Generation of 3D Virtual Geographic Environment Based on Laser Scanning Technique

This paper demonstrates an experiment on the generation of 3D virtual geographic environment on the basis of experimental flight laser scanning data by a set of algorithms and methods that were developed to automatically interpret range images for extracting geo-spatial features and then to reconstruct geo-objects. The algorithms and methods for the interpretation and modeling of laser scanner data include triangulated-irregular-network (TIN)-based range image interpolation; mathematical-morphology (MM)-based range image filtering, feature extraction and range image segmentation, feature generalization and optimization, 3D objects reconstruction and modeling; computer-graphics (CG)-based visualization and animation of geographic virtual reality environment.

Case Study: The Determination of a Complex Multi-Systemic Medical Condition by a Cognitive, Virtual Scanning Technique

The study of various medical conditions is limited by the current state of knowledge. New tech-nologies enable researchers to advance their understanding of various medical conditions and to advance their understanding of particular pathologies. Strannik Virtual Scanning (SVS) is such a technology. SVS is able to determine the genetic and non-genetic components of every pathology in each of the 30 main organs, and it is able to determine the onset of pathologies at a much earlier stage than any other technologies or techniques. This makes it an ideal tool to screen for the onset and progression of pathologies which are implicated in multi-systemic conditions and to determine the spectrum of pathologies i.e. comorbidities which are involved in diabetes, cardiovascular disease, migraine, chronic fatigue syndrome, fibromyalgia, depression, chronic kidney disease, etc. This case study illustrates how the technology can be usefully and cost-effectively deployed to determine the spectrum of pathologies which characterise Reynaud’s phenomenon. This includes pathologies in the liver and kidneys e.g. portal hypertension, renal insufficiency, nephritis, liver insufficiency, pre-symptomatic onset of heart attack, presymptomatic indications of dementia, pancreatic cancer, and ovarian cancer, which are difficult to diagnose and/or for which there is currently an unmet clinical need.

Intelligent virtualization of crane lifting using laser scanning technology

Background This paper presents an intelligent path planner for lifting tasks by tower cranes in highly complex environments,such as old industrial plants that were built many decades ago and sites used as tentative storage spaces.Generally,these environments do not have workable digital models and 3 D representations are impractical.Methods The current investigation introduces the use of cutting edge laser scanning technology to convert real environments into virtualized versions of the construction sites or plants in the form of point clouds.The challenge is in dealing with the large point cloud datasets from the multiple scans needed to produce a complete virtualized model.The tower crane is also virtualized for the purpose of path planning.A parallelized genetic algorithm is employed to achieve intelligent path planning for the lifting task performed by tower cranes in complicated environments taking advantage of graphics processing unit technology,which has high computing performance yet low cost.Results Optimal lifting paths are generate d in several seconds.

口腔修复诊疗中构建虚拟患者的机遇与挑战

在口腔修复领域,构建虚拟患者进行数字化仿生修复展现出广阔的应用前景。虚拟患者由包含口颌面部信息的数字化素材构成,能准确地反映出口颌面结构的形态和空间关系。然而,在数字化素材的获取、精确配准过程和动态颌位关系的记录与转移中,均存在诸多挑战。本文将围绕虚拟患者的构建流程,阐述目前构建虚拟患者的关键点和难点,推动虚拟患者技术在口腔修复领域的普及和推广。

大跨度钢桁梁桥智能建造技术应用的可行性研究

大跨度钢桁梁桥的构件制造及拼装复杂,采用场内预制组装仍需消耗大量的人力、财力及工期。因此,本文采用BIM桥梁建模、三维激光扫描和虚拟预拼装技术,进行了基于BIM技术的施工方案模拟的可行性研究和基于BIM技术与三维激光扫描方法结合的构件加工质量检测研究,并在此基础上进行了基于BIM技术与三维激光扫描方法结合的虚拟拼装技术研究,探索了大跨度钢桁梁桥智能建造技术应用于指导工程实施的可行性。

一种全数字化前伸髁导斜度测量方法的准确性研究

目的 探究一种全数字化前伸髁导斜度(SCI)测量方法的准确性,同时对获取的受试者左、右侧SCI值进行对比分析,为临床实践提供参考。方法 招募10名咬合关系良好、关节状态正常的受试者,分别使用方法A (传统机械面弓+基于实体架的实体前伸咬合记录)、B (基于面部扫描数据构建的虚拟面弓+基于虚拟(牙合)架的数字化前伸咬合记录)、C (电子面弓描记)测量受试者左、右侧SCI值。以传统机械面弓+基于实体架的实体前伸咬合记录组和电子面弓描记组作为对照组,基于面部扫描数据构建的虚拟面弓+基于虚拟(牙合)架的数字化前伸咬合记录组为实验组,对3种方法获得的左、右侧SCI值进行统计学分析,评估基于面部扫描数据构建的虚拟面弓+基于虚拟(牙合)架的数字化前伸咬合记录的全数字化方法用于SCI测量的准确性,同时分析同一受试者左、右侧SCI值之间差异是否存在统计学意义。结果 方法 A测量的左、右侧SCI值为41.70°±7.09°、42.80°±8.62°,方法 B测量的左、右侧SCI值为35.09°±12.49°、37.63°±12.10°,方法 C测量的左、右侧SCI值为39.43°±8.72°、38.45°±6.91°。3种方法测量的SCI值之间差异无统计学意义(P>0.05),同时同一受试者左、右侧SCI值之间差异也无统计学意义(P>0.05)。结论 基于虚拟面弓和虚拟咬合记录的全数字化SCI测量方法的准确性与基于机械面弓和实体咬合记录法、电子面弓描记法无差异,同一受试者左、右侧SCI值类似,临床诊疗过程中可以根据实际选择合适的SCI测量和设置策略。

基于虚实结合的混合式实验教学方法探索与实践——以“扫描电子显微分析实验”课程为例

扫描电子显微镜作为高等院校检测和分析材料的一种重要大型精密仪器,在材料科学中具有非常广泛的应用价值。针对传统实验教学中存在的诸多问题,通过虚拟仿真技术开发了扫描电子显微分析虚拟仿真实验教学系统,探索并实践了以虚拟仿真实验教学和实体实验教学有机结合的混合式实验教学方法。突破传统实验教学中时间、空间及教学方法的局限,丰富了实验教学内容和手段,激发教师的教学活力,调动学生的学习兴趣和积极性,切实提高实验教学质量,助力材料类专业对兼具创新意识和实践能力创新型人才的培养。

Grid-Scan定位算法的虚拟锚节点策略改进

针对无线传感器网络中Grid-Scan算法定位精度较低的问题,提出了一种基于虚拟锚节点策略的Grid-Scan定位算法。具体做了三个方面的工作:对未知节点设置可定位阈值,邻居锚节点数大于可定位阈值的未知节点使用Grid-Scan算法进行定位,定位后的节点升级为虚拟锚节点;邻居锚节点数小于可定位阈值的未知节点利用极大似然法完成定位,定位后的节点升级为虚拟锚节点;锚节点及虚拟锚节点共同参与对剩余未知节点的定位。仿真结果表明,改进算法在不同锚节点密度、不同通信半径和不同栅格大小的网络中以及通过不规则传播模型后都具有较好的定位精度。

海量数据链表的并行listscan随机算法

本文提出了一种基于 PVM的海量数据链表并行 listscan算法实现的方法和策略 ,并对它在曙光 10 0 0 A上的执行效果进行了分析 .结果显示所提出的并行处理策略对 10 0 M数据大小链表的 listscan并行操作是可行的 ,算法复杂度为 O(n/ p+ p) .

Role of 3-Dimentional Computed Tomography Scan in Video Assisted Major Pulmonary Resection in Patient with Situs Inversus Totalis

The aim of this case report is to raise awareness about the use of 3-Dimentional Computed Tomography (3D-CT) virtual reality imaging as a routine pre-operative tool for evaluation of unusual anatomy such as Situs Inversus Totalis (SIT). We present a case of presumed lung cancer in a 58 years old lady with SIT successfully treated by VATS lobectomy via an anterior approach. She presented with an incidental solitary pulmonary nodule in her right lower lobe, which had moderate FDG uptake on the PET scan. The nodule was too deep to permit safe wedge biopsy, due to proximity of a large pulmonary arterial branch. 3D-CT images were invaluable in pre-operative assessment of the anatomy and were the key to safe completion of right VATS lower lobectomy. Sectioning the lung after retrieval of the specimen suggested a chondroid hamartoma;therefore, systemic nodal dissection (SND) was not contemplated. The final histology confirmed the diagnosis of chondroid hamartoma. In an unusual anatomy such as SIT, 3D-CT allows construction of virtual reality models that can be viewed and manipulated before and during the operation to understand the anatomy better, highlight caveats around target structures and enable localisation of lesions unlikely to be palpated intra-operatively.

Magnified and enhanced computed virtual chromoendoscopy in gastric neoplasia: A feasibility study

AIM: To evaluate the feasibility of a new computed virtual chromoendoscopy (CVC) device (M i-scan) in the diagnosis of gastric neoplasia. METHODS: Patients with superficial lesions no larger than 1.0 cm found during high definition endoscopy were included. Those with advanced or obviously protruded or depressed lesions, lesions larger than 1.0 cm and/or lesions which were not amenable to observation by zoom function were excluded. The endoscopist was required to give the real-time descriptions of surface pit patterns of the lesions, based on surface pattern classification of enhanced magnification endoscopy. According to previous reports, types Ⅰ-Ⅲ represent nonneoplastic lesions, and types Ⅳ-Ⅴ represent neoplastic lesions. Diagnosis with M i-scan and biopsy was performed before histopathological diagnosis. Magnified images of gastric lesions with and without enhancement were collected for further analysis. The diagnostic yield of real-time M i-scan and effects on magnification image quality by tone enhancement (TE), surface enhancement (SE) and color enhancement (CE) were calculated. The selected images were sent to another endoscopist. The endoscopist rated the image quality of each lesion at 3 levels. Ratings of image quality were based on visualization of pit pattern, vessel and demarcation line. RESULTS: One hundred and eighty-three patients were recruited. Five patients were excluded for advanced gastric lesions, 1 patient was excluded for poor preparation and 2 patients were excluded for superficial lesions larger than 1.0 cm; 132 patients were excluded for no lesions found by high definition endoscopy. In the end, 43 patients with 43 lesions were included. Histopathology revealed 10 inflammation, 14 atrophy, 10 metaplasia, 1 low grade dysplasia (LGD), 5 high grade dysplasia (HGD) and 3 cancers. For 7 lesions classified into type Ⅰ, histopathology revealed 6 atrophy and 1 metaplasia; for 10 lesions classified into type Ⅱ, histopathology revealed 2 inflammation, 7 atrophy and 1 metaplasia; for 10 lesions classified into type Ⅲ, histopathology revealed 1 inflammation, 8 metaplasia and 1 LGD; for 9 lesions classified into type Ⅳ, histopathology revealed 4 inflammation, 1 atrophy and 4 HGD; for 7 lesions classified into type Ⅴ, histopathology revealed 3 inflammation, 1 HGD and 3 cancers. A total of 172 still images, including 43 images by white light (MWL) and 129 images by M i-scan (43 with TE, 43 with SE and 43 with CE), were selected and sent to the endoscopist who did the analysis. General image quality of M i-scan with TE and SE was significantly better than that of MWL (TE, 4.55 ± 1.07; SE, 4.30 ± 1.02; MWL, 3.25 ± 0.99; P < 0.001). Visualization of pit pattern was significantly improved by M i-scan with SE (1.93 ± 0.25 vs 1.50 ± 0.50, P < 0.001). Microvessel visualization was significantly improved by M i-scan with TE (1.23 ± 0.78 vs 0.76 ± 0.73, P < 0.001). Demarcation line visualization was improved by M i-scan with both TE and SE (TE, 1.75 ± 0.52; SE, 1.56 ± 0.59; MWL, 0.98 ± 0.44; P < 0.001). M i-scan with CE did not show any significant improvements of image quality in general or in the 3 key parameters. Although M i-scan with TE and SE slightly increased the diagnostic yield of MWL, there was no significant difference (P > 0.1). CONCLUSION: Although digital enhancement improves the image quality of magnification endoscopy, its value in improving the diagnostic yield seems to be limited.

面向Microsoft Virtual PC的虚拟机远程检测方法

虚拟机技术的广泛应用给信息安全带来新的问题和挑战,由于现有的安全扫描系统检测不到虚拟机的存在,所以无法扫描虚拟机的安全漏洞。文中提出了一种面向VPC(Microsoft Virtual PC)的虚拟机远程检测方法,此方法根据虚拟机MAC地址中携带的厂商标识符,能正确地识别网络中存在的VPC虚拟机;并利用虚拟机与宿主机的关联性快速寻找到虚拟机的宿主机,为进一步扫描虚拟机的安全漏洞和管理虚拟机网络提供基础。实验结果表明,该方法能准确地检测网络中存在的VPC虚拟机。

Gadolinium Enhances Dual-energy Computed Tomography Scan of Pulmonary Artery

Objective To evaluate the feasibility of using gadopentetate dimeglumine(Gd-DTPA)for dual-energy computed tomography pulmonary angiography(CTPA).Methods Sixty-six patients were randomly divided into three groups and underwent CTPA.Group A had a turbo flash scan using an iohexol injection,Group B had a turbo flash scan using Gd-DTPA,and Group C had a dual-energy scan using Gd-DTPA.The original images of Group C were linearly blended with a blending factor of 0.5 or reconstructed at 40,50,60,70,80,90,100,and 110 keV,respectively.The groups were compared in terms of pulmonary artery CT value,image quality,and radiation dose.Results The pulmonary artery CT values were significantly higher in Group C40keV than in Groups B and C,but lower than in Group A.There was no significant difference in the image noise of Groups C40keV,B,and C.Moreover,Group A had the largest beam hardening artifacts of the superior vena cava(SVC),followed by Groups B and C.Group C40keV showed better vascular branching than the other three groups,among which Group B was superior to Group A.The subjective score of the image quality of Groups A,B,and C showed no significant difference,but the score was significantly higher in Group C40keV than in Groups A and B.The radiation dose was significantly lower in Group B than in Groups A and C.Conclusion Gd-CTPA is recommended to patients who are unsuitable for receiving an iodine-based CTPA.Furthermore,a turbo flash scan could surpass a dual-energy scan without consideration for virtual monoenergetic imaging.

基于三维激光扫描的教学用飞机结构虚拟实践平台构建

依据教育部虚拟仿真实验教学课程的建设要求和航空类人才培养目标,结合飞行器设计与工程本科专业特点,利用三维激光扫描、逆向建模和可视化演示等数字化技术手段,为“飞行器结构设计”“结构维修与适航”等航空专业核心课构建了教学用飞机结构虚拟实践平台,营造了“沉浸式”“虚拟机库”的教学氛围,取得了显著的教学成效,满足了在线教学资源共享、多校区实物教学演示等要求,储备了大量的典型飞机结构数字化案例。

扫描电子显微镜虚拟仿真实验设计与教学实践

扫描电子显微镜虚拟仿真实验与武汉科技大学优势专业紧密结合,从微观(μm或nm)尺度研究材料的属性.采取虚实结合的层次化实验教学,线上线下相结合的个性化实验教学模式,模块化实验环节.采用“进阶交互式”教学方式,根据学生设定的参量提供基于真实仪器的反馈和相应的实验数据,培养学生的实验思维体系.采取“重点过程”与“结果”相结合的多元化评价体系,深化一流仿真实验教学的内涵,提高学生的实验操作能力和专业英语水平,激发教师进行教学改革.

Revolution CT虚拟平扫在直肠癌诊断中的应用价值研究

目的 研究Revolution CT虚拟平扫在直肠癌诊断中的应用价值。方法 搜集2017年10月至2018年7月在该院手术治疗并于术前行Revolution CT常规能谱平扫及双期虚拟平扫的70例直肠癌患者影像资料。对常规能谱平扫及双期虚拟平扫的图像质量进行主观评分及客观评价[计算对比噪声(CNR)],对直肠癌病灶的诊断准确性(包括对直肠癌肠壁厚度、浆膜面的受累情况、直肠癌周围淋巴结显示情况的评价)及扫描剂量进行评估,并进行对比研究。结果 常规能谱平扫及双期虚拟平扫图像质量主观评分比较,差异无统计学意义(P>0.05)。双期虚拟平扫CNR值均高于常规能谱平扫,差异有统计学意义(P<0.05)。常规能谱平扫及双期虚拟平扫对直肠癌肠壁厚度判断、浆膜面的受累情况、直肠癌周围淋巴结显示情况比较,差异均无统计学意义(P>0.05)。常规能谱平扫有效剂量值低于双期虚拟平扫,差异有统计学意义(P<0.05)。双期增强扫描分离出虚拟平扫图像,可以减少约30%辐射剂量。结论 在直肠癌诊断时,Revolution CT虚拟平扫代替常规能谱平扫可以在减少辐射剂量的同时满足临床诊断需求。

虚拟服装迁移在个性化服装定制中的应用

为解决服装定制中个性化服装开发效率低以及虚拟试衣过程繁琐等问题,首先,详细阐明了三维服装软件CLO 3D和Marvelous Designer的虚拟服装迁移原理;其次,结合CLO 3D的虚拟服装迁移和自动转换虚拟模特功能,提出了一套针对三维扫描人体的个性化服装定制方案;最后,采用三维扫描人体开展虚拟服装迁移实验,验证了该方案在实际个性化服装定制应用中的可行性。研究结果表明:针对不同体型的三维扫描人体,可快速生成个性化虚拟服装、个性化样板和展示个性化虚拟试衣效果;生成的虚拟服装能够满足不同体型的个性化需求。该方法可提高个性化虚拟服装开发效率,为个性化服装定制提供技术支持。

扫描电子显微镜虚拟实验的教学探索

为提升“现代仪器分析方法”课程教学质量,充分调动学生对实验仪器探索的积极性,在课堂教学过程中引入虚拟实验辅助教学模式.以扫描电子显微镜为例,针对扫描电子显微镜原理、成像分析等教学重点和难点,让学生通过虚拟实验的操作过程,熟悉仪器操作过程,加深对二次电子成像、背散射电子成像和能谱分析的理解.此过程不仅能保证学生的参与度,还能够激发学生的探索欲望.

自动乳腺容积成像联合声脉冲辐射力成像在可疑乳腺肿块鉴别诊断中的应用价值

目的:探讨自动乳腺容积成像(automated breast volume scanning,ABVS)和声脉冲辐射力成像(acoustic radiation force impulse,ARFI)两种超声技术联合对常规超声诊断为可疑乳腺肿块的良恶性鉴别诊断能力。方法:对118例乳腺肿块常规超声评估分类为乳腺影像报告和数据系统(Breast Imaging Reporting And Data System,BI-RADS)4类及以上的患者,应用ABVS分析肿块有无冠状面图像特征(汇聚征与微钙化),应用ARFI检测声触诊组织成像(virtual touch tissue imaging,VTI)中肿块在弹性图与二维图的面积比和声触诊组织量化成像(virtual touch tissue imaging quantification,VTIQ)中肿块剪切波速度的平均值(V_(mean)),对乳腺肿块良恶性的图像按照冠状面有无汇聚征、有无微钙化分类,有任意一种即记为阳性;VTI肿块面积比值大于1.65记为阳性;V_(mean)大于4.14 m/s为阳性。计算并比较ABVS、ARFI单独以及两者联合诊断BI-RADS 4类乳腺肿块的灵敏度、特异度、准确度、阳性预测值、阴性预测值。结果:乳腺肿块在ARFI的检查中,恶性肿块的VTI面积比(1.76±0.61)高于良性肿块VTI面积比(1.14±0.48),恶性肿块的V_(mean)[(6.38±1.76)m/s]高于良性肿块[(4.17±1.43)m/s],差异均有统计学意义(P<0.01)。在BI-RADS 4类乳腺肿块中,ABVS检查中汇聚征或微钙化对恶性乳腺肿块检出的灵敏度、特异度、准确度、阳性预测值及阴性预测值分别为92%、78.3%、84.5%、78.0%及92.2%;VTI诊断乳腺恶性肿块的灵敏度、特异度、准确度、阳性预测值及阴性预测值分别为70.0%、81.7%、76.4%、76.1%及76.6%;VTIQ诊断恶性乳腺肿块的灵敏度、特异度、准确度、阳性预测值、阴性预测值分别为96.0%、58.3%、75.5%、65.8%及94.6%。ABVS与ARFI两者联合诊断的灵敏度、特异度、准确度、阳性预测值、阴性预测值分别为100.0%、50.0%、72.7%、62.5%及100.0%。结论:ABVS与ARFI可补充常规二维超声无法获得的乳腺肿块信息,丰富肿块诊断的依据,扩展疾病鉴别诊断的思路,两者结合可达到优势互补的效果,有助于提高诊断的准确度。