期刊文献+
共找到363篇文章
< 1 2 19 >
每页显示 20 50 100
基于预训练模型与BiLSTM-CNN的多标签代码坏味检测方法
1
作者 刘海洋 张杨 +1 位作者 田泉泉 王晓红 《河北工业科技》 CAS 2024年第5期330-335,共6页
为了提高多标签代码坏味检测的准确率,提出一种基于预训练模型与BiLSTM-CNN的多标签代码坏味检测方法DMSmell(deep multi-smell)。首先,利用静态分析工具获取源代码中的文本信息和结构度量信息,并采用2种检测规则对代码坏味实例进行标记... 为了提高多标签代码坏味检测的准确率,提出一种基于预训练模型与BiLSTM-CNN的多标签代码坏味检测方法DMSmell(deep multi-smell)。首先,利用静态分析工具获取源代码中的文本信息和结构度量信息,并采用2种检测规则对代码坏味实例进行标记;其次,利用CodeBERT预训练模型生成文本信息对应的词向量,并分别采用BiLSTM和CNN对词向量和结构度量信息进行深度特征提取;最后,结合注意力机制和多层感知机,完成多标签代码坏味的检测,并对DMSmell方法进行了性能评估。结果表明:DMSmell方法在一定程度上提高了多标签代码坏味检测的准确率,与基于分类器链的方法相比,精确匹配率提高了1.36个百分点,微查全率提高了2.45个百分点,微F1提高了1.1个百分点。这表明,将文本信息与结构度量信息相结合,并利用深度学习技术进行特征提取和分类,可以有效提高代码坏味检测的准确性,为多标签代码坏味检测的研究和应用提供重要的参考。 展开更多
关键词 软件工程 代码坏味 预训练模型 多标签分类 深度学习
下载PDF
Research on QR Code Image Pre-processing Algorithm under Complex Background
2
作者 Lei Liu Lin-li Zhou Huifang Bao 《信息工程期刊(中英文版)》 2017年第1期1-7,共7页
关键词 预处理算法 复杂背景 代码 图象 精确定位 识别技术 基于特征 预先处理
下载PDF
HBV PreS2+S/IFN-α融合基因真核表达载体的构建及其表达 被引量:3
3
作者 陈红梅 白雪帆 +3 位作者 潘蕾 李光玉 韦三华 黄长形 《中国病毒学》 CSCD 2002年第4期312-314,共3页
构建含HBVPrdS2 +S和IFN α融合基因的真核表达载体pcDNA3.1.S2S/IFN α并在真核细胞中进行表达。应用重叠延伸剪切技术 (splicingbyoverlappingextension ,简称SOE)经两次PCR获得嵌合基因片段S2S/IFN α ,回收后直接克隆到 pcDNA3.1V5 ... 构建含HBVPrdS2 +S和IFN α融合基因的真核表达载体pcDNA3.1.S2S/IFN α并在真核细胞中进行表达。应用重叠延伸剪切技术 (splicingbyoverlappingextension ,简称SOE)经两次PCR获得嵌合基因片段S2S/IFN α ,回收后直接克隆到 pcDNA3.1V5 /HisTOPOTA克隆载体 ,得到真核重组载体pcDNA3.1.S2S/IFN α。然后用脂质体法转染VeroE6细胞。对重组载体进行了限制性酶切及PCR鉴定 ,证明连接正确 ;经间接免疫荧光检测证实该重组载体能在真核细胞中表达插入的外源性基因编码的融合蛋白。真核表达载体pcDNA3.1.S2S/IFN α的成功构建及在VeroE6细胞中的有效表达 。 展开更多
关键词 HBV preS2+S/INF-α融合基因 真核表达载体 乙型肝炎病毒 Α-干扰素 基因表达
下载PDF
Preβ-1高密度脂蛋白与心血管疾病关系的研究进展 被引量:1
4
作者 李凤芹 聂宏刚 刘友斌 《中国心血管病研究》 CAS 2019年第1期5-8,12,共5页
动脉粥样硬化是心血管疾病重要的病理生理基础,延缓和防治动脉粥样硬化对于减少和降低心血管疾病的发病率及病死率具有重要意义。高密度脂蛋白(high density lipoprotein,HDL)通过参与介导胆固醇逆向转运(reverse cholesterol transport... 动脉粥样硬化是心血管疾病重要的病理生理基础,延缓和防治动脉粥样硬化对于减少和降低心血管疾病的发病率及病死率具有重要意义。高密度脂蛋白(high density lipoprotein,HDL)通过参与介导胆固醇逆向转运(reverse cholesterol transport,RCT)在抗动脉粥样硬化的形成和进展中发挥了重要作用。Preβ-1高密度脂蛋白(prebeta-1 high density lipoprotein,Preβ-1HDL)作为HDL的一种亚类,是外周细胞移出胆固醇的最初接受体,直接参与了RCT的起始步骤,并在随后的胆固醇酯化及转运中起着重要作用。本文就Preβ-1HDL的结构、代谢及其与心血管疾病的关系作一简要综述。 展开更多
关键词 preβ-1高密度脂蛋白 胆固醇逆转运 动脉粥样硬化 心血管疾病
下载PDF
Pyrolysis Characteristics and Kinetics of the Preparation Process of Sludge-Based Activated Carbon by ZnCl_2 Activation Method 被引量:2
5
作者 Xin Li Guang-Zhi Wang +1 位作者 Wei-Guang Li Ping Wang 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2013年第6期29-36,共8页
To obtain the pyrolysis characteristics and kinetics of preparation process of sludge-based activated carbon by ZnCl2 activation method (i.e.the pyrolysis process of the sludge with ZnCl2 activation),the characteris... To obtain the pyrolysis characteristics and kinetics of preparation process of sludge-based activated carbon by ZnCl2 activation method (i.e.the pyrolysis process of the sludge with ZnCl2 activation),the characteristic of mass loss and gas products generated during pyrolysis of the sludge with ZnCl2 activation were analyzed by thermogravimetric analysis coupled with Fourier Transform Infrared Spectroscopy (TG-FTIR).The kinetic parameters were calculated by the Coats-Redfem method and the mechanism models were established.The role of ZnCl2 in the pyrolysis process of the sludge with ZnCl2 activation was also illustrated through the comparison of the pyrolysis characteristics and kinetics of the sludge with and without ZnCl2 activation.The results showed that the pyrolysis process of the sludge with ZnCl2 activation can be divided into four stages including the dehydration of sludge and initial depolymerization of a small portion of organics matters,the decomposition of large molecular organic matters into small molecular intermediates,the further degradation of intermediates and volatilization of ZnCl2,and the decomposition of inorganic minerals and undecomposed organic matters.CO2,CO,CH4,H2O,some aldehydes and carboxylic acids are the major pyrolysis gaseous products.The activation energies and pre-exponential factors are in the range of 28.84-206.42 kJ/mol and 9885.16-8.08× 1011 min-1,respectively.During the pyrolysis of sludge,ZnC12 not only can function as a dehydration agent and inhibit the formation of tar,but also can peptize the organic matters in the sludge,making them easier to be decomposed. 展开更多
关键词 SLUDGE ZNCL2 ACTIVATION pyrolysisCLC number:X705 Document code:AArticle ID:1005-9113(2013)06-0029-08
下载PDF
Integrated management system of agro-fishery products based on QR-code 被引量:1
6
作者 Namjin Bae Yongyun Cho +1 位作者 Jongsun Choi Jaeyoung Choi 《Journal of Measurement Science and Instrumentation》 CAS 2013年第3期252-255,共4页
Recently,both the importance and awareness relating to food safety relating to agrochemicals,chemical fertilizers,the pollution of ecosystem and unwholesome foods are growing rapidly.For the same reason,the purchaser&... Recently,both the importance and awareness relating to food safety relating to agrochemicals,chemical fertilizers,the pollution of ecosystem and unwholesome foods are growing rapidly.For the same reason,the purchaser's curiosity increases to know about the production process which can be accomplished by production traceability system.The traceability system can store and superintend the specific attribute information about products regarding the productive centre,producer and production finish data.The products undergo various circulation processes and they are being managed by individually constructed traceability system.Thus,it is difficult for the producer and the consumer to guarantee the safety from transpirable issues about the falsification of production traceability because the traceability information can be re-produced by forging through various ways.So in this paper,we proposed a system for integrated management of agro-fishery products based on quick response code(QR-code)for forgery prevention which may help to solve these issues.The proposed system makes QR-code using production information provided by producer.And then it is provided to the distributor and the consumer through integrated service model using the QR-code.Therefore,this system make sure to provide the same production traceability about the products to the distributor and the consumer and always keeps both updated with the same information. 展开更多
关键词 quick response code (QR-code) production traceability traceability systemCLC number:TP391.44 Document code:AArticle ID:1674-8042(2013)03-0252-04
下载PDF
Particle-filter-based walking prediction model for occlusion situations 被引量:1
7
作者 Yoonchang Sung Woojin Chung 《Journal of Measurement Science and Instrumentation》 CAS 2013年第3期263-266,共4页
In the field of mobile robotics,human tracking has emerged as an important objective for facilitating human-robot interaction.In this paper,we propose a particle-filter-based walking prediction model that will address... In the field of mobile robotics,human tracking has emerged as an important objective for facilitating human-robot interaction.In this paper,we propose a particle-filter-based walking prediction model that will address an occlusion situation.Since the target being tracked is a human leg,a motion model for a leg is required.The validity of the proposed model is verified experimentally. 展开更多
关键词 human-following particle filter motion modelCLC number:TP242.6 Document code:AArticle ID:1674-8042(2013)03-0263-04
下载PDF
JAG1影响单核-巨噬细胞重塑三阴性乳腺癌转移前微环境:基于外泌体中的LncRNA MALAT1 被引量:1
8
作者 徐梦歧 石宇彤 +4 位作者 刘俊平 吴敏敏 张凤梅 何志强 唐敏 《南方医科大学学报》 CAS CSCD 北大核心 2023年第9期1525-1535,共11页
目的探讨JAG1对单核-巨噬细胞在三阴性乳腺癌(TNBC)中肿瘤转移前微环境(PMN)中作用的影响及其可能的调控机制,以期为TNBC诊疗提供新的思路和靶点。方法人TNBC细胞MDA-MB-231,MDA-MB-231B体外培养,qRT-PCR检测JAG1的表达。动物实验将雌... 目的探讨JAG1对单核-巨噬细胞在三阴性乳腺癌(TNBC)中肿瘤转移前微环境(PMN)中作用的影响及其可能的调控机制,以期为TNBC诊疗提供新的思路和靶点。方法人TNBC细胞MDA-MB-231,MDA-MB-231B体外培养,qRT-PCR检测JAG1的表达。动物实验将雌性裸鼠分为MDA-MB-231组和MDA-MB-231B组,5只/组,分别往乳腺脂肪垫注射细胞5×10^(6),6周取肿瘤组织进行免疫组化分析。人源单核细胞THP-1为研究对象,分别经人源JAG1重组蛋白(rhJAG1)直接处理或经TNBC条件培养基(CM)处理,通过单核-内皮粘附、Transwell、qRT-PCR和Western blot实验检测JAG1对单核细胞的直接作用和在PMN中的影响。实验分为5组:Control组:THP-1正常培养;231-CM组:THP-1+231-CM;231-JAG1-CM组:THP-1+rhJAG1处理后231-CM;231B-CM组:THP-1+231B-CM;231-DAPT-CM组:THP-1+DAPT处理后231-CM。透射电镜(TEM)、纳米颗粒跟踪分析(NTA)检测JAG1对TNBC外泌体分泌影响。生物信息学筛选与LncRNA MALAT1相互作用的miRNA并行qRT-PCR验证。结果与MDA-MB-231相比,侵袭株MDA-MB-231B的JAG1表达更高(P<0.01),肝转移面积更大;rhJAG1直接处理和TNBC条件培养基处理均能促进单核细胞的黏附、迁移,并影响其分化(均P<0.05);透射电镜和NTA检测显示JAG1能促进MDA-MB-231外泌体分泌数量增多(P<0.01),外泌体中LncRNAMALAT1含量升高(P<0.0001)。生物信息学分析得到与LncRNA MALAT1和JAG1相关的5个候选miRNA,实验证实miR-26a-5p在TMN中的单核-巨噬细胞中受到MALAT1的靶向调控(P<0.0001)。结论JAG1能促进TNBC的外泌体分泌并影响其中Lnc MALAT1的表达,从而靶向PMN中单核-巨噬细胞miR-26a-5p的表达,从而使单核-巨噬细胞中JAG1表达升高,进而影响单核-巨噬细胞在PMN中的黏附、迁移和破骨分化作用。 展开更多
关键词 JAG1 三阴性乳腺癌 单核-巨噬细胞 外泌体 肿瘤转移前微环境 LncRNA MALAT1
下载PDF
Extending and analysis of X-Code
9
作者 金超 冯丹 刘景宁 《Journal of Shanghai University(English Edition)》 CAS 2011年第3期194-200,共7页
X-Code is one of the most important redundant array of independent disk (RAID)-6 codes which are capable of tolerating double disk failures. However, the code length of X-Code is restricted to be a prime number, and... X-Code is one of the most important redundant array of independent disk (RAID)-6 codes which are capable of tolerating double disk failures. However, the code length of X-Code is restricted to be a prime number, and such code length restriction of X-Code limits its usage in the real storage systems. Moreover, as a vertical RAID-6 code, X-Code can not be extended easily to an arbitrary code length like horizontal RAID-6 codes. In this paper, a novel and efficient code shortening algorithm for X-Code is proposed to extend X-Code to an arbitrary length. It can be further proved that the code shortening algorithm maintains the maximum-distance-separable (MDS) property of X-Code, and namely, the shortened X-Code is still MDS code with the optimal space efficiency. In the context of the shortening algorithm for X-Code, an in-depth performance analysis on X-Code at consecutive code lengths is conducted, and the impacts of the code shortening algorithm on the performance of X-Code in various performance metrics are revealed. 展开更多
关键词 redundant array of independent disk (RAID)-6 X-Code vertical code code shortening performance analysis
下载PDF
Low-Complexity Optimization Algorithm for Irregular Low-Density Parity-Check Codes
10
作者 左健存 邵宇丰 桂林 《Journal of Donghua University(English Edition)》 EI CAS 2013年第4期330-335,共6页
A low-complexity algorithm is proposed in this paper in order to optimize irregular low-density parity-check (LDPC) codes.The algorithm proposed can calculate the noise threshold by means of a one-dimensional densit... A low-complexity algorithm is proposed in this paper in order to optimize irregular low-density parity-check (LDPC) codes.The algorithm proposed can calculate the noise threshold by means of a one-dimensional density evolution and search the optimal degree profiles with fast-convergence differential evolution,so that it has a lower complexity and a faster convergence speed.Simulation resuits show that the irregular LDPC codes optimized by the presented algorithm can also perform better than Turbo codes at moderate block length even with less computation cost. 展开更多
关键词 irregular low-density parity-check (LDPC) codes Turbo codes optimizationCLC number:TN911.22Document code:AArticle ID:1672-5220(2013)04-0330-06
下载PDF
Controlled Synthesis of Dental Enamel-like Hydroxyapatite Whiskers via Hydrothermal Homogeneous Precipitation
11
作者 Wen-Xu Li Wen Yang +2 位作者 Qian Yu De-Zhen Yu Fu-Ping Wang 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2013年第6期77-83,共7页
Dental enamel-like hydroxyapatite whiskers with high crystallinity and homogeneous morphology were synthesized by a hydrothermal homogeneous precipitation method.The composition,crystallinity and morphology of prepare... Dental enamel-like hydroxyapatite whiskers with high crystallinity and homogeneous morphology were synthesized by a hydrothermal homogeneous precipitation method.The composition,crystallinity and morphology of prepared hydroxyapatite whiskers were characterized by Ⅹ-ray diffraction and scanning electron microscopy.The effects of urea and sorbitol on their morphology and composition were investigated.Homogeneous and well crystallized enamel-like hydroxyapatite whiskers with 1.17±0.08 μm in length and 84± 14 nm in width were obtained at 0.80 mol · L-1 urea and 0.26 mol · L-1 sorbitol.These hydroxyapatite whiskers may be close to nature hydroxyapatite dental enamel in terms of the morphology and composition,suggesting that they could have potential application as dental restorative materials in the field of stomatology. 展开更多
关键词 hydrothermal homogeneous precipitation dental enamel-like UREA sorbitolCLC number:TB321 Document code:AArticle ID:1005-9113(2013)06-0077-07
下载PDF
Preparation and characterization of TiO_2-SiO_2-Fe_3O_4 core-shell powders in nano scale
12
作者 徐宏妍 第五江涛 李智勇 《Journal of Measurement Science and Instrumentation》 CAS 2013年第4期402-404,共3页
TiO2/SiO2/Fe3O4 nanoparticles have bigger specific area which can greatly increase the efficiency of photo-catalysis.The TiO2/SiO2/Fe3O4 particles in nano scale were prepared with reduction method at high temperature ... TiO2/SiO2/Fe3O4 nanoparticles have bigger specific area which can greatly increase the efficiency of photo-catalysis.The TiO2/SiO2/Fe3O4 particles in nano scale were prepared with reduction method at high temperature in this paper,and their morphology,particle size and magnetic property were characterized by transmission electron microscope(TEM),Xray diffraction(XRD) and magnetometer.The results show that the grain sizes of Fe3O4,SiO2-Fe3O4 and TiO2-SiO2-Fe3O4 particles were 50nm,70nm and 120nm,respectively.With the modification of SiO2,Fe3O4 magnetic cores are protected from oxidation.Moreover,by the addition of TiO2 function layer,TiO2-SiO2-Fe3O4 functional nanoparticles,with the saturation magnetization density of 34.1emu/g,is magnetically recoverable.The processes of this method are so simple that the nanoparticles can be produced in large quantity. 展开更多
关键词 core-shell structure NANOPARTICLES magnetic separationDocument code:AArticle ID:1674-8042(2013)04-0402-03
下载PDF
Optimization of Process Parameters of Continuous Microwave Drying Raspberry Puree Based on RSM and ANN-GA 被引量:1
13
作者 Zheng Xian-zhe Gao Feng +2 位作者 Fu Ke-sen Lu Tian-lin Zhu Chong-hao 《Journal of Northeast Agricultural University(English Edition)》 CAS 2023年第1期69-84,共16页
To improve drying uniformity and anthocyanin content of the raspberry puree dried in a continuous microwave dryer,the effects of process parameters(microwave intensity,air velocity,and drying time)on evaluation indexe... To improve drying uniformity and anthocyanin content of the raspberry puree dried in a continuous microwave dryer,the effects of process parameters(microwave intensity,air velocity,and drying time)on evaluation indexes(average temperature,average moisture content,average retention rate of the total anthocyanin content,temperature contrast value,and moisture dispersion value)were investigated via the response surface method(RSM)and the artificial neural network(ANN)with genetic algorithm(GA).The results showed that the microwave intensity and drying time dominated the changes of evaluation indexes.Overall,the ANN model was superior to the RSM model with better estimation ability,and higher drying uniformity and anthocyanin retention rate were achieved for the ANN-GA model compared with RSM.The optimal parameters were microwave intensity of 5.53 W•g^(-1),air velocity of 1.22 m·s^(-1),and drying time of 5.85 min.This study might provide guidance for process optimization of microwave drying berry fruits. 展开更多
关键词 raspberry puree continuous microwave drying response surface method(RSM) artificial neural network(ANN) genetic algorithm(GA)CLC number:TG376 Document code:A Article ID:1006-8104(2023)-01-0069-16
下载PDF
Effects of precursor solution concentration on dielectric properties of (Pb,La)(Zr,Ti)O_3 antiferroelectric thick films by sol-gel processing
14
作者 吕永博 郭茂香 +2 位作者 关新锋 丑修建 张文栋 《Journal of Measurement Science and Instrumentation》 CAS 2013年第3期294-298,共5页
Pb0.97La0.02Zr0.95Ti0.05O3(PLZT)antiferroelectric thick films derived from different precursor solution concentrations are prepared on platinized silicon substrates by sol-gel processing.The films present polycrystall... Pb0.97La0.02Zr0.95Ti0.05O3(PLZT)antiferroelectric thick films derived from different precursor solution concentrations are prepared on platinized silicon substrates by sol-gel processing.The films present polycrystalline perovskite structure with a(100)preferred orientation by X-ray diffraction(XRD)analysis.The antiferroelectricity of the films is confirmed by the double hysteresis behaviors of polarization and double-bufferfly response of dielectric constant under the applied electrical field.Antiferroelectric properties and dielectric constant are improved while the polarization characteristic values are reduced with the increase of precursor solution concentration.The films at higher precursor solution concentration exhibit excellent dielectric properties. 展开更多
关键词 engineering ceramics precursor solution concentration microstructure antiferroelectric thick filmCLC number:TB34 Document code:AArticle ID:1674-8042(2013)03-0294-05
下载PDF
Analysis of GB 6675-2003 Nafional Safety Technical Code for Toys in Detail
15
作者 Liu Tangshu Feng Chunhua 《China Standardization》 2005年第3期32-38,共7页
GB 6675-2003 National Safety Technical Code for Toys, in which the safetylevel of toys has achieved the advanced international level, is the general standard of all kinds oftoys. It will facilitate the improvement of ... GB 6675-2003 National Safety Technical Code for Toys, in which the safetylevel of toys has achieved the advanced international level, is the general standard of all kinds oftoys. It will facilitate the improvement of the whole quality of toys and the development of toysindustry. It also improves the competitive ability of our toys in international market. It is a newlandmark of the development of toys industry in China. 展开更多
关键词 2003 Analysis of GB 6675-2003 Nafional Safety Technical Code for Toys in Detail GB
下载PDF
The Unexpected Existence of Coding and Non-Coding Fragments along the Eukaryotic Gene
16
作者 Pietro Volpe 《Advances in Biological Chemistry》 2015年第2期98-125,共28页
The pathways leading to synthesis and post-synthetic modification of DNA employed methionine as donor of atoms: the carbon that came from its –CH3 served for DNA replication and repair either in bacteria or humans;it... The pathways leading to synthesis and post-synthetic modification of DNA employed methionine as donor of atoms: the carbon that came from its –CH3 served for DNA replication and repair either in bacteria or humans;its entire –CH3 served instead for building N6-methyladenine and 5-methylcytosine on bacterial DNA and 5-methylcytosine alone on human DNA. In humans, although a slight extra-S asymmetric methylation appeared de novo yielding on parental DNA 5’-m5CpC-3’/ 3’-GpG-5’, 5’-m5CpT-3’/3’-GpA-5’ and 5’-m5CpA-3’/3’-GpT-5’ monomethylated dinucleotide pairs, a heavy symmetric methylation involved in S semiconservatively newly made DNA to guarantee genetic maintenance of –CH3 in 5’-m5CpG-3’/3’-Gpm5C-5’ dimethylated dinucleotide pairs. In this framework, an inverse correlation was found between bulk genomic DNA methylation occurring in S and bulk polyA-containing pre-mRNA transcription taking place in G1 and G2. Thus, probes of 1 × 106 Daltons (constructed using sheared by sonication newly made methylated DNA filaments) revealed a modular organization in genes: after the hypermethylated promoter, they exhibited an alternation of unmethylated coding and methylated uncoding sequences. This encouraged the search for a language that genes regulated by methylation should have in common. An initial deciphering of restriction minimaps with hypomethylatable exons vs. hypermethylatable promoters and introns was improved when the bisulfite technique allowed a direct sequencing of m5C. In lymphocytes, where the transglutaminase gene is inactive, its promoter exhibited two fully methylated CpG-rich domains at 5’ and one fully unmethylated CpG-rich domain at 3’, including the site +1 and a 5’-UTR. At variance, in HUVEC cells, where the transglutaminase gene is active, in the first CpG-rich domain of promoter few doublets lost their –CH3. Such an inverse correlation suggested new hypotheses especially in connection with repair-modification: UV radiation would cause demethylation in given loci of a promoter by chance, whilst even a partial demethylation in this promoter would be able to resume a previously silent pre-mRNA transcription. 展开更多
关键词 coding vs. NON-coding pre-Messenger RNA Regions EXONS and INTRONS Multigenic and MONOGENIC TRANSCRIPTIONAL Units Regulation of Gene Expression Repair-Modification
下载PDF
ISAR target recognition based on non-negative sparse coding
17
作者 Ning Tang Xunzhang Gao Xiang Li 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2012年第6期849-857,共9页
Aiming at technical difficulties in feature extraction for the inverse synthetic aperture radar (ISAR) target recognition, this paper imports the concept of visual perception and presents a novel method, which is ba... Aiming at technical difficulties in feature extraction for the inverse synthetic aperture radar (ISAR) target recognition, this paper imports the concept of visual perception and presents a novel method, which is based on the combination of non-negative sparse coding (NNSC) and linear discrimination optimization, to recognize targets in ISAR images. This method implements NNSC on the matrix constituted by the intensities of pixels in ISAR images for training, to obtain non-negative sparse bases which characterize sparse distribution of strong scattering centers. Then this paper chooses sparse bases via optimization criteria and calculates the corresponding non-negative sparse codes of both training and test images as the feature vectors, which are input into k neighbors classifier to realize recognition finally. The feasibility and robustness of the proposed method are proved by comparing with the template matching, principle component analysis (PCA) and non-negative matrix factorization (NMF) via simulations. 展开更多
关键词 inverse synthetic aperture radar (ISAR) pre-PROCESSING non-negative sparse coding (NNSC) visual percep-tion target recognition.
下载PDF
LOFT L9-3 Experiment Simulation Using the SPACE Code
18
作者 Chang-Keun Yang Yo-Han Kim Sang-Jun Ha 《Journal of Energy and Power Engineering》 2014年第10期1695-1702,共8页
The KHNP (Korea Hydro & Nuclear Power Co.) has developed a multipurpose nuclear safety analysis code called SPACE (the safety and performance analysis code) for nuclear power plants. SPACE code is a best-estimate... The KHNP (Korea Hydro & Nuclear Power Co.) has developed a multipurpose nuclear safety analysis code called SPACE (the safety and performance analysis code) for nuclear power plants. SPACE code is a best-estimated two-phase three-field thermal-hydraulic analysis code used to analyze the safety and performance of pressurized water reactors. In this paper, LOFT (loss of fluid test) L9-3 experiment using the SPACE code was selected to confirm the capability of SPACE code and the results calculated by the SPACE code are compared with those measured through the experiment. The results were compared with the experimental data and those of the other code simulations. Throughout the simulation result, it was concluded that the SPACE code can effectively simulate LOFT L9-3 experiment. 展开更多
关键词 SPACE code LOFT L9-3 ATWS.
下载PDF
基于Omega方法的ASME CC2605-4&3蠕变计算对比分析
19
作者 邓高荣 孙虎 《化工设备与管道》 CAS 北大核心 2023年第3期9-17,共9页
规范案例ASME CC2605-4于2021年7月实施。与CC2605-3相比,新标准的蠕变参数(Omega参数和应变率参数)有较大变化。通过解析计算,探讨了温度和等效应力对新旧规范蠕变参数的影响;结合算例,利用Ansys Workbench验算了新旧规范的蠕变损伤,... 规范案例ASME CC2605-4于2021年7月实施。与CC2605-3相比,新标准的蠕变参数(Omega参数和应变率参数)有较大变化。通过解析计算,探讨了温度和等效应力对新旧规范蠕变参数的影响;结合算例,利用Ansys Workbench验算了新旧规范的蠕变损伤,并与解析计算形成对比。结果表明,有限元与解析计算结果吻合,新旧规范中蠕变参数随温度、等效应力变化的规律是一致的,且新规范的Omega参数随等效应力单调递增变化的起点更低,可进一步降低蠕变子程序开发时的最低应力限制,更贴合实际;当温度恒定400℃,初始应力高于220 MPa时,CC2605-4的蠕变损伤总是高于CC2605-3的数值。 展开更多
关键词 Code Case 2605-4 Omega蠕变损伤 Ansys Workbench 有限元分析
下载PDF
基于提示学习和超球原型的小样本ICD自动编码方法
20
作者 徐春 吉双焱 马志龙 《计算机应用研究》 CSCD 北大核心 2024年第9期2670-2677,共8页
针对国际疾病分类(ICD)自动编码方法的长文本处理、编码的层次结构以及长尾分布等导致的模型泛化能力弱的问题,提出一种充分利用医学预训练语言模型的基于提示学习和超球原型的小样本ICD自动编码方法(hypersphere prototypical with pro... 针对国际疾病分类(ICD)自动编码方法的长文本处理、编码的层次结构以及长尾分布等导致的模型泛化能力弱的问题,提出一种充分利用医学预训练语言模型的基于提示学习和超球原型的小样本ICD自动编码方法(hypersphere prototypical with prompt learning,PromptHP)。首先,将编码描述与临床文本融合进提示学习模型中的提示模板,使得模型能够更加深入地理解临床文本;然后,充分利用预训练语言模型的先验知识进行初始预测;接着,在预训练语言模型输出表示的基础上引入超球原型进行类别建模和度量分类,并在医学数据集上微调网络,充分纳入数据知识,提高模型在小样本ICD编码分配任务上的性能;最后,对以上两部分预测结果集成加权获得最终编码预测结果。在公开医学数据集MIMIC-Ⅲ上的实验结果表明,该模型优于最先进的基线方法,PromptHP将小样本编码的macro-AUC、micro-AUC、macro-F_(1)和micro-F_(1)分别提高了1.77%、1.54%、14.22%、15.01%。实验结果验证了该模型在小样本编码分类任务中的有效性。 展开更多
关键词 自动ICD编码 小样本学习 提示学习 超球原型 预训练语言模型
下载PDF
上一页 1 2 19 下一页 到第
使用帮助 返回顶部