Optimization Models and Approximate Algorithms for the Aerial Refueling Scheduling and Rescheduling Problems

The Aerial Refueling Scheduling Problem (ARSP) can be defined as determining the refueling completion times for fighter aircrafts (jobs) on multiple tankers (machines) to minimize the total weighted tardiness. ARSP can be modeled as a parallel machine scheduling with release times and due date-to-deadline window. ARSP assumes that the jobs have different release times, due dates, and due date-to-deadline windows between the refueling due date and a deadline to return without refueling. The Aerial Refueling Rescheduling Problem (ARRP), on the other hand, can be defined as updating the existing AR schedule after being disrupted by job related events including the arrival of new aircrafts, departure of an existing aircrafts, and changes in aircraft priorities. ARRP is formulated as a multiobjective optimization problem by minimizing the total weighted tardiness (schedule quality) and schedule instability. Both ARSP and ARRP are formulated as mixed integer programming models. The objective function in ARSP is a piecewise tardiness cost that takes into account due date-to-deadline windows and job priorities. Since ARSP is NP-hard, four approximate algorithms are proposed to obtain solutions in reasonable computational times, namely (1) apparent piecewise tardiness cost with release time rule (APTCR), (2) simulated annealing starting from random solution (SArandom ), (3) SA improving the initial solution constructed by APTCR (SAAPTCR), and (4) Metaheuristic for Randomized Priority Search (MetaRaPS). Additionally, five regeneration and partial repair algorithms (MetaRE, BestINSERT, SEPRE, LSHIFT, and SHUFFLE) were developed for ARRP to update instantly the current schedule at the disruption time. The proposed heuristic algorithms are tested in terms of solution quality and CPU time through computational experiments with randomly generated data to represent AR operations and disruptions. Effectiveness of the scheduling and rescheduling algorithms are compared to optimal solutions for problems with up to 12 jobs and to each other for larger problems with up to 60 jobs. The results show that, APTCR is more likely to outperform SArandom especially when the problem size increases, although it has significantly worse performance than SA in terms of deviation from optimal solution for small size problems. Moreover CPU time performance of APTCR is significantly better than SA in both cases. MetaRaPS is more likely to outperform SAAPTCR in terms of average error from optimal solutions for both small and large size problems. Results for small size problems show that MetaRaPS algorithm is more robust compared to SAAPTCR. However, CPU time performance of SA is significantly better than MetaRaPS in both cases. ARRP experiments were conducted with various values of objective weighting factor for extended analysis. In the job arrival case, MetaRE and BestINSERT have significantly performed better than SEPRE in terms of average relative error for small size problems. In the case of job priority disruption, there is no significant difference between MetaRE, BestINSERT, and SHUFFLE algorithms. MetaRE has significantly performed better than LSHIFT to repair job departure disruptions and significantly superior to the BestINSERT algorithm in terms of both relative error and computational time for large size problems

Aerial Refueling Process Rescheduling Under Job Related Disruptions

The Aerial Refueling Scheduling Problem (ARSP) can be defined as determining the refueling completion times for each fighter aircraft (job) on the multiple tankers (machines) to minimize the total weighted tardiness. ARSP assumes that the jobs have different release times and due dates. The ARSP is dynamic environment and unexpected events may occur. In this paper, rescheduling in the aerial refueling process with a time set of jobs will be studied to deal with job related disruptions such as the arrival of new jobs, the departure of an existing job, high deviations in the release times and changes in job priorities. In order to keep the stability and to avoid excessive computation, partial schedule repair algorithm is developed and its preliminary results are presented

Meta-RaPS Algorithm for the Aerial Refueling Scheduling Problem

The Aerial Refueling Scheduling Problem (ARSP) can be defined as determining the refueling completion times for each fighter aircraft (job) on multiple tankers (machines). ARSP assumes that jobs have different release times and due dates, The total weighted tardiness is used to evaluate schedule's quality. Therefore, ARSP can be modeled as a parallel machine scheduling with release limes and due dates to minimize the total weighted tardiness. Since ARSP is NP-hard, it will be more appropriate to develop a ppro~imate or heuristic algorithm to obtain solutions in reasonable computation limes. In this paper, Meta-Raps-ATC algorithm is implemented to create high quality solutions. Meta-RaPS (Meta-heuristic for Randomized Priority Search) is a recent and promising meta heuristic that is applied by introducing randomness to a construction heuristic. The Apparent Tardiness Rule (ATC), which is a good rule for scheduling problems with tardiness objective, is used to construct initial solutions which are improved by an exchanging operation. Results are presented for generated instances

The Eleven-Dimensional Five-Brane

We consider the action, in arbitrary curved background, of the eleven-dimensional five-brane to second order in the curvature of the worldvolume tensor field. We show that this action gives upon double dimensional reduction the action of the Dirichlet four-brane up to the same order. We use this result as a starting point to discuss the structure of the action including terms of higher order in the worldvolume curvature.Comment: LaTeX file, 13page

Factors influencing the prognosis in Braf wild-type metastatic malignant melanoma and the role of novel inflammation indices

Background and Design: This study aims to investigate the prognostic factors in BRAF wild-type metastatic cutaneous melanoma and the prognostic role of inflammation indices. Materials and Methods: Metastatic BRAF wild-type cutaneous melanoma patients who presented to our clinic between 2011 and 2021 were enrolled. To investigate their prognostic roles, age, gender, performance status, first immunotherapy regimen received by the patient, metastatic sites, and seven inflammation indices [C-reactive protein (CRP)/albumin ratio (CAR), neutrophil lymphocyte ratio (NLR), prognostic nutritional index (PNI), platelet lymphocyte ratio (PLR), systemic immune-inflammation index (SII) and advanced lung cancer inflammation index (ALI) and hemoglobin, albumin levels, lymphocyte and platelet counts (HALP)] were studied. Results: Fourty-seven patients, consisting of 22 (46.8%) females and 25 (53.2%) males, were included in this study. Mean patient age was 54 (18-88) years. In our study, there were 16 (34%) patients with liver metastasis, 17 (36.2%) patients with lung metastasis, and 9 (19.1%) patients with brain metastasis. As immunotherapy, 34 (72.3%) patients had received Nivolumab, while 13 (27.7%) patients had received Ipilimumab therapy. When the relationships of the prognostic variables with overall survival were inspected in univariate and multivariate analyses, brain metastasis was found to be an independent prognostic factor (p=0.02). Lung metastasis approached the threshold of statistical significance in univariate analysis (p=0.09) and liver metastasis in multivariate analysis (p=0.07). The seven inflammation indices examined in the analyses [CAR, NLR, PNI, PLR, SII ALI and HALP] were found to have no prognostic role in both univariate and multivariate analyses. Conclusion: Our study determined that brain metastasis is an independent poor prognostic factor in BRAF wild-type metastatic melanoma. Prognostic roles of the CAR, NLR, PNI, PLR, SII ALI and HALP indices could not be demonstrated

Brief Report: Deficiency of Complement 1r Subcomponent in Early-Onset Systemic Lupus Erythematosus: The Role of Disease-Modifying Alleles in a Monogenic Disease

Objective: To identify a genetic cause of early-onset systemic lupus erythematosus (SLE) in a large consanguineous family from Turkey and to study the mechanisms of the disease. Methods: We performed whole-exome sequencing and single-nucleotide polymorphism array genotyping in family members with and without SLE. Protein and gene expression, cytokine profile, neutrophil extracellular trap (NET) formation, and presence of low-density granulocytes were evaluated in patient primary cells and serum samples. Results: We identified a novel, homozygous, loss-of-function mutation (p.Pro445Leufs*11) in the C1R gene. Using the Sanger method of DNA sequencing in 14 family members, we confirmed the presence of the mutation in 4 patients with SLE and in an asymptomatic 9-year-old girl. Complement levels were low in sera from patients with truncated C1r protein. Two siblings with SLE who were available for detailed evaluation exhibited strong type I interferon (IFN) inflammatory signatures despite their disease being clinically inactive at the time of sampling. The type I IFN transcriptional signature in the patients’ blood correlated with disease expressivity, whereas the neutrophil signature in peripheral blood mononuclear cells was likely associated with disease severity. The female patient with SLE with the most severe phenotype presented with a stronger neutrophil signature, defined by enhanced NET formation and the presence of low-density granulocytes. Analysis of exome data for modifying alleles suggested enrichment of common SLE-associated variants in the more severely affected patients. Lupus-associated HLA alleles or HLA haplotypes were not shared among the 4 affected subjects. Conclusion: Our findings revealed a novel high-penetrance mutation in C1R as the cause of monogenic SLE. Disease expressivity in this family appears to be influenced by additional common and rare genetic variants

A Variational Deduction of Second Gradient Poroelasticity Part I: General Theory

Second gradient theories have to be used to capture how local micro heterogeneities macroscopically affect the behavior of a continuum. In this paper a configurational space for a solid matrix filled by an unknown amount of fluid is introduced. The Euler-Lagrange equations valid for second gradient poromechanics, generalizing those due to Biot, are deduced by means of a Lagrangian variational formulation. Starting from a generalized Clausius-Duhem inequality, valid in the framework of second gradient theories, the existence of a macroscopic solid skeleton Lagrangian deformation energy, depending on the solid strain and the Lagrangian fluid mass density as well as on their Lagrangian gradients, is proven.Comment: 20 page

QCD and strongly coupled gauge theories : challenges and perspectives

We highlight the progress, current status, and open challenges of QCD-driven physics, in theory and in experiment. We discuss how the strong interaction is intimately connected to a broad sweep of physical problems, in settings ranging from astrophysics and cosmology to strongly coupled, complex systems in particle and condensed-matter physics, as well as to searches for physics beyond the Standard Model. We also discuss how success in describing the strong interaction impacts other fields, and, in turn, how such subjects can impact studies of the strong interaction. In the course of the work we offer a perspective on the many research streams which flow into and out of QCD, as well as a vision for future developments.Peer reviewe

EVALUATION OF EQUIPMENT INVESTMENT PROJECTS IN AIR DEFENCE SECTOR BY FUZZY AHP

Tez çalışmasının amacı, hava savunma sektöründe askerî sistemlerin bakım ve onarımı konusunda hizmet veren üç adet Hava İkmal Bakım Merkezinin (HİBM) geleceğe yönelik (2007-2016 Dönemi) tezgah yatırım proje tekliflerinin değerlendirilmesi ve önceliklendirilmesidir. Bu kapsamda, öncelikli olarak bakım merkezlerinin 2007 yılı teklifi olan 6 adet tezgah yatırım projesi değerlendirilmiş ve diğer yıllar için değerlendirmenin benzer olarak nasıl yapılacağı belirtilmiştir. Değerlendirmede, karmaşık problemlerin modellenmesinde kolaylık sağlaması, üzerinde çalışılan problemin yapısına uygun, teorik altyapısının anlaşılmasında kolay, kullanımda kolay, grup karar verme sürecine uygun, kullanımının yaygın ve yazılım araçlarının çok olması nedenleriyle bir çok nitelikli karar verme tekniği olan Analitik Hiyerarşi Prosesi (AHP) tercih edilmiştir. İkili karşılaştırma yargılarındaki sözel belirsizliği daha iyi ifade etmek amacıyla, Bulanık AHP tekniklerinden biri olan Chang'ın Mertebe Analiz Yöntemi kullanılmıştır. Bu yöntem, diğer bulanık AHP tekniklerine kıyasla, kullanımı yaygın, basit olduğu ve adımları AHP yöntemiyle benzerlik gösterdiği için tercih edilmiştir. Proje alternatifleri, hava lojistik sisteme potansiyel katkısı, projenin ekonomikliği, projenin gerçekleşmesinde karşılaşılacak riskler ve proje ile yatırımı gerçekleştirilecek tezgahların teknolojisi olarak dört ana kriter altında yer alan toplam 15 adet alt kriter üzerinden değerlendirilmiştir. Yöntemin aritmetik işlemlerine girdi niteliğindeki ikili karşılaştırma yargıları, konusunda uzman personele yapılan anketler yoluyla elde edilmiştir. Yöntem çözümü sonucunda her bir proje alternatifi için nihai önem ağırlıklarına ulaşılmıştır. Bulanık AHP sonuçlarının yanında, aynı ikili karşılaştırma verileri kullanılarak Expert Choice programı ile deterministik AHP sonuçları elde edilmiştir. Deterministik AHP sonuçlarına göre, nihai önem ağırlıkları birbirine yakın olan iki alternatif sıralamalarında farklılık görülmüştür. Sıralamadaki farklılıkların hangi kriterden kaynaklandığı ve her bir ana kriterdeki değişimin nihai sıralamayı nasıl değiştirdiği analiz edilmiştir. Ayrıca sıralama problemi, seçim problemine genişletilerek proje seçimi için bütçe kısıtının yer aldığı bir 0-1 tam sayılı programlama modeli oluşturulmuştur. Elde edilen sonuçların, HİBM'lerin ihtiyaç duydukları tezgah yatırım projelerinin bütçelenmeleri kapsamında üst komutanlıklar tarafından seçiminde, karar vericilere rasyonel, nesnel, tutarlı ve hızlı bir değerlendirme sağlaması ve böylelikle Hava Kuvvetleri mali kaynaklarının doğru kullanılması açısından faydalı ve uygulanabilir olduğu gözlenmiştir. izmir gundem komik videolar cizgi film izle cizgi film 3d oyunlar oyunlar The aim of this thesis study, evaluation and priorizitation of equipment investment project requirements for 2007-2016 years period of three Air Supply and Maintenance Centers which provide service in the air defence sector about repairment and maintenance of millitary systems. With regard to this aim, first of all, six equipment investment projects offered for the year of 2007 have been evaluated and then how similiarly evaluation for other years had to be done is determined. A multi criteria decision making method, Analytic Hierarcy Process (AHP) has been preferred in the evaluation of project alternatives because of its providing simplicity in modelling of the complex problems, suitability to structure of our evaluation problem, simplicity of its theorical infrastructure understanding, simplicity of usage, appropriateness for group decision making, robustness of theorical infrastructure, consistency of results, widely applicability and high number of software tools. In order to state the linguistic uncertainty in the alternative pairwise comparison judgements rightfully, Chang's Extent Analysis Method which is one of the Fuzzy AHP techniques, has been used as a priorizitation method. Chang's Extent Analysis Method has been preferred for this study because of its simplicity, number of application and similarity of solution steps to deterministic AHP. Project alternatives have been compared with each other according to total 15 sub-criteria which were hierarchically under main four main criteria : potential contribution of the project to air lojistic system, economy of the project, risks with the project and technology of the equipment. Pairwise comparison judgements which were used as input of arithmetical operations of the method, have been obtained by querries that had been applied to qualified experts. The final ranking of each project alternatives have been determined according to the final importance weights which were calculated by the method. In addition to Fuzzy AHP method results, deterministic AHP method results provided by Expert Choice software programme. According to deterministic AHP results, a difference in ranking has been seen between two alternatives which have close final importance weight values. Moreover, criteria which cause ranking reversal and effects of changes in each main criteria to the final ranking have been analyzed. Finally, by expanding the ranking problem to selection problem, a 0-1 integer programming model with budget constraint has been constructed for project selection. It is observed that results obtained by this thesis study are useful and applicable for Air Supply and Maintenance Centers because of obtaining to decision makers a rational, objective, consistent and rapid evaluation input regarding selection of equipment investment projects which will be budgeted and proper allocation of financial resources of Air Forces