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1
Koistinen, Tarja, Leena Ahola, and Jaakko Mononen. "Blue foxes’ (Alopex lagopus) preferences between earth floor and wire mesh floor." Applied Animal Behaviour Science 111, no. 1-2 (May 2008): 38–53. http://dx.doi.org/10.1016/j.applanim.2007.05.011.
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Ahola, Leena, Tarja Koistinen, and Jaakko Mononen. "Sand Floor for Farmed Blue Foxes: Effects on Claws, Adrenal Cortex Function, Growth and Fur Properties." International Journal of Zoology 2009 (2009): 1–6. http://dx.doi.org/10.1155/2009/563252.
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Farmed blue foxes (Vulpes lagopus) are traditionally housed on mesh floors where they are unable to perform certain species-specific behaviours, such as digging, which may compromise the animals' welfare. This study describes how a possibility to use in-cage sand floor affects welfare-related variables like growth of the claws, adrenal cortex function, and fur properties in juvenile blue foxes. The foxes (N=32) were housed in male-female sibling pairs in an outdoor fur animal shed in cage systems consisting of two traditional fox cages. For the eight male-female sibling pairs of the Control group, there was a mesh floor in both cages of each cage system, whereas for the eight pairs of the Sand group there was a mesh floor in one cage and a 30–40 cm deep earth floor in the other cage. The results show that sand floor is beneficial for the wearing of the claws of foxes. Furthermore, an early experience of sand floor may have positive effects on the foxes' fur development. The results, however, also suggest that there might appear welfare problems observed as disturbed claw growth and increased adrenal cortex activation if foxes that are once provided with clean and unfrozen sand floor are not allowed to enjoy this floor all the time.
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Wilson, Scott, Johan Potgieter, and Khalid Mahmood Arif. "Robot-Assisted Floor Surface Profiling Using Low-Cost Sensors." Remote Sensing 11, no. 22 (November 10, 2019): 2626. http://dx.doi.org/10.3390/rs11222626.
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Low cost and accurate 3D surface profiling can help in numerous industry applications including inspection tasks, cleaning, minimizing bumps in navigation of non-uniform terrain, aid navigation, and road/pavement condition analysis. However, most of the available systems are costly or inaccessible for widespread use. This research presents investigation into the capability of cheap and accessible sensors to capture the floor surface profile information. A differential drive robotic platform has been developed to perform testing and conduct the research. 2D localization methods are extrapolated into 3D for the floor capturing process. Two different types of sensors, a 2D laser scanner and an RGB-D camera, are used for comparison of the floor profile capture ability. The robotic system is able to successfully capture the floor surface profile of a number of different type floors such as carpet, asphalt, and a coated floor. A key finding is that the surface itself is a significant factor on the measured profile, i.e. dirt or differing materials can cause false height measurements. Overall the methodology has proved a successful real time solution for creating a point cloud of the floor surface.
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Liu, Hao, Pu Wang, Weihe Zhang, Qiang Liu, and Lijun Su. "Comprehensive Measurement of the Deformation and Failure of Floor Rocks: A Case Study of the Xinglongzhuang Coal Mine." Geofluids 2020 (November 12, 2020): 1–14. http://dx.doi.org/10.1155/2020/8830217.
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The isolated island panel 10304 of the Xinglongzhuang coal mine was used as the research subject to study the deformation and damage characteristics of the coal seam floor. The damage of the floor was studied using the borehole strain sensing method and borehole imaging technology, and FLAC3D was used to study the influence of abutment pressure on floor failure. The result shows that the floor under the superimposed area which is affected by lateral and advanced abutment pressure is damaged firstly, and the maximum depth reaches 26 m, other areas of the working face about 23 m. The degree of deformation and failure of floor rock at different depths is decreased. The deformation damage increases with the advancement of the working face until a certain distance at the same depth. The hole image can clearly show the influence range of the abutment pressure in front of the coal wall and influence the degree of the advancement and lag by means of the strain increment curve for each sensor probe and the images from different drilled positions. On the basis that the results of simulation and field measurement are consistent, the results can reflect the three-dimensional failure characteristics of the whole island working face floor in the process of coal mining more comprehensively and accurately; moreover, they also can provide important information for mine flood prevention and ecological environment protection.
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Sharma, Arvind, Uttara Kennedy, and Clive Phillips. "A Novel Method of Assessing Floor Friction in Cowsheds and Its Association with Cow Health." Animals 9, no. 4 (March 27, 2019): 120. http://dx.doi.org/10.3390/ani9040120.
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Measurement of friction of cowshed floors to determine slipperiness potential is important for cow comfort. Existing methods require elaborate equipment and procedures. A quick method for assessment of friction characteristics is proposed. Friction was measured in 54 cattle housing and yard facilities with earth, brick, concrete, and stone floors, and its association with cattle health parameters was investigated through assessment of 30 animals per facility. A 156 g cuboidal wooden block attached to a spring balance was pulled over 3 m, and the coefficient of friction was recorded as the force required to move the block at a constant speed. The coefficient of friction ranged from 0.3 to 0.7 and was lowest for concrete and highest for earth floors. A multivariate analysis found that cows were standing more and could be more easily approached when they were on floors with high friction levels. The proportion of cows with dirty hind limbs declined with increasing friction of the floor, probably reflecting the fact that they felt more confident to stand rather than lie on high friction floors. This simple measure of frictional characteristics of cattle floors offers promise to be included in welfare measures as an indicator of cow welfare.
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Cliver, E. W. "The floor in the solar wind: status report." Proceedings of the International Astronomical Union 7, S286 (October 2011): 179–84. http://dx.doi.org/10.1017/s1743921312004814.
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AbstractCliver & Ling (2010) recently suggested that the solar wind had a floor or ground-state magnetic field strength at Earth of ~2.8 nT and that the source of the field was the slow solar wind. This picture has recently been given impetus by the evidence presented by Schrijver et al. (2011) that the Sun has a minimal magnetic state that was approached globally in 2009, a year in which Earth was imbedded in slow solar wind ~70% of the time. A precursor relation between the solar dipole field strength at solar minimum and the peak sunspot number (SSNMAX) of the subsequent 11-yr cycle suggests that during Maunder-type minima (when SSNMAX was ~0), the solar polar field strength approaches zero - indicating weak or absent polar coronal holes and an increase to nearly ~100% in the time that Earth spends in slow solar wind.
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Chugh, Ashok K. "Influence of valley geometry on stability of an earth dam." Canadian Geotechnical Journal 51, no. 10 (October 2014): 1207–17. http://dx.doi.org/10.1139/cgj-2013-0407.
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Influence of valley geometry on stability of an earth dam is assessed in terms of its static slope stability. Numerical model results for an earth dam sited in a trapezoidal valley are presented for two combinations of dam crest length and valley floor width. In one combination, the valley floor width is held constant and the slope of valley walls is varied; in the second combination, the dam crest length is held constant and the slope of valley walls is varied. The results for the two combinations are not the same. The results presented are from three-dimensional (3-D) and two-dimensional (2-D) continuum-mechanics-based numerical analyses and are in terms of factor of safety (FoS) and associated slip surface. Significant results include: (i) influence of valley geometry on FoS is minimal when valley floor width exceeds about five times the dam height; and (ii) ratio of 3-D to 2-D FoS can be in the range of 1.03 to 1.30 depending on the valley geometry. Practical implications of the results are included.
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Arpul, Oksana Volodymyrivna, Anastasiya Yuriyivna Spilchuk, and Yuliia Viktorivna Melnyk. "ENERGY FLOOR AS NEW TECHNOLOGY FOR ELECTRICITY EQUIPMENT IN HOTELS OF UKRAINE." GEOGRAPHY AND TOURISM, no. 48 (2019): 74–82. http://dx.doi.org/10.17721/2308-135x.2019.48.74-82.
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The purpose of the article is to study the work of Energyfloor modules in hotels in Ukraine and their impact on energy conservation and sustainable innovations in buildings, public spaces. The Netherlands Energy Floor modules are an integral part of the Smart Floors Smart Grid. The grid can be used both for efficient energy management and for its diagnostics and can work by connecting to light-emitting diode lanterns, intelligent energy management systems. Method: energy Floor is designed to apply pressure on the floor. The energy floor uses the movement of people as a source of energy. A kinetic energy is converted into an electric one, which results in a load on the floor. The energy output of these types of energy-saving tiles depends on the applied force; the higher voltage corresponds to a greater potential difference and, consequently, greater energy. Results: in order to estimate the output power of one person passing through the center of the campus, it is important to determine the magnitude of the forces that experience the earth while walking. Using this concept, large hotels will be able to generate useful power up to 20 W per module. The scientific novelty of the results is to develop and substantiate the concept of using the Netherlands Energy Floor model as an alternative to power generation in hotels. Practical significance: electricity can also be supplied back to the grid, used for energy applications that create a unique energy effect or enhance other customized local systems. This technology provides intellectual use of electricity in the hotel enterprises.
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Yahya, N. N., M. Hashim, and S. Ahmad. "Remote Sensing of shallow sea floor for digital earth environment." IOP Conference Series: Earth and Environmental Science 18 (February 25, 2014): 012110. http://dx.doi.org/10.1088/1755-1315/18/1/012110.
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Hamrouni, Adam, Daniel Dias, and Badreddine Sbartai. "Probabilistic analysis of piled earth platform under concrete floor slab." Soils and Foundations 57, no. 5 (October 2017): 828–39. http://dx.doi.org/10.1016/j.sandf.2017.08.012.
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Du, Yanhui, Weitao Liu, Xiangxi Meng, Lifu Pang, and Mengke Han. "Effect of Crack Propagation on Mining-Induced Delayer Water Inrush Hazard of Hidden Fault." Geofluids 2021 (August 11, 2021): 1–12. http://dx.doi.org/10.1155/2021/6557578.
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Hidden faults in deep coal seam floor threaten the exploitation of coal resources. Under the influence of mining and water confined in the floor, the cemented filler in the hidden fault will be eroded by water flow, in order to investigate the fracture characteristics and water inrush risk of hidden faults in floors above confined aquifer. Using the 27305 working face as geological background, the influence of the seepage scouring filler on the mechanism of water inrush from hidden faults was assessed by developing a stress-seepage coupling model and employing the finite difference method to simulate the seepage process of hidden faults under the combined action of high ground stress and high confined water. The evolution of seepage, shear stress, and plastic zone was also assessed. The influence of the hydraulic pressure of the aquifer and the thickness of a waterproof rock floor on the formation of the water inrush pathway was analyzed. Results indicate that (1) under the influence of mining, the hidden fault experienced the change process of stress stability, stress concentration, and stress release. The shear stress increases first and then decreases. The compressive stress decreases gradually due to stress release. (2) Water inrush disaster will not occur immediately when the working face is above the hidden fault. The delayed water inrush occurs in the mined-out area when the working face advances to 160 m, the floor failure zone is connected with the hidden fault failure zone, and the delayed water inrush channel is formed. (3) With the mining advances, the water pressure of aquifer is the same. The larger-angle fault leads to the thinner thickness of floor aquifer. The greater the influence of hidden fault on coal seam mining, the higher the danger of water inrush.
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Reginella, Reginald L., Mark S. Redfern, and Joseph M. Furman. "Postural sway with earth-fixed and body-referenced finger contact in young and older adults." Journal of Vestibular Research 9, no. 2 (April 1, 1999): 103–9. http://dx.doi.org/10.3233/ves-1999-9204.
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Sensory information from lightly touching a reference with the hand is known to influence postural sway in young adults. The primary aim of this study was to compare the influence of finger contact (FC) with an earth-fixed reference to the influence of FC with a body-fixed reference. A second goal of this study was to determine if FC is used differently by older adults compared to younger adults. Using a force plate, center of pressure at the feet was recorded from blindfolded young and older subjects during several conditions. Subjects either did or did not lightly touch a force-sensitive plate that was either earth-fixed or moved forward and backward in synchrony with body sway (that is, sway-referenced). In addition, support surface conditions were also varied, including a fixed floor and a sway-referenced floor using an EquitestTM. Results showed that the type of FC, floor condition, and age each had an effect on postural sway. Touching an earth-fixed plate decreased postural sway as compared to no touching, while touching a sway-referenced plate incresased sway. This influence of FC was enhanced when the floor was sway-referenced. Although older subjects swayed more than young subjects overall, no age-FC interactions occurred, indicating that FC was not utilized differently between the age groups. This study suggests that FC cannot be disregarded as erroneous, especially when proprioceptive information from the legs is distorted. Further, FC is integrated with other sensory information by the postural control system similarly in young and older persons.
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Guo, Xiaofei, Yongen Li, Jun Li, Hongyu Liu, Xianjie Ma, Ji Li, Guoyu Li, and Jihao Tan. "Surrounding Rock Failure Characteristics and Water Inrush Mechanism of Roadway above the Aquifer in Nonuniform Stress Field." Geofluids 2021 (January 29, 2021): 1–10. http://dx.doi.org/10.1155/2021/6674616.
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The expansion of the roadway surrounding rock failure zone may connect the floor aquifer and cause the roadway water inrush. In order to reveal the mechanism of the roadway water inrush above confined water, we established the force model of the roadway surrounding rock above confined water in nonuniform stress field and studied the shape characteristics and expansion law of the roadway surrounding rock plastic zone. The results show that the roadway surrounding rock will form three kinds of plastic zone under different lateral pressure coefficients: circular, elliptical, and butterfly; when the shape of plastic zone is circular or elliptic, the maximum radius increases linearly with the increase of regional stress; when the shape is butterfly, the maximum radius increases exponentially with the increase of stress. Under the condition of a larger bidirectional stress ratio, the surrounding rock of the roadway will show butterfly-shaped failure, and small stress change will cause malignant expansion of the plastic zone; when the plastic zone is connected with the underlying aquifer, confined water of floor will enter the rock mass from the water diversion point and eventually flood into the roadway, causing floor water inrush.
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Takahashi, Masamichi. "Nutrient Storage and Stoichiometry of the Forest Floor Organic Matter in Japanese Forests." Soil Systems 5, no. 3 (August 29, 2021): 51. http://dx.doi.org/10.3390/soilsystems5030051.
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Nutrient storage in the forest floor is regulated through litter decomposition and nutrient cycling. Stoichiometry of nutrients can provide characterization of the forest floor. To quantify nutrient storage in the forest floor and to determine stoichiometry among different forest types, available data on nutrients were meta-analyzed. The data on nutrients—nitrogen, phosphorus, potassium, calcium, and magnesium—were collected from published reports and original data on Japanese forests. The relationship between nutrient storage and forest floor mass was also examined. Japanese cypress and cedar plantations had small N and P storage in the forest floor with high C:N and C:P ratios, whereas subalpine conifers had large N and P storage in the forest floor with low C:N and C:P ratios; cedar plantations showed large Ca-specific storage in the forest floor. The stoichiometry of the forest floor varied between different forest types, namely C:N:P ratios were 942:19:1 for cedar and cypress plantations, 625:19:1 for broad-leaved forests, and 412:13:1 for subalpine conifers and fir plantations. N storage was closely correlated; however, P and other mineral storages were weakly correlated with the forest floor mass. Nutrient storage and stoichiometry can provide a better perspective for the management of forest ecosystem.
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Goldberg, David. "Carbon below the sea floor." Nature Geoscience 4, no. 1 (November 14, 2010): 11–12. http://dx.doi.org/10.1038/ngeo1019.
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Bickle, Mike J., Heiko Pälike, and Damon A. H. Teagle. "Secrets of the sea floor." Nature Geoscience 4, no. 1 (December 21, 2010): 3–4. http://dx.doi.org/10.1038/ngeo1053.
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Guo, Xiaofei, Yongen Li, Guangdong Zhou, Zengji He, Haoran Yu, and Yichang Xu. "Stability Analysis and Reasonable Layout of Floor Drainage Roadway above Confined Water and under Mining Influence." Geofluids 2021 (March 12, 2021): 1–11. http://dx.doi.org/10.1155/2021/5578717.
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The surrounding rock failure range of floor drainage roadway under the mining influence and its effect on the aquiclude are the key to determine the aquiclude thickness of the floor. This paper studied the distribution characteristics of the surrounding rock plastic zone by the numerical simulation when the floor drainage roadway was located at different positions under the working face and determined the rational position. Results show that (1) when the floor drainage roadway is staggered inward, the floor surrounding rock is prone to appear the butterfly plastic zone under single work face mining. And the butterfly plastic zone increases sharply after being affected by secondary mining of adjacent working face. (2) When the floor drainage roadway is staggered outward, the floor surrounding rock plastic zone extends gently affected by a single working face. And the depth of the plastic zone has no obvious change after being affected by secondary mining of adjacent working face. (3) According to the risk of water inrush, the three layout schemes can be ranked as follows: stagger inward 25 m > stagger inward 80 m > stagger outward 15 m . (4) Considering the floor stress environment, gas extraction efficiency, and water prevention and control, the reasonable location of floor drainage roadway below the No. 11060 working face of Zhaogu No. 2 Coal Mine was finally determined. It was arranged in the sandy mudstone layer on the upper part of L9 limestone under the middle part of coal pillar and was drived along the seam floor.
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Fu, Baojie, and Bo Wang. "An Influence Study of Face Length Effect on Floor Stability under Water-Rock Coupling Action." Geofluids 2021 (March 10, 2021): 1–13. http://dx.doi.org/10.1155/2021/6655823.
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The Taiyuan Formation limestone aquifer and Ordovician limestone aquifer are widely distributed in the coal seam floor of coal measures in North China; the water hazard safety problem of the stope floor under the influence of mining is very prominent. The risk of the water inrush from the coal seam floor is closely related to the degree of full exploitation, so it is necessary to study the stability of the stope floor under aquifer conditions, especially the influence of the working face length effect on floor stability. Through numerical simulation of water-rock coupling action, the mine pressure behaviors of the water-resisting floor under different face lengths were analyzed based on the measured formation permeability coefficient. The Fish program was used to adjust rocks entering the plastic failure state into a strain softening model to investigate the influence of the face length effect, the damage degree of the water-resisting floor, and the morphology and deformation bearing capacity of the failure zone. The results show the following: (1) the face length effect is one of the main influence factors of the failure mode and failure degree of surrounding rocks in the stope; (2) as the face length increases, the obvious pressure relief zone of surrounding rocks presents a staged change, and the obvious pressure relief zone at the seam roof and floor is in an obvious “reverse saddle shape”; (3) the closer to the seam floor, the more remarkable the rock softening characteristic because of the compaction action of gangues caving from the roof; and (4) the rock mass close to the seam floor undergoes local tensile failure, and the water-resisting floor near the coal wall at two sides mainly bears compaction-shear action, leading to compression-shear failure of the rock mass at the floor and formation of water-conducting fractures. The study results can provide a reference for taking precautionary measures of safety mining above a confined aquifer.
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Sawaguchi, Takashi. "Geoscience education using a brand-new Google Earth." Terrae Didatica 14, no. 4 (December 5, 2018): 415–16. http://dx.doi.org/10.20396/td.v14i4.8654165.
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A brand-new browser-based Google Earth version 9.0 has been released in April 2017. This paper presents pedagogical ideas for geoscience education using Google Earth. Several KML files representing geospatial data and images are compiled into a downloadable file. Students can learn geoscience subjects through step-by-step interactive activities as they observe various geological and geographical information such as topography, bathymetry, volcanoes , ocean floor age, gravity anomaly and so on.
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Qi, Hongxia, Yunjia Wang, Jingxue Bi, Hongji Cao, and Shenglei Xu. "Research on HAR-Based Floor Positioning." ISPRS International Journal of Geo-Information 10, no. 7 (June 25, 2021): 437. http://dx.doi.org/10.3390/ijgi10070437.
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Floor positioning is an important aspect of indoor positioning technology, which is closely related to location-based services (LBSs). Currently, floor positioning technologies are mainly based on radio signals and barometric pressure. The former are impacted by the multipath effect, rely on infrastructure support, and are limited by different spatial structures. For the latter, the air pressure changes with the temperature and humidity, the deployment cost of the reference station is high, and different terminal models need to be calibrated in advance. In view of these issues, here, we propose a novel floor positioning method based on human activity recognition (HAR), using smartphone built-in sensor data to classify pedestrian activities. We obtain the degree of the floor change according to the activity category of every step and determine whether the pedestrian completes floor switching through condition and threshold analysis. Then, we combine the previous floor or the high-precision initial floor with the floor change degree to calculate the pedestrians’ real-time floor position. A multi-floor office building was chosen as the experimental site and verified through the process of alternating multiple types of activities. The results show that the pedestrian floor position change recognition and location accuracy of this method were as high as 100%, and that this method has good robustness and high universality. It is more stable than methods based on wireless signals. Compared with one existing HAR-based method and air pressure, the method in this paper allows pedestrians to undertake long-term static or round-trip activities during the process of going up and down the stairs. In addition, the proposed method has good fault tolerance for the misjudgment of pedestrian actions.
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Liu, Hongtao, Tianhong Huo, Yongen Li, Ming Luo, Guangdong Zhou, and Zengji He. "Numerical Simulation Study on the Distribution Law of Deviatoric Stress of Floor under the Influence of Mining." Geofluids 2021 (February 9, 2021): 1–14. http://dx.doi.org/10.1155/2021/6666621.
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The Zhaogu No. 2 coal mine is a single thick coal seam mining mine with high gas content. Due to the lack of protective layer mining conditions, we can only arrange the floor gas extraction roadway (FGER) to extract the gas from the overlying coal seam of the FGER to ensure safe production. However, improper placement of FGER will cause water inrush from the floor of FGER. Given above contradictions, this paper analyzes the stress-strain relationship of the fractured rock mass in the caving zone and the stress-recovery characteristics of the goaf from the perspective of the structural characteristics of the overlying strata above goaf. Based on this, a FLAC3D numerical model of equivalent delayed filling of caving rock mass was established by using the double-yield model filling method. The distribution of floor stress under the influence of mining is obtained after the model calculation, i.e., with the increase of the distance from the floor, the ratio of bidirectional stress to the peak value, and the stability value decrease, but the decrease amplitude becomes smaller and smaller. Therefore, floor roadway used for gas extraction should be located 10-15 m below the floor. Combined with the distribution of floor strata in 11060 working face, it is finally determined that FGER should be located 13 m below the floor. Such arrangement of FGER can not only ensure the effect of gas drainage but also prevent the occurrence of water inrush from floor.
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Weber, Felix, Peter Huber, Fredrik Borchsenius, and Christian Braun. "Performance of TMDI for Tall Building Damping." Actuators 9, no. 4 (December 15, 2020): 139. http://dx.doi.org/10.3390/act9040139.
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This study investigates the vibration reduction of tall wind-excited buildings using a tuned mass damper (TMD) with an inerter (TMDI). The performance of the TMDI is computed as a function of the floor to which the inerter is grounded as this parameter strongly influences the vibration reduction of the building and for the case when the inerter is grounded to the earth whereby the absolute acceleration of the corresponding inerter terminal is zero. Simulations are made for broadband and harmonic excitations of the first three bending modes, and the conventional TMD is used as a benchmark. It is found that the inerter performs best when grounded to the earth because, then, the inerter force is in proportion to the absolute acceleration of only the pendulum mass, but not to the relative acceleration of the two inerter terminals, which is demonstrated by the mass matrix. However, if the inerter is grounded to a floor below the pendulum mass, the TMDI only outperforms the TMD if the inerter is grounded to a floor within approximately the first third of the building’s height. For the most realistic case, where the inerter is grounded to a floor in the vicinity of the pendulum mass, the TMDI performs far worse than the classical TMD.
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Li, Zhu, Guorui Feng, and Jiaqing Cui. "Research on the Influence of Slurry Filling on the Stability of Floor Coal Pillars during Mining above the Room-and-Pillar Goaf: A Case Study." Geofluids 2020 (September 12, 2020): 1–21. http://dx.doi.org/10.1155/2020/8861348.
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Room-and-pillar mining is a commonly used mining method in previous practice in northwest China mining area. Due to priority selection of high-quality resources, coal mines in northwest China generally have to face upward mining above goaf. Thus, the stability of a floor coal pillar influenced by mining activities plays an essential role in upward mining above goaf. The results indicated that a floor coal pillar kept stable before coal excavation in the no. 6107 working face in the Yuanbaowan coal mine; however, the plastic zone in the floor coal pillar expanded sharply and the elastic core zone reduced suddenly on the influence of abutment pressure. Finally, the floor coal pillar supported failure. Accordingly, the paper proposed a floor coal pillar reinforcing technique through a grout injection filling goaf area. As physically limited by a different-height filling body on the double sides, the plastic zone scope and horizontal displacement and loading capacity of the floor coal pillar were studied, working out that the critical height of the filling body should be about 6 m which can ensure safe mining when upward mining above goaf. Case practice indicated that the fractures induced by mining in the floor coal pillar, filling body, and floor can be restrained effectively when the filling body height is 6 m, which can ensure floor coal pillar stability and safe mining of the no. 6107 working face in the Yuanbaowan coal mine. The research can provide theoretical and technical guidance for upward mining above goaf and have a critical engineering practice value.
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Ortega, J. A., L. Razola, and G. Garzón. "Recent human impacts and change in dynamics and morphology of ephemeral rivers." Natural Hazards and Earth System Sciences 14, no. 3 (March 31, 2014): 713–30. http://dx.doi.org/10.5194/nhess-14-713-2014.
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Abstract. Ephemeral streams induce flash-flood events, which cause dramatic morphological changes and impacts on population, mainly because they are intermittent and less predictable. Human pressures on the basin modify load and discharge relationships, inducing dormant instability on the fluvial system that will manifest abruptly during flood events. The flash-flood response of two ephemeral streams affected by load supply modification due to land use changes is discussed in a combination of geomorphic and hydraulic approaches. During the Rivillas flash flood, intensive clearing on the basin led to high rates of sediment flowing into an artificially straightened and inefficient channel. The stream evolved from a sinuous single channel into a shallow braiding occupying the entire width of the valley floor. Misfits and unsteady channel conditions increased velocity, stream power and sediment entrainment capacity and considerably magnified flood damage. Resulting morphosedimentary features revealed a close relationship with the valley floor post-flood hydraulic model, and pre-event awareness would have made it possible to predict risk-sensitive areas. In the second case, the Azohía stream, modelling of current pre-flood channel conditions make it possible to determine channel narrowing and entrenchment in the lower alluvial fan stretch. Abandonment of intensive agriculture, basin reforestation and urbanization diminish load contribution and trigger channel incision. This induces an increase in slope and velocity in the bankfull channel, producing renewed erosive energy and thus activating upstream propagation of incision and bank undermining. The absence of water-spreading dynamics on the alluvial fan in favour of confinement in a single channel produces an unstable dynamic in the system, also offering a false sense of stability, as long as no large magnitude floods occur. When modelling flood-prone areas and analysing hydraulic variables, it is important to detect possible anthropic disturbances that may affect basin load budgets in order to anticipate catastrophic consequences resulting from inappropriate fluvial management before the occurrence of an extraordinary event.
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Richardson, Randall M. "Stripes on the Sea Floor." Journal of Geoscience Education 48, no. 5 (November 2000): 575. http://dx.doi.org/10.5408/1089-9995-48.5.575a.
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Ning, Shan, Weibing Zhu, Xiaoyong Yi, and Laolao Wang. "Evolution Law of Floor Fracture Zone above a Confined Aquifer Using Backfill Replacement Mining Technology." Geofluids 2021 (March 3, 2021): 1–14. http://dx.doi.org/10.1155/2021/8842021.
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Disturbances owing to coal mining result in the movement and failure of floor strata. Mining-induced fractures within the floor may propagate to the confined aquifer, thereby causing water inrush disasters. In this study, we propose using strip mining and backfill replacement mining above the confined aquifer to investigate the failure depth of the floor. The problem is simplified as a distributed force model on a half-plane body. First, the stress disturbance of the floor during strip mining is calculated and the results are combined with the von Mises yield criterion. Then, the destruction of the floor after replacing the remaining coal pillars is explored. The results show that the widths of the strip mining face and coal pillars play an important role in affecting the failure depth of the floor: the greater the width, the larger the failure depth. Based on the parametric study results, the mining face and retention coal pillar width of 20 m is sufficient to prevent the occurrence of water inrush accidents. After the replacement of the remaining coal pillars, the failure area of the floor rock mass increases, but the maximum failure depth remains unchanged. Finally, we employed field measurement techniques at the Bucun coal mine to monitor the shear and vertical strains of the floor. The data collected was compared with the predicted results obtained from the proposed theoretical model. Good agreement was found between the monitoring and calculation results, which demonstrate the effectiveness of the proposed method.
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Chang, Jucai, Dong Li, Tengfei Xie, Wenbao Shi, and Kai He. "Deformation and Failure Characteristics and Control Technology of Roadway Surrounding Rock in Deep Coal Mines." Geofluids 2020 (September 22, 2020): 1–15. http://dx.doi.org/10.1155/2020/8834347.
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With the increase in mining depth, the problem of the floor heave of a roadway is becoming increasingly prominent. Solving this problem for a deep high-stress roadway is the key to ensure safe supply and utilization of coal resources in China. This study investigates the floor heave of a horizontal transportation rock roadway at the depth of 960 m at the Xieyi Mine. A four-way loading simulation test frame similar to the Xieyi Mine was used to reproduce the high-stress environment of a deep roadway by loading different pressures on the roof, floor, and two sides of the roadway. The experimental results show that after the tunnel had been excavated, the surrounding rock failure could be divided into three stages: the initial deformation stage, fissure development stage, and mild deformation stage. The destruction time periods of these stages were 0–0.5 h, 0.5–2 h, and 2–6 h, and the destruction ranges were 0.4 m, 1 m, and 1.5 m, respectively. The amount of roof subsidence, the displacement of the two sides, and the floor heave influence each other, and the range of the bearing ring (5.6 m) of the floor is larger than that of the roof (3.4 m) after the surrounding rock has been damaged. The findings suggest that the floor should be supported first, before the two sides and the roof; then, the support of the key parts (roof and floor corners) should be strengthened. The roof, floor, and two sides are considered for controlling the deformation of the surrounding rock in a coupled trinity support mode. Because of the unfavorable conditions in the area, overexcavation backfill technology was used. The new support was successfully applied during the subsequent construction of the rock tunnel. Based on the long-term monitoring results of the surrounding rock deformation, the floor heave control yielded satisfactory results and maintained the long-term stability of the roadway. Therefore, this study can serve as a reference for preventing floor heave in similar high-stress roadways in the future.
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Qu, Xin Bo, Bi Hua Zhou, Ya Peng Fu, Yan Xin Li, and Tao Wang. "Experiments and Analyses of Horizontal Earth Electrodes’ TGR on Various Grounds." Applied Mechanics and Materials 599-601 (August 2014): 935–39. http://dx.doi.org/10.4028/www.scientific.net/amm.599-601.935.
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In this paper, a new type of portable horizontal grid earth electrode has been designed for mobile equipments. With the impulse ground measurement system, the responses to double exponential pulse current of five earth electrodes in two arrangements have been tested on soil, grassplot and cement floor respectively. After filtering and calculating, the curve of transient grounding resistance (TGR) in time domain can be gotten. And in the end, some conclusions have been drawn. The analysis of discharging capacity of horizontal grid earth electrodes in time domain has great significance in the design of mobile equipments’ earth devices.
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Roof, Steven, and Charlie Callagan. "The Climate of Death Valley, California." Bulletin of the American Meteorological Society 84, no. 12 (December 1, 2003): 1725–40. http://dx.doi.org/10.1175/bams-84-12-1725.
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Death Valley, California, is one of the most extreme environments in the world. The floor of the valley, which is below sea level, is one of the hottest and driest places on Earth. This article and associated data files compile and describe the complete daily weather observations for Greenland Ranch and Furnace Creek (on the floor of Death Valley) for the entire period of record (1911–2002). This article explains the unique climate of Death Valley and serves two purposes: to make widely available the complete record of weather observations from the floor of Death Valley, California; and to encourage researchers, educators, and students to explore the available data and compare their local climate to that of Death Valley.
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Stavi, Ilan, Matan Chocron, Sagi Filin, Reuma Arav, Oren Ackermann, and Boaz Zissu. "Intentional, dual purpose of ancient wine presses as cisterns for runoff water harvesting in drylands." Holocene 28, no. 7 (April 12, 2018): 1107–12. http://dx.doi.org/10.1177/0959683618761550.
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Rock-quarried wine presses were prevalent across the Mediterranean Basin throughout ancient times and particularly during the Late Roman and Byzantine ages. Archeological surveys have uncovered many presses across Israel. Overall, a ratio of ~5 m−1 has been recorded between treading floor area (in m2) and volume of collecting vat (in m3). A recent survey of two presses located at the transition zone between the semi-arid northern Negev, Judean Lowlands, and Southern Hebron Hills of Israel revealed a considerably smaller ratio between the treading floor and collecting vat. In addition, extensive rock exposures were located around the treading floors of the two presses. A 3D laser scanning revealed that the surrounding rock exposure formed a drainage network which flows to the treading floor. Moreover, indications for light modifications of the surrounding rock exposure were recorded for the two presses. In one of the presses, this modification was indicated by remnants of ancient plaster, which were found filling several gaps in the surrounding rock exposure. It is suggested that the purpose of the plaster was for allowing hydrological connectivity between the upslope and downslope edges of these gaps. In the second press, this modification included the chiseling of adjacent bedrock, for the purpose of, it is suggested, channeling runoff water to the treading floor. The findings suggest the intentional collection of raindrops falling on the surrounding rock exposure, together with those falling on the treading floor, which were drained as runoff into the collecting vat. The collected runoff could be used for domestic consumption in this dryland region, augmenting the provision of water for the local populations during the agricultural off-season.
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McCarroll, Danny. "Upheaval from the abyss: ocean floor mapping and the earth science revolution." Area 35, no. 2 (June 2003): 223–24. http://dx.doi.org/10.1111/1475-4762.00bor.
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Smith, Deborah. "Mantle spread across the sea floor." Nature Geoscience 6, no. 4 (March 27, 2013): 247–48. http://dx.doi.org/10.1038/ngeo1786.
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Li, Ang, Bing nan Ji, Qiang Ma, Chaoyang Liu, Feng Wang, Li Ma, Pengfei Mu, Lin Mou, Yuxuan Yang, and Xuesong Ding. "Design of Longwall Coal Pillar for the Prevention of Water Inrush from the Seam Floor with Through Fault." Geofluids 2021 (July 22, 2021): 1–14. http://dx.doi.org/10.1155/2021/5536235.
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Setting up a waterproof coal pillar is an important measure to prevent water inrush from the Weibei mining through fault floor. Based on the plastic slip line field theory, a mechanical model of floor water inrush induced by confined water in the through fault zone was established. The mechanical expressions of confined water pressure and the width of the waterproof coal pillar under the state of limit equilibrium were derived. Combining the laws of floor deformation, failure and fault activation under two kinds of coal pillar width, the safety width of the waterproof coal pillar was determined. Furthermore, the safety threshold is better than the empirical value mentioned in the “coal mine safety regulations.” Following this, grouting transformation was carried out on the K2 sand layer of the cut roadway floor. This provided a theoretical basis and engineering practice for water disaster prevention and the control of the structural floor under similar conditions in the Weibei mining area for future benefit.
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Wang, Pu, Lishuai Jiang, Changqing Ma, and Anying Yuan. "Evolution Laws of Mining-induced Stress in Floor Strata and Its Influence on the Stability of a Floor Roadway Affected by Overhead Mining." Earth Sciences Research Journal 24, no. 1 (January 1, 2020): 45–54. http://dx.doi.org/10.15446/esrj.v24n1.67925.
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The study of evolution laws of the mining-induced stress in floor strata affected by overhead mining is extremely important with respect to the stability and support of a floor roadway. Based on the geological conditions of the drainage roadway in the 10th district in a coalmine, a mechanical model of a working face for overhead mining over the roadway is established, and the laws influencing mining stress on the roadway in different layers are obtained. The evolution of mining stress in floor with different horizontal distances between the working face and the floor roadway that is defined as LD are examined by utilizing UDEC numerical simulation, and the stability of roadway is analyzed. The results of the numerical simulation are verified via on-site tests of the deformation of the surrounding rocks and bolts pull-out from the drainage roadway. The results indicate that the mining stress in floor is high, which decreases slowly within a depth of less than 40 m where the floor roadway is significantly affected. The mining stress in the floor increases gradually, and the effect of the mining on the roadway is particularly evident within 0 m ≤ LD ≤ 40 m. Although the floor roadway is in a stress-relaxed state, the worst stability of the surrounding rocks is observed during the range -20 m ≤ LD < 0 m, in which the negative value indicates that the working face has passed the roadway. The roadway is affected by the recovery of the abutment stress in the goaf when -60 m ≤ LD <20 m, and thus it is important to focus on the strengthening support. The results may provide a scientific basis for establishing a reasonable location and support of roadways under similar conditions.
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Lu, Haifeng, Xiuyu Liang, Nan Shan, and You-Kuan Zhang. "Study on the Stability of the Coal Seam Floor above a Confined Aquifer Using the Structural System Reliability Method." Geofluids 2018 (November 12, 2018): 1–15. http://dx.doi.org/10.1155/2018/9580271.
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A quantitative method of structural system reliability was proposed to study the influence of random rock mechanical parameters and loads on the stability of the coal seam floor above confined aquifers. To obtain the reliability probability of the floor, two modes of water-resistant floor failure were suggested as follows: (1) mining completely removed the water-resistant key strata of the floor. In this case, the failure modes were of three main types: mining failure, confined water intrusion, and combined mining failure and intrusion. (2) Failure modes included shear and tensile failures when the thickness of the key strata was greater than 0. On the basis of the elastic thin plate theory, the performance function that calculates the reliability probability of all modes could be obtained. The failure modes were regarded as the series system. The Monte Carlo method was employed to calculate the reliability probability of each failure mode and series system. The results showed that the random rock mechanical parameters and loads of the key strata significantly influence the antiwater inrush capacity of the floor. In addition, the water inrush coefficient and reliability probability can be simultaneously used as the evaluation indexes of water inrush risk. Both these indexes could improve the assessment of the reliability of the floor.
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Milinovic, Jelena, Francisco J. L. Rodrigues, Fernando J. A. S. Barriga, and Bramley J. Murton. "Ocean-Floor Sediments as a Resource of Rare Earth Elements: An Overview of Recently Studied Sites." Minerals 11, no. 2 (January 30, 2021): 142. http://dx.doi.org/10.3390/min11020142.
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The rare earth elements (REE), comprising 15 elements of the lanthanum series (La-Lu) together with yttrium (Y) and scandium (Sc), have become of particular interest because of their use, for example, in modern communications, renewable energy generation, and the electrification of transport. However, the security of supply of REE is considered to be at risk due to the limited number of sources, with dependence largely on one supplier that produced approximately 63% of all REE in 2019. As a result, there is a growing need to diversify supply. This has resulted in the drive to seek new resources elsewhere, and particularly on the deep-ocean floor. Here, we give a summary of REE distribution in minerals, versatile applications, and an update of their economic value. We present the most typical onshore methods for the determination of REE and examine methods for their offshore exploration in near real time. The motivation for this comes from recent studies over the past decade that showed ΣREE concentrations as high as 22,000 ppm in ocean-floor sediments in the Pacific Ocean. The ocean-floor sediments are evaluated in terms of their potential as resources of REE, while the likely economic cost and environmental impacts of deep-sea mining these are also considered.
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Li, Ang, Qian Mu, Wenzhong Zhang, Chaoyang Liu, Feng Wang, and Lin Mou. "Research on a Numerical Simulation and Prediction Model of Floor Mining Failure Depth in the Chenghe Mining Area." Geofluids 2020 (October 17, 2020): 1–14. http://dx.doi.org/10.1155/2020/8850156.
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Ordovician limestone water on the floor is a serious threat to the safety of coal mine production in the Weibei coalfield, and prediction of the floor failure depth is the key for evaluating the mining conditions under pressure. This paper combines the hydrogeological conditions of the no. 5 coal seam and uses the FLAC3D program to determine the floor failure depth under two-factor (mining depth and width) and multifactor (mining depth, width, and height) conditions via numerical calculations and analysis. We obtain the fitting formula for the floor failure depth and analyze the influence of various factors on it. The results show that when the mining width does not exceed 200 m, the mining width has the greatest influence on the floor failure depth, followed by mining depth and mining height. In this paper, the working face floor failure depths measured values of 18 flat seams in China are taken as samples for comparison with the values calculated via empirical formulas and fitting formulas, and the maximum and minimum absolute errors and relative errors are analyzed. The nonlinear fitting regression formulas offered in this paper are found to provide strong predictive value, high accuracy, and a relatively small error range. The reliability and rationality of the models are further verified, thus providing a reference for future mining operations under safe aquifer water pressure conditions in the Weibei coalfield.
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Paprotny, Dominik, Heidi Kreibich, Oswaldo Morales-Nápoles, Paweł Terefenko, and Kai Schröter. "Estimating exposure of residential assets to natural hazards in Europe using open data." Natural Hazards and Earth System Sciences 20, no. 1 (January 28, 2020): 323–43. http://dx.doi.org/10.5194/nhess-20-323-2020.
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Abstract. Natural hazards affect many types of tangible assets, the most valuable of which are often residential assets, comprising buildings and household contents. Yet, information necessary to derive exposure in terms of monetary value at the level of individual houses is often not available. This includes building type, size, quality, or age. In this study, we provide a universal method for estimating exposure of residential assets using only publicly available or open data. Using building footprints (polygons) from OpenStreetMap as a starting point, we utilized high-resolution elevation models of 30 European capitals and pan-European raster datasets to construct a Bayesian-network-based model that is able to predict building height. The model was then validated with a dataset of (1) buildings in Poland endangered by sea level rise, for which the number of floors is known, and (2) a sample of Dutch and German houses affected in the past by fluvial and pluvial floods, for which usable floor space area is known. Floor space of buildings is an important basis for approximating their economic value, including household contents. Here, we provide average national-level gross replacement costs of the stock of residential assets in 30 European countries, in nominal and real prices, covering the years 2000–2017. We either relied on existing estimates of the total stock of assets or made new calculations using the perpetual inventory method, which were then translated into exposure per square metre of floor space using data on countries' dwelling stocks. The study shows that the resulting standardized residential exposure values provide much better coverage and consistency compared to previous studies.
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Li, Shaodong, Gangwei Fan, Dongsheng Zhang, Shizhong Zhang, Liang Chen, Shang Ren, and Yibo Fan. "Fracture Propagation and Hydraulic Properties of a Coal Floor Subjected to Thick-Seam Longwalling above a Highly Confined Aquifer." Geofluids 2021 (July 2, 2021): 1–12. http://dx.doi.org/10.1155/2021/6668644.
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The high-pressure and water-rich confined aquifer occurring in the Ordovician limestone sequence poses great threats to the routine production of underground longwall mining. Considering the intense cooperation of mining disturbance and water pressure, water-conducting fractures within a coal seam floor can connect the lower aquifer and upper goaf, and this hydraulic behavior is considered the root of water inrush hazard and water loss or contamination. In this paper, the panel 4301 of the Longquan coal mine serves as the case where the panel works closely above the floor with high water pressure. By the combination of physical and numerical modelling approaches, the variation characteristics of fracture development and volumetric strain of floor rocks subjected to mining disturbance are analyzed. A numerical computation model is constructed based on the volumetric strain-permeability equation obtained by curve fitting, and on such basis, the impacts of different mining parameters on floor rock permeability are studied. The results show that the floor rocks experience fracture generation, extension, and convergence procedures as the workface advances along the longitudinal direction, and fractures appearing in front of the workface are more developed. In the whole process of coal seam extraction, the volumetric strain profile exhibits “Λ” shape and an inverted saddle shape before and after overburden strata collapse. By controlling a single variable, the paper reveals that panel height is of greater impact on floor permeability changes than panel length and panel width.
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Fu, Xin, Hengcai Zhang, and Peixiao Wang. "Automatic Construction of Indoor 3D Navigation Graph from Crowdsourcing Trajectories." ISPRS International Journal of Geo-Information 10, no. 3 (March 8, 2021): 146. http://dx.doi.org/10.3390/ijgi10030146.
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Lacking indoor navigation graph has become a bottleneck in indoor applications and services. This paper presents a novel automated indoor navigation graph reconstruction approach from large-scale low-frequency indoor trajectories without any other data sources. The proposed approach includes three steps: trajectory simplification, 2D floor plan extraction and 3D navigation graph construction. First, we propose a ST-Join-Clustering algorithm to identify and simplify redundant stay points embedded in the indoor trajectories. Second, an indoor trajectory bitmap construction based on a self-adaptive Gaussian filter is developed, and we then propose a new improved thinning algorithm to extract 2D indoor floor plans. Finally, we present an improved CFSFDP algorithm with time constraints to identify the 3D topological connection points between two different floors. To illustrate the applicability of the proposed approach, we conducted a real-world case study using an indoor trajectory dataset of over 4000 indoor trajectories and 5 million location points. The case study results showed that the proposed approach improves the navigation network accuracy by 1.83% and the topological accuracy by 13.7% compared to the classical kernel density estimation approach.
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Hohler, Sabine. "Upheaval from the Abyss: Ocean Floor Mapping and the Earth Science Revolution (review)." Technology and Culture 44, no. 2 (2003): 435–37. http://dx.doi.org/10.1353/tech.2003.0068.
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Koistinen, Tarja, Leena Ahola, and Jaakko Mononen. "Blue foxes’ motivation for access to an earth floor measured by operant conditioning." Applied Animal Behaviour Science 107, no. 3-4 (November 2007): 328–41. http://dx.doi.org/10.1016/j.applanim.2006.09.024.
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Forsyth, Donald W., and Robert S. Detrick. "Probing geodynamic processes beneath the sea floor." Eos, Transactions American Geophysical Union 84, no. 47 (2003): 517. http://dx.doi.org/10.1029/2003eo470001.
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Masson, D. G. "The Morphostructure of the Atlantic Ocean floor." Earth-Science Reviews 23, no. 1 (February 1986): 66–67. http://dx.doi.org/10.1016/0012-8252(86)90006-1.
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Herzfeld, Ute C., Isaac I. Kim, and John A. Orcutt. "Is the ocean floor a fractal?" Mathematical Geology 27, no. 3 (April 1995): 421–62. http://dx.doi.org/10.1007/bf02084611.
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Benda, L., D. Miller, and J. Barquín. "Creating a catchment perspective for river restoration." Hydrology and Earth System Sciences Discussions 8, no. 2 (March 25, 2011): 2929–73. http://dx.doi.org/10.5194/hessd-8-2929-2011.
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Abstract. One of the major challenges in river restoration is to identify the natural fluvial landscape in catchments with a long history of river control. Intensive land use on valley floors often predates the earliest remote sensing: levees, dikes, dams, and other structures alter valley-floor morphology, river channels and flow regimes. Consequently, morphological patterns indicative of the fluvial landscape including multiple channels, extensive floodplains, wetlands, and fluvial-riparian and tributary-confluence dynamics can be obscured, and information to develop appropriate and cost effective river restoration strategies can be unavailable. This is the case in the Pas River catchment in northern Spain (650 km2), in which land use and development have obscured the natural fluvial landscape in many parts of the basin. To address this issue we coupled general principles of hydro-geomorphic processes with computer tools to characterize the fluvial landscape. Using a 5-m digital elevation model, valley-floor surfaces were mapped according to elevation above the channel and proximity to key geomorphic processes. The predicted fluvial landscape is patchily distributed according to topography, valley morphology, river network structure, and fan and terrace landforms. The vast majority of the fluvial landscape in the main segments of the Pas River catchment is presently masked by human infrastructure, with only 15% not impacted by river control structures and development. The reconstructed fluvial landscape provides a catchment scale context to support restoration planning, in which areas of potential ecological productivity and diversity could be targeted for in-channel, floodplain and riparian restoration projects.
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Dutch, Steven I. "An Advanced Sea-Floor Spreading Model." Journal of Geological Education 34, no. 1 (January 1986): 18–20. http://dx.doi.org/10.5408/0022-1368-34.1.18.
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MKenzie, Dan. "A Geologist Reflects on a Long Career." Annual Review of Earth and Planetary Sciences 46, no. 1 (May 30, 2018): 1–20. http://dx.doi.org/10.1146/annurev-earth-082517-010111.
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Fifty years ago Jason Morgan and I proposed what is now known as the theory of plate tectonics, which brought together the ideas of continental drift and sea floor spreading into what is probably their final form. I was twenty-five and had just finished my PhD. The success of the theory marked the beginning of a change of emphasis in the Earth sciences, which I have spent the rest of my career exploring. Previously geophysicists had principally been concerned with using ideas and techniques from physics to make measurements. But the success of plate tectonics showed that it could also be used to understand and model geological processes. This essay is concerned with a few such efforts in which I have been involved: determining the temperature structure and rheology of the oceanic and continental lithosphere, and with how mantle convection maintains the plate motions and the long-wavelength part of the Earth's gravity field. It is also concerned with how such research is supported.
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Spekkers, M. H., M. Kok, F. H. L. R. Clemens, and J. A. E. ten Veldhuis. "Decision-tree analysis of factors influencing rainfall-related building structure and content damage." Natural Hazards and Earth System Sciences 14, no. 9 (September 24, 2014): 2531–47. http://dx.doi.org/10.5194/nhess-14-2531-2014.
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Abstract. Flood-damage prediction models are essential building blocks in flood risk assessments. So far, little research has been dedicated to damage from small-scale urban floods caused by heavy rainfall, while there is a need for reliable damage models for this flood type among insurers and water authorities. The aim of this paper is to investigate a wide range of damage-influencing factors and their relationships with rainfall-related damage, using decision-tree analysis. For this, district-aggregated claim data from private property insurance companies in the Netherlands were analysed, for the period 1998–2011. The databases include claims of water-related damage (for example, damages related to rainwater intrusion through roofs and pluvial flood water entering buildings at ground floor). Response variables being modelled are average claim size and claim frequency, per district, per day. The set of predictors include rainfall-related variables derived from weather radar images, topographic variables from a digital terrain model, building-related variables and socioeconomic indicators of households. Analyses were made separately for property and content damage claim data. Results of decision-tree analysis show that claim frequency is most strongly associated with maximum hourly rainfall intensity, followed by real estate value, ground floor area, household income, season (property data only), buildings age (property data only), a fraction of homeowners (content data only), a and fraction of low-rise buildings (content data only). It was not possible to develop statistically acceptable trees for average claim size. It is recommended to investigate explanations for the failure to derive models. These require the inclusion of other explanatory factors that were not used in the present study, an investigation of the variability in average claim size at different spatial scales, and the collection of more detailed insurance data that allows one to distinguish between the effects of various damage mechanisms to claim size. Cross-validation results show that decision trees were able to predict 22–26% of variance in claim frequency, which is considerably better compared to results from global multiple regression models (11–18% of variance explained). Still, a large part of the variance in claim frequency is left unexplained, which is likely to be caused by variations in data at subdistrict scale and missing explanatory variables.
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Song, Jaeyoung, and Kiyun Yu. "Framework for Indoor Elements Classification via Inductive Learning on Floor Plan Graphs." ISPRS International Journal of Geo-Information 10, no. 2 (February 22, 2021): 97. http://dx.doi.org/10.3390/ijgi10020097.
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This paper presents a new framework to classify floor plan elements and represent them in a vector format. Unlike existing approaches using image-based learning frameworks as the first step to segment the image pixels, we first convert the input floor plan image into vector data and utilize a graph neural network. Our framework consists of three steps. (1) image pre-processing and vectorization of the floor plan image; (2) region adjacency graph conversion; and (3) the graph neural network on converted floor plan graphs. Our approach is able to capture different types of indoor elements including basic elements, such as walls, doors, and symbols, as well as spatial elements, such as rooms and corridors. In addition, the proposed method can also detect element shapes. Experimental results show that our framework can classify indoor elements with an F1 score of 95%, with scale and rotation invariance. Furthermore, we propose a new graph neural network model that takes the distance between nodes into account, which is a valuable feature of spatial network data.