Dynamic cellular manufacturing system considering machine failure and workload balance

Abstract Machines are a key element in the production system and their failure causes irreparable effects in terms of cost and time. In this paper, a new multi-objective mathematical model for dynamic cellular manufacturing system (DCMS) is provided with consideration of machine reliability and alternative process routes. In this dynamic model, we attempt to resolve the problem of integrated family (part/machine cell) formation as well as the operators’ assignment to the cells. The first objective minimizes the costs associated with the DCMS. The second objective optimizes the labor utilization and, finally, a minimum value of the variance of workload between different cells is obtained by the third objective function. Due to the NP-hard nature of the cellular manufacturing problem, the problem is initially validated by the GAMS software in small-sized problems, and then the model is solved by two well-known meta-heuristic methods including non-dominated sorting genetic algorithm and multi-objective particle swarm optimization in large-scaled problems. Finally, the results of the two algorithms are compared with respect to five different comparison metrics

Trombose venosa dos membros superiores Venous thrombosis of the upper limbs

Foi realizada uma revisão da evolução clínica de 52 pacientes portadores de trombose venosa axilar e/ou subclávia. Na opinião do autor, até o presente não se tem evidência do esforço na patogenia dessa forma topográfica de trombose venosa. A terminologia síndrome de Paget-Schrötter pode ser usada quando existe um trombo, conforme sugeriram esses autores. No que diz respeito aos pacientes cujo quadro clínico têm como fator preponderante uma compressão extrínseca dos troncos venosos, deve-se levar em consideração uma outra síndrome, como a do desfiladeiro torácico. Para a confirmação de uma suspeita clínica de trombose venosa profunda, a flebografia é o padrão-ouro. O tratamento ideal da oclusão venosa axilo-subclávia não foi ainda estabelecido, mas o anticoagulante tem a preferência. A eficácia do efeito trombolítico in situ é contestada em publicações da literatura médica. O acesso cirúrgico direto para a trombectomia pode ser feito somente em condições especiais.<br>Clinical course of 52 patients with axillary and/or subclavian vein thrombosis was reviewed. In the author's opinion, up to the present time we have no evidence of strain in the pathogenesis of this topographic vein thrombosis. The term Paget-Schrötter syndrome can be used when a thrombus is present, as these authors have suggested. With regard to the patients whose clinical picture is supported by an extrinsic compression on the venous trunks, another syndrome must be considered, such as the thoracic outlet syndrome. For the determination of a clinically suspected deep venous thrombosis, phlebography is the gold standard. The optimal treatment for the axillary-subclavian venous occlusion remains to be established, but the anticoagulant therapy has the preference. The efficacy of in situ thrombolytic effect is contested in medical publications. A direct surgical access for thrombectomy can be made only under special conditions

Interferon Lambda 4 Genotype Is Not Associated with Recurrence of Oral or Genital Herpes

IFNL4-ΔG/TT (rs368234815) genotype is associated with hepatitis C virus clearance and may play a role in other infections. IFN-λ4 protein is generated only in individuals who carry the IFNL4-ΔG allele. The IFNL4 rs12979860-T allele, which is in strong linkage disequilibrium with IFNL4-ΔG, was recently reported to be associated with more frequent and severe oral herpes episodes. We investigated the association of IFNL4-ΔG/TT with herpes simplex virus (HSV)-related outcomes among 2,192 African American and European American participants in the Women's Interagency HIV Study (WIHS). WIHS is a prospective cohort study of human immunodeficiency virus (HIV)-infected and at-risk women that began in 1994. This report includes follow-up through 2013. Available data included: HSV-1 and HSV-2 antibodies at study entry; bi-annually ascertained episodes of (self-reported) oral herpes, (self-reported) genital sores and (clinician-observed) genital ulcers; HSV-2 DNA in cervicovaginal lavage (CVL) specimens. IFNL4-ΔG/TT genotyping was determined by TaqMan. We compared women with IFNL4-ΔG/ΔG or IFNL4-TT/ΔG genotypes (i.e., IFNL4-ΔG carriers) to those with the IFNL4-TT/TT genotype, adjusting for age, race and HIV status. For outcomes with repeated measurements, the adjusted odds ratio (aOR), 95% confidence interval [CI] and p-value were determined using a generalized estimating equations approach. Median participant age at enrollment was 36 years; 81% were African American, 74% were HIV-infected. Among 1,431 participants tested for antibodies, 72.8% were positive for HSV-1 and 79.0% were positive for HSV-2. We observed no association between IFNL4-ΔG/TT genotype and any outcome: HSV-1 or HSV-2 antibody prevalence (p>0.1, all comparisons); oral herpes (aOR, 1.2; p = 0.35); genital sores (aOR, 1.0; p = 0.71); genital ulcers (aOR, 1.1; p = 0.53); detectable HSV-2 DNA in CVL (N = 322; aOR, 0.71; p = 0.49); HSV-2 DNA level (p = 0.68). In this large prospective study, IFNL4-ΔG/TT genotype was not associated with HSV-related outcomes, including episodes of oral or genital herpes