Engineering Commons^™

Numerical Simulations And Wavefield Analysis Of In-Seam Wave Advance Detection In Viscoelastic Media, He Dixiu, Ji Guangzhong, Jiao Wenjie, Zhang Yawei, Yu Kun

Coal Geology & Exploration

In-seam waves are commonly applied to the advance detection of hidden faults in front of mining faces. However, coal seams, which have viscoelasticity actually, imposing absorptive and attenuation effects on in-seam waves. To investigate the wave field characteristics and propagation patterns of in-seam waves in viscoelastic coal seam media, this study built a three-dimensional geological model of coal measures with faults based on Kelvin-Voigt’s first-order velocity-stress equation. Using this equation, three-dimensional finite-difference numerical simulation was carried out. The results indicate that (1) for reflected in-seam waves in viscoelastic media, which exhibit high energy attenuation, their propagation and attenuation characteristics are …

Manipulator Trajectory Planning Method Of Anchor Drilling Robot, Lei Mengyu, Zhang Xuhui, Yang Wenjuan, Dong Zheng, Wan Jicheng, Zhang Chao, Du Yuyang

Coal Geology & Exploration

In order to improve the support efficiency of coal mine roadway and the automation intelligence of heading face, an anchor drilling robot integrating the cantilever roadheader and the six-degree-of-freedom manipulator was designed, and studied on the anchor drilling sequence planning strategy and the drilling boom trajectory planning method. Firstly, the kinematics model of the manipulator structure was established based on the improved DH method. On this basis, the forward and inverse kinematics solutions were analyzed, and the spatial position and the corresponding joint variable values of the drilling rig were calculated. Secondly, the manipulator space was analyzed based on Monte …

Research Progress Of Rotary Steerable System And Its Control Methods, Li Wei, Mou Lei, Zhou Xiancheng, Tan Xianhui, Fu Quan

Coal Geology & Exploration

Rotary steerable system is a shining pearl in directional drilling technology and an important technical means to realize the low-cost and efficient development of oil and gas resources. First of all, the basic structure of the rotary steerable system was introduced. According to the different steering modes and bias effects, the rotary steerable system is divided into five categories: static push-the-bit type, dynamic push-the-bit type, static pointing type, dynamic point-the-bit type and mixed type, for which the steering principle was analyzed one by one. Secondly, according to the research and application of rotary steerable system technology at home and abroad, …

Pfc Numerical Analysis On Crack Initiation Mechanism Of Fracture Grouting In Top Of Ordovician Limestone, Liu Zhaoxing, Zhang Qi

Coal Geology & Exploration

The advanced regional grouting is an effective means to prevent and control the water hazard of limestone in coal seam floor, and the fracture grouting projects is a key link to determine the effect of the grouting in floor against water hazard. However, due to the unclear understanding of the fracture initiation mechanism of the injected limestone stratum, the grouting pressure, grout water-cement ratio and other grouting parameters in the process of fracture grouting are not effectively controlled. Thus, it is difficult to guarantee the grouting effect. In order to solve the above problems, numerical simulation calculation was conducted for …

Table Of Contents, The Editors

Coal Geology & Exploration

No abstract provided.

Gas Expansion Energy Of Coals With Different Metamorphic Degrees: Evolutionary Characteristics And Their Implications For The Outburst Prediction, Liu Gaofeng, Li Baolin, Zhang Zhen, Liu Huan, Guan Wenbo, Si Nian

Coal Geology & Exploration

To achieve an elevated accuracy in the prediction of coal and gas outbursts, this study conducted mercury injection capillary pressure (MICP) tests and isotherm adsorption experiments on selected six coal samples with different metamorphic degrees. Furthermore, it calculated the gas expansion energy of coals and analyzed the evolutionary characteristics of the gas expansion energy of coals with different metamorphic degrees, as well as their relationships with the prediction indices of coal and gas outbursts. The results of this study are as follows: (1) The differences in the pore structures and adsorptivity of coals with different metamorphic degrees led to different …

A Method For Identifying Faults Within Mining Faces Based On Spatial Statistics, Feng Yajie, Wen Guangchao, Wu Bingjie, Hu Zudong

Coal Geology & Exploration

Minor faults within mining faces of coal mines severely affect gas drainage and coal seam mining. Accurately identifying parameters such as positions, throws, and attitudes of these faults is of great significance for the safe production of coal mines. To effectively reduce gas emissions, prevent gas explosions, and exploit and utilize gas resources, many gas drainage holes have been drilled during the construction of coal mines, providing favorable engineering conditions for identifying minor faults within coal seams. Compared with the conventional fault identification methods, which rely on the expertise of geologists, the identification model based on mathematical statistics and space …

An Improved Automated Testing Model For Maceral Groups In Coals Based On Deeplabv3+, Hu Jinwei, Xi Zhenghao, Xu Guozhong, Li Zhongfeng, Liu Xiang

Coal Geology & Exploration

The identification of maceral groups in coals plays a critical role in analyzing the chemical properties of coals. However, manual identification is laborious and requires high expertise. Existing computer-assisted identification methods, mostly adopting deep learning-based semantic segmentation models, fail to accurately identify maceral groups in coals due to complex compositions of microscopic coal images and the presence of transitional components. Therefore, this study proposed an improved DeeplabV3+ semantic segmentation model integrating the Swin Transformer backbone network and the SkNet. First, to deal with the challenge of feature extraction caused by the intertwined maceral groups and the presence of transitional components …

Discovery And Generation Mechanisms Of Epigenetic Biogenic H2S From Coal Seams In The Fukang Block, Southern Junggar Basin, China, Yan Peipei, Su Xianbo, Zou Chenglong, Zhao Weizhong, Wang Lufei, Fu Haijiao

Coal Geology & Exploration

In the Fukang block located in the eastern part of the southern Junggar Basin, coalbed methane (CBM) from CBM wells exhibits a gradually increasing H₂S concentration in the process of CBM production via water drainage, severely threatening production safety. Based on the CBM exploration and extraction data, as well as the anaerobic fermentation experiments, this study preliminarily investigated the causes of abnormal H₂S concentrations during the CBM production in the Fukang block. As indicated by the gas content test in the CBM exploration stage, the original CBM showed a low H₂S concentration of only …

Water-Blocking Performance Of Laterite In Weak Deposition Areas Of Neogene Baode Formation And Its Significance Of Resource Exploitation, Zeng Yifan, Bao Han, Wu Qiang, Meng Shihao, Hua Zhaolai, Miao Yanping, Zhang Ye, Bu Wenyang

Coal Geology & Exploration

The in-depth study on the water-blocking performance of laterite in the weak deposition areas of the key aquiclude is of significant importance for mine production safety and ecological water resource protection. Specifically, the borehole data were re-optimized based on the regional sedimentary characteristics, the thickness distribution pattern of laterite deposit in Yushen mining area was studied, and the micro-engineering characteristics and control factors related to the water-blocking performance of laterite were explored. The results show that the deposition thickness of laterite gradually increases from northwest to southeast, the distribution of laterite becomes extremely uneven with the evolution of rivers, and …

Prediction Of Rockburst Intensity Grade Based On Convolutional Neural Network, Li Kangnan, Wu Yaqin, Du Feng, Zhang Xiang, Wang Yiqiao

Coal Geology & Exploration

Rockburst is one of the urgent problems to be addressed in the process of deep resource extraction. In order to predict the rockburst disasters safely and efficiently, a rockburst intensity grade prediction model (MICE-CNN) based on the Multiple Imputation by Chained Equations (MICE) and Convolutional Neural Network (CNN) was proposed. Specifically, a predictive indicator system was established based on the main influencing factors and the acquisition conditions of rockburst. A total of 120 sets of raw data from rockburst cases were collected, with the outliers processed by pauta criterion. Then, the missing data were interpolated with the four interpolation models …

Numerical Model Of Two-Region Flow By Constant-Head Pumping In An Unconfined Aquifer, Shi Pengyu, Zong Yijie, Teng Kaiqing, Liu Jianjun, Xiao Liang

Coal Geology & Exploration

In order to reveal the mechanism of two-region Darcian and non-Darcian flow induced by constant-head pumping tests in unconfined aquifers, a numerical model of well flow by constant-head pumping underground based on finite difference solution was proposed. In the model, it is assumed that the aquifer is divided into two regions according to the pumping flow characteristics: the finite non-Darcian flow region near the pumping well and the semi-infinite Darcian flow region far away from the pumping well. Specifically, the flow regime in the non-Darcian flow region was simulated by the Izbash’s equation, and the reliability of the proposed solution …

Status And Development Of Intelligent Drilling Tools For Coal Mine, Gao Xiaoliang

Coal Geology & Exploration

As an important part of intelligent drilling, the intelligence of drilling tool system plays a crucial role in the intelligent development of coal mine underground drilling. In order to deeply explore the development direction of intelligent drilling tools, the research results and technical characteristics of intelligent drilling tools in coal mines were systematically sorted out from the aspects of directional drilling tools, measurement while drilling (MWD) system, intelligent drilling pipes and drill bits with reference to the experience in development of oil and gas industry, and the existing shortcomings were also summarized. It is pointed out that screw motor is …

Notes For Contributors, Space And Defense

Space and Defense

No abstract provided.

Book Review: Spies, Lies, And Algorithms: The History And Future Of American Intelligence, Claire Benedix

Space and Defense

The security environment is entering a new threat landscape; one that must be fought in both the physical and virtual world. The seemingly instantaneous progress of digitization and the cyberspace domain threatens to destabilize traditional warfare strategies and intelligence norms. Amy Zegart, an American academic and leading national security expert, outlines the history and future of American intelligence with a specific emphasis on emerging cyber threats in the digital age. In Spies, Lies, and Algorithms, Zegart explains the roles of technological breakthroughs in a world of big data by chronicling the history of intelligence education and organizational reform, the evolution …

Communicating Deterrence Thresholds In Cyberspace Through Global Normas, Leila Yanni

Space and Defense

Student Contribution.

Cyberspace refers to a purely virtual arena that has become increasingly relevant in the past few years, as countries develop more cyber weapons and carry out more cyber attacks. The cyber domain has a large scope because of its virtual nature, and it has a high potential threat level as the full impact of cyber capabilities are not even understood yet. As the possibilities for destructive cyber weapons are virtually endless, the threats are also virtually endless. Because of the growing relevance of cyberspace and the high danger level, deterrence thresholds are a pressing issue in this domain. …

Us Blindness To Russian, Chinese Cultural Motives Risks Nuclear Escalation And Ill-Fit Response, Ryan C. Bushman

Space and Defense

Student Contribution.

This paper was authored prior to the 2022 Russian invasion of Ukraine and the publication of the 2022 Nuclear Posture Review.

The United States has taken numerous miscalculated steps with respect to foreign and nuclear policy based on an incomplete understanding of the motives of both China and Russia. This is, in part, due to a failure to acknowledge these nations' strategic culture - an enduring system of values that influence a nation's use of military force. As the US is about to put forth its 2022 Nuclear Posture Review (NPR), it is critical that future responses to …

Keynote Address: Dr. Kori Schake, Kori Schake

Space and Defense

2022 United Sates Strategic Command Academic Alliance Conference and Workshop, Mark 30-April 1, 2022, Conducted via Zoom

Addressing The American Approach To Emerging Technologies: Utilizing The Ai Arms Race To Highlight The Need To Develop Public-Private Partnerships In C4isr And 5g, Hugh Harsono, Nicholas Ondovcsik

Space and Defense

he world of emerging technologies has changed countries' access and placement to these digital enablement tools of the future, with blockchain, decentralization, and a myriad of other compounding technologies accelerating the pace of development and growth combining the physical and the digital world. Historically, America's Silicon Valley has led the world's development of new technologies, particularly during the latter part of the digital revolution. In contrast, China focused on enhancing its manufacturing capabilities, becoming a world leader by capitalizing on the ever-connected world and leveraging its economic prowess. These roles became reversed in the early-2000s,1 when China first surpassed the …

Technology: The Air And Space Force's Barrier To Innovation, William F. Cosgrove

Space and Defense

The Department of Defense is a rank-and-file institution that values orders adherence and a zero-error mentality, which has led commanders to be risk averse. This is exemplified in the cybersecurity realm, with controls attempting to protect all information, including uncontrolled unclassified information. Efforts that attempt to employ a new or different type of information technology are made very difficult by a number of existing policies. Additionally, customer surveys, service initiatives, and open user complaints have revealed dissatisfaction with Department of the Air Force (DAF) IT services. The millennial and post-millennial generations are the most technologically adept, yet the majority of …

A Great Nuclear Rejuvenation: What China Can Do With An Expanded Nuclear Arsenal, Grant Van Robays, Chloe Reynolds, Will Jackson, Tom Hammerle

Space and Defense

China's hypersonic glide vehicle test in October 2021 prompted widespread concern in the general public and within the defense intelligence community. General Mark A. Milley, Chairman of the Joint Chiefs of Staff, said the test was "very close" to a Sputnik moment.1 More than mere power projection by the People's Republic of China (PRC) and Chinese Communist Party ( CCP), the hypersonic test is an exemplification of rapid advancements in Chinese strategic nuclear forces writ large. Improved nuclear weapons capabilities will offer Beijing greater leverage in regional and international disputes with an increased capacity to coerce and compel adversaries into …

Editor's Note, Michelle Black

Space and Defense

No abstract provided.

Table Of Contents, Space And Defense

Space and Defense

Table of contents for Volume 14 issue 1 of Space and Defense

Front Matter, Space And Defense

Space and Defense

No abstract provided.

Challenging The Notion Of Role Models In Engineering Outreach Programs For Youth, Kelli M. Paul, Karen Miel, Merredith D. Portsmore, Adam Maltese

Journal of Pre-College Engineering Education Research (J-PEER)

Engineering outreach programs often portray outreach educators as role models for youth. It is widely believed that introducing youth, especially girls, to potential engineering role models will broaden participation in engineering majors and careers. Based on interviews with and surveys of fourth- and fifth-grade girls participating in an engineering outreach program, we question whether youth are looking for career role models, and we challenge the assumption that youth will take up an adult as a role model simply because the adult is presented as such. We question what role these ‘‘models’’ play in the minds and lives of youth and …

Leveraging Vr/Ar/Mr/Xr Technologies To Improve Cybersecurity Education, Training, And Operations, Paul Wagner, Dalal Alharthi

Journal of Cybersecurity Education, Research and Practice

The United States faces persistent threats conducting malicious cyber campaigns that threaten critical infrastructure, companies and their intellectual property, and the privacy of its citizens. Additionally, there are millions of unfilled cybersecurity positions, and the cybersecurity skills gap continues to widen. Most companies believe that this problem has not improved and nearly 44% believe it has gotten worse over the past 10 years. Threat actors are continuing to evolve their tactics, techniques, and procedures for conducting attacks on public and private targets. Education institutions and companies must adopt emerging technologies to develop security professionals and to increase cybersecurity awareness holistically. …

Effect Of Priming And Explosive Initiation Location On Pull In Hard Rock Underground Mine, K.K. Rao, B.S. Choudhary

Journal of Sustainable Mining

In the development of hard rock mines, achieving maximum pull after blasting plays a crucial role. Various machines have been developed for rock cutting, but still, due to flexibility and cost-effectiveness, drilling and blasting are preferred. To enhance the effectiveness of this method, several techniques have been developed, including the use of appropriate stemming material, double-primer placement, selecting optimal initiation locations, improving blast designs, and exploring stress superposition techniques through electronic detonators. This research paper focuses on investigating the effect of the priming and explosive initiation location on pull through an experimental approach. The study specifically examines the influence of …

Similarity Measure Of Plithogenic Cubic Vague Sets: Examples And Possibilities, S. Anitha, A. Francina Shalini

Neutrosophic Systems with Applications

The crisp, fuzzy, intuitionistic fuzzy, and neutrosophic sets are the extension of the plithogenic set, in which elements are characterized by the number of attributes and each attribute can assume many values. To achieve more accuracy and precise exclusion, a contradiction or dissimilarity degree is specified between each attribute and the values of the dominating attribute. A plithogenic cubic vague set is a combination of a plithogenic cubic set and a vague set. The key tool for resolving problems with pattern recognition and clustering analysis is the similarity measure. In this research, we characterize and investigate the similarities between two …

Similarity Measure Of Plithogenic Cubic Vague Sets: Examples And Possibilities, S. Anitha, A. Francina Shalini

Neutrosophic Systems with Applications

The crisp, fuzzy, intuitionistic fuzzy, and neutrosophic sets are the extension of the plithogenic set, in which elements are characterized by the number of attributes and each attribute can assume many values. To achieve more accuracy and precise exclusion, a contradiction or dissimilarity degree is specified between each attribute and the values of the dominating attribute. A plithogenic cubic vague set is a combination of a plithogenic cubic set and a vague set. The key tool for resolving problems with pattern recognition and clustering analysis is the similarity measure. In this research, we characterize and investigate the similarities between two …

Revolutionary Artificial Intelligence Architectural Design Solutions; Is It An Opportunity Or A Threat?, Mahmoud Desouki, T. A. El-Haddad, Bahaa El-Boshey

Mansoura Engineering Journal

Architectural design is uniquely complex, time-consuming work, so AI promises major benefits but also risks. Architectural design software programs have recently made an impressive development, especially those that use artificial intelligence. AI could transform design and construction with tools enabling generative design, parametric modeling, simulation, and optimization. However, AI’s impact remains unclear. Adoption depends on architects leveraging AI to augment judgment rather than replace it. Factors limiting AI include limited education/experience, threats to creative skills architects value, and unreliable AI design tools. While many see AI as an opportunity, not an endangerment, optimism and uncertainty prevail. AI may ultimately enhance …