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Lateral downslope transport and tentative sedimentary organic carbon box model in the southern Yap Trench,western Pacific Ocean 被引量:1
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作者 Dong Li Jun Zhao +2 位作者 Chenggang Liu Jianming Pan Ji Hu 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2023年第1期61-74,共14页
Sediment collapse and subsequent lateral downslope migration play important roles in shaping the habitats and regulating sedimentary organic carbon(SOC)cycling in hadal trenches.In this study,three sediment cores were... Sediment collapse and subsequent lateral downslope migration play important roles in shaping the habitats and regulating sedimentary organic carbon(SOC)cycling in hadal trenches.In this study,three sediment cores were collected using a human-occupied vehicle across the axis of the southern Yap Trench(SYT).The total organic carbon(TOC)and total nitrogen(TN)contents,δ13C,radiocarbon ages,specific surface areas,and grain size compositions of sediments from three cores were measured.We explored the influence of the lateral downslope transport on the dispersal of the sediments and established a tentative box model for the SOC balance.In the SYT,the surface TOC content decreased with water depth and was decoupled by the funneling effect of the V-shaped hadal trench.However,the sedimentation(0.0025 cm/a)and SOC accumulation rates(∼0.038 g/(m^(2)·a)(in terms of OC))were approximately 50%higher in the deeper hadal region than in the abyssal region(0.0016 cm/a and∼0.026 g/(m^(2)·a)(in terms of OC),respectively),indicating the occurrence of lateral downslope transport.The fluctuating variations in the prokaryotic abundances and the SOC accumulation rate suggest the periodic input of surficial sediments from the shallow region.The similar average TOC(0.31%–0.38%),TN(0.06%–0.07%)contents,and SOC compositions(terrestrial OC(11%–18%),marine phytoplanktonic OC(45%–53%),and microbial OC(32%–44%))of the three sites indicate that the lateral downslope transport has a significant mixing effect on the SOC composition.The output fluxes of the laterally transported SOC(0.44–0.56 g/(m^(2)·a)(in terms of OC))contributed approximately(47%–73%)of the total SOC input,and this proportion increased with water depth.The results of this study demonstrate the importance of lateral downslope transport in the spatial distribution and development of biomes. 展开更多
关键词 southern Yap Trench sedimentary organic carbon cycling lateral downslope transport diluting effect box model
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大豆MADS-box基因功能研究进展
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作者 姚晓琳 张晓芳 +4 位作者 王铮 郝俊莹 郑荣繁 张沿政 李帅 《植物遗传资源学报》 CAS CSCD 北大核心 2024年第6期909-918,共10页
MADS-box是植物体内一种重要的转录因子,其家族成员具有典型的MIKC结构、高度保守的N端MADS以及保守性较低的I域和C端。MADS-box基因广泛表达于植物的根、茎、叶、花、芽等组织部位,并参与调控花期、花器官发育、种子发育及非生物胁迫... MADS-box是植物体内一种重要的转录因子,其家族成员具有典型的MIKC结构、高度保守的N端MADS以及保守性较低的I域和C端。MADS-box基因广泛表达于植物的根、茎、叶、花、芽等组织部位,并参与调控花期、花器官发育、种子发育及非生物胁迫响应等过程。近年来的研究报道显示,不同MADS-box基因的表达模式不尽相同,其功能也存在较大差异。本文概述了大豆MADS-box基因家族的结构及分类,总结了大豆MADS-box基因家族花发育ABCDE模型中相关成员及SVP、SOC1、FLC等基因的研究进展。最后对大豆MADS-box的研究提出了展望,为今后进一步挖掘和利用该类转录因子基因进行大豆遗传改良和种质创新提供参考依据。 展开更多
关键词 大豆 MADS-box ABCDE模型 转录因子
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基于PSModel的海上风电场全电磁暂态建模与仿真
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作者 崔森 郁舒雁 《电网技术》 EI CSCD 北大核心 2024年第1期262-271,共10页
开发有效的风机电磁暂态模型是进行海上风电并网研究的基础。根据不同生产厂家所提供的直驱风机模型,提出了一种基于厂家黑盒模型的直驱风机电磁暂态建模方法。利用厂家所提供的模型测试数据解析风机的故障响应特性,推导了不同厂家在电... 开发有效的风机电磁暂态模型是进行海上风电并网研究的基础。根据不同生产厂家所提供的直驱风机模型,提出了一种基于厂家黑盒模型的直驱风机电磁暂态建模方法。利用厂家所提供的模型测试数据解析风机的故障响应特性,推导了不同厂家在电压故障下有功和无功功率响应表达式,包括故障期间的穿越控制过程及不同过程间的暂态切换策略。提出了加权平均压降的风电场等值方法,采用自主研发的全电磁暂态仿真软件(power system model,PSModel)对我国广东某海上风电场进行全电磁暂态建模。根据稳态潮流及暂态特性结果验证了模型可通过系统测试,且有效实现了海上风电场的全电磁暂态建模,从而为该风场接入大电网后的安全稳定分析提供了研究基础。 展开更多
关键词 直驱风电机组 黑盒模型 海上风电场 PSmodel 故障穿越
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用插值的粗粒化Box Model进行学习控制 被引量:2
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作者 刘斌 张承福 《自动化学报》 EI CSCD 北大核心 1996年第1期101-106,共6页
针对一类未知动力学方程的单输入系统,采用插值的粗粒化 Box M odel进行学习控制.与传统的Box Model及基于随机元胞自动机的控制模式比较,本模型设计思想自然,算法简单.计算量小(常常小几个数量级),训练时间短。
关键词 学习控制 随机元胞自动机 插值 反馈镇定
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基于互Box-Cox变换和Markov链风速云模型的发电系统充裕度评估
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作者 安睿 缪书唯 《电力自动化设备》 EI CSCD 北大核心 2024年第3期113-119,141,共8页
为准确计及风速随机性和自相关性对风电并网系统充裕度的影响,建立基于互Box-Cox变换和Markov链的风速云模型,并将该模型与时序Monte Carlo模拟法结合,提出计及风速随机性和自相关性的风电并网系统充裕度评估方法。仿真结果表明,所提模... 为准确计及风速随机性和自相关性对风电并网系统充裕度的影响,建立基于互Box-Cox变换和Markov链的风速云模型,并将该模型与时序Monte Carlo模拟法结合,提出计及风速随机性和自相关性的风电并网系统充裕度评估方法。仿真结果表明,所提模型产生的仿真风速样本与实测风速样本具备相似的概率分布特性和自相关性,所提方法可较精确地评估风电并网系统充裕度及风电容量可信度。 展开更多
关键词 box-Cox变换 MARKOV链 混合半云模型 风速自相关性 充裕度评估
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Numerical study on the ozone formation inside street canyons using a chemistry box model 被引量:2
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作者 Chun-Ho Liu Dennis Y.C.Leung 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2008年第7期832-837,共6页
Tropospheric ozone is a secondary air pollutant produced in the presence of nitrogen oxides (NO_x),volatile organic compounds (VOCs),and solar radiation.In an urban environment,ground-level vehicular exhaust is the ma... Tropospheric ozone is a secondary air pollutant produced in the presence of nitrogen oxides (NO_x),volatile organic compounds (VOCs),and solar radiation.In an urban environment,ground-level vehicular exhaust is the major anthropogenic source of ozone precursors.In the cases of street canyons,pollutant dilution is weakened by the surrounding buildings that creates localized high concentration of NO_x and VOCs,and thus leads to high potential of ozone formation.By considering the major physical and chemical p... 展开更多
关键词 volatile organic compounds VOCs-to-NO_x ratio air quality vehicular emission chemistry box model
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Analysis of Data on Xanthan Fermentation in Stationary Phase Using Black Box and Metabolic Network Models 被引量:2
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作者 马红武 赵学明 唐寅杰 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 1999年第4期321-325,共5页
The xanthan fermentation data in the stationary phase was analyzed using the black box and the metabolic network models. The data consistency is checked through the elemental balance in the black box model. In the met... The xanthan fermentation data in the stationary phase was analyzed using the black box and the metabolic network models. The data consistency is checked through the elemental balance in the black box model. In the metabolic network model, the metabolic flux distribution in the cell is calculated using the metabolic flux analysis method, then the maintenance coefficients is calculated. 展开更多
关键词 xanthan fermentation black box model metabolic flux analysis maintenance coefficients
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Nutrient fluxes in the Changjiang River estuary and adjacent waters——a modified box model approach 被引量:1
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作者 王晓红 俞志明 +3 位作者 樊伟 宋秀贤 曹西华 袁涌铨 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2015年第1期176-193,共18页
To solve nutrient flux and budget among waters with distinct salinity difference for water-salt- nutrient budget, a traditional method is to build a stoichiometrically linked steady state model. However, the tradition... To solve nutrient flux and budget among waters with distinct salinity difference for water-salt- nutrient budget, a traditional method is to build a stoichiometrically linked steady state model. However, the traditional way cannot cope appropriately with those without distinct salinity difference that parallel to coastline or in a complex current system, as the results would be highly affected by box division in time and space, such as the Changjiang (Yangtze) River estuary (CRE) and adjacent waters (30.75°-31.75°N, 122°10′-123°20′E). Therefore, we developed a hydrodynamic box model based on the traditional way and the regional oceanic modeling system model (ROMS). Using data from four cruises in 2005, horizontal, vertical and boundary nutrient fluxes were calculated in the hydrodynamic box model, in which flux fields and the major controlling factors were studied. Results show that the nutrient flux varied greatly in season and space. Water flux outweighs the nutrient concentration in horizontal flux, and upwelling flux outweighs upward diffusion flux in vertical direction (upwelling flux and upward diffusion flux regions overlap largely all the year). Vertical flux in spring and summer are much greater than that in autumn and winter. The maximum vertical flux for DIP (dissolved inorganic phosphate) occurs in summer. Additional to the fluxes of the ChanNiang River discharge, coastal currents, the Taiwan Warm Current, and the upwelling, nutrient flux inflow from the southern Yellow Sea and outflow southward are found crucial to nutrient budgets of the study area. Horizontal nutrient flux is controlled by physical dilution and confined to coastal waters with a little into the open seas. The study area acts as a conveyer transferring nutrients from the Yellow Sea to the East China Sea in the whole year. In addition, vertical nutrient flux in spring and summer is a main source of DIP. Therefore, the hydrodynamic ROMS-based box model is superior to the traditional one in estimating nutrient fluxes in a complicated hydrodynamic current system and provides a modified box model approach to material flux research. 展开更多
关键词 NUTRIENT box model HYDRODYNAMIC Changjiang (Yangtze) River estuary
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A DYNAMIC BOX MODEL OF BIOACTIVE ELEMENTS IN THE SOUTHERN TAIWAN STRAIT 被引量:4
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作者 洪华生 商少凌 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 1994年第2期120-129,共10页
A dynamic box model was applied to study the characteristics of biogeochemical cycling of PO<sub>4</sub>-P,NO<sub>3</sub>-N,AOU,POC and PON in the southern Taiwan Strait region based on field d... A dynamic box model was applied to study the characteristics of biogeochemical cycling of PO<sub>4</sub>-P,NO<sub>3</sub>-N,AOU,POC and PON in the southern Taiwan Strait region based on field data of the"Minnan Taiwan Bank Fishing Ground Upwelling Ecosystem Study" during the period of Dec.1987-Nov.1988.According to the unique hydrological and topographical features of the region,six boxesand three layers were considered in the model.The variation rates and fluxes of elements induced by hor-izontal current,upwelling,by diffusion,sinking of particles and biogeochemical processes were estimatedrespectively.Results further confirmed that upwellings had important effects in this region.Thenearshore upwelling areas had net input fluxes of nutrients brought by upwelling water,also had high de-pletion rates of nutrients and production rates of particulate organic matter and dissolved oxygen.Theabnormal net production of nutrients in the middle layer(10-30m) indicated the important role of bacte-ria in this high production region. 展开更多
关键词 box model bioactive ELEMENTS PARTICULATE ORGANIC carbon FLUX UPWELLING
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Hydrodynamic Modeling with Grey-Box Method of A Foil-Like Underwater Vehicle 被引量:3
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作者 LIU Xin-yu LI Yi-ping +1 位作者 WANG Ya-xing FENG Xi-sheng 《China Ocean Engineering》 SCIE EI CSCD 2017年第6期773-780,共8页
In this study, a dynamic modeling method for foil-like underwater vehicles is introduced and experimentally verified in different sea tests of the Hadal ARV. The dumping force of a foil-like underwater vehicle is sens... In this study, a dynamic modeling method for foil-like underwater vehicles is introduced and experimentally verified in different sea tests of the Hadal ARV. The dumping force of a foil-like underwater vehicle is sensitive to swing motion. Some foil-like underwater vehicles swing periodically when performing a free-fall dive task in experiments. Models using conventional modeling methods yield solutions with asymptotic stability, which cannot simulate the self-sustained swing motion. By improving the ridge regression optimization algorithm, a grey-box modeling method based on 378 viscous drag coefficients using the Taylor series expansion is proposed in this study. The method is optimized for over-fitting and convergence problems caused by large parameter matrices. Instead of the PMM test data, the unsteady computational fluid dynamics calculation results are used in modeling. The obtained model can better simulate the swing motion of the underwater vehicle. Simulation and experimental results show a good consistency in free-fall tests during sea trials, as well as a prediction of the dive speed in the swing state. 展开更多
关键词 unmanned underwater vehicle grey-box model HYDRODYNAMICS ridge regression CORRELATIONS
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Box-Behnken模型优化煤系高岭土增白实验研究及表征 被引量:2
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作者 王兴峰 刘豹 +3 位作者 李彩霞 洪琰 孙得智 宁琴 《煤炭转化》 CAS CSCD 北大核心 2023年第5期99-110,共12页
以山西塔山煤系高岭土为原料,采用“先煅烧后漂白”工艺对其进行增白实验研究。通过单因素实验探究煅烧、化学漂白阶段的工艺参数,并对化学漂白阶段进行Box-Behnken响应面实验,优化制备工艺参数。采用XRD、SEM和FT-IR等手段对原料及实... 以山西塔山煤系高岭土为原料,采用“先煅烧后漂白”工艺对其进行增白实验研究。通过单因素实验探究煅烧、化学漂白阶段的工艺参数,并对化学漂白阶段进行Box-Behnken响应面实验,优化制备工艺参数。采用XRD、SEM和FT-IR等手段对原料及实验各阶段产物进行表征,分析其理化性质以探究增白机理。实验结果表明:在煅烧温度为950℃、恒温时间为3.0 h和NaCl质量分数为2%的煅烧条件下可获得白度为83.51%的样品(calcined kaoline,CK);响应面回归模型的相关系数R^(2)=0.9979,优化模型可信度较高;化学漂白实验对白度的影响有显著性关系的四因素为草酸用量、Na_(2)S_(2)O_(4)用量、矿浆pH值及反应温度;在矿浆pH值为3.6、Na_(2)S_(2)O_(4)质量分数为3.4%、草酸质量分数为3.9%和反应温度为38℃的响应面优化方案下对样品CK进行化学漂白,最终产品的Fe_(2)O_(3)质量分数由原先的1.93%降至0.28%,白度由5.72%升至90.09%,满足GB/T 14563-2020优质高岭土白度要求。TG-DSC、XRD、SEM和FT-IR分析结果表明:原料的主要成分为高岭石,经950℃煅烧3.0 h后其晶体结构发生变化,形成无定形且活性更高的偏高岭石,而未形成莫来石;化学还原漂白过程对偏高岭石内部结构影响甚微,即不会破坏偏高岭石的晶体结构。 展开更多
关键词 煤系高岭土 box-Behnken模型 煅烧 化学漂白 工艺优化
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Time series modeling of animal bites 被引量:1
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作者 Fatemeh Rostampour Sima Masoudi 《Journal of Acute Disease》 2023年第3期121-128,共8页
Objective:To explore the modeling of time series of animal bite occurrence in northwest Iran.Methods:In this study,we analyzed surveillance time series data for animal bite cases in the northwest Iran province of Iran... Objective:To explore the modeling of time series of animal bite occurrence in northwest Iran.Methods:In this study,we analyzed surveillance time series data for animal bite cases in the northwest Iran province of Iran from 2011 to 2017.We used decomposition methods to explore seasonality and long-term trends and applied the Autoregressive Integrated Moving Average(ARIMA)model to fit a univariate time series of animal bite incidence.The ARIMA modeling process involved selecting the time series,transforming the series,selecting the appropriate model,estimating parameters,and forecasting.Results:Our results using the Box Jenkins model showed a significant seasonal trend and an overall increase in animal bite incidents during the study period.The best-fitting model for the available data was a seasonal ARIMA model with drift in the form of ARIMA(2,0,0)(1,1,1).This model can be used to forecast the frequency of animal attacks in northwest Iran over the next two years,suggesting that the incidence of animal attacks in the region would continue to increase during this time frame(2018-2019).Conclusion:Our findings suggest that time series analysis is a useful method for investigating animal bite cases and predicting future occurrences.The existence of a seasonal trend in animal bites can also aid in planning healthcare services during different seasons of the year.Therefore,our study highlights the importance of implementing proactive measures to address the growing issue of animal bites in Iran. 展开更多
关键词 Animal bites Time series analysis ARIMA model­ing box Jenkins model Northwest Iran
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Modelling Epidemiological Data Using Box-Jenkins Procedure 被引量:2
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作者 Stanley Jere Edwin Moyo 《Open Journal of Statistics》 2016年第2期295-302,共8页
In this paper, the Box-Jenkins modelling procedure is used to determine an ARIMA model and go further to forecasting. We consider data of Malaria cases from Ministry of Health (Kabwe District)-Zambia for the period, 2... In this paper, the Box-Jenkins modelling procedure is used to determine an ARIMA model and go further to forecasting. We consider data of Malaria cases from Ministry of Health (Kabwe District)-Zambia for the period, 2009 to 2013 for age 1 to under 5 years. The model-building process involves three steps: tentative identification of a model from the ARIMA class, estimation of parameters in the identified model, and diagnostic checks. Results show that an appropriate model is simply an ARIMA (1, 0, 0) due to the fact that, the ACF has an exponential decay and the PACF has a spike at lag 1 which is an indication of the said model. The forecasted Malaria cases for January and February, 2014 are 220 and 265, respectively. 展开更多
关键词 box-Jenkins modeling Procedure ARIMA model Exponential Decay SPIKE
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A Novel Black Box Based Behavioral Model of Power Amplifier for WCDMA Applications
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作者 Amandeep Singh Sappal Manjeet Singh Patterh Sanjay Sharma 《Communications and Network》 2010年第3期162-165,共4页
In this paper, Black Box approach is presented for behavioral modeling of a non linear power amplifier with memory effects. Large signal parameters of a Motorola LDMOS power amplifier driven by a WCDMA signal were ext... In this paper, Black Box approach is presented for behavioral modeling of a non linear power amplifier with memory effects. Large signal parameters of a Motorola LDMOS power amplifier driven by a WCDMA signal were extracted while taking into considerations the power amplifier’s bandwidth. The proposed model was validated based on the simulated data. Some validation results are presented both in the time and frequency domains, using WCDMA signal. 展开更多
关键词 BEHAVIORAL model BLACK box Power AMPLIFIERS
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Black Box Modeling Method and Its Application in Refractories Techniques
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作者 WANG Jiezeng YUAN Lin YE Yahong LI Penghai WANG Juntao 《China's Refractories》 CAS 2012年第4期1-6,共6页
Concept of black box, condition of modeling and control methods were introduced. Taking high purity silica brick as an example, the silica brick featured with high purity, low porosity, low true density and high stren... Concept of black box, condition of modeling and control methods were introduced. Taking high purity silica brick as an example, the silica brick featured with high purity, low porosity, low true density and high strength was developed through problem analysis, test design, modeling and optimization. Using information technology to upgrade refractories industry was discussed. 展开更多
关键词 black box modelING OPTIMIZATION TECHNIQUES REFRACTORIES
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Using Box-Jenkins Models to Forecast Mobile Cellular Subscription 被引量:3
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作者 Ian Siluyele Stanley Jere 《Open Journal of Statistics》 2016年第2期303-309,共7页
In this paper, the Box-Jenkins modelling procedure is used to determine an ARIMA model and go further to forecasting. The mobile cellular subscription data for the study were taken from the administrative data submitt... In this paper, the Box-Jenkins modelling procedure is used to determine an ARIMA model and go further to forecasting. The mobile cellular subscription data for the study were taken from the administrative data submitted to the Zambia Information and Communications Technology Authority (ZICTA) as quarterly returns by all three mobile network operators Airtel Zambia, MTN Zambia and Zamtel. The time series of annual figures for mobile cellular subscription for all mobile network operators is from 2000 to 2014 and has a total of 15 observations. Results show that the ARIMA (1, 2, 1) is an adequate model which best fits the mobile cellular subscription time series and is therefore suitable for forecasting subscription. The model predicts a gradual rise in mobile cellular subscription in the next 5 years, culminating to about 9.0% cumulative increase in 2019. 展开更多
关键词 Mobile Cellular Subscription box-Jenkins Methodology ARIMA model Autocorrelation Function Partial Autocorrelation Function
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Subsystem model-based close-loop grey-box identification method for hydraulic stewart platform
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作者 唐建林 董彦良 赵克定 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2011年第2期107-112,共6页
In order to solve the problem of difficult modeling and identification caused by time-variable parameters,multiple inputs and outputs and unstable open loop,a subsystem model-based close-loop grey-box identification m... In order to solve the problem of difficult modeling and identification caused by time-variable parameters,multiple inputs and outputs and unstable open loop,a subsystem model-based close-loop grey-box identification method was put forward when consider the main coupling effects of hydraulic Stewart platform.Firstly,the whole system is divided into three TITO(Two Input Two Output) subsystems according to the characteristics of the pseudo-mass matrix,hence transfer function matrix model of the subsystem can also be found.Secondly,since the Stewart platform is unstable,the close-loop transfer model of the subsystem is derived under the proportional controllers.The inverse M serial is adopted as the identification signal to get the experimental data.All parameters of the subsystem are determined in close-loop indirect identification by PEM(Prediction Error Method).Finally,a case study validates the correctness and effectiveness of the subsystem model-based close-loop grey-box identification method for hydraulic Stewart platform. 展开更多
关键词 hydraulic Stewart platform pseudo-mass matrix prediction error method close-loop indirect identification grey-box model
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基于Box-Cox和Informer的锂离子电池寿命预测
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作者 崔帆帆 袁晓静 +2 位作者 邱贺方 朱昭禹 梁铭哲 《兵器装备工程学报》 CAS CSCD 北大核心 2023年第S02期115-120,169,共7页
针对锂离子电池不同老化过程中隐含的噪声序列和强非线性特点,提出一种基于Box-Cox数据处理和Informer模型进行锂电池剩余使用寿命预测的方法。对新威电池检测仪采取的电池数据进行分析,确定数据特征进而健康指标,利用Box-Cox对数据进... 针对锂离子电池不同老化过程中隐含的噪声序列和强非线性特点,提出一种基于Box-Cox数据处理和Informer模型进行锂电池剩余使用寿命预测的方法。对新威电池检测仪采取的电池数据进行分析,确定数据特征进而健康指标,利用Box-Cox对数据进行预处理剔除部分噪声信号,使数据线性化;利用Informer模型输出的全连接层代替解码器层,建立锂离子电池RUL预测模型,并通过两组不同工况电池数据验证所提方法的有效性和泛化性。结果表明:该方法能够克服数据测量噪声的影响,有效地预测锂离子电池的剩余使用寿命,泛化性良好且精度较高。 展开更多
关键词 锂离子电池 剩余使用寿命 Informer模型 RUL预测 box-Cox
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不同倾斜方式对倾斜液化场地地震响应的影响分析
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作者 张小玲 赵显辉 +1 位作者 许成顺 贾科敏 《岩土工程学报》 EI CAS CSCD 北大核心 2024年第4期728-736,共9页
在倾斜场地地震液化后,土体的侧向流动扩展引起的场地失效以及大变形问题的研究中,不同的倾斜方式会对试验结果产生一定的影响,而目前针对不同倾斜方式对倾斜液化场地土体地震动力响应影响评价的研究成果还较为少见。根据课题组开展的... 在倾斜场地地震液化后,土体的侧向流动扩展引起的场地失效以及大变形问题的研究中,不同的倾斜方式会对试验结果产生一定的影响,而目前针对不同倾斜方式对倾斜液化场地土体地震动力响应影响评价的研究成果还较为少见。根据课题组开展的水平液化自由场振动台试验,首先基于OpenSees有限元平台建立了水平液化自由场有限元计算模型,在数值模型中考虑了模型箱对场地土地震响应的影响,通过对比数值计算结果与试验结果验证了数值模型的可靠性。在此基础上建立了倾斜液化自由场有限元计算模型,分别建立了层剪箱整体倾斜模型、层剪箱场地土倾斜模型和刚性箱场地土倾斜3种不同的数值模型来模拟振动台试验中采用的不同的倾斜方式。通过对比,分析了在0.3g汶川地震卧龙波作用下3个数值模型计算得到的自由场土体动力响应结果,并讨论了3种不同的倾斜方式对计算结果的影响,最后给出了针对倾斜液化场地地震动力响应数值模拟和振动台试验研究中的一些有参考价值的结论。 展开更多
关键词 倾斜方式 倾斜液化场地 层剪箱模型 刚性箱模型
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An Econometric Analysis of Hospital Length of Stay for Cataract Operations in Japan by the Box-Cox Transformation Model and Hausman Tests: Evaluation of the 2010 Revision of the Medical Payment System
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作者 Kazumitsu Nawata Koichi Kawabuchi 《Open Journal of Applied Sciences》 2015年第9期559-570,共12页
The Japanese medical costs for cataract treatments reached 270 billion yen in fiscal year 2012. Since the length of stay (LOS) in hospital is much longer than other major countries, controlling the medical costs by re... The Japanese medical costs for cataract treatments reached 270 billion yen in fiscal year 2012. Since the length of stay (LOS) in hospital is much longer than other major countries, controlling the medical costs by reducing LOS becomes an important issue in Japan. In this paper, we evaluated the effects of the 2010 revision of the Japanese medical payment system (DPC/PDPS) on LOS for cataract operations. The Box-Cox transformation model, Nawata’s estimators and Hausman tests were used in the analysis. To evaluate the effects, we analyzed a dataset obtained from 34 DPC hospitals (Hp1-34) where one-eye cataract operations were performed both before (April 2008-March 2010) and after (April 2010-March 2012) the 2010 revision and there were more than 500 patients. The dataset contained information from 32,593 patients. We did not admit the effect of the 2010 revision in this study, and there were large differences LOS among hospitals, even after removing the influences of factors such as patient characteristics and types of principal diseases. 展开更多
关键词 Diagnosis Procedure Combination (DPC) CATARACT Length of Stay (LOS) box-Cox TRANSFORMATION model
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