期刊文献+
共找到36篇文章
< 1 2 >
每页显示 20 50 100
LA-ICP-MS zircon U-Pb dating for high-pressure basic granulite from North Qinling and its geological significance 被引量:42
1
作者 CHENDanling LIULiang sunyong ZHANGAnda LIUXiaoming LUOJinhai 《Chinese Science Bulletin》 SCIE EI CAS 2004年第21期2296-2304,共9页
A combined study of CL imaging, LA-ICP-MS U-Pb dating and trace element analysis were carried out for zircon grains from high-pressure basic granulite at Song- shugou in North Qinling. The zircons display core-rim in-... A combined study of CL imaging, LA-ICP-MS U-Pb dating and trace element analysis were carried out for zircon grains from high-pressure basic granulite at Song- shugou in North Qinling. The zircons display core-rim in- ternal texture. The cores are made up of sector or planar domains, partially displaying weak zoning or misty texture, and have the feature of low content of Th, U, REE, HREE, low Th/U ratio and high (Nd/Yb)N ratio, and the REE pat- tern typical for zircon coexisting with garnet. These features indicate the metamorphic genesis for the zircon cores. The rims have narrow light margins (<30 μm in width) around the cores and boundaries between core and rim are rounded or lough-like, indicating that the rims were formed during retrograde metamorphism. U-Pb isotopic data of 24 spots from the cores of 11 zircon grains yield a 206 Pb/238U weighted average age of 485±3.3 Ma, which is interpreted as the peak metamorphic age of high-pressure (HP) basic granulite. This age is well consistent within error with that of ultra- high-pressure (UHP) eclogite and its country rock gneiss (507±37 Ma) that occur at the north side of the Qinling Group, possibly indicating the occurrence of two contempo- raneous Early-Paleozoic HP to UHP metamorphic rock belts on the north and south sides of the Qinling Group. Combin- ing with the regional geological studies and the distribution of Early-Paleozoic granites related to subduction and colli- sion, the two HP to UHP metamorphic belts may be the products of continental crust bi-directional deep subduction toward Qinling micro-block caused by the subduction and collision of Paleozoic Qinling ocean and Erlangping ocean, respectively. 展开更多
关键词 LA-ICP-MS UHP REE
原文传递
SHRIMP U-Pb zircon ages for the UHP metamorphosed granitoid gneiss in Altyn Tagh and their geological significance 被引量:21
2
作者 ZHANGAnda LIULiang sunyong CHENDanling WANGYan LUOJinhai 《Chinese Science Bulletin》 SCIE EI CAS 2004年第23期2527-2532,共6页
Cathodoluminescence (CL) and mineral inclu- sions investigations show that zircons from Yinggelisayi UHP metamorphosed granitoid gneiss in Altyn Tagh exhibit core-mantle-rim internal texture with magmatic residual cor... Cathodoluminescence (CL) and mineral inclu- sions investigations show that zircons from Yinggelisayi UHP metamorphosed granitoid gneiss in Altyn Tagh exhibit core-mantle-rim internal texture with magmatic residual core, the metamorphic overgrowth mantle and the late stage rim. SHRIMP 206 Pb/238U ages of 5 spots from the mantles vary from 484±11 to 491±12 Ma with Th/U ratios from 0.01 to 0.03, yielding a weighted average age of 487±10 Ma (2σ ) as the age of the UHP metamorphosed granitoid gneiss. The 206Pb/238U ages from the oscillatory zoned cores range from 809±19 to 885±21 Ma with Th/U ratios ranging from 0.42 to 0.83, which are interpreted as the crystallization age of the protolith of the granitoid gneiss. The metamorphic age (487±10 Ma) of the UHP metamorphosed granitoid gneiss, well consistent with the peak metamorphic age (about 500 Ma) of the UHP eclogite with crystallization age of the proto- lith between 809±19 and 885±21 Ma at Jianggelisayi in west- ern Altyn Tagh, indicates the existence of a UHPM belt along the south margin of the Altyn Tagh as a result of deep sub- duction during Early Paleozoic age of previously existing continental crust. 展开更多
关键词 锆石 UHP 片麻岩 地质学 地质年代 SHRIMP技术 分析方法
原文传递
Determination of the Neoproterozoic Shicaogou Syn-collisional Granite in the Eastern Qinling Mountains and Its Geological Implications 被引量:21
3
作者 CHENDanling LIULiang +4 位作者 sunyong ZHANGAnda ZHANGChengli LIUXiaoming LUOJinhai 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2004年第1期73-82,共10页
The Shicaogou granite has been identified as a magnesian (Fe-number=0.71-0.76), calcic to calc-alkalic (MALI=3.84-5.76) and peraluminous (ASI=1.06-1.13) granite of the syn-collisional S-type, with high SiO2(>71%), ... The Shicaogou granite has been identified as a magnesian (Fe-number=0.71-0.76), calcic to calc-alkalic (MALI=3.84-5.76) and peraluminous (ASI=1.06-1.13) granite of the syn-collisional S-type, with high SiO2(>71%), A12O3 (>13%) and Na2O+K2O (6.28%-7.33%, equal for NaO2 and K2O). Trace element and REE analyses show that the granite is rich in LILE such as of Rb, Sr, Ba and Th, and poor in HFSE like Yb, Y, Zr and Hf. Its Rb/Sr ratio is greater than 1; the contents of Nb and Ta, and the ratio of Nb/Ta as well as the REE geochemical features (e.g. REE abundance, visible fractionation of LREE and HREE and medium to pronounced negative Eu anomalies) are all similar to those of crust-origin, continent-continent syn-collisional granite. Moreover, the granite exhibits almost the same pattern as that of the typical continent-continent syn-collisional granite on the spider diagram and all samples fall within the syn-collisional granite field.The cathodoluminescence (CL) investigations have revealed that the zircon from the Shicaogou granite represents a typical magmatic product characterized by its colorless, transparent and euhedral crystals, and distinct zoning of oscillatory bands. Residual cores of irregular zircon can be found in a few enhedral grains. Trace element studies of the zircon grains, with high contents of P, Y, Hf, Th, U and REE and high ratios of Th/U, obviously positive Ce anomalies and HREE enrichment compared to LREE, also result in the same conclusion.The LA-ICP-MS U-Pb isotopic data from 24 spots of 21 zircon grains demonstrate that 20 spots in the oscillatory zone yield an average weighted 206Pb/238U age of 925±11 Ma, indicating that the Shicaogou granite was formed in the Neoproterozoic. Combined with other Neoproterozoic syn-collisional granites found in the study area, the present geochronological determination can further reveal that collision-amalgamation events could have occurred among some continental blocks in the Qinling orogenic belt during the Neoproterozoic. This in turn provides an accu 展开更多
关键词 LA-ICP-MS U-Pb dating ZIRCON syn-collisional S-type granite geological implication Shicaogou eastern Qinling Mountains
下载PDF
Overcoming the fundamental light-extraction efficiency limitations of deep ultraviolet light-emitting diodes by utilizing transverse-magnetic-dominant emission 被引量:6
4
作者 Dong Yeong Kim Jun Hyuk Park +6 位作者 Jong Won Lee sunyong Hwang Seung Jae Oh Jungsub Kim Cheolsoo Sone EFred Schubert Jong Kyu Kim 《Light(Science & Applications)》 SCIE EI CAS CSCD 2015年第1期422-429,共8页
While the demand for deep ultraviolet(DUV)light sources is rapidly growing,the efficiency of current AlGaN-based DUV light-emitting diodes(LEDs)remains very low due to their fundamentally limited light-extraction effi... While the demand for deep ultraviolet(DUV)light sources is rapidly growing,the efficiency of current AlGaN-based DUV light-emitting diodes(LEDs)remains very low due to their fundamentally limited light-extraction efficiency(LEE),calling for a novel LEE-enhancing approach to deliver a real breakthrough.Here,we propose sidewall emission-enhanced(SEE)DUV LEDs having multiple light-emitting mesa stripes to utilize inherently strong transverse-magnetic polarized light from the AlGaN active region and three-dimensional reflectors between the stripes.The SEE DUV LEDs show much enhanced light output power with a strongly upward-directed emission due to the exposed sidewall of the active region and Al-coated selective-area-grown n-type GaN micro-reflectors.The devices also show reduced operating voltage due to better n-type ohmic contact formed on the regrown n-GaN stripes when compared with conventional LEDs.Accordingly,the proposed approach simultaneously improves optical and electrical properties.In addition,strategies to further enhance the LEE up to the theoretical optimum value and control emission directionality are discussed. 展开更多
关键词 deep ultraviolet light-emitting diodes light-extraction efficiency
原文传递
OSCILLATION OF IMPULSIVE HYPERBOLIC PARTIAL DIFFERENTIAL EQUATION WITH DELAY 被引量:3
5
作者 Xue Qiutiao Wu sunyong (Dept. of Computational Sci. and Math., Guilin University of Electronic Technology, Guilin 541004) Liu Anping (School of Math, and Physics, China University of Geosciences, Wuhan 430074) 《Annals of Differential Equations》 2006年第3期400-405,共6页
In this paper, oscillation properties of the solutions of impulsive hyperbolic equation with delay are investigated via the method of differential inequalities. Sufficient conditions for oscillations of the solutions ... In this paper, oscillation properties of the solutions of impulsive hyperbolic equation with delay are investigated via the method of differential inequalities. Sufficient conditions for oscillations of the solutions are established. 展开更多
关键词 OSCILLATION IMPULSIVE hyperbolic differential equations DELAY
原文传递
Authorization Management Framework Based on Joint Trust-Risk Evaluation 被引量:1
6
作者 YANG Qiuwei WU sunyong +1 位作者 HONG Fan LIAO Junguo 《Wuhan University Journal of Natural Sciences》 CAS 2007年第1期9-12,共4页
Authorization management is important precondition and foundation for coordinating and resource sharing in open networks. Recently, authorization based on trust is widely used whereby access rights to shared resource ... Authorization management is important precondition and foundation for coordinating and resource sharing in open networks. Recently, authorization based on trust is widely used whereby access rights to shared resource are granted on the basis of their trust relation in distributed environment. Nevertheless, dynamic change of the status of credential and chain of trust induces to uncertainty of trust relation. Considering uncertainty of authorization and analyzing deficiency of authorization model only based on trust, we proposes joint trust-risk evaluation and build the model based on fuzzy set theory, and make use of the membership grade of fuzzy set to express joint trust-risk relation. Finally, derivation principle and constraint principle of joint trust-risk relationships are presented. The authorization management model is defined based on joint trust-risk evaluation, proof of compliance and separation of duty are analyzed. The proposed model depicts not only trust relationship between principals, but also security problem of authorization. 展开更多
关键词 trust management authorization management risk evaluation proof of compliance fuzzy set
下载PDF
水相和无溶剂体系中生物质基乙酰丙酸制备γ-戊内酯的研究进展
7
作者 唐兴 李伟乐 +3 位作者 刘淮 孙勇 曾宪海 林鹿 《精细化工》 EI CAS CSCD 北大核心 2021年第12期2385-2392,共8页
戊内酯(GVL)是一种颇具应用潜力的生物质基平台化合物,可通过乙酰丙酸(LA)催化加氢的方式合成。目前,研究者已针对不同的溶剂体系开发出多种催化剂用于LA选择性加氢还原制备GVL。其中,水相和无溶剂体系中催化LA加氢是绿色经济的GVL合成... 戊内酯(GVL)是一种颇具应用潜力的生物质基平台化合物,可通过乙酰丙酸(LA)催化加氢的方式合成。目前,研究者已针对不同的溶剂体系开发出多种催化剂用于LA选择性加氢还原制备GVL。其中,水相和无溶剂体系中催化LA加氢是绿色经济的GVL合成途径,但上述体系对催化剂的水热稳定性和耐酸稳定性具有非常高的要求。该文着重对近年来在水相和无溶剂体系中催化LA加氢合成GVL的进展进行了归纳总结。此外,还分析了不同催化体系中LA加氢合成GVL的优劣势。最后,对水相和无溶剂体系由LA制备GVL提出了建议。 展开更多
关键词 乙酰丙酸 γ-戊内酯 水相体系 无溶剂催化体系 催化剂
下载PDF
Sputum interleukin-17 is increased and associated with airway neutrophilia in patients with severe asthma 被引量:34
8
作者 sunyong-chang ZHOUQing-tao YAOWan-zhen 《Chinese Medical Journal》 SCIE CAS CSCD 2005年第11期953-956,共4页
关键词 ASTHMA airway inflammation INTERLEUKIN-17
原文传递
Crop Yield,N Uptake and Nitrates in a Fluvo-Aquic Soil Profile 被引量:16
9
作者 ZHANGShu-Xiang LIXiu-Ying LIXiao-Ping YUANFeng-Ming YAOZhao-Hua sunyong-Lin ZHANGFu-Dao 《Pedosphere》 SCIE CAS CSCD 2004年第1期131-136,共6页
The effects of different chemical fertilizer combinations (N, P and K) oncrop yield, N uptake and nitrate distribution and accumulation to a depth of 100 cm were studied ina cinnamon fluvo-aquic soil profile (Beijing)... The effects of different chemical fertilizer combinations (N, P and K) oncrop yield, N uptake and nitrate distribution and accumulation to a depth of 100 cm were studied ina cinnamon fluvo-aquic soil profile (Beijing) with a continuous winter wheat-summer maize croppingsystem for nine years. The experiment consisted of 7 treatments: no fertilizer control (CK); Nalone, N in combination with K (NK), P (NP), and P and K (NPK and N1PK); and P and K in combinationwithout N (PK). The rate of N was 150 kg ha^(-1) for the N treatments except Treatment N1PK withhigher N rate (195 kg ha^(-1)), and the rates of P (P_2O_5) and K (K2O) were 75 and 37.5 kg ha^(-1),respectively. The applications of N combined with P and K (NK, NP and NPK) resulted in higher cropyields than a single application of N. The yields followed the order: NPK > NP > N1PK > PK > NK > N> CK for winter wheat, and NPK > N1PK > NP > NK > N > PK > CK for summer maize. Supplement of N withP or K, or both P and K resulted in a higher average N uptake of the two crops, which was in adecreasing order NPK > NP > N1PK > NK > N > PK > CK. The combinations also increased apparent Nrecovery more than N alone and CK. The nitrate content in the profile was thus reduced more in thecombination treatments. The nitrate accumulation in the soil profiles followed the order: N > NK >N1PK > NPK > NP > CK > PK. Higher N uptake by the adequately fertilized crops (Treatment NPK)reduced nitrate accumulation in the profile and thus reduced nitrate leaching. The optimum N:P:Kratio was thus of paramount importance in increasing yields and N uptake of crops and reducingnitrate leaching losses. 展开更多
关键词 fertilizer combination N uptake nitrate distribution and accumulation YIELD
下载PDF
Regional ecological security anddiagnosisof obstaclefactors in underdevelopedregions:acasestudy in Yunnan Province,China 被引量:12
10
作者 OUZhao-rong ZHUQing-ke sunyong-yu 《Journal of Mountain Science》 SCIE CSCD 2017年第5期870-884,共15页
In order toclarify regional ecological security status and formation mechanism of regional ecological security barriers in underdeveloped regions of China,we took Yunnan province as a case to evaluate its regional eco... In order toclarify regional ecological security status and formation mechanism of regional ecological security barriers in underdeveloped regions of China,we took Yunnan province as a case to evaluate its regional ecological security by using entropy matter-element model,comprehensive index and GIS spatial method,and we diagnosed itsobstacle factors through obstacle degree model. We found a low overall level of regional ecological security in Yunnan. Only Kunmingfell into the good level, 68% of the regions were below the critical safe level. For the vast majority of regions in Yunnan, their regional ecological security was unstable. The indexes related to per capita resources, geological and topographyenvironment, economic, and technologywere at the unsafe or dangerous level.The indexes related to urban expansion, level of income, cultivated land quality were at the level of critical safety. The indexes concerning urban management capacity, airqualityand waterenvironment were at the good or ideallevel. Yunnan's regional ecological security was not good due to natural obstructive environment itself, simultaneously lower backward economic and social level restricted the ability of ecological security response to manage ragile ecological environment. The results of the composite index wereroughly consistent with those of the entropy weight matterelement model. The mean values of the classification index,from high to low, were: the state index>the response index>the pressure index. The state index and the response index had a significant mutual promotion to each other.The regions with good composite index, state index and response index mainly distributed in the central regions of Yunnan Province. Spatial autocorrelation of regional ecological security level in Yunnan was not obvious. Water resources, economic and social development were main obstacle factors of the regional ecological security.When distinguishing with obstacle type, Kunming belonged to natural ecological environment barrier type, while other regions 展开更多
关键词 Regional ecological security Pressure state-response model Entropy matter-element model Comprehensive index method Spatial heterogeneity Obstacle factors
下载PDF
Construction of a System for the Stable Expression of Foreign Genes in Dunaliella salina 被引量:9
11
作者 GENGDe-Gui HANYan +4 位作者 WANGYi-Qin WANGPeng ZHANGLi-Ming LIWen-Bin sunyong-Ru 《Acta Botanica Sinica》 CSCD 2004年第3期342-346,共5页
A stable transformation system for the expression of foreign genes in the unicellular greenmarine alga (Dunaliella salina Teod.) was established. Using electroporation, the alga was transformed witha plasmid containin... A stable transformation system for the expression of foreign genes in the unicellular greenmarine alga (Dunaliella salina Teod.) was established. Using electroporation, the alga was transformed witha plasmid containing the hepatitis B surface antigen (HBsAg) gene and the chloramphenicol acetyltransferase(CAT) gene as a selectable gene. PCR and Southern blotting analysis indicated that the HBsAEgene wasintegrated into the D. salina genome. Northern dotting analysis showed that the HBsAg gene was expressedat the mRNA level. The stable expression of HBsAg protein in transformants was confirmed by HBsAgenzyme-linked immunosorbent assay (HBsAg EUSA) and Western blotting analysis. Also, PCR and Southernblotting analyses showed that the CA Tgene was integrated into the D, salina genome, and CAT EUSAindicated that CAT protein was stably expressed in the cells. The introduced HBsAg DNA and HBsAgprotein expression were stably maintained for at least 60 generations in media devoid of chloramphenicol.This is the first report of the stable expression of foreign genes in D. salina. 展开更多
关键词 杜氏盐藻 外源基因 氯霉素乙酰转移酶 乙肝病毒表面抗原
下载PDF
Investigation and analysis of incidence of awareness in patients undergoing cardiac surgery in Beijing, China 被引量:8
12
作者 WANGYun YUEYun +4 位作者 sunyong-hai WUAn-shi WUQi-wei ZHANGYong-qian FENGChun-sheng 《Chinese Medical Journal》 SCIE CAS CSCD 2005年第14期1190-1194,共5页
Background Awareness under general anesthesia is a serious complication which leads to psychiatric disorders. The incidence of awareness in patients undergoing cardiac surgery has been reported in as many as 1.5%-23% ... Background Awareness under general anesthesia is a serious complication which leads to psychiatric disorders. The incidence of awareness in patients undergoing cardiac surgery has been reported in as many as 1.5%-23% in foreign countries. But so far, medical literature about awareness during cardiac surgery is still rare in China. Therefore, we investigated the incidence of awareness in patients undergoing different kinds of cardiac surgery, the phases when awareness occured and the effect of cardiopulmonary bypass on the incidence of awareness in coronary artery bypass grafting in Beijing.Methods Patients' recall of awareness during cardiac surgery was assessed. One hundred patients undergoing coronary artery bypass grafting (CABG) in Chaoyang Hospital, Beijing, one hundred patients undergoing CABG and one hundred patients undergoing valve replacement or septal defect repair in Fuwai Hospital, Beijing, were interviewed 3-6 days after surgery. Every report obout patients on recall of awareness was recorded. An independent research team, blinded to patients' surgery and anesthesia, assessed every report of awareness.Results The incidence of awareness of patients received CABG under cardiopulmonary bypass (CPB), off -pump CABG, septal repair or valve replacement under CPB was 4.7% (5 of 106 cases), 9.6% (9 of 94 cases) and 4% (4 of 100 cases), respectively. CPB did not greatly affect the incidence of awareness during the period of CABG (P>0.05). The incidence of awareness of patients who received CABG under CPB did not increase significantly, in comparison with that of patients who received septal repair or valve replacement under CPB in Fuwai Hospital (P>0.05). Awareness easily occurred before bypass grafting or CPB.Conclusions Awareness mainly occurs before bypass grafting or CPB in cardiac surgery. Most cases with awareness have auditory perceptions. CPB is not a main factor which affects the incidence of awareness of CABG. Surgical types do not affect the incidence of awareness of patients under CPB. 展开更多
关键词 ANESTHESIA memory HEART SURGERY
原文传递
杂波环境下基于粒子滤波的微弱扩展目标检测前跟踪算法 被引量:7
13
作者 吴孙勇 薛秋条 +2 位作者 朱圣棋 闫青竹 孙希延 《雷达学报(中英文)》 CSCD 2017年第3期252-258,共7页
针对杂波环境下微弱扩展目标的实时检测和跟踪问题,该文提出一种基于粒子滤波的检测前跟踪(TBD)算法。该算法以杆状物体作为研究对象,通过划分距离和方位上的单元格,提出了不同区域内含有Weibull杂波的量测模型。在TBD框架下,将二进制... 针对杂波环境下微弱扩展目标的实时检测和跟踪问题,该文提出一种基于粒子滤波的检测前跟踪(TBD)算法。该算法以杆状物体作为研究对象,通过划分距离和方位上的单元格,提出了不同区域内含有Weibull杂波的量测模型。在TBD框架下,将二进制目标存在变量和目标形状参数加入到状态向量中,通过抽样得到散射点集合,并利用粒子滤波实现杂波环境下对扩展目标状态和形状参数的检测和估计。仿真实验表明,该算法具有较好的稳定性。 展开更多
关键词 杂波 WEIBULL分布 粒子滤波 检测前跟踪 扩展目标
下载PDF
基于GLMB滤波的复杂场景下红外弱小目标自适应跟踪算法
14
作者 蔡如华 周健斌 +1 位作者 吴孙勇 郑翔飞 《红外技术》 CSCD 北大核心 2024年第7期743-753,共11页
针对红外弱小目标在复杂场景下受到漏检和杂波影响,导致跟踪不连续甚至失效的问题,本文提出一种红外弱小目标自适应跟踪算法。在预处理阶段,为了减少不必要的计算,首先定义一种衡量图像复杂度的算法。然后该算法通过计算红外图像多个特... 针对红外弱小目标在复杂场景下受到漏检和杂波影响,导致跟踪不连续甚至失效的问题,本文提出一种红外弱小目标自适应跟踪算法。在预处理阶段,为了减少不必要的计算,首先定义一种衡量图像复杂度的算法。然后该算法通过计算红外图像多个特征得到场景复杂度来确认场景类型,再根据场景类型选取对应的检测算法提取目标候选位置、灰度以及局部直方图等特征建立对应的量测模型与似然函数。在目标跟踪阶段,为了自适应地匹配广义标签多伯努利(Generalized Labeled Multi-Bernoulli,GLMB)滤波器的滤波参数,在GLMB的基础上提出一种适应视频图像的新生算法进行航迹起始;针对红外图像序列目标检测概率未知的情况,将未知检测概率的基数化概率假设密度(Cardinality Probability Hypothesis Density,CPHD)滤波器集成到GLMB中实时估计目标检测概率以提升跟踪精度。仿真结果表明,所提出算法能有效地排除量测漏检和虚警的干扰,跟踪不同红外复杂场景下的弱小目标。 展开更多
关键词 红外弱小目标 广义标签多伯努利滤波 自适应跟踪 复杂场景
下载PDF
有偏量测下基于最大相关熵卡尔曼滤波的目标跟踪方法
15
作者 韦春玲 余润华 +1 位作者 吴孙勇 李明 《电子技术应用》 2024年第7期7-13,共7页
针对传感器存在系统偏差且噪声非高斯条件下目标状态估计精度较差的问题,提出一种有偏量测下基于最大相关熵卡尔曼滤波(Maximum Correntropy Kalman Filter,MCKF)的目标跟踪方法。该方法通过引入差分机制,利用目标相邻时刻的有偏量测之... 针对传感器存在系统偏差且噪声非高斯条件下目标状态估计精度较差的问题,提出一种有偏量测下基于最大相关熵卡尔曼滤波(Maximum Correntropy Kalman Filter,MCKF)的目标跟踪方法。该方法通过引入差分机制,利用目标相邻时刻的有偏量测之差构建差分量测方程,有效克服了系统偏差的影响。随后基于最大相关熵准则(Maximum Correntropy Criterion,MCC)量化估计误差的高阶矩信息,并以差分量测为先验条件推导出有偏量测下算法的滤波迭代方程。仿真结果表明,当系统观测值受传感器系统偏差和非高斯噪声干扰时,与现有方法相比,所提方法具有更好的跟踪性能。 展开更多
关键词 系统偏差 非高斯噪声 最大相关熵准则 量测差分 卡尔曼滤波
下载PDF
脉冲噪声下多伯努利滤波的单声矢量DOA跟踪 被引量:5
16
作者 吴孙勇 赵君 +2 位作者 董续东 薛秋条 廖桂生 《信号处理》 CSCD 北大核心 2020年第1期139-148,共10页
针对单声矢量传感器(Acoustic vector sensor,AVS)脉冲噪声环境下的多声源波达方向(Direction of arrival,DOA)跟踪问题,利用α稳定分布能更好地建模脉冲噪声的性质,提出α稳定分布下的多伯努利DOA跟踪算法。由于α稳定分布不具有有限... 针对单声矢量传感器(Acoustic vector sensor,AVS)脉冲噪声环境下的多声源波达方向(Direction of arrival,DOA)跟踪问题,利用α稳定分布能更好地建模脉冲噪声的性质,提出α稳定分布下的多伯努利DOA跟踪算法。由于α稳定分布不具有有限协方差,该算法采用分数低阶距(Fractional Lower Order Moment,FLOM)代替协方差矩阵,对FLOM进行特征分解构造噪声子空间,生成FLOM-MUSIC空间谱函数作为多伯努利滤波器的伪似然函数,并对其指数加权,改善了传统似然函数的发散和平坦问题,使得粒子的重采样更有效。该算法的优点是不需要预先知道声源个数,利用先验信息和当前量测信息可以直接对当前声源进行跟踪。仿真结果表明,该算法能有效跟踪脉冲噪声环境下单一AVS声源的数目和状态。 展开更多
关键词 声矢量传感器 波达方向跟踪 多伯努利滤波器 粒子滤波
下载PDF
基于JMS-SMC-PHD滤波的检测前跟踪算法 被引量:5
17
作者 薛秋条 宁巧娇 +2 位作者 吴孙勇 蔡如华 伍雯雯 《红外技术》 CSCD 北大核心 2020年第8期783-788,共6页
针对低信噪比条件下机动目标的检测与跟踪问题,提出跳跃马尔可夫系统下的序贯蒙特卡罗概率假设密度(JMS-SMC-PHD)滤波的检测前跟踪算法。该算法在机动目标数目和模型未知情况下,直接利用红外传感器量测数据,通过在目标状态矢量中增加模... 针对低信噪比条件下机动目标的检测与跟踪问题,提出跳跃马尔可夫系统下的序贯蒙特卡罗概率假设密度(JMS-SMC-PHD)滤波的检测前跟踪算法。该算法在机动目标数目和模型未知情况下,直接利用红外传感器量测数据,通过在目标状态矢量中增加模型变量并利用马尔可夫模型概率转移矩阵结合序贯蒙特卡罗概率假设密度(SMC-PHD)滤波,实现机动弱小目标的检测前跟踪。仿真结果表明所提方法可以有效地实现目标的检测与跟踪。 展开更多
关键词 检测前跟踪 跳跃马尔可夫系统 概率假设密度滤波 序贯蒙特卡罗 机动弱小目标
下载PDF
多传感器箱粒子PHD滤波多目标跟踪算法 被引量:5
18
作者 蔡如华 杨标 吴孙勇 《红外技术》 CSCD 北大核心 2020年第4期385-392,共8页
针对目标检测概率较低导致单个传感器无法对目标进行有效检测并跟踪的问题,本文提出了多传感器箱粒子概率假设密度(multi-sensor box particle probability hypothesis density filter,MS-BOX-PHD)滤波器。MS-BOX-PHD滤波器首先将多个... 针对目标检测概率较低导致单个传感器无法对目标进行有效检测并跟踪的问题,本文提出了多传感器箱粒子概率假设密度(multi-sensor box particle probability hypothesis density filter,MS-BOX-PHD)滤波器。MS-BOX-PHD滤波器首先将多个传感器的量测转换、融合成为一个量测集合,并利用箱粒子概率假设密度(box particle probability hypothesis density filter,BOX-PHD)滤波器对多个目标的状态进行预测和更新。数值实验表明,相较于单传感器箱粒子概率假设密度(Single-BOX-PHD)滤波器,MS-BOX-PHD滤波器在目标检测概率较低时,能够有效地对多目标的状态和数目进行估计;相较于区间量测下多传感器标准PHD粒子(multi-sensor standard probability hypothesis density particle filter with interval measurement,IM-PHD-PF)滤波器,在达到相同的跟踪性能时,计算效率提升了38.57%。 展开更多
关键词 多传感器 箱粒子滤波 概率假设密度滤波 区间量测
下载PDF
基于MM-GGIW-PMBM滤波的扩展目标跟踪算法 被引量:3
19
作者 吴孙勇 周于松 +2 位作者 谢芸 蔡如华 樊向婷 《北京航空航天大学学报》 EI CAS CSCD 北大核心 2022年第12期2356-2364,共9页
针对多机动扩展目标跟踪问题,将交互式多模型的思想引入泊松多伯努利混合滤波(PMBM)算法中,提出了一种多模型的伽马高斯逆威夏特-泊松多伯努利混合滤波(MM-GGIW-PMBM)算法。该算法融合多种运动模型,通过模型的交互实现对机动扩展目标扩... 针对多机动扩展目标跟踪问题,将交互式多模型的思想引入泊松多伯努利混合滤波(PMBM)算法中,提出了一种多模型的伽马高斯逆威夏特-泊松多伯努利混合滤波(MM-GGIW-PMBM)算法。该算法融合多种运动模型,通过模型的交互实现对机动扩展目标扩展状态和质心状态的混合估计预测;通过引入强跟踪滤波(STF)中的渐消因子修正预测之后GGIW分量中的协方差矩阵,防止发生跟踪模型失配的现象;在PMBM更新阶段扩展目标外形和质心估计完成的基础上,利用似然函数完成模型概率的更新。仿真实验结果表明:MM-GGIW-PMBM算法能够对多机动扩展目标的数量和状态进行有效的估计。 展开更多
关键词 泊松多伯努利混合滤波 伽马高斯逆威夏特 扩展目标跟踪 强跟踪滤波 交互式多模型
下载PDF
基于STGP-ETCBMeMBer滤波器的扩展目标跟踪算法
20
作者 吴孙勇 吕晓燕 +1 位作者 薛秋条 周于松 《信号处理》 CSCD 北大核心 2023年第7期1319-1330,共12页
外形估计是扩展目标跟踪的难点之一,不精确的建模方法会导致较差的估计效果。针对不规则多扩展目标的跟踪问题,本文提出了一种基于时空高斯过程模型的势平衡多扩展目标多伯努利(Spatio-Temporal Gaussian Process Cardinality Balanced ... 外形估计是扩展目标跟踪的难点之一,不精确的建模方法会导致较差的估计效果。针对不规则多扩展目标的跟踪问题,本文提出了一种基于时空高斯过程模型的势平衡多扩展目标多伯努利(Spatio-Temporal Gaussian Process Cardinality Balanced Multi-Extended Target Multi-Target Multi-Bernoulli, STGP-ETCBMeMBer)滤波算法。首先,利用随机有限集方法将增广后的多扩展目标状态集合和量测集合分别建模为多伯努利随机有限集合和泊松随机有限集合,并在此基础上利用STGP方法对星凸形扩展目标的量测源建模,提高算法对扩展目标的外形估计精度。之后,在算法更新阶段,假设同一目标量测子集对应的多个似然函数服从高斯分布,推导得到了STGPETCBMeMBer滤波算法的高斯混合(Gaussian Mixture, GM)实现。最后,通过构造仿真对比实验验证了所提算法的有效性,仿真结果表明所提算法在扩展目标的外形估计上有更精确的效果。 展开更多
关键词 扩展目标 时空高斯过程 CBMeMBer滤波器 高斯混合
下载PDF
上一页 1 2 下一页 到第
使用帮助 返回顶部