24 research outputs found
Efficient hardware implementations of low bit depth motion estimation algorithms
In this paper, we present efficient hardware implementation of multiplication free one-bit transform (MF1BT) based and constraint one-bit transform (C-1BT) based motion estimation (ME) algorithms, in order to provide low bit-depth representation based full search block ME hardware for real-time video encoding. We used a source pixel based linear array (SPBLA) hardware architecture for low bit depth ME for the first time in the literature. The proposed SPBLA based implementation results in a genuine data flow scheme which significantly reduces the number of data reads from the current block memory, which in turn reduces the power consumption by at least 50% compared to conventional 1BT based ME hardware architecture presented in the literature. Because of the binary nature of low bit-depth ME algorithms, their hardware architectures are more efficient than existing 8 bits/pixel representation based ME architectures
Growth of thin graphene layers on stacked SiC surface in ultra high vacuum
We demonstrate a technique to produce thin graphene layers on C-face of SiC
under ultra high vacuum conditions. A stack of two SiC substrates comprising a
half open cavity at the interface is used to partially confine the depleted Si
atoms from the sample surface during the growth. We observe that this
configuration significantly slows the graphene growth to easily controllable
rates on C-face SiC in UHV environment. Results of low-energy electron
diffractometry and Raman spectroscopy measurements on the samples grown with
stacking configuration are compared to those of the samples grown by using bare
UHV sublimation process
Clinical and Laboratory Characteristics of Hyperprolactinemia in Children and Adolescents: National Survey
Conclusion: We present the largest cohort of children and adolescents with hyperprolactinemia in the literature to date. Hyperprolactinemia is more common in females and cabergoline is highly effective and practical to use in adolescents, due to its biweekly dosing. Indications for surgery in pediatric cases need to be revised
Social norms regarding alcohol use and associated factors among university students in Turkey
WOS: 000470653600004Background: Misperceptions on the higher rates of peer alcohol use are predictive of increased personal use among university students. Objectives: This study aims to assess the prevalence, perceived peers' social norms and other predictors of alcohol use in a sample of Turkish university students. Methods: This study is established upon the baseline Turkish data on alcohol use of the project Social Norms Intervention for the prevention of Polydrug usE (SNIPE). The data was obtained by a self-reported, online questionnaire from 858 students of Marmara University who were registered to the study web page. Results: Alcohol use and drunkenness rates were 62.6%, and 40.9%, respectively. Twenty point two percent of students reported drinking alcohol at least once a week in the last two months. Majority of students (70.4%) reported that religion has an important or very important role in their lives. Perceived higher frequency of peer alcohol use (p<0.000) and drunkenness (p<0.000) were significantly associated with personal alcohol use frequency. Tobacco use rate was 60.2% and positively associated with alcohol use frequency (p<0.000). In all participants, male gender (OR: 1.56; 95% CI: 1.07-2.28), giving less importance to religion (OR: 20.91; 95% CI: 10.95-39.95), tobacco use everyday/almost everyday (OR: 17.88; 95% CI: 9.33-34.29), perceived positive peer attitude towards alcohol use (OR: 2.192; 95% CI: 1.25-3.82) and perceived higher frequency of peer alcohol use (OR: 3.487; 95% CI: 1.66-7.31) were found to be associated risk factors for alcohol use. Age (OR: 1.186, CI 95%: 1.03-1.36) and perceived positive peer attitude towards alcohol use (OR 3.86, CI 95%: 1.84-8.09) were the additional risk factors among female student whereas perceived positive peer alcohol use frequency (OR: 8.08, CI 95%: 2.40-27.10) among male students. Discussion: As the first study conducted in Turkey applying social norms theory, our results indicate the noticeable misperceptions of students regarding their peers' alcohol use. Based on our results, targeting both tobacco and alcohol use, and a gender-sensitive approach employing social norms interventions may enhance the preventive strategies for risky alcohol use among university students
An all binary sub-pixel motion estimation approach and its hardware architecture
Motion estimation (ME) is the most computationally intensive part of a video coding system. Therefore it is very important to reduce its computational complexity. In this paper, a novel all-binary approach for reducing the computational complexity of sub-pixel accurate ME is proposed. An efficient hardware architecture for the proposed all-binary sub-pixel accurate motion estimation approach is also presented. The proposed hardware architecture has significantly low hardware complexity and therefore very low power consumption. It can process 720p video frames at 30 fps in a pipelined fashion together with the integer ME hardware. Therefore, it can be used in real-time low power video coding systems required by many mobile consumer electronics devices
MVBLA based design of constrained 1-bit transform based motion estimation algorithm
In this work a novel hardware proposed for Constrained 1-bit Transform based motion estimation to facilitate real time operation. The designed system occupies a small area in a general purpose FPGA fabric and it is therefore efficient to implement a whole video coding architecture on a single FPGA chip. The designed system can perform ME operation for a 2048×1152 pixel sized image frame at a speed of 20 frames/second
Control of the graphene growth rate on capped SiC surface under strong Si confinement
The effect of the degree of Si confinement on the thickness and morphology of UHV grown epitaxial graphene on (0 0 0 −1) SiC is investigated by using atomic force microscopy and Raman spectroscopy measurements. Prior to the graphene growth process, the C-face surface of a SiC substrate is capped by another SiC comprising three cavities on its Si-rich surface with depths varying from 0.5 to 2 microns. The Si atoms, thermally decomposed from the sample surface during high temperature annealing of the SiCcap/SiCsample stack, are separately trapped inside these individual cavities at the sample/cap interface. Our analyses show that the growth rate linearly increases with the cavity height. It was also found that stronger Si confinement yields more uniform graphene layers