期刊文献+
共找到144,854篇文章
< 1 2 250 >
每页显示 20 50 100
Effect of insomnia on anxiety and depression:Mediation of cognitive failures and moderated mediation of neuroticism
1
作者 Yue Li Jia-Long Yu +3 位作者 Shu-Yi Wang Lu-Xin Xie Jia-Long Hong Sha Liu 《World Journal of Psychiatry》 2025年第2期161-172,共12页
BACKGROUND The coronavirus disease 2019 pandemic has had an ongoing impact on the public’s mental health that requires long-term attention.Exploring the relationship between mental health indicators would aid in iden... BACKGROUND The coronavirus disease 2019 pandemic has had an ongoing impact on the public’s mental health that requires long-term attention.Exploring the relationship between mental health indicators would aid in identifying solutions to improve public mental health.AIM To investigate the prevalence of anxiety,depression,and insomnia and explore the relationship among neuroticism,cognitive failures,and mental health.METHODS A cross-sectional survey was conducted in December 2023 using an online platform to recruit adult participants.The neuroticism,subjective cognitive function,and mental health of the participants were assessed using the neuroticism subscale of the Chinese Big Five Personality Inventory Brief Version,cognitive failures questionnaire,generalized anxiety disorder-7,patient health questionnaire-9,and insomnia severity index.Pearson's correlation analysis,independent samples t-tests,one-way analysis of variance,and structural equation model were used to examine the relationship between mental health indicators.RESULTS A total of 1011 valid questionnaires were collected,of which 343 were completed by male(33.93%)respondents and 668 were completed by female(66.07%)respondents.The rates of anxiety,depression,and insomnia were 41.3%,44.6%,and 36.3%,respectively,most cases of which were mild.Among the mental health indicators,there were significant differences by age and between those with siblings and those who were only children.Neuroticism and cognitive failures were significantly positively correlated with mental health indicators.Further moderated mediation analysis showed that cognitive failures mediated the relationship between insomnia and anxiety and between insomnia and depression,with neuroticism moderating the first half of this pathway and the effect being greater in the low-neuroticism group.CONCLUSION Cognitive failures and neuroticism play important roles in mental health.Therefore,enhancing subjective cognitive function and regulating emotional stability may contribute to the improvement of mental health. 展开更多
关键词 INSOMNIA ANXIETY DEPRESSION NEUROTICISM Cognitive failures
暂未订购
Multiscale Mechanical Failures in Lithium-Ion Batteries:Experimental and Theoretical Approaches
2
作者 Chong Chen Yikun Wu +3 位作者 inbao Fan Zi-Ping Wang Lei Sun Hao-Sen Chen 《Acta Mechanica Solida Sinica》 2025年第3期344-357,共14页
The insertion and extraction of lithium ions in active materials lead to significant volumetric deformation,resulting in stresses that drive the mechanical degradation of these materials.This accumulation of mechanica... The insertion and extraction of lithium ions in active materials lead to significant volumetric deformation,resulting in stresses that drive the mechanical degradation of these materials.This accumulation of mechanical degradation ultimately leads to mechanical failure in lithium-ion batteries(LIB).This paper summarizes the experimental characterization techniques used to observe the mechanical degradation of lithium battery cells,electrodes,and particles across macro,micro,and nano scales.Additionally,the mechanical failure model for LIB that spans from the microscopic to the macroscopic scale has been outlined.Finally,we analyze the current challenges and opportunities,including the standardization of battery measurements,the quantification of mechanical failures,and the correlation between mechanical failures and electrochemical performance. 展开更多
关键词 Mechanical failure Experimental characterization Chemo-mechanical coupling Lithium-ion battery
原文传递
Study on Cascading Failures Based on Intra-Layer and Inter-Layer Structures of Multiplayer Networks
3
作者 CHEN Mengjiao WANG Niu WEI Daijun 《数学理论与应用》 2025年第3期107-124,共18页
Compared to single-layer networks,multilayer networks exhibit a more complex node degree composition,comprising both intra-layer and inter-layer degrees.However,the distinct impacts of these degree types on cascading ... Compared to single-layer networks,multilayer networks exhibit a more complex node degree composition,comprising both intra-layer and inter-layer degrees.However,the distinct impacts of these degree types on cascading failures remain underexplored.Distinguishing their effects is crucial for a deeper understanding of network structure,information propagation,and behavior prediction.This paper proposes a capacity-load model to influence and compare the influence of different degree types on cascading failures in multilayer networks.By designing three node removal strategies based on total degree,intra-layer degree,and inter-layer degree,simulation experiments are conducted on four types of networks.Network robustness is evaluated using the maximum number of removable nodes before collapse.The relationships between network robustness and the coupling coefficient,as well as load and capacity adjustment parameters,are also analyzed.The results indicate that the node removal strategy with the least impact on cascading failures varies across different types of networks,revealing the significance of different node degrees in failure propagation.Compared to other models,the proposed model enables networks to maintain a higher maximum number of removable nodes during cascading failures,demonstrating superior robustness. 展开更多
关键词 Multilayer network ROBUSTNESS Cascading failure Capacity load model
在线阅读 下载PDF
Frequent Pattern Growth-Based Identification of Critical Lines in Cascading Failures for Renewable-Dominant Hybrid AC/DC Power Systems
4
作者 Tianhao Liu Jiongcheng Yan Yutian Liu 《Engineering》 2025年第8期158-170,共13页
In wind and solar renewable-dominant hybrid alternating current/direct current(AC/DC)power systems,the active power of high-voltage direct current(HVDC)system is significantly limited by the security and stability eve... In wind and solar renewable-dominant hybrid alternating current/direct current(AC/DC)power systems,the active power of high-voltage direct current(HVDC)system is significantly limited by the security and stability events caused by cascading failures.To identify critical lines in cascading failures,a rapid risk assessment method is proposed based on the gradient boosting decision tree(GBDT)and frequent pat-tern growth(FP-Growth)algorithms.First,security and stability events triggered by cascading failures are analyzed to explain the impact of cascading failures on the maximum DC power.Then,a cascading failure risk index is defined,focusing on the DC power being limited.To handle the strong nonlinear relationship between the maximum DC power and cascading failures,a GBDT with an update strategy is utilized to rapidly predict the maximum DC power under uncertain operating conditions.Finally,the FP-Growth algorithm is improved to mine frequent patterns in cascading failures.The importance index for each fault in a frequent pattern is defined by evaluating its impact on cascading failures,enabling the identification of critical lines.Simulation results of a modified Ningxia–Shandong hybrid AC/DC system in China demonstrate that the proposed method can rapidly assess the risk of cascading failures and effectively identify critical lines. 展开更多
关键词 Cascading failure Risk assessment Frequent pattern Hybrid AC/DC power system Renewable energy
在线阅读 下载PDF
Audit Without Integrity:Ethical Failures and Fraud in High-Profile Corporate Cases
5
作者 Enda Putri Rudangta Meliala Julia +1 位作者 Iskandar Muda Erlina 《Journal of Modern Accounting and Auditing》 2025年第3期218-228,共11页
This study explores ethical violations and audit failures in various large-scale corporate fraud cases.Using a qualitative descriptive method and based on secondary data from documented fraud cases and published audit... This study explores ethical violations and audit failures in various large-scale corporate fraud cases.Using a qualitative descriptive method and based on secondary data from documented fraud cases and published audit reports,the study applies the Fraud Triangle framework,focusing on how weak integrity,objectivity,and professional competence have undermined public trust in the auditing profession.Using a qualitative descriptive method and the Fraud Triangle framework,which includes pressure,opportunity,and rationalization,the study analyzes cases from Indonesia(SNP Finance,Jiwasraya),China(Evergrande),and Germany(Wirecard).The analysis reveals that many audit failures observed in this study appear to stem more from ethical challenges than from technical incapability,driven by client pressure,weak internal controls,and compromised auditor independence.These cases demonstrate a recurring global pattern in which auditors neglect their responsibility to act in the public interest. 展开更多
关键词 auditor ethics internal auditor competence internal control fraud triangle audit failure professional responsibility SNP Finance Evergrande Wirecard Jiwasraya
在线阅读 下载PDF
Audit without Integrity:Ethical Failures and Fraud in High-Profile Corporate Cases
6
作者 Enda Putri Rudangta Meliala Julia +1 位作者 Iskandar Muda Erlina 《Journal of Modern Accounting and Auditing》 2025年第3期159-169,共11页
This study explores ethical violations and audit failures in various large-scale corporate fraud cases.Using a qualitative descriptive method and based on secondary data from documented fraud cases and published audit... This study explores ethical violations and audit failures in various large-scale corporate fraud cases.Using a qualitative descriptive method and based on secondary data from documented fraud cases and published audit reports,the study applies the Fraud Triangle framework,focusing on how weak integrity,objectivity,and professional competence have undermined public trust in the auditing profession.Using a qualitative descriptive method and the Fraud Triangle framework,which includes pressure,opportunity,and rationalization,the study analyzes cases from Indonesia(SNP Finance,Jiwasraya),China(Evergrande),and Germany(Wirecard).The analysis reveals that many audit failures observed in this study appear to stem more from ethical challenges than from technical incapability,driven by client pressure,weak internal controls,and compromised auditor independence.These cases demonstrate a recurring global pattern in which auditors neglect their responsibility to act in the public interest. 展开更多
关键词 auditor ethics internal auditor competence internal control fraud triangle audit failure professional responsibility SNP Finance Evergrande Wirecard Jiwasraya
在线阅读 下载PDF
Sustainable Emergency Rescue Products: Design and Monitoring Techniques for Preventing and Mitigating Construction Failures in Unforeseen Circumstances
7
作者 Xiaobo Jiang Hongchao Zheng 《Structural Durability & Health Monitoring》 2025年第6期1695-1716,共22页
Construction failures caused by unforeseen circumstances, such as natural disasters, environmental degradation, and structural weaknesses, present significant challenges in achieving durability, safety, and sustainabi... Construction failures caused by unforeseen circumstances, such as natural disasters, environmental degradation, and structural weaknesses, present significant challenges in achieving durability, safety, and sustainability. This research addresses these challenges through the development of advanced emergency rescue systems incorporating wood-derived nanomaterials and IoT-enabled Structural Health Monitoring (SHM) technologies. The use of nanocellulose which demonstrates outstanding mechanical capabilities and biodegradability alongside high resilience allowed developers to design modular rescue systems that function effectively even under challenging conditions while providing real-time failure protection. Experimental data from testing showed that the replacement system strengthened load-bearing limits by 20% while enhancing impact tolerance by 30% and decreasing lifecycle carbon footprints by 60% against conventional methods. FEA results alongside dynamic simulations established that the system maintains its strength across seismic events and thermal variations and environmental conditions. SHM systems that leverage the Internet of Things Platform revealed 95% accuracy rates in detecting anomalies while improving response speed by 30% for predictive maintenance operations. The innovative solutions support the special issue’s direction to push structural transformation through durable designs and creative materials with preventive failure solutions. The proposed solutions work together toward creating resilient infrastructure systems which resist unexpected stressors and environmental damage. 展开更多
关键词 Sustainable materials wood-derived nanomaterials structural durability emergency rescue products construction failures smart materials structural health monitoring IoT-based monitoring RESILIENCE environmental sustainability
在线阅读 下载PDF
Decade of insights on causes of scleral buckle failure in retinal detachment
8
作者 Hu Cheng Liu Yin +6 位作者 Du Fan Zhu Li Xiang Nian Huang Zhijian Yan Ying Zeng Bo Chen Xiao 《国际眼科杂志》 2026年第2期197-201,共5页
AIM:To investigate the underlying causes of surgical failure and reoperation management in patients with rhegmatogenous retinal detachment(RRD)who underwent scleral buckle surgery at our institution.METHODS:This was a... AIM:To investigate the underlying causes of surgical failure and reoperation management in patients with rhegmatogenous retinal detachment(RRD)who underwent scleral buckle surgery at our institution.METHODS:This was a single-center,retrospective,descriptive study.The clinical data of 368 patients(387 eyes)with RRD who underwent scleral buckling(SB)surgery between August 2013 and July 2023 at our institution were collected.The aim was to analyze the causes of recurrence and the rationale for selecting reoperation methods.RESULTS:Totally 368 patients(387 eyes)were included in the analysis,comprising 222 males and 146 females.The average age was 30.26±14.18 years,and the mean follow-up duration was(48.33±20.39)mo.The success rate of SB surgery was 90.2%.Recurrent retinal detachment occurred in 38 eyes.Based on surgical records,the causes of SB failure were analyzed.The recurrence causes included abnormal compression ridge position(position,height,or width)in 14 eyes(36.8%,14/38),hole omission in 11 eyes(29.0%,11/38),proliferative vitreoretinopathy(PVR)in 10 eyes(26.3%,10/38),and new holes in 3 eyes(7.9%,3/38).Among these,8 eyes(21.1%,8/38)underwent repeat SB surgery,while the remaining 30 eyes(78.9%,30/38)underwent pars plana vitrectomy(PPV).Regarding tamponade agents,silicone oil was used in 11 eyes(36.7%,11/30),C 3F 8 gas in 12 eyes(40.0%,12/30),and sterile air in 7 eyes(23.3%,7/30).CONCLUSION:SB surgery demonstrates a high success rate in the treatment of RRD.However,abnormal compression ridge position,missed holes during surgery,and PVR are the primary causes of SB failure.After addressing the reasons for failure,re-SB surgery or PPV can be effective alternatives. 展开更多
关键词 retinal detachment scleral buckling cause of failure REOPERATION
暂未订购
Correlation between life satisfaction,pleasure level,and negative emotion in patients with chronic renal failure
9
作者 Lin-Lin Zhang You-Li Zhang +3 位作者 Ting Liu Jian Wang Chen Chen Xiao-Yu Wang 《World Journal of Psychiatry》 2026年第1期291-298,共8页
BACKGROUND Anxiety,depression,and other negative emotions are common among patients with chronic renal failure(CRF).Analyzing the factors related to negative emotions is necessary to provide targeted nursing care.AIM ... BACKGROUND Anxiety,depression,and other negative emotions are common among patients with chronic renal failure(CRF).Analyzing the factors related to negative emotions is necessary to provide targeted nursing care.AIM To explore the correlations among life satisfaction,pleasure levels,and negative emotions in patients with CRF.METHODS One hundred patients with CRF who received therapy at the First Affiliated Hospital of Jinzhou Medical University between December 2022 and February 2025 were included.The Depression,Anxiety,and Stress Scale(DASS-21),Satisfaction with Life Scale(SWLS),and Temporal Experience of Pleasure Scale(TEPS)were used to evaluate negative emotions,life satisfaction,and pleasure level,respectively.Pearson’s correlation coefficient analyzed the correlation between life satisfaction,pleasure level,and negative emotions.Linear regression analysis identified the factors affecting negative emotions.RESULTS The average DASS-21 score among patients with CRF was 51.90±2.30,with subscale scores of 17.90±1.50 for depression,18.53±1.18 for anxiety,and 15.47±2.36 for stress,all significantly higher than the domestic norm(P<0.05).The average SWLS score was 22.17±4.90.Correlation analysis revealed a negative correlation between the SWLS and total DASS-21 scores(P<0.05),but not with the individual depression,anxiety,or stress dimensions.The average TEPS score was 67.80±8.34.TEPS scores were negatively correlated with the DASS-21 score and the stress dimension(P<0.05),but not with depression or anxiety.Linear regression analysis showed that TEPS scores significantly influenced DASS-21 scores(P<0.05).CONCLUSION Patients with CRF experience high levels of negative emotions,which are negatively correlated with life satisfaction and pleasure.Furthermore,pleasure level had an impact on negative emotions. 展开更多
关键词 Chronic renal failure HEMODIALYSIS Negative emotion Life satisfaction PLEASURE CORRELATION
暂未订购
Preterm heart failure and refractory lactic acidosis caused by congenital hypothyroidism:A case report and review of literature
10
作者 Hong-Ju Chen Jiao Li +3 位作者 Xiao-Ming Xu Bo Zhang Bo-Chao Cheng Jing Shi 《World Journal of Clinical Cases》 2026年第1期43-51,共9页
BACKGROUND Congenital hypothyroidism(CH)is a common condition in both preterm and term infants characterized by either thyroid gland absence or hypofunctionality.The clinical association of refractory lactic acidosis ... BACKGROUND Congenital hypothyroidism(CH)is a common condition in both preterm and term infants characterized by either thyroid gland absence or hypofunctionality.The clinical association of refractory lactic acidosis and heart failure has rarely been observed in cases of pediatric patients with CH pathology.Here,we explored the etiological relationship between CH,heart failure,and refractory lactic acidosis to reflect the importance of thyroid function screening in neonates with heart disease.CASE SUMMARY A 33-day-old extremely premature female infant presented with tachypnea,respiratory distress,recurrent infections,and abdominal distension postnatal.On admission to our facility,she had cardiomegaly,hepatomegaly,and lactic acidosis(revealed on blood gas analysis),with lactate progressively rising to 25 mmol/L.Chest radiographs showed pulmonary congestion,while echocardiography revealed cardiac enlargement,left ventricular wall thickening,and pericardial effusion.Initial management aimed at correcting acidosis and treating heart failure proved ineffective.After reassessment,thyroid function tests showed significantly decreased triiodothyronine,free triiodothyronine,thyroxine,and free thyroxine levels,with a significantly increased thyroidstimulating hormone level,confirming a CH diagnosis.Levothyroxine was administered,resulting in rapid correction of lactic acidosis and gradual improvement of thyroid function and systemic symptoms,culminating in full recovery and discharge.We also reviewed the relevant literature on thyroid and cardiac dysfunctions in order to explore their deeper association.CONCLUSION This case links CH-induced heart failure with refractory lactic acidosis,urging prompt thyroid screening in affected neonates to reduce mortality. 展开更多
关键词 Congenital hypothyroidism Lactic acidosis Heart failure NEONATE PRETERM Case report
暂未订购
Qi deficiency syndrome in heart failure:integrative analysis reveals CISD2-linked lipid metabolic dysregulation and prognostic implications
11
作者 Jia-Mei Huang Lu-Hua Xu +6 位作者 Yu-Wen Qi Jie-Ni Fang Teng-Yang Zhai Zhi-Cong Zeng Hong-Cai Shang Rong-Feng Yang Feng-Xia Lin 《Traditional Medicine Research》 2026年第4期39-49,共11页
Background:“Qi deficiency”(a pathological state where the body’s vital energy(Qi)is insufficient or weakened,impairing physiological functions and diminishing the body’s ability to perform daily activities,defend ... Background:“Qi deficiency”(a pathological state where the body’s vital energy(Qi)is insufficient or weakened,impairing physiological functions and diminishing the body’s ability to perform daily activities,defend against illness,and maintain homeostasis)syndrome is considered a critical syndrome in traditional Chinese medicine(TCM)and is associated with poor prognosis in heart failure(HF).This study investigates the clinical,metabolic,and transcriptomic differences between heart failure patients with and without Qi deficiency syndrome.Methods:56 heart failure patients were evaluated using a Qi deficiency syndrome scale and divided into Qi deficiency syndrome(QD)and non-Qi deficiency(non-QD)groups based on the median score.Clinical characteristics,including baseline N-terminal pro-B-type natriuretic peptide(NT-proBNP),left ventricular ejection fraction(LVEF),total diuretic use during hospitalization,and 90-day rehospitalization rates,were compared between the groups.Differentially expressed genes(DEGs)and differential metabolites were identified,followed by enrichment analyses and validation using qPCR and Western blot in AC16 cardiomyocytes.Results:QD patients exhibited significantly higher NT-proBNP levels,lower LVEF,and increased 90-day rehospitalization rates.Metabolomic profiling revealed lipid metabolism disruptions,notably in linoleic acid and phospholipid pathways.Transcriptomic analysis highlighted 17 DEGs,including CISD2,a critical mitochondrial regulator,which was downregulated in QD patients.Correlation analysis identified significant associations between DEGs(e.g.,CISD2,BPGM)and lipid metabolites such as PC(16:0/P-16:0).Functional knockdown of CISD2 in AC16 cells led to upregulation of lipid oxidation enzymes ALOX15 and CYP1A2,linking CISD2 dysfunction to lipid metabolic dysregulation.Conclusion:Qi deficiency is associated with more severe heart failure symptoms,worse prognosis,and distinct metabolic and transcriptomic profiles,particularly in lipid metabolism.CISD2 emerges as a potential therapeutic target,offering new avenues for integrating molecular insights with TCM approaches to optimize HF management. 展开更多
关键词 Qi deficiency syndrome heart failure lipid metabolism transcriptomic alterations CISD2
暂未订购
Successful rescue activation of unfertilized oocytes with calcium ionophore(A23187)in a case of recurrent ICSI fertilization failure:A case report
12
作者 Akash More Vilas Chimurkar +2 位作者 Namrata Choudhary Dipali More Sanket Mahajan 《Asian pacific Journal of Reproduction》 2026年第1期45-48,共4页
Rationale:This case report describes a couple with recurrent fertilization failure despite undergoing multiple cycles of intracytoplasmic sperm injection(ICSI).The principal clinical concern was suspected oocyte activ... Rationale:This case report describes a couple with recurrent fertilization failure despite undergoing multiple cycles of intracytoplasmic sperm injection(ICSI).The principal clinical concern was suspected oocyte activation deficiency(OAD),in which fertilization is impeded due to the oocyte’s inability to initiate embryogenesis,commonly attributed to inadequate intracellular calcium(Ca^(2+))release following sperm injection.Patient concerns:The couple repeatedly experienced complete or near-complete fertilization failure in previous ICSI cycles,raising suspicion of an underlying oocyte activation defect.Diagnosis:Based on the repeated absence of fertilization post-ICSI and clinical history,a diagnosis of suspected OAD leading to recurrent ICSI fertilization failure was considered.Interventions:Artificial oocyte activation(AOA)using the calcium ionophore A23187 was performed.After ICSI,unfertilized oocytes were exposed to the ionophore to induce Ca^(2+)influx,simulating physiological calcium oscillations essential for oocyte activation.The efficacy of intervention was evaluated through subsequent embryonic development,morphological grading,and chromosomal integrity.Outcomes:Following AOA treatment,successful oocyte activation occurred,resulting in the formation of high-grade embryos with normal developmental progression.Chromosomal analysis revealed no detectable abnormalities,indicating genomic stability.Lessons:Calcium ionophore–mediated AOA may serve as an effective adjunct in cases of recurrent ICSI failure attributed to OAD.This case highlights the importance of individualized therapeutic strategies in assisted reproduction;however,further research is needed to refine protocols,validate broader clinical efficacy,and assess long-term safety,including potential epigenetic risks. 展开更多
关键词 Oocyte activation deficiency Intracytoplasmic sperm injection Artificial oocyte activation Calcium ionophore A23187 Fertilization failure Assisted reproductive technology
暂未订购
DAMAGES AND FAILURES OF SMART STRUCTURES
13
作者 王鑫伟 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2003年第1期1-5,共5页
According to some observed dama ge phenomena in the smart structure systems, the issues related to the damage and failures of smart structures are addressed in this paper. A few possible damage patterns and the def... According to some observed dama ge phenomena in the smart structure systems, the issues related to the damage and failures of smart structures are addressed in this paper. A few possible damage patterns and the definition of the failure of the smart structures are given. It is pointed out that more attentions should be paid to the functional failures o f smart structures. The effects on the control the static deformation due to par tial debonding of PZT actuators are analyzed by the finite element method. Preli minary numerical results show that partial debonding of PZT actuators may have a p preciate reduction on their actuating ability thus reducing the control ability and accuracy of the smart structures. 展开更多
关键词 smart structures damag es failures FUNCTION
在线阅读 下载PDF
Adaptive Integral-type Sliding Mode Control for Spacecraft Attitude Maneuvering Under Actuator Stuck Failures 被引量:17
14
作者 HU Qinglei ZHANG Youmin +1 位作者 HUO Xing XIAO Bing 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2011年第1期32-45,共14页
A fault tolerant control (FTC) design technique against actuator stuck faults is investigated using integral-type sliding mode control (ISMC) with application to spacecraft attitude maneuvering control system. The... A fault tolerant control (FTC) design technique against actuator stuck faults is investigated using integral-type sliding mode control (ISMC) with application to spacecraft attitude maneuvering control system. The principle of the proposed FTC scheme is to design an integral-type sliding mode attitude controller using on-line parameter adaptive updating law to compensate for the effects of stuck actuators. This adaptive law also provides both the estimates of the system parameters and external disturbances such that a prior knowledge of the spacecraft inertia or boundedness of disturbances is not required. Moreover, by including the integral feedback term, the designed controller can not only tolerate actuator stuck faults, but also compensate the disturbances with constant components. For the synthesis of controller, the fault time, patterns and values are unknown in advance, as motivated from a practical spacecraft control application. Complete stability and performance analysis are presented and illustrative simulation results of application to a spacecraft show that high precise attitude control with zero steady-error is successfully achieved using various scenarios of stuck failures in actuators. 展开更多
关键词 integral sliding mode control attitude maneuvering stuck failure adaptive control SPACECRAFT
原文传递
Human-induced landslide on a high cut slope: a case of repeated failures due to multi-excavation 被引量:8
15
作者 Fanyu Zhang Gao Liu +3 位作者 Wenwu Chen Shouyun Liang Ransheng Chen Wenfeng Han 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE 2012年第4期367-374,共8页
The paper attempts to represent a case of repeated failures on a high cut slope due to multi-excavation. The characteristics of each failure induced by excavation are analyzed through geological investigation, and the... The paper attempts to represent a case of repeated failures on a high cut slope due to multi-excavation. The characteristics of each failure induced by excavation are analyzed through geological investigation, and then a geological model at different failure stages is proposed. The geological analysis shows that the excavation-induced repeated failures are related to the exposure of the weak bedding plane and the toe unloading of the cut slope, Numerical modeling is conducted based on a sequential method, taking into account the main failure stages of cut slope. The simulation results fairly coincide with the practical phenomena observed in field. It is shown that the decrease in normal stress of displaced mass on cut slope will induce the increase in shear stress in bedding planes and that at the toe of the cut slope. The released stress leads to repeated gravitational instabilities of cut slope due to the decrease in normal stress and the increase in shear stress along the bedding planes of mudstone. 展开更多
关键词 LANDSLIDE repeated failures multi-excavation instability of cut slope human activity
在线阅读 下载PDF
Recovery of coupled networks after cascading failures 被引量:7
16
作者 GAO Jiazi YIN Yongfeng +1 位作者 FIONDELLA Lance LIU Lijun 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2018年第3期650-657,共8页
With society's increasing dependence on critical infrastructure such as power grids and communications systems, the robustness of these systems has attracted significant attention.Failure of some nodes can trigger a ... With society's increasing dependence on critical infrastructure such as power grids and communications systems, the robustness of these systems has attracted significant attention.Failure of some nodes can trigger a cascading failure, which completely fragments the network, necessitating recovery efforts to improve robustness of complex systems. Inspired by real-world scenarios, this paper proposes repair models after two kinds of network failures, namely complete and incomplete collapse. In both models, three kinds of repair strategies are possible, including random selection(RS), node selection based on single network node degree(SD), and node selection based on double network node degree(DD). We find that the node correlation in each of the two coupled networks affects repair efficiency. Numerical simulation and analysis results suggest that the repair node ratio and repair strategies may have a significant impact on the economics of the repair process. The results of this study thus provide insight into ways to improve the robustness of coupled networks after cascading failures. 展开更多
关键词 networks reliability interdependent networks recovery strategy cascading failure
在线阅读 下载PDF
Robust fault-tolerant controller design for linear time-invariant systems with actuator failures:an indirect adaptive method 被引量:7
17
作者 Xiaozheng JIN Guanghong YANG Yanping LI 《控制理论与应用(英文版)》 EI 2010年第4期471-478,共8页
In this paper,indirect adaptive state feedback control schemes are developed to solve the robust fault-tolerant control (FTC) design problem of actuator fault and perturbation compensations for linear time-invariant... In this paper,indirect adaptive state feedback control schemes are developed to solve the robust fault-tolerant control (FTC) design problem of actuator fault and perturbation compensations for linear time-invariant systems.A more general and practical model of actuator faults is presented.While both eventual faults on actuators and perturbations are unknown,the adaptive schemes are addressed to estimate the lower and upper bounds of actuator-stuck faults and perturbations online,as well as to estimate control effectiveness on actuators.Thus,on the basis of the information from adaptive schemes,an adaptive robust state feed-back controller is designed to compensate the effects of faults and perturbations automatically.According to Lyapunov stability theory,it is shown that the robust adaptive closed-loop systems can be ensured to be asymptotically stable under the influence of actuator faults and bounded perturbations.An example is provided to further illustrate the fault compensation effectiveness. 展开更多
关键词 Fault-tolerant control Actuator failures Adaptive robust control Asymptotic stability
在线阅读 下载PDF
Measles Virus IgG Avidity Assay for Use in Identification of Measles Vaccine Failures in Tianjin, China 被引量:2
18
作者 DING Ya Xing MAO Nai Ying +4 位作者 ZHANG Yan LEI Yue GAO Zhi Gang XU Wen Bo ZHANG Ying 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2019年第11期804-811,共8页
Objective To identify measles vaccine failures in Tianjin, China using a measles virus Ig G avidity assay.Methods The China Information System for Disease Control and Prevention(CISDCP) was used to collect information... Objective To identify measles vaccine failures in Tianjin, China using a measles virus Ig G avidity assay.Methods The China Information System for Disease Control and Prevention(CISDCP) was used to collect information about measles cases and blood specimens in Tianjin from 2013 to 2015. Measlesspecific Ig M and Ig G antibodies were detected using Enzyme-Linked Immunosorbent Assay(ELISA).Avidity testing for measles Ig G was performed using a commercial enzyme immunoassay(EIA).Results A total of 284 confirmed measles cases were identified. Of this total, 262(92.25%) were in patients aged ≥ 20 years. High avidity was exhibited in 172(60.56%) cases, while 80(28.17%) cases demonstrated low avidity. High avidity was detected in only 21.43% of cases in patients aged < 1 year.The proportion of high avidity increased with age, and was significantly higher in patients aged 30–39 years at 70.07%(χ~2 = 17.27, P = 0.002). Of the 52 measles cases in patients with a history of vaccinations,41(78.85%) cases showed high avidity, indicating secondary vaccine failures(SVF). In these vaccinations,there was no significant difference(P > 0.05) in clinical severity between high avidity and low avidity cases. However, regardless of vaccination status, clinical severity was significantly lower in high avidity cases(P < 0.001) than in low avidity cases. The percentages of positive measles Ig M results in high avidity and low avidity cases were 66.28% and 91.25%, respectively. Geometric Mean Concentration(GMC) was significantly lower in high avidity cases at 33.73 U/m L, compared to 166.07 U/m L in low avidity cases.Conclusions Low clinical severity and inconclusive Ig M antibody results are more likely in high avidity measles cases. Measles cases were more common in adults. Therefore, a further dose of vaccines should be recommended for 30–39 years in Tianjin. 展开更多
关键词 MEASLES IgG avidity China Primary vaccine failures Secondary vaccine failures
暂未订购
Availability Analysis of Parallel Repairable System with Omitted Failures 被引量:4
19
作者 郑治华 崔利荣 《Journal of Beijing Institute of Technology》 EI CAS 2009年第1期117-120,共4页
The new model for parallel repairable system is introduced, and it is based on the practice problems of maintenance and the idea of Ion-Channel modeling. In the new model, repair times that are sufficiently short (le... The new model for parallel repairable system is introduced, and it is based on the practice problems of maintenance and the idea of Ion-Channel modeling. In the new model, repair times that are sufficiently short (less than some critical value) do not result in system failure, and such a repair interval is omitted from the downtime record. Usually, the underlying process is Markov process if the durations of working and repair time have the negative-exponential distributions, but the new system has not the Markov properties, which is worth to study. The reliability indexes such as instantaneous availability and steady-state availabilities for the new system are given through probability analysis. A numerical example is given to illustrate the results. 展开更多
关键词 parallel repairable system Markov process AVAILABILITY omitted failure
在线阅读 下载PDF
Postcapture stabilization of space robots considering actuator failures with bounded torques 被引量:4
20
作者 Xiaokui YUE Teng ZHANG +2 位作者 Honghua DAI Xin NING Jianping YUAN 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2018年第10期2034-2048,共15页
Space robotics is regarded as one of the most impressing approaches for space debris removal missions. Due to the residual momentum of debris, it is essential to stabilize the base rapidly after capture. This paper pr... Space robotics is regarded as one of the most impressing approaches for space debris removal missions. Due to the residual momentum of debris, it is essential to stabilize the base rapidly after capture. This paper presents a novel control strategy for stabilization of a space robot in postcapture considering actuator failures and bounded torques. In the control strategy, the motion of the manipulator is not regarded as a disturbance to the base; in contrast, it is utilized to compensate for the limitation of the control torques by means of an inverse dynamical model of the system. Different scenarios where actuators are external mechanisms or momentum exchange devices have been carried out, and for actuator failures, both single-and two-actuator failures have been considered. Regarding to the performance of actuators, control torques are bounded. In cases that either single or two actuators have failed, the base can be stabilized kinematically when actuators are external mechanisms, but can only be stabilized dynamically when only momentum exchange devices are used. Finally, a space robot with a seven-degree-of-freedom manipulator in postcapture is studied to verify the validity and feasibility of the proposed control scheme. Simulation results show that the whole system can be stabilized rapidly. 展开更多
关键词 Actuator failure Attitude control Bounded torque Postcapture Space robot
原文传递
上一页 1 2 250 下一页 到第
使用帮助 返回顶部