bluuebunny/crossref_metadata_2025_split huggingface dataset:
Study on Processing Method of Acoustic Emission Signal for Hydraulic Fracture Measurement
Authors: Fu Haifeng , Zheng Xinquan , Cai Bo , Liang Tiancheng , Qiu Jinping , Chen Feng , Liu Yunzhi , Rong Jiaojun 
Published: May 2021

Abstract
Hydraulic fracturing has become a key technology for the unconventional oil and gas development. Due to the complexity of geological conditions and the limitation of monitoring technology, it is still very difficult to accurately understand the three-dimensional distribution characteristics of hydraulic fractures. Based on the acoustic emission monitoring and three-dimensional laser scanning for large scale (762 mm * 762 mm * 914 mm) hydraulic fracturing test, hydraulic fracture morphology characterization is measured. The control method of acoustic emission signal quality based on amplitude, root-mean-square phase and multi-channel contrast signal recognition was explored. A multi-parameter constrained grid search and location method was established, which significantly improved the location accuracy and realized the dynamic and static real-time characterization of hydraulic fracture space expansion under indoor conditions. The results show that: based on laser scanning technology, the detailed characterization method of hydraulic fracture morphology is established, and the fracture morphology in laboratory experiment can be improved from two-dimensional observation to three-dimensional display. Due to mutual influence of natural fracture and in situ stress field, the hydraulic fracture appears complex geometry such as turning and bifurcation. The accuracy of acoustic emission location is improved by 10%, and the consistency with the actual fracture scale reaches 95%. The processing method of acoustic emission signal in this paper can be directly used in the optimization of field microseismic monitoring to guide the evaluation of unconventional reservoir stimulation, which shows a broad application prospect.
Realization of Accurate Modeling and Simulation of Oilfield Water Mixing Gathering and Transportation System
Authors: Wang Yan , Li Jie , Ruijie Zhang , Gao Sheng , Ren Yongliang 
Published: May 2021

Abstract
In order to solve the shortcomings that the simulation accuracy of oilfield water mixing gathering and transportation system is not high, the dual-process of mixing water and returning to the station cannot be realized at the same time, the system is accurately modeled, and the data structure and computer model suitable for calculation are established by reading static data. The design modeling software realizes the logical and data interface and realizes the display of the physical model on the computer. Based on the quasi-Newton loop iteration method, an online algorithm is proposed. Using the flow rate of each node of the system as the constraint condition, the water mixing process node and pipeline parameters are calculated. According to the calculation results and the oil well produced fluid parameters, the principle of mixed calorimetry is applied to construct the initial value and iterative formula of the return flow simulation. The temperature at the return station is consistent with the inlet temperature of the heating furnace at the joint station. It can dynamically reflect the production and operation status of the water mixing system, and provide a scientific basis for the control and operation of the water mixing system.
Research and Development of Drilling Operation Data Benchmarking Management System
Authors: He Jingbin , Chen Weilin , Chen Lin , Shi Chongdong 
Published: May 2021

Abstract
Benchmarking management, as a measure for the continuous improvement of scientific management of enterprises, provides advanced ideas for enterprises to analyze the problem of insufficient production capacity, and through data modeling can provide solutions for the improvement of deficiencies, which is conducive to the improvement of the overall management level and competitiveness of enterprises. Changqing Drilling Corporation has a large difference in the speed of drilling among the drilling crew, and has not formed an overall drilling speed-up plan. This paper uses an integrated data platform to establish a drilling operation benchmarking management system model, through the comparative analysis in different regions, different operation conditions of ROP and drilling cycle. Using machine learning to establish a benchmark optimization model for ROP and drilling cycle, in order to lay a foundation for drilling operations to improve operating efficiency and reduce operating costs.
Automatic Trend Tracking Model for Coalbed Methane Production Forecast
Authors: Qingzhong Zhu , Haiwei Du , Qiujia Hu , Bin Fan , Jigang Wang , Jiasheng Yu , Hongli Wang 
Published: May 2021

Abstract
Nowadays, huge quantities of coalbed methane (CMB) well production data have been saved in the fields’ database, which declares that the industry of CBM enters the age of Big Data. The traditional gas production data analysis methods, such as the decline curve and type curve, are not effective for complex production conditions. So, we proposed an automatic segmentation trend tracking Model for the CBM production forecast, which is based on the production data and is more robust for the complex production condition.
Calculation and Simulation of Eddy Current Magnetic Field of Ellipsoid in Changing Magnetic Field
Authors: Wen Haodong , Liu Shengdao , Ouyang Jianfeng 
Published: May 2021

Abstract
The eddy current magnetic field generated by the ellipsoid in the changing magnetic field is theoretically deduced and calculated and simulated. The theoretical calculation and the value obtained by the simulation are compared and verified and the error is analyzed. It can be seen from the fitting results that the theoretical calculation method used in this paper and the simulation result have reached a 93% degree of fit, indicating that this method has a certain reference value for the study of the spatial distribution of the eddy current magnetic field.
Material identification in nuclear waste drums using muon scattering tomography and multivariate analysis
Authors: Weekes M.J. , Alrheli A.F. , Barker D. , Kikoła D. , Kopp A.K. , Mhaidra M. , Stowell J.P. , Thompson L.F. , Velthuis J.J. 
Published: May 2021

Abstract
The use of muon scattering tomography for the non-invasive
characterisation of nuclear waste is well established. We report
here on the application of a combination of feature discriminators
and multivariate analysis techniques to locate and identify
materials in nuclear waste drums. After successful training and
optimisation of the algorithms they are then tested on a range of
material configurations to assess the system's performance and
limitations. The system is able to correctly identify uranium, iron
and lead objects on a few cm scale. The system's sensitivity
to small uranium objects is also established as
0.90+0.07
-0.12, with a false positive rate of
0.12+0.12
-0.07.
Flash drought in Australia and its relationship to evaporative demand
Authors: Parker Tess , Gallant Ailie , Hobbins Mike , Hoffmann David 
Published: May 2021

Abstract
Flash droughts can be distinguished by rapid intensification from near-normal soil moisture to drought conditions in a matter of weeks. Here, we provide the first characterisation of a climatology of flash drought across Australia using a suite of indices. The experiment is designed to capture a range of conditions related to drought: evaporative demand describes the atmospheric demand for moisture from the surface; precipitation, the supply of moisture from the atmosphere to the surface; and evaporative stress, the supply of moisture from the surface relative to the demand from the atmosphere. We show that regardless of the definition, flash droughts occur in all seasons. They can terminate as rapidly as they start, but in some cases can last many months, resulting in a seasonal-scale drought. We show that flash-drought variability and its prevalence can be related to phases of the El Niño–Southern Oscillation, highlighting scope for seasonal-scale prediction. Using a case study in southeast Australia, we show that monitoring precipitation is less useful for capturing the onset of flash drought as it occurs. Instead, indices like the Evaporative Demand Drought Index and Evaporative Stress Index are more useful for monitoring flash-drought development.
The 11 year solar cycle UV irradiance effect and its dependency on the Pacific Decadal Oscillation
Authors: Guttu Sigmund , Orsolini Yvan , Stordal Frode , Otterå Odd Helge , Omrani Nour-Eddine 
Published: May 2021

Abstract
The stratospheric, tropospheric and surface impacts from the 11 year ultraviolet solar spectral irradiance (SSI) variability have been extensively studied using climate models and observations. Here, we demonstrate using idealized model simulations that the Pacific Decadal Oscillation (PDO), which has been shown to impact the tropospheric and stratospheric circulation from sub-decadal to multi-decadal timescales, strongly modulates the solar-induced atmospheric response. To this end, we use a high-top version of the coupled ocean–atmosphere Norwegian Climate Prediction Model forced by the SSI dataset recommended for Coupled Model Intercomparison Project 6. We perform a 24-member ensemble experiment over the solar cycle 23 in an idealized framework. To assess the PDO modulation of the solar signal, we divide the model data into the two PDO phases, PDO+ and PDO−, for each solar (maximum or minimum) phase. By compositing and combining the four categories, we hence determine the component of the solar signal that is independent of the PDO and the modulation of the solar signal by the PDO, along with the solar signal in each PDO phase. Reciprocally, we determine the PDO effect in each solar phase. Our results show that the intensification of the polar vortex under solar maximum is much stronger in the PDO− phase. This signal is transferred into the troposphere, where we find a correspondingly stronger polar jet and weaker Aleutian Low. We further show that the amplification of the solar signal by the PDO− phase is driven by anomalous meridional advection of solar-induced temperature anomalies over northern North America and the North Pacific, which contributes to a decreased meridional eddy heat flux and hence to a decreased vertical planetary wave flux into the stratosphere.
Improving the snowpack monitoring in the mountainous areas of Sweden from space: a machine learning approach
Authors: Zhang Jie , Pohjola Veijo A , Pettersson Rickard , Norell Björn , Marchand Wolf-Dietrich , Clemenzi Ilaria , Gustafsson David 
Published: May 2021

Abstract
Under a warming climate, an improved understanding of the water stored in snowpacks is becoming increasingly important for hydropower planning, flood risk assessment and water resource management. Due to inaccessibility and a lack of ground measurement networks, accurate quantification of snow water storage in mountainous terrains still remains a major challenge. Remote sensing can provide dynamic observations with extensive spatial coverage, and has proved a useful means to characterize snow water equivalent (SWE) at a large scale. However, current SWE products show very low quality in the mountainous areas due to very coarse spatial resolution, complex terrain, large spatial heterogeneity and deep snow. With more high-quality satellite data becoming available from the development of satellite sensors and platforms, it provides more opportunities for better estimation of snow conditions. Meanwhile, machine learning provides an important technique for handling the big data offered from remote sensing. Using the Överuman Catchment in Northern Sweden as a case study, this paper explores the potentials of machine learning for improving the estimation of mountain snow water storage using satellite observations, topographic factors, land cover information and ground SWE measurements from the spatially distributed snow survey. The results show that significantly improved SWE estimation close to the peak of snow accumulation can be achieved in the catchment using the random forest regression. This study demonstrates the potentials of machine learning for better understanding the snow water storage in mountainous areas.
Linear stability analysis of double rows of point vortices for an inviscid generalized two-dimensional fluid system
Authors: Iwayama Takahiro , Watanabe Takeshi 
Published: May 2021

Abstract
The linear stability of double rows of equidistant point vortices for an inviscid generalized two-dimensional (2D) fluid system is studied. This system is characterized by the relation q = −(Δ)
α/2
ψ between the active scalar q and the stream function ψ. Here, α is a positive real number not exceeding 3, and q is referred to as the generalized vorticity. The stability of double rows of equidistant point vortices for a 2D Euler system (α = 2) is a well-known classical problem and was originally investigated by Kármán approximately 100 years ago. Two types of vortex rows, i.e., symmetrical and staggered arrangements of vortex rows, are considered in this study. Special attention is paid to the effect of the parameter α on the stability of vortex rows. As is well-known, the symmetrical vortex rows for the Euler system are unstable, whereas the staggered vortex rows are neutrally stable only when the transverse-to-longitudinal spacing ratio k is

k
=

π

−
1

cosh

−
1

2

. Irrespective of α, the symmetrical vortex rows for the generalized 2D fluid system are unstable, whereas the staggered vortex rows are neutrally stable. The stable spacing ratio of the staggered vortex rows is a decreasing function of α for 0.63 ≲ α and approaches zero as α → 3. In contrast, a finite stable region of the spacing ratio is found when α ≲ 0.63. It turns out that the deformation and usual vorticity induced by the point vortices and their coupling play important roles on the stability of the staggered vortex rows.
Retraction: Assessment of Ecological Risk of Soil in Rapid Urbanization Area by Risk Regionalization (IOP Conf. Ser.: Earth Environ. Sci.
687 012169)
Authors: Zhao Run , Li Ning 
Published: May 2021

This article has been retracted at the request of the authors, who admit a similar paper has already been published based on the same project [1] . IOP Publishing confirms significant overlap between the two articles and agrees to retract on the basis of redundant publication. IOP Publishing expresses additional concern regarding the authorship of the article, which differs between the two articles. The authors state that all authors of the two papers are members of the same research group, and research achievements are the joint property of the group. This conflicts with the IOP Publishing ethical policy, which states all those who have made a significant contribution are cited as co-authors. Any other individuals who have contributed to the study in a lesser capacity should be acknowledged.
[1] Xiaoying Ye and Chaofeng Shao 2018, Ecological Risk Assessment of Soil in Rapid Urbanization Area by Risk Regionalization, International Conference on Advanced Chemical Engineering and Environmental Sustainability (ICACEES 2018) http://www.dpi-proceedings.com/index.php/dtetr/article/view/25496/24910

Retraction published: 06 May 2021
The Analysis Research on the Scheme of Moving Functions in the NC Lathe Turning the Free Surface
Authors: Xu Qiang , jian Hai , Wan Jun , Baker Vernon 
Published: May 2021

Abstract
In order to solve the design problem of the scheme of moving functions in the NC lathe turning the free surface, the work piece is cut into n equal parts along the height h, set up the continuous and smooth Centre line of the n equal parts, each equal part is compared of a generatrix and a guide line. Using the generative design principle, the mathematical describing matrixes of the generating line and the cutting point of turning tool are first established. Thus, determine the positional and gesture matrixes of the turning tool. Since the positional and gesture matrixes are achieved through the cascade matrixes, the possible motion schemes of the tandem machine tools for turning free-form surface is decided, a solid foundation is laid for optimizing the design of the CNC lathes and compound machine tools.
Development and testing of a hydraulic-driven cutting saw system applied for 7,000m JIAOLONG Human Occupied Vehicle
Authors: Shi Xianpeng , Ren Chong , Liu Baohua 
Published: May 2021

Abstract
In this paper, a hydraulic-driven cutting saw system applied for 7,000m JIAOLONG Human Occupied Vehicle was researched and designed according to real applications including underwater cutting engineering, underwater salvage, marine scientific research and others. Firstly, based on the spatial arrangement of JIAOLONG manned submersible’s sampling basket and the actual operation requirement of JIAOLONG’s manipulator, the preliminary design for the cutting saw system is carried out using Solidworks software. Then, the detailed design of the system was conducted in accordance with the selected motor, and the the torque provided by the motor, the tangential force of the saw disk, the linear velocity of the saw disk, and the flow and power for this motor can be calculated successively. Based on the design and calculation, this system was assembled and the pressure-resistant test for this system was smoothly conducted in a pressure testing tank. Finally, the cutting experiment was carried out successfully, which had verified the feasibility of the system design.
Contribute to knowledge about risks in implementing green building projects in developing countries: a case of Vietnam
Authors: Nguyen Hung D , Do Quang N H , Macchion Laura 
Published: May 2021

Abstract
In recent years there has been significant interest in investigating risks linked to the implementation of Green Building (GB) projects that are in line with the developing trend of sustainable construction over the world. In an attempt to contribute to GB risks literature, this study explored risk factors that GB projects frequently confront in Vietnam. This study firstly conducted a comprehensive literature review to generate a preliminary list of risk factors. These risk factors were then confirmed and complemented by interviewing ten experts in the field. After that, the research assessed the risk factors by surveying 119 construction professionals to discover the most critical GB risks. Notably, this paper considered the effect on the risk assessment process of GB experience and project roles. Results showed that “The owner lacks determination,” “Late involvement of GB consultants,” and “Project evaluation result did not reach the expected GB standard” were the top three critical risks in GB projects. The statistical analysis also revealed that the assessment of GB risk negatively correlated with participants’ GB practical experience. Furthermore, hierarchical moderated regression analysis exposed differences in the risk assessment between various project roles, though these differences were relatively small and not statistically significant. By investigating GB projects’ main risks, this paper may become a useful reference guide within the construction sector. This research also enriches the literature by contributing empirical evidence of risk assessment in GB projects in a developing country.
Building techniques in the Late Upper Paleolithic of the Baikal-Patom Upland according to archaeological data
Authors: Tetenkin A V 
Published: May 2021

Abstract
The article is devoted to the description of the results of the study of key archaeological sites of the Late Upper Paleolithic (19–12 Kyr BP) Bolshoi Yakor I and Kovrizhka II-IV on the River Vitim, in the Baikal-Patom highlands, in such an activity as the organization of living space. We consider evidence from the simplest organization of a fireplace and hearth to the most complex building of dwellings. It is noted that this type of activity had practical and symbolic aspects. The data on chronologically in-depth translation of specific techniques in this area are given. In general, the type of activity on the arrangement of a comfortable living space is characterized as an important part of the adaptive cultural complex aimed at the survival of the ancient population under the conditions of the Last Glacial Period.
Economic and functional efficiency of the digital platform of urban traffic control
Authors: Grushina O V , Sergeev A A , Shelomentseva N N 
Published: May 2021

Abstract
The paper is devoted to the development of urban planning activities in the field of urban traffic control via the expedient economic methods for solving the problems of road congestion, in particular, using the tax on congestion. The present study includes a comprehensive analysis of economic factors and methods of economic regulation to address the issues related to traffic congestion in a modern city. It has been found that the total costs of the trip affect the individual decision concerning the method, time and route of the trip. The economic regulation of this allows the optimal value of traffic density to be achieved. The application of this approach in combination with other economic and urban-planning methods in the field of urban-planning regulation and transport planning enables to significantly reduce or completely eliminate the problem of traffic congestion on the main streets of the city. Consequently, a comprehensive economic approach to elimination of traffic congestion in Irkutsk has been developed. The effectiveness of investments in an IP video surveillance system and transport fixation is justified. The choice of time periods and sections of city roads for levying tax for maintaining good city roads is analyzed.
Innovative approaches to organizing examination work of expertise, promoting products and services based on the principles of system management
Authors: Olinovich N A , Ryabchenkova A V 
Published: May 2021

AbstractInnovation is an essential element of the economic development of modern organizations and enterprises. They have a dual impact on the dynamics of economic growth: on the one hand, they open up new opportunities for economic expansion, on the other, they make it impossible to continue this expansion in traditional directions. The state, society, business organizations are consumers of innovative products. This is why, as a research and educational system, many universities, especially National Research Universities, can become suppliers of innovative products based on their research, educational and manufacturing sites. The article considers one of the options for the possible integration of scientific and educational potential into the market of innovative products by organizing the work process of the Center for Expertise and Promotion of Innovative Urban Planning Products on the basis of the principles of system management: customer orientation, leadership, staff interaction, process approach, improvement, fact-based decisions, relationship management. This approach will ensure high productivity and will contribute to customer satisfaction with innovative products. The considered process includes the stages of creating a bank of innovative products and promoting products among potential consumers in the market.
Analysis of the population travel behavior and its impact on the urban environment improvement
Authors: Semenov Yu , Semenova O , Shtotskaya A 
Published: May 2021

AbstractThe article draws attention to the necessity of studying the composition of pedestrian flows and the urban areas where they form, move and disperse to improve the urban environment. In modern cities, especially megacities, most pedestrian flows participate in the transport correspondence appearance, which is due to long distances between the locations of origin and destination. A software package calculating the transport area capacity depending on the number of departees uses disaggregate models of travel demand and develops an O-D Matrix. Analysis of the results obtained allows us to assess changes in transportation demand caused by socioeconomic and urban development factors.