{"title":"Estimation Study of Multicomponent Stress-Strength Reliability Using Advanced Sampling Approach","authors":"A. Hassan, Rasha S. Elshaarawy, H. Nagy","doi":"10.35378/gujs.1132770","DOIUrl":"https://doi.org/10.35378/gujs.1132770","url":null,"abstract":"In this study, we analyze a multicomponent system with v independent and identical strength components X1, …, Xv and each of these components is exposed to a common random stress Y. The system is considered to be operating only if at least u out of v (1 u v) strength variables exceeds the random stress. The estimate of system reliability is investigated, assuming strength and stress random variables follow the exponentiated exponential distribution with different shape parameters. The maximum likelihood estimator for system reliability is derived from ranked set sampling (RSS), neoteric RSS (NRSS) and median RSS (MRSS). Some accuracy measurements, such as mean squared errors and efficiencies, are used to examine the behaviour of various estimators. Simulation studies demonstrate that the NRSS scheme's reliability estimates are chosen above those of the RSS and MRSS schemes in the majority of situations. Theoretical research is explained through real data analysis","PeriodicalId":12615,"journal":{"name":"gazi university journal of science","volume":"1 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-03-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69796052","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Detection of Bovine Species on Image Using Machine Learning Classifiers","authors":"Ali Tezcan Sarizeybek, A. Işık","doi":"10.35378/gujs.1203685","DOIUrl":"https://doi.org/10.35378/gujs.1203685","url":null,"abstract":"There are too many cattle in the world and too many breeds of cattle. For someone who is new to cattle breeding, it may be difficult to tell which species their cattle are. In some cases, an experienced person may not understand the breeds of two cattle that are similar in appearance. In this study, the aim is to classify the cattle species with image processing methods and mobile applications written in Flutter and TensorFlow Lite. For classifying breeds, The VGG-16 algorithm was used for feature extraction. XGBoost and Random Forest algorithms were used for classification and the combined versions of the two methods were compared. In addition, SMOTE algorithm and image augmentation algorithms were used to prevent the imbalance of the dataset, the performance results of the combined versions of the two methods were compared. Images of different cattle species from different farms were obtained and the dataset was prepared, then trained image classification models and tested the trained models. As a result of performance tests, it’s obtained that the best model is VGG16+Random Forest+SMOTE+Augmentation with 88.77% accuracy result for this study. In the mobile application, first the cattle is detected with a pre-trained object detection model, and then the breed classification of the cattle on the image is made with image classification model.","PeriodicalId":12615,"journal":{"name":"gazi university journal of science","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44257066","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Neslihan Delen, I. Tasçioglu, S. ALTINDAL YERİŞKİN, A. Özbay
{"title":"Voltage Dependent Profiles of the Surface States and Series Resistance (Rs) in the Al-(Cd:ZnO)-pSi Schottky Diodes (SDs) Utilizing Voltage-Current (IV) Characteristics","authors":"Neslihan Delen, I. Tasçioglu, S. ALTINDAL YERİŞKİN, A. Özbay","doi":"10.35378/gujs.1218206","DOIUrl":"https://doi.org/10.35378/gujs.1218206","url":null,"abstract":"In this work, the main electronic parameters of the performed Al-(CdxZn1-xO)-pSi Metal/İnterface-layer/Semiconductor (MIS) type Schotty Diodes (SDs) have been investigated by utilizing IV characteristics at 300 K. The (CdxZn1-xO) interfacial layer was enlarged on the pSi wafer by utilizing sol-gel technique. Ideality-factor(n), potential barrier Фbo, Rs, shunt resistances (Rsh) and rectification rate (RR) (Iforward/Ireverse) values have been calculated based on thermionic emission (TE) theory and Cheung function between -5V and 5V and they changed for 0.1, 0.2, and 0.3 Cd doped interfacial layer. Energy-dependent profiles of them were also extracted from the forward bias IV data and their magnitude was found as 1012eV-1.cm-2 order which are very appropriate for the MIS type SD. The values of n, barrier height (BH), Фbo, and RR were changed from the 4.347, 0.582 eV, 5.74x103 to 5.293, 0.607 eV, 2.83x106, These results show that electronic parameters of these SDs are strong function of voltage, calculated method, and the dopand rate of Cadminium (Cd) interfacial layer and the best one rate is the 30% Cd:ZnO. Thus such an interfacial layer may be used instead of traditional insulator layers and increase the quality of Metal/Semiconductor (MS) type SDs. \u0000.","PeriodicalId":12615,"journal":{"name":"gazi university journal of science","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49341851","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"On Quaternions with Higher Order Jacobsthal Numbers Components","authors":"Engin ÖZKAN, Mine UYSAL","doi":"10.35378/gujs.1002454","DOIUrl":"https://doi.org/10.35378/gujs.1002454","url":null,"abstract":"In this study, we present higher order Jacobsthal numbers. Then we define higher order Jacobsthal quaternions by using higher order Jacobsthal numbers. We give the concept of the norm and conjugate for these quaternions. We express and prove some propositions related to these quaternions. Also, we find the recurrence relation, the Binet formula and the generating function for these quaternions. Finally, we calculate Cassini, Catalan, Vajda and d’Ocagne identities for higher order Jacobsthal quaternions.","PeriodicalId":12615,"journal":{"name":"gazi university journal of science","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135907517","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hatice Mehtap BULUKLU, Filiz BAL KOÇYİĞİT, Ercan KÖSE
{"title":"Low-Cost Alpha Cabin Like Test Box Proposal for the Development of New Acoustic Sound Insulation Materials","authors":"Hatice Mehtap BULUKLU, Filiz BAL KOÇYİĞİT, Ercan KÖSE","doi":"10.35378/gujs.1010472","DOIUrl":"https://doi.org/10.35378/gujs.1010472","url":null,"abstract":"Experimental criteria for sound insulation material recommendation and design have an important share in indoor acoustic control. Among these criteria, laboratories with devices such as impedance tubes, alpha cabins and reverberation rooms used to measure and analyze parameters such as sound transmission loss and sound absorption coefficient have been investigated. In literature, it has been observed that there are studies on acoustic materials and the tests applied to these materials, but the application is more limited. According to research data, an Alpha Cabin model system design that can be used to develop new types of acoustic sound materials has been proposed. In addition to the fact that a large number of experimental measurements can be performed at lower costs using the designed Alpha Cabin model system, many tests can be performed easily for different material designs in a very short time. To perform these tests, the Alpha Cabin system has been designed based on noise and sound insulation. For example, floating flooring, ribbed connection, and so on. Afterward, different insulation materials were used for insulation purposes and standards were achieved. The Alpha Cabin test system, which was designed and developed, overlaps the experimental and theoretical data for 500, 2000, and 4000 Hz when compared with the values of 29.1 dB for 500 Hz, 38.6 dB for 2000 Hz, and 49 dB for 4000 Hz measured in the Acoustic Facade Panel Test Room, and it has been observed that it can be used in the development of new sound insulation materials.","PeriodicalId":12615,"journal":{"name":"gazi university journal of science","volume":"56 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136131247","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"The Production of Hollow Nanofibers from PBS / TPU Blends by Coaxial Electrospinning Method","authors":"Hatice Bilge İşgen, Sema Samatya Yılmaz, Ayse Aytac","doi":"10.35378/gujs.1199571","DOIUrl":"https://doi.org/10.35378/gujs.1199571","url":null,"abstract":"In this study, the production of hollow Polybutylene Succinate (PBS)/Thermoplastic Polyurethane (TPU) nanofibers as biodegradable nanomaterials with improved mechanical properties were carried out by coaxial electrospinning method. The polymer solutions of pure PBS, pure TPU, and PBS/TPU blends (60/40, 40/60, 20/80 w/w) (as the shell) versus pure Polyvinylpyrrolidone (PVP) (as core) were put together for bi-component nanofibers production. The core structure of nanofibers was dissolved in distilled water. Thus, hollow nanofibers were obtained with the removal of PVP from the structure. Characterization studies (SEM, FTIR, and Tensile tests) of hollow nanofibers were performed. The morphological properties of PBS/TPU blends in ratios of 60/40 and 20/80 were observed as homogeneous and non-adhered fiber structures. It was determined that the hollow PBS/TPU (60/40) mat has the thinnest nanofibers. New bond formations within the interactions of substances as studied in the chemistry of blended electrospun webs were examined with FTIR analysis. Therewithal, this test showed the removal of PVP in the core of all nanofibers. It was observed that the adhered fibers increased the tensile stress and decreased the tensile strain at mechanical test results that were verified also by SEM views. It is suggested that the hollow nanofibers produced by this study can be used in the biomedical field as a biodegradable and breathable wound dressing","PeriodicalId":12615,"journal":{"name":"gazi university journal of science","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49224708","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Detection of COVID-19 Disease with Machine Learning Algorithms from CT Images","authors":"Mahmut Nedim Ekersular, A. Alkan","doi":"10.35378/gujs.1150388","DOIUrl":"https://doi.org/10.35378/gujs.1150388","url":null,"abstract":"With the identification of the SARS-COV-2 virus in November 2019, the world has become very different. The COVID-19 disease caused by the virus has reached epidemic proportions and continues. This virus, which is one of the most contagious and deadly pathogens in human history with the number of cases approaching 600 million and the number of deaths exceeding 6 million, has shown and continues to show itself in every area that people come into contact with, from business life to economy, transportation to education, social life to psychology. Although the developed vaccines provide a partial decrease in the number of deaths, the mutations that the virus constantly undergoes and the increase in the transmission rate accordingly reduce the effectiveness of the vaccines, and the number of deaths tends to increase as the number of infected people. It is undoubtedly important that the detection of this epidemic disease, which is the biggest crisis that humanity has experienced in the last century after World War II, is carried out accurately and quickly. In this study, a machine learning-based artificial intelligence method has been proposed for the detection of COVID-19 from computed tomography images. The features of images with two classes are extracted using the Local Binary Pattern. The images reserved for training in the dataset were used for training machine learning models. Trained models were tested with previously unused test images. While the Fine K-Nearest Neighbors model reached the highest accuracy with a value of 0.984 for the training images, the highest accuracy value was obtained by the Cubic Support Vector Machine with 0.93 for the test images. These results are higher than the deep learning-based study using the same data set.","PeriodicalId":12615,"journal":{"name":"gazi university journal of science","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42343601","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. N. Esen, A. Azbouche, S. Haciyakupoğlu, Sema Erentürk, Zaida Melzi̇
{"title":"Accumulation of Heavy Metals and Determination of Natural Radioactivity in the Soil-Thyme System in Omerli, Istanbul: Assessment of Ecological and Health Risk","authors":"A. N. Esen, A. Azbouche, S. Haciyakupoğlu, Sema Erentürk, Zaida Melzi̇","doi":"10.35378/gujs.1150020","DOIUrl":"https://doi.org/10.35378/gujs.1150020","url":null,"abstract":"Transfer of metals from soil to plant is an important pathway of human exposure to environmental contaminants. In this study accumulation of different metals was investigated and natural radioactivity levels were measured in the soil–thyme system. Results showed that the concentration of Br, Cr, Mn, Ni, and Pb in the soil is higher than the World average value, and P, Ca, and Zn have higher transfer factors. The natural radioactivity level in the soils is similar to the World average. For thyme samples the average values for 226Ra, 232Th and 40K were found as 22.7 Bqkg-1, 61.3 Bqkg-1 and 722 Bqkg-1, respectively. The health and ecological risks of soil were evaluated. The total hazard index of the child was 1.453 on average, greater than that of the adult (0.175), primarily due to the contribution of Cr. Ecological risk assessed based on various indices indicated that Pb and Ni show contamination risk to the environment. Our study confirms that metals in soil influence metals in plants, and those metal interactions are critical for pollution risk control.","PeriodicalId":12615,"journal":{"name":"gazi university journal of science","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49563307","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Fabrication and Performance of a Perovskite Solar Cell: Effect of Acetylacetone on Compact TiO2 Layer","authors":"B. Kaya, İ. Boz, Mehtap ŞAFAK BOROĞLU","doi":"10.35378/gujs.1176183","DOIUrl":"https://doi.org/10.35378/gujs.1176183","url":null,"abstract":"Solar energy has been the most emphasized issue in recent years, as it is sustainable and causes zero emissions. Solar cells are of interest because they convert sunlight into electricity through photovoltaic effects. Over the last ten years, the efficiency of perovskite solar cells has achieved 25% due to the development of synthesis techniques and electrode materials etc. The electron transport layer, a hole transport layer their thickness and structure of surface etc. act an important role in improving the performance of perovskite solar cells. We have investigated the effect of the acid-assisted route and the acetylacetone-assisted (AA) route on TiO2 films and thus the effect of the efficiency of perovskite solar cells. Perovskite (CH3NH3PbI3) solar cells based on different c-TiO2 have been fabricated by the spin coating route, and the overall experimental section is made in the nitrogen medium at room temperature. Cracked c-TiO2 film obtained via the acid-assisted route. The planar heterojunction structure of ITO/AA-TiO2/CH3NH3PbI3/P3HT/Ag resulted 0.03% of power conversion efficiency (PCE). However, the perovskite solar cells with a mesoporous heterojunction structure of ITO/ AA-TiO2/m- TiO2 /CH3NH3PbI3/P3HT/Ag resulted 0.1% of PCE.","PeriodicalId":12615,"journal":{"name":"gazi university journal of science","volume":"1 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-01-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69795700","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Analytical Investigation of Microcrystalline Wood Charcoal Reinforced Polyester Composites Using ED-XRF, FTIR and SEM-EDS Techniques","authors":"Francis Edoziuno, R. Akaluzia","doi":"10.35378/gujs.794837","DOIUrl":"https://doi.org/10.35378/gujs.794837","url":null,"abstract":"Polyester based particle reinforced composites were developed using varying weight fractions (ranging from 0 to 30 wt%, at 5 wt% interval) of microcrystalline wood charcoal powder (75µm). Quantitative, qualitative and functional characterization of developed wood charcoal (WC) particles reinforced polyester matrix composites was carried out successfully using energy dispersive x-ray spectrophotometer (EDXRF), Fourier transform infrared spectrometer (FTIR) and scanning electron microscope (SEM) enhanced with ancillary EDS for elemental identification capability. The primary elements and oxides identified in wood charcoal by EDXRF include iron, copper, zinc, calcium and CaO, Fe2O3, CuO, ZnO respectively. These elements and oxides were noted to induce improvement on the properties of reinforced polymer composites. EDS elemental mapping also confirmed the major elements identified by EDXRF analysis. Composites reinforced with microcrystalline wood charcoal exhibited strong interfacial bonding and interlocking due to even dispersion of the filler particles as revealed by SEM images. Interactions of the microcrystalline wood charcoal fillers with the polyester matrix molecules were revealed by FTIR functional characterization as minor shifts in the frequency bands of functional groups normally present in unsaturated polyester resin.","PeriodicalId":12615,"journal":{"name":"gazi university journal of science","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41559659","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}