Weight Distribution for Non-binary Cluster LDPC Code Ensemble

In this paper, we derive the average weight distributions for the irregular non-binary cluster low-density parity-check (LDPC) code ensembles. Moreover, we give the exponential growth rate of the average weight distribution in the limit of large code length. We show that there exist $(2,d_c)$-regular non-binary cluster LDPC code ensembles whose normalized typical minimum distances are strictly positive.Comment: 12pages, 6 figures, To be presented in ISIT2013, Submitted to IEICE Trans. Fundamental

Interpretation of the mechanical behavior of embankments having various compaction properties based on the soil skeleton structure

AbstractAfter the Hanshin Awaji Earthquake disaster, the seismic resistance of embankments was evaluated, and design principles were changed from specification-based to performance-based. However, compaction properties and the mechanical behavior of compacted soil were not sufficiently considered in the Manual of Highway Earthworks on Embankments.The first objective of the present study is to reproduce the mechanical behavior of three embankment materials having different compaction properties. A series of triaxial compression tests and oedometer tests is carried out. The mechanical behavior is reproduced by the SYS Cam-clay model and the influence of compaction on the mechanical behavior is interpreted based on the soil skeleton structure. The second objective is to evaluate the seismic stability of the embankment, which depends on the compaction properties of the embankment material, using GEOASIA, a soil–water coupled finite deformation analysis code.The primary conclusions are as follows. (1) Through the triaxial tests, the maximum deviator stress increases as the degree of compaction, Dc, increases. However, the trends in the increase differ depending on the material. (2) Based on one-dimensional consolidation tests, the compression curve is approximately a straight line with a large vertical effective stress. In the present study, a greater maximum dry density corresponds to less compressibility and a lower compression curve. (3) The mechanical behavior of each material is reproduced by the SYS Cam-clay model using one set of material constants for each material and representing the differences in Dc by different initial conditions for the structure and overconsolidation. An increase in Dc causes the decay of the structure, as well as the accumulation of overconsolidation. In the case of material A, the decay of the structure and the loss of overconsolidation occur quickly, whereas in the case of material C, the decay of the structure is slight and the loss of overconsolidation is moderate. (4) The seismic response analysis reveals different deformations of the embankment for different materials, even for the same Dc. The seismic stability of the embankments was increased by increasing Dc. Materials, such as material A, that have fast decay of the structure and fast loss of overconsolidation produce embankments with high seismic stability

Orientation Optimization Based on Topological Derivatives in Cooperation with Multi-Material Topology Optimization Based on Extended Level Set Method

This paper provides an orientation angle optimization method for the design of fiber-reinforced composite materials using topology optimization. The orientation angle optimization is based on a topological derivative, which measures the sensitivity of an objective function with respect to a topological change of anisotropic materials. The sensitivity is incorporated into a new gradient-based optimization algorithm. This method allows us to avoid local optima and seek a global optimal solution. We provide some numerical examples and verify the effectiveness of the proposed method.Comment: 24 pages, 16 figure

Light Higgs boson scenario in the SUSY seesaw model

It is demonstrated that the light Higgs boson scenario, which the lightest Higgs mass is less than the LEP bound, mh > 114.4 GeV, is consistent with the SUSY seesaw model. With the assumptions of the universal right-handed neutrino mass and the hierarchical mass spectrum of the ordinary neutrinos, the bounds for the right-handed neutrino mass is investigated in terms of lepton flavor violating charged lepton decays. We also discuss the effect of the modification of renormalization group equations by the right-handed neutrinos on the b to s gamma process and the relic abundance of dark matter in the light Higgs boson scenario.Comment: 17 pages, 5 figure

Relationships between vegetation types and soil properties along a topographical gradient on the northern coast of the Brgger Peninsula, Svalbard

Vegetation patterns in the high Arctic vary not only with proglacial chronosequence but also with a topographical gradient on older deglaciated areas which are covered by mature vegetation. A preliminary survey of local scale vegetation patterns along a topographical gradient with special reference to soil properties was conducted on the northern coast of the Brgger Peninsula, Svalbard in the high Arctic. Three community types of vascular plants were distinguished by common dominants: Cardamine type, Salix type and Oxyria/Luzula type. Each community type was comprised of different habitat types. The Cardamine type was restricted to near the bottom of depressions, where there was high soil water content. The Oxyria/Luzula type was characterized by habitats belonging to upper slopes to ridges, having high gravel content soils. On the other hand, the habitat preference of the Salix type, which had higher vegetation cover and biomass of vascular plants compared to the other two types, was not clear. The core habitat of fertile/undisturbed area, as described by the centrifugal community organization model, might be dominated by Salix polaris in this area. The other species had a refugium from interspecific competition in their preferred peripheral habitats such as exposed ridge or wetland

Characterization of soil microflora on a successional glacier foreland in the high Arctic on Ellesmere Island, Nunavut, Canada using phospholipid fatty acid analysis

We investigated soil microbial biomass and community structure along a primary successional gradient after deglaciation in the high Arctic, at Ellesmere Island, Nunavut, Canada(80°50\u27N, 82°45\u27W). Soil samples were collected from five glacial moraines(M1 to M5) with different developmental periods. Time since the recession of glaciers at M1, M3, and M5 was estimated to be 300, 9000, and over 17000 years, respectively. Soil samples from five points in each moraine were subjected to phospholipid fatty acid(PLFA) analysis. Total PLFA content(an index of microbial biomass) in M1 was significantly lower than those in older moraines(M2-M5), whereas the content remained at an almost constant level from M2 to M5. Significant differences in PLFA composition(an index of microbial community structure) were also observed between M1 and older moraines(M2-M5); the proportion of straight chain saturated fatty acids in M1 was higher than those in older moraines(M2-M5), whereas those of branched fatty acids and unsaturated fatty acids in M1 were lower than those in older moraines(M2-M5). These results suggest that changes of microflora occurred in the early phase of succession after deglaciation and became stable thereafter. Microbial biomass had a positive correlation with soil carbon and nitrogen contents over the successional chronosequence, suggesting that development of soil microflora was affected in part by organic matter accumulation