Performance improvement in VSLAM using stabilized feature points

Simultaneous localization and mapping (SLAM) is the main prerequisite for the autonomy of a mobile robot. In this paper, we present a novel method that enhances the consistency of the map using stabilized corner features. The proposed method integrates template matching based video stabilization and Harris corner detector. Extracting Harris corner features from stabilized video consistently increases the accuracy of the localization. Data coming from a video camera and odometry are fused in an Extended Kalman Filter (EKF) to determine the pose of the robot and build the map of the environment. Simulation results validate the performance improvement obtained by the proposed technique

Under vehicle perception for high level safety measures using a catadioptric camera system

In recent years, under vehicle surveillance and the classification of the vehicles become an indispensable task that must be achieved for security measures in certain areas such as shopping centers, government buildings, army camps etc. The main challenge to achieve this task is to monitor the under frames of the means of transportations. In this paper, we present a novel solution to achieve this aim. Our solution consists of three main parts: monitoring, detection and classification. In the first part we design a new catadioptric camera system in which the perspective camera points downwards to the catadioptric mirror mounted to the body of a mobile robot. Thanks to the catadioptric mirror the scenes against the camera optical axis direction can be viewed. In the second part we use speeded up robust features (SURF) in an object recognition algorithm. Fast appearance based mapping algorithm (FAB-MAP) is exploited for the classification of the means of transportations in the third part. Proposed technique is implemented in a laboratory environment

On the curvature of Einstein-Hermitian surfaces

We give a mathematical exposition of the Page metric, and introduce an efficient coordinate system for it. We carefully examine the submanifolds of the underlying smooth manifold, and show that the Page metric does not have positive holomorphic bisectional curvature. We exhibit a holomorphic subsurface with flat normal bundle. We also give another proof of the fact that a compact complex surface together with an Einstein-Hermitian metric of positive orthogonal bisectional curvature is biholomorphically isometric to the complex projective plane with its Fubini-Study metric up to rescaling. This result relaxes the K\"ahler condition in Berger's theorem, and the positivity condition on sectional curvature in a theorem proved by the second author.Comment: 16 pages, Page metric coefficient and Vierbein are fixed, Journal info added. arXiv admin note: text overlap with arXiv:1112.418

Convergence in house prices across OECD countries: A panel data analysis

This study examines whether housing prices converged in OECD countries over the 1996–2015 period. The unconditional and conditional convergence hypotheses are tested via the system-GMM method using five-year span panel data of twenty OECD countries. The results reveal that there exists a significant convergence process within this country group. To test the conditional convergence hypothesis, the convergence equation is estimated also with some control variables that may reflect market activity and demand side impacts such as income level, construction, unemployment rate, permits for dwellings and share prices. The findings show that the speed of convergence is even higher when the above-mentioned variables are controlled

Conformally K\"ahler surfaces and orthogonal holomorphic bisectional curvature

We show that a compact complex surface which admits a conformally K\"ahler metric g of positive orthogonal holomorphic bisectional curvature is biholomorphic to the complex projective plane. In addition, if g is a Hermitian metric which is Einstein, then the biholomorphism can be chosen to be an isometry via which g becomes a multiple of the Fubini-Study metric.Comment: 12 pages. Journal information adde

Investigation of the clinical behaviors of pediatric dentists working in Turkey during the normalization period of the COVID-19 Pandemic

Objective: Our aim is to investigate the clinical attitudes and behaviors of pediatric dentists during the new normalization period of the COVID-19 pandemic.Materials and methods: Our study was conducted online among pediatric dentistry specialists working in Turkey and a total of 256 people participated. According to personal information, the six questions asked in the second part were analyzed in terms of physicians' adaptation to the new normal order, clinical arrangements, measures to be taken, and their approaches to treatment procedures.Results: The responses to the option "my anxiety has decreased and I have learned to live with this situation" were mostly found in women (42.86%), those with a working period of 1-5 years (42.11%) and pediatric dentists aged 20-25 years (42.86%). In our study, it was observed that ART was practiced more in public hospitals (100%) compared to university and private hospitals. It was observed that 73.91% of pediatric dentists working in university hospitals preferred panoramic films. This rate was significantly higher than those working in state and private hospitals.Conclusions: It was observed that the pediatric dentists participating in our study acted in accordance with the precautions and measures during the new normalization period. In this process, procedures that produce less aerosol were preferred more frequently

Experimental Heat Transfer Analysis from Helical Coiled Tubes with the Same Surface Area

Helical coiled tubes are commonly used in water storage tanks. In this study, an experimental investigation was carried out to obtain the heat transfer characteristics of different geometric dimensions of helical tubes under steady state conditions. Helical coiled tubes of different geometric dimensions with the same overall length and total surface area were fabricated from the same copper tubes. The helical coiled tubes were placed in a hot water tank which could be adjusted to different water temperatures. Cold water was pumped into the helical coiled tubes at different flow rates at 20 °C. The experiments were carried out for laminar flow in the range of Re numbers between 3394 and 8332. The helical coiled tube Nu number was determined and compared with the literature. Then, the effectiveness of the helical coiled tubes was calculated using the ε-NTU method

A través de los ojos de estudiantes de inglés como lengua extranjera en Turquía: ¿Qué hace a un profesor de lengua extranjera efectivo?

Research on the qualities of successful teachers in Turkey indicates that students consider teacher effectiveness as the ability to ensure an environment in which positive student-teacher interaction can take place. However, further studies are needed to clarify students’ perceptions of the qualities of effective foreign language teachers, in particular, thus providing educators with necessary information concerning the implementation of language teacher development programs. Therefore, 998 undergraduate students at a state university in Turkey were asked to complete a survey concerning the qualities they believed are characteristic of a successful English language teacher. The results provide a detailed profile of university English as a foreign language (EFL)students’ perceptions with respect to pedagogy-specific knowledge, personality traits, professional skills and classroom behavior