Efficient incremental modelling and solving

Funding: This work is supported by EPSRC grant EP/P015638/1. Nguyen Dang is a Leverhulme Trust Early Career Fellow (ECF-2020-168).In various scenarios, a single phase of modelling and solving is either not sufficient or not feasible to solve the problem at hand. A standard approach to solving AI planning problems, for example, is to incrementally extend the planning horizon and solve the problem of trying to find a plan of a particular length. Indeed, any optimization problem can be solved as a sequence of decision problems in which the objective value is incrementally updated. Another example is constraint dominance programming (CDP), in which search is organized into a sequence of levels. The contribution of this work is to enable a native interaction between SAT solvers and the automated modelling system Savile Row to support efficient incremental modelling and solving. This allows adding new decision variables, posting new constraints and removing existing constraints (via assumptions) between incremental steps. Two additional benefits of the native coupling of modelling and solving are the ability to retain learned information between SAT solver calls and to enable SAT assumptions, further improving flexibility and efficiency. Experiments on one optimisation problem and five pattern mining tasks demonstrate that the native interaction between the modelling system and SAT solver consistently improves performance significantly.Publisher PD

İçerik Analizi Çalışmalarında Örneklem Sorunu

Günümüzde, diğer araştırma yöntemlerinde olduğu gibi içerik analizinde de temel soru(n)lardan birisi, örneklemedir. Örneklem sorununa nasıl yaklaşılacağı belirsizlikler içerebilir. Ancak, araştırma sorusunun ortaya atılmasıyla birlikte, araştırmanın hemen her evresine ait sorunlar açıklığa kavuşacağı gibi, örnekleme ait belirsizlikler de ortadan kalkacaktır. Araştırma sürecinin herhangi bir evresinde verilen kararlar, ilk evrelerde verilen kararlardan bağımsız değildir. Bir başka deyişle, araştırma sorusu tanımlandığı anda örneklem tasarımı da kısmen belirlenmiş olur. Dolayısıyla, örneklem tasarımı bir sorun olmaktan çok, araştırmacıya elde ettiği bulguları değerlendirebileceği istatistik yöntemleri sunan ve böylece bulguların kalitesini daha da artıran bir çerçevedir

Intercostal Variation for Age Estimation – Are the Standards for the Right 4th Rib Applicable for Other Ribs?

Age estimation of unknown skeletal remains is very important in forensic medicine. Morphologic methods are fast and easy to use for purpose of age determination. The sternal ends of the ribs are a reliable method of age estimation from late adolescence to old age. Iscan et al developed a phase analysis method for the right 4th rib that was sex and race specific. The purpose of this study is to determine the accuracy of the standards of age estimation from the right 4th and other rib using the phase analysis for the Turkish population. The sample consisted of right and left 3rd, 4th and 5th ribs from 34 Turkish women and 76 men. There were statistically significant variations found on the right 5th, left 3rd, 4th, and 5th ribs according to these standards in men for phases 5, 6, and 7. For women, all the right and left ribs included in this study were in concordance with right 4th rib standards in all phases

Radiomics with artificial intelligence: a practical guide for beginners

Radiomics is a relatively new word for the field of radiology, meaning the extraction of a high number of quantitative features from medical images. Artificial intelligence (AI) is broadly a set of advanced computational algorithms that basically learn the patterns in the data provided to make predictions on unseen data sets. Radiomics can be coupled with AI because of its better capability of handling a massive amount of data compared with the traditional statistical methods. Together, the primary purpose of these fields is to extract and analyze as much and meaningful hidden quantitative data as possible to be used in decision support. Nowadays, both radiomics and AI have been getting attention for their remarkable success in various radiological tasks, which has been met with anxiety by most of the radiologists due to the fear of replacement by intelligent machines. Considering ever-developing advances in computational power and availability of large data sets, the marriage of humans and machines in future clinical practice seems inevitable. Therefore, regardless of their feelings, the radiologists should be familiar with these concepts. Our goal in this paper was three-fold: first, to familiarize radiologists with the radiomics and AI; second, to encourage the radiologists to get involved in these ever-developing fields; and, third, to provide a set of recommendations for good practice in design and assessment of future works

Tubular gastric adenocarcinoma: machine learning-based CT texture analysis for predicting lymphovascular and perineural invasion

PURPOSELymphovascular invasion (LVI) and perineural invasion (PNI) are associated with poor prognosis in gastric cancers. In this work, we aimed to investigate the potential role of computed tomography (CT) texture analysis in predicting LVI and PNI in patients with tubular gastric adenocarcinoma (GAC) using a machine learning (ML) approach.METHODSSixty-eight patients who underwent total gastrectomy with curative (R0) resection and D2-lymphadenectomy were included in this retrospective study. Texture features were extracted from the portal venous phase CT images. Dimension reduction was first done with a reproducibility analysis by two radiologists. Then, a feature selection algorithm was used to further reduce the high-dimensionality of the radiomic data. Training and test splits were created with 100 random samplings. ML-based classifications were done using adaptive boosting, k-nearest neighbors, Naive Bayes, neural network, random forest, stochastic gradient descent, support vector machine, and decision tree. Predictive performance of the ML algorithms was mainly evaluated using the mean area under the curve (AUC) metric.RESULTSAmong 271 texture features, 150 features had excellent reproducibility, which were included in the further feature selection process. Dimension reduction steps yielded five texture features for LVI and five for PNI. Considering all eight ML algorithms, mean AUC and accuracy ranges for predicting LVI were 0.777–0.894 and 76%–81.5%, respectively. For predicting PNI, mean AUC and accuracy ranges were 0.482–0.754 and 54%–68.2%, respectively. The best performances for predicting LVI and PNI were achieved with the random forest and Naive Bayes algorithms, respectively.CONCLUSIONML-based CT texture analysis has a potential for predicting LVI and PNI of the tubular GACs. Overall, the method was more successful in predicting LVI than PNI

Metallerin şekillendirilebilme analizleri

Workpieces during cold forging fail basically due to ductile fracture. Ductile fracture can be predicted by damage models. In this study, various damage models such as Cockcroft & Latham, McClintock, Freudenthal, Rice & Tracy, Oyane, Ayada, Brozzo are investigated for their applicability to three workpiece materials: bearing steel (100Cr6), stainless steel (X5CrNiMo1810) and brass (CuZn39). The damage material parameters have been obtained by various tests such as tensile, standard compression, ring compression, compression with flanges and conical compression tests. The characterization has been assisted by finite element simulation of the various tests. It has been shown that the available damage models can predict the location of failure satisfactorily but are no able to predict the onset of failure quantitatively.Soğuk şekillendirilen malzemelerde oluşan kusurlardaki temel neden sünek kırılmalardır. Sünek kırılmalar hasar modelleri ile tahmin edilebilir. Bu çalışmada Cockcroft & Latham, McClintock, Freudenthal, Rice & Tracy, Oyane, Ayada, Brozzo modelleri gibi çeşitli modellerin rulman çeliği (100Cr6), paslanmaz çelik (X5CrNiMo1810) ve pirinçten (CuZn39) oluşan toplam üç malzemeye uygulanabilirliği araştırılmıştır. Malzeme hasar parametrelerinin elde edilmesinde çekme, standart basma, halka basma, flanşlı parça basma ve konik parça basma testleri kullanılmıştır. Bu testlerin incelenmesinde sonlu elemanlar yöntemiyle yapılan simulasyonlardan yararlanılmıştır. Mevcut hasar modellerinin malzemedeki kusur yerlerini tesbit edebildiği, ancak kusur başlangıcını sayısal anlamda tespit edemediği gösterilmiştirM.S. - Master of Scienc

Berke Barajı ve hes enfeksiyon uygulamaları

TEZ3952Tez (Yüksek Lisans) -- Çukurova Üniversitesi, Adana, 2001.Kaynakça (s. 140-141) var.x, 141[30] s. ; res. ; 30 cm.

Tıp Fakültesi öğretim üyeleri arasında çocuk koltuğu ve emniyet kemeri kullanım yaygınlığı

Traffic accidents are one of the most important problems of our country, Turkey , causing many deaths, injuries and economic loss. Obligation of seat belt exists in our country like many other countries. However, this obligation consist people only sitting in front of the car. What would save the people sitting in the back is unclear. The previous studies showed that the most important trauma affects the people untied. Child board usage is very rare in our country. There is no company producing child seats and seat belts are designed for adults rather than children. This means, the ones sitting in front of the car will be in save using seat belt during traffic accidents, but their children, who are said to be the most important and lovely members of the family are in danger. We let than die. This can not be accepted. The aim of this study is to determine in the frequency of child seat usage in Turkey . This subject was not studied before. For this purpose a high economic and cultural group that the education staff of Ege Medicine Faculty was chosen. An inquiry with 13 questions was applied to 530 people who were chosen by systematic proposal method. The results were evaluated statistically by SPSS for Windows 9.05 program. 65 were male, 31 were female. Seat belt was always used by 78.1%, while 20.8% used only in long trips and 1% sometimes uses. 58 people have 1 child, 35 people have 2 children and 1 people have three children. 30.2% use child seat in the back.Ülkemizin en önemli sorunlarından birisi çok sayıda insan kaybına, yaralanmasına ve çok büyük maddi hasara neden olan trafik kazalarıdır. Emniyet kemeri (EK) takma zorunluluğu birçok ülkede olduğu gibi ülkemizde de vardır. Ancak ne ilginçtir ki bu zorunluluk sadece önde yolculuk yapanlar için geçerlidir. Yapılan araştırmalarda bir trafik kazasında ölümcül travmalar özellikle araç içinde bağlı olmayanlarda meydana gelmektedir. Çocukları araç içinde sabit tutacak çocuk koltukları (ÇK) kullanımı ülkemizde çok düşüktür. EK'leri sadece erişkinlere göre dizayn edilmiştir. Bunun anlamı; önde oturanlar EK'i ile bağlanarak kendilerini kazaya karşı güvence altına almakta ancak, aynı araca bindirdiğimiz çocuğumuzu ya da çocuklarımızı yani hayatta en değer verdiğimiz kişileri belki de göz göre göre ölüme kendi ellerimizle götürmekteyiz. Bu durumda çocukların ve arkada oturanların emniyetine hiç değer verilmemesinin mantıklı bir açıklaması olamaz. Çalışmada Türkiye'de otomobil ÇK kullanım yaygınlığını tespit etmeye yönelik şimdiye kadar hiç yapılmamış bir ön çalışma planlanmış ve bu amaçla özellikle toplumun eğitim ve kültür düzeyi en yüksek kesimi kabul edilen ve sağlıkla uğraşan tıp fakültesi öğretim üyeleri seçilmiştir. Ege Üniversitesi. Tıp Fakültesinde görev yapan toplam 530 öğretim üyesinden, 96'sına 13 sorudan oluşan anket uygulanmıştır. Ankete verilen cevaplar SPSS for Windows 9.05 programına yüklenerek istatistiksel testler uygulanmıştır. Ankete katılan öğretim üyelerinin 65'i erkek (%67,7), 31'i kadındır (%32,3). EK'ni ne sıklıkta kullanıyorsunuz sorusuna katılımcıların %78,1'i her zaman yanıtını verirken %20,8'i sadece uzun yolculuklarda, %1'i ise ara sıra EK'i kullandığını belirtmiştir. 58 tanesinin tek, 35 tanesinin iki ve 1 tanesinin üç çocuğu bulunmaktadır. Çocuklu öğretim üyelerinin seyahatleri sırasında çocuklarını nasıl oturttukları sorulduğunda; sadece %30,2'sinin ÇK kullandığı görülmüştür