The Role of Concept Images in Solving Geometric Word Problems

The purpose of this study was to investigate how eighth-grade students were affected by their concept images of mathematical concepts in solving geometric word problems. Five eighth-grade students from a public middle school participated in the study in the second semester of the 2016-2017 academic year. The data were obtained through semi-structured preliminary interviews to identify the students’ concept images of basic geometry concepts and task-based interviews in which thirteen word problems involving these concepts were presented. The data were analyzed using descriptive analysis techniques. The findings were classified within three themes as the role of concept images in understanding, modeling, and mathematical analysis stages of word problem solving. Concept images affected the students in constructing a situation model for the problem, transforming the situation model into a mathematical model, and performing mathematical operations to obtain a correct solution

Investigating 8th Grade Students' Modelling Processes of Verbal Problems Based on Daily Life Situations Containing Basic Geometric Concepts

Bu araştırmada, 8. sınıf öğrencilerinin temel geometrik kavramları içeren günlük hayat durumlarına dayalı sözel matematik problemlerini çözme süreçlerinin matematiksel modelleme kapsamında incelenmesi amaçlanmıştır. Amacı doğrultusunda nitel bir durum çalışması olarak araştırmanın katılımcıları, 2016-2017 eğitim- öğretim yılında bir devlet ortaokulunda öğrenim gören sekiz tane sekizinci sınıf öğrencisidir. Katılımcıları belirlemede amaçlı örneklem yönteminden yararlanılmıştır. Araştırma boyunca veri toplama araçları olarak, yarı yapılandırılmış ön görüşme formları, öğrencilerin yazılı dokümanları, görüşmeler ve gözlemler kullanılmıştır. Verilerin analiz edilme sürecinde, içerik analizinden yararlanılmıştır. Verilerin analizi sonucunda, öğrencilerin günlük hayat problemini anlama, problemi matematiksel olarak modelleme, matematiksel çözüm yapma ve çözümü günlük hayat durumuna aktarabilme noktalarında çeşitli sorunlar yaşadığı tespit edilmiştir. Araştırmadan elde edilen sonuçlara dayalı olarak, ortaokul matematik öğretmenlerine ve bu konularda çalışma yapmak isteyen araştırmacılara ve eğitimcilere yönelik önerilerde bulunulmuştur.The purpose of this study is to examine 8th grade students' problem solving process within mathematical modelling when they encounter verbal mathematical problems based on daily life situations including basic geometric concepts. Participants eight eighth-grade students who enrolled in a state secondary school in the 2016-2017 academic year. The purposeful sampling was used to identify the participants. Semi-structured pre-interview forms, written documents of students, interviews and observations were used as data collection tools throughout the research. Content analysis was used to analysis of the data. According to the results, the students hadve various problems in understanding the daily life problems, mathematically modeling the problem, doing the mathematical solution and transferring the solution to the daily life situation. Based on the results obtained from the research, some suggestions were made to the school mathematics teachers, researchers, and trainers who want to work on similar areas

The comparison of the calculated and observed behavior of an achoreged retaining wall

Çevresinde etkilenecek yapılar bulunan derin kazı dayanma yapılarında stabilitenin yanında göçmeden önce oluşan deformasyonların miktarı da önemli olmaktadır. Stabilite ve deformasyonlar bir derin kazı destekleme yapısının performansı oluşturan unsurlardır. Bu çalışmada Ankara Seyranbağları semtinde yapılan huzurevi inşaatı temel kazısı için oluşturulan iksa sisteminin davranışı incelenmiştir. Öncelikle arazi ve laboratuar verilerinin yanı sıra literatürdeki çalışmalar ve lokal korelasyonlardan hareketle zeminin mühendislik parametreleri belirlenerek iksa sistemi modellenmiştir. Daha sonra sonlu elemanlar yöntemi ile duvar davranışı incelenerek deformasyon tahminleri yapılmıştır. Sonlu eleman analiz sonuçları, araziden elde edilen ölçümler ve literatürdeki amprik yöntemlerle hesaplanan deformasyonlar ile karşılaştırılarak duvarın performansı değerlendirilmiştir. Sonuç olarak; zemin modeli, zemin modeline ait deformasyon parametreleri ve zemin dayanım parametrelerinin doğru seçilmesi durumunda sonlu eleman programları ile iksa sistemlerinde meydana gelecek deformasyonların kabul edilebilir bir doğrulukla tahmin edilebileceği görülmüştür.For deep excavation retaining systems within close proximity to existing structures, serviceability issues, i.e., deformations, are as important as the overall stability. Within this context, this study evaluates the deformation behavior of an anchored retaining wall in clay, which was constructed for supporting the excavation of nursing house in Seyranbağları district of Ankara. First, the geotechnical parameters of the soil was estimated using the result of in-situ and laboratory tests as well as those obtained by empirical correlations. Experience from previous local studies was utilized in selecting the proper correlations, as they are numerous in the literature. Then, finite element analyses were performed to predict the retaining wall behavior, focusing mainly on the deformations of the wall itself and surrounding ground. These numerical results were compared with those obtained from in-sit inclinometer and settlement measurements and those estimated by empirical methodologies. Back-calculations were also performed to determine the soil parameters, use of wich would result in exact agreement with in-situ measurements. The results indicate that, with selection of appropriate constitutive model and geotechnical parameters, finite element analyses are capable of predicting the behavior of anchored retaining wall systems with sufficient accurac

Effects of natural disasters on economic growth: the case of Turkey during the 1960-2018 period

Bu tez çalışmasının amacı Türkiye'de 1960-2018 yılları arasında yaşanan doğal afetlerin yaşattığı maliyet ile ekonomik büyüme arasındaki ilişkiyi zaman serisi verilerinin kullanarak analiz etmektir. Çalışmanın ilk bölümünde doğal afet kavramı, unsurları ve maliyetleri açıklanmıştır. Çalışmanın ikinci bölümünde, doğal afetlerin ekonomik etkilerine değinilmiştir. Çalışmanın ampirik kısmında ise Türkiye'de yaşanmış doğal afetlerin ekonomik büyümeye etkisi araştırılmıştır. Çalışmanın sonucunda Türkiye'de 1960-2018 yılları arasında yaşanan doğal afetlerin maliyeti ile ekonomik büyüme arasında uzun dönemde negatif bir ilişki olduğu ve nedenselliğin ekonomik büyümeden doğal afet maliyetine doğru olduğu tespit edilmiştir.The purpose of this thesis is to analyze the relationship between economic growth and the cost caused by natural disasters between the years of 1960 and 2018 in Turkey using time series data. In the first section of the study, the concept of natural disaster, its components and costs are explained. In the second section of the study, the economic effects of natural disasters are discussed. In the empirical section of the study, the effect of natural disasters experienced in Turkey on economic growth are investigated. At the end of the study, it is concluded that there is a long-term negative relationship between economic growth and the cost of natural disasters experienced in Turkey between the years of 1960-2018 and the causality is from economic growth to natural disaster cost

A Rare Complication of Transurethral Resection of the Prostate: Explosion of the Bladder

Monopolar and bipolar transurethral resection of the prostate is currently the gold standard modality in the treatment of bladder outlet obstruction due to prostatic enlargement. A rare complication of transurethral resection is the explosion of the bladder as may occur during resection of the prostate. The etiology of explosion is thought to be a result of ignition due to mixture of oxygen and hydrogen gas occurring during the resection under increased pressure of the bladder. To the best of our knowledge, our case is the first report of bladder explosion during transurethral resection with bipolar energy using saline solution

Incidentally Diagnosed Osteopoikilosis: A Case Report

Osteopoikilosis is a rare bone dysplasia. Patients are generally asymptomatic and are frequently identified during radiological imaging by coincidence. The epiphysis and metaphysis of the long bones, the phalanges and pelvic bones are the localizations which frequently involved. It appears as oval or round, homogeneous, symmetrical, uniform, radio-opacities. Osteoblastic metastases, mastocytosis, tuberous sclerosis and Paget’s disease should be considered in differential diagnosis

A Case of Posterior Mediastinal Ganglioneuroma: The Importance of Preoperative Multiplanar Radiological Imaging

Ganglioneuromas are mostly seen in adolescents and young adults and they are neurogenic tumors originating from sympathetic ganglions with a benign histology. Although ganglioneuromas are benign, the treatment is surgical as they can cause pain or compression symptoms, can be locally aggressive and can lead to cord compression. We present a young adult female with a ganglioneuroma of the right posterior mediastinum who presented with lower back pain, together with the clinical features, Computed Tomography (CT) and Magnetic Resonance Imaging (MRI) findings, differential diagnosis tips and their contribution to surgical planning