期刊文献+
共找到36,294篇文章
< 1 2 250 >
每页显示 20 50 100
The Youth’s View of Marriage in Chinese Mainstream Media Discourse-A Corpus-assisted Three-dimensional Discourse Analysis
1
作者 DING Shu-li LIN Ying 《Journal of Literature and Art Studies》 2024年第4期284-289,共6页
The rising of aging and the declining of birth rates have forced the public to focus on the youth’s view on marriage.Based on critical discourse analysis and combined with Fairclough’s three-dimensional discourse an... The rising of aging and the declining of birth rates have forced the public to focus on the youth’s view on marriage.Based on critical discourse analysis and combined with Fairclough’s three-dimensional discourse analysis model,this paper builds a“Chinese media News Report Corpus on the topic of‘marriage’”whose news are collected from China Daily.It is found that the discourses are neutral and objective with regard to the advantages and disadvantages of marriage,but in general,it is still a traditional view of marriage that is inevitable and closely related to fertility.Although this is controlled by the policies and the social reasons including declining fertility rate,it deviates from the current view of the youth towards marriage,resulting in many serious consequences such as young people’s rejection.In addition,this research found that male and female have great differences in their views on marriage,and men’s resistance to marriage is far greater than that of women,which is departure from the public’s cognition.The reasons behind this need to be explored in order to solve the marriage and love problems of young people in today’s era and realize the healthy development of young marriage. 展开更多
关键词 CORPORA Three-dimensional discourse analysis the youth’view of marriage
下载PDF
Low-Rank Multi-View Subspace Clustering Based on Sparse Regularization
2
作者 Yan Sun Fanlong Zhang 《Journal of Computer and Communications》 2024年第4期14-30,共17页
Multi-view Subspace Clustering (MVSC) emerges as an advanced clustering method, designed to integrate diverse views to uncover a common subspace, enhancing the accuracy and robustness of clustering results. The signif... Multi-view Subspace Clustering (MVSC) emerges as an advanced clustering method, designed to integrate diverse views to uncover a common subspace, enhancing the accuracy and robustness of clustering results. The significance of low-rank prior in MVSC is emphasized, highlighting its role in capturing the global data structure across views for improved performance. However, it faces challenges with outlier sensitivity due to its reliance on the Frobenius norm for error measurement. Addressing this, our paper proposes a Low-Rank Multi-view Subspace Clustering Based on Sparse Regularization (LMVSC- Sparse) approach. Sparse regularization helps in selecting the most relevant features or views for clustering while ignoring irrelevant or noisy ones. This leads to a more efficient and effective representation of the data, improving the clustering accuracy and robustness, especially in the presence of outliers or noisy data. By incorporating sparse regularization, LMVSC-Sparse can effectively handle outlier sensitivity, which is a common challenge in traditional MVSC methods relying solely on low-rank priors. Then Alternating Direction Method of Multipliers (ADMM) algorithm is employed to solve the proposed optimization problems. Our comprehensive experiments demonstrate the efficiency and effectiveness of LMVSC-Sparse, offering a robust alternative to traditional MVSC methods. 展开更多
关键词 CLUSTERING Multi-view Subspace Clustering Low-Rank Prior Sparse Regularization
下载PDF
Child’s Point of View vs.Adult’s in Melville’s Early Two Stories
3
作者 YANG Jiayun 《Sino-US English Teaching》 2023年第10期392-395,共4页
This paper aims to study the functions of two different points of view from the perspective of narratology,namely,the point of view of the adult and the one of the child,in two of Herman Melville’s early stories.By c... This paper aims to study the functions of two different points of view from the perspective of narratology,namely,the point of view of the adult and the one of the child,in two of Herman Melville’s early stories.By contrasting these two functions of the different perspectives,the author of this paper draws the conclusion that the child has a unique and significant perspective in Melville’s works. 展开更多
关键词 point of view child’s point of view adult’s point of view
下载PDF
跨学科视野下对Point of View的重新界定 被引量:3
4
作者 申丹 《上海交通大学学报(哲学社会科学版)》 北大核心 2023年第1期1-13,共13页
在西方叙事作品研究界,“point of view”自20世纪初以来一直是一个核心概念和热门话题。叙事学和文体学都十分关注这一话题。表面上看,两个学派对“point of view”进行了大致相同的探讨,而实际上两者在理念和路径上各行其道且相互排... 在西方叙事作品研究界,“point of view”自20世纪初以来一直是一个核心概念和热门话题。叙事学和文体学都十分关注这一话题。表面上看,两个学派对“point of view”进行了大致相同的探讨,而实际上两者在理念和路径上各行其道且相互排斥。叙事学界在探讨“point of view”时,将其囿于观察者的感知(区分“谁说”和“谁感知”),这种自我限制不合情理。与此相对照,文体学在探讨“point of view”时,聚焦于叙述者(说话者)的立场态度,这种自我限制也造成了很大问题。这两个学派在探讨“point of view”时各自的片面性以及相互之间的排他性还导致了不少理论上的混乱。这也对国内的研究造成了影响。本文在指出以往问题的基础上,对“point of view”提出切合实际的新的界定,旨在通过这一新的界定帮助推进理论探讨的发展并促进跨学科研究,以便对叙事作品进行更好、更为全面的分析。 展开更多
关键词 point of view 重新界定 叙事学与文体学 片面与混乱 跨学科研究
下载PDF
Recording the direct surgeon’s view with an operating microscopic view improves microscopic ophthalmic surgery training
5
作者 Masayuki Akimoto Kosei Tomita +1 位作者 Miyo Yoshida Yuki Hama 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2023年第9期1555-1558,共4页
AIM:To establish a recording system with a direct view of the surgeon to supplement video recording under an operating microscope,which lacks information on the movement and position of the surgeon’s hands,and to fac... AIM:To establish a recording system with a direct view of the surgeon to supplement video recording under an operating microscope,which lacks information on the movement and position of the surgeon’s hands,and to facilitate the reproduction of a skilled surgeon’s technique by a surgeon in training.METHODS:A small camera was attached to the operating microscope with a custom adapter.Microscopic surgeon’s view and direct surgeon’s view through this new camera were recorded in the surgical recording system.Both movies were synchronized and analyzed how do surgeons handle the instruments.RESULTS:A small camera attached to the operating microscope allowed the surgeon’s hands motion to be recorded without interfering with the surgeon’s movements.Different surgeons used different methods to manipulate the ultrasound handpiece and the irrigation/aspiration device.Even in the simple paracentesis procedure,different surgeons used different methods.Surgeons-in-training were able to identify and improve their weaknesses by watching synchronized movies of their hand motions and microscopic view.CONCLUSION:Simultaneous recording the surgical field out of the operating microscopic view by a small camera set on the microscope is comprehensive and improves surgeons-in-training understanding and learning surgeries. 展开更多
关键词 operating microscopic view direct surgeon’s view video recording microscopic surgery training
原文传递
Reconstruction Design of Zaozhuang Gangue Hill Based on the Interaction of“Scenery”and“View”
6
作者 CAO Ying LIANG Zhiwei ZHANG Li 《Journal of Landscape Research》 2023年第4期9-16,共8页
Gangue hill is the associated accumulation landscape of long-term coal mining.There are a large number of gangue hills left in coal mining cities,which not only causes ecological damage but also affects the urban envi... Gangue hill is the associated accumulation landscape of long-term coal mining.There are a large number of gangue hills left in coal mining cities,which not only causes ecological damage but also affects the urban environment,thus becoming the focus of urban landscape transformation of coal mining cities.With the increase of people’s demand for ecological leisure,it has become the first choice to transform gangue hill and its surrounding areas into community parks.From the perspective of urban space and landscape system,as a huge regeneration landform in the city and a unique landscape in the mining area,gangue hill not only needs to be afforested,but also needs to be connected with mining heritages and landscape nodes in the city to form the interaction between“scenery”and“view”,so as to form an integrated mining cultural landscape system at the urban level.On the basis of this concept,taking the gangue hill of Zhongxing in Zaozhuang City as an example,this paper quantitatively analyzes the best landscape construction site in the gangue hill via viewshed analysis in GIS.Through this method,the gangue hill and Zhongxing mining heritage are closely combined,so as to establish the interactive relationship between“scenery”and“view”.It can guide the planning and design of sightseeing route and footpath system,and also provide a technical support for the design of community parks transformed from gangue hills. 展开更多
关键词 Gangue hill Zhongxing mining heritage Interaction of“scenery”and“view viewshed analysis
下载PDF
3D view序列联合压缩感知技术精准诊断踝周韧带损伤
7
作者 张汉智 王植 +1 位作者 孟祥虹 孙曼 《中国CT和MRI杂志》 2023年第6期162-164,共3页
目的应用3 Dview序列联合压缩感知(Compressed Sensing,CS)技术观察踝关节扭伤患者韧带损伤情况,探讨3D view序列与常规2D序列相比能否提高诊断效能。方法前瞻性分析2021年2月至2021年11月来我院急诊就诊的踝关节急性扭伤患者共26例(26... 目的应用3 Dview序列联合压缩感知(Compressed Sensing,CS)技术观察踝关节扭伤患者韧带损伤情况,探讨3D view序列与常规2D序列相比能否提高诊断效能。方法前瞻性分析2021年2月至2021年11月来我院急诊就诊的踝关节急性扭伤患者共26例(26个踝关节)。上述受试均行MRI检查,扫描序列包括常规2D及3D view T2联合压缩感知序列。应用Mann-Whitney U检验评价常规序列及3D view序列的扫描时间、跟腱的信噪比及对比噪声比及评估患者在两序列下腓距前韧带、腓跟韧带、三角韧带、分歧韧带的损伤程度比较有无区别。应用Fisher确切概率法比较两序列对腓距前韧带、腓跟韧带、三角韧带、分歧韧带损伤的检出率有无差别。结果共纳入踝关节扭伤患者26例,3D view+CS序列的扫描时间为376.2±0s,略短于常规序列(381.479±7.3s),两者无明显差别(Z=-1.396,P=0.163)。3D view序列跟腱信噪比明显高于2D常规序列(Z=-3.441,P=0.001);对比噪声比明显高于2D常规序列(Z=-6.094,P<0.01);跟腓韧带和分歧韧带的损伤程度明显高于2D常规序列(Z=-2.67,P=0.008;Z=-2.67,P<0.001)。两序列对于距腓前韧带和内侧三角韧带的损伤程度差异无统计学差别(P<0.05)。3D View+CS序列对分歧韧带损伤的检出率明显高于2D常规序列(P<0.001)。3D View+CS序列较2D常规序列对距腓前韧带、跟腓韧带、内侧三角韧带损伤的检出率无明显差别(P>0.05)。结论在3D View+CS序列与常规2D序列扫描时间相当的情况下,3D View+CS序列图像质量较常规2D序列更高,踝周韧带的检出率更高,并更准确地评估韧带损伤程度。 展开更多
关键词 3D view 压缩感知 踝关节 韧带损伤
下载PDF
基于World View-2影像的西溪湿地悬浮泥沙遥感监测
8
作者 华康 肖晗 +4 位作者 于之锋 黄祺宇 周斌 方美红 袁小红 《杭州师范大学学报(自然科学版)》 CAS 2023年第1期28-35,共8页
西溪湿地作为城市次生湿地,其生态和旅游功能为人们所重视,因此监测其水质安全尤为重要.水体中悬浮泥沙浓度是评定水质的相关参数之一,利用环境遥感技术可对水体的悬浮泥沙浓度信息进行监测.以西溪湿地2个时相的World View-2影像为主要... 西溪湿地作为城市次生湿地,其生态和旅游功能为人们所重视,因此监测其水质安全尤为重要.水体中悬浮泥沙浓度是评定水质的相关参数之一,利用环境遥感技术可对水体的悬浮泥沙浓度信息进行监测.以西溪湿地2个时相的World View-2影像为主要数据源,通过水体光谱测量及水样采集,建立悬浮泥沙定量反演模型,并利用实测数据对反演模型精度进行验证评估.研究结果表明:1)采用第三、第五波段遥感反射率比值模型可削弱大气影响,突出悬浮泥沙信息,模型平均相对误差为19.98%;2)采用FLAASH大气校正方法,影像所有波段平均相对误差为17.58%;3)2011年、2013年选用的单景影像反演结果显示西溪湿地悬浮泥沙平均浓度分别为7.48mg/L、9.35mg/L,且湿地各区域悬浮泥沙浓度差异明显;4)采用合适的大气校正和悬浮泥沙反演模型,World View-2影像可较好地应用于西溪湿地悬浮泥沙浓度的遥感监测. 展开更多
关键词 World view-2 西溪湿地 悬浮泥沙 遥感监测
下载PDF
Integral imaging-based tabletop light field 3D display with large viewing angle 被引量:1
9
作者 Yan Xing Xing-Yu Lin +9 位作者 Lin-Bo Zhang Yun-Peng Xia Han-Le Zhang Hong-Yu Cui Shuang Li Tong-Yu Wang Hui Ren Di Wang Huan Deng Qiong-Hua Wang 《Opto-Electronic Advances》 SCIE EI CAS CSCD 2023年第6期19-30,共12页
Light field 3D display technology is considered a revolutionary technology to address the critical visual fatigue issues in the existing 3D displays.Tabletop light field 3D display provides a brand-new display form th... Light field 3D display technology is considered a revolutionary technology to address the critical visual fatigue issues in the existing 3D displays.Tabletop light field 3D display provides a brand-new display form that satisfies multi-user shared viewing and collaborative works,and it is poised to become a potential alternative to the traditional wall and portable display forms.However,a large radial viewing angle and correct radial perspective and parallax are still out of reach for most current tabletop light field 3D displays due to the limited amount of spatial information.To address the viewing angle and perspective issues,a novel integral imaging-based tabletop light field 3D display with a simple flat-panel structure is proposed and developed by applying a compound lens array,two spliced 8K liquid crystal display panels,and a light shaping diffuser screen.The compound lens array is designed to be composed of multiple three-piece compound lens units by employing a reverse design scheme,which greatly extends the radial viewing angle in the case of a limited amount of spatial information and balances other important 3D display parameters.The proposed display has a radial viewing angle of 68.7°in a large display size of 43.5 inches,which is larger than the conventional tabletop light field 3D displays.The radial perspective and parallax are correct,and high-resolution 3D images can be reproduced in large radial viewing positions.We envision that this proposed display opens up possibility for redefining the display forms of consumer electronics. 展开更多
关键词 tabletop light field 3D display integral imaging compound lens array radial viewing angle
下载PDF
基于LabVIEW的焓差试验室流量计现场自动校准系统
10
作者 郭凯晨 王崇兴 +3 位作者 张海云 韩鹏程 董森 杭晨哲 《洁净与空调技术》 2023年第3期80-83,共4页
设计并介绍了一种电磁流量计现场自动校准系统。详细介绍了基于Lab VIEW软件的使用质量流量计校准电磁流量计的具体实施方式,实现了自动采集校准数据、计算示值误差、生成原始记录等功能。系统即降低了人为因素引入误差的可能性,又提高... 设计并介绍了一种电磁流量计现场自动校准系统。详细介绍了基于Lab VIEW软件的使用质量流量计校准电磁流量计的具体实施方式,实现了自动采集校准数据、计算示值误差、生成原始记录等功能。系统即降低了人为因素引入误差的可能性,又提高了校准的工作效率。 展开更多
关键词 Lab view 电磁流量计 现场自动校准系统 原始记录
下载PDF
基于Lab VIEW的地下管道挖掘机远程状态监测探讨
11
作者 黄伟 《广东水利电力职业技术学院学报》 2023年第3期1-4,共4页
针对地下管道挖掘机远程状态监测精准度低的弊端,研究基于Lab VIEW的地下管道挖掘机远程状态监测方法。设计远程监测服务机制,在挖掘机库函数中设置数据采集卡功能;添加有关挖掘机故障的编程信息,使口令与动作程序间相关联,建立调用关... 针对地下管道挖掘机远程状态监测精准度低的弊端,研究基于Lab VIEW的地下管道挖掘机远程状态监测方法。设计远程监测服务机制,在挖掘机库函数中设置数据采集卡功能;添加有关挖掘机故障的编程信息,使口令与动作程序间相关联,建立调用关联函数,用于后续监测数据完成目标特征对比。设计周期性函数,运用Lab VIEW程序自动监测地下管道挖掘机中存在符合畸变成分的信号,提取信号特性,完成精准监测。实验数据证明,所提方法远程监测精准度高,具有一定实用价值。 展开更多
关键词 Lab view 地下管道挖掘机 远程状态监测 数据采集卡 动作程序
下载PDF
The Flipping-Free Full-Parallax Tabletop Integral Imaging with Enhanced Viewing Angle Based on Space-Multiplexed Voxel Screen and Compound Lens Array
12
作者 Peiren Wang Jinqiang Bi +3 位作者 Zilong Li Xue Han Zhengyang Li Xiaozheng Wang 《Computer Modeling in Engineering & Sciences》 SCIE EI 2023年第9期3197-3211,共15页
Tabletop integral imaging display with a more realistic and immersive experience has always been a hot spot in three-dimensional imaging technology,widely used in biomedical imaging and visualization to enhance medica... Tabletop integral imaging display with a more realistic and immersive experience has always been a hot spot in three-dimensional imaging technology,widely used in biomedical imaging and visualization to enhance medical diagnosis.However,the traditional structural characteristics of integral imaging display inevitably introduce the flipping effect outside the effective viewing angle.Here,a full-parallax tabletop integral imaging display without the flipping effect based on space-multiplexed voxel screen and compound lens array is demonstrated,and two holographic functional screens with different parameters are optically designed and fabricated.To eliminate the flipping effect in the reconstruction process,the space-multiplexed voxel screen consisting of a projector array and the holographic functional screen is presented to constrain light beams passing through the corresponding lens.To greatly promote imaging quality within the viewing area,the aspherical structure of the compound lens is optimized to balance the aberrations.It cooperates with the holographic functional screen to modulate the light field spatial distribution.Compared with the simulation results,the distortion rate of the imaging display is reduced to less than 9%from more than 30%.In the experiment,the floating high-quality reconstructed three-dimensional image without the flipping effect can be observed with the correct 3D perception at 96°×96°viewing angle,where 44,100 viewpoints are employed. 展开更多
关键词 Integral imaging display flipping effect large viewing angle optimized compound lens imaging distortion
下载PDF
A Novel Hybrid Optimization Algorithm for Materialized View Selection from Data Warehouse Environments
13
作者 Popuri Srinivasarao Aravapalli Rama Satish 《Computer Systems Science & Engineering》 SCIE EI 2023年第11期1527-1547,共21页
Responding to complex analytical queries in the data warehouse(DW)is one of the most challenging tasks that require prompt attention.The problem of materialized view(MV)selection relies on selecting the most optimal v... Responding to complex analytical queries in the data warehouse(DW)is one of the most challenging tasks that require prompt attention.The problem of materialized view(MV)selection relies on selecting the most optimal views that can respond to more queries simultaneously.This work introduces a combined approach in which the constraint handling process is combined with metaheuristics to select the most optimal subset of DW views from DWs.The proposed work initially refines the solution to enable a feasible selection of views using the ensemble constraint handling technique(ECHT).The constraints such as self-adaptive penalty,epsilon(ε)-parameter and stochastic ranking(SR)are considered for constraint handling.These two constraints helped the proposed model select the finest views that minimize the objective function.Further,a novel and effective combination of Ebola and coot optimization algorithms named hybrid Ebola with coot optimization(CHECO)is introduced to choose the optimal MVs.Ebola and Coot have recently introduced metaheuristics that identify the global optimal set of views from the given population.By combining these two algorithms,the proposed framework resulted in a highly optimized set of views with minimized costs.Several cost functions are described to enable the algorithm to choose the finest solution from the problem space.Finally,extensive evaluations are conducted to prove the performance of the proposed approach compared to existing algorithms.The proposed framework resulted in a view maintenance cost of 6,329,354,613,784,query processing cost of 3,522,857,483,566 and execution time of 226 s when analyzed using the TPC-H benchmark dataset. 展开更多
关键词 MATERIALIZATION ensemble approach stochastic ranking optimization optimal view selection
下载PDF
Speckle structured illumination endoscopy with enhanced resolution at wide field of view and depth of field
14
作者 Elizabeth Abraham Junxiao Zhou Zhaowei Liu 《Opto-Electronic Advances》 SCIE EI CAS CSCD 2023年第7期10-17,共8页
Structured illumination microscopy(SIM)is one of the most widely applied wide field super resolution imaging techniques with high temporal resolution and low phototoxicity.The spatial resolution of SIM is typically li... Structured illumination microscopy(SIM)is one of the most widely applied wide field super resolution imaging techniques with high temporal resolution and low phototoxicity.The spatial resolution of SIM is typically limited to two times of the diffraction limit and the depth of field is small.In this work,we propose and experimentally demonstrate a low cost,easy to implement,novel technique called speckle structured illumination endoscopy(SSIE)to enhance the resolution of a wide field endoscope with large depth of field.Here,speckle patterns are used to excite objects on the sample which is then followed by a blind-SIM algorithm for super resolution image reconstruction.Our approach is insensitive to the 3D morphology of the specimen,or the deformation of illuminations used.It greatly simplifies the experimental setup as there are no calibration protocols and no stringent control of illumination patterns nor focusing optics.We demonstrate that the SSIE can enhance the resolution 2–4.5 times that of a standard white light endoscopic(WLE)system.The SSIE presents a unique route to super resolution in endoscopic imaging at wide field of view and depth of field,which might be beneficial to the practice of clinical endoscopy. 展开更多
关键词 speckle structured illumination endoscopy wide field of view large depth of field easy-to-implement low cost
下载PDF
The Significance of Constructing TCM Psychosomatic Medicine from the Holistic View of the Unity of Nature and Man
15
作者 Wutong Song Hongxin Cao 《Chinese Medicine》 2023年第4期267-275,共9页
With the development of medical technology, the problem of fragmentation of medical research has become increasingly prominent, and a series of iatrogenic diseases, drug-induced diseases and drug toxicity and side eff... With the development of medical technology, the problem of fragmentation of medical research has become increasingly prominent, and a series of iatrogenic diseases, drug-induced diseases and drug toxicity and side effects have resulted in an increase in the number of diseases. In the face of these problems, the medical concept has been re-examined and re-thought. The concept of the holistic view of the unity of nature and man in traditional Chinese medicine has certain enlightenment for dealing with the problems in the current medical development. Based on the holistic view of the unity of nature and man, the overall connection between human’s heart and body and nature is explained, and the further construction of TCM psychosomatic medicine is conducive to guiding the diagnosis and treatment of clinical diseases, and providing new enlightenment for the current medical concept thinking and clinical disease research. 展开更多
关键词 Traditional Chinese Medicine The Unity of Nature and Man Holistic view TCM Psychosomatic Medicine
下载PDF
View interpolation networks for reproducing the material appearance of specular objects
16
作者 Chihiro HOSHIZAWA Takashi KOMURO 《Virtual Reality & Intelligent Hardware》 2023年第1期1-10,共10页
Background In this study, we propose view interpolation networks to reproduce changes in the brightness of an object′s surface depending on the viewing direction, which is important for reproducing the material appea... Background In this study, we propose view interpolation networks to reproduce changes in the brightness of an object′s surface depending on the viewing direction, which is important for reproducing the material appearance of a real object. Method We used an original and modified version of U-Net for image transformation. The networks were trained to generate images from the intermediate viewpoints of four cameras placed at the corners of a square. We conducted an experiment using with three different combinations of methods and training data formats. Result We determined that inputting the coordinates of the viewpoints together with the four camera images and using images from random viewpoints as the training data produces the best results. 展开更多
关键词 view synthesis Image transformation network Reflectance reproduction Material appearance U-Net
下载PDF
Changes of Street Quality Based on Street View Images in Different Periods:A Case Study of Jingshan East Street,Dongcheng District,Beijing City
17
作者 HUANG Yuhong 《Journal of Landscape Research》 2023年第2期39-44,共6页
With the continuous calls for energy conservation and emission reduction in recent years,more and more people choose walking as their travel mode.The improvement of the quality of street space will directly affect peo... With the continuous calls for energy conservation and emission reduction in recent years,more and more people choose walking as their travel mode.The improvement of the quality of street space will directly affect people's willingness to walk.By sorting out relevant research on street quality measurement,extracting quality keywords with high frequency of reference as impact factors,and using street view image data from different eras,semantic segmentation technology,factor analysis,and questionnaire survey methods,this paper evaluates the street quality of Jingshan East Street,Dongcheng District,Beijing,further explores the impact of different factors on street quality,and analyzes possible ways to improve it. 展开更多
关键词 Street quality Street view image Semantic segmentation Factor analysis
下载PDF
Impact of random and scattered coincidences from outside of field of view on positron emission tomography/computed tomography imaging with different reconstruction protocols
18
作者 Mahak Osouli Alamdari Pardis Ghafarian +2 位作者 Arman Rahmim Mehrdad Bakhshayesh‑Karam Mohammad Reza Ay 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2023年第12期40-52,共13页
Image quality in positron emission tomography(PET)is affected by random and scattered coincidences and reconstruction protocols.In this study,we investigated the effects of scattered and random coincidences from outsi... Image quality in positron emission tomography(PET)is affected by random and scattered coincidences and reconstruction protocols.In this study,we investigated the effects of scattered and random coincidences from outside the field of view(FOV)on PET image quality for different reconstruction protocols.Imaging was performed on the Discovery 690 PET/CT scanner,using experimental configurations including the NEMA phantom(a body phantom,with six spheres of different sizes)with a signal background ratio of 4:1.The NEMA phantom(phantom I)was scanned separately in a one-bed position.To simulate the effect of random and scatter coincidences from outside the FOV,six cylindrical phantoms with various diameters were added to the NEMA phantom(phantom II).The 18 emission datasets with mean intervals of 15 min were acquired(3 min/scan).The emission data were reconstructed using different techniques.The image quality parameters were evaluated by both phantoms.Variations in the signal-to-noise ratio(SNR)in a 28-mm(10-mm)sphere of phantom II were 37.9%(86.5%)for ordered-subset expectation maximization(OSEM-only),36.8%(81.5%)for point spread function(PSF),32.7%(80.7%)for time of flight(TOF),and 31.5%(77.8%)for OSEM+PSF+TOF,respectively,indicating that OSEM+PSF+TOF reconstruction had the lowest noise levels and lowest coefficient of variation(COV)values.Random and scatter coincidences from outside the FOV induced lower SNR,lower contrast,and higher COV values,indicating image deterioration and significantly impacting smaller sphere sizes.Amongst reconstruction protocols,OSEM+PSF+TOF and OSEM+PSF showed higher contrast values for sphere sizes of 22,28,and 37 mm and higher contrast recovery coefficient values for smaller sphere sizes of 10 and 13 mm. 展开更多
关键词 Positron emission tomography/computed tomography(PET/CT) Random coincidences Scatter coincidences·Time of flight(TOF) Point spread function(PSF) Field of view(FOV) Noise equivalent count rate(NECR) Signal-toNoise ratio(SNR)
下载PDF
On Laozi’s View of Desire
19
作者 QIN Xiao 《Cultural and Religious Studies》 2023年第8期368-375,共8页
Laozi’s concept of desire has rich ideological connotations,not only referring to reducing personal desires.Laozi’s concept of desire is based on“desire”as human nature,acknowledging the legitimacy and necessity o... Laozi’s concept of desire has rich ideological connotations,not only referring to reducing personal desires.Laozi’s concept of desire is based on“desire”as human nature,acknowledging the legitimacy and necessity of desire and demand.The rational criticism of“having desire”formed by“no desire”is the value pursuit of Laozi’s concept of desire.From both personal physical and mental aspects and social order,“no desire”plays an important guiding role.Nature is the essence of Laozi’s concept of desire,and being in harmony with nature is the best state of desire.Laozi’s concept of desire reveals a deep spirit of love,and the“ethics of love”highlights Laozi’s strong sense of care for the“other”and ethical attitude towards responsibility.Laozi’s contemplation of desire contains a strong humanistic spirit,with the aim of promoting the healthy and sustainable development of life and society. 展开更多
关键词 LAOZI desire view having desires having no desire NATURE KINDNESS
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部