scholarly journals Deflection Laws of Gas Drainage Boreholes in Interbedded Soft and Hard Seams: A Case Study at Xinzheng Coal Mine, China

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Xiaoyan Sun ◽  
Zhiheng Cheng ◽  
Liang Chen ◽  
Zhenhua Li ◽  
Hongbing Wang ◽  
...  
Keyword(s):  
Deflection Angle ◽  
Critical Value ◽  
Analytic Hierarchy ◽  
Gas Drainage ◽  
Effective Measure ◽  
Factors Affecting ◽  
Ahp Model ◽  
Theoretical Predictions ◽  
Geological Situation ◽  
Geological Factors

Coal and gas outbursts can lead to serious disasters in coal mines. The drilling of boreholes to predrain the gas is an effective measure for preventing such accidents. However, due to the complexity of the geological situation, the drilling trajectory often deviates from the design trajectory, resulting in poor gas extraction. To solve the problem of gas drainage borehole deflection, an analytic hierarchy process (AHP) model is established based on geological factors, technical factors, and human factors. The AHP model is used to rank the weights of various influencing factors, and the analysis is combined with a drilling model and engineering examples. Finally, the results show that soft and hard interlayers are the most important factors affecting the deflection of the borehole. The rock drilling model is mainly affected by the formation forces. The regularity of the change in the azimuth angle during drilling is not obvious when the angle of the encountered layer is less than some critical value. When the borehole is skewed downward, the deflection angle ranges from 0 to 4°, and the deflection of the borehole occurs mainly at the interface of the rock layers. When the angle of the encountered layer is greater than the critical value, the borehole is skewed upward, with a deflection angle of 0–6°, and the deflection occurs at the rock interface. The trajectory curve obtained by theoretical predictions from field data is found to be consistent with that of an actual project.

Flight Safety Assessment of Airlines Based on Analytic Hierarchy Process

2013 ◽  
Vol 706-708 ◽  
pp. 2002-2006
Author(s):  
Xing Zhong Wen
Keyword(s):  
Risk Assessment ◽  
Analytic Hierarchy Process ◽  
Flight Safety ◽  
Analytic Hierarchy ◽  
Effective Measure ◽  
Safety Risk ◽  
Factors Affecting ◽  
Set Up ◽  
Hierarchy Process ◽  
Airline Company

Risk assessment to flight safety is an effective measure to ensure safe operation of airline companies. There are many factors affecting the flight safety, so the analytic hierarchy process (AHP) is introduced to assess the risk. In this paper, an index system of airline company flight safety risk assessment is established. A model of airline company flight safety risk assessment based on analytic hierarchy process (AHP) is also set up. An example is used to show the application of this method. The result shows that this method is rational and pragmatic in airline company flight safety risk evaluation.

scholarly journals Application of Mathematical and Computational Methods to Identify Women’s Priorities in Transport

2021 ◽  
Vol 13 (5) ◽  
pp. 2845
Author(s):  
Sara Poveda-Reyes ◽  
Ashwani Kumar Malviya ◽  
Elena García-Jiménez ◽  
Gemma Dolores Molero ◽  
Maria Chiara Leva ◽  
...  
Keyword(s):  
Transport System ◽  
Autonomous Vehicles ◽  
Transport Sector ◽  
Sustainable Society ◽  
Analytic Hierarchy ◽  
Family Responsibilities ◽  
Factors Affecting ◽  
Participation Of Women ◽  
Bike Sharing ◽  
Safe Transport

It is well established that the transport sector is not an equalitarian sector. To develop a sustainable society, a more equalitarian and safe transport system for both users and transport sector employees is needed. This work prioritizes the needs and barriers previously identified as relevant among transport system users and employees for four different transport scenarios (railways, autonomous vehicles (AVs), bicycle-sharing services (BSSs), and employment). The aim of this paper is to prioritize the factors affecting women in these four transport scenarios with the help of a survey followed by the application of mathematical and computational algorithms based on the analytic hierarchy process (AHP) methodology. The identification of factors with higher influence in the fair participation of women in the transport sector will help transport planners, bike-sharing system owners, decision-makers, transport companies, and regulatory professionals to develop measures that could plausibly increase the proportion of women as users of BSSs, users of rail public transport, and AVs, as well as employees in the transport sector for a sustainable society. The results indicated that safety and security were the most challenging factors for railways. Weather, topography, and family responsibilities were shown to have a high influence on the use of BSSs. In the case of autonomous vehicles, the simultaneity and trust in the technology are the main opportunities to influence the acceptance of such vehicles. Finally, for transport employment, caring and parenting responsibilities were the factors that had the largest effect. Some differences in priorities were found for different profiles of women.

scholarly journals Socioeconomic Risks and Their Impacts on Ecological River Health in South Korea: An Application of the Analytic Hierarchy Process

2021 ◽  
Vol 13 (11) ◽  
pp. 6287
Author(s):  
Suyeon Kim ◽  
Sang-Woo Lee ◽  
Se-Rin Park ◽  
Yeeun Shin ◽  
Kyungjin An
Keyword(s):  
South Korea ◽  
Socioeconomic Factors ◽  
Ecosystem Health ◽  
Relative Importance ◽  
River Ecosystem ◽  
River Health ◽  
Analytic Hierarchy ◽  
Factors Affecting ◽  
Factors Influencing ◽  
Hierarchy Process

It is imperative to develop a methodology to identify river impairment sources, particularly the relative impact of socioeconomic sources, to enhance the efficiency of various river restoration schemes and policies and to have an internal diagnosis system in place. This study, therefore, aims to identify and analyze the relative importance of the socioeconomic factors affecting river ecosystem impairment in South Korea. To achieve this goal, we applied the Analytical Hierarchy Process (AHP) to evaluate expert judgement of the relative importance of different socioeconomic factors influencing river ecosystem impairment. Based on a list of socioeconomic factors influencing stream health, an AHP questionnaire was prepared and administered to experts in aquatic ecology. Our analysis reveals that secondary industries form the most significant source of stream ecosystem impairment. Moreover, the most critical socioeconomic factors affecting stream impairment are direct inflow pollution, policy implementation, and industrial wastewater. The results also suggest that the AHP is a rapid and robust approach to assessing the relative importance of different socioeconomic factors that affect river ecosystem health. The results can be used to assist decision makers in focusing on actions to improve river ecosystem health.

scholarly journals Analysis of Factors Influencing Effective Utilization Coefficient of Irrigation Water in the Manas River Basin

Water ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 189
Author(s):  
Lili Yang ◽  
Tong Heng ◽  
Guang Yang ◽  
Xinchen Gu ◽  
Jiaxin Wang ◽  
...  
Keyword(s):  
Irrigation Water ◽  
Large Scale ◽  
Grey Model ◽  
Analytic Hierarchy ◽  
Effective Utilization ◽  
Factors Affecting ◽  
Factors Influencing ◽  
Utilization Coefficient ◽  
Using Data ◽  
Effective Use

The factors influencing the effective utilization coefficient of irrigation water are not understood well. It is usually considered that this coefficient is lower in areas with large-scale irrigation. With this background, we analyzed the effective utilization coefficient of irrigation water using the analytic hierarchy process using data from 2014 to 2019 in Shihezi City, Xinjiang. The weights of the influencing factors on the effective utilization coefficient of irrigation water in different irrigation areas were analyzed. Predictions of the coefficient’s values for different years were made by understanding the trends based on the grey model. The results show that the scale of the irrigation area is not the only factor determining the effective utilization coefficient of irrigation water. Irrigation technology, organizational integrity, crop types, water price management, local economic level, and channel seepage prevention are the most critical factors affecting the effective use of irrigation water. The grey model prediction results show that the effective utilization coefficient of farmland irrigation water will continuously increase and reach 0.7204 in 2029. This research can serve as a reference for government authorities to make scientific decisions on water-saving projects in irrigation districts in terms of management, operation, and investment.

scholarly journals A Multi-Criteria Decision-Making (MCDM) Approach Using Hybrid SCOR Metrics, AHP, and TOPSIS for Supplier Evaluation and Selection in the Gas and Oil Industry

Processes ◽  
2018 ◽  
Vol 6 (12) ◽  
pp. 252 ◽  
Author(s):  
Chia-Nan Wang ◽  
Ying-Fang Huang ◽  
I-Fang Cheng ◽  
Van Nguyen
Keyword(s):  
Decision Making ◽  
Supplier Selection ◽  
Raw Materials ◽  
Oil Industry ◽  
Supplier Evaluation ◽  
Multi Criteria Decision Making ◽  
Analytic Hierarchy ◽  
Ahp Model ◽  
Decision Making Unit ◽  
Stability And Accuracy

Suppliers are extremely important in business operations. The supplier ensures the supply of materials, raw materials, commodities, etc. in sufficient quantity, quality, stability, and accuracy to meet the requirements of production and business with low costs and on-time deliveries. Therefore, selecting and managing good suppliers is a prerequisite for organizing the production of quality products as desired, according to the schedule, and with reasonable prices and competitiveness in the market. It is also important to gain the support of suppliers in order to continue to improve and achieve more as a business. The evaluation and selection of a supplier is a Multi-Criteria Decision-Making (MCDM) issue, in which the decision-maker is faced with both qualitative and quantitative factors. In this research, the authors propose an MCDM model using a hybrid of Supply Chain Operations Reference metrics (SCOR metrics), the Analytic Hierarchy Process (AHP) model, and the Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) approach for supplier evaluation and selection in the gas and oil industry. Using literature reviews on SCOR metrics, all criteria that impact supplier selection are defined in the first stage, the AHP model is applied to determine the weight of each factor in the second stage, and the optimal supplier is presented in final stage using the TOPSIS model. As a result, Decision-Making Unit 5 (DMU-05) is found to be the best supplier for the gas and oil industry in this research. The contribution of this work is to propose a new hybrid MCDM model for supplier selection in the gas and oil industry. This research also introduces a useful tool for supplier selection in other industries.

scholarly journals Assessing the Safety Factors of Ship Berthing Operations

2014 ◽  
Vol 68 (3) ◽  
pp. 576-588 ◽  
Author(s):  
Wen-Kai Kevin Hsu
Keyword(s):  
Emergency Response ◽  
Relevant Literature ◽  
Safety Index ◽  
Safety Factors ◽  
Mooring Lines ◽  
Analytic Hierarchy ◽  
Factors Affecting ◽  
Managerial Implications ◽  
Ship Berthing ◽  
Hierarchy Process

The purpose of this paper is to discuss the safety of ship berthing operations in port. Based on the features of ship's berthing operations and relevant literature, the Safety Factors (SFs) of ship berthing at docks are first investigated. A Safety Index (SI) with a Fuzzy Analytic Hierarchy Process (AHP) model is then proposed to assess those SFs from port marine pilots, by which port managers and ship carriers may make policies to improve ship berthing safety. To validate the model, berthing operations at Kaohsiung Port in Taiwan were empirically investigated. The results indicate the main safety factors affecting ship berthing at port docks are: working concentration, the condition of mooring lines, emergency response, port policy of improving business and berth length. Based on those results, the theoretical and managerial implications for ship berthing safety at dock are finally discussed.

scholarly journals Prioritization of factors affecting the safety of sport facilities in Kermanshah Based on AHP

2017 ◽  
Vol 7 (2) ◽  
pp. 129
Author(s):  
Bahieh Zarei ◽  
Kheidan Hatami ◽  
Zahra Keshtmand
Keyword(s):  
First Aid ◽  
Research Strategy ◽  
Warning Signs ◽  
Sports Facilities ◽  
Factors Affecting ◽  
Ahp Model ◽  
Expert Choice ◽  
Weight Room ◽  
Sport Facilities ◽  
Gathering Data

This prioritize the factors affecting the safety of sport facilities based on AHP model is examined. This research strategy in terms of quantity and type AHP, in terms of sectional, both practical and in terms of gathering data is the type of field. The study was based questionnaire measurement elite views were set. In order to test the hypothesis-of a comparison test was used categories together. The Expert Choice software was used in this study. The findings obtained showed that 27 items in 5 categories are involved in determining the safety of sporting venues. On this basis and according to safety experts, sports facilities and sports equipment is the most important component of the Earth's surface. 0.320 is the significance of these items. Management factors weighing 0.268, 0.182 weight room equipment, first aid dressing and platform weighing 0.134 and 0.094 in second weight with the audience. The results showed that the use of safe floors, the use of qualified instructors, the use of appropriate sports flooring, installing warning signs in the hall and regular periodic visits to the salon equipment coefficients 0.070, 0.059, 0.052, 0.049 and 0.047 of the most important items in the factors affecting the safety of the sport.

scholarly journals Perturbative deflection angle, gravitational lensing in the strong field limit and the black hole shadow

2021 ◽  
Vol 81 (3) ◽  
Author(s):  
Junji Jia ◽  
Ke Huang
Keyword(s):  
Gravitational Lensing ◽  
Deflection Angle ◽  
Strong Field ◽  
Distance Effect ◽  
Critical Value ◽  
Field Limit ◽  
Perturbative Method ◽  
The Deflection Angle ◽  
The Impact ◽  
Strong Field Limit

AbstractA perturbative method to compute the deflection angle of both timelike and null rays in arbitrary static and spherically symmetric spacetimes in the strong field limit is proposed. The result takes a quasi-series form of $$(1-b_c/b)$$ ( 1 - b c / b ) where b is the impact parameter and $$b_c$$ b c is its critical value, with coefficients of the series explicitly given. This result also naturally takes into account the finite distance effect of both the source and detector, and allows to solve the apparent angles of the relativistic images in a more precise way. From this, the BH angular shadow size is expressed as a simple formula containing metric functions and particle/photon sphere radius. The magnification of the relativistic images were shown to diverge at different values of the source-detector angular coordinate difference, depending on the relation between the source and detector distance from the lens. To verify all these results, we then applied them to the Hayward BH spacetime, concentrating on the effects of its charge parameter l and the asymptotic velocity v of the signal. The BH shadow size were found to decrease slightly as l increases to its critical value, and increase as v decreases from light speed. For the deflection angle and the magnification of the images however, both the increase of l and decrease of v will increase their values.

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