A Two-Step Global Maximum Error Controller-Based TPWL MOR with POD Basis Vectors and Its Applications to MEMS

In our previous study, we have proposed a linearization point (LP) selection method based on a global maximum error controller for the trajectory piecewise-linear (TPWL) method. It has been demonstrated that this method has many advantages over other existing methods. In this paper, a more efficient version of this method is presented, which introduces a preliminary LP selection procedure and constructs projection matrix by the proper orthogonal decomposition (POD) method. Compared with the original method, the improved method takes much less time for extracting a reduced-order model (ROM) of similar quality and gets some other benefits (such as being easier to implement, having lower memory requirement, and enhanced flexibility). The effectiveness of the new method is fully demonstrated by a diode transmission line RLC circuit. And then, the method is applied to three more complicated microelectromechanical systems (MEMS) devices, which are a micromachined switch, an electrostatic micropump diaphragm, and a thermomechanical in-plane microactuator

Interception Algorithm of S-cubed Signal Model in Stealth Radar Equipment

AbstractRadar equipment of stealth platforms such as aircraft have adopted the newest modern technology to design the signal waveforms. One of the important and effective methods is the hybrid waveform called spread spectrum stretch (S-cubed) which combines linear frequency modulation (LFM) and discrete phase code. In order to investigate the function of enemy's stealth radar equipment, the interception algorithm of S-cubed is needed. In this paper, a novel detection and parameter estimation approach for the reconnaissance S-cubed radar signal is presented. First, the generalized time-frequency representation of Zhao, Atlas, and Marks (ZAM-GTFR) and Hough transforms (HT) are applied to detecting the signal, and then the initial frequency and modulation slope of LFM are estimated from the ZAM-GTFR. On the basis of LFM information, the reconstructing signal is generated. Finally, the code rate of discrete phase code is extracted from the negative peaks of the ZAM-GTFR. Simulation results show that the proposed algorithm has higher estimation accuracy when the signal to noise ratio (SNR) is above 3 dB

Identification of a novel regulatory mechanism involved in inhibition of transcription of suvivin mRNA in breast cancer cells via p21cip–mediated regulation

Purpose: To evaluate the effect of p21Cip1 on survivin transcription levels in breast carcinoma, and to investigate the potential mechanisms.Methods: Epirubicin, a p21Cip1 activator, was used to treat MCF7 cells. Under the action of normal biological functions of p53, pEGFP-C2-p21 was transfected into MCF7 cells by lipofectamine and positive clones were screened out with G418. The expression levels of p21cip1, p53 and survivin mRNA were quantitated by real-time fluorescent polymerase chain reaction (RQ-PCR). MTT assay was utilized to measure cellular viability and proliferation after transfection. Flow cytometry was employed to determine the cell cycle. Hoechst 33342 staining was carried out to assess cell apoptosis. Lastly, several transcription factor sites located at the promoter region of survivin gene, such as, sp1 site, E2F site and p300/CBP, were measured by p21 overexpression using RT-PCR.Results: Following epirubicin treatment, within 24 h, the expression levels of endogenous p21cip1 and p53 were up-regulated, whereas that of survivin was down-regulated. After transfection treatment, p21 inhibited the proliferation of MCF7 cells on days 3 and 4, and MCF7 cells overexpressed p21 mRNA, whereas the level of survivin mRNA in MCF7-p21 groups was markedly down-regulated relative to control group, but overexpression of p21 was not sufficient to cause changes in p53 gene expression. The overexpressed p21 resulted in G1/G0 phase arrest based on cell cycle analysis, but apoptosis was not induced. In addition, co-transcription factors E2F-1, sp1 and p300/CBP mRNA levels decreased significantly compared with normal p21 expression groups.Conclusion: P21cip1 may down-regulate the expression of survivin gene partially by inhibiting the expression level of HAT.Keywords: Cyclin-dependent kinase inhibitor 1, Phosphoprotein p53, Survivin, Breast carcinoma, G1/G0 phase arrest, Epirubicin, Lipofectamin

GeoUDF: Surface Reconstruction from 3D Point Clouds via Geometry-guided Distance Representation

We present a learning-based method, namely GeoUDF,to tackle the long-standing and challenging problem of reconstructing a discrete surface from a sparse point cloud.To be specific, we propose a geometry-guided learning method for UDF and its gradient estimation that explicitly formulates the unsigned distance of a query point as the learnable affine averaging of its distances to the tangent planes of neighboring points on the surface. Besides,we model the local geometric structure of the input point clouds by explicitly learning a quadratic polynomial for each point. This not only facilitates upsampling the input sparse point cloud but also naturally induces unoriented normal, which further augments UDF estimation. Finally, to extract triangle meshes from the predicted UDF we propose a customized edge-based marching cube module. We conduct extensive experiments and ablation studies to demonstrate the significant advantages of our method over state-of-the-art methods in terms of reconstruction accuracy, efficiency, and generality. The source code is publicly available at https://github.com/rsy6318/GeoUDF

Study on corrosion resistance of Portland cement-calcium sulphoaluminate cement binary system in a sodium chloride environment

Portland cement is widely used in civil engineering. However, Portland cement-based materials are easy to be corroded by seawater in marine environment. Many research show the corrosion resistance of Portland cement mortar can be improved by add appropriate amount of mineral admixture.Sulphoaluminate cement have high strength and good corrosion seawater resistance. However, the short setting time and high hydration heat of sulphoaluminate cement limit its application in civil engineering.Portland cement-sulphoaluminate cement (PC-CSA) not only have high strength and corrosion resistance but also long setting time.In this work, the sulphoaluminate cement was used to partially replace Portland cement. The replacement level of sulphoaluminate cement was 10 %, 20 % and 30 % by weight of Portland cement. Mortar specimens was soaked in sodium chloride solution under standard curing after 28 days. The concentration of sodium chloride solution was 3.5wt %. Mechanical properties , corrosion resistance and setting time of PC-CSA binary system were tested in the research. The hydration behavior of binary system was determined by isothermal calorimetry and X-ray diffraction methods. Microstructure of the binary system at different ages were analyzed by scanning electron microscope. The strength of PC-CSA binary system was tested at different curing ages up to 28 days.The results show when replacement level of sulphoaluminate cement is 20%, the comprehensive strength up to 50MPa and higher than other groups at 28 days soaked in corrosion solution.when replacement level of sulphoaluminate cement is 20%,the corrosion resistance is best,and penetration depth of chloride ions is the least

Competitive Retailer Strategies for New Market Research, Entry and Positioning Decisions

This paper investigates strategies for new market research and positioning of stores or products by competing retailers in a duopoly setting. We examine the scenario where the two retailers are considering entry into an uncertain new market that is an extension of their existing markets. The retailers must make decisions on whether or not to first conduct research about the new market\u27s location relative to their existing markets and its size before deciding on their own positioning in it. We first study a sequential-move leader–follower setup to highlight the choice of an “innovate-or-imitate” strategy. We find when the potential new market is small, neither retailer is adequately incentivized to do research to acquire information about the new market. As the size of the new market increases, the follower is induced to do such research. When the new market is very sizable, the leader conducts research and knows the new market\u27s location while the follower free-rides. We then examine a simultaneous-move setup, in which one retailer might decide against acquiring new market information even when the cost of doing so is low. We further observe that differentiation (e.g., in terms of products or store locations) is greater in the simultaneous-move setup than in the sequential setup

Abrupt summer warming and changes in temperature extremes over Northeast Asia since the mid-1990s: drivers and physical processes

This study investigated the drivers and physical processes for the abrupt decadal summer surface warming and increases in hot temperature extremes that occurred over Northeast Asia in the mid-1990s. Observations indicate an abrupt increase in summer mean surface air temperature (SAT) over Northeast Asia since the mid-1990s. Accompanying this abrupt surface warming, significant changes in some temperature extremes, characterized by increases in summer mean daily maximum temperature (Tmax), daily minimum temperature (Tmin), annual hottest day temperature (TXx), and annual warmest night temperature (TNx) were observed. There were also increases in the frequency of summer days (SU) and tropical nights (TR). Atmospheric general circulation model experiments forced by changes in sea surface temperature (SST)/sea ice extent (SIE), anthropogenic greenhouse gas (GHG) concentrations, and anthropogenic aerosol (AA) forcing, relative to the period 1964–93, reproduced the general patterns of observed summer mean SAT changes and associated changes in temperature extremes, although the abrupt decrease in precipitation since the mid-1990s was not simulated. Additional model experiments with different forcings indicated that changes in SST/SIE explained 76% of the area-averaged summer mean surface warming signal over Northeast Asia, while the direct impact of changes in GHG and AA explained the remaining 24% of the surface warming signal. Analysis of physical processes indicated that the direct impact of the changes in AA (through aerosol–radiation and aerosol–cloud interactions), mainly related to the reduction of AA precursor emissions over Europe, played a dominant role in the increase in TXx and a similarly important role as SST/SIE changes in the increase in the frequency of SU over Northeast Asia via AA-induced coupled atmosphere–land surface and cloud feedbacks, rather than through a direct impact of AA changes on cloud condensation nuclei. The modelling results also imply that the abrupt summer surface warming and increases in hot temperature extremes over Northeast Asia since the mid-1990s will probably sustain in the next few decades as GHG concentrations continue to increase and AA precursor emissions over both North America and Europe continue to decrease