Statistics and Probability Commons^™

Study On Parameter Optimization Of Feet‐Lock Anchor Pipes Of Tunnels In Unconsolidated Formation, Tang Heqing, Jiang Xishan, Yang Peng

Journal of China & Foreign Highway

In order to give full play to the supporting role of the feet-lock anchor pipe in the tunnel with unconsolidated formation, it is necessary to obtain the optimal construction parameters of the feet-lock anchor pipe. Based on a tunnel project on the Huaping–Lijiang Expressway in Yunnan Province, this paper conducted numerical simulation and field test analysis. By comparing the arch subsidence and horizontal convergence of the supporting structure when the feet-lock anchor pipe with different parameters was constructed, the paper explored the characteristics and causes of the influence of construction parameters on the feet-lock effect. The results show that the …

Simulation Study On Flame Retardant Effect Of Warm‐Mixed Flame Retardant Pavement In Highway Tunnel

Journal of China & Foreign Highway

In order to obtain the flame retardant effect of the warm-mixed flame retardant asphalt pavement in highway tunnels, based on the finite element method and thermodynamics theory, the thermal analysis module of Ansys finite element software was used to study the flame retardant effect of ordinary asphalt pavement, flame retardant asphalt pavement, and warm-mixed flame retardant asphalt pavement under different fire scales. The maximum temperature of the three types of pavement increased with the increase in the fire scale. Under any fire scale, the flame retardant effect of the warm-mixed flame retardant asphalt pavement was increased by 4.9%–8.5% compared with …

Installation Construction Technology Of Composite Girder Cable‐Stayed Bridge Superstructure In Deep‐Cutting Gorge, Ren Lei, Lu Liang, Dong Zhengliang

Journal of China & Foreign Highway

In view of the installation problems of superimposed beam cable-stayed bridge across the deep canyon, this paper studied the superimposed beam lifting, transport on beam, and superimposed beam installation and proposed three kinds of lifting technology with tower truss crane, beam lifting door crane, and large tower crane, as well as two kinds of installation technology including piecemeal assembly by full rotating deck crane and whole segment assembly truss deck crane. It also made a relative comparative analysis, solving the difficulty in vertical lifting on such bridges and providing a reference for the construction of the same type of cable-stayed …

Experiment Research Of High Pressure Jet Grouting Pile On Ultra‐Shallow Buried Tunnel In Strong Weathered Stratum, Lu Liyang, Liu Huan, Li Pinpin

Journal of China & Foreign Highway

By taking the ultra-shallow buried construction of Xinwu Tunnel in Luoding–Xinyi Expressway in Guangdong Province as the engineering background, the key construction parameters and formation reinforcement effect of high-pressure rotary churning pile in ultra-shallow buried tunnel surrounding rock of fully weathered strata were compared. The results show that: ① slurry pressure, rotary churning speed, and lifting speed have obvious effects on the static load bearing capacity of a single pile. Under the same static load condition, greater slurry pressure indicates a lower cumulative settlement value of a single pile and a smaller increase in cumulative settlement value, and the change …

Study On Anti‐Scattering Performance Of Asphalt Concrete On Aggregate Scattering Pavement Of Highway, Yang Siyuan, Chen Guiliang

Journal of China & Foreign Highway

Due to the lack of quantitative evaluation methods for aggregate scattering degree of expressway asphalt pavement in China and abroad, according to the disease characteristics of surface layer spalling, this paper adopted the Cantabro standard dispersion test to sample the concrete of the section with aggregate scattering of Huangqunan Expressway (G3) in Zhejiang Province. The dispersion impact damage modes of the mixture with different severity were analyzed, and the anti-dispersion performance of concrete was evaluated by mass loss rate and water absorption rate. The results show that aggregate scattering will reduce the density of the concrete structure at the surface …

Variable Speed Limit Control Method For Highway Under Dense Fog, Sun Jiancheng, Qiao Jiaxing

Journal of China & Foreign Highway

In order to solve the problem of traffic safety on expressways under dense fog and change the original fixed speed limit measures, a variable speed limit control method based on the safe allowable speed was proposed. The speed limit value was calculated based on the regulations in road traffic safety law on the speed under dense fog by considering that the traffic law does not mention the road alignment conditions, road conditions, and other factors, and the monitor data was used to approximate replace the data of individual vehicles for data optimization, and the safe speed and safe distance of …

Application Of Digital Image Processing In Cracks Of Concrete Pavement, Gao Fan, He Chunguang, Wang Pengzhang, Qin Yanping, Duo Huaqiong

Journal of China & Foreign Highway

The image obtained by using the traditional crack detection method of concrete pavement has some problems, such as low contrast and high noise, which makes it difficult to meet the requirements of modern road engineering management or non-destructive testing. In order to eliminate the interference in crack images, digital image processing technology was used to improve the image quality through computers. This paper took digital image processing as the core and introduced its development and application in pavement cracks. Based on the research progress and achievements of digital image processing on pavement cracks in recent years, the principles and characteristics …

Design And Experimental Study On Special Spherical Support Of Pingtang Bridge, Tang Zhi, Ma Baihu, Du Bin, Xu Xiangdong, Xia Junyong

Journal of China & Foreign Highway

The vertical bearing capacity of the 16# pier of Pingtang Bridge is 10 000 kN, and the horizontal bearing capacity along the bridge is 12 000 kN, which is 120% of the vertical bearing capacity. The support angle needs to reach the technical parameter requirements of 0.05 rad, which far exceeds the requirements of 10–40% horizontal force of conventional highway supports. According to the specific engineering situation, a new type of support with a large horizontal bearing capacity was designed. Firstly, the finite element model of the support was established to analyze the mechanical properties of the support, and the …

Study On Practical Method Of Safety Assessment For Bridges Under Heavy‐Cargo Transportation, Jiang Xu, Wang Wanfeng, He Zhensheng, Gao Xuefeng

Journal of China & Foreign Highway

In order to meet the requirements of the industry for the high efficiency, safety, and reliability of the traffic safety assessment of heavy-duty vehicles, this paper proposed a method that combined a real-time monitoring system with a finite element method for the traffic safety assessment of heavy-duty vehicles on bridges and verified the method through practical projects. The paper evaluated the bridge’s technical condition level before the heavy-duty vehicle passes and determined the resistance reduction factor considering the bridge’s technical condition level. The finite element analysis model of the bridge was established, and the reliability of the model was verified …

Study On Pavement Performance Of Waterborne Epoxy Emulsified Asphalt And Its Application In Micro‐Surface, Jiang Hai, Liu Dachang

Journal of China & Foreign Highway

In order to improve the pavement performance at micro-surface, waterborne epoxy resin was used to modify the emulsified asphalt, and the compatibility, microstructure, mechanical properties, rheological properties, and pavement performance of mixtures of the modified emulsified asphalt were studied. The storage stability test shows that the epoxy emulsion has good compatibility with emulsified asphalt. With the increase in waterborne epoxy resin content, the modified emulsified asphalt tends to form an epoxy resin-dominated skeleton structure. At the same time, with the increase in waterborne epoxy resin content, the adhesion and mechanical properties of emulsified asphalt and aggregate are significantly improved. At …

Strong Recovery In Group Synchronization, Bradley Stich

Rose-Hulman Undergraduate Mathematics Journal

The group synchronization problem is to estimate unknown group elements at the vertices of a graph when given a set of possibly noisy observations of group differences at the edges. We consider the group synchronization problem on finite graphs with size tending to infinity, and we focus on the question of whether the true edge differences can be exactly recovered from the observations (i.e., strong recovery). We prove two main results, one positive and one negative. In the positive direction, we prove that for a sequence of synchronization problems containing the complete digraph along with a relatively well behaved prior …

Error Analysis Of A Fully Discrete Projection Method For Magnetohydrodynamic System, Qianqian Ding, Xiaoming He, Xiaonian Long, Shipeng Mao

Mathematics and Statistics Faculty Research & Creative Works

In this paper, we develop and analyze a finite element projection method for magnetohydrodynamics equations in Lipschitz domain. A fully discrete scheme based on Euler semi-implicit method is proposed, in which continuous elements are used to approximate the Navier–Stokes equations and H(curl) conforming Nédélec edge elements are used to approximate the magnetic equation. One key point of the projection method is to be compatible with two different spaces for calculating velocity, which leads one to obtain the pressure by solving a Poisson equation. The results show that the proposed projection scheme meets a discrete energy stability. In addition, with the …

Error Analysis Of A Fully Discrete Projection Method For Magnetohydrodynamic System, Qianqian Ding, Xiaoming He, Xiaonian Long, Shipeng Mao

Mathematics and Statistics Faculty Research & Creative Works

In this paper, we develop and analyze a finite element projection method for magnetohydrodynamics equations in Lipschitz domain. A fully discrete scheme based on Euler semi-implicit method is proposed, in which continuous elements are used to approximate the Navier–Stokes equations and H(curl) conforming Nédélec edge elements are used to approximate the magnetic equation. One key point of the projection method is to be compatible with two different spaces for calculating velocity, which leads one to obtain the pressure by solving a Poisson equation. The results show that the proposed projection scheme meets a discrete energy stability. In addition, with the …

Socioeconomic Factors In The Diagnosis And Treatment Of Malignant Melanoma In Hispanic Vs. Non-Hispanic Patients: A National Cancer Database (Ncdb) Study, Julia Griffin, Sarah J. Aurit, Timothy Malouff, Peter Silberstein

Department of Statistics: Faculty Publications

Background: The incidence of melanoma is rapidly increasing in the United States. There is a paucity of research of how melanoma affects the Hispanic population, the quickest growing population.

Objective: To identify and understand how socioeconomic factors affect a Hispanic patients health outcome and treatment of malignant melanoma with comparisons to white, non-Hispanic (WNH) patients.

Methods: A retrospective study utilizing the National Cancer Database (NCDB) was completed investigating Hispanic patients (n=2282) and WNH patients (n=190,469) with Stage I-IV malignant melanoma. Outcome and socioeconomic variables were identified and compared across groups. Data was analyzed with SPSS and SAS …

Estimating The Prevalence Of Two Or More Diseases Using Outcomes From Multiplex Group Testing, Md S. Warasi, Joshua M. Tebbs, Christopher S. Mcmahan, Christopher R. Bilder

Department of Statistics: Faculty Publications

When screening a population for infectious diseases, pooling individual specimens (e.g., blood, swabs, urine, etc.) can provide enormous cost savings when compared to testing specimens individually. In the biostatistics literature, testing pools of specimens is commonly known as group testing or pooled testing. Although estimating a population-level prevalence with group testing data has received a large amount of attention, most of this work has focused on applications involving a single disease, such as human immunodeficiency virus. Modern methods of screening now involve testing pools and individuals for multiple diseases simultaneously through the use of multiplex assays. Hou et al. (2017, …

Penguins Go Parallel: A Grammar Of Graphics Framework For Generalized Parallel Coordinate Plots, Susan Vanderplas, Yawei Ge, Antony Unwin, Heike Hofmann

Department of Statistics: Faculty Publications

Parallel Coordinate Plots (PCP) are a valuable tool for exploratory data analysis of high-dimensional numerical data. The use of PCPs is limited when working with categorical variables or a mix of categorical and continuous variables. In this article, we propose Generalized Parallel Coordinate Plots (GPCP) to extend the ability of PCPs from just numeric variables to dealing seamlessly with a mix of categorical and numeric variables in a single plot. In this process we find that existing solutions for categorical values only, such as hammock plots or parsets become edge cases in the new framework. By focusing on individual observations …

Patient And Physician Factors Associated With First Diagnosis Of Non-Affective Psychotic Disorder In Primary Care, Joshua C. Wiener, Rebecca Rodrigues, Jennifer N S Reid, Suzanne Archie, Richard G Booth, Chiachen Cheng, Saadia Hameed Jan, Paul Kurdyak, Arlene G Macdougall, Lena Palaniyappan, Bridget L Ryan, Kelly K. Anderson

Epidemiology and Biostatistics Publications

Primary care physicians play a central role in pathways to care for first-episode psychosis, and their increased involvement in early detection could improve service-related outcomes. The aim of this study was to estimate the proportion of psychosis first diagnosed in primary care, and identify associated patient and physician factors. We used linked health administrative data to construct a retrospective cohort of people aged 14-35 years with a first diagnosis of non-affective psychosis in Ontario, Canada between 2005-2015. We restricted the sample to patients with help-seeking contacts for mental health reasons in primary care in the six months prior to first …

Evaluating The Feasibility And Potential Impacts Of A Recovery-Oriented Psychosocial Rehabilitation Toolkit In A Health Care Setting In Kenya: A Mixed-Methods Study, Regina Casey, Joshua C. Wiener, Terry Krupa, Rosemary Lysaght, Marlene Janzen Le Ber, Ruth Ruhara, Elizabeth Price, Romaisa Pervez, Sean Kidd, Victoria Mutiso, David M Ndetei, Arlene G Macdougall

Epidemiology and Biostatistics Publications

OBJECTIVES: This pilot study evaluated the feasibility and potential impacts of delivering the Psychosocial Rehabilitation (PSR) Toolkit for people with serious mental illness within a health care setting in Kenya.

METHOD: This study used a convergent mixed-methods design. Participants were people with serious mental illness (n = 23), each with an accompanying family member, who were outpatients of a hospital or satellite clinic in semirural Kenya. The intervention consisted of 14 weekly group sessions of PSR cofacilitated by health care professionals and peers with mental illness. Quantitative data were collected from patients and family members using validated outcome measures before …

Examining Fuel Service System Failures Of The Usaf R11 Using Survival Analysis, Roed M.S. Mejia

Theses and Dissertations

Recent events show that fuel supply is a large contributor to the success or failure of a military operation in response to a contingency. Any future near-peer conflict will stress the supply chain and require fully operational vehicles to be ready for the primary mission sets they support. In the United States Air Force (USAF), the readiness of fuel distribution trucks is crucial to meeting those mission sets in global operations. Utilizing non-parametric and semi-parametric survival models, which do not assume specific probability distributions, this study analyzes maintenance data for R-11 trucks that refuel aircraft.

Examining Failures Of Kc-135 Boom Assemblies Using Survival Analysis, Benjamin D. Miller

Theses and Dissertations

The purposes of this study are to confirm the applicability of survival analysis for predicting recurrent failures of a component of a military aircraft and to provide practical insights to maintenance managers and mission planners. The results of this study also can help the United States Department of Defense improve the CBM+ program. This study was able to predict recurrent failures of the component using Nelson-Aalen cumulative estimates. In addition, this study used a Cox proportional hazards regression model with shared frailty for measuring the effect of covariates on recurrent failures and unidentified heterogeneity in the model, which warranted future …