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1
Kakkara, Varsha, Karthi Balasubramanian, B. Yamuna, Deepak Mishra, Karthikeyan Lingasubramanian, and Senthil Murugan. "A Viterbi decoder and its hardware Trojan models: an FPGA-based implementation study." PeerJ Computer Science 6 (March 2, 2020): e250. http://dx.doi.org/10.7717/peerj-cs.250.
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Integrated circuits may be vulnerable to hardware Trojan attacks during its design or fabrication phases. This article is a case study of the design of a Viterbi decoder and the effect of hardware Trojans on a coded communication system employing the Viterbi decoder. Design of a Viterbi decoder and possible hardware Trojan models for the same are proposed. An FPGA-based implementation of the decoder and the associated Trojan circuits have been discussed. The noise-added encoded input data stream is stored in the block RAM of the FPGA and the decoded data stream is monitored on the PC through an universal asynchronous receiver transmitter interface. The implementation results show that there is barely any change in the LUTs used (0.5%) and power dissipation (3%) due to the insertion of the proposed Trojan circuits, thus establishing the surreptitious nature of the Trojan. In spite of the fact that the Trojans cause negligible changes in the circuit parameters, there are significant changes in the bit error rate (BER) due to the presence of Trojans. In the absence of Trojans, BER drops down to zero for signal to noise rations (SNRs) higher than 6 dB, but with the presence of Trojans, BER doesn’t reduce to zero even at a very high SNRs. This is true even with the Trojan being activated only once during the entire duration of the transmission.
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Hazra, Suvadip, and Mamata Dalui. "CA-Based Detection of Coherence Exploiting Hardware Trojans." Journal of Circuits, Systems and Computers 29, no. 08 (October 18, 2019): 2050120. http://dx.doi.org/10.1142/s0218126620501200.
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Nowadays, Hardware Trojan threats have become inevitable due to the growing complexities of Integrated Circuits (ICs) as well as the current trend of Intellectual Property (IP)-based hardware designs. An adversary can insert a Hardware Trojan during any of its life cycle phases — the design, fabrication or even at manufacturing phase. Once a Trojan is inserted into a system, it can cause an unwanted modification to system functionality which may degrade system performance or sometimes Trojans are implanted with the target to leak secret information. Once Trojans are implanted, they are hard to detect and impossible to remove from the system as they are already fabricated into the chip. In this paper, we propose three stealthy Trojan models which affect the coherence mechanism of Chip Multiprocessors’ (CMPs) cache system by arbitrarily modifying the cache block state which in turn may leave the cache line states as incoherent. We have evaluated the payload of such modeled Trojans and proposed a cellular automaton (CA)-based solution for detection of such Trojans.
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Pirani, Simona, Anders Johansen, and Alexander J. Mustill. "On the inclinations of the Jupiter Trojans." Astronomy & Astrophysics 631 (October 25, 2019): A89. http://dx.doi.org/10.1051/0004-6361/201936600.
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Jupiter Trojans are a resonant asteroidal population characterised by photometric colours that are compatible with trans-Neptunian objects, high inclinations, and an asymmetric distribution of the number of asteroids between the two swarms. Different models have been proposed to explain the high inclination of the Trojans and to interpret their relation with the Trans-Neptunian objects, but none of these models can also satisfactorily explain the asymmetry ratio between the number of asteroids in the two swarms. It has recently been found that the asymmetry ratio can arise if Jupiter has migrated inwards through the protoplanetary disc by at least a few astronomical units during its growth. The more numerous population of the leading swarm and the dark photometric colours of the Trojans are natural outcomes of this new model, but simulations with massless unperturbed disc particles led to a flat distribution of the Trojan inclinations and a final total mass of the Trojans that was 3–4 orders of magnitude larger than the current mass. We here investigate the possible origin of the peculiar inclination distribution of the Trojans in the scenario where Jupiter migrates inwards. We analyse different possibilities: (a) the secular evolution of an initially flat Trojan population, (b) the presence of planetary embryos among the Trojans, and (c) capture of the Trojans from a pre-stirred planetesimal population in which Jupiter grows and migrates. We find that the secular evolution of the Trojans and secular perturbations from Saturn do not affect the inclination distribution of the Trojans appreciably, nor is there any significant mass depletion over the age of the Solar System. Embryos embedded in the Trojan swarms, in contrast, can stir the Trojans to their current degree of excitation and can also deplete the swarms efficiently, but it is very difficult to remove all of the massive bodies in 4.5 Gyr of evolution. We propose that the disc where Jupiter’s core was forming was already stirred to high inclination values by other planetary embryos competing in the feeding zone of Jupiter’s core. We show that the trapped Trojans preserve their high inclination through the gas phase of the protoplanetary disc and that Saturn’s perturbations are more effective on highly inclined Trojans, leading to a lower capture efficiency and to a substantial depletion of the swarms during 4.5 Gyr of evolution.
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Li, Dejian, Qizhi Zhang, Dongyan Zhao, Lei Li, Jiaji He, Yidong Yuan, and Yiqiang Zhao. "Hardware Trojan Detection Using Effective Property-Checking Method." Electronics 11, no. 17 (August 24, 2022): 2649. http://dx.doi.org/10.3390/electronics11172649.
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Hardware Trojans refer to additional logic maliciously implanted by attackers in integrated circuits (ICs). Because of the potential security threat of hardware Trojans, they have attracted extensive attention to security issues. As a formal verification method, property checking has been proved to be a powerful solution for hardware Trojan detection. However, existing property-checking methods are limited by the unity of security properties and the model explosion problem of formal models. The limitations above hinder the practical applications of these methods. To alleviate these challenges, we propose an effective property-checking method for hardware Trojan detection. Specifically, we establish the formal model based on the principle of finite state machine (FSM), and the method can alleviate the model explosion problem. For property writing, we extract the core behavior characteristics of hardware Trojans and then generate properties for the verification of certain types of hardware Trojans. Experimental results demonstrate that our approach is applicable to detect information leakage and denial of service (DoS) hardware Trojans by verifying security properties.
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Zhao, Meng Meng, and Lian Hai Wang. "Research on Trojan Detection Method of Computer Memory Mirroring." Applied Mechanics and Materials 701-702 (December 2014): 1013–17. http://dx.doi.org/10.4028/www.scientific.net/amm.701-702.1013.
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Trojan detection plays an important role in the discovery and treatment of Trojans. Acquisition and analysis of memory mirroring is a new research topic of computer live forensics. Computer forensics often need Trojan detection to determine whether target machine has been controlled. This paper proposed a Trojan detection method based on computer live forensics. Construct probabilistic fuzzy cognitive map(PFCM) through analysis of memory mirroring, use memory mirroring Trojan detection algorithm, calculate the probability of the existence of Trojan. The results showed that this method can effectively determine whether there were Trojan in memory mirroring. Detect Trojans through the analysis of various aspects of memory and numerical computation, proposed method improve the accuracy and reliability of Trojan detection.
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Napier, Kevin J., Larissa Markwardt, Fred C. Adams, David W. Gerdes, and Hsing Wen Lin. "A Collision Mechanism for the Removal of Earth's Trojan Asteroids." Planetary Science Journal 3, no. 5 (May 1, 2022): 121. http://dx.doi.org/10.3847/psj/ac6958.
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Abstract Due to their strong resonances with their host planet, Trojan asteroids can remain in stable orbits for billions of years. As a result, they are powerful probes for constraining the dynamical and chemical history of the solar system. Although we have detected thousands of Jupiter Trojans and dozens of Neptune Trojans, there are currently no known long-term stable Earth Trojans (ETs). Dynamical simulations show that the parameter space for stable ETs is substantial, so their apparent absence poses a mystery. This work uses a large ensemble of N-body simulations to explore how the Trojan population dynamically responds if Earth suffers large collisions, such as those thought to have occurred to form the Moon and/or to have given Earth its late veneer. We show that such collisions can be highly disruptive to the primordial Trojan population, and could have eliminated it altogether. More specifically, if Earth acquired the final 1% of its mass through ( 10 ) collisions, then only ∼1% of the previously bound Trojan population would remain.
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Wang, Lian Hai, and Qiu Liang Xu. "An APT Trojan Detection Method Based on Memory Forensics Techniques." Applied Mechanics and Materials 701-702 (December 2014): 927–34. http://dx.doi.org/10.4028/www.scientific.net/amm.701-702.927.
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Advanced Persistent Threat (APT) is currently reported to be one of the most serious threats. It is very important to detect the APT Trojan as early as possible. There are three types of approaches to conduct APT detection: network traffic analysis, change controlling and sandboxing. Unfortunately, all these approaches have limitations in detecting unknown APT Trojans. This paper proposes a novel APT Trojan detection method by utilizing memory forensics techniques. The proposed method first acquires the raw physical memory image from a target running system and then finds the APT’s traces in the memory image based on the ATP’s characteristics and memory forensics techniques. If enough traces are found, we can judge that there must be Trojans in the target system. Experimental results show that the proposed method can effectively detect new APT Trojans.
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Yoshikawa, Masaya, Yusuke Mori, and Takeshi Kumaki. "Implementation Aware Hardware Trojan Trigger." Advanced Materials Research 933 (May 2014): 482–86. http://dx.doi.org/10.4028/www.scientific.net/amr.933.482.
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Recently, the threat of hardware Trojans has garnered attention. Hardware Trojans are malicious circuits that are incorporated into large-scale integrations (LSIs) during the manufacturing process. When predetermined conditions specified by an attacker are satisfied, the hardware Trojan is triggered and performs subversive activities without the LSI users even being aware of these activities. In previous studies, a hardware Trojan was incorporated into a cryptographic circuit to estimate confidential information. However, Trojan triggers have seldom been studied. The present study develops several new Trojan triggers and each of them is embedded in a field-programmable gate array (FPGA). Subsequently, the ease of detection of each trigger is verified from the standpoint of area.
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Prathivi, Rastri, and Vensy Vydia. "ANALISA PENDETEKSIAN WORM dan TROJAN PADA JARINGAN INTERNET UNIVERSITAS SEMARANG MENGGUNAKAN METODE KALSIFIKASI PADA DATA MINING C45 dan BAYESIAN NETWORK." Jurnal Transformatika 14, no. 2 (January 30, 2017): 77. http://dx.doi.org/10.26623/transformatika.v14i2.440.
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<p>Worm attacks become a dangerous threat and cause damage in the Internet network. If the Internet network worms and trojan attacks the very disruption of traffic data as well as create bandwidth capacity has increased and wasted making the Internet connection is slow. Detecting worms and trojan on the Internet network, especially new variants of worms and trojans and worms and trojans hidden is still a challenging problem. Worm and trojan attacks generally occur in computer networks or the Internet which has a low level of security and vulnerable to infection. The detection and analysis of the worm and trojan attacks in the Internet network can be done by looking at the anomalies in Internet traffic and internet protocol addresses are accessed.<br />This research used experimental research applying C4.5 and Bayesian Network methods to accurately classify anomalies in network traffic internet. Analysis of classification is applied to an internet address, internet protocol and internet bandwidth that allegedly attacked and trojan worm attacks.<br />The results of this research is a result of analysis and classification of internet addresses, internet protocol and internet bandwidth to get the attack worms and trojans.</p>
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Rooney, Catherine, Amar Seeam, and Xavier Bellekens. "Creation and Detection of Hardware Trojans Using Non-Invasive Off-The-Shelf Technologies." Electronics 7, no. 7 (July 22, 2018): 124. http://dx.doi.org/10.3390/electronics7070124.
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As a result of the globalisation of the semiconductor design and fabrication processes, integrated circuits are becoming increasingly vulnerable to malicious attacks. The most concerning threats are hardware trojans. A hardware trojan is a malicious inclusion or alteration to the existing design of an integrated circuit, with the possible effects ranging from leakage of sensitive information to the complete destruction of the integrated circuit itself. While the majority of existing detection schemes focus on test-time, they all require expensive methodologies to detect hardware trojans. Off-the-shelf approaches have often been overlooked due to limited hardware resources and detection accuracy. With the advances in technologies and the democratisation of open-source hardware, however, these tools enable the detection of hardware trojans at reduced costs during or after production. In this manuscript, a hardware trojan is created and emulated on a consumer FPGA board. The experiments to detect the trojan in a dormant and active state are made using off-the-shelf technologies taking advantage of different techniques such as Power Analysis Reports, Side Channel Analysis and Thermal Measurements. Furthermore, multiple attempts to detect the trojan are demonstrated and benchmarked. Our simulations result in a state-of-the-art methodology to accurately detect the trojan in both dormant and active states using off-the-shelf hardware.
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Yao, Jiaqi, Ying Zhang, and Chen Xin. "Network-on-Chip hardware Trojan detection platform based on machine learning." Journal of Physics: Conference Series 2189, no. 1 (February 1, 2022): 012004. http://dx.doi.org/10.1088/1742-6596/2189/1/012004.
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Abstract The extensive use of the Network-on-Chip (NoC) architecture makes it vulnerable to malicious attacks by hardware Trojans, especially Denial of Service (DoS) attack. To address this issue, this paper proposes a general NoC hardware Trojan detection platform based on machine learning. The platform establishes a security detection module including traffic feature tracking unit, feature registration unit, change point detection unit, and random forest detection unit, to accomplish the traffic-related hardware Trojan detection. The live-lock and fault routing Trojans are inserted in the proposed platform, then the simulation results verify the effectiveness of platform function and show its superiority to other existing detection schemes.
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Ibrahim, Mohanad R., and Karam Thanoon. "Quasar Remote Access Trojan feature extraction depending on Ethical Hacking." Technium: Romanian Journal of Applied Sciences and Technology 4, no. 1 (January 27, 2022): 58–75. http://dx.doi.org/10.47577/technium.v4i1.5831.
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These days, computer Trojans had become in the top of the most dangerous types of malwares threats. There is a lot of remote access tools that have ability to manage and apply many features remotely. Quasar Trojan is one of the most uses for Remote Access Trojan (RAT). The researchers apply Quasar on real environment in lab (ethically and for education purposes) and this paper presents the capabilities of Trojans. This paper will present some of Quasar features by extract most important features also presents how to access remotely by using no-IP address (DUC) with other tools of applying access of internal network ethically.
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Yeager, Travis, and Nathan Golovich. "MEGASIM: Lifetimes and Resonances of Earth Trojan Asteroids—The Death of Primordial ETAs?" Astrophysical Journal 938, no. 1 (October 1, 2022): 9. http://dx.doi.org/10.3847/1538-4357/ac8e63.
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Abstract We present an analysis of lifetimes and resonances of Earth Trojan Asteroids (ETAs) in the MEGASIM data set. Trojan asteroids co-orbit the Sun with a planet, but remain bound to the Lagrange points, L4 (60° leading the planet) or L5 (60° trailing). In the circular three-body approximation, the stability of a Trojan asteroid depends on the ratio of the host planet mass and the central mass. For the inner planets, the range of stability becomes increasingly small, so perturbations from the planets have made primordial Trojans rare. To date, there have been just two ETAs (2010 TK7 and 2020 XL5), several Mars Trojans, and a Venus Trojan discovered. The estimated lifetimes of the known inner system Trojans are shorter than a million years, suggesting they are interlopers rather than members of a stable and long-lasting population. With the largest ETA n-body simulation to date, we are able to track their survival across a wide initialized parameter space. We find that the remaining fraction of ETAs over time is well fit with a stretched exponential function that, when extrapolated beyond our simulation run time, predicts zero ETAs by 2.33 Gyr. We also show correlations between ETA ejections and the periods of the Milankovitch cycles. Though Earth’s orbital dynamics dominate the instabilities of ETAs, we provide evidence that ETA ejections are linked to resonances found in the variation of the orbital elements of many if not all of the planets.
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Li, Jian, Hanlun Lei, and Zhihong J. Xia. "Apsidal asymmetric-alignment of Jupiter Trojans." Monthly Notices of the Royal Astronomical Society 505, no. 2 (May 10, 2021): 1730–41. http://dx.doi.org/10.1093/mnras/stab1333.
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ABSTRACT The most distant Kuiper belt objects exhibit the clustering in their orbits, and this anomalous architecture could be caused by Planet 9 with large eccentricity and high inclination. We then suppose that the orbital clustering of minor planets may be observed somewhere else in the Solar system. In this paper, we consider the over 7000 Jupiter Trojans from the Minor Planet Center, and find that they are clustered in the longitude of perihelion ϖ, around the locations ϖJ + 60○ and ϖJ − 60○ (ϖJ is the longitude of perihelion of Jupiter) for the L4 and L5 swarms, respectively. Then we build a Hamiltonian system to describe the associated dynamical aspects for the co-orbital motion. The phase space displays the existence of the apsidally aligned islands of libration centred on Δϖ = ϖ − ϖJ ≈ ±60○, for the Trojan-like orbits with eccentricities e < 0.1. Through a detailed analysis, we have shown that the observed Jupiter Trojans with proper eccentricities ep < 0.1 spend most of their time in the range of |Δϖ| = 0°–120○, while the more eccentric ones with ep > 0.1 are too few to affect the orbital clustering within this Δϖ range for the entire Trojan population. Our numerical results further prove that, even starting from a uniform Δϖ distribution, the apsidal alignment of simulated Trojans similar to the observation can appear on the order of the age of the Solar system. We conclude that the apsidal asymmetric-alignment of Jupiter Trojans is robust, and this new finding can be helpful to design the survey strategy in the future.
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Érdi, B. "On the dynamics of Trojan asteroids." Symposium - International Astronomical Union 172 (1996): 171–76. http://dx.doi.org/10.1017/s0074180900127305.
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The author's theory of Trojan asteroids (Érdi, 1988) is developed further. The motion of the Trojans is considered in the framework of the three-dimensional elliptic restricted three-body problem of the Sun-Jupiter-asteroid system including also the secular changes of Jupiter's orbital eccentricity and the apsidal motion of Jupiter's elliptic orbit. An asymptotic solution is derived, by applying the multiple-timescale method, for the cylindrical coordinates of the asteriods and for the perturbations of the orbital elements. This solution is used for the analysis of the long-time dynamical behaviour of the perihelion and the eccentricity of the Trojans.
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Li, J., and Y. S. Sun. "Constructing a refined model of small bodies in the solar system." Astronomy & Astrophysics 616 (August 2018): A70. http://dx.doi.org/10.1051/0004-6361/201832809.
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Aims. We construct a new arc model to represent the global perturbation induced by the Jupiter Trojans for the development of the modern planetary ephemerides. Methods. The Jupiter Trojans are divided into two groups: (1) the 226 biggest ones with absolute magnitudes H < 11, have well determined masses and are treated as individual bodies; (2) the remaining small ones with H ≥ 11, are modeled by two discrete arcs centered at Jupiter’s L4 and L5 points, respectively. Then we derived the parameters characterizing the arcs, such as the total mass, the mass ratio, and the spatial distributions. Uncertainties on the fitted parameters have also been taken into account. Results. We find that the total mass of all the Jupiter Trojans, including the undiscovered ones, is most likely about 1.861 × 10−5 Earth mass. Then the global perturbation of the trojan population induced on the Earth–Mars distance is numerically estimated to be about 70 m during the 2014–2114 time interval. We also give a simple analytic expression. For the satellites of Mars and Jupiter, however, the change of the distance between the Earth and a satellite can be much more significant, reaching on tens of thousands of meters over one century, due to perturbations of the Jupiter Trojans.
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Burger, Ch, E. Pilat-Lohinger, R. Dvorak, and A. Christaki. "Proper Elements and Stability of The Trojan Asteroids." International Astronomical Union Colloquium 172 (1999): 375–76. http://dx.doi.org/10.1017/s025292110007278x.
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Up to now ~ 400 asteroids are known which move close to the Lagrangian equilibrium points L4 (246) and L5 (167) of Jupiter. In this investigation the orbits of all known Trojans were integrated numerically for 10 million years using the Lie Series integrator with adaptive stepsize (Hanslmeier and Dvorak, 1984) in the dynamical model of the outer planetary system. The goal of the study was to extend the computation of the proper elements for all known Trojans for a longer time interval; the respective results are compared to already existing ones (e.g. Bien & Schubart, 1987; Milani, 1993).The determination of the characteristic quantities proper eccentricity ep, proper inclination ip and libration D was done by numerical filtering techniques using the method of Labrouste (Burger, 1998) and by a very precise frequency analysis (Chapront, 1997). Our results differ from the ones calculated for a shorter time interval by Milani (1993) between 5% and 10%. In Fig.1 we plotted the nomogram for the three proper elements mentioned above for L4 and the ep for L5. As a new interesting result we found Trojans with 0.15 < ep < 0.22 for L4 (upper left) and L5 (upper right) which answers an open question of an existing gap in this range of the ep. For L4 Trojans there is a well defined maximum in the nomogram for ep ∼ 0.06; for the L5 Trojans the maximum is flat and shifted versus ep ∼ 0.07. The proper elements sin(ip) for L4 (bottom left graph) show a maximum for Trojans moving in the plane of Jupiter’s orbit and a decrease versus larger inclinations, although a plateau for 14° < i < 27° is visible; this confirms that the Trojan orbits are more inclined that the orbits of the main belt asteroids.
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Holt, Timothy R., David Vokrouhlický, David Nesvorný, Miroslav Brož, and Jonathan Horner. "A pair of Jovian Trojans at the L4 Lagrange point." Monthly Notices of the Royal Astronomical Society 499, no. 3 (October 6, 2020): 3630–49. http://dx.doi.org/10.1093/mnras/staa3064.
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ABSTRACT Asteroid pairs, two objects that are not gravitationally bound to one another, but share a common origin, have been discovered in the Main belt and Hungaria populations. Such pairs are of major interest, as the study of their evolution under a variety of dynamical influences can indicate the time since the pair was created. To date, no asteroid pairs have been found in the Jovian Trojans, despite the presence of several binaries and collisional families in the population. The search for pairs in the Jovian Trojan population is of particular interest, given the importance of the Trojans as tracers of planetary migration during the Solar system’s youth. Here we report a discovery of the first pair, (258656) 2002 ES76 and 2013 CC41, in the Jovian Trojans. The two objects are approximately the same size and are located very close to the L4 Lagrange point. Using numerical integrations, we find that the pair is at least 360 Myr old, though its age could be as high as several Gyrs. The existence of the (258656) 2002 ES76–2013 CC41 pair implies there could be many such pairs scattered through the Trojan population. Our preferred formation mechanism for the newly discovered pair is through the dissociation of an ancient binary system, triggered by a sub-catastrophic impact, but we can not rule out rotation fission of a single object driven by YORP torques. A by-product of our work is an up-to-date catalogue of Jovian Trojan proper elements, which we have made available for further studies.
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Bajcsy, Peter, Nicholas J. Schaub, and Michael Majurski. "Designing Trojan Detectors in Neural Networks Using Interactive Simulations." Applied Sciences 11, no. 4 (February 20, 2021): 1865. http://dx.doi.org/10.3390/app11041865.
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This paper addresses the problem of designing trojan detectors in neural networks (NNs) using interactive simulations. Trojans in NNs are defined as triggers in inputs that cause misclassification of such inputs into a class (or classes) unintended by the design of a NN-based model. The goal of our work is to understand encodings of a variety of trojan types in fully connected layers of neural networks. Our approach is: (1) to simulate nine types of trojan embeddings into dot patterns; (2) to devise measurements of NN states; and (3) to design trojan detectors in NN-based classification models. The interactive simulations are built on top of TensorFlow Playground with in-memory storage of data and NN coefficients. The simulations provide analytical, visualization, and output operations performed on training datasets and NN architectures. The measurements of a NN include: (a) model inefficiency using modified Kullback–Liebler (KL) divergence from uniformly distributed states; and (b) model sensitivity to variables related to data and NNs. Using the KL divergence measurements at each NN layer and per each predicted class label, a trojan detector is devised to discriminate NN models with or without trojans. To document robustness of such a trojan detector with respect to NN architectures, dataset perturbations, and trojan types, several properties of the KL divergence measurement are presented.
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Milani, Andrea. "The Dynamics of the Trojan Asteroids." Symposium - International Astronomical Union 160 (1994): 159–74. http://dx.doi.org/10.1017/s0074180900046520.
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The state of the art in the dynamics of the Trojan asteroids has progressed rapidly, since it has been possible to perform numerical integrations of many orbits for millions of years. Accurate proper elements are now computed by the synthetic method, that is from the output of a numerical integration; their stability, at least for time spans of a few million years, is good. This has allowed identification of Trojan families with an automated procedure closely mimicking the one used in the main belt. Although the families identified in a reliable way are only four, the occurrence of significant collisional evolution, not unlike that of the main belt, can be confirmed. The dynamical structure of the Trojan cloud, including the location of the main secular resonances, can be deduced from the proper elements and frequencies by a simple fit. However, many problems are not solved: the origin of a significant percentage of chaotic orbits showing no indications of instability; the location of the stability boundary of the Trojan cloud; the origin of the high inclination of most Trojans. We also do not know if there are “Trojans” for some other planets beside Jupiter: only one Mars Trojan has been found.
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Timis, Grigore Mihai, and Alexandru Valachi. "Classification overview of the Hardware Trojans in digital circuits." Annals of “Dunarea de Jos“ University of Galati. Fascicle III, Electrotechnics, Electronics, Automatic Control, Informatics 43, no. 3 (December 29, 2020): 12–15. http://dx.doi.org/10.35219/eeaci.2020.3.02.
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This paper presents an overview of the Hardware Trojans classification methods. A malicious entity can introduce a Hardware Trojan (HT) into a design in order to denial of service, destroy or disable the system. Moreover, it could leak the confidential information and the secret keys before altered them. The Hardware Trojan (HT) threats should be analyzed with maximum importance through the entire lifecycle of the integrated circuit (ICs). A hardware protection against the detected harmful logic should also be implemented.
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Amelian, Atieh, and Shahram Etemadi Borujeni. "A Side-Channel Analysis for Hardware Trojan Detection Based on Path Delay Measurement." Journal of Circuits, Systems and Computers 27, no. 09 (April 26, 2018): 1850138. http://dx.doi.org/10.1142/s0218126618501384.
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Hardware Trojan Horses (HTHs) are malicious modifications inserted in Integrated Circuit during fabrication steps. The HTHs are very small and can cause damages in circuit function. They cannot be detected by conventional testing methods. Due to dangerous effects of them, Hardware Trojan Detection has become a major concern in hardware security. In this paper, a new HTH detection method is presented based on side-channel analysis that uses path delay measurement. In this method, we find and observe the paths that Trojans have most effect on them. Most of the previous works add some structures to the circuit and need a large overhead cost. But, in our method, there is no modification in the circuit and we can use it for testing the circuits received after fabrication. The proposed method is evaluated with Xilinx FPGA over a number of test circuits. The results show that measuring the delays on 20 paths with an accuracy of 0.01[Formula: see text]ns can detect more than 80% of Trojans.
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Dvorak, Rudolf, Li-Yong Zhou, and Helmut Baudisch. "Trojans in Exosystems with Two Massive Planets." Proceedings of the International Astronomical Union 8, S293 (August 2012): 152–58. http://dx.doi.org/10.1017/s1743921313012726.
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AbstractWe take as dynamical model for extrasolar planetary systems a central star like our Sun and two giant planets m1 and m2 like Jupiter and Saturn. We change the mass ratio μ=m2/m1 of the two large planets for a wide range of 1/16 < μ < 16. We also change the ratio between the initial semi-major axes (ν=a2/a1) in the range of 1.2 < ν < 3 to model the different architecture of extrasolar planetary systems hosting two giant planets. The results for possible Trojans (Trojan planets) in the equilateral equilibrium points of the inner planet m1 and the outer planet m2 were derived with the aid of numerical integration. It turned out that in many configurations – depending on the mass ratios μ and the semi-major axes ratio ν – giant planets may host Trojans.
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Maier, Felix K. "THE ALAMANNIC WAR WILL NOT TAKE PLACE—CONSTANTIUS’ II OPERATION AGAINST THE ALAMANNI IN 354." Classical Quarterly 68, no. 2 (October 23, 2018): 649–59. http://dx.doi.org/10.1017/s0009838818000356.
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In his playThe Trojan War will not take place(1955), French novelist and diplomat Jean Giraudoux has his protagonist Hector struggle tremendously with convincing both Trojans and Greeks alike to prevent the looming war. Despite coming very close to negotiating a truce, Hector fails in the end owing to the belligerent aspirations of some other protagonists led by the Trojan poet Demokos. Cassandra's famous final line, ‘war cannot be avoided’, comes true and, in contrast to the title of the play, the Trojan War does indeed take place.
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ABDULSALAM, Kadeejah, John ADEBISI, and Victor DUROJAIYE. "IMPLEMENTATION OF A HARDWARE TROJAN CHIP DETECTOR MODEL USING ARDUINO MICROCONTROLLER." Applied Computer Science 17, no. 4 (December 30, 2021): 20–33. http://dx.doi.org/10.35784/acs-2021-26.
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These days, hardware devices and its associated activities are greatly impacted by threats amidst of various technologies. Hardware trojans are malicious modifications made to the circuitry of an integrated circuit, Exploiting such alterations and accessing the level of damage to devices is considered in this work. These trojans, when present in sensitive hardware system deployment, tends to have potential damage and infection to the system. This research builds a hardware trojan detector using machine learning techniques. The work uses a combination of logic testing and power side-channel analysis (SCA) coupled with machine learning for power traces. The model was trained, validated and tested using the acquired data, for 5 epochs. Preliminary logic tests were conducted on target hardware device as well as power SCA. The designed machine learning model was implemented using Arduino microcontroller and result showed that the hardware trojan detector identifies trojan chips with a reliable accuracy. The power consumption readings of the hardware characteristically start at 1035-1040mW and the power time-series data were simulated using DC power measurements mixed with additive white Gaussian noise (AWGN) with different standard deviations. The model achieves accuracy, precision and accurate recall values. Setting the threshold proba¬bility for the trojan class less than 0.5 however increases the recall, which is the most important metric for overall accuracy acheivement of over 95 percent after several epochs of training.
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Horner, J., and P. S. Lykawka. "Planetary Trojans – the main source of short period comets?" International Journal of Astrobiology 9, no. 4 (July 27, 2010): 227–34. http://dx.doi.org/10.1017/s1473550410000212.
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AbstractOne of the key considerations when assessing the potential habitability of telluric worlds will be that of the impact regime experienced by the planet. In this work, we present a short review of our understanding of the impact regime experienced by the terrestrial planets within our own Solar system, describing the three populations of potentially hazardous objects which move on orbits that take them through the inner Solar system. Of these populations, the origins of two (the Near-Earth Asteroids and the Long-Period Comets) are well understood, with members originating in the Asteroid belt and Oort cloud, respectively. By contrast, the source of the third population, the Short-Period Comets, is still under debate. The proximate source of these objects is the Centaurs, a population of dynamically unstable objects that pass perihelion (closest approach to the Sun) between the orbits of Jupiter and Neptune. However, a variety of different origins have been suggested for the Centaur population. Here, we present evidence that at least a significant fraction of the Centaur population can be sourced from the planetary Trojan clouds, stable reservoirs of objects moving in 1:1 mean-motion resonance with the giant planets (primarily Jupiter and Neptune). Focussing on simulations of the Neptunian Trojan population, we show that an ongoing flux of objects should be leaving that region to move on orbits within the Centaur population. With conservative estimates of the flux from the Neptunian Trojan clouds, we show that their contribution to that population could be of order ~3%, while more realistic estimates suggest that the Neptune Trojans could even be the main source of fresh Centaurs. We suggest that further observational work is needed to constrain the contribution made by the Neptune Trojans to the ongoing flux of material to the inner Solar system, and believe that future studies of the habitability of exoplanetary systems should take care not to neglect the contribution of resonant objects (such as planetary Trojans) to the impact flux that could be experienced by potentially habitable worlds.
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Wong, Ian, and Michael E. Brown. "Photometric Confirmation and Characterization of the Ennomos Collisional Family in the Jupiter Trojans." Astronomical Journal 165, no. 1 (December 16, 2022): 15. http://dx.doi.org/10.3847/1538-3881/ac9eb3.
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Abstract Collisional families offer a unique window into the interior composition of asteroid populations. Previous dynamical studies of the Jupiter Trojans have uncovered a handful of potential collisional families, two of which have been subsequently confirmed through spectral characterization. In this paper, we present new multiband photometric observations of the proposed Ennomos family and derive precise g − i colors of 75 candidate family members. While the majority of the targets have visible colors that are indistinguishable from background objects, we identify 13 objects with closely grouped dynamical properties that have significantly bluer colors. We determine that the true Ennomos collisional family is tightly confined to a ′ p > 5.29 au and 0.45 < sin i p < 0.47 , and the majority of its confirmed members have near-solar spectral slopes, including some of the bluest objects hitherto discovered in the Trojan population. The property of distinctly neutral colors that is shared by both the Ennomos family and the previously characterized Eurybates family indicates that the spectral properties of freshly exposed surfaces in the Jupiter region are markedly different than the surfaces of uncollided Trojans. This implies that the processes of ice sublimation and space weathering at 5.2 au yield a distinct regolith chemistry from the primordial environment within which the Trojans were initially accreted. It also suggests that the Trojans were emplaced in their present-day location from elsewhere sometime after the initial population formed, which is a key prediction of recent dynamical instability models of solar system evolution.
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Simpson, Anna M., Michael E. Brown, Madeline J. Schemel, and Bryan J. Butler. "An ALMA Search for High-albedo Objects Among the Midsized Jupiter Trojan Population." Astronomical Journal 164, no. 1 (June 28, 2022): 23. http://dx.doi.org/10.3847/1538-3881/ac559e.
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Abstract We use Atacama Large Millimeter Array (ALMA) measurements of 870 μm thermal emission from a sample of midsized (15–40 km diameter) Jupiter Trojan asteroids to search for high-albedo objects in this population. We calculate the diameters and albedos of each object using a thermal model which also incorporates contemporaneous Zwicky Transient Facility photometry to accurately measure the absolute magnitude at the time of the ALMA observation. We find that while many albedos are lower than reported from WISE, several small Trojans have high albedos independently measured both from ALMA and from WISE. The number of these high-albedo objects is approximately consistent with expectations of the number of objects that recently have undergone large-scale impacts, suggesting that the interiors of freshly-crated Jupiter Trojans could contain high-albedo materials such as ices.
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Yin, Khin Swe, and May Aye Khine. "Optimal remote access trojans detection based on network behavior." International Journal of Electrical and Computer Engineering (IJECE) 9, no. 3 (June 1, 2019): 2177. http://dx.doi.org/10.11591/ijece.v9i3.pp2177-2184.
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<p>RAT is one of the most infected malware in the hyper-connected world. Data is being leaked or disclosed every day because new remote access Trojans are emerging and they are used to steal confidential data from target hosts. Network behavior-based detection has been used to provide an effective detection model for Remote Access Trojans. However, there is still short comings: to detect as early as possible, some False Negative Rate and accuracy that may vary depending on ratio of normal and malicious RAT sessions. As typical network contains large amount of normal traffic and small amount of malicious traffic, the detection model was built based on the different ratio of normal and malicious sessions in previous works. At that time false negative rate is less than 2%, and it varies depending on different ratio of normal and malicious instances. An unbalanced dataset will bias the prediction model towards the more common class. In this paper, each RAT is run many times in order to capture variant behavior of a Remote Access Trojan in the early stage, and balanced instances of normal applications and Remote Access Trojans are used for detection model. Our approach achieves 99 % accuracy and 0.3% False Negative Rate by Random Forest Algorithm.</p>
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Xiao, K., D. Forte, Y. Jin, R. Karri, S. Bhunia, and M. Tehranipoor. "Hardware Trojans." ACM Transactions on Design Automation of Electronic Systems 22, no. 1 (December 28, 2016): 1–23. http://dx.doi.org/10.1145/2906147.
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Duke, David. "Downloader Trojans." Network Security 2002, no. 11 (November 2002): 4–5. http://dx.doi.org/10.1016/s1353-4858(02)11006-3.
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Timiş, Grigore Mihai, and Alexandru Valachi. "Triggering detection technique of the hardware trojans in the combinational logic systems." Annals of “Dunarea de Jos“ University of Galati. Fascicle III, Electrotechnics, Electronics, Automatic Control, Informatics 44, no. 1 (February 22, 2022): 23–28. http://dx.doi.org/10.35219/eeaci.2021.1.04.
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This paper presents a new triggering detection method of the Hardware Trojans in the combinational logic systems, using static hazard analysis. A malicious entity can introduce a Hardware Trojan (HT) into a design in order to denial of service, destroy or disable the system. Moreover, it could leak the confidential information and the secret keys before altered them. The Hardware Trojan (HT) threats should be analyzed with maximum importance through the entire lifecycle of the integrated circuit (ICs). A hardware protection against the detected harmful logic should also be implemented.
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Zhou, Lei, Yang-Bo Xu, Li-Yong Zhou, Rudolf Dvorak, and Jian Li. "Orbital stability of Earth Trojans." Astronomy & Astrophysics 622 (February 2019): A97. http://dx.doi.org/10.1051/0004-6361/201834026.
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The only discovery of Earth Trojan 2010 TK7 and the subsequent launch of OSIRIS-REx have motived us to investigate the stability around the triangular Lagrange points of the Earth, L4 and L5. In this paper we present detailed dynamical maps on the (a0, i0) plane with the spectral number (SN) indicating the stability. Two main stability regions, separated by a chaotic region arising from the ν3 and ν4 secular resonances, are found at low (i0 ≤ 15°) and moderate (24 ° ≤i0 ≤ 37°) inclinations, respectively. The most stable orbits reside below i0 = 10° and they can survive the age of the solar system. The nodal secular resonance ν13 could vary the inclinations from 0° to ∼10° according to their initial values, while ν14 could pump up the inclinations to ∼20° and upwards. The fine structures in the dynamical maps are related to higher degree secular resonances, of which different types dominate different areas. The dynamical behaviour of the tadpole and horseshoe orbits, reflected in their secular precession, show great differences in the frequency space. The secular resonances involving the tadpole orbits are more sensitive to the frequency drift of the inner planets, thus the instabilities could sweep across the phase space, leading to the clearance of tadpole orbits. We are more likely to find terrestrial companions on horseshoe orbits. The Yarkovsky effect could destabilize Earth Trojans in varying degrees. We numerically obtain the formula describing the stabilities affected by the Yarkovsky effect and find the asymmetry between the prograde and retrograde rotating Earth Trojans. The existence of small primordial Earth Trojans that avoid being detected but survive the Yarkovsky effect for 4.5 Gyr is substantially ruled out.
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Reddy, Varun, and Nirmala Devi M. "FPGA Realization of Deep Neural Network for Hardware Trojan Detection." International Journal of Engineering & Technology 9, no. 3 (August 30, 2020): 764. http://dx.doi.org/10.14419/ijet.v9i3.30946.
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With the increase in outsourcing design and fabrication, malicious third-party vendors often insert hardware Trojan (HT) in the integrated Circuits(IC). It is difficult to identify these Trojans since the nature and characteristics of each Trojan differ significantly. Any method developed for HT detection is limited by its capacity on dealing with varied types of Trojans. The main purpose of this study is to show using deep learning (DL), this problem can be dealt with some extent and the effect of deep neural network (DNN) when it is realized on field programmable gate array (FPGA). In this paper, we propose a comparison of accuracy in finding faults on ISCAS’85 benchmark circuits between random forest classifier and DNN. Further for the faster processing time and less power consumption, the network is implemented on FPGA. The results show the performance of deep neural network gets better when a large number of nets are used and faster in the execution of the algorithm. Also, the speedup of the neuron is 100x times better when implemented on FPGA with 15.32% of resource utilization and provides less power consumption than GPU.
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Jain, Ayush, Ziqi Zhou, and Ujjwal Guin. "TAAL." ACM Transactions on Design Automation of Electronic Systems 26, no. 4 (April 2021): 1–22. http://dx.doi.org/10.1145/3442379.
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Due to the globalization of semiconductor manufacturing and test processes, the system-on-a-chip (SoC) designers no longer design the complete SoC and manufacture chips on their own. This outsourcing of the design and manufacturing of Integrated Circuits (ICs) has resulted in several threats, such as overproduction of ICs, sale of out-of-specification/rejected ICs, and piracy of Intellectual Properties (IPs). Logic locking has emerged as a promising defense strategy against these threats. However, various attacks about the extraction of secret keys have undermined the security of logic locking techniques. Over the years, researchers have proposed different techniques to prevent existing attacks. In this article, we propose a novel attack that can break any logic locking techniques that rely on the stored secret key. This proposed TAAL attack is based on implanting a hardware Trojan in the netlist, which leaks the secret key to an adversary once activated. As an untrusted foundry can extract the netlist of a design from the layout/mask information, it is feasible to implement such a hardware Trojan. All three proposed types of TAAL attacks can be used for extracting secret keys. We have introduced the models for both the combinational and sequential hardware Trojans that evade manufacturing tests. An adversary only needs to choose one hardware Trojan out of a large set of all possible Trojans to launch the TAAL attack.
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Lillo-Box, J., A. Leleu, H. Parviainen, P. Figueira, M. Mallonn, A. C. M. Correia, N. C. Santos, et al. "The TROY project." Astronomy & Astrophysics 618 (October 2018): A42. http://dx.doi.org/10.1051/0004-6361/201833312.
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Context.Co-orbital bodies are the byproduct of planet formation and evolution, as we know from the solar system. Although planet-size co-orbitals do not exists in our planetary system, dynamical studies show that they can remain stable for long periods of time in the gravitational well of massive planets. Should they exist, their detection is feasible with the current instrumentation.Aims.In this paper, we present new ground-based observations searching for these bodies co-orbiting with nine close-in (P< 5 days) planets, using various observing techniques. The combination of all of these techniques allows us to restrict the parameter space of any possible trojan in the system.Methods.We used multi-technique observations, comprised of radial velocity, precision photometry, and transit timing variations, both newly acquired in the context of the TROY project and publicly available, to constrain the presence of planet-size trojans in the Lagrangian points of nine known exoplanets.Results.We find no clear evidence of trojans in these nine systems through any of the techniques used down to the precision of the observations. However, this allows us to constrain the presence of any potential trojan in the system, especially in the trojan mass or radius vs. libration amplitude plane. In particular, we can set upper mass limits in the super-Earth mass regime for six of the studied systems.
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Sheppard, Scott S., and Chadwick A. Trujillo. "Detection of a Trailing (L5) Neptune Trojan: Fig. 1." Science 329, no. 5997 (August 12, 2010): 1304. http://dx.doi.org/10.1126/science.1189666.
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The orbits of small Solar System bodies record the history of our Solar System. Here, we report the detection of 2008 LC18, which is a Neptune Trojan in the trailing (L5) Lagrangian region of gravitational equilibrium within Neptune’s orbit. We estimate that the leading and trailing Neptune Trojan regions have similarly sized populations and dynamics, with both regions dominated by high-inclination objects. Similar populations and dynamics at both Neptune Lagrangian regions indicate that the Trojans were likely captured by a migrating, eccentric Neptune in a dynamically excited planetesimal population.
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Pan, Jiaming, Hsing Wen Lin, David W. Gerdes, Kevin J. Napier, Jichi Wang, T. M. C. Abbott, M. Aguena, et al. "Photometric Properties of Jupiter Trojans Detected by the Dark Energy Survey." Planetary Science Journal 3, no. 12 (December 1, 2022): 269. http://dx.doi.org/10.3847/psj/aca4d1.
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Abstract The Jupiter Trojans are a large group of asteroids that are coorbiting with Jupiter near its L4 and L5 Lagrange points. The study of Jupiter Trojans is crucial for testing different models of planet formation that are directly related to our understanding of solar system evolution. In this work, we select known Jupiter Trojans listed by the Minor Planet Center from the full six years data set (Y6) of the Dark Energy Survey (DES) to analyze their photometric properties. The DES data allow us to study Jupiter Trojans with a fainter magnitude limit than previous studies in a homogeneous survey with griz band measurements. We extract a final catalog of 573 unique Jupiter Trojans. Our sample include 547 asteroids belonging to L5. This is one of the largest analyzed samples for this group. By comparing with the data reported by other surveys we found that the color distribution of L5 Trojans is similar to that of L4 Trojans. We find that L5 Trojans’ g − i and g − r colors become less red with fainter absolute magnitudes, a trend also seen in L4 Trojans. Both the L4 and L5 clouds consistently show such a color–size correlation over an absolute magnitude range 11 < H < 18. We also use DES colors to perform taxonomic classifications. C- and P-type asteroids outnumber D-type asteroids in the L5 Trojans DES sample, which have diameters in the 5–20 km range. This is consistent with the color–size correlation.
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Holt, Timothy R., David Nesvorný, Jonathan Horner, Rachel King, Raphael Marschall, Melissa Kamrowski, Brad Carter, Leigh Brookshaw, and Christopher Tylor. "Stability of Jovian Trojans and their collisional families." Monthly Notices of the Royal Astronomical Society 495, no. 4 (May 15, 2020): 4085–97. http://dx.doi.org/10.1093/mnras/staa1348.
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ABSTRACT The Jovian Trojans are two swarms of objects located around the L4 and L5 Lagrange points. The population is thought to have been captured by Jupiter during the Solar system’s youth. Within the swarms, six collisional families have been identified in previous work, with four in the L4 swarm, and two in the L5. Our aim is to investigate the stability of the two Trojan swarms, with a particular focus on these collisional families. We find that the members of Trojan swarms escape the population at a linear rate, with the primordial L4 (23.35 per cent escape) and L5 (24.89 per cent escape) population sizes likely 1.31 and 1.35 times larger than today. Given that the escape rates were approximately equal between the two Trojan swarms, our results do not explain the observed asymmetry between the two groups, suggesting that the numerical differences are primordial in nature, supporting previous studies. Upon leaving the Trojan population, the escaped objects move on to orbits that resemble those of the Centaur and short-period comet populations. Within the Trojan collisional families, the 1996 RJ and 2001 UV209 families are found to be dynamically stable over the lifetime of the Solar system, whilst the Hektor, Arkesilos and Ennomos families exhibit various degrees of instability. The larger Eurybates family shows 18.81 per cent of simulated members escaping the Trojan population. Unlike the L4 swarm, the escape rate from the Eurybates family is found to increase as a function of time, allowing an age estimation of approximately 1.045 ± 0.364 × 109 yr.
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Kazantsev, A., and L. Kazantseva. "On a possibility of transfer of the planet troyans to centaurs." Bulletin of Taras Shevchenko National University of Kyiv. Astronomy, no. 62 (2020): 20–23. http://dx.doi.org/10.17721/btsnua.2020.62.20-23.
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Jupiter Trojans and Neptune Trojans have been selected from the Minor Planet center catalog for 2020. Numerical calculations of the evolution of orbits on intervals of up to 1 million years have been carried out. It has been established that all discovered by today Neptune Trojans and the numbered Jupiter Trojans are unlikely to transfer into the Centaur population during the next hundreds of thousands of years.
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Sun, Hai Tao, Jie Liu, Zhong Peng Liu, and Xun Lai He. "Design of Hardware Trojan Applying on Cryptogrammic-Board for PC." Advanced Materials Research 717 (July 2013): 794–96. http://dx.doi.org/10.4028/www.scientific.net/amr.717.794.
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The vulnerabilities in todays design and fabrication process have raised the possibility of malicious circuit modification as known as Trojans in a design to impact the functionality or transmit key information to the adversary. In this article the authors design a Hardware Trojan of transmitting key information towards FPGA. It is important to realize the implement mechanism and raise the attention to IC security.
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Lu, Yong Qiang, Fang Yong, and He Xiang. "The Research on Hybrid Communication Model for Trojan Based on P2P." Advanced Materials Research 791-793 (September 2013): 2038–42. http://dx.doi.org/10.4028/www.scientific.net/amr.791-793.2038.
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Direct connection and reflective connection are commonly used in traditional Trojans communication model, which have some significant deficiencies in hiding, anti-tracking, and efficiency. To improve the aspects above in traditional Trojan horse communication model, the author proposed a hybrid communication model based on P2P technology. The model uses P2P intranet penetration protocol to build the channel between the controlled station and the control station, and uses P2P node servers for saving the Trojans status and transferring some data between the controlled and the control. The topology of networks for controller will be very flexible. Using the IP traceback technology will be difficult to track the controllers. Using UDP protocol in the hybrid communication model for data transmission will hide the network status. Control sites can work in distributed mode. By using the model, the hiding-ability, anti-traceability and communication efficiency will be greatly improved.
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Maschall, Raphael, David Nesvorný, Rogerio Deienno, Ian Wong, Harold F. Levison, and William F. Bottke. "Implications for the Collisional Strength of Jupiter Trojans from the Eurybates Family." Astronomical Journal 164, no. 4 (September 29, 2022): 167. http://dx.doi.org/10.3847/1538-3881/ac8d6b.
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Abstract In this work, we model the collisional evolution of the Jupiter Trojans and determine under which conditions the Eurybates-Queta system survives. We show that the collisional strength of the Jupiter Trojans and the age of the Eurybates family and by extension Queta are correlated. The collisional grinding of the Jupiter Trojan population over 4.5 Gy results in a size–frequency distribution (SFD) that remains largely unaltered at large sizes (>10 km) but is depleted at small sizes (10 m to 1 km). This results in a turnover in the SFD, the location of which depends on the collisional strength of the material. It is to be expected that the Trojan SFD bends between 1 and 10 km. Based on the SFD of the Eurybates family, we find that the family was likely the result of a catastrophic impact onto a 100 km rubble pile target. This corresponds to objects with a rather low collisional strength (10 times weaker than that of basaltic material studied in Benz & Asphaug). Assuming this weak strength, and an initial cumulative slope of the size–frequency distribution of 2.1 between diameters of 2 m and 100 km when the Trojans were captured, the existence of Queta, the satellite of Eurybates, implies an upper limit for the family age of 3.7 Gy. Alternatively, we demonstrate that an unconventional collisional strength with a minimum at 20 m is a plausible candidate to ensure the survival of Queta over the age of the solar system. Finally, we show how different collisional histories change the expected number of craters on the targets of the Lucy mission and that Lucy will be able to differentiate between them.
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Qi, Yi, and Anton de Ruiter. "Orbital analysis of small bodies in co-orbital motion with Jupiter through the torus structure." Monthly Notices of the Royal Astronomical Society 502, no. 2 (January 11, 2021): 2183–97. http://dx.doi.org/10.1093/mnras/stab063.
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ABSTRACT In this paper, based on the torus structure, we investigate the orbital characteristics of Jupiter Trojans and Jupiter-family comets (JFCs) in co-orbital motion with Jupiter. The motivation of this paper is to test whether the semi-analytical approach and conclusions of the torus structure proposed in the circular restricted three-body problem are still valid for real small bodies in the ephemeris model, and how long they follow the prediction of the semi-analytical approach. Based on the topological structure of the co-orbital motion in the torus space, we propose a method for estimating the libration amplitude for Trojans. 873 Jupiter Trojans with well-determined orbits are picked as examples to demonstrate the validity of our estimation method. Numerical analysis reveals that the difference between the osculating semimajor axes of the Trojan and Jupiter can influence the accuracy of our estimation method significantly. Based on the semi-analytical approach, we predict orbital behaviours of three JFCs, 85P/Boethin, P/2012 US27 (Siding Spring), and P/2019 A1 (PANSTARRS). Numerical integration in the ephemeris model indicates that their real orbital behaviours are consistent with our predictions. In particular, we find that the current quasi-satellite state of P/2012 US27 (Siding Spring) can remain for about 1.5 × 105 yr, much longer than those that correspond to other previously reported QS companions of Jupiter.
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Mackie, C. J. "Zeus and Mount Ida in Homer’s Iliad." Antichthon 48 (2014): 1–13. http://dx.doi.org/10.1017/s0066477400004718.
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AbstractThis article explores the part played by Mount Ida in the Iliad. It begins with some consideration of Ida in the early ‘history’ of Troy – the stories of Dardanus and the early line of Trojan kings. The city of Troy (Ilios) has its origins on Mount Ida, and the mountain remains very dear to the Trojans in many different ways. The rivers at Troy have their source on the mountain, and the Trojans acquire their water and wood from there. Moreover, the mountain is a central part of Trojan religious life, including the peak at Gargarus, where Zeus resides for a significant part of the poem. This article considers the two journeys of Zeus to Mount Ida from Olympus in the Iliad, and the ways that these are dealt with in the text. It raises questions about the rationale for and the effect of his visits there. It is argued that the poet uses Zeus’s absence from Olympus to ‘open up’ the cosmos, and permit new kinds of divine conduct and intervention. The article concludes with some consideration of the fact that the text offers no reference to the return of Zeus from Ida to Olympus prior to the council of the gods and Theomachy in Book 20.
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Gasti, Helen. "Three notes on Virgil,Aeneid2." Cambridge Classical Journal 52 (2006): 128–33. http://dx.doi.org/10.1017/s1750270500000506.
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Aeneas begins his narrative with the story of the Trojan Horse. The Greeks, after constructing a huge wooden horse, within which they hide a great many armed soldiers, flee the land. The Trojans rejoice, thinking that they have driven off their opponents. Lines 27–8 express the joy of the Trojans as they visit the Greek camp:iuuat ire et Dorica castradesertosqueuidere locos litusquerelictumIt is disputed whetherdesertosandrelictumare used with an attributive or predicative function. The repeateddesertus(24huc se prouecti deserto in litore condunt, i.e. the Greeks) directs the reader's attention to its earlier use in an attributive function (‘they hid on thevacant shoreof Tenedos’). The image of the deserted shore of Tenedos is clearly meant to suggest the potential destructiveness of the Doric camp and shore deserted now. Such an interpretation seems to be further supported by the predicative use ofdesertosandrelictum, since we see the Greek camp through the eyes both of Aeneas and of his countrymen.
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Hellmich, S., S. Mottola, G. Hahn, E. Kührt, and D. de Niem. "Influence of the Yarkovsky force on Jupiter Trojan asteroids." Astronomy & Astrophysics 630 (October 2019): A148. http://dx.doi.org/10.1051/0004-6361/201834715.
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Aims. We investigate the influence of the Yarkovsky force on the long-term orbital evolution of Jupiter Trojan asteroids. Methods. Clones of the observed population with different sizes and different thermal properties were numerically integrated for 1 Gyr with and without the Yarkovsky effect. The escape rate of these objects from the Trojan region as well as changes in the libration amplitude, eccentricity, and inclination were used as a metric of the strength of the Yarkovsky effect on the Trojan orbits. Results. Objects with radii R ≤ 1 km are significantly influenced by the Yarkovsky force. The effect causes a depletion of these objects over timescales of a few hundred million years. As a consequence, we expect the size-frequency distribution of small Trojans to show a shallower slope than that of the currently observable population (R ≳ 1 km), with a turning point between R = 100 m and R = 1 km. The effect of the Yarkovsky acceleration on the orbits of Trojans depends on the sense of rotation in a complex way. The libration amplitude of prograde rotators decreases with time while the eccentricity increases. Retrograde rotators experience the opposite effect, which results in retrograde rotators being ejected faster from the 1:1 resonance region. Furthermore, for objects affected by the Yarkovsky force, we find indications that the effect tends to smooth out the differences in the orbital distribution between the two clouds.
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Montesinos, Matías, Juan Garrido-Deutelmoser, Johan Olofsson, Cristian A. Giuppone, Jorge Cuadra, Amelia Bayo, Mario Sucerquia, and Nicolás Cuello. "Dust trapping around Lagrangian points in protoplanetary disks." Astronomy & Astrophysics 642 (October 2020): A224. http://dx.doi.org/10.1051/0004-6361/202038758.
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Aims. Trojans are defined as objects that share the orbit of a planet at the stable Lagrangian points L4 and L5. In the Solar System, these bodies show a broad size distribution ranging from micrometer (μm) to centimeter (cm) particles (Trojan dust) and up to kilometer (km) rocks (Trojan asteroids). It has also been theorized that earth-like Trojans may be formed in extra-solar systems. The Trojan formation mechanism is still under debate, especially theories involving the effects of dissipative forces from a viscous gaseous environment. Methods. We perform hydro-simulations to follow the evolution of a protoplanetary disk with an embedded 1–10 Jupiter-mass planet. On top of the gaseous disk, we set a distribution of μm–cm dust particles interacting with the gas. This allows us to follow dust dynamics as solids get trapped around the Lagrangian points of the planet. Results. We show that large vortices generated at the Lagrangian points are responsible for dust accumulation, where the leading Lagrangian point L4 traps a larger amount of submillimeter (submm) particles than the trailing L5, which traps mostly mm–cm particles. However, the total bulk mass, with typical values of ~Mmoon, is more significant in L5 than in L4, in contrast to what is observed in the current Solar System a few gigayears later. Furthermore, the migration of the planet does not seem to affect the reported asymmetry between L4 and L5. Conclusions. The main initial mass reservoir for Trojan dust lies in the same co-orbital path of the planet, while dust migrating from the outer region (due to drag) contributes very little to its final mass, imposing strong mass constraints for the in situ formation scenario of Trojan planets.
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Pirani, S., A. Johansen, B. Bitsch, A. J. Mustill, and D. Turrini. "Consequences of planetary migration on the minor bodies of the early solar system." Astronomy & Astrophysics 623 (March 2019): A169. http://dx.doi.org/10.1051/0004-6361/201833713.
Full textAbstract:
Pebble accretion is an efficient mechanism that is able to build up the core of the giant planets within the lifetime of the protoplanetary disc gas-phase. The core grows via this process until the protoplanet reaches its pebble isolation mass and starts to accrete gas. During the growth, the protoplanet undergoes a rapid, large-scale, inward migration due to the interactions with the gaseous protoplanetary disc. In this work, we have investigated how this early migration would have affected the minor body populations in our solar system. In particular, we focus on the Jupiter Trojan asteroids (bodies in the coorbital resonance 1:1 with Jupiter, librating around the L4 and L5 Lagrangian points called, respectively, the leading and the trailing swarm) and the Hilda asteroids. We characterised their orbital parameter distributions after the disc dispersal and their formation location and compare them to the same populations produced in a classical in situ growth model. We find that a massive and eccentric Hilda group is captured during the migration from a region between 5 and 8 au and subsequently depleted during the late instability of the giant planets. Our simulations also show that inward migration of the giant planets always produces a Jupiter Trojans’ leading swarm more populated than the trailing one, with a ratio comparable to the current observed Trojan asymmetry ratio. The in situ formation of Jupiter, on the other hand, produces symmetric swarms. The reason for the asymmetry is the relative drift between the migrating planet and the particles in the coorbital resonance. The capture happens during the growth of Jupiter’s core and Trojan asteroids are afterwards carried along during the giant planet’s migration to their final orbits. The asymmetry and eccentricity of the captured Trojans correspond well to observations, but their inclinations are near zero and their total mass is three to four orders of magnitude higher than the current population. Future modelling will be needed to understand whether the dynamical evolution of the Trojans over billions of years will raise the inclinations and deplete the masses to observed values.
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Mohan, Navya, and J. P. Anita. "Early Detection of Clustered Trojan Attacks on Integrated Circuits Using Transition Delay Fault Model." Cryptography 7, no. 1 (January 28, 2023): 4. http://dx.doi.org/10.3390/cryptography7010004.
Full textAbstract:
The chances of detecting a malicious reliability attack induced by an offshore foundry are grim. The hardware Trojans affecting a circuit’s reliability do not tend to alter the circuit layout. These Trojans often manifest as an increased delay in certain parts of the circuit. These delay faults easily escape during the integrated circuits (IC) testing phase, hence are difficult to detect. If additional patterns to detect delay faults are generated during the test pattern generation stage, then reliability attacks can be detected early without any hardware overhead. This paper proposes a novel method to generate patterns that trigger Trojans without altering the circuit model. The generated patterns’ ability to diagnose clustered Trojans are also analyzed. The proposed method uses only single fault simulation to detect clustered Trojans, thereby reducing the computational complexity. Experimental results show that the proposed algorithm has a detection ratio of 99.99% when applied on ISCAS’89, ITC’99 and IWLS’05 benchmark circuits. Experiments on clustered Trojans indicate a 46% and 34% improvement in accuracy and resolution compared to a standard Automatic Test Pattern Generator (ATPG)Tool.