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Search Results: 1 - 10 of 46031 matches for " 韦峰 "
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基于高级局部二元模式直方图映射的表情识别*
付晓,
模式识别与人工智能 , 2009,
Abstract: 提出高级局部二元模式直方图映射(ALBPHP)方法,将标记信息完整且标记位置统一的高级局部二元模式(ALBP)直方图映射到局部保持投影(LPP)空间获得低维ALBPHP特征.相比于ALBP特征,ALBPHP特征不仅维数低而且在表征人脸图像时具有更强的鉴别力.在JAFFE和Cohn-Kanade两个人脸表情库上对ALBPHP和ALBP方法比较验证,结果表明:采用相同的分类器时ALBPHP的识别率总是高于ALBP.
广西亚热带主要森林植被气候及水文生态功能规律的研究
黄承标,
应用生态学报 , 1995,
Abstract: 1980-1991年对广西亚热带主要森林植被及草坡地的气象及水文要素进行定位对比研究表明,郁闭度较大的林分内年均气温及年较差比林外低0.1-0.7℃;但年均相对湿度比林外高0.7-6.7%;林内地面年均温及年较差比林外低2.3-7.8℃,相同层次的土壤年均温及年较差比林外低1.6-4.6℃.林内年均水面蒸发量比林外减少51.3一73.0%.各林分的林冠截留量占降雨量9.9-15.8%;树干茎流量占0.5-3.3%;穿透水量占83.9-88.0%.林地枯落物层的最大蓄水量一般比草地大4-13倍.林地年均地表径流量为0.46-22.31mm,一般比草地减少35.2-93.8%.
郑州大学药物安全性评价研究中心建筑设计理念剖析
,徐维波
工业建筑 , 2013, DOI: 10.13204/j.gyjz201309031
Abstract: 当代实验建筑正逐渐向着功能多样、技术复杂和空间灵活等方面发展,通过对郑州大学药物安全性评价研究中心设计理念的介绍,论述设计师如何在复杂的建筑设计过程中通过合理布局和精心设计,创造出理性与人文内涵相结合的精品建筑。
基于多尺度中心化二值模式的人脸表情识别
付晓,
控制理论与应用 , 2009,
Abstract: 现有局部二值模式(LBP)算子存在不足:产生的直方图维数过长、鉴别力不高、对噪声反应敏感。针对此类问题,提出中心化二值模式(CBP)算子,其优点:1)通过比较邻域中近邻点对,大大降低了直方图维数;2)考虑中心像素点的作用并赋予其最高权重,实现鉴别力的提高;3)改变LBP算子的符号函数,明显减弱白噪声对图像的影响。此外,为提高识别率,将多尺度CBP(MCBP)直方图作为人脸表征。为增强算法对表情图像中细小变形的鲁棒性,引入图像欧式距离(IMED)并将其嵌入MCBP方法。在JAFFE和Cohn-Kanade表情库的实验结果表明:所提方法优于其它表情识别方法,IMED可增强MCBP的表情识别能力。
基于多尺度中心化二值模式的人脸表情识别
付晓,
控制理论与应用 , 2009, DOI: 10.7641/j.issn.1000-8152.2009.6.008
Abstract: 现有局部二值模式(LBP)算子存在不足:产生的直方图维数过长、鉴别力不高、对噪声反应敏感.针对此类问题,提出中心化二值模式(CBP)算子,其优点:1)通过比较邻域中近邻点对,大大降低了直方图维数;2)考虑中心像素点的作用并赋予其最高权重,实现鉴别力的提高;3)改变LBP算子的符号函数,明显减弱白噪声对图像的影响.此外,为提高识别率,将多尺度CBP(MCBP)直方图作为人脸表征.为增强算法对表情图像中细小变形的鲁棒性,引入图像欧式距离(IMED)并将其嵌入MCBP方法.在JAFFE和Cohn-Kanade表情库的实验结果表明:所提方法优于其它表情识别方法,IMED可增强MCBP的表情识别能力.
汉语块扩句的自动分析
,张全?
计算机科学 , 2010,
Abstract: 块扩句是一类概念预期知识十分明确的句子。基于概念层次网络理论介绍了块扩句对应的块扩句类,总结了能够激活块扩句类的典型块扩动词。根据块扩动词的概念知识得到句子的特征语义块及块扩句类,依据块扩句类的知识对句子进行检验后可给出句子句类的分析结果。在已有的句类分析系统的基础上对真实语料中的块扩句进行了自动分析,实验表明正确率达到了71.29%,错误主要来自特征语义块动词辨识、动词多句类代码等。正确分析块扩句将有助于解决汉语句子的多动词处理难点。
Succession of dominant phytoplankton species in spring 2002 at Dapeng''Ao Cove, Daya Bay
大亚湾大鹏澳水域春季浮游植物优势种的演替

WEI Gui Feng,

生态学报 , 2003,
Abstract: Dapeng'Ao, a small cove at the southwest of Daya Bay in Guangdong Province of China is an area covering about 14 km 2 at an average water depth of 5 m with well developed mariculture of fish and shellfish. From April 28 to May 27 2002, a 30 day continuous observation was carried out in the cove to investigate the succession of dominant phytoplankton species. Water samples were taken from the surface and bottom layers of 3 sites in Dapeng'Ao cove at about 9 a.m. daily. Physico chemical factors were measured in situ (e.g. water temperature, dissolved oxygen) or analyzed in the laboratory of Marine Biology Research Station at Daya Bay within an hour after sampling (e.g. pH, salinity, ammonia, nitrite, nitrate, phosphate, silicate, chlorophyll a). Phytoplankton was fixed with Lugol's solution in situ , and dominant species were identified and their cell numbers were enumerated. In this continuous observation, it found that diatoms dominated (about 98.9% of total phytoplankton cells) in the waters, Skeletonema costatum, Nitzschia delicatissima, and Chaetoceros sp. were the dominant species. Skel. costatum was the leading species from April 28 to May 22 whileas Nitz. delicatissima took the leading role after May 22, resulting in a phytoplankton succession. Using Principal Component Analysis (PCA) method, the most important five components account for 78% of data information. Multiple regression method was used to elucidate the relationship among those dominant species and their contribution to the principal components (represented by the physico chemical factors), based upon the correlation coefficients between the dominant phytoplankton species and the main principal components ( p <0 01), and to develop a succession model for the dominant phytoplankton species in Dapeng'Ao cove in spring. The model shows that Skel. costatum has competitive relationship with Nitz. delicatissima and the most important physico chemical factors that are closely related to the growth of diatom dominated phytoplankton community are temperature, dissolved oxygen, ammonia, nitrite, phosphate and silicate; salinity, nitrate, and the ratio of nitrate to phosphate also influenced the growth of Skel. costatum. During the period of investigation, the most significant environment change was rainfall, which resulted in a decrease of salinity and an increase of nitrogenous nutrients in water column, and such an environment change promotes the growth of Skel. costatum. Along with phytoplankton growth, the nutrients (N, P, and Si) were exhausted gradually and could not further maintain the population growth of Skel. costatum and its density declined, which relieved the competition pressure for Nitz. delicatissima and it grew rapidly thereafter. The environment change (rainfall) occurring during the period of phytoplankton succession illustrated clearly how dominant species changed from Skel. costatum to Nitz. delicatissima in the succession process.
预应力混凝土箱梁开裂后的刚度损伤评估
徐向锋,,成龙
工程力学 , 2015, DOI: 10.6052/j.issn.1000-4750.2013.12.1161
Abstract: 箱梁容易在支座、1/4跨及跨中位置出现裂缝,箱梁开裂病害与箱梁过量下挠相互耦合,其作用机理较为复杂,评估箱梁过量下挠的难点在于箱梁裂后的刚度分布特性研究。为了有效评估箱梁裂后刚度,制作了大比例尺预应力混凝土连续箱梁模型,开展了反复荷载作用下的箱梁破坏性试验,分别采用两种方法开展了箱梁裂后刚度分布特性研究。第一种方法,结合试验数据,基于Levenberg-Marquardt优化算法,对已测试得到的不同开裂程度下的挠度进行刚度分布反演;第二种方法,基于模型试验测试的荷载挠度曲线直接建立刚度折减评估参数,对开裂后箱梁的刚度损伤分布进行统计分析。对比分析了两种方法计算得到的箱梁裂后刚度纵向分布特征,验证了评估结果的有效性。研究结果表明:箱梁裂后开裂区域的刚度折减系数以加载位置为参考点,其余部位的刚度损伤沿箱梁纵向呈线性分布。提出了箱梁裂后刚度损伤计算方法。该研究可对开裂后箱梁的服役性能评估提供了理论参考。
巷道围岩锚固体变形破坏特征的试验研究
四江,勾攀
采矿与安全工程学报 , 2013,
Abstract: 为了研究巷道围岩锚固体的破坏特征及裂隙演化规律,模拟组合载荷作用下巷道围岩锚固体的变形破坏失稳过程及锚杆工作阻力的变化。试验结果表明:当侧压系数1≤λ≤1.4时,锚固体则出现垂直于锚杆的水平层理;当1.4<λ≤1.6时,锚固体出现细小裂纹,锚杆托板陷入岩层,锚杆间出现片状脱落,锚固体下部岩层松动破坏,锚固体稳定,而锚固体外出现和岩层层面呈30°~40°的倾斜裂纹;当λ=2.0时,锚固体内外岩层离层量增加,锚固体下部片落块度和深度增加,托板失去作用,锚固体整体失稳;λ和巷道围岩锚固体裂隙维数D呈正变关系。随着λ的增加,各锚杆工作载荷相差不大,呈波状降低趋势;巷帮锚固体承载能力变化不大,而顶板锚固体承载能力逐渐降低。水平载荷对巷道顶板锚固体的稳定性影响较大,其离层量随λ的增加而加大,内部出现不均匀沉降。
锚杆预紧力对锚固体强度强化的模拟实验研究
四江,勾攀
煤炭学报 , 2012,
Abstract: 锚杆预紧力在巷道支护中发挥着重要作用,但其对锚固体强度强化特征的研究仍存在不少问题;以砂蜡材料、预紧力锚杆和平面应变约束装置制作锚固分离体,在RMT-150C实验机上对其力学特性进行了研究。实验结果表明:锚固体的峰值强度、残余强度的强化系数和岩体强度、锚杆预紧力呈正相关,岩体强度一定时,随着锚杆预紧力的增大,强化系数逐渐增加,锚杆预紧力对锚固体峰后残余强度的强化大于对锚固体峰值强度的强化。锚固体的应变-应力全程曲线与锚杆受力存在着对应关系,锚固体屈服之前,锚杆受力增加缓慢;屈服点之后,受力急剧增加;峰后软化阶段锚杆受力逐渐增加,摩擦阶段锚杆受力处在不断的调整下降中。预紧力一定时,岩体强度越高,锚杆受力增加幅度越小;岩体强度一定时,高预紧力锚杆受力增幅较小;软弱岩层破坏后,锚杆载荷的损失比坚硬岩层大,预紧力锚杆对软弱岩层的作用比坚硬岩层明显。现场实践表明,提高锚杆预紧力能够有效控制围岩的变形。
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