17,443 research outputs found
A Burgess-like subconvex bound for twisted L-functions
Let g be a cuspidal newform (holomorphic or Maass) of arbitrary level and nebentypus, X a primitive character of conductor q, and s a point on the critical line Rs = 1/2. It is proved that
L(g circle times chi, s) 0
is arbitrary and theta = 7/64 is the current known approximation towards the RamannJan-Petersson conjecture (which would allow theta = 0); moreover, the dependence on s and all the parameters of g is polynomial. This result is an analog of Burgess' classical subconvex bound for Dirichlet L-functions. In Appendix 2 the above result is combined with a theorem of Waldspurger and the adelic calculations of Baruch-Mao to yield an improved uniform upper bound for the Fourier coefficients of holomorphic half-integral weight cusp forms
A Mutual Information Based Sequence Distance For Vertebrate Phylogeny Using Complete Mitochondrial Genomes
Traditional sequence distances require alignment. A new mutual information based sequence distance without alignment is defined in this paper. This distance is based on compositional vectors of DNA sequences or protein sequences from complete genomes. First we establish the mathematical foundation of this distance. Then this distance is applied to analyze the phylogenetic relationship of 64 vertebrates using complete mitochondrial genomes. The phylogenetic tree shows that the mitochondrial genomes are separated into three major groups. One group corresponds to mammals; one group corresponds to fish; and the last one is Archosauria (including birds and reptiles). The structure of the tree based on our new distance is roughly in agreement in topology with the current known phylogenies of vertebrates
Towards Secure and Safe Appified Automated Vehicles
The advancement in Autonomous Vehicles (AVs) has created an enormous market
for the development of self-driving functionalities,raising the question of how
it will transform the traditional vehicle development process. One adventurous
proposal is to open the AV platform to third-party developers, so that AV
functionalities can be developed in a crowd-sourcing way, which could provide
tangible benefits to both automakers and end users. Some pioneering companies
in the automotive industry have made the move to open the platform so that
developers are allowed to test their code on the road. Such openness, however,
brings serious security and safety issues by allowing untrusted code to run on
the vehicle. In this paper, we introduce the concept of an Appified AV platform
that opens the development framework to third-party developers. To further
address the safety challenges, we propose an enhanced appified AV design schema
called AVGuard, which focuses primarily on mitigating the threats brought about
by untrusted code, leveraging theory in the vehicle evaluation field, and
conducting program analysis techniques in the cybersecurity area. Our study
provides guidelines and suggested practice for the future design of open AV
platforms
Crossover from a pseudogap state to a superconducting state
On the basis of our calculation we deduce that the particular electronic
structure of cuprate superconductors confines Cooper pairs to be firstly formed
in the antinodal region which is far from the Fermi surface, and these pairs
are incoherent and result in the pseudogap state. With the change of doping or
temperature, some pairs are formed in the nodal region which locates the Fermi
surface, and these pairs are coherent and lead to superconductivity. Thus the
coexistence of the pseudogap and the superconducting gap is explained when the
two kinds of gaps are not all on the Fermi surface. It is also shown that the
symmetry of the pseudogap and the superconducting gap are determined by the
electronic structure, and non-s wave symmetry gap favors the high-temperature
superconductivity. Why the high-temperature superconductivity occurs in the
metal region near the Mott metal-insulator transition is also explained.Comment: 7 pages, 2 figure
Public vs private administration of rural health insurance schemes: a comparative study in Zhejiang of China.
: Since 2003, China has experimented in some of the country's counties with the private administration of the New Cooperative Medical Scheme (NCMS), a publicly subsidized health insurance scheme for rural populations. Our study compared the effectiveness and efficiency of private vs public administration in four counties in one of China's most affluent provinces in the initial stage of the NCMS's implementation. The study was undertaken in Ningbo city of Zhejiang province. Out of 10 counties in Ningbo, two counties with private administration for the NCMS (Beilun and Ninghai) were compared with two others counties with public administration (Zhenhai and Fenghua), using the following indicators: (1) proportion of enrollees who were compensated for inpatient care; (2) average reimbursement-expense ratio per episode of inpatient care; (3) overall administration cost; (4) enrollee satisfaction. Data from 2004 to 2006 were collected from the local health authorities, hospitals and the contracted insurance companies, supplemented by a randomized household questionnaire survey covering 176 households and 479 household members. In our sample counties, private administration of the NCMS neither reduced transaction costs, nor improved the benefits of enrollees. Enrollees covered by the publicly administered NCMS were more likely to be satisfied with the insurance scheme than those covered by the privately administered NCMS. Experience in the selected counties suggests that private administration of the NCMS did not deliver the hoped-for results. We conclude that caution needs to be exercised in extending private administration of the NCMS
Observation of Andreev Surface Bound States in the 3-K phase Region of Sr_2RuO_4
The tunneling spectrum of the superconducting phase with T_c ~ 3.0 K has been
measured in the Ru-embedded region of Sr_2RuO_4 using cleaved junctions. A
sharp zero-bias conductance peak (ZBCP) has been observed below 3 K. All
characteristics of this ZBCP suggest that it originates from Andreev surface
bound states, indicating that the pairing in the 3-K phase is also non-s-wave.
Below the bulk T_c of Sr_2RuO_4 (~1.5 K), a bell-shaped ZBCP was found. This
supports that there is a phase transition in the 3-K phase region near the bulk
T_c.Comment: 4 pages, to appear in Phys. Rev. Lett. 87 (2001
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