5,134 research outputs found
A New Approach to Coding in Content Based MANETs
In content-based mobile ad hoc networks (CB-MANETs), random linear network
coding (NC) can be used to reliably disseminate large files under intermittent
connectivity. Conventional NC involves random unrestricted coding at
intermediate nodes. This however is vulnerable to pollution attacks. To avoid
attacks, a brute force approach is to restrict the mixing at the source.
However, source restricted NC generally reduces the robustness of the code in
the face of errors, losses and mobility induced intermittence. CB-MANETs
introduce a new option. Caching is common in CB MANETs and a fully reassembled
cached file can be viewed as a new source. Thus, NC packets can be mixed at all
sources (including the originator and the intermediate caches) yet still
providing protection from pollution. The hypothesis we wish to test in this
paper is whether in CB-MANETs with sufficient caches of a file, the performance
(in terms of robustness) of the restricted coding equals that of unrestricted
coding.
In this paper, we examine and compare unrestricted coding to full cache
coding, source only coding, and no coding. As expected, we find that full cache
coding remains competitive with unrestricted coding while maintaining full
protection against pollution attacks
Factors Influencing the Adoption of Mobile Learning
Education delivery by mobile devices enables anywhere / anytime learning. Mobile learning has the potential to allow students to more closely integrate learning activities into their busy lives. At this early stage in its development, this is an opportune time to initiate a stream of research that examines the adoption of m-learning applications. This study determines the key factors influencing the behavioural intention for adoption of mobile learning. Several external variables are incorporated into the Technology Acceptance Model and tested in six New Zealand universities. Six of the seven variables – self-efficacy, perceived usefulness, subjective norm, attitude, perceived ease of use, and perceived financial resources were accepted. Prior use of e-learning was not accepted and reasons for this are explored in the study
Double Secret Protection: Bridging Federal and State Law To Protect Privacy Rights for Telemental and Mobile Health Users
Mental health care in the United States is plagued by stigma, cost, and access issues that prevent many people from seeking and continuing treatment for mental health conditions. Emergent technology, however, may offer a solution. Through telemental health, patients can connect with providers remotely—avoiding stigmatizing situations that can arise from traditional healthcare delivery, receiving more affordable care, and reaching providers across geographic boundaries. And with mobile health technology, people can use smart phone applications both to self-monitor their mental health and to communicate with their doctors. But people do not want to take advantage of telemental and mobile health unless their privacy is protected. After evaluating the applicability of current health information privacy law to these new forms of treatment, this Note proposes changes to the federal regime to protect privacy rights for telemental and mobile health users
FFTPL: An Analytic Placement Algorithm Using Fast Fourier Transform for Density Equalization
We propose a flat nonlinear placement algorithm FFTPL using fast Fourier
transform for density equalization. The placement instance is modeled as an
electrostatic system with the analogy of density cost to the potential energy.
A well-defined Poisson's equation is proposed for gradient and cost
computation. Our placer outperforms state-of-the-art placers with better
solution quality and efficiency
Recommended from our members
Characteristics of magnetic carriers responsible for Late Paleozoic remagnetization in carbonate strata of the mid-continent, U.S.A.
Magnetic analysis of carbonate strata of the mid-continent region of the United States indicates that the Late Paleozoic remagnetization already recognized in the Appalachians also affects almost the entire mid-continent. Magnetic intensity is regionally variable, with more intense magnetizations occurring on intracratonic arches. Magnetization is carried predominately by magnetite, which often occurs in tiny hollow spheroids composed of well formed octahedral microcrysts. Spheroid chemistry and morphology suggests that the magnetite is authigenic, composed of iron extracted from pre-existing pyrite or clay. The timing of the remagnetization, the character of the magnetite, and the regional variation in magnetic intensity support the idea that the remagnetization is a diagenetic consequence of tectonically-driven brine migration
Persistent effects of early infant diet and associated microbiota on the juvenile immune system.
Early infant diet has significant impacts on the gut microbiota and developing immune system. We previously showed that breast-fed and formula-fed rhesus macaques develop significantly different gut microbial communities, which in turn are associated with different immune systems in infancy. Breast-fed animals manifested greater T cell activation and proliferation and harbored robust pools of T helper 17 (TH17) cells. These differences were sustained throughout the first year of life. Here we examine groups of juvenile macaques (approximately 3 to 5Â y old), which were breast-fed or formula-fed in infancy. We demonstrate that juveniles breast-fed in infancy maintain immunologic differences into the fifth year of life, principally in CD8(+) memory T cell activation. Additionally, long-term correlation networks show that breast-fed animals maintain persistent relationships between immune subsets that are not seen in formula-fed animals. These findings demonstrate that infant feeding practices have continued influence on immunity for up to 3 to 5Â y after birth and also reveal mechanisms for microbial modulation of the immune system
Design, fabrication, and characterization of engineered materials in the microwave and millimeter wave regime
In this paper we present the study of a two-dimensional square-lattice photonic crystal with all-angle negative refraction in its first band. Using this photonic crystal, we designed and fabricated a flat lens functioning as a cylindrical lens, by increasing the vertical dimension of the photonic crystal. Two-dimensional finite-difference time-domain simulation validated negative imaging and sub-wavelength resolution. To perform the experiment, a microwave imaging system was built based on a vector network analyzer. Field distributions were acquired by scanning the imaging plane and object plane. The experiment demonstrated negative refraction imaging in both amplitude and phase, and verified sub-wavelength resolution
Genes targeted by the Hedgehog-signaling pathway can be regulated by Estrogen related receptor β
Additional file 1. Table S1: Known Hh-signaling pathway target genes. Table S2: Result of all pairwise comparisons of differentially expressed genes. Table S3: Hh-signaling differentially responsive genes
- …