Topic
Trojan
About: Trojan is a research topic. Over the lifetime, 2028 publications have been published within this topic receiving 33209 citations.
Papers published on a yearly basis
Papers
More filters
••
TL;DR: In this article, the authors analyzed the dynamics of Jupiter Trojans during the resonance crossing and found that orbital instability is not confined to the central 2:1 resonance region but occurs in a more extended region where secular and secondary resonances perturb the Trojan orbits while the planets approach, cross and leave the 2: 1 resonance.
Abstract: In the early phase of the Solar system evolution, while the outer planets migrated due to their interaction with a planetesimal disc, Jupiter may have crossed the 2:1 mean motion resonance with Saturn. It is well known that this dynamical event has profound consequences on the evolution of an alleged initial Trojan population of Jupiter. In this paper, we analyse in details the dynamics of Jupiter Trojans during the resonance crossing. We find that orbital instability is not confined to the central 2:1 resonance region but occurs in a more extended region where secular and secondary resonances perturb the Trojan orbits while the planets approach, cross and leave the 2:1 resonance. In addition, Jupiter and Saturn are locked after the resonance crossing in an apsidal corotation which has an additional destabilizing effect on Trojans. The synergy of the secular resonance, secondary resonances and apsidal corotation is needed to fully remove an initial Trojan population. New Trojans can be temporarily captured from the planetesimal disc while Jupiter crosses this extended instability region. After the disappearance of major secondary resonances, the secular resonance and the break of the apsidal corotation, the temporarily captured Trojans are locked and can remain stable over long timescales .
15 citations
••
TL;DR: In this paper, the authors derive a model that constrains optimal sky search areas and present a strategy for the most efficient use of telescope survey timethat maximizes the probability of detecting Mars Trojans.
Abstract: Trojan asteroids are minor planets that share the orbit of a planet about the Sun andlibrate around the L4 or L5 Lagrangian points of stability. Although only three MarsTrojans have been discovered, models suggest that at least ten times this numbershould exist with diameters >1 km. We derive a model that constrains optimal skysearch areas and present a strategy for the most efficient use of telescope survey timethat maximizes the probability of detecting Mars Trojans. We show that the Gaiaspace mission could detect any Mars Trojans larger than 1 km in diameter, providedthe relative motion perpendicular to Gaia’s CCD array is less than 0.40 arcsec persecond.Keywords: methods: numerical – methods: observational – minor planets, asteroids:general – planets and satellites: general – celestial mechanics 1 INTRODUCTIONTrojan asteroids are minor planets that share the orbit ofa planet about the Sun and librate around the L4 and L5Lagrangian points of stability. The L4 and L5 points are 60
15 citations
••
01 Dec 2016TL;DR: This paper analyzes how combinational rare conditions can be constructed in a systemic way, so that a Trojan circuit with a desired triggering probability can be synthesized accordingly and a watch list of Trojan candidatesCan be constructed according to the analysis.
Abstract: Hardware Trojans become a security threat to the integrated circuit supply chain. Detecting hardware Trojans is difficult as such circuits are stealthy in nature and triggered only under rare conditions. Traditional ATPG patterns are not useful for Trojan activation, and in general random patterns have to be applied for Trojan detection. In this paper we will first analyze how combinational rare conditions can be constructed in a systemic way, so that a Trojan circuit with a desired triggering probability can be synthesized accordingly. A watch list of Trojan candidates can be constructed according to the analysis. A set of test cubes can be generated from the candidates, and experimental results that the number of test cubes is restricted in most cases. The number of test vectors can be further reduced when physical layout information is taken into account. In addition, we can augment the test cubes with random assignment of X-bits to deal with addition trigger signals other than the target events. The results of this study should be helpful to the development of Trojan detection methods.
15 citations
••
02 Nov 2015TL;DR: A new type of Trojan is presented that leaks secret information from the design by only modifying unspecified functionality, meaning the Trojan is no longer restricted to being active only under rare conditions.
Abstract: Existing functional Trojan detection methodologies assume Trojans violate the design specification under carefully crafted rare triggering conditions. We present a new type of Trojan that leaks secret information from the design by only modifying unspecified functionality, meaning the Trojan is no longer restricted to being active only under rare conditions. We provide a method based on mutation testing for detecting this new Trojan type along with mutant ranking heuristics to prioritize analysis of the most dangerous functionality. Applying our method to a UART controller design, we discover unspecified and untested bus functionality with the potential to leak 32 bits of information during hundreds of cycles without being detected! Our method also reveals poorly tested interrupt functionality with information leakage potential. After modifying the specification and test bench to remove the discovered vulnerabilities, we close the verification loop by re-analyzing the design using our methodology and observe the functionality is no longer flagged as dangerous.
15 citations