Publications

Seismic performance evaluation of corroded reinforced concrete structures by using default and user defined plastic hinge properties

The primary objectives of this study was to investigate the effects of default hinge properties based on FEMA-356 (FEMA-356, 2000) and user-defined hinge properties on the timedependent seismic performance levels of corroded RC buildings. An assumed corrosion rate was used to predict the capacity curve of the buildings by using default and user-defined plastic hinge properties as a function of time (t: 25 years, and t: 50 years). Two, four and seven stories of RC buildings were considered to represent the effects of default and user- defined hinge properties on story levels. For the modelling of user-defined hinge properties, the time-dependent moment-curvature relationships of structural members were predicted as a function of corrosion rate for two different time periods in order to perform push-over analyses, while default hinge properties were used for the other case based on the ready documents by FEMA-356 (FEMA-356, 2000). Then, the nonlinear time-history analyses for both corroded and non-corroded buildings were performed by using 20 individual earthquake motion records. Seismic performance levels of non-corroded buildings and predicted time-dependent seismic performance levels of corroded buildings were compared based on their story levels as a result of user-defined and default hinge properties. Limit–states at each performance levels (e.i. immediate occupancy, life safety, collapse prevention and collapse) were obtained. The obtained results were summarized to compare the differences in the results of seismic response of the buildings due to user-defined and default hinge properties for both corroded and non-corroded cases.

Trajectory Tracking Control of a Four Rotor Unmanned Aerial Vehicle Based on Continuous Sliding Mode Controller

In this paper, a nonlinear Continuous Sliding Mode control (CSMC) application is presented for trajectory tracking control of a four rotor unmanned aerial vehicle (UAV) called the Quadrotor, also known as micro helicopter. The proposed controller is tested with different time-varying reference routes to provide a stable flight for position control. To show the effectiveness of the designed CSMC, well-tuned PI controller is also applied to quadrotor for the same routes. The current position of the quadrotor is taken from accelerometer, gyroscope and ultrasonic sensors. The experimental results show that the CSMC is adequate to dealing with parameter uncertainties occur in the system dynamics while flying and has satisfactory performance in terms of robustness against to disturbances and error elimination when it compared with PI controller.DOI: http://dx.doi.org/10.5755/j01.eie.23.3.18325

Corrigendum to “Torsional behavior of reinforced concrete beams with corroded reinforcement” [Structures 20 (2019) 476–488]

The journal regret to find that Fig. 7c is not printed in the paper.

Paslandırıldıktan Sonra Basit Burulma Etkisinde Hasara Uğrayan Betonarme Kirişlerin U-Tipi Ankrajlı FRP ile Güçlendirilmesi

Prediction of Pedestrian Traffic Accident Severity and Evaluation of Driver and Pedestrian Faults

This study investigated pedestrians involved traffic accidents with the aim of classifying the severity of accidents based on the number of injured pedestrians using machine learning algorithms, including AdaBoost, Gradient Boosting, XGBoost, K-Nearest Neighbors (KNN), Logistic Regression, Support Vector Classifier, Decision Tree, and Random Forest. The Random Forest model was identified as the best model for classifying pedestrian-involved traffic accidents, achieving high predictive accuracy of 95%, an F1 score of 0.95, and demonstrating low error metrics. The research analyzed both driver and pedestrian faults, alongside factors such as the presence of pedestrian crossings, intersection type, driver age, time of day, month and seasonal variations. The results revealed that accidents at locations without intersections were primarily caused by driver faults, such as speeding, while pedestrian faults, such as crossing at unintended locations, also significantly contribute to the overall accident rate. The findings offered valuable insights into the characteristics of pedestrian accidents to improve traffic safety and reduce pedestrian injuries and fatalities.

Review of: "Analytical Study and Amelioration of Plastic Pavement Material Quality"

An experimental study on the bond strength between reinforcement bars and concrete as a function of concrete cover, strength and corrosion level

The effect of corrosion on the bond strength between reinforcement bars and concrete was studied in a series of experiments. An accelerated corrosion method was used to corrode the reinforcement bars embedded in concrete specimens. Pullout tests were performed to develop an empirical model for the ultimate bond strength by evaluating bond strengths in two different concrete mixes, three concrete cover depths and different mass losses of reinforcement bars after corrosion. Bond-slip relationships for the different corrosion levels were compared. It was found that the relationship between bond strength and concrete strength in uncorroded specimens differed from that of corroded specimens set in high-strength concrete because of brittleness in the corroded specimens, which caused a sudden loss of bond strength. The results revealed that specimens with higher concrete strength levels and corroded reinforcements showed a higher percentage of bond strength degradation due to concrete cracking during the pullout tests.

An experimental study on the bond strength of different geometries of corroded and uncorroded reinforcement bars

This study develops empirical models for the prediction of the bond strength of uncorroded and corroded reinforcement bars. The effects of hooked reinforcement on the bar’s development length when covered fully and partially are examined. An accelerated corrosion method is used to corrode the reinforcement bars embedded in concrete specimens. Pull-out tests are performed to investigate the ultimate bond strength of the concrete specimens. The effects of two different geometries of reinforcement bars are discussed by considering two different concrete strength levels and concrete cover depths. It is found that partly covered hooked reinforcement bars increase the radial stress on the concrete surface and reduce the bond strength. Increases in the bond strength due to the increased roughness of the steel bar caused by the confined corrosion products are less for hooked bars. The results reveal that the developed models show good relationships with the experimentally computed test results.

Enhanced thermal performance of a flat-plate solar water heating system using nanofluids: a TRNSYS-based analysis

BT ÇALIŞANLARININ YENİLİKÇİ DAVRANIŞLARININ DEMOGRAFİK ÖZELLİKLER AÇISINDAN İNCELENMESİ

Bu calismada, bilisim teknolojileri (BT) calisanlarinin yenilik yapma davranislarinin bazi demografik ozelliklere gore farklilik gosterip gostermediginin tespit edilmesi amaclanmistir. Bu amacla Istanbul’daki BT calisanlarina bazi demografik sorularin yaninda Yenilikci Davranis Anketi uygulanmistir. Verilerin analizinde; guvenilirlik analizi, aciklayici faktor analizi (AFA), dogrulayici faktor analizi (DFA) ve tek yonlu varyans analizi teknikleri kullanilmistir. AFA ile incelenen olcegin gecerliligi DFA ile de dogrulanmistir. Olcegin BT calisanlarinin yenilikci davranisini olcmek icin kullanilabilecegine karar verilmistir. Ayrica olcegin oldukca guvenilir oldugu gorulmustur (Cronbach Alpha katsayisi = 0.932). Arastirma sonucunda, BT calisanlarinin yenilikci davranisinin cinsiyet (p = 0.030) ve uzmanlik alanina (p = 0.008) gore anlamli farklilik gosterdigi, yas (p = 0.102), medeni durum (p = 0.633), egitim durumu (p = 0.840) ve mesleki deneyime (p = 0.536) gore farklilik gostermedigi tespit edilmistir.

The removal of copper (II) ion by using mushroom biomass (Agaricus bisporus) and kinetic modelling

İnsansız Hava Aracının (İHA) Kesir Dereceli Kayan Kipli Kontrolcü ile Yörünge Kontrolü

Jacketing of column-beam joints: A case study of an existing RC building in TRNC

Column-beam joints are the most critical regions to failure during earthquakes. The main reason of this failure is when the maximum shear force that the joint can resist is not greater than the shear force calculated in the left or right end of the beams. lnadequate attention to joints during structural designing, poor workmanships and less quality of concrete increase the shear failure of column-beam joints. The main objective of this study is to assess an existing reinforced concrete building to detect the not safety column-beam joints which are needed to strengthen. Besides, performance level of the existing structure has been evaluated before and after strengthening of the structure. in this study effective strengthening technique jacketing in increasing the shear strength and in improving the ductile behaviour of column-beam joint were investigated.

Paslanmaya maruz kalmış betonarme kolonlarda donatı sıyrılma hesabı için deneye dayalı bir modelin geliştirilmesi

Erzincan ağzında kullanılan +I pekiştirme ek-edatı

Türkçede kelimeleri pekiştirmenin bir yolu da ek-edat/enklitik kullanılmaktır. Türkçenin ilk yazılı metinlerinden beri örneklenebilen, ek veya edat oldukları hakkında ortak kanıya varılamayan ve bir başka kelimeyle var olabilen bu ifadeler, Anadolu ağızlarında yaygın kullanım alanı bulmuştur. Çoğu kullanımlarında eklerle karıştırılabilen bu yapıların eklere kıyasla geldiği kelimenin anlamına ek üstü bir işlevle anlam farkı oluşturduğu görülür. Genel kanı ek-edatların tüm kelimelere geldiği yönünde olsa da artık çoğu arkaik özellik taşıyan bu ifadelerin ağızlarda zamirler, bağlaçlar vb. kapalı kelimelere tutunarak varlığını sürdürdüğü görülmektedir. Erzincan ve yöresinde bilhassa zamirlere tutunarak onlara pekiştirmeli bir hitap işlevi veren +I ek-edatı, söz ile anlam arasında yeni bir boyut oluşturmakta; bilhassa alkış ve kargış ifadelerinde tüm cümleye etki edecek vurgulu bir anlatımı cümlenin anlamına yerleştirmektedir. Eldeki çalışmada Erzincan ve yöresinde rastlanılan +I ek-edatının örnekleri ve anlama olan katkısı üzerinde durulacaktır.

Comparative Streamflow Forecasting Using LSTM, GRU, and 1D-CNN Models with PSO-Based Hyperparameter Optimization and MANOVA Analysis

Olası Marmara depremi, İstanbul depremi ve kullanılan hasar degerlendirme metotları

Yurt dışında yayınlanan son araştırma (Yalçıner ve diğerleri 2012) göstermiştir ki, olası İstanbul depremi kapsamında sürdürülen çalışmalarda ciddi aksaklıklar ve hatalar söz konusudur. Kentsel dönüşüm projesi adı altında yapılan çalışmalarda çok ciddi hatalar yapılmaktadır. Bu çalışmalarda mevcut betonarme yapılar yerinde incelenerek, mevcut yapı hakkında değerlendirmelerde bulunulmaktadır. Bu değerlendirmelerin yapılabilmesi için genel olarak iki yöntem izlenmektedir.

Investigation of the compressive strength and flexural strength of concrete with perlite under the effect of high temperature

When the existing literature is examined, it can be seen that many studies have been carried out to improve the mechanical properties of concrete by using waste or additive materials with different mechanical and physical properties in various proportions instead of the conventional aggregate used in concrete production. Within the scope of this study, it was aimed to examine the physical and mechanical properties of the samples fabricated using natural perlite aggregate instead of conventional aggregate by exposing them to high temperature effects. In this context, a total of 96 concrete samples will be fabricated, including 48 rectangular prism beams with dimensions of 10x10x40 cm and 48 cube samples with dimensions of 15x15x15 cm, with a concrete compressive strength of 25 and 40 MPa, using perlite and conventional concrete. The samples were planned to be exposed to temperature effects of 200ºC, 400ºC and 600ºC at room temperature. Afterwards, the samples will be examined with destructive/non-destructive methods such as mass loss (ML), ultra sound transmission rate (USTR), compressive strength (CS), elasticity modulus (EM)and pure bending (PB) test, and the mechanical and physical properties of all samples will be compared.