A Nonparametric Approach to Foreground Detection in Dynamic Backgrounds

Foreground detection is a fundamental step in visual surveillance.However,accurate foreground detection is still a challenging task especially in dynamic backgrounds.In this paper,we present a nonparametric approach to foreground detection in dynamic backgrounds.It uses a history of recently pixel values to estimate background model.Besides,the adaptive threshold and spatial coherence are introduced to enhance robustness against false detections.Experimental results indicate that our approach achieves better performance in dynamic backgrounds compared with several approaches.

Foregrounding Features in the Background Introduction Partin Oliver Twist

The theory of foregrounding is a theory of crucial and critical importance in Stylistics.In stylistic analysis,foregrounding refers to the work with literary and artistic importance,especially the deviation of language,prominent in the background which belongs to the normal conventions of language.Charles Dickens is one of the greatest and critical realist writers of the Victorian Age in British.In his representative work Oliver Twist,by the bitter exposure of the terrible conditions in the English workhouse of the time and the cruel treatment of a poor orphan by all sorts of philanthropist,the author criticizes harshly the dark and criminal underworld life and succeeds in calling forth the reader's sympathy for the down-trodden people of the lower classes,especially the children.Through his master skill of the use of foregrounding,Dickens constructs various kinds of background introductions where is full of suspense and symbol,and it seems that all the backgrounds are inseparably closed to the fate of the protagonist,leaving a clue for the reader to pick out the main idea of the total work.This thesis firstly reviews the theory of foregrounding and then analyses the foregrounding using in the background introductions in Oliver Twist,presenting a holistic overview the aim of the author and what he aims at expressing through the intended background description.

The Lateral Occipital Complex is Activated by Melody with Accompaniment: Foreground and Background Segregation in Auditory Processing

Objective: Most of the western music consists of a melody and an accompaniment. The melody is referred to as the foreground, with the accompaniment the background. In visual processing, the lateral occipital complex (LOC) is known to participate in foreground and background segregation. We investigated the role of LOC in music processing with use of positron emission tomography (PET). Method: Musically na?ve subjects listened to unfamiliar novel melodies with (accompaniment condition) and without the accompaniment (melodic condition). Using a PET subtraction technique, we studied changes in regional cerebral blood flow (rCBF) during the accompaniment condition compared to the melodic condition. Results: The accompanyment condition was associated with bilateral increase of rCBF at the lateral and medial surfaces of both occipital lobes, medial parts of fusiform gyri, cingulate gyri, precentral gyri, insular cortices, and cerebellum. During the melodic condition, the activation at the anterior and posterior portions of the temporal lobes, medial surface of the frontal lobes, inferior frontal gyri, orbitofrontal cortices, inferior parietal lobules, and cerebellum was observed. Conclusions: The LOC participates in recognition of melody with accompaniment, a phenomenon that can be regarded as foreground and background segregation in auditory processing. The fusiform cortex which was known to participate in the color recognition might be activated by the recognition of flourish sounds by the accompaniment, compared to melodic condition. It is supposed that the LOC and fusiform cortex play similar functions beyond the difference of sensory modalities.

Improvement of three popular Indian groundnut varieties for foliar disease resistance and high oleic acid using SSR markers and SNP array in marker-assisted backcrossing

Foliar fungal diseases(rust and late leaf spot)incur large yield losses,in addition to the deterioration of fodder quality in groundnut worldwide.High oleic acid has emerged as a key market trait in groundnut,as it increases the shelf life of the produce/products in addition to providing health benefits to consumers.Marker-assisted backcrossing(MABC)is the most successful approach to introgressing or pyramiding one or more traits using traitlinked markers.We used MABC to improve three popular Indian cultivars(GJG 9,GG 20,and GJGHPS 1)for foliar disease resistance(FDR)and high oleic acid content.A total of 22 BC3F4 and 30 BC2F4 introgression lines(ILs)for FDR and 46 BC3F4 and 41 BC2F4 ILs for high oleic acid were developed.Recurrent parent genome analysis using the 58 K Axiom_Arachis array identified several lines showing upto 94%of genome recovery among second and third backcross progenies.Phenotyping of these ILs revealed FDR scores comparable to the resistant parent,GPBD 4,and ILs with high(~80%)oleic acid in addition to high genome recovery.These ILs provide further opportunities for pyramiding FDR and high oleic acid in all three genetic backgrounds as well as for conducting multi-location yield trials for further evaluation and release for cultivation in target regions of India.

On Foreground-Background and Transitivity in Chinese Shiwu(事物) Expository Discourse

Foreground-background and transitivity are very important in discourse linguistics,the features of which vary from types of discourse.Chinese shiwu expository discourse has its own semantic features about foreground-background;and this type of discourse is characterized by low transitivity,especially in foreground.

“不知道”的句法语义多角度研究

基于“不知道”进行多角度观察,主要讨论句法主语、言者主语和两解时的句法语义限制因素:第一,不同的句法层级对语义解读有着不同影响,其中语气>时体>句法成分。第二,主语、状语、宾语、谓词、固定结构及句式构成的事件能否表达强认识性或者[+控制性]是言者主语语义识解的关键因素;宾语小句的叙实性影响语义解读;不同的语气范畴倾向解读为不同的语义。第三,在叙实/非叙实框架下,“不知道”作为焦点敏感算子,与其他焦点敏感算子在句法语义各层面因素共同作用是这类特殊“S+不知道+VP”单解/歧解的必要条件,而充分条件或者内在动因则是信息结构的“完形重塑”。

6个抗稻瘟病基因在云南省勐海县水稻主栽品种中的分布

为了明确勐海县水稻主栽品种中已克隆的Pi2、Pi9、Piz-t、Pi50/Pigm、Pita-2和Pib等6抗稻瘟病基因的构成。通过对勐海县18个水稻主栽品种为试验材料,利用6个抗病基因的特异分子标记进行抗瘟基因的分子检测。结果显示:抗性基因Pib分布频率最高,检出率为77.78%,Pi2、Pita-2和Piz-t的检出率分别为22.22%、22.22%和11.11%;在供试品种中未检测出抗性基因Pi9和Pi50/Pigm基因。检测到2个抗性基因和1个抗性基因的品种均为8份(均占44.44%),未检测出抗性基因的品种为2份(占11.11%)。结果表明:勐海县水稻主栽品种的抗性遗传背景较为狭窄,需引入新的有效抗源以拓宽水稻品种的抗病性。

稀疏分解和图拉普拉斯正则化的图像前景背景分割方法

针对现有图像前景背景分割方法的分割结果存在孤立像素点的问题,利用图信号处理理论和稀疏分解模型,提出新的图像前景背景分割方法.将图像的内在结构建模为图,通过图模型有效地刻画像素之间的内在关联性.将图像的像素强度建模为图信号,其中图像背景作为平滑分量,由一组图傅里叶变换基函数线性表示,叠加在背景上的前景为稀疏分量,前景像素间的连通性可由图拉普拉斯正则化项进行刻画.将图像前景背景分割问题归结为包含稀疏分解模型和图拉普拉斯正则化项的约束优化问题,采用交替方向乘子法对该优化问题进行求解.实验结果表明,与现有的其他方法相比,所提方法具有更好的分割效果.

韩国语被动句语义色彩的认知解释

该文旨在探究韩国语被动句中的语义色彩及其认知解释。被动句有着不同的语义色彩,先行研究已经表明韩国语被动句具有极强的负面语义色彩倾向。文章从认知语言学的角度,基于前景—背景理论与原型范畴理论,对被动句负面语义色彩的认知理据进行研究。通过对负面语义色彩的被动句进行分析,发现被动语义色彩的倾向来源于事件中的受事角色在认知中经过前景化得到凸显和强调,而及物动词句的原型宾语,也就是受事角色的典型核心语义特征是[+受损],所以韩国语被动句也常常蕴含与[+受损]相关的负面语义色彩。这些发现不仅深化了韩国语被动句的理解,也为从认知角度阐释韩国语提供了参考。

Genetic background effects on QTL and QTL × environment interaction for yield and its component traits as revealed by reciprocal introgression lines in rice

QTLs for quantitative traits are influenced by genetic background(GB) and environment.Identification of QTL with GB independency and environmental stability is prerequisite for effective marker-assisted selection(MAS). In this study, QTLs and QTL × environment interactions affecting grain yield per plant(GY) and its component traits, filled grain number per panicle(FGN), panicle number per plant(PN) and 1000-grain weight(TGW) across six environments were dissected using two sets of reciprocal introgression lines(ILs) derived from the cross Lemont × Teqing and SNP genotypic data. ANOVA indicated that the differences among genotypes and environments within each set of ILs were highly significant for all traits. A total of 72 distinct QTLs for GY and its component traits including 15 for GY, 25 for FGN, 18 for PN, and 29 for TGW were detected over the six environments. Most QTLs(87.4%) showed significant QTL × environment interactions(QEIs) and appeared to be more or less environment-specific. Among 72 QTLs, 15(20.8%) QTLs and 12(16.7%) QEIs were commonly identified in both backgrounds, indicating QTL especially QEI for yield and its component traits had strong GB effects. Four QTL regions affecting GY and its component traits, including S1269707–S4288071, S16661497–S17511092, and S35861863–S36341768 on chromosome 3, and S4134205–S7643153 on chromosome 5, were detected in both backgrounds and coincided with cloned genes for yield-related traits. These regions can be the targeted in rice breeding for high yield potential through MAS. Application of QTL main effects and their environmental interaction effects in MAS was discussed in detail.

分子标记辅助选择改良南粳5055米香性状的研究

为进一步提高优良食味水稻品种南粳5055蒸煮食味品质,利用分子标记辅助选择,将米香基因badh2成功导入南粳5055中。在分子标记对目标基因进行前景选择的同时,利用《NY/T 1433-2014》推荐的48个以及作者实验室筛选的31个SSR标记进行背景检测;在BC3F2世代,筛选出遗传背景与轮回亲本一致的单株,结合农艺性状筛选及品质分析,获得所考察性状与南粳5055一致且携带米香基因的南粳5055新品系;并就背景选择中不同来源分子标记对江苏粳稻品种的鉴别力问题进行了讨论。

山桃杂交群体抗蚜优系的背景选择与标记优劣比较

【目的】筛选‘橡皮油桃’(果实大、感蚜)ב帚形山桃’(果实小、抗蚜)F2代杂交群体中,‘橡皮油桃’遗传背景回复率高且表现抗蚜的优系,探讨桃背景选择技术体系的建立方法。【方法】首先,利用3种方法选择背景标记,分别为前期研究得到的高多态性SNP(Pre-work SNP)、全基因组范围内随机挑选的SNP(Random SNP)、以及对SNP进行功能注释后,选择突变位点影响起始密码子与终止密码子的功能性SNP(Functional SNP),3种方法最终筛选的SNP个数统一设定为775个。然后,利用这775个SNP分别计算3种不同背景标记在F2代杂交群体中121个单株的双亲回复率。通过比较3种背景标记中‘橡皮油桃’背景回复率较高的前10个单株在两两之间的重复情况,比较不同背景标记的重复性。在完成F2群体单株的抗蚜性、单果重与可溶性固形物含量评价后,分别选择单果重与可溶性固形物含量2种性状的极端表型单株各10株,通过比较两类表型单株‘橡皮油桃’回复率的差异显著性,衡量不同选择方法的优劣。最后,以抗蚜定位区间内的SNP为抗蚜前景标记,筛选F2群体内‘橡皮油桃’遗传背景回复率高且表现抗蚜的优系。【结果】Pre-work SNP、Random SNP、Functional SNP 3种背景标记的F2代单株‘橡皮油桃’背景回复率分别在36.34%—71.99%、31.75%—74.92%、4.51%—66.53%。3种背景标记筛选的‘橡皮油桃’回复率较高的前10株中,Pre-work SNP与Random SNP和Functional SNP的重复单株分别均有2个,Random SNP与Functional SNP的重复单株有6个,即Random SNP和Functional SNP两种选择方法的重复率更高。Pre-work SNP、Random SNP、Functional SNP 3种背景标记在以单果重为选择目标时,极端表型单株间‘橡皮油桃’背景回复率显著性分别为0.069、0.26和0.092,即Pre-work SNP筛选的后代‘橡皮油桃’背景回复率与单果重表型相关性最高,Functional SNP次之,Random SNP差异不显著。在以可溶性固形物含量为选择目标时,极端表型单株间‘橡皮油桃’背景回复率显著性分别为0.77、0.65和0.31,3种背景标记差异均不显著。基于Pre-work SNP和Functional SNP的计算结果,本研究筛选出2个‘橡皮油桃’回复率高的单株,分别为N20和N36,其中N20携带抗蚜标记,单株表现抗蚜,平均单果重为34.42 g,可溶性固形物含量为16.1%,为山桃F2群体的优异单株。【结论】在本研究群体内,Pre-work SNP相较于Functional SNP与Random SNP,在单果重这一表型上与‘橡皮油桃’回复率的相关性较强,印证该背景标记选择方式的优异性,以这种背景标记挑选出的单株N20在目标性状的优异表现也支持这一结果。本研究提供一种背景选择的思路以及判断不同背景标记在研究群体内优劣性的方法,可为有效提高抗性育种效率提供参考。

基于U2Net的自动抠图技术研究

针对计算机视觉领域当中的抠图问题,提出了一种基于U2Net的自动抠图技术,以快速、准确地分离图像中的前景和背景。研究采用深度学习模型,通过学习图像中前景和背景的差异来实现高效、精准的抠图过程。在实验过程中,使用经过预训练的U2Net模型来进行抠图,采用均分误差等通用的抠图效果评价指标对结果进行评判,较其他抠图技术表现出更优的效果。实验表明,在各种复杂场景下,该技术展现出良好的抠图效果,并且具备更高的准确率和更快的处理速度。同时该技术在图像编辑、计算机视觉、医疗影像等多个领域都有广泛的应用前景。

基于MAS技术对水稻保持系软华B稻瘟病抗性的分子改良

为选育优质抗稻瘟病保持系软华B,以携带稻瘟病抗性基因Pi46和Pi2的优质籼稻H281作为供体亲本、以软华B为轮回亲本,利用分子标记辅助选择(MAS)技术结合系谱选育法,聚合2个外源基因以改良保持系软华B。对性状稳定的改良株系进行稻瘟病抗性鉴定、稻米品质分析等。通过回交及多代自交,并结合分子标记检测,获得以软华B为遗传背景且含有2个纯合目标基因的BC_(1)F_(6)群体2个、BC_(2)F_(5)群体2个、BC_(3)F_(4)群体2个。田间自然诱发鉴定结果表明,不同回交世代改良材料在自然病圃均抗稻瘟病;育性鉴定结果显示,回交世代对不育系的不育度为52.7%~100.0%;农艺性状考查及米质分析表明,改良株系基本保留了软华B的主要农艺性状和稻米品质特性。SNP基因芯片分析结果显示,BC_(1)F_(6)的背景回复率为74.42%~77.77%,BC_(2)F_(5)的背景回复率为86.42%~87.75%,BC_(3)F_(4)的背景回复率为92.27%~92.59%。利用连续回交、自交和分子标记辅助选择等技术可有效聚合多个抗性基因,获得抗稻瘟病的新保持系,快速实现保持系软华B的分子改良,为选育抗病、优质的杂交稻组合提供良好的亲本材料。

特征增强损失与前景注意力人群计数网络

人群计数旨在准确估计图像中的总人数并呈现其分布。相关数据集中的图像通常涉及各类场景且包含多人。为节约人力,大多数数据集通常在每个人头部以单点标注作为标签。然而,点标签无法囊括人头部的完整范围,使得人群特征与分布标签的匹配难以收敛,预测值无法聚集在前景区域,严重影响密度估计图质量和模型计数准确度。为了解决这个问题,使用计数损失来约束全图上的预测值范围,并佐以像素级的分布一致损失优化密度图匹配过程。此外,复杂场景中存在许多易与人群特征混淆的背景噪声,为了避免假阳性预测对后续计数和密度图估计的干扰,提出前景分割模块和特征增强损失来自适应地聚焦前景区域,并加大前景位置上人头特征对计数的贡献,从而达到抑制背景误判的作用。此外,为了使网络更好地适应人头的多尺度形态,对每个待训练图片分别进行上下采样操作,以获得具有同目标的多尺度形态。在多个数据集上进行了实验,结果表明,与最先进的方法相比,所提方法取得了更好或更有竞争力的结果。

在线视频会议虚拟背景人物融合工具设计与实现

虚拟背景是一种基于前后景分离技术的运用,该技术的目的是在带有人像的图片中将人物与背景分离出来,并用新的背景替换原背景。本文在此基础上研究并应用了重光照技术使新的背景与人像的光照强度和方向等光照参数融合,以达到图像和谐化的效果。该技术目的运用在视频会议的虚拟背景功能中,实现参会人与虚拟背景在光照效果上保持一致,以达到融合的效果。

改进中心先验的显著性检测

针对传统基于中心先验的显著性检测算法不能均匀突出显著性目标的问题,提出改进中心先验的显著性检测算法.首先将输入图像分割成4种不同超像素尺度,对输入图像计算凸包;然后计算4种不同尺度下的背景显著图和前景显著图,将对应尺度下的背景显著图和前景显著图融合得到该尺度下的融合显著图,将凸包和4种不同尺度的融合显著图作为先验,计算4种不同尺度下的中心先验图;最后将得到的不同尺度的中心先验图经MKB算法优化得到最终显著图.在MSRA1000,PASCAL和ECSSD数据集上进行,实验结果表明所述算法在显著目标检测的准确性方面优于14种对比算法.

社会批判理论的两种进路:霍耐特与弗雷泽之比较

对资本主义进行时代诊断,一直是批判理论言说著述不可回避的重要议题。面对这一时代重任,以霍耐特和弗雷泽为代表的法兰克福学派第三代进行了深入研究:霍耐特以自由正义论作为分析范式,对资本主义社会的“不自由”加以考察,并试图通过重组民主公共领域以实现超越。弗雷泽则通过一种“前景--背景式”二元结构体系,在拓展传统资本主义概念的同时揭示其系统性危机,并提出通过边界重组实现超越。二者对资本主义的批判与超越,可被视为对学派理论传统的继承和发展,并在一定程度上丰富了马克思主义的批判理论。

甘蓝型黄籽油菜分子标记辅助选择的效果分析

应用分子标记辅助选择的方法,将黄籽性状导入到波里马恢复系中,利用杂种优势,将是提高油菜产量的理想途径。分析了分子标记辅助选择甘蓝型黄籽油菜的前景和背景选择的效果,结果表明,在背景选择中,7种不同 RAPD引物数目组合方式的选择结果基本一致;应用少数连锁群上的标记可以获得与全基因组相似的选择结果。在前景选择中,随着世代的增加,每一个标记的选择准确率在降低;双侧标记的选择准确率比单侧的标记高,此外,多个单侧标记未能提高选择准确率。据此,提出了作物前景和背景选择过程中的一些改进策略。

动态背景下基于改进视觉背景提取的前景检测

由于视觉背景提取算法(ViBe)对存在动态背景的户外视频的前景检测结果依然不够精确,故提出了一种改进的ViBe算法。文中描述了经典ViBe算法及其特点;介绍了改进的ViBe算法针对动态背景的改进措施。该算法采用多帧连续图像初始化背景模型,降低了单帧图像初始化所产生的"鬼影"对前景检测精度的影响;在匹配过程中,引入自适应的匹配阈值,克服了单个的全局阈值对动态背景适应能力差的问题;最后,在更新过程引入空间一致性判断与模糊准则来减少算法的误检,提高了算法的鲁棒性。实验结果表明,该算法可以有效地检测动态背景下的运动目标,检测准确率比经典ViBe算法提高了20%以上。