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完备Riemann流形具有闭的割空间
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作者 黄保军 《数学学报(中文版)》 SCIE CSCD 北大核心 1998年第2期313-316,共4页
本文证明了完备的Riemann流形即拥有闭的割空间(cutspace),这一结论不但完满解答了段海豹在[1]中提出的问题1.6,大大地改进了他的主要结果([1],定理1.3),而且作为一个推论,我们还得到了经典Bor... 本文证明了完备的Riemann流形即拥有闭的割空间(cutspace),这一结论不但完满解答了段海豹在[1]中提出的问题1.6,大大地改进了他的主要结果([1],定理1.3),而且作为一个推论,我们还得到了经典Borsuk-Ulam定理的一个进一步推广. 展开更多
关键词 完备黎曼流形 B-U定理 割空间 黎曼流形
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空间中的光和影——影视灯光设计札记 被引量:2
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作者 彭巍 《视听界》 2003年第3期70-71,共2页
在影视创作中,光在营造空间、渲染气氛、深化意境方面发挥着重大作用。编导应该想方设法为摄影师提供创作便利,让光像流水一样活跃于画面。
关键词 割空间 空间结构 重大作用 空间层次 照明 营造 摄影师 影视创作 场景 电视剧
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“门”文化研究 被引量:3
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作者 许衍凤 《艺术生活》 2006年第4期23-25,共3页
“门”是中国建筑中最活跃的因素,门的资格几乎与建筑的资格一样老,在中国门除了具有防御和分割空间的功能之外还有一些象征意义,几千年来,中国形成了自己独特的门文化。近代以来在中外文化的碰撞中,门经历了“全盘西化”——复古——... “门”是中国建筑中最活跃的因素,门的资格几乎与建筑的资格一样老,在中国门除了具有防御和分割空间的功能之外还有一些象征意义,几千年来,中国形成了自己独特的门文化。近代以来在中外文化的碰撞中,门经历了“全盘西化”——复古——中西结合的过程,逐渐走向成熟。建筑界有学者认为中国建筑文化是一种门制文化,是“门”的艺术,这话听起来似乎是有些夸张,其实,从门洞在建筑个体与群体组合中的重要地位与文化意义来看,这样说并不过分。建筑的起源也就是门的起源,门文化的资格几乎与整个建筑一样的古老。很少有那一类中国建筑是不辟门的。除了亭子、华表、经幢之类一般不设门扉外,城有城门,宫有宫门,院有院门,庙有庙门,墓有墓门……就连万里长城,也在山海关、嘉峪关等关隘处设定了座座关门。 展开更多
关键词 中国传统文化 中国建筑文化 象征意义 传统建筑 文化研究 全盘西化 中外文化 割空间 现代建筑 大门
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孙新建和他的散文诗创作
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作者 夏文 《当代文坛》 CSSCI 北大核心 1993年第1期27-29,共3页
一个偶然的机会,我听了四川人民广播电台播出的我省青年诗人孙新建(笔名文磊)的配乐散文诗《读雨》,深感陶醉。轻快的旋律中,那些美妙的诗句,把我带入了一个清新而空灵的境界。就兴趣而言,我对散文诗一类的东西并不喜欢,但不知怎的,这... 一个偶然的机会,我听了四川人民广播电台播出的我省青年诗人孙新建(笔名文磊)的配乐散文诗《读雨》,深感陶醉。轻快的旋律中,那些美妙的诗句,把我带入了一个清新而空灵的境界。就兴趣而言,我对散文诗一类的东西并不喜欢,但不知怎的,这首诗却给我留下了深刻的印象。这以后,我又在省内外各种刊物上读到了孙新建的作品,并萌发了写篇评论的念头。我找孙新建作了几次长谈,增进了对他的了解。 展开更多
关键词 散文诗 作品 纸鸢 理趣 曹雪芹 比喻 《无题》 放风筝 墨香 割空间
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水力割缝空间分布模式对煤层卸压增透的作用规律 被引量:39
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作者 刘生龙 朱传杰 +1 位作者 林柏泉 刘厅 《采矿与安全工程学报》 EI CSCD 北大核心 2020年第5期983-990,共8页
水力割缝技术是实现煤层卸压增透的有效手段,目前由水力割缝技术形成的致裂裂缝空间分布模式对煤层卸压增透的作用规律尚不明确。本文采用颗粒流模拟方法(PFC2D)对内含不同角度单缝及不同空间排布方式多缝的煤体开展了单轴压缩数值模拟... 水力割缝技术是实现煤层卸压增透的有效手段,目前由水力割缝技术形成的致裂裂缝空间分布模式对煤层卸压增透的作用规律尚不明确。本文采用颗粒流模拟方法(PFC2D)对内含不同角度单缝及不同空间排布方式多缝的煤体开展了单轴压缩数值模拟试验,针对水力割缝周围微裂缝大量发育与连通促使煤层卸压增透的物理机制,提出了评价煤层割缝卸压增透效果的2个指标:加载过程中微裂缝显著产生时的单轴应力门限(σγ)与多条割缝的连通性。其中,σγ越低、多条割缝的连通性越强,割缝间的微裂缝越容易在低应力条件下形成并相互连通,割缝的卸压增透效果越好。模拟结果表明,单条割缝与煤体边界最大主应力方向夹角(α)呈90°时γ最小(3.2MPa);2条割缝(α为90°)排布方向与煤体边界最大主应力方向(割缝排布角β)呈45°时,水力割缝间具有最高的连通性与较低的应力门限(σγ为2.4 MPa);3条割缝(α为90°且β为45°)呈折线型交错排布模式时,割缝间的连通程度最高,且σγ较双割缝进一步降低了16.7%。通过上述模拟结果,确定了有利于煤层卸压增透的割缝最优空间分布模式,即α为90°的多条割缝以45°的排布角(β)交错分布。 展开更多
关键词 水力 卸压增透 缝倾角 空间分布 颗粒流模拟
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我是明星
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《中国会展》 2007年第10期40-40,共1页
我们有的展商习惯于将自己的展品全部陈列在展台上,没有主次之分,让观众看不出头绪。演戏靠明星,展示应有焦点。展品中的焦点就是主推的产品。可通过位置、布置、灯光等手段烘托它。但是焦点不可过多,通常只设一个。当然,如果参展面积较... 我们有的展商习惯于将自己的展品全部陈列在展台上,没有主次之分,让观众看不出头绪。演戏靠明星,展示应有焦点。展品中的焦点就是主推的产品。可通过位置、布置、灯光等手段烘托它。但是焦点不可过多,通常只设一个。当然,如果参展面积较大,也可以通过分割空间的方式营造多个焦点。 展开更多
关键词 焦点 展品 割空间 明星 观众 陈列 布置 主次 灯光 产品
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怎样欣赏江南园林
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《今日中国》 1997年第3期62-62,共1页
关键词 江南园林 拱形桥 古典园林 审美特性 中国园林 太湖地区 园林艺术 私家花园 割空间 皇家园林
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Science Letters:Dynamic concision for three-dimensional reconstruction of human organ built with virtual reality modelling language (VRML) 被引量:3
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作者 禹正杨 郑树森 +2 位作者 陈雷霆 何晓乾 王建军 《Journal of Zhejiang University-Science B(Biomedicine & Biotechnology)》 SCIE CAS CSCD 2005年第7期611-616,共6页
This research studies the process of 3D reconstruction and dynamic concision based on 2D medical digital images using virtual reality modelling language (VRML) and JavaScript language, with a focus on how to realize t... This research studies the process of 3D reconstruction and dynamic concision based on 2D medical digital images using virtual reality modelling language (VRML) and JavaScript language, with a focus on how to realize the dynamic concision of 3D medical model with script node and sensor node in VRML. The 3D reconstruction and concision of body internal organs can be built with such high quality that they are better than those obtained from the traditional methods. With the function of dynamic concision, the VRML browser can offer better windows for man-computer interaction in real-time environment than ever before. 3D reconstruction and dynamic concision with VRML can be used to meet the requirement for the medical observation of 3D reconstruction and have a promising prospect in the fields of medical imaging. 展开更多
关键词 Virtual Reality Modelling Language (VRML) Direct texture mapping Three-dimensional reconstruction Dynamic concision
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An Urban Open Space Extraction Method: Combining Spectral and Geometric Characteristics 被引量:1
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作者 ZHUGuobin DanG.Blumberg 《Geo-Spatial Information Science》 2004年第4期249-254,共6页
This paper introduces an advanced method based on remote sensing and Geographic Information System for urban open space extraction combining spectral and geometric characteristics. From both semantic and remote sensin... This paper introduces an advanced method based on remote sensing and Geographic Information System for urban open space extraction combining spectral and geometric characteristics. From both semantic and remote sensing perspectives, a hybrid hierarchy structure and class organization of open space are issues and mapped from one to another. Based on per-pixel and segmentation mechanism separately, two classification approaches are performed. Owing to prior of spatial aggregation and spectral contribution, the segmentation-based classification exhibits its superiority over a pixel-based classification. Finally a GIS-based post procedure is hired to eliminate some unsuitable open space components in both spatial and numerical constraints on the one hand, and separate open space some fabrics from fused remote sensing classes by defining their Shape Index on the other hand. The case study of Beer Sheva based on ASTER data proves this method is a feasible way for open space extraction. 展开更多
关键词 urban open space remote sensing geographic information systems (GIS) SEGMENTATION classification (ASTER
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Color space lip segmentation for drivers' fatigue detection 被引量:1
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作者 孙伟 Zhang Xiaorui +2 位作者 Sun Yinghua Tang Huiqiang Song Aiguo 《High Technology Letters》 EI CAS 2012年第4期416-422,共7页
to the chroma distribution diversity (CDD) between lip color and skin color, the lip color area is segmented by the back propagation neural network (BPNN) with three typical color features. Isolated noisy points o... to the chroma distribution diversity (CDD) between lip color and skin color, the lip color area is segmented by the back propagation neural network (BPNN) with three typical color features. Isolated noisy points of the lip color area in binary image are eliminated by a proposed re- gion connecting algorithm. An improved integral projection algorithm is presented to locate the lip boundary. Whether a driver is fatigued is recognized by the ratio of the frame number of the images with mouth opening continuously to the total image frame number in every 20s. The experiments show that the proposed algorithm provides higher correct rate and reliability for fatigue driving detec- tion, and is superior to the single color feature-based method in the lip color segmention. Besides, it improves obviously the accuracy and speed of the lip boundary location compared with the traditional integral projection algrothm. 展开更多
关键词 fatigue driving detection machine vision CHROMA back propagation neural net-work (BPNN) lip color segmention
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AUTOMATIC SEGMENTATION OF VIDEO OBJECT PLANES IN MPEG-4 BASED ON SPATIO-TEMPORAL INFORMATION
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作者 XiaJinxiang HuangShunji 《Journal of Electronics(China)》 2004年第3期206-212,共7页
Segmentation of semantic Video Object Planes (VOP's) from video sequence is a key to the standard MPEG-4 with content-based video coding. In this paper, the approach of automatic Segmentation of VOP's Based on... Segmentation of semantic Video Object Planes (VOP's) from video sequence is a key to the standard MPEG-4 with content-based video coding. In this paper, the approach of automatic Segmentation of VOP's Based on Spatio-Temporal Information (SBSTI) is proposed.The proceeding results demonstrate the good performance of the algorithm. 展开更多
关键词 Video sequence segmentation Video Object Plane (VOP) Based on spatiotemporal information MPEG-4
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AN AUTOMATIC SEGMENTATION METHOD FOR MOVING OBJECTS BASED ON THE SPATIAL-TEMPORAL INFORMATION OF VIDEO
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作者 Xie Mei Luo Ling 《Journal of Electronics(China)》 2005年第5期498-504,共7页
The new MPEG-4 video coding standard enables content-based functions. In order to support the new standard, frames should be decomposed into Video Object Planes (VOP), each VOP representing a moving object. This pap... The new MPEG-4 video coding standard enables content-based functions. In order to support the new standard, frames should be decomposed into Video Object Planes (VOP), each VOP representing a moving object. This paper proposes an image segmentation method to separate moving objects from image sequences. The proposed method utilizes the spatial-temporal information. Spatial segmentation is applied to divide each image into connected areas and to find pre~:ise object boundaries of moving objects. To locate moving objects in image sequences, two consecutive image frames in the temporal direction are examined and a hypothesis testing is performed with Neyman-Pearson criterion. Spatial segmentation produces a spatial segmentation mask, and temporal segmentation yields a change detection mask that indicates moving objects and the background. Then spatial-temporal merging can be used to get the final results. This method has been tested on several images. Experimental results show that this segmentation method is efficient. 展开更多
关键词 Spatial-temporal segmentation Strong filter Watersheds Motion compensation
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Segmentation of High Spatial Resolution Remote Sensing Images of Mountainous Areas Based on the Improved Mean Shift Algorithm 被引量:3
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作者 LU Heng LIU Chao +1 位作者 LI Nai-wen GUO Jia-wei 《Journal of Mountain Science》 SCIE CSCD 2015年第3期671-681,共11页
Using conventional Mean Shift Algorithm to segment high spatial resolution Remote sensing images of mountainous areas usually leads to an unsatisfactory result, due to its rich texture information. In this paper, we p... Using conventional Mean Shift Algorithm to segment high spatial resolution Remote sensing images of mountainous areas usually leads to an unsatisfactory result, due to its rich texture information. In this paper, we propose an improved Mean Shift Algorithm in consideration of the characteristics of these images. First, images were classified into several homogeneous color regions and texture regions by conducting variance detection on the color space. Next, each homogeneous color region was directly segmented to generate the preliminary results by applying the Mean Shift Algorithm. For each texture region, we conduct a high-dimensional feature space by extracting information such as color, texture and shape comprehensively, and work out a proper bandwidth according to the normalized distribution density. Then the bandwidth variable Mean Shift Algorithm was applied to obtain segmentation results by conducting the pattern classification in feature space. Last, the final results were obtained by merging these regions by means of the constructed cost functions and removing the oversegmented regions from the merged regions. It has been experimentally segmented on the high spatial resolution remote sensing images collected by Quickbird and Unmanned Aerial Vehicle(UAV). We put forward an approach to evaluate the segmentation results by using the segmentation matching index(SMI). This takes into consideration both the area and the spectrum. The experimental results suggest that the improved Mean Shift Algorithm outperforms the conventional one in terms of accuracy of segmentation. 展开更多
关键词 Mean Shift Image segmentation Regionmerging UAV image Quickbird image
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A feature extraction and correspondence algorithm for laser range finder with sensor uncertainty
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作者 孙英杰 曹其新 李杰 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2004年第4期361-367,共7页
This paper presents a feature extraction and correspondence algorithm which employs a novel feature transform. Unlike conventional approaches such as Hough Transform, we employ a robust but simple approach to extract ... This paper presents a feature extraction and correspondence algorithm which employs a novel feature transform. Unlike conventional approaches such as Hough Transform, we employ a robust but simple approach to extract the geometrical feature under real dynamic world conditions. Multi-threshold segmentation and the split-and-merge method are employed to interpret geometrical features such as edge, concave corners, convex corners, and segments in a unified framework. The features are represented by feature tree (F-Tree) so as to compactly represent the environments and some important properties of the F-Tree are discussed in this paper. To demonstrate the validity of the approach, we show the actual experiment results which are based on real Laser Range Finder data and real time analysis. The comparative study with Hough Transform shows the advantages and the high performance of the proposed algorithm. 展开更多
关键词 feature extraction and correspondence multi-threshold segmentation EIGENSPACE feature tree sensor uncertainty
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Subdivision of Polygon Parcel in Land-Use Data Generalization
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作者 AI Tinghua 《Geo-Spatial Information Science》 2003年第3期56-61,共6页
In land-use data generalization, the removal of insignificant parcel withsmall size is the most frequently used operator. Traditionally for the generalization method, thesmall parcel is assigned completely to one of i... In land-use data generalization, the removal of insignificant parcel withsmall size is the most frequently used operator. Traditionally for the generalization method, thesmall parcel is assigned completely to one of its neighbors. This study tries to improve thegeneralization by separating the insignificant parcel into parts around the weighted skeleton andassigning these parts to different neighbors. The distribution of the weighted skeleton depends onthe compatibility between the removed object and its neighbor, which considers not only topologicalrelationship but also distance relationship and semantic similarity. This process is based on theDelaunay triangulat'on model. This paper gives the detailed geometric algorithms for this operation. 展开更多
关键词 map generalization spatial partitioning neighborhood analysis
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THE SPATIAL DIVISION OF INDUSTRIES OF THE PEARL RIVER DELTA IN THE 1990s: CHARACTERISTICS AND TRENDSS
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作者 XU Yong-jian,YAN Xiao-pei,XU Xue-qiang (Center for Urban and Regional Studies, Zhongshan University, Guangzhou 510275, P. R. China) 《Chinese Geographical Science》 SCIE CSCD 2001年第1期63-69,共7页
The article analyzed the spatial division of industries of the Pearl River Delta (PRD) in the 1990s, a period that witnessed the deepening of the reform and opening policies and continued rapid development of the regi... The article analyzed the spatial division of industries of the Pearl River Delta (PRD) in the 1990s, a period that witnessed the deepening of the reform and opening policies and continued rapid development of the region. By adopting the index of specialization, the extent of specialization, its change and its spatial distribution in the region are measured and demonstrated. The research revealed that, despite the trend of more balanced development of the secondary sector between the PRD and the rest of the province, in the PRD, it is the unbalanced development that dominated and the spatial division of the secondary sector has been shaped. The tertiary industry has also been experiencing unbalance development and the spatial division of the tertiary sector has been emerging, its extent of concentration appearing even more evident than that of the secondary sector. The author also discussed the linkage between the spatial division of the two sectors. In the end of the paper, the trends of the spatial division of the industries in the PRD are forecasted. 展开更多
关键词 Pearl River Delta spatial division of industries characteristics and trends
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Dynamic Behavior of Entanglement Between Two Spatially Separated Atoms in Two Dissipative and Driven Cavity Fields
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作者 CUI Hui-Ping LI Jian LIU Jin LI Jun-Gang 《Communications in Theoretical Physics》 SCIE CAS CSCD 2009年第3期509-513,共5页
We consider two two-level atoms, interacting with two independent dissipative cavities, each of which is driven by an external source. The two cavity fields are both initially prepared in the coherent states, and the ... We consider two two-level atoms, interacting with two independent dissipative cavities, each of which is driven by an external source. The two cavity fields are both initially prepared in the coherent states, and the two two-level atoms are initially prepared in the singlet state |ψ^-〉 =(|eg〉 - |ge〉 ) / √2. We investigate the influence of the damping constant n, the intensity of the external sources F, and the relative difference of the atomic couplings r on the entanglement between the two atoms. In the dispersive approximation, we find that the entanglement between the two atoms decreases with the time evolution, and the decreasing rate of entanglement depends on the values of F/k, k/ω, and r. For the given small values of F/k and k/ω, on the one hand, the increasing of r favors entanglement decreasing of the atomic system, on the other hand, when r → 1 the entanglement decreasing becomes slower. With the increasing of the value of k/ω, the influence of r on the decreasing rate of entanglement becomes smaller, and gradually disappears for the big value of k/ω. 展开更多
关键词 ENTANGLEMENT DISSIPATION driven field
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Microscopic Halftone Image Segmentation
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作者 王永刚 杨杰 丁永生 《Journal of Donghua University(English Edition)》 EI CAS 2004年第5期83-87,共5页
Microscopic halftone image recognition and analysis can provide quantitative evidence for printing quality control and fault diagnosis of printing devices, while halftone image segmentation is one of the significant s... Microscopic halftone image recognition and analysis can provide quantitative evidence for printing quality control and fault diagnosis of printing devices, while halftone image segmentation is one of the significant steps during the procedure. Automatic segmentation on microscopic dots by the aid of the Fuzzy C-Means (FCM) method that takes account of the fuzziness of halftone image and utilizes its color information adequately is realized. Then some examples show the technique effective and simple with better performance of noise immunity than some usual methods. In addition, the segmentation results obtained by the FCM in different color spaces are compared, which indicates that the method using the FCM in the f 1f 2f 3 color space is superior to the rest. 展开更多
关键词 image segmentation color halftone printing FCM color space
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Deterministic Generation of Quantum State Transfer Between Spatially Separated Single Molecule Magnets
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作者 宋佩君 吕新友 +2 位作者 黄培 郝向英 杨晓雪 《Communications in Theoretical Physics》 SCIE CAS CSCD 2010年第8期278-286,共9页
We propose a new scheme for realizing deterministic quantum state transfer (QST) between two spatially separated single molecule magnets (SMMs) with the framework of cavity quantum eleetrodynamics (QED). In the ... We propose a new scheme for realizing deterministic quantum state transfer (QST) between two spatially separated single molecule magnets (SMMs) with the framework of cavity quantum eleetrodynamics (QED). In the present scheme, two SMMs are trapped in two spatially separated optical cavities coupled by an optical fiber. Through strictly numerically simulating, we demonstrate that our scheme is robust with respect to the SMMs' spontaneous decay and fiber loss under the conditions of dispersive SMMs-field interaction and strong coupling of cavity fiber. In addition, we also discuss the influence of photon leakage out of cavities and show that our proposal is good enough to demonstrate the generation of QST with high fidelity utilizing the current experimental technology. The present investigation provides research opportunities for realizing QST between solid-state qubits and may result in a substantial impact on the progress of solid-state-based quantum communications network. 展开更多
关键词 quantum state transfer cavity QED single molecule magnet
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Segmentation of Somatic Cells in Goat Milk Using Color Space CIELAB
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作者 Gabriel Jesus Alves de Melo Viviani Gomes +2 位作者 Camila Costa Baccili Luiz Alberto Luz de Almeida AntonioCezar de Castro Lima 《Journal of Agricultural Science and Technology(A)》 2014年第10期865-873,共9页
Somatic cell counts (SCCs) levels indicate the occurrence of infections in goat udders and are related to the productivity of goat milk, cheese and yoghurt. This work presents a segmentation method for counting soma... Somatic cell counts (SCCs) levels indicate the occurrence of infections in goat udders and are related to the productivity of goat milk, cheese and yoghurt. This work presents a segmentation method for counting somatic cells in goat milk images, intending to detect an infection known as mastiffs, which is the major cause of loss in dairy farming. The image segmentation procedure is devised by using the lab color space and the watershed transform. A large number of samples under variable preparation conditions are treated with the proposed method. A comparison between manual and the proposed technique is presented. Promising results indicates that video-microscopy systems may be employed to develop automated SCC for goat milk. 展开更多
关键词 Image processing distance transform SEGMENTATION somatic cells.
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