期刊文献+
共找到566篇文章
< 1 2 29 >
每页显示 20 50 100
Mesh representation matters:investigating the influence of different mesh features on perceptual and spatial fidelity of deep 3D morphable models
1
作者 Robert KOSK Richard SOUTHERN +3 位作者 Lihua YOU Shaojun BIAN Willem KOKKE Greg MAGUIRE 《虚拟现实与智能硬件(中英文)》 EI 2024年第5期383-395,共13页
Background Deep 3D morphable models(deep 3DMMs)play an essential role in computer vision.They are used in facial synthesis,compression,reconstruction and animation,avatar creation,virtual try-on,facial recognition sys... Background Deep 3D morphable models(deep 3DMMs)play an essential role in computer vision.They are used in facial synthesis,compression,reconstruction and animation,avatar creation,virtual try-on,facial recognition systems and medical imaging.These applications require high spatial and perceptual quality of synthesised meshes.Despite their significance,these models have not been compared with different mesh representations and evaluated jointly with point-wise distance and perceptual metrics.Methods We compare the influence of different mesh representation features to various deep 3DMMs on spatial and perceptual fidelity of the reconstructed meshes.This paper proves the hypothesis that building deep 3DMMs from meshes represented with global representations leads to lower spatial reconstruction error measured with L_(1) and L_(2) norm metrics and underperforms on perceptual metrics.In contrast,using differential mesh representations which describe differential surface properties yields lower perceptual FMPD and DAME and higher spatial fidelity error.The influence of mesh feature normalisation and standardisation is also compared and analysed from perceptual and spatial fidelity perspectives.Results The results presented in this paper provide guidance in selecting mesh representations to build deep 3DMMs accordingly to spatial and perceptual quality objectives and propose combinations of mesh representations and deep 3DMMs which improve either perceptual or spatial fidelity of existing methods. 展开更多
关键词 Shape modelling Deep 3D morphable models Representation learning feature engineering Perceptual metrics
下载PDF
Tissue inhibitor of metalloproteinase-3 expression affects clinicopathological features and prognosis of aflatoxin B1-related hepatocellular carcinoma
2
作者 Qiu-Ju Liang Qin-Qin Long +3 位作者 Feng-Qin Tian Qun-Ying Su Xiao-Ying Zhu Xi-Dai Long 《World Journal of Hepatology》 2024年第8期1131-1144,共14页
BACKGROUND The dysregulation of tissue inhibitor of metalloproteinase-3(TIMP3)was positively correlated with the progression of hepatocellular carcinoma(HCC).However,it is not clear whether TIMP3 expression is associa... BACKGROUND The dysregulation of tissue inhibitor of metalloproteinase-3(TIMP3)was positively correlated with the progression of hepatocellular carcinoma(HCC).However,it is not clear whether TIMP3 expression is associated with the clinico-pathological features and prognosis of aflatoxin B1(AFB1)-related HCC(AHCC).A retrospective study,including 182 patients with AHCC,was conducted to explore the link between TIMP3 expression in cancerous tissues and the clinico-pathological characteristics and prognosis of AHCC.TIMP3 expression was detected by immunohistochemistry and its effects on the clinicopathological features and prognosis of AHCC were evaluated by Kaplan-Meier survival analysis and Cox regression survival analysis.Odds ratio,hazard ratio(HR),median overall survival time(MST),median tumor recurrence-free survival time(MRT),and corresponding 95%confidential interval(CI)was calculated to RESULTS Kaplan-Meier survival analysis showed that compared with high TIMP3 expression,low TIMP3 expression in tumor tissues significantly decreased the MST(36.00 mo vs 18.00 mo)and MRT(32.00 mo vs 16 mo)of patients with AHCC.Multivariate Cox regression survival analysis further proved that decreased expression of TIMP3 increased the risk of death(HR=2.85,95%CI:2.04-4.00)and tumor recurrence(HR=2.26,95%CI:1.57-3.26).Furthermore,decreased expression of TIMP3 protein in tissues with AHCC was significantly correlated with tumor clinicopatho-logical features,such as tumor size,tumor grade and stage,tumor microvessel density,and tumor blood invasion.Additionally,TIMP3 protein expression was also negatively associated with amount of AFB1-DNA adducts in tumor tissues.CONCLUSION These findings indicate that the dysregulation of TIMP3 expression is related to AHCC biological behaviors and affects tumor outcome,suggesting that TIMP3 may act as a prognostic biomarker for AHCC. 展开更多
关键词 Tissue inhibitor of metalloproteinase-3 expression Aflatoxin B1 Hepatocellular carcinoma Clinicopathological feature PROGNOSIS
下载PDF
Attention Guided Multi Scale Feature Fusion Network for Automatic Prostate Segmentation
3
作者 Yuchun Li Mengxing Huang +1 位作者 Yu Zhang Zhiming Bai 《Computers, Materials & Continua》 SCIE EI 2024年第2期1649-1668,共20页
The precise and automatic segmentation of prostate magnetic resonance imaging(MRI)images is vital for assisting doctors in diagnosing prostate diseases.In recent years,many advanced methods have been applied to prosta... The precise and automatic segmentation of prostate magnetic resonance imaging(MRI)images is vital for assisting doctors in diagnosing prostate diseases.In recent years,many advanced methods have been applied to prostate segmentation,but due to the variability caused by prostate diseases,automatic segmentation of the prostate presents significant challenges.In this paper,we propose an attention-guided multi-scale feature fusion network(AGMSF-Net)to segment prostate MRI images.We propose an attention mechanism for extracting multi-scale features,and introduce a 3D transformer module to enhance global feature representation by adding it during the transition phase from encoder to decoder.In the decoder stage,a feature fusion module is proposed to obtain global context information.We evaluate our model on MRI images of the prostate acquired from a local hospital.The relative volume difference(RVD)and dice similarity coefficient(DSC)between the results of automatic prostate segmentation and ground truth were 1.21%and 93.68%,respectively.To quantitatively evaluate prostate volume on MRI,which is of significant clinical significance,we propose a unique AGMSF-Net.The essential performance evaluation and validation experiments have demonstrated the effectiveness of our method in automatic prostate segmentation. 展开更多
关键词 Prostate segmentation multi-scale attention 3D Transformer feature fusion MRI
下载PDF
Building Facade Point Clouds Segmentation Based on Optimal Dual-Scale Feature Descriptors
4
作者 Zijian Zhang Jicang Wu 《Journal of Computer and Communications》 2024年第6期226-245,共20页
To address the current issues of inaccurate segmentation and the limited applicability of segmentation methods for building facades in point clouds, we propose a facade segmentation algorithm based on optimal dual-sca... To address the current issues of inaccurate segmentation and the limited applicability of segmentation methods for building facades in point clouds, we propose a facade segmentation algorithm based on optimal dual-scale feature descriptors. First, we select the optimal dual-scale descriptors from a range of feature descriptors. Next, we segment the facade according to the threshold value of the chosen optimal dual-scale descriptors. Finally, we use RANSAC (Random Sample Consensus) to fit the segmented surface and optimize the fitting result. Experimental results show that, compared to commonly used facade segmentation algorithms, the proposed method yields more accurate segmentation results, providing a robust data foundation for subsequent 3D model reconstruction of buildings. 展开更多
关键词 3D Laser Scanning Point Clouds Building Facade Segmentation Point Cloud Processing feature Descriptors
下载PDF
Cancellable Multi-Biometric Feature Veins Template Generation Based on SHA-3 Hashing
5
作者 Salwa M.Serag Eldin Ahmed Sedik +1 位作者 Sultan S.Alshamrani Ahmed M.Ayoup 《Computers, Materials & Continua》 SCIE EI 2023年第1期733-749,共17页
In this paper,a novel cancellable biometrics technique calledMulti-Biometric-Feature-Hashing(MBFH)is proposed.The MBFH strategy is utilized to actualize a single direction(non-invertibility)biometric shape.MBFH is a t... In this paper,a novel cancellable biometrics technique calledMulti-Biometric-Feature-Hashing(MBFH)is proposed.The MBFH strategy is utilized to actualize a single direction(non-invertibility)biometric shape.MBFH is a typical model security conspire that is distinguished in the utilization of this protection insurance framework in numerous sorts of biometric feature strategies(retina,palm print,Hand Dorsum,fingerprint).A more robust and accurate multilingual biological structure in expressing human loneliness requires a different format to record clients with inseparable comparisons from individual biographical sources.This may raise worries about their utilization and security when these spread out designs are subverted as everybody is acknowledged for another biometric attribute.The proposed structure comprises of four sections:input multi-biometric acquisition,feature extraction,Multi-Exposure Fusion(MEF)and secure hashing calculation(SHA-3).Multimodal biometrics systems that are more powerful and precise in human-unmistakable evidence require various configurations to store a comparative customer that can be contrasted with biometric wellsprings of people.Disparate top words,biometrics graphs can’t be denied and change to another request for positive Identifications(IDs)while settling.Cancellable biometrics is may be the special procedure used to recognize this issue. 展开更多
关键词 feature extraction multi-biometrics SHA-3 MEF
下载PDF
Lie symmetry analysis and invariant solutions for the(3+1)-dimensional Virasoro integrable model
6
作者 胡恒春 李雅琦 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第4期249-254,共6页
Lie symmetry analysis is applied to a(3+1)-dimensional Virasoro integrable model and the corresponding similarity reduction equations are obtained with the different infinitesimal generators.Invariant solutions with a... Lie symmetry analysis is applied to a(3+1)-dimensional Virasoro integrable model and the corresponding similarity reduction equations are obtained with the different infinitesimal generators.Invariant solutions with arbitrary functions for the(3+1)-dimensional Virasoro integrable model,including the interaction solution between a kink and a soliton,the lump-type solution and periodic solutions,have been studied analytically and graphically. 展开更多
关键词 (3+1)-dimensional Virasoro integrable model Lie symmetry invariant solutions
下载PDF
Adaptive Window Based 3-D Feature Selection for Multispectral Image Classification Using Firefly Algorithm
7
作者 M.Rajakani R.J.Kavitha A.Ramachandran 《Computer Systems Science & Engineering》 SCIE EI 2023年第1期265-280,共16页
Feature extraction is the most critical step in classification of multispectral image.The classification accuracy is mainly influenced by the feature sets that are selected to classify the image.In the past,handcrafte... Feature extraction is the most critical step in classification of multispectral image.The classification accuracy is mainly influenced by the feature sets that are selected to classify the image.In the past,handcrafted feature sets are used which are not adaptive for different image domains.To overcome this,an evolu-tionary learning method is developed to automatically learn the spatial-spectral features for classification.A modified Firefly Algorithm(FA)which achieves maximum classification accuracy with reduced size of feature set is proposed to gain the interest of feature selection for this purpose.For extracting the most effi-cient features from the data set,we have used 3-D discrete wavelet transform which decompose the multispectral image in all three dimensions.For selecting spatial and spectral features we have studied three different approaches namely overlapping window(OW-3DFS),non-overlapping window(NW-3DFS)adaptive window cube(AW-3DFS)and Pixel based technique.Fivefold Multiclass Support Vector Machine(MSVM)is used for classification purpose.Experiments con-ducted on Madurai LISS IV multispectral image exploited that the adaptive win-dow approach is used to increase the classification accuracy. 展开更多
关键词 Multispectral image modifiedfirefly algorithm 3-D feature extraction feature selection multiclass support vector machine CLASSIFICATION
下载PDF
Monocular 3D object detection with Pseudo-LiDAR confidence sampling and hierarchical geometric feature extraction in 6G network
8
作者 Jianlong Zhang Guangzu Fang +3 位作者 Bin Wang Xiaobo Zhou Qingqi Pei Chen Chen 《Digital Communications and Networks》 SCIE CSCD 2023年第4期827-835,共9页
The high bandwidth and low latency of 6G network technology enable the successful application of monocular 3D object detection on vehicle platforms.Monocular 3D-object-detection-based Pseudo-LiDAR is a low-cost,lowpow... The high bandwidth and low latency of 6G network technology enable the successful application of monocular 3D object detection on vehicle platforms.Monocular 3D-object-detection-based Pseudo-LiDAR is a low-cost,lowpower solution compared to LiDAR solutions in the field of autonomous driving.However,this technique has some problems,i.e.,(1)the poor quality of generated Pseudo-LiDAR point clouds resulting from the nonlinear error distribution of monocular depth estimation and(2)the weak representation capability of point cloud features due to the neglected global geometric structure features of point clouds existing in LiDAR-based 3D detection networks.Therefore,we proposed a Pseudo-LiDAR confidence sampling strategy and a hierarchical geometric feature extraction module for monocular 3D object detection.We first designed a point cloud confidence sampling strategy based on a 3D Gaussian distribution to assign small confidence to the points with great error in depth estimation and filter them out according to the confidence.Then,we present a hierarchical geometric feature extraction module by aggregating the local neighborhood features and a dual transformer to capture the global geometric features in the point cloud.Finally,our detection framework is based on Point-Voxel-RCNN(PV-RCNN)with high-quality Pseudo-LiDAR and enriched geometric features as input.From the experimental results,our method achieves satisfactory results in monocular 3D object detection. 展开更多
关键词 Monocular 3D object detection Pseudo-LiDAR Confidence sampling Hierarchical geometric feature extraction
下载PDF
Interaction solutions for the second extended(3+1)-dimensional Jimbo–Miwa equation
9
作者 马红彩 毛雪 邓爱平 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第6期112-121,共10页
Based on the Hirota bilinear method,the second extended(3+1)-dimensional Jimbo–Miwa equation is established.By Maple symbolic calculation,lump and lump-kink soliton solutions are obtained.The interaction solutions be... Based on the Hirota bilinear method,the second extended(3+1)-dimensional Jimbo–Miwa equation is established.By Maple symbolic calculation,lump and lump-kink soliton solutions are obtained.The interaction solutions between the lump and multi-kink soliton,and the interaction between the lump and triangular periodic soliton are derived by combining a multi-exponential function or trigonometric sine and cosine functions with quadratic functions.Furthermore,periodiclump wave solution is derived via the ansatz including hyperbolic and trigonometric functions.Finally,3D plots,2D curves,density plots,and contour plots with particular choices of the suitable parameters are depicted to illustrate the dynamical features of these solutions. 展开更多
关键词 Hirota bilinear method second extended(3+1)-dimensional Jimbo–Miwa equation lump solution interaction solution
下载PDF
宫颈癌组织中KLF12、STAT3的表达及其与临床病理特征和预后的相关性
10
作者 何永亮 章培 +4 位作者 吴宁 蒋炳林 成永莲 欧阳海英 涂媛 《现代肿瘤医学》 CAS 2024年第7期1305-1310,共6页
目的:分析宫颈癌中Krüpple样转录因子12(KLF12),信号转导和转录激活因子3(STAT3)的表达,并探讨其与临床病理特征和预后的相关性。方法:收集2017年07月至2020年07月收治于本院的82例宫颈癌患者活检及手术宫颈癌标本。采用免疫组化... 目的:分析宫颈癌中Krüpple样转录因子12(KLF12),信号转导和转录激活因子3(STAT3)的表达,并探讨其与临床病理特征和预后的相关性。方法:收集2017年07月至2020年07月收治于本院的82例宫颈癌患者活检及手术宫颈癌标本。采用免疫组化法检测患者宫颈癌组织及宫颈癌KLF12、STAT3表达情况。通过χ^(2)检验分析KLF12、STAT3表达与宫颈癌患者临床病理特征的关系。采用多因素Cox回归分析宫颈癌患者预后的相关因素。绘制Kaplan-Meier曲线分析KLF12、STAT3表达与宫颈癌患者3年生存率的关系。结果:宫颈癌组织KLF12阳性表达率高于癌旁组织(P<0.05),STAT3阳性表达率高于癌旁组织(P<0.05)。不同年龄、产次、月经状态、肿瘤直径、组织学分类、浸润深度患者宫颈癌组织中KLF12、STAT3表达差异无统计学意义(P>0.05)。FIGO分期Ⅱ期、低分化、有淋巴结转移的宫颈癌患者组织中KLF12、STAT3阳性表达率较高(P<0.05)。多因素Cox回归分析显示,FIGO分期Ⅱ期、KLF12、STAT3阳性表达均是宫颈癌患者3年内死亡的独立危险因素(P<0.05)。Kaplan-Meier曲线结果显示,KLF12阳性表达患者3年生存率66.66%(28/42)低于KLF12阴性表达患者90.00%(36/40)(P<0.05),STAT3阳性表达患者3年生存率70.49%(43/61)低于STAT3阴性表达患者100%(21/21)(P<0.05)。结论:宫颈癌组织中KLF12、STAT3阳性表达升高,两者异常表达与FIGO分期、分化程度、淋巴结转移及预后有关,可作为用于评估预后的生物标志物。 展开更多
关键词 宫颈癌 KLF12基因 信号转导和转录激活因子3 临床病理特征 预后
下载PDF
SMAD3和CD44在甲状腺乳头状癌组织中的表达水平与临床病理特征及预后的关系
11
作者 刘延彬 左丽娟 +3 位作者 辛运超 刘亚超 田泽东 尚小领 《中国耳鼻咽喉颅底外科杂志》 CAS CSCD 2024年第5期83-88,共6页
目的探讨信号转导分子3(SMAD3)和白细胞分化抗原44(CD44)在甲状腺乳头状癌(PTC)组织中的表达水平与临床病理特征及预后的关系。方法选取2019年6月-2020年6月收治的PTC患者88例为研究对象,同期取距离癌组织3 cm以上癌旁组织作为对照,实... 目的探讨信号转导分子3(SMAD3)和白细胞分化抗原44(CD44)在甲状腺乳头状癌(PTC)组织中的表达水平与临床病理特征及预后的关系。方法选取2019年6月-2020年6月收治的PTC患者88例为研究对象,同期取距离癌组织3 cm以上癌旁组织作为对照,实时荧光定量PCR(qRT-PCR)检测SMAD3和CD44的mRNA表达水平;免疫组化法检测SMAD3和CD44的阳性表达情况。Spearman相关性分析PTC患者癌组织中SMAD3和CD44的mRNA表达水平的关系。SMAD3和CD44与PTC患者预后的关系采用Kaplan-Meier法进行分析。COX回归分析影响PTC患者预后的危险因素。结果与癌旁组织相比,PTC组SMAD3的表达水平显著降低(t=8.484,P<0.05),CD44表达水平显著升高(t=11.232,P<0.05)。相关性分析显示,PTC患者癌组织中SMAD3和CD44的mRNA表达水平呈负相关(r s=-0.519,P<0.05)。与癌旁组织相比,PTC组SMAD3阳性表达率显著降低(χ^(2)=41.905,P<0.05),CD44阳性表达率显著升高(χ^(2)=62.888,P<0.05)。SMAD3表达与TNM分期(χ^(2)=7.678,P=0.006)、淋巴结转移(χ^(2)=20.398,P<0.05)、侵犯包膜(χ^(2)=9.881,P=0.002)有关。CD44表达与TNM分期(χ^(2)=3.959,P=0.047)、淋巴结转移(χ^(2)=20.702,P<0.05)、侵犯包膜(χ^(2)=10.363,P=0.001)有关。术后随访3年发现,SMAD3阳性表达PTC患者生存率高于阴性表达患者生存率(χ^(2)=4.644,P=0.031)。CD44阳性表达PTC患者生存率显著低于阴性表达患者生存率(χ^(2)=5.331,P=0.021)。多因素COX回归分析显示,淋巴结转移、SMAD3和CD44表达是影响PTC患者预后的危险因素(P<0.05)。结论PTC组织中SMAD3呈异常低表达,CD44呈高表达,其水平与PTC患者临床病理特征及预后有关。 展开更多
关键词 甲状腺乳头状癌 信号转导分子3 白细胞分化抗原44 预后 临床病理特征
下载PDF
Bridge Crack Segmentation Method Based on Parallel Attention Mechanism and Multi-Scale Features Fusion 被引量:1
12
作者 Jianwei Yuan Xinli Song +2 位作者 Huaijian Pu Zhixiong Zheng Ziyang Niu 《Computers, Materials & Continua》 SCIE EI 2023年第3期6485-6503,共19页
Regular inspection of bridge cracks is crucial to bridge maintenance and repair.The traditional manual crack detection methods are timeconsuming,dangerous and subjective.At the same time,for the existing mainstream vi... Regular inspection of bridge cracks is crucial to bridge maintenance and repair.The traditional manual crack detection methods are timeconsuming,dangerous and subjective.At the same time,for the existing mainstream vision-based automatic crack detection algorithms,it is challenging to detect fine cracks and balance the detection accuracy and speed.Therefore,this paper proposes a new bridge crack segmentationmethod based on parallel attention mechanism and multi-scale features fusion on top of the DeeplabV3+network framework.First,the improved lightweight MobileNetv2 network and dilated separable convolution are integrated into the original DeeplabV3+network to improve the original backbone network Xception and atrous spatial pyramid pooling(ASPP)module,respectively,dramatically reducing the number of parameters in the network and accelerates the training and prediction speed of the model.Moreover,we introduce the parallel attention mechanism into the encoding and decoding stages.The attention to the crack regions can be enhanced from the aspects of both channel and spatial parts and significantly suppress the interference of various noises.Finally,we further improve the detection performance of the model for fine cracks by introducing a multi-scale features fusion module.Our research results are validated on the self-made dataset.The experiments show that our method is more accurate than other methods.Its intersection of union(IoU)and F1-score(F1)are increased to 77.96%and 87.57%,respectively.In addition,the number of parameters is only 4.10M,which is much smaller than the original network;also,the frames per second(FPS)is increased to 15 frames/s.The results prove that the proposed method fits well the requirements of rapid and accurate detection of bridge cracks and is superior to other methods. 展开更多
关键词 Crack detection DeeplabV3+ parallel attention mechanism feature fusion
下载PDF
Depositional Patterns and Oil/Gas Accumulation Features of Sha-3 Member Turbidites in Dongying Depression, Bohai Bay Basin 被引量:11
13
作者 BaiGuoping ZhangShanwen 《Petroleum Science》 SCIE CAS CSCD 2004年第2期105-110,共6页
Recent exploration results indicate that a significant exploration potential remains in the Dongying Depression of the Bohai Bay Basin and the undiscovered oil and gas are largely reservoired in subtle traps including... Recent exploration results indicate that a significant exploration potential remains in the Dongying Depression of the Bohai Bay Basin and the undiscovered oil and gas are largely reservoired in subtle traps including turbidite litholigcal traps of the Sha-3 Member. In order to effectively guide the exploration program targeting turbidites, this study will focus on the depositional models of the Sha-3 Member turbidites and oil/gas accumulation characteristics in these turbidites. Two corresponding relationships were found. One is that the East African Rift Valley provides a modern analog for the depositional systems in the Dongying Depression. The other is that the depositional models of line-sourced slope aprons, single point-source submarine fan and multiple source ramp turbidite, established for deep-sea turbidites, can be applied to interpret the depositional features of the turbidite fans of three different origins: slope turbidite aprons, lake floor turbidite fans and delta-fed turbidite fans in the Sha-3 Member. Updip sealing integrity is the key factor determining whether oil/gas accumulates or not in the slope aprons and lake floor fans. The factors controlling oil/gas migration and accumulation in the delta-fed turbidite fans are not very clear. Multiple factors rather than a single factor probably played significant roles in these processes. 展开更多
关键词 Dongying Depression Sha-3 Member TURBIDITE depositional model migration and accumulation features
下载PDF
A 3-DIMENSIONAL DATA MODEL FOR VISUALIZING CLOVERLEAF JUNCTION IN A CITY MODEL 被引量:6
14
作者 Chen Jun Sun Min Zhou Qiming 《Geo-Spatial Information Science》 1999年第1期9-15,共7页
The research work has been seldom done about cloverleaf junction expression in a 3-dimensional city model (3DCM). The main reason is that the cloverleaf junction is often in a complex and enormous construction. Its ma... The research work has been seldom done about cloverleaf junction expression in a 3-dimensional city model (3DCM). The main reason is that the cloverleaf junction is often in a complex and enormous construction. Its main body is bestraddle in air,and has aerial intersections between its parts. This complex feature made cloverleaf junction quite different from buildings and terrain, therefore, it is difficult to express this kind of spatial objects in the same way as for buildings and terrain. In this paper,authors analyze spatial characteristics of cloverleaf junction, propose an all-constraint points TIN algorithm to partition cloverleaf junction road surface, and develop a method to visualize cloverleaf junction road surface using TIN. In order to manage cloverleaf junction data efficiently, the authors also analyzed the mechanism of 3DCM data management, extended BLOB type in relational database, and combined R-tree index to manage 3D spatial data. Based on this extension, an appropriate data 展开更多
关键词 3-dimensional CITY model (3DCM) GIS cloverleaf JUNCTION DATA STRUCTURE DATABASE
下载PDF
All Single Traveling Wave Solutions to (3+1)-Dimensional Nizhnok-Novikov-Veselov Equation 被引量:12
15
作者 LIU Cheng-Shi 《Communications in Theoretical Physics》 SCIE CAS CSCD 2006年第6期991-992,共2页
Using elementary integral method, a complete classification of all possible exact traveling wave solutions to (3+1)-dimensional Nizhnok-Novikov-Veselov equation is given. Some solutions are new.
关键词 3+1)-dimensional Nizhnok-Novikov-Veselov equation traveling wave solution elementary integral method
下载PDF
New Exact Solutions and Conservation Laws to (3+1)-Dimensional Potential-YTSF Equation 被引量:10
16
作者 ZHANG Li-Hua LIU Xi-Qiang 《Communications in Theoretical Physics》 SCIE CAS CSCD 2006年第3期487-492,共6页
Using the modified find some new exact solutions to Lie point symmetry groups and also get conservation laws, of the CK's direct method, we build the relationship between new solutions and old ones and the (3+1)-d... Using the modified find some new exact solutions to Lie point symmetry groups and also get conservation laws, of the CK's direct method, we build the relationship between new solutions and old ones and the (3+1)-dimensional potentiaial-YTSF equation. Baaed on the invariant group theory, Lie symmetries of the (3+1)-dimensional potential-YTSF equation are obtained. We equation with the given Lie symmetry. 展开更多
关键词 new exact solutions Lie point symmetry groups conservation laws 3+1)-dimensional potential-YTSF equation
下载PDF
Evaluation of Airway Obstruction at Soft Palate Level in Male Patients with Obstructive Sleep Apnea/Hypopnea Syndrome:Dynamic 3-Dimensional CT Imaging of Upper Airway 被引量:10
17
作者 肖英 陈雄 +4 位作者 史河水 杨阳 何烈纯 董家琪 孔维佳 《Journal of Huazhong University of Science and Technology(Medical Sciences)》 SCIE CAS 2011年第3期413-418,共6页
This study examined the dynamic characteristics of upper airway collapse at soft palate level in patients with obstructive sleep apnea/hypopnea syndrome(OSAHS) by using dynamic 3-Dimensional(3-D) CT imaging.A tota... This study examined the dynamic characteristics of upper airway collapse at soft palate level in patients with obstructive sleep apnea/hypopnea syndrome(OSAHS) by using dynamic 3-Dimensional(3-D) CT imaging.A total of 41 male patients who presented with 2 of the following symptoms,i.e.,daytime sleepiness and fatigue,frequent snoring,and apnea with witness,were diagnosed as having OSAHS.They underwent full-night polysomnography and then dynamic 3-D CT imaging of the upper airway during quiet breathing and in Muller's maneuver.The soft palate length(SPL),the minimal cross-sectional area of the retropalatal region(mXSA-RP),and the vertical distance from the hard palate to the upper posterior part of the hyoid(hhL) were compared between the two breathing states.These parameters,together with hard palate length(HPL),were also compared between mild/moderate and severe OSAHS groups.Association of these parameters with the severity of OSAHS [as reflected by apnea hypopnea index(AHI) and the lowest saturation of blood oxygen(LSaO2)] was examined.The results showed that 31 patients had severe OSAHS,and 10 mild/moderate OSAHS.All the patients had airway obstruction at soft palate level.mXSA-RP was significantly decreased and SPL remarkably increased during Muller's maneuver as compared with the quiet breathing state.There were no significant differences in these airway parameters(except the position of the hyoid bone) between severe and mild/moderate OSAHS groups.And no significant correlation between these airway parameters and the severity of OSAHS was found.The position of hyoid was lower in the severe OSAHS group than in the mild/moderate OSAHS group.The patients in group with body mass index(BMI)≥26 had higher collapse ratio of mXSA-RP,greater neck circumference and smaller mXSA-RP in the Muller's maneuver than those in group with BMI26(P0.05 for all).It was concluded that dynamic 3-D CT imaging could dynamically show the upper airway changes at soft palate level in OSAHS patients.All the OSAHS patients had airway obstruction of various degrees at soft palate level.But no correlation was observed between the airway change at soft palate level and the severity of OSAHS.The patients in group with BMI≥26 were more likely to develop airway obstruction at soft palate level than those with BMI26. 展开更多
关键词 obstructive sleep apnea/hypopnea syndrome upper airway obstruction soft palate level dynamic computed tomography 3-dimensional imaging
下载PDF
Grammian Determinant Solution and Pfaffianization for a (3+1)-Dimensional Soliton Equation 被引量:5
18
作者 WU Jian-Ping GENG Xian-Guo2 《Communications in Theoretical Physics》 SCIE CAS CSCD 2009年第11期791-794,共4页
Based on the Pfaffian derivative formulae,a Grammian determinant solution for a(3+1)-dimensionalsoliton equation is obtained.Moreover,the Pfaffianization procedure is applied for the equation to generate a newcoupled ... Based on the Pfaffian derivative formulae,a Grammian determinant solution for a(3+1)-dimensionalsoliton equation is obtained.Moreover,the Pfaffianization procedure is applied for the equation to generate a newcoupled system.At last,a Gram-type Pfaffian solution to the new coupled system is given. 展开更多
关键词 3+1)-dimensional soliton equation Grammian determinant solution PFAFFIANIZATION Gram-type Pfaffian solution
下载PDF
NOVEL 6-SPS PARALLEL 3-DIMENSIONAL PLATFORM MANIPULATOR AND ITS FORCE/MOTION TRANSMISSION ANALYSIS 被引量:2
19
作者 Jin Zhenlin School of Mechanical Engineering, Yanshan University, Qinhuangdao 066004, ChinaGao Feng Hebei University of Technology 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2002年第4期298-302,共5页
The unique design for a novel 6-SPS parallel 3-dimensional platformmanipulator with an orthogonal configuration is investigated. The layout feature of the parallelmanipulator is described. Its force/motion transmissio... The unique design for a novel 6-SPS parallel 3-dimensional platformmanipulator with an orthogonal configuration is investigated. The layout feature of the parallelmanipulator is described. Its force/motion transmission capability, evaluation criteria arepresented. At the orthogonal configuration, the criteria and the relationships between the criteriaand the link lengths are analyzed, which is important since it can provide designer a piece ofvaluable information about how to choose the linear actuators. From the analysis of the results itis shown that the force/motion transmission capabilities of the parallel manipulator arecharacterized by isotropy at the orthogonal configuration. The manipulator is particularly suitablefor certain applications in 6-DOF micromanipulators and 6-axis force/moment transducers. 展开更多
关键词 6-SPS parallel manipulator 3-dimensional platform manipulator ISOTROPY
下载PDF
Spatiotemporal Similaritons in (3+l)-Dimensional Inhomogeneous Nonlinear Medium with Cubic-Quintic Nonlinearity 被引量:3
20
作者 陈翼翔 陆璇辉 《Communications in Theoretical Physics》 SCIE CAS CSCD 2011年第5期871-877,共7页
We obtain exact spatiotemporal similaritons to a (3+ l)-dimensional inhomogeneous nonlinear Schrodinger equation, which describes the propagation of optical pulses in a cubic-quintic nonlinearity medium with distri... We obtain exact spatiotemporal similaritons to a (3+ l)-dimensional inhomogeneous nonlinear Schrodinger equation, which describes the propagation of optical pulses in a cubic-quintic nonlinearity medium with distributed dispersion and gain. A one-to-one correspondence between such self-similar waves and solutions of the elliptic equation is found when a certain compatibility condition is satisfied. Based on exact solutions, we discuss evolutional behaviors of self-similar cnoidal waves and chirped similaritons in two kind of typicai soliton control systems. Moreover, the comparison between chirped similaritons and chirp-free solitons is given. 展开更多
关键词 spatiotemporal similaritons 3+l)-dimensional cubic-quintic nonlinear SchrSdinger equation dynamical behaviors
下载PDF
上一页 1 2 29 下一页 到第
使用帮助 返回顶部