The effective depth of soil stratum for plates resting on elastic foundation

Daloglu, Ayse T.,Ozgan, K. Techno-Press 2004 Structural Engineering and Mechanics, An Int'l Jou Vol.18 No.2

The purpose of this paper is to determine the subsoil depth affected from the load on the plate resting on elastic foundation using stress distribution within the subsoil that will be occurred depending on the loading and dimension of the plate. An iterative method is developed in order to determine the effective depth of the subsoil under the plate. Numerical examples from the technical literature are solved by means of the method suggested herein and displacements, bending moments and shear forces are presented in graphical and tabular forms to evaluate the effects of the limit depth considered in the study. Results showed the efficiency and simplicity of the present approach for the plate resting on an elastic foundation.

Cervical Cytological Screening Results of 8,495 Cases in Turkey - Common Inflammation but Infrequent Epithelial Cell Abnormalities?

Daloglu, Ferah Tuncel,Karakaya, Yeliz Arman,Balta, Hilal,Altun, Eren,Duman, Aslihan Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.13

Background: Cervical cancer is the ninth most common cancer among females in Turkey. Cervical smear is a routine screening test used for the detection of cervical abnormalities and also it detects certain infections of the cervix. Objective: To analyze cervical smear results of our clinic in order to determine most frequent pathology of the women in North Eastern Anatolia Region of Turkey. Materials and Methods: In a retrospective study design, 8,495 cervical cytology cases diagnosed at the Pathology Department of the Regional Education and Research Hospital in Erzurum over the last one and half years extending from August 2012 to December 2013 were investigated. Results: The most common diagnosis was found to be inflammation, 65.5 % (5,566 out of 8,495), and the least was squamous epithelial abnormalities 0.2% (13 out of 8,495). There was some variation among the three pathologists regarding diagnosis but findings for the latter. Conclusions: Regular cervical smear tests are one of the most important strategies in early diagnosis of cervical cancer but there are conflicting data regarding the prevalence of epithelial cell abnormalities in Turkey, and the reasons o f this should be investigated.

The effective depth of soil stratum for plates resting on elastic foundation

Ayse T. Daloglu,K. Ozgan 국제구조공학회 2004 Structural Engineering and Mechanics, An Int'l Jou Vol.18 No.2

Optimization of trusses under uncertainties with harmony search

Togan, Vedat,Daloglu, Ayse T.,Karadeniz, Halil Techno-Press 2011 Structural Engineering and Mechanics, An Int'l Jou Vol.37 No.5

In structural engineering there are randomness inherently exist on determination of the loads, strength, geometry, and so on, and the manufacturing of the structural members, workmanship etc. Thus, objective and constraint functions of the optimization problem are functions that depend on those randomly natured components. The constraints being the function of the random variables are evaluated by using reliability index or performance measure approaches in the optimization process. In this study, the minimum weight of a space truss is obtained under the uncertainties on the load, material and cross-section areas with harmony search using reliability index and performance measure approaches. Consequently, optimization algorithm produces the same result when both the approaches converge. Performance measure approach, however, is more efficient compare to reliability index approach in terms of the convergence rate and iterations needed.

Optimum design of parabolic and circular arches with varying cross section

Uzman, Umit,Daloglu, Ayse,Saka, M. Polat Techno-Press 1999 Structural Engineering and Mechanics, An Int'l Jou Vol.8 No.5

A structural optimization process is presented for arches with varying cross-section. The optimality criteria method is used to develop a recursive relationship for the design variables considering displacement, stresses and minimum depth constraints. The depth at the crown and at the support are taken as design variables first. Then the approach is extended by taking the depth values of each joint as design variable. The curved beam element of constant cross section is used to model the parabolic and circular arches with varying cross section. A number of design examples are presented to demonstrate the application of the method.

Alternative plate finite elements for the analysis of thick plates on elastic foundations

Ozgan, K.,Daloglu, Ayse T. Techno-Press 2007 Structural Engineering and Mechanics, An Int'l Jou Vol.26 No.1

A four-noded plate bending quadrilateral (PBQ4) and an eight-noded plate bending quadrilateral (PBQ8) element based on Mindlin plate theory have been adopted for modeling the thick plates on elastic foundations using Winkler model. Transverse shear deformations have been included, and the stiffness matrices of the plate elements and the Winkler foundation stiffness matrices are developed using Finite Element Method based on thick plate theory. A computer program is coded for this purpose. Various loading and boundary conditions are considered, and examples from the literature are solved for comparison. Shear locking problem in the PBQ4 element is observed for small value of subgrade reaction and plate thickness. It is noted that prevention of shear locking problem in the analysis of the thin plate is generally possible by using element PBQ8. It can be concluded that, the element PBQ8 is more effective and reliable than element PBQ4 for solving problems of thin and thick plates on elastic foundations.

Incidence and Clinicopathologic Features of Primary Lung Cancer: A North-Eastern Anatolia Region Study in Turkey (2006-2012)

Demirci, Elif,Daloglu, Ferah,Gundogdu, Cemal,Calik, Muhammet,Sipal, Sare,Akgun, Metin Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.3

Background: Lung cancer is the most frequent cancer among men and second highest among women overall, including in Turkey. Cigarette smoking is the most important etiologic factor for the development of cancer in both men and women. Objective: To determine the lung cancer incidence in Northeastern Anatolia Region of Turkey with a focus on clinical properties, cancer subtypes, the relationships of tumors with cigarette smoking and radiological properties of the lesions. Materials and Methods: In a retrospective study design, 566 lung cancer cases diagnosed at the Pathology Department of Ataturk University in Erzurum over the last seven years extending from January 2006 to June 2012 were investigated. The results were compared with statistical analyses. Results: The most common histopathological subtype of primary bronchogenic carcinoma in our study was found to be the squamous cell carcinoma, 46.1% (261 out of 566), and the second was small cell lung carcinoma 15.7% (89 out of 566). Based on our data, an overall male predominance was noted with a male/female ratio of 6.1/1. While 296 (52.2%) of the patients were found to be smokers at the time of diagnosis, 125 (22.0%) were nonsmokers and 145 (25.6%) were ex-smokers. Smoking status was found to have a strong correlation with primary lung cancer (p<0.05), and there were significant differences between males and females (p<0.001). Conclusion: Although relative prominence of subtypes of lung cancers differ between Turkish and other populations, lung cancer overall remains as an important health problem in Turkey. Our findings stress the critical need for effective cancer prevention programs such as anti-smoking campaigns.

Optimum design of steel bridges including corrosion effect using TLBO

Artar, Musa,Catar, Recep,Daloglu, Ayse T. Techno-Press 2017 Structural Engineering and Mechanics, An Int'l Jou Vol.63 No.5

This study presents optimum design of plane steel bridges considering corrosion effect by using teaching-learning based optimization (TLBO) method. Optimum solutions of three different bridge problems are linearly carried out including and excluding corrosion effect. The member cross sections are selected from a pre-specified list of 128 W profiles taken from American Institute of Steel Construction (AISC). A computer program is coded in MATLAB to carry out optimum design interacting with SAP2000 using OAPI (Open Application Programming Interface). The stress constraints are incorporated as indicated in AISC Allowable Stress Design (ASD) specifications and also displacement constraints are applied in optimum design. The results obtained from analysis show that the corrosion effect on steel profile surfaces causes a crucial increase on the minimum steel weight of bridges. Moreover, the results show that the method proposed is applicable and robust to reach the destination even for complex problems.

An Investigation on the Behavior of 3D Steel Frames Under Progressive Collapse Effect Using Nonlinear Dynamic Analysis

Bilal Tayfur,Ayșe T. Daloglu 한국강구조학회 2023 International Journal of Steel Structures Vol.23 No.3

In this study, the nonlinear dynamic analysis of steel structures against progressive collapse was examined, and the adequacy and validity of the analysis duration defined in the regulation were investigated. In addition, the effects of the seismic resistance and design against progressive collapse constraints on the structure were investigated. An optimization algorithm was used in order to conduct the iterative process with appropriate sections. The frames were analyzed to perform one cycle as recommended in the UFC, and then the analysis duration was extended until at least five cycles had been completed. When the UFC was considered only, it was observed that while some of the designs were classified as safe within the duration specified in the UFC, the structural integrity was seen to get into danger in the subsequent cycles. When constraints related to seismic effect are also included in the process, it was seen that the threat disappeared for the frames examined. In addition, it was observed that the steel frame resisted progressive collapse scenarios by creating formations like Vierendeel beams.

Optimization of trusses under uncertainties with harmony search

Vedat Togan,Ayse T. Daloglu,Halil Karadeniz 국제구조공학회 2011 Structural Engineering and Mechanics, An Int'l Jou Vol.37 No.5

In structural engineering there are randomness inherently exist on determination of the loads, strength, geometry, and so on, and the manufacturing of the structural members, workmanship etc. Thus, objective and constraint functions of the optimization problem are functions that depend on those randomly natured components. The constraints being the function of the random variables are evaluated by using reliability index or performance measure approaches in the optimization process. In this study, the minimum weight of a space truss is obtained under the uncertainties on the load, material and crosssection areas with harmony search using reliability index and performance measure approaches. Consequently, optimization algorithm produces the same result when both the approaches converge. Performance measure approach, however, is more efficient compare to reliability index approach in terms of the convergence rate and iterations needed.