Game Theory Meets Network Security: A Tutorial at ACM CCS

The increasingly pervasive connectivity of today's information systems brings up new challenges to security. Traditional security has accomplished a long way toward protecting well-defined goals such as confidentiality, integrity, availability, and authenticity. However, with the growing sophistication of the attacks and the complexity of the system, the protection using traditional methods could be cost-prohibitive. A new perspective and a new theoretical foundation are needed to understand security from a strategic and decision-making perspective. Game theory provides a natural framework to capture the adversarial and defensive interactions between an attacker and a defender. It provides a quantitative assessment of security, prediction of security outcomes, and a mechanism design tool that can enable security-by-design and reverse the attacker's advantage. This tutorial provides an overview of diverse methodologies from game theory that includes games of incomplete information, dynamic games, mechanism design theory to offer a modern theoretic underpinning of a science of cybersecurity. The tutorial will also discuss open problems and research challenges that the CCS community can address and contribute with an objective to build a multidisciplinary bridge between cybersecurity, economics, game and decision theory

On the gravitational wave background from compact binary coalescences in the band of ground-based interferometers

This paper reports a comprehensive study on the gravitational wave (GW) background from compact binary coalescences. We consider in our calculations newly available observation-based neutron star and black hole mass distributions and complete analytical waveforms that include post-Newtonian amplitude corrections. Our results show that: (i) post-Newtonian effects cause a small reduction in the GW background signal; (ii) below 100 Hz the background depends primarily on the local coalescence rate $r_0$ and the average chirp mass and is independent of the chirp mass distribution; (iii) the effects of cosmic star formation rates and delay times between the formation and merger of binaries are linear below 100 Hz and can be represented by a single parameter within a factor of ~ 2; (iv) a simple power law model of the energy density parameter $\Omega_{GW}(f) ~ f^{2/3}$ up to 50-100 Hz is sufficient to be used as a search template for ground-based interferometers. In terms of the detection prospects of the background signal, we show that: (i) detection (a signal-to-noise ratio of 3) within one year of observation by the Advanced LIGO detectors (H1-L1) requires a coalescence rate of $r_0 = 3 (0.2) Mpc^{-3} Myr^{-1}$ for binary neutron stars (binary black holes); (ii) this limit on $r_0$ could be reduced 3-fold for two co-located detectors, whereas the currently proposed worldwide network of advanced instruments gives only ~ 30% improvement in detectability; (iii) the improved sensitivity of the planned Einstein Telescope allows not only confident detection of the background but also the high frequency components of the spectrum to be measured. Finally we show that sub-threshold binary neutron star merger events produce a strong foreground, which could be an issue for future terrestrial stochastic searches of primordial GWs.Comment: A few typos corrected to match the published version in MNRA

Far-infrared vibrational properties of tetragonal C60 polymer

We report high-resolution far-infrared transmittance measurements and quantum-molecular-dynamics calculations of the two-dimensional tetragonal (7) high-temperature/high-pressure C-60 polymer, as a complement to our previous work on the C-60 dimer, and the one-dimensional orthorhombic (O) and two-dimensional rhombohedral (R) C-60 Polymers [V. C. Long et at., Phys. Rev. B 61, 13 191 (2000)]. The spectral features are assigned as intramolecular modes according to our quantum-molecular-dynamics calculations. In addition, we determine the I-h C-60 parent symmetry of each polymer vibrational mode by expanding the calculated polymer eigenvectors in terms of our calculated eigenvectors for I-h C-60. We find that many of the T-polymer vibrational modes are derived from more than one I-h C-60 parent symmetry, confirming that a weak perturbation model is inadequate for these covalently bonded C-60 balls. In particular, strongly infrared-active T-polymer modes with frequencies of 606 and 610 cm(-1) are found to be derived from a linear combination of three or more I-h C-60 parent modes. As in the O and R polymers, modes of the T polymer with substantial T-1u(2) character, which are polarized in the stretched directions, are found to have large downshifts. Finally, in our comparison of theory with experiment, we find indications that the in-plane lattice of the T polymer may not actually be square

Reality of Complex Affine Toda Solitons

There are infinitely many topological solitons in any given complex affine Toda theories and most of them have complex energy density. When we require the energy density of the solitons to be real, we find that the reality condition is related to a simple ``pairing condition.'' Unfortunately, rather few soliton solutions in these theories survive the reality constraint, especially if one also demands positivity. The resulting implications for the physical applicability of these theories are briefly discussed.Comment: LaTeX, 15 pages, UBTH-049

Effect and Compensation of Timing Jitter in Through-Wall Human Indication via Impulse Through-Wall Radar

Impulse through-wall radar (TWR) is considered as one of preferred choices for through-wall human indication due to its good penetration and high range resolution. Large bandwidth available for impulse TWR results in high range resolution, but also brings an atypical adversity issue not substantial in narrowband radars — high timing jitter effect, caused by the non-ideal sampling clock at the receiver. The fact that impulse TWR employs very narrow pulses makes little jitter inaccuracy large enough to destroy the signal correlation property and then degrade clutter suppression performance. In this paper, we focus on the timing jitter impact on clutter suppression in through-wall human indication via impulse TWR. We setup a simple timing jitter model and propose a criterion namely average range profile (ARP) contrast is to evaluate the jitter level. To combat timing jitter, we also develop an effective compensation method based on local ARP contrast maximization. The proposed method can be implemented pulse by pulse followed by exponential average background subtraction algorithm to mitigate clutters. Through-wall experiments demonstrate that the proposed method can dramatically improve through-wall human indication performance

Tackling Challenges in Seebeck Coefficient Measurement of Ultra-High Resistance Samples with an AC Technique

Seebeck coefficient is a widely studied semiconductor property. Conventional Seebeck coefficient measurements are based on DC voltage measurement. Normally this is performed on samples with moderate resistances (e.g., below a few MΩ level). Certain semiconductors are intrinsic and highly resistive. Many examples can be found in optical and photovoltaic materials. The hybrid halide perovskites that have gained extensive attention recently are a good example. Despite great attention from the materials and physics communities, few successful studies exist of the Seebeck coefficient of these compounds, for example CH3NH3PbI3. An AC-technique-based Seebeck coefficient measurement is reported, which makes high-quality Seebeck voltage measurements on samples with resistances up to the 100 GΩ level. This is achieved through a specifically designed setup to enhance sample isolation and increase capacitive impedance. As a demonstration, Seebeck coefficient measurement of a CH3NH3PbI3 thin film is performed at dark, with sample resistance 150 GΩ, and found S = +550 µV K−1. The strategy reported could be applied to the studies of fundamental transport parameters of all intrinsic semiconductors that have not been feasible

Very Light Axigluons and the Top Asymmetry

We show that very light (50 - 90 GeV) axigluons with flavor-universal couplings of order g_{s}/3 may explain the anomalous top forward-backward asymmetry reported by both CDF and D0 collaborations. The model is naturally consistent with the observed t \bar t invariant mass distribution and evades bounds from light Higgs searches, LEP event shapes, and hadronic observables at the Z pole. Very light axigluons can appear as resonances in multijet events, but searches require sensitivity to masses below current limits.Comment: 10 pages, 5 figures, references added, discussion of constraints expanded, general conclusions unchange

PDMS/PVA composite ferroelectret for improved energy harvesting performance

This paper address the PDMS ferroelectret discharge issue for improved long- term energy harvesting performance. The PDMS/PVA ferroelectret is fabricated using a 3D-printed plastic mould technology and a functional PVA composite layer is introduced. The PDMS/PVA composite ferroelectret achieved 80% piezoelectric coefficient d33 remaining, compared with 40% without the proposed layer over 72 hours. Further, the retained percentage of output voltage is about 73% over 72 hours