Gravitational Corrections to Fermion Masses in Grand Unified Theories

We reconsider quantum gravitational threshold effects to the unification of fermion masses in Grand Unified Theories. We show that the running of the Planck mass can have a sizable effect on these thresholds which are thus much more important than naively expected. These corrections make any extrapolation from low energy measurements challenging.Comment: 7 page

Scanning Near-shore Intertidal Terrain Using Ground LiDAR

Intertidal zone refers to the area under and above the water during high and low tides. Traditionally, this zone is not within the scope of land management authorities. Moreover, in accordance with principals set out by existing plans, intertidal zones are excluded from management zones. Boundaries should therefore be set at the land and sea border. Traditionally, methods in determining this have included the traditional theodolite (total station) method, mapping and aerial photography (photogrammetry). However, existing operational restrictions lower efficiency, in addition to increasing time and operational costs. Therefore this paper explores the practicality of a user- friendly, ground-based high resolution laser scanning technology. This method offers easy operation and high-density characteristics with an instrument platform that can be installed on elevated rooftops. High accuracy and resolution is achieved using a stop-and-go method producing Digital Terrain Model (DTM) data. The range of the completed data is 61km in length, 2.5km in width, and -0.5m depth, with a sampling error of approximately ±2cm. Through the implementation discussed in this research, accurate information about the changes of topography in intertidal areas can be obtained

Assertion Checking by Combined Word-level ATPG and Modular Arithmetic Constraint-Solving Techniques

We present a new approach to checking assertion properties for RTL design verification. Our approach combines structural, word-level automatic test pattern generation (ATPG) and modular arithmetic constraint-solving techniques to solve the constraints imposed by the target assertion property. Our word-level ATPG and implication technique not only solves the constraints on the control logic, but also propagates the logic implications to the datapath. A novel arithmetic constraint solver based on modular number system is then employed to solve the remaining constraints in datapath. The advantages of the new method are threefold. First, the decision-making process of the word-level ATPG is confined to the selected control signals only. Therefore, the enumeration of enormous number of choices at the datapath signals is completely avoided. Second, our new implication translation techniques allow word-level logic implication being performed across the boundary of datapath and control logic, and therefore, efficiently cut down the ATPG search space. Third, our arithmetic constraint solver is based on modular instead of integral number system. It can thus avoid the false negative effect resulting from the bit-vector value modulation. A prototype system has been built which consists of an industrial front-end HDL parser, a propertyto -constraint converter and the ATPG/arithmetic constraint-solving engine. The experimental results on some public benchmark and industrial circuits demonstrate the efficiency of our approach and its applicability to large industrial designs

A Study of Fermi-LAT GeV gamma-ray Emission towards the Magnetar-harboring Supernova Remnant Kesteven 73 and Its Molecular Environment

We report our independent GeV gamma-ray study of the young shell-type supernova remnant (SNR) Kes 73 which harbors a central magnetar, and CO-line millimeter observations toward the SNR. Using 7.6 years of Fermi-LAT observation data, we detected an extended gamma-ray source ("source A") with the centroid on the west of the SNR, with a significance of 21.6 sigma in 0.1-300 GeV and an error circle of 5.4 arcminute in angular radius. The gamma-ray spectrum cannot be reproduced by a pure leptonic emission or a pure emission from the magnetar, and thus a hadronic emission component is needed. The CO-line observations reveal a molecular cloud (MC) at V_LSR~90 km/s, which demonstrates morphological correspondence with the western boundary of the SNR brightened in multiwavelength. The 12CO (J=2-1)/12CO (J=1-0) ratio in the left (blue) wing 85-88 km/s is prominently elevated to ~1.1 along the northwestern boundary, providing kinematic evidence of the SNR-MC interaction. This SNR-MC association yields a kinematic distance 9 kpc to Kes 73. The MC is shown to be capable of accounting for the hadronic gamma-ray emission component. The gamma-ray spectrum can be interpreted with a pure hadronic emission or a magnetar+hadronic hybrid emission. In the case of pure hadronic emission, the spectral index of the protons is 2.4, very similar to that of the radio-emitting electrons, essentially consistent with the diffusive shock acceleration theory. In the case of magnetar+hadronic hybrid emission, a magnetic field decay rate >= 10^36 erg/s is needed to power the magnetar's curvature radiation.Comment: 7 figures, published in Ap

Two-gap superconducting properties of alkaline-earth intercalated Ax(NH3)Fe2Se2A_{x}(NH_{3})Fe_{2}Se_{2} (A = Ba or Sr)

Superconducting properties were studied on high quality superconductors $Ba_{x}(NH_{3})Fe_{2}Se_{2}$ ($T_{c}$ = 39 K) and $Sr_{x}(NH_{3})Fe_{2}Se_{2}$ ($T_{c}$ = 44 K) prepared by intercalating Ba/Sr atoms into tetragonal $\beta$-FeSe by liquid ammonia. The elongated c-axis and almost unchanged a-axis of $Ba_{x}(NH_{3})Fe_{2}Se_{2}$, comparing with $\beta$-FeSe, suggested an unchanged intra-$Fe_{2}Se_{2}$-layer structure and the $T_{c}$ enhancement is due to a 3D to 2D-like Fermi surface transformation. The superconducting coherent lengths $\xi$(0), Ginzburg-Landau parameters $\kappa$ and penetration depths $\lambda$(0) obtained from the extrapolated lower and upper critical fields $B_{c1}$(0) and $B_{c2}$(0) indicates that both compounds are typical type-II superconductors. The temperature dependence of 1/$\lambda^{2}$(T) of $Ba_{x}(NH_{3})Fe_{2}Se_{2}$ deduced from the low field magnetic susceptibility shows a two-gap s-wave behaviour with superconducting gaps of $\Delta_{1}$ = 6.47 meV and $\Delta_{2}$ = 1.06 meV