Physical Explication and Realization of the Turning Motion of a Cat by Analysis and Experiment Using a Robot Cat

1991 ◽  
Vol 3 (5) ◽  
pp. 437-442
Author(s):  
Takashi Kawamura ◽  
◽  
Kazuo Yamafuji ◽  
Tsuyoshi Kobayashi

Over turning motion of a cat at free fall in the air was investigated analytically and experimentally. Firstly, a live cat was modeled by a double circular column jointed with a spine at the one end of each column. And the dynamic characteristics of the model was analyzed based on the law of conservation of angular momentum. Then computer simulation was carried out. The results due to the simulation coincide well with those derived by the analysis, and validity of the modeling was shown. And a ROBOT CAT composed of a double circular column and a new type of backbone was developed in order to execute turning motion at free fall just like a cat. The robot successfully performed the complete overturning (180 degrees rotation) from the upside-down posture within 0.6 second. Therefore, the robot can change its posture to land on its feet if released from about 1.8m height quite upside-down.

Author(s):  
Ali Meghdari ◽  
Seyed Hossein Tamaddoni ◽  
Farid Jafari

The motivation of this work is to synthesize a kicking pattern for a humanoid robot with consideration of various objectives such as retaining its balance even after the kick is done and reducing the undesired angular momentum using both hands and torso. This kick pattern is designed so that a desirable ball velocity is achieved. In this paper, the law of conservation of angular momentum is used to generate a less energy consuming trajectory. Effectiveness of the proposed method is verified using computer simulation and is tested on Sharif CEDRA humanoid robot.


Author(s):  
Nimer Sultany

This chapter analyzes concrete Egyptian and Tunisian cases that showcase the interplay between continuity and rupture. These cases illustrate the lack of a systemic relation between law and revolution. On the one hand, the judiciary that interprets and applies the law is part of the very social and political conflicts it is supposed to resolve. On the other hand, the law is incoherent and there are often resources within the legal materials to play it both ways. Thus, the different forces at work use both continuity and rupture to advance their positions. Furthermore, legitimacy discourse mediates the contradictions between law and revolution in the experience of different legal and political actors. This mediation serves an ideological role because it presupposes a binary dichotomy between continuity and rupture, papers over law’s incoherence by reducing it to a singular voice, and reduces revolution to an event rather than a process.


Author(s):  
Nathalie Deruelle ◽  
Jean-Philippe Uzan

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.


Author(s):  
Monica Dapiaggi ◽  
Marco Alloni ◽  
Riccardo Carli ◽  
Nicola Rotiroti ◽  
Giorgia Confalonieri

Abstract The paper presents a quick method for the quantification of nickel species in spent FFC catalysts; the quantification of known quantities NiO and $$\hbox{NiAl}_2\hbox{O}_{4}$$ NiAl 2 O 4 is first done in a matrix of fresh zeolite Y, and then in a complex matrix, similar to the one of a real spent catalyst. The method is carefully checked and the errors in the quantification are critically evaluated. After the validation of the method with known quantities of NiO, well below the law limit for direct re-use, a set of real spent catalysts (representative of a period of 12 months) is analysed. Graphic Abstract


1972 ◽  
Vol 7 (3) ◽  
pp. 373-410
Author(s):  
Aharon Yoran

It is submitted that even if the hapless outsider cannot bring an action for damages because of the existing state of the law regarding fiduciary duties and breach of statutory duties, he still has an equitable remedy of rescission of the contract based on quasi-contractual principles. The crime of fraud, under secs. 13 and 54, respectively, would be made the basis of setting the contract (of sale or purchase) aside. To support this proposition we shall explore the quasi-contractual principles which enable one contracting party, the victim of a crime committed by the other party in entering the contract, to defeat this contract.In Browning v. Morris, in an oft-quoted statement by Lord Mansfield, the following principle was declared: But, where contracts or transactions are prohibited by positive statutes, for protecting one set of men from another set of men; the one, from their situation and condition, being liable to be oppressed or imposed upon by the other; there, the parties are not in pan delicto; and in furtherance of these statutes, the person injured, after the transaction is finished and completed, may bring an action and defeat the contract.


2015 ◽  
Vol 741 ◽  
pp. 28-31 ◽  
Author(s):  
Chang Hyun Cho ◽  
Seung Bok Choi

In modern society, a plenty of car accident is occurred and a lot of people get injury every day. For this reason, the importance of car safety has been increased and car safety has been extensively studied. Especially in many countries, the law about using baby safety seat is legislated to protect babies and children from accident. Thus, recently numerous products for baby safety have been developed. In this paper, a new type baby car seat is proposed to protect babies and children from frontal accident. In order to achieve this goal, design requirements of spring and MR(Magnetorheological) Damper which are main elements for a new type baby car seat are investigated.


The Chert Bed of Middle, or possibly Lower, Old Red Sandstone age discovered by Dr. W. Mackie (1914) at Rhynie, in Aberdeenshire, has become famous among palæo-botanists on account of the beautifully preserved remains of the earliest known land plants, described by the late Dr. Kidston and Prof. Lang (1917-1921). In addition to the plants, however, the Rhynie Chert also contains animal remains, for the most part very small and in a very fragmentary condition, although the fragments themselves are in many cases exceedingly well preserved. The vast majority of these animal remains are evidently Crustacean in character, and it was at first thought (see British Association Report, 1919, p. 110) that they belonged to several, or at least to two, different species. Subsequent work has, however, convinced me that all the Crustacean remains so far seen in the Rhynie Chert belong to the one species described in this paper.


Author(s):  
Liu Ruiwei ◽  
Hongwei Guo ◽  
Zhang Qinghua ◽  
Rongqiang Liu ◽  
Tang Dewei

Balancing stiffness and weight is of substantial importance for antenna structure design. Conventional fold-rib antennas need sufficient weight to meet stiffness requirements. To address this issue, this paper proposes a new type of cable-rib tension deployable antenna that consists of six radial rib deployment mechanisms, numerous tensioned cables, and a mesh reflective surface. The primary innovation of this study is the application of numerous tensioned cables instead of metal materials to enhance the stiffness of the entire antenna while ensuring relatively less weight. Dynamic characteristics were analyzed to optimize the weight and stiffness of the antenna with the finite element model by subspace method. The first six orders of natural frequencies and corresponding vibration modes of the antenna structure are obtained. In addition, the effects of structural parameters on natural frequency are studied, and a method to improve the rigidity of the deployable antenna structure is proposed.


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