Engineering Commons^™

Fault-Tolerant Capability Of Star Connected Symmetrical Six-Phase Induction Machine With Single And Two Isolated Neutrals, Wan Noraishah Wan Abdul Munim

Student Works (2020-2029)

Traditionally, electrical machines have been designed to operate with single- or three phase power supplies. In the early stage of power electronics development, three-phase machine suffers problems such as high torque ripple due to low order harmonics during six-step switching and limited current handling capacity of the power switches. This has motivated the use of multiphase machines which is capable of mitigating the aforementioned issues. The revival of multiphase machine research is mainly motivated by the need for more reliable drive systems. The vector space decomposition (VSD) model is used for a healthy multiphase machine as the basis for control …

Evaluation Of Standard And Semantically-Augmented Distance Metrics For Neurology Patients, Daniel B. Hier, Jonathan Kopel, Steven U. Brint, Donald C. Wunsch, Gayla R. Olbricht, Sima Azizi, Blaine Allen

Electrical and Computer Engineering Faculty Research & Creative Works

Background: Patient distances can be calculated based on signs and symptoms derived from an ontological hierarchy. There is controversy as to whether patient distance metrics that consider the semantic similarity between concepts can outperform standard patient distance metrics that are agnostic to concept similarity. The choice of distance metric can dominate the performance of classification or clustering algorithms. Our objective was to determine if semantically augmented distance metrics would outperform standard metrics on machine learning tasks.

Methods: We converted the neurological findings from 382 published neurology cases into sets of concepts with corresponding machine-readable codes. We calculated patient distances by …

Table Of Contents, The Editors

Coal Geology & Exploration

No abstract provided.

Layer-Penetrating Staged Fracturing Law Of Horizontal Wells Within Roof Of Coal Seams Under Stress Interference, Xu Yaobo

Coal Geology & Exploration

Layer-penetrating fracturing is the key link to improve production in horizontal well within roof, and stress interference has important influence on layer-penetrating segmental fracturing effect in the horizontal well within roof. Therefore, the layer-penetrating segmental fracturing numerical model of horizontal well within roof is set up, the influence law of fracture propagation on stress interference to layer-penetrating segmental fracturing is studied. The results show that:the rock mechanics parameters, the interval distance and the fracturing construction method are the three important factors affecting the intersegment disturbance of the horizontal well within roof. As the Poisson's ratio of the coal seam goes …

Multi Frequency Perspective Fine Detection Of Radio Wave For Thin Coal Areas In Fully Mechanized Coal Face, Wu Rongxin, Shen Guoqing, Wang Hanqing, Xiao Yulin

Coal Geology & Exploration

The large area of thin coal area in the fully mechanized coal mining face is difficult to be detected accurately by the single frequency perspective detection of radio wave, which seriously affects the efficient and safe production of coal face. In order to detect the occurrence of thin coal area more precisely, a method of multi frequency perspective detection of radio wave is put forward. Taking coalface 1610A of Zhangji mine of Huaihe Energy Group as the research object, according to the geological conditions, four frequency(0.088, 0.158, 0.365 and 0.965 MHz) perspective detection are selected to delineate the thin coal …

Development And Application Of Lightweight Underground Drill Rig, Fan Dong, Wang Ruize, Tian Hongliang, Chang Jianghua

Coal Geology & Exploration

The underground drill rig is too heavy, so it is difficult to move and transport in the roadway with poor conditions. In order to solve the problem, ZDY1200G lightweight underground drill rig with 5052-h38 state high strength aluminum alloy as the main material is developed. The idea of light structure design and modular assembly is adopted, combined with the application of light materials. The maximum weight of single component after quick disassembly of the drill rig is 292.5 kg. The three-dimensional DIC speckle system was used to measure and analyze the strain and displacement of the aluminum alloy feed body …

Summary Of Water Disaster Characteristics And Water Prevention And Control Technology In Open-Pit Coal Mines In China, Huang Xuanming, Zhang Yan, Li Wensong, Tian Zenglin

Coal Geology & Exploration

Opencast mining is one of the two ways of coal mining in China. Similar to the underground coal mine, the open-pit coal mine also faces the problem of water prevention and control in the process of mining. Due to the relatively single type of water disaster in open-pit coal mines in China, domestic scholars have conducted in-depth study on the characteristics of water disaster and water control technology. Based on the distribution of open-pit coal mines in China, this paper analyzes the characteristics of water hazards in open-pit coal mines from three aspects of water filling source, water filling channel …

Water Cutoff Curtain Technology Of Open-Pit Coal Mine Based On Low Strength Impermeable Concrete, Cao Haidong, Miao Hechao, Chi Zan, Gao Sihua

Coal Geology & Exploration

The concrete underground continuous wall has the advantages of convenient construction, reliable quality, good impermeability and so on. It is widely used in water conservancy, hydropower, foundation pit support, subway and other impermeability projects. The materials used are both plastic concrete and rigid concrete. In the water-cutting curtain project of an open-pit coal mine in Inner Mongolia, according to its engineering geological and hydrogeological characteristics, a kind of low-strength(8-10 MPa) impermeable(P6 grade) concrete was developed as the wall casting material, which water/cementitious materials ratio is 0.68, sand ratio is 45%, For 1 m³ of concrete, the content of each …

Technology Of High Pressure Jet Grouting Water Cutoff Curtain In Gravel Aquifer, Zhu Mingcheng, Han Qiang, Zhao Guibin, Liu Yuzhu

Coal Geology & Exploration

The high-pressure jet grouting pile is mainly suitable for the muddy soil, cohesive soil, silt, sand, loess and gravelly soil, but it is seldom used in the gravel stratum or under the dynamic water condition. A water cutoff certain in an open-pit coal mine was constructed by using RJP method, and the high pressure jet grouting technique was successfully applied to gravel aquifer. Based on the pile test and screening test, the influence of gravel layer characteristics on the size of pile diameter was analyzed. The results show that the RJP method had good effect and reliable quality in the …

Properties Of The Occluded Pile Curtain Material Under Low Temperature And Dynamic Water Condition In Deep And Thick Gravel Layer, Peng Wei, Wang Hai, Wang Zhongquan, Bu Guiling

Coal Geology & Exploration

In order to reduce the water drainage of the studied open-pit mine, a curtain wall is proposed to cut off the river supply on the north side. With full consideration of the realities of construction site, the occluded pile curtain method is applied in an areas with a high voltage line overhead. The gravel layer thickness of the construction area is 45 m and the permeability coefficient is up to 100 m/d, with 0.033 hydraulic gradient and 5℃ groundwater temperature maintained for a long time. In order to ensure fast pile formation in deep gravel layer and low temperature dynamic …

Inspection Method And Analysis Of The Effect Of Water Cutoff Curtain In Open-Pit Coal Mine, Wang Hai, Peng Wei, Cao Haidong, Wang Li

Coal Geology & Exploration

In order to reduce the water drainage of the studied open-pit mine, a curtain wall was constructed to cut off the river supply on the north side. According to the site construction conditions, four technologies were applied to construct the water cutoff curtain, such as the low-strength impermeable concrete underground continuous wall, HDPE impermeable film, ultra-high pressure angular variable speed jet grouting, and occluding pile. To test the effect of water cutoff curtain in the open-pit coal mine during construction, four surrounding well tests were carried out for three kinds of water cutoff curtain technologies, including low-strength impermeable concrete underground …

Relationship Between Ndvi And Hydromet Factors In Grassland Area Of Open-Pit Coal Mine, Zhang Yan, Huang Xuanming, Chen Shi, Shi Bingxing

Coal Geology & Exploration

The groundwater level of an open-pit coal mine in the grassland area of the east Inner Mongolia has been decreasing continuously under the condition of long-term drainage. In order to study whether the growth of vegetation around the mining area was affected by the decline of groundwater level, the NDVI method was used to analyze the change trend of vegetation index in the study area from 2013 to 2019. Based on the joint entropy theory, the mutual information between NDVI and different meteorological and hydrological elements(temperature, rainfall and groundwater depth)were calculated, and the main influencing factors of vegetation growth were …

Genesis Analysis And Study On Tectonic Control On Water Of Huainan North China-Type Coal Field, Ding Tongfu, Wang Minhua, Zhao Junfeng

Coal Geology & Exploration

In order to analyze deeply the genesis and tectonic control on water of the macrostructures of the fourth stage of the Huainan North China-type coalfield, the forms of folds and faults of the Huainan coalfield were used to verify and compare the North China craton geohistory, stratigraphy, and regional tectonics. Quantitative evaluation of the impact of mining area 8 on production mines was conducted. The results show that the Huainan coalfield was formed by the superposition of the Indosinian, Yanshan and Himalayan movements. The Indosinian movement formed the Huainan coalfield at near-east-west tectonic line(body) in the first stage, and the …

Geochemical Characteristics Of Elements In The Paleogene Yunlong Formation And The Restoration Of Paleoenvironment In Lanping Basin, Liu Xiaokang, Zhang Zhibo, Zhu Zhijun, Wu Chuanfu, Wei Xingxing, Liu Haiyan, Jin Tengrui, Baima Quzong

Coal Geology & Exploration

In order to restore the sedimentary environment of the Paleogene Yunlong Formation in the Lanping basin, inductively coupled plasma mass spectrometry(ICP-MS) was used to analyze trace elements in 13 samples of gypsum, limestone, gypsum mud, mudstone and sandstone from the Paleogene Yunlong Formation in Lanping Basin. The sedimentary environments and paleoclimate are estimated based on the spider diagram of trace elements in each lithology and the characteristics of the ratio of Cu/Zn, Sr/Cu and Sr/Ba and the content of Sr. The results show that:gypsum, limestone, gypsum mud, mudstone and sandstone are all rich in Rb, Pb, Zr; gypsum and gypsum …

Applicability Of Mercury Injection Test To The Characterization Of Low Rank Coal And Its Correction Method, Liu Yinan, Liu Yong, Xin Fudong, Wei Hongyu

Coal Geology & Exploration

As an effective method for coal reservoir characterization, mercury intrusion has been widely used in reservoir property analysis of medium-high rank coal. However, for low-rank coal, due to its loose and brittle nature, the process of mercury intrusion will destroy the pore structure, resulting in poor applicability of mercury intrusion experiments. In order to accurately assess the damage to the pore structure of low-rank coal by mercury intrusion experiments, lignite and long flame coal were selected as the research objects, and the pore size distribution of coal was tested by mercury intrusion and nuclear magnetic resonance. The results show that …

Biogas Production And Variation Of The Chemical Composition Of The High Temperature Water Extract Of Lignite, Ren Hengxing, He Huan, Liu Fangjing, Wang Meilin, Guo Xin, Chen Linyong, Zhao Han, Yuan Xuefang, Guan Jiadong, Yue Lijiao

Coal Geology & Exploration

The interaction process between microorganism and coal is complicated. In order to deeply analyze the function and change rule of organic matter in coal in the process of biological gas production, taking Yima lignite and methanogens preserved in laboratory as research objects, the gas production characteristics of water-soluble organic matter of lignite and its chemical composition change before and after gas production were studied. The water-soluble organic components of Yima lignite obtained by deionized water extraction at 70℃ and the extraction residue were used as substrates for biogas production. High performance liquid chromatography-mass spectrometry (HPLC-MS), gas chromatography(GC) and gas chromatography-mass …

Application Of Controllable Electric Pulse Wave Permeability-Enhancing Technology In The Low-Permeability Coal Seams, An Shigang, Chen Dianfu, Zhang Yongmin, Kong Delei, Li Yang, Zhang Di, Wang Yang

Coal Geology & Exploration

Controllable electric pulse wave permeability-enhancing technology is one of the ideal measures for anti-reflection transformation of low-permeability coal seams. The optimization of construction schemes needs to be solved urgently. Aiming at this problem, in the low-permeability coal seam of Baode coal mine, controllable electric pulse wave permeability-enhancing technology was adopted to optimize the permeability-enhancing construction scheme of the boreholes. Test results show that the controllable electric pulse wave permeability-enhancing effect is the best under the condition of the average permeability-enhancing section of 131 m, the impact density of 0.5 times/m and the average daily extraction volume in an anti-reflection borehole …

Geochemical Characteristics And Their Origin Of Cbm In Xingxian Area, Ordos Basin, Wang Xiangye, Sun Baoping

Coal Geology & Exploration

The distribution of carbon and hydrogen isotope of methane is of signification in revealing the origin, the distribution of CBM reservoir, and the source evaluation of CBM. To study the origins of coalbed methane and carbon dioxide, the data of the components、carbon and hydrogen isotopes of CBM from the desorption gas of coal core from Xingxian area were analyzed. With the CBM origins chart board, and the geological environment, the geological effect of the formation and the evolution of CBM were analyzed. the ratios of CBM with different origins were estimated. The results show that the δ¹³C, values …

Corrosion And Degradation Of Feldspar Sandstone In Acidic Environment, Zhou Bin, Zhang Dongming, Xu Jiang, Cheng Liang, Li Jiaxin

Coal Geology & Exploration

In order to study the effect of acidic environment on the corrosion and deterioration of rocks, CT images processing technology was used to analyze the meso-composition and structural changes of feldspar sandstone after soaking in acidic water. Shimadzu AGI-250 servo material testing machine was used to carry out uniaxial compression test to observe the deterioration of mechanical parameters. The results show that the total density of the feldspar sandstone decreased Ofter the acidic environment treatment, the distribution trend is homogeneous, and the mineral with higher density is formed in the local area. The secondary pores of the feldspar sandstone increased …

Overburden Failure Simulation Under Double Coal Seams Mining In A Coal Mine In North Shaanxi Province, Sun Xueyang, Zhang Qi, Li Cheng, Zhang Lei

Coal Geology & Exploration

Under the conditions of multi-seam mining, the overburden failure of coal seams has unique characteristics, which affects the mine production arrangement. Taking a mine in northern Shaanxi Province as an example, based on the geological and mining conditions of the mine, the influence of double-seam mining on overburden rock damage was analyzed by using the method of similar material simulation experiment and numerical simulation. The results show that the height of the caving zone and the height of the fractured zone in the overburden of coal seam obtained by using similar material simulation and numerical simulation with different widths of …

Sensitivity Analysis Of Disaster-Pregnant Environmental Factors For Slope Geological Hazards In Kaiyang County, Guizhou Province, Qin Yigen, Yang Genlan, Xie Jin, Liu Bangyu

Coal Geology & Exploration

The geological conditions are complex in Kaiyang County, and geological disasters occur frequently. On the basis of field geological hazard investigation, 8 factors including elevation, slope, slope direction, engineering petrofabric, slope structure, fault, drainage and NDVI value are selected as the disaster-pregnant factors of slope geohazards. Based on the GIS platform, and by using the certainty factor model(CF) and the sensitivity-exponential(E), susceptibility of these 8 factors are researched. The results show that the areas with elevation from 515 to 993 m, the slope degree from 20° to 50°, the aspect of the west, the northwest and the southeast, …

Spatial Distribution Of Soil Nutrients In Reclamation Dump Sites Based On Subdivision Idw, Zhao Yanling, Zhao Bincheng, Wang Xin, Xiao Wu, Liu Huifang

Coal Geology & Exploration

Accurately grasping the spatial distribution of soil nutrients is of great significance for evaluating the soil quality of reclamation dumps and formulating corresponding reclamation measures. The general interpolation method of the complex terrain of the dump site has a poor prediction effect. The northern dump of Shengli No.1 open-pit mine in Xilinhot, Inner Mongolia was selected as an example in the paper. The soil nutrients(available nitrogen, available potassium, available phosphorus and organic matter) were spatially interpolated using the inverse distance weighting method based on terrain partitioning, and compared with the conventional inverse distance weighting method and kriging interpolation method. The …

Study On The Effect Of Dual-Freedom Coupling Between The Tilt Geophones And The Surface, Sun Chao, Sun Liang, He Dengke, Tian Siqing

Coal Geology & Exploration

In the process of coalfield seismic data acquisition, there is a situation of repeated geophone layout at the same point. The tilt angle difference of the geophones will leads the change of coupling condition between the geophone and the surface, which affects the quality of seismic data acquisition. In this paper, the tilt angle parameters of geophone were introduced into the coupling system of the geophone and the surface. From the point of view of vibration mechanics, the "vibration system with coupling of the dual degree of freedom" of tilt geophone was deduced. The influences of the tilt angle of …

The High-Resolution Transient Electromagnetic Detection Technology For Ultra-Shallow Layer In Coal Mine, Zhang Jun

Coal Geology & Exploration

In order to reduce the blind zone of the transient electromagnetic detection in mines and improve the detection accuracy, the high-resolution transient electromagnetic detection technology for the ultra shallow layer in mines is studied. The high-resolution transient electromagnetic detection technology for ultra-shallow layer in mines is not only suitable for conventional mine geological exploration, but also for high-resolution detection of shallow geological bodies such as cracks in the roof of the mine roadway, ensuring the safe and efficient mining. Through theoretical research, the feasibility of the shallow high-resolution transient electromagnetic method in mine was established; the hardware system of the …

Design Of Piezoelectric Effect-Based Energy Recovery Device Wile Drilling, Wu Tianyu, Zheng Jun, Zhang Bo, Chen Yu, Tian Hong, Dou Bin

Coal Geology & Exploration

Aiming at the problem of continuous power supply of downhole instruments and the recovery of longitudinal vibration energy of drill pipe in drilling field, a new type of energy recovery device based on positive piezoelectric effect was designed. The radial dimension parameters and piezoelectric materials were designed by field experiences and geological survey reports. The piezoelectric coupling model was established based on the numerical simulation software COMSOL Multiphysics, and the length range and the best installation position of the piezoelectric plate were obtained through forced vibration analysis. Through modal analysis and frequency response research, it is obtained that the natural …

Waveform Cross Correlation-Based Imaging Of Underground Seismic Data While Mining, Zhang Huanlan, Wang Baoli

Coal Geology & Exploration

Seismics while mining is a passive seismic detection technique using a shearer as seismic source. Because the shearer moves unceasingly and excites the continuous signals, the conventional data processing method cannot be applied directly. In the paper a cross-correlation method of segmented waveform was put forward, the effective signal travel time was extracted through the segmentation of the data generated the shear, and then the velocity imaging method was used to image the interior of the working face and the front of the cutting hole. The wave equation was used to carry out the seismics while mining numerical simulation of …

Rapid Visual Presentation To Support Geospatial Big Data Processing, E. Levin, W. Roland, R. Habibi, Z. An, R. Shults

Michigan Tech Publications, Part 1

Given the limited number of human GIS/image analysts at any organization, use of their time and organizational resources is important, especially in light of Big Data application scenarios when organizations may be overwhelmed with vast amounts of geospatial data. The current manuscript is devoted to the description of experimental research outlining the concept of Human-Computer Symbiosis where computers perform tasks, such as classification on a large image dataset, and, in sequence, humans perform analysis with Brain-Computer Interfaces (BCIs) to classify those images that machine learning had difficulty with. The addition of the BCI analysis is to utilize the brain's ability …

Model And Selection Criterion Of Zonal Preact Grouting To Prevent Mine Water Disasters Of Coal Floor Limestone Aquifer In North China Type Coalfield, Dong Shuning, Guo Xiaoming, Liu Qisheng, Wang Hao, Nan Shenghui, Zheng Shitian, Wang Yuhang

Coal Geology & Exploration

In order to promote the development of zonal preact grouting technology and establish a system of the technology to prevent mine water disasters of coal floor aquifer, the authors analyze and summarize the coal seam occurrence and hydrogeological conditions of the Carboniferous-Permian coalfields in China, starting from the engineering systematicity, focusing on the three main factors of drilling conditions, grouting layer selection and drilling technology in the engineering of zonal preact grouting to prevent mine water disasters of coal floor aquifer. The model of zonal preact grouting to prevent mine water disasters of coal floor aquifer is established, which can …

Integrated Monitoring Technology Of Water Inrush From Coal Seam Floor And Its Application, Duan Jianhua

Coal Geology & Exploration

Karst water damage in floor is a common problem in North China type coalfield. Because of its characteristics of concealment and emergency, the prevention and control of water is faced with huge problems and challenges, monitoring and early warning technology of floor water inrush has become a necessary measure in the process of the safe production in coal mines. The formation and occurrence of floor water disaster have a process of evolution from conception, development to occurrence. In this process, the corresponding water inrush symptoms will be released in different stages of the floor crack and apparent resistivity of the …

Application Of Borehole Transient Electromagnetic Detection In The Test Of Hydraulic Fracturing Effect, Zhao Rui, Fan Tao, Li Yuteng, Wang Jikuang, Ma Yuan, Wang Bingchun, Liu Lei, Fang Zhe

Coal Geology & Exploration

Hydraulic fracturing technology is widely used in various aspects such as mine rock burst prevention and surrounding rock depressurization, but there has been a lack of efficient and intuitive technology for evaluating the fracturing effectiveness. To solve this problem, a three-component borehole TEM detection method using dynamic source and reception unit was proposed, and detection equipment and supporting construction techniques suitable for construction in hydraulic fracturing holes were developed. Two engineering tests have been carried out in a coal mine. By comparing the processing results of the vertical components of the two detection data before and after fracturing, a pure …