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Articles 43261 - 43290 of 294613

Full-Text Articles in Physical Sciences and Mathematics

Mother Earth, Lance Daley Apr 2023

Mother Earth, Lance Daley

D.U.Quark

No abstract provided.

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Quantification Of Various Types Of Biases In Large Language Models, Sudhashree Sayenju Apr 2023

Quantification Of Various Types Of Biases In Large Language Models, Sudhashree Sayenju

Doctor of Data Science and Analytics Dissertations

Natural Language Processing (NLP) systems are included everywhere on the internet from search engines, language translations to more advanced systems like voice assistant and customer service. Since humans are always on the receiving end of NLP technologies, it is very important to analyze whether or not the Large Language Models (LLMs) in use have bias and are therefore unfair. The majority of the research in NLP bias has focused on societal stereotype biases embedded in LLMs. However, our research focuses on all types of biases, namely model class level bias, stereotype bias and domain bias present in LLMs. Model class …

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Mechanical Property Evaluation Of Coal Bed And Favorable Area Prediction Of Coalbed Methane (Cbm) Development Based On Well Logging: A Case Study Of No. 3 Coal Bed In Zhengzhuang Block, Southern Qinshui Basin, Qiu Feng, Liu Jinhua, Cai Yidong, Liu Dameng, Sun Fengrui Apr 2023

Mechanical Property Evaluation Of Coal Bed And Favorable Area Prediction Of Coalbed Methane (Cbm) Development Based On Well Logging: A Case Study Of No. 3 Coal Bed In Zhengzhuang Block, Southern Qinshui Basin, Qiu Feng, Liu Jinhua, Cai Yidong, Liu Dameng, Sun Fengrui

Coal Geology & Exploration

Accurately grasping the mechanical properties of coal is of great significance to reservoir reconstruction and CBM development. Herein, the prediction model of shear wave time difference in coal reservoir based on multiple logging parameters and the brittleness index evaluation model based on dynamic and static mechanical parameter conversion were established for the research horizon of No.3 coal bed in Zhengzhuang Block. The brittleness index of coal reservoir in the study area was comprehensively evaluated by elastic parameter method. By this way, it is found that the brittleness index of coal bed in single well is obviously affected by “boundary effect” …

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Volcano Opto-Acoustics: Mapping The Infrasound Wavefield At Yasur Volcano (Vanuatu), J. B. Johnson, T. Boyer, L. M. Watson, J. F. Anderson Apr 2023

Volcano Opto-Acoustics: Mapping The Infrasound Wavefield At Yasur Volcano (Vanuatu), J. B. Johnson, T. Boyer, L. M. Watson, J. F. Anderson

Geosciences Faculty Publications and Presentations

We explore the capabilities of volcano opto-acoustics, a promising technique for measuring explosion and infrasound resonance phenomena at open-vent volcanoes. Joint visual and infrasound study at Yasur Volcano (Vanuatu) demonstrate that even consumer-grade cameras are capable of recording infrasound with high fidelity. Passage of infrasonic waves, ranging from as low as 5 Pa to hundreds of Pa, from both explosions and persistent tremor, pressurizes and depressurizes ambient plumes inducing visible vaporization and condensation respectively. Optical tracking of these pressure wavefields can be used to identify spectral characteristics, which vary within Yasur's two deep craters and are distinct for explosion and …

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Application Of Deep Learning For Classification Of Intertidal Eelgrass From Drone-Acquired Imagery, Krti Tallam, Nam Nguyen, Jonathan Ventura, Andrew G. Fricker, Sadie Calhoun, Jennifer O’Leary, Mauriça Fitzgibbons, Ian C. Robbins, Ryan K. Walter Apr 2023

Application Of Deep Learning For Classification Of Intertidal Eelgrass From Drone-Acquired Imagery, Krti Tallam, Nam Nguyen, Jonathan Ventura, Andrew G. Fricker, Sadie Calhoun, Jennifer O’Leary, Mauriça Fitzgibbons, Ian C. Robbins, Ryan K. Walter

Physics

Shallow estuarine habitats are globally undergoing rapid changes due to climate change and anthropogenic influences, resulting in spatiotemporal shifts in distribution and habitat extent. Yet, scientists and managers do not always have rapidly available data to track habitat changes in real-time. In this study, we apply a novel and a state-of-the-art image segmentation machine learning technique (DeepLab) to two years of high-resolution drone-based imagery of a marine flowering plant species (eelgrass, a temperate seagrass). We apply the model to eelgrass (Zostera marina) meadows in the Morro Bay estuary, California, an estuary that has undergone large eelgrass declines and the subsequent …

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Threshold Segmentation Method Of Ct Scanning Data Of Coal And Rock Samples Considering Beam Hardening Effect And Its Application, Wang Kai, Fu Qiang, Xu Chao, Ai Zibo, Wang Lei, Shu Longyong Apr 2023

Threshold Segmentation Method Of Ct Scanning Data Of Coal And Rock Samples Considering Beam Hardening Effect And Its Application, Wang Kai, Fu Qiang, Xu Chao, Ai Zibo, Wang Lei, Shu Longyong

Coal Geology & Exploration

Beam hardening is a common phenomenon in the application of industrial computerized tomography (ICT). It can cause different grayscale values in components with the same density, which affects the threshold segmentation and later reconstruction of components seriously. Herein, study was conducted on the distribution law of grayscale values under the effect of beam hardening, so as to segment the CT scanning data of coal and rock samples under the beam hardening effect accurately. Through the study, it is found that the change in grayscale value on the grayscale beam could truly reflect the change in component density, which is proved …

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Sedimentary Coal-Controlling Effect And Coal-Forming Model Of Paleogene Coal Measures In Paralic Faulted Basin：A Case Study Of Huangxian Basin, Shandong Province, Wu Yue, Wang Dongdong, Wang Hailiang, Liu Haiyan, Li Zengxue, Zheng Xue Apr 2023

Sedimentary Coal-Controlling Effect And Coal-Forming Model Of Paleogene Coal Measures In Paralic Faulted Basin：A Case Study Of Huangxian Basin, Shandong Province, Wu Yue, Wang Dongdong, Wang Hailiang, Liu Haiyan, Li Zengxue, Zheng Xue

Coal Geology & Exploration

There are abundant coal-type oil and gas resources in Chinese sea area, but few researches have been conducted on the coal-type source rock, which seriously restricts the exploration of coal-type oil and gas resources in the sea area. Herein, this study on sedimentary coal-controlling effect and coal-forming model was carried out based on Huangxian Basin that is a paralic faulted basin with same coal-forming period, similar geological conditions and high degree of research for the coal basins in the sea area. Specifically, the pattern, evolution and sedimentary coal-controlling effect of paleogeography during the coal-forming period were reconstructed with full consideration …

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Deterioration Characteristics Of Water-Rock Interaction On Combustion Metamorphic Rocks In Northern Shaanxi, Hu Xin, Sun Qiang, Yan Changgen, Zhao Chunhu, Wang Shaofei Apr 2023

Deterioration Characteristics Of Water-Rock Interaction On Combustion Metamorphic Rocks In Northern Shaanxi, Hu Xin, Sun Qiang, Yan Changgen, Zhao Chunhu, Wang Shaofei

Coal Geology & Exploration

There are a lot of combustion metamorphic (CM) rocks formed by high temperature baking of coal fires in the border area of Shaanxi, Shanxi and Inner Mongolia in the northeastern margin of Ordos Basin. Compared with the virgin rock, the rock mass subjected to combustion metamorphism is broken in structure, with pores developed, and a large number of dangerous rock masses are formed under the long-term water-rock interaction. Herein, 50 dry-wet cycle experiments were carried out with the CM rocks in Daliuta Area of Shenmu in Shaanxi Province. Meanwhile, the changes in the physical and mechanical properties of CM rocks …

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Ecological Natural Restoration And Its Artificial Promotion Mode In Coal Mining Area, Liu Wei, Yin Qinrui, Liu Xianghong Apr 2023

Ecological Natural Restoration And Its Artificial Promotion Mode In Coal Mining Area, Liu Wei, Yin Qinrui, Liu Xianghong

Coal Geology & Exploration

The natural ecological restoration is an important direction of the national ecological restoration policy. Taking limited artificial measures to promote the natural ecological restoration in coal mining areas is in line with the actual engineering requirements under the context of "double carbon" goal and thus has a better prospect in market application. Herein, the research results in terms of natural ecological restoration were sorted out systematically for the three main types of damaged land in the coal mining areas. Meanwhile, the concept connotation of artificial promotion of natural restoration was studied and analyzed. Besides, the governance mode by zone and …

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Hydrochemical Characteristics And Source Analysis Of Mine Water In Shallow Coal Seams In Shaanxi And Inner Mongolia Contiguous Area, Wang Yutong, Wang Hao, Wang Tiantian, Xue Jiankun, Shang Hongbo, Zhou Zhenfang Apr 2023

Hydrochemical Characteristics And Source Analysis Of Mine Water In Shallow Coal Seams In Shaanxi And Inner Mongolia Contiguous Area, Wang Yutong, Wang Hao, Wang Tiantian, Xue Jiankun, Shang Hongbo, Zhou Zhenfang

Coal Geology & Exploration

In order to study the hydrochemical characteristics and sources of mine water under the mining of shallow coal seams in the contiguous area of Inner Mongolia and Shaanxi, the hydrochemical characteristics and the formation action of mine water in this area were investigated through the study of hydrochemical characteristics, mathematical statistics, ion ratio coefficient method and the hydrogen and oxygen isotopes in combination, by collecting samples of the mine water, groundwater in different aquifers and surface water in the study area. Based on this, the main sources of mine water in the study area were identified. The results show that …

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Automated Classification Of Pectinodon Bakkeri Teeth Images Using Machine Learning, Jacob A. Bahn Apr 2023

Automated Classification Of Pectinodon Bakkeri Teeth Images Using Machine Learning, Jacob A. Bahn

MS in Computer Science Project Reports

Microfossil dinosaur teeth are studied by paleontologists in order to better under- stand dinosaurs. Currently, tooth classification is a long, manual, error-ridden process. Deep learning offers a solution that allows for an automated way of classifying images of these microfossil teeth. In this thesis, we aimed to use deep learning in order to develop an automated approach for classifying images of Pectinodon bakkeri teeth. The proposed model was trained using a custom topology and it classified the images based on clusters created via K-Means. The model had an accuracy of 71%, a precision of 71%, a recall of 70.5%, and …

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Draft Final 2023 Residential Metals Abatement Program (Rmap) Park Soil Sampling Field Sampling Plan (Fsp) Submittal #8 [Ramsay Skating Rink, Skyline Park, Butte Vigilante Saddle Club, Butte Country Club, Fairmont Hot Springs, Silver Bow Homes Park, Gloria Dei Lutheran Church, And United Congregational Church)], Pioneer Technical Services, Inc. Apr 2023

Draft Final 2023 Residential Metals Abatement Program (Rmap) Park Soil Sampling Field Sampling Plan (Fsp) Submittal #8 [Ramsay Skating Rink, Skyline Park, Butte Vigilante Saddle Club, Butte Country Club, Fairmont Hot Springs, Silver Bow Homes Park, Gloria Dei Lutheran Church, And United Congregational Church)], Pioneer Technical Services, Inc.

Silver Bow Creek/Butte Area Superfund Site

No abstract provided.

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Synthesis Of 2-Bromo-6-Alkylaminopyridines, 2,6-Dialkylaminopyridines, And Tren Based Ligands, Stephanie E. Carter Apr 2023

Synthesis Of 2-Bromo-6-Alkylaminopyridines, 2,6-Dialkylaminopyridines, And Tren Based Ligands, Stephanie E. Carter

Honors College Theses

Extended metal atom chains (EMAC) are multimetallic complexes that feature a linear metal chain with metal-metal bonds surrounded by stabilizing ligand molecules. When EMACs are formed with paramagnetic metal ions, unique magnetic properties can be derived from direct metal to metal communication. The challenge is that EMAC complexes are challenging to synthesize due to the inherent weakness of most M-M bonds and the specificity of the ligands required to stabilize EMACs. In prior work by the Guillet group, the silyl aminopyridine (SAP) ligands were observed to stabilize very unique triiron complexes, but they were inherently unstable. In other work, scaffolded …

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Visco-Elastic Full-Waveform Inversion Based On Multi-Objective Function, Liang Xu, Ma Yue, Liu Chao, Chen Zhen, Jia Dongdong, Li Zhiyong, Pan Wenyong Apr 2023

Visco-Elastic Full-Waveform Inversion Based On Multi-Objective Function, Liang Xu, Ma Yue, Liu Chao, Chen Zhen, Jia Dongdong, Li Zhiyong, Pan Wenyong

Coal Geology & Exploration

Full-waveform inversion (FWI) is one of the core technologies developed in exploration geophysics. Through FWI, the subsurface velocity structures can be constructed and the attenuation parameter (the quality factor Q) model can be inverted, which is helpful to characterize the types and structures of subsurface media (such as the fluid and collapse column in collapse column). This is significant for the exploration and development of natural resources such as coal, oil and gas. Parameter crosstalk is the key difficulty of visco-elastic FWI. Due to the influences of velocity errors, the inverted Q models contain very strong crosstalk noise. To …

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Design Of Multi-Channel Continuous Cable Duct For Double-Bit Self-Balancing Drilling System, Zhao Yan, Ai Hongxin, Gao Ke, Zhang Congshan, Lyu Xiaoshu, Xie Xiaobo Apr 2023

Design Of Multi-Channel Continuous Cable Duct For Double-Bit Self-Balancing Drilling System, Zhao Yan, Ai Hongxin, Gao Ke, Zhang Congshan, Lyu Xiaoshu, Xie Xiaobo

Coal Geology & Exploration

The problems, such as low drilling efficiency, large disturbance to the hole wall and long assistance time of tripping caused by the “long arm jurisdiction” drive of the ground drilling rig to the underground drill bit, are faced during the drilling rescue of mine disaster. In order to solve these problems, the bionic self-balancing continuous cable duct drilling technology of double drill bit without drilling rig was proposed, the design of the multi-function continues cable duct is one of the key and challenging aspects of this technology. In terms of the technology, a multi-functional continuous cable duct with built-in channels …

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Mathworks Fitness Tracker, Tuan Quoc Le Apr 2023

Mathworks Fitness Tracker, Tuan Quoc Le

2023 MathWorks Fitness Tracker Challenge-Archive

Mobile fitness app that utilizes the sensors in mobile phone in order to determine the position, velocity, number of calories burned, and other potentially useful fitness information.

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Using Machine Learning To Measure Political Polarization On Social Media, Veronica Cagle Apr 2023

Using Machine Learning To Measure Political Polarization On Social Media, Veronica Cagle

Departmental Honors & Graduate Capstone Projects

Polarization in the political sphere, seen through combative communication and stalemate, may impose negative social impacts on the population. Attempting to measure political polarization in the masses through self-reported surveys and interviews can present response biases of social desirability. The classification of thought freely written online allows political polarization to be measured in an impartial manner. Reddit is one application that enables users to share opinions and create discussions anonymously; this text can be used to measure the political climate at any given time. Disagreement has grown over the perceived level of polarization in our society. The purpose of my …

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Collisional Excitation Of C2h- By H2: New Interaction Potential And Scattering Calculations, Fabien Dumouchel, Ernesto Quintas-Sánchez, Christian Balança, Richard Dawes, François Lique, Nicole Feautrier Apr 2023

Collisional Excitation Of C2h- By H2: New Interaction Potential And Scattering Calculations, Fabien Dumouchel, Ernesto Quintas-Sánchez, Christian Balança, Richard Dawes, François Lique, Nicole Feautrier

Chemistry Faculty Research & Creative Works

Interstellar Anions Play an Important Role in Astrochemistry as Being Tracers of the Physical and Chemical Conditions in Cold Molecular Clouds and Circumstellar Gas. the Local Thermodynamic Equilibrium is Generally Not Fulfilled in Media Where Anions Are Detected and Radiative and Collisional Data Are Required to Model the Observed Lines. the C2H- Anion Has Not Yet Been Detected in the Interstellar Medium; However, Collisional Data Could Be Used for Non-LTE Models that Would Help in Identifying the Most Intense Lines. for This Purpose, We Have Computed the First 4D Potential Energy Surface (PES) of the C2H--H2 Complex using an Explicitly …

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Development Of A Biobased Carbon Adsorbent For Treating Emerging Contaminants In Recycled Water On The International Space Station, Savanna Vacek, Madeline Carroll, Gabson Baguma Apr 2023

Development Of A Biobased Carbon Adsorbent For Treating Emerging Contaminants In Recycled Water On The International Space Station, Savanna Vacek, Madeline Carroll, Gabson Baguma

Undergraduate Research Symposium Posters

The International Space Station (ISS) operates as a closed system. Water is recycled from humidity and urine and held in a wastewater tank; part of the Water Processing Assembly (WPA). Potable treated water is used indirectly in the Sabatier Reactor.The Sabatier Reactor is a key component in the Environmental Control and Life Support System (ECLSS). Three main functions of ECLSS: water recovery, air revitalization, and oxygen generation Sabatier Reactor recently failed due to contamination of DMSO2, dimethyl sulfone, and DMSD, dimethylsilanediol. DMSO2 and DMSD are emerging contaminants that are not removed by the media used in the WPA due to …

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A Preliminary Evaluation Method For Coal-Based Graphite, Liu Kang, Ning Shuzheng, Cao Daiyong, Wu Guoqiang, Wang Lu, Lin Zhongyue, Wang Anmin Apr 2023

A Preliminary Evaluation Method For Coal-Based Graphite, Liu Kang, Ning Shuzheng, Cao Daiyong, Wu Guoqiang, Wang Lu, Lin Zhongyue, Wang Anmin

Coal Geology & Exploration

Coal-based graphite is a type of strategic mineral resource and has unique advantages in the fields such as nuclear graphite and military aircraft tires. The evaluation of coal-based graphite is crucial to its exploration and development, upgrading and storage increase, and strategic resource security. Owing to the continuous transition between coal-based graphite and highly metamorphosed coals, some coal-based graphite tends to be wrongly treated as blind coal, and, accordingly, the identified resources of existing coal-based graphite may have been greatly underestimated. In fact, the resources of coal-based graphite are directly related to those of high-rank coals. Therefore, it is significant …

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Study On Methane Adsorption/Desorption And Flow Law In The Nanopores Of Coal Based On Lammps, Shi Yu, Liu Yang, Xue Junhua, Li Shugang, Zhang Chao Apr 2023

Study On Methane Adsorption/Desorption And Flow Law In The Nanopores Of Coal Based On Lammps, Shi Yu, Liu Yang, Xue Junhua, Li Shugang, Zhang Chao

Coal Geology & Exploration

In this work, the influence rules of driving force, pore size, temperature and pressure on methane adsorption/desorption and flow in coal nanopores were investigated by the molecular dynamic method based on Large-scale Atomic/Molecular Massively Parallel Simulator (LAMMPS). The investigation results show that the viscosity of methane gradually decreases with the increasing driving force, while its fluidity and flow velocity increase. Meanwhile, the absolute slip length decreases and the flow tends to the non-slip state. Generally, the adsorption density of methane is independent of the driving force, but greatly affected by the gas-solid action. Methane can be adsorbed on the pore …

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Application Of Ecological Geological Layer Theory In Coal Seam Protection And Ecological Restoration—An Example Of Ecological Management Practice In Plateau Alpine Mining Areas, Wang Qingwei, Xing Xiafan, Zou Mingjun, Guo Biao, Zhao Xin, Wang Tong Apr 2023

Application Of Ecological Geological Layer Theory In Coal Seam Protection And Ecological Restoration—An Example Of Ecological Management Practice In Plateau Alpine Mining Areas, Wang Qingwei, Xing Xiafan, Zou Mingjun, Guo Biao, Zhao Xin, Wang Tong

Coal Geology & Exploration

The ecological management of alpine permafrost area in plateau is a global problem, with few precedents for coal resource protection while ecological management. In this paper, the following results achieved in the ecological management in Muli area of Qinghai Province were understood in accordance with the idea of systematic engineering for the purpose of ecological environmental protection, with consideration to the protection of residual coal resources. Specifically, study was conducted on the ecological vulnerability of Muli mining area to damage and the difficulty of restoration under the control of natural climatic characteristics. Meanwhile, the characteristics of soil erosion and vegetation …

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Processing Of Coal Mine Csamt Data With Wide Field Electromagnetic Method, Zhu Yunqi, Li Diquan, Liu Zuiliang, Zhang Xin Apr 2023

Processing Of Coal Mine Csamt Data With Wide Field Electromagnetic Method, Zhu Yunqi, Li Diquan, Liu Zuiliang, Zhang Xin

Coal Geology & Exploration

A CSAMT detection test was carried out for a coal mine with V8 multi-functional electrical instrument. Due to the serious electromagnetic interference within the area, the Cagniard apparent resistivity was low in quality. In order to improve the quality and utilization rate of data, authors attempted to process the CSAMT data collected by V8 with the wide field electromagnetic method, which used single-component method and ratio method (Electric field divided by magnetic field) to calculate apparent resistivity. The results showed that there was some deviation between the single-component wide field apparent resistivity and the actual terrestrial electricity because the emission …

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Experimental Study On Heat Transfer Performance Of Double U-Shaped Buried Tube Heat Exchanger, Li Lei, Zhang Weidong, Xu Shuanhai, Zhao Yongzhe, Dang Dongsheng, Wang Qilong, Gou Li, Lei Yanzi Apr 2023

Experimental Study On Heat Transfer Performance Of Double U-Shaped Buried Tube Heat Exchanger, Li Lei, Zhang Weidong, Xu Shuanhai, Zhao Yongzhe, Dang Dongsheng, Wang Qilong, Gou Li, Lei Yanzi

Coal Geology & Exploration

Double U-shaped buried tube heat exchanger (DUBTHE) are prone to pipe crossing and thermal short-circuiting in the practical applications, resulting in the reduced heat transfer performance and directly affecting the operational efficiency of shallow geothermal heat pump system. Based on the initial line thermal average temperature, thermal conductivity theory and slope method, and taking a shallow geothermal heat pump project in Xi'an as the engineering background. Then, this study investigate the effects of initial average temperature, thermal conductivity and volumetric heat capacity of rock-soil, and tube clamp spacing on the heat transfer performance of DUBTHE through field geotechnical thermal response …

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Quality Assessment Of Resistivity Monitoring Data Of Coal Mines, Cui Weixiong, Yuan Bo Apr 2023

Quality Assessment Of Resistivity Monitoring Data Of Coal Mines, Cui Weixiong, Yuan Bo

Coal Geology & Exploration

Resistivity monitoring of coal mines is an important technical means of preventing water hazards on the roof and floor of a mining face. However, it is difficult to guarantee high-quality resistivity data monitored and collected due to the complex and extremely strong electromagnetic interference in the monitoring environment, as well as the limitations of the maximum emission current for the purpose of safe coal mining. To select and utilize highly reliable data from the massive data monitored daily, this study compared and analyzed the advantages and disadvantages of commonly used methods for quality assessment of data obtained using the DC …

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Key Technology Of Automatic Loading And Unloading System For Dual-Pipe Directional Drilling Rig And Its Application In Soft–Fragmentized Coal Seam, Li Kun, Ting Ren, Yao Yafeng Apr 2023

Key Technology Of Automatic Loading And Unloading System For Dual-Pipe Directional Drilling Rig And Its Application In Soft–Fragmentized Coal Seam, Li Kun, Ting Ren, Yao Yafeng

Coal Geology & Exploration

To improve the automatic level and efficiency of loading and unloading of drilling rigs during the construction of dual-pipe directional drilling, an automatic loading and unloading device of dual pipe was developed to realize the fully automatic loading and unloading of drilling rigs under different working conditions and to solve the technical problems of loading and unloading the drill pipes and casing simultaneously during the dual-pipe directional drilling. Meanwhile, the device structure and control system was designed to restrict the load applied to the device during construction with the end-compliant technique. Besides, the key boundary conditions of the control program …

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Effects Of Mos2 On The Matrix Performance Of Hot-Pressed Fe-Based Diamond Drill Bit, Zhang Wenjiao, Tan Songcheng, Pan Bingsuo, Jin Xin, Kong Xiangqing, Long Shanglin Apr 2023

Effects Of Mos2 On The Matrix Performance Of Hot-Pressed Fe-Based Diamond Drill Bit, Zhang Wenjiao, Tan Songcheng, Pan Bingsuo, Jin Xin, Kong Xiangqing, Long Shanglin

Coal Geology & Exploration

Diamond drill bit is a common rock breaking tool in various exploration works, but the diamond in drill bit has poor thermal stability. As heat is constantly generated during the drilling process, the self-cooling of diamond drill bit under the condition of drought and water shortage is very important to improve the drilling efficiency. In order to decrease the friction coefficient between bit matrix and rock interface under dry drilling condition and reduce the thermal damage of diamond during drilling, molybdenum disulfide (MoS2) was added into the Fe-based diamond bit matrix, and research was performed for the effects …

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Study On Construction Of Microbial Solid-Free Drilling Fluid System And Its Borehole Wall Enhancement Mechanism, Li Zhijun, Zhu Mao, Zhi Jingzi, Han Yi, Chen Junxiu, Zhao Gan Apr 2023

Study On Construction Of Microbial Solid-Free Drilling Fluid System And Its Borehole Wall Enhancement Mechanism, Li Zhijun, Zhu Mao, Zhi Jingzi, Han Yi, Chen Junxiu, Zhao Gan

Coal Geology & Exploration

Broken formations are often encountered during drilling, which is prone to the instability of wellbore wall and induces serious downhole accidents. Enhancing the cementing force between the broken blocks and improving the mechanical strength of the surrounding rocks of a wellbore is one of the effective ways to solve the instability of wellbore in this type of formation, for which the microbially induced calcite precipitation (MICP) technology provides a good reference. To this end, the growth of Bacillus pasteurii in the solid-free drilling fluid system was analyzed through experimental study, and thus a solid-free drilling fluid suitable for its growth …

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Developing Weak Galerkin Finite Element Methods, Ahmed Sallal Joudah Al-Taweel Apr 2023

Developing Weak Galerkin Finite Element Methods, Ahmed Sallal Joudah Al-Taweel

Theses and Dissertations

The weak Galerkin finite element method is a flexible and effective numerical technique for solving partial differential equations (PDEs). The goal of this dissertation is to develop new weak Galerkin schemes for solving PDEs on uniform triangular partitions in 2D. These schemes will improve the efficiency of the weak Galerkin method and avoiding numerical locking. First, we investigate the lowest-order weak Galerkin finite element method for solving reaction-diffusion equations with singular perturbations. Then, we propose a weak Galerkin method for the Laplace equation using harmonic polynomial finite elements instead of the full polynomial space $P_k$ to achieve the same order …

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Head And Neck Tumor Histopathological Image Representation With Pre- Trained Convolutional Neural Network And Vision Transformer, Ranny Rahaningrum Herdiantoputri, Daisuke Komura, Tohru Ikeda, Shumpei Ishikawa Apr 2023

Head And Neck Tumor Histopathological Image Representation With Pre- Trained Convolutional Neural Network And Vision Transformer, Ranny Rahaningrum Herdiantoputri, Daisuke Komura, Tohru Ikeda, Shumpei Ishikawa

Journal of Dentistry Indonesia

Image representation via machine learning is an approach to quantitatively represent histopathological images of head and neck tumors for future applications of artificial intelligence-assisted pathological diagnosis systems. Objective: This study compares image representations produced by a pre-trained convolutional neural network (VGG16) to those produced by a vision transformer (ViT-L/14) in terms of the classification performance of head and neck tumors. Methods: W hole-slide images of five oral t umor categories (n = 319 cases) were analyzed. Image patches were created from manually annotated regions at 4096, 2048, and 1024 pixels and rescaled to 256 pixels. Image representations were …

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