharge operation regime of pulse modulated atmospheric radio frequency (RF) glow discharge in helium is investigated on the duty cycle and frequency of modulation pulses. The characteristics of radio frequenc... The discharge operation regime of pulse modulated atmospheric radio frequency (RF) glow discharge in helium is investigated on the duty cycle and frequency of modulation pulses. The characteristics of radio frequency discharge burst in terms of breakdown voltage, alpha(s)- gamma(γ) mode transition voltage and current are demonstrated by the discharge current voltage characteristics. The minimum breakdown voltage of RF discharge burst was obtained at the duty cycle of 20% and frequency of 400 kHz, respectively. The α-γ mode transition of RF discharge burst occurs at higher voltage and current by reducing the duty cycle and elevating the modulation frequency before the RF discharge burst evolving into the ignition phase, in which the RF discharge burst can operate stably in the γ mode. It proposes that the intensity and stability of RF discharge burst can be improved by manipulating the duty cycle and modulation frequency in pulse modulated atmospheric RF glow discharge. 展开更多
关键词 pulse modulation atmospheric glow discharge discharge operation mode
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An Improved Submodule Unified Pulse Modulation Scheme for a Hybrid Modular Multilevel Converter 被引量:2
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作者 Sizhao Lu Kai Li +2 位作者 Xiaoting Deng Siqi Li Zhengming Zhao 《CES Transactions on Electrical Machines and Systems》 2017年第3期322-333,共12页
This paper presents an improved submodule unified pulse width modulation(SUPWM)scheme for a hybrid modular multilevel converter(MMC)composed of half-bridge submodules(HBSMs)and full-bridge submodules(FBSMs).The propos... This paper presents an improved submodule unified pulse width modulation(SUPWM)scheme for a hybrid modular multilevel converter(MMC)composed of half-bridge submodules(HBSMs)and full-bridge submodules(FBSMs).The proposed SUPWM scheme can achieve an output voltage of(2N+1)(where N is the number of submodules in each arm)levels,which is the same as that of the carrier-phase-shifted PWM(CPSPWM)scheme.Meanwhile,the proposed SUPWM scheme can alleviate the uneven loss distributions between the left leg and right leg in FBSMs of the hybrid MMC.Moreover,the capacitor voltages of the sub-modules can be well balanced without complicated closed-loop voltage balancing controllers.The validity of the proposed SUPWM scheme is verified by both the simulated and experimental results. 展开更多
关键词 Hybrid MMC loss distribution pulse width modulation
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Pulsed Modulation in Electro-Hyperthermia
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作者 Janos Szucs Lajos Konyha +1 位作者 Gabor Kertesz Andras Szasz 《Open Journal of Biophysics》 2024年第4期374-398,共25页
Modulated electro-hyperthermia (mEHT) is one of the novel oncological treatments with many preclinical and clinical results showing its advantages. The basis of the method is the synergy of thermal and nonthermal effe... Modulated electro-hyperthermia (mEHT) is one of the novel oncological treatments with many preclinical and clinical results showing its advantages. The basis of the method is the synergy of thermal and nonthermal effects, similar to the thermal action of conventional hyperthermia combined with ionizing radiation (radiotherapy). The electric field and the radiofrequency current produced both the thermal and nonthermal processes. The thermal effects produce the elevated temperature as a thermal background to optimize the nonthermal impacts. The low frequency amplitude modulation ensures accurate targeting and promotes immunogenic cell death to develop the tumor specific memory T cells disrupting the malignant cells by immune surveillance. This process (abscopal effect) works like a vaccination. The low frequency amplitude modulation is combined in the new method with the high power pulses for short time, increasing the tumor distortion ability of the electric field. The new modulation combination has much deeper penetration triplicating the active thickness of the effective treatment. The short pulse absorption increases the safety and decreases the thermal toxicity of the treatment, making the treatment safer. The increased power allows for reduced treatment time with the prescribed dose. 展开更多
关键词 Tumor pulsed modulation Nonthermal Excitation Thermal Homeostasis Cell-Killing RF Current Immunogenic Cell Death Apoptosis
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Indirect Vector Control of Linear Induction Motors Using Space Vector Pulse Width Modulation 被引量:1
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作者 Arjmand Khaliq Syed Abdul Rahman Kashif +5 位作者 Fahad Ahmad Muhammad Anwar Qaisar Shaheen Rizwan Akhtar Muhammad Arif Shah Abdelzahir Abdelmaboud 《Computers, Materials & Continua》 SCIE EI 2023年第3期6263-6287,共25页
Vector control schemes have recently been used to drive linear induction motors(LIM)in high-performance applications.This trend promotes the development of precise and efficient control schemes for individual motors.T... Vector control schemes have recently been used to drive linear induction motors(LIM)in high-performance applications.This trend promotes the development of precise and efficient control schemes for individual motors.This research aims to present a novel framework for speed and thrust force control of LIM using space vector pulse width modulation(SVPWM)inverters.The framework under consideration is developed in four stages.To begin,MATLAB Simulink was used to develop a detailed mathematical and electromechanical dynamicmodel.The research presents a modified SVPWM inverter control scheme.By tuning the proportional-integral(PI)controller with a transfer function,optimized values for the PI controller are derived.All the subsystems mentioned above are integrated to create a robust simulation of the LIM’s precise speed and thrust force control scheme.The reference speed values were chosen to evaluate the performance of the respective system,and the developed system’s response was verified using various data sets.For the low-speed range,a reference value of 10m/s is used,while a reference value of 100 m/s is used for the high-speed range.The speed output response indicates that themotor reached reference speed in amatter of seconds,as the delay time is between 8 and 10 s.The maximum amplitude of thrust achieved is less than 400N,demonstrating the controller’s capability to control a high-speed LIM with minimal thrust ripple.Due to the controlled speed range,the developed system is highly recommended for low-speed and high-speed and heavy-duty traction applications. 展开更多
关键词 Space vector pulse width modulation linear induction motor proportional-integral controller indirect vector control electromechanical dynamic modeling
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An Optoelectronic Pulse Frequency Modulation Circuit for Retinal Prosthesis
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作者 刘金彬 陈弘达 +2 位作者 高鹏 裴为华 隋晓红 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2006年第4期700-704,共5页
A pulse frequency modulation(PFM) circuit for retinal prosthesis,which generates electrical pulses with frequency proportional to the intensity of incident light, is presented. The fundamental characteristic of the ... A pulse frequency modulation(PFM) circuit for retinal prosthesis,which generates electrical pulses with frequency proportional to the intensity of incident light, is presented. The fundamental characteristic of the circuit is described and analyzed. The circuit is realized in 0.6μm CMOS process,and the simulation results testify to the possibility of sub-retinal implantation. 展开更多
关键词 retinal prosthesis sub-retinal implant pulse frequency modulation
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Linear and nonlinear characteristics of time-resolved photoluminescence modulation by terahertz pulse
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作者 龚姣丽 刘劲松 +4 位作者 张曼 褚政 杨振刚 王可嘉 姚建铨 《Chinese Physics B》 SCIE EI CAS CSCD 2017年第10期1-6,共6页
The linear and nonlinear characteristics of time-resolved photoluminescence (PL) of n-type bulk semiconductor GaAs modulated with terahertz (THz) pulse are studied by using an ensemble Monte Carlo (EMC) method. ... The linear and nonlinear characteristics of time-resolved photoluminescence (PL) of n-type bulk semiconductor GaAs modulated with terahertz (THz) pulse are studied by using an ensemble Monte Carlo (EMC) method. In this paper the center energy valley (Г valley) electron concentration changes with the pulse delay time, sampling time and the outfield are mainly discussed. The results show that the sampling time and the THz field should exceed certain thresholds to effectively excite photoluminescence quenching (PLQ). Adopting a direct current (DC) field makes the sampling time threshold shortened and the linear range of THz field-modulation PL expanded. Moreover, controlling the sampling time and the outfield intensity can improve the linear quality: with forward time, the larger outfield is used; with backward time, the smaller outfield is used. This study can provide a theoretical basis of THz field linear modulation in a larger range for new light emitting devices. 展开更多
关键词 THz pulse modulation PHOTOLUMINESCENCE ensemble Monte Carlo intervalley scattering
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Kinetic simulation of the transition from a pulse-modulation microwave discharge to a continuous plasma
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作者 Guan WANG Ye KUANG Yuantao ZHANG 《Plasma Science and Technology》 SCIE EI CAS CSCD 2020年第1期45-52,共8页
The generation of a very strong peak current in the first period(PCFP)in a pulse-modulated microwave discharge has been discussed in previous studies.In this paper we focus on the transition process from a pulsed disc... The generation of a very strong peak current in the first period(PCFP)in a pulse-modulated microwave discharge has been discussed in previous studies.In this paper we focus on the transition process from a pulsed discharge to a fully continuous one driven by the pulsed microwave power source by means of a kinetic model.The computational results show that by increasing the duty cycle or voltage modulation rate(VMR).the discharge eventually becomes fully continuous and PCFP can no longer he observed.In the transition process,the distributions of the electric field,electron energy probability function(EEPF)and plasma density are discussed according to the simulation data,showing different discharge structures.The simulations indicate that many high-energy electrons with electron energy larger than 20eV and low-energy electrons with electron energy less than 3eV could he generated in a pulsed microwave discharge,together with a reversal electric field formed in the anode sheath when PCFP occurs.However,only medium-energy electrons could be observed in a fully continuous discharge.Therefore,by investigating the transition process the pulse-modulated microwave discharges can be further optimized for plasma applications at atmospheric pressure. 展开更多
关键词 atmospheric plasmas pulse modulation radio-frequency discharge.PIC-MCC model
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Spectrum for Pulse Interval Modulation Signal
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作者 HUANG Yuan,WU Wensi (Jinan University,Guangzhou 510632,CHN) 《Semiconductor Photonics and Technology》 CAS 1998年第1期10-17,共8页
A static approach method method is used to get the spectrum expression of the pulse interval modulation signal.The expression is simple,has a clear physical concept and it has been confirmed by a simultaneous experiment.
关键词 Asynchronous Analog pulse modulation pulse Interval modulation SPECTRUM
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Efficient combination and enhancement of high-power mid-infrared pulses in plasmas
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作者 朱兴龙 《Plasma Science and Technology》 SCIE EI CAS CSCD 2023年第2期1-5,共5页
High-power intense optical sources in the mid-to-long wavelength infrared region are very attractive for a wide range of fields from fundamental research to materials science and biology applications.However,there are... High-power intense optical sources in the mid-to-long wavelength infrared region are very attractive for a wide range of fields from fundamental research to materials science and biology applications.However,there are still significant challenges in extending long-wavelength infrared pulses into the relativistic regime using conventional optical techniques.Here,based upon a new type of plasma-based optical method,we present an efficient scheme capable of combining several high-power long-wavelength infrared laser pulses into one single,more intense pulse,thus bringing the intensity of the output pulse to the relativistic regime.Such intense infrared pulses will open up new possibilities for strong-field physics and ultrafast applications.Furthermore,this is beneficial to understand the underlying physics and nonlinear processes of modulation,propagation and energy transfer of high-power intense laser pulses in plasmas. 展开更多
关键词 laser plasma interaction infrared pulses plasma optics pulse modulation energy transfer
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CONTROL STRATEGY FOR ELECTRO-HYDRAULIC POSITION SERVO SYSTEM WITH GENERALIZED PULSE CODE MODULATION 被引量:1
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作者 LIU Rong PAN Huachen CHEN Ying 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2007年第3期50-53,共4页
A hybrid control strategy has been designed and developed for the electro-hydraulic posi-tion servo control system with generalized Pulse code modulation (GPCM), which is suitable for the area where the work conditi... A hybrid control strategy has been designed and developed for the electro-hydraulic posi-tion servo control system with generalized Pulse code modulation (GPCM), which is suitable for the area where the work condition is poor and a large flow rate is required. It is difficult to control the GPCM system because the system is discrete. With consideration of the stability and speediness of the GPCM position servo control system, a control strategy is developed through the theoretical and ex-perimental analyses. The control strategy integrates the merits of Bang-Bang control, PID control and fuzzy control. With this hybrid control strategy, the electro hydraulic control system has good per-formances, and the servo control is carried out with GPCM through on-off valves. 展开更多
关键词 Generalized pulse code modulation (GPCM) Position control Electro hydraulic control
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Chaotic pulse position modulation ultra-wideband system based on particle filtering 被引量:1
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作者 李辉 Zhang Li 《High Technology Letters》 EI CAS 2013年第1期48-52,共5页
Traditional chaotic pulse position modulation(CPPM)system has many drawbacks.It introduces delay into the feedback loop,which will lead to divergence of chaotic map easily.The wrong decision of data will cause error p... Traditional chaotic pulse position modulation(CPPM)system has many drawbacks.It introduces delay into the feedback loop,which will lead to divergence of chaotic map easily.The wrong decision of data will cause error propagation.Mismatch of parameters and synchronization error between the receiver and transmitter will arouse high bit error rate.To solve these problems,a demodulation algorithm of CPPM based on particle filtering is proposed.According to the mathematical model of the system,it tracks the real signal by online separation in demodulation.Simulation results show that the proposed method can track the true signal better than the traditional CPPM scheme.What's more,it has good synchronization robustness,reduced error propagation by wrong decision and low bit error rate. 展开更多
关键词 chaotic communications chaotic pulse position modulation (CPPM) particle filtering ULTRA-WIDEBAND
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Ultra-low power anti-crosstalk collision avoidance light detection and ranging using chaotic pulse position modulation approach 被引量:2
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作者 郝杰 巩马理 +4 位作者 杜鹏飞 卢宝杰 张帆 张海涛 付星 《Chinese Physics B》 SCIE EI CAS CSCD 2016年第7期250-257,共8页
A novel concept of collision avoidance single-photon light detection and ranging(LIDAR) for vehicles has been demonstrated, in which chaotic pulse position modulation is applied on the transmitted laser pulses for r... A novel concept of collision avoidance single-photon light detection and ranging(LIDAR) for vehicles has been demonstrated, in which chaotic pulse position modulation is applied on the transmitted laser pulses for robust anti-crosstalk purposes. Besides, single-photon detectors(SPD) and time correlated single photon counting techniques are adapted, to sense the ultra-low power used for the consideration of compact structure and eye safety. Parameters including pulse rate, discrimination threshold, and number of accumulated pulses have been thoroughly analyzed based on the detection requirements, resulting in specified receiver operating characteristics curves. Both simulation and indoor experiments were performed to verify the excellent anti-crosstalk capability of the presented collision avoidance LIDAR despite ultra-low transmitting power. 展开更多
关键词 collision avoidance chaotic pulse position modulation time-correlated single photon counting anti-crosstalk
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Spectrum for Pulse Frequency Modulation 被引量:1
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作者 HUANG Yuan SUN Jianjun(Jinan University, Guangzhou 510632, CHN) 《Semiconductor Photonics and Technology》 CAS 1996年第3期194-198,共5页
This paper gives a spectrum expression which is simple and has a clear physical conception for pulse frequency modulation signal, and has been confirmed by an experiment simultaneously.
关键词 Spectral Analysis pulse Frequency modulation modulation Instanta neous Frequency
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Modeling and Analysis of Pulse Skip Modulation 被引量:2
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作者 罗萍 张波 《Journal of Electronic Science and Technology of China》 2006年第1期1-7,共7页
The state space average model and the large signal models of Pulse Skip Modulation (PSM) mode are given in this paper. Farther more, based on these models and simulations of PSM converter circuits, the analysis of t... The state space average model and the large signal models of Pulse Skip Modulation (PSM) mode are given in this paper. Farther more, based on these models and simulations of PSM converter circuits, the analysis of the characteristics of PSM converter is described in this paper, of which include efficiency, frequency spectrum analysis, output voltage ripple, response speed and interference rejection capability. Compared with PWM control mode, PSM converter has high efficiency, especially with fight loads, quick response, good interference rejection and good EMC characteristic. Improved PSM slightly, it could be a kind of good independent regulating mode during the whole operating process for a DC-DC converter. Finally, some experimental results are also presented in this paper. 展开更多
关键词 pulse Skip modulation (PSM) state space averaged model large signalmodel efficiency Electro Magnetic Interference (EMI) output voltage ripple improved PSM
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Performance analysis of a low-complexity nonorthogonal multiple access scheme in visible light communication downlinks using pulse modulations 被引量:1
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作者 Jian Song Tian Cao Hongming Zhang 《Intelligent and Converged Networks》 2021年第1期50-65,共16页
Although Successive Interference Cancellation(SIC)decoding is widely adopted in Nonorthogonal Multiple Access(NOMA)schemes for the recovery of user data at acceptable complexity,the imperfect SIC would cause Error Pro... Although Successive Interference Cancellation(SIC)decoding is widely adopted in Nonorthogonal Multiple Access(NOMA)schemes for the recovery of user data at acceptable complexity,the imperfect SIC would cause Error Propagation(EP),which can severely degrade system performance.In this work,we propose an SIC-free NOMA scheme in pulse modulation based Visible Light Communication(VLC)downlinks,including two types of users with different data rate requirements.Low bit-rate users adopt on-off keying,whereas high bit-rate ones use Multiple Pulse Position Modulation(MPPM).The soft decision decoding scheme is exploited by high bit-rate users to decode MPPM signals,which could fundamentally eliminate the detrimental effect of EP;the scheme is also easier and faster to execute compared with the conventional SIC decoding scheme.Expressions of the symbol error rate and achievable data rate for two types of users are derived.Results of the Monte Carlo simulation are provided to confirm the correctness of theoretical results. 展开更多
关键词 visible light communication nonorthogonal multiple access error propagation on-off keying multiple pulse position modulation symbol error rate achievable data rate
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Comparison of performance between bipolar and unipolar double-frequency sinusoidal pulse width modulation in a digitally controlled H-bridge inverter system
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作者 雷博 肖国春 吴旋律 《Chinese Physics B》 SCIE EI CAS CSCD 2013年第6期277-284,共8页
By deriving the discrete-time models of a digitally controlled H-bridge inverter system modulated by bipolar sinu- soidal pulse width modulation (BSPWM) and unipolar double-frequency sinusoidal pulse width modulati... By deriving the discrete-time models of a digitally controlled H-bridge inverter system modulated by bipolar sinu- soidal pulse width modulation (BSPWM) and unipolar double-frequency sinusoidal pulse width modulation (UDFSPWM) respectively, the performances of the two modulation strategies are analyzed in detail. The circuit parameters, used in this paper, are fixed. When the systems, modulated by BSPWM and UDFSPWM, have the same switching frequency, the stabil- ity boundaries of the two systems are the same. However, when the equivalent switching frequencies of the two systems are the same, the BSPWM modulated system is more stable than the UDFSPWM modulated system. In addition, a convenient method of establishing the discrete-time model of piecewise smooth system is presented. Finally, the analytical results are confirmed by circuit simulations and experimental measurements. 展开更多
关键词 bipolar sinusoidal pulse width modulation (SPWM) unipolar double-frequency SPWM H-bridgeinverter discrete-time model
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Pulse Propagation with Self-Phase Modulation in Nonlinear Chiral Fiber and Its Applications
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作者 Demissie Gelmecha 李俊庆 Merhawit Teklu 《Chinese Physics Letters》 SCIE CAS CSCD 2016年第9期43-47,共5页
From Maxwell's equations and Post's formalism, a generalized chiral nonlinear Schr6dinger equation (CNLSE) is obtained for the nonlinear chiral fiber. This equation governs light transmission through a dispersive ... From Maxwell's equations and Post's formalism, a generalized chiral nonlinear Schr6dinger equation (CNLSE) is obtained for the nonlinear chiral fiber. This equation governs light transmission through a dispersive nonlinear chiral fiber with joint action of chirality in linear and nonlinear ways. The generalized CNLSE shows a modu- lation of chirality to the effect of attenuation and nonlinearity compared with the case for a conventional fiber. Simulations based on the split-step beam propagation method reveal the role of nonlinearity with cooperation to chirality playing in the pulse evolution. By adjusting its strength the role of chirality in forming solitons is demonstrated for a given circularly polarized component. The application of nonlinear optical rotation is also discussed in an all-optical switch. 展开更多
关键词 of on for in pulse Propagation with Self-Phase modulation in Nonlinear Chiral Fiber and Its Applications with that IS
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Research and Making of a High-Power Switching Supply Using Pulse Width Modulation
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作者 焦斌 《Journal of Donghua University(English Edition)》 EI CAS 2005年第2期87-89,共3页
Compared with the traditional SCR phase-shift regulated power supply, a new type of power semiconductor , noncrystalline state magnetic material and pulse width modulation technology, high-power switching supply has m... Compared with the traditional SCR phase-shift regulated power supply, a new type of power semiconductor , noncrystalline state magnetic material and pulse width modulation technology, high-power switching supply has many advantages: small volume, high converting efficiency, good dynamic performance, small harmonic componont and small pollution to AC supply. 展开更多
关键词 IGBT pulse width modulation SWITCHING supply
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Realization of Space Vector Pulse Width Modulation Method Based on DSP
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作者 HAN Rukun ZHAO Yulin 《Journal of Northeast Agricultural University(English Edition)》 CAS 2008年第3期56-59,共4页
In order to compensate for the deficiency of Sine Pulse Width Modulation(SPWM), on the base of analyzing the principle of space w tot pulse width modulation and being compared with SPWM, the method of solving workin... In order to compensate for the deficiency of Sine Pulse Width Modulation(SPWM), on the base of analyzing the principle of space w tot pulse width modulation and being compared with SPWM, the method of solving working time of adjacent vector and the method of generate space voltage vector were introduced. The experiment to the inverter which consists of IGBT proves that SVPWM centrol algorithm can reduce harmonic effectively, it is beneficial to enhancing the utilization rate of voltage source inverter direct current power supply. 展开更多
关键词 space vector pulse width modulation DSP space vector
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PRI modulation recognition and sequence search under small sample prerequisite 被引量:2
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作者 ZHANG Chunjie LIU Yuchen SI Weijian 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2023年第3期706-713,共8页
Pulse repetition interval(PRI)modulation recognition and pulse sequence search are significant for effective electronic support measures.In modern electromagnetic environments,different types of inter-pulse slide rada... Pulse repetition interval(PRI)modulation recognition and pulse sequence search are significant for effective electronic support measures.In modern electromagnetic environments,different types of inter-pulse slide radars are highly confusing.There are few available training samples in practical situations,which leads to a low recognition accuracy and poor search effect of the pulse sequence.In this paper,an approach based on bi-directional long short-term memory(BiLSTM)networks and the temporal correlation algorithm for PRI modulation recognition and sequence search under the small sample prerequisite is proposed.The simulation results demonstrate that the proposed algorithm can recognize unilinear,bilinear,sawtooth,and sinusoidal PRI modulation types with 91.43% accuracy and complete the pulse sequence search with 30% missing pulses and 50% spurious pulses under the small sample prerequisite. 展开更多
关键词 inter-pulse slide pulse repetition interval(PRI)modulation type bi-directional long short-term memory(BiLSTM)network sequence search
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