21,585 research outputs found
A Rate-Splitting Based Bound-Approaching Transmission Scheme for the Two-User Symmetric Gaussian Interference Channel with Common Messages
This paper is concerned with a rate-splitting based transmission strategy for the two-user symmetric Gaussian interference channel that contains common messages only. Each transmitter encodes its common message into multiple layers by multiple codebooks that drawn from one separate code book, and transmits the superposition of the messages corresponding to these layers; each receiver decodes the messages from all layers of the two users successively. Two schemes are proposed for decoding order and optimal power allocation among layers respectively. With the proposed decoding order scheme, the sum-rate can be increased by rate-splitting, especially at the optimal number of rate-splitting, using average power allocation in moderate and weak interference regime. With the two proposed schemes at the receiver and the transmitter respectively, the sum-rate achieves the inner bound of HK without time-sharing. Numerical results show that the proposed optimal power allocation scheme with the proposed decoding order can achieve significant improvement of the performance over equal power allocation, and achieve the sum-rate within two bits per channel use (bits/channel use) of the sum capacity
Delay-dependent robust stability of stochastic delay systems with Markovian switching
In recent years, stability of hybrid stochastic delay systems, one of the important issues in the study of stochastic systems, has received considerable attention. However, the existing results do not deal with the structure of the diffusion but estimate its upper bound, which induces conservatism. This paper studies delay-dependent robust stability of hybrid stochastic delay systems. A delay-dependent criterion for robust exponential stability of hybrid stochastic delay systems is presented in terms of linear matrix inequalities (LMIs), which exploits the structure of the diffusion. Numerical examples are given to verify the effectiveness and less conservativeness of the proposed method
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
Microdistribution of oxygen in silicon and its effects on electronic properties
The effects of interstitial oxygen on the electrical characteristics of Czochralski-grown silicon crystals were investigated for the first time on a microscale. It was found that the generation of thermal donors is not a direct function of the oxygen concentration. It was further found that the minority carrier life-time decreases with increasing oxygen concentration, on a microscale in as-grown crystals. It was thus shown, again for the first time, that oxygen in as grown crystals is not electronically inert as generally believed. Preannealing at 1200 C commonly employed in device fabrication, was found to suppress the donor generation at 450 C and to decrease the deep level concentrations
Theoretical studies of the local structures and EPR parameters for Cu center in Cd(NH)(SO) single crystal
The electron paramagnetic resonance (EPR) parameters ( factors and
the hyperfine structure constants , ) are
interpreted by using the perturbation formulae for a ion in
rhombically ({D}) elongated octahedra. In the calculated formulae, the
crystal field parameters are set up from the superposition model, and the
contribution to the EPR parameters from the admixture of -orbitals in the
ground state wave function of the Cu ion was taken into account. Based
on the calculation, local structural parameters of the impurity Cu
center in Cd(NH)(SO) (CAS) crystal were obtained
(i.e., {\AA}, {\AA},
{\AA}). The theoretical EPR parameters based on the
above Cu-O bond lengths in CAS crystal show a good agreement with
the observed values. The results are discussed.Comment: 5 page
PO-0987: MiR-432 inhibits tumor progression by targeting IGSF3 in esophageal squamous cell carcinoma
Solvable senescence model with positive mutations
We build upon our previous analytical results for the Penna model of
senescence to include positive mutations. We investigate whether a small but
non-zero positive mutation rate gives qualitatively different results to the
traditional Penna model in which no positive mutations are considered. We find
that the high-lifespan tail of the distribution is radically changed in
structure, but that there is not much effect on the bulk of the population. Th
e mortality plateau that we found previously for a stochastic generalization of
the Penna model is stable to a small positive mutation rate.Comment: 3 figure
A 1.3 cm line survey toward IRC +10216
IRC +10216 is the prototypical carbon star exhibiting an extended molecular
circumstellar envelope. Its spectral properties are therefore the template for
an entire class of objects. The main goal is to systematically study the
1.3 cm spectral line characteristics of IRC +10216. We carried
out a spectral line survey with the Effelsberg-100 m telescope toward IRC
+10216. It covers the frequency range between 17.8 GHz and 26.3 GHz (K-band).
In the circumstellar shell of IRC +10216, we find 78 spectral lines, among
which 12 remain unidentified. The identified lines are assigned to 18 different
molecules and radicals. A total of 23 lines from species known to exist in this
envelope are detected for the first time outside the Solar System and there are
additional 20 lines first detected in IRC +10216. The potential orgin of "U"
lines is also discussed. Assuming local thermodynamic equilibrium (LTE), we
then determine rotational temperatures and column densities of 17 detected
molecules. Molecular abundances relative to H are also estimated. A
non-LTE analysis of NH shows that the bulk of its emission arises from
the inner envelope with a kinetic temperature of 7020 K. Evidence for
NH emitting gas with higher kinetic temperature is also obtained, and
potential abundance differences between various C-bearing isotopologues
of HCN are evaluated. Overall, the isotopic C/C ratio is
estimated to be 499. Finally, a comparison of detected molecules in the
1.3 cm range with the dark cloud TMC-1 indicates that
silicate-bearing molecules are more predominant in IRC +10216.Comment: 32 pages, 9 figures, Accepted by A&
Discrete Razumikhin-type technique and stability of the Euler-Maruyama method to stochastic functional differential equations
A discrete stochastic Razumikhin-type theorem is established to investigate whether the Euler--Maruyama (EM) scheme can reproduce the moment exponential stability of exact solutions of stochastic functional differential equations (SFDEs). In addition, the Chebyshev inequality and the Borel-Cantelli lemma are applied to show the almost sure stability of the EM approximate solutions of SFDEs. To show our idea clearly, these results are used to discuss stability of numerical solutions of two classes of special SFDEs, including stochastic delay differential equations (SDDEs) with variable delay and stochastically perturbed equations
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