Autonomous Underwater Vehicles(AUVs)are pivotal for deep-sea exploration and resource exploitation,yet their reliability in extreme underwater environments remains a critical barrier to widespread deployment.Through s...Autonomous Underwater Vehicles(AUVs)are pivotal for deep-sea exploration and resource exploitation,yet their reliability in extreme underwater environments remains a critical barrier to widespread deployment.Through systematic analysis of 150 peer-reviewed studies employing mixed-methods research,this review yields three principal advancements to the reliability analysis of AUVs.First,based on the hierarchical functional division of AUVs into six subsystems(propulsion system,navigation system,communication system,power system,environmental detection system,and emergency system),this study systematically identifies the primary failure modes and potential failure causes of each subsystem,providing theoretical support for fault diagnosis and reliability optimization.Subsequently,a comprehensive review of AUV reliability analysis methods is conducted from three perspectives:analytical methods,simulated methods,and surrogate model methods.The applicability and limitations of each method are critically analyzed to offer insights into their suitability for engineering applications.Finally,the study highlights key challenges and research hotpots in AUV reliability analysis,including reliability analysis under limited data,AI-driven reliability analysis,and human reliability analysis.Furthermore,the potential of multi-sensor data fusion,edge computing,and advanced materials in enhancing AUV environmental adaptability and reliability is explored.展开更多
Continuously increasing inflation is a major challenge in presenting reliable and relevant financial reports,especially in developing countries like Indonesia.This study aims to analyze the role of inflation accountin...Continuously increasing inflation is a major challenge in presenting reliable and relevant financial reports,especially in developing countries like Indonesia.This study aims to analyze the role of inflation accounting in increasing the reliability of financial reports during times of high inflation.With a qualitative-descriptive approach,this research examines two main methods in inflation accounting,namely General Price Level Accounting(GPLA)and Current Cost Accounting(CCA),and their impact on the value of assets,liabilities,income,and costs.The analysis results show that historical cost-based financial reports do not reflect actual economic conditions during inflation,so they can be misleading in decision making.The application of inflation accounting,through adjustments to purchasing power and current prices,has been proven to be able to increase the relevance and reliability of financial information.However,limitations in implementation in Indonesia are due to the lack of regulations and practical understanding regarding this method.Therefore,the application of inflation accounting is important in supporting the quality of financial reports and more accurate decision making amidst economic instability.展开更多
The study aims to determine the validity and reliability of the Wechsler Preschool and Primary Scale of Intelligence–Third Edition(WPPSI-III)scores in a sample of kindergarten and lower primary pupils from Khartoum S...The study aims to determine the validity and reliability of the Wechsler Preschool and Primary Scale of Intelligence–Third Edition(WPPSI-III)scores in a sample of kindergarten and lower primary pupils from Khartoum State,Sudan.It also aims to examine whether test’s factor structure in this sample replicated that of the original WPPSI-III.The study sample consisted of 384 kindergarten and primary school children in Khartoum State(females=50%mean age=4.14,SD=1.37),selected using stratified random sampling across its seven localities:Khartoum,Jebel Awliya,Khartoum Bahri,East Nile,Omdurman,Ombada,Karari.For concurrent validation,the children additionally completed the Goodenough Draw-a-Man Test,and the Colored Progressive Matrices.WPPSI-III scores demonstrated high internal consistency across the subtest items.Confirmatory factor analysis indicators for total,verbal,and performance intelligence were all excellent.The scale also showed weak to strong score stability ranging from 0.25(weak)to 0.88(strong)based on the Spearman-Brown equation,0.25 to 0.75 based on the Guttman split-half method.The Cronbach’s alpha coefficient scores ranged from 0.54 to 0.93.The WPPSI-III and Goodenough Draw-a-Man Test scores concurrent validity scores were poor(0.05)to modest(0.31),and while those with the Colored Progressive Matrices test were poor(r=0.04–0.18).Thesefindings provide evidence to suggest that the WPPSI-III is appropriate for research use with kindergarten and lower primary school students in Khartoum State,Sudan.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
The dynamic avalanche effect is a critical factor influencing the performance and reliability of the field-stop insulated gate bipolar transistors(FS-IGBT).Unclamped inductive switching(UIS)is the primary method for t...The dynamic avalanche effect is a critical factor influencing the performance and reliability of the field-stop insulated gate bipolar transistors(FS-IGBT).Unclamped inductive switching(UIS)is the primary method for testing the dynamic avalanche capability of FS-IGBTs.Numerous studies have demonstrated that factors such as device structure,avalanche-generating current filaments,and electrical parameters influence the dynamic avalanche effect of the FS-IGBT.However,few studies have focused on enhancing the avalanche reliability of the FS-IGBT by adjusting circuit parameters during operation.In this paper,the dynamic avalanche effect of the FS-IGBT under UIS conditions is comprehensively investigated through a series of comparative experiments with varying circuit parameters,including bus voltage V_(DC),gate voltage V_(G),gate resistance R_(g),load inductance L,and temperature TC.Furthermore,a method to enhance the dynamic avalanche reliability of the FS-IGBT under UIS by optimizing circuit parameters is proposed.In practical applications,reducing gate voltage,increasing load inductance,and lowering temperature can effectively improve the dynamic avalanche capability of the FS-IGBT.展开更多
BACKGROUND The Victorian institute of sports assessment for patellar tendons questionnaire(VISA-P),a valid tool for patellar tendinopathy,has been used for patellofemoral pain(PFP).AIM To validate VISA-P in PFP.METHOD...BACKGROUND The Victorian institute of sports assessment for patellar tendons questionnaire(VISA-P),a valid tool for patellar tendinopathy,has been used for patellofemoral pain(PFP).AIM To validate VISA-P in PFP.METHODS Study of validity,responsiveness and feasibility following COSMIN.Inclusion criteria:Subjects with PFP,aged 18 to 55.Agreement among 10 experts on the relevance and clarity of each item using Aiken's V coefficient determined content validity.An exploratory factorial analysis established structural validity.The correlation of VISA-P with knee injury and osteoarthritis outcome score for PFP and Osteoarthritis(KOOS-PF)and Kujala patellofemoral score(KPS;specific for PFP)analyzed the construct validity.Internal consistency was calculated with Cronbach'sαand test-retest reliability with the intraclass correlation coefficient(ICC).Feasibility considered the subjects'self-completion time.RESULTS The sample consisted of 103 knees from 73 subjects(47 female/26 male;aged 34.9±13 SD).The items were relevant and clear,with the exception of item-8,which didn't reach an acceptable level of agreement on clarity.Exploratory factorial analysis found a 2-factor solution,which explained 63.48%of the variance.VISAP achieved a strong and significant correlation with KOOS-PF(Spearman rho=0.826;P<0.001)and KPS(Spearman rho=0.771;P<0.001).The questionnaire showed adequate reliability(Cronbach'sα:0.752;ICC:0.934;P<0.0001;95%CI:0.902-0.955).The mean self-completion time was 232±0.52 SD seconds.CONCLUSION VISA-P proved to be valid and reliable to functionally assess PFP and/or chondromalacia patella.VISA-P is a feasible tool in the clinical and research environment,quick and easy to complete.展开更多
Bonding quality at the interface of solid propellant grains is crucial for the reliability and safety of solid rocket motors.Although bonding reliability is influenced by numerous factors,the lack of quantitative char...Bonding quality at the interface of solid propellant grains is crucial for the reliability and safety of solid rocket motors.Although bonding reliability is influenced by numerous factors,the lack of quantitative characterization of interface debonding mechanisms and the challenge of identifying key factors have made precise control of process variables difficult,resulting in unpredictable failure risks.This paper presents an improved fuzzy failure probability evaluation method that combines fuzzy fault tree analysis with expert knowledge,transforming process data into fuzzy failure probability to accurately assess debonding probabilities.The predictive model is constructed through a general regression neural network and optimized using the particle swarm optimization algorithm.Sensitivity analysis is conducted to identify key decision variables,including normal force,grain rotation speed,and adhesive weight,which are verified experimentally.Compared with classical models,the maximum error margin of the constructed reliability prediction model is only 0.02%,and it has high stability.The experimental results indicate that the main factors affecting debonding are processing roughness and coating uniformity.Controlling the key decision variable as the median resulted in a maximum increase of 200.7%in bonding strength.The feasibility of the improved method has been verified,confirming that identifying key decision variables has the ability to improve bonding reliability.The proposed method simplifies the evaluation of propellant interface bonding reliability under complex conditions by quantifying the relationship between process parameters and failure risk,enabling targeted management of key decision variables.展开更多
Nodal pricing is a critical mechanism in electricity markets,utilized to determine the cost of power transmission to various nodes within a distribution network.As power systems evolve to incorporate higher levels of ...Nodal pricing is a critical mechanism in electricity markets,utilized to determine the cost of power transmission to various nodes within a distribution network.As power systems evolve to incorporate higher levels of renewable energy and face increasing demand fluctuations,traditional nodal pricing models often fall short to meet these new challenges.This research introduces a novel enhanced nodal pricing mechanism for distribution networks,integrating advanced optimization techniques and hybrid models to overcome these limitations.The primary objective is to develop a model that not only improves pricing accuracy but also enhances operational efficiency and system reliability.This study leverages cutting-edge hybrid algorithms,combining elements of machine learning with conventional optimization methods,to achieve superior performance.Key findings demonstrate that the proposed hybrid nodal pricing model significantly reduces pricing errors and operational costs compared to conventional methods.Through extensive simulations and comparative analysis,the model exhibits enhanced performance under varying load conditions and increased levels of renewable energy integration.The results indicate a substantial improvement in pricing precision and network stability.This study contributes to the ongoing discourse on optimizing electricity market mechanisms and provides actionable insights for policymakers and utility operators.By addressing the complexities of modern power distribution systems,our research offers a robust solution that enhances the efficiency and reliability of power distribution networks,marking a significant advancement in the field.展开更多
The beyond fifth-generation Internet of Things requires more capable channel coding schemes to achieve high-reliability,low-complexity and lowlatency communications.The theoretical analysis of error-correction perform...The beyond fifth-generation Internet of Things requires more capable channel coding schemes to achieve high-reliability,low-complexity and lowlatency communications.The theoretical analysis of error-correction performance of channel coding functions as a significant way of optimizing the transmission reliability and efficiency.In this paper,the efficient estimation methods of the block error rate(BLER)performance for rate-compatible polar codes(RCPC)are proposed under several scenarios.Firstly,the BLER performance of RCPC is generally evaluated in the additive white Gaussian noise channels.That is further extended into the Rayleigh fading channel case using an equivalent estimation method.Moreover,with respect to the powerful decoder such as successive cancellation list decoding,the performance estimation is derived analytically based on the polar weight spectrum and BLER upper bounds.Theoretical evaluation and numerical simulation results show that the estimated performance can fit well the practical simulated results of RCPC under the objective conditions,verifying the validity of our proposed performance estimation methods.Furthermore,the application designs of the reliability estimation of RCPC are explored,particularly in the advantages of the signal-to-noise(SNR)estimation and throughput efficiency optimization of polar coded hybrid automatic repeat request.展开更多
Objective:This study aimed to translate the de Morton Mobility Index(DEMMI)into Thai and assess its measurement properties.Methods:The de Morton Mobility Index(DEMMI)was translated into Thai using a cross-cultural tra...Objective:This study aimed to translate the de Morton Mobility Index(DEMMI)into Thai and assess its measurement properties.Methods:The de Morton Mobility Index(DEMMI)was translated into Thai using a cross-cultural translation method.A cross-sectional study was conducted in four public hospitals in Thailand between January and March 2023.A total of 260 patients were recruited from outpatient clinics.Convergent and known-group validity were evaluated through hypothesis testing.Construct validity was examined using confirmatory factor analysis.Reliability was assessed using Cronbach’s a coefficient.We also employed the Rasch analysis to validate validity and person reliability.Results:Content validity was high(S-CVI=0.96,I-CVI range:0.80e1.00).Strong convergent validity was observed,with a significant correlation(r=0.761,P<0.001)between the Thai DEMMI and the Parker Mobility Scale(PMS).Known-group validity was evident,demonstrating differences in scores across various patient groups.A confirmatory factor analysis supported the hypothesized factor structure of the Thai DEMMI with good fit indices:χ^(2)(df=4)=5.101,P=0.2771;χ^(2)/df=1.275,RMSEA=0.033;CFI=0.998;TLI=0.995;SRMR=0.016.The Thai DEMMI exhibited high internal consistency(Cronbach’s a=0.88).Rasch analysis revealed good person reliability(0.91)and acceptable information-weighted fit means square statistic(0.73-1.06).However,most items showed good fit based on the outlier-sensitive fit means square statistics(Outfit MNSQ),one exhibited a high Outfit MNSQ value of 29.94,suggesting a potential misfit.Conclusion:This study demonstrated the acceptable validity and reliability of the Thai DEMMI.Further evaluation of its responsiveness to change is still recommended.展开更多
The swinging-loading process is essential for automatic artillery loading systems.This study focuses on the problems of reliability analysis that affect swinging-loading positioning accuracy.A dynamic model for a mult...The swinging-loading process is essential for automatic artillery loading systems.This study focuses on the problems of reliability analysis that affect swinging-loading positioning accuracy.A dynamic model for a multi degree-of-freedom swinging-loading-integrated rigid-flexible coupling system is established.This model is based on the identification of key parameters and platform experiments.Based on the spatial geometric relationship between the breech and loader during modular charge transfer and the possible maximum interference depth of the modular charge,a new failure criterion for estimating the reliability of swinging-loading positioning accuracy is proposed.Considering the uncertainties in the operation of the pendulum loader,the direct probability integration method is introduced to analyze the reliability of the swinging-loading positioning accuracy under three different charge numbers.The results indicate that under two and four charges,the swinging-loading process shows outstanding reliability.However,an unstable stage appears when the swinging motion occurred under six charges,with a maximum positioning failure probability of 0.0712.A comparison between the results obtained under the conventional and proposed criteria further reveals the effectiveness and necessity of the proposed criterion.展开更多
Proton Exchange Membrane Water Electrolyzers(PEMWE)are efficient and sustainable hydrogen production devices.This article analyzes their static and dynamic electrical models integrated with degradation mechanisms.Stat...Proton Exchange Membrane Water Electrolyzers(PEMWE)are efficient and sustainable hydrogen production devices.This article analyzes their static and dynamic electrical models integrated with degradation mechanisms.Static models reveal steady-state behavior,while dynamic models capture transient responses to input variations.The developed modeling approach combines the activation and diffusion phenomena,resulting in a novel PEMWE model that closely reflects real-world conditions and enables fast simulations.The electrical model is integrated with the aging model through two key ratios,surface degradation ratio and membrane degradation ratio,which characterize degradation mechanisms affecting electrode and membrane performance.The linear model using second-order Taylor approximation enables the development of a diagnosis approach that can contribute to estimating the remaining useful life of PEMWEs.By associating aging models with electrical models through the proposed ratios,a deeper understanding is achieved regarding how degra-dation phenomena evolve and influence electrolyzer efficiency and durability.The integrated framework enables predictive maintenance strategies,making it valuable for industrial hydrogen production applications.展开更多
The utilization of high-strength steel bars(HSSB)within concrete structures demonstrates significant advantages in material conservation and mechanical performance enhancement.Nevertheless,existing design codes exhibi...The utilization of high-strength steel bars(HSSB)within concrete structures demonstrates significant advantages in material conservation and mechanical performance enhancement.Nevertheless,existing design codes exhibit limitations in addressing the distinct statistical characteristics of HSSB,particularly regarding strength design parameters.For instance,GB50010-2010 fails to specify design strength values for reinforcement exceeding 600 MPa,creating technical barriers for advancing HSSB implementation.This study systematically investigates the reliability of eccentric compression concrete columns reinforced with 600 MPa-grade HSSB through high-order moment method analysis.Material partial factors were calibrated against target reliability indices prescribed by GB50068-2018,incorporating critical variables including live-to-dead load ratios,design methodologies,and service conditions.The findings show that the value of k significantly affects the calibration of material partial factors,impacting the reliability of bearing capacity.Considering various k values and target reliability indices,it is recommended that the material partialfactorbe setat1.15,implyingthatthedesignstrengthfor600MPahigh-strengthsteelbars shouldbe considered as 522 MPa.For safety levels I and II,load adjustment factors of 1.1 and 0.9,respectively,may be applied.展开更多
The novel structural reliability methodology presented in this study is especially well suited for multidimensional structural dynamics that are physically measured or numerically simulated over a representative timel...The novel structural reliability methodology presented in this study is especially well suited for multidimensional structural dynamics that are physically measured or numerically simulated over a representative timelapse.The Gaidai multivariate reliability method is applied to an operational offshore Jacket platform that operates in Bohai Bay.This study demonstrates the feasibility of this method to accurately estimate collapse risks in dynamic systems under in situ environmental stressors.Modern reliability approaches do not cope easily with the high dimensionality of real engineering dynamic systems,as well as nonlinear intercorrelations between various structural components.The Jacket offshore platform is chosen as the case study for this reliability analysis because of the presence of various hotspot stresses that synchronously arise in its structural parts.The authors provide a straightforward,precise method for estimating overall risks of operational failure,damage,or hazard for nonlinear multidimensional dynamic systems.The latter tool is important for offshore engineers during the design stage.展开更多
Thermal Protection System(TPS)with thick tiles,low thermal conductivity,and a short re-entry stage stands as a critical element within reusable aircraft,whose reliability is related to the function and changes with th...Thermal Protection System(TPS)with thick tiles,low thermal conductivity,and a short re-entry stage stands as a critical element within reusable aircraft,whose reliability is related to the function and changes with their physical properties,external conditions,and degradation.Meanwhile,due to the limitation of testing resources,epistemic uncertainties stemming from the small samples are present in TPS reliability modeling.However,current TPS reliability modeling methods face challenges in characterizing the relationships among reliability and physical properties,external conditions,degradation,and epistemic uncertainties.Therefore,under the framework of belief reliability theory,a TPS reliability model is constructed,which takes into account the physical principle,external conditions,performance degradation,and epistemic uncertainties.A reliability simulation algorithm is proposed to calculate TPS reliability.Through a case study and comparison analysis,the proposed method is validated as more effective than the existing method.Additionally,reliability sensitivity analysis is conducted to identify the sensitive factors of reliability under the condition of small samples,through which suggestions are provided for TPS functional design and improvement.展开更多
This paper proposes a reliability evaluation model for a multi-dimensional network system,which has potential to be applied to the internet of things or other practical networks.A multi-dimensional network system with...This paper proposes a reliability evaluation model for a multi-dimensional network system,which has potential to be applied to the internet of things or other practical networks.A multi-dimensional network system with one source element and multiple sink elements is considered first.Each element can con-nect with other elements within a stochastic connection ranges.The system is regarded as successful as long as the source ele-ment remains connected with all sink elements.An importance measure is proposed to evaluate the performance of non-source elements.Furthermore,to calculate the system reliability and the element importance measure,a multi-valued decision diagram based approach is structured and its complexity is analyzed.Finally,a numerical example about the signal transfer station system is illustrated to analyze the system reliability and the ele-ment importance measure.展开更多
Background:In this study,we aimed to validate and test the reliability of the Yonsei lifestyle profile(YLP)in assessing multifaceted health lifestyle levels in a study population from the United States.Methods:The YLP...Background:In this study,we aimed to validate and test the reliability of the Yonsei lifestyle profile(YLP)in assessing multifaceted health lifestyle levels in a study population from the United States.Methods:The YLP-English version and health-promoting lifestyle profile II were administered to 100 individuals living in the United States.Concurrent validity was analyzed using Pearson's correlation coefficient,and discriminant validity was examined by comparing sex and age differences through t-tests and multiple variance analysis.Internal consistency was assessed using Cronbach'sαfor each sub-factor.Results:The YLP-English Version demonstrated concurrent validity with the Health-Promoting Lifestyle Profile II,showing consistent correlations for the total score(0.3,p<0.01)and frequency sub-factors(0.25-0.69,p<0.01).Among the satisfaction sub-factors,only nutrition showed a weak negative correlation(-0.19,p<0.01);all others were nonsignificant.Discriminant validity revealed no significant sex differences,but physical activity frequency varied across age groups.Internal consistency was high(Cronbach'sα=0.80-0.86).Conclusion:In this study,we validated the YLP-English version as a reliable instrument for assessing health-related lifestyle behaviors.The YLP uniquely captures both lifestyle frequency and satisfaction,offering a comprehensive perspective on health behaviors.Although this tool is currently most applicable in population-level studies,future research should establish clinical thresholds to enhance its utility in individualized health assessments and interventions.展开更多
The volatility introduced by the integration of renewable energy poses challenges to the reliability of power supply,increasing the demand for energy storage in distribution networks.Shared energy storage in distribut...The volatility introduced by the integration of renewable energy poses challenges to the reliability of power supply,increasing the demand for energy storage in distribution networks.Shared energy storage in distribution networks can participate in energy storage allocation as a provider of reliability ancillary services.This paper proposes a novel Nash bargaining based energy storage coordinated allocation method to fully incentivize shared energy storage to participate in reliability services within the distribution network.First,an analytical reliability assessment model is constructed and embedded into the energy storage allocation model,where the impact of renewable energy uncertainty is described using chance constraints.Considering the interests of both the distribution network and shared energy storage operators,a Nash bargaining based energy storage coordinated allocation and benefit sharing mechanism is established,which is then transformed into a mixed-integer linear programming(MILP)model for efficient solution.Case studies show that the proposed method,through cooperation between the distribution system operator and shared energy storage operators,signif-icantly reduces investment cost of energy storage and ensures a rational distribution of the benefits obtained.展开更多
This study aimed to determine the reliability,validity and measurement invariance of scores from the Difficulties in Emotion Regulation Scale-8 in Chinese context.A total of 1114 Chinese adolescents were participants ...This study aimed to determine the reliability,validity and measurement invariance of scores from the Difficulties in Emotion Regulation Scale-8 in Chinese context.A total of 1114 Chinese adolescents were participants in three phases:N=424 for the initial DERS-8 measure completion;N=586 the DERS-8,General Anxiety Disorder Scale,Depression Scale and Emotion Regulation Scale completion,with an interval of one month.Then an additional 104 adolescents also completed DERS-8,General Anxiety Disorder Scale,Depression Scale and Emotion Regulation Scale.Both exploratory and confirmatory factor analyses confirmed the one-factor model of the scale,and the fitness indicators wereχ^(2)/df=4.05,RMSEA=0.07,CFI=0.98,and TLI=0.97.Each item of the DERS-8 had good discrimination.The internal consistency reliability coefficient,split-half reliability coefficient and test-retest reliability coefficient of the scale scores were 0.90,0.87 and 0.66,respectively.The findings suggest the Chinese version of the DERS-8 is a reliable measure of difficulty of emotion regulation in Chinese adolescents.展开更多
Long-term responses of floating structures pose a great concern in their design phase. Existing approaches for addressing long-term extreme responses are extremely cumbersome for adoption. This work aims to develop an...Long-term responses of floating structures pose a great concern in their design phase. Existing approaches for addressing long-term extreme responses are extremely cumbersome for adoption. This work aims to develop an approach for the long-term extreme-response analysis of floating structures. A modified gradient-based retrieval algorithm in conjunction with the inverse first-order reliability method(IFORM) is proposed to enable the use of convolution models in long-term extreme analysis of structures with an analytical formula of response amplitude operator(RAO). The proposed algorithm ensures convergence stability and iteration accuracy and exhibits a higher computational efficiency than the traditional backtracking method. However, when the RAO of general offshore structures cannot be analytically expressed, the convolutional integration method fails to function properly. A numerical discretization approach is further proposed for offshore structures in the case when the analytical expression of the RAO is not feasible. Through iterative discretization of environmental contours(ECs) and RAOs, a detailed procedure is proposed to calculate the long-term response extremes of offshore structures. The validity and accuracy of the proposed approach are tested using a floating offshore wind turbine as a numerical example. The long-term extreme heave responses of various return periods are calculated via the IFORM in conjunction with a numerical discretization approach. The environmental data corresponding to N-year structural responses are located inside the ECs, which indicates that the selection of design points directly along the ECs yields conservative design results.展开更多
基金The National Key R&D Program Projects(Grant No.2022YFC2803601)the Natural Science Foundation of Shandong Province(Grant No.ZR2021YQ29)+1 种基金the Natural Science Foundation of Heilongjiang Province(Grant No.YQ2024E036)the Taishan Scholars Project(Grant No.tsqn202312317).
文摘Autonomous Underwater Vehicles(AUVs)are pivotal for deep-sea exploration and resource exploitation,yet their reliability in extreme underwater environments remains a critical barrier to widespread deployment.Through systematic analysis of 150 peer-reviewed studies employing mixed-methods research,this review yields three principal advancements to the reliability analysis of AUVs.First,based on the hierarchical functional division of AUVs into six subsystems(propulsion system,navigation system,communication system,power system,environmental detection system,and emergency system),this study systematically identifies the primary failure modes and potential failure causes of each subsystem,providing theoretical support for fault diagnosis and reliability optimization.Subsequently,a comprehensive review of AUV reliability analysis methods is conducted from three perspectives:analytical methods,simulated methods,and surrogate model methods.The applicability and limitations of each method are critically analyzed to offer insights into their suitability for engineering applications.Finally,the study highlights key challenges and research hotpots in AUV reliability analysis,including reliability analysis under limited data,AI-driven reliability analysis,and human reliability analysis.Furthermore,the potential of multi-sensor data fusion,edge computing,and advanced materials in enhancing AUV environmental adaptability and reliability is explored.
文摘Continuously increasing inflation is a major challenge in presenting reliable and relevant financial reports,especially in developing countries like Indonesia.This study aims to analyze the role of inflation accounting in increasing the reliability of financial reports during times of high inflation.With a qualitative-descriptive approach,this research examines two main methods in inflation accounting,namely General Price Level Accounting(GPLA)and Current Cost Accounting(CCA),and their impact on the value of assets,liabilities,income,and costs.The analysis results show that historical cost-based financial reports do not reflect actual economic conditions during inflation,so they can be misleading in decision making.The application of inflation accounting,through adjustments to purchasing power and current prices,has been proven to be able to increase the relevance and reliability of financial information.However,limitations in implementation in Indonesia are due to the lack of regulations and practical understanding regarding this method.Therefore,the application of inflation accounting is important in supporting the quality of financial reports and more accurate decision making amidst economic instability.
基金The authors extend their appreciation to the Ongoing Research Funding Program,number(ORF2025R705),King Saud University,Riyadh,Saudi Arabia,for funding this work.
文摘The study aims to determine the validity and reliability of the Wechsler Preschool and Primary Scale of Intelligence–Third Edition(WPPSI-III)scores in a sample of kindergarten and lower primary pupils from Khartoum State,Sudan.It also aims to examine whether test’s factor structure in this sample replicated that of the original WPPSI-III.The study sample consisted of 384 kindergarten and primary school children in Khartoum State(females=50%mean age=4.14,SD=1.37),selected using stratified random sampling across its seven localities:Khartoum,Jebel Awliya,Khartoum Bahri,East Nile,Omdurman,Ombada,Karari.For concurrent validation,the children additionally completed the Goodenough Draw-a-Man Test,and the Colored Progressive Matrices.WPPSI-III scores demonstrated high internal consistency across the subtest items.Confirmatory factor analysis indicators for total,verbal,and performance intelligence were all excellent.The scale also showed weak to strong score stability ranging from 0.25(weak)to 0.88(strong)based on the Spearman-Brown equation,0.25 to 0.75 based on the Guttman split-half method.The Cronbach’s alpha coefficient scores ranged from 0.54 to 0.93.The WPPSI-III and Goodenough Draw-a-Man Test scores concurrent validity scores were poor(0.05)to modest(0.31),and while those with the Colored Progressive Matrices test were poor(r=0.04–0.18).Thesefindings provide evidence to suggest that the WPPSI-III is appropriate for research use with kindergarten and lower primary school students in Khartoum State,Sudan.
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.
基金supported in part by the National Natural Science Foundation of China under Grant 62071073in part by the Fundamental Research Funds for Central Universities under Grant 2023CDJXY-041in part by the Foundation from Guangxi Key Laboratory of Optoelectronic Information Processing under Grant GD20201.
文摘The dynamic avalanche effect is a critical factor influencing the performance and reliability of the field-stop insulated gate bipolar transistors(FS-IGBT).Unclamped inductive switching(UIS)is the primary method for testing the dynamic avalanche capability of FS-IGBTs.Numerous studies have demonstrated that factors such as device structure,avalanche-generating current filaments,and electrical parameters influence the dynamic avalanche effect of the FS-IGBT.However,few studies have focused on enhancing the avalanche reliability of the FS-IGBT by adjusting circuit parameters during operation.In this paper,the dynamic avalanche effect of the FS-IGBT under UIS conditions is comprehensively investigated through a series of comparative experiments with varying circuit parameters,including bus voltage V_(DC),gate voltage V_(G),gate resistance R_(g),load inductance L,and temperature TC.Furthermore,a method to enhance the dynamic avalanche reliability of the FS-IGBT under UIS by optimizing circuit parameters is proposed.In practical applications,reducing gate voltage,increasing load inductance,and lowering temperature can effectively improve the dynamic avalanche capability of the FS-IGBT.
文摘BACKGROUND The Victorian institute of sports assessment for patellar tendons questionnaire(VISA-P),a valid tool for patellar tendinopathy,has been used for patellofemoral pain(PFP).AIM To validate VISA-P in PFP.METHODS Study of validity,responsiveness and feasibility following COSMIN.Inclusion criteria:Subjects with PFP,aged 18 to 55.Agreement among 10 experts on the relevance and clarity of each item using Aiken's V coefficient determined content validity.An exploratory factorial analysis established structural validity.The correlation of VISA-P with knee injury and osteoarthritis outcome score for PFP and Osteoarthritis(KOOS-PF)and Kujala patellofemoral score(KPS;specific for PFP)analyzed the construct validity.Internal consistency was calculated with Cronbach'sαand test-retest reliability with the intraclass correlation coefficient(ICC).Feasibility considered the subjects'self-completion time.RESULTS The sample consisted of 103 knees from 73 subjects(47 female/26 male;aged 34.9±13 SD).The items were relevant and clear,with the exception of item-8,which didn't reach an acceptable level of agreement on clarity.Exploratory factorial analysis found a 2-factor solution,which explained 63.48%of the variance.VISAP achieved a strong and significant correlation with KOOS-PF(Spearman rho=0.826;P<0.001)and KPS(Spearman rho=0.771;P<0.001).The questionnaire showed adequate reliability(Cronbach'sα:0.752;ICC:0.934;P<0.0001;95%CI:0.902-0.955).The mean self-completion time was 232±0.52 SD seconds.CONCLUSION VISA-P proved to be valid and reliable to functionally assess PFP and/or chondromalacia patella.VISA-P is a feasible tool in the clinical and research environment,quick and easy to complete.
基金supported in part by the Equipment Development Pre-research Project funded by Equipment Development Department,PRC under Grant No.50923010501Fundamental Research Program of Shenyang Institute of Automation(SIA),Chinese Academy of Sciencess under Grant No.355060201。
文摘Bonding quality at the interface of solid propellant grains is crucial for the reliability and safety of solid rocket motors.Although bonding reliability is influenced by numerous factors,the lack of quantitative characterization of interface debonding mechanisms and the challenge of identifying key factors have made precise control of process variables difficult,resulting in unpredictable failure risks.This paper presents an improved fuzzy failure probability evaluation method that combines fuzzy fault tree analysis with expert knowledge,transforming process data into fuzzy failure probability to accurately assess debonding probabilities.The predictive model is constructed through a general regression neural network and optimized using the particle swarm optimization algorithm.Sensitivity analysis is conducted to identify key decision variables,including normal force,grain rotation speed,and adhesive weight,which are verified experimentally.Compared with classical models,the maximum error margin of the constructed reliability prediction model is only 0.02%,and it has high stability.The experimental results indicate that the main factors affecting debonding are processing roughness and coating uniformity.Controlling the key decision variable as the median resulted in a maximum increase of 200.7%in bonding strength.The feasibility of the improved method has been verified,confirming that identifying key decision variables has the ability to improve bonding reliability.The proposed method simplifies the evaluation of propellant interface bonding reliability under complex conditions by quantifying the relationship between process parameters and failure risk,enabling targeted management of key decision variables.
文摘Nodal pricing is a critical mechanism in electricity markets,utilized to determine the cost of power transmission to various nodes within a distribution network.As power systems evolve to incorporate higher levels of renewable energy and face increasing demand fluctuations,traditional nodal pricing models often fall short to meet these new challenges.This research introduces a novel enhanced nodal pricing mechanism for distribution networks,integrating advanced optimization techniques and hybrid models to overcome these limitations.The primary objective is to develop a model that not only improves pricing accuracy but also enhances operational efficiency and system reliability.This study leverages cutting-edge hybrid algorithms,combining elements of machine learning with conventional optimization methods,to achieve superior performance.Key findings demonstrate that the proposed hybrid nodal pricing model significantly reduces pricing errors and operational costs compared to conventional methods.Through extensive simulations and comparative analysis,the model exhibits enhanced performance under varying load conditions and increased levels of renewable energy integration.The results indicate a substantial improvement in pricing precision and network stability.This study contributes to the ongoing discourse on optimizing electricity market mechanisms and provides actionable insights for policymakers and utility operators.By addressing the complexities of modern power distribution systems,our research offers a robust solution that enhances the efficiency and reliability of power distribution networks,marking a significant advancement in the field.
基金supported by National Natural Science Foundation of China(No.62201596)Research Planning Project of National University of Defense Technology(ZK22-45).
文摘The beyond fifth-generation Internet of Things requires more capable channel coding schemes to achieve high-reliability,low-complexity and lowlatency communications.The theoretical analysis of error-correction performance of channel coding functions as a significant way of optimizing the transmission reliability and efficiency.In this paper,the efficient estimation methods of the block error rate(BLER)performance for rate-compatible polar codes(RCPC)are proposed under several scenarios.Firstly,the BLER performance of RCPC is generally evaluated in the additive white Gaussian noise channels.That is further extended into the Rayleigh fading channel case using an equivalent estimation method.Moreover,with respect to the powerful decoder such as successive cancellation list decoding,the performance estimation is derived analytically based on the polar weight spectrum and BLER upper bounds.Theoretical evaluation and numerical simulation results show that the estimated performance can fit well the practical simulated results of RCPC under the objective conditions,verifying the validity of our proposed performance estimation methods.Furthermore,the application designs of the reliability estimation of RCPC are explored,particularly in the advantages of the signal-to-noise(SNR)estimation and throughput efficiency optimization of polar coded hybrid automatic repeat request.
文摘Objective:This study aimed to translate the de Morton Mobility Index(DEMMI)into Thai and assess its measurement properties.Methods:The de Morton Mobility Index(DEMMI)was translated into Thai using a cross-cultural translation method.A cross-sectional study was conducted in four public hospitals in Thailand between January and March 2023.A total of 260 patients were recruited from outpatient clinics.Convergent and known-group validity were evaluated through hypothesis testing.Construct validity was examined using confirmatory factor analysis.Reliability was assessed using Cronbach’s a coefficient.We also employed the Rasch analysis to validate validity and person reliability.Results:Content validity was high(S-CVI=0.96,I-CVI range:0.80e1.00).Strong convergent validity was observed,with a significant correlation(r=0.761,P<0.001)between the Thai DEMMI and the Parker Mobility Scale(PMS).Known-group validity was evident,demonstrating differences in scores across various patient groups.A confirmatory factor analysis supported the hypothesized factor structure of the Thai DEMMI with good fit indices:χ^(2)(df=4)=5.101,P=0.2771;χ^(2)/df=1.275,RMSEA=0.033;CFI=0.998;TLI=0.995;SRMR=0.016.The Thai DEMMI exhibited high internal consistency(Cronbach’s a=0.88).Rasch analysis revealed good person reliability(0.91)and acceptable information-weighted fit means square statistic(0.73-1.06).However,most items showed good fit based on the outlier-sensitive fit means square statistics(Outfit MNSQ),one exhibited a high Outfit MNSQ value of 29.94,suggesting a potential misfit.Conclusion:This study demonstrated the acceptable validity and reliability of the Thai DEMMI.Further evaluation of its responsiveness to change is still recommended.
文摘The swinging-loading process is essential for automatic artillery loading systems.This study focuses on the problems of reliability analysis that affect swinging-loading positioning accuracy.A dynamic model for a multi degree-of-freedom swinging-loading-integrated rigid-flexible coupling system is established.This model is based on the identification of key parameters and platform experiments.Based on the spatial geometric relationship between the breech and loader during modular charge transfer and the possible maximum interference depth of the modular charge,a new failure criterion for estimating the reliability of swinging-loading positioning accuracy is proposed.Considering the uncertainties in the operation of the pendulum loader,the direct probability integration method is introduced to analyze the reliability of the swinging-loading positioning accuracy under three different charge numbers.The results indicate that under two and four charges,the swinging-loading process shows outstanding reliability.However,an unstable stage appears when the swinging motion occurred under six charges,with a maximum positioning failure probability of 0.0712.A comparison between the results obtained under the conventional and proposed criteria further reveals the effectiveness and necessity of the proposed criterion.
文摘Proton Exchange Membrane Water Electrolyzers(PEMWE)are efficient and sustainable hydrogen production devices.This article analyzes their static and dynamic electrical models integrated with degradation mechanisms.Static models reveal steady-state behavior,while dynamic models capture transient responses to input variations.The developed modeling approach combines the activation and diffusion phenomena,resulting in a novel PEMWE model that closely reflects real-world conditions and enables fast simulations.The electrical model is integrated with the aging model through two key ratios,surface degradation ratio and membrane degradation ratio,which characterize degradation mechanisms affecting electrode and membrane performance.The linear model using second-order Taylor approximation enables the development of a diagnosis approach that can contribute to estimating the remaining useful life of PEMWEs.By associating aging models with electrical models through the proposed ratios,a deeper understanding is achieved regarding how degra-dation phenomena evolve and influence electrolyzer efficiency and durability.The integrated framework enables predictive maintenance strategies,making it valuable for industrial hydrogen production applications.
基金supported by grants from the Natural Science Foundation of Fujian Province(Grant No.2022J05184).
文摘The utilization of high-strength steel bars(HSSB)within concrete structures demonstrates significant advantages in material conservation and mechanical performance enhancement.Nevertheless,existing design codes exhibit limitations in addressing the distinct statistical characteristics of HSSB,particularly regarding strength design parameters.For instance,GB50010-2010 fails to specify design strength values for reinforcement exceeding 600 MPa,creating technical barriers for advancing HSSB implementation.This study systematically investigates the reliability of eccentric compression concrete columns reinforced with 600 MPa-grade HSSB through high-order moment method analysis.Material partial factors were calibrated against target reliability indices prescribed by GB50068-2018,incorporating critical variables including live-to-dead load ratios,design methodologies,and service conditions.The findings show that the value of k significantly affects the calibration of material partial factors,impacting the reliability of bearing capacity.Considering various k values and target reliability indices,it is recommended that the material partialfactorbe setat1.15,implyingthatthedesignstrengthfor600MPahigh-strengthsteelbars shouldbe considered as 522 MPa.For safety levels I and II,load adjustment factors of 1.1 and 0.9,respectively,may be applied.
文摘The novel structural reliability methodology presented in this study is especially well suited for multidimensional structural dynamics that are physically measured or numerically simulated over a representative timelapse.The Gaidai multivariate reliability method is applied to an operational offshore Jacket platform that operates in Bohai Bay.This study demonstrates the feasibility of this method to accurately estimate collapse risks in dynamic systems under in situ environmental stressors.Modern reliability approaches do not cope easily with the high dimensionality of real engineering dynamic systems,as well as nonlinear intercorrelations between various structural components.The Jacket offshore platform is chosen as the case study for this reliability analysis because of the presence of various hotspot stresses that synchronously arise in its structural parts.The authors provide a straightforward,precise method for estimating overall risks of operational failure,damage,or hazard for nonlinear multidimensional dynamic systems.The latter tool is important for offshore engineers during the design stage.
基金supported by the steady supports scientific research of Key Laboratory of Defense Science and Technology,China(No.WDZC20220105)the National Natural Science Foundation of China(Nos.51775020,62073009,U20B2002)the Science Challenge Project,China(No.TZ2018007)。
文摘Thermal Protection System(TPS)with thick tiles,low thermal conductivity,and a short re-entry stage stands as a critical element within reusable aircraft,whose reliability is related to the function and changes with their physical properties,external conditions,and degradation.Meanwhile,due to the limitation of testing resources,epistemic uncertainties stemming from the small samples are present in TPS reliability modeling.However,current TPS reliability modeling methods face challenges in characterizing the relationships among reliability and physical properties,external conditions,degradation,and epistemic uncertainties.Therefore,under the framework of belief reliability theory,a TPS reliability model is constructed,which takes into account the physical principle,external conditions,performance degradation,and epistemic uncertainties.A reliability simulation algorithm is proposed to calculate TPS reliability.Through a case study and comparison analysis,the proposed method is validated as more effective than the existing method.Additionally,reliability sensitivity analysis is conducted to identify the sensitive factors of reliability under the condition of small samples,through which suggestions are provided for TPS functional design and improvement.
基金supported by the National Natural Science Foundation of China(72101025,72271049),the Interdisciplinary Research Project for Young Teachers of USTB(Fundamental Research Funds for the Central Universities,FRF-IDRY-24-024)the Hebei Natural Science Foundation(F2023501011)+1 种基金the Fundamental Research Funds for the Central Universities(FRF-TP-20-073A1)the R&D Program of Beijing Municipal Education Commission(KM202411232015).
文摘This paper proposes a reliability evaluation model for a multi-dimensional network system,which has potential to be applied to the internet of things or other practical networks.A multi-dimensional network system with one source element and multiple sink elements is considered first.Each element can con-nect with other elements within a stochastic connection ranges.The system is regarded as successful as long as the source ele-ment remains connected with all sink elements.An importance measure is proposed to evaluate the performance of non-source elements.Furthermore,to calculate the system reliability and the element importance measure,a multi-valued decision diagram based approach is structured and its complexity is analyzed.Finally,a numerical example about the signal transfer station system is illustrated to analyze the system reliability and the ele-ment importance measure.
基金supported by the Ministry of Education of the Republic of Korea and the National Research Foundation of Republic of Korea(NRF-2021S1A3A2A02096338).
文摘Background:In this study,we aimed to validate and test the reliability of the Yonsei lifestyle profile(YLP)in assessing multifaceted health lifestyle levels in a study population from the United States.Methods:The YLP-English version and health-promoting lifestyle profile II were administered to 100 individuals living in the United States.Concurrent validity was analyzed using Pearson's correlation coefficient,and discriminant validity was examined by comparing sex and age differences through t-tests and multiple variance analysis.Internal consistency was assessed using Cronbach'sαfor each sub-factor.Results:The YLP-English Version demonstrated concurrent validity with the Health-Promoting Lifestyle Profile II,showing consistent correlations for the total score(0.3,p<0.01)and frequency sub-factors(0.25-0.69,p<0.01).Among the satisfaction sub-factors,only nutrition showed a weak negative correlation(-0.19,p<0.01);all others were nonsignificant.Discriminant validity revealed no significant sex differences,but physical activity frequency varied across age groups.Internal consistency was high(Cronbach'sα=0.80-0.86).Conclusion:In this study,we validated the YLP-English version as a reliable instrument for assessing health-related lifestyle behaviors.The YLP uniquely captures both lifestyle frequency and satisfaction,offering a comprehensive perspective on health behaviors.Although this tool is currently most applicable in population-level studies,future research should establish clinical thresholds to enhance its utility in individualized health assessments and interventions.
基金supported in part by the National Science Foundation of China(Grant.U24B6009)Beijing Natural Science Foundation(L243003).
文摘The volatility introduced by the integration of renewable energy poses challenges to the reliability of power supply,increasing the demand for energy storage in distribution networks.Shared energy storage in distribution networks can participate in energy storage allocation as a provider of reliability ancillary services.This paper proposes a novel Nash bargaining based energy storage coordinated allocation method to fully incentivize shared energy storage to participate in reliability services within the distribution network.First,an analytical reliability assessment model is constructed and embedded into the energy storage allocation model,where the impact of renewable energy uncertainty is described using chance constraints.Considering the interests of both the distribution network and shared energy storage operators,a Nash bargaining based energy storage coordinated allocation and benefit sharing mechanism is established,which is then transformed into a mixed-integer linear programming(MILP)model for efficient solution.Case studies show that the proposed method,through cooperation between the distribution system operator and shared energy storage operators,signif-icantly reduces investment cost of energy storage and ensures a rational distribution of the benefits obtained.
基金funded by Science Research Project of Hebei Education Department(BJ2025238)Humanities and Social Science Research Project of Hebei Normal University(S24YX002)Humanities and Social Science Research Foundation of Hebei Normal University(S22B019).
文摘This study aimed to determine the reliability,validity and measurement invariance of scores from the Difficulties in Emotion Regulation Scale-8 in Chinese context.A total of 1114 Chinese adolescents were participants in three phases:N=424 for the initial DERS-8 measure completion;N=586 the DERS-8,General Anxiety Disorder Scale,Depression Scale and Emotion Regulation Scale completion,with an interval of one month.Then an additional 104 adolescents also completed DERS-8,General Anxiety Disorder Scale,Depression Scale and Emotion Regulation Scale.Both exploratory and confirmatory factor analyses confirmed the one-factor model of the scale,and the fitness indicators wereχ^(2)/df=4.05,RMSEA=0.07,CFI=0.98,and TLI=0.97.Each item of the DERS-8 had good discrimination.The internal consistency reliability coefficient,split-half reliability coefficient and test-retest reliability coefficient of the scale scores were 0.90,0.87 and 0.66,respectively.The findings suggest the Chinese version of the DERS-8 is a reliable measure of difficulty of emotion regulation in Chinese adolescents.
基金Supported by the National Natural Science Foundation of China (Grant Nos.52088102 and 51879287)National Key Research and Development Program of China (Grant No.2022YFB2602301)。
文摘Long-term responses of floating structures pose a great concern in their design phase. Existing approaches for addressing long-term extreme responses are extremely cumbersome for adoption. This work aims to develop an approach for the long-term extreme-response analysis of floating structures. A modified gradient-based retrieval algorithm in conjunction with the inverse first-order reliability method(IFORM) is proposed to enable the use of convolution models in long-term extreme analysis of structures with an analytical formula of response amplitude operator(RAO). The proposed algorithm ensures convergence stability and iteration accuracy and exhibits a higher computational efficiency than the traditional backtracking method. However, when the RAO of general offshore structures cannot be analytically expressed, the convolutional integration method fails to function properly. A numerical discretization approach is further proposed for offshore structures in the case when the analytical expression of the RAO is not feasible. Through iterative discretization of environmental contours(ECs) and RAOs, a detailed procedure is proposed to calculate the long-term response extremes of offshore structures. The validity and accuracy of the proposed approach are tested using a floating offshore wind turbine as a numerical example. The long-term extreme heave responses of various return periods are calculated via the IFORM in conjunction with a numerical discretization approach. The environmental data corresponding to N-year structural responses are located inside the ECs, which indicates that the selection of design points directly along the ECs yields conservative design results.
