scholarly journals Calculation of 3D Coordinates of a Point on the Basis of a Stereoscopic System

2018 ◽  
Vol 8 (1) ◽  
pp. 109-117
Author(s):  
R.R. Mussabayev ◽  
M.N. Kalimoldayev ◽  
Ye.N. Amirgaliyev ◽  
A.T. Tairova ◽  
T.R. Mussabayev
Keyword(s):  
Optical System ◽  
Three Dimensional ◽  
Material Point ◽  
Experimental Investigations ◽  
Unknown Parameters ◽  
Wide Range ◽  
Stereoscopic System ◽  
3D Scene ◽  
The Right ◽  
The Given

Abstract The solution of three-dimensional (3D) coordinate calculation task for a material point is considered. Two flat images (a stereopair) which correspond to the left and to the right viewpoints of a 3D scene are used for this purpose. The stereopair is obtained using two cameras with parallel optical axes. The analytical formulas for calculating 3D coordinates of a material point in the scene were obtained on the basis of analysis of the stereoscopic system optical and geometrical schemes. The detailed presentation of the algorithmic and hardware realization of the given method was discussed with the the practical. The practical module was recommended for the determination of the optical system unknown parameters. The series of experimental investigations were conducted for verification of theoretical results. During these experiments the minor inaccuracies were occurred by space distortions in the optical system and by it discrecity. While using the high quality stereoscopic system, the existing calculation inaccuracy enables to apply the given method for the wide range of practical tasks.

Investigation of Vortex Reacting Flows in Asymmetric Meso Scale Combustor

2013 ◽  
Vol 388 ◽  
pp. 246-250 ◽  
Author(s):  
Mostafa Khaleghi ◽  
Mazlan A. Wahid ◽  
Mohsin M. Seis ◽  
Aminuddin Saat
Keyword(s):  
Flame Structure ◽  
Three Dimensional ◽  
Reacting Flows ◽  
Experimental Investigations ◽  
Flame Stability ◽  
Three Dimensional Flow ◽  
Asymmetric Vortex ◽  
Wide Range ◽  
Basic Characteristics ◽  
Exceptional Stability

In the current study computational and experimental investigations of a turbulent asymmetric vortex flame is presented. The three dimensional flow fields have been described using a computational methodology that impalements the kε turbulence model. The computational model is validated for isothermal flow. Moreover, the visible flame structure was captured by direct photography at a wide range of equivalence ratios in order to emphasize the exceptional stability of such flame. The mechanism of flame stability and interaction with the forced vortex field is preliminarily discussed. Finally, the basic characteristics of the asymmetric vortex flames are concluded.

Tourism demonstration system for large-scale museums based on 3D virtual simulation technology

2020 ◽  
Vol 38 (2) ◽  
pp. 367-381
Author(s):  
Yongcai Hu ◽  
Wei Sun ◽  
Xigang Liu ◽  
Quan Gan ◽  
Jie Shi
Keyword(s):  
Large Scale ◽  
Three Dimensional ◽  
Virtual Simulation ◽  
Simulation Technology ◽  
Large Space ◽  
Content Type ◽  
3D Network ◽  
Wide Range ◽  
3D Scene

Purpose The purpose of this study is to enhance audience experience in museum by using three-dimensional (3D) virtual simulation technology. Design/methodology/approach In this study, a large space museum building tourism demonstration system based on 3D virtual simulation technology was proposed. Starting from the concept of virtual reality (VR), the characteristics of VR and the classification of VR systems were introduced, and the research status of VR technology at home and abroad and the application of 3D virtual simulation were discussed. Then the key technologies of 3D modeling, 3D scene optimization and 3D simulation driving of 3D virtual simulation were expounded, and the characteristics and application scope of different technical methods were analyzed. Finally, an example of the Hongzhou Kiln 3D network museum was listed. Findings The research results showed that 3D virtual simulation has a wide range of applications in the field of VR. Different elements need to be considered for different types of applications, and different contents need to be integrated to achieve the corresponding interaction modes. Originality/value Virtual image; multimedia; large space museum; tourism demonstration system; 3D virtual simulation technology.

The Occurrence of Humping in Welding with Highest Beam Qualities

2007 ◽  
Vol 344 ◽  
pp. 731-743 ◽  
Author(s):  
Claus Thomy ◽  
Thomas Seefeld ◽  
Frank Vollertsen
Keyword(s):  
Three Dimensional ◽  
Welding Process ◽  
Single Mode ◽  
Fibre Laser ◽  
Experimental Investigations ◽  
Single Mode Fibre ◽  
Inviscid Incompressible Fluid ◽  
Wide Range ◽  
Welding Processes ◽  
Mode Fibre

The availability of lasers with highest beam qualities at laser powers of 1 kW (such as single-mode fibre laser, which nowadays come close to the theoretical limits) provides a unique tool to investigate welding process phenomena in a wide range of potential applications from welding with penetrations of some 50 "m to penetrations of some mm. Thus covering the field of micro welding as well as of macro welding, scalability of welding processes as well as size effects associated with the underlying physical phenomena may be of significance. In this paper, the humping effect will be given a closer look, as this periodic melt pool instability is an important limitation to possible welding speeds both in the micro and the macro range. Based on experimental investigations with a single-mode fibre laser (YLR-1000, laser power 1 kW, BPP < 0.4 mm*mrad), a model based on a modification of Rayleigh’s considerations on the stability of an inviscid incompressible fluid which is freely suspended in space and maintained only by surface tension is developed and discussed. It is shown that, within the scope of the investigations, humping to a large extent can be explained by Rayleigh’s theory, permitting to neglect the influence of three-dimensional melt flow.

scholarly journals Changes of cerebral cortical structure and cognitive dysfunction in “healthy hemisphere” after stroke: a study about cortical complexity and sulcus patterns in bilateral ischemic adult moyamoya disease

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Ziqi Liu ◽  
Shihao He ◽  
Yanchang Wei ◽  
Ran Duan ◽  
Cai Zhang ◽  
...  
Keyword(s):  
Cognitive Dysfunction ◽  
Moyamoya Disease ◽  
Right Hemisphere ◽  
Quantitative Description ◽  
Three Dimensional ◽  
Wide Range ◽  
Magnetic Resonance Imaging Mri ◽  
The Right ◽  
Adult Moyamoya Disease ◽  
Surface Based Morphometry

Abstract Background Moyamoya disease (MMD) is an uncommon cerebrovascular disease which leads to progressive stenosis and occlusion of the bilateral internal carotid artery and main intracerebral arteries. Concerns are always on how the hemisphere with infarction affects cognitive function, while little attention is paid to the role that the non-infarcted hemisphere plays. Therefore, we aimed to detect cortical indexes, especially cortical complexity in the left or right hemisphere separately in patients with MMD after stroke. Methods 28 patients with MMD (14 males, 14 females) and 14 healthy controls were included in this study. All participants underwent cognitive tests and magnetic resonance imaging (MRI) scan. The preprocessing of three-dimensional T1 weighted images were performed by standard surface-based morphometry. Surface-based morphometry statistical analysis was carried out with a threshold of False Discovery Rate (FDR) P < 0.05 and fractal dimension (FD) was used to provide a quantitative description of cerebral cortical complexity. Results Widespread cognitive dysfunctions were found in MMD patient with stroke. Extensive FD reduction in the left hemisphere with right-sided infarction, mainly in the superior temporal, inferior frontal, and insula, while the post central gyrus, superior parietal, and inferior parietal gyrus also showed a wide range of significant differences (FDR corrected P < 0.05). Meanwhile, FD changes in the right hemisphere with left-sided infarction are restricted to the precuneus and cingulate isthmus (FDR corrected P < 0.05). Conclusions Extensive cognitive impairment was reconfirmed in Moyamoya disease with stroke, while wild and asymmetrical decrease of cortical complexity is observed on both sides. These differences could be relative to unbalanced cognitive dysfunction, and may be the result of a long-term chronic ischemia and compensatory of the contralateral hemisphere to the infarction.

scholarly journals Three-dimensional and real-scale modeling of flow regimes in dense snow avalanches

Landslides ◽  
2021 ◽  
Author(s):  
Xingyue Li ◽  
Betty Sovilla ◽  
Chenfanfu Jiang ◽  
Johan Gaume
Keyword(s):  
Three Dimensional ◽  
Economic Loss ◽  
Density Variation ◽  
Material Point ◽  
Snow Avalanche ◽  
Snow Avalanches ◽  
Computationally Efficient ◽  
Mountainous Regions ◽  
Depth Direction ◽  
Wide Range

AbstractSnow avalanches cause fatalities and economic loss worldwide and are one of the most dangerous gravitational hazards in mountainous regions. Various flow behaviors have been reported in snow avalanches, making them challenging to be thoroughly understood and mitigated. Existing popular numerical approaches for modeling snow avalanches predominantly adopt depth-averaged models, which are computationally efficient but fail to capture important features along the flow depth direction such as densification and granulation. This study applies a three-dimensional (3D) material point method (MPM) to explore snow avalanches in different regimes on a complex real terrain. Flow features of the snow avalanches from release to deposition are comprehensively characterized for identification of the different regimes. In particular, brittle and ductile fractures are identified in the different modeled avalanches shortly after their release. During the flow, the analysis of local snow density variation reveals that snow granulation requires an appropriate combination of snow fracture and compaction. In contrast, cohesionless granular flows and plug flows are mainly governed by expansion and compaction hardening, respectively. Distinct textures of avalanche deposits are characterized, including a smooth surface, rough surfaces with snow granules, as well as a surface showing compacting shear planes often reported in wet snow avalanche deposits. Finally, the MPM modeling is verified with a real snow avalanche that occurred at Vallée de la Sionne, Switzerland. The MPM framework has been proven as a promising numerical tool for exploring complex behavior of a wide range of snow avalanches in different regimes to better understand avalanche dynamics. In the future, this framework can be extended to study other types of gravitational mass movements such as rock/glacier avalanches and debris flows with implementation of modified constitutive laws.

Atomic Resolution in Crystal Aperture Stem

1990 ◽  
Vol 48 (1) ◽  
pp. 236-237
Author(s):  
J T Fourie
Keyword(s):  
Optical System ◽  
Spherical Aberration ◽  
Three Dimensional ◽  
Transmission Function ◽  
Optical Systems ◽  
Bragg Angle ◽  
Electron Optical System ◽  
Intimate Contact ◽  
Diffraction Effects ◽  
Design Aspect

The attempts at improvement of electron optical systems to date, have largely been directed towards the design aspect of magnetic lenses and towards the establishment of ideal lens combinations. In the present work the emphasis has been placed on the utilization of a unique three-dimensional crystal objective aperture within a standard electron optical system with the aim to reduce the spherical aberration without introducing diffraction effects. A brief summary of this work together with a description of results obtained recently, will be given.The concept of utilizing a crystal as aperture in an electron optical system was introduced by Fourie who employed a {111} crystal foil as a collector aperture, by mounting the sample directly on top of the foil and in intimate contact with the foil. In the present work the sample was mounted on the bottom of the foil so that the crystal would function as an objective or probe forming aperture. The transmission function of such a crystal aperture depends on the thickness, t, and the orientation of the foil. The expression for calculating the transmission function was derived by Hashimoto, Howie and Whelan on the basis of the electron equivalent of the Borrmann anomalous absorption effect in crystals. In Fig. 1 the functions for a g220 diffraction vector and t = 0.53 and 1.0 μm are shown. Here n= Θ‒ΘB, where Θ is the angle between the incident ray and the (hkl) planes, and ΘB is the Bragg angle.

Evaluation of 99mTc-Label led Vitamin K4 as an Agent for Testicular Imaging

1991 ◽  
Vol 30 (01) ◽  
pp. 35-39 ◽  
Author(s):  
H. S. Durak ◽  
M. Kitapgi ◽  
B. E. Caner ◽  
R. Senekowitsch ◽  
M. T. Ercan
Keyword(s):  
Soft Tissue ◽  
Room Temperature ◽  
Normal Subjects ◽  
Left Testis ◽  
Wide Range ◽  
Activity Ratios ◽  
The Right ◽  
Radioactivity Levels

Vitamin K4 was labelled with 99mTc with an efficiency higher than 97%. The compound was stable up to 24 h at room temperature, and its biodistribution in NMRI mice indicated its in vivo stability. Blood radioactivity levels were high over a wide range. 10% of the injected activity remained in blood after 24 h. Excretion was mostly via kidneys. Only the liver and kidneys concentrated appreciable amounts of radioactivity. Testis/soft tissue ratios were 1.4 and 1.57 at 6 and 24 h, respectively. Testis/blood ratios were lower than 1. In vitro studies with mouse blood indicated that 33.9 ±9.6% of the radioactivity was associated with RBCs; it was washed out almost completely with saline. Protein binding was 28.7 ±6.3% as determined by TCA precipitation. Blood clearance of 99mTc-l<4 in normal subjects showed a slow decrease of radioactivity, reaching a plateau after 16 h at 20% of the injected activity. In scintigraphic images in men the testes could be well visualized. The right/left testis ratio was 1.08 ±0.13. Testis/soft tissue and testis/blood activity ratios were highest at 3 h. These ratios were higher than those obtained with pertechnetate at 20 min post injection.99mTc-l<4 appears to be a promising radiopharmaceutical for the scintigraphic visualization of testes.

It is better an approximate answer to the right question than the exact answer to the wrong question : the case of the psychometric analysis of the ASQ:SE

2020 ◽  
Author(s):  
Luis Anunciacao ◽  
janet squires ◽  
J. Landeira-Fernandez
Keyword(s):  
Internal Structure ◽  
Statistical Methods ◽  
Principal Component ◽  
Psychological Theory ◽  
Published Data ◽  
Multivariate Statistical ◽  
Exact Answer ◽  
Wide Range ◽  
Ages And Stages Questionnaire ◽  
The Right

One of the main activities in psychometrics is to analyze the internal structure of a test. Multivariate statistical methods, including Exploratory Factor analysis (EFA) and Principal Component Analysis (PCA) are frequently used to do this, but the growth of Network Analysis (NA) places this method as a promising candidate. The results obtained by these methods are of valuable interest, as they not only produce evidence to explore if the test is measuring its intended construct, but also to deal with the substantive theory that motivated the test development. However, these different statistical methods come up with different answers, providing the basis for different analytical and theoretical strategies when one needs to choose a solution. In this study, we took advantage of a large volume of published data (n = 22,331) obtained by the Ages and Stages Questionnaire Social-Emotional (ASQ:SE), and formed a subset of 500 children to present and discuss alternative psychometric solutions to its internal structure, and also to its subjacent theory. The analyses were based on a polychoric matrix, the number of factors to retain followed several well-known rules of thumb, and a wide range of exploratory methods was fitted to the data, including EFA, PCA, and NA. The statistical outcomes were divergent, varying from 1 to 6 domains, allowing a flexible interpretation of the results. We argue that the use of statistical methods in the absence of a well-grounded psychological theory has limited applications, despite its appeal. All data and codes are available at https://osf.io/z6gwv/.

THE VALUE OF LOVE IN THE SYSTEM OF FORMATION OF THE PROFESSIONAL MATURITY OF THE EDUCATOR

2020 ◽  
Vol 1 (10(79)) ◽  
pp. 12-18
Author(s):  
G. Bubyreva
Keyword(s):  
Russian Federation ◽  
The State ◽  
Educational Process ◽  
Wide Range ◽  
The Family ◽  
The Russian Federation ◽  
The Government ◽  
The Individual ◽  
The Right

The existing legislation determines the education as "an integral and focused process of teaching and upbringing, which represents a socially important value and shall be implemented so as to meet the interests of the individual, the family, the society and the state". However, even in this part, the meaning of the notion ‘socially significant benefit is not specified and allows for a wide range of interpretation [2]. Yet the more inconcrete is the answer to the question – "who and how should determine the interests of the individual, the family and even the state?" The national doctrine of education in the Russian Federation, which determined the goals of teaching and upbringing, the ways to attain them by means of the state policy regulating the field of education, the target achievements of the development of the educational system for the period up to 2025, approved by the Decree of the Government of the Russian Federation of October 4, 2000 #751, was abrogated by the Decree of the Government of the Russian Federation of March 29, 2014 #245 [7]. The new doctrine has not been developed so far. The RAE Academician A.B. Khutorsky believes that the absence of the national doctrine of education presents a threat to national security and a violation of the right of citizens to quality education. Accordingly, the teacher has to solve the problem of achieving the harmony of interests of the individual, the family, the society and the government on their own, which, however, judging by the officially published results, is the task that exceeds the abilities of the participants of the educational process.  The particular concern about the results of the patriotic upbringing served as a basis for the legislative initiative of the RF President V. V. Putin, who introduced the project of an amendment to the Law of RF "About Education of the Russian Federation" to the State Duma in 2020, regarding the quality of patriotic upbringing [3]. Patriotism, considered by the President of RF V. V. Putin as the only possible idea to unite the nation is "THE FEELING OF LOVE OF THE MOTHERLAND" and the readiness for every sacrifice and heroic deed for the sake of the interests of your Motherland. However, the practicing educators experience shortfalls in efficient methodologies of patriotic upbringing, which should let them bring up citizens, loving their Motherland more than themselves. The article is dedicated to solution to this problem based on the Value-sense paradigm of upbringing educational dynasty of the Kurbatovs [15].

The Right to Bodily Integrity

2018 ◽  
Author(s):  
Alison Brysk
Keyword(s):  
Sexual Assault ◽  
Sexual Violence ◽  
Public Space ◽  
Transitional Justice ◽  
The United States ◽  
Bodily Integrity ◽  
Global Pattern ◽  
Popular Resistance ◽  
Wide Range ◽  
The Right

In Chapter 7, we profile the global pattern of sexual violence. We will consider conflict rape and transitional justice response in Peru and Colombia, along with the plight of women displaced by conflict from Syria and Central America, and limited international policy response. State-sponsored sexual violence and popular resistance to reclaim public space will be chronicled in Egypt as well as Mexico. We will track intensifying public sexual assault amid social crisis in Turkey, South Africa, and India, which has been met by a wide range of public protest, legal reform, and policy change. For a contrasting experience of the privatization of sexual assault in developed democracies, we will trace campus, workplace, and military rape in the United States.

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