A note on optimization in deteriorating systems using scheduling problems with the aging effect and resource allocation models

AbstractThis paper concerns scheduling problems with the aging effect and additional resource allocation. A measurable result of the aging phenomenon is that the time required to perform a job increases whereas the additional resource allocation allows one to decrease it. As an example of a deteriorating system that can be described and optimized by the application of the models and algorithms considered, we choose the pickling process, where cleaning of metal items decreases the efficiency of the pickling (cleaning) bath (i.e., one containing an active substance), whereas heating it up can improve the efficiency. In particular, we focus on the optimization problems for such systems and model them as single-machine scheduling problems with job processing times dependent on the fatigue of a machine and on the allocation of additional resources. The objectives considered are the minimization of time criteria (the maximum completion time and the maximum lateness) under a given resource consumption as well as the minimization of the resource consumption under given time criteria. The computational complexity of the problems is determined and solution properties are proved. On the basis of these, we construct optimal polynomial time algorithms for some cases of the problems considered

Metaheuristic algorithms for scheduling on parallel machines with variable set-up times

In order to meet growing demands of the market modern manufacturing and service environments must offer an increasingly broad range of services or products as well as ensure their required amount and short lead times. It can be done by the application of universal machines or workers which are able to perform different tasks. On the other hand, human activity environments are often affected by learning. Therefore, in this paper, we analyse related problems, which can be expressed as the makespan minimization scheduling problem on identical parallel machines with variable setup times affected by learning of workers. To provide an efficient schedule, we propose metaheuristic algorithms. Their potential applicability is verified numerically

Recent achievements in transcatheter closure of ventricular septal defects : a systematic review of literature and a meta-analysis

Background: Ventricular septal defect (VSD) is one of the most common congenital heart defects. Currently, surgery remains the treatment of choice. However, transcatheter techniques for closing of various types of VSDs have become an alternative. Aims: The objective of our study was to present the outcomes of transcatheter closure of various types of VSD based on a systematic review of recent publications. Methods: A systematic review of studies published in English between January 2014 and March 2020 was performed using the PubMed database (MEDLINE) independently by 2 reviewers. Data on success and complication rates were extracted. Studies including fewer than 5 patients and those with acquired VSD were excluded from the analysis. Results: Finally, 44 studies were included for analysis, with a total number of 4050 patients. The pooled estimate of the overall success rate based on the random effects model was 97.96% (95% CI, 97.37–98.56; Q test P 0.99; I 2 = 0%) for permanent VSD. Conclusions: Transcatheter closure of selected VSDs appears to be an effective and safe method of treatment. Recent studies have shown high rates of successful interventions with a low incidence of complications

Technical aspects of inter-recti distance measurement with ultrasonographic imaging for physiotherapy purposes: the scoping review

Background: Inter-recti distance (IRD) measurement using musculoskeletal USI has been used in physiotherapy research, in particular, to investigate pregnancy-related diastasis recti abdominis (DRA) and to seek its effective treatment methods. Severe and untreated diastasis may result in the formation of umbilical or epigastric hernias. Objective: This study aimed to systematically map physiotherapy-related research articles that included descriptions of IRD measurement procedures using USI to present their similarities and differences, and formulate recommendations on the procedure. Design: A scoping review was conducted according to PRISMA-ScR guidelines, including 49 of 511 publications from three major databases. Publications were selected and screened by two independent reviewers whose decisions were consulted with a third reviewer. The main synthesized data items were: the examinees' body position, breathing phase, measurement sites, and DRA screening methods. The final conclusions and recommendations were the result of a consensus between seven reviewers from four research centers. Results: Studies used 1-5 measurement sites that were differently determined. IRD was measured at the umbilicus (n = 3), at its superior (n = 16) and/or inferior border (n = 9), and at different levels: between 2 and 12 cm above the umbilicus, or a third of the distance and halfway between the umbilicus and xiphoid (n = 37); between 2 and 4.5 cm below the umbilicus or halfway between the umbilicus and pubis (n = 27). Different approaches were used to screen subjects for DRA. Conclusions: The discrepancies between the measurement procedures prevent between-study comparisons. The DRA screening method should be standardized. IRD measurement protocol standardization has been proposed. Critical relevance statement: This scoping review indicates that the inter-recti distance measurement procedures using ultrasound imaging differ between studies, preventing between-study comparisons. Based on the synthesis of the results, measurement protocol standardization has been proposed. Key points: The inter-recti distance measurement procedures using USI differ between studies. Proposed standardization concerns body position, breathing phase, and measurement number per location. Determination of measurement locations considering individual linea alba length is suggested. Recommended locations: umbilical top, ½ of umbilical top-xiphoid, ¼ of umbilical top-xiphoid/pubis distances. Diastasis recti abdominis diagnostic criteria are needed for proposed measurement locations.The Jerzy Kukuczka Academy of Physical Education has funded the article’s editorial expenses.info:eu-repo/semantics/publishedVersio

Exogenous vitamins K exert anti-inflammatory effects dissociated from their role as substrates for synthesis of endogenous MK-4 in murine macrophages cell line

Vitamins K exert a range of activities that extend far beyond coagulation and include anti-inflammatory effects, but the mechanisms involved in anti-inflammatory action remain unclear. In the present study, we showed that various forms of exogenous vitamins—K(1), K(3), K(2) (MK-4, MK-5, MK-6 and MK-7)—regulated a wide scope of inflammatory pathways in murine macrophages in vitro, including NOS-2, COX-2, cytokines and MMPs. Moreover, we demonstrated for the first time that macrophages are able to synthesise endogenous MK-4 on their own. Vitamins with shorter isoprenoid chains—K(1), K(3) and MK-5—exhibited stronger anti-inflammatory potential than vitamins with longer isoprenoid chains (MK-6 and MK-7) and simultaneously were preferably used as a substrate for MK-4 endogenous production. Most interesting, atorvastatin pretreatment inhibited endogenous MK-4 production but had no impact on the anti-inflammatory activity of vitamins K. In summary, our results demonstrate that macrophages are able to synthesise endogenous MK-4 using exogenous vitamins K, and statin inhibits this process. However, the anti-inflammatory effect of exogenous vitamins K was independent of endogenous MK-4 synthesis