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In order to meet the challenges on the global market and to maximize productivity, production companies need to develop an effective production planning strategy. Production planning is a complex process that underlies a dynamic, fast-paced behavior: influences like machine failure, change of order or absence of employees regularly require an adaptation of the existing production plan. In this paper, we present a methodology that models phenomena influencing the production plan and evaluates their effects on the completion times via a Monte Carlo simulation. Focusing on short-notice incoming orders, the methodology provides statements on the robustness of the production plan by estimating the anticipated change in the completion times under the occurrence of uncertain events.

In Fabrikplanungsprojekten liegen häufig komplexe Zusammenhänge vor, die eine Verbesserung der Planungsprozesse erschweren. Mittels matrixbasierter Ansätze können Strukturen ganzheitlich modelliert und analysiert werden. Der vorliegende Beitrag überträgt den Ansatz der Multiple-Domain-Matrizen auf die Fabrikplanung und schlägt ein Vorgehen für die zielgerichtete Matrixklassifikation und -kombination vor. Dieses Vorgehen wird an einem Fallbeispiel zur Anwendung gebracht, indem komplexe Kommunikationsstrukturen innerhalb einer Planungsaufgabe untersucht werden.

Using the Karush–Kuhn–Tucker conditions for the convex lower level problem, the bilevel optimization problem is transformed into a single-level optimization problem (a mathematical program with com...

The simple convex bilevel programming problem is a convex minimization problem whose feasible set is the solution set of another convex optimization problem. Such problems appear frequently when se...

In production, an intelligent analysis of the data provided along the production line bears huge potential for increasing process efficiency and reducing production costs. The (continuous) collection of relevant data is a crucial precondition for every Industry 4.0 or smart technology. While new machines have internal controllers and sensors to meet those requirements, this is usually not the case for machines being already in use. Especially in the textile industry, it is often standard to keep old machines since the manufacturing methods themselves haven’t changed significantly over the past decades. Hence, the successful exploitation of digitalization advantages requires these companies to first develop and implement a digitization strategy. In this paper we present a concept which allows to develop modular, scalable, flexible solutions considering the whole digitization process from data acquisition to storage. The concept is complemented by a guideline for its application in industry. Experience from a prototypical application in a textile company is described. The concept enables companies to determine the various conditions and requirements for digitization, to analyze different possibilities and to deduce scenarios that lead to a solution for the effective utilization of Industry 4.0 technologies.

An algorithm is presented for solving bilevel optimization problems with fully convex lower level problems. Convergence to a local optimal solution is shown under certain weak assumptions. This algorithm uses the optimal value transformation of the problem. Transformation of the bilevel optimization problem using the Fritz-John necessary optimality conditions applied to the lower level problem is shown to exhibit almost the same difficulties for solving the problem as the use of the Karush---Kuhn---Tucker conditions.

Deletions within the mitochondrial DNA (mtDNA) are thought to contribute to extrinsic skin aging. To study the translation of mtDNA deletions into functional and structural changes in the skin, we seeded human skin fibroblasts into collagen gels to generate dermal equivalents. These cells were either derived from Kearns-Sayre syndrome (KSS) patients, who constitutively carry large amounts of the UV-inducible mitochondrial common deletion, or normal human volunteers. We found that KSS fibroblasts, in comparison with normal human fibroblasts, contracted the gels faster and more strongly, an effect that was dependent on reactive oxygen species. Gene expression and Western blot analysis revealed significant upregulation of lysyl oxidase (LOX) in KSS fibroblasts. Treatment with the specific LOX inhibitor β-aminopropionitrile decreased the contraction difference between KSS and normal human fibroblast equivalents. Also, addition of the antioxidant N-tert-butyl-α-phenylnitrone reduced the contraction difference by inhibiting collagen gel contraction in KSS fibroblasts, and both β-aminopropionitrile and N-tert-butyl-α-phenylnitrone diminished LOX activity. These data suggest a causal relationship between mtDNA deletions, reactive oxygen species production, and increased LOX activity that leads to increased contraction of collagen gels. Accordingly, increased LOX expression was also observed in vivo in photoaged human and mouse skin. Therefore, mtDNA deletions in human fibroblasts may lead to functional and structural alterations of the skin.

The 'matrikine' concept claims that processing of the precursors for collagen results in the formation of peptides such as KTTKS which in turn augments extracellular matrix (ECM) production. In the present study, we show the development of an anti-ageing active from an in silico approach by molecular design resulting in the tetrapeptide GEKG derived from ECM proteins. The efficacy of the peptide to significantly induce collagen production of the protein level and mRNA level has been demonstrated in vitro in human dermal fibroblasts and in vivo in a double-blind, randomized, placebo-controlled study enroling 10 volunteers with an average age of 48.2 years. The effect of GEKG on facial wrinkles was studied in 30 volunteers using state of the art fringe projection, which allows determination of surface roughness in three-dimensions. Here, only GEKG but not the placebo was able to significantly decrease skin roughness as a measure for wrinkles.

The 'matrikine' concept claims that processing of the precursors for collagen results in the formation of peptides such as KTTKS which in turn augments extracellular matrix (ECM) production. In the present study, we show the development of an anti-ageing active from an in silico approach by molecular design resulting in the tetrapeptide GEKG derived from ECM proteins. The efficacy of the peptide to significantly induce collagen production of the protein level and mRNA level has been demonstrated in vitro in human dermal fibroblasts and in vivo in a double-blind, randomized, placebo-controlled study enroling 10 volunteers with an average age of 48.2 years. The effect of GEKG on facial wrinkles was studied in 30 volunteers using state of the art fringe projection, which allows determination of surface roughness in three-dimensions. Here, only GEKG but not the placebo was able to significantly decrease skin roughness as a measure for wrinkles.

The repair of tissue damage is a key survival process in all organisms and involves the coordinated activation of several cell types. Cell-cell communication is clearly fundamental to this process, and a great deal is known about extracellular communication within the wound site via cytokines [1, 2]. Here we show that direct cell-cell communication through connexin 43 (Cx43) gap junction channels [3, 4] also plays a major role in the wound healing process. In two different wound healing models, incisional and excisional skin lesions, we show that a single topical application of Cx43 antisense gel brings about a transient downregulation of Cx43 protein levels, and this results in a dramatic increase in the rate of wound closure. Cx43 knockdown reduces inflammation, seen both macroscopically, as a reduction in swelling, redness, and wound gape, and microscopically, as a significant decrease in neutrophil numbers in the tissue around the wound. One long-term consequence of the improved rate of healing is a significant reduction in the extent of granulation tissue deposition and the subsequent formation of a smaller, less distorted, scar. This approach is likely to have widespread therapeutic applications in other injured tissues and opens up new avenues of research into improving the wound healing process.

Nachdem sich junge Studentinnen und Studenten durch ein muhseliges Unileben gequalt, eine Arbeit unter Bedingungen geschrieben haben, die das Wort Askese in einem ganz neuen Licht erscheinen last, und letztendlich je nach Fachbereich dann noch einige Klausuren und/oder mundliche Prufungen abgeschlossen haben, sollte man annehmen konnen, das eine grose und umfassende Fluchtbewegung erfolgen sollte. Bis auf einen kleinen Rest findet diese auch statt, doch eben dieser Rest ist einer besonderen Untersuchung wert, da er auf den ersten Blick bar jeder Vernunft zu handeln scheint. In diesem Aufsatz soll deswegen eben jene Gruppe von Menschen im Vordergrund stehen, was sie antreibt, was sie zu erdulden hat und wie sie sich dabei verhalt. Er beruht auf den reichhaltigen Erfahrungen der Autoren, die wir in unserer langjahrigen Tatigkeit an der Universitat sammeln durften.