Free vibration analysis of plates resting on elastic foundations using modified Vlasov model

Ayvaz, Yusuf,Oguzhan, Celal Burak Techno-Press 2008 Structural Engineering and Mechanics, An Int'l Jou Vol.28 No.6

An application is presented of a modified Vlasov model to the free vibration analysis of plates resting on elastic foundations. The effects of the subsoil depth, the ratio of the plate dimensions, the ratio of the subsoil depth to the plate dimension in the longer direction, and the value of the vertical deformation parameter within the subsoil on the frequency parameters of plates on an elastic foundation are investigated. This analysis has been caried out by the aid of a computer program. The first ten frequency parameters are presented in tabular and the graphical forms to evaluate the effects of the parameters considered in this study. Then mode shapes corresponding to the first six of the frequency parameters are given in graphs. It is concluded that the effect of the subsoil depth on the frequency parameters of the plates on an elastic foundation is generally larger than those of the other parameters considered in this study.

Free vibration analysis of plates resting on elastic foundations using modified Vlasov model

Yusuf Ayvaz,Celal Burak O uzhan 국제구조공학회 2008 Structural Engineering and Mechanics, An Int'l Jou Vol.28 No.6

An application is presented of a modified Vlasov model to the free vibration analysis of plates resting on elastic foundations. The effects of the subsoil depth, the ratio of the plate dimensions, the ratio of the subsoil depth to the plate dimension in the longer direction, and the value of the vertical deformation parameter within the subsoil on the frequency parameters of plates on an elastic foundation are investigated. This analysis has been caried out by the aid of a computer program. The first ten frequency parameters are presented in tabular and the graphical forms to evaluate the effects of the parameters considered in this study. Then mode shapes corresponding to the first six of the frequency parameters are given in graphs. It is concluded that the effect of the subsoil depth on the frequency parameters of the plates on an elastic foundation is generally larger than those of the other parameters considered in this study.

Simultaneous forequarter amputation and radical mastectomy for metastatic breast carcinoma in a male patient: a case report

Mehmet Ayvaz,Caglar Yilgor,Musa Ugur Mermerkaya,Ali Konan,Erhan Sonmez,Rifat Emre Acaroglu 대한외과학회 2011 Annals of Surgical Treatment and Research(ASRT) Vol.81 No.6

Although the majority of forequarter amputations are performed for high-grade bone and soft tissue sarcomas or extensive osteomyelitis of the upper extremity, this radical operation may also be indicated for the curative treatment of recurrent breast cancer and for the palliation of locally advanced breast cancer. We report a male patient with metastatic breast adenocarcinoma who underwent simultaneous mastectomy and forequarter amputation for the management of both his primary and metastatic disease.

Characterization and Tribological Properties of Novel AlCu4.5SiMg Alloy–(B4C/TiO2/nGr) Quaternary Hybrid Composites Sintered via Microwave

Mehmet Ayvaz 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.3

In the future, hybrid aluminum matrix composites, which are the second generation composites, will be replaced by solidreinforced third-generation quaternary hybrid composites in which nano- and micro-scale reinforcement particles are usedtogether. In this study, microwave sinterability of B4C,TiO2(nm + μm), and nGr reinforced quaternary hybrid compositesthat had AlCu4.5SiMg alloyed Matrix, and their microstructural and tribological properties after sintering were examined. The proportion of nGr in the composite sample was taken as 0.5 wt%, while B4Cand TiO2were used in three different proportions(3, 9, 12 wt%). After being compressed under 600 MPa pressure, the composite samples were sintered for 60 minat 550 °C by a microwave oven with a power of 2.9 kW and a frequency of 2.45 GHz. It was determined that due to its highmicrowave absorbency, B4Creinforcement improved the microwave sinterability more compared to TiO2. In XRD analyses,whereas Al4C3and Al3BCreaction products were not seen as harmful, the intermetallic phase of Al2Cuwas detected. Itwas determined that both friction coefficient and wear resistance increased as the proportion of B4Cincreased in compositesamples. In AlCu4.5SiMg–(12 wt% B4C/3 wt% TiO2/0.5 wt% nGr) quaternary hybrid composites with the highest hardness(97.6 HV), the lowest specific wear rate (0.118 mm3 Nm × 10−3) was detected.

Structural optimization with teaching-learning-based optimization algorithm

Dede, Tayfun,Ayvaz, Yusuf Techno-Press 2013 Structural Engineering and Mechanics, An Int'l Jou Vol.47 No.4

In this paper, a new efficient optimization algorithm called Teaching-Learning-Based Optimization (TLBO) is used for the least weight design of trusses with continuous design variables. The TLBO algorithm is based on the effect of the influence of a teacher on the output of learners in a class. Several truss structures are analyzed to show the efficiency of the TLBO algorithm and the results are compared with those reported in the literature. It is concluded that the TLBO algorithm presented in this study can be effectively used in the weight minimization of truss structures.

Earthquake behavior of stiffened RC frame structures with/without subsoil

Y. I. Özdemir,Y. Ayvaz 국제구조공학회 2008 Structural Engineering and Mechanics, An Int'l Jou Vol.28 No.5

The purpose of this study is to investigate the linear earthquake behavior of the frame structures including subsoil with different stiffening members and to compare the results of each frame considered. These comparisons are made separately for displacement, bending moments and axial forces for frames with different storey and bay numbers for the time history and the modal analyses. The results of both methods are also compared. The results of the frames with subsoil are also compared with the results of the frames without subsoil. It is concluded that all stiffening members considered in this study decrease the lateral displacement of the frame and the bending moment of the columns and increase the axial force in the columns and that configuration of the bracing members come out to be an important parameter in braced frames since the frames with the same type of bracing give different results depending on configuration. It is also concluded that, in general, the absolute maximum displacements of the frames modeled with subsoil are larger than those of the frames modeled without subsoil.

Earthquake behavior of stiffened RC frame structures with/without subsoil

Ozdemir, Y.I.,Ayvaz, Y. Techno-Press 2008 Structural Engineering and Mechanics, An Int'l Jou Vol.28 No.5

The purpose of this study is to investigate the linear earthquake behavior of the frame structures including subsoil with different stiffening members and to compare the results of each frame considered. These comparisons are made separately for displacement, bending moments and axial forces for frames with different storey and bay numbers for the time history and the modal analyses. The results of both methods are also compared. The results of the frames with subsoil are also compared with the results of the frames without subsoil. It is concluded that all stiffening members considered in this study decrease the lateral displacement of the frame and the bending moment of the columns and increase the axial force in the columns and that configuration of the bracing members come out to be an important parameter in braced frames since the frames with the same type of bracing give different results depending on configuration. It is also concluded that, in general, the absolute maximum displacements of the frames modeled with subsoil are larger than those of the frames modeled without subsoil.

Shear locking-free earthquake analysis of thick and thin plates using Mindlin's theory

Ozdemir, Y.I.,Ayvaz, Y. Techno-Press 2009 Structural Engineering and Mechanics, An Int'l Jou Vol.33 No.3

The purpose of this paper is to study shear locking-free parametric earthquake analysis of thick and thin plates using Mindlin's theory, to determine the effects of the thickness/span ratio, the aspect ratio and the boundary conditions on the linear responses of thick and thin plates subjected to earthquake excitations. In the analysis, finite element method is used for spatial integration and the Newmark-${\beta}$ method is used for the time integration. Finite element formulation of the equations of the thick plate theory is derived by using higher order displacement shape functions. A computer program using finite element method is coded in C++ to analyze the plates clamped or simply supported along all four edges. In the analysis, 17-noded finite element is used. Graphs are presented that should help engineers in the design of thick plates subjected to earthquake excitations. It is concluded that 17-noded finite element can be effectively used in the earthquake analysis of thick and thin plates. It is also concluded that, in general, the changes in the thickness/span ratio are more effective on the maximum responses considered in this study than the changes in the aspect ratio.

Probabilistic Power Flow Analysis Using Matlab Graphical User Interface (GUI)

Kurt Unal,Ozgonenel Okan,Ayvaz Birsen Boylu 대한전기학회 2022 Journal of Electrical Engineering & Technology Vol.17 No.2

In today’s power systems, there are renewable energy sources such as wind energy systems and solar energy systems. Renewable energy sources cause extra power fl uctuation in the system. Rising of the fl uctuation incresas the uncertainties of the power system. Since deterministic methods that do not contain uncertainty because of using certain fi xed values instead of probabilistic values, these methods can not give reliable results under uncertainties. Therefore, statistical load fl ow, also known as probabilistic load fl ow, has taken its place as a new title in the literature in order to overcome the defi ciencies of conventional load fl ow methods which do not contain uncertainty. In this study, a comparative analysis of Monte Carlo simulation with Latin Hypercube sampling method and Unscented transformation methods are presented. These methods are compared with the results obtained from the classical Monte Carlo simulation method. IEEE 14 and 30 bus test systems and Ondokuz Mayıs University campus distribution system were chosed as a test system for the application of the proposed methods. The results show that Unscented transformation method is faster and more reliable than the other two methods.

Prediction of Drug–Drug Interactions by Using Profile Fingerprint Vectors and Protein Similarities

Selma Dere,Serkan Ayvaz 대한의료정보학회 2020 Healthcare Informatics Research Vol.26 No.1

Objectives: Drug–drug interaction (DDI) is a vital problem that threatens people’s health. However, the prediction of DDIs through in-vivo experiments is not only extremely costly but also difficult as many serious side effects are hard to detect in in-vivo and in-vitro settings. The aim of this study was to assess the effectiveness of similarity-based in-silico computational DDI prediction approaches and to provide a cost effective and scalable solution to predict potential DDIs. Methods: In this study, widely known similarity-based computational DDI prediction methods were utilized to discover novel potential DDIs. More specifically, known interactions, drug targets, adverse effects, and protein similarities of drug pairs were used to construct drug fingerprints for the prediction of DDIs. Results: Using the drug interaction profile, our approach achieved an area under the curve (AUC) of 0.975 in the prediction of a potential DDI. The drug adverse effect profile and protein profile similarity-based methods resulted in AUC values of 0.685 and 0.895, respectively, in the prediction of DDIs. Conclusions: In this study, we developed a computational approach to the prediction of potential drug interactions. The performance of the similarity-based computational methods was comparatively evaluated using a comprehensive real-world DDI dataset. The evaluations showed that the drug interaction profile information is a better predictor of DDIs compared to drug adverse effects and protein similarities among DDI pairs.