Further SEASAT SAR coastal ocean wave analysis

Analysis techniques used to exploit SEASAT synthetic aperture radar (SAR) data of gravity waves are discussed and the SEASAT SAR's ability to monitor large scale variations in gravity wave fields in both deep and shallow water is evaluated. The SAR analysis techniques investigated included motion compensation adjustments and the semicausal model for spectral analysis of SAR wave data. It was determined that spectra generated from fast Fourier transform analysis (FFT) of SAR wave data were not significantly altered when either range telerotation adjustments or azimuth focus shifts were used during processing of the SAR signal histories, indicating that SEASAT imagery of gravity waves is not significantly improved or degraded by motion compensation adjustments. Evaluation of the semicausal (SC) model using SEASAT SAR data from Rev. 974 indicates that the SC spectral estimates were not significantly better than the FFT results

Misuse Detection in Consent-based Networks

Consent-based networking, which requires senders to have permission to send traffic, can protect against multiple attacks on the network. Highly dynamic networks like Mobile Ad-hoc Networks (MANETs) require destination-based consent networking, where consent needs to be given to send to a destination in any path. These networks are susceptible to multipath misuses by misbehaving nodes. In this paper, we identify the misuses in destination-based consent networking, and provide solution for detecting and recovering from the misuses. Our solution is based on our previously introduced DIPLOMA architecture. DIPLOMA is a deny-by-default distributed policy enforcement architecture that can protect the end-host services and network bandwidth. DIPLOMA uses capabilities to provide consent for sending traffic. In this paper, we identify how senders and receivers can misuse capabilities by using them in multiple paths, and provide distributed solutions for detecting those misuses. To that end, we modify the capabilities to aid in misuse detection and provide protocols for exchanging information for distributed detection. We also provide efficient algorithms for misuse detection, and protocols for providing proof of misuse. Our solutions can handle privacy issues associated with the exchange of information for misuse detection. We have implemented the misuse detection and recovery in DIPLOMA systems running on Linux operating systems, and conducted extensive experimental evaluation of the system in Orbit MANET testbed. The results show our system is effective in detecting and containing multipath misuses

Understanding Multiple Adoption in C2C Platforms in China

The network effect is the general principle that the value of connecting to a network depends on the number of existing customers in the network. Usually, the network effect makes strong firms stronger and weak firms weaker. In e-commerce, however, the power of network effects can be mitigated when users adopt multiple transaction platforms (i.e., multiple adoption). Owing to multiple adoption, emerging firms have a chance to compete with or surpass strong incumbents. This empirical study showed that, because of multiple adoption, smaller players can still exist in the face of a dominant player in China’s competitive online auction platforms

Hereditary Character of Photonics Structure in Pachyrhynchus sarcitis Weevils: Color Changes via One Generation Hybridization

Pachyrhynchus sarcitis weevils are flightless weevils characterized by colored patches of scales on their dark elytra. The vivid colors of such patches result from the reflection of differently oriented three-dimensional photonic crystals within their scales. Our results show that hybrid P. sarcitis, the first filial generation of two P. sarcitis populations from Lanyu Island (Taiwan) and Babuyan Island (Philippines), mixes the color of its ancestors by tuning the photonic structure in its scales. A careful spectroscopical and anatomical analysis of the weevils in the phylogeny reveals the hereditary characteristics of the photonic crystals within their scales in terms of lattice constant, orientation and domain size. Monitoring how structural coloration is inherited by offspring highlights the versatility of photonic structures to completely redesign the optical response of living organisms. Such finding shed light onto the evolution and development mechanisms of structural coloration in Pachyrhynchus weevils and provides inspiration for the design of visual appearance in artificial photonic materials.NanoBio-ICMG platform (FR 2607) Cambridge Trus

NbSe3: Effect of Uniaxial Stress on the Threshold Field and Fermiology

We have measured the effect of uniaxial stress on the threshold field ET for the motion of the upper CDW in NbSe3. ET exhibits a critical behavior, ET ~ (1 - e/ec)^g, wher e is the strain, and ec is about 2.6% and g ~ 1.2. This ecpression remains valid over more than two decades of ET, up to the highest fields of about 1.5keV/m. Neither g nor ec is very sensitive to the impurity concentraction. The CDW transition temperature Tp decreases linearly with e at a rate dTp/de = -10K/%, and it does not show any anomaly near ec. Shubnikov de-Haas measurements show that the extremal area of the Fermi surface decreases with increasing strain. The results suggest that there is an intimate relationship between pinning of the upper CDW and the Fermiology of NbSe3.Comment: 4 pages, 5 figure

Cosmic positron and antiproton constraints on the gauge-Higgs Dark Matter

We calculate the cosmic ray positron and antiproton spectra of a gauge-Higgs dark matter candidate in a warped five-dimensional $SO(5) \times U(1)$ gauge-Higgs unification model. The stability of the gauge-Higgs boson is guaranteed by the H parity under which only the Higgs boson is odd at low energy. The 4-point vertices of HHW^+W^- and HHZZ, allowed by H parity conservation, have the same magnitude as in the standard model, which yields efficient annihilation rate for $m_H > m_W$. The most dominant annihilation channel is $H H \to W^+ W^-$ followed by the subsequent decays of the $W$ bosons into positrons or quarks, which undergo fragmentation into antiproton. Comparing with the observed positron and antiproton spectra with the PAMALA and Fermi/LAT, we found that the Higgs boson mass cannot be larger than 90 GeV, in order not to overrun the observations. Together with the constraint on not overclosing the Universe, the valid range of the dark matter mass is restricted to 70-90 GeV.Comment: 13 pages, 3 figure