12,213 research outputs found
Simulated Annealing for Location Area Planning in Cellular networks
LA planning in cellular network is useful for minimizing location management
cost in GSM network. In fact, size of LA can be optimized to create a balance
between the LA update rate and expected paging rate within LA. To get optimal
result for LA planning in cellular network simulated annealing algorithm is
used. Simulated annealing give optimal results in acceptable run-time.Comment: 7 Pages, JGraph-Hoc Journa
A Study on the Catch Composition of Set Bag Net Used in the Ramnabad River, Patuakhali District (in Bangladesh)
The field study was conducted on the set bag net (Behundi jal) fishery and species composition of set bag net in the Ramnabad River adjacent to the Galachipa upazila of Patuakhali district. The study was conducted for a period of eight months from July-2012 to February-2013. A total of twelve fishes and shellfishes such as Poa, Tengra, Ilish, Chewya, Golda chingri, Ramsos, Horina chingri, Kajli, Chapila, Motka chingri, Dogri, Boiragi were identified in the catches of set bag net used by the fishermen during the study period. Among that species Chewya (Taenioides cirratus ) and Horina chingri (Metapenaeus monoceros) were the dominant fishes. The Chewya was dominant in winter season while salinity was high. Horina chingri was dominant in rainy season when water current increased. The other fishes were found a little amount but not significant and had no relation with salinity and current. Salinity and water current was the main factors for the variation of total catch and availability of fish. In July to October the water level of the river remained high, so the abundance and availability of fish was high. For fishing fishermen used set bag net from July to February when the water level was high in rainy season and salinity was high in winter season. During high tide the water entered into the adjacent estuary and the fishermen used set bag net in the mouth of the estuary. Keywords: Catch composition, set bag net, SBN, Ramnsbad Rive
Performance of nanocrystalline Ni3N as a negative electrode for sodium-ion batteries
Nickel nitride is synthesised by high temperature ammonolysis of nickel(II) hexamine and tris(ethylenediamine) salts. Its electrochemical characteristics are examined in half-cells vs. lithium and sodium. Samples with high surface area are found to have significant reversible charge storage capacity in sodium cells and hence to be a promising negative electrode material for sodium-ion batteries
Towards the Formal Reliability Analysis of Oil and Gas Pipelines
It is customary to assess the reliability of underground oil and gas
pipelines in the presence of excessive loading and corrosion effects to ensure
a leak-free transport of hazardous materials. The main idea behind this
reliability analysis is to model the given pipeline system as a Reliability
Block Diagram (RBD) of segments such that the reliability of an individual
pipeline segment can be represented by a random variable. Traditionally,
computer simulation is used to perform this reliability analysis but it
provides approximate results and requires an enormous amount of CPU time for
attaining reasonable estimates. Due to its approximate nature, simulation is
not very suitable for analyzing safety-critical systems like oil and gas
pipelines, where even minor analysis flaws may result in catastrophic
consequences. As an accurate alternative, we propose to use a
higher-order-logic theorem prover (HOL) for the reliability analysis of
pipelines. As a first step towards this idea, this paper provides a
higher-order-logic formalization of reliability and the series RBD using the
HOL theorem prover. For illustration, we present the formal analysis of a
simple pipeline that can be modeled as a series RBD of segments with
exponentially distributed failure times.Comment: 15 page
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