Artykuły w czasopismach: „Single phase sampling”

1

Arun, K., i K. Selvajyothi. "Single Phase Variable Sampling Phase Locked Loop using Composite Observer". Indonesian Journal of Electrical Engineering and Computer Science 2, nr 1 (1.04.2016): 49. http://dx.doi.org/10.11591/ijeecs.v2.i1.pp49-60.

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An observer based variable sampling period phase locked loop is introduced for grid connected systems. The composite observer acts as an efficient estimator of the fundamental components from a periodic input signal rich in DC and harmonics. The observer gains are designed using pole placement technique, which inherently ensures the stability of this estimator. Even under drift frequency, a constant number of samples (512) per cycle are maintained with the help of the numerically controlled oscillator. This makes the oscillator gain elements in the observer a constant and eliminates the trigonometric computation. This phase locked loop is found to be working in a wide range of frequency 40 – 70Hz. The performance of the proposed scheme is studied with a synthetic harmonic rich signal as well as validated by implementing the PLL in Cyclone IV FPGA with a real time grid voltage.

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Hu, Xinyao, Hao Zhang, Qian Zhao, Panpan Yu, Yinmei Li i Lei Gong. "Single-pixel phase imaging by Fourier spectrum sampling". Applied Physics Letters 114, nr 5 (4.02.2019): 051102. http://dx.doi.org/10.1063/1.5087174.

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Shields, Taylor, Adetunmise C. Dada, Lennart Hirsch, Seungjin Yoon, Jonathan M. R. Weaver, Daniele Faccio, Lucia Caspani, Marco Peccianti i Matteo Clerici. "Electro-Optical Sampling of Single-Cycle THz Fields with Single-Photon Detectors". Sensors 22, nr 23 (2.12.2022): 9432. http://dx.doi.org/10.3390/s22239432.

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Electro-optical sampling of Terahertz fields with ultrashort pulsed probes is a well-established approach for directly measuring the electric field of THz radiation. This technique usually relies on balanced detection to record the optical phase shift brought by THz-induced birefringence. The sensitivity of electro-optical sampling is, therefore, limited by the shot noise of the probe pulse, and improvements could be achieved using quantum metrology approaches using, e.g., NOON states for Heisenberg-limited phase estimation. We report on our experiments on THz electro-optical sampling using single-photon detectors and a weak squeezed vacuum field as the optical probe. Our approach achieves field sensitivity limited by the probe state statistical properties using phase-locked single-photon detectors and paves the way for further studies targeting quantum-enhanced THz sensing.

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Sud, U. C., Hukum Chandra i V. K. Gupta. "Calibration-Based Product Estimator in Single- and Two-Phase Sampling". Journal of Statistical Theory and Practice 8, nr 1 (23.12.2013): 1–11. http://dx.doi.org/10.1080/15598608.2014.840487.

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Ri, Shien, Takashi Muramatsu i Masumi Saka. "A Phase Compensation Technique of Sampling Moiré Method for Accurate Single-Shot Phase Analysis". Applied Mechanics and Materials 70 (sierpień 2011): 243–48. http://dx.doi.org/10.4028/www.scientific.net/amm.70.243.

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Recently, a technique for fast and accurate phase analysis called sampling moiré method has been developed for measurement of small-displacement distribution. In this study, a distribution of phase error caused by linear interpolation in case with mismatch between the sampling pitch and the grating pitch is theoretically analyzed. Moreover, a technique for effective phase compensation is proposed to reduce the periodic phase error. The performance of our compensation method is validated by a computer simulation. Phase analysis can be performed more accurately even in the case that the sampling pitch does not match to the grating pitch strictly.

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Parker, Robert C., i David L. Evans. "LiDAR Forest Inventory with Single-Tree, Double-, and Single-Phase Procedures". International Journal of Forestry Research 2009 (2009): 1–6. http://dx.doi.org/10.1155/2009/864108.

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Light Detection and Ranging (LiDAR) data at 0.5–2 m postings were used with double-sample, stratified procedures involving single-tree relationships in mixed, and single species stands to yield sampling errors ranging from % to %. LiDAR samples were selected with focal filter procedures and heights computed from interpolated canopy and DEM surfaces. Tree dbh and height data were obtained at various ratios of LiDAR, ground samples for DGPS located ground plots. Dbh-height and ground-LiDAR height models were used to predict dbh and compute Phase 2 estimates of basal area and volume. Phase 1 estimates were computed using the species probability distribution from ground plots in each strata. Phase 2 estimates were computed by randomly assigning LiDAR heights to species groups using a Monte Carlo simulation for each ground plot. There was no statistical difference between volume estimates from 0.5 m and 1 m LiDAR densities. Volume estimates from single-phase LiDAR procedures utilizing existing tree attributes and height bias relationships were obtained with sampling errors of 1.8% to 5.5%.

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Dar, Amber Yousaf, Nadia Saeed, Moustafa Omar Ahmed Abu-Shawiesh, Saman Hanif Shahbaz i Muhammad Qaiser Shahbaz. "A new class of ratio type estimators in single- and two-phase sampling". AIMS Mathematics 7, nr 8 (2022): 14208–26. http://dx.doi.org/10.3934/math.2022783.

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<abstract> The estimation of a certain population characteristics is required for several situations. The estimates are built so that the error of estimation is minimized. In several situations estimation of the population mean is required. Different estimators for the mean are available but, there is still room for improvement. In this paper, a new class of ratio-type estimators is proposed for the estimation of the population mean. The estimators are proposed for single- and two-phase sampling schemes. The expressions for bias and mean square error are obtained for single-phase and two-phase sampling estimators. Mathematical comparison of the proposed estimators has been achieved by using some existing single-phase and two-phase sampling estimators. Extensive simulations have been conducted to compare the proposed estimators with some available single- and two-phase sampling estimators. It has been observed that the proposed estimators are better than the existing estimators. Consequently, the proposed ratio estimators are recommended for use by the practitioners in various fields of industry, engineering and medical and physical sciences. </abstract>

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Pei, Yu Jie, Yun Shan Zhang, Jian Guo Xu, Jing Long Mu, Lei Zhang, Pin Dong, Bo Cong i Shu Han Wang. "Implementation of Single Phase Locked Loop Based on FPGA and its Application in SVC". Advanced Materials Research 986-987 (lipiec 2014): 1826–32. http://dx.doi.org/10.4028/www.scientific.net/amr.986-987.1826.

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Whereas three-phase phase locked loop could not get accurate phase position under three-phase unbalanced condition of the power grid, the design of single phase locked loop is implemented in the principle of single phase locked loop, based on FPGA technology. the paper explains design difficulties of single phase locked loop in detail, puts forward adaptive sampling scheme using single phase locked loop under variable frequency, increases accuracy of SVC sampling system. And tests response speed of phase locked loop via Real Time Digital Simulator for Power Systems (RTDS), through final verification in Fushun Lishizhai SVC Project, the design could meet system requirement for voltage phase accuracy.

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Tang, Yaojing, Yongle Chang, Jinrui Tang, Bin Xu, Mingkang Ye i Hongbo Yang. "A Novel Faulty Phase Selection Method for Single-Phase-to-Ground Fault in Distribution System Based on Transient Current Similarity Measurement". Energies 14, nr 15 (3.08.2021): 4695. http://dx.doi.org/10.3390/en14154695.

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In modern electrical power distribution systems, the effective operation of inverter-based arc suppression devices relies on the accuracy of faulty phase selection. In the traditional methods of faulty phase selection for single-phase-to-ground faults (SPGs), power frequency-based amplitude and phase characteristics are used to identify the faulty phase. In the field, when a high-resistance SPG occurs in the system, traditional methods are difficult for accurately identifying the faulty phase because of the weak fault components and complicated process. A novel realizable and effective method of faulty phase selection based on transient current similarity measurements is presented when SPGs occur in resonantly grounded distribution systems in this paper. An optimized Hausdorff distance matrix (MOHD) is proposed and constructed by the transient currents of three phases’ similarity measurements within a certain time window of our method. This MOHD is used to select the sampling time window adaptively, which allows the proposed method to be applied to any scale of distribution systems. Firstly, when a SPG occurs, the expressions for the transient phase current mutation in the faulty and sound phases are analyzed. Then, the sampling process is segmented into several selection units (SUs) to form the MOHD-based faulty phase selection method. Additionally, the Hausdorff distance algorithm (HD) is used to calculate the waveform similarities of the transient phase current mutation among the three phases to form the HD-based faulty phase selection method. Finally, a practical resonant grounded distribution system is modeled in PSCAD/EMTDC, and the effectiveness and performance of the proposed method is compared and verified under different fault resistances, fault inception angles, system topologies, sampling time windows and rates of data missing.

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Kung’u, John, i Leo Odongo. "Ratio-Cum-Product Estimator Using Multiple Auxiliary Attributes in Single Phase Sampling". Open Journal of Statistics 04, nr 04 (2014): 239–45. http://dx.doi.org/10.4236/ojs.2014.44023.

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Williams, D. F., H. Khenissi, F. Ndagijimana, K. A. Remley, J. P. Dunsmore, P. D. Hale, J. C. M. Wang i T. S. Clement. "Sampling-oscilloscope measurement of a microwave mixer with single-digit phase accuracy". IEEE Transactions on Microwave Theory and Techniques 54, nr 3 (marzec 2006): 1210–17. http://dx.doi.org/10.1109/tmtt.2005.864102.

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Liu, Zhichao, Bin Zhang, Keliang Zhou, Yongheng Yang i Jingcheng Wang. "Virtual Variable Sampling Repetitive Control of Single-Phase DC/AC PWM Converters". IEEE Journal of Emerging and Selected Topics in Power Electronics 7, nr 3 (wrzesień 2019): 1837–45. http://dx.doi.org/10.1109/jestpe.2018.2862411.

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Wang, Zilu, i Xuehao He. "Phase transition of a single star polymer: A Wang-Landau sampling study". Journal of Chemical Physics 135, nr 9 (7.09.2011): 094902. http://dx.doi.org/10.1063/1.3629849.

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Shahbaz, Saman Hanif, Aisha Fayomi i Muhammad Qaiser Shahbaz. "Estimation of the general population parameter in single- and two-phase sampling". AIMS Mathematics 8, nr 7 (2023): 14951–77. http://dx.doi.org/10.3934/math.2023763.

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<abstract>Estimation of population characteristics has been an area of interest for many years. Various estimators of the population mean and the population variance have been proposed from time-to-time with a view to improve efficiency of the estimates. In this paper, we have proposed some estimators for estimation of the general population parameters. The estimators have been proposed for single-phase and two-phase sampling using information of single and multiple auxiliary variables. The bias and mean square errors of the proposed estimators have been obtained. Some comparison of the proposed estimators has been done with some existing estimators of mean and variance. Some specific cases of the proposed estimators have been discussed. Simulation and numerical study have also been conducted to see the performance of the proposed estimators.</abstract>

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Fujigaki, Motoharu, Yuji Sasatani, Akihiro Masaya, Hiroyuki Kondo, Makiko Nakabo, Takuya Hara, Yoshiharu Morimoto, Daisuke Asai, Teiji Miyagi i Noboru Kurokawa. "Development of Sampling Moire Camera for Real-Time Phase Analysis". Applied Mechanics and Materials 83 (lipiec 2011): 48–53. http://dx.doi.org/10.4028/www.scientific.net/amm.83.48.

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Sampling Moire method is one of the convenient phase analysis methods. The accuracy of phase difference analysis is from 1/100 to 1/1000 of the grating pitches. This method is useful for a real-time measurement because the phase analysis can be performed from a single-shot image. In this paper, we developed a sampling moire camera which can analyze grating phase in real time. This camera is composed of a CMOS sensor and a FPGA. A two-dimensional grating image taken by the CMOS sensor was analyzed by the FPGA in real time. An application on a real-time deformation measurement of a cantilever is demonstrated.

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Tum, Everline Chemutai, John Kung’u i Leo Odongo. "A New Regression Type Estimator with Two Auxiliary Variables for Single-Phase Sampling". Open Journal of Statistics 04, nr 09 (2014): 789–96. http://dx.doi.org/10.4236/ojs.2014.49074.

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Saw, C. B., i C. K. Campbell. "Sampling effect of distributed reflector arrays within a single-phase unidirectional SAW transducer". IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control 37, nr 2 (marzec 1990): 116–17. http://dx.doi.org/10.1109/58.46976.

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Ri, Shien, i Takashi Muramatsu. "Theoretical error analysis of the sampling moiré method and phase compensation methodology for single-shot phase analysis". Applied Optics 51, nr 16 (23.05.2012): 3214. http://dx.doi.org/10.1364/ao.51.003214.

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Li, Hong, i Jun Yu. "Single-Phase Sine Inverter Power Supply Based on PIC18F2431". Advanced Materials Research 487 (marzec 2012): 258–62. http://dx.doi.org/10.4028/www.scientific.net/amr.487.258.

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According to the principle of equivalent surface area and Nyquist sampling theorem, this paper introduces the method which takes PIC18F2431 SCM as the control center in details, and it forms Single-phase sine inverter power supply by adopting the principle of equivalent surface area directly. This method that can be widely used in controlling Single-phase AC motor speed is simple and cost-effective.

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Ringvall, Anna, Göran Ståhl, Vera Teichmann, Jeffrey H. Gove i Mark J. Ducey. "Two-phase approaches to point and transect relascope sampling of downed logs". Canadian Journal of Forest Research 31, nr 6 (1.06.2001): 971–77. http://dx.doi.org/10.1139/x01-027.

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Point relascope sampling and transect relascope sampling were recently proposed as methods for the inventory of downed coarse woody debris. By only counting logs with a relascope device, the total length squared (with point relascope sampling) or the total length (with transect relascope sampling) of downed logs in an area can be estimated. For estimates of other variables, such as volume, additional measurements on the sampled logs are required. In this article, two-phase approaches to the methods are presented that makes use of the estimates from fast counts of logs as auxiliary data. The presented approaches serve two purposes: (i) to improve the efficiency of the methods and (ii) to avoid the bias that is likely to occur if careful checks of whether or not doubtful logs should be counted are neglected. Each two-phase design was compared with a single-phase design in terms of the standard error obtained for a given inventory cost. The two-phase designs decreased the standard errors with ca. 1718% for points and 1015% for lines. Including subjective judgements as additional auxiliary variables further decreased the standard errors in the line case but not in the point case. In the former case, the improvement in comparison with the single-phase design was 1723%.

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Xie, Tiantian, Marc Olano, Brian Karis i Krzysztof Narkowicz. "Real-time subsurface scattering with single pass variance-guided adaptive importance sampling". Proceedings of the ACM on Computer Graphics and Interactive Techniques 3, nr 1 (18.04.2020): 1–21. http://dx.doi.org/10.1145/3384536.

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In real-time applications, it is difficult to simulate realistic subsurface scattering with differing degrees translucency. Burley's reflectance approximation by empirically fitting the diffusion profile as a whole makes it possible to achieve realistic looking subsurface scattering for different translucent materials in screen space. However, achieving a physically correct result requires real-time Monte Carlo sampling of the analytic importance function per pixel per frame, which seems prohibitive to achieve. In this paper, we propose an approximation of the importance function that can be evaluated in real-time. Since subsurface scattering is more pronounced in certain regions (e.g., with light gradient change), we propose an adaptive sampling method based on temporal variance to lower the required number of samples. We propose a one phase adaptive sampling pass that is unbiased, and able to adapt to scene changes due to motion and lighting. To further improve the quality, we explore temporal reuse with a guiding pass prior to the final temporal anti-aliasing (TAA) phase that further improves the quality. Our local guiding pass does not constrain the TAA implementation, and only requires one additional texture to be passed between frames. Our proposed variance-guided algorithm has the potential to make stochastic sampling algorithm effective for real-time rendering.

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Abe, Hironori, i Hiroshi Fujimoto. "Multirate Perfect Tracking Control of Single-Phase Inverter with Inter Sampling for Arbitrary Waveform". IEEJ Transactions on Industry Applications 128, nr 2 (2008): 110–16. http://dx.doi.org/10.1541/ieejias.128.110.

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Salim, Nujayma M. A., i Christopher O. Onyango. "A Modified Regression Estimator for Single Phase Sampling in the Presence of Observational Errors". Open Journal of Statistics 12, nr 02 (2022): 175–87. http://dx.doi.org/10.4236/ojs.2022.122012.

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Lu, Jiadong, Yihua Hu, Jinglin Liu i Huiqing Wen. "Self-Calibration of Phase Current Sensors With Sampling Errors by Multipoint Sampling of Current Values in a Single PWM Cycle". IEEE Transactions on Industrial Electronics 68, nr 4 (kwiecień 2021): 2942–51. http://dx.doi.org/10.1109/tie.2020.2982110.

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Ma, Yu Quan, Li Hong Zhang, Shu Fen Han i Dong Dong Song. "The Design of Single Phase AC Regulated Power Supply with PWM Chopping Control Compensation". Advanced Materials Research 383-390 (listopad 2011): 6880–85. http://dx.doi.org/10.4028/www.scientific.net/amr.383-390.6880.

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In view of the large volume and complex control circuit of current AC regulated power supply, a unipolar AC regulated power supply with chopping control compensation is designed, and the calculation method of output filter parameter of chopping circuit is given. In the system, MCU of STC12C5A62AD with 8-bit A/D input and PWM output is adopted, by which not only simple structure and control but also fast dynamic response are get; DC voltage sampling technique is adopted, so sampling frequency is up to 12.8kHz, sampling precision is high too; PWM chopping frequency is 4kHz, so capacity of filter capacitor and inductors are small, and harmonic is little. Experiment results of prototype show that the system has high precision of output voltage and greater practical value.

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Chen, Peng Lai, Chun Yu Lin, Yu Lin Juan, Te Chau Chen i Chin Sung Lin. "A Low Cost MCU Based Single Phase Sinusoidal Pulse-Width-Modulated Inverter". Advanced Materials Research 1014 (lipiec 2014): 241–44. http://dx.doi.org/10.4028/www.scientific.net/amr.1014.241.

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Sinusoidal pulse width modulation (SPWM) technique has been widely used in inverters and motor driver ciruits. In this paper, SPWM was generated by a low cost HT66F50 single-chip, wherein the reduced sampling points of a sine wave, and the fewer sampling points were then used to produce SPWM singals. The full-bridge inverter was modulated by the high switching frequency SPWM for the high side switches and the 60Hz control signals for the low side switches. Thus, it not only reduces the required memory spacein MCU, but also reduces the switching power losses. When the SPWM frequency is 19.53 kHz or 11.72 kHz, the total harmonic distortion (THD) of the inverter’s output is less than 0.6% under the load resistance 50, which is in compliance with the specification of IEEE STD. 519-1992.

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She, Yunfeng, Xiaoxiao Huo, Xiaoshan Tong, Chunjie Wang i Kunkun Fu. "Multi-Sampling Rate Finite Control Set Model Predictive Control and Adaptive Method of Single-Phase Inverter". Electronics 12, nr 13 (27.06.2023): 2848. http://dx.doi.org/10.3390/electronics12132848.

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With the development of power switches and processor performance in recent years, the control frequency of inverters has been significantly improved. However, limited by technology and price, the sensor sampling frequency in large-scale industrial applications is much lower than the inverter control frequency that can be realized. This frequency mismatch limits the performance improvement of the inverter. In this article, the current and voltage at the non-sampling time are reconstructed using the current prediction control principle and the input observer theory, allowing a single-phase inverter to implement multi-sampling rate control with a low sampling frequency and high control frequency. In addition, an improved adaptive controller is designed to solve the effect of incorrect model parameters, which realizes adaptive control when the sampling frequency and control frequency are mismatched. Finally, the effectiveness of the method is verified through a simulation and experiments. The proposed method can solve the problem of high-speed switching for inverters under low-sampling-frequency conditions, improving the inverter’s adaptive performance and robustness.

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Yuan, Gu, Xing i Chen. "Phase Difference Measurement of Under-Sampled Sinusoidal Signals for InSAR System Phase Error Calibration". Sensors 19, nr 23 (3.12.2019): 5328. http://dx.doi.org/10.3390/s19235328.

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Phase difference measurement of sinusoidal signals can be used for phase error calibration of the spaceborne single-pass interferometric synthetic aperture radar (InSAR) system. However, there are currently very few papers devoted to the discussion of phase difference measurement of high-frequency internal calibration signals of the InSAR system, especially the discussion of sampling frequency selection and the corresponding measuring method when the high-frequency signals are sampled under the under-sampling condition. To solve this problem, a phase difference measurement method for high-frequency sinusoidal signals is proposed, and the corresponding sampling frequency selection criteria under the under-sampling condition is determined. First, according to the selection criteria, the appropriate under-sampling frequency was chosen to sample the two sinusoidal signals with the same frequency. Then, the sampled signals were filtered by limited recursive average filtering (LRAF) and coherently accumulated in the cycle of the baseband signal. Third, the filtered and accumulated signals were used to calculate the phase difference of the two sinusoidal signals using the discrete Fourier transform (DFT), digital correlation (DC), and Hilbert transform (HT)-based methods. Lastly, the measurement accuracy of the three methods were compared respectively by different simulation experiments. Theoretical analysis and experiments verified the effectiveness of the proposed method for the phase error calibration of the InSAR system.

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Endo, Yutaka, i Gai Nakajima. "Compressive phase object classification using single-pixel digital holography". Optics Express 30, nr 15 (15.07.2022): 28057. http://dx.doi.org/10.1364/oe.463395.

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A single-pixel camera (SPC) is a computational imaging system that obtains compressed signals of a target scene using a single-pixel detector. The compressed signals can be directly used for image classification, thereby bypassing image reconstruction, which is computationally intensive and requires a high measurement rate. Here, we extend this direct inference to phase object classification using single-pixel digital holography (SPDH). Our method obtains compressed measurements of target complex amplitudes using SPDH and trains a classifier using those measurements for phase object classification. Furthermore, we present a joint optimization of the sampling patterns used in SPDH and a classifier to improve classification accuracy. The proposed method successfully classified phase object images of handwritten digits from the MNIST database, which is challenging for SPCs that can only capture intensity images.

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Zhang, Cheng, Ru Zhang, Yuanyuan Zhu, Hairong Yang, Chuan Shen i Sui Wei. "Single-Shot Compressed Imaging via Random Phase Modulation". Applied Sciences 12, nr 9 (29.04.2022): 4536. http://dx.doi.org/10.3390/app12094536.

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Compressed sensing (CS) provides an innovative framework for signal sampling, which enables accurate recovery of the sparse or compressible signal from a small set of linear measurements far fewer than the Nyquist rate in traditional signal processing. In compressed sensing, random modulation plays a key role, which can spread out the signal information more or less evenly across all locations. There are many modulation techniques, such as amplitude modulation, frequency modulation, phase modulation, spectrum modulation, and so on. Among these modulation techniques, phase modulation is vital due to the efficiency and convenience of modulation. In this paper, we review both the theoretical and application of compressed sensing and several compressed imaging systems using random phase modulation. First, we review the fundamentals of compressed sensing, dividing it into three parts: sparse representation, incoherent measurement, and nonlinear reconstruction algorithm. We then show how phase modulation can be applied to compressed sensing and compressed imaging, where the presentation can be divided into six main parts, corresponding to different aspects of phase modulation applied in compressed sensing or compressed imaging: (1) Fundamentals of compressed sensing. (2) Principles of phase modulation. (3) Single-shot compressed imaging with spatial-domain single random phase mask (CI-SSRPM). (4) Single-shot compressed imaging with a random convolution using a double random phase mask (CI-DRPM). (5) Single-shot compressed imaging with Fourier-domain single random phase mask (CI-FSRPM). (6) Single-shot compressed imaging with double random phase encoding (CI-DRPE).

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Mutembei, Teresio, John Kung’u i Christopher Ouma. "Mixture Regression-Cum-Ratio Estimator Using Multi-Auxiliary Variables and Attributes in Single-Phase Sampling". Open Journal of Statistics 04, nr 05 (2014): 367–76. http://dx.doi.org/10.4236/ojs.2014.45036.

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Xu, Yongxiang, Hao Yan, Jibin Zou, Baochao Wang i Yunhui Li. "Zero Voltage Vector Sampling Method for PMSM Three-Phase Current Reconstruction Using Single Current Sensor". IEEE Transactions on Power Electronics 32, nr 5 (maj 2017): 3797–807. http://dx.doi.org/10.1109/tpel.2016.2588141.

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González, Humberto, Lluís Martínez-León, Fernando Soldevila, Ma Araiza-Esquivel, Jesús Lancis i Enrique Tajahuerce. "High sampling rate single-pixel digital holography system employing a DMD and phase-encoded patterns". Optics Express 26, nr 16 (25.07.2018): 20342. http://dx.doi.org/10.1364/oe.26.020342.

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Zhou, Dong, Jie Cao, Huan Cui, Qun Hao, Bing-kun Chen i Kai Lin. "Complementary Fourier Single-Pixel Imaging". Sensors 21, nr 19 (30.09.2021): 6544. http://dx.doi.org/10.3390/s21196544.

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Single-pixel imaging, with the advantages of a wide spectrum, beyond-visual-field imaging, and robustness to light scattering, has attracted increasing attention in recent years. Fourier single-pixel imaging (FSI) can reconstruct sharp images under sub-Nyquist sampling. However, the conventional FSI has difficulty balancing imaging quality and efficiency. To overcome this issue, we proposed a novel approach called complementary Fourier single-pixel imaging (CFSI) to reduce the number of measurements while retaining its robustness. The complementary nature of Fourier patterns based on a four-step phase-shift algorithm is combined with the complementary nature of a digital micromirror device. CFSI only requires two phase-shifted patterns to obtain one Fourier spectral value. Four light intensity values are obtained by loading the two patterns, and the spectral value is calculated through differential measurement, which has good robustness to noise. The proposed method is verified by simulations and experiments compared with FSI based on two-, three-, and four-step phase shift algorithms. CFSI performed better than the other methods under the condition that the best imaging quality of CFSI is not reached. The reported technique provides an alternative approach to realize real-time and high-quality imaging.

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Anieting, Akan. "Two- Phase Stratified Sampling Estimator for Population Mean in The Presence of Nonresponse Using Single Auxiliary Variable". Mathematical Journal of Interdisciplinary Sciences 8, nr 2 (30.03.2020): 49–56. http://dx.doi.org/10.15415/mjis.2020.82006.

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In this article, a new estimator for population mean in two-phase stratified sampling in the presence of nonresponse using single auxiliary variable has been proposed. The bias and Mean Squared Error (MSE) of the proposed estimator has been given using large sample approximation. The empirical study shows that the MSE of the proposed estimator is more efficient than existing estimators. The optimum values of first and second phase sample have been determined.

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Chen, Wei, Ze Sen Shi, Yi Li Zhou, Qiang Chang i Wei Ping Wang. "A Single-Phase AC/DC Conversion Circuit with APFC". Applied Mechanics and Materials 740 (marzec 2015): 490–94. http://dx.doi.org/10.4028/www.scientific.net/amm.740.490.

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This system uses the MSP430F6638 and FPGA as the core, includes full bridge rectifier circuit, power factor correction circuit, Boost/Buck circuit and sample circuit. According to the sampling voltage and current value, The FPGA adjusts PWM wave duty ratio of power factor correction chip UC3854, completing single phase AC/DC conversion circuit with a voltage outer closed-loop and current inner closed-loop and active power factor correction (APFC). Test shows that the output voltage can stable in a setting value, with amplitude range ±0.05V, and when load’s impedance changes, this circuit can keep a small voltage adjustment rate and load adjustment rate. We use electronic parameter measurement device to measure the efficiency of AC/DC converter in a specified condition (voltage input Us=24V, current output Io=2A, voltage output Uo=36V), result demonstrates it’s a relatively ideal value. At the same time, under the control of UC3854, the power factor of alternating current input is 0.9734.And when we set the range of power factor between 0.8~1.0, The circuit can automatically adjust the power factor to track the set value.

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37

Luo, Zhihao, Jianbing Li, Xueyu Dong i Jianbang Sun. "Research on Non-uniform Interrupted Sampling Repeater Jamming for Phase Coded Radar". Journal of Physics: Conference Series 2209, nr 1 (1.02.2022): 012004. http://dx.doi.org/10.1088/1742-6596/2209/1/012004.

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Abstract Because of using correlation processing technology, it is difficult for traditional jamming patterns to achieve the desired jamming effect on phase coded radar. At present, the forward deception jamming of phase coded radar is mainly realized by uniform interrupted sampling repeater jamming (UISRJ). In order to solve the problem that the UISRJ can only produce a single and delayed false target, a kind of non-uniform interrupted sampling repeater jamming (NUISRJ) is proposed. The non-uniform sampling pulse train is generated through pseudo random sequence, and then sampled and forwarded to generate jamming signal, which is processed by radar pulse compression to form dense false targets. Combining the theoretical analysis and simulation results, it can be seen that the NUISRJ has the dual effects of suppressing jamming and spoofing jamming, and the distribution of false target string is more random, including the leading and lagging false target. The amplitude and coverage area of false targets group can be controlled by adjusting sampling pulse width and forwarding times to effectively implement jamming.

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孟, 祥飞. "Influence of Sampling Period on the Accuracy of Single Phase to Ground Fault in Transmission Line". Smart Grid 06, nr 02 (2016): 47–55. http://dx.doi.org/10.12677/sg.2016.62006.

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Tang, Qipeng, Anwen Shen, Wuhua Li, Pan Luo, Min Chen i Xiangning He. "Multiple-Positions-Coupled Sampling Method for PMSM Three-Phase Current Reconstruction With a Single Current Sensor". IEEE Transactions on Power Electronics 35, nr 1 (styczeń 2020): 699–708. http://dx.doi.org/10.1109/tpel.2019.2913684.

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Christ, Clara D., i Wilfred F. van Gunsteren. "Multiple free energies from a single simulation: Extending enveloping distribution sampling to nonoverlapping phase-space distributions". Journal of Chemical Physics 128, nr 17 (7.05.2008): 174112. http://dx.doi.org/10.1063/1.2913050.

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Borga, Andrea, Eric Church, Frank Filthaut, Enrico Gamberini, Jong Paul de, René Habraken, Giovanna Lehmann Miotto i in. "Felix Based Readout of The Single-Phase Protodune Detector". EPJ Web of Conferences 214 (2019): 01013. http://dx.doi.org/10.1051/epjconf/201921401013.

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The liquid argon Time Projection Chamber technique has matured and is now in use by several short-baseline neutrino experiments. This technology will be used in the long-baseline DUNE experiment; however, this experiment represents a large increase in scale, for which the technology needs to be validated explicitly. To this end, both the single-phase and dual-phase implementations of the technology are being tested at CERN in two full-scale (10 × 10 × 10 m3) ProtoDUNE setups. Besides the detector technology, these setups also allow for extensive tests of readout strategies. The Front-End LInk eXchange (FELIX) system was initially developed within the ATLAS collaboration and is based on custom FPGA-based PCIe I/O cards in combination with commodity servers. FELIX will be used in the single-phase ProtoDUNE setup to read the data coming from 2560 anode wires organized in a single Anode Plane Assembly structure. With a sampling rate of 2 MHz, the system must buffer and process an input rate of 74 Gb/s. Event building requests will arrive at a target rate of 25 Hz, and loss-less compression must reduce the data within the requested time windows before it is sent to the experiment’s event building farm. This paper discusses the design of the system as well as first operational experiences.

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Vu The, Ninh, Loc Dinh Xuan i Tai Tran Anh. "Study on synthesis and characterization of nano scale spinel Mn0.5Fe2.5O4 by micro-emulsion method". Vietnam Journal of Catalysis and Adsorption 9, nr 4 (31.12.2020): 29–35. http://dx.doi.org/10.51316/jca.2020.066.

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The single phase of Mn0.5Fe2.5O4 spinel crystals was prepared by the micro-emulsion method with the oil phase is DGDE (diethylene glycol diethyl ether). The characteristics of the materials have been determined by the X-ray diffraction (XRD), Energy-dispersive X-ray spectroscopy (EDX), Scanning electron microscopy (SEM) and Brunaure-Emmet-Teller (BET) nitrogen adsorption and desorption, Vibration sampling magnetometer (VSM), Fourier transform infrared spectroscopy (FTIR). The results showed that the single phase of Fe0.5Mn0.5Fe2O4 crystalline was formed due to the substitution of Fe by Mn in the Fe3O4 crystal lattice and single phase spinel crystal is formed with the size of 6.7 nm, specific surface area ≈ 193 m2.g-1, the saturation magnetization reaches ≈ 27 emu.g-1.

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Pozzato, Gabriele, Aki Takahashi, Xueyan Li, Donghoon Lee, Johan Ko i Simona Onori. "Core-Shell Enhanced Single Particle Model for Lithium Iron Phosphate Batteries: Model Formulation and Analysis of Numerical Solutions". Journal of The Electrochemical Society 169, nr 11 (1.11.2022): 113501. http://dx.doi.org/10.1149/1945-7111/ac86fc.

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In this paper, a core-shell enhanced single particle model for iron-phosphate battery cells is formulated, implemented, and verified. Starting from the description of the positive and negative electrodes charge and mass transport dynamics, the positive electrode intercalation and deintercalation phenomena and associated phase transitions are described with the core-shell modeling paradigm. Assuming two phases are formed in the positive electrode, one rich and one poor in lithium, a core-shrinking problem is formulated and the phase transition is modeled through a shell phase that covers the core one. A careful discretization of the coupled partial differential equations is proposed and used to convert the model into a system of ordinary differential equations. To ensure robust and accurate numerical solutions of the governing equations, a sensitivity analysis of numerical solutions is performed and the best setting, in terms of solver tolerances, solid phase concentration discretization points, and input current sampling time, is determined in a newly developed probabilistic framework. Finally, unknown model parameters are identified at different C-rate scenarios and the model is verified against experimental data.

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Li, Jianke, Jinquan Wang, Ye Xu, Jianting Li, Jingjing Chen, Pengfei Hou i Shuhua Qian. "Research on Discretization PI Control Technology of Single-Phase Grid-Connected Inverter with LCL Filter". Mathematical Problems in Engineering 2014 (2014): 1–9. http://dx.doi.org/10.1155/2014/129619.

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Compared with L-type filter, LCL-type filter is more suitable for high-power low-switching frequency applications with reducing the inductance, improving dynamic performance. However, the parameter design for the LCL filter is more complex due to the influence of the controller response performance of the converter. If the harmonic current around switching frequency can be fully suppressed, it is possible for inverter to decrease the total inductance as well as the size and the cost. In this paper, the model of the LCL filter is analyzed and numerical algorithms are adopted to analyze the stability of the closed-loop control system and stable regions are deduced with different parameters of LCL filter. Then, the minimum sampling frequencies are deduced with different conditions. Simulation and experimental results are provided to validate the research on the generating mechanism for the unstable region of sampling frequency.

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Moore, Matthew R., Marsha Pryor, Barry Fields, Claressa Lucas, Maureen Phelan i Richard E. Besser. "Introduction of Monochloramine into a Municipal Water System: Impact on Colonization of Buildings by Legionella spp". Applied and Environmental Microbiology 72, nr 1 (styczeń 2006): 378–83. http://dx.doi.org/10.1128/aem.72.1.378-383.2006.

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ABSTRACT Legionnaires' disease (LD) outbreaks are often traced to colonized potable water systems. We collected water samples from potable water systems of 96 buildings in Pinellas County, Florida, between January and April 2002, during a time when chlorine was the primary residual disinfectant, and from the same buildings between June and September 2002, immediately after monochloramine was introduced into the municipal water system. Samples were cultured for legionellae and amoebae using standard methods. We determined predictors of Legionella colonization of individual buildings and of individual sampling sites. During the chlorine phase, 19 (19.8%) buildings were colonized with legionellae in at least one sampling site. During the monochloramine phase, six (6.2%) buildings were colonized. In the chlorine phase, predictors of Legionella colonization included water source (source B compared to all others, adjusted odds ratio [aOR], 6.7; 95% confidence interval [CI], 2.0 to 23) and the presence of a system with continuously circulating hot water (aOR, 9.8; 95% CI, 1.9 to 51). In the monochloramine phase, there were no predictors of individual building colonization, although we observed a trend toward greater effectiveness of monochloramine in hotels and single-family homes than in county government buildings. The presence of amoebae predicted Legionella colonization at individual sampling sites in both phases (OR ranged from 15 to 46, depending on the phase and sampling site). The routine introduction of monochloramine into a municipal drinking water system appears to have reduced colonization by Legionella spp. in buildings served by the system. Monochloramine may hold promise as community-wide intervention for the prevention of LD.

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Yao, Wei, Jiamin Cui i Wenxi Yao. "Single-Phase Inverter Deadbeat Control with One-Carrier-Period Lag". Electronics 9, nr 1 (14.01.2020): 154. http://dx.doi.org/10.3390/electronics9010154.

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This paper presents a novel digital control scheme for the regulation of single-phase voltage source pulse width modulation (PWM) inverters used in AC power sources. The proposed scheme adopts two deadbeat controllers to regulate the inner current loop and the outer voltage loop of the PWM inverter. For the overhead of digital processing, the change of duty of PWM lags one carrier period behind the sampling signal, which is modeled as a first-order lag unit in a discrete domain. Based on this precise modeling, the deadbeat controllers make the inverter get a fast dynamic response, so that the inverter’s output voltage is obtained with a very low total harmonic distortion (THD), even when the load is fluctuating. The parameter sensitivity of the deadbeat control was analyzed, which shows that the proposed deadbeat control system can operate stably when the LC filter’s parameters vary within the range allowed. The experimental results of a 2kW inverter prototype show that the THD of the output voltage is less than 3% under resistive and rectifier loads, which verifies the feasibility of the proposed scheme. An additional advantage of the proposed scheme is that the parameter design of the controller can be fully programmed without the experience of a designer.

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Hu, Xiao Fang, Lei Zhao, Xing Shun Gao, Shu Bin Liu i Qi An. "A Fully Digital Beam Position and Phase Measurement Electronics for the Proton LINAC in ADS". Applied Mechanics and Materials 333-335 (lipiec 2013): 379–88. http://dx.doi.org/10.4028/www.scientific.net/amm.333-335.379.

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The beam measurement is essential for an accelerator. In the proton LINAC in China Accelerator Driven Sub-critical system (ADS), a high resolution measurement of beam position and phase is required within one single system. To meet the requirement, this beam position and phase measurement (BPPM) electronics is designed based on a direct RF under-sampling technique, which simplifies both the analog and digital processing circuits. The signals received from the LINAC are narrow pulses with a repetition frequency of 162.5 MHz and a dynamic range more than 40 dB. After analog manipulation, the input RF signals are directly converted to In-phase and Quadrature-phase (IQ) streams through under-sampling based on the high-speed high-resolution Analog-to-Digital conversion technique. All signal processing is integrated in one single FPGA, in which real-time beam position, phase and current can be obtained. A series of simulations and tests have been conducted to evaluate the performance. Initial test results indicate that this system achieves a position resolution better than 20 um and a phase resolution better than 0.1 degree over a 40 dB dynamic range with the bandwidth of 780 kHz, which is well beyond the application requirements.

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Wang, Peng, Xiong Shen, Yaping Xuan, Shunlin Huang i Jun Liu. "High-performance single-shot fourth-order auto-correlator with real-time accuracy self-validation". Applied Physics Letters 121, nr 7 (15.08.2022): 071104. http://dx.doi.org/10.1063/5.0098148.

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An improved single-shot fourth-order auto-correlator for temporal contrast measurement is proposed, in which spectral broadening based on self-phase modulation, followed by spectral filtering, is used for sampling pulse generation. When the input pulse energy is 5.5 mJ, the device has a measurement dynamic range of 3 × 10−11, a temporal resolution of approximately 200 fs, and a time window of 68 ps in a single shot. In addition, benefiting from the sCMOS camera data acquisition system, the measurement accuracy is self-verified using simply a tilted glass plate in the optical path of the sampling pulse. Since there is only one input beam without spatiotemporal overlap during sampling pulse generation, the setup is stable and easy to adjust.

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Raman, Rohan Kumar, U. C. Sud i Hukum Chandra. "Calibration approach for estimating population total with subsampling of non respondents under single- and two-phase sampling". Communications in Statistics - Theory and Methods 45, nr 10 (18.04.2016): 2842–56. http://dx.doi.org/10.1080/03610926.2014.889164.

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Chen, Hung-Chi, Che-Yu Lu i Li-Ming Huang. "Decoupled Current-Balancing Control With Single-Sensor Sampling-Current Strategy For Two-Phase Interleaved Boost-Type Converters". IEEE Transactions on Industrial Electronics 63, nr 3 (marzec 2016): 1507–18. http://dx.doi.org/10.1109/tie.2015.2498135.

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