Turan, Ahmet İhsan

Reinforced concrete (RC) structures constructed in accordance with earthquake regulations and design principles are subjected to numerous effects, including wind, dead, live, snow, rain, seismic loads, and environmental effects on their service life. One of the most common problems caused by environmental effects is corrosion that occurs in the reinforced concrete reinforcement bar. Concrete can protect the reinforcement bar with sufficient strength and durability properties and undamaged cross-section integrity from corrosion under normal conditions. However, poor concrete quality, high permeability, insufficient concrete cover thickness, and workmanship defects can lead to corrosion of the reinforcement bars. Corrosion in the reinforcement bars can weaken the mechanical properties of the material and shorten the service life of the structure. In this study, the deterioration of concrete and reinforcement in a reinforced concrete structure built in 1982 in Erzincan was investigated using both destructive and non-destructive methods. The aim of examining these materials together was to evaluate the parameters affecting corrosion mechanisms at the material level as well. The results were interpreted by evaluating the climatic data (precipitation, humidity, wind, and temperature) and air quality at the structure's location. Qualitative and quantitative analyses revealed that the increasing corrosion rate causes deterioration in the mechanical properties of the reinforcement bars and that this deterioration is closely related to the type of corrosion. Additionally, it was concluded that the temperature differences and air pollution in Erzincan caused structural deterioration in reinforced concrete elements and accelerated corrosion of the reinforcement bars.

Zirek, Zühal; Çolak, Muhammed Ali

Transportation has an important connection in many aspects such as economic growth, trade, tourism and social interaction. Today, the demand for transportation services is increasing with the rapid socio-economic development. This increase brings with it various traffic problems. Effective intersection design in preventing congestion, delays and accidents is of great importance in terms of ensuring traffic safety and sustainability. In this study, Gürcükapı Intersection and Taşhan Intersection were remodeled with Aimsun software in order to reduce the density at the intersections in Erzurum province and to meet traffic needs. Signalization was added to the modeled intersections, the directions of the intersection arms were changed and four alternative scenarios were created with these changes using current scenario. A total of five scenarios, including the current scenario and the developed alternatives, were evaluated and compared based on travel time, delay time, waiting time, speed, queuing, instant CO2, NOx, PM (Particulate Matter) and VOC (Volatile Organic Compounds) values. As a result of the comparison, the scenario in which the current intersection arm direction and Gürcükapı and Taşhan intersections are modernized and there is no signaling system was determined as the most effective scenario.

Kandil, Ufuk; Bulut, H. Alperen

This study investigates the alkali-silica reaction (ASR) and mechanical properties of mortars containing crumb and powder rubber instead of river sand. In this regard, mortars were produced using waste rubber whose ratios in the mixture are 0%, 3%, 6%, 9%, 12%, 15%, 18%, and 21%. ASR expansion, compressive and flexural strength tests were conducted on the samples. ASR measurements were performed on days 3, 7, 14, 21, and 28. Besides, at the end of the ASR experiment, the microstructures of the mortars were examined using scanning electron microscope (SEM) images. Examining the results of this study reveals that the use of waste rubber in rising portions in the mortars led to an increase in the ASR expansions of the mortars. The study shows that the ASR expansions of the mortar samples that have 9% and 15% waste rubber replacement are comparatively higher than the other mortar samples. Furthermore, the results of the SEM analysis verified this finding. The study demonstrates that 3% of waste rubber mortar samples have the highest compressive and flexural strengths. On the other side, the ASR expansion of the mortars with 3% substituted waste rubber was considerably low compared to other mortars containing waste rubber. These findings (ASR, compressive and flexural strength tests results) show that using 3% waste rubber is ideal for producing mortars and supports a sustainable production approach in the sector.

Yesilyurt, Sefa Nur; Dalkilic, Huseyin Yildirim; Samui, Pijush

Modeling of data is critical in the analysis and evaluation of hydrological behavior. River flow data is one of the most important data in explaining hydrology. Management of water resources; It takes place in the literature as an area that needs to be investigated in order to provide early warning for undesirable situations such as floods and drought. For this reason, it is of important to develop different techniques for the estimation and modeling of river flow or to make comparisons between techniques. In this study, the flow data of fourteen stations located in the Euphrates-Tigris basin between 1981 and 2010 were used. Adaptive Network Based Fuzzy Inference Systems (ANFIS), Support Vector Machine (SVM) techniques that are frequently used in the literature, and newly introduced Gaussian Process Regression (GPR), Extreme Learning Machine (ELM) and Emotional Neural Network (ENN) artificial intelligence techniques are compared. In addition, considering all performance indices, it was determined which technique gave better results with rank analysis. Although all models worked well, it was seen that the methods were ranked as ELM, GPR, ENN, SVM and ANFIS starting from the best. This has shown that ELM, GPR and ENN methods, which have been used recently in flow modeling, give better results than traditional methods with complex structures. In addition, flow values were used in the whole study and these values were examined in 3 different combinations. It was seen that the model structure that gave the best performance was the model structure that used the flow data from one, two and three days ago as an estimator. The results were analyzed with a Taylor diagram and time series graphs.

Akgül, İsmail

With the innovations in technology, the interest in the use of mobile devices is increasing day by day. Any defect that may occur during the production of smart mobile phones, which is among mobile devices, causes significant damage to both the manufacturer and the user. The careful detection of defects that may occur on the screen glass, which is one of the most striking defects among these defects, with the human eye significantly affects the workforce cost. Therefore, it is important to detect defects with the help of software. In recent years, many methods based on machine vision have been developed for the detection of any object or difference in the image. In this study, a new model structure called Yolo-MSD, based on machine vision and the Yolov3 deep learning model, which detects and classifies oil, scratch, and stain defect types on the glass on the touch screen surface used in the design of smart mobile phones, is proposed. The proposed model structure (Yolo-MSD) is obtained by reducing the number of blocks in the Darknet-53 network structure developed in Yolo-v3. As a result of the training, a success rate of 98.50% with the Yolo-v3 model and 98.72% with the Yolo-MSD model was achieved in detecting and classifying defect types. Therefore, it has been observed that the Yolo-MSD model structure is better than the Yolo-v3 model structure by making better feature extraction from the types of defects on the screen glass since it is both faster and has less complexity.

Taşyurdu, Yasemin; Cengiz, Berke

In this paper, we define new kinds of Fibonacci numbers, which generalize both Fibonacci, Jacobsthal, Narayana numbers and Fibonacci ρ-numbers in the distance sense, using the definition of a distance between numbers by a recurrence relation according to a new parameter k. Tiling and combinatorial interpretations of these numbers are presented, and explicit formulas that allow us to calculate the nth number are given. Also, their generating functions are obtained and sums formulas of these numbers with special subscripts are given by tiling interpretations that allow the derivation of their properties.

Taşyurdu, Yasemin; Türkoğlu, Naime Şeyda

In this paper, we define bi-periodic (p, ợ)-Fibonacci and bi-periodic (p, ợ)-Lucas sequences, which generalize Fibonacci type, Lucas type, bi-periodic Fibonacci type and bi-periodic Lucas type sequences, using recurrence relations of (p, ợ)-Fibonacci and (p, ợ)-Lucas sequences. Generating functions and Binet formulas that allow us to calculate the th terms of these sequences are given and the convergence properties of their consecutive terms are examined. Also, we prove some fundamental identities of bi-periodic (p, ợ)-Fibonacci and bi-periodic (p, ợ)-Lucas sequences conform to the well-known properties of Fibonacci and Lucas sequences.

Kuloğlu, Bahar; Eser, Engin; Özkan, Engin

r-circulant matrices have applied in numerical computation, signal processing, coding theory, etc. In this study, our main goal is to investigate the r-circulant matrices of generalized Fermat numbers which are shown by We obtain the eigenvalues, determinants, sum identity of matrices. Also we find upper and lower bounds for the spectral norms of generalized Fermat r-circulant matrices. Beside these, we present GR*a,b,r matrix in the form of ∗ the Hadamard product of two matrices as GR*a,b,r = A. B. In addition, we get the right and skew-right circulant matrices for. Finally, we examine their different norms (Spectral and Euclidean) and limits for matrix norms.

Toksoy, Mustafa Serdar

Researchers have studied discrete location problems for a long time because of their importance in practice. The Discrete Ordered Median Problem (DOMP) generalizes discrete facility location problems. The DOMP generalizes the main facility location problems' objective functions such as the p-median, p-center and p-centdian location problems. As these problems, also known as the problems of location-allocation, have NP-hard structure, it is inevitable to use heuristic methods for solution. In this study, a metaheuristic algorithmic suggestion will be put forward by examining the DOMP to find optimal solutions. For that purpose, we proposed a Simulated Annealing (SA) metaheuristic with K-means Clustering Algorithm in initialization for the DOMP. Novel approaches for initial solution and K-exchange algorithm-based neighborhoods for local search were analysed. In addition, best level of selected parameters were determined by Taguchi method. Forty common p-median instances derived from OR-LIB were used to test the SA performance, and the results were compared with three state-of-art algorithms in the literature. According to the computational results, 21 best solutions were obtained on instances despite gap values and CPU times increasing proportionally to the scale of the instances. In a conclusion, the proposed clustering-based SA algorithm is competitive and can be a robust alternative for the DOMP.

Akkuş, Hakan; Üregen, Rabia Nagehan; Özkan, Engin

In this study, Catalan transformation CSk,n of k--Jacobsthal-Lucas sequences Sk,n is defined. In addition, the transformation of CSkn is written as the product of the Catalan matrix C which is the lower triangular matrix and the Sk matrix of type n x 1, and the Hankel transformations of some fc-Jacobsthal-Lucas numbers is found.