检索结果-南通市图书馆

Estimating the air exchange rates in naturally ventilated cattle houses using Bayesian-optimized GBDT

International Journal of Agricultural and Biological Engineering 2023年第1期16卷 73-80页

作者： Luyu Ding Lei E Yang Lyu Chunxia Yao Qifeng Li Shiwei Huang Weihong Ma Ligen Yu Ronghua Gao Information Technology Research Center Beijing Academy of Agriculture and Forestry SciencesBeijing 100097China National Innovation Center of Digital Technology in Animal Husbandry Beijing 100097China Beijing Technology Innovation Strategic Alliance for Intelligence Internet of Things Industry in Agriculture Beijing 100097China Department of Agricultural Structure and Bioenvironmental Engineering College of Water Resources and Civil EngineeringChina Agricultural UniversityBeijing 100083China

It is challenging to estimate the air exchange rate(AER)dynamically in naturally ventilated livestock buildings such as dairy houses due to the influence of complex and variable outdoor environmental factors,large opening ratios,and the confusion of inflow and outflow at openings.This makes it difficult to efficiently regulate the opening ratio to meet the ventilation requirements in naturally ventilated livestock buildings.In this study,the air exchange rates of naturally ventilated cattle houses(NVCHs)in different seasons and opening ratios were obtained through field measurements and computational fluid dynamics(CFD)simulations.A fast and efficient machine learning framework was proposed and examined to predict AER based on the gradient boosting decision tree(GBDT)combined with Bayesian optimization.Compared with commonly used machine learning models such as multilayer perceptrons(MLPs)and support vector machines(SVMs),the proposed GBDT model has higher prediction accuracy and can avoid falling easily into local optima.Compared with the existing mechanical model based on the Bernoulli equation,the proposed GBDT model showed a slightly higher prediction than the mechanistic model and was much easier to use in AER estimation when inputting easily collected environmental factors in practical applications.Using Bayesian optimization could dramatically reduce the computing time when determining the optimal hyperparameter for establishing the GBDT model,dramatically saving on computing resources.Based on the Bayesian optimized GBDT model,the desirable opening ratio of the side curtain can be determined for automatically regulating the AER of cattle houses in future applications.

关键词： natural ventilation Bayesian GBDT air exchange rate cattle house

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

GPA: A Microbial Genetic Polymorphisms Assignments Tool in Metagenomic Analysis by Bayesian Estimation

引用

Genomics, Proteomics & Bioinformatics 2019年第1期17卷 106-117页

作者： Jiarui Li Pengcheng Du Adam Yongxin Ye Yuanyuan Zhang Chuan Song Hui Zeng Chen Chen Beijing Key Laboratory of Emerging Infectious Diseases Institute of Infectious Diseases Beijing Ditan Hospital Capital Medical University Center for Bioinformatics State Key Laboratory of Protein and Plant Gene Research School of Life Sciences Peking University

Identifying antimicrobial resistant(AMR) bacteria in metagenomics samples is essential for public health and food safety. Next-generation sequencing(NGS) technology has provided a powerful tool in identifying the genetic variation and constructing the correlations between genotype and phenotype in humans and other species. However, for complex bacterial samples, there lacks a powerful bioinformatic tool to identify genetic polymorphisms or copy number variations(CNVs) for given genes. Here we provide a Bayesian framework for genotype estimation for mixtures of multiple bacteria, named as Genetic Polymorphisms Assignments(GPA). Simulation results showed that GPA has reduced the false discovery rate(FDR) and mean absolute error(MAE) in CNV and single nucleotide variant(SNV) identification. This framework was validated by whole-genome sequencing and Pool-seq data from Klebsiella pneumoniae with multiple bacteria mixture models, and showed the high accuracy in the allele fraction detections of CNVs and SNVs in AMR genes between two populations. The quantitative study on the changes of AMR genes fraction between two samples showed a good consistency with the AMR pattern observed in the individual strains. Also, the framework together with the genome annotation and population comparison tools has been integrated into an application, which could provide a complete solution for AMR gene identification and quantification in unculturable clinical samples. The GPA package is available at https://***/IID-DTH/GPA-package.

关键词： Next-generation sequencing Pool-seq Bayesian model Metagenomics Genetic polymorphisms

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Finding patterns in subsurface using Bayesian machine learning approach

引用

Underground Space 2020年第1期5卷 84-92页

作者： Hui Wang Department of Civil and Environmental Engineering and Engineering Mechanics University of DaytonDaytonOH 45469-0243United States

Stochastic simulation approaches and uncertainty quantification are usually adopted for gaining insight into variability in soil stratigraphy configurations.Previous investigations at geotechnical site characterization and interpretation can be broadly categorized into geostatistics-and process-based methods.On the other hand,modern site exploration techniques provide high-quality,dense datasets in physical spaces with high resolution,either directly from sensors(for example,cone penetration testing data)or indirectly from geophysical inversion(such as seismic inversion,electromagnetic induction inversion,and ground penetrating radar).In this work,anisotropy and heterogeneity are considered as possible patterns that inherently exist in the observations,and these are inferred and described in a Bayesian manner.To this end,a Bayesian machine learning approach is employed to extract these patterns from the original or interpreted data.The patterns are divided into two parts:spatial and statistical patterns.These patterns are considered as the"hidden link"among multiple spatial datasets.The proposed modeling method is demonstrated using a real-world,one-dimensional example as well as two two-dimensional numerical examples.It is revealed that the proposed clustering approach is a promising tool for subsurface modeling and pattern extraction.

关键词： Subsurface modeling Pattern extraction Machine learning Bayesian Random field

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Comparative efficacy and safety of cognitive enhancers for treating vascular cognitive impairment: systematic review and Bayesian network meta-analysis

引用

Neural Regeneration Research 2019年第5期14卷 805-816页

作者： Bo-Ru Jin Hua-Yan Liu Department of Neurology First Affiliated Hospital China Medical University

Objective: To assess and compare the clinical efficacy and safety of cognitive enhancers(donepezil, galantamine, rivastigmine, and memantine) on cognition, behavior, function, and global status in patients with vascular cognitive impairment.Data sources: The initial literature search was performed with PubMed, EMBASE, the Cochrane Methodology Register, the Cochrane Central Register of Controlled Trials, and Cumulative Index to Nursing & Allied Health(CINAHL) from inception to January 2018 for studies regarding donepezil, galantamine, rivastigmine, and memantine for treatment of vascular cognitive impairment.Data selection: Randomized controlled trials on donepezil, galantamine, rivastigmine, and memantine as monotherapy in the treatment of vascular cognitive impairment were included. A Bayesian network meta-analysis was conducted. Outcome measures: Efficacy was assessed by changes in scores of the Alzheimer's Disease Assessment Scale, cognitive subscale, Mini-Mental State Examination, Neuropsychiatric Inventory scores and Clinician's Interview-Based Impression of Change Scale Plus Caregiver's Input, Activities of Daily Living, the Clinical Dementia Rating scale. Safety was evaluated by mortality, total adverse events(TAEs), serious adverse events(SAEs), nausea, vomiting. diarrhea, or cerebrovascular accidents(CVAs). Results: After screening 1717 citations, 12 randomized controlled trials were included. Donepezil and rivastigmine(mean difference(e) = –0.77, 95% confidence interval(CI): 0.25–1.32; MD = 1.05, 95% CI: 0.18–1.79) were significantly more effective than placebo in reducing Mini-Mental State Examination scores. Donepezil, galantamine, and memantine(MD = –1.30, 95% CI: –2.27 to –0.42; MD = –1.67, 95% CI: –3.36 to –0.06; MD = –2.27, 95% CI: –3.91 to –0.53) showed superior benefits on the Alzheimer's Disease Assessment Scale–cognitive scores compared with placebo. Memantine(MD = 2.71, 95% CI: 1.05–7.29) improved global status(Clinician's Interview-Based Impression of Change Scale Plus Caregiver's Input) mor

关键词： nerve regeneration vascular cognitive impairment vascular dementia pharmacotherapy cholinesterase inhibitors donepezil galantamine rivastigmine memantine systematic review Bayesian network meta-analysis neural regeneration

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Capture-aware Bayesian RFID Tag Estimate for Large-scale Identification

引用

IEEE/CAA Journal of Automatica Sinica 2018年第1期5卷 119-127页

作者： Haifeng Wu Yang Wang Yu Zeng School of Electrical and Information Technology Yunnan Minzu University

Dynamic framed slotted Aloha algorithm is one of popular passive radio frequency identification(RFID) tag anticollision algorithms. In the algorithm, a frame length requires dynamical adjustment to achieve higher identification efficiency.Generally, the adjustment of the frame length is not only related to the number of tags, but also to the occurrence probability of capture effect. Existing algorithms could estimate both the number of tags and the probability of capture effect. Under large-scale RFID tag identification, however, the number of tags would be much larger than an initial frame length. In this scenario, the existing algorithm's estimation errors would substantially increase. In this paper, we propose a novel algorithm called capture-aware Bayesian estimate, which adopts Bayesian rules to accurately estimate the number and the probability simultaneously. From numerical results, the proposed algorithm adapts well to the large-scale RFID tag identification. It has lower estimation errors than the existing algorithms. Further,the identification efficiency from the proposed estimate is also higher than the existing algorithms.

关键词： Aloha Bayesian capture effect large-scale radio frequency identification(RFID)

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

A parallel and robust object tracking approach synthesizing adaptive Bayesian learning and improved incremental subspace learning

引用

Frontiers of Computer Science 2019年第5期13卷 1116-1135页

作者： Kang LI Fazhi HE Haiping YU Xiao CHEN State Key Laboratory of Software Engineering School of Computer Science Wuhan University Wuhan 430072 China School of Computer Science and Information Engineering Hubei University Wuhan 430062 China

This paper presents a novel tracking algorithm which integrates two complementary trackers. Firstly, an improved Bayesian tracker(B-tracker) with adaptive learning rate is presented. The classification score of B-tracker reflects tracking reliability, and a low score usually results from large appearance change. Therefore, if the score is low, we decrease the learning rate to update the classifier fast so that B-tracker can adapt to the variation and vice versa. In this way, B-tracker is more suitable than its traditional version to solve appearance change problem. Secondly, we present an improved incremental subspace learning method tracker(Stracker). We propose to calculate projected coordinates using maximum posterior probability, which results in a more accurate reconstruction error than traditional subspace learning tracker. Instead of updating at every time, we present a stopstrategy to deal with occlusion problem. Finally, we present an integrated framework(BAST), in which the pair of trackers run in parallel and return two candidate target states separately. For each candidate state, we define a tracking reliability metrics to measure whether the candidate state is reliable or not, and the reliable candidate state will be chosen as the target state at the end of each frame. Experimental results on challenging sequences show that the proposed approach is very robust and effective in comparison to the state-of-the-art trackers.

关键词： object tracking Bayesian learning subspace learning particle filter principal component analysis

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Learning Bayesian networks by constrained Bayesian estimation

引用

Journal of Systems Engineering and Electronics 2019年第3期30卷 511-524页

作者： GAO Xiaoguang YANG Yu GUO Zhigao School of Electronics and Information Northwestern Polytechnical University

Bayesian networks (BNs) have become increasingly popular in recent years due to their wide-ranging applications in modeling uncertain knowledge. An essential problem about discrete BNs is learning conditional probability table (CPT) parameters. If training data are sparse, purely data-driven methods often fail to learn accurate parameters. Then, expert judgments can be introduced to overcome this challenge. Parameter constraints deduced from expert judgments can cause parameter estimates to be consistent with domain knowledge. In addition, Dirichlet priors contain information that helps improve learning accuracy. This paper proposes a constrained Bayesian estimation approach to learn CPTs by incorporating constraints and Dirichlet priors. First, a posterior distribution of BN parameters is developed over a restricted parameter space based on training data and Dirichlet priors. Then, the expectation of the posterior distribution is taken as a parameter estimation. As it is difficult to directly compute the expectation for a continuous distribution with an irregular feasible domain, we apply the Monte Carlo method to approximate it. In the experiments on learning standard BNs, the proposed method outperforms competing methods. It suggests that the proposed method can facilitate solving real-world problems. Additionally, a case study of Wine data demonstrates that the proposed method achieves the highest classification accuracy.

关键词： Bayesian networks (BNs) parameter learning constraints sparse data

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Finding optimal Bayesian networks by a layered learning method

引用

Journal of Systems Engineering and Electronics 2019年第5期30卷 946-958页

作者： YANG Yu GAO Xiaoguang GUO Zhigao School of Electronics and Information Northwestern Polytechnical University

It is unpractical to learn the optimal structure of a big Bayesian network(BN)by exhausting the feasible structures,since the number of feasible structures is super exponential on the number of nodes.This paper proposes an approach to layer nodes of a BN by using the conditional independence testing.The parents of a node layer only belong to the layer,or layers who have priority over the layer.When a set of nodes has been layered,the number of feasible structures over the nodes can be remarkably reduced,which makes it possible to learn optimal BN structures for bigger sizes of nodes by accurate algorithms.Integrating the dynamic programming(DP)algorithm with the layering approach,we propose a hybrid algorithm—layered optimal learning(LOL)to learn BN structures.Benefitted by the layering approach,the complexity of the DP algorithm reduces to O(ρ2^n?1)from O(n2^n?1),whereρBayesian information criterion(BIC)score criterion,over the hill-climbing,max-min hill-climbing,PC,and three-phrase dependency analysis algorithms.

关键词： Bayesian network (BN) structure learning layeredoptimal learning (LOL)

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

模态识别的Bayesian TDD-FFT法及其应用

引用

振动与冲击 2019年第15期38卷 142-148,171页

作者：吴杰徐洪俊张其林同济大学土木工程学院

针对Bayesian FFT(Fast Fourier Transform)在多自由度下的病态Hessian矩阵求逆和模态参数不确定性评估问题,提出了Bayesian TDD-FFT模态方法。提出Bayesian TDD(Time Domain Decomposition)方法,将多测点多自由度信号转变为单测点单自由度信号;结合Bayesian FFT和蒙特卡罗方法获取模态参数的最佳估计和后验概率分布,进行不确定性分析,并通过数值模拟验证了Bayesian TDD-FFT法的有效性;基于上海中心大厦实测数据,通过对比分析指出Bayesian TDD-FFT法能够获得Fast Bayesian FFT法的结果精度,同时发现频率和阻尼没有相关性,而激励谱密度和预测误差谱密度存在明显的相关性。

关键词：模态识别 Bayesian TDD-FFT Fast Bayesian FFT 蒙特卡罗方法上海中心

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Estimating survival benefit of adjuvant therapy based on a Bayesian network prediction model in curatively resected advanced gallbladder adenocarcinoma

引用

World Journal of Gastroenterology 2019年第37期25卷 5655-5666页

作者： Zhi-Min Geng Zhi-Qiang Cai Zhen Zhang Zhao-Hui Tang Feng Xue Chen Chen Dong Zhang Qi Li Rui Zhang Wen-Zhi Li Lin Wang Shu-Bin Si Department of Hepatobiliary Surgery The First Affiliated Hospital of Xi’an Jiaotong UniversityXi’an 710061Shaanxi ProvinceChina Department of Industrial Engineering School of Mechanical EngineeringNorthwestern Polytechnical UniversityXi’an 710072Shaanxi ProvinceChina Department of General Surgery Shanghai Xin Hua Hospital Affiliated to School of MedicineShanghai Jiaotong UniversityShanghai 200092China

BACKGROUND The factors affecting the prognosis and role of adjuvant therapy in advanced gallbladder carcinoma(GBC)after curative resection remain unclear.AIM To provide a survival prediction model to patients with GBC as well as to identify the role of adjuvant therapy.METHODS Patients with curatively resected advanced gallbladder adenocarcinoma(T3 and T4)were selected from the Surveillance,Epidemiology,and End Results database between 2004 and 2015.A survival prediction model based on Bayesian network(BN)was constructed using the tree-augmented na?ve Bayes algorithm,and composite importance measures were applied to rank the influence of factors on survival.The dataset was divided into a training dataset to establish the BN model and a testing dataset to test the model randomly at a ratio of 7:3.The confusion matrix and receiver operating characteristic curve were used to evaluate the model accuracy.RESULTS A total of 818 patients met the inclusion criteria.The median survival time was 9.0 mo.The accuracy of BN model was 69.67%,and the area under the curve value for the testing dataset was 77.72%.Adjuvant radiation,adjuvant chemotherapy(CTx),T stage,scope of regional lymph node surgery,and radiation sequence were ranked as the top five prognostic factors.A survival prediction table was established based on T stage,N stage,adjuvant radiotherapy(XRT),and CTx.The distribution of the survival time(>9.0 mo)was affected by different treatments with the order of adjuvant chemoradiotherapy(cXRT)>adjuvant radiation>adjuvant chemotherapy>surgery alone.For patients with node-positive disease,the larger benefit predicted by the model is adjuvant chemoradiotherapy.The survival analysis showed that there was a significant difference among the different adjuvant therapy groups(log rank,surgery alone vs CTx,P<0.001;surgery alone vs XRT,P=0.014;surgery alone vs cXRT,P<0.001).CONCLUSION The BN-based survival prediction model can be used as a decision-making support tool for advanced GBC patients.Adjuvant chemoradiotherapy is expec

关键词： Gallbladder carcinoma Bayesian network Surgery Adjuvant therapy Prediction model

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：