scholarly journals Interaction Between a Robot and Bunimovich Stadium Billiards

2021 ◽  
Author(s):  
J. V. A. Vasconcelos ◽  
L. H. Miranda-Filho ◽  
A. J. F. Souza ◽  
A. R. C. Romaguera ◽  
A. L. R. Barbosa
Keyword(s):  
Initial Conditions ◽  
Specular Reflection ◽  
Video Camera ◽  
Simple Experiment ◽  
Surface Of Section ◽  
Digital Video Camera ◽  
Physical Problems ◽  
Theoretical Predictions ◽  
Experimental Time Series ◽  
Dynamic Time

Abstract The robot–environment–task triad provides many opportunities to revisit physical problems with fresh eyes. Hence, we develop a simple experiment to observe chaos in classical billiards with a macroscopic 3.38-meter long setup. Using a digital video camera, one records the dynamic time evolution of the interaction between a robot and Bunimovich stadium billiards with specular reflection. From the experimental time series, we calculate the Lyapunov exponent λ as a function of a geometric parameter. The results are in concordance with theoretical predictions. In addition, we determine the Poincaré surface of section from the experimental data and check its sensitivity to the initial conditions as a function of time.

Microvascular damage in the cortex of cat brain from middle cerebral artery occlusion and reperfusion

1993 ◽  
Vol 74 (2) ◽  
pp. 580-589 ◽  
Author(s):  
D. F. Wilson ◽  
S. Gomi ◽  
A. Pastuszko ◽  
J. H. Greenberg
Keyword(s):  
Middle Cerebral Artery ◽  
Cerebral Artery ◽  
Oxygen Pressure ◽  
Video Camera ◽  
Artery Occlusion ◽  
Microvascular Damage ◽  
Excitation Light ◽  
Irreversible Brain Damage ◽  
Dynamic Time ◽  
Cerebral Artery Occlusion

Oxygen-dependent quenching of phosphorescence provides an extraordinarily powerful method for examining the effects of ischemia/hypoxia on the cortex of the brain. Video camera technology has permitted imaging, through a window in the skull, of the phosphorescence of an oxygen probe, Pd meso-tetra-(4-carboxyphenyl)-porphine, bound to albumin in the blood of anesthetized animals. Images of the phosphorescence taken at different times after the flash of excitation light were used to generate high-resolution two-dimensional maps of the oxygen pressure. These maps show that cortical oxygenation is spatially heterogeneous and that there is dynamic time-dependent modulation of regional oxygen pressures. When the middle cerebral artery was occluded, the region for which it supplied blood became hypoxic, the severity of the hypoxia varying among animals. Release after 60 min of occlusion resulted in a rapid rise of the oxygen pressure to above-normal levels followed by onset of a delayed period of hypoxia. This period is characterized by generally low tissue oxygen pressures with local regions of more severe hypoxia. The delayed period of hypoxia appears to result from damage to the microvasculature, and this microvascular damage is proposed to be an important determinant of the extent of irreversible brain damage.

AN OBJECT LOCATION SPECIFYING METHODOLOGY USING ONE CAMERA

2001 ◽  
Vol 09 (06) ◽  
pp. 685-702 ◽  
Author(s):  
WIRAT KESRARAT ◽  
THOTSAPON SORTRAKUL
Keyword(s):  
Image Processing ◽  
Image Plane ◽  
Video Camera ◽  
Object Location ◽  
Target Point ◽  
Target Area ◽  
Digital Video Camera ◽  
The World ◽  
The Difference ◽  
Point Center

This research proposed a methodology for specifying the location of an object with image processing. The objectives of this methodology are to capture the target area, and specify the location of the object by using image. In order to locate the dropping object on the image plane efficiently, consecutive images are analyzed and a threshold operation is proposed. Because the accuracy of the dropping objects location on the difference of consecutive images image plane is usually influenced by noise. Moreover, transformation unit is adopted to map the XY coordinate on image plane into the world coordinate for an accuracy of the dropping objects position. After we get the actual XY coordinate of the dropping object, we can find the distance from the target point (center) and clock direction of the dropping object related to the center also. In addition, by using one digital video camera set on the tower and pan to capture the image on the target area to detect the dropping object from the air to the ground. It made the proposed methodology provide easier portability to detect the dropping object in any area.

scholarly journals AFM investigation of hyaline cartilage’s surface destruction

2016 ◽  
Author(s):  
Mikhail Ihnatouski ◽  
Dmitriy Karev ◽  
Boris Karev ◽  
Jolanta Pauk ◽  
Kristina Daunoravičienė
Keyword(s):  
Video Camera ◽  
Optical Microscope ◽  
Collagen Fibers ◽  
Force Microscopy ◽  
Digital Video Camera ◽  
Atomic Force ◽  
Reflected Light ◽  
Longitudinal Orientation ◽  
Chronic Progressive Disease ◽  
Surface Destruction

Introduction: Osteoarthritis is a chronic, progressive disease. The aim of this paper is presenting the AFM investigation of cartilage in relation to the assessment of degenerative changes in the surface of hyaline cartilage. It can be useful in choosing the most effective methods of therapy. Methods: Samples were taken from the cartilage surface of the femoral head after its removal during total hip arthroplasty. Images of the surface of the sample were obtained using an optical microscope equipped with a digital video camera, in the reflected light and by atomic force microscopy. Results: The longitudinal orientation of the collagen fibers and sub-fibers beams on the surface, up to a diameter of 50 nm are identified in non-destroyed area sites. Conclusions: Images of the destroyed areas displaying separately passing collagen fibers, strongly exposed to the surface: the size measured and found substructure.

A digital video camera system

1990 ◽  
Vol 36 (4) ◽  
pp. 3866-3876 ◽  
Author(s):  
A. Morimura ◽  
K. Uomori ◽  
Y. Kitamura ◽  
A. Fujioka ◽  
J. Harada ◽  
...  
Keyword(s):  
Digital Video ◽  
Video Camera ◽  
Camera System ◽  
Digital Video Camera ◽  
Video Camera System

Nonlinear Dynamics of an Electrically Actuated MEMS Device: Experimental and Theoretical Investigation

2013 ◽  
Author(s):  
Laura Ruzziconi ◽  
Abdallah H. Ramini ◽  
Mohammad I. Younis ◽  
Stefano Lenci
Keyword(s):  
Nonlinear Dynamics ◽  
Theoretical Investigation ◽  
Initial Conditions ◽  
Micro Electro Mechanical System ◽  
Mass Model ◽  
Design Guideline ◽  
Electrically Actuated ◽  
Theoretical Predictions ◽  
Frequency Sweeps ◽  
Safe Condition

This study deals with an experimental and theoretical investigation of an electrically actuated micro-electro-mechanical system (MEMS). The experimental nonlinear dynamics are explored via frequency sweeps in a neighborhood of the first symmetric natural frequency, at increasing values of electrodynamic excitation. Both the non-resonant branch, the resonant one, the jump between them, and the presence of a range of inevitable escape (dynamic pull-in) are observed. To simulate the experimental behavior, a single degree-of-freedom spring mass model is derived, which is based on the information coming from the experimentation. Despite the apparent simplicity, the model is able to catch all the most relevant aspects of the device response. This occurs not only at low values of electrodynamic excitation, but also at higher ones. Nevertheless, the theoretical predictions are not completely fulfilled in some aspects. In particular, the range of existence of each attractor is smaller in practice than in the simulations. This is because, under realistic conditions, disturbances are inevitably encountered (e.g. discontinuous steps when performing the sweeping, approximations in the modeling, etc.) and give uncertainties to the operating initial conditions. A reliable prediction of the actual (and not only theoretical) response is essential in applications. To take disturbances into account, we develop a dynamical integrity analysis. Integrity profiles and integrity charts are performed. They are able to detect the parameter range where each branch can be reliably observed in practice and where, instead, becomes vulnerable. Moreover, depending on the magnitude of the expected disturbances, the integrity charts can serve as a design guideline, in order to effectively operate the device in safe condition, according to the desired outcome.

The Digital Video Camera

2018 ◽  
pp. 199-229
Author(s):  
Mick Hurbis-Cherrier
Keyword(s):  
Digital Video ◽  
Video Camera ◽  
Digital Video Camera

Evaluation of Non-Uniform Deformation of Multi-Layered Ceramic Sheets with Printed Electrodes during Compression

2011 ◽  
Vol 418-420 ◽  
pp. 1647-1653
Author(s):  
Fumio Naruse ◽  
Naoya Tada
Keyword(s):  
Deformation Behavior ◽  
Recent Trend ◽  
Video Camera ◽  
Transverse Displacement ◽  
Compression Tests ◽  
Electronic Components ◽  
Uniform Deformation ◽  
Digital Video Camera ◽  
Layered Ceramic

With the recent trend of down-sizing and more efficient use of electric power in electric appliances, there is a growing need of smaller electronic components, such as multi-layered ceramic capacitors (MLCCs). However, it was found that the non-uniform deformation occurred in MLCC block during the pressing process and it hinders the miniaturization of MLCCs. In this study, compression tests of multi-layered ceramic sheets with printed electrodes were carried out and the deformation behavior was observed in situ and recorded by digital video camera. The change in area fraction and transverse displacement were evaluated and the deformation mechanism was inferred from the results.

Effect of Hydrated Salt Additives on Film Boiling Behavior at Vapor Film Collapse

2008 ◽  
Author(s):  
Takahiro Arai ◽  
Masahiro Furuya
Keyword(s):  
High Speed ◽  
Video Camera ◽  
Film Boiling ◽  
Vapor Film ◽  
Quenching Temperature ◽  
Steel Sphere ◽  
Digital Video Camera ◽  
Collapse Temperature ◽  
Test Film ◽  
Film Collapse

A high-temperature stainless-steel sphere was immersed into various salt solutions to test film boiling behavior at vapor film collapse. The film boiling behavior around the sphere was observed with a high-speed digital-video camera. Because salt additives enhanced condensation heat transfer, the observed vapor film was thinner. Surface temperature of the sphere was measured. Salt additives increased the quenching (vapor film collapse) temperature, because frequency of direct contact between sphere surface and coolant increased. Quenching temperature rises with increased salt concentration. The quenching temperature, however, approaches a constant value when the slat concentration is close to its saturation concentration. The quenching temperature is well correlated with ion molar concentration, which is a number density of ions, regardless of the type of hydrated salts.

Development of a Crack Type Index

2005 ◽  
Vol 1940 (1) ◽  
pp. 99-109 ◽  
Author(s):  
Hosin (David) Lee ◽  
Jungyong (Joe) Kim
Keyword(s):  
Spatial Distribution ◽  
Video Camera ◽  
Multiple Cracks ◽  
Crack Analysis ◽  
Transverse Cracking ◽  
Digital Video Camera ◽  
Crack Type ◽  
Image Pixels ◽  
Analysis System ◽  
Utility Vehicle

Many automated systems for crack analysis have been developed to measure the extent and severity of pavement cracking objectively. However, the accuracy of such an automated crack analysis system has not been satisfactory. This paper presents a crack type index (CTI) that can be easily adopted to determine the crack type objectively as longitudinal, transverse, and alligator cracking. The CTI is based on the spatial distribution of the image tiles rather than image pixels, where a tile is defined as a subimage of a whole digital image. The spatial distribution of image tiles is analyzed vertically and horizontally, with a resulting single index, which can be used to identify a spatial orientation of cracking. To determine the accurate CTI threshold values for longitudinal, transverse, and alligator cracks, 150 pavement images were captured with a digital video camera mounted on a sport-utility vehicle: 50 images for each of three types of cracking. These 150 images were analyzed automatically to compute the CTI values that correlate with crack types. To validate the CTI system, another 150 pavement images were captured. The CTI system identified 150 images as proper crack types with an 86% accuracy for alligator cracking, 92% accuracy for transverse cracking, and 94% accuracy for longitudinal cracking. The CTI system is further validated against images of block cracking and multiple cracks. The validation result against block cracking and multiple cracks indicates that the proposed CTI system in conjunction with UCI is robust and can be extended to identify block cracking and multiple cracks. The CTI method can be used to determine crack types from the digital images automatically without any human intervention.

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