Search

Copyright of Journal of China University of Petroleum is the property of China University of Petroleum and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This paper provides a new idea for interpolating complex curves and surfaces by fractal interpolation. A type of bivariate fractal interpolation functions with function vertical scaling factors for the special interpolation data set is presented. The interpolation algorithm is proposed for complex curves by contour lines of two types of fractal interpolation functions which are proposed by this paper and Navascués et al. [Construction of fractal surfaces, Fractals 28(2) (2020) 2050033], respectively. Meanwhile, some properties of the interpolation algorithm are introduced. Then, the two classes of fractal interpolation functions are extended to the cases of trivariate functions. We also introduce the interpolation algorithm for complex surfaces based on iso-surfaces of fractal interpolation functions constructed. Finally, several examples are provided. [ABSTRACT FROM AUTHOR]

Cone-shaped volcanoes have important research significance and application value due to their typical cone shape and unique structural features. The existing methods for recognizing volcanoes are mainly morphological feature matching and machine learning. In general, the former has low recognition accuracy, while the latter requires a large number of training samples. The contour lines of cone-shaped volcanoes are distributed in concentric circles. Furthermore, from the center outwards, the elevation of the contour lines increases first and then decreases. Based on the morphological characteristics of cone-shaped volcanoes and the Hough transform algorithm, the main algorithm includes (1) preliminary filtering of contour lines, (2) filtering circular contour lines based on random Hough transform, (3) grouping contour lines based on contour trees, (4) recognizing cone-shaped volcanoes based on concentric-circle contour lines, and (5) automatically mapping cone-shaped volcanoes. Case studies demonstrate the effectiveness of this method for detecting cone-shaped volcanoes in the Western Galapagos shield volcanoes and the Mariana Trench submarine volcano group. The proposed algorithm has low missed and false alarm rates, which is basically consistent with the manual recognition results. This method can effectively automatically recognize cone-shaped volcanoes and cone-shaped landscapes and is a powerful means to support deep-space and deep-sea exploration. [ABSTRACT FROM AUTHOR]

In this study, natural orthogonal expansion was performed on earthquake frequencies to compute the pre-quake frequency fields of 9 Ms ≥7.0 earthquakes in mainland China from 1980 to 2020. The temporal and spatial pre-quake anomalies of these earthquakes were extracted from their frequency fields. We found that the majority of pre-quake temporal anomalies (i.e., variations exceeding two-times the absolute mean square error) of a strong earthquake are condensed within the first four frequency fields, and typically comprise multiple components. The temporal factor of the first frequency field usually accounts for the largest proportion of these anomalies (40%–60% of the entire field). Most Ms ≥7.0 earthquakes exhibited long-term anomalies 5–8 years before their occurrence; some presented medium-term anomalies 1–2 years prior to the quake, and only a few presented short-term and imminent anomalies (≤3 months before the quake). Anomalous seismic hazard zones have high-gradient turning points in regional frequency-field contour maps, and the epicenters of strong earthquakes are often located in areas containing active faults that have contour values. Through the comparison of seismic frequency field and the traditional method of regional seismic activity frequency (3 months), it is shown that the frequency-field time factor has the advantages of diversified and rich abnormal information. The slope comparison between the frequency field and the cumulative frequency curve shows that the frequency anomaly time of the two is consistent, and the conclusion is reliable. Therefore, the seismic frequency method can predict the occurrence time and location of strong earthquakes, which is closer to the predictable seismic model.

In order to establish the technology system for the tissue culture and rapid propagation of Acacia podalyriifolia, the response surface method (RSM) was used to optimize the adventitious bud induction, proliferation and the rooting medium formula. Based on the previous single factor pre-test, the induction rate, proliferation coefficient and rooting rate were taken as the response values. The response surface methods of Central Composite Design (CCD) and Box-Behnken (BBD) test design were used to optimize the optimal hormone ratio for the adventitious bud induction, proliferation and rooting culture of Acacia podalyriifolia. The results showed that the optimum induction medium was MS+3. 0 mg • L_1 6-BA+0. 35 mg • L_1 IBA+0. 2 mg • L_1 GA3, and the induction rate was 62. 89%. The optimal proliferation medium was 1/2MS+0. 66 mg/L 6-BA+0. 45 mg • L_1 IBA+0. 11 mg • L_1 GA3, and the proliferation coefficient was 3. 78. The optimal rooting medium was 1/2MS+0. 64 mg • L_1 IBA+0. 14 mg • L_1 NAA, and the rooting rate was 79. 91%. At the same time, the actual value was found to be in line with the expectation according to the contour line map and response surface analysis of the interaction between the factors of response surface method. In conclusion, the prediction of the regression equation established by using the response surface method had a good fitting degree with the actual experiment, which could be used to optimize the medium conditions for tissue culture of Acacia podalyriifolia, The transplanting substrate was yellow subsoil + sand (the volume ratio of yellow subsoil and sand was 2: 1), and the transplanting survival rate could reach more than 90%. [ABSTRACT FROM AUTHOR]

Copyright of Cotton Textile Technology is the property of Cotton Textile Technology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

To study the waterproof coal pillar design for mining in the outcrop area of thick coal seam in Shanxi Formation under the large Jurassic red stratum in the seventh mining area planned and designed by Dongtan Coal Mine, the systematic analysis is carried out on six boring-enclosed areas near the typical outcrop area, and the Jurassic thickness and the interval contour line between the top plate of the third upper coal seam and the bottom of the Jurassic red stratum are drawn. On this basis, the engineering geological profile of typical third upper coal seam mining is established, and the typical borehole is taken as the case to discuss the waterproof coal pillar design for thick coal seam mining under thick red stratum by using the analogy analysis and related specification.

Sloping farmlands are the major sources of soil, water and nutrient losses in arid and semi-arid regions. Information about the impacts of different tillage practices on soil erosion, nutrient loss and crop nutrient uptake on the sloping farmland of semi- arid soil is, however, limited. This study was carried out to investigate the effects of tillage direction on soil, water, nitrogen and phosphorous losses and their uptake by plant in a rainfed wheat land. Field experiments were conducted in two tillage directions: downslope tillage and contour line tillage with four fertilization treatments: control, urea, triple superphosphate, and urea + triple superphosphate at the field plots with 1.75 m ´ 8 m in dimensions by using the randomized completely block design at three replications in Zanjan Township during 2014-2015. According to the results, Significant differences were found between the two tillage practices in soil loss (P < 0.001), water loss (P < 0.001), nitrogen loss soil loss (P < 0.001), and nitrogen uptake by wheat grain (P < 0.001), while phosphorous loss and its uptake did not show any statistically significant difference. Soil and water loss in the downslope tilled plots was 1.65 and 2.50 times higher than the contour line tillage, respectively. Nitrogen loss in the downslope tilled plots was 1.29 times more than that in the contour line tilled plots. Nitrogen loss in the plots was attributed to soil and water loss, so significant relationships were observed between nitrogen loss and soil loss (R2 = 0.59) and water loss (R2 = 0.55). This study, therefore, revealed that the tillage direction is an important factor controlling runoff, soil loss, and nitrogen loss and its uptake by wheat in the rainfed lands of semi-arid regions. Application of the contour tillage is, therefore, the first step to conserve soil and water and to improve soil productivity in these regions.

In this paper several well-known filtering techniques were compared in the purpose of automatic line generalization. The used methods for line simplification are digital first order low-pass filter, Savitzky-Golay (SG) filter and Whittaker filter. Two versions of the algorithm for line feature generalization were tested, from source scale 1:25 000 towards target scale of 1:100 000 and from source scale 1:25 000 towards scale of 1:50 000. Also, GPS data filtering for the target scale 1:50 000 was tested. The first version of the algorithm considers that there are no control data, and the filtering parameter is dictated by the desired accuracy for the target scale. The second version involves control data in the target scale. This means that the optimal value for the filtering parameter is the value for which the difference between input and control data is the smallest. Analysis showed that the SG filter yielded the best results in general. The proposed filters can be considered as a new solution for automated cartographic line simplification.

This study aims to employ both central processing units (CPUs) and graphics processing units (GPUs) to collaboratively generate contour lines from a large-scale digital elevation model (DEM). The performance was improved with regard to three aspects. First, the original DEM data were decomposed and assigned according to the GPU's limited memory so that large-scale data could be correctly addressed. Second, different types of computational tasks between the CPUs and GPUs were dynamically scheduled to ensure that both accelerators cooperate for performance improvement. Third, parallel processing on GPUs and CPUs was separately optimized for more efficient acceleration. Experimental results indicated that applying the parallel algorithm to data with a volume of 37.81 GB and area of 5,975,625.16 km2 reduced the total execution time from 332.84 min to 8.29 min for an optimal speedup of 40.15. In addition, we investigated the effects of the computational intensity, decomposition granularity, and task scheduling on parallel efficiency and performance improvement. We also discussed its degree of effectiveness, broader application, and the future direction of research in the field of geographic information systems. [ABSTRACT FROM AUTHOR]

Proper management of solid waste collection is one of the challenges in the urban areas of developing countries like Jimma town. Therefore, this study aims to assess the municipal solid waste collection system in Jimma town using geographical information system, GIS, techniques. Data used were digital elivation model, DEM, river shapefile, and coordinates of the locations of municipal solid waste, MSW, collection containers and open disposal site. Distances of the locations of existing MSW collection bins from the surface water, the contour lines and flow directions of areas around the existing Qofe Open Dump Site were evaluated. The findings of the study indicate that there was one waste container that was allocated in a 20 m buffer distance from the river. The solid waste collection bins in the town were not evenly allocated. The allocated waste collection containers covered only 12.32% of the total area of the town. There were about 34(51.52%) shortage of MSW collection bins in the town. The municipality should transfer collection bins placed in the river buffer zone of 20 m to other suitable locations. Unserved areas of the town should have waste collection containers after further detail investigation. Water sources near the open disposal site need to be regularly monitored for quality degradation. [ABSTRACT FROM AUTHOR]

Contour lines are a key features of topographic maps as they make the comprehension of terrain more easy. But they are no longer drawn by cartographers, they are mostly automatically derived from digital terrain models. Despite real progress in this automated derivation, some specific terrain landscapes remain incorrectly depicted with such techniques, and this is the case for karstic plateaus full of sinkholes. This paper proposes a specific automated method to derive better contour lines in plateaus, particularly around sinkholes. The process first detects karstic plateaus with many sinkholes, as well as the individual sinkholes. Then, the MNT is smoothed to better reflect the terrain in the plateau and in its surroundings. As a third step, the contour lines around sinkholes are enhanced to draw legible round features that better reflect the real terrain. The process was implemented in a QGIS plugin and tested on a small area with a karstic plateau in the Jura mountain in France, and the cartographers of IGN, the French national mapping agency assessed the results as a great improvement compared to the generic automated process to derive contour lines. [ABSTRACT FROM AUTHOR]

Presentation algorithm of the closed contour in sceletons collection is presented. Sceletons collection represents sequence of segments which connect circle centers. Circles fit into the generated contour segment. The major direction of algorithm usage is text information processing without setting up the certain type face.

Safe landing site selection of a planetary lander is one of the most important technologies for the lander's mission success. In this paper, a new concept for safe landing site selection is proposed based on the digital terrain map and contour lines generated by light detection and ranging (LIDAR) measurements. The design parameters of the proposed approach are defined and systematically classified. Then, the effect of key parameters related to the performance of the algorithm, i.e., terrain roughness is analyzed by comparing the results of three different types of terrain. The simulation results show that the proposed method is well-performed under various circumstances. [ABSTRACT FROM AUTHOR]

Sloping farmlands are the major sources of soil, water and nutrient losses in arid and semi-arid regions. Information about the impacts of different tillage practices on soil erosion, nutrient loss and crop nutrient uptake on the sloping farmland of semi- arid soil is, however, limited. This study was carried out to investigate the effects of tillage direction on soil, water, nitrogen and phosphorous losses and their uptake by plant in a rainfed wheat land. Field experiments were conducted in two tillage directions: downslope tillage and contour line tillage with four fertilization treatments: control, urea, triple superphosphate, and urea + triple superphosphate at the field plots with 1.75 m 8 m in dimensions by using the randomized completely block design at three replications in Zanjan Township during 2014-2015. According to the results, Significant differences were found between the two tillage practices in soil loss (P < 0.001), water loss (P < 0.001), nitrogen loss soil loss (P < 0.001), and nitrogen uptake by wheat grain (P < 0.001), while phosphorous loss and its uptake did not show any statistically significant difference. Soil and water loss in the downslope tilled plots was 1.65 and 2.50 times higher than the contour line tillage, respectively. Nitrogen loss in the downslope tilled plots was 1.29 times more than that in the contour line tilled plots. Nitrogen loss in the plots was attributed to soil and water loss, so significant relationships were observed between nitrogen loss and soil loss (R2 = 0.59) and water loss (R2 = 0.55). This study, therefore, revealed that the tillage direction is an important factor controlling runoff, soil loss, and nitrogen loss and its uptake by wheat in the rainfed lands of semi-arid regions. Application of the contour tillage is, therefore, the first step to conserve soil and water and to improve soil productivity in these regions. [ABSTRACT FROM AUTHOR]

A contour line model for end milling simulation, which realizes high-speed arithmetic processing by reducing memory usage, is proposed. In this model, a 3-dimensional shape can be expressed by superimposing the contour lines of the cross-sections obtained by dividing the workpiece along any axial direction. Therefore, the memory usage is reduced compared to a Z-map model or a voxel model as the interior information of the object can be eliminated. The contour line model can also be applied to complicated shapes having overhangs. Furthermore, cutting volume can be calculated from the interference area enclosed by two contour lines of the workpiece and the tool cross-sections. The workpiece shape can be changed by eliminating the interference area. In the contour line model, cutting force can also be predicted with an instantaneous rigid force model using the uncut chip thickness for each cutting edge from the positional relationship between the interference area and the cutting edge. To validate the proposed model, cutting experiments were conducted, which confirmed that the predicted machining shape had good agreement with the actual machined shape. Furthermore, it was confirmed that the cutting force can be predicted accurately. [ABSTRACT FROM AUTHOR]

Foam image segmentation, represented by watershed algorithm, is wildly used in the extraction of bubble morphology features. H-minima transformation was proved to be effective in locating the catchment basins in the traditional watershed segmentation method. To further improve the accuracy of watershed segmentation, method of top- bottom-cap filters and method of morphological reconstruction were implied to marking the catchment basins. In this paper, instead of H-minima transformation, a method of contour lines is specially proposed to obtain the catchment basins for foam image segmentation by using top-bottom-cap filters and less morphological reconstruction. Experimental results in foam segmentation show that the proposed method is equally accurate but more efficient than the method of H-minima plus morphological reconstruction, and equally efficient but more accurate than the method of H-minima plus top-bottom-cap filters. [ABSTRACT FROM AUTHOR]

An embedding of one-dimensional generic growth functions into a two-dimensional diffeomorphism is considered. This family of unimodal maps naturally incorporates a key item of ecological and biological research: the Allee effect. Consequently, the presence of this species extinction phenomenon leads us to a new definition of bifurcation for this two-dimensional exponential diffeomorphism: Allee's effect bifurcation. The stability and the nature of the fixed points of the two-dimensional diffeomorphism are analyzed, by studying the corresponding contour lines. Fold and flip bifurcation structures of this exponential diffeomorphism are investigated, in which there are flip codimension-2 bifurcation points and cusp points, when some parameters evolve. Numerical studies are included. [ABSTRACT FROM AUTHOR]

Abstract Decimal reduction time (D -value) based on the first-order survival kinetics model is not sufficient for reliable estimation of the bacterial survivors of inactivation treatment because the model does not consider inactivation curvature. However, even though doubt exists in the calculation of D -value, it is still widely used for risk assessment and sterilisation time estimation. This paper proposes an approach for estimating the time-to-inactivation and death probability of bacterial population that considers individual cell heterogeneity and initial number of cells via computer simulation. In the proposed approach, Weibull and Poisson distributions are respectively used to provide individual cell inactivation time variability and initial number of cells variability. Our simulation results show that the time-to-inactivation significantly depends on kinetics curvature and initial number of cells. For example, with increases in the initial number of cells, the respective variance of the time-to-inactivation of log-linear, concave downward curve, and concave upward curve remains constant, decreases, and increases, respectively. The death probability contour plot was successfully generated via our computer simulation approach without using D -value estimation. Further, the death probability calculated using our stochastic approach was virtually the same as that obtained using inactivation kinetics. We validated the simulation by using literature data for acid inactivation of Salmonella population. The results of this study indicate that inactivation curvature can replace D -value extrapolation to estimate the death probability of bacterial population. Further, our computer simulation facilitates realistic estimation of the time-to-inactivation of bacterial population. The R code used for the above stochastic calculation is outlined. Highlights • Bacterial time-to-inactivation and death probability estimation approach is proposed • Proposed approach considers individual cell heterogeneity and initial number of cells • Decimal reduction time extrapolation is replaced with stochastics estimation • The variance of the time-to-inactivation depends on kinetics curvature and initial number of cells. [ABSTRACT FROM AUTHOR]