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Rock mass quality prediction on tunnel faces with incomplete multi-source dataset via tree-augmented naive Bayesian network 被引量:1
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作者 Hongwei Huang Chen Wu +3 位作者 Mingliang Zhou Jiayao Chen Tianze Han Le Zhang 《International Journal of Mining Science and Technology》 SCIE EI CAS CSCD 2024年第3期323-337,共15页
Rock mass quality serves as a vital index for predicting the stability and safety status of rock tunnel faces.In tunneling practice,the rock mass quality is often assessed via a combination of qualitative and quantita... Rock mass quality serves as a vital index for predicting the stability and safety status of rock tunnel faces.In tunneling practice,the rock mass quality is often assessed via a combination of qualitative and quantitative parameters.However,due to the harsh on-site construction conditions,it is rather difficult to obtain some of the evaluation parameters which are essential for the rock mass quality prediction.In this study,a novel improved Swin Transformer is proposed to detect,segment,and quantify rock mass characteristic parameters such as water leakage,fractures,weak interlayers.The site experiment results demonstrate that the improved Swin Transformer achieves optimal segmentation results and achieving accuracies of 92%,81%,and 86%for water leakage,fractures,and weak interlayers,respectively.A multisource rock tunnel face characteristic(RTFC)dataset includes 11 parameters for predicting rock mass quality is established.Considering the limitations in predictive performance of incomplete evaluation parameters exist in this dataset,a novel tree-augmented naive Bayesian network(BN)is proposed to address the challenge of the incomplete dataset and achieved a prediction accuracy of 88%.In comparison with other commonly used Machine Learning models the proposed BN-based approach proved an improved performance on predicting the rock mass quality with the incomplete dataset.By utilizing the established BN,a further sensitivity analysis is conducted to quantitatively evaluate the importance of the various parameters,results indicate that the rock strength and fractures parameter exert the most significant influence on rock mass quality. 展开更多
关键词 Rock mass quality Tunnel faces incomplete multi-source dataset Improved Swin Transformer Bayesian networks
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Influence of Incomplete Soil Plugs on Bearing Capacities of Bucket Foundations in Clay
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作者 LI Hui-shan LIU Run +1 位作者 YANG Xu LIAN Ji-jian 《China Ocean Engineering》 SCIE EI CSCD 2024年第1期144-155,共12页
Due to the uneven seabed and heaving of soil during pumping,incomplete soil plugs may occur during the installation of bucket foundations,and the impacts on the bearing capacities of bucket foundations need to be eval... Due to the uneven seabed and heaving of soil during pumping,incomplete soil plugs may occur during the installation of bucket foundations,and the impacts on the bearing capacities of bucket foundations need to be evaluated.In this paper,the contact ratio(the ratio of the top diameter of the soil plug to the diameter of the bucket)and the soil plug ratio(the ratio of the soil heave height to the skirt height)are defined to describe the shape and size of the incomplete soil plug.Then,finite element models are established to investigate the bearing capacities of bucket foundations with incomplete soil plugs and the influences of the contact ratios,and the soil plug ratios on the bearing capacities are analyzed.The results show that the vertical bearing capacity of bucket foundations in homogeneous soil continuously improves with the increase of the contact ratio.However,in normally consolidated soil,the vertical bearing capacity barely changes when the contact ratio is smaller than 0.75,while the bearing capacity suddenly increases when the contact ratio increases to 1 due to the change of failure mode.The contact ratio hardly affects the horizontal bearing capacity of bucket foundations.Moreover,the moment bearing capacity improves with the increase of the contact ratio for small aspect ratios,but hardly varies with increasing contact ratio for aspect ratios larger than 0.5.Consequently,the reduction coefficient method is proposed based on this analysis to calculate the bearing capacities of bucket foundations considering the influence of incomplete soil plugs.The comparison results show that the proposed reduction coefficient method can be used to evaluate the influences of incomplete soil plug on the bearing capacities of bucket foundations. 展开更多
关键词 bucket foundation incomplete soil plug uniaxial bearing capacity contact ratio soil plug ratio
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Value Iteration-Based Cooperative Adaptive Optimal Control for Multi-Player Differential Games With Incomplete Information
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作者 Yun Zhang Lulu Zhang Yunze Cai 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2024年第3期690-697,共8页
This paper presents a novel cooperative value iteration(VI)-based adaptive dynamic programming method for multi-player differential game models with a convergence proof.The players are divided into two groups in the l... This paper presents a novel cooperative value iteration(VI)-based adaptive dynamic programming method for multi-player differential game models with a convergence proof.The players are divided into two groups in the learning process and adapt their policies sequentially.Our method removes the dependence of admissible initial policies,which is one of the main drawbacks of the PI-based frameworks.Furthermore,this algorithm enables the players to adapt their control policies without full knowledge of others’ system parameters or control laws.The efficacy of our method is illustrated by three examples. 展开更多
关键词 Adaptive dynamic programming incomplete information multi-player differential game value iteration
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Reliability-BasedModel for Incomplete Preventive ReplacementMaintenance of Photovoltaic Power Systems
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作者 Wei Chen Ming Li +2 位作者 Tingting Pei Cunyu Sun Huan Lei 《Energy Engineering》 EI 2024年第1期125-144,共20页
At present,the operation and maintenance of photovoltaic power generation systems mainly comprise regular maintenance,breakdown maintenance,and condition-based maintenance,which is very likely to lead to over-or under... At present,the operation and maintenance of photovoltaic power generation systems mainly comprise regular maintenance,breakdown maintenance,and condition-based maintenance,which is very likely to lead to over-or under-repair of equipment.Therefore,a preventive maintenance and replacement strategy for PV power generation systems based on reliability as a constraint is proposed.First,a hybrid failure function with a decreasing service age factor and an increasing failure rate factor is introduced to describe the deterioration of PV power generation equipment,and the equipment is replaced when its reliability drops to the replacement threshold in the last cycle.Then,based on the reliability as a constraint,the average maintenance cost and availability of the equipment are considered,and the non-periodic incomplete maintenance model of the PV power generation system is established to obtain the optimal number of repairs,each maintenance cycle and the replacement cycle of the PV power generation system components.Next,the inverter of a PV power plant is used as a research object.The model in this paper is compared and analyzed with the equal cycle maintenance model without considering reliability and the maintenance model without considering the equipment replacement threshold,Through model comparison,when the optimal maintenance strategy is(0.80,4),the average maintenance cost of this paper’s model are decreased by 20.3%and 5.54%and the availability is increased by 0.2395% and 0.0337%,respectively,compared with the equal-cycle maintenance model without considering the reliability constraint and the maintenance model without considering the equipment replacement threshold.Therefore,this maintenance model can ensure the high reliability of PV plant operation while increasing the equipment availability to improve the system economy. 展开更多
关键词 RELIABILITY photovoltaic power system average maintenance cost AVAILABILITY incomplete preventive maintenance hybrid failure rate
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Pharmacodynamic Experiment of Dachengqi Decoction and Separated Decoction on Incomplete Intestinal Obstruction in Rats
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作者 Jiangcun WEI Xiumei MA +5 位作者 Bing QING Meiyan QIU Qingmei DENG Hong LEI Zengyan YANG Zujie QIN 《Medicinal Plant》 2024年第4期107-110,共4页
[Objectives]To investigate the effect and mechanism of Dachengqi Decoction and separated decoction on incomplete intestinal obstruction in rats.[Methods]80 healthy SD rats were selected to establish incomplete intesti... [Objectives]To investigate the effect and mechanism of Dachengqi Decoction and separated decoction on incomplete intestinal obstruction in rats.[Methods]80 healthy SD rats were selected to establish incomplete intestinal obstruction model by silk ligation.The dosage was 20 mL/kg for 3 d,and the damage index of ileocecal mucosa was analyzed;the morphology of ileocecal mucosa was observed by HE staining;the serum levels of IL-1α,IL-1β,IL-6,IL-18,Ach,NO,ET,IL-1,TNF-αand ultra-micro Na+-K+-ATPase were detected by ELISA.[Results]Compared with the model group,the mucosal damage index of Dachengqi Decoction and each separated decoction group decreased significantly(P<0.05);compared with the normal group and sham operation group,the serum level of IL-1,IL-6,TNF-αand other factors in the model group increased significantly(P<0.05);compared with the model group,the serum IL-1,IL-6 and TNF-αsecretion levels of rats in Dachengqi Decoction group and separated decoction group decreased(P<0.01).[Conclusions]Dachengqi Decoction and each separated decoction can effectively improve intestinal tissue pathological damage in the incomplete intestinal obstruction model rats,and reduce the inflammatory reaction in the rat body. 展开更多
关键词 Dachengqi Decoction Separated decoction incomplete intestinal obstruction Inflammatory factor
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Disease networks. Uncovering disease-disease relationships through the incomplete interactome
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作者 Jorg Menche 《四川生理科学杂志》 2024年第1期199-199,共1页
According to the disease module hypothesis,the cellular components associated with a disease segregate in the same neighborhood of the human interactome,the map of biologically relevant molecular interactions.Yet,give... According to the disease module hypothesis,the cellular components associated with a disease segregate in the same neighborhood of the human interactome,the map of biologically relevant molecular interactions.Yet,given the incompleteness of the interactome and the limited knowledge of disease-associated genes,it is not obvious if the available data have sufficient coverage to map out modules associated with each disease. 展开更多
关键词 incomplete interactions. networks.
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Disease networks. Uncovering disease-disease relationships through the incomplete interactome
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作者 Jörg Menche 《四川生理科学杂志》 2024年第4期772-772,共1页
According to the disease module hypothesis,the cellular components associated with a disease segregate in the same neighborhood of the human interactome,the map of biologically relevant molecular interactions.Yet,give... According to the disease module hypothesis,the cellular components associated with a disease segregate in the same neighborhood of the human interactome,the map of biologically relevant molecular interactions.Yet,given the incompleteness of the interactome and the limited knowledge of disease-associated genes,it is not obvious if the available data have sufficient coverage to map out modules associated with each disease.Here we derive mathematical conditions for the identifiability of disease modules and show that the network-based location of each disease module determines its pathobiological relationship to other diseases.For example,diseases with overlapping network modules show significant coexpression patterns,symptom similarity,and comorbidity,whereas diseases residing in separated network neighborhoods are phenotypically distinct.These tools represent an interactome-based platform to predict molecular commonalities between phenotypically related diseases,even if they do not share primary disease genes. 展开更多
关键词 incomplete NEIGHBORHOOD network
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Cooperative maneuver decision making for multi-UAV air combat based on incomplete information dynamic game 被引量:4
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作者 Zhi Ren Dong Zhang +2 位作者 Shuo Tang Wei Xiong Shu-heng Yang 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2023年第9期308-317,共10页
Cooperative autonomous air combat of multiple unmanned aerial vehicles(UAVs)is one of the main combat modes in future air warfare,which becomes even more complicated with highly changeable situation and uncertain info... Cooperative autonomous air combat of multiple unmanned aerial vehicles(UAVs)is one of the main combat modes in future air warfare,which becomes even more complicated with highly changeable situation and uncertain information of the opponents.As such,this paper presents a cooperative decision-making method based on incomplete information dynamic game to generate maneuver strategies for multiple UAVs in air combat.Firstly,a cooperative situation assessment model is presented to measure the overall combat situation.Secondly,an incomplete information dynamic game model is proposed to model the dynamic process of air combat,and a dynamic Bayesian network is designed to infer the tactical intention of the opponent.Then a reinforcement learning framework based on multiagent deep deterministic policy gradient is established to obtain the perfect Bayes-Nash equilibrium solution of the air combat game model.Finally,a series of simulations are conducted to verify the effectiveness of the proposed method,and the simulation results show effective synergies and cooperative tactics. 展开更多
关键词 Cooperative maneuver decision Air combat incomplete information dynamic game Perfect bayes-nash equilibrium Reinforcement learning
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Physics-Informed AI Surrogates for Day-Ahead Wind Power Probabilistic Forecasting with Incomplete Data for Smart Grid in Smart Cities 被引量:1
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作者 Zeyu Wu Bo Sun +2 位作者 Qiang Feng Zili Wang Junlin Pan 《Computer Modeling in Engineering & Sciences》 SCIE EI 2023年第10期527-554,共28页
Due to the high inherent uncertainty of renewable energy,probabilistic day-ahead wind power forecasting is crucial for modeling and controlling the uncertainty of renewable energy smart grids in smart cities.However,t... Due to the high inherent uncertainty of renewable energy,probabilistic day-ahead wind power forecasting is crucial for modeling and controlling the uncertainty of renewable energy smart grids in smart cities.However,the accuracy and reliability of high-resolution day-ahead wind power forecasting are constrained by unreliable local weather prediction and incomplete power generation data.This article proposes a physics-informed artificial intelligence(AI)surrogates method to augment the incomplete dataset and quantify its uncertainty to improve wind power forecasting performance.The incomplete dataset,built with numerical weather prediction data,historical wind power generation,and weather factors data,is augmented based on generative adversarial networks.After augmentation,the enriched data is then fed into a multiple AI surrogates model constructed by two extreme learning machine networks to train the forecasting model for wind power.Therefore,the forecasting models’accuracy and generalization ability are improved by mining the implicit physics information from the incomplete dataset.An incomplete dataset gathered from a wind farm in North China,containing only 15 days of weather and wind power generation data withmissing points caused by occasional shutdowns,is utilized to verify the proposed method’s performance.Compared with other probabilistic forecastingmethods,the proposed method shows better accuracy and probabilistic performance on the same incomplete dataset,which highlights its potential for more flexible and sensitive maintenance of smart grids in smart cities. 展开更多
关键词 Physics-informed method probabilistic forecasting wind power generative adversarial network extreme learning machine day-ahead forecasting incomplete data smart grids
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Power Incomplete Data Clustering Based on Fuzzy Fusion Algorithm
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作者 Yutian Hong Yuping Yan 《Energy Engineering》 EI 2023年第1期245-261,共17页
With the rapid development of the economy,the scale of the power grid is expanding.The number of power equipment that constitutes the power grid has been very large,which makes the state data of power equipment grow e... With the rapid development of the economy,the scale of the power grid is expanding.The number of power equipment that constitutes the power grid has been very large,which makes the state data of power equipment grow explosively.These multi-source heterogeneous data have data differences,which lead to data variation in the process of transmission and preservation,thus forming the bad information of incomplete data.Therefore,the research on data integrity has become an urgent task.This paper is based on the characteristics of random chance and the Spatio-temporal difference of the system.According to the characteristics and data sources of the massive data generated by power equipment,the fuzzy mining model of power equipment data is established,and the data is divided into numerical and non-numerical data based on numerical data.Take the text data of power equipment defects as the mining material.Then,the Apriori algorithm based on an array is used to mine deeply.The strong association rules in incomplete data of power equipment are obtained and analyzed.From the change trend of NRMSE metrics and classification accuracy,most of the filling methods combined with the two frameworks in this method usually show a relatively stable filling trend,and will not fluctuate greatly with the growth of the missing rate.The experimental results show that the proposed algorithm model can effectively improve the filling effect of the existing filling methods on most data sets,and the filling effect fluctuates greatly with the increase of the missing rate,that is,with the increase of the missing rate,the improvement effect of the model for the existing filling methods is higher than 4.3%.Through the incomplete data clustering technology studied in this paper,a more innovative state assessment of smart grid reliability operation is carried out,which has good research value and reference significance. 展开更多
关键词 Power system equipment parameter incomplete data fuzzy analysis data clustering
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Damage Identification under Incomplete Mode Shape Data Using Optimization Technique Based on Generalized Flexibility Matrix
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作者 Qianhui Gao Zhu Li +1 位作者 Yongping Yu Shaopeng Zheng 《Journal of Applied Mathematics and Physics》 2023年第12期3887-3901,共15页
A generalized flexibility–based objective function utilized for structure damage identification is constructed for solving the constrained nonlinear least squares optimized problem. To begin with, the generalized fle... A generalized flexibility–based objective function utilized for structure damage identification is constructed for solving the constrained nonlinear least squares optimized problem. To begin with, the generalized flexibility matrix (GFM) proposed to solve the damage identification problem is recalled and a modal expansion method is introduced. Next, the objective function for iterative optimization process based on the GFM is formulated, and the Trust-Region algorithm is utilized to obtain the solution of the optimization problem for multiple damage cases. And then for computing the objective function gradient, the sensitivity analysis regarding design variables is derived. In addition, due to the spatial incompleteness, the influence of stiffness reduction and incomplete modal measurement data is discussed by means of two numerical examples with several damage cases. Finally, based on the computational results, it is evident that the presented approach provides good validity and reliability for the large and complicated engineering structures. 展开更多
关键词 Generalized Flexibility Matrix Damage Identification Constrained Nonlinear Least Squares Trust-Region Algorithm Sensitivity Analysis incomplete Modal Data
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Risk factors for incomplete polyp resection during colonoscopy
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作者 Weifeng Lao Pankaj Prasoon +4 位作者 Gaoyang Cao Lian Tat Tan Sheng Dai Giridhar Hanumappa Devadasar Xuefeng Huang 《Laparoscopic, Endoscopic and Robotic Surgery》 2021年第4期105-110,共6页
Colonoscopic polypectomy is extremely effective in protecting against colorectal cancers,and recognition of adenomas by colonoscopy is of paramount importance in preventing colorectal cancer(CRC)and CRC-associated mor... Colonoscopic polypectomy is extremely effective in protecting against colorectal cancers,and recognition of adenomas by colonoscopy is of paramount importance in preventing colorectal cancer(CRC)and CRC-associated mortality.Incomplete polyp resection(IPR)occurs routinely in medical practice following polypectomy.We conducted a comprehensive literature search to identify studies that reported on the potential risk factors for IPR using MEDLINE,EMBASE,and PubMed.Publication time was limited between January 2004 and July 2021.Our search revealed assessments of the position,morphology,and histologic variation of the polypsdas well as the relevant skills that may interfere with IPR.The included studies showed that colonic polyps with a diameter>20 mm and proximal in location should be dealt with cautiously.For smaller polyps,cold-snare polypectomy appeared to be the most effective method used to accomplish comprehensive polyp removal.In addition,endoscopist experience in narrow-band imaging in polyp detection were also associated with IPR.Therefore,polypectomy should be performed cautiously if the polyp growth is expected to be cancerous and situated in the proximal portion of the colon or rectum,and modalities should be standardized so as to lower the potential risk for IPR. 展开更多
关键词 Colon cancer incomplete resection of polyp incomplete endomucosal resection Colorectal polyps Colonoscopic polypectomy
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Design of PID controller with incomplete derivation based on differential evolution algorithm 被引量:15
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作者 Wu Lianghong Wang Yaonan +1 位作者 Zhou Shaowu Tan Wen 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2008年第3期578-583,共6页
To determine the optimal or near optimal parameters of PID controller with incomplete derivation, a novel design method based on differential evolution (DE) algorithm is presented. The controller is called DE-PID co... To determine the optimal or near optimal parameters of PID controller with incomplete derivation, a novel design method based on differential evolution (DE) algorithm is presented. The controller is called DE-PID controller. To overcome the disadvantages of the integral performance criteria in the frequency domain such as IAE, ISE, and ITSE, a new performance criterion in the time domain is proposed. The optimization procedures employing the DE algorithm to search the optimal or near optimal PID controller parameters of a control system are demonstrated in detail. Three typical control systems are chosen to test and evaluate the adaptation and robustness of the proposed DE-PID controller. The simulation results show that the proposed approach has superior features of easy implementation, stable convergence characteristic, and good computational efficiency. Compared with the ZN, GA, and ASA, the proposed design method is indeed more efficient and robust in improving the step response of a control system. 展开更多
关键词 PID controller incomplete derivation differential evolution parameter tuning.
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Fault detection and diagnosis for data incomplete industrial systems with new Bayesian network approach 被引量:15
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作者 Zhengdao Zhang Jinlin Zhu Feng Pan 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2013年第3期500-511,共12页
For the fault detection and diagnosis problem in largescale industrial systems, there are two important issues: the missing data samples and the non-Gaussian property of the data. However, most of the existing data-d... For the fault detection and diagnosis problem in largescale industrial systems, there are two important issues: the missing data samples and the non-Gaussian property of the data. However, most of the existing data-driven methods cannot be able to handle both of them. Thus, a new Bayesian network classifier based fault detection and diagnosis method is proposed. At first, a non-imputation method is presented to handle the data incomplete samples, with the property of the proposed Bayesian network classifier, and the missing values can be marginalized in an elegant manner. Furthermore, the Gaussian mixture model is used to approximate the non-Gaussian data with a linear combination of finite Gaussian mixtures, so that the Bayesian network can process the non-Gaussian data in an effective way. Therefore, the entire fault detection and diagnosis method can deal with the high-dimensional incomplete process samples in an efficient and robust way. The diagnosis results are expressed in the manner of probability with the reliability scores. The proposed approach is evaluated with a benchmark problem called the Tennessee Eastman process. The simulation results show the effectiveness and robustness of the proposed method in fault detection and diagnosis for large-scale systems with missing measurements. 展开更多
关键词 fault detection and diagnosis Bayesian network Gaussian mixture model data incomplete non-imputation.
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Analysis of Incomplete Data of Accelerated Life Testing with Competing Failure Modes 被引量:10
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作者 TAN Yuanyuan ZHANG Chunhua CHEN Xun 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2009年第6期883-889,共7页
Data obtained from accelerated life testing (ALT) when there are two or more failure modes, which is commonly referred to as competing failure modes, are often incomplete. The incompleteness is mainly due to censori... Data obtained from accelerated life testing (ALT) when there are two or more failure modes, which is commonly referred to as competing failure modes, are often incomplete. The incompleteness is mainly due to censoring, as well as masking which might be the case that the failure time is observed, but its corresponding failure mode is not identified. Because the identification of the failure mode may be expensive, or very difficult to investigate due to lack of appropriate diagnostics. A method is proposed for analyzing incomplete data of constant stress ALT with competing failure modes. It is assumed that failure modes have s-independent latent lifetimes and the log lifetime of each failure mode can be written as a linear function of stress. The parameters of the model are estimated by using the expectation maximum (EM) algorithm with incomplete data. Simulation studies are performed to check'model validity and investigate the properties of estimates. For further validation, the method is also illustrated by an example, which shows the process of analyze incomplete data from ALT of some insulation system. Because of considering the incompleteness of data in modeling and making use of the EM algorithm in estimating, the method becomes more flexible in ALT analysis. 展开更多
关键词 accelerated life testing competing failure modes expectation maximum algorithm incomplete data Monte Carlo simulation
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Iterative Learning Control With Incomplete Information: A Survey 被引量:11
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作者 Dong Shen Senior Member IEEE 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2018年第5期885-901,共17页
Abstract--This paper conducts a survey on iterative learn- ing control (ILC) with incomplete information and associated control system design, which is a frontier of the ILC field. The incomplete information, includ... Abstract--This paper conducts a survey on iterative learn- ing control (ILC) with incomplete information and associated control system design, which is a frontier of the ILC field. The incomplete information, including passive and active types, can cause data loss or fragment due to various factors. Passive incomplete information refers to incomplete data and information caused by practical system limitations during data collection, storage, transmission, and processing, such as data dropouts, delays, disordering, and limited transmission bandwidth. Active incomplete information refers to incomplete data and information caused by man-made reduction of data quantity and quality on the premise that the given objective is satisfied, such as sampling and quantization. This survey emphasizes two aspects: the first one is how to guarantee good learning performance and tracking performance with passive incomplete data, and the second is how to balance the control performance index and data demand by active means. The promising research directions along this topic are also addressed, where data robustness is highly emphasized. This survey is expected to improve understanding of the restrictive relationship and trade-off between incomplete data and tracking performance, quantitatively, and promote further developments of ILC theory. Index Terms--Data dropout, data robustness, incomplete in- formation, iterative learning controi(ILC), quantized control, sampled control, varying lengths. 展开更多
关键词 Data dropout data robustness incomplete information iterative learning control(ILC) quantized control sampled control varying lengths
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CONSISTENCY OF MLE OF THE PARAMETER OF EXPONENTIAL LIFETIME DISTRIBUTION FOR RANDOM CENSORING MODEL WITH INCOMPLETE INFORMATION 被引量:18
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作者 YE ERHUA 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 1995年第4期379-386,共8页
In this paper, we have discussed a random censoring test with incomplete information, and proved that the maximum likelihood estimator(MLE) of the parameter based on the randomly censored data with incomplete informat... In this paper, we have discussed a random censoring test with incomplete information, and proved that the maximum likelihood estimator(MLE) of the parameter based on the randomly censored data with incomplete information in the case of the exponential distribution has the strong consistency. 展开更多
关键词 Random censoring test with incomplete information exponential distribution maximum likelihood estimator consistency.
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Factors associated with incomplete small bowel capsule endoscopy studies 被引量:10
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作者 Mitchell M Lee Andrew Jacques +7 位作者 Eric Lam Ricky Kwok Pardis Lakzadeh Ajit Sandhar Brandon Segal Sigrid Svarta Joanna Law Robert Enns 《World Journal of Gastroenterology》 SCIE CAS CSCD 2010年第42期5329-5333,共5页
AIM:To identify patient risk factors associated with incomplete small bowel capsule endoscopy(CE) studies.METHODS:Data from all CE procedures performed at St.Paul's Hospital in Vancouver,British Columbia,Canada,be... AIM:To identify patient risk factors associated with incomplete small bowel capsule endoscopy(CE) studies.METHODS:Data from all CE procedures performed at St.Paul's Hospital in Vancouver,British Columbia,Canada,between December 2001 and June 2008 were collected and analyzed on a retrospective basis.Data collection for complete and incomplete CE study groups included patient demographics as well as a number of potential risk factors for incomplete CE including indication for the procedure,hospitalization,diabetes mellitus with or without end organ damage,limitations in mobility,renal insufficiency,past history of bowel obstruction,abdominal surgery,abdominal radiation therapy and opiate use.Risk factors were analyzed using a univariable and multivariable logistic regression model.RESULTS:From a total of 535 CE procedures performed,158 were incomplete(29.5%).The univariable analysis showed that CE procedures performed for overt gastrointestinal bleeding(P = 0.002),and for patients with a prior history of abdominal surgery(P = 0.023) or bowel obstruction(P = 0.023) were significantly associated with incomplete CE studies.Patients on opiate medications(P = 0.094) as well as hospitalized patients(P = 0.054) were not statistically significant,but did show a trend towards incomplete CE.The multivariable analysis showed that independent risk factors for an incomplete CE procedure include prior history of bowel obstruction [odds ratios(OR) 2.77,P = 0.02,95% confidence intervals(CI):1.17-6.56] and procedures performed for gastrointestinal bleeding(Occult OR 2.04,P = 0.037,95% CI:1.04-4.02 and Overt OR 2.69,P = 0.002,95% CI:1.44-5.05).Patients with a prior history of abdominal surgery(OR 1.46,P = 0.068,95% CI:0.97-2.19),those taking opiate medications(OR 1.54,P = 0.15,95% CI:0.86-2.76) and hospitalized patients(OR 1.82,P = 0.124,95% CI:0.85-3.93) showed a trend towards statistical significance.CONCLUSION:We have identified a number of risk factors for incomplete CE procedures that can be used to risk-stratify patients and guide interventions to improve completion rates. 展开更多
关键词 CAPSULE Capsule endoscopy incomplete endoscopy
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Factors associated with incomplete colonoscopy at a Japanese academic hospital 被引量:7
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作者 Shigeo Koido Toshifumi Ohkusa +9 位作者 Kosaburo Nakae Tetsuji Yokoyama Tomoyoshi Shibuya Naoto Sakamoto Kan Uchiyama Hiroshi Arakawa Taro Osada Akihito Nagahara Sumio Watanabe Hisao Tajiri 《World Journal of Gastroenterology》 SCIE CAS 2014年第22期6961-6967,共7页
AIM: To evaluate significant risk factors for incomplete colonoscopy at a Japanese academic hospital.
关键词 COLONOSCOPY incomplete Intubation rates Japanese academic hospital Risk factors Inflammatory bowel disease
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Design of PID controller with incomplete derivation based on ant system algorithm 被引量:6
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作者 Guanzheng TAN Qingdong ZENG Wenbin LI 《控制理论与应用(英文版)》 EI 2004年第3期246-252,共7页
A new and intelligent design method for PID controller with incomplete derivation is proposed based on the ant system algorithm ( ASA) . For a given control system with this kind of PID controller, a group of optimal ... A new and intelligent design method for PID controller with incomplete derivation is proposed based on the ant system algorithm ( ASA) . For a given control system with this kind of PID controller, a group of optimal PID controller parameters K p * , T i * , and T d * can be obtained by taking the overshoot, settling time, and steady-state error of the system's unit step response as the performance indexes and by use of our improved ant system algorithm. K p * , T i * , and T d * can be used in real-time control. This kind of controller is called the ASA-PID controller with incomplete derivation. To verify the performance of the ASA-PID controller, three different typical transfer functions were tested, and three existing typical tuning methods of PID controller parameters, including the Ziegler-Nichols method (ZN),the genetic algorithm (GA),and the simulated annealing (SA), were adopted for comparison. The simulation results showed that the ASA-PID controller can be used to control different objects and has better performance compared with the ZN-PID and GA-PID controllers, and comparable performance compared with the SA-PID controller. 展开更多
关键词 PID controller incomplete derivation Parameter tuning Ant system algorithm Genetic algorithm Simulated annealing
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