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Real-Time 3D Ultrasound Imaging System Based on a Hybrid Reconstruction Algorithm

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Chinese Journal of Electronics 2024年第1期33卷 245-255页

作者： Yifei lyu Yu SHEN Mingbo ZHANG Junchen WANG School of Mechanical Engineering and Automation Beihang University The First Medical Center General Hospital of Chinese PLA

As a safe and convenient imaging technology in clinical routine diagnosis, ultrasound imaging can provide real-time 2D images of internal tissues and organs. To realize real-time 3D image reconstruction, pixel nearest neighbor interpolation(PNN) reconstruction algorithm and Bezier interpolation algorithm are combined into a hybrid reconstruction algorithm. On this basis, a real-time interactive 3D ultrasound imaging system is *** temporal calibration and spatial calibration, the six degrees of freedom poses of 2D ultrasound images can be accurately collected. The 3D volume reconstructed by the proposed 3D reconstruction algorithm is visualized by volume rendering. A multi-thread software system allows parallel operation of data acquisition, 3D reconstruction,volume visualization and other functions. 3D imaging experiments on a 3D printing femur model, a neck phantom and the neck of human volunteers were performed for systematic evaluation. When the reconstruction voxel size was set to be(0.53 mm3, 1.03 mm3, 1.53 mm3), the reconstruction errors of the femur and trachea model were respectively(0.23 mm, 0.31 mm, 0.56 mm) and(0.62 mm, 0.88 mm, 1.41 mm). Clinical feasibility was demonstrated by application of the 3D ultrasound imaging on the neck of human volunteers.

关键词： Interpolation Three-dimensional displays Ultrasonic imaging Imaging Data visualization Reconstruction algorithms Real-time systems

Experimental study on the activation of coal gasification fly ash from industrial CFB gasifiers

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Chinese Journal of Chemical Engineering 2024年第1期65卷 8-18页

作者： Qiyao Yang Xiaobin Qi Qinggang lyu Zhiping Zhu North China Electric Power University Beijing 102206China Institute of Engineering Thermophysics Chinese Academy of SciencesBeijing 100190China Shanxi Key Laboratory of Coal Flexible Combustion and Thermal Conversion Datong 037000China University of Chinese Academy of Sciences Beijing 100049China Shanxi Engineering Research Center of Coal Clean Efficient Combustion and GasificationDatong 037000China

Coal gasification fly ash(CGFA)is an industrial solid waste from the coal circulating fluidized bed(CFB)gasification process,and it needs to be effectively disposed to achieve sustainable development of the *** realize the application of CGFA as a precursor of porous carbon materials,the physicochemical properties of three kinds of CGFA from industrial CFB gasifiers are ***,the activation potential of CGFA is acquired via steam activation experiments in a tube furnace ***,the fluidization activation technology of CGFA is practiced in a bench-scale CFB test rig,and its advantages are *** results show that CGFA is characterized by a high carbon content in the range of 54.06%–74.09%,an ultrafine particle size(d50:16.3–26.1 μm),and a relatively developed pore structure(specific surface area SSA:139.29–551.97 m^(2)·g^(-1)).The proportion of micropores in CGFA increases gradually with the coal *** activation experiments show that the pore development of CGFA mainly includes three stages:initial pore development,dynamic equilibrium between micropores and mesopores and pore *** SSA of lignite fly ash(LFA),subbituminous fly ash(SBFA)and anthracite fly ash(AFA)is maximally increased by 105%,13%and 72%after steam activation;the order of the largest carbon reaction rate and decomposition ratio of steam among the three kinds of CGFA is SBFA>LFA>*** the ratio of oxygen to carbon during the fluidization activation of LFA is from 0.09 to 0.19,the carbon conversion ratio increases from 14.4%to 26.8%and the cold gas efficiency increases from 6.8%to 10.2%.The SSA of LFA increases by up to 53.9%during the fluidization activation process,which is mainly due to the mesoporous *** to steam activation in a tube furnace reactor,fluidization activation takes an extremely short time(seconds)to achieve the same activation *** is expected to further improve the activation effect of LFA by regulating the carbo

关键词： Circulating fluidized bed Coal gasification fly ash Steam activation Pore structure evolution Fluidization activation

Efficient unequal error protection for online fountain codes

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Journal of Systems Engineering and Electronics 2024年第2期35卷 286-293页

作者： SHI Pengcheng WANG Zhenyong LI Dezhi lyu Haibo School of Electronics and Information Engineering Harbin Institute of TechnologyHarbin 150001China Shenzhen Academy of Aerospace Technology Shenzhen 518057China

In this paper,an efficient unequal error protection(UEP)scheme for online fountain codes is *** the buildup phase,the traversing-selection strategy is proposed to select the most important symbols(MIS).Then,in the completion phase,the weighted-selection strategy is applied to provide low *** performance of the proposed scheme is analyzed and compared with the existing UEP online fountain *** results show that in terms of MIS and the least important symbols(LIS),when the bit error ratio is 10-4,the proposed scheme can achieve 85%and 31.58%overhead reduction,respectively.

关键词： online fountain code random graph unequal error protection(UEP) rateless code

Short-time maritime target detection based on polarization scattering characteristics

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Journal of Systems Engineering and Electronics 2024年第1期35卷 55-64页

作者： CHEN Shichao LUO Feng TIAN Min lyu Wanghan College of Computer and Information Engineering(College of Artificial Intelligence) Nanjing Tech UniversityNanjing 211816China Hangzhou Institute of Technology Xidian UniversityHangzhou 311200China

In this paper,a detection method combining Cameron decomposition based on polarization scattering characteristics in sea clutter background is ***,the Cameron decomposition is exploited to fuse the radar echoes of full polarization channels at the data *** to the artificial material structure on the surface of the target,it can be shown that the non-reciprocity of the target cell is stronger than that of the clutter ***,based on the analysis of the decomposition results,a new feature with scattering geometry characteristics in polarization domain,denoted as Cameron polarization decomposition scattering weight(CPD-SW),is extracted as the test statistic,which can achieve more detailed descriptions of the clutter scattering characteristics utilizing the difference between their scattering ***,the superiority of the proposed CPD-SW detector over traditional detectors in improving detection performance is verified by the IPIX measured dataset,which has strong stability under short-time observation in threshold detection and can also improve the separability of feature space zin anomaly detection.

关键词： sea clutter small target radar detection Cameron decomposition characteristics analysis

Effects of Co-Firing Biomass and Pulverized Coal on NO Reduction in Cement Precalciner

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Journal of Thermal Science 2024年第2期33卷 751-760页

作者： LI Pengpeng REN Qiangqiang lyu Qinggang WANG Mingyue School of Energy Power and Mechanical Engineering North China Electric Power UniversityBeijing102206China Institute of Engineering Thermophysics Chinese Academy of SciencesBeijing100190China University of Chinese Academy of Sciences Beijing100049China

With increased awareness of the large-scale CO_(2) emissions from the cement industry,there has been growing focus on greenhouse gas reduction *** all these strategies,fuel substitution using biomass fuel is extensively used to achieve CO_(2) zero-emission in cement *** to the avoidable high-temperature-generated thermal nitrogen oxides during cement production,research on the impact of biomass application on nitrogen oxide emissions shall be carried *** types of biomass fuel and bituminous coal were used to investigate the NO reduction characteristics under different O_(2) concentrations on experimental *** was found that the change in oxygen concentration from 9% to 1% increased the reaction time in the reactor from 555 s to 1425 s,which means the increase in oxygen concentration can lead to shorter reaction time,and correspondingly,the existing time of nitric oxide in the flue gas is also shortened,but the peak value of nitric oxide rises,during the process of O_(2) concentration changing from 1% to 9%,the peak NO concentration in the flue gas increased from 5.4×10^(-5) to 1.05×10^(-4).An increase in O_(2) concentration greatly reduces the total reduction of NO and the minimum change in NO *** peak NO concentration during the combustion process of corn stalk is 4.56×10^(-4),which is approximately 7 times higher than that of coal,and it is caused by the high amount of N in corn *** addition of raw meal has an inhibitory effect on the reduction of NO:after adding raw meal,the effective reduction time of NO by fuel decreased by about 20%,but adding raw meal raises CO_(2) concentration of fuel gas in the early stage of reaction.

关键词： cement precalciner biomass fuel coal NO reduction co-firing

Numerical study on the cavity dynamics for vertical water entries of twin spheres

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Defence Technology（防务技术） 2024年第2期32卷 459-472页

作者： Xu Wang Xujian lyu Ruisheng Sun Dongdong Tang School of Energy and Power Engineering Nanjing University of Science and TechnologyNanjing210094China Shanghai Institute of Spacecraft Equipment Shanghai200240China

In this study, a three dimensional(3D) numerical model of six-degrees-of-freedom(6DOF) is applied to simulate the water entries of twin spheres side-by-side at different lateral distances and time *** turbulence structure is described using the shear-stress transport k-ω(SST k-ω) model, and the volume of fluid(VOF) method is used to track the complex air-liquid interface. The motion of spheres during water entry is simulated using an independent overset grid. The numerical model is verified by comparing the cavity evolution results from simulations and experiments. Numerical results reveal that the time interval between the twin water entries evidently affects cavity expansion and contraction behaviors in the radial direction. However, this influence is significantly weakened by increasing the lateral distance between the two spheres. In synchronous water entries, pressure is reduced on the midline of two cavities during surface closure, which is directly related to the cavity volume. The evolution of vortexes inside the two cavities is analyzed using a velocity vector field, which is affected by the lateral distance and time interval of water entries.

关键词： Twin water entries Side-by-side Cavity Numerical simulation

Risk Factors Asscociated with Hypokalemia during Postanesthesia Recovery and Its Impact on Outcomes in Gynecological Patients:A Propensity Score Matching Study

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Current Medical Science 2024年第2期44卷 441-449页

作者： bei-bei WANG Li HU Xin-yue HU Dong HAN Jing WU Department of Anesthesiology Union HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan430022China Institute of Anesthesia and Critical Care Medicine Union HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan430022China Key Laboratory of Anesthesiology and Resuscitation(Huazhong University of Science and Technology) Ministry of EducationWuhan430022China

Objective:This study aimed to explore the risk factors and outcomes of hypokalemia during the recovery period from anesthesia in the gynecological ***:This retrospective cohort study included 208 patients who underwent gynecological surgery at our institution between January 2021 and March *** were collected for each patient,including demographics,disease status,surgical data,and clinical *** bowel preparation,postoperative gastrointestinal function,and electrolyte levels were compared between the two groups using propensity score matching(PSM).Results:The incidence of hypokalemia(serum potassium level<3.5 mmol/L)during the recovery period from anesthesia was approximately 43.75%.After PSM,oral laxative use(96.4%vs.82.4%,P=0.005),the number of general enemas(P=0.014),and the rate of≥2 general enemas(92.9%vs.77.8%,P=0.004)were identified as risk factors for hypokalemia,which was accompanied by decreased PaCO_(2) and *** were no significant differences in postoperative gastrointestinal outcomes,such as the time to first flatus or feces,the I-FEED score(a scoring system was created to evaluate impaired postoperative gastrointestinal function),or postoperative recovery outcomes,between the hypokalemia group and the normal serum potassium ***:Hypokalemia during postanesthesia recovery period occurred in 43.75%of gynecological patients,which resulted from preoperative mechanical bowel preparation;however,it did not directly affect clinical outcomes,including postoperative gastrointestinal function,postoperative complications,and length of hospital stay.

关键词： hypokalemia gynecological surgery postanesthesia recovery perioperative electrolyte disturbances postoperative recovery

Application-driven development of a thermal imaging-based cabin occupant thermal sensation assessment model and its validation

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Building Simulation 2024年第8期17卷 1401-1417页

作者： Junmeng lyu Yuxin Yang Yongxiang Shi Zhiwei Lian Department of Architecture School of DesignShanghai Jiao Tong UniversityShanghaiChina

The air conditioning(A/C)of cabins allows for customized control,but manual adjustments may distract drivers,as well as result in energy *** existing thermal sensation models require complex inputs,which are challenging to gather whilst *** address this issue,this study developed a non-contact thermal sensation model for cabin occupants based on thermal imaging *** collect actual data used for modeling,an outdoor subject experiment was *** this study,initial training was conducted to compare the performance of six algorithms in building the model,with random forests algorithm showing the best ***,this study employed the recursive feature elimination(RFE)method with cross-validation algorithm for identifying the key *** the end,the model was retrained using the selected *** model that incorporated both environmental parameters and facial-temperature features demonstrated the best performance,with an R2 of 0.659 on the test *** the hard-to-measure windshield surface temperature resulted in a slight reduction in accuracy,yielding an R2 of *** verify the generalizability of the model,this study further conducted independent validation *** selected model,which exhibited a mean absolute error(MAE)of less than 0.4 in thermal sensation units,was proven to be highly *** results can offer new solutions for automatic control of cabin A/C.

关键词： model assessment thermal imaging vehicle air conditioner thermal sensation transient cabin indoor environment

Process synthesis for the separation of coal-to-ethanol products

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Chinese Journal of Chemical Engineering 2024年第5期69卷 263-278页

作者： Qingping Qu Daoyan Liu Hao lyu Jinsheng Sun School of Chemical Engineering and Technology Tianjin UniversityTianjin 300072China Sustainable Energy and Environment Thrust The Hong Kong University of Science and Technology(Guangzhou)Nansha 511400China

The coal-to-ethanol process,as the clean coal utilization,faces challenges from the energy-intensive distillation that separates multi-component effluents for pure *** to at least eight columns,the synthesis of the ethanol distillation system is impracticable for exhaustive comparison and difficult for conventional superstructure-based optimization as rigorous models are *** work adopts a superstructure-based framework,which combines the strategy that adaptively selects branches of the state-equipment network and the parallel stochastic algorithm for process ***-performance computing significantly reduces time consumption,and the adaptive strategy substantially lowers the complexity of the superstructure ***,parallel computing,elite search,population redistribution,and retention strategies for irrelevant parameters are used to improve the optimization efficiency *** optimization terminates after 3000 generations,providing a flowsheet solution that applies two non-sharp splitting options in its distillation *** a result,the 59-dimension superstructure-based optimization was solved efficiently via a differential evolution algorithm,and a high-quality solution with a 28.34%lower total annual cost than the benchmark was ***,the solution of the superstructure-based optimization is comparable to that obtained by optimizing a single specific configuration one by *** indicates that the superstructure-based optimization that combines the adaptive strategy can be a promising approach to handling the process synthesis of large-scale and complex chemical processes.

关键词： Coal-to-ethanol Process synthesis Superstructure-based optimization Differential evolution algorithm Distillation