BACKGROUND Among the most frequent hip fractures are trochanteric fractures,which usually occur from low-energy trauma like minor falls,especially in older people with osteoporotic bones.AIM To evaluate the treatment ...BACKGROUND Among the most frequent hip fractures are trochanteric fractures,which usually occur from low-energy trauma like minor falls,especially in older people with osteoporotic bones.AIM To evaluate the treatment efficacy of dynamic condylar screws(DCS)and proximal femoral nails(PFN)for unstable intertrochanteric fractures.METHODS To find pertinent randomized controlled trials and retrospective observational studies comparing PFN with DCS for the management of unstable femoral intertrochanteric fractures,a thorough search was carried out.For research studies published between January 1996 and April 2024,PubMed,EMBASE,Scopus,Web of Science,Cochrane Library,and Google Scholar were all searched.The complete texts of the papers were retrieved,vetted,and independently examined by two investigators.Disputes were settled by consensus,and any disagreements that persisted were arbitrated by a third author.RESULTS This study included six articles,comprising a total of 173 patients.Compared to the DCS,the PFN had a shorter operation time[mean difference(MD):-41.7 min,95%confidence interval(95%CI):-63.04 to-20.35,P=0.0001],higher success rates with closed reduction techniques[risk ratio(RR):34.05,95%CI:11.12-104.31,P<0.00001],and required less intraoperative blood transfusion(MD:-1.4 units,95%CI:-1.80 to-1.00,P<0.00001).Additionally,the PFN showed shorter fracture union time(MD:-6.92 wk,95%CI:-10.27 to-3.57,P<0.0001)and a lower incidence of reoperation(RR:0.37,95%CI:0.17-0.82,P=0.01).However,there was no discernible variation regarding hospital stay,implant-related complications,and infections.CONCLUSION Compared to DCS,PFN offers shorter operative times,reduces the blood transfusions requirements,achieves higher closed reduction success,enables faster fracture healing,and lowers reoperation incidence.展开更多
The US market for women's synthetic trou-sers is characterised by intense competition,with Asian countries playing a dominant role in exports.This analysis delves into the market performance of leading exporters,a...The US market for women's synthetic trou-sers is characterised by intense competition,with Asian countries playing a dominant role in exports.This analysis delves into the market performance of leading exporters,assessing key indicators such as export values,revealed comparative advantage(RCA).unit value realisation(UVR),and the effect of tariff rates.展开更多
This paper presents dynamic-behavior comparisons and related forensic analyses of a submerged floating tunnel(SFT)between numerical simulation and physical experiment under regular and irregular waves.The experiments ...This paper presents dynamic-behavior comparisons and related forensic analyses of a submerged floating tunnel(SFT)between numerical simulation and physical experiment under regular and irregular waves.The experiments are conducted in the 3Dwave tank with 1:33.3 scale,and the corresponding coupled time-domain simulation tool is devised for comparison.The entire SFT systemconsists of a long concrete tunnel and 12 tubular aluminummooring lines.Two numerical simulation models,the Cummins equation with 3D potential theory including second-order wave-body interaction effects and the much simpler Morison-equation-based formula with the lumped-massbased line model,are designed and compared.Forensic analyses for mooring-line adjustments in the simulation are carried out in view of the best representation of the physical system.After that,the measured pre-tension distribution and systemstiffness of twelvemooring lines arewell reproduced in the numericalmodel.Subsequently,the dynamic responses and mooring tensions of the SFT are compared under regular and irregular waves.The measured and simulated results coincide reasonably well for both regular-and irregular-wave conditions.展开更多
A numerical study of ship-to-ship interaction forces is performed using a commercial CFD code,and the results are compared with experimental data and with the results of a panel method analysis.Two ship models have be...A numerical study of ship-to-ship interaction forces is performed using a commercial CFD code,and the results are compared with experimental data and with the results of a panel method analysis.Two ship models have been used in the interaction forces analysis:a tug and a tanker,advancing parallel to each other with different lateral distances and two different values of the fluid depth.Computations are carried out with four different flow models:inviscid and viscous flow with the free surface modeled as a rigid wall and inviscid and viscous flow with the deformable free surface.A fair agreement was obtained with available experimental data and results obtained by panel method.The influence of viscosity in the computations is found to be comparatively weak,while the wavemaking effects may be important,at small magnitude of the horizontal clearance.展开更多
A low-power,high-speed dynamic comparator with the addition of a cross-coupled pair in the pre-amplifier stage,followed by a strong-arm latch,is presented.The proposed modification increases the pre-amplifier’s diffe...A low-power,high-speed dynamic comparator with the addition of a cross-coupled pair in the pre-amplifier stage,followed by a strong-arm latch,is presented.The proposed modification increases the pre-amplifier’s differential and common-mode gains,improving the latch’s differential and common-mode input voltage,resulting in faster regeneration with 22%speed improvement as compared to conventional comparator at small input differential voltages(V_(i,id)).The proposed technique boosts the comparator’s speed and helps achieve 21%lower energy per conversion delay product(EDP)compared to the literature.Analytical modeling of the delay that proves the improvement in the speed of the proposed comparator is also presented and verified with the simulation results.The proposed comparator’s delay is insensitive to the common-mode voltage(V_(i,cm)).The proposed comparator is fabricated in 180-nm CMOS technology and measurement shows less than 160 ps relative CLK-Q delay with 81 fJ.ns EDP and 0.8 mV input-referred rms noise with 1.8 V supply.To demonstrate the scalability of the proposed technique to advanced technology nodes,the proposed design is also simulated in 65-nm CMOS technology with a 1.1 V supply for 5 GHz frequency.For V_(i,cm) of 0.3 V and V_(i,id) of 1 mV and 10 mV,the proposed comparator exhibits a 40.69 ps and 32.41 ps delay and has 3.74 fJ.ns and 2.78 fJ.ns EDP respectively.展开更多
基于高速低功耗混合应用场景下对互补金属氧化物半导体(Complementary Metal Oxide Semiconductor,CMOS)比较器性能的综合需求,系统研究其结构优化设计。阐述动态比较器在响应速度、功耗控制、输入失调与噪声抑制等方面的关键技术,介绍...基于高速低功耗混合应用场景下对互补金属氧化物半导体(Complementary Metal Oxide Semiconductor,CMOS)比较器性能的综合需求,系统研究其结构优化设计。阐述动态比较器在响应速度、功耗控制、输入失调与噪声抑制等方面的关键技术,介绍前置放大器、电源控制、闭环反馈及偏置电路的协同优化策略。结合65 nm CMOS工艺下的仿真测试结果,分析主要性能指标在典型工况下的表现,验证所提结构的可实现性与工程适应性。结果表明,该设计能够在低功耗约束下保持高速响应。展开更多
Fluid dynamics simulation is often repeated under varying conditions.This leads to a generation of large amounts of results,which are difficult to compare.To compare results under different conditions,it is effective ...Fluid dynamics simulation is often repeated under varying conditions.This leads to a generation of large amounts of results,which are difficult to compare.To compare results under different conditions,it is effective to overlap the streamlines generated from each condition in a single three-dimensional space.Streamline is a curved line,which represents a wind flow.This paper presents a technique to automatically select and visualize important streamlines that are suitable for the comparison of the simulation results.Additionally,we present an implementation to observe the flow fields in virtual reality spaces.展开更多
A novel fully differential high speed high resolution low offset CMOS dynamic comparator has been implemented in the SMIC 0.18 μm process used for a sample-and-hold amplifier （SHA）-less pipelined analog-to-digital ...A novel fully differential high speed high resolution low offset CMOS dynamic comparator has been implemented in the SMIC 0.18 μm process used for a sample-and-hold amplifier （SHA）-less pipelined analog-to-digital converters （ADC）. Based on the analysis and optimization between delay time and offset, an enhanced reset architecture with transmission gate was introduced to speed up the comparison and reset procedure. Four inputs with two cross coupled differential pairs, reconstituted bias circuit for tail current transistor and common centroid layouts make the comparator more robust against mismatch and process variations. The simulation results demonstrate that the proposed design achieves 1 mV sensitivity at 2.2 GHz sampling rate with a power consumption of 510 μW, while the mean offset voltage is equal to 10.244 mV.展开更多
Increasing importance of heat transfer in chemical engineering science causes that investigation in the field of enhancement techniques is always one of the up-to-date topics for study.In the current comparative analy...Increasing importance of heat transfer in chemical engineering science causes that investigation in the field of enhancement techniques is always one of the up-to-date topics for study.In the current comparative analysis,the thermal enhancement and friction penalty are explored numerically for curved tubes via twisted configuration.To accomplish this,three common geometries namely helical,serpentine,and Archimedes spiral,are considered at different coil-pitches and twist-pitches as well as five Reynolds numbers in the laminar flow regime.The results exhibit noticeable enhancements(up to 60%)in the thermal performance of the twisted cases as compared to the smooth cases.The highest increases are recorded for the serpentine case,followed by the helical and spiral cases.It is found that these enhancements vary via coil-pitch and twist-pitch.Increasing coil-pitch and twist-pitch augments both heat transfer coefficient and pressure drop in all curved-twisted tubes,however,the effects of twist-pitch are more pronounced.To predict Nusselt number and friction factor,new correlations are also proposed.The maximum deviations of the predicted results compared to the simulated data are within±5%.展开更多
The aim of this study is to identify the functions and states of the brains according to the values of the complexity measure of the EEG signals. The EEG signals of 30 normal samples and 30 patient samples are collect...The aim of this study is to identify the functions and states of the brains according to the values of the complexity measure of the EEG signals. The EEG signals of 30 normal samples and 30 patient samples are collected. Based on the preprocessing for the raw data, a computational program for complexity measure is compiled and the complexity measures of all samples are calculated. The mean value and standard error of complexity measure of control group is as 0.33 and 0.10, and the normal group is as 0.53 and 0.08. When the confidence degree is 0.05, the confidence interval of the normal population mean of complexity measures for the control group is (0.2871,0.3652), and (0.4944,0.5552) for the normal group. The statistic results show that the normal samples and patient samples can be clearly distinguished by the value of measures. In clinical medicine, the results can be used to be a reference to evaluate the function or state, to diagnose disease, to monitor the rehabilitation progress of the brain.展开更多
文摘BACKGROUND Among the most frequent hip fractures are trochanteric fractures,which usually occur from low-energy trauma like minor falls,especially in older people with osteoporotic bones.AIM To evaluate the treatment efficacy of dynamic condylar screws(DCS)and proximal femoral nails(PFN)for unstable intertrochanteric fractures.METHODS To find pertinent randomized controlled trials and retrospective observational studies comparing PFN with DCS for the management of unstable femoral intertrochanteric fractures,a thorough search was carried out.For research studies published between January 1996 and April 2024,PubMed,EMBASE,Scopus,Web of Science,Cochrane Library,and Google Scholar were all searched.The complete texts of the papers were retrieved,vetted,and independently examined by two investigators.Disputes were settled by consensus,and any disagreements that persisted were arbitrated by a third author.RESULTS This study included six articles,comprising a total of 173 patients.Compared to the DCS,the PFN had a shorter operation time[mean difference(MD):-41.7 min,95%confidence interval(95%CI):-63.04 to-20.35,P=0.0001],higher success rates with closed reduction techniques[risk ratio(RR):34.05,95%CI:11.12-104.31,P<0.00001],and required less intraoperative blood transfusion(MD:-1.4 units,95%CI:-1.80 to-1.00,P<0.00001).Additionally,the PFN showed shorter fracture union time(MD:-6.92 wk,95%CI:-10.27 to-3.57,P<0.0001)and a lower incidence of reoperation(RR:0.37,95%CI:0.17-0.82,P=0.01).However,there was no discernible variation regarding hospital stay,implant-related complications,and infections.CONCLUSION Compared to DCS,PFN offers shorter operative times,reduces the blood transfusions requirements,achieves higher closed reduction success,enables faster fracture healing,and lowers reoperation incidence.
文摘The US market for women's synthetic trou-sers is characterised by intense competition,with Asian countries playing a dominant role in exports.This analysis delves into the market performance of leading exporters,assessing key indicators such as export values,revealed comparative advantage(RCA).unit value realisation(UVR),and the effect of tariff rates.
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korea Government(MSIT)(No.2017R1A5A1014883).
文摘This paper presents dynamic-behavior comparisons and related forensic analyses of a submerged floating tunnel(SFT)between numerical simulation and physical experiment under regular and irregular waves.The experiments are conducted in the 3Dwave tank with 1:33.3 scale,and the corresponding coupled time-domain simulation tool is devised for comparison.The entire SFT systemconsists of a long concrete tunnel and 12 tubular aluminummooring lines.Two numerical simulation models,the Cummins equation with 3D potential theory including second-order wave-body interaction effects and the much simpler Morison-equation-based formula with the lumped-massbased line model,are designed and compared.Forensic analyses for mooring-line adjustments in the simulation are carried out in view of the best representation of the physical system.After that,the measured pre-tension distribution and systemstiffness of twelvemooring lines arewell reproduced in the numericalmodel.Subsequently,the dynamic responses and mooring tensions of the SFT are compared under regular and irregular waves.The measured and simulated results coincide reasonably well for both regular-and irregular-wave conditions.
基金the project PTDC/EMSTRA/5628/2014 "Maneuvering and moored ships in ports-physical and numerical modeling,"funded by the Portuguese Foundation for Science and Technology(FCT)financed by FCT under contract number SFRH/BD/67070/2009
文摘A numerical study of ship-to-ship interaction forces is performed using a commercial CFD code,and the results are compared with experimental data and with the results of a panel method analysis.Two ship models have been used in the interaction forces analysis:a tug and a tanker,advancing parallel to each other with different lateral distances and two different values of the fluid depth.Computations are carried out with four different flow models:inviscid and viscous flow with the free surface modeled as a rigid wall and inviscid and viscous flow with the deformable free surface.A fair agreement was obtained with available experimental data and results obtained by panel method.The influence of viscosity in the computations is found to be comparatively weak,while the wavemaking effects may be important,at small magnitude of the horizontal clearance.
基金supported by the Anusandhan National Research Foundation of India under Grant CRG/2021/007283 for Tapeout and MeitY(C2S programme).
文摘A low-power,high-speed dynamic comparator with the addition of a cross-coupled pair in the pre-amplifier stage,followed by a strong-arm latch,is presented.The proposed modification increases the pre-amplifier’s differential and common-mode gains,improving the latch’s differential and common-mode input voltage,resulting in faster regeneration with 22%speed improvement as compared to conventional comparator at small input differential voltages(V_(i,id)).The proposed technique boosts the comparator’s speed and helps achieve 21%lower energy per conversion delay product(EDP)compared to the literature.Analytical modeling of the delay that proves the improvement in the speed of the proposed comparator is also presented and verified with the simulation results.The proposed comparator’s delay is insensitive to the common-mode voltage(V_(i,cm)).The proposed comparator is fabricated in 180-nm CMOS technology and measurement shows less than 160 ps relative CLK-Q delay with 81 fJ.ns EDP and 0.8 mV input-referred rms noise with 1.8 V supply.To demonstrate the scalability of the proposed technique to advanced technology nodes,the proposed design is also simulated in 65-nm CMOS technology with a 1.1 V supply for 5 GHz frequency.For V_(i,cm) of 0.3 V and V_(i,id) of 1 mV and 10 mV,the proposed comparator exhibits a 40.69 ps and 32.41 ps delay and has 3.74 fJ.ns and 2.78 fJ.ns EDP respectively.
文摘Fluid dynamics simulation is often repeated under varying conditions.This leads to a generation of large amounts of results,which are difficult to compare.To compare results under different conditions,it is effective to overlap the streamlines generated from each condition in a single three-dimensional space.Streamline is a curved line,which represents a wind flow.This paper presents a technique to automatically select and visualize important streamlines that are suitable for the comparison of the simulation results.Additionally,we present an implementation to observe the flow fields in virtual reality spaces.
基金supported by the National Natural Science Foundation of China(Nos.61234002,61006028)the National High-Tech Program of China(Nos.2012AA012302,2013AA014103)the PhD Programs Foundation of Ministry of Education of China(No.20120203110017)
文摘A novel fully differential high speed high resolution low offset CMOS dynamic comparator has been implemented in the SMIC 0.18 μm process used for a sample-and-hold amplifier （SHA）-less pipelined analog-to-digital converters （ADC）. Based on the analysis and optimization between delay time and offset, an enhanced reset architecture with transmission gate was introduced to speed up the comparison and reset procedure. Four inputs with two cross coupled differential pairs, reconstituted bias circuit for tail current transistor and common centroid layouts make the comparator more robust against mismatch and process variations. The simulation results demonstrate that the proposed design achieves 1 mV sensitivity at 2.2 GHz sampling rate with a power consumption of 510 μW, while the mean offset voltage is equal to 10.244 mV.
文摘Increasing importance of heat transfer in chemical engineering science causes that investigation in the field of enhancement techniques is always one of the up-to-date topics for study.In the current comparative analysis,the thermal enhancement and friction penalty are explored numerically for curved tubes via twisted configuration.To accomplish this,three common geometries namely helical,serpentine,and Archimedes spiral,are considered at different coil-pitches and twist-pitches as well as five Reynolds numbers in the laminar flow regime.The results exhibit noticeable enhancements(up to 60%)in the thermal performance of the twisted cases as compared to the smooth cases.The highest increases are recorded for the serpentine case,followed by the helical and spiral cases.It is found that these enhancements vary via coil-pitch and twist-pitch.Increasing coil-pitch and twist-pitch augments both heat transfer coefficient and pressure drop in all curved-twisted tubes,however,the effects of twist-pitch are more pronounced.To predict Nusselt number and friction factor,new correlations are also proposed.The maximum deviations of the predicted results compared to the simulated data are within±5%.
基金International Joint Research Program from the Ministry of Science and Technology of Chinagrant number:20070667+1 种基金Education Commission of Chongqing of Chinagrant number:KJ081209
文摘The aim of this study is to identify the functions and states of the brains according to the values of the complexity measure of the EEG signals. The EEG signals of 30 normal samples and 30 patient samples are collected. Based on the preprocessing for the raw data, a computational program for complexity measure is compiled and the complexity measures of all samples are calculated. The mean value and standard error of complexity measure of control group is as 0.33 and 0.10, and the normal group is as 0.53 and 0.08. When the confidence degree is 0.05, the confidence interval of the normal population mean of complexity measures for the control group is (0.2871,0.3652), and (0.4944,0.5552) for the normal group. The statistic results show that the normal samples and patient samples can be clearly distinguished by the value of measures. In clinical medicine, the results can be used to be a reference to evaluate the function or state, to diagnose disease, to monitor the rehabilitation progress of the brain.
