Low Density Lattice Codes

Low density lattice codes (LDLC) are novel lattice codes that can be decoded efficiently and approach the capacity of the additive white Gaussian noise (AWGN) channel. In LDLC a codeword x is generated directly at the n-dimensional Euclidean space as a linear transformation of a corresponding integer message vector b, i.e., x = Gb, where H, the inverse of G, is restricted to be sparse. The fact that H is sparse is utilized to develop a linear-time iterative decoding scheme which attains, as demonstrated by simulations, good error performance within ~0.5dB from capacity at block length of n = 100,000 symbols. The paper also discusses convergence results and implementation considerations.Comment: 24 pages, 4 figures. Submitted for publication in IEEE transactions on Information Theor

Perbandingan Kadar Low Density Lipoprotein Cholesterol( Ldl-c) Pada Perokok Dan Bukan Perokok

: Smoking in many forms is the main risks factor of atherosclerotic process and coronay heart diseases. Cigarette smoking results in increases of total cholesterol, triglyserida, LDL-C, and VLDL-C, and a decrease of HDL-C blood levels. The aim of this study was to compare the LDL-C levels of smokers with non-smokers males. This was an observational study with a cross sectional design. This study was done in the Faculty of Medicine, University of Sam Ratulangi Manado from November to Desember 2012, by using a purposive sampling technique. There were 60 smoker students and non-smoker students of semester 7 Faculty of Medicine, University of Sam Ratulangi, Manado who fulfilled the inclulsion criteria. Data were taken from questionnaires and examinations of LDL-C levels. LDL-C levels were analyzed by using the SPSS version 20. The results showed that the analysis of the comparison of LDL-C levels of the smoker students' with of the non-smokers'students had a P-value 0.911. Conclusion: There was no significant difference of the LDL-C levels between smokers and non-smokers

Driven low density granular mixtures

We study the steady state properties of a 2D granular mixture in the presence of energy driving by employing simple analytical estimates and Direct Simulation Monte Carlo. We adopt two different driving mechanisms: a) a homogeneous heat bath with friction and b) a vibrating boundary (thermal or harmonic) in the presence of gravity. The main findings are: the appearance of two different granular temperatures, one for each species; the existence of overpopulated tails in the velocity distribution functions and of non trivial spatial correlations indicating the spontaneous formation of cluster aggregates. In the case of a fluid subject to gravity and to a vibrating boundary, both densities and temperatures display non uniform profiles along the direction normal to the wall, in particular the temperature profiles are different for the two species while the temperature ratio is almost constant with the height. Finally, we obtained the velocity distributions at different heights and verified the non gaussianity of the resulting distributions.Comment: 19 pages, 12 figures, submitted for publicatio

Analisis Kadar Kolesterol Low Density Lipoproteinsebagai Faktor Risiko Komplikasi Pada Pasien Diabetes Melitus Tipe 2

Dyslipidemia in type 2 diabetes mellitus (T2DM) can be increased the cardiovascular risk and this condition was equivalent with the elevated of LDL-cholesterol. In type 2 diabetes, LDL was small, dense and more aterogenic. This research was an observational study used cross sectional approach. The samples were 50 samples consist of twenty five of T2DM with non-CHD patient (50%) and twenty five of T2DM with CHD patient (50%) with age 45 years old or more. The level of serum LDL was measured by photometry used ABX Pentra 400. The data was analyzed by statistical method. The result study was conducted that normal LDL level was 9 (18%) patients and abnormal LDL level was 16 (32%) in T2DM with non-CHD patient. While in patient with T2DM with CHD had abnormal LDL level overall (50%). The high level of LDL in T2DM was accelerated complication occurrence, mainly coronary heart disease (CHD)

Probing low-density carriers in a single atomic layer using terahertz parallel-plate waveguides

As novel classes of two-dimensional (2D) materials and heterostructures continue to emerge at an increasing pace, methods are being sought for elucidating their electronic properties rapidly, non-destructively, and sensitively. Terahertz (THz) time-domain spectroscopy is a well-established method for characterizing charge carriers in a contactless fashion, but its sensitivity is limited, making it a challenge to study atomically thin materials, which often have low conductivities. Here, we employ THz parallel-plate waveguides to study monolayer graphene with low carrier densities. We demonstrate that a carrier density of ~2 × 1011 cm−2, which induces less than 1% absorption in conventional THz transmission spectroscopy, exhibits ~30% absorption in our waveguide geometry. The amount of absorption exponentially increases with both the sheet conductivity and the waveguide length. Therefore, the minimum detectable conductivity of this method sensitively increases by simply increasing the length of the waveguide along which the THz wave propagates. In turn, enabling the detection of low-conductivity carriers in a straightforward, macroscopic configuration that is compatible with any standard time-domain THz spectroscopy setup. These results are promising for further studies of charge carriers in a diverse range of emerging 2D materials

Pairing in low-density Fermi gases

We consider pairing in a dilute system of Fermions with a short-range interaction. While the theory is ill-defined for a contact interaction, the BCS equations can be solved in the leading order of low-energy effective field theory. The integrals are evaluated with the dimensional regularization technique, giving analytic formulas relating the pairing gap, the density, and the energy density to the two-particle scattering length.Comment: 12 pages, 2 EPS-figures, uses psfig.sty, eq.(9) correcte

Cratering in low-density targets

Cratering in low density targets, and comparisons of various hypervelocity projectile-target combination