13,897 research outputs found
Topology Control in Heterogeneous Wireless Networks: Problems and Solutions
Previous work on topology control usually assumes homogeneous wireless nodes with uniform transmission ranges. In this paper, we propose two localized topology control algorithms for heterogeneous wireless multi-hop networks with nonuniform transmission ranges: Directed Relative Neighborhood Graph (DRNG) and Directed Local Spanning Subgraph (DLSS). In both algorithms, each node selects a set of neighbors based on the locally collected information. We prove that (1) the topologies derived under DRNG and DLSS preserve the network connectivity; (2) the out degree of any node in the resulting topology by DLSS is bounded, while the out degree cannot be bounded in DRNG; and (3) the topologies generated by DRNG and DLSS preserve the network bi-directionality
Stocking, Enhancement, and Mariculture of Penaeus orientalis and Other Species in Shanghai and Zhejiang Provinces, China
China's marine aquaculture landings provide only 18% of its combined freshwater and amrine capture and culture landings, at a per-capita consumption of only 3.2 kg/yr out of a total of 18.1 kg/yr. We described development and some of the results of long-term mariculture and stocking/enhancement projects that have been underway for up to 20 years in the Hangzhou Bay area. Penaeus orientalis (also referred to as P. chinensis) stocking provided up to 400 t/yr, at a total cost-benefit ratio of up to 8 Yuan of landed shrimp per Yuan invested in shrimp stocking. Over 40 t of Penaeus orientalis were produced commercially in 1993, with proceeds being used to fund mariculture and fisheries research. Large scale edible jellyfish restocking is also underway, while semicommercial culture of abalone, Haliotis diversicolor, has been successful. Technical problems limitig mariculture have been solved successfully for some species
Mandarin Chinese: Four-Year Instructional Goals, Curriculum Outline, and Institutional Measures to facilitate implementation of the curriculum utilizing a performance-based approach
NW47This curriculum outline includes student profiles, objectives, and an instructional outline for a Chinese language core program which utilizes a performance-based methodology
Millet agriculture dispersed from Northeast China to the Russian Far East: integrating archaeology, genetics, and linguistics
Broomcorn and foxtail millets were being cultivated in the West Liao River basin in Northeast China by at least the sixth millennium BCE. However, when and how millet agriculture spread from there to the north and east remains poorly understood. Here, we trace the dispersal of millet agriculture from Northeast China to the Russian Far East and weigh demic against cultural diffusion as mechanisms for that dispersal. We compare two routes for the spread of millet into the Russian Far East discussed in previous researchâan inland route across Manchuria, and a coastal/inland route initially following the Liaodong Peninsula and Yalu Riverâusing an archaeological dataset including millet remains, pottery, stone tools, spindle whorls, jade and figurines. We then integrate the archaeological evidence with linguistic and genetic findings in an approach we term âtriangulationâ. We conclude that an expansion of agricultural societies in Northeast China during the Middle to Late Hongshan (4000â3000 BCE) coincided with the arrival of millet cultivation in eastern Heilongjiang and the Primorye province of the Russian Far East. Our findings support the inland, Manchuria route for the dispersal of millet to the Primorye and suggest that, as well as long-distance cultural exchange, demic diffusion was also involved. Our results are broadly compatible with the farming/language dispersal hypothesis and consistent with a link between the spread of millet farming and proto-Tungusic, the language ancestral to the contemporary Tungusic languages, in late Neolithic Northeast Asia. © 2020 The Author
Dynamical Mean Field Theory for the Bose-Hubbard Model
The dynamical mean field theory (DMFT), which is successful in the study of
strongly correlated fermions, was recently extended to boson systems [Phys.
Rev. B {\textbf 77}, 235106 (2008)]. In this paper, we employ the bosonic DMFT
to study the Bose-Hubbard model which describes on-site interacting bosons in a
lattice. Using exact diagonalization as the impurity solver, we get the DMFT
solutions for the Green's function, the occupation density, as well as the
condensate fraction on a Bethe lattice. Various phases are identified: the Mott
insulator, the Bose-Einstein condensed (BEC) phase, and the normal phase. At
finite temperatures, we obtain the crossover between the Mott-like regime and
the normal phase, as well as the BEC-to-normal phase transition. Phase diagrams
on the plane and on the plane are
produced ( is the scaled hopping amplitude). We compare our results
with the previous ones, and discuss the implication of these results to
experiments.Comment: 11 pages, 8 figure
Power-Law Distributions in Circulating Money: Effect of Preferential Behavior
We introduce preferential behavior into the study on statistical mechanics of
money circulation. The computer simulation results show that the preferential
behavior can lead to power laws on distributions over both holding time and
amount of money held by agents. However, some constraints are needed in
generation mechanism to ensure the robustness of power-law distributions.Comment: 4 pages, 2 figure
Dynamics of evaporative colloidal patterning
Drying suspensions often leave behind complex patterns of particulates, as
might be seen in the coffee stains on a table. Here we consider the dynamics of
periodic band or uniform solid film formation on a vertical plate suspended
partially in a drying colloidal solution. Direct observations allow us to
visualize the dynamics of the band and film deposition, and the transition in
between when the colloidal concentration is varied. A minimal theory of the
liquid meniscus motion along the plate reveals the dynamics of the banding and
its transition to the filming as a function of the ratio of deposition and
evaporation rates. We also provide a complementary multiphase model of colloids
dissolved in the liquid, which couples the inhomogeneous evaporation at the
evolving meniscus to the fluid and particulate flows and the transition from a
dilute suspension to a porous plug. This allows us to determine the
concentration dependence of the bandwidth and the deposition rate. Together,
our findings allow for the control of drying-induced patterning as a function
of the colloidal concentration and evaporation rate.Comment: 11 pages, 7 figures, 2 table
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