CVABS: Moving Object Segmentation with Common Vector Approach for Videos

Background modelling is a fundamental step for several real-time computer vision applications that requires security systems and monitoring. An accurate background model helps detecting activity of moving objects in the video. In this work, we have developed a new subspace based background modelling algorithm using the concept of Common Vector Approach with Gram-Schmidt orthogonalization. Once the background model that involves the common characteristic of different views corresponding to the same scene is acquired, a smart foreground detection and background updating procedure is applied based on dynamic control parameters. A variety of experiments is conducted on different problem types related to dynamic backgrounds. Several types of metrics are utilized as objective measures and the obtained visual results are judged subjectively. It was observed that the proposed method stands successfully for all problem types reported on CDNet2014 dataset by updating the background frames with a self-learning feedback mechanism.Comment: 12 Pages, 4 Figures, 1 Tabl

Motion Planning for Autonomous Vehicles in Partially Observable Environments

Unsicherheiten, welche aus Sensorrauschen oder nicht beobachtbaren Manöverintentionen anderer Verkehrsteilnehmer resultieren, akkumulieren sich in der Datenverarbeitungskette eines autonomen Fahrzeugs und führen zu einer unvollständigen oder fehlinterpretierten Umfeldrepräsentation. Dadurch weisen Bewegungsplaner in vielen Fällen ein konservatives Verhalten auf. Diese Dissertation entwickelt zwei Bewegungsplaner, welche die Defizite der vorgelagerten Verarbeitungsmodule durch Ausnutzung der Reaktionsfähigkeit des Fahrzeugs kompensieren. Diese Arbeit präsentiert zuerst eine ausgiebige Analyse über die Ursachen und Klassifikation der Unsicherheiten und zeigt die Eigenschaften eines idealen Bewegungsplaners auf. Anschließend befasst sie sich mit der mathematischen Modellierung der Fahrziele sowie den Randbedingungen, welche die Sicherheit gewährleisten. Das resultierende Planungsproblem wird mit zwei unterschiedlichen Methoden in Echtzeit gelöst: Zuerst mit nichtlinearer Optimierung und danach, indem es als teilweise beobachtbarer Markov-Entscheidungsprozess (POMDP) formuliert und die Lösung mit Stichproben angenähert wird. Der auf nichtlinearer Optimierung basierende Planer betrachtet mehrere Manöveroptionen mit individuellen Auftrittswahrscheinlichkeiten und berechnet daraus ein Bewegungsprofil. Er garantiert Sicherheit, indem er die Realisierbarkeit einer zufallsbeschränkten Rückfalloption gewährleistet. Der Beitrag zum POMDP-Framework konzentriert sich auf die Verbesserung der Stichprobeneffizienz in der Monte-Carlo-Planung. Erstens werden Informationsbelohnungen definiert, welche die Stichproben zu Aktionen führen, die eine höhere Belohnung ergeben. Dabei wird die Auswahl der Stichproben für das reward-shaped Problem durch die Verwendung einer allgemeinen Heuristik verbessert. Zweitens wird die Kontinuität in der Reward-Struktur für die Aktionsauswahl ausgenutzt und dadurch signifikante Leistungsverbesserungen erzielt. Evaluierungen zeigen, dass mit diesen Planern große Erfolge in Fahrversuchen und Simulationsstudien mit komplexen Interaktionsmodellen erreicht werden

Examining Development of Curriculum Knowledge of Prospective Mathematics Teachers

Explanatory-confirmatory research design, one of the mixed methods research designs, was used in this study to investigate Curriculum Knowledge developments of prospective teachers regarding algebra. Cross-sectional study method, as a type of descriptive research and one of the non-experimental research designs, was used to collect quantitative data in the study. In the qualitative part of the study, case study was used. The participants of the study were composed of 176 prospective teachers studying in the elementary mathematics education department of a university in Turkey, who were first, second, third, and fourth year students with equal numbers. Interview, observation (observation notes, lesson video recordings, in-class observation form), knowledge test were used as the instruments for the purpose of examining prospective teachers’ curriculum knowledge development. Kruskal-Wallis test, which is a non-parametric test, was used to compare the means of prospective teachers’ Algebra Curriculum Knowledge Test (ACKT) scores since these scores are not normally distributed. According to the results of the study, it was observed that knowledge levels of the prospective teachers in terms of curriculum knowledge developed as directly proportional depending on the class level. In addition, it was also observed that the knowledge of prospective teachers in terms of curriculum knowledge was not at the desired level. Also, considering the general centrality of prospective teachers’ answers on the partially true A and partially true B categories, it can be already concluded that prospective teachers’ curriculum knowledge is inadequate. Keywords: Curriculum Knowledge, Pedagogical Content Knowledge, Prospective Mathematics Teacher

Hızlı bir feribotun düşey ivmelenmesinin T-Foil ve trim tab sistem

his study is concerned with the active T-foil placed near the bow on the keel line of the fast ferry and two active trim tab controls placed at the stern to improve the maritime performance of a fast ferry, whilst improving the comfort and safety of passengers and crew. In the scope of the study, the vertical direction of the fast ferry under the random head waves, heave and pitch motions were taken into account. For the control of T-foil and trim Tabs, PID and LQR control methods were used. The purpose of these controllers is to reduce the acceleration of the heave and pitch motions of the fast ferry by changing the operating angles of the T-foil and trim tab wings. A random wave model was created using the Pierson-Moskowitz model, and simulations were done assuming that the fast ferry was subjected to random head waves. Finally, in order to see the effect of vertical acceleration on passengers, the rate of seasickness (MSI) change of the fast ferry in uncontrolled and controlled states was examined. Mathematical models of fast ferry, T-foil and trim tab and their simulations were carried out in MATLAB / Simulink environment. The simulation results show that T-foil and trim tab Active systems can effectively reduce vertical acceleration by improving heave and pitch motions.Bu çalışma, hızlı bir feribotun denizcilik performansını iyileştirmek, yolcu ile mürettebatın konfor ve güvenliğini artırmak için hızlı feribotun omurga hattında pruvaya yakın bir noktaya yerleştirilen hareketli T-foil ve kıç tarafına yerleştirilen iki adet hareketli trim tab kontrolü ile ilgilidir. Çalışma kapsamında baştan gelen düzensiz dalgaların etkisindeki hızlı feribotun düşey yönde yaptığı baş kıç vurma ve dalıp çıkma hareketleri dikkate alınmıştır. T-foil ve trim tabların kontrolü için ise PID ve LQR kontrol yöntemleri kullanılmıştır. Bu kontrolörlerin amacı, T-foil ve trim tab kanatlarının çalışma açılarının değiştirilmesiyle hızlı feribotun pozisyonunu kontrol ederek baş kıç vurma ve dalıp çıkma hareketlerinin ivmelenmesini azaltmaktır. Pierson-Moskowitz modelinden yararlanılarak düzensiz bir dalga modeli oluşturulmuş ve çalışmalar hızlı feribotun baştan gelen düzensiz dalgalara maruz kaldığı varsayılarak yapılmıştır. Son olarak düşey ivmelenmenin yolcular üzerindeki etkisini görebilmek için hızlı feribotun kontrolsüz ve kontrollü durumda deniz tutması oranı (MSI) değişimi incelenmiştir. Hızlı feribotun, T-foilin ve trim tabın matematiksel modelleri MATLAB / Simulink ortamında elde edilerek simülasyonları gerçekleştirilmiştir. Simülasyon sonuçları, T-foil ve trim tab aktif sistemlerinin baş kıç vurma ve dalıp çıkma hareketlerini iyileştirerek düşey ivmelenmeyi etkili bir şekilde azaltabildiğini göstermektedir

Fatih’in kullarından Vezir-i Azam Mahmud Paşa ve faaliyetleri

Çalışmamız II. Mehmed Dönemi’nin önemli siyasi karakterlerinden Mahmud Paşa’nın askeri ve siyasi faaliyetleri ile dönemin sosyal ve edebi yaşantısına olan katkısını kapsamaktadır. Bu ölçekte Osmanlı ve Bizans kaynaklarının yanı sıra Mahmud Paşa üzerine yapılan araştırmaları ve konu hakkında bilgi veren tetkik eserlerler tahlil edilip biyografik bir ürün ortaya konulmaya çalışılmıştır. Çalışma esnasında özellikle birinci ve ikinci el kaynaklar üzerinden yapılan yorumlarda eserin diğer kaynaklar ile olan uyumu titizlikle incelenmiştir. Ulaşılan tüm veriler dikkatle terkip edilmiş ve Osmanlı İmparatorluğu’nun en ünlü sadrazamlarından Mahmud Paşa hakkında güvenilir bir eser hedeflenmiştir.Our study covers the contribution of Mahmud Pasha to the social and literary life of the period with his military and political activities, who was one of the most important political characters of Mehmed II Period. In this scale, besides Ottoman and Byzantine sources, studies on Mahmud Pasha and research studies, which give information about subject, were analyzed and biographical study were tried to be presented. During this study, compatibility of the study with other sources were examined meticulously in the interpretations on especially primary and secondary sources. All the obtained datas were compiled carefully and it was aimed that revealing reliable study about Mahmud Pasha who was one of the most famous grand veziers of the Ottoman Empire

AO* and penalty based algorithms for the Canadian traveler problem

Tezin basılısı İstanbul Şehir Üniversitesi Kütüphanesi'ndedir.The Canadian Traveler Problem (CTP) is a challenging path planning problem on stochastic graphs where some edges are blocked with certain probabilities and status of edges can be disambiguated only upon reaching an end vertex. The goal is to devise a traversal policy that results in the shortest expected traversal length between a given starting vertex and a termination vertex. The organization of this thesis is as follows: In the first chapter we define CTP and its variant SOSP and present an extensive literature review related to these problems. In the second chapter, we introduce an optimal algorithm for the problem, based on an MDP formulation which is a new improvement on AO* search that takes advantage of the special problem structure in CTP. The new algorithm is called CAO*, which stands for AO* with Caching. CAO* uses a caching mechanism and makes use of admissible upper bounds for dynamic state-space pruning. CAO* is not polynomial-time, but it can dramatically shorten the execution time needed to find an exact solution for moderately sized instances. We present computational experiments on a realistic variant of the problem involving an actual maritime minefield data set. In the third chapter, we introduce a simple, yet fast and effective penalty-based heuristic for CTP that can be used in an online fashion. We present computational experiments involving real-world and synthetic data that suggest our algorithm finds near-optimal policies in very short execution times. Another efficient method for sub-optimally solving CTP, rollout-based algorithms, have also been shown to provide high quality policies for CTP. In the final chapter, we com- pare the two algorithmic frameworks via computational experiments involving Delaunay and grid graphs using one specific penalty-based algorithm and four rollout-based algo- rithms. Our results indicate that the penalty-based algorithm executes several orders of magnitude faster than rollout-based ones while also providing better policies, suggest- ing that penalty-based algorithms stand as a prominent candidate for fast and efficient sub-optimal solution of CTP.Declaration of Authorship ii Abstract iii Öz iv Acknowledgments v List of Figures viii List of Tables ix Abbreviations x 1 Introduction 1 1.1 Overview .................................... 1 1.2 The Canadian Traveler Problem ........................ 1 1.2.1 The Discrete Stochastic Obstacle Scene Problem .......... 2 1.3 Literature Review ................................ 3 1.4 Organization of the Thesis ........................... 4 2 An AO* Based Exact Algorithm for the Canadian Traveler Problem 5 2.1 Introduction ................................... 5 2.2 MDP and POMDP Formulations ....................... 6 2.2.1 MDP Formulation and The Bellman Equation ............ 7 2.2.2 Deterministic POMDP Formulation ................. 9 2.3 The CAO* Algorithm ............................. 11 2.3.1 AO Trees ................................ 11 2.3.2 The AO* Algorithm .......................... 14 2.3.3 The CAO* Algorithm ......................... 16 2.4 Computational Experiments .......................... 19 2.4.1 The BAO* and PAO* Algorithms ................... 19 2.4.2 Experimental Setup .......................... 21 2.4.3 Simulation Environment A ...................... 21 2.4.4 Simulation Environment B ....................... 22 2.4.5 Simulation Environment C....................... 24 2.4.6 Simulation Environment D ...................... 25 2.5 Summary and Conclusions ........................... 26 3 A Fast and Effective Online Algorithm for the Canadian Traveler Prob- lem 29 3.1 Introduction ................................... 29 3.2 The DT Algorithm ............................... 30 3.3 Computational Experiments .......................... 32 3.3.1 Environment 1 ............................. 32 3.3.2 Environment 2 ............................. 34 3.4 Conclusions and Future Research ....................... 34 3.4.1 Conclusions ............................... 34 3.4.2 Limitations and Future Research ................... 35 4 A Comparison of Penalty and Rollout-Based Policies for the Canadian Traveler Problem 36 4.1 Introduction ................................... 36 4.2 Algorithms for CTP .............................. 37 4.2.1 Optimism (OMT) ........................... 37 4.2.2 Hindsight Optimization (HOP) .................... 38 4.2.3 Optimistic Rollout (ORO) ....................... 39 4.2.4 Blind UCT (UCTB) .......................... 39 4.2.5 Optimistic UCT (UCTO) ....................... 40 4.3 Computational Experiments .......................... 41 4.3.1 Delaunay Graph Results ........................ 43 4.3.2 Grid Graph Results .......................... 45 4.4 Conclusions and Future Research ....................... 46 4.4.1 Conclusions ............................... 46 4.4.2 Limitations and Future Research ................... 46 A Problem Instances in Simulation Environments C and D 48 Bibliography 5

Intermittent demand forecasting: A guideline for method selection

Intermittent demand shows irregular pattern that differentiates it from all other demand types. It is hard to forecasting intermittent demand due to irregular occurrences and demand size variability. Due to this reason, researchers developed ad hoc intermittent demand forecasting methods. Since intermittent demand has peculiar characteristics, it is grouped into categories for better management. In this paper, specialized methods with a focus of method selection for each intermittent demand category are considered. This work simplifies the intermittent demand forecasting and provides guidance to market players by leading the way to method selection based on demand categorization. By doing so, the paper will serve as a useful tool for practitioners to manage intermittent demand more easily.Q1WOS:0005179795000012-s2.0-8507967227

Sol anterior fasiküler bloğun stabil anginalı hastalarda sol ana ve/veya proksimal sol ön inen koroner arter hastalığının belirlenmesinde öngördürücü değerinin araştırılması: bir eğilim skoru eşleştirme analizi

Introduction: Successful revascularization of lesions located in the left main and/or proximal left anterior descending (LM and/or pLAD) coronary artery improves survival than medical therapy only. Therefore, accurate identification of high-risk patients with suspected stable angina pectoris is critical for outpatient clinics. Since the septal perforators of the left anterior descending coronary artery are the main source of blood supply of the left anterior fascicle, we hypothesized that the presence of left anterior fascicular block (LAFB) can predict obstructive stenoses of LM and/or pLAD coronary arteries in patients with suspected stable angina pectoris. Methods: We consecutively enrolled 790 patients referred for invasive coronary angiography due to suspected stable angina pectoris. Results: The number of patients with LAFB5 was 68 (8.6%). Furthermore, 218 patients (27.6%) had obstructive coronary artery disease (CAD). The prevalence of obstructive CAD, revascularization with coronary artery bypass graft surgery, and obstructive LM and/or pLAD coronary artery lesions was higher in patients with LAFB. From univariate analysis, the presence of LAFB was significantly associated with predicting obstructive LM and/or pLAD lesions (odds ratio: 3,587; 95% confidence interval: 1,465-5,785; p=0.005). However, this association disappeared after adjustment for other cardiovascular risk factors. Conclusion: In patients with suspected stable angina pectoris, LAFB is not frequently a 'normal variant" and is associated with known cardiovascular risk factors. It acts as a marker rather than a determinant of obstructive LM and/or pLAD coronary artery lesions

ATYPICAL CT FINDINGS AND CLINICAL CORRELATION OF COVID-19 PNEUMONIA

Aim: Our study aimed to evaluate the atypical CT findings and concomitant pathologies of COVID-19 pneumonia and clinical and laboratory findings and compare them with typical CT findings.Materials and Methods: A total of 69 patients were diagnosed with COVID-19, 14 of which were atypical (20.2%), and 55 of which were typical (79%) chest computed tomography (CT) findings. CT images and clinical and laboratory data of patients with atypical findings were retrospectively analyzed. Lesions of the typical and atypical group and CT severity scores were compared.Results: Atypical CT findings were centrilobular nodule, tree in bud, pleural effusion, lobar/segmental consolidation, bronchiectasis, pulmonary embolism, and mosaic attenuation by typical lesions with ground-glass opacity with/without consolidation. CT severity score was significantly higher in the atypical group (p <0.001). CRP, procalcitonin, the neutrophil rate increased, and the lymphocyte count decreased in patients with a high CT severity score. Comorbidity was common in the atypical group (50%).Conclusion: High CT severity score and widespread lung involvement of the patient group with atypical CT findings may be due to disease progression or other concomitant diseases. Atypical lesions accompanying typical lesions may cause false negativity in reporting. As radiologists' experience with COVID-19 pneumonia increases, it may improve that they categorize these images as typical or atypical