8 research outputs found
Essays on Integer Programming in Military and Power Management Applications
This dissertation presents three essays on important problems motivated by military and power management applications. The array antenna design problem deals with optimal arrangements of substructures called subarrays. The considered class of the stochastic assignment problem addresses uncertainty of assignment weights over time. The well-studied deterministic counterpart of the problem has many applications including some classes of the weapon-target assignment. The speed scaling problem is of minimizing energy consumption of parallel processors in a data warehouse environment. We study each problem to discover its underlying structure and formulate tailored mathematical models. Exact, approximate, and heuristic solution approaches employing advanced optimization techniques are proposed. They are validated through simulations and their superiority is demonstrated through extensive computational experiments. Novelty of the developed methods and their methodological contribution to the field of Operations Research is discussed through out the dissertation
Çok amaçlı kar getiren gezgin satıcı problemi için genetik bir algoritma.
In Traveling Salesman Problem (TSP) with profits, a profit is associated with each city and the requirement to visit all cities is removed. The purpose is to simultaneously minimize cost (excluding as many cities as possible) and maximize profit (including as many cities as possible). Although the reduced single-objective case of the problem has been well-studied, the true biobjective problem has been studied only by a few researchers. In this paper we study the true biobjective problem using the Multiobjective Genetic Algorithm NSGA II and the Lin-Kernighan Heuristic. We propose several improvements for NSGA II in solving the problem. Based on these improvements, we provide computational results of the approximated Pareto-optimal front for a set of practically large size TSP instances. Finally, we provide a framework and its computational results for a post-optimality analysis to guide the decision maker, using the data mining software Clementine.M.S. - Master of Scienc
In Vitro Comparison of ICDAS And DIAGNOdent Pen in The Diagnosis and Treatment Decisions of Non-Cavitated Occlusal Caries
The aim of this study was to compare the efficacy of the ICDAS and the DIAGNOdent Pen in the diagnosis of occlusal caries lesions without cavitation, and for basing treatment decisions on the results obtained. Eighty permanent molar teeth that were healthy and non-cavitated or that had an initial occlusal lesion were evaluated. All teeth were investigated using DIAGNOdent Pen and ICDAS by four examiners. Histological evaluation of teeth was performed using stereomicroscopy by a histologist and different experienced dentist. For evaluation of the data, weighted kappa values (kw), sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and likelihood ratio (LR+) values of the tests were calculated. The diagnostic results obtained using the DIAGNOdent Pen were found to correlate better with the results obtained from histological sections than those obtained using ICDAS. When the treatment decisions of the observers depending on the results of ICDAS, and ICDAS and DIAGNOdent Pen combination were compared with the decisions made based on histological examinations, the decisions based on ICDAS and DIAGNOdent Pen combined (kw: 0.522) were more accurate than the ones based on ICDAS (kw: 0.415) alone. In conclution, professional experience is an effective factor in diagnosing occlusal caries lesions without cavitation with ICDAS and in making treatment decisions for them. DIAGNOdent Pen is sufficient in diagnosing occlusal caries lesions without cavitation.El objetivo de este estudio fue comparar la eficacia de ICDAS y de DIAGNOdent Pen en el diagnóstico de lesiones de caries oclusales no cavitadas. Ochenta molares permanentes sanos y no cavitados fueron utilizados. Todos los dientes fueron investigados usando DIAGNOdent Pen e ICDAS por cuatro examinadores. La evaluación histológica de los dientes se realizó mediante estereomicroscopía por un histólogo y por un dentista con previa experiencia. Los resultados diagnósticos obtenidos con el DIAGNOdent Pen se correlacionan mejor con los resultados obtenidos a partir de las secciones histológicas cuando comparados a los obtenidos utilizando ICDAS. Las decisiones basadas en el uso combinado de ICDAS y DIAGNOdent Pen (kw: 0.522) fueron más precisas que los basados en ICDAS (kw: 0.415). En conclusión, la experiencia profesional es un factor eficaz en diagnóstico de lesiones de caries oclusal sin cavitación con ICDAS y en la toma de decisiones de tratamiento. DIAGNOdent Pen es una herramienta confiable para diagnosticar lesiones de caries oclusales sin cavitación
In vitro effect of temperature on dentin bond strength of universal adhesive systems
The aim of this study was to evaluate the shear bond strength (SBS) of two universal adhesives (Universal Single Bond and All Bond Universal) and a two-step self-etch adhesive system (Clearfil SE Bond) to dentine at various temperatures. Materials and Methods: One hundred and twenty dentin specimens were divided randomly to 12 groups, according to adhesive systems (Universal Single Bond and All Bond Universal, Clearfil SE Bond) and temperature ( 4ºC, 20 ºC, 36ºC, 55ºC) used. Dentin specimens were prepared (n :10, adhesives were applied, and composite cylinders were polymerized. Statistical analysis of the SBS data was performed using Two-way analysis of variance (ANOVA) and Tukey’s Honestly Significant Differences post-hoc test. Results: The Clearfil SE Bond was shown to have higher SBS than the universal adhesives at all temperatures; however, there was no statistically significant difference (P>0.05). In both groups, the lowest SBS values were observed in the samples at 4°C while the highest SBS values were observed in the samples at 55°C. In this case, there was a statistically significant difference (P 0.05). En todos los grupos, los valores más bajos de SBS se observaron en las muestras a 4°C, mientras que los valores de SBS más altos fueron obtenidos en las muestras a 55°C (P <0.05). Conclusiones: Los resultados sugieren que la efectividad de un adhesivo puede aumentar si se precalienta a 36°C o superior, antes de usarlo inmediatamente después de sacarlo del refrigerador o a temperatura ambiente.
OFSET BASKI MERDANELERİ VE MÜREKKEPLERİ ARASI KİMYASAL UYGUNLUK
Ofset baskı makinelerini incelediğimizde mürekkep miktarının belirlenmesi, ezilmesi, homojen şekilde dağıtılması, transfer edilmesi, emülsifikasyon oluşturulması, baskı kalıbında mürekkep filmi oluşturulması, nemlendirme suyunun dozajlanması, kalıba doğru aktarılması, kalıpta temizliğin sağlanması gibi süreçlerde merdaneler son derece önemli bir etkiye sahiptir. En basit anlamıyla baskıyı gerçekleştiren yani mürekkep ile baskı altı malzemenin bir araya gelmesini sağlayan unsurların en başında, baskı sürecinde en asli görevleri yerine getiren makine parçalarının kauçuk esaslı viskoelastik özelliklere sahip merdaneler olduğu açıktır.
Kauçuk esaslı merdaneler baskı sürecinde, başta mürekkepler olmak üzere çeşitli kimyasal maddelerle sürekli temas ve etkileşim halindedir. Yanlış merdane mürekkep kombinasyonları sonucu, merdane kauçuklarının kimyasal ve fiziksel yapıları bozularak mukavemet özelliklerinin değişmesi ise istenen baskı kalitesinin elde edilmesini güçleştirmekte, verimlilik kaybına neden olmaktadır
A Significant Difference Between Survival Estimates Predicted by National Institutes of Health and Pulmonary Hypertension Connection Models Based on Same Hemodynamic Measures in Patients with Pulmonary Arterial Hypertension Associated with Congenital Heart Disease
PROKSİMAL PANKREATİKODUODENEKTOMİ SONRASI ORTAYA ÇIKAN POSTOPERATİF PANKREATİK FİSTÜLLERİN RİSK FAKTÖRLERİNİN ARAŞTIRILMASI
Incidence and clinical characteristics of acute rheumatic fever in Turkey: Results of a nationwide multicentre study
© 2021 Paediatrics and Child Health Division (The Royal Australasian College of Physicians)Aim: To evaluate the incidence and clinical features of acute rheumatic fever (ARF) in Turkey, following the revised Jones criteria in 2015. Methods: This multicentre study was designed by the Acquired Heart Diseases Working Group of the Turkish Pediatric Cardiology and Pediatric Cardiac Surgery Association in 2016. The data during the first attack of 1103 ARF patients were collected from the paediatric cardiologists between 1 January 2016 and 31 December 2016. Results: Turkey National Institute of Statistics records of 2016 were used for the determination of ARF incidence with regard to various cities and regions separately. The estimated incidence rate of ARF was 8.84/100 000 in Turkey. The ARF incidence varied considerably among different regions. The highest incidence was found in the Eastern Anatolia Region as 14.4/100 000, and the lowest incidence was found in the Black Sea Region as 3.3/100 000 (P < 0.05). Clinical carditis was the most common finding. The incidence of clinical carditis, subclinical carditis, polyarthritis, aseptic monoarthritis, polyarthralgia and Sydenham's Chorea was 53.5%, 29.1%, 52.8%, 10.3%, 18.6% and 7.9%, respectively. The incidences of clinical carditis, subclinical carditis, polyarthritis and polyarthralgia were found to be significantly different among different regions (P < 0.05). Conclusion: The findings of this nationwide screening of ARF suggest that Turkey should be included in the moderate-risk group