A rate adaptive bit-loading algorithm for in-building power-line communications based on DMT-modulated systems

This paper deals with a variable rate discrete multitone modulation system for broadband power-line communications, based on the bit-loading algorithm proposed by Leke and Cioffi. In the proposed system a suitable least mean square channel estimator is considered, which is based on the insertion of a training sequence (TS). The proposed approach will be compared with the ideal channel estimates, showing its effectiveness. Moreover, different TS lengths will be compared. The system performance, expressed in terms of bit rate and bit-error rate, is derived by simulation with and without estimation errors. The propagation environment has been assumed as a frequency-selective multipath fading channel with additive colored Gaussian noise, according to the in-building networks model.     

A Low-Complexity Multiuser Detector for Asynchronous CDMA QPSK Adaptive Antenna Array Systems

This paper proposes a low complexity joint space-time multiuser detection algorithm for asynchronous DS/CDMA antenna array systems. The proposed multiuser detector is composed of an adaptive antenna array, used as a linear beamformer, and a sliding window decorrelator. A QPSK modulation scheme is used in order to increase bandwidth efficiency. Numerical results are given in terms of Bit Error Rate (BER) under the assumption of a frequency-selective Rayleigh slow fading channel. In particular, the proposed receiver is shown to be near-far resistant, even in worst fading cases, and to exploit completely array introduction while maintaining acceptable computational complexity. The proposed architecture avoids linear filter realization of the decorrelator, which is impractical in the case of a large number of users, and operates with relatively short data frames instead of the complete information sequence. Finally, this receiver is very flexible to changes in timing configuration.     

Microstructural transformations of heat affected zones in duplex steel welded joints

The influence of the welding thermal conditions exemplified by heat input and heat treatment after welding on the structure of the heat affected zone (HAZ) UNS S31803 has been analysed. The post weld treatment was used to create the precisely defined thermal conditions for the decomposition of primary phases in the HAZ, by a multi-layer welding thermal cycle stimulation. Detailed analyses of the microstructure and chemical composition of the phases in the different post welded conditions were performed by scanning electron microscopy (SEM) combined with energy dispersive spectrometry (EDS) and transmission electron microscopy (TEM). Three types of secondary precipitates have been observed: secondary austenite (γ₂), carbides: M₂₃C₆ and M₇C₃. The dependence of the secondary austenite volume fraction and morphology in the HAZ on thermal cycle have been interpreted. The eutectoid decomposition of the primary phases in the analysed thermal conditions was confirmed.     

Exact solution of elasto-plastic stresses in a metal-matrix composite beam of arbitrary orientation subjected to transverse loads

An analytical elasto-plastic stress analysis is presented for a metal-matrix composite beam of arbitrary orientation subjected to a single transverse force applied to the free end of the beam and a uniformly distributed load. The material is assumed to be perfectly plastic in the elasto-plastic solution. A composite consisting of stainless-steel-reinforced aluminum was produced for this work. Sample problems are given for various orientation angles. Elastic, elastoplastic and residual normal and shear stresses are calculated. The location of the elasto-plastic boundary of the beam is obtained according to the x coordinates of the beam.     

The polymerase chain reaction detects B cell clonalities in patients with Sj?gren's syndrome and suspected malignant lymphoma

OBJECTIVE: To investigate the usefulness of the polymerase chain reaction (PCR) to detect B cell clonal expansions in tissues where lymphoproliferative disease was suspected in the course of Sj?gren's syndrome (SS). METHODS: Tissue samples from 7 patients with definite (5 cases) or probable (2 cases) SS were subjected to routine histopathologic studies, immunophenotyping, and genotypic analysis, including Southern blotting and PCR amplification of immunoglobulin heavy chain (IgH) variable-diversity-joining (VDJ) region gene rearrangements. RESULTS: Malignant lymphoma was detected in 3 cases, and myoepithelial sialadenitis in the remaining 4. B cell clonal expansion was detected in 7/7 cases by PCR, 5/7 by Southern blotting, and in no case of myoepithelial sialadenitis by kappa/lambda light chain immunophenotyping. CONCLUSION: PCR may represent a quick and powerful tool to detect B cell clonalities in SS. Such information may provide new insights into the pathogenesis of the disease and may improve the clinical approach to the patients.     

Fast Recognition of Fibonacci Cubes

Fibonacci cubes are induced subgraphs of hypercubes based on Fibonacci strings. They were introduced to represent interconnection networks as an alternative to the hypercube networks. We derive a characterization of Fibonacci cubes founded on the concept of resonance graphs. The characterization is the basis for an algorithm which recognizes these graphs in O(mlog n) time. A. Vesel supported by the Ministry of Science of Slovenia under the grant 0101-P-297.     

Direct data‐driven control of linear time‐delay systems

This paper presents an extension of the Virtual Reference Feedback Tuning (VRFT) methodology dedicated to linear time‐delay systems with known delay and unknown dynamics. The standard VRFT is not well suited for systems with dominant time‐delay as it yields high order controllers. The proposed direct approach, relying on a Smith Predictor structure, guarantees the same level of performance as the standard VRFT but with lower order controllers. The joint direct data‐driven design of the controller and the predictor is facilitated by the introduction of an ad‐hoc optimization initialization. Effectiveness and robustness to uncertainty in the time‐delay estimation are shown in a vehicle dynamics control problem. Copyright © 2011 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society     

Ubiquitin-Specific Protease 29 Regulates Cdc25A-Mediated Tumorigenesis

Cell division cycle 25A (Cdc25A) is a dual-specificity phosphatase that is overexpressed in several cancer cells and promotes tumorigenesis. In normal cells, Cdc25A expression is regulated tightly, but the changes in expression patterns in cancer cells that lead to tumorigenesis are unknown. In this study, we showed that ubiquitin-specific protease 29 (USP29) stabilized Cdc25A protein expression in cancer cell lines by protecting it from ubiquitin-mediated proteasomal degradation. The presence of USP29 effectively blocked polyubiquitination of Cdc25A and extended its half-life. CRISPR-Cas9-mediated knockdown of USP29 in HeLa cells resulted in cell cycle arrest at the G0/G1 phase. We also showed that USP29 knockdown hampered Cdc25A-mediated cell proliferation, migration, and invasion of cancer cells in vitro. Moreover, NSG nude mice transplanted with USP29-depleted cells significantly reduced the size of the tumors, whereas the reconstitution of Cdc25A in USP29-depleted cells significantly increased the tumor size. Altogether, our results implied that USP29 promoted cell cycle progression and oncogenic transformation by regulating protein turnover of Cdc25A.     

基于CFD的坐便器出水孔设计与数值分析

针对节水坐便器的研究开发问题,采用CFD多相流数值模拟手段,探究了出水孔形状与结构对坐便器水包壁面清洗效果以及排污能力的影响.结果表明,出水孔形状与坐便器冲洗效果密切相关,十字形出水孔坐便器,特别是正十字形出水孔坐便器,其清洁能力远优于常规圆形出水孔坐便器;改变出水孔内部流道结构同样可以有效提高坐便器清洁效果,相比传统圆柱型结构出水孔,锥直型以及余弦型结构出水孔坐便器水包壁面冲洗效果更好、排污能力提升均在15％以上.