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Association of neuroelectrophysiology and analysis of cerebrospinal fluid immunoglobulin with pathogenetic conditions of patients with Guillain-Barre syndrome
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作者 Haibin Huang Xunliang Mai Xiaohong Ye 《Neural Regeneration Research》 SCIE CAS CSCD 2006年第3期271-273,共3页
BACKGROUND: Guillain-Barre syndrome (GBS) is an autoimmune disease which is characterized by demyelination of peripheral nerve and nerve root, and inflammatory reaction of lymphocyte and macrophage. Neuroelectrophy... BACKGROUND: Guillain-Barre syndrome (GBS) is an autoimmune disease which is characterized by demyelination of peripheral nerve and nerve root, and inflammatory reaction of lymphocyte and macrophage. Neuroelectrophysiological examination and cerebrospinal fluid (CSF) analysis are of significance for its diagnosis. OBJECTIVE: To study the association of neuroelectrophysiology and cerebrospinal fluid immunoglobulin (CSF-lg) with pathogenetic conditions of patients with GBS. DESIGN: Case control study SETTING: Department of Neurology, Shenzhen Municipal Shekou Group Hospital; Department of Neuroelectrophysiology, People's Hospital of Guangdong Province. PARTICIPANTS: A total of 32 GBS patients including 18 males and 14 females who aged from 17 to 72 years were selected as experimental group from the Department of Neurology, People's Hospital of Guang- dong Province from January 2004 to December 2005. All cases conformed with GBS diagnostic criteria established by Asbury in 1990 and they were divided into three types according to neurological criteria established by Chinese Neurology and Psychology Journal in 1993: mild, moderate and severe types. Another 30 patients with vascular headache were selected as control group from the same hospital including 14 males and 16 females who aged from 17 to 79 years. METHODS: ① Neuroelectrophysiological examination: Multiple-functional electromyography device provided by Nicolet Company, USA was used to measure nerve conduction velocity (NCV), including motor nerve conduction velocity (MCV) and sensory nerve conduction velocity (SCV); meanwhile, electromyologram (EMG), somatosensory evoked potential (SEP) and electroencephalogram (EEG) were also measured. ② Detection of CSF-lg: Concentrations of IgG, IgA and IgM were measured with immunofixation electrophoresis. ③Follow-up: Among 32 GBS patients, 14 cases received follow-up after treatment and the longest fol- low-up time was 1 year after onset. Among them, 8 cases were reexaminined with neuroelectrophysiological and CSF examinations. MAIN OUTCOME MEASURES: Results of NCV, EMG, SEP and EEG; comparison of CSF-lg content; results of follow-up examinations. RESULTS: All 32 GBS cases and 30 patients with vascular headache were involved in the final analysis. ① Abnormal rate of neuroelectrophysiological test: 75% of NCV, 88% of F-wave, 53% of MCV, 25% of SEP, 47% of EMG and 31% of EEG. There were no significant differences among various types (P 〉 0.05). ② Results of CSF-lg test: There were no significant differences among various types (P 〉 0.05); however, abnormalities in experimental group was higher than those in control group (P 〈 0.01). CONCLUSION : Results of follow-up study suggest that improvement of clinical symptom is earlier than neuroelectrophysiological recovery; MCV and EMG recoveries are faster than that of NCV; the earlier the abnormality of EMG, the poorer the recovery. CSF4g recovers normally along improvement of clinical symptoms. It is of significance for neuroelectrophysiology and abnormality of CSF-Ig to determine degree of peripheral nerve demyelination and prognosis. 展开更多
关键词 CSF GBS Association of neuroelectrophysiology and analysis of cerebrospinal fluid immunoglobulin with pathogenetic conditions of patients with Guillain-Barre syndrome
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Analysis of the effect and present conditions to platelet transfusion on clinical tumor
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《中国输血杂志》 CAS CSCD 2001年第S1期394-,共1页
关键词 analysis of the effect and present conditions to platelet transfusion on clinical tumor
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Analysis of the Conditional Correlations from Different Genetic Systems Between the Protein Content and the Appearance Quality Traits of Indica Rice 被引量:4
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作者 葛国科 郑希 +2 位作者 吴建国 叶子弘 石春海 《Journal of Genetics and Genomics》 SCIE CAS CSCD 北大核心 2007年第2期129-137,共9页
A factorial mating design in two environments was conducted using 7 cytoplasmic male sterile lines (A) and 5 restorer lines (R) along with their F1 (A × R) and F2 populations. The unconditional and conditio... A factorial mating design in two environments was conducted using 7 cytoplasmic male sterile lines (A) and 5 restorer lines (R) along with their F1 (A × R) and F2 populations. The unconditional and conditional analyses of genetic models and the corresponding statistic methods, including endospermic, cytoplasmic, and maternal plant genetic systems, were used to analyze the genetic relationships between protein content (PC) and the appearance quality traits of indica rice (Oryza sativa L.). The results from unconditional analysis indicated that PC was significantly correlated with the appearance quality traits of rice, except for the brown rice thickness (BRT). Only the genetic covariance between PC and the brown rice width (BRW) was positively correlative, whereas all the other pairwise traits were negatively correlative. The results from conditional analysis revealed that the weight of brown rice (WBR) or the amylose content (AC) could significantly affect the relationships between PC and the appearance quality traits of indica rice. The conditional analysis showed that WBR might negatively affect the relationships between PC and the brown rice length (BRL), BRW, or BRT through the geuotype x environmental (GE) interaction effects, but positively affected the relationships between PC and the ratio of brown rice length to width (RLW) or the ratio of brown rice length to thickness (RLT). The amylase content could positively affect the relationships between PC and BRL, RLW, RLT through the cytoplasmic effects and maternal additive effects, but negatively affected the relationships between PC and BRW. 展开更多
关键词 indica rice (Oryza sativa L.) COVARIANCE unconditional and conditional analysis methods protein content amylose content appearance quality
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Analysis on Agricultural Meteorological Condition of Osmanthus Blooming 被引量:1
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作者 白先达 《Agricultural Science & Technology》 CAS 2014年第9期1612-1615,共4页
Osmanthus, an ornamental plants, is favored by people, and forecast of Osmanthus florescence is of vital significance for enjoying the sight. Based on 15 years of flowering observation data, analysis was made on agric... Osmanthus, an ornamental plants, is favored by people, and forecast of Osmanthus florescence is of vital significance for enjoying the sight. Based on 15 years of flowering observation data, analysis was made on agricultural meteorologi- cal conditions of Osmanthus in Guilin and the results showed that ground tempera- ture, humidity, precipitation, sunshine have significant effects on Osmanthus flores- cence. In forecasting florescence, therefore, it is necessary to take comprehensive consideration of weather conditions and changes in the future, to release Osman- thus flowering forecast as per method of combination of long-term forecasting and short-term forecast. 展开更多
关键词 Osmanthus flowering Agricultural meteorology Condition analysis
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Axisymmetric Powell-Eyring fluid flow with convective boundary condition: optimal analysis 被引量:1
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作者 T.HAYAT S.MAKHDOOM +2 位作者 M.AWAIS S.SALEEM M.M.RASHIDI 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2016年第7期919-928,共10页
The effects of axisymmetric flow of a Powell-Eyring fluid over an impermeable radially stretching surface are presented. Characteristics of the heat transfer process are analyzed with a more realistic condition named ... The effects of axisymmetric flow of a Powell-Eyring fluid over an impermeable radially stretching surface are presented. Characteristics of the heat transfer process are analyzed with a more realistic condition named the convective boundary condition. Governing equations for the flow problem are derived by the boundary layer approximations. The modeled highly coupled partial differential system is converted into a system of ordinary differential equations with acceptable similarity transformations. The convergent series solutions for the resulting system are constructed and analyzed. Optimal values are obtained and presented in a numerical form using an optimal homotopy analysis method (OHAM). The rheological characteristics of different parameters of the velocity and temperature profiles are presented graphically. Tabular variations of the skin friction coefficient and the Nusselt number are also calculated. It is observed that the temperature distribution shows opposite behavior for Prandtl and Biot numbers. Furthermore, the rate of heating/cooling is higher for both the Prandtl and Biot numbers. 展开更多
关键词 axisymmetric flow optimal homotopy analysis method (OHAM) analysis convective boundary condition
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Landslide Susceptibility Assessment Using Conditional Analysis and Rare Events Logistics Regression: A Case-Study in the Antrodoco Area (Rieti, Italy) 被引量:1
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作者 Vittorio Chiessi Simona Toti Valerio Vitale 《Journal of Geoscience and Environment Protection》 2016年第12期1-21,共22页
This paper discusses some methodological aspects for the production of susceptibility maps of slope instability developed within the CARG Project (Geological Cartography of Italy at 1:50,000 scale). It describes an ex... This paper discusses some methodological aspects for the production of susceptibility maps of slope instability developed within the CARG Project (Geological Cartography of Italy at 1:50,000 scale). It describes an example of a susceptibility map in the presence of low susceptibility, using database having zero or negligible cost, with the aim to test some methodologies that can be easily reproducible to get a first estimate of the landslide susceptibility on a wide area. Two statistical approaches have been applied: the non-parametric conditional analysis and the logistic analysis for rare events. The predictive ability obtained from the two methodologies, was evaluated by the success-prediction curves for the conditional analysis, and by the Receiver Operating Characteristic curve (ROC), for the logistic model. The landslide susceptibility maps have been classified into four classes using both the Natural Breaks algorithm and the method proposed by Chung and Fabbri (2003). The paper considers the influence of these two classification methods on the quality of final results. 展开更多
关键词 Landslide Susceptibility Antrodoco Conditional analysis Rare Events Logistic Regression Classification Methods
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Longitudinal genetic analysis of growth-related traits in red swamp crayfish Procambarus clarkii (Girard)
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作者 Hui WANG Yi ZHANG +3 位作者 Guoliang CHANG Nan WU Zhiqiang XU Jianqing TANG 《Journal of Oceanology and Limnology》 SCIE CAS CSCD 2022年第2期775-785,共11页
The red swamp crayfish,Procambarus clarkii,is an economically important species especially in China.Their exoskeleton places serious constraints on growth and culture management.Their growth is achieved through interm... The red swamp crayfish,Procambarus clarkii,is an economically important species especially in China.Their exoskeleton places serious constraints on growth and culture management.Their growth is achieved through intermittent molting/ecdysis.The longitudinal genetic dynamics for growth-related traits at different ecdysial points in P.clarkii has been unclear to date.In this study,conditional genetic analysis was carried out for growth-related traits(body weight,body length,chela length,and cephalothorax length)based upon a mixed genetic model with conditional additive,dominance,and genotype by environment effects in P.clarkii.A complete diallel cross was made among three geographic populations of P.clarkii for the genetic mating design.Results of the conditional genetic analysis showed that from 4 th molt to 9 th molt the conditional additive variations were increased significantly whereas the conditional non-additive genetic variations(dominance and genotype by environment interaction)were decreased significantly for these growth-related traits.This indicated that lots of new expression of additive effect genes for body weight,body length,chela length,and cephalothorax length occurred during ontogeny,and environment played a signifi cant role in the expression of genes affecting these growth-related traits.Growth of the four traits was mainly affected by non-additive genetic effects in early developmental stage(prior to 4 th molt).The cumulative conditional additive variation for the growth-related traits from 4 th molt to 9 th molt accounted for a large majority of the total conditional additive variations from 2 nd molt to 9 th molt,indicating that this period was very important for the growth of this species.Using the conditional analysis method,dynamics of growth-related traits during an important ontogenetic phase of red swamp crayfish was uncovered.Our results provide valuable insights into refining production of this species. 展开更多
关键词 mating design conditional genetic analysis model Procambarus clarkii genetic effect conditional variance component longitudinal genetic analysis
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Condition analysis of HCV infection of blood donors in nanchang area
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《中国输血杂志》 CAS CSCD 2001年第S1期339-,共1页
关键词 HCV Condition analysis of HCV infection of blood donors in nanchang area
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The Analysis on Comparison of Forming Condition with Abroad Palaeo-Epicontinental Marine Basin and Possibility of Potash Formation in North China
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作者 ZHANG Yongsheng XING Enyuan +2 位作者 PAN Wei ZHAI Daxing WU Feimeng 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2014年第S1期278-280,共3页
1 Introduction Currently,all six different continents have discovered potash deposits and potash-bearing salt lake saline water.However,the distribution is extremely uneven,which is mostly concentrated in Canada,Russi... 1 Introduction Currently,all six different continents have discovered potash deposits and potash-bearing salt lake saline water.However,the distribution is extremely uneven,which is mostly concentrated in Canada,Russia,Middle-Asia and 展开更多
关键词 The analysis on Comparison of Forming Condition with Abroad Palaeo-Epicontinental Marine Basin and Possibility of Potash Formation in North China
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Genetic Dissection of Net Effects Between Yield and Its Components in Sea Island Cotton (Gossypium barbadense L.)
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作者 YE Zi-hong MEI Yong-jun +2 位作者 ZOU Ke-qin FU Xian-shu JIANG Lin-shu 《Agricultural Sciences in China》 CAS CSCD 2008年第9期1052-1060,共9页
The number of bolls, individual boll weight, and lint percentage are three important yield components of lint yield of cotton. In the present study, nine parents, twenty F1, and twenty F2 crosses of intraspecific hybr... The number of bolls, individual boll weight, and lint percentage are three important yield components of lint yield of cotton. In the present study, nine parents, twenty F1, and twenty F2 crosses of intraspecific hybrids of sea island cotton (Gossypium barbadense L.) were grown at Tarim University, Alar, Xinjiang, China, in 2000 and 2001. Lint yield and its three component traits were measured and analyzed by an extended conditional mixed linear model approach. Lint percentage made the largest contribution to additive, additive x environment, and dominance x environment variations for lint yield. The contribution ratios of number of bolls, individual boll weight, and combined contribution of these two traits to additive x environment and dominance x environment variations for lint yield were not statistically significant. Lint yield of different parents could be affected differently by lint percentage. Lint yield of some parents was closely correlated with lint percentage, whereas for other parents, the behavior of individual boll weight and number of bolls played much more important roles on lint yield than that of lint percentage. It was shown by the conditional and conventional predicted additive x environment interaction effects of parents that the environment condition could influence different parents with varied effects. 展开更多
关键词 YIELD yield components Gossypium barbadense L. conditional analysis
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Heterosis Study on Developmental Behavior of Flowering and Boll Setting in Upland Cotton
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作者 YE Zi-hong ZHU Jun 《Agricultural Sciences in China》 CAS CSCD 2006年第1期23-32,共10页
The developmental behavior was examined for flowering and boll setting in upland cotton (Gossypium hirsutum L.) at different boll-setting sites and blooming periods. Conventional and conditional methods were applied... The developmental behavior was examined for flowering and boll setting in upland cotton (Gossypium hirsutum L.) at different boll-setting sites and blooming periods. Conventional and conditional methods were applied to analyze heterosis by an additive-dominance model with genotype by environment (GE) interaction effects. Positive general heterosis was significantly detected on middle-lower nodes at positions 1 and 2 for a number of flowers and bolls per plant. Deviation between HPBE1 and HPBE2 was relatively large for a number of flowers per plant at positions 3, 4, and 5, but much smaller for number of bolls per plant. There was increase of heterosis before the end of July, and the highest heterosis was observed at 22 DAF (22 days after flowering) for flowers and at 16 DAF for bolls, and then declined. There existed significant diversity of interaction heterosis for flowers as well as for bolls during blooming stages, but deviation between HPBE1 and HPBE2 was smaller for number of bolls per plant than that of flowers per plant. The cross of DP-15 (late-season variety)' HG-H-12 had positive general heterosis since 19 DAF, and negative HPB was observed for the cross of GL-5 (early-season variety)' HG-H-12 after 37 DAF. Interaction heterosis was mostly not significant for cross DP-15' HG-H-12, but the reverse was true for cross GL-5' HG-H-12. Positive conditional HPB was detected since 16 DAF until 43 DAF for cross DP-15' HG- H-12, and before 13 DAF for cross GL-5' HG-H-12. 展开更多
关键词 Gossypium hirsutum L. HETEROSIS conditional analysis number of flowers number of bolls
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THE EXACT SOLUTIONS OF ELASTIC-PLASTIC CRACK LINE FIELD FOR MODE Ⅱ PLANE STRESS CRACK
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作者 易志坚 王士杰 王向坚 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 1995年第10期977-984,共8页
The near crack line field analysis method has been used io investigate into theexact elastic-plastic solutions of a mode II crack under plane stress condilion in anelastic-perfectly plastic solid. The assumptions of t... The near crack line field analysis method has been used io investigate into theexact elastic-plastic solutions of a mode II crack under plane stress condilion in anelastic-perfectly plastic solid. The assumptions of the usual small scale yielding theory.hare been completely. dbandoned and the correct formulations of matching conditionsat the elaslic-plastic boundary. have been given. By, matching the general solution ofthe plastic slress field (bul not the special solution used to be adopted) with the exactelastic stress field (but not the crack tip K-dominant field) at the elastic-plasticboundary, near the crack line, the plastic stresses. the length of the plastic =one and theunit normal vector of the elastic-plastic boundary.which are sufficiently precise near the crack line region ,have been given. 展开更多
关键词 mode II crack. near crack line analysis method. crack line. elastic-plastic boundary. matching conditions
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THE EXACT SOLUTIONS OF ELASTIC-PLASTIC CRACK LINE FIELD FOR MODE Ⅱ PLANE STRESS CRACK
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作者 易志坚 王士杰 王向坚 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 1995年第5期977-984,共8页
The near crack line field analysis method has been used to investigate into the exact elastic-plastic solutions of a mode Ⅱ crack under plane stress condition in anelastic-perfectly plastic solid. The assumptions of ... The near crack line field analysis method has been used to investigate into the exact elastic-plastic solutions of a mode Ⅱ crack under plane stress condition in anelastic-perfectly plastic solid. The assumptions of the usual small scale yielding theoryhave been completely. dbandoned and the correct .formulations of matching conditionsat the elastic-plastic boundary have been given. By matching the general solution of the plastic stress field (but not the special solution used to be adopted) will the exactelastic stress field (but not the crack tip K-dominant field) at the elastic-plasticboundary. near the crack line, the plastic .stresses, the length of the plastic zone and theunit normal vector of the elaslic-plastic boundary. which sufficiently precise nearthe crack line region, hare been given. 展开更多
关键词 mode Ⅱcrack. near crack line analysis method. crack line. elastic-plastic boundary. matching conditions
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Implementation of a drainage information, analysis and management system 被引量:1
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作者 J. N. Meegoda T. M. Juliano +2 位作者 L. Potts C. Tang T. Marhaba 《Journal of Traffic and Transportation Engineering(English Edition)》 2017年第2期165-177,共13页
An integrated drainage information, analysis and management system (DIAMS) was developed and implemented for the New Jersey Department of Transportation (N/DOT). The purpose of the DIAMS is to provide a useful too... An integrated drainage information, analysis and management system (DIAMS) was developed and implemented for the New Jersey Department of Transportation (N/DOT). The purpose of the DIAMS is to provide a useful tool for managers to evaluate drainage infrastructure, to facilitate the determination of the present costs of preserving those in- frastructures, and to make decisions regarding the optimal use of their infrastructure budgets. The impetus for DIAMS is the culvert information management system (CIMS), which is developed to manage the data for culvert pipes. DIAMS maintains and summa- rizes accumulated inspection data for all types of drainage infrastructure assets, including pipes, inlet/outlet structures, outfalls and manufactured treatment devices. DIAMS capa- bilities include identifying drainage infrastructure, maintaining inspection history, map- ping locations, predicting service life based on the current condition states, and assessing present asset value. It also includes unit cost values of 72 standard items to estimate the current cost for new assets with the ability to adjust for future inflation. In addition, DIAMS contains several different repair, rehabilitation and replacement options to remedy the drainage infrastructure. DIAMS can analyze asset information and determine decisions to inspect, rehabilitate, replace or do nothing at the project and network levels by comparing costs with risks and failures. Costs may be optimized to meet annual maintenance budget allocations by pfioritizing drainage infrastructure needing inspection, cleaning and repair. DIAMS functional modules include vendor data uploading, asset identification, system administration and financial analysis. Among the significant performance feature of DIAMS is its proactive nature, which affords decision makers the means of conducting a comprehensive financial analysis to determine the optimal proactive schedule for the proper maintenance actions and to prioritize them accordingly. Benefits of DIAMS include long-term savings that accrue by adopting optimized preventive maintenance strategies and facilitating compliance with Governmental Accounting Standards Board (GASB) and federal storm water regulations. 展开更多
关键词 Financial analysis Pipe Condition assessment Data collection Inspection Inventory
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A Simplified Model, Dynamic Analysis and Force Estimation for a Large-scale Orinthopter in Forward Flight Based on Flight Data
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作者 Mohammad Ali Amini Moosa Ayati Mohammad Mahjoob 《Journal of Bionic Engineering》 SCIE EI CSCD 2020年第5期989-1008,共20页
Similarities and differences of a large-scale flapping-wing robot with fixed-wing UAVs in equations of motion,trim curves,and aerodynamic forces in forward flight are discussed in this paper and a simplified model for... Similarities and differences of a large-scale flapping-wing robot with fixed-wing UAVs in equations of motion,trim curves,and aerodynamic forces in forward flight are discussed in this paper and a simplified model for flapping flight is presented.Due to the high Wing to Total Weight(WTW)ratio of large-scale omithopters,simple rigid body dynamics is not accurate enough for flight dynamics modeling.On the other hand,the multi-body dynamics associated with flapping gives little insight into the behavior of the resulting model due to complexity of equations.It is also difficult to design proper controllers for such complicated models.In this paper,the effects of different terms of multi-body equations of ornithopter on the estimated aerodynamic forces are studied via experimental flight data.A simpler but yet accurate set of equations is obtained by removing less effective terms from original relations.The presented model is in the form of normal aircraft equations plus some additional terms which can be used in different control and estimation processes.In addition,trim conditions of forward flight are extracted using several flight tests,and corresponding periodic behavior of states and forces are studied.These studies are applicable for identifying time-periodic models. 展开更多
关键词 flapping wing robot bionic robot ornithopter trim condition analysis low-order modeling aerodynamic force estimation
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ADRC in output and error form:connection,equivalence,performance 被引量:2
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作者 Rafal Madonski Gernot Herbst Momir Stankovic 《Control Theory and Technology》 EI CSCD 2023年第1期56-71,共16页
In this work,we investigate two specific linear ADRC structures,namely output-and error-based.The former is considered a“standard”version of ADRC,a title obtained primarily thanks to its simplicity and effectiveness... In this work,we investigate two specific linear ADRC structures,namely output-and error-based.The former is considered a“standard”version of ADRC,a title obtained primarily thanks to its simplicity and effectiveness,which have spurred its adoption across multiple industries.The latter is found to be especially appealing to practitioners as its feedback error-driven structure bares similarities to conventional control solutions,like PI and PID.In this paper,we describe newly found connections between the two considered ADRC structures,which allowed us to formally establish conditions for their equivalence.Furthermore,the conducted comprehensive performance comparison between output-and error-based ADRCs has facilitated the identification of specific modules within them,which can now be conveniently used as building blocks,thus aiding the control designers in customizing ADRC-based solutions and making them most suitable for their applications. 展开更多
关键词 Active disturbance rejection control(ADRC)-Output-based form Error-based form Equivalence condition:Comparative analysis
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Multiaxial fatigue life prediction of composite materials 被引量:5
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作者 Jingmeng WENG Weidong WEN Hongjian ZHANG 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2017年第3期1012-1020,共9页
In order to analyze the stress and strain fields in the fibers and the matrix in composite materials,a fiber-scale unit cell model is established and the corresponding periodical boundary conditions are introduced.Ass... In order to analyze the stress and strain fields in the fibers and the matrix in composite materials,a fiber-scale unit cell model is established and the corresponding periodical boundary conditions are introduced.Assuming matrix cracking as the failure mode of composite materials,an energy-based fatigue damage parameter and a multiaxial fatigue life prediction method are established.This method only needs the material properties of the fibers and the matrix to be known.After the relationship between the fatigue damage parameter and the fatigue life under any arbitrary test condition is established,the multiaxial fatigue life under any other load condition can be predicted.The proposed method has been verified using two different kinds of load forms.One is unidirectional laminates subjected to cyclic off-axis loading,and the other is filament wound composites subjected to cyclic tension-torsion loading.The fatigue lives predicted using the proposed model are in good agreements with the experimental results for both kinds of load forms. 展开更多
关键词 Fatigue damage parameter Finite element analysis Life prediction Multiaxial fatigue Periodical boundary condition
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"Weather" transit is reliable? Using AVL data to explore tram performance in Melbourne,Australia 被引量:1
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作者 Mahmoud Mesbah Johnny Lin Graham Currie 《Journal of Traffic and Transportation Engineering(English Edition)》 2015年第3期125-135,共11页
This paper uses automatic vehicle location (AVL) records to investigate the effect of weather conditions on the travel time reliability of on-road rail transit, through a case study of the Melbourne streetcar (tram... This paper uses automatic vehicle location (AVL) records to investigate the effect of weather conditions on the travel time reliability of on-road rail transit, through a case study of the Melbourne streetcar (tram) network. The datasets available were an extensive historica; AVL dataset as well as weather observations. The sample size used in the analysis included all trips made over a period of five years (2006-2010 inclusive), during the morning peak (7 am-9 am) for fifteen randomly selected radial tram routes, all traveling to the Melbourne CBD create a linear model Ordinary least square (OLS) regression analysis was conducted to with tram travel time being the dependent variable. An alternative formulation of the model is also compared. Travel time was regressed on various weather effects including precipitation, air temperature, sea level pressure and wind speed; as well as indicator variables for weekends, public holidays and route numbers to investigate a correlation between weather condition and the on-time performance of the trams. The results indicate that only precipitation and air temperature are significant in their effect on tram travel time. The model demonstrates that on average, an additional millimeter of precipitation during the peak period adversely affects the average travel time during that period by approximately 8 s, that is, rainfall tends to increase the travel time. The effect of air temperature is less intuitive, with the model indicating that trams adhere more closely to schedule when the temperature is different in absolute terms to the mean operating conditions (taken as 15 ℃). 展开更多
关键词 Automatic vehicle location Transit performance Weather condition Regression analysis
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Effect of speed hump characteristics on pavement condition 被引量:1
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作者 Talaat Ali Abdel-Wahed Ibrahim Hassan Hashim 《Journal of Traffic and Transportation Engineering(English Edition)》 2017年第1期103-110,共8页
Speed humps are the most common type of traffic calming devices due to their low cost and easy installation. However, in many Egyptian roads, considerable number of these humps is randomly placed without proper engine... Speed humps are the most common type of traffic calming devices due to their low cost and easy installation. However, in many Egyptian roads, considerable number of these humps is randomly placed without proper engineering studies and justifications. Deteri- oration of pavement condition is observed near these humps. This paper presents a case study applied to collect and analyze visual inspection data for the reason of evaluating the impact of speed humps on pavement condition on intercity rural roads. The paper used 52 speed humps located in an intercity two-lane, two-way road that connects two cities, Tahta and Gerga, in Upper Egypt. The total length of this road is about 34 km. Pavement condition index (PCI), in road sections, near speed humps in the two directions of travel were calculated from the visual inspection measurements. The characteristics of each speed hump (width, height, and distance from preceding hump) were measured. Using statistical analyses, the correlations between the pavement conditions and hump char- acteristics were examined. Regression analysis models were developed to represent the relationships between pavement conditions and hump characteristics. Generally, the re- sults proved that the pavement conditions are greatly influenced by the presence of speed humps and hump characteristics. 展开更多
关键词 Speed hump Pavement condition Pavement condition index (PCI)Two-lane road Regression analysis
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