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Simulation research on scattering characteristics by complex targets 被引量:4
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作者 Guo Kunyi Sheng Xinqing 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2007年第4期685-691,共7页
A simulation approach based on a full-wave numerical method is presented to study electromagnetic characteristics by complex targets. How to validate simulation results is considered thoroughly under no analytical and... A simulation approach based on a full-wave numerical method is presented to study electromagnetic characteristics by complex targets. How to validate simulation results is considered thoroughly under no analytical and measured data, where a double-check criterion is designed for our simulation approach. As an example, the scattering of F-117A is studied by using our simulation approach under all polarizations, different frequency bands, incident and scattering directions, etc., some of which, such as cross-polarization, bistatic RCS, have not been considered in the previous literature. 展开更多
关键词 electromagnetic characteristics SIMULATION complex targets hybrid FE-BI-MLFMA.
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Support vector regression model for complex target RCS predicting
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作者 Wang Gu Chen Weishi Miao Jungang 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2009年第1期65-68,共4页
The electromagnetic scattering computation has developed rapidly for many years; some computing problems for complex and coated targets cannot be solved by using the existing theory and computing models. A computing m... The electromagnetic scattering computation has developed rapidly for many years; some computing problems for complex and coated targets cannot be solved by using the existing theory and computing models. A computing model based on data is established for making up the insufficiency of theoretic models. Based on the "support vector regression method", which is formulated on the principle of minimizing a structural risk, a data model to predicate the unknown radar cross section of some appointed targets is given. Comparison between the actual data and the results of this predicting model based on support vector regression method proved that the support vector regression method is workable and with a comparative precision. 展开更多
关键词 radar cross section complex target coated target support vector regression.
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Effect of Jiawei Huangqi Guizhi decoction(加味黄芪桂枝汤)on theexpression of gastrin content and phosphatidylinositol 3-kinase/protein kinase B/mechanistic target of rapamycin complex 2 signallingpathways in rats with chronic atrophic gastritis 被引量:1
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作者 ZHOU Xia LIANG Kaiqing +4 位作者 CHEN Weigang CAO Yong DUO Hongdong LI Qiangbin AN Yun 《Journal of Traditional Chinese Medicine》 2025年第4期770-776,共7页
OBJECTIVE:To investigate the effects of Jiawei Huangqi Guizhi decoction(加味黄芪桂枝汤)on chronic atrophic gastritis(CAG)in rats and its modulation of the phosphatidylinositol 3-kinase/protein kinase B/mechanistic tar... OBJECTIVE:To investigate the effects of Jiawei Huangqi Guizhi decoction(加味黄芪桂枝汤)on chronic atrophic gastritis(CAG)in rats and its modulation of the phosphatidylinositol 3-kinase/protein kinase B/mechanistic target of rapamycin complex 2(PI3K/Akt/m TORC2)signaling pathway.METHODS:CAG was induced in rats and treated with high-,medium-,or low-dose Jiawei Huangqi Guizhi decoction.Gastric histopathology was observed by hematoxylin and eosin staining.Serum levels of gastrin,PI3K,Akt,and m TORC2 were detected by enzyme-linked immunosorbent assay.Gene and protein expression levels were analyzed by reverse transcription polymerase chain reaction and western blot.RESULTS:The decoction alleviated gastric mucosal injury,reduced inflammation,and restored epithelial structure.It regulated PI3K,Akt,and m TORC2 expression at both m RNA and protein levels.CONCLUSION:Jiawei Huangqi Guizhi decoction may prevent CAG progression by improving gastric tissue and modulating the PI3K/Akt/m TORC2 signaling pathway. 展开更多
关键词 GASTRINS PI3K Akt mechanistic target of rapamycin complex 2 signal transduction PATHOLOGY Jiawei Huangqi Guizhi decoction
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SCTE: RCS Prediction System for ComplexTarget and Interaction with Environment
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作者 Cao Qin-feng Lu Shu Xu Peng-gen 《Wuhan University Journal of Natural Sciences》 CAS 1999年第3期299-303,共5页
A RCS prediction system named SCTE (Scattering from Complex Target and Environment) for calculating high-frequency electromagnetic scattering from complex target within complex environment is presented. The scattering... A RCS prediction system named SCTE (Scattering from Complex Target and Environment) for calculating high-frequency electromagnetic scattering from complex target within complex environment is presented. The scattering body is described by Computer-Aided-Design (CAD) representations in which the complex body is modeled as NURBS (Non-Uniform Rational B-spline) surfaces. The complex environment (rough surface of sea or ground) is also carefully considered by using fractal function. Scattering fields are calculated by using physical optics and the equivalent currents methods. There is a good agreement between the present results and that from measurements which demonstrates the accuracy of this system. 展开更多
关键词 RCS complex target EM scattering
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An Approach to RCS Computation for Complex Targets
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作者 Zhao Weijiang & Wang Maoguang Xidian University, Xi’an 710071, P. R. China 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 1997年第4期56-60,共5页
A practical approach for calculating the RCS (Radar Cross Section) of complex targets modeled with wire-grid-frame is presented. A way for generating a polyhedron model (facet-wedge model) with the wire-grid-frame dat... A practical approach for calculating the RCS (Radar Cross Section) of complex targets modeled with wire-grid-frame is presented. A way for generating a polyhedron model (facet-wedge model) with the wire-grid-frame data is described. For storing and reading the data of the polyhedron model in an easy way, a data structure is given. 展开更多
关键词 Radar cross section Geometry modeling complex target.
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Mammalian target of rapamycin complex 1 as an inducer of neurotrophic factors in dopaminergic neurons 被引量:1
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作者 Sang Ryong Kim 《Neural Regeneration Research》 SCIE CAS CSCD 2014年第23期2036-2037,共2页
The defining neuropathological feature of Parkinson's disease (PD) is the loss of nigrostriatal dopaminergic (DA) projections. This results in striatal dopamine levels and a biochemical reduction of movement diso... The defining neuropathological feature of Parkinson's disease (PD) is the loss of nigrostriatal dopaminergic (DA) projections. This results in striatal dopamine levels and a biochemical reduction of movement disorders, such as a tremor at rest, rigidity of the limbs, bradykinesia, and postural instability (Kim et al., 2011; Kim et al., 2012; Burke and O'Malley, 2013; Leem et al., 2014; Namet al., 2014). 展开更多
关键词 RHEB Mammalian target of rapamycin complex 1 as an inducer of neurotrophic factors in dopaminergic neurons GDNF BDNF
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Role of mammalian target of rapamycin complex 2 in primary and secondary liver cancer 被引量:1
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作者 Katharina Joechle Jessica Guenzle +4 位作者 Claus Hellerbrand Pavel Strnad Thorsten Cramer Ulf Peter Neumann Sven Arke Lang 《World Journal of Gastrointestinal Oncology》 SCIE 2021年第11期1632-1647,共16页
The mammalian target of rapamycin(mTOR)acts in two structurally and functionally distinct protein complexes,mTOR complex 1(mTORC1)and mTOR complex 2(mTORC2).Upon deregulation,activated mTOR signaling is associated wit... The mammalian target of rapamycin(mTOR)acts in two structurally and functionally distinct protein complexes,mTOR complex 1(mTORC1)and mTOR complex 2(mTORC2).Upon deregulation,activated mTOR signaling is associated with multiple processes involved in tumor growth and metastasis.Compared with mTORC1,much less is known about mTORC2 in cancer,mainly because of the unavailability of a selective inhibitor.However,existing data suggest that mTORC2 with its two distinct subunits Rictor and mSin1 might play a more important role than assumed so far.It is one of the key effectors of the PI3K/AKT/mTOR pathway and stimulates cell growth,cell survival,metabolism,and cytoskeletal organization.It is not only implicated in tumor progression,metastasis,and the tumor microenvironment but also in resistance to therapy.Rictor,the central subunit of mTORC2,was found to be upregulated in different kinds of cancers and is associated with advanced tumor stages and a bad prognosis.Moreover,AKT,the main downstream regulator of mTORC2/Rictor,is one of the most highly activated proteins in cancer.Primary and secondary liver cancer are major problems for current cancer therapy due to the lack of specific medical treatment,emphasizing the need for further therapeutic options.This review,therefore,summarizes the role of mTORC2/Rictor in cancer,with special focus on primary liver cancer but also on liver metastases. 展开更多
关键词 Mammalian target of rapamycin Mammalian target of rapamycin complex 2 RICTOR Liver cancer Liver metastases Hepatocellular carcinoma Cholangiocellular carcinoma
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Mediator complex components are frequent targets for genetic alterations in various types of human cancer
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作者 Libin Deng Cheng Zhang +4 位作者 Duling Miao Xiaoli Tang Shiwen Luo Hong-Bo Xin Huidong Shi 《Journal of Genetics and Genomics》 SCIE CAS CSCD 2017年第12期587-591,共5页
The Mediator co-activator complex is a highly conserved,multisubunit protein complex required for gene transcription by RNA polymerase Ⅱ(RNAPⅡ)in all eukaryotes(Allen and Taatjes,2015).This complex,which consist... The Mediator co-activator complex is a highly conserved,multisubunit protein complex required for gene transcription by RNA polymerase Ⅱ(RNAPⅡ)in all eukaryotes(Allen and Taatjes,2015).This complex,which consists of at least 30 polypeptides,can be divided into four structurally distinct sub-modules including the head,middle,tail,and cyclin-dependent kinase 8(CDK8)modules (CKM) (Fig. 1A) (Yin and Wang, 2014; Allen and Taatjes, 2015). 展开更多
关键词 Mediator complex component frequent targets genetic alterations
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Targeting Ageing to Decrease Complex Non-Communicable Human Diseases
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作者 Jing-Dong J.Han John R.Speakman 《Journal of Genetics and Genomics》 SCIE CAS CSCD 2014年第9期457-458,共2页
During the last two centuries, there have been many spectacular advances in medical science, the main consequence of which has been the dramatically reduced burden of infectious diseases. While in the 1800s many peopl... During the last two centuries, there have been many spectacular advances in medical science, the main consequence of which has been the dramatically reduced burden of infectious diseases. While in the 1800s many people died before reaching adult- hood, nowadays most people survive. Hence average life ex- pectancy in 1800s was around 30-40, which was barely higher than it had been in Greek and Roman times (Finch, 2010), but nowadays life expectancy in most modernised economies is around 75 - 80. This demographic shift, which has happened in only 200 years, has created a dramatic change in the causes of mortality. The major killers in the modern world are non- communicable diseases (NCDs): principally cardiovascular disease, cancer and neurodegenerative disorders such as Alz- heimer's disease. A major factor that influences susceptibility to all these diseases is age. As we get older, our risk of developing these NCDs increases enormously. For example, the rate of breast cancer in females at age 15-19 is less than 10 per 100,000 population, but this increases to 100 at age 40-44, 275 at age 55--59 and 450 at age 85 + (http://www.cancerresearchuk.org/ cancer-info/cancerstats/types/breast/incidence/#age). Ageing has consequently become a major medical, social and economic burden to many countries. 展开更多
关键词 targeting Ageing to Decrease complex Non-Communicable Human Diseases
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3,6-dichlorobenzo[b]thiophene-2-carboxylic acid alleviates ulcerative colitis by suppressing mammalian target of rapamycin complex 1 activation and regulating intestinal microbiota
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作者 Qiong-Zi He Peng Wei +5 位作者 Jun-Zhi Zhang Tong-Tong Liu Kun-Qun Shi Huan-Huan Liu Jing-Wei Zhang Shi-Jia Liu 《World Journal of Gastroenterology》 SCIE CAS 2022年第46期6522-6536,共15页
BACKGROUND 3,6-dichlorobenzo[b]thiophene-2-carboxylic acid(BT2)is a benzothiophene carboxylate derivative that can suppress the catabolism of branched-chain amino acid(BCAA)-associated mammalian target of rapamycin co... BACKGROUND 3,6-dichlorobenzo[b]thiophene-2-carboxylic acid(BT2)is a benzothiophene carboxylate derivative that can suppress the catabolism of branched-chain amino acid(BCAA)-associated mammalian target of rapamycin complex 1(mTORC1)activation.Previous studies have demonstrated the therapeutic effects of BT2 on arthritis,liver cancer,and kidney injury.However,the effects of BT2 on ulcerative colitis(UC)are unknown.AIM To investigate the anti-UC effects of BT2 and the underlying mechanism.METHODS Mouse UC models were created through the administration of 3.5%dextran sodium sulfate(DSS)for 7 d.The mice in the treated groups were administered salazosulfapyridine(300 mg/kg)or BT2(20 mg/kg)orally from day 1 to day 7.At the end of the study,all of the mice were sacrificed,and colon tissues were removed for hematoxylin and eosin staining,immunoblot analyses,and immunohistochemical assays.Cytokine levels were measured by flow cytometry.The contents of BCAAs including valine,leucine,and isoleucine,in mouse serum were detected by liquid chromatography-tandem mass spectrometry,and the abundance of intestinal flora was analyzed by 16S ribosomal DNA sequencing.RESULTS Our results revealed that BT2 significantly ameliorated the inflammatory symptoms and pathological damage induced by DSS in mice.BT2 also reduced the production of the proinflammatory cytokines interleukin 6(IL-6),IL-9,and IL-2 and increased the anti-inflammatory cytokine IL-10 level.In addition,BT2 notably improved BCAA catabolism and suppressed mTORC1 activation and cyclooxygenase-2 expression in the colon tissues of UC mice.Furthermore,highthroughput sequencing revealed that BT2 restored the gut microbial abundance and diversity in mice with colitis.Compared with the DSS group,BT2 treatment increased the ratio of Firmicutes to Bacteroidetes and decreased the abundance of Enterobacteriaceae and Escherichia-Shigella.CONCLUSION Our results indicated that BT2 significantly ameliorated DSS-induced UC and that the latent mechanism involved the suppression of BCAA-associated mTORC1 activation and modulation of the intestinal flora. 展开更多
关键词 3 6-dichlorobenzo[b]thiophene-2-carboxylic acid Ulcerative colitis Mechanistic target of rapamycin complex 1 Intestinal flora Dextran sodium sulfate Cyclooxygenase-2
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Attractive target wave patterns in complex networks consisting of excitable nodes
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作者 张立升 廖旭红 +2 位作者 弥元元 钱郁 胡岗 《Chinese Physics B》 SCIE EI CAS CSCD 2014年第7期171-182,共12页
This review describes the investigations of oscillatory complex networks consisting of excitable nodes, focusing on the target wave patterns or say the target wave attractors. A method of dominant phase advanced drivi... This review describes the investigations of oscillatory complex networks consisting of excitable nodes, focusing on the target wave patterns or say the target wave attractors. A method of dominant phase advanced driving (DPAD) is introduced to reveal the dynamic structures in the networks supporting osciUations, such as the oscillation sources and the main excitation propagation paths from the sources to the whole networks. The target center nodes and their drivers are regarded as the key nodes which can completely determine the corresponding target wave patterns. Therefore, the center (say node A) and its driver (say node B) of a target wave can be used as a label, (A, B), of the given target pattern. The label can give a clue to conveniently retrieve, suppress, and control the target waves. Statistical investigations, both theoretically from the label analysis and numerically from direct simulations of network dynamics, show that there exist huge numbers of target wave attractors in excitable complex networks if the system size is large, and all these attractors can be labeled and easily controlled based on the information given by the labels. The possible applications of the physical ideas and the mathematical methods about multiplicity and labelability of attractors to memory problems of neural networks are briefly discussed. 展开更多
关键词 dominant phase advanced driving method complex networks labelable attractors target wavepatterns
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Targeting Ras homolog enriched in brain 1 to restore β-cell mass and function:A potential therapeutic strategy for diabetes
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作者 Yao Peng Dong-Dong Zhang +1 位作者 Ling Gan Jia-Qi Zhang 《World Journal of Diabetes》 2025年第9期8-13,共6页
This editorial highlighted the central role of pancreatic β-cell dysfunction in the pathogenesis of diabetes mellitus and discussed the emerging significance of Ras homolog enriched in brain 1(Rheb1)as a key regulato... This editorial highlighted the central role of pancreatic β-cell dysfunction in the pathogenesis of diabetes mellitus and discussed the emerging significance of Ras homolog enriched in brain 1(Rheb1)as a key regulator of β-cell mass and insulinsecretory capacity.While molecular mechanisms governing β-cell homeostasis remain incompletely defined,Yang et al have recently demonstrated that Rheb1 could promote β-cell proliferation through dual activation of mechanistic target of rapamycin complex 1 and AMP-activated protein kinase signaling pathways,rather than relying solely on mechanistic target of rapamycin complex 1.Notably,Rheb1 expression is higher in pancreatic islets from younger individuals and upregulates hepatocyte nuclear factor 4 alpha,which is recognized as a transcription factor essential for β-cell identity and insulin production.These insights position Rheb1 as a pivotal regulator of β-cell growth and metabolic function,with potential therapeutic implications for diabetes.Targeting Rheb1 may shift treatment paradigms from conventional glucose-lowering strategies towardβ-cell restoration,providing a novel approach to preserve or enhance functionalβ-cell mass in diabetic patients.Further investigation into Rheb1’s upstream regulators and downstream effectors may provide innovative therapeutic directions. 展开更多
关键词 Diabetes mellitus βcell dysfunction Ras homolog enriched in brain 1 Mechanistic target of rapamycin complex 1 pathway AMP-activated protein kinase pathway Hepatocyte nuclear factor 4 alpha
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重构YOLOv11的无人机小目标检测算法
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作者 孟昱煜 孔垂乐 +1 位作者 火久元 武泽宇 《浙江大学学报(工学版)》 北大核心 2026年第2期303-312,331,共11页
无人机视角下目标偏小、背景复杂、场景包含多尺度信息,现有算法在小目标检测中特征提取不充分、检测效果不佳,为此提出面向多尺度复杂场景、无人机视角下基于重构YOLOv11的小目标检测算法DLSRF-Net.提出自适应深度可分离感受野注意力... 无人机视角下目标偏小、背景复杂、场景包含多尺度信息,现有算法在小目标检测中特征提取不充分、检测效果不佳,为此提出面向多尺度复杂场景、无人机视角下基于重构YOLOv11的小目标检测算法DLSRF-Net.提出自适应深度可分离感受野注意力卷积模块(DSRFAConv),提升模型对小目标感受野特征的提取能力并降低模型负载;设计多分支轻量化多尺度线性注意力机制,提升模型对小目标的关注度;设计RSCDI模块作为模型的上采样层和全连接层,解决特征信息丢失问题并抑制无用信息,提升模型的检测精度.按照参数量和计算量将模型尺寸分为2类,并在VisDrone2021数据集上进行实验验证,结果表明,所提算法在2类模型尺寸下均取得了最优性能.在DOTA和SSDD数据集上验证了所提算法的泛化能力. 展开更多
关键词 小目标检测 复杂场景 YOLOv11 多尺度线性注意力 RSCDI
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高分辨率SAR车辆目标识别数据集
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作者 王威 张会强 +7 位作者 范红旗 吴中杰 回丙伟 刘天鹏 吴舒捷 项德良 卫朝富 马营兵 《中国科学数据(中英文网络版)》 2026年第1期419-436,共18页
SAR车辆目标识别在战场态势感知、目标精确打击等方面具有非常重要的研究和应用价值。针对当前SAR车辆目标实测数据较为匮乏、背景单一、样本多样性不足等情况,通过典型场景布设、外场无人机挂飞试验、SAR数据成像处理、SAR目标切片制... SAR车辆目标识别在战场态势感知、目标精确打击等方面具有非常重要的研究和应用价值。针对当前SAR车辆目标实测数据较为匮乏、背景单一、样本多样性不足等情况,通过典型场景布设、外场无人机挂飞试验、SAR数据成像处理、SAR目标切片制备等步骤构建了一个高分辨率SAR车辆目标识别数据集。本数据集涵盖7大类21型车辆目标,包括水泥地面、草地与树丛3种背景,Ku与X两个波段,5个俯仰角以及多达72个方位角,共计3308张SAR幅度图像数据以及对应的复数据。所有样本均结合专家判读与图像质量评估双重校验,确保了成像质量与标注信息的可靠性。本数据集可为SAR车辆目标特性分析、车辆细粒度识别、小样本识别、域适应目标识别等研究提供基础数据支撑,提升SAR目标识别领域研究水平以及应用效果。 展开更多
关键词 SAR图像 车辆目标 地面背景 目标识别 复数据
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多尺度信息增强的遥感图像目标检测算法
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作者 杨路 刘俊杰 余翔 《计算机工程》 北大核心 2026年第4期200-213,共14页
针对复杂背景遥感图像中小目标密集、目标尺度变化大等因素给目标检测带来的特征提取困难、精度不佳的问题,在YOLOv5s基础上提出一种多尺度信息增强的目标检测算法——深度学习YOLO(DL-YOLO)。首先,改进算法在主干网络顶部采用基于快速... 针对复杂背景遥感图像中小目标密集、目标尺度变化大等因素给目标检测带来的特征提取困难、精度不佳的问题,在YOLOv5s基础上提出一种多尺度信息增强的目标检测算法——深度学习YOLO(DL-YOLO)。首先,改进算法在主干网络顶部采用基于快速空间金字塔池化设计的空洞卷积快速空间金字塔池化,通过其中的感受野增强模块(RFEB)融合多尺度目标的细节信息与语义信息,提高网络的特征提取能力。其次,改进算法的检测头部分采用以YOLOv6s解耦头(DH)为基础设计的轻量高效解耦头(LEDH)来替换原有的检测头,在该解耦头中设计了轻量化空洞全局深度卷积(GDConv)模块来增强分类与回归任务关联信息的学习,以及引用轻量化卷积实现轻量化,在提高各尺度目标检测精度的同时,降低解耦头参数量。在DIOR数据集上的实验结果表明,与YOLOv5s相比,提出的DL-YOLO算法在精确率、召回率、mAP@0.5、mAP上分别提高了1.6、2.1、2.1和4.7百分点,综合指标超过了现有优秀的目标检测算法,对遥感图像中多尺度目标检测具有实际应用意义。 展开更多
关键词 遥感图像 复杂背景 YOLOv5s算法 多尺度目标检测 解耦头
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复杂战场环境下的任务驱动智能目标识别方法综述
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作者 罗志军 王健瑞 殷佳伟 《空天防御》 2026年第1期1-11,共11页
复杂战场环境具有目标类型多样、任务约束复杂、环境状态高度动态变化等特征,因此对智能目标识别技术提出了超越传统感知精度优化的新要求。在此类环境中,目标识别结果不仅用于描述目标本身,还直接影响任务规划与决策执行的可靠性,现有... 复杂战场环境具有目标类型多样、任务约束复杂、环境状态高度动态变化等特征,因此对智能目标识别技术提出了超越传统感知精度优化的新要求。在此类环境中,目标识别结果不仅用于描述目标本身,还直接影响任务规划与决策执行的可靠性,现有目标识别研究大多以静态场景和感知性能指标为核心,难以充分刻画识别结果在任务执行过程中的实际价值。近年来逐步形成以任务需求为导向的目标识别研究范式,即在模型设计、训练与评价过程中显式引入任务相关信息,使识别结果能更有效支撑任务运用与系统级决策,围绕这一研究趋势,本文从方法论角度对任务驱动智能目标识别技术进行系统综述。首先,分析任务驱动目标识别的基本内涵,阐明其与传统感知驱动方法在输出形式、优化目标与系统角色定位等方面的本质差异;其次,立足任务相关信息建模视角,对面向语义与属性、目标状态与行为,以及不确定性与风险表达的目标识别方法进行系统梳理;再次,讨论任务约束条件在训练与优化阶段的建模方式及识别结果与任务执行和决策模块之间的协同接口问题;最后,结合复杂战场环境的典型特征与应用需求,总结任务驱动目标识别在动态环境适应、未知目标管理、不确定性可信表达和系统协同面临的关键挑战,并展望未来发展趋势。 展开更多
关键词 任务驱动目标识别 复杂战场环境 任务相关信息建模 不确定性与风险表达 深度学习
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基于S-PGA-YOLOv12的复杂场景小目标火灾检测方法
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作者 李海 孙鹏 +1 位作者 张志佳 沈喆 《控制与决策》 北大核心 2026年第3期728-740,共13页
基于深度学习的复杂场景下小目标火灾检测方法主要面临两方面挑战:其一,在复杂场景中采集小目标火灾视频图像成本高昂且难度颇大,导致模型的泛化能力和鲁棒性受限;其二,复杂场景下小目标火灾检测易受火灾尺度、场景类型、光照条件等因... 基于深度学习的复杂场景下小目标火灾检测方法主要面临两方面挑战:其一,在复杂场景中采集小目标火灾视频图像成本高昂且难度颇大,导致模型的泛化能力和鲁棒性受限;其二,复杂场景下小目标火灾检测易受火灾尺度、场景类型、光照条件等因素影响,导致检测精度不高.对此,提出一种基于S-PGA-YOLOv12的复杂场景下小目标火灾检测模型.首先,基于YOLOv12融合了用于突出小目标关键信息的并行补丁感知注意(PPA)模块、用于平衡速度与精度的GOLD模块、用于通过自适应学习不同尺度特征图的空间融合权重的小目标检测头(Detect-ASFF)模块;然后,针对复杂场景下小目标火灾图像采集成本高、难度大等问题,提出一种基于模拟仿真的数据集构建方法;最后,基于模拟仿真构建的复杂场景小目标火灾数据集,通过消融实验、对比实验、鲁棒性和泛化性分析来验证S-PGA-YOLOv12模型的有效性.在所构建的3个数据集上进行大量实验,表明所提出方法具有有效性和优越性. 展开更多
关键词 复杂场景 小目标火灾 目标检测 注意力机制 仿真技术
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基于自适应转移概率矩阵的IMM-ISTUKF复杂机动目标跟踪算法
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作者 王一朋 王鼎衡 +6 位作者 杨维 卢永超 张霄嵩 李昊飞 贾世诚 刘保荣 韩崇伟 《科学技术与工程》 北大核心 2026年第8期3304-3318,共15页
针对高炮火控系统在小微型无人机(unmanned aerial vehicle,UAV)复杂机动跟踪中误差较大的问题,提出了基于自适应转移概率矩阵(adaptive transition probability matrix,ATPM)的交互式多模型改进强跟踪无迹卡尔曼滤波(interacting multi... 针对高炮火控系统在小微型无人机(unmanned aerial vehicle,UAV)复杂机动跟踪中误差较大的问题,提出了基于自适应转移概率矩阵(adaptive transition probability matrix,ATPM)的交互式多模型改进强跟踪无迹卡尔曼滤波(interacting multiple model-improved strong tracking unscented Kalman filter,IMM-ISTUKF)算法。该算法结合多重渐消因子增强STUKF的滤波性能,并利用后验概率与似然函数信息自适应调整马尔可夫转移概率矩阵的每个元素。设计了基于模型极化校正与模型转移加速的双阶段ATPM更新机制,在模型稳定阶段抑制非匹配模型干扰,在模型切换阶段加快模型转换,降低了状态估计误差。仿真结果表明:所提算法比传统IMM算法及改进型IMM算法的跟踪精度更高,为高炮反无人机作战提供技术支撑。 展开更多
关键词 复杂机动目标跟踪 交互式多模型 改进强跟踪无迹卡尔曼滤波(IMM-ISTUKF) 自适应转移概率矩阵(ATPM)
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逆生:完全分化细胞可塑性在再生与肿瘤发生中的双重角色
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作者 袁梦 薛帆 +2 位作者 王心雨 欧阳成 苗智峰 《中国医科大学学报》 北大核心 2026年第1期1-8,共8页
逆生是指完全分化的成熟细胞在组织损伤后,通过内源性程序逆向转化为前体状态并参与修复的过程。这一过程分为3个关键阶段:(1)通过抑制哺乳动物雷帕霉素靶蛋白复合物1(mTORC1)信号激活自噬,降解分化特征性结构;(2)解除分化状态,激活干... 逆生是指完全分化的成熟细胞在组织损伤后,通过内源性程序逆向转化为前体状态并参与修复的过程。这一过程分为3个关键阶段:(1)通过抑制哺乳动物雷帕霉素靶蛋白复合物1(mTORC1)信号激活自噬,降解分化特征性结构;(2)解除分化状态,激活干细胞相关基因(如SOX9、LGR5);(3)重启细胞周期实现功能性增殖。其中,mTORC1的抑制与再激活是核心调控机制,发挥协调自噬、代谢重编程及基因组监护作用。逆生具有生理与病理双重角色,胃主细胞、胰腺腺泡细胞等可通过逆生参与损伤修复,但异常激活会导致肠上皮化生,增加癌变风险;在肿瘤发生中,逆生会驱动突变累积,突破“癌症干细胞”理论框架,使分化细胞直接参与肿瘤起源,并通过表型可塑性介导耐药与转移。本文系统阐述逆生的分子机制、在组织修复中的作用模式及与肿瘤发生的关联,揭示其在健康与疾病中的双重角色,并展望未来研究方向。 展开更多
关键词 逆生 自噬 细胞可塑性 哺乳动物雷帕霉素靶蛋白复合物1
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VARIATION METHOD FOR ACOUSTIC WAVE IMAGING OF TWO DIMENSIONAL TARGETS
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作者 冯文杰 邹振祝 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2003年第6期700-705,共6页
A new way of acoustic wave imaging was investigated. By using the Green function theory a system of integral equations,which linked wave number perturbation function with wave field, was firstly deduced. By taking var... A new way of acoustic wave imaging was investigated. By using the Green function theory a system of integral equations,which linked wave number perturbation function with wave field, was firstly deduced. By taking variation on these integral equations an inversion equation,which reflected the relation between the little variation of wave number perturbation function and that of scattering field, was further obtained. Finally, the perturbation functions of some identical targets were reconstructed, and some properties of the novel method including converging speed, inversion accuracy and the abilities to resist random noise and identify complex targets were discussed. Results of numerical simulation show that the method based on the variation principle has great theoretical and applicable value to quantitative nondestructive evaluation. 展开更多
关键词 acoustic wave flaw identification perturbation function VARIATION complex target quantitative nondestructive evaluation
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