Pilot-based carrier frequency offset estimation in OFDM systems

The ability of OFDM to mitigate channel frequency selectivity is impaired by its vulnerability to carrier frequency offset (CFO). In this paper, a new pilot-based carrier frequency offset estimation scheme for frequency selective slowly-varying channels is proposed. This scheme exploits the inherent redundancy introduced by the OFDM signaling and no additional training symbol is needed. The synchronization process is to minimize a LMS-like cost function, which essentially quantifies the variance of the pilot tones across several OFDM symbols. Moreover, a reduced-complexity estimator is also developed to reduce the implementation complexity. The CFO estimation range can span the whole OFDM signal bandwidth by nonuniformly distributing the embedded pilot tones in the frequency domain. Computer simulation results show that the performance of the proposed estimator can meet the requirement of typical OFDM communication systems.published_or_final_versio

High compression ratio image processing techniques using combinations of WT and IFS

Many works of compressing image based on wavelet transformation have been presented in recent years. Also, the method of fractals is used in this field. The first method uses the pyramid subband decomposition, and the second takes advantage of the self-similarity between the basic image and subimages. We combine these two methods as a hybrid algorithm to complete the image compression. The experiments show that this method has a better performance than many others, especially, in a high compression ratio situation. A comparison with the famous embedded zero tree wavelet (EZW) algorithm shows that its performance is close to the EZW algorithm.published_or_final_versio

Regional disparity and convergence of electricity consumption in China: A distribution dynamics approach

© 2018 Elsevier Inc. One critical factor that affects China's achievement of its peak emission by 2030 is total electricity demand. The aim of this study is to examine regional disparity in electricity consumption in China. The analysis is based on a panel database which is compiled at the provincial level. A distributional dynamics approach is then employed to reveal the trend and movement of each province within the distributions in different regional groupings. The mobility probability plot (MPP) is also employed to provide detailed information on the probability of change in electricity consumption. The results demonstrate significant divergence presents across provinces, over time and within different regional groups. The results can pinpoint the transition mechanism within each region so that appropriate energy policy can be formulated to accommodate future demand in electricity for different regions in China. The results suggest that regional specific energy efficiency policy is needed

Novel therapeutic targets in epilepsy: oxidative stress and iron metabolism

Malformations of Cortical Development (MCD) are one of the most frequent causes of multidrug‐resistant focal epilepsy, of which focal cortical dysplasia type IIb (FCDIIb) and Tuberous Sclerosis

160-fold acceleration of the Smith-Waterman algorithm using a field programmable gate array (FPGA)

<p>Abstract</p> <p>Background</p> <p>To infer homology and subsequently gene function, the Smith-Waterman (SW) algorithm is used to find the optimal local alignment between two sequences. When searching sequence databases that may contain hundreds of millions of sequences, this algorithm becomes computationally expensive.</p> <p>Results</p> <p>In this paper, we focused on accelerating the Smith-Waterman algorithm by using FPGA-based hardware that implemented a module for computing the score of a single cell of the SW matrix. Then using a grid of this module, the entire SW matrix was computed at the speed of field propagation through the FPGA circuit. These modifications dramatically accelerated the algorithm's computation time by up to 160 folds compared to a pure software implementation running on the same FPGA with an Altera Nios II softprocessor.</p> <p>Conclusion</p> <p>This design of FPGA accelerated hardware offers a new promising direction to seeking computation improvement of genomic database searching.</p

Recording of natural head position using stereophotogrammetry: A new technique and reliability study

The purpose of this study was to develop a technique to record physical references and orient digital mesh models to natural head position (NHP) using stereo-photogrammetry (SP). The first step was to record the digital mesh model of a hanging reference board placed at the capturing position of the SP machine. The board was aligned to the true vertical using a plumb bob. It was also aligned with laser plane parallel to the hanging mirror which was located at the center of the machine. Parameter derived from the digital mesh model of the board was then used to adjust the roll, pitch and yaw of the subsequent captures of subjects. This information was valid until the next machine calibration. The board placement was repeatable with standard deviation of less than 0.1 degrees for both pitch and yaw; 0.15 degrees for roll angles.postprin

Diabetic Impairment of C-Kit+ Bone Marrow Stem Cells Involves the Disorders of Inflammatory Factors, Cell Adhesion and Extracellular Matrix Molecules

Bone marrow stem cells from diabetes mellitus patients exhibit functional impairment, but the relative molecular mechanisms responsible for this impairment are poorly understood. We investigated the mechanisms responsible for diabetes-related functional impairment of bone marrow stem cells by extensively screening the expression levels of inflammatory factors, cell cycle regulating molecules, extracellular matrix molecules and adhesion molecules. Bone marrow cells were collected from type 2 diabetic (db/db) and healthy control (db/m+) mice, and c-kit+ stem cells were purified (purity>85%) for experiments. Compared with the healthy control mice, diabetic mice had significantly fewer c-kit+ stem cells, and these cells had a lower potency of endothelial differentiation; however, the production of the angiogenic growth factor VEGF did not differ between groups. A pathway-focused array showed that the c-kit+ stem cells from diabetic mice had up-regulated expression levels of many inflammatory factors, including Tlr4, Cxcl9, Il9, Tgfb1, Il4, and Tnfsf5, but no obvious change in the expression levels of cell cycle molecules. Interestingly, diabetes-related alterations of the extracellular matrix and adhesion molecules were varied; Pecam, Mmp10, Lamc1, Itgb7, Mmp9, and Timp4 were up-regulated, but Col11a1, Fn1, Admts2, and Itgav were down-regulated. Some of these changes were also confirmed at the protein level by flow cytometry analysis. In conclusion, c-kit+ bone marrow stem cells from diabetic mice exhibited an extensive enhancement of inflammatory factors and disorders of the extracellular matrix and adhesion molecules. Further intervention studies are required to determine the precise role of each molecule in the diabetes-related functional impairment of c-kit+ bone marrow stem cells

The Efficacy of Triamcinolone Acetonide in Keloid Treatment: A Systematic Review and Meta-analysis

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Active routing service for the next-generation network/ISDN3

In recent years, a new routing method, known as active routing, has been emerging. This involves using active packets to configure customized network paths. Based on a Markov decision model, this paper presents an active routing service for active networks in general and the next generation network, called ISDN3, in particular. Our aim is to determine the active routing policy so as to minimize the network cost. Theoretical analysis is presented to show the advantages of our proposal as compared with three other approaches.published_or_final_versio