Digital reconstruction of ancient Egyptian tombs

From the pyramids of Giza to the tombs of Thebes at Luxor, the glorious ancient Egyptian history has produced remarkable architecture. Sadly, tourists, numbering nearly four million per year, have taken a heavy toll on many of these ancient structures. Of particular concern are many of tombs located opposite Luxor on the western bank of the Nile. Digital reconstruction of these tombs has the potential of helping to document and preserve these important historical structures. Issues concernng new and unique problems involving the photographing and digital reconstruction of these tombs are addressed. Techniques for removing image distortions, recovering 3-D shapes and correcting for lighting imbalances are discussed. A complete reconstruction of the tomb of Sennediem is shown.

New approach for the digital reconstruction of complex mine faults and its application in mining

Visualization of complex geological structures can technically support the accurate prediction and prevention of coal mine disasters.This study proposed a new digital reconstruction method to visualize geological structures based on establishing a virtual model in the digital twin system.This methodology for the digital reconstruction of complex fault structures comprises the following four aspects:(1)collection and fdelity of multi-physical feld data of the fault structures,(2)the transmission of multi-physical feld data,(3)the normalization of multi-physical feld data,and(4)digital model reconstruction of fault structures.The key scientifc issues of this methodology to be resolved include in situ fdelity of multi-feld data and normalized programming of multi-source data.In addition,according to the geological background and conditions in Da’anshan coal mine in western Beijing,China,a preliminary attempt is made to reconstruct a digital model of fault and fold structures using the methodology proposed in this study.

Digital Imaging Reconstruction from Multiple Angle Diversity Using Digital Filtering Technique

Microwave diffraction tomography is a process to infer the internal structure of an objectfrom multiple angle views of microwave diffraction shadow. Being sensitive to variations in refractive index of the object, the procedure can be used to measure permittivity distributions within dielectric objects and to image soft tissues for biomedical applications. The optimal resolution distance obtainable is half a wavelength, but this can rarely be achieved because of practical limitations. Some procedures, however, are available to improve the practical resolution. One, which is suitable for microwave tomography, is to use multiple angle views data and to combine the resulting images. The other, which is suitable for improving the image reconstruction resolution, is to use the digital filtering technique and the filtered backpropagation algorithm. A system operating over the X-band microwave frequency is described and some experimental results for objects in air are given.

Digital measurement of bone tumor volume by CT three-dimensional reconstruction technology

Objective To discuss the measurement of bone tumor volume on the basis of three dimensional images segmentation technology. Methods Twenty patients with lacunar bone tumor from Tianjin Hospital and Tongji Hospital were included in the

新质教育:从理念构想到实施路径

新质教育是教育发展的新“蓝海”,发展新质教育的目标是为了培养新质人才。新质教育主张突破学校教育的藩篱,发展终身教育、个性化学习和人机合作学习,以培养具有创新能力、合作能力、解决复杂问题能力和高阶思维的复合型人才。新质教育相较于传统教育的优势体现在,教育本质从培养“有知识”的人向培养“懂合作、会创新”的人转变,教育特征由统一性、集中性和标准化向多样性、泛在性和差异化转变,教育内容从经典知识为主向新知识为主转变,教学模式由学科导向的系统学习向问题导向的按需学习转变,教育对象由以未成年人和青年人为主向面向全体人群转变。未来发展新质教育应以培养新质人才为导向,开启教育体系变革;以改变办学模式为契机,推动学校教育转型;以思维和能力培养为核心,改变教育教学模式;以终身学习为基础和目的,探索学校—社会循环教育新机制;以通识教育与专题研究相结合,创新人才培养模式。

建构新教育学体系,发展新质教育--从数智时代新知识观入手

新质生产力是经济学和哲学概念,指社会生产过程中出现的新的、具有变革性和创新性的生产力要素或形态。发展新质生产力离不开新质教育。新质教育强调人的全面发展、个性化学习与终身教育,以培养创新型人才。当今教育学理论滞后、实践指导力不足、学科分类和组织架构不合理,已不能适应时代需要,建构新教育学理论与实践体系已成为发展新质教育的关键。本文从数智时代新知识观出发,提出建构新教育学的原则是从以学校教育为核心向终身教育为核心转变、打破“以知识传授为中心”的传统教育教学模式,实现真正意义上的个性化学习,培养与智能机器分工合作、擅长创新创造的数智时代新人。构建新教育学的理论基础需要跨学科合作。新教育学作为一级学科应包括教育学基本理论、学校教育学、终身教育学、人工智能教育学和教育伦理学五个二级学科;研究内容应涵盖教育目的与价值观、学习者与学习过程、教育技术与学习环境、教育政策与管理、教师教育与专业发展;除传统方法外,研究方法应包括数据挖掘与分析。教学模式创新应包括个性化教学、项目式教学、人—机合作式教学、跨学科教学;学习方式变革应包括个人导向的系统学习、新社会化学习和人—机合作式学习;教育技术应用应包括智能辅导系统、自动化评估、在线学习平台和虚拟现实与增强现实技术等。面对理论建构、教育观念和机构设置等挑战,本研究建议采取先易后难、循序渐进的策略,分观念引导与资源整合、实践探索与机构协作、系统构建与政策支持三阶段稳步推进。

A Method of Digitally Reconstructed Radiographs Based on Medical CT Images

A complete and detail method is described to get digitally reconstructed radiographs （DRRs）. Casting rays to traverse CT images, computing CT values of resample points by interpolation, then converting CT value to its attenuation coefficient by using simplified segment function. Finally, DRRs enhancement is made to get the better display of region of interest （ROI）, and a new way is adopted to adjust the customization coefficient. The experimental results show that the proposed method is effective in generating the satisfied DRRs.

Application of a medical image processing system in liver transplantation

BACKGROUND: At present, imaging is used not only to show the form of images, but also to make three-dimensional (3D) reconstructions and visual simulations based on original data to guide clinical surgery. This study aimed to assess the use of a medical image-processing system in liver transplantation surgery. METHODS: The data of abdominal 64-slice spiral CT scan were collected from 200 healthy volunteers and 37 liver cancer patients in terms of hepatic arterial phase, portal phase, and hepatic venous phase. A 3D model of abdominal blood vessels including the abdominal aorta system, portal vein system, and inferior vena cava system was reconstructed by an abdominal image processing system to identify vascular variations. Then, a 3D model of the liver was reconstructed in terms of hepatic segmentation and liver volume was calculated. The Free Form modeling system with a PHANTOM force feedback device was used to simulate the real liver transplantation environment, in which the total process of liver transplantation was completed. RESULTS: The reconstructed model of the abdominal blood vessels and the liver was clearly demonstrated to be three-dimensionally consistent with the anatomy of the liver, in which the variations of abdominal blood vessels were identified and liver segmentation was performed digitally. In the model, liver transplantation was simulated subsequently, and different modus operandi were selected successfully. CONCLUSION: The digitized medical image processing system may be valuable for liver transplantation.

Application of 3D Digital Reconstruction and Printing to the Diagnosis and Treatment of Iliac Vein Compression

The objective of this research was to explore the feasibility and clinical application of a new diagnostic imaging method for the diagnosis and treatment of iliac vein compression(IVC)based on three-dimensional(3D)digital reconstruction and printing.This study included patients with chronic venous disease(CVD)who were admitted to the Department of Vascular Surgery,Shanghai Ninth People’s Hospital,Shanghai Jiao Tong University School of Medicine,from January to March,2019,and underwent computed tomography venography(CTV)to detect IVC.CTV findings were used to reconstruct 3D-printed models of blood vessels.A total of 17 patients(5 men and 12 women)with IVC,who were primarily diagnosed with CTV,were included in this study.In addition,24 significant venous compression sites were found in 17 patients,of which 7 patients had only one compression site(41.2%),nine patients had two compression sites(52.9%),and one patient had three compression sites(5.9%).3D digital reconstruction and printing is a convenient,noninvasive,and accurate diagnostic imaging method that provides a clear and accurate evaluation of veins and arteries,as well as the anatomical positional relationship for the diagnosis and treatment of IVC.

The reconstruction of diffractive object digital hologramat a short distance

By using a spherical wave as the reference wave, we recorded the in-line phase-shifting digital hologram of the 25th element of Chinese standard No. 3 resolution test pattern, and gave the corresponding numerical reconstructed results. Some problems concerning with the digital hologram recording and reconstruction of the diffractive object at a short distance are discussed. The experimental result shows that the resolution of the reconstructed image is better than 10μm, which is the limit by using this experimental arrangement.

Mechanism analysis of cheetah’s high-speed locomotion based on digital reconstruction

As the fastest land animal,cheetah has important reference significance for the research of high-speed quadruped robots in terms of its body structure,motion characteristics and control mechanism.In this paper,we used digital reconstruction to analyze the mechanism of the cheetah’s high-speed movement.Considering the body size and quality of a real cheetah,a simplified virtual model of cheetah was built.Using the D-H method,the kinematics and dynamics of the cheetah’s leg mechanism were established.By using the foot trajectory data of the cheetah’s running gait obtained from biological research,each joint angle,virtual leg length,leg-to-ground contact angle,leg energy,joint torque,and the manipulability of the leg mechanism were analyzed and compared in the time dimension.Finally,the high-speed motion law of engineering guiding significance was extracted.

Three-Dimensional Computerized Tomography-Assisted Identification of Necrotic Volume, Distribution, Shape and Prognosis of Collapse in ONFH

Objective: We constructed 3D-model of ONFH in computer according to three-dimensional computerized tomography (3D-CT) data. We determined the location and volume of necrosis to investigate its clinical efficacy. Method: Totally 92 hips (59 cases) with ONFH (44 males, 15 females) were included, with mean age of 37.5 years (range from 26 to 58). Totally 20 cases (35 hips) were induced by corticosteroid (CTSs), 31 (49 hips) induced by alcohol, 4 (4 hips) induced by trauma and 4 (4 hips) idiopathic. All the hips were categorized into stage ARCO II. Finally diagnosed by MRI, all hips were scanned by CT to acquire data in DICOM format. The images were imported into software to extract 3D-shape of femoral heads, necrotic foci, their volumes and distribution in each quadrant. Deviation of volumes between digital image and biopsy specimen was analyzed by SAS9.1 package. Correlativity between collapse and volume of necrosis under specific pathogeneses was also analyzed. Among the cases necessitating total hip arthroplasty (THA) due to advancing to ARCO III, we randomly selected 8 of them to perform 3D-CT scanning thrice prior to surgical operation. Total femoral heads harvested were torn asunder. Cubic capacity of femoral heads and necrotic foci were hereby measured and compared with those acquired from digital models. Result: Through the digital model, necrotic foci were found mainly locating within the super lateral portion of femoral head, coinciding with those observed in biopsy specimen. Average volumetric ratio of digitally acquired necrosis focus/femoral head in 58 collapsed hips was 36.8%. The ratio of the 34 hips without collapse was 17.3%. In collapsed femoral heads, the distribution of necrosis focus was 23.4% in quadrant 1 (q1), 23.6% in q2, 12.1% in q3, 14.4% in q4, 9.0% in q5, 11.8% in q6, 1.6% in q7 and 3.9% in q8. In femoral heads without collapse, the distribution was 34.2% in q1, 29.6% in q2, 11.8% in q3, 11.3% in q4, 6.0% in q5, 6.0% in q6, 0.5% in q7 and 0.4% in q8. As for the average cubic capacities of femoral heads and necrotic foci, those acquired from the digital model and biopsy specimen had no significant difference in matched-pairs test (t = -1.49, P = 0.179 for femoral heads and t = -1.52, P = 0.172 for necrotic foci). There was significant difference (F = 2.720, P = 0.035 P was respectively 0.0001 and 0.0005). Decision tree model showed that 94.6% (53/56) hips would progress into collapse if the volumetric ratio of necrotic tissue was over 23.48%. Otherwise, if distribution in q2 was over 45.13%, 83.3% (5/6) hips would progress into collapse. No collapse (0/30) would occur if the distribution of necrotic tissue in q2 was under 45.13%. Conclusion: Digital 3D-model reconstructed from CT scanning can precisely incarnate spatial orientation of necrotic foci in femoral head. Multinomial logistic regression and decision-making tree shows that volumetric ratio of necrotic tissues plays an important role in anticipating collapse of femoral head.

A new projection model based robust 2D-3D registration method on Fourier-Mellin space for image guided intervention

An automatic method is proposed to solve the registration problem,which aligns a single 2D fluoroscopic image to a 3D image volume without demanding any additional media like calibration plate or user interactions.First,a mathematic projection model is designed which can reduce the influence of projection distortion on parameter optimization and improve the registration accuracy.Then,a two stage optimization method is proposed,which enables a robust registration in a wide parameter space.Furthermore,an automatic registration framework is proposed based on the FourierMellin robust image comparison descriptor.Experimental results show that the registration method has a high accuracy with average rotation error of 0.6 degree and average translation error of 1.4mm.

Compressed sensing reconstruction of sparse spectrum based on digital micro-mirror device platform

A new method which employs compressive sensing(CS) to reconstruct the sparse spectrum is designed and experimentally demonstrated. On the basis of CS theory, the simulation results indicate that the probability of reconstruction is high when the step of the sparsity adaptive matching pursuit algorithm is confirmed as 1. Contrastive analysis for four kinds of commonly used measurement matrices: part Hadamard, Bernoulli, Toeplitz and Circular matrix, has been conducted. The results illustrate that the part Hadamard matrix has better performance of reconstruction than the other matrices. The experimental system of the spectral compression reconstruction is mainly based on the digital micro-mirror device(DMD). The experimental results prove that CS can reconstruct sparse spectrum well under the condition of 50% sampling rate. The system error 0.0781 is obtained, which is defined by the average value of the 2-norm. Furthermore, the proposed method shows a dominant ability to discard redundancy.

An image-based approach to the reconstruction of ancient architectures by extracting and arranging 3D spatial components

The objective of this research is the rapid reconstruction of ancient buildings of historical importance using a single image. The key idea of our approach is to reduce the infinite solutions that might otherwise arise when recovering a 3D geometry from 2D photographs. The main outcome of our research shows that the proposed methodology can be used to reconstruct ancient monuments for use as proxies for digital effects in applications such as tourism, games, and entertainment, which do not require very accurate modeling. In this article, we consider the reconstruction of ancient Mughal architecture including the Taj Mahal. We propose a modeling pipeline that makes an easy reconstruction possible using a single photograph taken from a single view, without the need to create complex point clouds from multiple images or the use of laser scanners. First, an initial model is automatically reconstructed using locally fitted planar primitives along with their boundary polygons and the adjacency relation among parts of the polygons. This approach is faster and more accurate than creating a model from scratch because the initial reconstruction phase provides a set of structural information together with the adjacency relation, which makes it possible to estimate the approximate depth of the entire structural monument. Next, we use manual extrapolation and editing techniques with modeling software to assemble and adjust different 3D components of the model. Thus, this research opens up the opportunity for the present generation to experience remote sites of architectural and cultural importance through virtual worlds and real-time mobile applications. Variations of a recreated 3D monument to represent an amalgam of various cultures are targeted for future work.