330 research outputs found
Handover parameter optimization in LTE self-organizing networks
This paper presents a self-optimizing algorithm that tunes the handover (HO) parameters of a LTE (Long-Term Evolution) base station in order to improve the overall network performance and diminish negative effects (call dropping, HO failures). The proposed algorithm picks the best hysteresis and time-to-trigger combination for the current network status. We examined the effects of this self-optimizing algorithm in a realistic scenario setting and the results show an improvement from the static value settings
An enhanced weighted performance-based handover parameter optimization algorithm for LTE networks
This article introduces an enhanced version of previously developed self-optimizing algorithm that controls the handover (HO) parameters of a long-term evolution base station in order to diminish and prevent the negative effects that can be introduced by HO (radio link failures, HO failures and ping-pong HOs) and thus improve the overall network performance. The default algorithm selects the best hysteresis and time-to-trigger combination based on the current network status. The enhancement proposed here aims to maximize the gain provided by the algorithm by improving its convergence time. The effects of this enhancement have been studied in a rural scenario setting and compared to the original algorithm; the results show a clear improvement, faster convergence, and better network performance, because of the enhancement
Control of Tension-Compression Asymmetry in Ogden Hyperelasticity with Application to Soft Tissue Modelling
This paper discusses tension-compression asymmetry properties of Ogden
hyperelastic formulations. It is shown that if all negative or all positive
Ogden coefficients are used, tension-compression asymmetry occurs the degree of
which cannot be separately controlled from the degree of non-linearity. A
simple hybrid form is therefore proposed providing separate control over the
tension-compression asymmetry. It is demonstrated how this form relates to a
newly introduced generalised strain tensor class which encompasses both the
tension-compression asymmetric Seth-Hill strain class and the
tension-compression symmetric Ba\v{z}ant strain class. If the control parameter
is set to q=0.5 a tension-compression symmetric form involving Ba\v{z}ant
strains is obtained with the property
{\Psi}({\lambda}_1,{\lambda}_2,{\lambda}_3 )={\Psi}(1/{\lambda}_1
,1/{\lambda}_2 ,1/{\lambda}_3 ). The symmetric form may be desirable for the
definition of ground matrix contributions in soft tissue modelling allowing all
deviation from the symmetry to stem solely from fibrous reinforcement. Such an
application is also presented demonstrating the use of the proposed formulation
in the modelling of the non-linear elastic and transversely isotropic behaviour
of skeletal muscle tissue in compression (the model implementation and fitting
procedure have been made freely available). The presented hyperelastic
formulations may aid researchers in independently controlling the degree of
tension-compression asymmetry from the degree of non-linearity, and in the case
of anisotropic materials may assist in determining the role played by, either
the ground matrix, or the fibrous reinforcing structures, in generating
asymmetry.Comment: 20 page
Handover parameter optimization in LTE self-organizing networks
This paper presents a self-optimizing algorithm that tunes the handover (HO) parameters of a LTE (Long-Term Evolution) base station in order to improve the overall network performance and diminish negative effects (call dropping, HO failures). The proposed algorithm picks the best hysteresis and time-to-trigger combination for the current network status. We examined the effects of this self-optimizing algorithm in a realistic scenario setting and the results show an improvement from the static value settings
Detection of Noble Gas Scintillation Light with Large Area Avalanche Photodiodes (LAAPDs)
Large Area Avalanche Photodiodes (LAAPDs) were used for a series of
systematic measurements of the scintillation light in Ar, Kr, and Xe gas.
Absolute quantum efficiencies are derived. Values for Xe and Kr are consistent
with those given by the manufacturer. For the first time we show that argon
scintillation (128 nm) can be detected at a quantum efficiency above 40%.
Low-pressure argon gas is shown to emit significant amounts of non-UV
radiation. The average energy expenditure for the creation of non-UV photons in
argon gas at this pressure is measured to be below 378 eV.Comment: 16 pages, 7 figure
A simple method to alter the binding specificity of DNA-coated colloids that crystallize
DNA-coated colloids can crystallize into a multitude of lattices, ranging from face-centered cubic to diamond, opening avenues to producing structures with useful photonic properties. The potential design space of DNA-coated colloids is large, but its exploration is hampered by a reliance on chemically modified DNA that is slow and expensive to commercially synthesize. Here we introduce a method to controllably tailor the sequences of DNA-coated particles by covalently appending new sequence domains onto the DNA grafted to colloidal particles. The tailored particles crystallize as readily and at the same temperature as those produced via direct chemical synthesis, making them suitable for self-assembly. Moreover, we show that particles coated with a single sequence can be converted into a variety of building blocks with differing specificities by appending different DNA sequences to them. This method will make it practical to identify optimal and complex particle sequence designs and paves the way to programming the assembly kinetics of DNA-coated colloids.</p
A simple method to alter the binding specificity of DNA-coated colloids that crystallize
DNA-coated colloids can crystallize into a multitude of lattices, ranging from face-centered cubic to diamond, opening avenues to producing structures with useful photonic properties. The potential design space of DNA-coated colloids is large, but its exploration is hampered by a reliance on chemically modified DNA that is slow and expensive to commercially synthesize. Here we introduce a method to controllably tailor the sequences of DNA-coated particles by covalently appending new sequence domains onto the DNA grafted to colloidal particles. The tailored particles crystallize as readily and at the same temperature as those produced via direct chemical synthesis, making them suitable for self-assembly. Moreover, we show that particles coated with a single sequence can be converted into a variety of building blocks with differing specificities by appending different DNA sequences to them. This method will make it practical to identify optimal and complex particle sequence designs and paves the way to programming the assembly kinetics of DNA-coated colloids.</p
High-Throughput In Vivo Analysis of Gene Expression in Caenorhabditis elegans
Using DNA sequences 5′ to open reading frames, we have constructed green fluorescent protein (GFP) fusions and generated spatial and temporal tissue expression profiles for 1,886 specific genes in the nematode Caenorhabditis elegans. This effort encompasses about 10% of all genes identified in this organism. GFP-expressing wild-type animals were analyzed at each stage of development from embryo to adult. We have identified 5′ DNA regions regulating expression at all developmental stages and in 38 different cell and tissue types in this organism. Among the regulatory regions identified are sequences that regulate expression in all cells, in specific tissues, in combinations of tissues, and in single cells. Most of the genes we have examined in C. elegans have human orthologs. All the images and expression pattern data generated by this project are available at WormAtlas (http://gfpweb.aecom.yu.edu/index) and through WormBase (http://www.wormbase.org)
- …