数据故事化解释中分类型预测结果的反转点识别方法研究——基于LIME算法

[目的/意义]实现数据故事化中的反转点识别,有助于非专业人士理解分类型预测结果的产生原因,同时对于推动故事情节发展并使其快速到达故事高潮点具有促进作用。[方法/过程]提出故事点与反转点概念,基于LIME解释技术和反转点识别过程,设计了用于数据故事化中反转点识别的算法方案,并提出了面向分类模型的反转点识别流程。[结果/结论]将反转点识别算法应用到贷款数据集,证明此算法在数据故事化过程中寻找反转点的有效性,在获得用户期望的预测结果和快速识别反转点方面具有应用价值。

Multi-scale analysis of carbon mineralization in lime-treated soils considering soil mineralogy

Mineral carbonation is emerging as a reliable CO_(2) capture technology that can mitigate climate change.In lime-treated clayey soils,mineral carbonation occurs through the carbonation of free lime and cementitious products derived from pozzolanic reactions.The kinetics of the reactions in lime-treated clayey soils are variable and depend primarily on soil mineralogy.The present study demonstrates the role of soil mineralogy in CO_(2) capture and the subsequent changes caused by carbon mineralization in terms of the unconfined compressive strength(UCS)of lime-treated soils during their service life.Three clayey soils(kaolin,bentonite,and silty clay)with different mineralogical characteristics were treated with 4%lime content,and the samples were cured in a controlled environment for 7 d,90 d,180 d,and 365 d.After the specified curing periods,the samples were exposed to CO_(2) in a carbonation cell for 7 d.The non-carbonated samples purged with N2 gas were used as a benchmark to compare the mechanical,chemical-mineralogical,and microstructure changes caused by carbonation reactions.Experimental investigations indicated that exposure to CO_(2) resulted in an average increase of 10%in the UCS of limetreated bentonite,whereas the strength of lime-treated kaolin and silty clay was reduced by an average of 35%.The chemical and microstructural analyses revealed that the precipitated carbonates effectively filled the macropores of the treated bentonite,compared to the inadequate cementation caused by pozzolanic reactions,resulting in strength enhancement.In contrast,strength loss in lime-treated kaolin and silty clay was attributed to the carbonation of cementitious phases and partly to the tensile stress induced by carbonate precipitation.In terms of carbon mineralization prospects,lime-treated kaolin exhibited maximum carbonation due to the higher availability of unreacted lime.The results suggest that,in addition to the increase in compressive strength,adequate calcium-bearing phases and macropores determine the efficiency of carbon mineralization in lime-treated clayey soils.

Performance evaluation of laterite soil embankment stabilized with bottom ash,coir fiber,and lime

In tropical regions,heavy rainfall induces erosion and shallow landslides on road embankments.Cement-based stabilization methods,common in these regions,contribute to climate change due to their high carbon footprint.This study explored the potential application of coir fiber-reinforced laterite soil-bottom ash mixtures as embankment materials in the tropics.The objective is to enhance engineered embankment slopes'erosion resistance and stability while offering reuse options for industrial byproducts.This study examined various mix designs for unconfined compressive strength(UCS)and permeability,utilizing 30%bottom ash(BA)and 1%coir fiber(CF)with varying sizes ranging from 10 to 40 mm,6%lime,and laterite soil(LS),followed by microstructural analyses.The results demonstrate that the compressive strength increases as the CF length increases to 25 mm.In contrast,permeability increases continuously with increasing CF length.Lime-treated mixtures exhibit superior short-and long-term strength and reduce permeability owing to the formation of cementitious materials,as confirmed by microstructural analyses.A lab-scale slope box was constructed to evaluate the surface erosion of the stabilized laterite soil embankment.Based on the rainfall simulation results,the LS-BA-CF mixtures show better resistance to erosion and deformation compared to untreated LS,especially when lime is added to the top layer.This study provides insights into a sustainable and cost-effective approach for slope stabilization using BA and CF,offering a promising solution for tropical regions susceptible to surface erosion and landslides.

Prediction of lime utilization ratio of dephosphorization in BOF steelmaking based on online sequential extreme learning machine with forgetting mechanism

The machine learning models of multiple linear regression(MLR),support vector regression(SVR),and extreme learning ma-chine(ELM)and the proposed ELM models of online sequential ELM(OS-ELM)and OS-ELM with forgetting mechanism(FOS-ELM)are applied in the prediction of the lime utilization ratio of dephosphorization in the basic oxygen furnace steelmaking process.The ELM model exhibites the best performance compared with the models of MLR and SVR.OS-ELM and FOS-ELM are applied for sequential learning and model updating.The optimal number of samples in validity term of the FOS-ELM model is determined to be 1500,with the smallest population mean absolute relative error(MARE)value of 0.058226 for the population.The variable importance analysis reveals lime weight,initial P content,and hot metal weight as the most important variables for the lime utilization ratio.The lime utilization ratio increases with the decrease in lime weight and the increases in the initial P content and hot metal weight.A prediction system based on FOS-ELM is applied in actual industrial production for one month.The hit ratios of the predicted lime utilization ratio in the error ranges of±1%,±3%,and±5%are 61.16%,90.63%,and 94.11%,respectively.The coefficient of determination,MARE,and root mean square error are 0.8670,0.06823,and 1.4265,respectively.The system exhibits desirable performance for applications in actual industrial pro-duction.

Mechanism of lime decomposing Al_(2)O_(3)-containing fayalite melt

A method to upgrade the iron grade in copper slag was proposed using lime to decompose Al_(2)O_(3)-containing fayalite melt(AFMT).Thermodynamic calculations indicated that adjusting the CaO/AFMT ratio can yield a residual melt with a FeO concentration of 75−88 wt.%and produce Ca_(2)SiO_(4).In-situ observations suggested that the reaction was impeded in some way.Quenching experiments revealed that the initial reaction products consisted of calcium ferrite compounds and FeO−CaO melt.At the FeO−CaO melt/AFMT interface,Ca_(2)SiO_(4) particles precipitated,forming a dense Ca_(2)SiO_(4) film that significantly impeded mass transfer.Although trace amounts of Al_(2)O_(3) in AFMT temporarily enhanced mass transfer,they were insufficient to overcome this retardation effect.The decomposition reaction was far from achieving equilibrium,demonstrating a self-retardation effect.Measures must be implemented to eliminate this self-retardation effect and enhance the efficiency of reaction kinetics.

Cement and Lime Stabilization Effect on the Evolutivity of an Expansive Overconsolidated Clay

This paper presents and analyzes the results of a series of compaction,fragmentability and damage tests performed on an expansive overconsolidated clay treated with cement and lime.This clay was obtained from the urban site of Sidi-Hadjrès city(wilaya of M'sila,Algeria),where significant damages frequently appears in the road infrastructures,roadway systems and light structures.Tests results obtained show that the geotechnical parameters values deduced from these tests are concordant and confirm the evolutivity of this natural clay treated with composed Portland cement or extinct lime and compacted under optimum Proctor conditions.

Effects of Phosphate and Lime Application on Growth of Trifolium repens,Chamaecrista rotundifolia and Macroptilium atropurpureum in Red Soils

[Objective] The aim was to research effects of P fertilizer and lime on growth of Trrifolium repens, Chamaecrista rotundifolia and Macroptilium atropur- pureum, to provide references for cultivation of the three plants. [Method] Pot experiments were conducted with Trrifolium repens, Charnaecrista rotundifolia and Macroptilium atropurpureum in 2010 in order to research effects of lime and P fer-tilizer mixture on growth of the plants in southern hilly acidic red soils. [Result] With lime amount fixed, application of P fertilizer would enhance plant height, total tiller number and dry matter. When P fertilizer was not applied, however, plant height of the three plants achieved the peak by lime at 1.4 g/kg which proved best for improvement of acidity of red soils. With P fertilizer at 200 mg/kg was applied, biomass of Trifolium repens and Macroptilium atropurpureum achieved the highest by lime at 2.1 g/kg, but total biomass of Chamaecrista rotundifolia was the highest by lime at 1.4 g/kg. [Conclusion] The research provides references for planting and production of Trifolium repens, Chamaecrista rotundifolia and Macroptilium atropur-pureum in southern hilly regions.

The Electrical Resistivity Characteristics of Cement-Soil and Flyash-Lime-Soil

The electrical resistivity characteristics of cement soil and flyash lime soil are investigated in the laboratory and the field. It is shown that the electrical resistivities of the cement soil and flyash lime soil are sensitive to water content, degree of saturation and unconfined strength. The cement soil and flyash lime soil with higher water content, greater degree of saturation, lower unconfined strength has lower electrical resistivity. Electrical resistivity is also correlated with additives. Based on the tests, it is concluded that the electrical resistivity method is available for checking the effectiveness of the soil improvement by the cement soil and flyash lime soil mixing pile in terms of engineering practice.

Study on Food-making Quality of Strong-gluten Wheat Varieties from Lime Concretion Black Soil Area in the Huanghuai Wheat Region

In this study, 13 strong-gluten wheat varieties screened by the Key Project of Modern Agricultural Industry Technology System ＂Study on Industrial Technology for Strong-gluten Wheat from Lime Concretion Black Soil Area in the Huanghuai Wheat Region＂ were used as experimental materials to investigate their bread-making quality, noodle-making quality and other related characteristics. The results showed that more than half of the wheat varieties had better bread-making quality; the bread made from wheat with longer dough mixing time than 3.0 min had better texture, lighter color, and better taste. All these 13 strong-gluten wheat varieties showed good noodle-making quality in color, appearance, smoothness and taste; the differences between varieties were mainly found in palatability and viscoelasticity. Jimai 20, Xinong 979, Zhengmai 7698, Ji＇nan 17 and Zhengmai 9023 exhibited excellent bread-making quality; Zhengmai 366, Jimai 20 and Xinong 979 displayed excellent noodle-making quality. Fresh dough sheets made from Zhengmai 366, Jimai 20 and Xinong 979 exhibited slight color variation within 24 h and high peak starch paste viscosity; dry and cooked noodles made from Zhengmai 366, Jimai 20 and Xinong 979 had good quality.

利用LIME对脓毒症预测模型进行可解释性分析

针对机器学习应用于脓毒症预测存在预测准确率低和可解释性不足的问题,提出了利用LIME对基于机器学习的脓毒症预测模型进行可解释性分析。模型由预测和解释两部分组成:预测部分使用XGBoost和线性回归(LR),首先通过XGBoost进行特征提取,再利用LR对提取到的特征进行分类;解释部分使用LIME模型提取出关键的预测指标对模型进行解释。实验结果表明,通过XGBoost+LR模型进行脓毒症预测的准确率为99%,受试者工作特征曲线下面积(AUROC)为0.984,优于单独使用XGBoost(准确率:95%,AUROC:0.953)和LR(准确率:53%,AUROC:0.556)或者LGBM(准确率:90%,AUROC:0.974),同时通过LIME能有效地提取出前10个最重要的指标,对脓毒症预测模型进行可解释性分析,提高了模型的可信度。

基于LIME-BP神经网络的医疗费用预测研究

目的针对BP神经网络无法解释、规则不透明的问题,引入LIME算法,建立可解释的医疗费用预测模型,有效预测并解释脑梗死患者医疗费用及其来源。方法使用五折交叉验证对模型进行调参,并以外推检验集的预测结果对模型进行评价。然后通过LIME算法对每条模型预测结果进行解释,最后统计费用等级的LIME解释结果,分析特征重要性。结果微查准率、宏查准率、微查全率、宏查全率、微F1、宏F1分别为0.73、0.75、0.75、0.71、0.74、0.73;患者查体特征与并发症维度的特征对医疗费用的影响最强。结论基于LIME-BP神经网络的医疗费用预测模型可以有效预测医疗费用并解释其费用来源,对降低医疗费用,改善医患关系有重要参考价值。

Stabilization of saline silty sand using lime and micro silica

Many construction and post-construction problems have been reported in the literature when saline soils have been used without understanding of their abnormal behavior,especially their inferior bearing capacity in the natural condition.The strength of these soils further decreases on soaking.Saline soil deposits cover extensive areas in central Iran and are associated with geotechnical problems such as excessive differential settlement,susceptibility to strength loss and collapse upon wetting.Because of these characteristics,some of the roads constructed on saline soils in Taleghan area have exhibited deterioration in the form of raveling,cracking and landslides.The main objective of this work is to improve the load-bearing capacity of pavements constructed on Taleghan saline soils using lime and micro silica.Soil samples from Hashtgerd-Taleghan road were collected and tested for improving their properties using lime and micro silica at different dosages ranging from 0 to 6%.The load-bearing capacity of stabilized soil mixtures was evaluated using California Bearing Ratio(CBR) and unconfined compressive strength tests.The test results indicate that the lime improves the performance of soil significantly.The addition of 2% lime with 3% micro silica has satisfied the strength-deformation requirements.Therefore,improved soil can be used as a good subbase in flexible pavements.

Pre-desilication and digestion of gibbsitic bauxite with lime in sodium aluminate liquor

The effect of lime on the pre-desilication and digestion of gibbsitic bauxite in synthetic sodium aluminate liquor at different tem- peratures was investigated. The bauxite is comprised of gibbsite, aluminogoethite, hematite, kaolin, quartz, and minor boehmite. Lime in- creases the desilication efficiency of the bauxite during the pre-desilication process by promoting the conversion of sodalite and cancrinite to hydrogamet. Desilication reactions during the digestion process promoted by lime result in the loss of A1203 entering the red mud, but the amount of aluminogoethite-to-hematite conversion promoted by lime leads to the increase of aluminogoethific A1203 entering the digested liquor. The alumina digestion rate at 245~C is higher than that at 145 C due to the more pronounced conversion of aluminogoethite to hema- tite. The soda consumption during the digestion process decreases due to lime addition, especially at higher temperatures.

Physicochemical properties of arsenic-bearing lime-ferrate sludge and its leaching behaviors

Physicochemical properties and leaching behaviors of two typical arsenic-bearing lime?ferrate sludges(ABLFS),waste acid residue(WAR)and calcium arsenate residue(CAR),are comprehensively described.The chemical composition,morphological features,phase composition and arsenic occurrence state of WAR and CAR are analyzed by ICP?AES,SEM?EDS,XRD,XPS and chemical phase analysis.The toxicity leaching test and three-stage BCR sequential extraction procedure are utilized to investigate arsenic leaching behaviors.The results show that the contents of arsenic in WAR and CAR are2.5%and21.2%and mainly present in the phases of arsenate and arsenic oxides dispersed uniformly or agglomerated in amorphous particles.The leaching concentrations of arsenic excess119and1063times of TCLP standard regulatory level with leaching rates of47.66%and50.15%for WAR and CAR,respectively.About90%of extracted arsenic is in the form of acid soluble and reducible,which is the reason of high arsenic leaching toxicity and environmental activity of ABLFS.This research provides comprehensive information on harmless disposal of ABLFS from industrial wastewater treatment of lime?ferrate process.

Reaction kinetics and mechanism of calcium oxide in dilute sodium aluminate solution with oxalate based on lime causticization

The formation kinetics and mechanism of tricalcium aluminate hydrate and calcium oxalate in dilute sodium aluminate solution and sodium oxalate solution were studied respectively based on the lime causticization, and the optimal conditions for removing the oxalate in dilute sodium aluminate solution as well as the mechanism were finally obtained.The formation processes of tricalcium aluminate hydrate and calcium oxalate are mainly controlled by the chemical reaction and the inner diffusion respectively,and the corresponding reaction rate equations as well as the apparent activation energy were calculated. The hydrocalumite with a spatially interleaved structure will form in dilute sodium aluminate solution with sodium oxalate, greatly removing the oxalate impurity by absorption. Calcium oxalate can be converted to tricalcium aluminate hydrate with the increasing reaction time. The oxalate causticization efficiency and the alumina loss rate can be over 90% and below 31% respectively when reacted at 50℃ with a stirring rate of 200 r/min.

Sugarcane press mud modification of expansive soil stabilized at optimum lime content:Strength,mineralogy and microstructural investigation

This study attempted to investigate the potential of sugarcane press mud(PM) as a secondary additive in conjunction with lime for the stabilization of an expansive soil.The physico-mechanical properties of an expansive soil,such as plasticity,shrink-swell behavior,unconfined compressive strength(UCS),mineralogical and microstructural characteristics were investigated.The expansive soil was stabilized at its optimum lime content(7%) for producing maximum strength,and was modified with four different quantities of PM in small dosages(0.25%-2%).Cylindrical soil samples,38 mm in diameter and 76 mm in height,were cast and cured for varying periods to evaluate the strength of the amended soil.The spent samples after strength tests were further used for determination of other properties.The test results revealed that PM modification led to a substantial improvement in 7-d strength and noticeable increase in 28-d strength of the lime-stabilized soil(LSS).The addition of PM does not cause any detrimental changes to the shrink-swell properties as well as plasticity nature of the stabilized soil,despite being a material of organic origin.Mineralogical investigation revealed that the formation of calcium silicate hydrate(CSH) minerals,similar to that of pure lime stabilization with only the type of mineral varying due to the modification of PM addition,does not significantly alter the microstructure of the LSS except for superficial changes being noticed.

Dynamic characteristics of lime-treated expansive soil under cyclic loading

To better understand the dynamic properties of expansive clay treated with lime, a series of laboratory tests were conducted using a dynamic triaxial test system. The influential factors, including moisture content, confining pressure, vibration frequency, consolidation ratio, and cycle number on the dynamic characteristics were discussed. Experimental results indicate that specimens at low moisture contents tend to damage along the 30~ shear plane and they present brittle failure, while saturated specimens show swelling phenomenon and plastic failure. A redtiction in cohesion has been observed for unsaturated samples at large number of cycles, while it is opposite for the internal friction angle. For the saturated specimens, both the cohesion and internal friction angle decrease with increasing number of cycles.

Behavior of fluxed lime iron oxide pellets in hot metal bath during melting and refining

Lump lime as a fiux material in a basic oxygen furnace （BOF） often creates problems in operation due to its high melting point, poor dissolution property, hygroscopic nature, and fines generation tendency. To alleviate these problems, fluxed lime iron oxide pellets （FLIP） containing 30% CaO were developed in this study using waste iron oxide fines and lime. The suitable handling strengths of the pellet （crushing strength： 300 N; drop strength： 130 times） of FLIP were developed by treating with CO2 or industrial waste gas at room temperature, while no separate binders were used. When the pellet was added into hot metal bath （carbon-containing molten iron）, it was decomposed, melted, and transformed to produce low melting oxidizing slag, because it is a combination of main CaO and Fe2O3. This slag is suitable for facilitating P and C removal in refining. Furthermore, the pellet enhances waste utilization and use of CO2 in waste gas. In this article, emphasis is given on studying the behavior of these pellets in hot metal bath during melting and refining along with thermodynamics and kinetics analysis. The observed behaviors of the pellet in hot metal bath confirm that it is suitable and beneficial for use in BOF and replaces lump lime.

Reactive Crystallization of Calcium Sulfate Dihydrate from Acidic Wastewater and Lime

The present work focused on the recycle of the sulfate and the metal ions from acidic wastewater dis charged by nonferrous metallurgical industry. The effects of the temperature, the reactant concentration, the stirring speed and the metal ions on the reactive crystallization process of calcium sulfate between sulfuric acid and lime were systematically investigated. The morphology of the precipitated crystals evolved from plateletlike and nee dlelike shape to rodlike shape when the temperature was increased from 25 to 70 ℃. An increase in the agglom.

An investigation into the effects of lime on compressive and shear strength characteristics of fiber-reinforced clays

To meet the ever-increasing construction demands around the world during recent years,reinforcement and stabilization methods have been widely used by geotechnical engineers to improve the performances and behavior of fine-grained soils.Although lime stabilization increases the compressive strength of soils,it reduces the soil ductility at the same time.Recent research shows that random fiber inclusion modifies the brittleness of soils.In the current research,the effects of lime and polypropylene(PP)fiber additions on such characteristics as compressive and shear strengths,failure strain,secant modulus of elasticity(E50)and shear strength parameters of mixtures were investigated.Kaolinite was treated with 1%,3% and 5% lime by dry weight of soil and reinforced with 0.1% monovalent PP fibers with the length of 6 mm.Samples were prepared at optimum conditions and cured at 35℃ for 1 d,7 d and 28 d at 90% relative humidity and subsequently subjected to uniaxial and triaxial compression tests(UCT and TCT)under cell pressures of 25 kPa,50 kPa and 100 kPa.Results showed that inclusion of random PP fibers to clay-lime mixtures increases both compressive and shear strengths as well as the ductility.Lime content and curing period were found to be the most influential factors.Scanning electron microscopy(SEM)analysis showed that lime addition and the formation of cementitious compounds bind soil particles and increase soil/fiber interactions at interface,leading to enhanced shear strength.The more ductile the stabilized and reinforced composition,the less the cracks in roads and waste landfill covers.