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1.
Mutual information (MI)-based image registration is effective in registering medical images, but it is computationally expensive.
This paper accelerates MI-based image registration by dividing computation of mutual information into spatial transformation
and histogram-based calculation, and performing 3D spatial transformation and trilinear interpolation on graphic processing
unit (GPU). The 3D floating image is downloaded to GPU as flat 3D texture, and then fetched and interpolated for each new
voxel location in fragment shader. The transformed results are rendered to textures by using frame buffer object (FBO) extension,
and then read to the main memory used for the remaining computation on CPU. Experimental results show that GPU-accelerated
method can achieve speedup about an order of magnitude with better registration result compared with the software implementation
on a single-core CPU. 相似文献
2.
A new lighting and enlargement on phase spectrogram （PS） and frequency spectrogram （FS） is presented in this paper. These representations result from the coupling of power spectrogram and short time Fourier transform （STFT）. The main contribution is the construction of the 3D phase spectrogram （3DPS） and the 3D frequency spectrogram （3DFS）. These new tools allow such specific test signals as small slope linear chirp, phase jump case of musical signal analysis is reported. The main objective is to and small frequency jump to be analyzed. An application detect small frequency and phase variations in order to characterize each type of sound attack without losing the amplitude information given by power spectrogram 相似文献
3.
Huixiang Wang Fei Lyu Kapil Sugand Sheungting Wong Yanping Lin Qiugen Wang 《Anatomical sciences education》2019,12(6):655-663
Acetabular fractures are a real challenge for junior doctors as well as experienced orthopedic surgeons. Correct fracture classification is crucial for appreciating the fracture type, surgical planning, and predicting prognosis. Although three-dimensional (3D) tutorial is believed to improve the understanding of the complex anatomy structure, there have been few applications and randomized controlled trials to confirm it in orthopedics. This study aims to develop a 3D interactive software system for teaching acetabular fracture classification and evaluate its efficacy. Participants were randomly but evenly allocated into either the experimental group (who learned the acetabular fracture classification using a 3D software) or the control group (who used a traditional two-dimensional [2D] tutorial). Both groups were then tasked to classify 10 acetabular fractures and complete a five-point Likert scale on their satisfaction of each learning modality. To calculate significance (P < 0.05), independent t-test was used for normally distributed data whereas Mann-Whitney U test for non-normally distributed data. The experimental group significantly outperformed the control group (t (28) = 2.526, P = 0.017) with identifying correct acetabular fracture classification. Moreover, Likert scale score in the experimental group was also significantly higher than in the control group (Z = 2.477, P = 0.013). This 3D classification software has objectively and subjectively showed an advantage over the traditional 2D tutorial, resulting in an improved classification accuracy and higher Likert scale score. The 3D software has the potential to improve both clinical knowledge as well as identifying correct patient management in orthopedics. 相似文献
4.
Example based painting generation 总被引：1，自引：0，他引：1
GUO Yan-wen YU Jin-hui XU Xiao-dong WANG Jin PENG Qun-sheng 《浙江大学学报(A卷英文版)》2006,7(7):1152-1159
INTRODUCTION Non-photorealistic rendering (NPR) is a domain of computer graphics that has received more and more attention in the past decade. Different from realistic rendering, NPR concentrates on communicating the main context of an image and explores the rendering effect of the scene with the artistic styles, rather than seeking subtle geometry details and naturally physical attribute. Many research efforts were dedicated to simu- lating the traditional media (Hertzmann et al., 2001… 相似文献
5.
降低能耗、节约能源成为城市道路照明设计及布局的必然选择。通过对德州市城区主要道路路灯进行测量,并采用路面平均亮度、路面平均照度等相关参数模型进行实证分析,结果显示,城区各路段的路灯布局配置相差较大,部分路段与国家标准值相差甚远,新老城区及繁华地段的各项指标相差很大,配置LED路灯的主干道照明效果也不理想。基于此,提出了城市道路路灯布局优化设计的合理建议。 相似文献
6.
Advances in computer and interface technologies have made it possible to create three‐dimensional (3D) computerized models of anatomical structures for visualization, manipulation, and interaction in a virtual 3D environment. In the past few decades, a multitude of digital models have been developed to facilitate complex spatial learning of the human body. However, there is limited empirical evidence to guide the development and integration of effective computer models for teaching and learning. The purpose of this article is to describe the development of a dynamic head and neck model with flexible displays (2D, 3D, and stereoscopic 3D) and interactive control features that can be later used to design and test the efficacy of computer models as a means of improving student learning. The model was created using computer tomography scans of a human cadaver. Anatomical structures captured on the scans were segmented into discreet areas, and then reconstructed in three‐dimensions using specialized software. The final model consists of 70 distinct anatomical structures that can be displayed in 2D, 3D, or stereoscopic 3D. In 3D mode, a mouse can be used to actively and continuously interact with the model by manipulating viewer orientation, altering surface transparency, superimposing 2D scans with 3D reconstructions, removing or adding structures sequentially, and customizing animated scenes to show complex anatomical pathways or relationships. Anat Sci Educ 2: 294–301, 2009. © 2009 American Association of Anatomists. 相似文献
7.
The goal of this study was to develop and evaluate a structural model of the relations among cognitive abilities and arithmetic skills and college students’ algebra achievement. The model of algebra achievement was compared to a model of performance on the Scholastic Assessment in Mathematics (SAT‐M) to determine whether the pattern of relations is similar for different types of higher level maths achievement. Structural equation modelling was used to test the effects of working memory, 3D spatial ability, and computational fluency on both types of higher order maths achievement. Computational fluency had the strongest effect on algebra achievement, with 3D spatial ability and working memory showing moderate effects. In contrast, 3D spatial ability had a stronger effect on SAT‐M scores than did computational fluency. Computational fluency and 3D spatial ability completely mediated the effect of working memory for both algebra and SAT‐M achievement. 相似文献
8.
Leah Labranche Timothy D. Wilson Mark Terrell Randy J. Kulesza 《Anatomical sciences education》2022,15(2):291-303
Three-dimensional (3D) digital anatomical models show potential to demonstrate complex anatomical relationships; however, the literature is inconsistent as to whether they are effective in improving the anatomy performance, particularly for students with low spatial visualization ability (Vz). This study investigated the educational effectiveness of a 3D stereoscopic model of the pelvis, and the relationship between learning with 3D models and Vz. It was hypothesized that participants learning with a 3D pelvis model would outperform participants learning with a two-dimensional (2D) visualization or cadaveric specimen on a spatial anatomy test, particularly when comparing those with low Vz. Participants (n = 64) were stratified into three experimental groups, who each attended a learning session with either a 3D stereoscopic model (n = 21), 2D visualization (n = 21), or cadaveric specimen (n = 22) of the pelvis. Medical and pre-medical student participants completed a multiple-choice pre-test and post-test during their respective learning session, and a long-term retention (LTR) test 2 months later. Results showed no difference in anatomy test improvement or LTR performance between the experimental groups. A simple linear regression analysis showed that within the 3D group, participants with high Vz tended to retain more than those with low Vz on the LTR test (R2 = 0.31, P = 0.01). The low Vz participants may be cognitively overloaded by the complex spatial cues from the 3D stereoscopic model. Results of this study should inform resource selection and curriculum design for health professional students, with attention to the impact of Vz on learning. 相似文献
9.
张礼芳 《中国现代教育装备》2010,(1):54-56
在摄影教学中,教师应用多媒体技术演示与教学内容有关的照片,主要有6个方面的作用：有利于新课导入、节省绘图时间并且获得准确度很高的图像、解决教材中的重点和难点、激发学生学习摄影的兴趣、培养学生的观察能力和创造性思维能力、提高学生的审美能力。 相似文献
10.
Theaimofthecomputergraphicsistoachieverea listicimage .Traditionalmethods ,suchasradiosity ,hav ingconstructedthemodelofthescene,produceimagesbyilluminationalgorithm .Conventional graphicsfacegreatdifficultiesintwoaspects :over complicatedcom putingandunrealisticimages.Theimage basedmodelingandrendering(IBMR)techniquesareapowerfulalterna tivetothetraditionalgeometry basedtechniquesforim agesynthesisandarewidelystudiedinrecentyears .Im age basedrendering(IBR)techniquesdirectlyrenderthenovelv… 相似文献
11.
Cluster parallel rendering based on encoded mesh 总被引：2，自引：0，他引：2
QIN Ai-hong XIONG Hua PENG Hao-yu LIU Zhen SHI Jiao-ying 《浙江大学学报(A卷英文版)》2006,7(7):1124-1133
INTRODUCTION Three dimensional (3D) meshes are widely used to represent 3D objects. With the rapid advances in digital acquisition technology, meshes with millions of vertices are becoming increasingly common. Be- cause of memory constraints and lack of graphics power, visualizations of this magnitude are difficult or impossible to perform even on the most powerful workstations. Therefore, the need for parallel im- plementation is clear. Most previous work in high performance rendering h… 相似文献
12.
为适应改变中的卫生服务需要，2001年美国旧金山加州大学医学院开发了一种以生物-心理-社会模式为基础的新课程。这一课程将四年的医学院教育区分成三个阶段：基础核心课程、临床核心课程和高级学习。本文扼要介绍了社会科学和行为科学在基础核心课程阶段以临床病例为中心的各学段中的作用。对基本的专题领域、内容例证、医学文化和过程均作了介绍，对新课程存在的问题和局限也进行了讨论。 相似文献
13.
魏荣峰 《宁德师专学报(自然科学版)》2005,17(4):395-397
应用“绿色照明”理念,在校园的照明工程中,探索采用高效节能型灯具,改善校园照明设施,创设舒适、经济、有益的环境,从而充分体现现代文明校园的绿色照明. 相似文献
14.
ZOU Wan-hong DING Zhan YE Xiu-zi CHEN Zhi-yang 《浙江大学学报(A卷英文版)》2007,8(10):1633-1641
With the rapid development of 3D digital photography and 3D digital scanning devices, massive amount of point samples can be generated in acquisition of complex, real-world objects, and thus create an urgent need for advanced point-based processing and editing. In this paper, we present an interactive method for blending point-based geometries by dragging-and- dropping one point-based model onto another model’s surface metaphor. We first calculate a blending region based on the polygon of interest when the user drags-and-drops the model. Radial basis function is used to construct an implicit surface which smoothly interpolates with the transition regions. Continuing the drag-and-drop operation will make the system recalculate the blending regions and reconstruct the transition regions. The drag-and-drop operation can be compound in a constructive solid geometry (CSG) manner to interactively construct a complex point-based model from multiple simple ones. Experimental results showed that our method generates good quality transition regions between two raw point clouds and can effectively reduce the rate of overlapping during the blending. 相似文献
15.
According to the features of the turning simulation, a simplified Whitted lighting model is proposed based on the analysis of Phong and other local illumination model. Moreover, in order to obtain the natural lighting effects, local ray tracing algorithm is given to calculate the light intensity of every position during the course of the simulation. This method can calculate the refresh area before calculating the intersection line,simulate the machining environment accurately and reduce the calculating time. Finally, an example of the virtual cutting scene is shown to demonstrate the effects of the global illumination model. If the CUP is 1.3 G and the internal memory is 128 M, the refreshing time of virtual turning scene can be reduced by nine times. This study plays an important role in the enrichment of the virtual manufacturing theory and the promotion of the development of the advanced manufacturing technology. 相似文献
16.
主要介绍了一种简化处理液压支架Pro/E三维模型的方法。经过处理的三维模型可以直接导入Work-bench中进行分析,从分析结果可直接查看支架每个零件的应力、应变及位移。而如果把三维模型的各个部件做成一个实体去分析,这种方法的结果显示时只能用切割的方式查看各个零件的应力、应变及位移。 相似文献
17.
覃海川 《南宁职业技术学院学报》2013,(6):93-96
三维动画制作产业化进程中渲染是十分重要的,提高渲染效率的途径有多种,但使用有限的硬件资源,如何高效地渲染得到真实生动的效果是每个从业人员的追求。基于此目的进行探讨有限硬件条件下三维动画分层渲染的三种技术。 相似文献
18.
XING Yu-zhong FAN Tai-liang ZHENG Li-hui 《浙江大学学报(A卷英文版)》2006,7(11):1904-1910
INTRODUCTION Several fields in Liaohe Basin are host to frac- tured hydrocarbon oil reservoir, fractures are consid- ered to influence productivity significantly in these reservoirs, which not only form a large part of the overall porosity, but also are responsible for the po- tential reservoir volume. More importantly, the frac- ture system facilitates permeability and flow. Ce- mented and closed fractures act as barriers to flow, whereas open fractures intersected by the wellbore may in… 相似文献
19.
The inherent spatial complexity of the human cerebral ventricular system, coupled with its deep position within the brain, poses a problem for conceptualizing its anatomy. Cadaveric dissection, while considered the gold standard of anatomical learning, may be inadequate for learning the anatomy of the cerebral ventricular system; even with intricate dissection, ventricular structures remain difficult to observe. Three-dimensional (3D) computer reconstruction of the ventricular system offers a solution to this problem. This study aims to create an accurate 3D computer reconstruction of the ventricular system with surrounding structures, including the brain and cerebellum, using commercially available 3D rendering software. Magnetic resonance imaging (MRI) scans of a male cadaver were segmented using both semiautomatic and manual tools. Segmentation involves separating voxels of different grayscale values to highlight specific neural structures. User controls enable adding or removing of structures, altering their opacity, and making cross-sectional slices through the model to highlight inner structures. Complex physiologic concepts, such as the flow of cerebrospinal fluid, are also shown using the 3D model of the ventricular system through a video animation. The model can be projected stereoscopically, to increase depth perception and to emphasize spatial relationships between anatomical structures. This model is suited for both self-directed learning and classroom teaching of the 3D anatomical structure and spatial orientation of the ventricles, their connections, and their relation to adjacent neural and skeletal structures. 相似文献
20.
A novel three-dimensional tool for teaching human neuroanatomy 总被引：1，自引：0，他引：1
Three‐dimensional (3D) visualization of neuroanatomy can be challenging for medical students. This knowledge is essential in order for students to correlate cross‐sectional neuroanatomy and whole brain specimens within neuroscience curricula and to interpret clinical and radiological information as clinicians or researchers. This study implemented and evaluated a new tool for teaching 3D neuroanatomy to first‐year medical students at Boston University School of Medicine. Students were randomized into experimental and control classrooms. All students were taught neuroanatomy according to traditional 2D methods. Then, during laboratory review, the experimental group constructed 3D color‐coded physical models of the periventricular structures, while the control group re‐examined 2D brain cross‐sections. At the end of the course, 2D and 3D spatial relationships of the brain and preferred learning styles were assessed in both groups. The overall quiz scores for the experimental group were significantly higher than the control group (t(85) = 2.02, P < 0.05). However, when the questions were divided into those requiring either 2D or 3D visualization, only the scores for the 3D questions were significantly higher in the experimental group (F1,85= 5.48, P = 0.02). When surveyed, 84% of students recommended repeating the 3D activity for future laboratories, and this preference was equally distributed across preferred learning styles (χ2 = 0.14, n.s.). Our results suggest that our 3D physical modeling activity is an effective method for teaching spatial relationships of brain anatomy and will better prepare students for visualization of 3D neuroanatomy, a skill essential for higher education in neuroscience, neurology, and neurosurgery. Anat Sci Educ. © 2010 American Association of Anatomists. 相似文献