Search results for "multiple"
showing 10 items of 2678 documents
Joint Spectral and Energy Efficiency Optimization for Downlink NOMA Networks
2020
Non-orthogonal multiple access (NOMA) holds the promise to be a key enabler of 5G communication. However, the existing design of NOMA systems must be optimized to achieve maximum rate while using minimum transmit power. To do so, this paper provides a novel technique based on multi-objective optimization to efficiently allocate resources in the multi-user NOMA systems supporting downlink transmission. Specifically, our unique optimization technique jointly improves spectrum and energy efficiency while satisfying the constraints on users quality of services (QoS) requirements, transmit power budget and successive interference cancellation. We first formulate a joint problem for spectrum and …
Prevalence of tooth erosion and associated factors in 13-16-year old adolescents in Greece
2012
Objectives: The aim of this study was to estimate the prevalence of dental erosion and to investigate possible associations among dental erosion and medical history, dietary and lifestyle habits in a sample of adolescents in Greece. Study design: The study sample consisted of 770 adolescents, 374 boys and 396 girls aged 13 to 16 years. All individuals were clinically examined and answered questions regarding their medical history, rate and frequency of drinks and food consumption and lifestyle habits. Statistical analysis of the questionnaire items was performed by using the multiple logistic regression analysis model. Results: Two hundreds and sixty adolescents were diagnosed as having den…
Oral, facial, digital, vertebral anomalies with psychomotor delay: a mild form of OFD type Gabrielli?
2002
A girl with oral, facial, and digital anomalies presented at birth with a large cleft palate filled by a nasopharyngeal mass and was found later to have several vertebral anomalies and mental retardation. A similar phenotype has been previously reported in a sporadic male patient [Gabrielli et al., 1994: Am J Med Genet 53:290-293], suggesting a new variant form of oral-facial-digital syndrome.
Oral health-related quality of life after dental treatment in patients with intellectual disability
2020
Background The influence of dental treatment on oral health-related quality of life (OHRQOL) has rarely been evaluated in patients with intellectual disability (ID) through validated questionnaires. The aim of this study was to estimate the changes on OHRQOL in patients with ID after the implementation of an institutional dental treatment program under general anesthesia using the Franciscan Hospital for Children Oral Health-Related Quality of Life questionnaire (FHCOHRQOL-Q). Material and Methods A prospective longitudinal study was conducted on 85 patients (mean age=24.85 years) classified according to DSM-V whose parents/caregivers completed the FHC-OHRQOL-Q. We analyzed the changes in t…
Hundreds of nuclear and plastid loci yield insights into orchid relationships
2020
ABSTRACTPremise of the studyEvolutionary relationships in the species-rich Orchidaceae have historically relied on organellar DNA sequences and limited taxon sampling. Previous studies provided a robust plastid-maternal phylogenetic framework, from which multiple hypotheses on the drivers of orchid diversification have been derived. However, the extent to which the maternal evolutionary history of orchids is congruent with that of the nuclear genome has remained uninvestigated.MethodsWe inferred phylogenetic relationships from 294 low-copy nuclear genes sequenced/obtained using the Angiosperms353 universal probe set from 75 species representing 69 genera, 16 tribes and 24 subtribes. To test…
Pseudo-Abelian integrals along Darboux cycles
2008
We study polynomial perturbations of integrable, non-Hamiltonian system with first integral of Darboux-type with positive exponents. We assume that the unperturbed system admits a period annulus. The linear part of the Poincare return map is given by pseudo-Abelian integrals. In this paper we investigate analytic properties of these integrals. We prove that iterated variations of these integrals vanish identically. Using this relation we prove that the number of zeros of these integrals is locally uniformly bounded under generic hypothesis. This is a generic analog of the Varchenko-Khovanskii theorem for pseudo-Abelian integrals. Finally, under some arithmetic properties of exponents, the p…
Family-supportive organization perceptions, multiple dimensions of work–family conflict, and employee satisfaction : a test of model across five samp…
2008
Work-family conflict (WFC) is recognized as a major issue affecting both individual employees and their employers. Preliminary research shows that the more employees perceive their work environment as family-supportive, the less they experience WFC (Allen, 2001). Moreover, there are theoretical and empirical reasons to expect that by reducing WFC, a family-supportive work environment would enhance employees’ satisfaction with their job, family, and life in general. In addition, despite the impressive body of research that has been devoted to WFC, there have been few studies that have assessed WFC as a multidimensional construct, other than those that distinguish between directions of confli…
A Comparative Study of Cyclic Fatigue of 10 Different Types of Endodontic Instruments: an in Vitro Study
2019
Objective This study was designed to test the null hypothesis that there were no significant differences between size 25 files F360, F6 SkyTaper, Hyflex EDM, iRace, Neoniti, One Shape Protaper Next, Reciproc, Revo-S and Wave One Gold in terms of resistance to cyclic fatigue and length of broken fragments. Material and methods 300 new size 25 files of the systems studied were selected (n=30). The instruments were mechanized with a X-Smart Plus endo motor at the speed and torque recommended by the manufacturer, holding the instruments steady with a clamping mechanism, with passive adjustment and without pressure in a stainless-steel block. The time was calculated in seconds until fracture. Th…
Blind source separation based interference suppression schemes for OFDM and DS-CDMA
2015
In statistical wireless signal processing, extraction of unobserved signals from observed mixtures can be achieved using Blind Source Separation (BSS) algorithms. Orthogonal Frequency Division Multiplexing (OFDM) and Direct Sequence-Code Division Multiple Access (DS-CDMA) can be pronounced as the well established predominant air interface communication techniques. Consequences of an effort taken and counteractive solutions to diminish the undesirable influences encountered within the wireless air interface of those techniques with aid of BSS schemes are disclosed. Filter coefficients for the receiver are ascertained with the support of a set of energy functions and the iterative fixed point…
Efficient Simulation of Orthogonal Multicarrier Transmission over Multipath Fading Channels
2011
Filterbank orthogonal multicarrier transmission schemes, such as OFDM/OQAM, are currently under intense study for their spectral efficiency and suitability for the physical layer of Cognitive Radio. Nonetheless, the mathematical description of the signal is cumbersome, and closed form expressions for performance figures are not available, so performance analysis on fading channels has to be performed by means of simulations. We propose an algorithm for simulating the received signal over multipath frequency selective fading channels, based on Taylor series expansion of the channel transfer function. The proposed method is compared to the state-of-the-art FFT-based method in terms of computa…