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线性规划在多元线性回归中的解法及应用

昆明理工大学学报（自然科学版） 2014年第1期39卷 53-57页

作者：张爱兰唐虹昆明理工大学管理与经济学院云南昆明650093 昆明理工大学管理与经济学院公共基础设施项目管理研究所云南昆明650093

在多元线性回归模型估计回归方程式的参数时,最小二乘法是一种常用的方法.绝对离差和最小准则、最大绝对离差最小准则是针对最小二乘法的两个替代准则,本文利用线性规划构造一个目标函数,将线性回归模型转换为线性规划模型,利用线性规... 详细信息

在多元线性回归模型估计回归方程式的参数时,最小二乘法是一种常用的方法.绝对离差和最小准则、最大绝对离差最小准则是针对最小二乘法的两个替代准则,本文利用线性规划构造一个目标函数,将线性回归模型转换为线性规划模型,利用线性规划模型得出的参数进行预测.案例分析结果表明,线性规划模型比较有效地消除了数据中异常值对回归方程的影响,具有较好的预测效果.

关键词：线性回归模型线性规划模型最小二乘法参数估计

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AZ31镁合金铸坯均匀化退火

金属热处理 2009年第12期34卷 23-26页

作者：艾秀兰杨军权高峰大连交通大学材料科学与工程学院辽宁省轨道交通关键材料重点实验室辽宁大连116028

研究了一种新的均匀化退火工艺对AZ31镁合金铸坯组织转变和成分均匀化的影响,保温温度为530、540和550℃以及保温时间为30、60和90min。结果表明,AZ31镁合金在固相线温度以下应尽可能提高退火温度,同时缩短退火时间可使铸坯达到较好的... 详细信息

研究了一种新的均匀化退火工艺对AZ31镁合金铸坯组织转变和成分均匀化的影响,保温温度为530、540和550℃以及保温时间为30、60和90min。结果表明,AZ31镁合金在固相线温度以下应尽可能提高退火温度,同时缩短退火时间可使铸坯达到较好的均匀化效果,消除大部分枝晶偏析,γ-Mg17Al12相在α-Mg基体上呈细小的颗粒状分布;AZ31镁合金铸锭的优化退火工艺为540℃保温60min。

关键词： AZ31镁合金均匀化退火显微组织

Coupling Effect of Cryogenic Freeze-Thaw Cycles and Chloride Ion Erosion Effect in Pre-Cracked Reinforced Concrete

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Structural Durability & Health Monitoring 2024年第3期18卷 255-276页

作者： Yang Li Sibo Jiang Ruixin lan School of Civil Engineering and Architecture Hubei University of TechnologyWuhan430068China

Chloride (Cl−) ion erosion effects can seriously impact the safety and service life of marine liquefied natural gas(LNG) storage tanks and other polar offshore structures. This study investigates the impact of different low-temperaturecycles (20°C, –80°C, and −160°C) and concrete specimen crack widths (0, 0.3, and 0.6 mm) on the Cl−ion diffusion performance through rapid erosion tests conducted on pre-cracked concrete. The results show thatthe minimum temperature and crack width of freeze-thaw cycles enhance the erosive effect of chloride ions. TheCl− ion concentration and growth rate increased with the increasing crack width. Based on the experimental modeland in accordance with Fick’s second law of diffusion, the Cl− ion diffusion equation was modified by introducingcorrection factors in consideration of the freeze-thaw temperature, crack width, and their coupling *** experimental and fitting results obtained from this model can provide excellent reference for practical engineeringapplications.

关键词： Chloride ions freeze-thaw cycles cracks

The Completeness of Accreting Neutron Star Binary Candidates from the Chinese Space Station Telescope

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Research in Astronomy and Astrophysics 2024年第9期24卷 30-38页

作者： Hao Shen Shun-Yi lan Xiang-Cun Meng Yunnan Observatories Chinese Academy of Sciences University of Chinese Academy of Sciences International Centre of Supernovae Yunnan Key Laboratory

A neutron star（NS） has many extreme physical conditions, and one may obtain some important information about an NS via accreting neutron star binary（ANSB） systems. The upcoming Chinese Space Station Telescope（CSST）provides an opportunity to search for a large sample of ANSB candidates. Our goal is to check the completeness of the potential ANSB samples from CSST data. In this paper, we generate some ANSBs and normal binaries under the CSST photometric system by binary evolution and binary population synthesis method and use a machine learning method to train a classification model. Although the Precision（94.56%） of our machine learning model is as high as before study, the Recall is only about 63.29%. The Precision/Recall is mainly determined by the mass transfer rate between the NSs and their companions. In addition, we also find that the completeness of ANSB samples from CSST photometric data by the machine learning method also depends on the companion mass and the age of the system. ANSB candidates with a low initial mass companion star（0.1 M⊙to 1 M⊙） have a relatively high Precision（94.94%） and high Recall（86.32%）, whereas ANSB candidates with a higher initial mass companion star（1.1 M⊙to 3 M⊙） have similar Precision（93.88%） and quite low Recall（42.67%）. Our results indicate that although the machine learning method may obtain a relatively pure sample of ANSBs, a completeness correction is necessary for one to obtain a complete sample.

关键词： methods: analytical stars: neutron X-rays: binaries

Technical review of electric vehicle charging distribution models with considering driver behaviors impacts

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Journal of Traffic and Transportation Engineering(English Edition) 2024年第4期11卷 643-666页

作者： Wei Lin Heng Wei lan Yang Xiangmo Zhao ART-Engine S Transportation Research Laboratory Department of Civil and Architectural Engineering and Construction Management University of Cincinnati School of Information Engineering Chang'an University

A massive market penetration of electric vehicles(EVs) associated with nonnegligible energy consumption and environmental issues has imposed a big challenge on evaluating electrical power distribution and related transportation facilities improvement in response to the largescale EV charging service need. Strategical deployment of EV charging stations including location and determination of number of slow charging stations and fast charging stations has become an emerging concern and one of the most pressing needs in planning. This paper conducts a comprehensive survey of EV charging demand and distribution models with consideration of realistic driver behaviors impacts. This is currently a shortage in academic literature, but indeed has drawn practical attention in the strategic planning process. To address the need, this paper presents an in-depth literature review of relevant studies that have identified different types of EV charging facilities, needs or concerns that are considered into EV charging demand and distribution modeling, alongside critical impacting factor identification, mathematical relationships of the contributing factors and EV charging demand and distribution modeling. Key findings from the current literature are summarized with strategies for optimized plan of charging station deployments(i.e., location and related number of charging station), in an attempt to provide a valuable reference for interested readers.

关键词： Charging demand estimation Strategic charging station deployment Electric vehicle Driver behavior

A unified pre-training and adaptation framework for combinatorial optimization on graphs

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Science China Mathematics 2024年第6期67卷 1439-1456页

作者： Ruibin Zeng Minglong Lei Lingfeng Niu lan Cheng School of Computer Science and Technology University of Chinese Academy of SciencesBeijing100049China Faculty of Information Technology Beijing University of TechnologyBeijing100124China School of Economics and Management University of Chinese Academy of SciencesBeijing100190China School of Mathematics and Statistics Central South UniversityChangsha410075China

Combinatorial optimization(CO)on graphs is a classic topic that has been extensively studied across many scientific and industrial ***,solving CO problems on graphs through learning methods has attracted great *** deep learning methods,e.g.,graph neural networks(GNNs),have been used to effectively assist the process of solving ***,current frameworks based on GNNs are mainly designed for certain CO problems,thereby failing to consider their transferable and generalizable abilities among different COs on ***,simply using original graphs to model COs only captures the direct correlations among objects,which does not consider the mathematical logicality and properties of *** this paper,we propose a unified pre-training and adaptation framework for COs on graphs with the help of the maximum satisfiability(Max-SAT)*** first use Max-SAT to bridge different COs on graphs since they can be converted to Max-SAT problems represented by standard formulas and clauses with logical *** we further design a pre-training and domain adaptation framework to extract the transferable and generalizable features so that different COs can benefit from *** the pre-training stage,Max-SAT instances are generated to initialize the parameters of the *** the fine-tuning stage,instances from CO and Max-SAT problems are used for adaptation so that the transferable ability can be further *** experiments on several datasets show that features extracted by our framework exhibit superior transferability and Max-SAT can boost the ability to solve COs on graphs.

关键词： combinatorial optimization graph neural networks domain adaptation maximum satisfiability problem

Snowpack variations and their hazardous effects under climate warming in the central Tianshan Mountains

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Advances in Climate Change Research 2024年第3期15卷 442-451页

作者： Jian-Sheng HAO Yan WANG lan-Hai LI Key Laboratory of land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of Sciences(CAS)Beijing 100101China Xinjiang Key Laboratory of Water Cycle and Utilization in Arid Zone Urumqi 830011China State Key Laboratory of Desert and Oasis Ecology Xinjiang Institute of Ecology and GeographyChinese Academy of SciencesUrumqi 830011China Tianshan Snowcover and Avalanche Observation and Research Station of Xinjiang Xinyuan 835800China CAS Research Center for Ecology and Environment of Central Asia Urumqi 830011China

Climate change alters snowpack evolution,which in turn influences the likelihood of snow avalanches and flood *** lack of systemic observational data on key snow characteristics in high mountains remains a scientific challenge in terms of systematically elucidating the dynamic chain of variations in climate-snowpack-snow *** restricts our understanding and poses challenges in the prediction of snow-related disaster *** such,this study analysed the variations of temperature and snowfall and the physical characteristics of snowpacks based on ground-based observations from the Kunse River Valley situated in the Tianshan Mountains from 1967 to *** results reveal that the temperature increased significantly by 0.32°C per decade(plands,road transportation,water-electricity infrastructure and several other human ***,these insights are critical for providing vital information that can deepen our understanding of the impact of climate change on snowpack characteristics and improve management strategies for snow-related disaster prevention and mitigation.

关键词： Climate change Snowpack variations Snow-related disaster Tianshan Mountains

Simulation of Underground Reservoir Stability of Pumped Storage Power Station Based on Fluid-Structure Coupling

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Computer Modeling in Engineering & Sciences 2024年第5期139卷 1381-1399页

作者： Peng Qiao Shuangshuang lan Hongbiao Gu Zhengtan Mao Faculty of Architecture Civil and Transportation EngineeringBeijing University of TechnologyBeijing100020China College of Transportation Engineering Nanjing Tech UniversityNanjing210000China

Based on global initiatives such as the clean energy transition and the development of renewable energy,the pumped storage power station has become a new and significant way of energy storage and regulation,and its construction environment is more complex than that of a traditional *** particular,the stability of the rock strata in the underground reservoirs is affected by the seepage pressure and rock stress,which presents some challenges in achieving engineering safety and *** the advantages of the numerical simulation method in dealing deal with nonlinear problems in engineering stability,in this study,the stability of the underground reservoir of the Shidangshan(SDS)pumped storage power station was numerically calculated and quantitatively analyzed based on fluid-structure coupling theory,providing an important reference for the safe operation and management of the underground ***,using the COMSOL software,a suitablemechanicalmodel was created in accordance with the geological structure and project characteristics of the underground ***,the characteristics of the stress field,displacement field,and seepage field after excavation of the underground reservoir were simulated in light of the seepage effect of groundwater on the nearby rock of the underground ***,based on the construction specifications and Molar-Coulomb criterion,a thorough evaluation of the stability of the underground reservoir was performed through simulation of the filling and discharge conditions and anti-seepage strengthening *** findings demonstrate that the numerical simulation results have a certain level of reliability and are in accordance with the stress measured in the project *** underground reservoir excavation resulted in a maximum displacement value of the rock mass around the caverns of 3.56 mm in a typical section,and the safety coefficient of the parts,as determined using the Molar-Coulomb criterion,was highe

关键词： Underground reservoir fluid-structure coupling numerical simulation pumped storage power station filling and discharge

辉光放电光谱仪逐层分析Cr12钢表面渗硼层

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冶金分析 2007年第9期27卷 12-16页

作者：范爱兰刘小平秦林常大庆唐宾太原理工大学表面工程研究所平朔煤炭工业公司

采用两种不同的工艺在Cr12钢表面制备渗硼层,利用辉光放电光谱仪对两种工艺形成的Cr12表面渗硼层进行逐层分析。结果表明:1#试样(1000℃处理10h)渗硼层在距表面0～20μm内均由质量分数为8.8%的硼组成,随后硼的含量逐渐降低;2#试样(900... 详细信息

采用两种不同的工艺在Cr12钢表面制备渗硼层,利用辉光放电光谱仪对两种工艺形成的Cr12表面渗硼层进行逐层分析。结果表明:1#试样(1000℃处理10h)渗硼层在距表面0～20μm内均由质量分数为8.8%的硼组成,随后硼的含量逐渐降低;2#试样(900℃处理10h)渗硼层的硼含量在表面较低,随后逐渐升高到质量分数为5%左右,接着又缓慢降低。由此推测1#试样的表面可能存在Fe2B;2#试样的表面可能由硼在铁中的α固溶体组成。为了验证辉光放电光谱仪逐层分析渗硼层的可靠性,利用XRD分析了渗硼层的相结构,结果表明:两者的测试结果相吻合。

关键词：渗硼层辉光放电光谱法逐层分析 Cr12钢