Trojan

About: Trojan is a research topic. Over the lifetime, 2028 publications have been published within this topic receiving 33209 citations.

Comedy and the trojan war

Abstract: The role of the Trojan War in epic and tragic poetry is well known, its role in comic poetry less so. Yet the war did feature in a number of ancient comedies. This fact might seem surprising, not only because fighting and death are subjects unlikely to give rise to much hilarity, but also because one tends to associate comedy with a type of subject matter markedly different from that of tragedy and epic. Nevertheless, many comedies did adopt mythological subjects,1 and even those set in present-day Athens might allude to myth. This article aims to examine the Trojan War theme as it appears in Old Comedy, and to explain its function with reference to the social and intellectual context of late fifth-century Greece. Thinking about this topic may also open up certain larger questions about the genre of comedy and its relation to myth and tragedy. First, a caveat: there is no extant comedy of the ‘mythological’ type, and for the most part one has to deal with sparse fragments and testimonia.2 This makes it hard to be confident about the manner in which comedians handled the myth. Not only the content but also the date of most plays is unknown. Thus a degree of imagination and guesswork is called for—which, though unprovable, may allow one to situate otherwise unrewarding shards within a satisfying conceptual framework. And there is considerable room for optimism. A number of comedies demonstrably made use of the Trojan War theme—including Aristophanes’ Acharnians, Birds and Daedalus, Cratinus’ Dionysalexandros and Nemesis, Eupolis’ Prospaltians, and Plato’s Menelaus— and for some of these plays the evidence is reasonably substantial. Apart from a few insignificant passing references, and a few allusions which are too insubstantial to interpret,3 the evidence adds up to a remarkably consistent picture. In the first place, it appears that the comedians were interested in the Trojan War less for 412

The role of secular resonances on trojans of the terrestrial planets

Abstract: We investigate the role of secular resonances on the motion of terrestrial-planet trojans in tadpole motion for 5 Myr in the inclination range i ≤ 90°. We use a Fourier spectrum of the eccentricity vector, e, and angular momentum vector, L. When i > 40°, the trojans are in a Kozai resonance with Jupiter, which increases the eccentricity to planet-crossing values on a time-scale of 0.1 Myr; hence we found no stable trojan motion when i > 40°. Trojans of Mercury are unstable for a large range in inclination due to the resonances v 1 , v 1 2 and v 5 , and only those with low and high inclinations survived in our simulations. For Venus and Earth trojans, the v 3 and v 4 secular resonances with the Earth and Mars respectively increase the eccentricity to planet-crossing values for moderate inclinations. Venus trojans are also affected by the v 1 1 resonance with Mercury at high inclinations hence Venus and Earth trojans are stable only at low inclinations. Mars trojans are affected by the v 3 , v 4 , v 1 3 and v 1 4 resonances with the Earth and Mars for low inclinations which increase the eccentricity and suppress oscillations of the inclination. At i = 32°, the v 5 resonance destabilizes Mars trojans, although its width is less than a degree in inclination. The typical lifetime of inner-planet trojans trapped in a secular resonance is 1 Myr for Venus, Earth and Mars trojans, while it is 10 5 yr for Mercury trojans. Trojans in secular resonances are chaotic on time-scales of 10 3 -10 4 yr for all inner planets, while outside the resonances this becomes typically 10 6 yr.

On the stability regions of the Trojan asteroids

Abstract: The orbits of fictitious bodies around Jupiter’s stable equilibrium points L 4 and L 5 were integrated for a fine grid of initial conditions up to 100 million years. We checked the validity of three different dynamical models, namely the spatial, restricted three body problem, a model with Sun, Jupiter and Saturn and also the dynamical model with the Outer Solar System (Jupiter to Neptune). We determined the chaoticity of an orbit with the aid of the Lyapunov Characteristic Exponents (=LCE) and used also a method where the maximum eccentricity of an orbit achieved during the dynamical evolution was examined. The goal of this investigation was to determine the size of the regions of motion around the equilibrium points of Jupiter and to find out the dependance on the inclination of the Trojan’s orbit. Whereas for small inclinations (up to i = 20°) the stable regions are almost equally large, for moderate inclinations the size shrinks quite rapidly and disappears completely for i > 600. Additionally, we found a difference in the dynamics of orbits around L 4 which — according to the LCE — seem to be more stable than the ones around L 5.

Ten years of hardware Trojans: a survey from the attacker's perspective

Abstract: Hardware Trojan detection techniques have been studied extensively However, to develop reliable and effective defenses, it is important to figure out how hardware Trojans are implemented in practical scenarios The authors attempt to make a review of the hardware Trojan design and implementations in the last decade and also provide an outlook Unlike all previous surveys that discuss Trojans from the defender's perspective, for the first time, the authors study the Trojans from the attacker's perspective, focusing on the attacker's methods, capabilities, and challenges when the attacker designs and implements a hardware Trojan First, the authors present adversarial models in terms of the adversary's methods, adversary's capabilities, and adversary's challenges in seven practical hardware Trojan implementation scenarios: in-house design team attacks, third-party intellectual property vendor attacks, computer-aided design tools attacks, fabrication stage attacks, testing stage attacks, distribution stage attacks, and field-programmable gate array Trojan attacks Second, the authors analyse the hardware Trojan implementation methods under each adversarial model in terms of seven aspects/metrics: hardware Trojan attack scenarios, the attacker's motivation, feasibility, detectability (anti-detection capability), protection and prevention suggestions for the designer, overhead analysis, and case studies of Trojan implementations Finally, future directions on hardware Trojan attacks and defenses are also discussed