"畸变工程":从系统的角度探讨零件的畸变现象

在产品的最终加工过程中用精磨去除零件中的畸变是一个既费钱又费时的事情。例如，仅在(车辆)传动技术领域，1995年德国用于最后精磨以消除工件的畸变而增加的成本已达8．5亿欧元。迄今为止，行业人士认为在最后的产品加工过程中导致零件产生畸变的主要原因在于淬火过程，而今大家普遍认为这个观点不是很对，认为淬火过程只是释放了在各个加工环节中积累在工件中的畸变潜能，如铸造、车削加工、铣削、淬火、磨削。由不来梅大学创立及Deutsche Forschungsgemeinschaft资助的合作研究中心SFB570“畸变工程”的研究方针是从系统导向着手，分析零件的畸变。合作研究中心由12个子项目组成，涉及20多位来自材料科学、制造技术、数学及过程控制工程的研究人员。根据系统导向的方法，合作研究中心SFB570“畸变工程”认为，与优化零件整个生产过程(工序链)相比，对零件生产过程中的单个过程的优化是第二位的。为了推广系统导向的方法，保证SFB570“畸变工程”中集中在不同工序和技术的这12个子项目问的一个连续、协调的知识和信息交换，已成立了一个系统模式工作组。这个工作组的焦点在于详细阐述和进一步发展系统导向的方法以及协调应用于这些子项目中的工序和方法。和其它方法相比较，整体方法包括了零件的生命周期分析、因果分析、失效模式和效果分析(FMEA)以及试验设计(DOE)。除畸变潜能这个新概念外，同时还发展了生产过程补偿潜能这一概念。文中讨论并描述了整体步骤(包括相关方法和手段)，以及迄今为止取得的结果。     

Knowledge Management for Building Learning Software Organizations

Due to the steadily increasing demands of the market, strategic management of knowledge assets, or learning organizations, are becoming a must in industrial software development. This paper presents work done at Fraunhofer IESE, where learning organizations for software development organizations are being developed and transferred into industrial practice. It describes how learning organizations for the software domain can be built upon both mature approaches from Software Engineering like the experience factory model and industrial strength technology from knowledge management. A system to support the learning software organization is sketched and experiences regarding the implementation of this system and learning software organizations in general are presented.     

An approach to monitoring quality in manufacturing using supervised machine learning on product state data

Increasing market demand towards higher product and process quality and efficiency forces companies to think of new and innovative ways to optimize their production. In the area of high-tech manufacturing products, even slight variations of the product state during production can lead to costly and time-consuming rework or even scrapage. Describing an individual product’s state along the entire manufacturing programme, including all relevant information involved for utilization, e.g., in-process adjustments of process parameters, can be one way to meet the quality requirements and stay competitive. Ideally, the gathered information can be directly analyzed and in case of an identified critical trend or event, adequate action, such as an alarm, can be triggered. Traditional methods based on modelling of cause-effect relations reaches its limits due to the fast increasing complexity and high-dimensionality of modern manufacturing programmes. There is a need for new approaches that are able to cope with this complexity and high-dimensionality which, at the same time, are able to generate applicable results with reasonable effort. Within this paper, the possibility to generate such a system by applying a combination of Cluster Analysis and Supervised Machine Learning on product state data along the manufacturing programme will be presented. After elaborating on the different key aspects of the approach, the applicability on the identified problem in industrial environment will be discussed briefly.     

Experimente zur feinstaubscheidung im hochleistungs-venturiwäscher mit mehrstufigen eindüsen der waschflüssigkeitExperiments with highly efficient Venturi scrubbers for aerosol separation from gases under multi-plane water injection

Venturi scrubbers achieve very high separating efficiencies also for particles with very small diameters. An essential draw-back of the design used upto now with single-plane washing-liquid injection, however, is the high pressure loss of the gas flow with respect to the cleaning efficiency. By injecting the washing liquid in several planes it is possible not only to improve the cleaning efficiency but also to reduce considerably the energy consumption of the apparatus.     

Erratum to “Axiomatisations of functional dependencies in the presence of records, lists, sets and multisets”

This note corrects two errors that occurred during the typesetting of our paper “Axiomatisations of functional dependencies in the presence of records, lists, sets and multisets”, which appeared in Hartmann et al. [Axiomatisations of functional dependencies in the presence of records, lists, sets and multisets, Theoret. Comput. Sci. 353(2) (2006) 167–196].     

Combining Biocompatible and Biodegradable Scaffolds and Cold Atmospheric Plasma for Chronic Wound Regeneration

Skin regeneration is a quite complex process. Epidermal differentiation alone takes about 30 days and is highly regulated. Wounds, especially chronic wounds, affect 2% to 3% of the elderly population and comprise a heterogeneous group of diseases. The prevailing reasons to develop skin wounds include venous and/or arterial circulatory disorders, diabetes, or constant pressure to the skin (decubitus). The hallmarks of modern wound treatment include debridement of dead tissue, disinfection, wound dressings that keep the wound moist but still allow air exchange, and compression bandages. Despite all these efforts there is still a huge treatment resistance and wounds will not heal. This calls for new and more efficient treatment options in combination with novel biocompatible skin scaffolds. Cold atmospheric pressure plasma (CAP) is such an innovative addition to the treatment armamentarium. In one CAP application, antimicrobial effects, wound acidification, enhanced microcirculations and cell stimulation can be achieved. It is evident that CAP treatment, in combination with novel bioengineered, biocompatible and biodegradable electrospun scaffolds, has the potential of fostering wound healing by promoting remodeling and epithelialization along such temporarily applied skin replacement scaffolds.