机器学习在深冲钢质量自动判级中的应用

在流程工业中,生产过程需根据客户对产品质量要求进行判级,以满足客户提出的产品质量需求。目前,企业主要采用“事后”抽检方式,但因无法对所有产品实现在线自动判级,常发生索赔和退货,导致我国钢铁企业每年近100亿元损失。为了实现产品质量在线自动判级,提出基于高维数据非线性同等缩放与核简支集类边界确定相结合的质量在线智能判级方法。首先,将高维的工艺参数通过非线性同等缩放算法变换成低维的数据集,并对缩放后数据集进行聚类,分析工艺参数的类分布特征。然后,根据分类后样本的质量指标值分布,采用核简支集类边界算法来确定不同产品质量级别的类边界。最后,依据已确定的类边界,通过质量指标预测实现产品在线判级。通过深冲钢(IF钢)应用实例,证实该方法在训练阶段的在线自动判级准确率达到97.2%,测试阶段的准确率为96%。      

Evolutionary Multivariate Dynamic Process Model Induction for a Biological Nutrient Removal Process

This paper proposes an automatic process model induction system using an evolutionary computational intelligence, called grammar-based genetic programming, that is specially designed to automatically discover multivariate dynamic process models that best fit observed process data. This automatic process model induction system combines an evolutionary self-organizing system of genetic programming paradigm with various mathematical functions for a multivariate nonlinear model evolution using a grammar system via the mechanism of genetics and natural selection. The results demonstrate how the automatic process model induction system based on grammar-based genetic programming can be used to develop accurate and relatively cost-effective multivariate dynamic process models for the full-scale biological nutrient removal process. Multivariate dynamic process models are derived automatically in the form of understandable mathematical formulas that enable engineers to extract important knowledge hidden in the data and develop better operation and control strategies.     

Gender and smoking cessation: A factor structure comparison of processes of change.

This study examined gender differences in the pattern of process use for smoking cessation using the Processes of Change Questionnaire (J. O. Prochaska et al; see record 1989-03620-001). The goals were (a) to determine the degree to which the covariance structure of the Processes of Change Questionnaire is invariant across gender, (b) to test the existence of the theoretical 2-factor process model using confirmatory factor analysis, and (c) to explore mean differences, if found, in the use of the 10 processes of change across 4 stages of change (precontemplation, contemplation, preparation, and action). The sample (N?=?516) had an equal distribution of men and women across the stages of change. Results demonstrated that the structure of the measure for men and women was invariant at the level of the variance–covariance matrices and that the hypothesized 2-factor model fit the data. Only stage of change predicted the experiential and behavioral process factors. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Impact of Using an E-Marketplace in the Construction Supply Process: Lessons from a Case Study

The procurement process is critical for construction companies. To improve it, many are resorting to e-marketplaces although they usually do not know exactly how much they can gain by doing so. This paper describes a study that measured the benefits of using an e-marketplace to support the procurement process of a construction company. The study included three marketplaces currently operating in Chile. However, in this paper, we focus on Iconstruye, the most important one. 70 executives and professionals from 25 construction companies randomly selected from the 89 that used this marketplace, were interviewed and asked to fill out a questionnaire. This data was validated using data from Iconstruye and from 33 suppliers. The results show that the adoption of an e-marketplace reduces turnaround time, errors, urgent orders, and irregular purchases. A more reliable procurement process directly contributes to a leaner construction process by reducing upstream variability, procurement cycle times, and the need for large inventories on site. Users also perceive an improvement in certain global indicators when using an e-marketplace.     

Aging, selective attention, and feature integration.

This study used feature-integration theory as a means of determining the point in processing at which selective attention deficits originate. The theory posits an initial stage of processing in which features are registered in parallel and then a serial process in which features are conjoined to form complex stimuli. Performance of young and older adults on feature versus conjunction search is compared. Analyses of reaction times and error rates suggest that elderly adults, in addition to young adults, can capitalize on the early parallel processing stage of visual information processing, and that age decrements in visual search arise as a result of the later, serial stage of processing. Analyses of a third, unconfounded, conjunction search condition reveal qualitatively similar modes of conjunction search in young and older adults. The contribution of age-related data limitations is found to be secondary to the contribution of age decrements in selective attention. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Observation and Modeling of Stress Corrosion Cracking in High Pressure Gas Pipe Steel

Stress corrosion cracking (SCC) is commonly observed to form a colony of closely spaced multiple cracks. Four stages of SCC colony evolution are discussed. The first is the colony initiation stage (CIS), which is associated with formation of corrosion pits randomly distributed over a certain domain of the surface exposed to an aggressive environment. Electrochemical processes play a leading role in CIS. The individual crack growth (ICG) driven by a combination of mechanical stresses and electrochemical processes constitutes the second stage. At the end of the second stage, the individual cracks reach certain proximity of one another resulting in much crack interaction. This becomes a transition to the third, strong crack interaction and clusters formation, stage. Cluster growth and individual crack or a cluster instability leading to the ultimate failure constitute the final, fourth stage of the SCC evolution process. In this article, we present observations and a general approach to modeling the first two stages of SCC, i.e., CIS and ICG, that together constitute the major part of the total lifetime of an engineering structure serving under SCC conditions. A computer simulation of individual SC crack growth is developed and compared with a large set of SCC observation data.     

Pregnancy smoking cessation: a case of mistaken identity

This study examined the process of change in pregnancy smoking cessation, using the stages and processes of change from the Transtheoretical Model, to compare women who stopped smoking during pregnancy with women who were in the process of smoking cessation, but were not pregnant. Differences in smoking cessation process activity and abstinence self-efficacy were hypothesized between the pregnant and nonpregnant groups of women. Study participants were 89 pregnant women who quit smoking, 28 nonpregnant women in the action stage of smoking cessation, and 92 nonpregnant women in the preparation stage. The Smoking Cessation Processes of Change Scale and the Smoking Abstinence Self-Efficacy Scale served as dependent measures. One-way MANOVA and follow-up Newman-Keuls comparisons indicated significant differences between pregnant and nonpregnant women in their levels of process activity and self-efficacy. Pregnancy smoking cessation differed dramatically from the process of nonpregnancy smoking cessation. Pregnant quitters were not engaging in experiential and behavioral processes at levels associated with the action stage of change. Low levels of process use and high efficacy indicated an externally (for the baby) motivated stopping rather than an internal, intentional process of change, which may account for high relapse rates postpartum.     

Remediation of Contaminated Soils with PCBs Using an Integrated Treatment: Desorption and Oxidation

During most of the past century, large quantities of substances were produced and utilized that subsequently proved harmful. This is the case with polychlorinated biphenyls (PCBs) which only became prohibited by law in the 1970s. As a result of their physicochemical properties, these substances are now present everywhere, although they are mainly found in soils, since they are hydrophobic in character. The present study evaluates an innovatory treatment for the remediation ex situ of soils contaminated by PCBs. This treatment consists of a first stage of desorption using a surfactant agent, followed by a second stage of oxidation with the object of transforming the PCBs into innocuous substances through successive oxidations using the photo-Fenton process. The results obtained (87% remediation in the desorption and 100% in the oxidation stages) show this new treatment to be a highly effective alternative, which does not generate dangerous residues of any type.     

Redundancy gain in the stop-signal paradigm: Implications for the locus of coactivation in simple reaction time.

The authors carried out 2 experiments designed to cast light on the locus of redundancy gain in simple visual reaction time by using a stop-signal paradigm. In Experiment 1, the authors found that single visual stimuli were more easily inhibited than double visual stimuli by an acoustic stop signal. This result is in keeping with the idea that redundancy gain occurs prior to the ballistic stage of the stop-signal task. In Experiment 2, the authors found that the response to an acoustic go signal was more easily inhibited by a double than by a single visual stop signal. This result provides conclusive evidence for a redundancy gain in the stop process—in a process that does not involve a motor response but rather its inhibition. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Application of pulse distribution analysis with optical emission spectroscopy (PDA/OES) method during production of duplex stainless steel

Liquid steel samples were taken during ladle treatment and continuous casting of 37 heats of two duplex stainless steel grades. These samples were used to study inclusion characteristics and potential process control using the pulse distribution analysis with optical emission spectroscopy method (PDA/OES). In addition, a few samples were chosen for a scanning electron microscope examination. A simplified approach of presenting the inclusion composition in ternary diagrams using the PDA/OES method is discussed. More specifically, by defining an operating window, potential deviations can be identified early in the steelmaking process. The variation of the B factor for Al (B_Al) with process time was presented showing similar tendencies for several heats. For that reason, the B factor is considered to be a reliable parameter to study any process changes with respect to inclusion characteristics. Parameters such as B_Al and the number of inclusions per unit volume larger than 4 μm obtained using the PDA/OES method showed a moderate correlation with a slivers index. Statistically, more data have to be collected for further studies. Nevertheless, the PDA/OES method is judged to be a promising tool to determine a slivers risk factor at an early stage of the process.     

改进分段尝试法研究焦炭气化反应动力学

焦炭作为高炉炼铁的主要燃料,对高炉的正常运行以及高效冶炼发挥着至关重要的作用.伴随着现代高炉大型智能化的发展趋势,面对资源的不断消耗,用于冶炼优质冶金焦的原料逐渐减少,低质冶金焦引起了冶金工作者越来越多的关注.在测定高炉使用的焦炭基础理化特性后,通过对不同升温速率下不同质量焦炭与CO2的气化反应试验,采用分段尝试法建立...     

Logistic Likelihood Analysis of Mediation Outcomes

Dispute persists in all building and construction projects. Alternative dispute resolution methods are now commonly used as a means to resolve construction disputes. Mediation, interalia, is the popular choice in Hong Kong due to its cost-saving, flexible, speedy, confidential, and voluntary attributes. In mediation, tactics used by a mediator is central in driving desired outcomes. This paper reports a study that employs logistic regression (LR) to predict mediation outcomes respective to the tactics used. To achieve this, three main stages of work are involved. First, taxonomies of mediator tactics and mediation outcomes were developed. With these, the second stage included the development of logistic regression models each with a mediation outcome taxonomy as dependent variables and the taxonomies of tactics as independent variables. In the third stage of the study, the LR models were validated using an independent set of testing data. The LR models suggested that “win-win settlement,” “progress,” “improvement,” and “time advantage” are responsive to mediator tactics of “ice-breaking,” “trust building,” “encourage for self-improve,” and “process control,” respectively. In addition, it is observed that these relationships are positively correlated.     

VOD冶炼超纯铁素体不锈钢的脱氮研究

分析了VOD冶炼超纯铁素体不锈钢过程的脱氮热力学和动力学,得出其脱氮反应接近二级反应,可用Δ(1/w[N])来表示脱氮效果。用前期开发的脱氮模型计算并分析了VOD的脱氮过程,在VOD吹氧脱碳阶段,脱氮效果Δ(1/w[N])与脱碳量Δw[C]成正比,可用脱氮指数Δ(1/w[N])/Δw[C]来表征此阶段的脱氮能力,铬含量为11.6%、17.6%及20.5%的钢液脱氮指数计算值分别为208%-2、109%-2及81%-2,实际生产数据分析得出的对应的脱氮指数略高于计算值,而在VOD自由脱碳阶段,Δ(1/w[N])随时间变化的计算曲线基本不受初始氮含量的影响,温度是影响脱氮的主要因素。     

Cutaneous innervation of the medial ankle: an anatomic study of the saphenous, sural, and tibial nerves and their clinical significance

Quantitative research is an objective process used to obtain numerical data. The form of quantitative research used is influenced by current knowledge of the problem. Careful planning in the design stage is essential when undertaking quantitative research.     

Normoxic cardiopulmonary bypass reduces oxidative myocardial damage and nitric oxide during cardiac operations in the adult

The purpose of this study was to explain smoking habits amongst middle-aged men in Finland by describing their experiences of smoking and their attitudes towards smoking. As a pilot survey for a major health campaign targeted at 40-year-old men, the data for this study were collected using two questionnaires in connection with voluntary medical examinations. The first questionnaire was based on Prochaska's theory of stages of change in health behaviour. The second instrument was an attitude scale developed specifically for this study on the basis of Green and Kreuter's theory of factors influencing health behaviour. According to the results 31% of males aged 40 were regular smokers. Men with a lower level of education and out of work smoked more often than others. Non-smokers reported a better self-perceived health than smokers. Smoking cessation is a process in which men gradually proceed from one step to the next. In this study 12% of the men were in the contemplation stage and 11% in the preparation stage. One-quarter of the men had recently given up the habit and were in the action stage, while 2% had quit smoking over 6 months ago and were in the maintenance stage. One-quarter of the men regarded smoking as an integral part of their way of life and felt that public opinion towards smoking is hostile.     

Structural Damage Detection and Assessment from Modal Response

This paper presents a global damage detection and assessment algorithm based on a parameter estimation method using a finite-element model and the measured modal response of a structure. Damage is characterized as a reduction of the member constitutive parameter from a known baseline value. An optimization scheme is proposed to localize damaged parts of the structure. The algorithm accounts for the possibility of multiple solutions to the parameter estimation problem that arises from using spatially sparse measurements. Errors in parameter estimates caused by sensitivity to measurement noise are reduced by selecting a near-optimal measurement set from the data at each stage of the localization algorithm. Damage probability functions are computed upon completion of the localization process for candidate elements. Monte Carlo methods are used to compute the required probabilities based on the statistical distributions of the parameters for the damaged and the associated baseline structure. The algorithm is tested in a numerical simulation environment using a planar bridge truss as a model problem.     

Growth and coarsening of g. p. Zones in Al- Zn alloys

The structural changes during the precipitation of G. P. zones in Al-Zn binary alloys have been investigated by means of anin situ small-angle scattering technique using synchrotron radiation. Defining a specific time, normalized by the half-completion time, the time-dependent evolution of the precipitation process can be divided into three periods, independent of alloy composition and quench-ing conditions. The structural and kinetic features of the first two periods have been analyzed in detail. The first stage represents a growing process of clusters with diffuse interface into the well-defined G. P. zones. The average size of these clusters increases, and the density decreases. The second stage corresponds to the Ostwald ripening process. This mechanism is described by utilizing a modified Lifshitz-Slyozov-Wagner theory.     

The concept of transformation in psychoanalysis.

Transformation is viewed as the essential process of structure building. This article delineates levels of meaning organization that undergo alteration and move increasingly toward higher levels of symbolization. The transition from each stage of mental organization involves a dialectic conflict leading to reorganization at a higher level. This general thesis is illustrated by clinical material, reference to the literature, and a body of research data. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

What Is the Right Thing at the Right Time? Interactions Between Stages and Processes of Change Among Smokers Who Make a Quit Attempt.

C. A. Perz, C. C. DiClemente, and J. P. Carbonari (1996) claim support for the transtheoretical model notion that success in smoking cessation involves doing the right thing at the right time: emphasising experiential change processes during the contemplation and preparation stages and shifting to behavioral process activities during action. A key methodological limitation of Perz et al. was their failure to control for stage of change, a measure that has been shown to be predictive of cessation. This study replicates the prospective findings of Perz et al. in a different data set, then controls for stage of change when it is predictive of cessation, and finds that the measures of "appropriate" change process use developed by Perz et al. no longer predict cessation. The authors conclude that stage of change, in particular the distinction between smoking and not smoking, is more important than change process use in predicting cessation outcomes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)