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Scanline observation is known to introduce an angular bias into the probability distribution of orientation in three-dimensional space. In this paper, numerical solutions expressing the functional relationship between the scanline-observational distribution (in one-dimensional space) and the inherent distribution (in three-dimensional space) are derived using probability theory and calculus under the independence hypothesis of dip direction and dip angle. Based on these solutions, a noveldoi:10.1038/srep22942 pmid:26961249 pmcid:PMC4785530 fatcat:j4fgzjcobnedva5dtnvfbqzjqu
more »... for obtaining the inherent distribution (also for correcting the bias) is proposed, an approach which includes two procedures: 1) Correcting the cumulative probabilities of orientation according to the solutions, and 2) Determining the distribution of the corrected orientations using approximation methods such as the one-sample Kolmogorov-Smirnov test. The inherent distribution corrected by the proposed method can be used for discrete fracture network (DFN) modelling, which is applied to such areas as rockmass stability evaluation, rockmass permeability analysis, rockmass quality calculation and other related fields. To maximize the correction capacity of the proposed method, the observed sample size is suggested through effectiveness tests for different distribution types, dispersions and sample sizes. The performance of the proposed method and the comparison of its correction capacity with existing methods are illustrated with two case studies. no orientation is observed in this set ( Supplementary Fig. S1(b) ). As this example suggests, it is easy to see that this angular bias exists in orientation observation using scanline, especially with small intersection angles. The first approach for correcting this bias, the Terzaghi method which appeared in 1965, obtained the corrected frequency by dividing the observed frequency by the sine of intersection angle 27 . A detailed explanation of this method can be found in past research 28 . Since its introduction, most orientation corrections have adopted this method or one of its improved versions. For example, this method was applied to discontinuity orientation data obtained from scanline and borehole sampling in road cuts 29 . Subsequently, the application of this method was extended to curved scanlines and boreholes 30 , with a modification being applied to the sampling of fractures with a borehole and the sampling with the surface of a borehole 31 . A revision of this method, the Fouché method, which adds the discontinuity sample size into the original equation was developed to improve correction capacity 32 . The work reported here found that the correction of the Fouché method still results in a considerable error as mentioned in the Results Section. To address this issue, this paper proposes a more effective correction method. Firstly, the solutions for expressing the functional relationship between the distribution observed by a scanline (in one-dimensional space) and the inherent distribution (in three-dimensional space) are derived using probability theory and calculus (shown in the Supplementary Information) . Secondly, based on these solutions, a novel method for correcting the bias is proposed, one which includes a hypothesis and two procedures (shown in Methods). Thirdly, the effect of the observed sample size on the correction capacity of the proposed method is examined based on 84 artificial datasets. Then, the optimal sample size, defined as that which can achieve the maximum correction capacity with few observations, is determined (shown in Results). Finally, the correction capacity of the proposed method is compared with the existing Fouché method using two discontinuity orientation samples, one from a lithic arkose exposure at Wenchuan, Sichuan, and a second from a dacite tunnel wall in Mankang, Tibet, China (shown in Results).
. _________________________________________ Harry de Gorter and David Just are Associate Professors and Qinwen Tan is Graduate Research Assistant in the Department of Applied Economics and Management at ...doi:10.1017/s1068280500000198 fatcat:nikszujs65hlfikjvpjmx6vdd4
Li, Tan, et al., 2017) . ... Li, Tan, et al., 2017; Polissar et al., 2001; W. ...doi:10.1029/2018jd028479 fatcat:7n66j75ymrbyzfzll3ib75epzm
Tan et al. ... ϕ′+N ϕ′ − 1 1 N ϕ′ tan ϕ ′ exp D 1 − D 2 D 2 N ϕ′ tan φ ′ tan π 8 + ϕ ′ 4 − 2N (1/2) ϕ′ tan ϕ ′ − 1 ⎡ ⎣ + 2 tan ϕ ′ + 2N (1/2) ϕ′ + N − (1/2) ϕ′ N (1/2) ϕ′ tan ϕ ′ + N ϕ′ − 1 ⎤ ...doi:10.1155/2020/1298912 fatcat:k2g7fen3ibb2lbsbvyccq7jpyi
In the process of rapid drawdown of reservoir water level, the seepage force in the slide mass is an important factor for the stability reduction and deformation increment of many landslides in the reservoir areas. It is feasible to improve the stability of seepage-induced landslide by employing a drainage well to reduce or eliminate the water head difference that generates the seepage force. In this paper, the Shuping landslide, a typical seepage-induced landslide in the Three Gorges Reservoirdoi:10.3390/ijerph17176030 pmid:32825026 fatcat:qgdmb5qoibbppp6y6kkr3rhhcq
more »... area of China, is taken as an example. A series of numerical simulations were carried out to figure out the seepage field, and the Morgenstein–Price method was adopted to calculate the landslide stability. Then the influence of horizontal location of the drainage well, drainage well depth, drainage mode on the landslide treatment effect, and the applicability of drainage well were analyzed. The results show that: (1) landslide stability increases obviously with the well depth in the slide mass, while the increment of landslide stability with the well depth is limited in the slide bed; (2) the sensitivity of the stability improvement with the depth is greater than that with the horizontal positions of the drainage wells in the slide mass; (3) the drainage well is suggested to be operated when the reservoir water falls rather than operates all the time; and (4) the drainage method is most suitable for landslides with low and medium permeability. These results provide deep insights into the treatment of seepage-induced landslides.
However, the averaged kOH was comparable in two sites (Tan et al., 2018a) . ... The study in Wangdu (summer) and Beijing (winter) found an evidence of missing RO2 sources, which could lead to strong underestimation of ozone production (Tan et al., 2017; Tan et al., 2018c) . ...doi:10.5194/acp-2018-959 fatcat:2x3tndhsafgjbpdesqnbne7v6m
.: Comparative performance of cement and metakaolin based-geopolymer blocks for strontium immobilization Before After Loss (%) Geopolymer 41.7 37.51 10 Cement 40.39 33.87 16 Tan Journal ...doi:10.2109/jcersj2.18130 fatcat:hweqnpqd6fgy3a4xetnpizdxzy
An estimation model on LTO emissions of civil aviation airports was developed in this paper, LTO big data was acquired by analysing the internet with Python, while the LTO emissions was dynamically calculated based on daily LTO data, an uncertainty analysis was conducted with Monte Carlo method. Through the model, the emission of LTO in Shuangliu International Airport was calculated , and the characteristics and temporal distribution of LTO in 2015 was analysed. Results indicates that compareddoi:10.1088/1755-1315/128/1/012069 fatcat:mdgcg66owjd4jppnosmpey7p64
more »... ith the traditional methods, the model established can calculate the LTO emissions from different types of airplanes more accurately. Based on the hourly LTO information of 302 valid days, it was obtained that the total number of LTO cycles in Chengdu Shuangliu International Airport was 274,645 and the annual amount of emission of SO2, NOx, VOCs, CO, PM10 and PM2.5 was estimated, and the uncertainty of the model was around 7% to 10% varies on pollutants.
Ground-level ozone (O3), which is mainly from the photochemical reactions of NOx and volatile organic compounds (VOCs), has become a crucial pollutant obstructing air quality improvement in China. Understanding the composition, temporal variability and source apportionment of VOCs is necessary for determining effective control measures to minimize VOCs and their related photochemical pollution. To provide a comprehensive analysis of VOC sources and their contributions to ozone formation in thedoi:10.3390/atmos11121278 fatcat:otatez427bfstlistqcmeiyrye
more »... ity of Chengdu—a megacity with the highest rates of industrial and economic development in southwest China—we conducted a one-month monitoring project at three urban sites (Shuangliu, Xindu, Junpingjie; SL, XD and JPJ, respectively) along the main north–south meteorological transport channel before and during the implemented control measures. Alkanes were the dominant group at each site, contributing to around 50% of the observed total VOCs, followed by oxygen-containing VOCs (OVOCs), aromatics, halohydrocarbons and alkenes. During the control period, the mixing ratios of most measured VOC species decreased, and O3 concentrations were down by at least 20%. VOC species experiencing the most effect from control were aromatics and OVOCs, which had higher O3 formation reactivity. This indicated that the control policies had significant influence on reductions of reactive VOC species. We also identified VOC sources at SL and XD using positive matrix factorization (PMF) and assessed their contributions to photochemical O3 formation by calculating the O3 formation potential (OFP) based on mass concentrations and maximum incremental reactivity of related VOCs. Five dominant VOC sources were identified, with the highest contributions from vehicular exhaust and fuel evaporation before control, followed by solvent utilization, biogenic background and secondary formation, and industrial emissions. Contribution from vehicular exhaust was reduced the most at SL, while at XD, secondary formation VOCs decreased significantly. VOCs from vehicular and industrial emissions and solvent utilization were found to be the dominant precursors for OFPs, particularly the species of xylenes, toluene and propene. Our results therefore suggest that priority should be given to the alleviation of photochemical pollutants for effective control of O3 formation in Chengdu. The findings from this work have important implications for formulating effective emission control policies in Chengdu.
et al., 2017 Tan et al., , 2018a . ... et al., 2017 Tan et al., , 2018d ; Whalley et al., 2018) . ...doi:10.5194/acp-19-3493-2019 fatcat:oefhqpw5nncmhmworbx46shcoy
Social support received by patients from family and community has been identified as a key factor for success in improving medication adherence in those patients. This pilot study aimed to investigate the usability and feasibility of PillPal, a smartphone application that uses video-chatting as a social motivation medium to encourage medication adherence in cardiovascular disease (CVD) patients. We additionally gathered feedback on the Physician Calendar, an accompanying web platform thatdoi:10.21037/mhealth.2017.11.01 pmid:29445730 pmcid:PMC5803115 fatcat:b7chjehoyjbalmjcykwmahd5b4
more »... clinicians to view patient adherence data generated from the app. Methods: Thirty patients were recruited from the Johns Hopkins Hospital (JHH) Lipid Clinic (n=14) and Inpatient Cardiology Service (n=16) to pilot test the app. Data were obtained through in-person interviews in which patients tested out the app and answered standardized questions regarding the app's feasibility as a means to enhance social support, as well as its usability measured in terms of ease of use and patient comfort level with the video-chat technology. Cardiologists (n=10) from JHH were interviewed to gain feedback on the Physician Calendar. Results: We recorded 43.4% participants who stated that PillPal would increase their motivation to take their medications; 96.7% stated the app was easy to use; and 70% stated they were comfortable with videochatting while taking their medications. Patient factors such as current adherence level, disease severity, and personality were more predictive of positive app reviews than the perceived level of social support. Clinicians generally approved of the Physician Calendar, as they would be able to quickly screen for non-adherence and begin conversations with patients to address the root cause of their non-adherence. Conclusions: Based on pilot testing and interviews, using a smartphone app for video-chatting as a social support medium to improve patient medication adherence is feasible and has potential to increase medication adherence depending on certain patient characteristics. The Physician Calendar was deemed a useful tool by clinicians to quickly identify and understand reasons for medication non-adherence.
Accurately predicting the surface displacement of the landslide is important and necessary. However, most of the existing research has ignored the frequency component of inducing factors and how it affects the landslide deformation. Therefore, a hybrid displacement prediction model based on time series theory and various intelligent algorithms was proposed in this paper to study the effect of frequency components. Firstly, the monitoring displacement of landslide from the Three Gorges Reservoirdoi:10.3390/s20154287 pmid:32752029 fatcat:ixhblrdykzaonlfv2p4sjr3ep4
more »... area (TGRA) was decomposed into the trend and periodic components by complete ensemble empirical mode decomposition (CEEMD). The trend component can be predicted by the least square method. Then, time series of inducing factors like rainfall and reservoir level was reconstructed into high frequency components and low frequency components with CEEMD and t-test, respectively. The dominant factors were selected by the method of dynamic time warping (DTW) from the frequency components and other common factors (e.g., current monthly rainfall). Finally, the ant colony optimization-based support vector machine regression (ACO-SVR) is utilized for prediction purposes in the TGRA. The results demonstrate that after considering the frequency components of landslide-induced factors, the accuracy of the displacement prediction model based on ACO-SVR is better than that of other models based on SVR and GA-SVR.
The original publication of this paper contains a mistake.doi:10.1007/s11356-020-07720-9 pmid:31965492 fatcat:wve23pi3zzevvndk6sl3isdysm
The host–guest interaction with cyclodextrins is an effective method to modulate the spin–spin interaction of trityl-nitroxide biradicals and enhance their redox sensitivity.doi:10.1039/c5ob02450a pmid:26700002 pmcid:PMC4823007 fatcat:fatc4czswnaazj343uqe7fa7se
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