期刊文献+
共找到10,517篇文章
< 1 2 250 >
每页显示 20 50 100
Finding the magnetopause location using soft X-ray observations and a statistical inverse method 被引量:1
1
作者 Gonzalo Cucho-Padin Hyunju Connor +2 位作者 Jaewoong Jung Brian Walsh David G.Sibeck 《Earth and Planetary Physics》 EI CSCD 2024年第1期184-203,共20页
Variability in the location and shape of the dayside magnetopause is attributed to magnetic reconnection,a fundamental process that enables the transfer of mass,energy,and momentum from the solar wind into the magneto... Variability in the location and shape of the dayside magnetopause is attributed to magnetic reconnection,a fundamental process that enables the transfer of mass,energy,and momentum from the solar wind into the magnetosphere.The spatial and temporal properties of the magnetopause,under varying solar and magnetospheric conditions,remain largely unknown because empirical studies using in-situ observations are challenging to interpret.Global wide field-of-view(FOV)imaging is the only means to simultaneously observe the spatial distribution of the plasma properties over the vast dayside magnetospheric region and,subsequently,quantify the energy transport from the interplanetary medium into the terrestrial magnetosphere.Two upcoming missions,ESA/CAS SMILE and NASA’s LEXI will provide wide-field imagery of the dayside magnetosheath in soft X-rays,an emission generated by charge exchange interactions between high charge-state heavy ions of solar wind origin and exospheric neutral atoms.High-cadence two-dimensional observations of the magnetosheath will allow the estimation of dynamic properties of its inner boundary,the magnetopause,and enable studies of its response to changes in the solar wind dynamic pressure and interplanetary magnetic field orientation.This work introduces a statistically-based estimation approach based on inverse theory to estimate the spatial distribution of magnetosheath soft X-ray emissivities and,with this,identify the location of the magnetopause over the Sun−Earth line.To do so,we simulate the magnetosheath structure using the MHD-based OpenGGCM model and generate synthetic soft X-ray images using LEXI’s orbit and attitude information.Our results show that 3-D estimations using the described statistically-based technique are robust against Poisson-distributed shot noise inherent to soft X-ray images.Also,our proposed methodology shows that the accuracy of both three-dimensional(3-D)estimation and the magnetopause standoff distance calculation highly depends on the observational point. 展开更多
关键词 MAGNETOPAUSE soft x-ray TOMOGRAPHY
下载PDF
New complex physiological findings evolve hypothesized mechanisms of Dravet syndrome
2
作者 MacKenzie A.Howard 《Neural Regeneration Research》 SCIE CAS CSCD 2024年第9期1867-1868,共2页
Developmental and epileptic encephalopathies(DEEs)are neurological disorders generally involving medically intractable seizures and a diverse array of comorbid neuropsychiatric delays and deficits that may severely af... Developmental and epileptic encephalopathies(DEEs)are neurological disorders generally involving medically intractable seizures and a diverse array of comorbid neuropsychiatric delays and deficits that may severely affect cognition,mood,sleep,social behavior,movement control,learning,and/or memory.Dravet syndrome(DS),also known as Severe Myoclonic Epilepsy of Infancy. 展开更多
关键词 sized finding seizures
下载PDF
Pathfinding Pulsar Observations with the CVN Incorporating the FAST
3
作者 Zhen Yan Zhiqiang Shen +21 位作者 Peng Jiang Bo Zhang Haiyan Zhang Lang Cui Jintao Luo Rurong Chen Wu Jiang Hua Zhang De Wu Rongbing Zhao Jianping Yuan Yue Hu Yajun Wu Bo Xia Guanghui Li Yongnan Rao Chenyu Chen Xiaowei Wang Hao Ding Yongpeng Liu Fuchen Zhang Yongbin Jiang 《Chinese Physics Letters》 SCIE EI CAS CSCD 2024年第11期170-176,共7页
The importance of Very Long Baseline Interferometry(VLBI)for pulsar research is becoming increasingly prominent and receiving more and more attention.We present the pathfinding pulsar observation results with the Chin... The importance of Very Long Baseline Interferometry(VLBI)for pulsar research is becoming increasingly prominent and receiving more and more attention.We present the pathfinding pulsar observation results with the Chinese VLBI Network(CVN)incorporating the Five-hundred-meter Aperture Spherical radio Telescope(FAST).On MJD 60045(11th April 2023),PSRs B0919+06 and B1133+16 were observed with the phase-referencing mode in the L-band using four radio telescopes(FAST,TianMa,Haoping,and Nanshan)and correlated with the pulsar binning mode of the distributed FX-style software correlator in Shanghai.After further data processing with the NRAO Astronomical Image Processing System(AIPS),we detected these two pulsars and fitted their current positions with accuracy at the milliarcsecond level.By comparison,our results show significantly better agreement with predicted values based on historical VLBI observations than those with previous timing observations,as pulsar astrometry with the VLBI provides a more direct and model-independent method for accurately obtaining related parameters. 展开更多
关键词 VLBI finding OBSERVATION
下载PDF
Association between stress hyperglycemia ratio and in-hospital outcomes:findings from the improving Care for Cardiovascular Disease in China-Acute Coronary Syndrome(CCC-ACS)Project
4
作者 Wen-Jie WANG Ke-Xin WANG +4 位作者 Jia-Long NIU Yi-Xuan LIU Hai-Long GE Hua SHEN On behalf of CCC-ACS investigators 《Journal of Geriatric Cardiology》 SCIE CAS CSCD 2024年第6期658-668,共11页
BACKGROUND Stress hyperglycemia ratio(SHR)could provide accurate information on the acute status of hyperglycemia.The relationship between SHR and acute coronary syndrome(ACS)prognosis remains unclear.This study was c... BACKGROUND Stress hyperglycemia ratio(SHR)could provide accurate information on the acute status of hyperglycemia.The relationship between SHR and acute coronary syndrome(ACS)prognosis remains unclear.This study was conducted to identity the association between SHR and in-hospital outcomes in patients with ACS.METHODS A total of 12,010 patients were eventually enrolled in the study.The relationship between SHR and in-hospital major adverse cardiovascular events(MACEs)was then modeled by restricted cubic spline(RCS)curves,and all patients were divided into three groups according to the results.The multivariate logistic regression analysis was used to determine the associations between the SHR and in-hospital outcomes,described as odds ratios(ORs)and 95%confidence intervals(CIs).Subgroup analyses were also performed on different diseases.RESULTS The median age of this cohort was 63(54,71)years old,and 8942(74.5%)were male.Group 1 was defined as SHR<0.6(n=426),Group 2 was defined as SHR between 0.6 and 1(n=5821),and Group 3 was defined as SHR>1(n=5763).Compared with Group 2,Group 1(OR=1.891,95%CI:1.028-3.479,P<0.001)and Group 3(OR=1.868,95%CI:1.434-2.434,P<0.001)had higher risks of suffering from in-hospital MACEs.SHR was associated with higher risks of in-hospital MACEs in the subgroups of DM[OR=2.282,95%CI:1.477-3.524).CONCLUSIONS Both low and high SHR levels were independently associated with in-hospital MACEs.Young males with DM,hypertension,and decreased renal function had much higher risks of suffering from SHR-correlated MACEs. 展开更多
关键词 acute CARDIOVASCULAR finding
下载PDF
Cardiovascular risk burden and disability:findings from the International Mobility in Aging Study(IMIAS)
5
作者 Juan-David Martinez-Aristizábal Carmen-Lucia Curcio +3 位作者 Juliana Fernandes Afshin Vafael Cristiano dos Santos Gomes Fernando Gomez 《Journal of Geriatric Cardiology》 SCIE CAS CSCD 2024年第3期331-339,共9页
BACKGROUND The association of cardiovascular risk burden with disability is unclear.We examined the association between trajectories of the Framingham general cardiovascular disease risk score(FGCRS)with the trajector... BACKGROUND The association of cardiovascular risk burden with disability is unclear.We examined the association between trajectories of the Framingham general cardiovascular disease risk score(FGCRS)with the trajectories of limitations of physical function in older adults.METHODS A total of 1219 participants with no disabilities from the International Mobility in Aging Study(IMIAS)study who had up to three repeated measures of FGCRS between 2012–2016 and without a history of stroke or coronary heart disease at baseline and follow-up were included.FGCRS at baseline was assessed and categorized into tertiles.Physical function was evaluated with the Short Physical Performance Battery(SPPB).The data were analyzed using linear mixed-effects models.RESULTS At baseline,FGCRS ranged between 3–94(mean score:24±15.8),participants were 32(2.6%),502(41.2%)and 685(56.2%)in lowest,middle,and highest tertiles,respectively.In the trajectories of limitations of physical function,the lowest FGCRS had no differences,while the middle and highest had a decrease in physical performance between 2012–2014(P=0.0001).Age,being female,living in Andes Mountains,having middle and highest FGCRS,higher alcohol consumption,being obese,lack of exercise and cognitive impairment increase the probability of disability(P<0.05).Alternatively,living in more developed regions and having a higher educational level reduced the probability of disability during the follow-up time(P<0.05).CONCLUSIONS Higher cardiovascular risk burden is associated with decreased physical performance,especially in gait.Results suggest SPPB may provide a measure of cardiovascular health in older adults. 展开更多
关键词 finding BATTERY BURDEN
下载PDF
Alcohol drinking triggered decrease of oxidative balance score is associated with high all-cause and cardiovascular mortality in hypertensive individuals:findings from NHANES 1999–2014
6
作者 Yu-Jun ZHANG Jing-Jing SONG +9 位作者 Jian-Hao ZHAN Chu-Lin ZHOU Ao LI Mao-Qi WANG Ben-Jie LI Cong-Cong DING Yi-Wei ZHANG Zi-Heng TAN Zai-Hua CHENG Xiao HUANG 《Journal of Geriatric Cardiology》 SCIE CAS CSCD 2024年第8期779-790,共12页
BACKGROUND Oxidative stress is closely associated with hypertensive outcomes.The oxidative balance score(OBS)measures oxidative stress exposure from dietary and lifestyle elements.The objective of this study was to in... BACKGROUND Oxidative stress is closely associated with hypertensive outcomes.The oxidative balance score(OBS)measures oxidative stress exposure from dietary and lifestyle elements.The objective of this study was to investigate the association between OBS and mortality in hypertensive patients.METHODS This study included 7823 hypertensive patients from the National Health and Nutrition Examination Survey(NHA-NES)1999-2014.Several models,including Cox regression,restricted cubic splines(RCS),Kaplan-Meier survival analysis,subgroup,and sensitivity analyses,were exploited to investigate the relationship between OBS and the risk of mortality.RESULTS Controlling for all potential confounders,a significantly inverse association was observed between elevated OBS and all-cause[hazard ratio(HR)=0.90,95%CI:0.85-0.95]and cardiovascular mortality(HR=0.85,95%CI:0.75-0.95).With adjustment for covariates,significant associations between lifestyle OBS and mortality risks diminished,whereas associations between dietary OBS and these mortality risks remained robust(all-cause mortality:HR=0.91,95%CI:0.86-0.96;cardiovascular mortality:HR=0.85,95%CI:0.76-0.96).RCS demonstrated a linear relationship between OBS and all-cause and cardiovascular mortality risk(P_(nonlinear)=0.088 and P_(nonlinear)=0.447,respectively).Kaplan-Meier curves demonstrated that the mortality rate was lower with a high OBS(P<0.001).The consistency of the association was demonstrated in subgroup and sensitivity analyses.RCS after stratification showed that among current drinkers,those with higher OBS had a lower risk of mortality compared with former or never drinkers.CONCLUSIONS In hypertensive individuals,there was a negative association between OBS and all-cause and cardiovascular mortality.Encouraging hypertensive individuals,especially those currently drinking,to maintain high levels of OBS may be beneficial in improving their prognosis. 展开更多
关键词 HIGH finding Alcohol
下载PDF
Community Caregivers’ Experiences and Programmatic Strategies to Improve Active Case Finding in Community Tuberculosis Care in Botswana 2016-2021
7
作者 Unami Modongo-Mathebula Mary Moleki Tefera Agizew 《Journal of Tuberculosis Research》 2024年第2期105-118,共14页
Background: The community tuberculosis care program was started to reduce the impact of TB and increase successful treatment outcomes, thus contributing to meeting WHO targets on TB. According to the Botswana Ministry... Background: The community tuberculosis care program was started to reduce the impact of TB and increase successful treatment outcomes, thus contributing to meeting WHO targets on TB. According to the Botswana Ministry of Health, community tuberculosis care was introduced with the main goal of reducing tuberculosis-related morbidity and mortality among communities through the expansion of direct observed therapy and community involvement to community settings. The community caregivers were to support tuberculosis patients throughout their treatment period until they were cured or had completed their treatment. Settings: Two major cities of Botswana, Francistown and Gaborone, with more than twenty-two health clinics offering tuberculosis care. Objective: To investigate community caregivers’ experiences and identify programmatic strategies to improve active TB case findings under the community TB care (CTBC) program in Botswana during 2016-2021. Methods: We adopted a descriptive qualitative research design, followed by convenience purposive sampling. We obtained consent and interviewed 40 participants who met the inclusion criteria, 16 out of 73 in Gaborone and 24 out of 38 from Francistown. Results: We interviewed 40 caregivers with a mean age of 43.4 years. Accepting the caregiving role was identified as the main experience by more than two thirds of the caregivers. While at least more than two-fifth felt obligated to care for the patient at home due to personal relations. More than half of the respondents found caregiving difficult or frustrating due to some challenges encountered during the caregiving role. Behavioral modifications were suggested under different subthemes as strategies to improve active case finding. [-rId13-]Conclusion: Acceptance was the major experience in CTBC. Intensification of known programmatic strategies was suggested by caregivers to improve tuberculosis active case finding in CTBC. 展开更多
关键词 Community Experiences CAREGIVERS Active Case finding TUBERCULOSIS Community Tuberculosis Care
下载PDF
Hepatic organoids: ideal models for non-alcoholic fatty liver disease drug finding and molecular mechanism research
8
作者 Wei Peng 《Integrative Medicine Discovery》 2024年第12期1-1,共1页
With the improvement of living standards and changes in dietary habits,the non-alcoholic fatty liver disease(NAFLD)has become one of the most common metabolic diseases clinically,with a global prevalence exceeding 25%... With the improvement of living standards and changes in dietary habits,the non-alcoholic fatty liver disease(NAFLD)has become one of the most common metabolic diseases clinically,with a global prevalence exceeding 25%.NAFLD often presents as a multisystem disease characterized by excessive deposition of triglycerides within hepatocytes,with over 5%of hepatocytes exhibiting steatosis.The clinical progression of NAFLD can mainly be divided into two stages:non-alcoholic fatty liver(NAFL)and non-alcoholic steatohepatitis(NASH).NAFL represents the early stage,primarily characterized by hepatocellular steatosis(which can be reversed with early intervention)and further progression leading to NASH.Besides hepatocellular steatosis,NASH also exhibits hepatocyte inflammation,injury,and fibrosis.Research indicates that 25%of NAFL patients may progress to NASH,and 35%to 50%of NASH patients further develop into liver cirrhosis or even liver cancer.Additionally,NAFLD is closely associated with various chronic diseases and tumors,such as obesity,hyperlipidemia,diabetes,breast cancer,and colorectal cancer.Despite the high and rising incidence of NAFLD,there are currently no clinically proven safe and effective drugs specifically targeting each stage of NAFLD. 展开更多
关键词 DRUGS finding reversed
下载PDF
Pneumoparotid with imaging findings:A case report and review of literature
9
作者 Wakako Kubota Makiko Kyan-Onodera +3 位作者 Yasuomi Fujimoto Akihiro Sakuma Ryuji Katada Chihiro Sugiura 《World Journal of Clinical Cases》 SCIE 2024年第34期6705-6714,共10页
BACKGROUND Pneumoparotid is a rare disease associated with retrograde airflow into the ductal system.There is no established treatment for this disease,which has no known complications.Mouth puffing and playing wind i... BACKGROUND Pneumoparotid is a rare disease associated with retrograde airflow into the ductal system.There is no established treatment for this disease,which has no known complications.Mouth puffing and playing wind instruments are known to be the causes of this disease.CASE SUMMARY We managed a case,in which pneumoparotid suddenly recurred 4 months after surgery for purulent parotiditis.The patient did not report any obvious etiological factors,such as mouth puffing or playing a wind instrument.We reviewed 128 articles(from 1941 to 2023)that reported on a total of 166 patients with pneumoparotid,including the patient from the present case report,with imaging findings.This is the first reported case of pneumoparotid following surgery for purulent parotitis.The etiology in our case was classified as idiopathic.CONCLUSION Imaging findings could be sufficient for accurate pneumoparotid diagnoses and the exclusion of complications;computed tomography could be useful. 展开更多
关键词 Computed tomography Imaging findings Parotid gland Pneumoparotid Pneumoparotitis Case report
下载PDF
An Improved Bounded Conflict-Based Search for Multi-AGV Pathfinding in Automated Container Terminals
10
作者 Xinci Zhou Jin Zhu 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第6期2705-2727,共23页
As the number of automated guided vehicles(AGVs)within automated container terminals(ACT)continues to rise,conflicts have becomemore frequent.Addressing point and edge conflicts ofAGVs,amulti-AGVconflict-free path pla... As the number of automated guided vehicles(AGVs)within automated container terminals(ACT)continues to rise,conflicts have becomemore frequent.Addressing point and edge conflicts ofAGVs,amulti-AGVconflict-free path planning model has been formulated to minimize the total path length of AGVs between shore bridges and yards.For larger terminalmaps and complex environments,the grid method is employed to model AGVs’road networks.An improved bounded conflict-based search(IBCBS)algorithmtailored to ACT is proposed,leveraging the binary tree principle to resolve conflicts and employing focal search to expand the search range.Comparative experiments involving 60 AGVs indicate a reduction in computing time by 37.397%to 64.06%while maintaining the over cost within 1.019%.Numerical experiments validate the proposed algorithm’s efficacy in enhancing efficiency and ensuring solution quality. 展开更多
关键词 Automated terminals multi-AGV multi-agent path finding(MAPF) conflict based search(CBS) AGV path planning
下载PDF
Direction finding of bistatic MIMO radar in strong impulse noise
11
作者 CHEN Menghan GAO Hongyuan +2 位作者 DU Yanan CHENG Jianhua ZHANG Yuze 《Journal of Systems Engineering and Electronics》 SCIE CSCD 2024年第4期888-898,共11页
For bistatic multiple-input multiple-output(MIMO)radar,this paper presents a robust and direction finding method in strong impulse noise environment.By means of a new lower order covariance,the method is effective in ... For bistatic multiple-input multiple-output(MIMO)radar,this paper presents a robust and direction finding method in strong impulse noise environment.By means of a new lower order covariance,the method is effective in suppressing impulse noise and achieving superior direction finding performance using the maximum likelihood(ML)estimation method.A quantum equilibrium optimizer algorithm(QEOA)is devised to resolve the corresponding objective function for efficient and accurate direc-tion finding.The results of simulation reveal the capability of the presented method in success rate and root mean square error over existing direction-finding methods in different application situations,e.g.,locating coherent signal sources with very few snapshots in strong impulse noise.Other than that,the Cramér-Rao bound(CRB)under impulse noise environment has been drawn to test the capability of the presented method. 展开更多
关键词 bistatic multiple-input multiple-output(MIMO)radar impulse noise direction finding lower order covariance quan-tum equilibrium optimizer algorithm(QEOA) maximum likeli-hood estimation method Cramér-Rao bound(CRB)
下载PDF
Analyzing the Form-Finding of a Large-Span Transversely Stiffened Suspended Cable System: A Method Considering Construction Processes
12
作者 Junyu Chen Yanfei Wang +2 位作者 Ke Chen Shiqing Huang Xiaowen Xu 《World Journal of Engineering and Technology》 2024年第2期229-244,共16页
The precise control of the shape of transversely stiffened suspended cable systems is crucial. However, existing form-finding methods primarily rely on iterative calculations that treat loads as fixed known conditions... The precise control of the shape of transversely stiffened suspended cable systems is crucial. However, existing form-finding methods primarily rely on iterative calculations that treat loads as fixed known conditions. These methods are inefficient and fail to accurately control shape results. In this study, we propose a form-finding method that analyzes the load response of models under different sag and stress levels, taking into account the construction process. To analyze the system, a structural finite element model was established in ANSYS, and geometric nonlinear analysis was conducted using the Newton-Raphson method. The form-finding analysis results demonstrate that the proposed method achieves precise control of shape, with a maximum shape error ranging from 0.33% to 0.98%. Furthermore, the relationships between loads and tension forces are influenced by the deformed shape of the structures, exhibiting significant geometric nonlinear characteristics. Meanwhile, the load response analysis reveals that the stress level of the self-equilibrium state in the transversely stiffened suspended cable system is primarily governed by strength criteria, while shape is predominantly controlled by stiffness criteria. Importantly, by simulating the initial tensioning process as an initial condition, this method solves for a counterweight that satisfies the requirements and achieves a self-equilibrium state with the desired shape. The shape of the self-equilibrium state is precisely controlled by simulating the construction process. Overall, this work presents a new method for analyzing the form-finding process of large-span transversely stiffened suspended cable system, considering the construction process which was often overlooked in previous studies. 展开更多
关键词 Cable Structure Long-Span Structure Form-finding Analysis Finite Element Simulation Transverse Cable Stiffening System
下载PDF
Why caution should be applied when interpreting and promoting findings from Mendelian randomisation studies 被引量:2
13
作者 Alice R Carter Abigail Fraser +2 位作者 Laura D Howe Sian Harris Amanda Hughes 《General Psychiatry》 CSCD 2023年第4期334-338,共5页
Introduction In their article entitled‘Investigating genetic causal relationships between blood pressure and anxiety,depressive symptoms,neuroticism and subjective well-being’,Cai and colleagues1 presented the resul... Introduction In their article entitled‘Investigating genetic causal relationships between blood pressure and anxiety,depressive symptoms,neuroticism and subjective well-being’,Cai and colleagues1 presented the results of a two-sample Mendelian randomisation2(MR)study examining associations between blood pressure traits(systolic,diastolic,hypertension and pulse pressure)and psychological traits(anxiety,depression,neuroticism and subjective well-being).After correction for multiple testing. 展开更多
关键词 random finding INTERPRETING
下载PDF
Cost-benefit and discriminant validity of a stepwise dementia case-finding approach in an Asian older adult community 被引量:1
14
作者 Ting Pang Binte Xia +9 位作者 Xuhao Zhao Yaping Zhang Cheuk Ni Kan Saima Hilal Christopher Chen Narayanaswamy Venketasubramanian Tien Yin Wong Ching-YuCheng Changzheng Yuan Xin Xu 《General Psychiatry》 CSCD 2023年第5期393-401,共9页
Background Case-finding is a recommended approach for dementia early detection in the community.Aims To investigate the discriminant validity and cost-effectiveness of a stepwise dementia case-finding approach in a Si... Background Case-finding is a recommended approach for dementia early detection in the community.Aims To investigate the discriminant validity and cost-effectiveness of a stepwise dementia case-finding approach in a Singaporean older adult community.Methods The two-phase study was conducted in the community from 2009 to 2015 in Singapore.A total of 3780 participants(age≥60 years)completed phase I(a brief cognitive screening);918 completed phase II and were included in the final analysis.In phase I,all participants were administered the Abbreviated Mental Test(AMT)and the Progressive Forgetfulness Question(PFQ).Those who screened positive on either test were invited to phase II,whereby the Mini-Mental State Examination(MMSE),Montreal Cognitive Assessment(MoCA)and a formal neuropsychological battery were administered,followed by the research diagnosis of no cognitive impairment,cognitive impairment no dementia(CIND)-Mild(≤2 impaired cognitive domains),CIND-Moderate(>2 impaired domains)or dementia.Receiver operating characteristic curve analyses were conducted for the different cognitive instruments.All discriminant indices were calculated,including sensitivity,specificity,positive and negative predictive values(NPV)and accuracy.Cost-effectiveness analysis was conducted by estimating the amount of screening time needed and the number of older adults requiring re-evaluation in two case-finding scenarios,ie,with or without preselection by the PFQ.Results The stepwise case-finding approach(preselection by the PFQ,then MMSE or MoCA or AMT)showed an excellent NPV(>99%)and accuracy(>86%)for excluding dementia-free cases.Without preselection by the PFQ,screening time for the three cognitive tools were 317.5,317.5 and 254 hours,with 159,302 and 175 screen-positive older adults involved in further evaluation.By adopting the stepwise case-finding approach,total screening time were 156.5,156.5 and 126.2 hours,which decreased by 50.7%,50.7% and 50.3% as compared with those without preselection.Furthermore,after preselection,only 98,167 and 145 screen-positive older adults required further evaluation,corresponding to a reduction of 38.4%,44.7% and 17.1% in the numbers compared with those without preselection.Conclusions A stepwise approach for dementia case-finding should be implemented in the community to minimise the time and resources needed for large-scale early detection of dementia. 展开更多
关键词 IMPAIRED finding STEPWISE
下载PDF
The dynamic relaxation form finding method aided with advanced recurrent neural network 被引量:1
15
作者 Liming Zhao Zhongbo Sun +1 位作者 Keping Liu Jiliang Zhang 《CAAI Transactions on Intelligence Technology》 SCIE EI 2023年第3期635-644,共10页
How to establish a self‐equilibrium configuration is vital for further kinematics and dynamics analyses of tensegrity mechanism.In this study,for investigating tensegrity form‐finding problems,a concise and efficien... How to establish a self‐equilibrium configuration is vital for further kinematics and dynamics analyses of tensegrity mechanism.In this study,for investigating tensegrity form‐finding problems,a concise and efficient dynamic relaxation‐noise tolerant zeroing neural network(DR‐NTZNN)form‐finding algorithm is established through analysing the physical properties of tensegrity structures.In addition,the non‐linear constrained opti-misation problem which transformed from the form‐finding problem is solved by a sequential quadratic programming algorithm.Moreover,the noise may produce in the form‐finding process that includes the round‐off errors which are brought by the approximate matrix and restart point calculating course,disturbance caused by external force and manufacturing error when constructing a tensegrity structure.Hence,for the purpose of suppressing the noise,a noise tolerant zeroing neural network is presented to solve the search direction,which can endow the anti‐noise capability to the form‐finding model and enhance the calculation capability.Besides,the dynamic relaxation method is contributed to seek the nodal coordinates rapidly when the search direction is acquired.The numerical results show the form‐finding model has a huge capability for high‐dimensional free form cable‐strut mechanisms with complicated topology.Eventually,comparing with other existing form‐finding methods,the contrast simulations reveal the excellent anti‐noise performance and calculation capacity of DR‐NTZNN form‐finding algorithm. 展开更多
关键词 dynamic relaxation form‐finding noise‐tolerant zeroing neural network sequential quadratic programming TENSEGRITY
下载PDF
M^(3)Res-Transformer:新冠肺炎胸部X-ray图像识别模型 被引量:1
16
作者 周涛 刘赟璨 +3 位作者 侯森宝 常晓玉 叶鑫宇 陆惠玲 《电子学报》 EI CAS CSCD 北大核心 2024年第2期589-601,共13页
新冠肺炎(COVID-19)自爆发以来严重影响人类生命健康,近年来残差神经网络广泛应用于COVID-19识别任务中,辅助医生快速地诊断COVID-19患者,但是COVID-19图像病变区域形状复杂、大小不一,与周围组织的边界模糊,导致网络难以提取有效特征.... 新冠肺炎(COVID-19)自爆发以来严重影响人类生命健康,近年来残差神经网络广泛应用于COVID-19识别任务中,辅助医生快速地诊断COVID-19患者,但是COVID-19图像病变区域形状复杂、大小不一,与周围组织的边界模糊,导致网络难以提取有效特征.本文针对上述问题,提出一种M^(3)Res-Transformer的新冠肺炎胸部X-ray图像识别模型,采用Res-Transformer作为模型的主干网络,结合ResNet和ViT,有效地整合局部病变特征和全局特征;设计混合残差注意力模块(mixed residual attention Module,mraM),同时考虑通道和空间位置的相互依赖性,增强网络的特征表达能力;为了增大感受野,提取多尺度特征,通过叠加具有不同扩张率的扩张卷积构造多尺度扩张残差模块(multiscale dilated residual Module,mdrM),根据不同层次特征尺度的差异,使用3个逐渐收缩尺度的mdrM进行多尺度特征提取;提出上下文交叉感知模块(contextual cross-awareness Module,ccaM),使用深层特征中的语义信息来引导浅层特征,然后将浅层特征中的空间信息嵌入深层特征中,采用交叉加权注意力机制高效聚合深层和浅层特征,获得更丰富的上下文信息.为了验证本文所提模型的有效性,在新冠肺炎胸部X-ray图像数据集上进行实验,与先进的CNN分类模型、融合不同注意力机制的ResNet50模型、基于Transformer的分类模型对比以及消融实验.结果表明,本文所提模型的Acc、Pre、Rec、F1-Score与Spe指标分别为96.33%、96.36%、96.33%、96.35%与96.26%,在COVID-19胸部X-ray图像识别任务中有效提升了识别精度,并通过可视化方法对其进行进一步验证,为COVID-19的辅助诊断提供重要的参考价值. 展开更多
关键词 COVID-19 胸部x-ray图像 残差神经网络 vision transformer 注意力机制
下载PDF
X-ray在鱼体组织及微量元素检测中的应用
17
作者 宋一帆 张胜茂 +4 位作者 张衡 唐峰华 张寒野 石永闯 崔雪森 《应用光学》 CAS 北大核心 2024年第1期166-176,共11页
鱼类硬质组织物,特别是骨骼支持鱼体和保护其体内器官的组织,对其进行特征检测分析是研究鱼类游泳运动、鱼类解剖、鱼体建模等的数据基础。随着X-ray技术的发展和国产设备的广泛应用,其仪器设备成本明显降低,使得X-ray在渔业研究与自动... 鱼类硬质组织物,特别是骨骼支持鱼体和保护其体内器官的组织,对其进行特征检测分析是研究鱼类游泳运动、鱼类解剖、鱼体建模等的数据基础。随着X-ray技术的发展和国产设备的广泛应用,其仪器设备成本明显降低,使得X-ray在渔业研究与自动化生产中的应用成为可能。首先介绍了X-ray技术的基本原理与其在鱼体组织检测中的应用,X-ray技术在鱼体组织及微量元素检测中的应用主要分为鱼类组织器官的无损检测和鱼体微量元素检测两部分,其中分别介绍了包括照相法、数字成像法、衍射技术和吸收光谱法等X-ray技术;然后综述其在鱼体组织器官建模、鱼骨检测、鱼类化石研究、鱼耳石分析和鱼体微量元素检测方面的应用,总结了Xray在渔业领域应用中存在的问题;最后对X-ray的渔业应用方向进行展望。 展开更多
关键词 x-ray 鱼体骨骼 鱼类耳石 鱼体建模 鱼体微量元素
下载PDF
Global hybrid simulations of soft X-ray emissions in the Earth’s magnetosheath 被引量:2
18
作者 Jin Guo TianRan Sun +6 位作者 San Lu QuanMing Lu Yu Lin XueYi Wang Chi Wang RongSheng Wang Kai Huang 《Earth and Planetary Physics》 EI CSCD 2024年第1期47-58,共12页
Earth’s magnetopause is a thin boundary separating the shocked solar wind plasma from the magnetospheric plasmas,and it is also the boundary of the solar wind energy transport to the magnetosphere.Soft X-ray imaging ... Earth’s magnetopause is a thin boundary separating the shocked solar wind plasma from the magnetospheric plasmas,and it is also the boundary of the solar wind energy transport to the magnetosphere.Soft X-ray imaging allows investigation of the large-scale magnetopause by providing a two-dimensional(2-D)global view from a satellite.By performing 3-D global hybrid-particle-in-cell(hybrid-PIC)simulations,we obtain soft X-ray images of Earth’s magnetopause under different solar wind conditions,such as different plasma densities and directions of the southward interplanetary magnetic field.In all cases,magnetic reconnection occurs at low latitude magnetopause.The soft X-ray images observed by a hypothetical satellite are shown,with all of the following identified:the boundary of the magnetopause,the cusps,and the magnetosheath.Local X-ray emissivity in the magnetosheath is characterized by large amplitude fluctuations(up to 160%);however,the maximum line-of-sight-integrated X-ray intensity matches the tangent directions of the magnetopause well,indicating that these fluctuations have limited impact on identifying the magnetopause boundary in the X-ray images.Moreover,the magnetopause boundary can be identified using multiple viewing geometries.We also find that solar wind conditions have little effect on the magnetopause identification.The Solar wind Magnetosphere Ionosphere Link Explorer(SMILE)mission will provide X-ray images of the magnetopause for the first time,and our global hybrid-PIC simulation results can help better understand the 2-D X-ray images of the magnetopause from a 3-D perspective,with particle kinetic effects considered. 展开更多
关键词 MAGNETOPAUSE x-ray emissivity x-ray imaging SMILE global hybrid-PIC simulation
下载PDF
The Soft X-ray Imager(SXI)on the SMILE Mission 被引量:4
19
作者 S.Sembay A.L.Alme +83 位作者 D.Agnolon T.Arnold A.Beardmore A.Belén Balado Margeli C.Bicknell C.Bouldin G.Branduardi-Raymont T.Crawford J.P.Breuer T.Buggey G.Butcher R.Canchal J.A.Carter A.Cheney Y.Collado-Vega H.Connor T.Crawford N.Eaton C.Feldman C.Forsyth T.Frantzen G.Galgóczi J.Garcia G.Y.Genov C.Gordillo H-P.Gröbelbauer M.Guedel Y.Guo M.Hailey D.Hall R.Hampson J.Hasiba O.Hetherington A.Holland S-Y.Hsieh M.W.J.Hubbard H.Jeszenszky M.Jones T.Kennedy K.Koch-Mehrin S.Kögl S.Krucker K.D.Kuntz C.Lakin G.Laky O.Lylund A.Martindale J.Miguel Mas Hesse R.Nakamura K.Oksavik N.Østgaard H.Ottacher R.Ottensamer C.Pagani S.Parsons P.Patel J.Pearson G.Peikert F.S.Porter T.Pouliantis B.H.Qureshi W.Raab G.Randal A.M.Read N.M.M.Roque M.E.Rostad C.Runciman S.Sachdev A.Samsonov M.Soman D.Sibeck S.Smit J.Søndergaard R.Speight S.Stavland M.Steller TianRan Sun J.Thornhill W.Thomas K.Ullaland B.Walsh D.Walton C.Wang S.Yang 《Earth and Planetary Physics》 EI CSCD 2024年第1期5-14,共10页
The Soft X-ray Imager(SXI)is part of the scientific payload of the Solar wind Magnetosphere Ionosphere Link Explorer(SMILE)mission.SMILE is a joint science mission between the European Space Agency(ESA)and the Chinese... The Soft X-ray Imager(SXI)is part of the scientific payload of the Solar wind Magnetosphere Ionosphere Link Explorer(SMILE)mission.SMILE is a joint science mission between the European Space Agency(ESA)and the Chinese Academy of Sciences(CAS)and is due for launch in 2025.SXI is a compact X-ray telescope with a wide field-of-view(FOV)capable of encompassing large portions of Earth’s magnetosphere from the vantage point of the SMILE orbit.SXI is sensitive to the soft X-rays produced by the Solar Wind Charge eXchange(SWCX)process produced when heavy ions of solar wind origin interact with neutral particles in Earth’s exosphere.SWCX provides a mechanism for boundary detection within the magnetosphere,such as the position of Earth’s magnetopause,because the solar wind heavy ions have a very low density in regions of closed magnetic field lines.The sensitivity of the SXI is such that it can potentially track movements of the magnetopause on timescales of a few minutes and the orbit of SMILE will enable such movements to be tracked for segments lasting many hours.SXI is led by the University of Leicester in the United Kingdom(UK)with collaborating organisations on hardware,software and science support within the UK,Europe,China and the United States. 展开更多
关键词 Soft x-ray Imaging micropore optics large area CCD
下载PDF
Two methods for separating the magnetospheric solar wind charge exchange soft X-ray emission from the diffuse X-ray background 被引量:2
20
作者 YingJie Zhang TianRan Sun +5 位作者 JenniferACarter WenHao Liu Steve Sembay ShuiNai Zhang Li Ji Chi Wang 《Earth and Planetary Physics》 EI CSCD 2024年第1期119-132,共14页
Solar wind charge exchange(SWCX)is the process of solar wind high-valence ions exchanging charges with neutral components and generating soft X-rays.Recently,detecting the SWCX emission from the magnetosphere is propo... Solar wind charge exchange(SWCX)is the process of solar wind high-valence ions exchanging charges with neutral components and generating soft X-rays.Recently,detecting the SWCX emission from the magnetosphere is proposed as a new technique to study the magnetosphere using panoramic soft X-ray imaging.To better prepare for the data analysis of upcoming magnetospheric soft X-ray imaging missions,this paper compares the magnetospheric SWCX emission obtained by two methods in an XMM-Newton observation,during which the solar wind changed dramatically.The two methods differ in the data used to fit the diffuse X-ray background(DXB)parameters in spectral analysis.The method adding data from the ROSAT All-Sky Survey(RASS)is called the RASS method.The method using the quiet observation data is called the Quiet method,where quiet observations usually refer to observations made by the same satellite with the same target but under weaker solar wind conditions.Results show that the spectral compositions of magnetospheric SWCX emission obtained by the two methods are very similar,and the changes in intensity over time are highly consistent,although the intensity obtained by the RASS method is about 2.68±0.56 keV cm^(-2)s^(-1)sr^(-1)higher than that obtained by the Quiet method.Since the DXB intensity obtained by the RASS method is about 2.84±0.74 keV cm^(-2)s^(-1)sr^(-1)lower than that obtained by the Quiet method,and the linear correlation coefficient between the difference of SWCX and DXB obtained by the two methods in diffe rent energy band is close to-1,the diffe rences in magnetospheric SWCX can be fully attributed to the diffe rences in the fitted DXB.The difference between the two methods is most significant when the energy is less than 0.7 keV,which is also the main energy band of SWCX emission.In addition,the difference between the two methods is not related to the SWCX intensity and,to some extent,to solar wind conditions,because SWCX intensity typically va ries with the solar wind.In summary,both methods are robust and reliable,and should be considered based on the best available options. 展开更多
关键词 solar wind charge exchange(SWCX) ROSAT All-Sky Survey(RASS) soft x-ray x-ray imaging MAGNETOSPHERE
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部