• Title/Summary/Keyword: Restricted Three Body Problem

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Perception and Body: with a focus on Noe's theory (지각과 몸: 노에의 이론을 중심으로)

  • Yoon, Bosuk
    • Korean Journal of Cognitive Science
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    • v.25 no.4
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    • pp.277-302
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    • 2014
  • This paper aims at providing a critical review of Alva Noe's enactive theory of perception. The discussion will be organized around the three issues: (i) Does the body make an ineliminable contribution to shaping the mind? (ii) Does Noe succeed in providing effective arguments against the brain-centrism? (iii) Does Noe's theory give a satisfactory explanation of how we can perceive external objects? In the sections 2 and 3 of the paper, I discuss possible criticisms that can be raised against Noe with regard to (i) and (ii). Although these are serious criticisms, they apply to the embodied cognition in general. That is, those criticisms are not restricted to Noe's theory. In order to understand the core aspect of Noe's theory, we need to pay attention to "the problem of perceptual presence" that is brought up in (iii). It is here that Noe's theory is supposed to make a distinct contribution to the discussion about the nature of perception. I argue, however, in the section 4 that Noe's theory fails to provide a satisfactory explanation of perceptual presence.

Comparison of Global Optimization Methods for Insertion Maneuver into Earth-Moon L2 Quasi-Halo Orbit Considering Collision Avoidance

  • Lee, Sang-Cherl;Kim, Hae-Dong;Yang, Do-Chul;Cho, Dong-Hyun;Im, Jeong-Heum;No, Tae-Soo;Kim, Seungkeun;Suk, Jinyoung
    • International Journal of Aeronautical and Space Sciences
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    • v.15 no.3
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    • pp.267-280
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    • 2014
  • A spacecraft placed in an Earth-Moon L2 quasi-halo orbit can maintain constant communication between the Earth and the far side of the Moon. This quasi-halo orbit could be used to establish a lunar space station and serve as a gateway to explore the solar system. For a mission in an Earth-Moon L2 quasi-halo orbit, a spacecraft would have to be transferred from the Earth to the vicinity of the Earth-Moon L2 point, then inserted into the Earth-Moon L2 quasi-halo orbit. Unlike the near Earth case, this orbit is essentially very unstable due to mutually perturbing gravitational attractions by the Earth, the Moon and the Sun. In this paper, an insertion maneuver of a spacecraft into an Earth-Moon L2 quasi-halo orbit was investigated using the global optimization algorithm, including simulated annealing, genetic algorithm and pattern search method with collision avoidance taken into consideration. The result shows that the spacecraft can maintain its own position in the Earth-Moon L2 quasi-halo orbit and avoid collisions with threatening objects.

A Parametric Study on Optimal Earth-Moon Transfer Trajectory Design Using Mixed Impulsive and Continuous Thrust (혼합 추력 방식의 지구-달 최적 전이궤적 설계인자에 따른 비교연구)

  • Lee, Dae-Ro;No, Tae-Soo;Lee, Ji-Marn;Jeon, Gyeong-Eon
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.39 no.11
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    • pp.1021-1032
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    • 2011
  • This paper presents the results of a parametric study for the design of optimal Earth-Moon transfer trajectory using mixed impulsive and continuous thrust. Various types of the optimal Earth-Moon transfer trajectories were designed by adjusting the relative weight between the impulsive and the continuous thrust, and flight time. Two very different transfer trajectories can be obtained by different combination of design parameters. Furthermore, it was found that all thus designed trajectories permit the ballistic capture by the Moon gravity. Finally, the required thrust profiles are presented and analyzed in detail.

Some New Problems of International Aviation Security- Considerations Forcused on its Legal Aspects (최근국제항공보안대책(最近國際航空保安対策)의 제간제(諸間題) -특히 법적측면(法的測面)을 중심(中心)으로-)

  • Choi, Wan-Sik
    • The Korean Journal of Air & Space Law and Policy
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    • v.5
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    • pp.53-75
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    • 1993
  • This article is concerned with the comment on "Some New Problems of International Aviation Security-Considerations Forcused on its Legal Aspects". Ever since 1970, in addition to the problem of failure to accept the Tokyo, Hague and Montreal Conventions, there has been also the problem of parties to them, failing to comply with their obligations under the respective treaties, in the form especially of nominal penalties or the lack of any effort to prosecute after blank refusals to extradite. There have also been cases of prolonged detention of aircraft, passengers and hostages. In this regard, all three conventions contain identical clauses which submit disputes between two or more contracting States concerning the interpretation or application of the respective conventions to arbitration or failing agreement on the organization of the arbitration, to the International Court of Justice. To the extent to which contracting States have not contracted out of this undertaking, as I fear they are expressly allowed to do, this promision can be used by contracting States to ensure compliance. But to date, this avenue does not appear to have been used. From this point of view, it may be worth mentioning that there appears to be an alarming trend towards the view that the defeat of terrorism is such an overriding imperative that all means of doing so become, in international law, automatically lawful. In addition, in as far as aviation security is concerned, as in fact it has long been suggested, what is required is the "application of the strictest security measures by all concerned."In this regard, mention should be made of Annex 17 to the Chicago Convention on Security-Safeguarding International Civil Aviation against Acts of Unlawful Intereference. ICAO has, moreover, compiled, for restricted distribution, a Security Manual for Safeguarding Civil Aviation Against Acts of Unlawful Interference, which is highly useful. In this regard, it may well be argued that, unless States members of ICAO notify the ICAO Council of their inability to comply with opecific standards in Annex 17 or any of the related Annexes in accordance with Article 38 of the 1944 Chicago Convention on International Civil Aviation, their failure to do so can involve State responsibility and, if damage were to insure, their liability. The same applies to breaches of any other treaty obligation. I hope to demonstrate that although modes of international violence may change, their underlying characteristics remain broadly similar, necessitating not simply the adoption of an adequate body of domestic legislation, firm in its content and fairly administered, but also an international network of communication, of cooperation and of coordination of policies. Afurther legal instrument is now being developed by the Legal Committee of ICAO with respect to unlawful acts at International airports. These instruments, however, are not very effective, because of the absence of universal acceptance and the deficiency I have already pointed out. Therefore, States, airports and international airlines have to concentrate on prevention. If the development of policies is important at the international level, it is equally important in the domestic setting. For example, the recent experiences of France have prompted many changes in the State's legislation and in its policies towards terrorism, with higher penalties for terrorist offences and incentives which encourage accused terrorists to pass informations to the authorities. And our government has to tighten furthermore security measures. Particularly, in the case an unarmed hijacker who boards having no instrument in his possession with which to promote the hoax, a plaintiff-passenger would be hard-pressed to show that the airline was negligent in screening the hijacker prior to boarding. In light of the airline's duty to exercise a high degree of care to provide for the safety of all the passengers on board, an acquiescence to a hijacker's demands on the part of the air carrier could constitute a breach of duty only when it is clearly shown that the carrier's employees knew or plainly should have known that the hijacker was unarmed. The general opinion is that the legal oystem could be sufficient, provided that the political will is there to use and apply it effectively. All agreed that the main responsibility for security has to be borne by the governments. A state that supports aviation terrorism is responsible for violation of International Aviation Law. Generally speaking, terrorism is a violation of international law. It violates the sovereign rights of states, and the human rights of the individuals. We have to contribute more to the creation of a general consensus amongst all states about the need to combat the threat of aviation terrorism. I think that aviation terrorism as becoming an ever more serious issue, has to be solved by internationally agreed and closely co - ordinated measures.

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