Neural network based model for seismic assessment of existing RC buildings

Naci Caglar,Zehra Sule Garip 사단법인 한국계산역학회 2013 Computers and Concrete, An International Journal Vol.12 No.2

The objective of this study is to reveal the sufficiency of neural networks (NN) as a securer, quicker, more robust and reliable method to be used in seismic assessment of existing reinforced concrete buildings. The NN based approach is applied as an alternative method to determine the seismic performance of each existing RC buildings, in terms of damage level. In the application of the NN, a multilayer perceptron (MLP) with a back-propagation (BP) algorithm is employed using a scaled conjugate gradient. NN based model wasd eveloped, trained and tested through a based MATLAB program. The database of this model was developed by using a statistical procedure called P25 method. The NN based model was also proved by verification set constituting of real existing RC buildings exposed to 2003 Bingol earthquake. It is demonstrated that the NN based approach is highly successful and can be used as an alternative method to determine the seismic performance of each existing RC buildings.

Microstructural, optical and electrical studies on sol gel derived ZnO and ZnO:Al films

Yasemin Caglar,Müjdat Caglar,Saliha Ilican 한국물리학회 2012 Current Applied Physics Vol.12 No.3

ZnO and ZnO:Al films were deposited onto glass substrates by the sol gel method using spin coating technique. The effects of aluminum dopant on the crystalline structure and orientation of the ZnO films have been investigated by X-ray diffraction (XRD) study. Surface morphology of the films has also been analyzed by a field emission scanning electron microscope (FESEM) and atomic force microscope (AFM). The average optical transmittance values of all the films is over >83% in the visible region. The optical band gap and Urbach energy values of these films were determined. The absorption edge shifted to the lower energy depending on the Al doping level. The shift of absorption edge is associated with shrinkage effect. The electrical conductivity of the ZnO film enhanced with the Al dopant. From the temperature dependence of conductivity measurements, the activation energy of the films was also calculated. ZnO and ZnO:Al films were deposited onto glass substrates by the sol gel method using spin coating technique. The effects of aluminum dopant on the crystalline structure and orientation of the ZnO films have been investigated by X-ray diffraction (XRD) study. Surface morphology of the films has also been analyzed by a field emission scanning electron microscope (FESEM) and atomic force microscope (AFM). The average optical transmittance values of all the films is over >83% in the visible region. The optical band gap and Urbach energy values of these films were determined. The absorption edge shifted to the lower energy depending on the Al doping level. The shift of absorption edge is associated with shrinkage effect. The electrical conductivity of the ZnO film enhanced with the Al dopant. From the temperature dependence of conductivity measurements, the activation energy of the films was also calculated.

Structural performance of recycled aggregates concrete sourced from low strength concrete

Caglar Goksu,Ilyas Saribas,Ergun Binbir,Yılmaz Akkaya,Alper Ilki 국제구조공학회 2019 Structural Engineering and Mechanics, An Int'l Jou Vol.69 No.1

Although much research has been carried out using recycled aggregates sourced from normal strength concrete, most of the buildings to be demolished are constructed with low strength concrete. Therefore, the properties of the concrete incorporating recycled aggregates, sourced from the waste of structural elements cast with low strength concrete, were investigated in this study. Four different concrete mixtures were designed incorporating natural and recycled aggregates with and without fly ash. The results of the mechanical and durability tests of the concrete mixtures are presented. Additionally, full-scale one-way reinforced concrete slabs were cast, using these concrete mixtures, and subjected to bending test. The feasibility of using conventional reinforced concrete theory for the slabs made with structural concrete incorporating recycled aggregates was investigated.

Spinal Hydatid Cyst Disease : Challenging Surgery - an Institutional Experience

Caglar, Yusuf Sukru,Ozgural, Onur,Zaimoglu, Murat,Kilinc, Cemil,Eroglu, Umit,Dogan, Ihsan,Kahilogullari, Gokmen The Korean Neurosurgical Society 2019 Journal of Korean neurosurgical society Vol.62 No.2

Objective : Hydatid cyst disease is caused by the parasite Echinococcus granulosus. It is rarely seen in the vertebral system, occurring at a rate of 0.2-1%. The aim of this study is to present 12 spinal hydatid cyst cases, and propose a new type of drainage of the cyst. Methods : Twelve cases of spinal hydatid cysts, surgical operations, multiple operations, chronic recurrences, and spinal hydatic cyst excision methods are discussed in the context of the literature. Patients are operated between 2005 and 2016. All the patients are kept under routine follow up. Patient demographic data and clinicopathologic characteristics are examined. Results : Six male and six female patients with a median age of 38.6 at the time of surgery were included in the study. Spinal cyst hydatid infection sites were one odontoid, one cervical, five thoracic, two lumbar, and three sacral. In all cases, surgery was performed, with the aim of total excision of the cyst, decompression of the spinal cord, and if necessary, stabilization of the spinal column. Mean follow up was 61.3 months (10-156). All the patients were prescribed Albendazole. Three patients had secondary hydatid cyst infection (one lung and two hepatic). Conclusion : The two-way drainage catheter placed inside a cyst provides post-operative chlorhexidine washing inside the cavity. Although a spinal hydatid cyst is a benign pathology and seen rarely, it is extremely difficult to achieve a real cure for patients with this disease. Treatment modalities should be aggressive and include total excision of cyst without rupture, decompression of spinal cord, flushing of the area with scolicidal drugs, and ensuring spinal stabilization. After the operation the patients should be kept under routine follow up. Radiological and clinical examinations are useful in spotting a recurrence.

COVID-19 and Plasmodium ovale Malaria: A Rare Case of Co-Infection

Bilge Caglar,Ridvan Karaali,Ilker Inanc Balkan,Bilgul Mete,Gokhan Aygun 대한기생충학열대의학회 2021 The Korean Journal of Parasitology Vol.59 No.4

Failure analysis of reinforced concrete frames with short column effect

Naci Caglar,Mahir Mutlu 사단법인 한국계산역학회 2009 Computers and Concrete, An International Journal Vol.6 No.5

Short column effect is cause to failure of columns which may result in severe damages or even collapse during earthquakes. The scope of the study is mainly to reveal the effect of short column on the holistic behaviour of the buildings. The nonlinear analysis of 31 different frame buildings containing short column problem are carried out using finite element method. The finite element models were selected by 2 bays and 3 stories. Since the short columns are generally seen in the first storey of the buildings, in the study, they are only constructed in the same storey. The adverse effect of the short column on the response of buildings was shown in terms of the total load factor and displacement capacity of building. The response of buildings in terms of ground storey displacements is presented in figures and discussed. It is revealed that if the window openings are constructed along the bays, the total load capacity is decreased 85% compared with reference model in which all of bays are filled with infill walls.

Long-Term Palliative Effect of Stenting in Gastric Outlet Obstruction Due to Transarterial Chemoembolization with Yttrium-90 in a Patient with Metastatic Neuroendocrine Tumor

Erkan Caglar,Gulen Doğusoy,Levent Kabasakal,Ahmet Dobrucali 대한소화기내시경학회 2016 Clinical Endoscopy Vol.49 No.5

Internal radioembolization with yttrium-90 is a promising treatment method, predominantly for liver tumors. However, the shifting of yttrium-90-loaded spherules into the arteries and veins that supply the duodenum and stomach, leading to ulceration, hemorrhage, perforation, and outlet obstruction of these organs, is one of the major undesirable consequences of this technique. We report a case of gastric outlet obstruction (GOO) due to antropyloric stenosis with ulceration, edema, and inflammation following transarterial yttrium-90 treatment for a metastatic neuroendocrine tumor in a 58-year-old man. Stenting was used for palliation in this case. GOO improved after stenting and recovery of oral intake was permanent after stent removal.

Robust H_∞control applied on a fixed wing unmanned aerial vehicle

Uyulan, Caglar,Yavuz, Mustafa Tolga Techno-Press 2019 Advances in aircraft and spacecraft science Vol.6 No.5

The implementation of a robust $H_{\infty}$ Control, which is numerically efficient for uncertain nonlinear dynamics, on longitudinal and lateral autopilots is realised for a quarter scale Piper J3-Cub model accepted as an unmanned aerial vehicle (UAV) under the condition of sensor noise and disturbance effects. The stability and control coefficients of the UAV are evaluated through XFLR5 software, which utilises a vortex lattice method at a predefined flight condition. After that, the longitudinal trim point is computed, and the linearization process is performed at this trim point. The "${\mu}$-Synthesis"-based robust $H_{\infty}$ control algorithm for roll, pitch and yaw displacement autopilots are developed for both longitudinal and lateral linearised nonlinear dynamics. Controller performances, closed-loop frequency responses, nominal and perturbed system responses are obtained under the conditions of disturbance and sensor noise. The simulation results indicate that the proposed control scheme achieves robust performance and guarantees stability under exogenous disturbance and measurement noise effects and model uncertainty.

Experience of the Endoscopists Matters in Endoscopic Retrograde Cholangiopancreatography in Billroth II Gastrectomy Patients

Erkan Caglar,Deniz Atasoy,Mukaddes Tozlu,Engin Altınkaya,Serkan Dogan,Hakan Senturk 대한소화기내시경학회 2020 Clinical Endoscopy Vol.53 No.1

Background/Aims: Altered anatomy is a challenge in endoscopic retrograde cholangiopancreatography (ERCP) for patients withBillroth II anastomosis. In this study, we investigated the overall success and role of endoscopist experience. Methods: Data of patients who underwent ERCP between 2014 and 2018 after a previous Billroth II operation were retrievedretrospectively from 2 tertiary ERCP centers. The procedures were performed by 2 endoscopists with different levels of experience. Clinical success was defined as extraction of the stone, placement of a stent through a malignant stricture, and clinical and laboratoryimprovements in patients. Results: Seventy-five patients were included. The technical success rate was 83% for the experienced endoscopist and 75% for theinexperienced endoscopist (p=0.46). The mean (±standard deviation) procedure time was 23.8±5.7 min for the experienced endoscopistand 40.68±6.07 min for the inexperienced endoscopist (p<0.001). In total, 3 perforations (4%) were found. The rate of afferent loopperforation was 6.25% (1/16) for the inexperienced endoscopist and 0% (0/59) for the experienced endoscopist (p=0.053). Conclusions: ERCP in patients who had undergone Billroth II gastrectomy was time consuming for the inexperienced endoscopistwho should beware of the unique adverse events related to ERCP in patients with altered anatomy.

The effect of various polishing systems on surface roughness and phase transformation of monolithic zirconia

Ipek Caglar,Sabit Melih Ates,Zeynep Yesil Duymus 대한치과보철학회 2018 The Journal of Advanced Prosthodontics Vol.10 No.2

PURPOSE. The purpose of this study was to evaluate and compare three polishing systems on the surface roughness and phase transformation of monolithic zirconia. MATERIALS AND METHODS. 100 disk shaped specimens (10 mm diameter, 3 mm thickness) were fabricated from monolithic zirconia blocks. 20 specimens were left as a control group and remaining specimens were grinded by diamond bur to simulate the occlusal adjustments. Grinded specimens were randomly divided into 4 groups: group G (no polishing), group M (Meisinger, zirconia polishing kit), group E (EVE Diacera, zirconia polishing kit), and group P (EVE Diapol, porcelain polishing kit). Surface roughness was measured with profilometer and surface topography was observed with SEM. XRD analysis was performed to investigate the phase transformation. Statistical analysis was performed with one-way ANOVA and Tukey’s post hoc tests at a significance level of P=.05. RESULTS. All polishing groups showed a smoother surface than group G. Among 3 polishing systems, group M and group E exhibited a smoother surface than the group P. However, no significant differences were observed between group M and group E (P˃.05). Grinding and polishing did not cause phase transformations in zirconia specimens. CONCLUSION. Zirconia polishing systems created a smoother surface on zirconia than the porcelain polishing system. Phase transformation did not occur during the polishing procedure.