Understanding of Falling Cat Phenomenon and Realization by Robot

2014 ◽  
Vol 26 (6) ◽  
pp. 685-690 ◽  
Author(s):  
Takashi Kawamura ◽  
Keyword(s):  
Angular Momentum ◽  
The Self ◽  
The Law ◽  
Cat Model

<div class=""abs_img""><img src=""[disp_template_path]/JRM/abst-image/00260006/02.jpg"" width=""250"" /> Cat-turn by cat and robotic cat</div> The movement of live cat righting itself in midair, is investigated analytically and experimentally. The objective of the author is to develop a robot that lands upright on its feet like a cat. Interestingly, explanations in physics and dynamics textbooks that dealing with feline the self-righting remain contradictory and ambiguous. This is analyzed based on the law of conservation of angular momentum using a cat model. A robotic cat was then developed to turn in mid air. The robot righted itself completely after performing a 180° turn in the air. </span>

„Rzymski” Żyd – nieznana twórczość Romana Brandstaettera

2012 ◽  
Vol 53 (1) ◽  
pp. 47-61
Author(s):  
Dariusz Konrad Sikorski
Keyword(s):  
New York ◽  
Social Norms ◽  
Cultural Values ◽  
Interwar Period ◽  
Free Speech ◽  
Role Model ◽  
The Self ◽  
Polish Literature ◽  
The Bible ◽  
The Law

Summary After 1946, ie. after embracing Christianity, Roman Brandstaetter would often point to the Biblical Jonah as a role model for both his life and his artistic endeavour. In the interwar period, when he was a columnist of Nowy Głos, a New York Polish-Jewish periodical, he used the penname Romanus. The ‘Roman’ Jew appears to have treated his columns as a form of an artistic and civic ‘investigation’ into scandalous cases of breaking the law, destruction of cultural values and violation of social norms. Although it his was hardly ‘a new voice’ with the potential to change the course of history, he did become an intransigent defender of free speech. Brought up on the Bible and the best traditions of Polish literature and culture, Brandstaetter, the self-appointed disciple of Adam Mickiewicz, could not but stand up to the challenge of anti-Semitic aggression.

Conservation laws

2018 ◽  
Author(s):  
Nathalie Deruelle ◽  
Jean-Philippe Uzan
Keyword(s):  
Dynamical System ◽  
Angular Momentum ◽  
Conservation Laws ◽  
Total Energy ◽  
Superposition Principle ◽  
Momentum Conservation ◽  
Conserved Quantities ◽  
Angular Momentum Conservation ◽  
Third Law ◽  
The Law

This chapter defines the conserved quantities associated with an isolated dynamical system, that is, the quantities which remain constant during the motion of the system. The law of momentum conservation follows directly from Newton’s third law. The superposition principle for forces allows Newton’s law of motion for a body Pa acted on by other bodies Pa′ in an inertial Cartesian frame S. The law of angular momentum conservation holds if the forces acting on the elements of the system depend only on the separation of the elements. Finally, the conservation of total energy requires in addition that the forces be derivable from a potential.

scholarly journals ACCRETION AND PLASMA OUTFLOW FROM DISSIPATIONLESS DISCS

2010 ◽  
Vol 19 (03) ◽  
pp. 339-365 ◽  
Author(s):  
S. V. BOGOVALOV ◽  
S. R. KELNER
Keyword(s):  
Angular Momentum ◽  
Similar Case ◽  
Gravitational Energy ◽  
Accretion Disc ◽  
The Self ◽  
Low Viscosity ◽  
Variable Polarity ◽  
Self Similar ◽  
Similar Solutions ◽  
High Electric Conductivity

We consider the specific case of disc accretion for negligibly low viscosity and infinitely high electric conductivity. The key component in this model is the outflowing magnetized wind from the accretion disc, since this wind effectively carries away angular momentum of the accreting matter. Assuming magnetic field has variable polarity in the disc (to avoid magnetic flux and energy accumulation at the gravitational center), this leads to radiatively inefficient accretion of the disc matter onto the gravitational center. In such a case, the wind forms an outflow, which carries away all the energy and angular momentum of the accreted matter. Interestingly, in this framework, the basic properties of the outflow (as well as angular momentum and energy flux per particle in the outflow) do not depend on the structure of accretion disc. The self-similar solutions obtained prove the existence of such an accreting regime. In the self-similar case, the disc accretion rate (Ṁ) depends on the distance to the gravitational center, r, as [Formula: see text], where λ is the dimensionless Alfvenic radius. Thus, the outflow predominantly occurs from the very central part of the disc provided that λ ≫ 1 (it follows from the conservation of matter). The accretion/outflow mechanism provides transformation of the gravitational energy from the accreted matter into the energy of the outflowing wind with efficiency close to 100%. The flow velocity can essentially exceed the Kepler velocity at the site of the wind launch.

From Knives to Kites: Developments and Dilemmas around the Use of Force in the Israeli–Palestinian Conflict since ‘Protective Edge’

2019 ◽  
Vol 10 (2) ◽  
pp. 303-336 ◽  
Author(s):  
Hilly Moodrick-Even Khen
Keyword(s):  
Law Enforcement ◽  
International Law ◽  
Use Of Force ◽  
Legal Regulation ◽  
The Self ◽  
Military Operations ◽  
Legal Questions ◽  
The Law ◽  
Israeli Occupation ◽  
Self Defence

This article analyses the legal regulation of the use of force in international law in the context of three emerging Palestinian forms of struggle against Israeli occupation: the Knife Intifada, the disturbances at the border, and the launching of incendiary kites. It discusses what legal paradigms or concepts should regulate the type and level of force used in each situation – a question that is complicated by various dilemmas – and finally, appraises the Israel Defence Forces policies tailored in response. The article evaluates the applicability of two legal paradigms regulating the use of force in military operations – (i) the conduct of hostilities and (ii) law enforcement – as well as the concept of personal self-defence in international law and the escalation of force procedure. While the Knife Intifada clearly falls under the law enforcement paradigm, the disturbances at the border and the launching of incendiary kites raise more difficult legal questions. Categorising them under a paradigm of law enforcement is less straightforward, and may have undesirable ramifications for safeguarding humanitarian interests. The article argues that the use of force in the disturbances at the border and the incendiary kites cases should be regulated by the concept of self-defence and escalation of force procedure, and that the application of the self-defence concept should be adapted, mutatis mutandis, to situations of law enforcement and to situations of hostilities.

Attosecond Extreme Ultraviolet Beams with Time-Varying Orbital Angular Momentum: The Self-Torque of Light

2019 ◽  
Author(s):  
Kevin M. Dorney ◽  
Laura Rego ◽  
Nathan J. Brooks ◽  
Quynh Nguyen ◽  
Chen-Ting Liao ◽  
...  
Keyword(s):  
Angular Momentum ◽  
Orbital Angular Momentum ◽  
Extreme Ultraviolet ◽  
The Self ◽  
Time Varying
Sign in / Sign up

Export Citation Format

Share Document