catcher: A software program to detect answer copying in multiple-choice tests based on nominal response model

Cataloged from PDF version of article.catcher is a software program designed to compute the v index, a common statistical index for the identification of collusions (cheating) among examinees taking an educational or psychological test. It requires (a) responses and (b) ability estimations of individuals, and (c) item parameters to make computations and outputs the results of the analyses in two text files. The program uses the nominal response model to estimate v index and is based on residuals between expected and observed values of matched answers between examinee pairs (copier and source) by considering correct and incorrect answers, conditioning on source’s answers, copier’s ability level, and item parameters

Reliability-Related Issues in the Context of Student Evaluations of Teaching in Higher Education

Cataloged from PDF version of article.Student evaluations of teaching (SET) have been the principal instrument to elicit students’ opinions in higher education institutions. Many decisions, including high-stake ones, are made based on SET scores reported by students. In this respect, reliability of SET scores is of considerable importance. This paper has an argument that there are some problems in choosing and using of reliability indices in SET context. Three hypotheses were tested: (i) using internal consistency measures is misleading in SET context since the variability is mainly due to disagreement between students’ ratings, which requires use of inter-rater reliability coefficients, (ii) number of minimum feedbacks is not achieved in most of the classes, resulting unreliable decisions, and (iii) calculating reliability coefficient assuming a common factor structure across all classes is misleading because a common model may not be tenable for all. Results showed that use of internal consistency only to assess reliability of SET scores may result in wrong decisions. Considerable large numbers of missing feedbacks were observed to achieve acceptable reliability levels. Findings also indicated that factorial model differed across several groups

Performance assessment of proton exchange membrane fuel cell (PEMFC) stack by means of semi-empirical model

Thesis (Master)--Izmir Institute of Technology, Energy Engineering, Izmir, 2011Includes bibliographical references (leaves: 72-75)Text in English; Abstract: Turkish and Englishxiii, 77 leavesThe charge transfer coefficient estimated around 0.4In this study, the performance of a 10 kW peak power proton exchange membrane fuel cell stack under different operating conditions was investigated experimentally by its i-V polarization curve. The stack has been fed with pure hydrogen and air and PEM fuel cell stack has active area 200 cm2 and is composed of 75 single cells. The stack was tested for different reactant inlet temperatures as from 50 °C to 65 °C with 5 °C intervals keeping constant other conditions and for different relative humidities as 75%, 85% and 95% again keeping constant other operation conditions. Then the analytical nonlinear model adapted to describe the polarization curve has been discussed. Model parameters have been simultaneously estimated by fitting data into model by using LABFIT nonlinear regression program. These parameters are the cathode exchange current density, charge transfer coefficient and polymer electrolyte membrane internal resistance. The polarization curve of the fuel cell stack showed the stack performance improved from 50 °C to 65 °C temperature with the decrease of voltage losses. However the decrease of relative humidity from 95% to 75% did not show any explicit effect onto stack performance. Data fitting was obtained with reasonable model parameters in accordance with literature and with high coefficient of determination (R2) values. The effect of temperature on model parameters was also investigated. The cathode exchange current density value increased from 2.247X10-6 A/cm2 at T=50 °C to 5.643X10-6 A/cm2 at T=65 °C. The charge transfer coefficient estimated around 0.4 coherently with literature. The membrane internal resistance value followed the slightly decreasing tendency with increasing temperature as the value around 0.1 cm2

Üniversite Öğrencilerinin Öğretim Elemanlarını Değerlendirmesinde Etkili Olan Faktörler

The present study seeks to determine the variables explaining differences between the scores of student ratings given to instructors within the context of the university through discriminant analysis. Ratings given by students were grouped into two groups based on their means and instructors were labeled as low-rated and high-rated. Predictors identified by discriminant analysis are (i) class size, (ii) credit, (iii) grade level, (iv) mean grade, and (v) number of sections. Results of the study suggested that low rated instructors are those who teach courses with smaller number of students, lower credits, higher grade levels, higher mean grades, and one section. Identification of source of differences between ratings may provide invaluable information for those who are interested in assessment of instructional effectiveness.Bu çalışma, üniversite ortamında öğretim görevlilerine verilen öğrenci değerlendirme puanları arasındaki farklılıkları, ayırma analizi yöntemi ile belirlemeye çalışmaktadır. Öğrenciler tarafından verilen puanlar ortalamalarına göre iki gruba ayrılmış ve öğretim görevlileri düşük-puanlı ve yüksek-puanlı olarak iki grup halinde tanımlanmıştır. Ayırma analizi ile tanımlanan kestiriciler; (i) sınıf mevcudu, (ii) dersin kredisi, (iii) sınıf düzeyi, (iv) sınıf ortalaması ve (v) aynı dersi alan grup sayısıdır. Çalışmanın sonuçları düşük-puanlı öğretim görevlilerinin düşük sınıf mevcudu olan, düşük kredili, üst sınıf düzeylerinde, sene sonu not ortalaması yüksek olan ve tek grupla sınıflarda eğitim yapanlar olduğunu ortaya çıkartmıştır. Öğrenci değerlendirmeleri arasındaki farklılıkları açıklayan faktörlerin tanımlanması, öğretimin etkinliğinin değerlendirilmesi ve iyileştirilmesi açısından konu ile ilgili olan kişiler için önemli bulgular sağlayabilir

Uğur Tanyeli – Engin Gerçek, İstanbul’da Mekân Mahremiyetinin İhlali ve Teşhiri: Gerilimli Bir Tarihçe ve 41 Fotoğraf

Uğur Tanyeli ve Engin Gerçek tarafından hazırlanan bu eserde, İstanbul konut ve barınma tarihi mekân ve mahremiyet ilişkisi bağlamında incelemektedir. Kitabın ilk kısmında Uğur Tanyeli’nin kaleme aldığı metinde; “konut” üzerinden kamusal-özel alan kavramlarının 15.yüzyıldan günümüze seyri ve Türkiye’de nasıl algılandığı anlatılmaktadır. Literatürde Habermas ile anılan kamusal alan kavramının geçirdiği dönüşümü mekân üzerinden ortaya koyan en iyi isimlerden birisi de Richard Sennett’tir. Tanyeli’nin bu çalışması Sennett’in batı toplumlarında yaşanan kamusal-özel alan evrimini mekân üzerinden anlattığı metinleriyle paralellik gösterir. Tüm bu isimler de dahil olmak üzere dipnotlardaki referans çeşitliliği eserin ampirik olarak konuyu zengin bir kavramsal çerçevede ele alındığını bize göstermektedir. Kitabın ikinci kısmı ise Engin Gerçek’in Kuştepe mahallesinde yaşayanların evlerinde çektiği fotoğraflardan oluşmaktadır. Engin Gerçek’in bu fotoğrafları, insanların kendi rızasıyla yaşam alanlarını ifşa etmesine olanak sağlamasıyla mahrem kavramını, bu güne kadar merak edilmeyen ve dolayısıyla basında pek sık gözükmeyen düşük gelirli insanların yaşam mekânlarını görünür hale getirmesiyle de zihinlere yerleştirilen klasik kent, kentli kavramlarını sorgulamaya zorlamaktadır

Hybrid debranching and TEVAR of the aortic arch off-pump, in re-do patients with complicated chronic type-A aortic dissections : a critical report

Background: Patients suffering from acute type A aortic dissection undergo replacement of the ascending aorta, the proximal hemiarch or complete aortic arch, depending on the extent of the individual pathology. In a subset of these treated patients, secondary pathologies of the distal anastomosis or the remaining distal part of the aorta occur. The treatment of these pathologies is challenging, requiring major surgical re-do procedures with aortic arch replacement under extracorporeal circulation and hypothermic circulatory arrest. Methods: We report our experience of five patients with complex aortic pathologies after previous aortic surgery treated with a single stage re-do hybrid procedure, consisting of bypass grafting of the supraaortic branches off-pump, stent graft placement for endovascular aortic repair (TEVAR) and surgical debranching of the aortic arch. Results: In all patients the surgical vascular grafts and stent grafts were deployed successfully, there were no intraoperative deaths. Four out of five patients were discharged from hospital in good clinical condition. One patient died postoperatively due to cardiac tamponade. In one patient a type I endoleak persisted leading to occlusion of a bypass branch requiring surgical revision at one year after debranching. Conclusion: We discuss the prerequisites, all steps and potential pitfalls of this hybrid aortic arch replacement. The current procedure avoids cardiopulmonary bypass and circulatory arrest, which may benefit early patient outcome; however, patient and device selection plays a key role for immediate success and midterm outcomes. In addition, precise procedural planning and development of customized stents may help to develop this procedure into a true alternative for conventional aortic arch replacement

The worsening impacts of land reclamation assessed with Sentinel-1: The Rize (Turkey) test case

Massive amounts of land are being reclaimed to build airports, new cities, ports, and highways. Hundreds of kilometers are added each year, as coastlines are extended further out to the sea. In this paper, this urbanization approach is monitored by Persistent Scatterer Interferometry (PSI) technique with Sentinel-1 SAR data. The study aims to explore this technology in order to support local authorities to detect and evaluate subtle terrain displacements. For this purpose, a large 3-years Sentinel-1 stack composed by 92 images acquired between 07/01/2015 to 27/01/2018 is employed and stacking techniques are chosen to assess ground motion. The test site of this study, Rize, Turkey, has been declared at high risk of collapse and radical solutions such as the relocation of the entire city in another area are been taken into consideration. A media fact-checking approach, i.e. evaluating national and international press releases on the test site, is considered for the paper and this work presents many findings in different areas of the city. For instance, alerts are confirmed by inspecting several buildings reported by the press. Critical infrastructures are monitored as well. Portions of the harbor show high displacement rates, up to 1 cm/year, proving reported warnings. Rural villages belonging to the same municipality are also investigated and a mountainous village affected by landslide is considered in the study. Sentinel-1 is demonstrated to be a suitable system to detect and monitor small changes or buildings and infrastructures for these scenarios. These changes may be highly indicative of imminent damage which can lead to the loss of the structural integrity and subsequent failure of the structure in the long-term. In Rize, only a few known motion-critical structures are monitored daily with in-situ technologies. SAR interferometry can assist to save expensive inspection and monitoring services, especially in highly critical cases such as the one studied in this paper

Ölümünün 10. yılı:Edip Cansever

Taha Toros Arşivi, Dosya No: 20-Edip-Turgut-Hasan Ferit CanseverUnutma İstanbul projesi İstanbul Kalkınma Ajansı'nın 2016 yılı "Yenilikçi ve Yaratıcı İstanbul Mali Destek Programı" kapsamında desteklenmiştir. Proje No: TR10/16/YNY/010

Mercury chloride-induced oxidative stress in human erythrocytes and the effect of vitamins C and E in vitro

Mercury can exist in the environment as metal, as monovalent and divalent salts and as organomercurials, one of the most important of which is mercuric chloride (HgCl2). It has been shown to induce oxidative stress in erythrocytes through the generation of free radicals and alteration of thecellular antioxidant defense system. The effect of simultaneous pretreatment with vitamins C and E on the toxicity of HgCl2 in human erythrocytes was evaluated. We examined the effect of several differentdoses of HgCl2 (1.052, 5.262, 10.524 M), or HgCl2 in combination with vitamin C (VC; 10 M) and vitamin E (VE; 30 M), on the levels of malondialdehyde (MDA) and superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) activities in human erythrocytes in vitro. Erythrocytes were incubated under various treatment conditions (HgCl2 alone, vitamins alone, or HgCl2 plus vitamin) at 37°C for 60 min and the levels of MDA and SOD, CAT and GPx activities, were determined. Treatment with HgCl2 alone increased the levels of MDA and decreased SOD, CAT and GPx activities in erythrocytes (P < 0.05). VC and VE-pretreated erythrocytes showed a significant protection aganist thecytotoxic effects induced by HgCl2 on the studied parameters. There were no statistical differences among VC+VE-treated erythrocytes, as compared to non-treated control cells. These results indicated that the presence of vitamins at concentrations that are similar to the levels found in plasma could be able to ameliorate HgCl2-induced oxidative stress by decreasing lipid peroxidation and altering antioxidant defense system in erythrocytes