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Cumulative effects of excess high-normal alanine aminotransferase levels in relation to new-onset metabolic dysfunction-associated fatty liver disease in China 被引量:6
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作者 Jing-Feng Chen Zhuo-Qing Wu +5 位作者 Hao-Shuang Liu Su Yan You-Xiang Wang Miao Xing Xiao-Qin Song Su-Ying Ding 《World Journal of Gastroenterology》 SCIE CAS 2024年第10期1346-1357,共12页
BACKGROUND Within the normal range,elevated alanine aminotransferase(ALT)levels are associated with an increased risk of metabolic dysfunction-associated fatty liver disease(MAFLD).AIM To investigate the associations ... BACKGROUND Within the normal range,elevated alanine aminotransferase(ALT)levels are associated with an increased risk of metabolic dysfunction-associated fatty liver disease(MAFLD).AIM To investigate the associations between repeated high-normal ALT measurements and the risk of new-onset MAFLD prospectively.METHODS A cohort of 3553 participants followed for four consecutive health examinations over 4 years was selected.The incidence rate,cumulative times,and equally and unequally weighted cumulative effects of excess high-normal ALT levels(ehALT)were measured.Cox proportional hazards regression was used to analyse the association between the cumulative effects of ehALT and the risk of new-onset MAFLD.RESULTS A total of 83.13%of participants with MAFLD had normal ALT levels.The incidence rate of MAFLD showed a linear increasing trend in the cumulative ehALT group.Compared with those in the low-normal ALT group,the multivariate adjusted hazard ratios of the equally and unequally weighted cumulative effects of ehALT were 1.651[95%confidence interval(CI):1.199-2.273]and 1.535(95%CI:1.119-2.106)in the third quartile and 1.616(95%CI:1.162-2.246)and 1.580(95%CI:1.155-2.162)in the fourth quartile,respectively.CONCLUSION Most participants with MAFLD had normal ALT levels.Long-term high-normal ALT levels were associated with a cumulative increased risk of new-onset MAFLD. 展开更多
关键词 Metabolic dysfunction-associated fatty liver disease High-normal alanine aminotransferase level cumulative effect Cox proportional hazards regression Cohort study
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The Cumulative Method for Multiplication and Division
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作者 Muna Mohammed Hammuda 《Applied Mathematics》 2024年第5期349-354,共6页
This paper provides a method of the process of computation called the cumulative method, it is based upon repeated cumulative process. The cumulative method is being adapted to the purposes of computation, particularl... This paper provides a method of the process of computation called the cumulative method, it is based upon repeated cumulative process. The cumulative method is being adapted to the purposes of computation, particularly multiplication and division. The operations of multiplication and division are represented by algebraic formulas. An advantage of the method is that the cumulative process can be performed on decimal numbers. The present paper aims to establish a basic and useful formula valid for the two fundamental arithmetic operations of multiplication and division. The new cumulative method proved to be more flexible and made it possible to extend the multiplication and division based on repeated addition/subtraction to decimal numbers. 展开更多
关键词 Multiplication and Division cumulative Method Repeated Process Decimal Numbers
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Study on cumulative effects of biological craniocerebral trauma under repeated blast
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作者 Xingyuan Huang Bingchen Xia +3 位作者 Lijun Chang Zhikang Liao Hui Zhao Zhihua Cai 《Theoretical & Applied Mechanics Letters》 CAS CSCD 2024年第3期174-183,共10页
Repeated blast impacts on personnel in explosive environments can exacerbate craniocerebral trauma.Most existing studies focus on the injury effects of a single blast,lacking in-depth analysis on the injury effects an... Repeated blast impacts on personnel in explosive environments can exacerbate craniocerebral trauma.Most existing studies focus on the injury effects of a single blast,lacking in-depth analysis on the injury effects and cumulative effects of repeated blasts.Therefore,rats were used as the experimental samples to suffer from explosion blasts with different peak air overpressures(167 kPa~482 kPa)and varying number of repeated blasts.The cumulative effect of craniocerebral trauma was most pronounced for moderate repeated blast,showing approximately 95%increase of trauma severity with penta blast,and an approximately 85%increase of trauma severity with penta minor blast.The cumulative effect of craniocerebral trauma from severe,repeated blast has a smaller rate of change compared to the other two conditions.The severity of trauma from penta blast increased by approximately 69%compared to a single blast.Comprehensive physiological,pathological and biochemical analysis show that the degree of neurological trauma caused by repeated blasts is higher than that of single blasts,and the pathological trauma to brain tissue is more extensive and severe.The trauma degree remains unchanged after double blast,increases by one grade after triple or quadruple blast,and increases by two grades after penta blast. 展开更多
关键词 Repeated blast Craniocerebral trauma Trauma severity grade cumulative effects
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Development of a novel critical nitrogen concentration-cumulative transpiration curve for optimizing nitrogen management under varying irrigation conditions in winter wheat
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作者 Tianyang Ye Yu Zhang +9 位作者 Jingyan Xuan Xintian Wang Yang Li Junhao Xu Liujun Xiao Leilei Liu Liang Tang Weixing Cao Bing Liu Yan Zhu 《The Crop Journal》 SCIE CSCD 2024年第4期1242-1251,共10页
Accurate nitrogen(N)nutrition diagnosis is essential for improving N use efficiency in crop production.The widely used critical N(Nc)dilution curve traditionally depends solely on agronomic variables,neglecting crop w... Accurate nitrogen(N)nutrition diagnosis is essential for improving N use efficiency in crop production.The widely used critical N(Nc)dilution curve traditionally depends solely on agronomic variables,neglecting crop water status.With three-year field experiments with winter wheat,encompassing two irrigation levels(rainfed and irrigation at jointing and anthesis)and three N levels(0,180,and 270 kg ha1),this study aims to establish a novel approach for determining the Nc dilution curve based on crop cumulative transpiration(T),providing a comprehensive analysis of the interaction between N and water availability.The Nc curves derived from both crop dry matter(DM)and T demonstrated N concentration dilution under different conditions with different parameters.The equation Nc=6.43T0.24 established a consistent relationship across varying irrigation regimes.Independent test results indicated that the nitrogen nutrition index(NNI),calculated from this curve,effectively identifies and quantifies the two sources of N deficiency:insufficient N supply in the soil and insufficient soil water concentration leading to decreased N availability for root absorption.Additionally,the NNI calculated from the Nc-DM and Nc-T curves exhibited a strong negative correlation with accumulated N deficit(Nand)and a positive correlation with relative grain yield(RGY).The NNI derived from the Nc-T curve outperformed the NNI derived from the Nc-DM curve concerning its relationship with Nand and RGY,as indicated by larger R2 values and smaller AIC.The novel Nc curve based on T serves as an effective diagnostic tool for assessing winter wheat N status,predicting grain yield,and optimizing N fertilizer management across varying irrigation conditions.These findings would provide new insights and methods to improve the simulations of water-N interaction relationship in crop growth models. 展开更多
关键词 Crop dry matter Crop cumulative transpiration Bayesian statistical model Critical nitrogen dilution curve Nitrogen nutrition index
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Cumulative Air Quality Impacts from Twenty-Two Major Power Plants
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作者 Md M.Karim Navin Bindra Arub Masud 《Journal of Environmental Science and Engineering(A)》 CAS 2024年第1期1-14,共14页
Cumulative assessment is a tool for the project developer to try and take into consideration not only their contribution to cumulative impacts but also other projects and external factors that may place their developm... Cumulative assessment is a tool for the project developer to try and take into consideration not only their contribution to cumulative impacts but also other projects and external factors that may place their developments at risk.This study assessed the cumulative impacts of air emissions from 22 major power plants in southeast Bangladesh planned to generate 21,550 MW of electricity.It also includes anticipated growth in small to medium size industries,brickfields,highway traffic,inland water transport,transhippers,jetty,and vessel transports used for transporting fuel resources for these power plants.A 50 km by 50 km airshed is considered for air quality modeling.Cumulative analysis indicates that predicted MGLCs(Maximum Ground Level Concentrations)of NO2 and CO are complying with both Bangladesh NAAQS(National Ambient Air Quality Standards)and WBG(World Bank Group)Guidelines.The daily average MGLC of PM_(2.5)(62.45µg/m^(3))from all sources complies with NAAQS,however,exceeds the WBG Guidelines.Annual PM_(2.5) concentration(15.45µg/m^(3))exceeds NAAQS and WBG Guidelines.The PM10 concentration complies with the NAAQS for both 24-hour and annual averaging times.Annual average concentration(23.12µg/m^(3))exceeds WBG Guidelines.Daily average SO2 concentration(102.49µg/m^(3))complies with the NAAQS however,it exceeds the WBG guideline values.High concentrations of PM_(2.5) and SO2 are due to the contribution of transboundary emissions and secondary pollutants in the atmosphere.This dispersion modeling outcome can be used by the policymakers for the pollution reduction strategy. 展开更多
关键词 CIA(cumulative Impact Assessment) dispersion modeling power generation Bangladesh.
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Rational screening of metal coating on Zn anode for ultrahigh-cumulative-capacity aqueous zinc metal batteries 被引量:1
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作者 Dan Lv Huili Peng +4 位作者 Cheng Wang Hongxia Liu Dongdong Wang Jian Yang Yitai Qian 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2023年第9期81-88,共8页
Aqueous zinc metal batteries feature intrinsic safety,but suffer from severe dendrite growth and water-derived side reactions.Many metal coatings have been explored for stabilizing Zn metal anode via a trialand-error ... Aqueous zinc metal batteries feature intrinsic safety,but suffer from severe dendrite growth and water-derived side reactions.Many metal coatings have been explored for stabilizing Zn metal anode via a trialand-error approach.Here,we propose an exercisable way to screen the potential metal coating on Zn anodes in view of de-polarization effect and dendrite-suppressing ability theoretically.As an output of this screening,cadmium(Cd) metal is checked experimentally.Therefore,symmetric ZnllZn cells using Cd coated Zn(Zn@Cd) exhibit an ultra-long cycle life of 3500 h(nearly 5 months) at a high current density of 10 mA cm^(-2),achieving a record-high cumulative capacity(35 A h cm^(-2)) compared to the previous reports.The full cells of Zn@Cd‖MnO_(2) display a markedly improved cycling performance under harsh conditions including a limited Zn supply(N/P ratio=1.7) and a high areal capacity(3.5 mA h cm^(-2)).The significance of this work lies in not only the first report of Cd coating for stabilizing Zn metal anode,but also a feasible way to screen the promising metal materials for other metal anodes. 展开更多
关键词 Zinc metal batteries Cadmium coating Redox potentials Surface energy cumulative capacity
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Association ofβ-lactam antimicrobial's exposure with carbapenem-resistant Pseudomonas aeruginosa infection:a cumulative meta-analysis 被引量:1
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作者 Prity Rani Deshwal Muskan Aggarwal +2 位作者 Nalla Surender Reddy Raisa Fathima Pramil Tiwari 《Global Health Journal》 2023年第3期137-146,共10页
Background:Carbapenems are effective against severe Pseudomonas aeruginosa nosocomial infections.Therefore,carbapenem-resistant Pseudomonas aeruginosa is a serious public health threat.An understanding of the risk of ... Background:Carbapenems are effective against severe Pseudomonas aeruginosa nosocomial infections.Therefore,carbapenem-resistant Pseudomonas aeruginosa is a serious public health threat.An understanding of the risk of inappropriate exposure to different antimicrobials in resistant Pseudomonas aeruginosa infection could help in elucidating the effective approach towards using antimicrobials in vulnerable patients with CRPA infection.Object:To investigate the association between exposure ofβ-lactam antimicrobials and CRPA infection relative to control patients.Methods:The MEDLINE/PubMed and OVID/Embase databases were used to search case-control and cohort studies in English language which reported antimicrobial exposure as risk factors for CRPA infection.The pooled odds ratios(OR)were calculated using a random-effect and fixed-effect model,and forest plots from a cumulative meta-analysis method were used to better show how pooled OR changed as updated evidence accumulated.Results:A total of 24 studies comprising 7039 participants were included for cumulative meta-analysis.A positive correlation was found between development of CRPA infection and exposure of beta-lactam antimicrobials:carbapenems(OR=7.60,95%CI:3.95 to 14.62,P<0.0001),imipenem(OR=9.81,95%CI:5.56 to 17.33),ampicillin(OR=1.86,95%CI:1.14 to 2.41),piperacillin(OR=2.82,95%CI:1.46 to 2.43),penicillins(OR=1.42,95%CI:0.90 to 2.24),cephalosporins(OR=1.88,95%CI:1.46 to 2.43)andβlactamase inhibitors(OR=1.96,95%CI:1.44 to 2.67).Further,exposure of other antimicrobial agents like quinolone(OR=2.35,95%CI:1.78 to 3.10),ciprofloxacin(OR=2.35,95%CI:1.66 to 3.95),aminoglycoside(OR=2.17,95%CI:1.60 to 2.95),amikacin(OR=3.11,95%CI:2.10 to 4.61),glycopeptides(OR=3.02,95%CI:1.92 to 4.75)and vancomycin(OR=3.26,95%CI:1.48 to 7.18),were also found to be positively associated with development of CRPA infection.Conclusions:Exposure of all kinds ofβ-lactams is significantly associated with development of carbapenemresistant Pseudomonas aeruginosa infection.These findings provide an impetus to take a more active approach while usingβ-lactam antimicrobials in patients with resistant Pseudomonas aeruginosa infections. 展开更多
关键词 CARBAPENEM-RESISTANT Pseudomonas aeruginosa cumulative meta-analysis Β-LACTAMS
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学生通学出行的家长接送方式的选择 被引量:2
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作者 马书红 邵恒 陈西芳 《深圳大学学报(理工版)》 CAS CSCD 北大核心 2024年第2期213-220,共8页
研究家长接送方式选择的影响因素,对于早晚高峰交通出行政策的制定具有重要意义.考虑家长、学生的个人属性与家庭属性,以及后续行程目的、生理成本与延误时间等出行属性因素,基于多项logit(multinomial logit,MNL)模型分析对于家长接送... 研究家长接送方式选择的影响因素,对于早晚高峰交通出行政策的制定具有重要意义.考虑家长、学生的个人属性与家庭属性,以及后续行程目的、生理成本与延误时间等出行属性因素,基于多项logit(multinomial logit,MNL)模型分析对于家长接送学生交通方式选择的影响因素,并通过中国海宁市居民出行数据进行验证.研究结果表明,家长年龄越大,选择步行接送的可能性越大;学生性别对于家长接送方式的选择没有显著影响;家长性别和学生年龄对接送方式具有显著影响,其中,女性接送者更偏向于选择非机动车接送,学生年龄越小,家长更偏向于选择非机动车接送;后续行程目的为上班的家长更偏向于选择机动车接送;小汽车接送者的接送时间相对较长,但该接送方式承担的生理成本和延误时间相对较少;电动车接送者承担的生理成本和时间成本都较低.依据研究结果,从家庭、学校和交通管制等维度对学生通学出行提出相关改善建议,能够为相关部门从学生通学的角度制定交通规划管理政策、方案提供指导. 展开更多
关键词 交通工程 通学出行 家长接送 多项logit模型 影响因素 方式选择
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Needs and Challenges of Nigeria Petroleum Industry in Assessing Process Safety Cumulative Risk
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作者 Emeka Maduabuchi John N. Ugbebor Gogomary Oyet Israel 《Journal of Geoscience and Environment Protection》 2023年第7期192-204,共13页
A cross-sectional exploratory assessment of the needs and challenges of petroleum industry in Nigeria, in assessing process safety cumulative risk for major accidents prevention was investigated. A purposive cum rando... A cross-sectional exploratory assessment of the needs and challenges of petroleum industry in Nigeria, in assessing process safety cumulative risk for major accidents prevention was investigated. A purposive cum random sampling technique was used in this study, among selected petroleum companies operating in Nigeria. Survey questionnaires were received from 216 participants made up of asset integrity engineers/operators, process safety experts, production safety professionals in the petroleum industry in Nigeria. Data analyses were carried out to cover descriptive and inferential statistics. Overall, the study recognized that assessing process safety cumulative risk is not a simple process due largely to the changing nature of safety critical barriers degradation data. The study result showed four main challenges faced by petroleum industries in Nigeria, in assessing process safety cumulative risk: 1) the study showed that 94% of the respondents agreed that there is limited accessibility to safety critical barriers degradation data (little automation). Also 2) 94% of the respondents accounted for poor knowledge of process safety cumulative risk is and agreed it to be of low rating. The result further showed that 3) 90% of the respondents demonstrated that there are no guidance and procedures in assessing process safety cumulative risk and finally 4) 92% of the respondents reported that there is no real-time risk visualization model/ tool. Addressing these issues and challenges by the petroleum industries in the study area, will lead to successful assessment of process safety cumulative risk, thereby reducing the risk of major accidents. 展开更多
关键词 Process Safety cumulative Risk Assessment Major Accident Prevention Petroleum Industry
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数字金融发展与中小城市劳动力回流——基于CHFS数据的考察 被引量:1
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作者 陈南旭 张嘉同 《西北师大学报(社会科学版)》 北大核心 2024年第4期133-144,共12页
伴随着数字技术的日新月异,数字金融发展给中小城市吸引劳动力回流带来了重要机遇。基于经典理论对劳动力回流动机的阐述,借助2017年和2019年CHFS数据,运用Logit模型实证检验了数字金融发展对中小城市劳动力回流的影响。研究发现:数字... 伴随着数字技术的日新月异,数字金融发展给中小城市吸引劳动力回流带来了重要机遇。基于经典理论对劳动力回流动机的阐述,借助2017年和2019年CHFS数据,运用Logit模型实证检验了数字金融发展对中小城市劳动力回流的影响。研究发现:数字金融发展在研究期内能够有效吸引中小城市劳动力回流,这一结论在经过内生性讨论和一系列稳健性检验后依然成立;机制检验表明,数字金融发展通过提高预期收入进而吸引劳动力回流的作用渠道存在,创业环境在数字金融发展促进劳动力回流过程中发挥了中介作用,数字金融发展吸引劳动力回流的过程受到了数字经济发展的正向调节;异质性分析显示,更小家庭规模的劳动力在回流过程中对数字金融发展更为关注,其他婚姻状况和已婚且年龄较大的劳动力在回流过程中受数字金融发展的吸引更强,传统金融发展水平较高城市的回流劳动力更加关注数字金融发展。研究结论丰富了学界对劳动力回流的认知,为后续相关研究和政策制定提供了参考。 展开更多
关键词 数字金融 劳动力回流 中小城市 LOGIT模型
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基于随机系数Logit模型的专利价值评估研究——以主动降噪技术为例 被引量:1
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作者 何文韬 张宁 《情报杂志》 北大核心 2024年第1期191-198,共8页
[研究目的]从分析专利价值入手,通过经济学研究方法围绕专利侵权损害赔偿的标准进行定量研究,为评估专利价值提供有意义的知识增量。[研究方法]基于实证产业组织理论,采用随机系数Logit模型,以无线蓝牙耳机主动降噪(ANC)技术作为研究对... [研究目的]从分析专利价值入手,通过经济学研究方法围绕专利侵权损害赔偿的标准进行定量研究,为评估专利价值提供有意义的知识增量。[研究方法]基于实证产业组织理论,采用随机系数Logit模型,以无线蓝牙耳机主动降噪(ANC)技术作为研究对象,构建该技术遭受侵权的反事实情形来估计经济指标变化,由此评估专利价值及侵权赔偿比例。[研究结论]专利侵权企业的行为产生了反竞争效应,提升了企业垄断势力,挤占了其他耳机企业的生存空间,也对潜在进入企业形成了进入威胁。蓝牙耳机价格中约有4.06%源于ANC专利标识。如果发生ANC专利侵权,赔偿额度应是侵权企业利润的2.6~2.8倍。该方法利用市场数据在均衡框架下评估专利价值,为相关研究提供了新方向。 展开更多
关键词 专利价值 专利侵权 专利评估 损害赔偿 随机系数Logit模型 主动降噪技术 蓝牙耳机
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Shaking table test and cumulative deformation evaluation analysis of a tunnel across the hauling sliding surface
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作者 Lifang Pai Honggang Wu Xu Wang 《Deep Underground Science and Engineering》 2023年第4期371-393,共23页
To explore the cumulative deformation effect of the dynamic response of a tunnel crossing the hauling sliding surface under earthquakes,the shaking table test was conducted in this study.Combined with the numerical ca... To explore the cumulative deformation effect of the dynamic response of a tunnel crossing the hauling sliding surface under earthquakes,the shaking table test was conducted in this study.Combined with the numerical calculations,this study proposed magnification of the Arias intensity(MIa)to characterize the overall local deformation damage of the tunnel lining in terms of the deformation characteristics,frequency domain,and energy.Using the time‐domain analysis method,the plastic effect coefficient(PEC)was proposed to characterize the degree of plastic deformation,and the applicability of the seismic cumulative failure effect(SCFE)was discussed.The results show that the low‐frequency component(f1 and f2≤10 Hz)and the high‐frequency component(f3 and f4>10 Hz)acceleration mainly cause global and local deformation of the tunnel lining.The local deformation caused by the high‐frequency wave has an important effect on the seismic damage of the lining.The physical meaning of PEC is more clearly defined than that of the residual strain,and the SCFE of the tunnel lining can also be defined.The SCFE of the tunnel lining includes the elastic deformation effect stage(<0.15g),the elastic–plastic deformation effect stage(0.15g–0.30g),and the plastic deformation effect stage(0.30g–0.40g).This study can provide valuable theoretical and technical support for the construction of traffic tunnels in high‐intensity earthquake areas. 展开更多
关键词 magnification of Arias intensity plastic effect coefficient seismic action seismic cumulative failure effect shaking table test tunnel engineering
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考虑建成环境的电动自行车事故严重程度致因分析
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作者 王菁 董春娇 +2 位作者 李鹏辉 姜文龙 邵春福 《交通运输系统工程与信息》 EI CSCD 北大核心 2024年第1期179-187,共9页
为探究考虑建成环境影响下,电动自行车交通事故严重程度的影响因素,本文从事故属性、骑行者属性、对象车辆及驾驶员属性、道路属性及建成环境属性这5个方面,选取18个影响电动自行车交通事故严重性的潜在变量。在此基础上,构建考虑均值... 为探究考虑建成环境影响下,电动自行车交通事故严重程度的影响因素,本文从事故属性、骑行者属性、对象车辆及驾驶员属性、道路属性及建成环境属性这5个方面,选取18个影响电动自行车交通事故严重性的潜在变量。在此基础上,构建考虑均值及方差异质性的随机参数Logit模型,利用边际效应量化显著变量对事故严重程度的影响差异。基于北京市近5年电动自行车事故抽样数据进行实证研究,结果表明:事故时段19:00-次日7:00、骑行者年龄大于40岁、重(大)型货车、到最近医院的距离增大及恶劣天气等因素会增加电动自行车事故严重程度。建成环境属性中,到最近医院的距离在死亡事故中的参数为服从正态分布的随机参数,路段及恶劣天气会增大其均值异质性,驾驶员年龄为(40,60]岁会增大其方差异质性;其他属性中,一般城市道路在受伤事故中的参数为服从正态分布的随机参数,路段会增大其均值异质性。研究结果可以为降低电动自行车事故严重程度提供理论支撑。 展开更多
关键词 交通工程 事故严重程度 随机参数Logit模型 电动自行车 建成环境
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考虑乘客起讫点选择的可变线路公交服务设计优化
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作者 范文博 唐慧祥 +1 位作者 杨鸿泰 赵海宾 《交通运输工程与信息学报》 2024年第3期52-67,共16页
可变线路公交可以在一定距离内偏离固定线路接送乘客,具有提高公共交通服务可达性的优势。然而,公交车过多访问非站点处的乘客,会增加车辆的行驶距离与时间,导致车内和站点等候乘客时间延误。因此,本文提出以浮动票价来调控乘客的接送需... 可变线路公交可以在一定距离内偏离固定线路接送乘客,具有提高公共交通服务可达性的优势。然而,公交车过多访问非站点处的乘客,会增加车辆的行驶距离与时间,导致车内和站点等候乘客时间延误。因此,本文提出以浮动票价来调控乘客的接送需求,优化可变线路公交的固定站点个数、发车间隔和基础票价以实现单位时间内的社会福利(运营商利润和消费者剩余之和)最大化。首先,本文利用连续近似法分别在无财政限制(允许盈利赤字)和有财政限制(在财政补贴下确保运营不亏损)的情况下构建了最优化模型;其次,通过BONMIN求解器,求出无财政限制的模型的最优固定站点个数、发车间隔和基础票价;最后,通过对潜在出行需求、服务区域的矩形长宽比、票价调整系数及车容量等进行灵敏度分析,验证了模型的有效性。结果表明,单位时间财政补贴存在两个阈值。实例分析表明,对洛杉矶MTA646路夜间公交分别实行统一票价和差异化票价时,潜在出行需求存在一个阈值。当潜在出行需求超过120人/h时,票价调整系数为1时对单位时间社会福利的优化度比票价调整系数为0.2、0.4、0.6和0.8时更高,约为1%。本研究为可变线路公交系统的服务设计与财政补贴计算提供了重要参考依据。 展开更多
关键词 灵活公交 公交服务设计 LOGIT模型 可变线路公交 非线性优化
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高速铁路旅客购票时间选择行为研究
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作者 徐光明 林珊珊 +1 位作者 胡心磊 秦进 《铁道学报》 EI CAS CSCD 北大核心 2024年第4期9-19,共11页
研究高速铁路旅客的购票行为对铁路企业预测需求、优化票价、分配票额等具有重要意义。考虑旅客个体和群体层面的异质性,分别构建混合和潜在类别Logit模型,研究出行时段、票种和供需关系等因素对旅客购票时间选择的影响。利用售票数据... 研究高速铁路旅客的购票行为对铁路企业预测需求、优化票价、分配票额等具有重要意义。考虑旅客个体和群体层面的异质性,分别构建混合和潜在类别Logit模型,研究出行时段、票种和供需关系等因素对旅客购票时间选择的影响。利用售票数据估计模型参数,得到高速铁路旅客购票时间选择的规律:一天中下午和晚上出行的旅客在出行当日或前一天购票的可能性更高;购买全价票、儿童票、半价票的旅客偏向于在距离出发日9~30 d内购票,免票旅客往往选择随到随走;供需关系会显著影响旅客的购票时间选择而且越临近出发日影响越显著。进一步结合预售期购票量预测值和旅客购票选择概率,计算各预售阶段的购票量,可为铁路企业制定票额预分和浮动票价等策略提供决策依据。 展开更多
关键词 高速铁路 购票时间选择 购票量分布 LOGIT模型 交互效应分析 售票数据
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基于Logit模型的技术供需交易影响因素分析
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作者 何喜军 石安杰 +1 位作者 吴爽爽 武玉英 《科技管理研究》 2024年第7期80-86,共7页
将技术供方和专利视为整体,将供需双方是否通过某专利交易视为被解释变量,系统研究技术特征、组织实力和供需方多维邻近关系等对技术交易的影响。基于Logit模型对燃料电池领域专利数据实证研究发现:(1)考虑三维特征建立Logit模型,对交... 将技术供方和专利视为整体,将供需双方是否通过某专利交易视为被解释变量,系统研究技术特征、组织实力和供需方多维邻近关系等对技术交易的影响。基于Logit模型对燃料电池领域专利数据实证研究发现:(1)考虑三维特征建立Logit模型,对交易形成预测的精度高达83.3%;(2)技术特征、组织实力特征、多维邻近特征对技术交易均有显著正向影响;(3)多维邻近特征对技术交易的促进程度远高于其他维度特征,供需双方信任是交易形成的关键因素。最后,从建立高质量技术供需数据库、技术交易信任体系、技术交易网络及交易推荐机制等方面提出对策思考。 展开更多
关键词 多维邻近性 技术特征 技术供需交易 LOGIT模型
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考虑空间异质性的短距离上学方式选择机理
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作者 刘阳 付庭友 +1 位作者 石庄彬 何明卫 《深圳大学学报(理工版)》 CAS CSCD 北大核心 2024年第2期202-212,共11页
短距离出行是学生日常出行的重要组成部分,合理引导短距离上学群体交通方式选择对于促进学生健康发展和缓解高峰期间道路交通拥堵具有重要意义.本研究以中国南京市为例,利用贝叶斯分类法识别出南京市学生的短距离出行阈值为2.7 km,在此... 短距离出行是学生日常出行的重要组成部分,合理引导短距离上学群体交通方式选择对于促进学生健康发展和缓解高峰期间道路交通拥堵具有重要意义.本研究以中国南京市为例,利用贝叶斯分类法识别出南京市学生的短距离出行阈值为2.7 km,在此基础上,分别构建多项logit(multinomial logit,MNL)模型与地理加权多项logit(geographically weighted multinominal logit,GWMNL)模型,探讨个人属性、出行特征、家庭特征及建成环境对短距离学生群体上学方式选择的影响及其空间异质性.结果表明,相比MNL模型,GWMNL模型具有更好的拟合度和解释能力,说明学生上学交通方式选择行为因居住位置不同存在明显差异.与居住在学校附近的低龄学生相比,核心区与近郊区较短出行距离的高龄学生更倾向于乘坐小汽车上学,而远郊区(六合区和江宁区)的高龄学生更倾向于选择积极出行(步行和自行车)和电动自行车上学.小汽车数量对学生选择积极出行、电动自行车及公共交通上学均有消极影响,且这种消极影响从市中心向外围区域逐渐增强.最近公交站距离对居住在核心区与近郊区的学生选择公共交通具有明显促进作用,而对部分远郊地区的学生选择公共交通具有抑制作用,且在南京市的北部和东部地区尤为明显.研究结果可为不同区域学生群体短距离积极出行引导策略的制定提供参考. 展开更多
关键词 交通工程 上学方式选择 学生通学 地理加权多项logit模型 空间异质性 短距离出行
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考虑健康信念的游客分时预约行为分析
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作者 韩艳 晋翎钰 +1 位作者 韩佳乔 关宏志 《北京工业大学学报》 CAS CSCD 北大核心 2024年第7期845-853,共9页
为探索新冠肺炎疫情背景下景区分时预约策略、游客健康信念和风险预防行为之间的关系,需考虑健康信念,分析疫情防控期间游客分时预约行为机理。采用意愿调查法获取旅游信息、健康信念、分时预约行为意向数据,分析各预约时段余票比例和... 为探索新冠肺炎疫情背景下景区分时预约策略、游客健康信念和风险预防行为之间的关系,需考虑健康信念,分析疫情防控期间游客分时预约行为机理。采用意愿调查法获取旅游信息、健康信念、分时预约行为意向数据,分析各预约时段余票比例和门票预售期等信息对游客分时预约行为的影响。基于Nested Logit(NL)模型,建立考虑健康信念的游客游玩日期-时段预约选择联合模型,并进行敏感性分析。结果表明:预约信息、健康信念对游客预约节假日或非节假日游玩有显著影响;票价、各预约时段余票比例和健康信念对游客游玩时段预约选择行为有显著影响。游客感知新冠的严重性由1上升至5时,选择节假日出行的概率由30.46%下降至12.28%。研究可为景区分时预约策略的制定提供参考依据。 展开更多
关键词 交通工程 分时预约选择联合模型 健康信念 Nested Logit(NL)模型 分时预约 敏感性分析
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The Evaluation of Alternative Risk Control Schemes Based on Cumulative Prospect Theory
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作者 Hai Zhao Yuliang Wang 《Journal of Architectural Research and Development》 2023年第6期17-22,共6页
Based on the analysis of the evaluation problems associated with the risk control scheme for major engineering projects,the evaluation method of the risk control scheme considering the irrational behavior of evaluatio... Based on the analysis of the evaluation problems associated with the risk control scheme for major engineering projects,the evaluation method of the risk control scheme considering the irrational behavior of evaluation members in fuzzy random environment is proposed.Firstly,a maximum entropy model corresponding to any evaluation member is es-tablished by using triangular fuzzy random variables and grey correlation coefficient in order to obtain the weight of each risk factor of the member.Secondly,a nonlinear programming model is established according to the principle of minimiz-ing deviation to estimate the weight of different evaluation members on the evaluation of alternative risk control schemes.Lastly,the cumulative entropy model is used to calculate the weight of risk control schemes.Cumulative prospect theory obtains the comprehensive prospect utility value of each alternative to determine the optimal alternative. 展开更多
关键词 Major project Risk assessment cumulative prospect theory
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重大节假日出行方式选择模型研究
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作者 何永明 张磊 +2 位作者 魏堃 曹剑 王锦扬 《大连交通大学学报》 CAS 2024年第1期13-19,共7页
为优化节假日高速公路免费政策,选取出行者变量、出行方式相关变量和行程特性变量作为效用变量,构建了出行方式位于上层、出行距离位于下层的NL模型。利用弧弹性法分析不同收费标准和收费里程条件下出行者的行为特性,并利用场景仿真评... 为优化节假日高速公路免费政策,选取出行者变量、出行方式相关变量和行程特性变量作为效用变量,构建了出行方式位于上层、出行距离位于下层的NL模型。利用弧弹性法分析不同收费标准和收费里程条件下出行者的行为特性,并利用场景仿真评价多种收费组合对出行方式的影响。研究结果表明:提高收费标准,汽车出行比例会显著降低,且高速铁路承担了大部分的转移交通量。随着收费里程的增加,出行者逐渐倾向于出行成本较小的普通铁路。对长距离出行收费可以提升公共交通分担率,缓解节假日高速公路的交通拥堵。 展开更多
关键词 节假日出行 免费政策 Nested Logit模型 出行方式 场景仿真
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