İnsansız hava araçları için test düzeneği tasarımı ve üretimi

Boyutları kullanım amaçlarına göre değiskenlik gösteren insansız hava araçlarının (ĐHA), mekanik, elektronik ve yazılım alanlarında birçok yenilikler getiriyor olması bu konuda çalısan arastırmacıların günden güne daha çok ilgisini çekmektedir. Bu çalısmada, bir ĐHA için kontrol algoritmalarının test edilebileceği bir düzeneğin tasarım ve üretimi anlatılmıstır. Düzeneğin üretilmesini takiben gerekli dayanıklılık testleri yapılmış ve benzetimlerle örtüşen dayanıklılık sonuçları elde edilmistir

Design and implementation of an isolated-word Turkish speech recognition system with data augmentation

Bu çalışmada toplamda doksan iki adet sesli komuttan oluşan bir yalıtık sözcüklü Türkçe konuşma tanıma sistemi tasarlanmış ve gerçekleştirilmiştir. Sistem, destek vektör makinesi (SVM) tabanlı olup, eğitimde kullanılan veri kümesi kaydedilen konuşmaların yapay olarak çeşitlendirilip artırılmasıyla elde edilmiştir. Farklı yapay veri oranlarının tanıma başarımı üzerindeki etkisi incelenmiştir. Akustik öznitelik olarak, mel frekansı kepstral katsayıları (MFCC) kullanılmıştır. Ayrıca, ses aktivitesi tespitinin ve MFCC katsayılarının tanıma başarımına etkileri de irdelenmiştir. Sonuçta doksan iki yalıtık komut için ortalama %92.6’lık doğrulukla çalışan bir konuşma tanıma sistemi geliştirilmiştir.In this study, an isolated-word Turkish speech recognition system comprising of ninety-two voiced commands has been designed and implemented. The system is support vector machine (SVM) based and the data set used in training has been obtained by augmenting the original recordings artificially. The effect of different augmented data amounts on recognition performance has been examined. As acoustic features, mel frequency cepstral coefficients (MFCC) were used. Moreover, the effects of voice activity detection and MFCCs on recognition performance have also been investigated. In the end, 92.6% recognition accuracy on average has been obtained for ninety-two isolated commands

Performance of neutrophil to lymphocyte ratio for the prediction of long-term morbidity and mortality in coronary slow flow phenomenon patients presented with non-ST segment elevation acute coronary syndrome

Introduction: In this study, we aimed to determine if neutrophil to lymphocyte ratio could predict long term morbidity and mortality in patients who hospitalized for non-ST segment elevation acute coronary syndrome (NSTE-ACS) and had coronary slow flow on coronary angiography. Methods: In this observational study, 111 patients who presented with NSTE-ACS and diagnosed with coronary slow flow phenomenon on angiographic examination were included. Neutrophil to lymphocyte ratio (NLR) calculated as the ratio of the number of neutrophils to the number of lymphocytes. Patients classified into three groups according to NLR values. The term coronary slow flow phenomenon was depicted by calculating Thrombolysis in Myocardial Infarction frame count.Patients were followed up and the occurrence of recurrent angina, recurrent myocardial infarction, and long-term mortality was determined using medical records, phone calls, or face-to-face interviews. P values <0.05 considered to indicate statistical significance. Results: Recurrent angina and myocardial infarction occurred more frequently in the highest NLR tertile compared with middle and lowest NLR tertiles. High NLR group (NLR≥ 3.88 n=38) was significantly associated with younger age and smoking status. WBC, troponin I and CRP levels increased as the NLR tertile increased. Recurrent myocardial infarction and angina showed strong relationship with increasing NLR values. In multivariate regression analyses smoking and high NLR levels were independent predictors of recurrent myocardial infarction (HR:4.64 95%CI 0.95-22.52 P=0.04, HR: 1.48 95%CI 1.16-1.90 P<0.01 respectively) in the long term follow up. Conclusion: Our study demonstrated that high NLR values can be a valuable prognostic tool in the long term follow up of patients who presented with NSTE-ACS and diagnosed with slow flow phenomenon on coronary angiography

Outcomes of endovascular treatment of thoracic aorta pathologies: 10-year single-center results

PURPOSEThoracic endovascular aortic repair (TEVAR) is a safe and effective treatment method for a variety of thoracic aortic pathologies. We aimed to investigate the mortality and complication outcomes and associated factors of TEVAR treatment in Turkey.METHODSIn this single-centered retrospective study, patients with thoracic aorta pathologies treated with TEVAR at Gazi University School of Medicine, Department of Radiology, between January 2009 and January 2020 were included. Perioperative, early, and late mortality, complications, and technical success were the outcomes.RESULTSThe sample comprised 58 patients with 68 TEVAR interventions. Eleven (16.2%) patients were female, the mean age was 60.1 ± 13.4 years. Emergent TEVAR was required in 20.7% of the patients. The main indications of TEVAR were intact descending aorta aneurysms in 37.9% of the sample, 31.0% Stanford type-B dissection, and 12.1% traumatic transections. The technical success rate of primary and secondary interventions was 98.3% and 100%, respectively. The mortality rate in the first 30 days was 8.6%. Seventeen (29.3%) cases had at least 1 complication related to TEVAR treatment. The most common complication was type-1A endoleak (10.3%). Having acute symptoms, stroke, and acute renal failure were significantly associated with mortality (P=.020, .049, and .009, respectively).CONCLUSIONThis study reported the outcomes of TEVAR treatment from a tertiary medical center in Turkey over a decade. Patients presenting with acute symptoms and who developed stroke and acute renal failure after the procedure should be carefully followed up as these factors were found to be associated with mortality

Coronary artery fistula: Review of 54 cases from single center experience

Background: Demographic and clinical characteristics and angiographic findings of Turkish patients with coronary artery fistula have been investigated in this study and diagnostic tests and treatment methods used in these patients have also been evaluated in detail. Methods: We have examined the cardiac catheterization laboratory database retrospectively between March 2006 and July 2010. Among 49,567 patients, we have noted 60 patients diagnosed as coronary artery fistula. After coronary angiographic images were evaluated by two invasive cardiologists, 54 patients who had clear evidence of vessel of origin and drainage were included in the study. Results: A total of 54 (0.1%) patients with coronary artery fistula were noted. Mean age was 56.7 ± 10.7 years; 42 out of 54 patients had accompanying cardiac disorders. Patients’ complaints were directly associated with the presence of the fistula. Chest pain was the admission symptom in all of the patients with isolated coronary artery fistula. Six patients had coexistent congenital anomalies. Myocardial infarction with ST segment elevation occurred in 11 of the patients. In contrast to the previous reports, the most common artery of origin of the fistula was left anterior descending artery (50.8%) and pulmonary artery was found to be the most frequent region of the fistula drainage by 53.7%. Conclusions: Our findings suggest that large fistulas originating from the proximal segments of coronary arteries may increase the likelihood of atherosclerosis and myocardial infarction even in asymptomatic patients with no evidence of ischemia in noninvasive tests and no dilatation of cardiac chambers, and should therefore be closed

Joinning of 304 stainless steel and St 37 steell with welding and mechanical properties

Bu çalışmada st37 çeliği ile 304 paslanmaz çeliğinin birbirine MAG kaynağıyla birleştirilmesi ve oluşan kaynak dikişinin sıcaklık ve zaman ile değişen mekanik özellikleri incelenmiştir. İncelemeler sonucu en yüksek kopma mukavemet değeri difüzyon ve Krom – Karbür çökelmesi sebebiyle ısıl işlem uygulanmamış parçada bulunmuş (64,53 DaN/mm2 ) en düşük kopma mukavemeti ise 450°C de 4 saat bekletilmiş parçada elde edilmiştir (44,96 DaN/mm2 ). En yüksek sertlik değeri ise 450°C de 4 saat bekletilmiş parçada elde edilmiştir (547 HV)In this study St37 and 304 steels are welded with MAG welding method. Changing mechanical properties of welded area under high temperatures and time is researched. According to the results the highest tensile strength value was determined on the piece that was not treated with heat (64,53 DaN/mm2 ) and the lowest tensile strength value was determined on the piece that had been kept under 450°C for 4 hours (44,96 DaN/mm2 ). The highest hardness value was determined in the piece that had been kept under 450°C for 4 hours (547 HV)

The relationship between senile hearing loss and vestibular activity

Abstract Introduction: A considerable high number of SNHL patients also suffer from dizziness and related vestibular symptoms. Objective: To evaluate the association of vestibular dysfunction and sensorineural hearing loss (SNHL) in adult patients. Methods: Prospective, double-blinded, controlled studies composed by 63 adult patients without any vestibular symptoms or diagnosed vestibular diseases. Audiological status was measured with pure tone audiometry and the vestibular system was tested with vestibular evoked myogenic potential (VEMP). Patients were divided into two groups: a study group (patients with SNHL) and a control group (patients without SNHL). VEMP results of the groups were calculated and compared. Results: Mean P1 (23.54) and N1 (30.70) latencies were prolonged in the study group (p < 0.001) and the amplitudes of the study group were significantly reduced (p < 0.001). Both parameters of the VEMP test were abnormal in the study group when compared to the control group. Conclusions: These findings suggest that age-related SNHL may be accompanied by vestibular weakness without any possible predisposing factors for vestibulopathy

Acı Göl ve Meke Gölü’ nün (Konya / Türkiye) bazı su kalitesi özellikleri

Canlılar yaşamlarını sürdürmek için suya ihtiyaç duyarlar. Su kaynaklarının kullanımı, korunması ve yönetimi bu nedenle son derece önemlidir. Sucul ekosistemlerin, su kalitesi özelliklerinin araştırılmasına yönelik çalışmalar sıklıkla yapılmaktadır. Bu çalışmanın amacı, Acı Göl ve Meke Gölü'nün bazı su kalitesi özelliklerini belirlemektir. Göller Konya İli Karapınar İlçesi'nde yer almaktadır ayrıca kuşlar ve diğer canlılar için önemli yaşam alanları durumundadırlar. Bu çalışmada, Temmuz 2014 - Ocak 2015 tarihleri arasında Acı Göl ve Meke Gölü'nde bazı fiziksel ve inorganik parametreler incelenmiştir. Çalışma sırasında göllerden belirlenen istasyonlardan, mevsimsel olarak su örnekleri alınmıştır. Sonuçlar, Su Kirliliği Kontrol Yönetmeliği (SKKY) ve İnsani Tüketim Amaçlı Sular Hakkında Yönetmeliği göre (TS-266) karşılaştırılmıştır. Pearson Correlation Matrix (PCA) analizine göre fiziksel ve inorganik parametrelerin ilişkileri belirlenmiştir. İki göldeki fiziksel ve inorganik parametrelerin ölçümlerine göre bazı sonuçların yönetmelikte belirtilen değerleri aştığı belirlenmiştir. Pearson Correlation Matrix (PCA) analizine göre Acı Göl ve Meke Gölü'nde fiziksel ve inorganik parametreler birbirleriyle pozitif ve negatif korelasyon göstermiştir