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Piecewise linear mapping algorithm for SAR raw data compression

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Science in China(Series F) 2008年第12期51卷 2126-2134页

作者： qi HaiMing YU weidong CHEN Xi Institute of Electronics Chinese Academy of Sciences Beijing 100080 China

When the saturation degree （SD） of space-borne SAR raw data is high, the performance of conventional block adaptive quantization （BAQ） deteriorates obviously. In order to overcome the drawback, this paper studies the mapping between the average signal magnitude （ASM） and the standard deviation of the input signal （SDIS） to the A/D from the original reference. Then, it points out the mistake of the mapping and introduces the concept of the standard deviation of the output signal （SDOS） from the A/D. After that, this paper educes the mapping between the ASM and SDOS from the A/D. Monte-Carlo experiment shows that none of the above two mappings is the optimal in the whole set of SD. Thus, this paper proposes the concept of piecewise linear mapping and the searching algorithm in the whole set of SD. According to the linear part, this paper gives the certification and analytical value of k and for nonlinear part, and utilizes the searching algorithm mentioned above to search the corresponding value of k. Experimental results based on simulated data and real data show that the performance of new algorithm is better than conventional BAQ when raw data is in heavy SD.

关键词： synthetic aperture radar (SAR) raw data saturation compression block adaptive quantization (BAQ)

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离心泵浮筏隔振系统设计及其效果分析

机电设备 2024年第4期41卷 44-50页

作者：祁伟栋杨晓一曹杰徐尧上海海迅机电工程有限公司上海201111

以某船多台离心泵为隔振对象,开展浮筏隔振系统设计,并根据设计方案建立浮筏隔振系统的动力学模型。通过模态分析验证筏架、基座以及浮筏隔振系统的各阶模态频率,可避开离心泵主要扰动频率。基于有限元法和统计能量法,计算浮筏隔振系统... 详细信息

以某船多台离心泵为隔振对象,开展浮筏隔振系统设计,并根据设计方案建立浮筏隔振系统的动力学模型。通过模态分析验证筏架、基座以及浮筏隔振系统的各阶模态频率,可避开离心泵主要扰动频率。基于有限元法和统计能量法,计算浮筏隔振系统在各工况下的隔振效果,并与试验结果进行对比分析。结果表明:理论计算值与实测值较为吻合,验证了设计和计算方法的可行性,可为离心泵浮筏隔振系统设计及其隔振效果的工程预测提供技术支撑。

关键词：离心泵浮筏隔振系统模态分析隔振效果

Anti-saturation block adaptive quantization algorithm for SAR raw data compression over the whole set of saturation degrees

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Progress in Natural Science:Materials International 2009年第8期19卷 1003-1009页

作者： Haiming qi , weidong Yu Institute of Electronics, Chinese Academy of Sciences, Beijing 100190, China Institute of Electronics Chinese Academy of Sciences Beijing 100190 China

In order to improve the performance of block adaptive quantization (BAQ) when the output of the analog to digital converter (ADC) is saturated, this paper proposes an anti-saturation BAQ algorithm. First, the concept of the standard deviation of the output signal (SDOS) of the ADC is proposed. Also, unlike traditional normalization processing, SDOS is used and the mapping between SDOS and the average signal magnitude is deduced. Second, the saturation term is introduced to the Lloyd–Max quantizer and an optimal non-uniform scalar quantizer for saturated SAR raw data quantization is proposed. After this, the implementation scheme for the proposed algorithm using an FPGA is analyzed in detail. Third, the relationships among the saturation degree of the signal, the peak-topeak value of the ADC, standard deviation of the input and output signal of the ADC and the average signal magnitude are deduced. Based on these relationships, a power compensation decoder is designed for encoding. Numerical experiment results based on ERS-1 and the simulated data show that the performance of the proposed algorithm is better than that of BAQ.

关键词： Synthetic aperture radar (SAR) Raw data compression Block adaptive quantization (BAQ) Anti-saturation

Systematic Characterization of Long Non-Coding RNAs and Their Responses to Drought Stress in Dongxiang Wild Rice

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Rice science 2020年第1期27卷 21-31页

作者： qi weidong CHEN Hongping YANG Zuozhen HU Biaolin LUO Xiangdong AI Bing LUO Yuan HUANG Yu XIE Jiankun ZHANG Fantao College of Life Sciences Jiangxi Normal UniversityNanchang 330022China Rice Research Institute Jiangxi Academy of Agricultural SciencesNanchang 330200China Cipher Gene Limited Liability Company Beijing 100080China

Long non-coding RNAs(lncRNAs) play important roles in response to various biotic and abiotic stresses. So far, systematic identification and characterization of lncRNAs have been reported in a few model plant species and major crops, but their roles in abiotic stress response have not yet been reported in common wild rice(Oryza rufipogon). Dongxiang wild rice(DXWR) possesses a high degree of drought resistance and has been well recognized as a precious genetic resource for drought resistant rice breeding. We presented the reference catalog of 1 655 novel lncRNA transcripts in DXWR using strand-specific RNA sequencing and bioinformatics approaches. Meanwhile, a total of 1092 lncRNAs were determined as differentially expressed lncRNAs under drought stress. Quantitative real-time PCR results exhibited a high concordance with RNA sequencing data, which confirmed that the expression patterns of lncRNAs based on RNA sequencing were highly reliable. Furthermore, 8 711 transcripts were predicted as target genes of the differentially expressed lncRNAs. Functional annotation analysis based on Gene Ontology and Kyoto Encyclopedia of Genes and Genomes databases showed that the target genes were significantly enriched in cellular and metabolic processes, cell part, binding and plant hormone signal transduction, as well as many other terms related to abiotic stress resistance. These results expanded our understanding of lncRNA biology and provided candidate regulators for genetic improvement of drought resistance in rice cultivars.

关键词： Dongxiang wild rice drought stress long non-coding RNA systematic characterization

Assessing target optical camouflage effects using brain functional networks:A feasibility study

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Defence Technology（防务技术） 2024年第4期34卷 69-77页

作者： Zhou Yu Li Xue weidong Xu Jun Liu qi Jia Jianghua Hu Jidong Wu National Key Laboratory of Lightning Protection and Electromagnetic Camouflage Army Engineering University Nanjing 210007JiangsuChina Unit 31608 of PLA Xiamen 361000FujianChina School of Biological Sciences&Medical Engineering Southeast UniversityNanjing 210096JiangsuChina

Brain functional networks model the brain's ability to exchange information across different regions,aiding in the understanding of the cognitive process of human visual attention during target searching,thereby contributing to the advancement of camouflage *** this study,images with various camouflage effects were presented to observers to generate electroencephalography(EEG)signals,which were then used to construct a brain functional *** topological parameters of the network were subsequently extracted and input into a machine learning model for *** results indicate that most of the classifiers achieved accuracy rates exceeding 70%.Specifically,the Logistic algorithm achieved an accuracy of 81.67%.Therefore,it is possible to predict target camouflage effectiveness with high accuracy without the need to calculate discovery *** proposed method fully considers the aspects of human visual and cognitive processes,overcomes the subjectivity of human interpretation,and achieves stable and reliable accuracy.

关键词： Camouflage effect evaluation Electroencephalography(EEG) Brain functional networks Machine learning

Joint training with local soft attention and dual cross-neighbor label smoothing for unsupervised person re-identification

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Computational Visual Media 2024年第3期10卷 543-558页

作者： qing Han Longfei Li weidong Min qi Wang qingpeng Zeng Shimiao Cui Jiongjin Chen School of Mathematics and Computer Sciences Nanchang UniversityNanchang 330031China Institute of Metaverse Nanchang UniversityNanchang 330031China Jiangxi Key Laboratory of Smart City Nanchang 330031China

Existing unsupervised person re-identification approaches fail to fully capture thefine-grained features of local regions,which can result in people with similar appearances and different identities being assigned the same label after *** identity-independent information contained in different local regions leads to different levels of local *** address these challenges,joint training with local soft attention and dual cross-neighbor label smoothing(DCLS)is proposed in this ***,the joint training is divided into global and local parts,whereby a soft attention mechanism is proposed for the local branch to accurately capture the subtle differences in local regions,which improves the ability of the re-identification model in identifying a person’s local significant ***,DCLS is designed to progressively mitigate label noise in different local *** DCLS uses global and local similarity metrics to semantically align the global and local regions of the person and further determines the proximity association between local regions through the cross information of neighboring regions,thereby achieving label smoothing of the global and local regions throughout the training *** extensive experiments,the proposed method outperformed existing methods under unsupervised settings on several standard person re-identification datasets.

关键词： person re-identification(Re-ID) unsupervised learning(USL) local soft attention joint training dual cross-neighbor label smoothing(DCLS)

Cisplatin-induced vestibular hair cell lesion-less damage at high doses

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Journal of Otology 2018年第4期13卷 115-121页

作者： Dalian Ding Haiyan Jiang Jianhui Zhang Xianrong Xu weidong qi Haibo Shi Shankai Yin Richard Salvi Center for Hearing and Deafness University at BuffaloUSA Department of Otolaryngology Head and Neck Surgery The Third People’s Hospital of ChengduChina Air Force General Hospital BeijingChina Department of Otolaryngology Head and Neck Surgery Huashan HospitalFudan UniversityShanghaiChina Department of Otorhinolaryngology Affiliated Sixth People’s Hospital of Shanghai Jiaotong UniversityShanghaiChina Department of Audiology and Speech-Language Pathology Asia UniversityChina

Cisplatin, a widely used anticancer drug, damages hair cells in cochlear organotypic cultures at low doses, but paradoxically causes little damage at high doses resulting in a U-shaped dose-response function. To determine if the cisplatin dose-response function for vestibular hair cells follows a similar pattern, we treated vestibular organotypic cultures with doses of cisplatin ranging from 10 to 1000 μM. Vestibular hair cell lesions progressively increased as the dose of cisplatin increased with maximum damage occurring around 50-100 μM, but the lesions progressively decreased at higher doses resulting in little hair cell loss at 1000 μM. The U-shaped doseresponse function for cisplatin-treated vestibular hair cells in culture appears to be regulated by copper transporters, Ctrl, ATP7A and ATP7B, that dose-dependently regulate the uptake, sequestration and extrusion of cisplatin.

关键词： Cisplatin Ototoxicity Copper transporters Vestibular organotypic cultures

Protective mechanism of Coprinus comatus polysaccharide on acute alcoholic liver injury in mice,the metabolomics and gut microbiota investigation

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Food Science and Human Wellness 2024年第1期13卷 401-413页

作者： Jinyan Yu Jianguang Sun Min Sun weidong Li Dongmei qi Yongqing Zhang Chunchao Han School of Pharmacy Shandong University of Traditional Chinese MedicineJinan 250355China Hepatology Department of Affiliated Hospital of Shandong University of Traditional Chinese Medicine Jinan 250355China Experimental center Shandong University of Traditional Chinese MedicineJinan 250355China

Coprinus comatus polysaccharide(CCP)has significant hepatoprotective *** explore hepatoprotective mechanism of CCP,the study analyzed preventive effect of CCP on acute alcoholic liver injury in mice by histopathological examination and biochemical ***,hepatoprotective mechanism was also analyzed in conjunction with metabolomics and proliferation of gut *** results showed that CCP significantly decreased alanine aminotransferase(ALT),aspartate aminotransferase(AST)and triglyceride(TG)levels in serum of alcoholic liver disease(ALD)*** examination showed that CCP can significantly improve liver *** results showed that there were significant differences in the level of metabolites in liver tissue of control group,ALD group and CCP group,including taurine,xanthosine,fumaric acid and arachidonic acid,among *** pathways analysis showed that hepatoprotective effect of CCP was related to energy metabolism,biosynthesis of unsaturated fatty acids,amino acids metabolism and lipid ***,CCP inhibited an increase in the number of Clostridium perfringens,Enterobacteriaceae and Enterococcus,and a decrease in the number of Lactobacillus and Bifidobacterium in the gut of ALD *** these findings suggested that CCP treatment reversed the phenotype of ethanol-induced liver injury and the associated metabolites pathways.

关键词： Coprinus comatus Polysaccharide Alcoholic liver disease Metabolomics Gut microbiota

Damage evolution of rock-encased-backfill structure under stepwise cyclic triaxial loading

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第2期16卷 597-615页

作者： Xin Yu Yuye Tan weidong Song John Kemeny Shengwen qi Bowen Zheng Songfeng Guo Key Laboratory of Shale Gas and Geoengineering Institute of Geology and GeophysicsChinese Academy of SciencesBeijing100089China Innovation Academy for Earth Science Chinese Academy of SciencesBeijing100089China University of Chinese Academy of Sciences Beijing100049China School of Civil and Resources Engineering University of Science and Technology BeijingBeijing100083China Key Laboratory of High-Efficient Mining and Safety of Metal Mines(Ministry of Education of China) University of Science and Technology BeijingBeijing100083China Department of Mining and Geological Engineering University of ArizonaTucsonAZ86721USA

Rock-encased-backfill(RB)structures are common in underground mining,for example in the cut-andfill and stoping *** understand the effects of cyclic excavation and blasting activities on the damage of these RB structures,a series of triaxial stepwise-increasing-amplitude cyclic loading experiments was conducted with cylindrical RB specimens(rock on outside,backfill on inside)with different volume fractions of rock(VF=0.48,0.61,0.73,and 0.84),confining pressures(0,6,9,and 12 MPa),and cyclic loading rates(200,300,400,and 500 N/s).The damage evolution and meso-crack formation during the cyclic tests were analyzed with results from stress-strain hysteresis loops,acoustic emission events,and post-failure X-ray 3D fracture *** results showed significant differences between cyclic and monotonic loadings of RB specimens,particularly with regard to the generation of shear microcracks,the development of stress memory and strain hardening,and the contact forces and associated friction that develops along the rock-backfill *** important finding is that as a function of the number of cycles,the elastic strain increases linearly and the dissipated energy increases ***,compared with monotonic loading,the cyclic strain hardening characteristics are more sensitive to rising confining pressures during the initial compaction *** finding is that compared with monotonic loading,more shear microcracks are generated during every reloading stage,but these microcracks tend to be dispersed and lessen the likelihood of large shear fracture *** transition from elastic to plastic behavior varies depending on the parameters of each test(confinement,volume fraction,and cyclic rate),and an interesting finding was that the transformation to plastic behavior is significantly lower under the conditions of 0.73 rock volume fraction,400 N/s cyclic loading rate,and 9 MPa *** the findings have important practical implications on t

关键词： Rock and backfill Triaxial cyclic loading Volume fraction Damage evolution 3D visualization