1,290 research outputs found
Image based visual servoing using bitangent points applied to planar shape alignment
We present visual servoing strategies based on bitangents for aligning planar shapes. In order to acquire bitangents we use convex-hull of a curve. Bitangent points are employed in the construction of a feature vector to be used in visual control. Experimental results obtained on a 7 DOF Mitsubishi PA10 robot, verifies the proposed method
Positioning and trajectory following tasks in microsystems using model free visual servoing
In this paper, we explore model free visual servoing algorithms by
experimentally evaluating their performances for various tasks
performed on a microassembly workstation developed in our lab. Model
free or so called uncalibrated visual servoing does not need the
system calibration (microscope-camera-micromanipulator) and the
model of the observed scene. It is robust to parameter changes and
disturbances. We tested its performance in point-to-point
positioning and various trajectory following tasks. Experimental
results validate the utility of model free visual servoing in
microassembly tasks
Lip segmentation using adaptive color space training
In audio-visual speech recognition (AVSR), it is beneficial
to use lip boundary information in addition to texture-dependent
features. In this paper, we propose an automatic lip segmentation
method that can be used in AVSR systems. The algorithm
consists of the following steps: face detection, lip corners extraction,
adaptive color space training for lip and non-lip regions
using Gaussian mixture models (GMMs), and curve evolution
using level-set formulation based on region and image
gradients fields. Region-based fields are obtained using adapted
GMM likelihoods. We have tested the proposed algorithm on a
database (SU-TAV) of 100 facial images and obtained objective
performance results by comparing automatic lip segmentations
with hand-marked ground truth segmentations. Experimental
results are promising and much work has to be done to improve
the robustness of the proposed method
Model-based vs. model-free visual servoing: A Performance evaluation in microsystems
In this paper, model-based and model-free image based visual servoing (VS) approaches are implemented on a microassembly workstation, and their regulation and tracking performances are evaluated. A precise image based VS relies on computation of the image jacobian. In the model-based visual servoing, the image Jacobian is computed via calibrating the optical system. Precisely calibrated model based VS promises better positioning and tracking performance than the model-free approach. However, in the model-free approach, optical system calibration is not required due to the dynamic Jacobian estimation, thus it has the advantage of adapting to the different operating modes
İki noktada teğetler kullanarak görüntü tabanlı görsel geri beslemeli kontrol ile düzlemsel şekil hizalama
Bu bildiride, düzlemsel şekilleri hizalamak için iki noktada teğetlerden (bitangent) faydalanan görsel geri beslemeli kontrol stratejileri sunulmuştur. Bitangentları elde etmek ic¸in bir eğrinin dışbükey zarfından (convex-hull) yararlanılmıştır. İmge nitelik vektörü bitangent noktalarından oluşturularak görsel kontrolde kullanılmıştır. 7 serbestlik dereceli Mitsubishi PA10 robotu üzerinde gerçekleştirilen deneyler önerilen metodun geçerliliğini göstermiştir
Reconsideration of Classical and Quantum Physics Deterministically and Probabilistically: Nanophysicalism
This work focuses on resolving the origins of the probability theory and also reconsiders the classical and quantum physics both theoretically and experimentally in terms of deterministic and probabilistic processes. Primarily, the probability theory briefly re-examined in terms of its origins, validity and limitations. Additionally, classical physics and quantum physics are re-analysed both theoretically and experimentally in terms of deterministic and probabilistic mechanisms. Finally, philosophical argumentations are compared, combined and some important concluding remarks are briefly expressed. It is concluded that, unknown environmental effects and uncontrollability of that environmental effects, philosophically named as NanoPhysicalism, governs the probability theory, decisively influences some classical physical measurements and also the probabilistic structure of the quantum physics
Time Dependant Momentum Operator and Time Evolution of Free Quantum Particles
In spite of outstanding achievement of the quantum theory, the theory is under never-ending judgment due to probabilistic character and certain unresolved paradoxes arising from the very fundamentals. Additionally, it is debated that a more sophisticated theory beyond the quantum theory emerges as a need for a better understanding of the atomic and sub atomic worlds. This paper, for that reason, focuses on the very fundamental structure of the quantum theory such as the physical and philosophical meanings of the wave functions, the probability and the Schrödinger Wave Equation (SWE). Specifically deals with the time evolution of the free quantum particles. The work just arises from the difference of the classical and quantum waves, specifically the comparison of the time and space dependence of classical waves and Schrödinger waves, for the free space, indicates that time dependence shows a clear dissimilarity. In order to tackle the problem, a time dependent momentum operator, for the first time, is defined and consequently an alternative TDSWE is straightforwardly derived and its philosophical implications have been discussed. Additionally, time and position dependence of the probability functions, relating free particles, have been physically and philosophically discussed and some alternative approaches and comments are forwarded. Finally, the approaches, comments and mathematical equations are in good agreement with the standard quantum theory and interestingly go further possibly tracing some signs of new pathways to resolve the mysterious quantum world. Keywords: Schrödinger wave equation, fundamentals of quantum mechanics, momentum operator, quantum probabilities, time evolution of quantum systems
Measurement of Specific Heat of Organic Materials Using Non-Isolating Container and Arduino
This study reports a novel method for specific heat measurements of organic materials namely potaoes, quinces and radishes. The method proposed in this work is novel in the sense that it employs a non-isolated container and an Arduino microprocessors. The actual measurements are simply managed by placing the organic materials within hot water in a non-isolating container and by monitoring the temperature and time by means of Arduino UNO microprocessor. The heat leakage due to the non-isolated container is determined by using the heat versus time graph of the system and by mathematically modeling the temperature decrease by the time due to the heat exchange between the hot water and the environment. The measurements have revealed that the relative errors for the measurements are approximately % 4.75 for potatoes, % 21.50 for radishes and % 1.30 for quinces. The approach described in this work is inexpensive, very easy to apply and can potentially be beneficial for basic physics, science and engineering research activities
A Comparasion of Laboratory and Cardiopulmonary Effects of Desflurane, Detomidine and Medetomidine Anaesthetic Combinations in Horses
Background: Equine anesthesia morbidity and mortality rates are greater than in other domestic animals because of hypotension and hypoventilation. The important features desired in general anesthesia for horses are a rapid effect, rapid emergence and balanced anesthesia. The long duration of action of currently used anesthetic agents cause various complications in horses. The aim of the present study was to compare the clinical effects of combination of the anesthetics desflurane, detomidine and medetomidine in horses.Materials, Methods & Results: Eight healthy mixed-breed horses (four males and four females) with weighing 275 ± 56 kg [mean ± standard deviation (SD)] and aged 6.8 ± 5 years [(mean ± SD)] were used for this study. The horses were placed into one of four groups: group I (detomidine-desflurane), group II (detomidine-desflurane-atipamezole), group III (medetomidinedesflurane), or group IV (medetomidine-desflurane-atipamezole). Horses were rested for 15 days before each group starts to study. Intravenous detomidine (25 µg/kg) was used for premedication in groups I and II, and intravenous medetomidine (7 µg/ kg) was used for premedication in groups III and IV. Ketamine hydrocholoride (2 mg/kg) and midazolam (0.03 mg/kg) were intravenously administered in the same syringe to induce anesthesia. After induction of anesthesia, horses were placed in the left lateral recumbent position, and the trachea was intubated with a cuffed endotracheal tube with an internal diameter of 28 mm. The endotracheal tube was attached to a large animal circle breathing system anesthesia machine, and anesthesia was maintained with desflurane for 90 min. The initial dosage of desflurane was 14% + 4 L O2/min, and was reduced by 2% every 10 min over the first 30 min of anesthesia. After 30 min, the desflurane dose was changed to 8% + 4 L, which was maintained until the end of anesthesia (90 min). After 90 min, the administration of desflurane was discontinued, and all animals were supported by O2, with groups II and IV receiving 0.06 mg/kg atipamezole in addition to oxygen. Anaesthetic action times, hematological parameters, blood gas levels, electrolyte levels, biochemical values, electrocardiography values and end-tidal carbon dioxide volume were measured before, during, at the end of, and 24 h after anesthesia.Discussion: In this study, medetomidine (7 µg/kg) and detomidine (25 µg/kg) were intravenously administered, which was adequate and suitable for sedating horses. At the end of anesthesia, 0.06 mg/kg atipamezole was intravenously administered in groups II and IV. However, atipamezole did not affect the clinical parameters. Stress, excitement, fear, catecholamine exchange in blood circulation, hyperglycemia, and hypoxia can all cause changes in venous blood parameters. These are potential reasons for the changes in venous blood parameters (i.e., WBC and Hb) observed at the beginning of and during anesthesia in the present study. During and after the anesthetic period, serum biochemical values can be different from baseline values. They are dependent on the effects of anesthetic agents. During anesthesia, the decrease and increase of biochemical values stabilize the changes in the enzyme system that develops because of the effects of anesthetic agents. In the present study, it was considered that the changes in the biochemical values aimed to stabilize the changes induced by anesthesia. Regarding the electrolyte parameters evaluated in the study, there was a statistical difference detected in Na values between 90 min after induction of anesthesia and 24 h after induction of anesthesia in group IV. However, in previous studies, the changes in Na values did not influence the cardiac pressure during general anesthesia. In our study, significant changes were not seen in any electrolyte parameters except Na, and atrioventricular block was not detected in ECG traces. Generally, decreased ETCO2 levels are evidence of lung perfusion deficiency. It depends on the effects of anesthetic agents on the cardiopulmonary, cardiovascular, and respiratory systems. In particular, the higher pressure and dose of desflurane supress respiratory system. Oxygen supplementation in general anesthesia increases respiratory rate, but a-2 agonists and ketamine-midazolam effects can eliminate the increasing respiratory rate in general anesthesia
El Impacto de las Actividades de Educación Ambiental en la Conciencia Ambiental y las Expresiones Visuales de los Estudiantes de Primaria
The aim of this research is to improve environmental awareness in primary school students. For this purpose, the study was carried out within the scope of action research pattern from qualitative research patterns. The study group was determined by selecting easily accessible samples. The study group consisted of second year students attending a state primary school in Gungoren District of Istanbul in the 2018-2019 academic year. The data of the study were obtained by the students’ environmental pictures, observation forms and semi-structured interview forms. The data obtained were analyzed by content analysis. According to the findings of the research, it is determined that students who received environmental education, draw pictures enthusiastically and reflecting environmental awareness, also after interviews students gain awareness toward environment, empathized with nature and draw highly esthetically appreciated pictures.El objetivo de esta investigación es mejorar la conciencia ambiental en los estudiantes de primaria. Para este propósito, el estudio se realizó dentro del alcance del patrón de investigación-acción a partir de patrones de investigación cualitativa. El grupo de estudio se determinó seleccionando muestras de fácil acceso y consistió en estudiantes de segundo año que asistieron a una escuela primaria estatal en el distrito Gungoren de Estambul en el año académico 2018-2019. Los datos del estudio fueron obtenidos por las imágenes ambientales, los formularios de observación y los formularios de entrevista semiestructurados de los estudiantes. Los datos obtenidos fueron analizados por análisis de contenido. De acuerdo con los resultados de la investigación, se determina que los estudiantes que recibieron educación ambiental, hacen dibujos con entusiasmo y reflejan la conciencia ambiental, también después de las entrevistas, los estudiantes adquieren conciencia hacia el medio ambiente, empatizan con la naturaleza y dibujan imágenes muy apreciadas estéticamente
- …