62 research outputs found
Macular Imaging Characteristics in Children with Myelinated Retinal Nerve Fiber and High Myopia Syndrome
Objectives:To investigate the macular imaging features in patients with unilateral myelinated retinal nerve fiber (MRNF) and high myopia syndrome.Materials and Methods:Six patients with unilateral MRNF and high myopia syndrome and 13 myopic controls were enrolled in this study. Spectral domain (SD) optical coherence tomography (OCT), SD enhanced depth imaging OCT, and OCT angiography (OCTA) imaging results of MRNF-affected eyes were compared with the fellow eyes and myopic controls.Results:All patients had abnormal foveal reflex and/or ectopia. No significant difference in retinal thickness parameters were noted between the groups. In OCT scans, posterior vitreous detachment (PVD) was observed in 4 out of the 6 MRNF-affected eyes. Regarding OCTA parameters, only a significant increase in acircularity index was noted in myelinated eyes (p=0.01).Conclusion:All patients demonstrated normal foveal contours, macular structure, and OCTA features except for a higher acircularity index. The incidence of PVD was notably increased in the myelinated eyes
Interval type-2 fuzzy program evaluation and review technique for project management in shipbuilding
Ship production occurs at the end of a complex process and needs effective and efficient Project Management (PM). Uncertainty in project management parameters always exists and is inevitable. The Fuzzy Set Theory is capable of capturing uncertainty through the membership functions of the parameters. We proposed a model of Interval Type-2 Fuzzy Sets (IT2FSs) Program Evaluation and Review Technique (PERT) method to literature and applied this to the production scheduling of an electric yacht to study this proposed method in terms of PM in the shipbuilding industry. The proposed model contains Forward Pass and Backward Pass calculations for IT2FPERT with a new ranking method, and a Slack Time calculation for IT2FPERT, which develops a Criticality Degree (CD) on the possible path for IT2FPERT and determines the Critical Path. Robustness tests of the proposed model were carried out by comparing results to the Critical Path Method (CPM), PERT, and PERT Simulation solutions
An evaluation of ship investment in interval type-2 fuzzy environment
Investment is one of the most crucial factors for a company. The decisions that a company makes in an investment uncertainty environment with high global competition, such as in the shipping industry, affects the life of the company either positively or negatively. Therefore, correct decision-making is extremely important particularly in an environment of investment uncertainty. Fuzzy set theory can be used to represent uncertainty and vagueness to generate decisions in decision-making problems. In this study, the aim is to evaluate ship investment by means of Net Present Value (NPV), Profitability Index (PI), and Payback Period (PP) under the Trapezoidal Interval Type-2 Fuzzy environment. In addition, two methods, Interval Type-2 Fuzzy Payback Period (IT2FPP) and Interval Type-2 Fuzzy Profitability Index (IT2FPI), were developed for the first time in the literature by integrating Interval Type-2 Fuzzy with traditional methods. These methods were then successfully applied to a real case study of ship investment for evaluation in the shipping industry in an uncertain environment
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