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Improved Segmented Belief Propagation List Decoding for Polar Codes with Bit-Flipping
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作者 Mao Yinyou Yang Dong +1 位作者 Liu Xingcheng Zou En 《China Communications》 SCIE CSCD 2024年第3期19-36,共18页
Belief propagation list(BPL) decoding for polar codes has attracted more attention due to its inherent parallel nature. However, a large gap still exists with CRC-aided SCL(CA-SCL) decoding.In this work, an improved s... Belief propagation list(BPL) decoding for polar codes has attracted more attention due to its inherent parallel nature. However, a large gap still exists with CRC-aided SCL(CA-SCL) decoding.In this work, an improved segmented belief propagation list decoding based on bit flipping(SBPL-BF) is proposed. On the one hand, the proposed algorithm makes use of the cooperative characteristic in BPL decoding such that the codeword is decoded in different BP decoders. Based on this characteristic, the unreliable bits for flipping could be split into multiple subblocks and could be flipped in different decoders simultaneously. On the other hand, a more flexible and effective processing strategy for the priori information of the unfrozen bits that do not need to be flipped is designed to improve the decoding convergence. In addition, this is the first proposal in BPL decoding which jointly optimizes the bit flipping of the information bits and the code bits. In particular, for bit flipping of the code bits, a H-matrix aided bit-flipping algorithm is designed to enhance the accuracy in identifying erroneous code bits. The simulation results show that the proposed algorithm significantly improves the errorcorrection performance of BPL decoding for medium and long codes. It is more than 0.25 d B better than the state-of-the-art BPL decoding at a block error rate(BLER) of 10^(-5), and outperforms CA-SCL decoding in the low signal-to-noise(SNR) region for(1024, 0.5)polar codes. 展开更多
关键词 belief propagation list(BPL)decoding bit-flipping polar codes segmented CRC
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AN ALGORITHM FOR LINE GENERATION BASED ON SEGMENT CODE IN PAN-EUCLIDEAN GEOMETRY
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作者 LIU Hongjian DU Jiangchuan Optical Electro Precision Instrument,Chongqing University Sichuan 630044,P.R.China 《Computer Aided Drafting,Design and Manufacturing》 1992年第1期1-8,共8页
In Comparison with the traditional point-by-point line generation method,the method we present is based on segment code in Pan-Euclidean geometric space and is quite different in re- spect of running speed and theoret... In Comparison with the traditional point-by-point line generation method,the method we present is based on segment code in Pan-Euclidean geometric space and is quite different in re- spect of running speed and theoretical basis.This paper presents an approach of using segment code to draw straight lines and shows the characteristics of a digital line.It is a newly proposed al- gorithm applicable in CAD. 展开更多
关键词 segment code pan-euclidean geometry fractal dimension
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MOTION-BASED REGION GROWING SEGMENTATION OF IMAGE SEQUENCES 被引量:1
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作者 Lu Guanming Bi Houjie Jiang Ping(Department of Information Engineering, Nanjing University ofPosts & Telecommunications, Nanjing 210003) 《Journal of Electronics(China)》 2000年第1期53-58,共6页
This paper proposes a motion-based region growing segmentation scheme for the object-based video coding, which segments an image into homogeneous regions characterized by a coherent motion. It adopts a block matching ... This paper proposes a motion-based region growing segmentation scheme for the object-based video coding, which segments an image into homogeneous regions characterized by a coherent motion. It adopts a block matching algorithm to estimate motion vectors and uses morphological tools such as open-close by reconstruction and the region-growing version of the watershed algorithm for spatial segmentation to improve the temporal segmentation. In order to determine the reliable motion vectors, this paper also proposes a change detection algorithm and a multi-candidate pro- screening motion estimation method. Preliminary simulation results demonstrate that the proposed scheme is feasible. The main advantage of the scheme is its low computational load. 展开更多
关键词 CHANGE detection MOTION estimation Image segmentATION Object-based VIDEO CODING
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Integrated management system of agro-fishery products based on QR-code 被引量:1
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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
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A NEW DECODER OF SYNCHRONOUS OPTICAL CODE DIVISION MULTIPLE ACCESS SYSTEMS USING SEGMENTED CORRELATION
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作者 Li Ou Wu Jiangxing Lan Julong(National Digital Switching System Engineering & Technology Research Center, Zhengzhou 450002) 《Journal of Electronics(China)》 2001年第2期135-139,共5页
A new segmented correlating decoder of synchronous optical CDMA using modified prime sequence codes is proposed. The performance of the proposed system is analyzed under the assumption of Poisson shot noise model for ... A new segmented correlating decoder of synchronous optical CDMA using modified prime sequence codes is proposed. The performance of the proposed system is analyzed under the assumption of Poisson shot noise model for the receiver photodetector. The decoder technique is shown to be more effective to improve the bit error probability performance than the method using an optical hard-limiter. 展开更多
关键词 SYNCHRONOUS optical CDMA PRIME codeS Multiple access system segmentED CORRELATION
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高温结构蠕变-疲劳强度评价方法的分析与比较
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作者 钮鹏 张威 +3 位作者 王骁晓 王步美 贺小华 周昌玉 《化工设备与管道》 北大核心 2025年第3期16-25,共10页
随着高温压力容器设计技术的发展,蠕变-疲劳耦合失效作为高温设备的主要破坏形式之一,是目前石油化工和核电高温设备设计时需要考虑的重要因素。文章分别介绍了ASME III-5 HBB、RCC-MRx和R5规程中的蠕变-疲劳弹性分析方法以及ASME Code ... 随着高温压力容器设计技术的发展,蠕变-疲劳耦合失效作为高温设备的主要破坏形式之一,是目前石油化工和核电高温设备设计时需要考虑的重要因素。文章分别介绍了ASME III-5 HBB、RCC-MRx和R5规程中的蠕变-疲劳弹性分析方法以及ASME Code Case 2605蠕变-疲劳非弹性分析法,并对一高温反应釜上封头结构进行了蠕变-疲劳损伤分析,探讨了各规范的差异及其产生原因。结果表明:ASME Code Case 2605非弹性分析方法能够有效降低评价的保守度,相比于RCC-MRx和ASME III-5 HBB弹性分析法,R5规程弹性分析法采用了蠕变速率直接计算蠕变损伤更为保守。 展开更多
关键词 高温设备 蠕变-疲劳 ASME III-5 HBB RCC-MRx R5 ASME code Case 2605
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A Method for Head-shoulder Segmentation and Human Facial Feature Positioning 被引量:1
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作者 HuTianjian CaiDejun 《通信学报》 EI CSCD 北大核心 1998年第5期28-33,共6页
AMethodforHeadshoulderSegmentationandHumanFacialFeaturePositioningHuTianjianCaiDejunDepartmentofElectricalan... AMethodforHeadshoulderSegmentationandHumanFacialFeaturePositioningHuTianjianCaiDejunDepartmentofElectricalandInformationEngi... 展开更多
关键词 模型适应 边缘检测 图像编码 头肩分节 人面部特征定位
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Extending and analysis of X-Code
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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
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Low-Complexity Optimization Algorithm for Irregular Low-Density Parity-Check Codes
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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
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外周血TGF-β、lncRNA ATB与急性STEMI患者PCI术后心肌缺血再灌注损伤的相关性 被引量:1
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作者 姬林娟 姚永伟 +4 位作者 田欣 王聪 芮涛 王好 俞捷 《临床与病理杂志》 2025年第4期433-442,共10页
目的:转化生长因子-β(transforming growth factor beta,TGF-β)和长链非编码RNA ATB(long non-coding RNA ATB,lncRNA ATB)在急性心肌梗死中被诱导,协同调控炎症和细胞凋亡等病理过程,与疾病的发生、发展密切相关。因此,本研究拟探究T... 目的:转化生长因子-β(transforming growth factor beta,TGF-β)和长链非编码RNA ATB(long non-coding RNA ATB,lncRNA ATB)在急性心肌梗死中被诱导,协同调控炎症和细胞凋亡等病理过程,与疾病的发生、发展密切相关。因此,本研究拟探究TGF-β和lncRNA ATB在心肌缺血再灌注损伤(myocardial ischemia reperfusion injury,MIRI)患者外周血中的表达情况及其相关性。方法:纳入2023年7月至2024年8月于江苏大学附属人民医院因急性ST段抬高型心肌梗死(ST-segment elevation myocardial infarction,STEMI)首次就诊的156例患者为研究对象。根据经皮冠状动脉介入治疗(percutaneous coronary intervention,PCI)开通罪犯血管后是否发生MIRI事件,分为MIRI组(n=76)和非MIRI组(n=80)。比较2组的临床资料,分析外周血血浆TGF-β与白细胞中lncRNA ATB的相对表达水平。采用Spearman相关性分析探讨TGF-β和lncRNA ATB及二者与MIRI后的炎症指标和心肌损伤指标的相关性。采用单因素及多因素Logistic回归分析探究MIRI的影响因素。应用受试者操作特征(receiver operating characteristic,ROC)曲线分析TGF-β和lncRNA ATB及二者联合对MIRI的潜在诊断效能。结果:MIRI组TGF-β和lncRNA ATB水平高于非MIRI组,收缩压和舒张压均低于非MIRI组,罪犯血管为右冠状动脉比例高于非MIRI组,差异均有统计学意义(均P<0.05);2组在年龄、性别、高血压史、糖尿病史、吸烟史、体重指数、门-导丝时间、罪犯血管为左前降支及左回旋支方面比较,差异均无统计学意义(均P>0.05)。MIRI组PCI术后次日的白细胞计数、中性粒细胞计数、超敏C反应蛋白、血小板计数及肌钙蛋白I(cardiac troponin I,cTnI)水平均高于非MIRI组(均P<0.05);2组术后次日的单核细胞计数、淋巴细胞计数、N末端-B型钠尿肽前体(N-terminal B-type natriuretic peptide precursor,NT-proBNP)及左室射血分数比较差异均无统计学意义(均P>0.05)。Spearman相关性分析发现TGF-β与白细胞计数、中性粒细胞计数、单核细胞计数、淋巴细胞计数、血小板计数、cTnI及NT-proBNP均呈正相关(均P<0.05);lncRNA ATB与白细胞计数、中性粒细胞计数及NT-proBNP均呈正相关(均P<0.05);TGF-β与lncRNA ATB呈正相关(P<0.001)。多因素Logistic回归分析显示:TGF-β、lncRNA ATB、罪犯血管为右冠状动脉、白细胞计数、hs-CRP及cTnI是MIRI的独立危险因素(分别OR=1.208、OR=1.512、OR=3.142、OR=1.164、OR=1.047、OR=1.033,均P<0.05),舒张压是MIRI的独立保护因素(OR=0.920,P<0.05)。ROC曲线分析结果显示:TGF-β、lncRNA ATB及二者联合对MIRI的潜在诊断曲线下面积分别为0.751、0.767、0.799,灵敏度分别为52.6%、72.4%、82.9%,特异度分别为90.0%、76.2%、71.2%,三者ROC曲线下面积两两比较,差异均无统计学意义(均P>0.05)。结论:TGF-β和lncRNA ATB是MIRI的独立危险因素,与急性STEMI患者经PCI术后发生MIRI具有显著相关性,提示二者可能参与了MIRI的炎症反应等病理过程。 展开更多
关键词 转化生长因子-Β 长链非编码RNA ATB 急性ST段抬高型心肌梗死 经皮冠状动脉介入治疗 心肌缺血再灌注损伤
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Analysis of GB 6675-2003 Nafional Safety Technical Code for Toys in Detail
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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
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LOFT L9-3 Experiment Simulation Using the SPACE Code
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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.
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基于NI-VISION在线喷码字符分割系统设计
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作者 王贺杰 陈奎 +2 位作者 蒋巧红 张美雪 徐瑞洋 《商丘师范学院学报》 2025年第3期35-38,共4页
产品外包装上的喷码含有产品的重要信息,对其进行字符分割有利于检测喷码质量.选取某款盒装牛奶包装上的喷码为实测对象,结合喷码字符的先验信息,设计多次投影法对喷码字符分割.实时喷码图像首先进行预处理和二值化,再通过找边进行角度... 产品外包装上的喷码含有产品的重要信息,对其进行字符分割有利于检测喷码质量.选取某款盒装牛奶包装上的喷码为实测对象,结合喷码字符的先验信息,设计多次投影法对喷码字符分割.实时喷码图像首先进行预处理和二值化,再通过找边进行角度校正.水平投影估计出文本行信息、垂直投影获取字符宽度信息,两者结合最终得到字符分割的ROI信息.实验结果表明:背景相对简单情况下该方法可准确分割多行字符,可直接部署到产线上,提高了投影法的适用范围. 展开更多
关键词 文字喷码 字符分割 投影法
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核废料处置库近场热-水-力耦合性状 被引量:13
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作者 秦爱芳 赵小龙 王海堂 《地下空间与工程学报》 CSCD 北大核心 2013年第5期1201-1207,共7页
采用高放射性核废料处置库模型试验,以核废料处置库近场的膨润土及岩石为研究对象,建立轴对称模型,选用适当的热、水、力本构方程,运用有限元软件code-bright对核废料处置库关闭后处置库近场的温度场、渗流场、应力场进行考虑TH,HM,TM... 采用高放射性核废料处置库模型试验,以核废料处置库近场的膨润土及岩石为研究对象,建立轴对称模型,选用适当的热、水、力本构方程,运用有限元软件code-bright对核废料处置库关闭后处置库近场的温度场、渗流场、应力场进行考虑TH,HM,TM部分耦合与THM完全耦合的数值模拟分析。得到处置库关闭后近场膨润土及岩石内温度、液体饱和度、应力的变化规律及不同耦合对这些性状影响的敏感度。结果可为核废料处置库的规划、设计以及数值分析时耦合类型的选择提供参考。 展开更多
关键词 有限元软件code—bright 核废料处置库 --力耦合 数值模拟
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改进型Logistic-Map混沌扩频序列 被引量:78
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作者 王亥 胡健栋 《通信学报》 EI CSCD 北大核心 1997年第8期71-77,共7页
本文推导了改进型Logistic-Map映射产生的混沌序列的统计特性的数学表达式,发现其与白噪声的统计特性一致,适合作为扩频地址码,仿真实验得到了与理论值很接近的结果。实际使用中,扩频地址码的长度是有限的,本文用仿真... 本文推导了改进型Logistic-Map映射产生的混沌序列的统计特性的数学表达式,发现其与白噪声的统计特性一致,适合作为扩频地址码,仿真实验得到了与理论值很接近的结果。实际使用中,扩频地址码的长度是有限的,本文用仿真手段得到了针对此混沌扩频序列的每个信息比特所含的合适的切普数。 展开更多
关键词 混沌序列 扩频通信 相关特性
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《GB50446-2017盾构法隧道施工与验收规范》中管片部分章节的修订简介 被引量:3
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作者 蔡亚宁 张晋勋 武福美 《现代隧道技术》 EI CSCD 北大核心 2019年第5期72-76,共5页
文章首先介绍了国内第一部规范盾构法隧道施工与验收的标准——《GB50446-2017盾构法隧道施工与验收规范》(以下简称《规范》2017版)管片部分章节的修订背景,解析了《规范》2017版的管片部分各章节的结构层次,梳理了修订的主要内容及理... 文章首先介绍了国内第一部规范盾构法隧道施工与验收的标准——《GB50446-2017盾构法隧道施工与验收规范》(以下简称《规范》2017版)管片部分章节的修订背景,解析了《规范》2017版的管片部分各章节的结构层次,梳理了修订的主要内容及理由,然后总结了针对近年来需要突破《规范》2008版规范中关于模具、主筋连接和混凝土坍落度等与钢筋混凝土管片生产质量和技术强相关的内容所开展的专题研究结果,确保《规范》2017版中管片部分内容在实施中的可操作性、实用性和先进性,以进一步规范和指导管片的绿色保质高效生产,提升盾构法施工隧道的实体质量。 展开更多
关键词 盾构法 隧道 管片 规范 修订
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MPEG-4编码的现状和研究 被引量:35
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作者 高文 吴枫 《计算机研究与发展》 EI CSCD 北大核心 1999年第6期641-652,共12页
随着计算机和通信技术的发展,多媒体编码进入了一个新的时代,即将公布的MPEG-4国际标准表明基于对象的编码、基于模型的编码等第二代编码技术趋于成熟.文中首先从MPEG-4所支持的各种视频对象及其特点、场景的描述和不同... 随着计算机和通信技术的发展,多媒体编码进入了一个新的时代,即将公布的MPEG-4国际标准表明基于对象的编码、基于模型的编码等第二代编码技术趋于成熟.文中首先从MPEG-4所支持的各种视频对象及其特点、场景的描述和不同应用的框架/级别等3个方面讨论了新的编码标准的主要内容和现状.新的标准用于实际应用还需要提供大量的标准之外的配套工具和研究.在随后的内容中,文中讨论了图像和视频的分割、全景图像的生成、人脸的检测与跟踪、2D网格模型的建立与跟踪以及3D人脸的分析和合成等相关领域的研究和进展情况. 展开更多
关键词 MPEG-4 图像编码 多媒体 视频通信 图像分割
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ASME规范案例2605-2的修订解读及算法实现 被引量:7
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作者 沈鋆 陈志伟 刘应华 《压力容器》 2017年第12期39-44,62,共7页
ASME规范案例2605于2008年10月出版,其目的是为了满足炼化行业中加氢工艺设备蠕变疲劳寿命设计的需要。2010年1月第1次修订,即ASME规范案例2605-1,目前,最新的版本为2015年6月第2次修订的ASME规范案例2605-2,这一版修订中有如下重要修改... ASME规范案例2605于2008年10月出版,其目的是为了满足炼化行业中加氢工艺设备蠕变疲劳寿命设计的需要。2010年1月第1次修订,即ASME规范案例2605-1,目前,最新的版本为2015年6月第2次修订的ASME规范案例2605-2,这一版修订中有如下重要修改:温度上限由454℃(850℉)提高到了482℃(900℉);对上版有误的公式和表格数据及温度单位进行了修正;在蠕变棘轮的校核中引入了弹性分析来代替非弹性分析。将对ASME规范案例2605-2的分析步骤、修订要点和算法实现进行解读和探讨,为国内工程应用和规范修订提供参考。 展开更多
关键词 code CASE 2605 蠕变疲劳 蠕变寿命 ASME -2 分析设计
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基于Erasure Code的分割文件P2P存储结构设计 被引量:3
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作者 陶钧 沙基昌 王晖 《国防科技大学学报》 EI CAS CSCD 北大核心 2008年第6期57-62,共6页
在充分考虑P2P存储特点的前提下,设计了一种新颖的基于Erasure Code的分割文件P2P存储方案,构建Chord协议上的P2P文件存储结构。通过设计有效的文件存储、访问和更新功能,克服传统Erasure Code冗余文件存储方案的不足,使存储文件具有一... 在充分考虑P2P存储特点的前提下,设计了一种新颖的基于Erasure Code的分割文件P2P存储方案,构建Chord协议上的P2P文件存储结构。通过设计有效的文件存储、访问和更新功能,克服传统Erasure Code冗余文件存储方案的不足,使存储文件具有一定的数据修改能力和结构伸缩能力。理论分析和实验仿真验证了设计方案在P2P存储系统中的可行性和有效性。 展开更多
关键词 P2P存储 ERASURE code 文件分割 存储策略
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一种基于N-Gram技术的中文文献自动分类方法 被引量:19
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作者 何浩 杨海棠 《情报学报》 CSSCI 北大核心 2002年第4期421-427,共7页
本文介绍一种基于n gram技术的、与语言无关的文献分类方法K meansaxiales (KMA) ,及其在中文文献自动分类中的应用。这种方法将文献转换成由n gram(n个连续的字符 )频次构成的向量。为压缩存储空间、提高处理速度 ,我们运用哈希函数将n... 本文介绍一种基于n gram技术的、与语言无关的文献分类方法K meansaxiales (KMA) ,及其在中文文献自动分类中的应用。这种方法将文献转换成由n gram(n个连续的字符 )频次构成的向量。为压缩存储空间、提高处理速度 ,我们运用哈希函数将n gram映射为哈希码 ,对文献的分析实际上以哈希码频次为基础运行。采用KMA算法 ,我们对一个中文数据库进行了自动分类的实验研究 ,在比较实验结果的基础上 ,我们对KMA算法初始参数的选择进行了初步探讨。 展开更多
关键词 N-GRAM 汉字切分 哈密码 文献向量 KMA 自动分类 文献分类
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