Planning of a make-to-order production process in the printing industry

Offset printing is a common method to produce large amounts of printed matter. We consider a real-world offset printing process that is used to imprint customer-specific designs on napkin pouches. The production equipment used gives rise to various technological constraints. The planning problem consists of allocating designs to printing-plate slots such that the given customer demand for each design is fulfilled, all technological and organizational constraints are met and the total overproduction and setup costs are minimized. We formulate this planning problem as a mixed-binary linear program, and we develop a multi-pass matching-based savings heuristic. We report computational results for a set of problem instances devised from real-world data.

A continuous-time MILP model for short-term scheduling of make-and-pack production processes

In process industries, make-and-pack production is used to produce food and beverages, chemicals, and metal products, among others. This type of production process allows the fabrication of a wide range of products in relatively small amounts using the same equipment. In this article, we consider a real-world production process (cf. Honkomp et al. 2000. The curse of reality – why process scheduling optimization problems are diffcult in practice. Computers & Chemical Engineering, 24, 323–328.) comprising sequence-dependent changeover times, multipurpose storage units with limited capacities, quarantine times, batch splitting, partial equipment connectivity, and transfer times. The planning problem consists of computing a production schedule such that a given demand of packed products is fulfilled, all technological constraints are satisfied, and the production makespan is minimised. None of the models in the literature covers all of the technological constraints that occur in such make-and-pack production processes. To close this gap, we develop an efficient mixed-integer linear programming model that is based on a continuous time domain and general-precedence variables. We propose novel types of symmetry-breaking constraints and a preprocessing procedure to improve the model performance. In an experimental analysis, we show that small- and moderate-sized instances can be solved to optimality within short CPU times.

Scheduling the production of rolling ingots: Industrial context, model, and solution method

We study a real-world scheduling problem arising in the context of a rolling ingots production. First we review the production process and discuss peculiarities that have to be observed when scheduling a given set of production orders on the production facilities. We then show how to model this scheduling problem using prescribed time lags between operations, different kinds of resources, and sequence-dependent changeovers. A branch-and-bound solution procedure is presented in the second part. The basic principle is to relax the resource constraints by assuming infinite resource availability. Resulting resource conflicts are then stepwise resolved by introducing precedence relationships among operations competing for the same resources. The algorithm has been implemented as a beam search heuristic enumerating alternative sets of precedence relationships.

Heuristic decomposition and LP-based scheduling in make-and-pack production

In this paper, we are concerned about the short-term scheduling of industrial make-and-pack production processes. The planning problem consists in minimizing the production makespan while meeting given end-product demands. Sequence-dependent changeover times, multi-purpose storage units with finite capacities, quarantine times, batch splitting, partial equipment connectivity, material transfer times, and a large number of operations contribute to the complexity of the problem. Known MILP formulations cover all technological constraints of such production processes, but only small problem instances can be solved in reasonable CPU times. In this paper, we develop a heuristic in order to tackle large instances. Under this heuristic, groups of batches are scheduled iteratively using a novel MILP formulation; the assignment of the batches to the groups and the scheduling sequence of the groups are determined using a priority rule. We demonstrate the applicability by means of a real-world production process.

Measurement of Top Quark Polarization in Top-Antitop Events from Proton-Proton Collisions at s√=7 TeV Using the ATLAS Detector

his Letter presents measurements of the polarization of the top quark in top-antitop quark pair events, using 4.7  fb−1 of proton-proton collision data recorded with the ATLAS detector at the Large Hadron Collider at s√=7  TeV. Final states containing one or two isolated leptons (electrons or muons) and jets are considered. Two measurements of αℓP, the product of the leptonic spin-analyzing power and the top quark polarization, are performed assuming that the polarization is introduced by either a CP conserving or a maximally CP violating production process. The measurements obtained, αℓPCPC=−0.035±0.014(stat)±0.037(syst) and αℓPCPV=0.020±0.016(stat)+0.013−0.017(syst), are in good agreement with the standard model prediction of negligible top quark polarization.

Patient information leaflets: informing or frightening? A focus group study exploring patients' emotional reactions and subsequent behavior towards package leaflets of commonly prescribed medications in family practices.

BACKGROUND The purpose of patient information leaflets (PILs) is to inform patients about the administration, precautions and potential side effects of their prescribed medication. Despite European Commission guidelines aiming at increasing readability and comprehension of PILs little is known about the potential risk information has on patients. This article explores patients' reactions and subsequent behavior towards risk information conveyed in PILs of commonly prescribed drugs by general practitioners (GPs) for the treatment of Type 2 diabetes, hypertension or hypercholesterolemia; the most frequent cause for consultations in family practices in Germany. METHODS We conducted six focus groups comprising 35 patients which were recruited in GP practices. Transcripts were read and coded for themes; categories were created by abstracting data and further refined into a coding framework. RESULTS Three interrelated categories are presented: (i) The vast amount of side effects and drug interactions commonly described in PILs provoke various emotional reactions in patients which (ii) lead to specific patient behavior of which (iii) consulting the GP for assistance is among the most common. Findings show that current description of potential risk information caused feelings of fear and anxiety in the reader resulting in undesirable behavioral reactions. CONCLUSIONS Future PILs need to convey potential risk information in a language that is less frightening while retaining the information content required to make informed decisions about the prescribed medication. Thus, during the production process greater emphasis needs to be placed on testing the degree of emotional arousal provoked in patients when reading risk information to allow them to undertake a benefit-risk-assessment of their medication that is based on rational rather than emotional (fearful) reactions.

High Prevalence of Extended-Spectrum β-Lactamase, Plasmid-Mediated AmpC and Carbapenemase genes in Food for Pets

We evaluated the pet food contained in thirty packages as potential origin of extended-spectrum cephalosporin-resistant Gram-negative organisms and β-lactamase genes (bla). Alive bacteria were not detected by selective culture. However, PCR investigations on food DNA extracts indicated that samples harbored blaCTX-M-15 (53.3%), blaCMY-4 (20%), and blaVEB-4-like (6.7%). Particularly worrisome was the presence of blaOXA-48-like carbapenemases (13.3%). Original pet food ingredients and/or the production process were highly contaminated with bacteria carrying clinically relevant acquired bla genes.