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Optimization study of station track utilization in high-speed railroad based on constraints of control in random origin and process
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作者 Yajing Zheng Dekun Zhang 《Railway Sciences》 2024年第3期332-343,共12页
Purpose-The purpose of this paper is to eliminate the fluctuations in train arrival and departure times caused by skewed distributions in interval operation times.These fluctuations arise from random origin and proces... Purpose-The purpose of this paper is to eliminate the fluctuations in train arrival and departure times caused by skewed distributions in interval operation times.These fluctuations arise from random origin and process factors during interval operations and can accumulate over multiple intervals.The aim is to enhance the robustness of high-speed rail station arrival and departure track utilization schemes.Design/methodologylapproach-To achieve this objective,the paper simulates actual train operations,incorporating the fluctuations in interval operation times into the utilization of arrival and departure tracks at the station.The Monte Carlo simulation method is adopted to solve this problem.This approach transforms a nonlinear model,which includes constraints from probability distribution functions and is difficult to solve directly,into a linear programming model that is easier to handle.The method then linearly weights two objectives to optimize the solution.Findings-Through the application of Monte Carlo simulation,the study successfully converts the complex nonlinear model with probability distribution function constraints into a manageable linear programming model.By continuously adjusting the weighting coefficients of the linear objectives,the method is able to optimize the Pareto solution.Notably,this approach does not require extensive scene data to obtain a satisfactory Pareto solution set.Originality/value-The paper contributes to the field by introducing a novel method for optimizing high-speed rail station arrival and departure track utilization in the presence of fluctuations in interval operation times.The use of Monte Carlo simulation to transform the problem into a tractable linear programming model represents a significant advancement.Furthermore,the method's ability to produce satisfactory Pareto solutions without relying on extensive data sets adds to its practical value and applicability in real-world scenarios. 展开更多
关键词 Control in random origin Control in random process High-speed railroad station Arrival and departure track utilization optimization Paper type research paper
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Evaluation of the effectiveness of preventive nursing measures for pressure injuries in patients in the neurology intensive care unit
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作者 Rong Zhang Peng-Xin Ma Juan-Juan Zhang 《World Journal of Clinical Cases》 SCIE 2024年第19期3807-3814,共8页
BACKGROUND Patients in neurology intensive care units(ICU)are prone to pressure injuries(PU)due to factors such as severe illness,long-term bed rest,and physiological dysfunction.PU not only causes pain and complicati... BACKGROUND Patients in neurology intensive care units(ICU)are prone to pressure injuries(PU)due to factors such as severe illness,long-term bed rest,and physiological dysfunction.PU not only causes pain and complications to patients,but also increases medical burden,prolongs hospitalization time,and affects the recovery process.AIM To evaluate and optimize the effectiveness of pressure injury prevention nursing measures in neurology ICU patients.METHODS A retrospective study was conducted,and 60 patients who were admitted to the ICU of the Department of Neurology were selected and divided into an observation group and a control group according to the order of admission,with 30 people in each group.The observation group implemented pressure injury prevention and nursing measures,while the control group adopted routine care.RESULTS Comparison between observation and control groups following pressure injury prevention nursing intervention revealed significantly lower incidence rates in the observation group compared to the control group at 48 h(8.3%vs 26.7%),7 d(16.7%vs 43.3%),and 14 d(20.0%vs 50.0%).This suggests a substantial reduction in pressure injury incidence in the observation group,with the gap widening over time.Additionally,patients in the observation group exhibited quicker recovery,with a shorter average time to get out of bed(48 h vs 72 h)and a shorter average length of stay(12 d vs 15 d)compared to the control group.Furthermore,post-intervention,patients in the observation group reported significantly improved quality of life scores,including higher scores in body satisfaction,feeling and function,and comfort(both psychological and physiological),indicating enhanced overall well-being and comfort following the implementation of pressure injury prevention nursing measures.CONCLUSION Implementing pressure injury preventive care measures for neurology ICU patients will have better results. 展开更多
关键词 Neurology intensive care units Pressure injury Preventive care Effect evaluation optimization research Prognostic effect
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Optimization of energy consumption structure based on carbon emission reduction target:A case study in Shandong Province,China 被引量:1
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作者 Jixiang Liu Haichao Ma +7 位作者 Qingsong Wang Shu Tian Yue Xu Yujie Zhang Xueliang Yuan Qiao Ma Yuan Xu Shuo Yang 《Chinese Journal of Population,Resources and Environment》 2022年第2期125-135,共11页
It is urgent to significantly reduce greenhouse gas emissions to actively deal with global warming.This paper investigates Shandong Province,a typical province of energy consumption,as the research object,aiming to op... It is urgent to significantly reduce greenhouse gas emissions to actively deal with global warming.This paper investigates Shandong Province,a typical province of energy consumption,as the research object,aiming to optimize total energy consumption and consumption structure in the future planning year.This paper constructs a methodological system to optimize energy consumption structure in Shandong Province,using a scenario combination of system dynamics(SD)prediction and analysis based on the coupling of key scenario elements affecting different energy consumption from different perspectives.Structural equation modeling and SD sensitivity analysis indicate an overlap between key factors restricting energy consumption.Pairing the key scenario factors can better reflect the internal mechanism of energy consumption development.Based on this,21 scenarios based on different combinations of the key elements are constructed.Through SD prediction and analysis,the most suitable scenario mode for optimizing energy consumption structure in Shandong Province is selected.This paper provides a suitable development range for the average gross domestic product growth rate,the proportion of secondary industry,energy consumption intensity of secondary industry,and the urbanization rate for Shandong Province.This paper can provide a reference for similar research and the government in formulating the optimization scheme of energy consumption structure. 展开更多
关键词 Energy consumption structure System dynamics Structural equation Scenario combination analysis Carbon emissions optimization research
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Research on and Design of Mechanical System with Optimal Cutting Movement Trajectory of Energy-Saving Stone-Sawing Machine
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作者 WANG Ji-rong 1, LI Lan-ji 1, LI Jun 1,3, LI Hua 2, ZHONG Yun-qing 3 (1.Qingdao University, Qingdao 266071, China 2.Wendeng Foreign Economic and Trade Corp, Wendeng 264400, China 3.Qingdao University of Science and Technology, Qingdao 266042, China) 《厦门大学学报(自然科学版)》 CAS CSCD 北大核心 2002年第S1期140-141,共2页
The technique of cutting slabstone with stone-sawi ng machine is analyzed completely. A new kind of cutting movement trajectory is gi ven whose actual cutting efficiency is near to 100%. It can reduce the energy w ear... The technique of cutting slabstone with stone-sawi ng machine is analyzed completely. A new kind of cutting movement trajectory is gi ven whose actual cutting efficiency is near to 100%. It can reduce the energy w earing greatly, and the surface quality of the product is improved to the utmost extent. The design mechanism of the optimal cutting movement trajectory system structure is analyzed incisively. At the same time, the principle of the complex movement of horizontal movement and swing is researched. The optimal design scheme of th e cutting movement trajectory system structure is set up. The choice method to g et the superior value of the movement system structure is found. The mathematics function formula is established which exhibits the relationship between the par ameter of the complex movement structure and that of the system movement structu re. By the formula, the precision value of the offset can be figured out. The r ule is adapted to different types of energy-saving stone-sawing machines. The complex movement structure of horizontal movement and swing is designed to f ulfill the cutting movement. It can make the saw frame move up with the hanging pod deviating from the vertical direction. At the same time, the saw frame have a down-movement. Then the sum of the two movements is near to zero, and the saw blade and the stone can keep in touch during the whole horizontal cutting. The result is that the actual cutting efficiency is 100%. Also, when the hanging pod moves to the limited position, the saw frame can keep the original inertia, and continue to swing up. It makes the back-cutting have high energy-storing. The optimal design of the eccentricity balance wheel is done. The mathematics fo rmula for expressing the movement system structure is deduced. The calculation m ethod and formula is set up which is used to get the value of important componen ts such as offset. The choice method and formula of elasticity distortion coeffi cient is set up when the saw frame moves smoothly. It is concluded that the offs et is the key dimension to actualize the optimal cutting movement trajectory. The resolving of the technical problems discussed above offers a theoretic and technical basis for optimal design of energy-saving stone-sawing machines. 展开更多
关键词 DESIGN research on and Design of Mechanical System with Optimal Cutting Movement Trajectory of Energy-Saving Stone-Sawing Machine
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Series.the university English four, six level of test examination management in institutions of higher education
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作者 Hu Shuangxi 《Review of Global Academics》 2015年第2期544-549,共6页
college English test band 4 and band 6 is a national examination, the examination organization work is particularly important in this article, through combing the examination link, and takes the examination of the for... college English test band 4 and band 6 is a national examination, the examination organization work is particularly important in this article, through combing the examination link, and takes the examination of the foreign affairs college as an example summarizes work experience, and examination work for the future optimization put forward opinions and Suggestions, in order to achieve the purpose of better service for the teaching service for students. 展开更多
关键词 college English cet examinationmanagement optimization of research
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NEW METHOD OF SIMULATING CONCENTRATED DRAIN HOLES IN SEEPAGE CONTROL ANALYSIS 被引量:22
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作者 Zhan Mei li, Su Bao yu , Liu Jun yong, Shen Zhen zhong College of Water Conservancy and Hydropower Engineering, Hohai University, Nanjing 210098, P.R.China (Received Aug.1, 1998) 《Journal of Hydrodynamics》 SCIE EI CSCD 1999年第3期27-35,共9页
In this paper, based upon the basic solution of sink, the approximate solution of single drain hole in finite elements is derived by use of the superposition principle. Then, the theoretical solution is extended to th... In this paper, based upon the basic solution of sink, the approximate solution of single drain hole in finite elements is derived by use of the superposition principle. Then, the theoretical solution is extended to the case of some drain holes in one finite element, and the method is used in seepage control analysis with quick convergence and high accuracy. On the other hand, if the positions of the drain holes are changed, only some control factors of drain holes are changed, but the finite element grid need not to be reformed. Therefore, the method is more suitable in optimal research of seepage control. 展开更多
关键词 concentrated drain hole approximate solution seepage control optimal research
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