Three-Dimensional Extended Object Tracking and Shape Learning Using Gaussian Processes

In this study, we investigate the problem of tracking objects with unknown shapes using three-dimensional (3D) point cloud data. We propose a Gaussian process-based model to jointly estimate object kinematics, including position, orientation and velocities, together with the shape of the object for online and offline applications. We describe the unknown shape by a radial function in 3D, and induce a correlation structure via a Gaussian process. Furthermore, we propose an efficient algorithm to reduce the computational complexity of working with 3D data. This is accomplished by casting the tracking problem into projection planes which are attached to the object's local frame. The resulting algorithms can process 3D point cloud data and accomplish tracking of a dynamic object. Furthermore, they provide analytical expressions for the representation of the object shape in 3D, together with confidence intervals. The confidence intervals, which quantify the uncertainty in the shape estimate, can later be used for solving the gating and association problems inherent in object tracking. The performance of the methods is demonstrated both on simulated and real data. The results are compared with an existing random matrix model, which is commonly used for extended object tracking in the literature

An applied study on the customer retention dynamics of organized ready-to-wear textiles retailers in real and virtual markets in Turkey

Purpose - This descriptive field study aims to reveal customer retention strategy formulation insights among top level marketing professionals of the organized ready-to-wear textiles retailers, who are members of United Brands Association (BMD) both active in off-line and online channels, in the Turkish market. Methodology - Regarding the literature review conducted a research model with seven variables was proposed, and depending on the proposed research model, six hypotheses were formulated. The research is conducted by a questionnaire which has been applied on-line, by e-mail, post; which is designed specifically to test the proposed relationships, namely the hypotheses constructed. Factor analysis has been conducted to reveal the dimensionality of the variables in the research model. In this regard, principle component analysis using Varimax rotation was performed and the reliabilities of the scales have been assessed by alpha coefficient. Depending on the results of the factor analysis, correlation and regression analyses have been used to test the hypotheses of the study. Findings - Results indicate that perceived product quality, service support and complaint handling, customer experience and suggestions provided and perceived price fairness have significant and positive effects on customer satisfaction. Furthermore, customer satisfaction, trust towards service provided, trust towards company and brand, corporate reputation and corporate social responsibility have significant and positive effects on customer retention. Conclusion - The outcomes and findings of the study were found to support the objectives of the study and the results of the statistical analysis were found to accept hypotheses of the study. Perceived product quality, perceived service quality, perceived price fairness, trust and corporate image are some vital challenges for customer retention.Publisher's Versio

Management of traumatic pneumothorax in isolated blunt chest trauma

Objectives: Pneumothorax is an important complication of blunt chest trauma. The aim of this study was toreport our experience in treatment strategy and outcomes of traumatic pneumothorax.Methods: A total of 78 patients who developed pneumothorax due to isolated blunt chest trauma were evaluatedin terms of age, gender, size of pneumothorax, treatment methods, complications and length of hospital stay.The size of pneumothorax was calculated with computer-aided volumetry.Results: Tube thoracostomy was performed for 48 patients while observation was undertaken for 30 cases.Chest tubes were inserted in 6 patients after 24 hours following the traumatic event. A total of 8 patients whodeveloped prolonged air leakage and hemothorax as complications underwent video-assisted thoracoscopicsurgery. None of the patients developed any mortality or morbidity.Conclusions: Traumatic pneumothorax demands prompt diagnosis and treatment. Monitoring all patients evenwith small sizes of traumatic pneumothorax for at least 24 hours onset of their initial assessment and applyingchest tubes for cases who have pneumothorax larger than 50% at first examination should be an appropriatemodality for treatment. Moreover, the minimally invasive approach of video-assisted thoracoscopic surgerybenefits to overcome the complications of thoracic trauma

Extended Target Tracking and Classification Using Neural Networks

Extended target/object tracking (ETT) problem involves tracking objects which potentially generate multiple measurements at a single sensor scan. State-of-the-art ETT algorithms can efficiently exploit the available information in these measurements such that they can track the dynamic behaviour of objects and learn their shapes simultaneously. Once the shape estimate of an object is formed, it can naturally be utilized by high-level tasks such as classification of the object type. In this work, we propose to use a naively deep neural network, which consists of one input, two hidden and one output layers, to classify dynamic objects regarding their shape estimates. The proposed method shows superior performance in comparison to a Bayesian classifier for simulation experiments

Endoskopik ultrason görüntülerinde kronik pankreatit ve pankreas kanserinin yaşa göre bilgisayar destekli teşhisi

06.03.2018 tarihli ve 30352 sayılı Resmi Gazetede yayımlanan “Yükseköğretim Kanunu İle Bazı Kanun Ve Kanun Hükmünde Kararnamelerde Değişiklik Yapılması Hakkında Kanun” ile 18.06.2018 tarihli “Lisansüstü Tezlerin Elektronik Ortamda Toplanması, Düzenlenmesi ve Erişime Açılmasına İlişkin Yönerge” gereğince tam metin erişime açılmıştır.Kronik pankreatit (KP) ve pankreas kanseri (PK), pankreasın fonksiyonlarını bozan ve ölümcül olabilen rahatsızlıkların başında gelmektedir. Pankreas kanseri, kötü huylu tümörlerin pankreas bölgesinde gelişmesi sonucu ortaya çıkmaktadır. Bu tümörler çok kısa süre içerisinde büyümesine karşın diğer organlara baskı yapmadığı için hastada önemli belirtiler görülmemektedir. Çoğu durumda da belirtilerin ortaya çıkması kanserin tedavi edilemeyecek hale gelmesi anlamına gelebilmektedir. Dolayısıyla, kanserin erken dönemde teşhisi hayatta kalma oranlarının arttırılması açısından son derece önemlidir. Kronik pankreatit ise pankreasın iltihaplanma hastalığıdır ve bu rahatsızlıkta değişikliklerin ortaya çıkması uzun yıllar alabileceği için erken evrede tanınması oldukça zordur. Hastalığı normal pankreas dokusundan ve pankreas kanserinden ayırmak da son derece güç olabilmektedir. Pankreas kanserinin ve kronik pankreatitin teşhisinde, MR ve BT'ye oranla daha yüksek hassasiyete sahip olduğu için Endoskopik Ultrason (EUS) tercih edilmektedir. Ancak, uzmanlar kesin tanı için genelde biyopsiye başvurmaktadır. Fakat biyopsinin invazif bir yöntem olması ve özellikle de pankreas bölgesi için uygulanmasının zor olması daha farklı çözümlerin geliştirilmesini gerektirmektedir. Son yıllarda, yapay zeka tekniklerindeki gelişmeler, hekimlere tanıda yardımcı olacak Bilgisayar Destekli Teşhis (BDT) sistemlerinin geliştirilmesinin önünü açmış ve farklı bir çok rahatsızlığın teşhisine katkı için BDT sistemleri geliştirilmiştir. Bu tez çalışmasında, EUS görüntülerinde pankreas kanserinin ve kronik pankreatitin normal pankreas dokusundan ayrılmasını sağlayacak yarı-otomatik bir BDT sistemi geliştirilmiştir. Önerilen sistemde, literatürdekilerden farklı olarak pankreasın yaşa göre gösterdiği morfolojik değişiklikler dikkate alınarak EUS görüntüleri hastaların yaşına göre 3 ayrı gruba bölünmüştür. 40 yaşından küçük, 40 ile 60 yaş arası ve 60 yaşından büyük olarak ayrılan görüntüler ayrı ayrı sisteme öğretilmiş ve sınıflandırma ayrı bir şekilde gerçekleştirilmiştir. Böylece, daha yüksek başarım elde edilmesi hedeflenmiştir. Tasarımın ilk adımında uzman eşliğinde pankreas bölgesi işaretlenerek kesilmiştir. Sonrasında, bu bölgeden 122 adet özellik çıkarılmıştır, son olarak da Destek Vektör Makinaları (DVM) ile vakalar PK-sağlıklı, KP-sağlıklı, KP-PK olmak üzere ikili olarak sınıflandırılmıştır. Sistemin başarım değerlendirilmesi için 202 kanserli, 130 sağlıklı ve 69 pankreatitli olmak üzere toplamda 401 adet EUS görüntüsü kullanılmıştır. Gerçekleştirilen deney sonuçlarına göre önerilen sistem ile yaş grupları dikkate alındığında pankreas kanseri ile kronik pankreatit vakaları %97.95 doğruluk ile panreas kanseri ile normal pankreas ayrımı %96.15 oranında, kronik pankreatit ile normal pankreas dokusu ise %100 oranı ile teşhis edilebilmiştir. Sonuç olarak hekimlere kronik pankreatit ve pankreas kanserinin ayrımında destek olabilecek bir BDT sistemi önerilmiştir.Chronic Pancreatitis (CP) and Pancreatic Cancer (PC) are the leading diseases that impair pancreas functions and that can be fatal. PC is caused by the development of malignant tumors in pancreas region. Although these tumors grow in a very short time, important symptoms are not observable in patients since these tumors do not press on the other organs. In most cases, when symptoms occur, the cancer has already spread too far to be cured. Therefore, early detection of PC is crucial to increase the survival rate. CP is the inflammation of the pancreas and early diagnosis is difficult since it may take years for the changes to emerge. It is also extremely hard to differentiate this disease from normal pancreas tissues and pancreatic cancer as well. Endoscopic Ultrasonography (EUS) is preferred in the diagnosis of pancreatic cancer and chronic pancreatitis due to better precision compared to MR and CT. However; experts normally resort to biopsy for definitive diagnosis. Since biopsy is an invasive method and especially difficult to be implemented in the pancreas region, different solutions need to be developed in this field. Recent developments in artificial intelligence techniques have paved the way for physicians to develop Computer-aided Detection (CAD) systems and CAD systems have been developed to contribute to the diagnosis of many diseases. In this thesis, different from the studies in the literature, a semi-automatic CAD system was developed that allows separation of normal pancreatic tissues from tissues with pancreatic cancer and chronic pancreatitis. EUS images in the proposed system were divided into three groups based on patients' ages considering the morphological changes observed in the pancreas due to aging. Images divided into three groups as younger than 40, between 40 and 60 and older than 60 were taught to the system separately and classified to obtain higher performance. The first step in the design includes marking and cutting the pancreas region. Later 122 features were extracted from this region and the most important 20 features were selected. At the final stage, the cases were dyadically classified with the help of Support Vector Machines (SVM) as PC-healthy, CP-healthy and CP-PC. A total of 401 EUS images were utilized (202 cancer, 130 healthy and 69 pancreatic) for system performance. According to the results of the experiment and taking the age groups into account, the proposed system detected pancreatic cancer and chronic pancreatitis cases with 97.95% accuracy rate, differentiated between pancreatic cancer and normal pancreas with 96.15% accuracy and chronic pancreatitis and normal pancreas tissues with 100% accuracy rate. Results indicate that the study proposes a CAD system that can support physicians in differentiating between pancreatic cancer and chronic pancreatitis cases

AÇIK OCAK NİHAİ SINIRLARININ BELİRLENMESİNDE KULLANILAN YÖNTEMLER

Bu çalışmada, madencilikte açık ocak nihai sınırlarının belirlenmesinin önemi ve bu amaçla kullanılan blok model kavramı incelenmiştir. Daha sonra açık ocak nihai sınırlarını bulmak için sık kullanılan yöntemlerden Dinamik Programlama, Grafik Teorisi, Hareketli Koni Algoritması ve Maksimum Akış Algoritması detaylı olarak incelenmiştir. Bu dört yöntem kullanılarak iki boyutlu bir blok model örneği üzerinde uygulama yapılmış ve elde edilen sonuçlar karşılaştırılmıştır. Elde edilen sonuçlara göre yöntemlerin avantaj ve dezavantajları belirtilmiştir

A maturity based qualitative information systems effectiveness evaluation of a public organization in Turkey

Among the top issues of information systems (IS) management is measuring and improving IS effectiveness. In that, the concept of IS effectiveness is widely accepted throughout IS research as the principle criterion for evaluating information systems. IS effectiveness is defined as the extent to which a given information system actually contributes to achieving organizational goals.. As the society moves from the industrial era to the information age,,ıs role in any organization shifts from efficiency to effectiveness. This case study presents an IS effectiveness evaluation methodology applied on a public organization. The paper supports in general the claim that the use of a systematic IS effectiveness evaluation approach can improve organizational performance

Job Satisfaction, Anxiety Level and Associated Factors in a Group of Residents in a University Hospital

In present study, we aimed to research the job satisfaction among the residents at Dicle University Medical Faculty Hospital, some factors affecting this and some psychological effects of not being pleased with their jobs. With respect to this aim, socio demographic data form, Minnesota Job Satisfaction, Beck Anxiety Inventory, State Trait Anger Scale were given to 140 residents at University who accepted to join this study and were collected the following day. In study, 35 percent of the participants having joined the study weren’t pleased with their works. The number of satisfied residents was higher among the willingly choice making residents in favour of their Works(34.8%) than the participants who were unwilling to choice the department (65.2%) they are working now (x2:11.046, p<0.01). Beck anxiety results were found to be much higher in the residents who were not pleased with their workers than the workers pleased with their works. Finally, there are some factors determining the job satisfaction. There is relationship between job satisfaction and mental health. Because this can give rise to negative effects on the performance of the work, it is required that some solution ways be found in order to increase the work contention

The effect of motivational music on wingate anaerobic test performance

The aim of this study is to examine the effect of the motivational music on the Wingate Anaerobic Test (WAnT) performance. 16 male students who studied at School of Physical Education and Sports, Kocatepe University participated in the study voluntarily. After demographic characteristics of the voluntaries [age, height, body weight (BW), body mass index (BMI)] were measured without music (pre-test) and with motivational music [&gt;120 bpm (beats per minute)] conditions (post-test). For the analyses of the data; Wilcoxon Rank Test was used in order to detect the difference among the variables. As a result of the measurements taken in with and without music conditions; it was found out that there was a statistically significant difference on behalf of condition with music in terms of maximum anaerobic power (MaxAP), maximum anaerobic capacity (MAC), relative anaerobic power (RAP), relative anaerobic capacity (RAC) and fatigue index (FI) values (p&lt;0,05), while there was no statistically significant difference in terms of minimum anaerobic power (MinAP) values (p&gt;0,05). It was determined that the motivational music has positive effects on the WAnT performance. However; although it was seen that motivational music increased the WAnT performance, we were of the opinion that this effect emerged thanks to the increased psycho-physiological factors caused by music