Physical Sciences and Mathematics Commons^™

Effects Of Missing Data Imputation Methods On Univariate Blood Pressure Time Series Data Analysis And Forecasting With Arima And Lstm, Nicholas Niako, Jesus D. Melgarejo, Gladys E. Maestre, Kristina Vatcheva

School of Mathematical & Statistical Sciences Faculty Publications

Background

Missing observations within the univariate time series are common in real-life and cause analytical problems in the flow of the analysis. Imputation of missing values is an inevitable step in every incomplete univariate time series. Most of the existing studies focus on comparing the distributions of imputed data. There is a gap of knowledge on how different imputation methods for univariate time series affect the forecasting performance of time series models. We evaluated the prediction performance of autoregressive integrated moving average (ARIMA) and long short-term memory (LSTM) network models on imputed time series data using ten different imputation techniques. …

Microbial Diversity And Biogeochemical Interactions In The Seismically Active And Co2-Rich Eger Rift Ecosystem, Daniel Lipus, Zeyu Jia, Megan Sondermann, Robert Bussert, Alexander Bartholomäus, Sizhong Yang, Dirk Wagner, Jens Kallmeyer

College of Life Sciences Faculty Papers

The Eger Rift subsurface is characterized by frequent seismic activity and consistently high CO2 concentrations, making it a unique deep biosphere ecosystem and a suitable site to study the interactions between volcanism, tectonics, and microbiological activity. Pulses of geogenic H2 during earthquakes may provide substrates for methanogenic and chemolithoautotrophic processes, but very little is currently known about the role of subsurface microorganisms and their cellular processes in this type of environment. To assess the impact of geologic activity on microbial life, we analyzed the geological, geochemical, and microbiological composition of rock and sediment samples from a 238 m deep drill …

Commingling Production Of Deep Coal-Measure Gas Through Hydraulic Fracturing: Propagation Patterns Of Induced Fractures And Their Determinants, Chen Hao, Li Guozhang, Qin Yong, Wang Jianguo, Shen Jian, Sun Yuqi, Yuan Erjun, Li Dian

Coal Geology & Exploration

Objective The commingling production of coal-measure gas represents a pivotal approach to enhancing the single-well production of unconventional gas in China. However, coal-measure gas reservoirs exhibit distinctly different material compositions and physical properties, leading to uncertainty of the propagation modes and developmental degrees of fractures in different reservoirs during the hydraulic fracturing of coal-measure gas reservoirs subjected to commingling production. Therefore, effectively coordinating the stimulation of multiple reservoirs for multi-gas commingling production is crucial for minimizing production costs and maximizing production capacity. Methods This study investigated the Linxing block along the northeastern margin of the Ordos Basin as an example …

Microscopic Fracture Characterization And Permeability Evolutionary Patterns Of Granites Under Cyclic Thermal Shock, He Jiangfu, Ren Chengcheng, He Kun, Yu Qihang, Li Xinru, Deng Xu

Coal Geology & Exploration

Objective This study aims to reveal the microscopic damage characteristics and permeability evolutionary patterns of high-temperature granite reservoirs fractured under cyclic thermal shock produced by low-temperature fluids like drilling fluids and circulating heat recovery media in the exploitation process of the enhanced geothermal systems (EGSs). Methods Using experiments on the fracturing characteristics of high-temperature granites under the conditions of varying cooling methods, numbers of thermal shock cycles, and cooling temperatures, this study determined microstructural characteristic parameters such as compressional wave (P-wave) velocity, pore volumetric fraction, and fractal dimension of granites across a temperature range of 25 to 700 ℃ under …

Identifying The Lithologies And Thicknesses Of Coal Seam Roofs And Floors Based On Multiparameter Logging Of Boreholes, Li Zhe, Gao Baobin, Lei Wenjie, Li Donghui, Li Zixin

Coal Geology & Exploration

Background In the process of coal mining, effective exploration methods for stratigraphic characteristics are crucial to underground operations. The reason is that the accurate stratigraphic characteristics of coal seams, along with the surrounding rocks of coal seam roofs and floors, facilitate the treatment of gas in coal seams, thereby ensuring safe and efficient coal mining. Methods Based on the multiparameter logging of boreholes crossing strata in a bottom drainage roadway, this study highlighted the lowstand, upgoing borehole trajectories, as well as the variations in parameters including natural gamma rays, spontaneous potential, and resistivity. By comprehensive comparison of the trajectories, video-derived …

Table Of Contents, The Editors

Coal Geology & Exploration

No abstract provided.

Influence Mechanisms Of Dynamic Metamorphism On The Evolution Of Micro/Nano Pore Structures In Tectonically Deformed Coals, Liu Hewu, Lyu Xiaoxue, Hou Chenliang, Xiong Zuopeng

Coal Geology & Exploration

Objective Micro/nano pore structures in coals act as a significant space for gas occurrence. Exploring the evolutionary mechanisms of micro/nano pore structures in tectonically deformed coals (TDCs) under the influence of dynamic metamorphism assists in gaining a deep understanding of the mechanisms underlying coal and gas outbursts. Methods Using CO₂ adsorption experiments, Fourier transform infrared (FTIR) spectroscopy, and molecular dynamics simulations, this study investigated the evolutionary characteristics and mechanisms of micro/nano pore structures in different TDCs occurring within the No.72 coal seam of the Qi’nan Coal Mine in Suzhou Province. Results and Conclusions The results indicate that with enhanced …

Failure Depths Of Stope Floors Under Dynamic Loading Induced By Roof Breaking, Huang Qisong, Xu Bo, Feng Junjun, Lin Xiaofei, Cheng Jiulong, Peng Jun

Coal Geology & Exploration

Objective Accurately assessing the failure depths of stope floors is crucial for assessing floor water inrush risks. Conventional theoretical models for calculating the failure depths generally merely consider static loads from the support pressure and confined water's pressure in stopes, leading to large deviations between calculation results and actual situations. Therefore, constructing a more practical computational model that comprehensively considers the coupled effects of multiple force sources on the failure of deep floors can provide a scientific basis for the effective prevention and control of water hazards in deep coal seam floors. Methods Based on the dynamic elasticity theory and …

Construction And Correction Of A 3d Digital Twin For A Complex Gangue-Bearing Coal Seam, Zhang Meichen, Zhao Lijuan, Wang Yadong, Zhang Kai

Coal Geology & Exploration

Objective 3D digital twin for complex gangue-bearing coal seams are designed to achieve an information-based description of physical coal seams and faithfully map their virtual forms. digital twin is identified as a prerequisite for exploring the efficient cutting of intelligent shearers while providing an effective data guarantee for achieving unmanned mining. Methods Using data on samples from the mining face of coal seam 17 in the Yankuang Energy Group Co., Ltd. Shandong Province, this study proposed a methodology that integrates more information about the geological structural conditions of coal seams. Specifically, digital twining of iron sulfide nodules was performed using …

A Calculational Model For 3d Fault Complexity Based On Curvature Analysis And Fractal Dimensions, Yan Junsheng, Liu Zaibin, Fan Tao, Yang Hui, Liu Wenming, Du Wengang, An Lin, Liu Chenguang, Wang Xiaohui

Coal Geology & Exploration

Objective and Methods Faults are identified as one of the most threatening geological structural factors among hidden disaster-causing factors in coal mines. However, the 3D quantitative assessment of them remains challenging. Considering that existing quantitative indicators fail to fully reflect fault morphologies and there is a lack of 3D methods, this study proposed a calculational model for 3D fault complexity based on curvature analysis and fractal dimensions. This model improved the morphologies of traditional measurement volumes of fractal dimensions by employing the Delaunay tetrahedralization algorithm, thus effectively reducing the invalid values in calculating the 3D fractal dimensions of faults. Moreover, …

Exploration Of The Impacts Of Cement Sheath On Casing Stress Based On The Arching Effects Of Formations, An Fengchen, Miao Zhibo, Meng Siwei, Wei Ziying, Zhang Xiao, Zeng Jiaming, Wang Xiaohua

Coal Geology & Exploration

Objective With the growth in the demand for natural oil and gas and the technological progress of their production, the oil and gas well depths have been constantly setting new records. The increase in the depth corresponds to sharply increasing in-situ stress, leading to increasingly severe damage to the casing of ultradeep oil and gas wells. To enhance the bearing capacity of the casing under high in-situ stress, high-strength casing with a large wall thickness is typically employed, a measure which has been proved, however, less effective. Methods This study established a finite element model of the casing-cement sheath-formation system …

Hydrochemical Characteristics And Component Sources Of Water In Underground Reservoirs In The Daliuta Coal Mine, Zhang Haitao, Jiang Binbin, Zhang Haiqin, Li Peng, Wu Min, Hao Jingwei, Hu Yutian

Coal Geology & Exploration

Objective Underground reservoirs in coal mines are capable of storing and purifying mine water. A deep understanding of the hydrochemical characteristics and formation mechanisms of water in underground reservoirs is identified as an important prerequisite for large-scale development of technologies for mine water treatment. Methods This study investigated the underground reservoirs in the Daliuta Coal Mine within the Shendong area by testing and analyzing their influent and effluent water samples. Using methods such as the ion ratio method, multivariate statistical analyses (e.g., correlation analysis and principal component analysis (PCA)), and the positive matrix factorization (PMF) model, this study delved into …

Artificial Intelligence In Fetal And Pediatric Echocardiography, Alan Wang, Tam T Doan, Charitha Reddy, Pei-Ni Jone

Faculty, Staff and Students Publications

Echocardiography is the main modality in diagnosing acquired and congenital heart disease (CHD) in fetal and pediatric patients. However, operator variability, complex image interpretation, and lack of experienced sonographers and cardiologists in certain regions are the main limitations existing in fetal and pediatric echocardiography. Advances in artificial intelligence (AI), including machine learning (ML) and deep learning (DL), offer significant potential to overcome these challenges by automating image acquisition, image segmentation, CHD detection, and measurements. Despite these promising advancements, challenges such as small number of datasets, algorithm transparency, physician comfort with AI, and accessibility must be addressed to fully integrate AI …

Mechanisms And Influential Factors Of Rock Bursts In Tunneling Roadways Of Extra-Thick Coal Seams, Peng Yujie, Wang Qiang, Cao Anye, Xue Chengchun, Lyu Guowei, Hao Qi, Liu Yaoqi, Bai Xianxi, Li Dong

Coal Geology & Exploration

Objective Rock bursts occur frequently in tunneling roadways of extra-thick coal seams, significantly constraining safe coal mining. Investigating their mechanisms and influential factors is crucial to preventing and controlling such disasters in tunneling roadways of extra-thick coal seams. Methods Focusing on the tunneling roadway of mining face 250107-1 for an extra-thick coal seam within a coal mine in Gansu Province, this study established the discriminant indices for rock burst-induced roadway instability. By simulating the energy distribution patterns of surrounding rocks in the tunneling roadway using the FLAC^3D software, this study revealed the zonal energy characteristics of the surrounding rocks …

Coal Gasification Through Microbial Degradation In A Low-Pressure Co2 And H2 Environment: An Experimental Study, Jian Kuo, Fu Xuehai, Liu Mingjie, Liu Jian, Li Jin, Ru Zhongliang, Ji Xiaofeng, Wang Qiang

Coal Geology & Exploration

Objective and Methods This study aims to investigate the characteristics of CO₂ biomethanation and coal gasification through microbial degradation in a low-pressure environment. With low-rank bituminous coals (R_max = 0.67%) as fermentable substrates, this study conducted a 96-day gas production experiment through microbial fermentation in a low-pressure CO₂ and H₂ environment. Using techniques including gas chromatography, 16S rRNA gene sequencing, and low-temperature liquid nitrogen adsorption, this study delved into the intrinsic variation patterns of biogenic gas production, microbial communities, and coal structures. Results and Conclusions The results indicate that compared to conventional fermentation, the injection …

Application Of D-Insar In Monitoring The Impacts Of Shaft Grouting On Surface And Building Deformations, Liu Hui, Lu Rumeng, Su Lijuan, Cheng Shiguang, Zhang Pengfei, Cheng Hua

Coal Geology & Exploration

Objective In coal mining engineering, damaged well walls pose a threat to the safety of production facilities and mines. Comprehensively monitoring the impacts of shaft grouting on the deformations of mine surface plants and surface buildings is critical for ensuring the safe production of mines. Methods This study investigated a coal mine in the mining area within northern Anhui Province. Using the 15 scenes of Sentinel-1A image data covering the coal mine and the differential interferometric synthetic aperture radar (D-InSAR) technology, this study comprehensively monitored the subsidence of mine surface plants and surface buildings before and after shaft grouting, obtaining …

Fracture Structure Of The Overburden In The Layered Mining Of Extremely Thick Coal Seams: Developmental Patterns Of Caving Zones And Hydraulically Conductive Fracture Zones And Fracture Characteristics, Zhang Xin, Chen Youkuo, Meng Hailun, Qin Qifa, Cheng Xianggang, Huang Rongjie, Dong Hairui, Sun Wenbin, Qiao Wei

Coal Geology & Exploration

Objective The Zhunnan Coalfield, a coalfield on the southern margin of the Junggar Basin in Xinjiang, boasts abundant coal resources. However, water hazards in mines severely constrain the safe and efficient coal production in the coalfield. Since hydraulically conductive fractures in roofs serve as primary hydraulically conductive channels formed in the mining of the mining face, it is particularly crucial to investigate the developmental patterns of these fractures during the layered mining of extremely thick coal seams. Methods This study explored the (9-15)08 mining face of the Liuhuanggou Coal Mine in Xinjiang. Using ground exploration holes and borehole televiewers, this …

An Integrated Ecosystem Monitoring Technology For Coal Mining Subsidence Areas And Its Application In The Shendong Mining Area, Cheng Yang, Liu Wei, Zhang Na, Li Guanjie, Liu Kai, Zhang Chengye, Li Jun

Coal Geology & Exploration

Background The ecosystem monitoring of arid and semi-arid coal mining subsidence areas acts as a significant prerequisite for regional ecosystem conservation and management, holding critical significance for accelerating green mine construction. Methods Based on the Chinese government's regulatory requirements for mine ecosystems, this study analyzed the difficulties in ecosystem monitoring in the coal mining subsidence area of the Shendong mining area (also referred to as the Shendong coal mining subsidence area). By detailing the integrated coal-rock-water-soil-air-vegetation-carbon monitoring technology system, this study determined the factors, principal methods, and technology roadmap for the integrated ecosystem monitoring in the Shendong coal mining subsidence …

Predicted Water Yield Of Open-Pit Metal Mines Based On A Bi-Rnn And Gms Coupling Model, Zhao Yuxing, Li Xiangwen

Coal Geology & Exploration

Objective Accurately predicting water yield of mine before mining can provide directive guidance for preventing potential water hazards and ensuring safe production. Methods To enhance the prediction accuracy and stability of water yield of open-pit metal mines, for which atmospheric precipitation acts as the primary recharge source of water, this study developed a prediction model that coupled a bidirectional recurrent neural network (Bi-RNN) and the Groundwater Modeling System (GMS) software. Specifically, based on historical forecasted precipitation data provided by the Global Forecast System (GFS), the fluctuation pattern of differences between predicted forecasted and actual precipitation was analyzed. After being corrected …

An Experimental Study Of The Application Of The Spectral Acoustic Method To The Advance Detection Of Geologic Structures In Tunnelling Working Site, Zhang Jianguo, Feng Zhicheng, Wei Fengqing, Ma Ji, Zhao Kai, Wang Man, Guo Minggong, Шилов Владимир Иванович

Coal Geology & Exploration

Objective The practice of coal mine production has proved that the vast majority of coal and gas outbursts are controlled by geological structures, and mainly occur in tunnelling working site. Therefore, continuous advanced detection of geological structures is an important technical means to prevent and control coal and gas outbursts in tunnelling working site, and is of great significance to ensure safe production in mines. Methods Based on the research results of spectral acoustic method in Russia for many years, the resonance phenomenon generated at the weakened contact surface of the roof rock layer by the artificial acoustic signal excited …

Application Of Microseismic Monitoring In The Optimization Of Control Strategy For Roofs Composed Of Composite Hard Sandstone Masses, Zhang Yin, Li Jiajun, Zhao Qian, Yang Chenchen, Liu Jiaqi, Zhou Yu

Coal Geology & Exploration

Objective With a gradual increase in the coal mining depth in China, the movement of overlying thick and hard rock layers exerts increasingly complex impacts on the mine pressure. Methods In the Ordos area, the overburden of the mining face of most mines hosts composite hard sandstone masses, serving as key layers characterized by considerable thicknesses, high hardness, and close proximity. Results and Conclusions As a result, the risks of mine earthquakes and dynamic manifestation co-exist in the mining face. With the roof of mining face11-3106 in a coal mine within the Ordos mining area as the engineering background, this …

Spatiotemporal Response Characteristics Of Transient Electromagnetic Field In Water-Bearing Goaves And Their Applications, Song Guilei, Gong Xufei, Yang Fuqiang, Cui Jianting, Li Zhanling, Liu Lina

Coal Geology & Exploration

Objective and Methods This study aims to enhance the accuracy of the mine transient electromagnetic method (MTEM) in of imaging of water-bearing goaves. Based on the geological conditions of the Gaojialiang Coal Mine, this study simulated the spatiotemporal response characteristics of the induced magnetic field in the water-bearing goaf model under varying stratigraphic spacings using finite element software COMSOL. Accordingly, this study analyzed the distribution patterns of the induced magnetic field on the apparent resistivity pseudosections and the plots of the differentials of longitudinal apparent conductivity. Using the results, the water-bearing conditions of goaves in the Ordos Gaojialiang Coal Mine …

Biomimetic Technologies For Drill Rods: Advances In Research And Development Trends, Wang Chuanliu, Ju Pei

Coal Geology & Exploration

Significance Drill rods are recognized as core tools in drilling engineering, and their performance exerts a significant influence on drilling efficiency and safety. Over recent years, applying biomimetic technologies to drill rod design has gradually emerged as a hot research topic. By imitating the remarkable structures, morphologies, and material properties of living organisms in nature, biomimetic technologies provide entirely new philosophies and approaches for the innovative design of drill rods. Advances This study summarizes the advances in research on biomimetic technologies for drill rods in terms of the biomimetic design of structures, morphologies, and materials. Regarding the biomimetic design of …

A Dc-Unet-Based Image Processing Method For Detecting Fractures Along Roadway Sections Of Coal Mines, Dong Zheng, Zhang Xuhui, Yang Wenjuan, Kang Le, Tang Duwei, Tian Chenhui

Coal Geology & Exploration

Objective Detecting fractures along roadway sections of coal mines allows for the characterization of the geologic conditions of roadways, thus providing guidance for roadway tunneling and support engineering. However, conventional image processing methods for fractures along roadway sections are susceptible to complex environments in underground coal mines, exhibiting a low fracture detection efficiency. Methods This study proposed a novel image processing method for detecting fractures along roadway sections based on a DC-UNet model. This method can be deployed on a mobile terminal and an embedded device, thereby allowing for real-time and effective detection of fractures along roadway sections and enhancing …

Development Of A Power Recovery-Based Dynamic Loading System For Full-Size Drill Rods In Coal Mines, Zhang Jing, Wang Jie

Coal Geology & Exploration

Objective This study aims to simulate the actual forces applied to drill rods during the borehole drilling for gas drainage from underground coal mines to satisfy the requirements of drill rods’ fatigue tests. Methods This study designed a dynamic loading system for full-size drill rods in coal mines. This system consists of a drill rod loading platform, a hydraulic pump unit with power recovery, and a measurement and control system, allowing for the composite loading of dynamic torque, axial force, and radial displacement on drill rods of different specifications. In this system, torque is loaded to drill rods using the …

Changes In Climate And Their Implications For Cattle Nutrition And Management, Bashiri Iddy Muzzo, R. Douglas Ramsey, Juan J. Villalba

Wildland Resources Faculty Publications

Climate change is a global challenge that impacts rangeland and pastureland landscapes by inducing shifts in temperature variability, precipitation patterns, and extreme weather events. These changes alter soil and plant conditions, reducing forage availability and chemical composition and leading to nutritional stress in cattle. This stress occurs when animals lack adequate water and feed sources or when these resources are insufficient in quantity, composition, or nutrient balance. Several strategies are essential to address these impacts. Genetic selection, epigenetic biomarkers, and exploration of epigenetic memories present promising avenues for enhancing the resilience of cattle populations and improving adaptation to environmental stresses. …

Digital Twin And Cybersecurity In Additive Manufacturing, Lidong Wang

Journal of Cybersecurity Education, Research and Practice

Additive manufacturing (AM) has been applied to automotive, aerospace, medical sectors, etc., but there are still challenges such as parts’ porosity, cracks, surface roughness, intrinsic anisotropy, and residual stress because of the high level of thermal gradient. It is significant to conduct the modeling and simulation of the AM process and achieve quality products. Digital Twin (DT) can help AM with forecasting defects/errors through simulation and real-time process monitoring. DT is a concept of Industry 4.0, and its digital structure reflects the real-time behaviors of a cyber-physical or physical system. This paper introduces the progress of DT applications in AM, …

Apex Graphs And Cographs, Jagdeep Singh, Vaidy Sivaraman, Thomas Zaslavsky

Theory & Applications of Graphs

A class G of graphs is called hereditary if it is closed under taking induced subgraphs. We denote by G^{apex} the class of graphs G that contain a vertex v such that G − v is in G. Borowiecki, Drgas-Burchardt, and Sidorowicz proved that if a hereditary class G has finitely many forbidden induced subgraphs, then so does G^{apex}. We provide an elementary proof of this result.

The hereditary class of cographs consists of all graphs G that can be generated from K_1 using complementation and disjoint union. A graph is an apex cograph if it contains a …

An Ontology-Based Approach For Understanding Appendicectomy Processes And Associated Resources, Nadeesha Pathiraja Rathnayaka Hitige, Ting Song, Steven J Craig, Kimberley J Davis, Xubing Hao, Licong Cui, Ping Yu

Faculty, Staff and Student Publications

Background: Traditional methods for analysing surgical processes often fall short in capturing the intricate interconnectedness between clinical procedures, their execution sequences, and associated resources such as hospital infrastructure, staff, and protocols.

Aim: This study addresses this gap by developing an ontology for appendicectomy, a computational model that comprehensively represents appendicectomy processes and their resource dependencies to support informed decision making and optimise appendicectomy healthcare delivery.

Methods: The ontology was developed using the NeON methodology, drawing knowledge from existing ontologies, scholarly literature, and de-identified patient data from local hospitals.

Results: The resulting ontology comprises 108 classes, including 11 top-level classes and …

Re: Silver Bow Creek Butte Area Npl Site Spring Semi-Annual 2024 Butte Priority Soils Operable Unit Interim Site-Wide Groundwater Monitoring Data Report. Consent Decree- Civil Action No. Cv 89-039-Bu-She, Josh Bryson

Silver Bow Creek/Butte Area Superfund Site

No abstract provided.