Master Degree / Yüksek Lisans Tezleri
Permanent URI for this collectionhttps://hdl.handle.net/11147/3008
Browse
2 results
Search Results
Master Thesis In-Depth Investigation of the Effects of Different Preprocessing Strategies on Infrared Spectroscopic Data(01. Izmir Institute of Technology, 2021) Deniz, Elin İlayda; Özdemir, Durmuş; Özdemir, Durmuş; 04.01. Department of Chemistry; 01. Izmir Institute of Technology; 04. Faculty of ScienceWhenever collecting experimental data, they may contain several spurious sources of variability which can hinder the extraction of the desired relevant information so that it is rarely the case that they can be processed as such by chemometrics approaches. In recent years, pre-processing techniques has become an integral part of chemometrics modeling with the purpose of providing better endmodels through fundamental knowledge for Near-Infrared (NIR) users. The aim of pre-processing techniques is to improve success of multivariate regression by reducing undesired physical phenomena in the spectra. This thesis describes the theory of present pre-processing techniques and compares the qualitative and quantitative results of their application. Mean centering, scatter-correction methods and spectral derivatives are the instances of those pre-processing techniques used in this thesis. Those techniques and combinations of them have been applied in order to find the best pre-processing strategy. To be able to observe the results and compare the effects of the applied methods, Partial Least Squares and Genetic Inverse Laast Squares are carried out as multivariate calibration methods. When comparing the calibration results of raw data with pre-processing techniques applied data, decreasement standard eror of prediction (SEP) values observed after appliying those techniques, which is good manner. However, better in comparison, t-Test: Paired Two Sample for Means applied. The results demontrates that there is no significant difference within 95% confidence level.Master Thesis Development of Real Time Blood Vessel Imaging System for Early Diagnosis of Vascular Diseases(01. Izmir Institute of Technology, 2020) Gümüş, Abdurrahman; Gümüş, Abdurrahman; 03.05. Department of Electrical and Electronics Engineering; 03. Faculty of Engineering; 01. Izmir Institute of TechnologyDisorders in the circulatory system may cause various diseases and tissue damage. The early detection of abnormalities in blood circulation has an important role in terms of treatment and also raising awareness of the patient. Vascular imaging methods used by today's technology are invasive, and/ or radiation-based. As an alternative to high-cost near infrared (NIR) vascular imaging devices in the market, a microcomputer-based, real-time, non-contact and safe vascular imaging system has been developed with low- cost. Due to the higher absorption coefficient of blood than skin and fat and also the differences in the spectra of oxy and deoxyhemoglobin in blood, the vascular structures were obtained using light at NIR region. A device, which uses NIR LED light operated at 850 nm, was designed using optical and electronic components. Image and video analysis were performed using OpenCV, which is an open-source software library, and data visualization libraries. Tests were carried out to optimize the best imaging conditions for the device. To be able to show abnormalities in the vascular structures and to test the effectiveness of the device, "diabetes", which can cause various vascular disease complications, was selected. Superficial vascular structures were observed in the near infrared images captured from people at different stages of this disease. As expected, the vessel images captured from the participants revealed deterioration in vascular structures in diabetic patients compared to healthy people. In order to make a clear inference about the accuracy of the images, it is necessary to compare them to the angiography images of the individuals and be interpreted by vascular surgery specialist.