Efficient Robust Optimization of Metal Forming Processes using a Sequential Metamodel Based Strategy

The coupling of Finite Element (FE) simulations to mathematical optimization techniques has contributed significantly to product improvements and cost reductions in the metal forming industries. The next challenge is to bridge the gap between deterministic optimization techniques and the industrial need for robustness. This paper introduces a new and generally applicable structured methodology for modeling and solving robust optimization problems. Stochastic design variables or noise variables are taken into account explicitly in the optimization procedure. The metamodel-based strategy is combined with a sequential improvement algorithm to efficiently increase the accuracy of the objective function prediction. This is only done at regions of interest containing the optimal robust design. Application of the methodology to an industrial V-bending process resulted in valuable process insights and an improved robust process design. Moreover, a significant improvement of the robustness (> 2s ) was obtained by minimizing the deteriorating effects of several noise variables. The robust optimization results demonstrate the general applicability of the robust optimization strategy and underline the importance of including uncertainty and robustness explicitly in the numerical optimization procedure

A numerical approach to robust in-line control of roll forming processes

The quality of roll formed products is known to be highly sensitive and dependent on the process parameters and thus the unavoidable variations of these parameters during mass production. To maintain a constant high product quality, a new roll former with an adjustable final roll forming stand is developed at Deakin University enabling the continuous compensation for possible shape defects. In this work, a numerical approach to robust in-line control of the roll forming of a V-section profile is presented, combining the aspects of robust process design and in-line compensation methods. A numerical study is performed to determine the relationship between controllable process settings and uncontrollable variation of incoming material properties with respect to the common product defects longitudinal bow and springback. The computationally expensive non-linear FE simulations used in this study are subsequently replaced by metamod-els based on efficient Single Response Surfaces. Using these metamodels, the optimal setting for the adjustable stand is determined with robust optimization techniques and the effect on product quality analyzed. It is shown that the subsequent adjustment of the final roll stand position leads to a significantly improved product quality by preventing product defects and minimizing the deteriorating effects of scattering variables

Accounting for material scatter in sheet metal forming simulations

Robust design of forming processes is gaining attention throughout the industry. To analyze the robustness of a sheet metal forming process using Finite Element (FE) simulations, an accurate input in terms of parameter variation is required. This paper presents a pragmatic, accurate and economic approach for measuring and modeling one of the main inputs, i.e. material properties and its associated scattering. For the purpose of this research, samples of 41 coils of a forming steel DX54D+Z (EN 10327:2004) from multiple batches have been collected. Fully determining the stochastic material behavior to the required accuracy for precise modeling in FE simulations would involve performing many mechanical experiments. Instead, the present work combines mechanical testing and texture analysis to limit the required effort. Moreover, use is made of the correlations between the material parameters to efficiently model the material property scatter for use in the numerical robustness analysis. The proposed approach is validated by the forming of a series of cup products using the collected material. The observed experimental scatter can be reproduced efficiently using FE simulations, demonstrating the potential of the modeling approach and robustness analysis in general

Комбинированная кинезотерапия в лечении больных коксартрозом

Вивчені результати лікування 54 пацієнтів з коксартрозом. Включення комплексного лікування даного контингенту пацієнтів комбінованої кінезотерапії методикою Євмінова дозволяє підвищити ефективність проведеної терапії.This article studied results of treatment of 54 patients with coxarthrosis. Upon inclusion of the combined kinesitherapy under Evminov method into the complex treatment of the mentioned group of patients it became possible to increase the effectiveness of the whole therapy

Maternal mortality at Queen Elizabeth Central Hospital, 1989 to 1990

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Transcriptome analysis of Aspergillus niger xlnR and xkiA mutants grown on corn Stover and soybean hulls reveals a highly complex regulatory network.

BACKGROUND:Enzymatic plant biomass degradation by fungi is a highly complex process and one of the leading challenges in developing a biobased economy. Some industrial fungi (e.g. Aspergillus niger) have a long history of use with respect to plant biomass degradation and for that reason have become 'model' species for this topic. A. niger is a major industrial enzyme producer that has a broad ability to degrade plant based polysaccharides. A. niger wild-type, the (hemi-)cellulolytic regulator (xlnR) and xylulokinase (xkiA1) mutant strains were grown on a monocot (corn stover, CS) and dicot (soybean hulls, SBH) substrate. The xkiA1 mutant is unable to utilize the pentoses D-xylose and L-arabinose and the polysaccharide xylan, and was previously shown to accumulate inducers for the (hemi-)cellulolytic transcriptional activator XlnR and the arabinanolytic transcriptional activator AraR in the presence of pentoses, resulting in overexpression of their target genes. The xlnR mutant has reduced growth on xylan and down-regulation of its target genes. The mutants therefore have a similar phenotype on xylan, but an opposite transcriptional effect. D-xylose and L-arabinose are the most abundant monosaccharides after D-glucose in nearly all plant-derived biomass materials. In this study we evaluated the effect of the xlnR and xkiA1 mutation during growth on two pentose-rich substrates by transcriptome analysis. RESULTS:Particular attention was given to CAZymes, metabolic pathways and transcription factors related to the plant biomass degradation. Genes coding for the main enzymes involved in plant biomass degradation were down-regulated at the beginning of the growth on CS and SBH. However, at a later time point, significant differences were found in the expression profiles of both mutants on CS compared to SBH. CONCLUSION:This study demonstrates the high complexity of the plant biomass degradation process by fungi, by showing that mutant strains with fairly straightforward phenotypes on pure mono- and polysaccharides, have much less clear-cut phenotypes and transcriptomes on crude plant biomass

Suicidal Ideation and Behavior:Prevalence, Course and Determinants in Psychiatric Patients

Globally, the annual age-standardized suicide rate is 9 per 100,000 individuals. In the Netherlands, we are faced with an average of 5 suicides per day. While mental health disorders, like depressive or anxiety disorders, elevate suicide risk, these conditions alone are insufficient for determining who will develop suicidal thoughts and which suicidal individuals will act on suicidal thoughts via a suicide attempt. Enhancing suicide risk detection requires a nuanced understanding of suicidal processes within specific mental health disorder populations. Hence, the goals of this thesis were to: 1) investigate the prevalence and course of suicide ideation and attempts in individuals with a depressive and/or anxiety disorder and 2) examine risk determinants (sociodemographics, clinical, personality, psychosocial and (neuro)biological) and mechanisms of suicide ideation and attempts in psychiatric populations. The goals were investigated using data from two different studies: The Netherlands Study of Depression and Anxiety (NESDA) and Trauma tO Personality Spectrum Study (TOPSS). The main aims of NESDA are to study the longitudinal course of depression and anxiety and their predictors and repercussions. The NESDA sample consists of 2981 respondents between 18 and 65 years old form different areas in The Netherlands and multiple follow-up measurements have been completed across 9-years since the baseline measurement. The presence of a depressive and/or anxiety disorder as defined by the DSM-IV classification system was assessed using a structured diagnostic interview. Suicide outcomes were measured in several ways. The Scale for Suicidal Ideation was used to measure suicide ideation and a history of suicide attempts was measured using a question developed by the WHO/Euro multicenter study on parasuicide. The cross-sectional observational study TOPSS contains 120 respondents between the age of 18 and 65 years with a personality disorder and/or post-traumatic stress disorder as defined by the DSM-IV that were recruited at the specialized outpatient department of mental healthcare center GGZ inGeest in The Netherlands. Chapter 2 of the thesis provides information on the prevalence of suicide ideation and attempts across a 9-year timespan and a synthesis of NESDA articles that investigated the course and most important cross-sectional and longitudinal determinants of suicide ideation and attempts found so far. Chapter 3 examined the extent to which various sociodemographic, clinical, personality and psychosocial variables can distinguish individuals that attempt suicide from those that only think about suicide and non-suicidal individuals. Next, associations between individual markers and cumulative indices of three major physiological stress systems and suicide ideation and attempts were investigated in Chapter 4. Chapter 5 built upon findings in Chapter 3 by investigating to what extent the association found between higher levels of childhood trauma and suicide ideation and suicide attempts is mediated by psychosocial, personality, lifestyle, and biological variables. In Chapter 6, the association between personality traits and suicide ideation and attempts was investigated among individuals with a personality disorder. Finally, all of the results from the previous chapters were combined and discussed and ideas for future research directions and clinical implications of the results were considered in Chapter 7

Проблемы формирования механизма мотивации персонала промышленного предприятия

Цель данной работы — углубление теоретических положений проблемы мотивации и разработка механизмов мотивации, стимулирования труда персонала промышленных предприятий в условиях формирования рыночных отношений.Исследованы теоретические и практические аспекты мотивации персонала, её структура и содержание. Разработаны критерии оценки эффективности систем мотивации персонала, модель формирования и мониторинга системы мотивации на основе уточненных факторов РичиМартина, трудовой концепции работника, построения «мотивационного профиля бюллетеня работника».Досліджені теоретичні і практичні аспекти мотивації персоналу, її структура і зміст. Розроблені критерії оцінки ефективності систем мотивації персоналу, модель формування і моніторингу системи мотивації на основі уточнених чинників Ричи-Мартіна, трудової концепції працівника, побудови «мотиваційного профілю бюлетеня працівника».The theoretical and practical aspects of motivation, its structure and content. Develop criteria for evaluating the effectiveness of staff motivation, a model of monitoring and incentive system based on the corrected factors Richie Martin, working the concept of worker, building a «motivational profile employee newsletter