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风险分析 9

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Hybrid deep learning model for risk prediction of fracture in patients with diabetes and osteoporosis

《医学前沿(英文)》 2022年 第16卷 第3期   页码 496-506 doi: 10.1007/s11684-021-0828-7

摘要: The fracture risk of patients with diabetes is higher than those of patients without diabetes due to hyperglycemia, usage of diabetes drugs, changes in insulin levels, and excretion, and this risk begins as early as adolescence. Many factors including demographic data (such as age, height, weight, and gender), medical history (such as smoking, drinking, and menopause), and examination (such as bone mineral density, blood routine, and urine routine) may be related to bone metabolism in patients with diabetes. However, most of the existing methods are qualitative assessments and do not consider the interactions of the physiological factors of humans. In addition, the fracture risk of patients with diabetes and osteoporosis has not been further studied previously. In this paper, a hybrid model combining XGBoost with deep neural network is used to predict the fracture risk of patients with diabetes and osteoporosis, and investigate the effect of patients’ physiological factors on fracture risk. A total of 147 raw input features are considered in our model. The presented model is compared with several benchmarks based on various metrics to prove its effectiveness. Moreover, the top 18 influencing factors of fracture risks of patients with diabetes are determined.

关键词: XGBoost     deep neural network     healthcare     risk prediction    

SinoSCORE: a logistically derived additive prediction model for post-coronary artery bypass grafting

null

《医学前沿(英文)》 2013年 第7卷 第4期   页码 477-485 doi: 10.1007/s11684-013-0284-0

摘要:

This study aims to construct a logistically derived additive score for predicting in-hospital mortality risk in Chinese patients undergoing coronary artery bypass surgery (CABG). Data from 9839 consecutive CABG patients in 43 Chinese centers were collected between 2007 and 2008 from the Chinese Coronary Artery Bypass Grafting Registry. This database was randomly divided into developmental and validation subsets (9:1). The data in the developmental dataset were used to develop the model using logistic regression. Calibration and discrimination characteristics were assessed using the validation dataset. Thresholds were defined for each model to distinguish different risk groups. After excluding 275 patients with incomplete information, the overall mortality rate of the remaining 9564 patients was 2.5%. The SinoSCORE model was constructed based on 11 variables: age, preoperative NYHA stage III or IV, chronic renal failure, extracardiac arteriopathy, chronic obstructive pulmonary disease, preoperative atrial fibrillation or flutter (within 2βweeks), left ventricular ejection fraction, other elective surgery, combined valve procedures, preoperative critical state, and BMI. In the developmental dataset, calibration using a Hosmer-Lemeshow (HL) test was at =β0.44 and discrimination based on the area under the receiver operating characteristic curve (ROC) was 0.80. In the validation dataset, the HL test was at =β0.34 and the area under the ROC (AUC) was 0.78. A logistically derived additive model for predicting in-hospital mortality among Chinese patients undergoing CABG was developed based on the most up-to-date multi-center data from China.

关键词: coronary artery bypass grafting     risk stratification     in-hospital mortality    

灰色预测模型GM(1,1)的适用性分析及在火灾风险预测中的应用

陈子锦,王福亮,陆守香

《中国工程科学》 2007年 第9卷 第5期   页码 91-94

摘要:

通过对灰色预测模型———GM(1,1)的理论分析,证明了该模型的预测值及其变化趋势均具有单调 性,进而提出了GM(1,1)模型的适用性判据,并给出了该判据在火灾风险灰色预测中的应用实例。

关键词: 火灾预测     GM(1     1)模型     火灾伤人率    

Understanding and addressing the environmental risk of microplastics

《环境科学与工程前沿(英文)》 2023年 第17卷 第1期 doi: 10.1007/s11783-023-1612-5

摘要:

Over the past decades, the plastic production has been dramatically increased. Indeed, a category of small plastic particles mainly with the shapes of fragments, fibers, or spheres, called microplastics (particles smaller than 5 mm) and nanoplastics (particles smaller than 1 μm) have attracted particular attention. Because of its wide distribution in the environment and potential adverse effects to animal and human, microplastic pollution has been reported as a serious environment problem receiving increased attention in recent years. As one of the commonly detected emerging contaminants in the environment, recent evidence indicates that the concentration of microplastics show an increasing trend, for the reason that up to 12.7 million metric tons of plastic litter is released into aquatic environment from land-based sources each year. Furthermore, microplastic exposure levels of model organisms in laboratory studies are usually several orders of magnitude higher than those found in environment, and the microplastics exposure conditions are also different with those observed in the environment. Additionally, the detection of microplastics in feces indicates that they can be excreted out of the bodies of animal and human. Hence, great uncertainties might exist in microplastics exposure and health risk assessment based on current studies, which might be exaggerated. Policies reduce microplastic emission sources and hence minimize their environmental risks are determined. To promote the above policies, we must first overcome the technical obstacles of detecting microplastics in various samples.

关键词: Emerging contaminants     Microplastics     Environment risk     Health effect    

Spatial prediction of soil contamination based on machine learning: a review

《环境科学与工程前沿(英文)》 2023年 第17卷 第8期 doi: 10.1007/s11783-023-1693-1

摘要:

● A review of machine learning (ML) for spatial prediction of soil contamination.

关键词: Soil contamination     Machine learning     Prediction     Spatial distribution    

Ecological Risk Management of Drinking Water Project: The Case Study of Kunming City

Ji-liang Zheng,Jun Hu,Xuan Zhou,Ching Yuen Luk

《工程管理前沿(英文)》 2015年 第2卷 第3期   页码 311-319 doi: 10.15302/J-FEM-2015045

摘要: Following rapid infrastructure development and industrialization, the problems of water pollution and water shortage have become more severe. Whether there is safe drinking water in cities has attracted wide attention. The ecological risk management of drinking water project is an important means of ensuring the safety of a drinking water source. Based on ecological risk assessment and management theories, this paper establishes an ecological risk management model and assessment system with the aim of providing theoretical guidance and scientific basis for formulating a policy on the safety and protection of drinking water sources in a city. Kunming is one of the cities plagued by severe water shortage in China. Its ecological risk management of drinking water has attracted the attention of both the local government and the public. Using Kunming as the case study, this paper conducts a comparative analysis and assessment on three major reservoirs that face ecological risks. It highlights the existing problems and gives helpful suggestions.

关键词: drinking water project     ecological risk     ecological risk assessment     risk management    

Position-varying surface roughness prediction method considering compensated acceleration in milling

《机械工程前沿(英文)》 2021年 第16卷 第4期   页码 855-867 doi: 10.1007/s11465-021-0649-z

摘要: Machined surface roughness will affect parts’ service performance. Thus, predicting it in the machining is important to avoid rejects. Surface roughness will be affected by system position dependent vibration even under constant parameter with certain toolpath processing in the finishing. Aiming at surface roughness prediction in the machining process, this paper proposes a position-varying surface roughness prediction method based on compensated acceleration by using regression analysis. To reduce the stochastic error of measuring the machined surface profile height, the surface area is repeatedly measured three times, and Pauta criterion is adopted to eliminate abnormal points. The actual vibration state at any processing position is obtained through the single-point monitoring acceleration compensation model. Seven acceleration features are extracted, and valley, which has the highest R-square proving the effectiveness of the filtering features, is selected as the input of the prediction model by mutual information coefficients. Finally, by comparing the measured and predicted surface roughness curves, they have the same trends, with the average error of 16.28% and the minimum error of 0.16%. Moreover, the prediction curve matches and agrees well with the actual surface state, which verifies the accuracy and reliability of the model.

关键词: surface roughness prediction     compensated acceleration     milling     thin-walled workpiece    

Improved prediction of pile bending moment and deflection due to adjacent braced excavation

《结构与土木工程前沿(英文)》 doi: 10.1007/s11709-023-0961-2

摘要: Deep excavations in dense urban areas have caused damage to nearby existing structures in numerous past construction cases. Proper assessment is crucial in the initial design stages. This study develops equations to predict the existing pile bending moment and deflection produced by adjacent braced excavations. Influential parameters (i.e., the excavation geometry, diaphragm wall thickness, pile geometry, strength and small-strain stiffness of the soil, and soft clay thickness) were considered and employed in the developed equations. It is practically unfeasible to obtain measurement data; hence, artificial data for the bending moment and deflection of existing piles were produced from well-calibrated numerical analyses of hypothetical cases, using the three-dimensional finite element method. The developed equations were established through a multiple linear regression analysis of the artificial data, using the transformation technique. In addition, the three-dimensional nature of the excavation work was characterized by considering the excavation corner effect, using the plane strain ratio parameter. The estimation results of the developed equations can provide satisfactory pile bending moment and deflection data and are more accurate than those found in previous studies.

关键词: pile responses     excavation     prediction     deflection     bending moments    

Reliability prediction and its validation for nuclear power units in service

Jinyuan SHI,Yong WANG

《能源前沿(英文)》 2016年 第10卷 第4期   页码 479-488 doi: 10.1007/s11708-016-0425-7

摘要: In this paper a novel method for reliability prediction and validation of nuclear power units in service is proposed. The equivalent availability factor is used to measure the reliability, and the equivalent availability factor deducting planed outage hours from period hours and maintenance factor are used for the measurement of inherent reliability. By statistical analysis of historical reliability data, the statistical maintenance factor and the undetermined parameter in its numerical model can be determined. The numerical model based on the maintenance factor predicts the equivalent availability factor deducting planed outage hours from period hours, and the planed outage factor can be obtained by using the planned maintenance days. Using these factors, the equivalent availability factor of nuclear power units in the following 3 years can be obtained. Besides, the equivalent availability factor can be predicted by using the historical statistics of planed outage factor and the predicted equivalent availability factor deducting planed outage hours from period hours. The accuracy of the reliability prediction can be evaluated according to the comparison between the predicted and statistical equivalent availability factors. Furthermore, the reliability prediction method is validated using the nuclear power units in North American Electric Reliability Council (NERC) and China. It is found that the relative errors of the predicted equivalent availability factors for nuclear power units of NERC and China are in the range of –2.16% to 5.23% and –2.15% to 3.71%, respectively. The method proposed can effectively predict the reliability index in the following 3 years, thus providing effective reliability management and maintenance optimization methods for nuclear power units.

关键词: nuclear power units in service     reliability     reliability prediction     equivalent availability factors    

风险矩阵方法与应用述评

朱启超,匡兴华,沈永平

《中国工程科学》 2003年 第5卷 第1期   页码 89-94

摘要:

技术项目的风险管理一直深受美国国防部的重视。介绍了在美国国防采办风险管理中广泛应用的风险矩阵方法,并对其优缺点和适用性进行分析,结合我国国防预研技术项目管理的特点,提出我国开展技术性项目风险管理的思路。

关键词: 风险矩阵     风险管理     项目管理    

Trend prediction technology of condition maintenance for large water injection units

Xiaoli XU, Sanpeng DENG

《机械工程前沿(英文)》 2010年 第5卷 第2期   页码 171-175 doi: 10.1007/s11465-009-0091-0

摘要: Trend prediction technology is the key technology to achieve condition-based maintenance of mechanical equipment. Large-sized water injection units are key equipment in oilfields. The traditional preventive maintenance is not economical and cannot completely avoid vicious accidents. To ensure the normal operation of units and save maintenance costs, trend prediction technology is studied to achieve condition-based maintenance for water injection units. The main methods of the technology are given, the trend prediction method based on neural network is put forward, and the expert system based on the knowledge is developed. The industrial site verification shows that the proposed trend prediction technology can reflect the operating condition trend change of the water injection units and provide technical means to achieve condition-based predictive maintenance.

关键词: water injection units     condition-based maintenance     trend prediction    

Bioaerosol emissions variations in large-scale landfill region and their health risk impacts

《环境科学与工程前沿(英文)》 2022年 第16卷 第12期 doi: 10.1007/s11783-022-1593-9

摘要:

● The airborne bacteria in landfills were 4–50 times higher than fungi.

关键词: Microbial aerosols     Landfill sites     Health risk assessment     CALPUFF    

Dynamic prediction of moving trajectory in pipe jacking: GRU-based deep learning framework

《结构与土木工程前沿(英文)》   页码 994-1010 doi: 10.1007/s11709-023-0942-5

摘要: The moving trajectory of the pipe-jacking machine (PJM), which primarily determines the end quality of jacked tunnels, must be controlled strictly during the entire jacking process. Developing prediction models to support drivers in performing rectifications in advance can effectively avoid considerable trajectory deviations from the designed jacking axis. Hence, a gated recurrent unit (GRU)-based deep learning framework is proposed herein to dynamically predict the moving trajectory of the PJM. In this framework, operational data are first extracted from a data acquisition system; subsequently, they are preprocessed and used to establish GRU-based multivariate multistep-ahead direct prediction models. To verify the performance of the proposed framework, a case study of a large pipe-jacking project in Shanghai and comparisons with other conventional models (i.e., long short-term memory (LSTM) network and recurrent neural network (RNN)) are conducted. In addition, the effects of the activation function and input time-step length on the prediction performance of the proposed framework are investigated and discussed. The results show that the proposed framework can dynamically and precisely predict the PJM moving trajectory during the pipe-jacking process, with a minimum mean absolute error and root mean squared error (RMSE) of 0.1904 and 0.5011 mm, respectively. The RMSE of the GRU-based models is lower than those of the LSTM- and RNN-based models by 21.46% and 46.40% at the maximum, respectively. The proposed framework is expected to provide an effective decision support for moving trajectory control and serve as a foundation for the application of deep learning in the automatic control of pipe jacking.

关键词: dynamic prediction     moving trajectory     pipe jacking     GRU     deep learning    

Prediction of the shear wave velocity

Amoroso SARA

《结构与土木工程前沿(英文)》 2014年 第8卷 第1期   页码 83-92 doi: 10.1007/s11709-013-0234-6

摘要: The paper examines the correlations to obtain rough estimates of the shear wave velocity from non-seismic dilatometer tests (DMT) and cone penetration tests (CPT). While the direct measurement of is obviously preferable, these correlations may turn out useful in various circumstances. The experimental results at six international research sites suggest that the DMT predictions of from the parameters (material index), (horizontal stress index), (constrained modulus) are more reliable and consistent than the CPT predictions from (cone resistance), presumably because of the availability, by DMT, of the stress history index .

关键词: horizontal stress index     shear wave velocity     flat dilatometer test     cone penetration test    

Liquefaction prediction using support vector machine model based on cone penetration data

Pijush SAMUI

《结构与土木工程前沿(英文)》 2013年 第7卷 第1期   页码 72-82 doi: 10.1007/s11709-013-0185-y

摘要: A support vector machine (SVM) model has been developed for the prediction of liquefaction susceptibility as a classification problem, which is an imperative task in earthquake engineering. This paper examines the potential of SVM model in prediction of liquefaction using actual field cone penetration test (CPT) data from the 1999 Chi-Chi, Taiwan earthquake. The SVM, a novel learning machine based on statistical theory, uses structural risk minimization (SRM) induction principle to minimize the error. Using cone resistance ( ) and cyclic stress ratio ( ), model has been developed for prediction of liquefaction using SVM. Further an attempt has been made to simplify the model, requiring only two parameters ( and maximum horizontal acceleration ), for prediction of liquefaction. Further, developed SVM model has been applied to different case histories available globally and the results obtained confirm the capability of SVM model. For Chi-Chi earthquake, the model predicts with accuracy of 100%, and in the case of global data, SVM model predicts with accuracy of 89%. The effect of capacity factor ( ) on number of support vector and model accuracy has also been investigated. The study shows that SVM can be used as a practical tool for prediction of liquefaction potential, based on field CPT data.

关键词: earthquake     cone penetration test     liquefaction     support vector machine (SVM)     prediction    

标题 作者 时间 类型 操作

Hybrid deep learning model for risk prediction of fracture in patients with diabetes and osteoporosis

期刊论文

SinoSCORE: a logistically derived additive prediction model for post-coronary artery bypass grafting

null

期刊论文

灰色预测模型GM(1,1)的适用性分析及在火灾风险预测中的应用

陈子锦,王福亮,陆守香

期刊论文

Understanding and addressing the environmental risk of microplastics

期刊论文

Spatial prediction of soil contamination based on machine learning: a review

期刊论文

Ecological Risk Management of Drinking Water Project: The Case Study of Kunming City

Ji-liang Zheng,Jun Hu,Xuan Zhou,Ching Yuen Luk

期刊论文

Position-varying surface roughness prediction method considering compensated acceleration in milling

期刊论文

Improved prediction of pile bending moment and deflection due to adjacent braced excavation

期刊论文

Reliability prediction and its validation for nuclear power units in service

Jinyuan SHI,Yong WANG

期刊论文

风险矩阵方法与应用述评

朱启超,匡兴华,沈永平

期刊论文

Trend prediction technology of condition maintenance for large water injection units

Xiaoli XU, Sanpeng DENG

期刊论文

Bioaerosol emissions variations in large-scale landfill region and their health risk impacts

期刊论文

Dynamic prediction of moving trajectory in pipe jacking: GRU-based deep learning framework

期刊论文

Prediction of the shear wave velocity

Amoroso SARA

期刊论文

Liquefaction prediction using support vector machine model based on cone penetration data

Pijush SAMUI

期刊论文