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    题名 作者 年代 出处 被引量
1Target classification with low-resolution radar based on dispersion situations of eigenvalue spectra显示文摘Most low-resolution radar systems, especially ground surveillance radar systems, work at relatively low pulse repeat frequency (PRF) and with short time-on-target (TOT) (duration in scanning). Low PRF leads to Doppler ambiguity and short TOT results in low Doppler resolution, which poses a problem to target classification with low-resolution radar based on the jet engine modulation (JEM) characteristic of radar echo. From the pattern classification viewpoint, we propose a method of using dispersion situations of JEM eigenvalue spectra to categorize aeroplanes into three kinds, namely turbojet aircraft, prop aircraft and helicopter. We analyze the mathematical model of JEM echoes consisting of a series of line spectra and regard them as a sum of several series of harmonious waves. Classification features can be extracted based on the harmonious wave sum model. Some schemes for extracting features from echoes within or between pulses are proposed. Low-dimensional features are extracted to reduce computation burden. Our methods do not compensate for the fuselage echoes and are insensitive to the variation of fuselage Doppler. The feasibility of our methods is demonstrated by simulation experiment.CHEN Feng, LIU HongWei, DU Lan & BAO Zheng National Laboratory of Radar Signal Processing, Xidian University, Xi’an 710071, China 2010Science China(Information Sciences)2010,53,7:12
2DNA chip-based expression profile analysis indicates involvement of the phosphatidylinositol signaling pathway in multiple plant responses to hormone and abiotic treatments显示文摘The phosphatidylinositol (PI) metabolic pathway is considered critical in plant responses to many environmental factors,and previous studies have indicated the involvement of multiple PI-related gene families during cellular responses.Through a detailed analysis of the Arabidopsis thaliana genome,82 polypeptides were identified as being involved in PI signaling. These could be grouped into different families including PI synthases (PIS),PI-phosphate kinases (PIPK),phospholipases (PL),inositol polyphosphate phosphatases (IPPase),inositol polyphosphate kinases (IPK),PI transfer proteins and putative inositol polyphosphate receptors. The presence of more than 10 isoforms of PIPK,PLC,PLD and IPPase suggested that these genes might be differentially expressed during plant cellular responses or growth and development. Accordingly,DNA chip technology was employed to study the expression patterns of various isoforms.In total,79 mRNA clones were amplified and used for DNA chip generation. Expression profile analysis was performed using samples that represented multiple tissues or cellular responses. Tested samples included normal leaf,stem and flower tissues,and leaves from plants treated with various hormones (auxin,cytokinin,gibberellin,abscisic acid and brassinosteroid) or environmental factors (temperature,calcium,sodium,drought,salicylic acid and jasmonic acid).Results showed that many PI pathway-related genes were differentially expressed under these experimental conditions.In particular,the different isoforms of each family were specifically expressed in many cases,suggesting their involvement in tissue specificity and cellular responses to environmental conditions. This work provides a starting point for functional studies of the relevant PI-related proteins and may help shed light onto the role of PI pathways in development and cellular responses.Wen Hui LIN, Rui YE, Hui MA, Zhi Hong XU, Hong Wei XUE National Laboratory of Plant Molecular Genetics, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences (SIBS), Chinese Academy of Sciences and Partner Group of Max-Planck-Institute of Molecular Plant Physiology (MPI-MP) on 'Plant Molecular Physiology and Signal Transduction', 300 Fenglin Road, 200032 Shanghai, China 2004Cell Research2004,14,1:12
3Gene and protein expressions of p28^(GANK)in rat with liver regeneration显示文摘AIM: To observe the gene and protein expression changes of p28GANK in regenerating liver tissues, and to reveal the biological function of p28GANK on the regulation of liver regeneration.METHODS: One hundred and thirty two adult male Sprague-Dawley rats were selected, weighing 200-250 g,and divided randomly into sham operation (SO) group and partial hepatectomy (PH) group. Each group had eleven time points: 0, 2, 6, 12, 24, 30, 48, 72, 120, 168 and 240 h,six rats were in each time point. The rats were undergone 70 % PH under methoxyflurane anesthesia by resection of the anterior and left lateral lobes of the liver. SO was conducted by laparotomy plus slight mobilization of the liver without resection. Liver specimens were collected at the indicated time points after PH or SO. The expression level of p28GANK mRNA was determined by Northern blot as well as at protein level via immunohistochemical staining.The expressions of p28GANK mRNA in these tissues were analyzed by imaging analysis system of FLA-2000 FUJIFILM and one way analysis of variance. The protein expressions of p28GANK in these tissues were analyzed with Fromowitz'method and Rank sum test.RESULTS: The expression of p28GANK mRNA in bhe regenerating liver tissues possessed two transcripts, which were 1.5 kb and 1.0 kb. There was a significantly different expression patterns of p28GANK mRNA between SO and PH groups (P<0.01). The expression of p28GANK mRNA increased 2 h after PH, the peak time was 72 h (SO group: 163.83±1.4720; PH group: 510.5±17.0499, P<0.01). There was a significant difference in the 1.5 kb transcript, which decreased gradually after 72 hours. The protein expression of p28GANK was mainly in the cytoplasm of regenerating hepatocytes, and increased near the central region 24 h after PH, and became strongly positive at 48 h (+++, vs the other time points P<0.05),but decreased 72 h after PH.CONCLUSION: The expression of p28GANK mRNA increases in the early stage of rat liver regeneration, the protein expression of p28GANK is mainly in the cytoplasm of regenerating liver cells. It suggests that the gene of p28GANK may be an important regulatory and controlled factor involved in hepatocyte proliferation during liver regeneration.Jian-Min Qin Xiao-Yong Fu Shen-Jing Li Shu-Qin Liu Jin-Zhang Zeng Xiu-Hua Qiu Meng-Chao Wu Hong-Yang Wang, International Co-operation Laboratory on Signal Transduction, Eastern Hepatobiliary Surgery Institute, Second Military Medical University, Shanghai, 200438, China 2003World Journal of Gastroenterology2003,9,11:12
4Time-frequency characteristics based motion estimation and imaging for high speed spinning targets via narrowband waveforms显示文摘This paper focuses on the motion parameters estimation and inversed synthetic aperture radar (ISAR) imaging for the high-speed spinning targets via the time-frequency characteristics. Assuming that the translational motion is compensated with the available motion compensation techniques, then the residual part of translational motion and the spinning motion are estimated with high precision based on the timefrequency characteristics. Combining with the procedure of the motion estimation, a novel coherent timefrequency spectrum intensity redistribution method, coherent single range Doppler interferometry (CSRDI), is proposed, which provides higher resolution and sustain lower signal to noise rate (SNR) than the current approach. Numerical simulation confirms the validity and high precision of the proposed approaches.ZHANG Lei , LI YaChao, LIU Yan, XING MengDao & BAO Zheng National Lab for Radar Signal Processing, Xidian University, Xi’an 710071, China 2010Science China(Information Sciences)2010,53,8:9
5FAST RECURSIVE LEAST SQUARES LEARNING ALGORITHM FOR PRINCIPAL COMPONENT ANALYSIS显示文摘Based on the least-square minimization a computationally efficient learning algorithm for the Principal Component Analysis(PCA) is derived. The dual learning rate parameters are adaptively introduced to make the proposed algorithm providing the capability of the fast convergence and high accuracy for extracting all the principal components. It is shown that all the information needed for PCA can be completely represented by the unnormalized weight vector which is updated based only on the corresponding neuron input-output product. The convergence performance of the proposed algorithm is briefly analyzed.The relation between Oja’s rule and the least squares learning rule is also established. Finally, a simulation example is given to illustrate the effectiveness of this algorithm for PCA.Ouyang Shan Bao Zheng Liao Guisheng(Guilin Institute of Electronic Technology, Guilin 541004)(Key Laboratory of Radar Signal Processing, Xidian Univ., Xi’an 710071) 2000Journal of Electronics(China)2000,17,3:8
6cAMP elevators inhibit LPS-induced IL-12 p40 expression by interfering with phosphorylation of p38 MAPK in Murine Peritoneal Macrophages显示文摘cAMP mediated signaling may play a suppressive role in immune response. We previously found that the cAMP-elevators (CTx and 8-Br-cAMP) inhibited IL-12, IL-la, IL-6 gene expression, but increased the transcriptional levels of IL-10 and IL-1Ra in LPS-treated murine peritoneal macrophages. The present study examined a possible molecular mechanism involved in cAMP elevators-induced inhibition of IL-12 p40 expression in response to LPS. Our data demonstrated that cAMP elevators downregulated IL-12 p40 mRNA expression and IL-12 pT0 production in murine peritoneal macrophages. Subsequent studies revealed that cAMP-elevators blocked phosphorylation of p38 MAPK, but did not affect the activity of NF-κB binding to IL-12 promoter (-136/-112). This is the first report that cAMP elevators inhibit LPS-induced IL-12 production by a mechanism that is associated, at least in part, with p38-dependent inhibition by cAMP signaling pathways.WEI Guo FENG, YI BING WANG, JIN SONG ZHANG, XING Yu WANG, CHANG LIN LI, ZONG LIANG CHANGLaboratory of Immune Signaling Transduction, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China 2002Cell Research2002,12,5:6
7A new real-time eye tracking based on nonlinear unscented Kalman filter for monitoring driver fatigue显示文摘A new scheme for driver fatigue detection is presented, which is based on the nonlinear unscented Kalman filter and eye tracking. Assuming a probability distribution than to approximate an arbitrary nonlinear function or transformation, eye nonlinear tracking can be achieved using an unscented transformation (UT), which adopts a set of deterministic sigma points to match the posterior probability density function of the eye movement. Driver fatigue can be detected using the percentage of eye closure (PERCLOS) framework in a realistic driving condition after the eye nonlinear tracking. This system was tested adequately in realistic driving environments with subjects of different genders, with/without glasses, in day/night driving, being commercial/noncommercial drivers, in continuous driving time, and under different road conditions. The last experimental results show that the proposed method not only improves the robustness for nonlinear eye tracking, but also can provide more accurate estimation than the traditional Kalman filter.Zutao ZHANG 1 , 2 , Jiashu ZHANG 2 (1.School of Mechanical Engineering, Southwest Jiaotong University, Chengdu Sichuan 610031, China 2.Sichuan Key Lab of Signal and Information Processing, Southwest Jiaotong University, Chengdu Sichuan 610031, China) 2010控制理论与应用(英文版)2010,8,2:5
8Multistage decomposition algorithm for blind source separation显示文摘A new algorithm for blind source separation is proposed, which only extracts the single independent component at each stage. The single independent component is acquired by an iterative algorithm for searching for the optimal solution of the defined cost function. Moreover, all the independent components are obtained by systematic multistage decomposition and multistage reconstruction. When there is spatially colored noise, the performance of this algorithm is advantageous over jointly approximated diagonalization of eigen-matrices (JADE). Simulated results show that if the number of source signals is more than 25, its computational complexity is lower than that of JADE.FENG Dazheng, BAO Zheng and ZHANG Xianda(Key Laboratory for Radar Signal Processing, Xidian University, Xi’an 710071, China) 2002Progress in Natural Science:Materials International2002,12,5:5
9Characteristic analysis of unsteady viscous flow around a cavitating propeller显示文摘Based on viscous multiphase flow theory, this paper presents some recent validation results with a hybrid grid and sliding mesh solving Unsteady Navier-Stokes (N-S) and Bubble Dynamics equations as applied to prediction of pressure, velocity and vapor volume fraction in the wake in an uniform inflow. Comparable to experimental results, numerical predictions of sheet cavitation, tip vortex cavitation and hub vortex cavitation are in agreement with the corresponding experimental data, the same as numerical predictions of pressure in wake. Tip vortex cavitation is the most important to generate the pressure fluctuation within the near wake. The characteristics such as blade and shaft rate frequency of propeller pressure in wake coincide with its geometric model and parameters. With increasing distance from propeller disk, the pressure signals at blade frequency de-crease. The process of attenuation becomes fast with the decreased advance coefficient and cavitation number.ZHU ZhiFeng1, 2, FANG ShiLang1 & WANG XiaoYan1 1 Key Laboratory of Underwater Acoustic Signal Processing of Ministry of Education, Southeast University, Nanjing 210096, China 2 School of Electrical Engineering and Information, Anhui University of Technology, Maanshan 243002, China 2010Science China(Technological Sciences)2010,53,7:4
10Multiuser detection and independent component analysis——Progress and perspective显示文摘The latest progress in the multiuser detection and independent component analysis (ICA) is reviewed systematically. Then two novel classes of multiuser detection methods based on ICA algorithms and feedforward neural networks are proposed. Theoretical analysis and computer simulation show that ICA algorithms are effective to detect multiuser signals in code-division multiple-access (CDMA) system. The performances of these methods are not identical entirely in various channels, but all of them are robust, efficient, fast and suitable for real-time implementations.JIAO Licheng , MA Haibo and LIU Fang( State Key Laboratory for Radar Signal Processing, Xidian University, Xi’an 710071, China) 2002Progress in Natural Science:Materials International2002,12,7:3
11Volterra Feedforward Neural Networks:Theory and Algorithms显示文摘Volterra Feedforward Neural Networks: Theory and AlgorithmsJiaoLichengl;LiuFang&XieQin(NationalLab.forRadarSignalProcessingan...Jiao Lichengl Liu Fang & Xie Qin(National Lab. for Radar Signal Processing and Center for Neural Networks,Xidian University, Xian 710071, P.R.China) 1996Journal of Systems Engineering and Electronics1996,7,4:3
12Effects of signal regulatory proteinα1 on proliferation of hepatocellular carcinoma: a preliminary study显示文摘BACKGROUND: Signal regulatory protein alpha1 (Sirpα1) is a negative regulatory factor, and inhibits receptor tyro- sine kinase-dependent cell proliferating signal. This study was undertaken to observe the effect of signal regulatory proteinα1 ( Sirpα1) on gankyrin, cyclin D1, CDK4 and Fas expression in Sk-hep1 mouse hepatoma carcinoma cell line. METHODS: BOSC 23 packed cells were respectively trans- fected by means of recombinated retrovirus including pLX- SN, pLXSN-Sirpα1 and pLXSN-Sirpα1Δ4Y2 with lipofec- tin, and various plasmid virus media (viral titer 2.1 × 106 CFU/ml) were collected and infected respectively in 80% confluent Sk-hepl cells. Transfected Sk-hep1 cells were se- lectively screened with G418 (1200 μg/ml), and Sk-hep1 cell lines transfected with various plasmids were obtained. The protein expressions of gankyrin, cyclin D1, CDK4 and Fas in various Sk-hep1 lines were determined by Western blotting. Various Sk-hep1 lines were recovered to culture with 10% fetal bovine serum at 12 hours and 24 hours after starving culture with free serum for 72 hours, and cells were collected to determine the percentage of S phase cells of proliferating cycle by flow cytometry. RESULTS: Sirpα1 transfection remarkably downregulated gankyrin and cyclin D1 expression. Sirpα1Δ4Y2 downregu- lation of gankyrin expression was greater than that of Sirpα1(P <0.05), but no significant effect of Sirpα1 and Sirpα1Δ4Y2 on CDK4 and Fas protein expression was ob- served in transfected Sk-hep1 lines (P >0.05). The per- centage of S phase cells significantly decreased in Sk-hep1 cells transfected with Sirpα1 and Sirpα1Δ4Y2 plasmids (vs pLXSN Sk-hep1, P <0.05). The percentage of S phase cells in various Sk-hep1 cells increased when recovering to culture with 10% fetal bovine serum at 12 hours, but the percentage of S phase cells in Sk-hep1 cells transfected with Sirpα1 was the lowest ( vs pLXSN and Sirpα1Δ4Y2 Sk- hepl, P<0.05). The percentage of S phase cells in trans- fected pLSXN Sk-hep1 cells was the largest (vs Sirpα1 and Sirpα1Δ4Y2 Sk-hepl, P <0. 05). There was no significant difference between the transfected Sirpα1 Sk-hepl cells and Sirpα1Δ4Y2 Sk-hep1 cells (P>0.05). CONCLUSIONS: Sirpα1 decreases gankyrin and cyclin D1 expression, and inhibits proliferation of liver carcinoma cells. It may be one of the forms for an Sirpα1 negative regulation of carcinogenesis and development of hepatocel- lular carcinoma.Jian-Min Qin, He-Xin Yan, Xing-Wang Wan, Shu-Qin Liu, Jin-Zhang Zeng, Hui-Fang Cao, Meng-Chao Wu and Hong-Yang Wang Shanghai, China International Cooperative Laboratory on Signal Trans- duction, Eastern Hepatobiliary Surgery Institute, Second Military Medical University, Shanghai 200438, China 2005Hepatobiliary & Pancreatic Diseases International2005,4,2:3
13Data Mining and Neural Network Techniques in Case Based System显示文摘This paper first puts forward a case based system framework based on data mining techniques. Then the paper examines the possibility of using neural networks as a method of retrieval in such a case based system. In this system we propose data mining algorithms to discover case knowledge and other algorithms.Ni Zhi wei 1,2 , Cai Qing sheng 1, Li Long shu 2 1.Department of Computer Science, University of Science and Technology of China,Hefei 230027,China 2.The Key Laboratory of Intelligent Computing and Signal Processing ,Ministry of Education 2001Wuhan University Journal of Natural Sciences2001,6,Z1:2
14RATE CONTROL ALGORITHM FOR H.264 VIDEO ENCODER显示文摘This letter proposes a rate control algorithm for H.264 video encoder, which is based on block activity and buffer state. Experimental results indicate that it has an excellent performance by providing much accurate bit rate and better coding efficiency compared with H.264. The computational complexity of the algorithm is reduced by adopting a novel block activity description method using the Sum of Absolute Difference (SAD) of 16× 16 mode, and its robustness is enhanced by introducing a feedback circuit at frame layer.Xue Jinzhu Shen Lansun (Signal & Information Processing Lab, Beijing University of Technology, Beijing 100022) 2003Journal of Electronics(China)2003,20,6:2
15In vitro enzyme activities and product of 14 CO2assimilation in flag leaf and ear parts of wheat显示文摘Signal H R Sheoran I S Singh R 1986Photosynthesis Research1986,8,:1
16Heart failure/ myocarditis/ transplantation: probucol promotes endogenous antioxidants and provides protection against adriamycin - induced cardiomyopathy in rats 显示文摘Siveski Y liskovic N Kaul N Signal PK 1994Circulation1994,89,6:1
17BMP-4 induces P21 and is associated with apoptosis in the mouse tooth enamel knot显示文摘JernvaU J Aberg T Kettunen E The life history of an embryonic signaling center 1998Development1998,125,2:1
18Inflammatory response alteration induced by PCB77 显示文摘WANG J signaling LYU X DU Y 2010J and insulin Environ Sci (China)2010,22,7:1
19Sleep duration and quality in healthy nuniparous and multiparous women across pregnancy and post- partum显示文摘Signal TL Gander PH Sangani MR 2007Aust N Z J Obstet Gyaecol2007,47,1:1
20A Target Recognition Approach to Projecting HRR Profiles onto Subspace显示文摘A array of the azimuthally averaged range-profile vectors and the inter-class and intra-class divergence matrixes are constructed iwth many frames of the high resolution range profiles which result from radar echoes of airplanes. Taking the methods of whitening transformation and SVD produces a system of subspace vectors for target recognition. Whereupon, a template library for target recognition is built by the projection of a class-mean vector made from the radar data onto the subspace for recognition. By Euclidean distance, a comparison is made between the above projection and each template in the library, to decide which class the target belongs to. Finally, simulations with the experimental radar data arte given to show that the proposed method is robust to variation in azimuth and immune to additive Gaussian noise when SNR≥5dB.Pei Bingnan & Bao ZhengKey Lab. of Radar Signal Processing, Xidian University, Xi’an 710071, P. R. China Dept. of Electronic Engineering, Zhengzhou University, Zhengzhou 450052, P.R. China 2003Journal of Systems Engineering and Electronics2003,14,1:1
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