Statistical Methodology Commons^™

Research On Automatic Review Method Of Highway Bim Based On Knowledge Graph, Wang Wuyu, Shao Kebo, Zhang Feng

Journal of China & Foreign Highway

Building information modeling (BIM ),characterized by multi-dimensional modeling and multi-source data integration,is becoming a key technology to promote the innovation and digital transformation of the highway design industry.Taking BIM as the design deliverable is an inevitable trend in the future development of highway engineering design.However,the current highway BIM review is mainly conducted manually,which brings about problems such as low efficiency,susceptibility to errors,and high subjectivity.This makes it difficult to adapt to the review requirements of the three-dimensional (3D) digital design mode.To this end,this study proposed an automatic review method of highway BIM based on a knowledge graph.By constructing the knowledge graph …

Research On Multi-Classification Prediction Of Traffic Accident Severity On Mountainous Expressways, Wang Hao, Yan Jie, Guo Jianmin, Zhang Yu, Sun Chengji

Journal of China & Foreign Highway

To enhance the safety level of mountainous expressways and establish an accurate and effective prediction model for traffic accident severity,this study analyzed 2 484 traffic accidents on mountainous expressways in Chongqing from 2010 to 2016.A total of 17 influencing factors were selected from four aspects:human,vehicle,road,and environment,to serve as explanatory variables.Partial proportional odds model,random forest algorithm,and XGBoost algorithm were used to construct multi-class prediction models for traffic accident severity.The model performance was evaluated using the confusion matrix,accuracy,and minority class recall rate.The results show that the XGBoost model achieves the highest prediction accuracy in multi-class prediction of traffic accident severity on mountainous …

Research On Prefabrication Scheme Of Concrete Barrier Based On Anchorage In Cast-In-Situ Layer, Liang Xiaochong, Kang Hanjing, Luo Yongchuan, Wen Zhiquan, Deng Bao

Journal of China & Foreign Highway

In order to improve the on-site construction efficiency of bridge concrete barriers,a prefabrication scheme for bridge concrete barrier installation was proposed.A structure scheme was developed by anchoring transverse steel bars at the bottom of prefabricated wall panels into the integrated cast-in-situ layer,adopting tongue-and-groove connections between adjacent wall panels,and optimizing the structural configuration and reinforcement of the panels.According to the requirements of the Level VI protection standard,full-scale impact tests using a large bus and a large truck were organized in turn.The results show that the prefabricated concrete bridge barrier can effectively withstand continuous impacts from both large buses and trucks.Its structural …

Application And Analysis Of Energy-Conservation And Carbon-Reduction Technologies In Green Highways, Huang Xuewen, Wang Kai, Huang Shanqian, Xiong Xinzhu, Fu Jinsheng

Journal of China & Foreign Highway

To improve the low-carbon development level of highway engineering,this study relied on a typical green highway in Anhui Province and established a calculation model for energy-conservation and carbon-reduction in highway engineering based on the emission factor method.A combination of quantitative and qualitative approaches was adopted to evaluate the benefits of 33 energy-conservation and carbon-reduction technologies in reducing life cycle energy consumption and carbon emissions,based on life cycle assessment (LCA ) theory.The results show that during the material production stage,through channel resource coordination and the application of low-carbon,energy-saving materials,comprehensive reductions in the embodied carbon can be achieved.During the construction stage,energy consumption …

Influence Of Horizontal Curve Radius On Vehicle Fuel Consumption And Pollutant Emissions On Tw O-Lane Highways, Tu Shengwen, Lei Meimei, Guo Wenyu

Journal of China & Foreign Highway

To investigate the influence of horizontal curve radius on vehicle fuel consumption and pollutant emissions on two-lane highways,this study developed a model based on running speed theory,vehicle driving dynamics,and a fuel consumption and emission analysis system.Fuel consumption and emissions of CO2,CO,HC,and NOx were calculated for a passenger car traveling along horizontal curves under three design speeds:40 km/h,60 km/h,and 80 km/h.The results show that the horizontal curve radius has a significant effect on vehicle fuel consumption and pollutant emissions.The trends of fuel consumption,CO2,and NOx emissions vary consistently with curve radius,while CO and HC emissions follow a similar but different trend.At the …

Reference And Inspi Ration From Low-Carbon Development Experience Of Foreign Highway Infrastructure, Lu Chunying, Gao Shuohan, Du Xueyua N, Jian Li, Wang Xinjun, Kong Yaping

Journal of China & Foreign Highway

In order to provide supp ort for the scie ntific formulation of low-carbon highway infrastructure development policies in China,empirical analysis,comparative analysis,and other methods were utilized,and the construction goals and action strategies of low-carbon highway infrastructure in the United Kingdom,the United States,and Australia were sorted out.Advanced experience in the development of low-carbon highways abroad was summarized.On this basis,combined with the current situation and existing problems of low-carbon development of China ’s highway infrastructure,the following countermeasures and suggestions were proposed:① strengthening top-level design and formulating low-carbon development goals and paths;② implementing the concept of life cycle and strengthening the research and promotion …

Towards Reliable Clinical Applications Of Ai Models In Radiotherapy, Biling Wang

Statistical Science Theses and Dissertations

Over the past decade, artificial intelligence (AI), particularly through deep learning (DL) techniques, has made significant strides in fields like computer vision (CV) and natural language processing (NLP), leading to transformative advancements across numerous applications. This progress has sparked considerable enthusiasm within the medical field, where DL-related research has grown exponentially since 2015. However, despite these promising developments, the real-world deployment of DL models in healthcare remains limited, especially in safety-critical domains such as radiotherapy (RT), where reliability, safety, and sustained performance are critical. This thesis addresses three core challenges associated with the clinical application of DL models: (1) post-deployment …

Estimation Methods For Bayesian Exponential Random Graph Models Under The Horseshoe Prior., Pamela Linares

Electronic Theses and Dissertations

Networks are powerful tools for modeling the complexity of social interactions, biological systems, and information spread. A leading statistical frameworks for analyzing network data are Exponential Random Graph Models (ERGMs), which provide a principled approach to capturing structural dependencies. However, ERGMs remain challenging to estimate, especially in sparse or high-dimensional settings where models suffer from degeneracy and unstable parameter inference. This paper proposes a penalized Bayesian approach to ERGMs that utilizes the horseshoe prior, a sparsity-inducing global-local shrinkage prior. This prior offers robust regularization while preserving important signals, improving estimation by shrinking irrelevant parameters and reducing the impact of extreme …

Performance Of The Two Sample Likelihood Ratio Test Under A Nested Dirichlet: A Simulation Study, Edwina Agyeman

Electronic Theses and Dissertations

Compositional data analysis (CoDA) addresses multivariate data constrained to a constant sum, such as proportions or percentages. Originating from early warnings regarding misinterpretation by Pearson (1897), the field was formalized by John Aitchison in 1986, whose foundational work remains highly influential. Over time, new modeling techniques and visualization tools have advanced the field, as noted by Greenacre et al. More recently, Turner et al. proposed an approach based on the Nested Dirichlet Distribution (NDD), which accommodates more flexible dependence structures than the standard Dirichlet model. This thesis builds on the methodology of Turner et al. Chapter 1 introduces the nature …

Evaluating Alpha Spending Functions Applied To Observational Time-To-Event Analysis, Moses Torgbenu

Electronic Theses and Dissertations

This thesis explores the theoretical foundation of the alpha spending approach and extends its application beyond the conventional setting of randomized controlled trials (RCTs) to observational studies with time to event analyses. In these less structured environments, key design parameters such as the total number of events are often unknown, posing challenges for the standard implementation of sequential analysis methods.

Through simulation studies, this research delivers several important contributions. First, it presents a modified approach that uses calendar time to define the timing of interim analyses while relying on event-based information to estimate the correlation among test statistics. This adjustment …

Multivariate Mixture Regression Models With Known Group Membership And Informative Priors, Pahalapathirage Dona Kalani Hasanthika

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

We introduced couple different novel approaches to incorporate latent variable information to multivariate mixture regression models with both Gaussian and count data. We also evaluated the performance of these models with existing best approaches with simulated data from various sampling structures and also evaluated one of the models performance with rice metabolite data that provided some novel insights as well as validating existing literature about performance and behavior of these metabolites. We validated the method using extensive simulations and a real-world application. In both quantitative covariate designs and complex treatment design simulations, our method consistently outperformed established tools like limma, …

Experimental Design And Analysis For Decision Making: Methodology And Applications, Yezhuo Li

All Dissertations

This dissertation develops and applies advanced statistical and optimization frameworks to enhance decision-making under uncertainty, particularly in engineering and manufacturing contexts. First, we introduce an approach for the optimal design of controlled experiments that accounts for observational covariates, enabling more precise and personalized decisions. Second, we explore the application of constrained Bayesian optimization, using Gaussian process surrogate models, to optimize composite cure processes, significantly reducing computational effort while maintaining high predictive accuracy. Building on this foundation, we extend Bayesian optimization to bivariate Gaussian process models that capture correlations between objective and constraint functions, offering new insights into multidimensional decision landscapes. …

Discontinuous Deforma Tion Analysis Of Progressive Toppling Of Rock Slopes With Fractured Slab Structure, Yuan Sifan, Li Tonglu, Haider Mumtaz, Zhang Changliang, Li Ping

Journal of China & Foreign Highway

Progressive toppling of rock sl opes with fractured slab structures is quite common in the slopes of hydropower and highway engineering,posing a potential safety risk during both construction and operational phases.The field investigation found that progressive toppling mostly occurs on slopes with concentrated tectonic stress,intense river incision,and high steepness.Typically,these slopes are composed of hard,thinly-layered,and overthrusted rock mass with a fractured slab structure.From a macroscopic point of view,progressive toppling failure is neither a collapse nor a slide but a form of discontinuous deformation.The traditional limit equilibrium method for slope stability analysis is not suitable for evaluating such slopes.In this paper,by taking …

Prediction For Humidity Adjustment Factor And Dry-Wet Cycle Reduction Factor Of Resilient Modulus Of Subgrade Soil Based On Ann, Wang Xufeng, Fu Wei, Peng Junhui, Hu Jiankun, Zhang Junhui, Li Zhiguang

Journal of China & Foreign Highway

Existing methods for determining the humidity adjustment factor and dry-wet cycle reduction factor of the resilient modulus of subgrade soil are mostly based on laboratory tests that consume a large amount of manpower and time,and the prediction accuracy is limited due to the constraints of specification value ranges.In order to achieve fast and accurate prediction of these two factors,the effects of stress state,moisture content,and the number of dry-wet cycles on the resilient modulus of subgrade soil were investigated through laboratory dynamic triaxial tests.Based on existing literature,physical parameters,state parameters,and stress parameters of subgrade soil were selected,and an artificial neural network prediction …

Experimental Study On Engineering Performance Of Post-Planted Precast Concrete Pile With Prebored Grouting, Zhao Yu, Wang Wei, Jiang Lei, Song Zhenya, Zhang Hao

Journal of China & Foreign Highway

The traditional piling methods of precast concrete (PC) piles are difficult to pass through the hard soil layers and tend to induce severe soil squeezing effects.To address this issue,the technology of a post-planted PC pile with prebored grouting was analyzed.Based on the project of the Hefei‒ Zongyang section of G3W Dezhou ‒ Shangrao Expressway,the bearing characteristics of post-planted PC piles were researched by the load tests of five piles in two different field test sections.The results show that the bearing capacity of the PC piles can be effectively improved by setting the cement mortar coating layer around the PC piles.The …

Research On Evaluation Index Of Low-Temperature Semi-Circular Bending Test Of Asphalt Mixtures, Lyu Songtao, Chen Qi, Lu Weiwei, Zhao Pei, Wang Jinping

Journal of China & Foreign Highway

This article aims to investigate the low-temperature crack resistance performance of asphalt mixtures under different aging conditions and loading rates and select appropriate indicators to accurately characterize and quantify their performance.Based on the semi-circular bending test,the influence of different aging degrees (unaged,short-term aged,long-term aged for three days,and long-term aged for five days ) and loading rates (50 mm/min,5 mm/min,0.5 mm/min,and 0.1 mm/min ) on the low-temperature performance of asphalt mixtures was investigated.The evaluation effect and applicable range of five crack resistance performance indicators,namely fracture energy (Gf),stress intensity factor (KIC),flexibility index (IFI),crack resistance index (ICRI),and balanced cracking index (IBCI),were studied through …

Research On Pavement Crack Segmentation Based On Swin-U, Wang Hua, Wang Liangcai, Xiong Feng, Hu Jing

Journal of China & Foreign Highway

To address the issues of overfitting,low computational speed,and insufficient target information extraction in pavement crack segmentation tasks,this study proposed a Swin-U network model based on the U-Net architecture.The model adopted the Swin-Transformer as the feature extraction module to enhance the model ’s fitting capability and enable more accurate crack feature extraction,thereby enhancing segmentation accuracy.Additionally,a stable loss function,Focal Loss,was introduced to improve the accuracy of target segmentation.Experiment results on a proprietary pavement crack dataset show that the Swin-U network model achieves pixel-level segmentation of crack images and significantly outperforms the traditional U-Net.On the test set,it improves the intersection over union and …

Study On Salt Release Mechanism Of Self-Melting Ice Asphalt Mixture And Its Impact On Road Performance, Li Tao, Zhang Xiu ’Ang

Journal of China & Foreign Highway

To study the long-term salt release characteri stics of self-melting ice asphalt mixture and the impact of the complete salt release on pavement durability,an accelerated salt release method was developed using a Los Angeles abrasion tester.The salt release mechanism under varying asphalt types,deicing agent contents,and gradation types was revealed.The impact of the complete salt release on road performance was analyzed.Results show that the Los Angeles abrasion tester-based salt release method achieves 91 times and 114 times higher salt release efficiency than the magnetic stirrer and natural immersion methods,respectively.SBS-modified asphalt mixture exhibits a longer salt release duration.The salt release duration is …

Long-Term Water P Ermeability Performance Of Asphalt Mixtures Under Wide-Scope Void Ratio, Chen Sanxi, Guan Hongxin, Yao Ming, Mo Zhiwei, Jiang Wangheng

Journal of China & Foreign Highway

In order to compare the water pe rmeability performance of asphalt mixtures with different void ratios after scouring and clogging,self-developed equipment was adopted to conduct vertical water permeability tests,dynamic water scouring-based water permeability tests,water pressure tests,and simulated clogging tests on semi-open-graded DK- 13 mixtures with void ratios of 9%,11%,and 13%,as well as open-graded PA- 13 mixtures with void ratios of 15%,17%,and 19%.The experimental results show that:① The water permeability performance of the asphalt mixture becomes better as the void ratio increases.The water permeability coefficient changes relatively small after the void ratio of the asphalt mixture reaches 15%,which is attributed to …

Research On Size Effect On Cubic Compressive Strength Of Ground Granulated Blast Furnace Slag-Fly Ash Stabilized Large-Size Macadam, Liu Qunyan, Liu Liping, He Miao, Yuan Lingqing, Zhang Liang

Journal of China & Foreign Highway

To analyze the effect of specimen size on the compressive strength of ground granulated blast furnace slag-fly ash (GGBFS-FA ) stabilized large-size macadam,the 200 mm × 200 mm × 200 mm cubic specimen and 3 d compressive strength were designated as a reference specimen and strength in this study,and numerical simulations of compressive strength were performed by using a discrete element method for GGBFS-FA stabilized large-size macadam specimens with a maximum particle size (dmax) of 73 mm and five side lengths of 2.0dmax,2.5dmax,3.0dmax,3.5dmax,and 4.0dmax.The size effect mechanism on the mixture ’s compressive strength was revealed from the perspective of energy.By …