Mason Reset(MR),a groundbreaking invention by Clesson E.Mason in 1930 that later became a part of“the universal approach to process control instrumentation”,is revisited in this paper and is shown to consists of thr...Mason Reset(MR),a groundbreaking invention by Clesson E.Mason in 1930 that later became a part of“the universal approach to process control instrumentation”,is revisited in this paper and is shown to consists of three actions:fast(errorcorrection),medium(negative feedback for expanded proportional band)and slow(reset for zero steady-state error).The focus of the paper is on the reset action,generated from a positive feedback loop,and its underlying principles with profound implications to our understanding and practice of automatic control,both basic and advanced.For example,we note that reset control and integral control,contrary to common belief,differ fundamentally in design principle and in practicality.Such difference comes to a head in the event of integrator windup:while reset windup is a problem of actuator saturation,the integrator windup is a runaway situation due to controller instability.In fact,there is no advantage gained in replacing MR with an integrator.In other words,one should not integrate the error directly as in standard PID,since doing so makes the closed-loop system internally unstable.With MR-based control formulated in this paper,there is no such threat of instability and,therefore,no need for any anti-windup mechanisms.Furthermore,the integral control is made scalable in this framework as a tradeoff between the steady-state accuracy and the controller stability.This leads to a novel MR-based control design,scalable in gain and in time to accommodate various process characteristics and design specifications.Simple in construction and transparent in principle,this MR-based control,as a basic framework of design,is readily deployable in scale.展开更多
An improved model based on you only look once version 8(YOLOv8)is proposed to solve the problem of low detection accuracy due to the diversity of object sizes in optical remote sensing images.Firstly,the feature pyram...An improved model based on you only look once version 8(YOLOv8)is proposed to solve the problem of low detection accuracy due to the diversity of object sizes in optical remote sensing images.Firstly,the feature pyramid network(FPN)structure of the original YOLOv8 mode is replaced by the generalized-FPN(GFPN)structure in GiraffeDet to realize the"cross-layer"and"cross-scale"adaptive feature fusion,to enrich the semantic information and spatial information on the feature map to improve the target detection ability of the model.Secondly,a pyramid-pool module of multi atrous spatial pyramid pooling(MASPP)is designed by using the idea of atrous convolution and feature pyramid structure to extract multi-scale features,so as to improve the processing ability of the model for multi-scale objects.The experimental results show that the detection accuracy of the improved YOLOv8 model on DIOR dataset is 92%and mean average precision(mAP)is 87.9%,respectively 3.5%and 1.7%higher than those of the original model.It is proved the detection and classification ability of the proposed model on multi-dimensional optical remote sensing target has been improved.展开更多
Background The patient-reported Dimensional Anhedonia Rating Scale(DARS)has been adapted into Chinese,so there is a need to evaluate its measurement properties in a Chinese population.Aims To evaluate the reliability ...Background The patient-reported Dimensional Anhedonia Rating Scale(DARS)has been adapted into Chinese,so there is a need to evaluate its measurement properties in a Chinese population.Aims To evaluate the reliability and validity of the DARS among Chinese individuals with major depressive disorder(MDD)and its treatment sensitivity in a prospective clinical study.Methods Data were from a multicentre,prospective clinical study(NCT03294525),which recruited both patients with MDD,who were followed for 8 weeks,and healthy controls(HCs),assessed at baseline only.The analysis included confirmatory factor analysis,validity and sensitivity to change.Results Patients’mean(standard deviation(SD))age was 34.8(11.0)years,with 68.7%being female.75.2%of patients with MDD had melancholic features,followed by 63.8%with anxious distress.Patients had experienced MDD for a mean(SD)of 9.2(18)months.DARS scores covered the full range of severity with no major floor or ceiling effects.Confirmatory factor analysis showed adequate fit statistics(comparative fit index 0.976,goodness-of-fit index 0.935 and root mean square error of approximation 0.055).Convergent validity with anhedonia-related measures was confirmed.While the correlation between the DARS and the Hamilton Depression Rating Scale was not strong(r=0.31,baseline),the DARS was found to differentiate between levels of depression.Greater improvements in DARS scores were seen with the Hamilton Rating Scale for Depression responder group(effect size 1.16)compared with the non-responder group(effect size 0.46).Conclusions This study comprehensively evaluated the measurement properties of the DARS using a Chinese population with MDD.Overall,the Chinese version of DARS demonstrates good psychometric properties and has been found to be responsive to change during antidepressant treatment.The DARS is a suitable scale for assessing patient-reported anhedonia in future clinical trials.展开更多
Background The effectiveness of life skills-based prevention programs to prevent substance addiction has been underexplored in Türkiye,likely in part due to the lack of validated measurement tools developed speci...Background The effectiveness of life skills-based prevention programs to prevent substance addiction has been underexplored in Türkiye,likely in part due to the lack of validated measurement tools developed specifically for that purpose.Therefore,the aim of this study is to develop a tool to measure life skills for middle school students.The present study aims to test the factorial structure,reliability,convergent and discriminant validity,and measurement invariance across gender and age groups of the Green Crescent Life Skills(GCLS)Scale.Methods The study was conducted in Istanbul with two different sample groups.The first sample consisted of 566 and the second sample consisted of 885 middle school students.In the study,exploratory factor analysis(EFA)was applied to the first sample,and confirmatory factor analysis(CFA)was applied to the second sample to test the factorial structure of the scale.Convergent and discriminant validity were examined to provide evidence for construct-based validity.The reliability of the scale was assessed with Cronbach’sα,composite reliability,McDonald’sω,and test-retest.Results The EFA results showed that the scale consisted of four factors(self-awareness,coping with negative emotions,thinking skills,and peer relations).CFA results also confirmed this structure.The results revealed a significant positive correlation(r=0.52,p<0.01)between life skills and avoidance self-efficacy scores,as well as a significant negative correlation(r=−0.53,p<0.01)between life skills and attitude toward drug use scores.Additionally,it was found that measurement invariances based on gender and age groups were provided.It was determined that all sub-dimensions had sufficient reliability levels.Conclusion The findings of this validation study show that the GCLS Scale,which assesses four skills in a self-reported format,is a valid and reliable scale with considerable potential utility in monitoring life skills in Turkish adolescent populations.展开更多
BACKGROUND During the gradual decline of physical and social functioning associated with end-stage renal disease,patients might experience a premonition of impending death,resulting in a series of pre-mourning grief r...BACKGROUND During the gradual decline of physical and social functioning associated with end-stage renal disease,patients might experience a premonition of impending death,resulting in a series of pre-mourning grief responses called preparatory grief.The preparatory grief in advanced cancer patients(PGAC)scale is the most widely used preparatory grief scale for patients on hemodialysis in China.AIM To verify the reliability and validity of the PGAC scale in patients on hemodialysis.METHODS In total,327 patients undergoing regular hemodialysis in the blood purification center of three grade-A tertiary hospitals in Guangdong and Guizhou provinces were selected by convenience sampling.The assessment was administered using the general information questionnaire and the Chinese version of PGAC.SPSS 25.0 and Amos 24.0 were used for item analysis,confirmatory factor analysis(CFA),convergent validity,and internal consistency reliability estimation.RESULTS In the modified Chinese version of PGAC,7 dimensions covering 27 total items were retained.CFA revealed a good fit of the factor model(chi-square degree of freedom=2.056,standardized root mean square residual=0.0479,root mean square error of approximation=0.0570,GFI=0.872,AGFI=0.841,IFI=0.931,CFI=0.930,TLI=0.919).The factor loadings of the items ranged 0.503-0.884.The composite reliability ranged 0.664-0.914,and the average variance extracted ranged 0.366-0.747.Cronbach’sαof the scale was 0.945,and Cronbach’sαfor various dimensions ranged 0.662-0.914.CONCLUSION The modified PGAC has good reliability and validity,and it can effectively measure preparatory grief in patients on hemodialysis.展开更多
Objective:To translate,adapt,and validate the Indonesian version of the Prenatal Health Behavior Scale.Methods:This cross-sectional,cross-cultural adaptation study was conducted between September 2024 and October 2024...Objective:To translate,adapt,and validate the Indonesian version of the Prenatal Health Behavior Scale.Methods:This cross-sectional,cross-cultural adaptation study was conducted between September 2024 and October 2024 in Ngrambe and Sine,subdistricts in Ngawi,East Java,Indonesia.We selected participants using purposive convenience sampling and matched them with inclusion and exclusion criteria.We collected sociodemographic,Prenatal Health Behavior Scale,and anthropometrics(height,weight,body mass index,and middle-upper arm circumference)data.We analyzed the content validity using the content validity index and Gwet's chance-corrected Agreement Coefficient 2,face validity by pilot-testing on several pregnant women,and construct validity using exploratory factor analysis.We measured reliability using McDonald's omega coefficient.Results:We recruited 183 pregnant women in this study(median age 28 years).The item-content validity index(I-CVI)of all items was 1.00,with Gwet's chance-corrected Agreement Coefficient 2 was 0.945.The face validity resulted in a clear statement of all items.The exploratory factor analysis showed the two-factor model best suited to the questionnaire.Omega coefficients for the overall scale,health-impairing,and health-promoting domains were 0.696,0.507,and 0.678,respectively.Conclusions:The Indonesian version of the Prenatal Health Behavior Scale is a valid and reliable instrument to assess prenatal health behavior in Indonesian-speaking pregnant women.Future studies may implement this scale in community and clinical settings.展开更多
Background and Objective Patients with glioma experience a high symptom burden and have diverse palliative care needs.However,the assessment scales used in palliative care remain non-standardized and highly heterogene...Background and Objective Patients with glioma experience a high symptom burden and have diverse palliative care needs.However,the assessment scales used in palliative care remain non-standardized and highly heterogeneous.To evaluate the application patterns of the current scales used in palliative care for glioma,we aim to identify gaps and assess the need for disease-specific scales in glioma palliative care.Methods We conducted a systematic search of five databases including PubMed,Web of Science,Medline,EMBASE,and CINAHL for quantitative studies that reported scale-based assessments in glioma palliative care.We extracted data on scale characteristics,domains,frequency,and psychometric properties.Quality assessments were performed using the Cochrane ROB 2.0 and ROBINS-I tools.Results Of the 3,405 records initially identified,72 studies were included.These studies contained 75 distinct scales that were used 193 times.Mood(21.7%),quality of life(24.4%),and supportive care needs(5.2%)assessments were the most frequently assessed items,exceeding half of all scale applications.Among the various assessment dimensions,the Distress Thermometer(DT)was the most frequently used tool for assessing mood,while the Short Form-36 Health Survey Questionnaire(SF-36)was the most frequently used tool for assessing quality of life.The Mini Mental Status Examination(MMSE)was the most common tool for cognitive assessment.Performance status(5.2%)and social support(6.8%)were underrepresented.Only three brain tumor-specific scales were identified.Caregiver-focused scales were limited and predominantly burden-oriented.Conclusions There are significant heterogeneity,domain imbalances,and validation gaps in the current use of assessment scales for patients with glioma receiving palliative care.The scale selected for use should be comprehensive and user-friendly.展开更多
The topographic factor(LS factor),derived from the multiplication of the slope length(L)and slope steepness(S)factors,is a vital parameter in soil erosion models.Generated from the digital elevation model(DEM),the LS ...The topographic factor(LS factor),derived from the multiplication of the slope length(L)and slope steepness(S)factors,is a vital parameter in soil erosion models.Generated from the digital elevation model(DEM),the LS factor always varies with the changing DEM resolution,i.e.,the LS factor scale effect.Previous studies have found the phenomenon of the LS factor scale effect,but the underlying causes of this phenomenon has not been well explored.Therefore,how the DEM resolution affects the LS factor and how the scale effect of the L and S factors influence the LS factor scale effect remains unclear.To address these problems,we collected 20 watersheds from the Guangdong Province with different topographic reliefs,and compared the corresponding L,S and LS factors at 10-m and 30-m resolution DEMs.Our results indicate that the S factor,heavily influenced by slope underestimation in coarse-resolution DEMs,makes a difference in the LS factor scale effect.In addition,the LS factor scale effect becomes less significant with increasing reliefs,suggesting the possibility of using 30-m DEM for LS calculation in rugged terrains.Our findings on the underlying mechanisms of the LS factor scale effect help to identify the uncertainty in the LS factor estimation,thereby enhancing the accuracy of soil erosion assessment,particularly in regions with different topographic characteristics and contribute to more effective soil conservation strategies and decision-making.展开更多
With growing interest in its potential applications across both stationary and transportation sectors,hydrogen has emerged as a promising alternative for environmentally responsible power generation.By replacing tradi...With growing interest in its potential applications across both stationary and transportation sectors,hydrogen has emerged as a promising alternative for environmentally responsible power generation.By replacing traditional fuels,hydrogen can significantly reduce greenhouse gas emissions in the transportation sector.This study focuses on the design and downsizing of a green hydrogen fuel cell car,aiming to scale the concept for larger vehicles.Key components,including fuel cells,electrolysers,and solar panels,were evaluated through extensive laboratory testing.Thefindings reveal that variations in sunlight impact the solar panel’shydrogenproductionrate,withdifferences of approximately 4.9%attributed to changes in time and date.Analysis of consumption rates showed that a 17.4%increase in current consumption leads to a significant reduction in operational time.Further testing under varying loads demonstrated that higher current demands,such as those from a DC motor,accelerate hydrogen depletion,whereas lower currents extend operational duration.These results underscore the importance of maximizing solar energy efficiency,reducing reliance on conventional energy sources,and regulating consumption rates to optimize fuel cell performance.Since hydrogen is produced using renewable energy,fuel cell technology is virtually emission-free.Additionally,the study highlights the viability of powering vehicles with renewable energy,emphasizing the potential of green hydrogen fuel cell technology as a sustainable transportation solution.展开更多
Background:Excess submental fat(SMF)is a common facial aesthetic concern,and assessment scales play a crucial role in its evaluation.Existing SMF scales are based on Caucasian populations,although genetic background s...Background:Excess submental fat(SMF)is a common facial aesthetic concern,and assessment scales play a crucial role in its evaluation.Existing SMF scales are based on Caucasian populations,although genetic background significantly influences SMF distribution.Therefore,this study aimed to develop and validate a 5-point Chinese version of the Clinician-Reported Submental Fat Rating Scale(CR-SMFRS).Methods:The study included 150 volunteers,and captured photographs from the frontal,oblique,and lateral views were combined for each participant.A 5-point scale with descriptive criteria was primarily designed.Internal validation involved three experienced plastic surgeons,while external validation was conducted on 50 live volunteers by six additional raters.Intra-and inter-rater reliability were assessed.Results:A 5-point grading system with descriptive criteria was developed and validated as the Chinese CR-SMFRS.Internal validation demonstrated a good intra-and inter-rater consistency.During external validation,intraclass correlation coefficient values for each rater exceeded 0.850,indicating high intra-rater consistency.Moreover,the inter-rater reliability showed good consistency.Conclusion:The Chinese version of the SMF rating scale is a reliable tool for clinical use.展开更多
Because the physiological characteristics and melanin regulation mechanism of zebrafish are highly similar with those of humans,it is of high reference value to use zebrafish model in the evaluation of cosmetic whiten...Because the physiological characteristics and melanin regulation mechanism of zebrafish are highly similar with those of humans,it is of high reference value to use zebrafish model in the evaluation of cosmetic whitening efficacy.In this study,zebrafish embryos are used as biological models to evaluate the whitening efficacy of six kinds of cosmetics raw materials,such as antioxidant,preservative and essence,and the formula of facial cleanser and facial mask products,and the limitations of the zebrafish melanin production grayscale detection method in practical application are discussed.The results show that the selection of different types of components can also reduce the production of melanin and show whitening effect.It can be seen that the gray scale method of melanin production in zebrafish is suitable for the evaluation of the efficacy of raw materials.In practical application,due to the complexity of the formula,the toxic effects of different types of ingredients may interfere with the melanin generation of zebrafish,affecting the judgment and evaluation of whitening efficacy.For the detection of whitening efficacy of products,a comprehensive evaluation system should be built together with other methods to accurately evaluate the whitening efficacy.展开更多
Objectives:Schizophrenia is a profoundly stigmatized mental health condition,characterized by misconceptions that affect societal attitudes,policy development,and the lived experiences of individuals with the conditio...Objectives:Schizophrenia is a profoundly stigmatized mental health condition,characterized by misconceptions that affect societal attitudes,policy development,and the lived experiences of individuals with the condition.This study aimed to develop and validate a multidimensional scale for assessing societal stigma towards schizophrenia,while exploring how demographic factors influence such attitudes.Methods:Drawing on an extensive literature review and consultations,the study identified five domains of stigma:Workplace Capability,Intimate Relationships,Autonomy,Risk Perception,and Recovery.Using a two-phase methodology,a preliminary 38-itemscale was administered to 729 participants from the general Spanish population,refining the measure through descriptive and exploratory factor analysis.Subsequently,a revised 34-item scale was validated through confirmatory factor analysis with an independent sample of 417 participants.Results:The final model showed good fit(RMSEA=0.056,CFI=0.938,TLI=0.933)and strong internal consistency(α=0.73–0.86).Findings revealed that stigma was most pronounced in the domain of Autonomy(Mean=2.83,SD=0.91),reflecting pervasive doubts about individuals’ability to live independently and achieve meaningful integration into society.Stigma varied significantly across demographic variables,with higher levels reported among men,older individuals,married participants,and those outside health professions(p<0.01).Conversely,healthcare professionals,younger individuals,and those familiar with someone with schizophrenia generally reported less stigma(p<0.01).Conclusion:This study developed and validated a robust multidimensional scale for assessing societal stigma toward schizophrenia.The five-factor model—Workplace Capability,Intimate Relationships,Autonomy,Risk Perception,and Recovery—was empirically supported.Autonomy and Recovery emerged as themost stigmatized domains across the Spanish general population.The scale demonstrated strong psychometric properties and effectively captured stigma patterns linked to key sociodemographic variables.展开更多
We propose a hierarchical multi-scale attention mechanism-based model in response to the low accuracy and inefficient manual classification of existing oceanic biological image classification methods. Firstly, the hie...We propose a hierarchical multi-scale attention mechanism-based model in response to the low accuracy and inefficient manual classification of existing oceanic biological image classification methods. Firstly, the hierarchical efficient multi-scale attention(H-EMA) module is designed for lightweight feature extraction, achieving outstanding performance at a relatively low cost. Secondly, an improved EfficientNetV2 block is used to integrate information from different scales better and enhance inter-layer message passing. Furthermore, introducing the convolutional block attention module(CBAM) enhances the model's perception of critical features, optimizing its generalization ability. Lastly, Focal Loss is introduced to adjust the weights of complex samples to address the issue of imbalanced categories in the dataset, further improving the model's performance. The model achieved 96.11% accuracy on the intertidal marine organism dataset of Nanji Islands and 84.78% accuracy on the CIFAR-100 dataset, demonstrating its strong generalization ability to meet the demands of oceanic biological image classification.展开更多
The impacts of lateral boundary conditions(LBCs)provided by numerical models and data-driven networks on convective-scale ensemble forecasts are investigated in this study.Four experiments are conducted on the Hangzho...The impacts of lateral boundary conditions(LBCs)provided by numerical models and data-driven networks on convective-scale ensemble forecasts are investigated in this study.Four experiments are conducted on the Hangzhou RDP(19th Hangzhou Asian Games Research Development Project on Convective-scale Ensemble Prediction and Application)testbed,with the LBCs respectively sourced from National Centers for Environmental Prediction(NCEP)Global Forecast System(GFS)forecasts with 33 vertical levels(Exp_GFS),Pangu forecasts with 13 vertical levels(Exp_Pangu),Fuxi forecasts with 13 vertical levels(Exp_Fuxi),and NCEP GFS forecasts with the vertical levels reduced to 13(the same as those of Exp_Pangu and Exp_Fuxi)(Exp_GFSRDV).In general,Exp_Pangu performs comparably to Exp_GFS,while Exp_Fuxi shows slightly inferior performance compared to Exp_Pangu,possibly due to its less accurate large-scale predictions.Therefore,the ability of using data-driven networks to efficiently provide LBCs for convective-scale ensemble forecasts has been demonstrated.Moreover,Exp_GFSRDV has the worst convective-scale forecasts among the four experiments,which indicates the potential improvement of using data-driven networks for LBCs by increasing the vertical levels of the networks.However,the ensemble spread of the four experiments barely increases with lead time.Thus,each experiment has insufficient ensemble spread to present realistic forecast uncertainties,which will be investigated in a future study.展开更多
Multi-label image classification is a challenging task due to the diverse sizes and complex backgrounds of objects in images.Obtaining class-specific precise representations at different scales is a key aspect of feat...Multi-label image classification is a challenging task due to the diverse sizes and complex backgrounds of objects in images.Obtaining class-specific precise representations at different scales is a key aspect of feature representation.However,existing methods often rely on the single-scale deep feature,neglecting shallow and deeper layer features,which poses challenges when predicting objects of varying scales within the same image.Although some studies have explored multi-scale features,they rarely address the flow of information between scales or efficiently obtain class-specific precise representations for features at different scales.To address these issues,we propose a two-stage,three-branch Transformer-based framework.The first stage incorporates multi-scale image feature extraction and hierarchical scale attention.This design enables the model to consider objects at various scales while enhancing the flow of information across different feature scales,improving the model’s generalization to diverse object scales.The second stage includes a global feature enhancement module and a region selection module.The global feature enhancement module strengthens interconnections between different image regions,mitigating the issue of incomplete represen-tations,while the region selection module models the cross-modal relationships between image features and labels.Together,these components enable the efficient acquisition of class-specific precise feature representations.Extensive experiments on public datasets,including COCO2014,VOC2007,and VOC2012,demonstrate the effectiveness of our proposed method.Our approach achieves consistent performance gains of 0.3%,0.4%,and 0.2%over state-of-the-art methods on the three datasets,respectively.These results validate the reliability and superiority of our approach for multi-label image classification.展开更多
Background:Mental health literacy(MHL)refers to one’s knowledge and understanding of mental health disorders and their treatments.This literacy may be influenced by cultural norms and values that shape individuals’e...Background:Mental health literacy(MHL)refers to one’s knowledge and understanding of mental health disorders and their treatments.This literacy may be influenced by cultural norms and values that shape individuals’experiences,beliefs,attitudes,and behaviors regarding mental health.This study focuses on adapting the Mental health literacy scale(MHLS)for use in the multicultural context of Israel.Objectives include validating its construct,assessing its accuracy in measuring MHL in this diverse setting and examining and comparing levels of MHL across different cultural groups.Methods:The data collection included 1057 participants,representing all the ethnic groups of the Israeli population aged 18 and over.The tools included the MHLS and a demographic questionnaire.Confirmatory factor analysis(CFA)was employed to assess the original structure of the MHLS.Results:The results revealed that after evaluating the original MHLS,five items were excluded,leading to the validation of a modified version—Israeli mental health scale(IMHLS)with four factors and 25 items.CFA and reliability analyses supported an established and robust four-factor model.Significant ethnic differences in MHLS scores were identified,with Muslim participants showing the highest familiarity with mental disorders,followed by Druze and Christian participants,while Jewish participants had the lowest familiarity.Conclusion:The study concluded that the IMHLS is a valid and reliable tool for assessing MHL in Israel’s diverse and multicultural population.The revised scale better reflects the cultural nuances of the Israeli context.The significant ethnic differences that the study revealed in IMHLS emphasize the importance of culturally sensitive mental health interventions tailored to different ethnic groups in Israel.展开更多
The impact of location services on people’s lives has grown significantly in the era of widespread smart device usage.Due to global navigation satellite system(GNSS)signal rejection,weak signal strength in indoor env...The impact of location services on people’s lives has grown significantly in the era of widespread smart device usage.Due to global navigation satellite system(GNSS)signal rejection,weak signal strength in indoor environments and radio signal interference caused by multiwall environments,which collectively lead to significant positioning errors,vision-based positioning has emerged as a crucial method in indoor positioning research.This paper introduces a scale hierarchical matching model to tackle challenges associated with large visual databases and high scene similarity,both of which will compromise matching accuracy and lead to prolonged positioning delays.The proposed model establishes an image feature database using GIST features and speeded up robust feature(SURF)in the offline stage.In the online stage,a positioning navigating algorithm is constructed based on Dijkstra’s path planning.Additionally,a corresponding Android application has been developed to facilitate visual positioning and navigation in indoor environments.Experimental results obtained in real indoor environments demonstrate that the proposed method significantly enhances positioning accuracy compared with similar algorithms,while effectively reducing time overhead.This improvement caters to the requirements for indoor positioning and navigation,thereby meeting user needs.展开更多
The ground-based experimental tests are crucial to verify the related technologies of the drag-free satellite.This work presents a design method of the ground simulator testbed for emulating the planar dynamics of the...The ground-based experimental tests are crucial to verify the related technologies of the drag-free satellite.This work presents a design method of the ground simulator testbed for emulating the planar dynamics of the space drag-free systems.In this paper,the planar dynamic characteristics of the drag-free satellite with double test masses are analyzed and nondimensionalized.A simulator vehicle composed of an air bearing testbed and two inverted pendulums is devised on the basic of equivalent mass and equivalent stiffness proposed firstly in this paper.And the dynamic model of the simulator equivalent to the sensitive axis motion of the test mass and the planar motion of the satellite is derived from the Euler-Lagrange method.Then,the dynamic equivalence conditions between the space prototype system and the ground model system are derived from Pi theorem.To satisfy these conditions,the scaling laws of two systems and requirements for the inverted pendulum are put forward.Besides,the corresponding control scaling laws and a closed-loop control strategy are deduced and applied to establishing the numerical simulation experiments of underactuated system.Subsequently,the comparative simulation results demonstrate the similarity of dynamical behavior between the scaled-down ground model and the space prototype.As a result,the rationality and effectiveness of the design method are proved,facilitating the ground simulation of future gravitational wave detection satellites.展开更多
文摘Mason Reset(MR),a groundbreaking invention by Clesson E.Mason in 1930 that later became a part of“the universal approach to process control instrumentation”,is revisited in this paper and is shown to consists of three actions:fast(errorcorrection),medium(negative feedback for expanded proportional band)and slow(reset for zero steady-state error).The focus of the paper is on the reset action,generated from a positive feedback loop,and its underlying principles with profound implications to our understanding and practice of automatic control,both basic and advanced.For example,we note that reset control and integral control,contrary to common belief,differ fundamentally in design principle and in practicality.Such difference comes to a head in the event of integrator windup:while reset windup is a problem of actuator saturation,the integrator windup is a runaway situation due to controller instability.In fact,there is no advantage gained in replacing MR with an integrator.In other words,one should not integrate the error directly as in standard PID,since doing so makes the closed-loop system internally unstable.With MR-based control formulated in this paper,there is no such threat of instability and,therefore,no need for any anti-windup mechanisms.Furthermore,the integral control is made scalable in this framework as a tradeoff between the steady-state accuracy and the controller stability.This leads to a novel MR-based control design,scalable in gain and in time to accommodate various process characteristics and design specifications.Simple in construction and transparent in principle,this MR-based control,as a basic framework of design,is readily deployable in scale.
基金supported by the National Natural Science Foundation of China(No.62241109)the Tianjin Science and Technology Commissioner Project(No.20YDTPJC01110)。
文摘An improved model based on you only look once version 8(YOLOv8)is proposed to solve the problem of low detection accuracy due to the diversity of object sizes in optical remote sensing images.Firstly,the feature pyramid network(FPN)structure of the original YOLOv8 mode is replaced by the generalized-FPN(GFPN)structure in GiraffeDet to realize the"cross-layer"and"cross-scale"adaptive feature fusion,to enrich the semantic information and spatial information on the feature map to improve the target detection ability of the model.Secondly,a pyramid-pool module of multi atrous spatial pyramid pooling(MASPP)is designed by using the idea of atrous convolution and feature pyramid structure to extract multi-scale features,so as to improve the processing ability of the model for multi-scale objects.The experimental results show that the detection accuracy of the improved YOLOv8 model on DIOR dataset is 92%and mean average precision(mAP)is 87.9%,respectively 3.5%and 1.7%higher than those of the original model.It is proved the detection and classification ability of the proposed model on multi-dimensional optical remote sensing target has been improved.
基金supported by the National Natural Science Foundation of China(No.82371530,82171529)the Capital Health Development Special Research Project(2022-1-4111)the National Key Technology R and D Program(No.2015BAI13B01).
文摘Background The patient-reported Dimensional Anhedonia Rating Scale(DARS)has been adapted into Chinese,so there is a need to evaluate its measurement properties in a Chinese population.Aims To evaluate the reliability and validity of the DARS among Chinese individuals with major depressive disorder(MDD)and its treatment sensitivity in a prospective clinical study.Methods Data were from a multicentre,prospective clinical study(NCT03294525),which recruited both patients with MDD,who were followed for 8 weeks,and healthy controls(HCs),assessed at baseline only.The analysis included confirmatory factor analysis,validity and sensitivity to change.Results Patients’mean(standard deviation(SD))age was 34.8(11.0)years,with 68.7%being female.75.2%of patients with MDD had melancholic features,followed by 63.8%with anxious distress.Patients had experienced MDD for a mean(SD)of 9.2(18)months.DARS scores covered the full range of severity with no major floor or ceiling effects.Confirmatory factor analysis showed adequate fit statistics(comparative fit index 0.976,goodness-of-fit index 0.935 and root mean square error of approximation 0.055).Convergent validity with anhedonia-related measures was confirmed.While the correlation between the DARS and the Hamilton Depression Rating Scale was not strong(r=0.31,baseline),the DARS was found to differentiate between levels of depression.Greater improvements in DARS scores were seen with the Hamilton Rating Scale for Depression responder group(effect size 1.16)compared with the non-responder group(effect size 0.46).Conclusions This study comprehensively evaluated the measurement properties of the DARS using a Chinese population with MDD.Overall,the Chinese version of DARS demonstrates good psychometric properties and has been found to be responsive to change during antidepressant treatment.The DARS is a suitable scale for assessing patient-reported anhedonia in future clinical trials.
基金supported by the Turkish Green Crescent Society under Grant[41402653-160-6/333].
文摘Background The effectiveness of life skills-based prevention programs to prevent substance addiction has been underexplored in Türkiye,likely in part due to the lack of validated measurement tools developed specifically for that purpose.Therefore,the aim of this study is to develop a tool to measure life skills for middle school students.The present study aims to test the factorial structure,reliability,convergent and discriminant validity,and measurement invariance across gender and age groups of the Green Crescent Life Skills(GCLS)Scale.Methods The study was conducted in Istanbul with two different sample groups.The first sample consisted of 566 and the second sample consisted of 885 middle school students.In the study,exploratory factor analysis(EFA)was applied to the first sample,and confirmatory factor analysis(CFA)was applied to the second sample to test the factorial structure of the scale.Convergent and discriminant validity were examined to provide evidence for construct-based validity.The reliability of the scale was assessed with Cronbach’sα,composite reliability,McDonald’sω,and test-retest.Results The EFA results showed that the scale consisted of four factors(self-awareness,coping with negative emotions,thinking skills,and peer relations).CFA results also confirmed this structure.The results revealed a significant positive correlation(r=0.52,p<0.01)between life skills and avoidance self-efficacy scores,as well as a significant negative correlation(r=−0.53,p<0.01)between life skills and attitude toward drug use scores.Additionally,it was found that measurement invariances based on gender and age groups were provided.It was determined that all sub-dimensions had sufficient reliability levels.Conclusion The findings of this validation study show that the GCLS Scale,which assesses four skills in a self-reported format,is a valid and reliable scale with considerable potential utility in monitoring life skills in Turkish adolescent populations.
文摘BACKGROUND During the gradual decline of physical and social functioning associated with end-stage renal disease,patients might experience a premonition of impending death,resulting in a series of pre-mourning grief responses called preparatory grief.The preparatory grief in advanced cancer patients(PGAC)scale is the most widely used preparatory grief scale for patients on hemodialysis in China.AIM To verify the reliability and validity of the PGAC scale in patients on hemodialysis.METHODS In total,327 patients undergoing regular hemodialysis in the blood purification center of three grade-A tertiary hospitals in Guangdong and Guizhou provinces were selected by convenience sampling.The assessment was administered using the general information questionnaire and the Chinese version of PGAC.SPSS 25.0 and Amos 24.0 were used for item analysis,confirmatory factor analysis(CFA),convergent validity,and internal consistency reliability estimation.RESULTS In the modified Chinese version of PGAC,7 dimensions covering 27 total items were retained.CFA revealed a good fit of the factor model(chi-square degree of freedom=2.056,standardized root mean square residual=0.0479,root mean square error of approximation=0.0570,GFI=0.872,AGFI=0.841,IFI=0.931,CFI=0.930,TLI=0.919).The factor loadings of the items ranged 0.503-0.884.The composite reliability ranged 0.664-0.914,and the average variance extracted ranged 0.366-0.747.Cronbach’sαof the scale was 0.945,and Cronbach’sαfor various dimensions ranged 0.662-0.914.CONCLUSION The modified PGAC has good reliability and validity,and it can effectively measure preparatory grief in patients on hemodialysis.
文摘Objective:To translate,adapt,and validate the Indonesian version of the Prenatal Health Behavior Scale.Methods:This cross-sectional,cross-cultural adaptation study was conducted between September 2024 and October 2024 in Ngrambe and Sine,subdistricts in Ngawi,East Java,Indonesia.We selected participants using purposive convenience sampling and matched them with inclusion and exclusion criteria.We collected sociodemographic,Prenatal Health Behavior Scale,and anthropometrics(height,weight,body mass index,and middle-upper arm circumference)data.We analyzed the content validity using the content validity index and Gwet's chance-corrected Agreement Coefficient 2,face validity by pilot-testing on several pregnant women,and construct validity using exploratory factor analysis.We measured reliability using McDonald's omega coefficient.Results:We recruited 183 pregnant women in this study(median age 28 years).The item-content validity index(I-CVI)of all items was 1.00,with Gwet's chance-corrected Agreement Coefficient 2 was 0.945.The face validity resulted in a clear statement of all items.The exploratory factor analysis showed the two-factor model best suited to the questionnaire.Omega coefficients for the overall scale,health-impairing,and health-promoting domains were 0.696,0.507,and 0.678,respectively.Conclusions:The Indonesian version of the Prenatal Health Behavior Scale is a valid and reliable instrument to assess prenatal health behavior in Indonesian-speaking pregnant women.Future studies may implement this scale in community and clinical settings.
文摘Background and Objective Patients with glioma experience a high symptom burden and have diverse palliative care needs.However,the assessment scales used in palliative care remain non-standardized and highly heterogeneous.To evaluate the application patterns of the current scales used in palliative care for glioma,we aim to identify gaps and assess the need for disease-specific scales in glioma palliative care.Methods We conducted a systematic search of five databases including PubMed,Web of Science,Medline,EMBASE,and CINAHL for quantitative studies that reported scale-based assessments in glioma palliative care.We extracted data on scale characteristics,domains,frequency,and psychometric properties.Quality assessments were performed using the Cochrane ROB 2.0 and ROBINS-I tools.Results Of the 3,405 records initially identified,72 studies were included.These studies contained 75 distinct scales that were used 193 times.Mood(21.7%),quality of life(24.4%),and supportive care needs(5.2%)assessments were the most frequently assessed items,exceeding half of all scale applications.Among the various assessment dimensions,the Distress Thermometer(DT)was the most frequently used tool for assessing mood,while the Short Form-36 Health Survey Questionnaire(SF-36)was the most frequently used tool for assessing quality of life.The Mini Mental Status Examination(MMSE)was the most common tool for cognitive assessment.Performance status(5.2%)and social support(6.8%)were underrepresented.Only three brain tumor-specific scales were identified.Caregiver-focused scales were limited and predominantly burden-oriented.Conclusions There are significant heterogeneity,domain imbalances,and validation gaps in the current use of assessment scales for patients with glioma receiving palliative care.The scale selected for use should be comprehensive and user-friendly.
基金funded by the Guangdong Major Project of Basic and Applied Basic Research(2021B0301030007)the Supplemental Funds for Major Scientific Research Projects of Beijing Normal University,Zhuhai(ZHPT2023013)+1 种基金the National Natural Science Foundation of China(42301387)the Science and Technology Program of Guangdong(No.2024B1212070012)。
文摘The topographic factor(LS factor),derived from the multiplication of the slope length(L)and slope steepness(S)factors,is a vital parameter in soil erosion models.Generated from the digital elevation model(DEM),the LS factor always varies with the changing DEM resolution,i.e.,the LS factor scale effect.Previous studies have found the phenomenon of the LS factor scale effect,but the underlying causes of this phenomenon has not been well explored.Therefore,how the DEM resolution affects the LS factor and how the scale effect of the L and S factors influence the LS factor scale effect remains unclear.To address these problems,we collected 20 watersheds from the Guangdong Province with different topographic reliefs,and compared the corresponding L,S and LS factors at 10-m and 30-m resolution DEMs.Our results indicate that the S factor,heavily influenced by slope underestimation in coarse-resolution DEMs,makes a difference in the LS factor scale effect.In addition,the LS factor scale effect becomes less significant with increasing reliefs,suggesting the possibility of using 30-m DEM for LS calculation in rugged terrains.Our findings on the underlying mechanisms of the LS factor scale effect help to identify the uncertainty in the LS factor estimation,thereby enhancing the accuracy of soil erosion assessment,particularly in regions with different topographic characteristics and contribute to more effective soil conservation strategies and decision-making.
文摘With growing interest in its potential applications across both stationary and transportation sectors,hydrogen has emerged as a promising alternative for environmentally responsible power generation.By replacing traditional fuels,hydrogen can significantly reduce greenhouse gas emissions in the transportation sector.This study focuses on the design and downsizing of a green hydrogen fuel cell car,aiming to scale the concept for larger vehicles.Key components,including fuel cells,electrolysers,and solar panels,were evaluated through extensive laboratory testing.Thefindings reveal that variations in sunlight impact the solar panel’shydrogenproductionrate,withdifferences of approximately 4.9%attributed to changes in time and date.Analysis of consumption rates showed that a 17.4%increase in current consumption leads to a significant reduction in operational time.Further testing under varying loads demonstrated that higher current demands,such as those from a DC motor,accelerate hydrogen depletion,whereas lower currents extend operational duration.These results underscore the importance of maximizing solar energy efficiency,reducing reliance on conventional energy sources,and regulating consumption rates to optimize fuel cell performance.Since hydrogen is produced using renewable energy,fuel cell technology is virtually emission-free.Additionally,the study highlights the viability of powering vehicles with renewable energy,emphasizing the potential of green hydrogen fuel cell technology as a sustainable transportation solution.
基金supported by the National High Level Hospital Clinical Research Funding(grant no.2022-PUMCH-A-208).
文摘Background:Excess submental fat(SMF)is a common facial aesthetic concern,and assessment scales play a crucial role in its evaluation.Existing SMF scales are based on Caucasian populations,although genetic background significantly influences SMF distribution.Therefore,this study aimed to develop and validate a 5-point Chinese version of the Clinician-Reported Submental Fat Rating Scale(CR-SMFRS).Methods:The study included 150 volunteers,and captured photographs from the frontal,oblique,and lateral views were combined for each participant.A 5-point scale with descriptive criteria was primarily designed.Internal validation involved three experienced plastic surgeons,while external validation was conducted on 50 live volunteers by six additional raters.Intra-and inter-rater reliability were assessed.Results:A 5-point grading system with descriptive criteria was developed and validated as the Chinese CR-SMFRS.Internal validation demonstrated a good intra-and inter-rater consistency.During external validation,intraclass correlation coefficient values for each rater exceeded 0.850,indicating high intra-rater consistency.Moreover,the inter-rater reliability showed good consistency.Conclusion:The Chinese version of the SMF rating scale is a reliable tool for clinical use.
文摘Because the physiological characteristics and melanin regulation mechanism of zebrafish are highly similar with those of humans,it is of high reference value to use zebrafish model in the evaluation of cosmetic whitening efficacy.In this study,zebrafish embryos are used as biological models to evaluate the whitening efficacy of six kinds of cosmetics raw materials,such as antioxidant,preservative and essence,and the formula of facial cleanser and facial mask products,and the limitations of the zebrafish melanin production grayscale detection method in practical application are discussed.The results show that the selection of different types of components can also reduce the production of melanin and show whitening effect.It can be seen that the gray scale method of melanin production in zebrafish is suitable for the evaluation of the efficacy of raw materials.In practical application,due to the complexity of the formula,the toxic effects of different types of ingredients may interfere with the melanin generation of zebrafish,affecting the judgment and evaluation of whitening efficacy.For the detection of whitening efficacy of products,a comprehensive evaluation system should be built together with other methods to accurately evaluate the whitening efficacy.
文摘Objectives:Schizophrenia is a profoundly stigmatized mental health condition,characterized by misconceptions that affect societal attitudes,policy development,and the lived experiences of individuals with the condition.This study aimed to develop and validate a multidimensional scale for assessing societal stigma towards schizophrenia,while exploring how demographic factors influence such attitudes.Methods:Drawing on an extensive literature review and consultations,the study identified five domains of stigma:Workplace Capability,Intimate Relationships,Autonomy,Risk Perception,and Recovery.Using a two-phase methodology,a preliminary 38-itemscale was administered to 729 participants from the general Spanish population,refining the measure through descriptive and exploratory factor analysis.Subsequently,a revised 34-item scale was validated through confirmatory factor analysis with an independent sample of 417 participants.Results:The final model showed good fit(RMSEA=0.056,CFI=0.938,TLI=0.933)and strong internal consistency(α=0.73–0.86).Findings revealed that stigma was most pronounced in the domain of Autonomy(Mean=2.83,SD=0.91),reflecting pervasive doubts about individuals’ability to live independently and achieve meaningful integration into society.Stigma varied significantly across demographic variables,with higher levels reported among men,older individuals,married participants,and those outside health professions(p<0.01).Conversely,healthcare professionals,younger individuals,and those familiar with someone with schizophrenia generally reported less stigma(p<0.01).Conclusion:This study developed and validated a robust multidimensional scale for assessing societal stigma toward schizophrenia.The five-factor model—Workplace Capability,Intimate Relationships,Autonomy,Risk Perception,and Recovery—was empirically supported.Autonomy and Recovery emerged as themost stigmatized domains across the Spanish general population.The scale demonstrated strong psychometric properties and effectively captured stigma patterns linked to key sociodemographic variables.
基金supported by the National Natural Science Foundation of China (Nos.61806107 and 61702135)。
文摘We propose a hierarchical multi-scale attention mechanism-based model in response to the low accuracy and inefficient manual classification of existing oceanic biological image classification methods. Firstly, the hierarchical efficient multi-scale attention(H-EMA) module is designed for lightweight feature extraction, achieving outstanding performance at a relatively low cost. Secondly, an improved EfficientNetV2 block is used to integrate information from different scales better and enhance inter-layer message passing. Furthermore, introducing the convolutional block attention module(CBAM) enhances the model's perception of critical features, optimizing its generalization ability. Lastly, Focal Loss is introduced to adjust the weights of complex samples to address the issue of imbalanced categories in the dataset, further improving the model's performance. The model achieved 96.11% accuracy on the intertidal marine organism dataset of Nanji Islands and 84.78% accuracy on the CIFAR-100 dataset, demonstrating its strong generalization ability to meet the demands of oceanic biological image classification.
基金supported by the Strategic Research and Consulting Project of the Chinese Academy of Engineering[grant number 2024-XBZD-14]the National Natural Science Foundation of China[grant numbers 42192553 and 41922036]the Fundamental Research Funds for the Central Universities–Cemac“GeoX”Interdisciplinary Program[grant number 020714380207]。
文摘The impacts of lateral boundary conditions(LBCs)provided by numerical models and data-driven networks on convective-scale ensemble forecasts are investigated in this study.Four experiments are conducted on the Hangzhou RDP(19th Hangzhou Asian Games Research Development Project on Convective-scale Ensemble Prediction and Application)testbed,with the LBCs respectively sourced from National Centers for Environmental Prediction(NCEP)Global Forecast System(GFS)forecasts with 33 vertical levels(Exp_GFS),Pangu forecasts with 13 vertical levels(Exp_Pangu),Fuxi forecasts with 13 vertical levels(Exp_Fuxi),and NCEP GFS forecasts with the vertical levels reduced to 13(the same as those of Exp_Pangu and Exp_Fuxi)(Exp_GFSRDV).In general,Exp_Pangu performs comparably to Exp_GFS,while Exp_Fuxi shows slightly inferior performance compared to Exp_Pangu,possibly due to its less accurate large-scale predictions.Therefore,the ability of using data-driven networks to efficiently provide LBCs for convective-scale ensemble forecasts has been demonstrated.Moreover,Exp_GFSRDV has the worst convective-scale forecasts among the four experiments,which indicates the potential improvement of using data-driven networks for LBCs by increasing the vertical levels of the networks.However,the ensemble spread of the four experiments barely increases with lead time.Thus,each experiment has insufficient ensemble spread to present realistic forecast uncertainties,which will be investigated in a future study.
基金supported by the National Natural Science Foundation of China(62302167,62477013)Natural Science Foundation of Shanghai(No.24ZR1456100)+1 种基金Science and Technology Commission of Shanghai Municipality(No.24DZ2305900)the Shanghai Municipal Special Fund for Promoting High-Quality Development of Industries(2211106).
文摘Multi-label image classification is a challenging task due to the diverse sizes and complex backgrounds of objects in images.Obtaining class-specific precise representations at different scales is a key aspect of feature representation.However,existing methods often rely on the single-scale deep feature,neglecting shallow and deeper layer features,which poses challenges when predicting objects of varying scales within the same image.Although some studies have explored multi-scale features,they rarely address the flow of information between scales or efficiently obtain class-specific precise representations for features at different scales.To address these issues,we propose a two-stage,three-branch Transformer-based framework.The first stage incorporates multi-scale image feature extraction and hierarchical scale attention.This design enables the model to consider objects at various scales while enhancing the flow of information across different feature scales,improving the model’s generalization to diverse object scales.The second stage includes a global feature enhancement module and a region selection module.The global feature enhancement module strengthens interconnections between different image regions,mitigating the issue of incomplete represen-tations,while the region selection module models the cross-modal relationships between image features and labels.Together,these components enable the efficient acquisition of class-specific precise feature representations.Extensive experiments on public datasets,including COCO2014,VOC2007,and VOC2012,demonstrate the effectiveness of our proposed method.Our approach achieves consistent performance gains of 0.3%,0.4%,and 0.2%over state-of-the-art methods on the three datasets,respectively.These results validate the reliability and superiority of our approach for multi-label image classification.
文摘Background:Mental health literacy(MHL)refers to one’s knowledge and understanding of mental health disorders and their treatments.This literacy may be influenced by cultural norms and values that shape individuals’experiences,beliefs,attitudes,and behaviors regarding mental health.This study focuses on adapting the Mental health literacy scale(MHLS)for use in the multicultural context of Israel.Objectives include validating its construct,assessing its accuracy in measuring MHL in this diverse setting and examining and comparing levels of MHL across different cultural groups.Methods:The data collection included 1057 participants,representing all the ethnic groups of the Israeli population aged 18 and over.The tools included the MHLS and a demographic questionnaire.Confirmatory factor analysis(CFA)was employed to assess the original structure of the MHLS.Results:The results revealed that after evaluating the original MHLS,five items were excluded,leading to the validation of a modified version—Israeli mental health scale(IMHLS)with four factors and 25 items.CFA and reliability analyses supported an established and robust four-factor model.Significant ethnic differences in MHLS scores were identified,with Muslim participants showing the highest familiarity with mental disorders,followed by Druze and Christian participants,while Jewish participants had the lowest familiarity.Conclusion:The study concluded that the IMHLS is a valid and reliable tool for assessing MHL in Israel’s diverse and multicultural population.The revised scale better reflects the cultural nuances of the Israeli context.The significant ethnic differences that the study revealed in IMHLS emphasize the importance of culturally sensitive mental health interventions tailored to different ethnic groups in Israel.
基金Supported by the National Natural Science Foundation of China(No.61971162,61771186)the Natural Science Foundation of Heilongjiang Province(No.PL2024F025)+1 种基金the Open Research Fund of National Mobile Communications Research Laboratory in Southeast University(No.2023D07)the Fundamental Scientific Research Funds of Heilongjiang Province(No.2022-KYYWF-1050).
文摘The impact of location services on people’s lives has grown significantly in the era of widespread smart device usage.Due to global navigation satellite system(GNSS)signal rejection,weak signal strength in indoor environments and radio signal interference caused by multiwall environments,which collectively lead to significant positioning errors,vision-based positioning has emerged as a crucial method in indoor positioning research.This paper introduces a scale hierarchical matching model to tackle challenges associated with large visual databases and high scene similarity,both of which will compromise matching accuracy and lead to prolonged positioning delays.The proposed model establishes an image feature database using GIST features and speeded up robust feature(SURF)in the offline stage.In the online stage,a positioning navigating algorithm is constructed based on Dijkstra’s path planning.Additionally,a corresponding Android application has been developed to facilitate visual positioning and navigation in indoor environments.Experimental results obtained in real indoor environments demonstrate that the proposed method significantly enhances positioning accuracy compared with similar algorithms,while effectively reducing time overhead.This improvement caters to the requirements for indoor positioning and navigation,thereby meeting user needs.
基金supported by the National Key Research and Development Program of China (Grant No.2021YFC2202604)the Strategy Priority Research Program of Chinese Academy of Sciences (Grant No.XDA1502110101).
文摘The ground-based experimental tests are crucial to verify the related technologies of the drag-free satellite.This work presents a design method of the ground simulator testbed for emulating the planar dynamics of the space drag-free systems.In this paper,the planar dynamic characteristics of the drag-free satellite with double test masses are analyzed and nondimensionalized.A simulator vehicle composed of an air bearing testbed and two inverted pendulums is devised on the basic of equivalent mass and equivalent stiffness proposed firstly in this paper.And the dynamic model of the simulator equivalent to the sensitive axis motion of the test mass and the planar motion of the satellite is derived from the Euler-Lagrange method.Then,the dynamic equivalence conditions between the space prototype system and the ground model system are derived from Pi theorem.To satisfy these conditions,the scaling laws of two systems and requirements for the inverted pendulum are put forward.Besides,the corresponding control scaling laws and a closed-loop control strategy are deduced and applied to establishing the numerical simulation experiments of underactuated system.Subsequently,the comparative simulation results demonstrate the similarity of dynamical behavior between the scaled-down ground model and the space prototype.As a result,the rationality and effectiveness of the design method are proved,facilitating the ground simulation of future gravitational wave detection satellites.
