期刊文献+
共找到47,881篇文章
< 1 2 250 >
每页显示 20 50 100
Comparison of QT Correction Methods in the Pediatric Population of a Community Hospital: A Retrospective Study
1
作者 Koren Hyogene Kwag Ibrahim Kak +5 位作者 Ying Li Walid Khass Alec McKechnie Oksana Nulman Brande Brown Manoj Chhabra 《Congenital Heart Disease》 SCIE 2024年第1期107-121,共15页
Objective:Accurate measurement of QT interval,the ventricular action potential from depolarization to repolarization,is important for the early detection of Long QT syndrome.The most effective QT correction(QTc)formul... Objective:Accurate measurement of QT interval,the ventricular action potential from depolarization to repolarization,is important for the early detection of Long QT syndrome.The most effective QT correction(QTc)formula has yet to be determined in the pediatric population,although it has intrinsically greater extremes in heart rate(HR)and is more susceptible to errors in measurement.The authors of this study compare six dif-ferent QTc methods(Bazett,Fridericia,Framingham,Hodges,Rautaharju,and a computer algorithm utilizing the Bazett formula)for consistency against variations in HR and RR interval.Methods:Descriptive Retrospective Study.We included participants from a pediatric cardiology practice of a community hospital who had an ECG performed in 2017.All participants were healthy patients with no past medical history and no regular med-ications.Results:ECGs from 95 participants from one month to 21 years of age(mean 9.7 years)were included with a mean HR of 91 beats per minute(bpm).The two-sample paired t-test or Wilcoxon signed-rank test assessed for any difference between QTc methods.A statistically significant difference was observed between every combination of two QTc formulae.The Spearman’s rank correlation analysis explored the QTc/HR and QTc/RR relationships for each formula.Fridericia method was most independent of HR and RR with the lowest absolute value of correlation coefficients.Bazett and Computer had moderate correlations,while Framingham and Rautaharju exhibited strong correlations.Correlations were positive for Bazett and Computer,reflecting results from prior studies demonstrating an over-correction of Bazett at higher HRs.In the linear QTc/HR regression analysis,Bazett had the slope closest to zero,although Computer,Hodges,and Fridericia had comparable values.Alternatively,Fridericia had the linear QTc/RR regression coefficient closest to zero.The Bland-Altman method assessed for bias and the limits of agreement between correction formulae.Bazett and Computer exhibited good agreement with minimal bias along with Framingham and Rautaharju.To account for a possible skewed distri-bution of QT,all the above analyses were also performed excluding the top and bottom 2%of data as sorted by heart rate ranges(N=90).Results from this data set were consistent with those derived from all participants(N=95).Conclusions:Overall,the Fridericia correction method provided the best rate correction in our pedia-tric study cohort. 展开更多
关键词 corrected QT interval QT prolongation long QT syndrome ELECTROCARDIOGRAM retrospective study bazett fridericia FRAMINGHAM hodges rautaharju computer algorithm
下载PDF
Power Factor Correction Rectifier with a Variable Frequency Voltage Source in Vehicular Application 被引量:1
2
作者 Amine Toumi Mohamed Radhouan Hachicha +1 位作者 Moez Ghariani Rafik Neji 《Intelligent Control and Automation》 2014年第1期1-11,共11页
This paper presents a PFCVF (Power Factor Correction) rectifier that uses a variable frequency source for alternators for electric and hybrid vehicles application. In such application, the frequency of the signal in t... This paper presents a PFCVF (Power Factor Correction) rectifier that uses a variable frequency source for alternators for electric and hybrid vehicles application. In such application, the frequency of the signal in the alternator changes according to the vehicle speed, more over the loading effect on the alternator introduces harmonic currents and increases the alternator apparent power requirements. To overcome these problems and aiming more stability and better design of the alternator, a new third harmonic injection technique is proposed. This technique allows to preserve a good THD (Total Harmonic Distortion) of the input source at any frequency and to decrease losses in semiconductors switches, thereby allowing more stability and reducing the apparent power requirements. A comparative study between the standard and the new technique is made and highlights the effectiveness of the new design. A detailed analysis of the proposed topology is presented and simulations as well as experimental results are shown. 展开更多
关键词 ASYNCHRONOUS Machine Control-Oriented Vector of Rotor Flux PWM BOOST Converter HARMONIC Injection Power Factor correction THREE-PHASE RECTIFIER JUNCTION Temperature
下载PDF
Parallel Algorithms for Residue Scaling and Error Correction in Residue Arithmetic
3
作者 Hao-Yung Lo Ting-Wei Lin 《Wireless Engineering and Technology》 2013年第4期198-213,共16页
In this paper, we present two new algorithms in residue number systems for scaling and error correction. The first algorithm is the Cyclic Property of Residue-Digit Difference (CPRDD). It is used to speed up the resid... In this paper, we present two new algorithms in residue number systems for scaling and error correction. The first algorithm is the Cyclic Property of Residue-Digit Difference (CPRDD). It is used to speed up the residue multiple error correction due to its parallel processes. The second is called the Target Race Distance (TRD). It is used to speed up residue scaling. Both of these two algorithms are used without the need for Mixed Radix Conversion (MRC) or Chinese Residue Theorem (CRT) techniques, which are time consuming and require hardware complexity. Furthermore, the residue scaling can be performed in parallel for any combination of moduli set members without using lookup tables. 展开更多
关键词 Chinese REMAINDER Theorem (CRT) ERROR correction ERROR Detection Parallel RESIDUE SCALING RESIDUE Number Systems (RNS) TARGET Race Distance (TRD) TARGET Residue-Digit Difference
下载PDF
Can a Subcapital Osteotomy Fixed with an Intramedullary Locking Plate Correct all Possible Deformities of a Mild to Moderate Hallux Valgus?
4
作者 Michael Vitek Hannes Kugler +1 位作者 Felix Fink Ornella Vitek 《Open Journal of Orthopedics》 2017年第9期254-283,共30页
Background: There are at least 5 very popular methods described for the correction of mild to moderate hallux valgus deformities. Despite of reported and self experienced good results in favorable fitting preoperative... Background: There are at least 5 very popular methods described for the correction of mild to moderate hallux valgus deformities. Despite of reported and self experienced good results in favorable fitting preoperative anatomical conditions of some of these methods;it seems that no one is really satisfying under “difficult” or non favorable preoperative anatomic conditions. How could an optimum operation method for a satisfying correction of a mild to moderate hallux valgus look like? The well known criteria for an optimally satisfying method to achieve full normalization of important forefoot parameters under all conditions should be a lateralization, plantarization and derotation of the Ist metatarsal head and also a normalization of the distal metatarsal articular angle (DMAA) in combination with a soft tissue correction. Methods: In order to achieve this outcome without the disadvantages of shortening or the need for unloading, we developed a new operation technique and new fixation devices. We performed a simple transverse lazy-L subcapital osteotomy and after an additional soft tissue release the Ist metatarsal head was restored to its preplaned optimum position in terms of narrowing the IM angle, plantarization, correction of the hallux valgus angle, derotation of a pronation l malrotation and improvement of the DMAA. Fixation was achieved with an intramedullary angel-stable transfixed 30 mm titanium plate. The rigidity of the implant rendered interfragmental compression or solid bone contact unnecessary. The goal was only an optimal correction. All patients were allowed to ambulate with full weightbearing immediately after the operation. Results: We retrospectively reviewed 346 patients (433 feet) who underwent subcapital osteotomy between May 2007 and December 2011;308 were women and 38 men;their mean age was 65 years. The follow-up investigation was performed on average after 6.5 years (78 months);range 5.5 to 10 years (66 to 120 months). The AOFAS Score improved from 61.18 to 96.82 (t = 55.13, p ° to 4.21° (t = 89.70, p ° to 7.75° (t = 51.68, p ° to 6.61° (t = 29.34, p < 0.001). Minimal shortening of the first metatarsal (0.33 mm) and no recurrence of the deformity was observed. Conclusion: A new access to hallux valgus surgery is presented. Our results show that interfragmental compression between the osteotomy partners or good interfragmental contact is not necessary when a rigid intramedullary fixation device is used. The goal of this approach to hallux valgus surgery was to achieve excellent correction and a very rigid intramedullary angle-stable locked implant. The procedure yielded excellent results and was associated with no recurrence of hallux valgus. 展开更多
关键词 HALLUX VALGUS MILD MODERATE Toe Deformity Lateralization Plantarization Derotation Improvement of DMAA Full Weightbearing HALLUX VALGUS Surgery New Access Lazy-L OSTEOTOMY Soft Tissue correction IM-Angle Angle-Stable Locking Screws INTRAMEDULLARY Locking Plate
下载PDF
Performance analysis and design of MIMO-OFDM system using concatenated forward error correction codes 被引量:3
5
作者 Arun Agarwal Saurabh N.Mehta 《Journal of Central South University》 SCIE EI CAS CSCD 2017年第6期1322-1343,共22页
This work investigates the performance of various forward error correction codes, by which the MIMO-OFDM system is deployed. To ensure fair investigation, the performance of four modulations, namely, binary phase shif... This work investigates the performance of various forward error correction codes, by which the MIMO-OFDM system is deployed. To ensure fair investigation, the performance of four modulations, namely, binary phase shift keying(BPSK), quadrature phase shift keying(QPSK), quadrature amplitude modulation(QAM)-16 and QAM-64 with four error correction codes(convolutional code(CC), Reed-Solomon code(RSC)+CC, low density parity check(LDPC)+CC, Turbo+CC) is studied under three channel models(additive white Guassian noise(AWGN), Rayleigh, Rician) and three different antenna configurations(2×2, 2×4, 4×4). The bit error rate(BER) and the peak signal to noise ratio(PSNR) are taken as the measures of performance. The binary data and the color image data are transmitted and the graphs are plotted for various modulations with different channels and error correction codes. Analysis on the performance measures confirm that the Turbo + CC code in 4×4 configurations exhibits better performance. 展开更多
关键词 bit ERROR rate (BER) convolutional CODE (CC) forward ERROR correction peak signal to noise ratio (PSNR) Turbo CODE
下载PDF
Ballistic Trajectory Extrapolation and Correction of Firing Precision for Multiple Launch Rocket System
6
作者 ZHA Qicheng RUI Xiaoting +1 位作者 WANG Guoping YU Hailong 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI CSCD 2019年第2期232-241,共10页
The research on multiple launch rocket system(MLRS)is now even more demanding in terms of reducing the time for dynamic calculations and improving the firing accuracy,keeping the cost as low as possible.This study emp... The research on multiple launch rocket system(MLRS)is now even more demanding in terms of reducing the time for dynamic calculations and improving the firing accuracy,keeping the cost as low as possible.This study employs multibody system transfer matrix method(MSTMM),to model MLRS.The use of this method provides effective and fast calculations of dynamic characteristics,initial disturbance and firing accuracy.Further,a new method of rapid extrapolation of ballistic trajectory of MLRS is proposed by using the position information of radar tests.That extrapolation point is then simulated and compared with the actual results,which demonstrates a good agreement.The closed?loop fire correction method is used to improve the firing accuracy of MLRS at low cost. 展开更多
关键词 multi-body SYSTEM transfer matrix method(MSTMM) multiple launch ROCKET system(MLRS) dynamic modeling BALLISTIC trajectory EXTRAPOLATION fire correction METHOD
下载PDF
Atmospheric transmission algorithm for pulsed X-rays from high-altitude nuclear detonations based on scattering correction
7
作者 Ding-Han Zhu Xiong Zhang +3 位作者 Xiao-Qiang Li Peng Li Yan-Bin Wang Shuang Zhang 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2024年第3期40-52,共13页
In high-altitude nuclear detonations,the proportion of pulsed X-ray energy can exceed 70%,making it a specific monitoring signal for such events.These pulsed X-rays can be captured using a satellite-borne X-ray detect... In high-altitude nuclear detonations,the proportion of pulsed X-ray energy can exceed 70%,making it a specific monitoring signal for such events.These pulsed X-rays can be captured using a satellite-borne X-ray detector following atmospheric transmission.To quantitatively analyze the effects of different satellite detection altitudes,burst heights,and transmission angles on the physical processes of X-ray transport and energy fluence,we developed an atmospheric transmission algorithm for pulsed X-rays from high-altitude nuclear detonations based on scattering correction.The proposed method is an improvement over the traditional analytical method that only computes direct-transmission X-rays.The traditional analytical method exhibits a maximum relative error of 67.79% compared with the Monte Carlo method.Our improved method reduces this error to within 10% under the same conditions,even reaching 1% in certain scenarios.Moreover,its computation time is 48,000 times faster than that of the Monte Carlo method.These results have important theoretical significance and engineering application value for designing satellite-borne nuclear detonation pulsed X-ray detectors,inverting nuclear detonation source terms,and assessing ionospheric effects. 展开更多
关键词 High-altitude nuclear detonation Atmospheric transmission Pulsed X-rays Scattering correction Analytical method Monte Carlo method
下载PDF
The Evil of ‘Reciting’
8
作者 邢蓓蓓 《科技经济市场》 2007年第8期41-42,共2页
  First of all it is necessary to point out that 'reciting' is the wrong term for what Chinese students are often asked to do when they are learning English. The correct terms are, 'learning by heart'...   First of all it is necessary to point out that 'reciting' is the wrong term for what Chinese students are often asked to do when they are learning English. The correct terms are, 'learning by heart' or 'rote learning'. In this article the term 'rote learning' will be used.…… 展开更多
关键词 ROTE learning language LEARNING First of all it IS necessary to point out that 'reciting' IS the WRONG TERM for what Chinese students ARE often asked to do when they ARE LEARNING English. The correct terms are 'learning by heart' or 'rote learning'. In this article the TERM 'rote learning' will be used.
下载PDF
A Gas Dynamics Method Based on the Spectral Deferred Corrections (SDC) Time Integration Technique and the Piecewise Parabolic Method (PPM)
9
作者 Samet Y. Kadioglu 《American Journal of Computational Mathematics》 2011年第4期303-317,共15页
We present a computational gas dynamics method based on the Spectral Deferred Corrections (SDC) time integration technique and the Piecewise Parabolic Method (PPM) finite volume method. The PPM framework is used to de... We present a computational gas dynamics method based on the Spectral Deferred Corrections (SDC) time integration technique and the Piecewise Parabolic Method (PPM) finite volume method. The PPM framework is used to define edge-averaged quantities, which are then used to evaluate numerical flux functions. The SDC technique is used to integrate solution in time. This kind of approach was first taken by Anita et al in [1]. However, [1] is problematic when it is implemented to certain shock problems. Here we propose significant improvements to [1]. The method is fourth order (both in space and time) for smooth flows, and provides highly resolved discontinuous solutions. We tested the method by solving variety of problems. Results indicate that the fourth order of accuracy in both space and time has been achieved when the flow is smooth. Results also demonstrate the shock capturing ability of the method. 展开更多
关键词 Gas Dynamics Conservation Laws SPECTRAL Deferred corrections (SDC) METHODS Piecewise Parabolic METHOD (PPM) GODUNOV METHODS High Resolution Schemes
下载PDF
Dispersed Wind Power Planning Method Considering Network Loss Correction with Cold Weather
10
作者 Hanpeng Kou Tianlong Bu +2 位作者 Leer Mao Yihong Jiao Chunming Liu 《Energy Engineering》 EI 2024年第4期1027-1048,共22页
In order to play a positive role of decentralised wind power on-grid for voltage stability improvement and loss reduction of distribution network,a multi-objective two-stage decentralised wind power planning method is... In order to play a positive role of decentralised wind power on-grid for voltage stability improvement and loss reduction of distribution network,a multi-objective two-stage decentralised wind power planning method is proposed in the paper,which takes into account the network loss correction for the extreme cold region.Firstly,an electro-thermal model is introduced to reflect the effect of temperature on conductor resistance and to correct the results of active network loss calculation;secondly,a two-stage multi-objective two-stage decentralised wind power siting and capacity allocation and reactive voltage optimisation control model is constructed to take account of the network loss correction,and the multi-objective multi-planning model is established in the first stage to consider the whole-life cycle investment cost of WTGs,the system operating cost and the voltage quality of power supply,and the multi-objective planning model is established in the second stage.planning model,and the second stage further develops the reactive voltage control strategy of WTGs on this basis,and obtains the distribution network loss reduction method based on WTG siting and capacity allocation and reactive power control strategy.Finally,the optimal configuration scheme is solved by the manta ray foraging optimisation(MRFO)algorithm,and the loss of each branch line and bus loss of the distribution network before and after the adoption of this loss reduction method is calculated by taking the IEEE33 distribution system as an example,which verifies the practicability and validity of the proposed method,and provides a reference introduction for decision-making for the distributed energy planning of the distribution network. 展开更多
关键词 Decentralised wind power network loss correction siting and capacity determination reactive voltage control two-stage model manta ray foraging optimisation algorithm
下载PDF
Spectral Correction Method of Multi-Channels Near-Infrared Spectrometer and Applications
11
作者 Tao Pan Weiqun Xu +1 位作者 Hongping Shen Dingzhou Xu 《American Journal of Analytical Chemistry》 2017年第2期158-170,共13页
Near-infrared (NIR) spectrometer based on semiconductor lasers can combine light source and splitter into one, which is an important direction for development of miniature instruments. In order to avoid random interfe... Near-infrared (NIR) spectrometer based on semiconductor lasers can combine light source and splitter into one, which is an important direction for development of miniature instruments. In order to avoid random interference caused by inconsistency between light sources, the novel evaluation indicators for global stability of multi-channels spectral system were proposed based on the correlation between dynamic deviation spectra of any two channels. The NIR analysis of moisture for corn powder samples based on the partial least squares combined with Savitzky-Golay (SG) smoothing was taken as an example, and a spectral correction method for enhancing prediction performance of multi-channels spectral system was further provided using above evaluation indicators. The experiment results showed that the global stability evaluation indicators significantly increased after SG smoothing correction. Meanwhile, the root-mean-square errors of prediction for corn moisture reduced from 0.373 to 0.283 (%), and the correlation coefficient between predicted and actual values was improved from 0.702 to 0.855. The above results indicated that by improving global stability indicators, the prediction ability of multi-channels spectral system can be improved. The proposed method provided a valuable reference for designing multi-channels diminutive spectrometer with high prediction performance, which had significance for large-scale application of NIR technology. 展开更多
关键词 DIMINUTIVE NEAR-INFRARED SPECTROMETER Semiconductor Lasers Global Stability Evaluation Indicators for Multi-Channels SPECTRAL System SPECTRAL correction Savitzky-Golay SMOOTHING
下载PDF
Nanofabrication of 50 nm zone plates through e-beam lithography with local proximity effect correction for x-ray imaging 被引量:3
12
作者 朱静远 张思超 +8 位作者 谢珊珊 徐晨 张丽娟 陶旭磊 任玉琦 王玉丹 邓彪 邰仁忠 陈宜方 《Chinese Physics B》 SCIE EI CAS CSCD 2020年第4期456-461,共6页
High resolution Fresnel zone plates for nanoscale three-dimensional imaging of materials by both soft and hard x-rays are increasingly needed by the broad applications in nanoscience and nanotechnology.When the outmos... High resolution Fresnel zone plates for nanoscale three-dimensional imaging of materials by both soft and hard x-rays are increasingly needed by the broad applications in nanoscience and nanotechnology.When the outmost zone-width is shrinking down to 50 nm or even below,patterning the zone plates with high aspect ratio by electron beam lithography still remains a challenge because of the proximity effect.The uneven charge distribution in the exposed resist is still frequently observed even after standard proximity effect correction(PEC),because of the large variety in the line width.This work develops a new strategy,nicknamed as local proximity effect correction(LPEC),efficiently modifying the deposited energy over the whole zone plate on the top of proximity effect correction.By this way,50 nm zone plates with the aspect ratio from 4:1 up to 15:1 and the duty cycle close to 0.5 have been fabricated.Their imaging capability in soft(1.3 keV)and hard(9 keV)x-ray,respectively,has been demonstrated in Shanghai Synchrotron Radiation Facility(SSRF)with the resolution of 50 nm.The local proximity effect correction developed in this work should also be generally significant for the generation of zone plates with high resolutions beyond 50 nm. 展开更多
关键词 FRESNEL zone PLATES electron beam LITHOGRAPHY LOCAL PROXIMITY effect correction x-ray imaging 50 NM resolution
下载PDF
The Coherent State of the Landau Hamiltonian and the Relativistic Corrections to the Zeeman Effect in He<sup>+</sup>Ions
13
作者 Kunnat Sebastian Wangyao Li 《Journal of Modern Physics》 2020年第3期455-474,共20页
We calculate the energy levels of He+ ion placed in a uniform magnetic field directed perpendicular to the direction of its center of mass (CM) velocity vector, correct to relative order . Our calculations are within ... We calculate the energy levels of He+ ion placed in a uniform magnetic field directed perpendicular to the direction of its center of mass (CM) velocity vector, correct to relative order . Our calculations are within the frame work of an approximately relativistic theory, correct to relative order , of a two-particle composite system bound by electromagnetic forces, and written in terms of the position, momentum and spin operators of the constituent particles as proposed by Krajcik and Foldy, and also by Close and Osborn. Since the He+ ion has a net electric charge, the total or the CM momentum is not conserved and a neat separation of the CM and the internal motion is not possible. What is new in our approach is that, for the basis states in a first order degenerate perturbation theory to calculate the effects of the external magnetic field, we use the direct product of the coherent state of the Landau Hamiltonian of the He+ ion in a uniform magnetic field and of the simultaneous eigenstate of the internal Hamiltonian h, j2, l2, s2 and jz,?where j, l and s are the internal total, orbital and spin angular moments of the He+ ion. The coherent state is an excellent approximation to the expected classical circular motion of the center of mass (CM) of the He+ ion. In addition to the Z2 a2 corrections to the usual nonrelativistic results, including the small corrections due to the nuclear motion, we also obtain corrections which depend on the kinetic energy (ECM ) of the CM circular motion of the He+ ion, in a nontrivial way. Even though these corrections are proportional to , where M is the mass of the He+ ion, and are small for nonrelativistic CM motion, the results should be verifiable in careful experiments. Our results may also have application in astrophysical observations of the spectral lines of He+ ions in magnetized astrophysical objects. 展开更多
关键词 RELATIVISTIC correctionS Zeman Effect Helium Ion in a Magnetic Field Coherent State LANDAU HAMILTONIAN Energy Levels
下载PDF
Adaptation analysis and fusion correction method of CMIP6 precipitation simulation data on the Qinghai-Tibetan Plateau
14
作者 PENG Hao QIN Dahui +3 位作者 WANG Zegen ZHANG Menghan YANG Yanmei YONG Zhiwei 《Journal of Mountain Science》 SCIE CSCD 2024年第2期555-573,共19页
In order to obtain more accurate precipitation data and better simulate the precipitation on the Tibetan Plateau,the simulation capability of 14 Coupled Model Intercomparison Project Phase 6(CMIP6)models of historical... In order to obtain more accurate precipitation data and better simulate the precipitation on the Tibetan Plateau,the simulation capability of 14 Coupled Model Intercomparison Project Phase 6(CMIP6)models of historical precipitation(1982-2014)on the Qinghai-Tibetan Plateau was evaluated in this study.Results indicate that all models exhibit an overestimation of precipitation through the analysis of the Taylor index,temporal and spatial statistical parameters.To correct the overestimation,a fusion correction method combining the Backpropagation Neural Network Correction(BP)and Quantum Mapping(QM)correction,named BQ method,was proposed.With this method,the historical precipitation of each model was corrected in space and time,respectively.The correction results were then analyzed in time,space,and analysis of variance(ANOVA)with those corrected by the BP and QM methods,respectively.Finally,the fusion correction method results for each model were compared with the Climatic Research Unit(CRU)data for significance analysis to obtain the trends of precipitation increase and decrease for each model.The results show that the IPSL-CM6A-LR model is relatively good in simulating historical precipitation on the Qinghai-Tibetan Plateau(R=0.7,RSME=0.15)among the uncorrected data.In terms of time,the total precipitation corrected by the fusion method has the same interannual trend and the closest precipitation values to the CRU data;In terms of space,the annual average precipitation corrected by the fusion method has the smallest difference with the CRU data,and the total historical annual average precipitation is not significantly different from the CRU data,which is better than BP and QM.Therefore,the correction effect of the fusion method on the historical precipitation of each model is better than that of the QM and BP methods.The precipitation in the central and northeastern parts of the plateau shows a significant increasing trend.The correlation coefficients between monthly precipitation and site-detected precipitation for all models after BQ correction exceed 0.8. 展开更多
关键词 GCM CMIP6 Precipitation correction BP-QM fusion correction Spatio-temporal characteristics
下载PDF
Real-time model correction using Kalman filter for Raman-controlled cell culture processes
15
作者 Xiaoxiao Dong Zhuohong He +5 位作者 Xu Yan Dong Gao Jingyu Jiao Yan Sun Haibin Wang Haibin Qu 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2024年第6期251-260,共10页
Raman spectroscopy has found extensive use in monitoring and controlling cell culture processes.In this context,the prediction accuracy of Raman-based models is of paramount importance.However,models established with ... Raman spectroscopy has found extensive use in monitoring and controlling cell culture processes.In this context,the prediction accuracy of Raman-based models is of paramount importance.However,models established with data from manually fed-batch cultures often exhibit poor performance in Raman-controlled cultures.Thus,there is a need for effective methods to rectify these models.The objective of this paper is to investigate the efficacy of Kalman filter(KF)algorithm in correcting Raman-based models during cell culture.Initially,partial least squares(PLS)models for different components were constructed using data from manually fed-batch cultures,and the predictive performance of these models was compared.Subsequently,various correction methods including the PLS-KF-KF method proposed in this study were employed to refine the PLS models.Finally,a case study involving the auto-control of glucose concentration demonstrated the application of optimal model correction method.The results indicated that the original PLS models exhibited differential performance between manually fed-batch cultures and Raman-controlled cultures.For glucose,the root mean square error of prediction(RMSEP)of manually fed-batch culture and Raman-controlled culture was 0.23 and 0.40 g·L^(-1).With the implementation of model correction methods,there was a significant improvement in model performance within Raman-controlled cultures.The RMSEP for glucose from updating-PLS,KF-PLS,and PLS-KF-KF was 0.38,0.36 and 0.17 g·L^(-1),respectively.Notably,the proposed PLS-KF-KF model correction method was found to be more effective and stable,playing a vital role in the automated nutrient feeding of cell cultures. 展开更多
关键词 Raman spectroscopy Model correction Algorithm Model-predictive control BIOPROCESS
下载PDF
The application of the strip-shaped cymba conchae orthosis in the nonsurgical correction of complex auricular deformity
16
作者 Huijuan Xu Shaoguang Ding +6 位作者 Fei Zhang Zhifeng Zhang Xiangyu Chen Mingyang Li Haitao Yang Fugen Han Hongjian Liu 《Journal of Otology》 CAS CSCD 2024年第1期24-29,共6页
Objective: This study aims to evaluate the efficacy and safety of using a strip-shaped cymba conchae orthosis for the nonsurgical correction of complex auricular deformities. Methods: Clinical data were collected from... Objective: This study aims to evaluate the efficacy and safety of using a strip-shaped cymba conchae orthosis for the nonsurgical correction of complex auricular deformities. Methods: Clinical data were collected from 2020 to 2021 for 6 patients who underwent correction using a stripshaped cymba conchae orthosis. The indications, corrective effects, and complications associated with use of the orthosis were analyzed. Results: There were four indications for treatment: cryptotia with helix adhesion;cryptotia with grade I microtia;cryptotia with excessive helix thickness;and auricular deformity beyond the treatment time window(≥6 months). Excellent corrective effects were observed in all 6 patients. Complications occurred in one patient, who recovered after symptomatic treatment. Conclusion: The use of a strip-shaped cymba conchae orthosis alone or combined with a U-shaped helix orthosis presents a feasible approach for correcting complex auricular deformities or deformities beyond the treatment time window in pediatric patients. 展开更多
关键词 Cymba conchae Auricular deformity Cryptotia Nonsurgical correction ORTHOSIS
下载PDF
Methodology for local correction of the heights of global geoid models to improve the accuracy of GNSS leveling
17
作者 Stepan Savchuk Alina Fedorchuk 《Geodesy and Geodynamics》 EI CSCD 2024年第1期42-49,共8页
At present,one of the methods used to determine the height of points on the Earth’s surface is Global Navigation Satellite System(GNSS)leveling.It is possible to determine the orthometric or normal height by this met... At present,one of the methods used to determine the height of points on the Earth’s surface is Global Navigation Satellite System(GNSS)leveling.It is possible to determine the orthometric or normal height by this method only if there is a geoid or quasi-geoid height model available.This paper proposes the methodology for local correction of the heights of high-order global geoid models such as EGM08,EIGEN-6C4,GECO,and XGM2019e_2159.This methodology was tested in different areas of the research field,covering various relief forms.The dependence of the change in corrected height accuracy on the input data was analyzed,and the correction was also conducted for model heights in three tidal systems:"tide free","mean tide",and"zero tide".The results show that the heights of EIGEN-6C4 model can be corrected with an accuracy of up to 1 cm for flat and foothill terrains with the dimensionality of 1°×1°,2°×2°,and 3°×3°.The EGM08 model presents an almost identical result.The EIGEN-6C4 model is best suited for mountainous relief and provides an accuracy of 1.5 cm on the 1°×1°area.The height correction accuracy of GECO and XGM2019e_2159 models is slightly poor,which has fuzziness in terms of numerical fluctuation. 展开更多
关键词 GNSS leveling Global geoid model Gravity anomaly Weight data correcting data
下载PDF
Balancing act:The dilemma of rapid hyperglycemia correction in diabetes management
18
作者 Ke-Xin Zhang Cheng-Xia Kan Xiao-Dong Sun 《World Journal of Diabetes》 SCIE 2024年第2期129-132,共4页
The global diabetes surge poses a critical public health challenge,emphasizing the need for effective glycemic control.However,rapid correction of chronic hyperglycemia can unexpectedly trigger microvascular complicat... The global diabetes surge poses a critical public health challenge,emphasizing the need for effective glycemic control.However,rapid correction of chronic hyperglycemia can unexpectedly trigger microvascular complications,necessitating a reevaluation of the speed and intensity of glycemic correction.Theories suggest swift blood sugar reductions may cause inflammation,oxidative stress,and neurovascular changes,resulting in complications.Healthcare providers should cautiously approach aggressive glycemic control,especially in long-standing,poorly controlled diabetes.Preventing and managing these complications requires a personalized,comprehensive approach with education,monitoring,and interdisciplinary care.Diabetes management must balance short and longterm goals,prioritizing overall well-being.This editorial underscores the need for a personalized,nuanced approach,focusing on equilibrium between glycemic control and avoiding overcorrection. 展开更多
关键词 DIABETES Hyperglycemia correction Management Microvascular complications Glucose control
下载PDF
Chord length sampling correction analysis for dispersion fuel in Monte Carlo simulation
19
作者 Zhao-Yu Liang Ding She +1 位作者 Yu-Tong Wen Lei Shi 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2024年第4期57-64,共8页
Dispersion fuels,knowned for their excellent safety performance,are widely used in advanced reactors,such as hightemperature gas-cooled reactors.Compared with deterministic methods,the Monte Carlo method has more adva... Dispersion fuels,knowned for their excellent safety performance,are widely used in advanced reactors,such as hightemperature gas-cooled reactors.Compared with deterministic methods,the Monte Carlo method has more advantages in the geometric modeling of stochastic media.The explicit modeling method has high computational accuracy and high computational cost.The chord length sampling(CLS)method can improve computational efficiency by sampling the chord length during neutron transport using the matrix chord length?s probability density function.This study shows that the excluded-volume effect in realistic stochastic media can introduce certain deviations into the CLS.A chord length correction approach is proposed to obtain the chord length correction factor by developing the Particle code based on equivalent transmission probability.Through numerical analysis against reference solutions from explicit modeling in the RMC code,it was demonstrated that CLS with the proposed correction method provides good accuracy for addressing the excludedvolume effect in realistic infinite stochastic media. 展开更多
关键词 Stochastic media Monte Carlo Chord length sampling Excluded-volume effect Chord length correction
下载PDF
Single Photon Detection Technology in Underwater Wireless Optical Communication:Modulation Modes and Error Correction Coding Analysis
20
作者 GAI Lei LI Wendong WANG Guoyu 《Journal of Ocean University of China》 CAS CSCD 2024年第2期405-414,共10页
This study explores the application of single photon detection(SPD)technology in underwater wireless optical communication(UWOC)and analyzes the influence of different modulation modes and error correction coding type... This study explores the application of single photon detection(SPD)technology in underwater wireless optical communication(UWOC)and analyzes the influence of different modulation modes and error correction coding types on communication performance.The study investigates the impact of on-off keying(OOK)and 2-pulse-position modulation(2-PPM)on the bit error rate(BER)in single-channel intensity and polarization multiplexing.Furthermore,it compares the error correction performance of low-density parity check(LDPC)and Reed-Solomon(RS)codes across different error correction coding types.The effects of unscattered photon ratio and depolarization ratio on BER are also verified.Finally,a UWOC system based on SPD is constructed,achieving 14.58 Mbps with polarization OOK multiplexing modulation and 4.37 Mbps with polarization 2-PPM multiplexing modulation using LDPC code error correction. 展开更多
关键词 error correction coding modulation mode single photon detection underwater communication wireless optical communication
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部