87 research outputs found

    A Novel PTS Scheme for PAPR Reduction of Filtered-OFDM Signals without Side Information

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    In this paper, a novel partial transmit sequence (PTS) scheme is proposed for reducing the peak-to-average power ratio (PAPR) of filtered orthogonal frequency division multiplexing (f-OFDM) systems. The PTS method is modified such that no side information (SI) transmission is needed. The data and pilot recovery are accomplished by a simple detector, making use of the correlation property of the Hadamard sequence and the transparency property of the pilot signal and an iterative phase detection is further added in a fading channel. Simulation results show that the modified solution provides a higher correct detection probability without increasing the system complexity nor affecting the PAPR suppression performance

    A Life Prediction Model of Multilayered PTH Based on Fatigue Mechanism.

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    Plated through hole (PTH) plays a critical role in printed circuit board (PCB) reliability. Thermal fatigue deformation of the PTH material is regarded as the primary factor affecting the lifetime of electrical devices. Numerous research efforts have focused on the failure mechanism model of PTH. However, most of the existing models were based on the one-dimensional structure hypothesis without taking the multilayered structure and external pad into consideration. In this paper, the constitutive relation of multilayered PTH is developed to establish the stress equation, and finite element analysis (FEA) is performed to locate the maximum stress and simulate the influence of the material properties. Finally, thermal cycle tests are conducted to verify the accuracy of the life prediction results. This model could be used in fatigue failure portable diagnosis and for life prediction of multilayered PCB

    Transcriptional peroxisome proliferator-activated receptor γ coactivator-1 (PGC-1α) regulates transformation of muscle fiber type in Schizothorax prenanti

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    Peroxisome proliferator-activated receptor γ coactivator (PGC)-1ɑ, a well-known member of PGC-1 transcriptional coactivator’s family, plays a key role in various metabolic pathways. Here, we investigated the role of PGC-1ɑ in the transformation of muscle fiber type in Schizothorax prenanti. The expression of PGC-1ɑ was induced in S. prenanti muscles following fasting. Following the induction of PGC-1ɑ, the expressions of mitochondrial-related enzyme cytochrome c oxidase (COX), citrate synthase (CS) and cytochrome c oxidase IV was also increased in white muscles, but the expression of carnitine palmitoyltransferase II (CPT II) has no change in this condition. Notably, when the levels of PGC-1ɑ was upregulated in the condition of fasting, muscle fibres type II showed the characteristics of muscle fibres type I, with expressed myosin heavy chain I (MyHC I) and myoglobin (Mb), and suppressed myosin heavy chain II (MyHC II) in response to fasting. Therefore, we can draw conclusion that PGC-1ɑ up-regulates slow fiber type formation during the transformation of muscle fiber type in S. prenanti.Keywords: PGC-1ɑ, muscle fiber type, transformation, Schizothorax prenanti, MyHC I, MyHC I

    Model Building and Optimization Analysis of MDF Continuous Hot-Pressing Process by Neural Network

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    We propose a one-layer neural network for solving a class of constrained optimization problems, which is brought forward from the MDF continuous hot-pressing process. The objective function of the optimization problem is the sum of a nonsmooth convex function and a smooth nonconvex pseudoconvex function, and the feasible set consists of two parts, one is a closed convex subset of Rn, and the other is defined by a class of smooth convex functions. By the theories of smoothing techniques, projection, penalty function, and regularization term, the proposed network is modeled by a differential equation, which can be implemented easily. Without any other condition, we prove the global existence of the solutions of the proposed neural network with any initial point in the closed convex subset. We show that any accumulation point of the solutions of the proposed neural network is not only a feasible point, but also an optimal solution of the considered optimization problem though the objective function is not convex. Numerical experiments on the MDF hot-pressing process including the model building and parameter optimization are tested based on the real data set, which indicate the good performance of the proposed neural network in applications

    A Novel Synthetic Analog of 5, 8-Disubstituted Quinazolines Blocks Mitosis and Induces Apoptosis of Tumor Cells by Inhibiting Microtubule Polymerization

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    Many mitosis inhibitors are powerful anticancer drugs. Tremendous efforts have been made to identify new anti-mitosis compounds for developing more effective and less toxic anti-cancer drugs. We have identified LJK-11, a synthetic analog of 5, 8-disubstituted quinazolines, as a novel mitotic blocker. LJK-11 inhibited growth and induced apoptosis of many different types of tumor cells. It prevented mitotic spindle formation and arrested cells at early phase of mitosis. Detailed in vitro analysis demonstrated that LJK-11 inhibited microtubule polymerization. In addition, LJK-11 had synergistic effect with another microtubule inhibitor colchicine on blocking mitosis, but not with vinblastine or nocodazole. Therefore, LJK-11 represents a novel anti-microtubule structure. Understanding the function and mechanism of LJK-11 will help us to better understand the action of anti-microtubule agents and to design better anti-cancer drugs
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