Electron Density Fitting with Computer Graphics: A Review and a Glimpse

In order to better meet user needs, user-oriented interactive design introduces computer graphics technology to generate, process, and transmit graphical information more effectively, thereby enhancing the practicality, simplicity, convenience, and enjoyment of interactive media. This paper aims to discuss the application of computer graphics in interactive media design. In order to analyze and compare the use of different computer graphics (CG) technologies in different scenarios, this paper classifies the interactive media into three categories according to the different focuses of the purposes, namely distributed interaction media, commercial interaction media and informational interaction media, and discusses the application of computer graphics in interactive media design with specific examples. This paper analyzes and compares the use of different CG technologies in interactive media according to their different purposes, namely distributed interaction media, commercial interaction media and informational interaction media. The paper concludes with a summary of the current applications of computer graphics in interactive media design, and an outlook on the future use of CG technology in interactive media design.

Development of a reservoir simulation model involves collection and analysis of an enormous amount of reservoir and well data for initial input. Computer graphics is the most effective tool for geologists and engineers to visualize, verify, and analyze the input data. After each simulation run, simulation engineers then have to depend heavily on computer graphics to analyze an even more intimidating amount of simulation results data. This is especially true at Saudi Aramco because of the large simulation models used to simulate the world's largest hydrocarbon reservoirs. Saudi Aramco's EXPEC Computer Center supports a wide spectrum of computer graphics applications to aid the exploration and engineering staffs through the entire cycle of reservoir characterization. The graphics applications help during the pre-simulation model data analysis as well as in the post-simulation results analysis. Larger and more accurate simulation models are currently being developed In Saudi Aramco. Computer technology (both software and hardware) needs to advance continually such that computer graphics can be utilized as an effective and efficient engineering tool by reservoir simulation professionals. This paper addresses Saudi Aramco's experience in dealing with very large simulation models and using computer graphics as an engineering tool. The program efficiency, device dependence, and data management problems will be discussed. The computer speed, data storage and access methods, data transmission speed, and graphics devices will also be detailed.

Computer graphics is receiving much attention in the development of interactive educational software, multimedia systems, and many other applications. It not only adds a new dimension to such applications but also makes them more exciting and dynamic. Furthermore, the use of computer graphics is already well accepted in computer science education. If skillfully and relevantly used, it can be an important component of computer-assisted instruction, which is an educational application area with tremendous potential.

Bezier and B-spline curves are among the most powerful tools used for complex graphical approximation. In this paper, we will use them to recreate the hydrographic map of the Republic of Macedonia. The results obtained in this paper show that cubic spline curves have smaller average deviation in respect to B-spline curves, in contrast to Bezier curves. The results and the images are obtained by using the software package Wolfram Mathematica. Key words: Bezier curves; B-spline; cubic spline REFERENCES [1] Vera B. Anand: Computer Graphics and Geometric Modeling for Engineers, John Wiley & Sons Inc. 1996. [2] V. Andova, S. Atanasova, K. Bacev, Gj. Peev, G.Kostov: Approximation of map borders using Mathematica, ETAI (2015). [3] R. H. Bartels, J. C. Beatty, B. A. Barsky: An Introduction to Splines for Use in Computer Graphics and Geometric Modeling, Morgan Kaufmann Publishers Inc. 1987. [4] R. C. Beach: An Introduction to the Curves and Surfaces of Computer-Aided Design, Van Nostrand Reinhold, 1991. [5] E. Cohen: Discrete B-splines and Subdivision Techniques in Computer Aided Geometric Design and Computer Graphics, International Association for Bridge and Structural Engineering, 1979. [6] C. De Boor: A Practical Guide to Splines, Revised Edition, Springer, 1978. [7] G. Farin: Curves and Surfaces for CAGD. A Practical Guide, fifth edition, Academic Press, 2002. [8] G. Farin, J. Hoschek, M.-S. Kim: Handbook of Computer Aided Geometric Design, Elsevier, 2002. [9] G. Farin: NURBS: From Projective Geometry to Practical Use, 2nd edition, AK Peters, 1999. [10] J. Fiorot, P. Jeannin: Rational Curves and Surfaces, Wiley, 1992. [11] J. Gallier: Curves and Surfaces. In: Geometric Modeling:Theory and Algorithms, Morgan Kofman Publishers,2000. [12] G. G. Lorentz: Bernstein Polynomials, University of Toronto Press, 1953. [13] R. F. Riesenfeld: Applications of B-spline Approximation to Geometric Problems of Computer-Aided Design, Syracuse University, 1973. [14] D. Rogers: An Introduction to NURBS with Historical Perspective, Elsevier, 2001. [15] W. Rudin: Real and Complex Analysis, McGraw-Hill Higher Education, 1986. [16] D. Salomon: Curves and Surfaces for Computer Graphic, Springer, 2006. [17] S. Wagon: Mathematica in Action Problem Solving Through Visualization and Computation, Springer, 2010. [18] S. Wolfram: The Mathematica Book, Fifth Edition, Wolfram Media, 2003.

70 years ago, the bloodiest of wars had ended. Literally,
 the next day the USA started the ruthless Cold war against the
 USSR. Goal – to destroy the USSR as political and military enemy.
 Ironically, it was the Russian Empire (and the Soviet Union
 – its successor) that first in the world recognized the USA as an
 independent state. In 1991, the goal was achieved. Russia considered
 the cold war over, and the USA a partner in all matters. In
 vain. It is no secret the CIA felt home in Russian governmental
 buildings. It is no secret that Department of State advisers sat in
 every Russian Ministry. Unsurprisingly, imposed reforms have led
 to destruction of industry, agriculture, and medicine. The country
 was flooded with imports, and Russia has lost the basic security of
 state.
 Obviously, the same benefactors from the CIA forced the Ministry
 of Education and Science to adopt the surrogate instead of the
 Soviet system of education. Moreover, the well-wishers perfectly
 knew that this surrogate was of very low quality. Introduction of
 the American system of education instead of the Soviet one is the
 manifestation of the cold war.
 Artificial confrontation of computer graphics vs. descriptive
 geometry arose. Enforced antagonism resulted in elimination of
 teaching descriptive geometry in many areas. Known: computers
 and computer graphics come from the USA. Note that geometry
 experts do not oppose to the use of computer graphics. More obscure
 is the position of some of our partners, when they advocate destruction
 of science in favor of a drawing instrument. In this mortal
 combat of geeks, the author sees a manifestation of the same cold
 war that the United States maintains with Russia. Deduction: it is
 so because computer graphics took all its geometric methods of
 constructing from descriptive geometry.
 Minimal program of overcoming this geometric crisis in higher
 education is provided.

The primary purpose of the research is to investigate long-term memory and its relationship to computer graphics incorporated shots in commercial Tamil films. Also,this research focused on the use of visual effects shots for the effective memory and recalling factors of the Tamil film audience. Throughout the sequels of movies like Enthiran and Bahubali, many of CG incorporated symbols, signs, and shots are extensively used to create visual pleasure among the audience. So, the movie sequels like Enthiran, 2.0, Bahubali 1-The beginning, and Bahubali 2-The conclusion are selected to study the positive impact of CG incorporated shots. According to the psychologist’s views, there are three classifications present in memory. They are sensory memory, short-term memory, and long-term memory. Sensory memory is a very basic type of memory, which present only as long as the visual /sound is present in front of the viewers. The short-term memory is present only up to 20 seconds. Long-term memory has the capability to store unlimited information and data for a few minutes to many years. To store the information in long-term memory the visual or auditory stimulus should be very strong. In this research, the qualitative analysis of interview data is used to study the relationships. Furthermore, the cued recall test is used to gather the information from the film audience. Computer graphics are used in the Enthiran and Bahubali movie series to create visual signs. These visual signs are present in the form of crowns, armours, swords, chariots, architectures, guns, costumes, tattoos, and property materials. This research shows that stories are effectively visualized with the use of computer graphics and visual effects. In addition, the interesting result of this research is the memory and recall ability of the film audience.This research concludes that the effective use of CG incorporated shots gives more effectiveness to the memory due to the individual’s thought engagement with the story.

We review the recent application of computer graphics to problems in the history and interpretation of master artworks. Carefully constructed computer graphics models of tableaus in paintings allow scholars to explore what if scenarios concerning lighting, geometry, placement of subjects, physical properties (such as color and reflectance characteristics), and more. A special application of computer graphics is to dewarp images depicted in spherical mirrors, such as appear in works from the northern Renaissance, thus revealing new views into artists' studios. We present a number of methodological recommendations to help ensure the results of such studies are valid. We describe some successes of these new techniques and conclude by discussing several outstanding problems and future directions for the use of computer graphics in the analysis of realist art.

BackgroundMacromolecular structures are modeled by conformational optimization within experimental and knowledge-based restraints. Discrete restraint-based sampling generates high-quality structures within these restraints and facilitates further refinement in a continuous all-atom energy landscape. This approach has been used successfully for protein loop modeling, comparative modeling and electron density fitting in X-ray crystallography.ResultsHere we present a software toolkit (Rappertk) which generalizes discrete restraint-based sampling for use in structural biology. Modular design and multi-layered architecture enables Rappertk to sample conformations of any macromolecule at many levels of detail and within a variety of experimental restraints. Performance against a Cα-tracing benchmark shows that the efficiency has not suffered despite the overhead required by this flexibility. We demonstrate the toolkit's capabilities by building high-quality β-sheets and by introducing restraint-driven sampling. RNA sampling is demonstrated by rebuilding a protein-RNA interface. Ability to construct arbitrary ligands is used in sampling protein-ligand interfaces within electron density. Finally, secondary structure and shape information derived from EM are combined to generate multiple conformations of a protein consistent with the observed density.ConclusionThrough its modular design and ease of use, Rappertk enables exploration of a wide variety of interesting avenues in structural biology. This toolkit, with illustrative examples, is freely available to academic users from .

The structure of cytidilyl(2′,5′)adenosine when bound to pancreatic ribonuclease S

Computational strategies based on electron density fitting in relativistic density functional theory

With the development and popularization of computer application technology, the use of computer graphics and image processing technology has become the main means of modern engineering design and drawing. Learning and mastering 3D modeling technology and mechanical information modeling technology have become an important goal of learning engineering drawing. To meet the teaching requirements of the “New Engineering” program, higher education should cultivate innovative talents with the ability to identify, express, analyze, and solve complex engineering problems; promote the transformation of teaching methods for the course of “Mechanical Drawing and Computer Drawing” from “teaching well” to “learning well.” This change is not only a change in course content, but also a change in training objectives. It introduces modern 3D design concepts into the drawing course, constructs a learning system with 3D modeling technology as the main line, solves the problem of imagination in traditional teaching, makes the learning process more in line with scientific cognitive laws, better meets the needs of modern manufacturing industry for new technologies, and improves students’ drawing skills and ability to use modern tools (computer drawing).

Analytical models of light reflection are in common use in computer graphics. However, models based on measured reflectance data promise increased realism by making it possible to simulate many more types of surfaces to a greater level of accuracy than with analytical models. They also require less expert knowledge about the illumination models and their parameters. There are a number of hurdles to using measured reflectance functions, however. The data sets are very large. A reflectance distribution function sampled at five degrees angular resolution, arguably sparse enough to miss highlights and other high frequency effects, can easily require over a million samples, which in turn amount to over four megabytes of data. These data then also require some form of interpolation and filtering to be used effectively. We examine issues of representation of measured reflectance distribution functions. In particular, we examine a wavelet basis representation of reflectance functions, and the algorithms required for efficient point-wise reconstruction of the BRDF. We show that the nonstandard wavelet decomposition leads to considerably more efficient algorithms than the standard wavelet decomposition. We also show that thresholding allows considerable improvement in running times, without unduly sacrificing image quality.

This paper describes how evolutionary techniques of variation and selection can be used to create complex simulated structures, textures, and motions for use in computer graphics and animation. Interactive selection, based on visual perception of procedurally generated results, allows the user to direct simulated evolutions in preferred directions. Several examples using these methods have been implemented and are described. 3D plant structures are grown using fixed sets of genetic parameters. Images, solid textures, and animations are created using mutating symbolic lisp expressions. Genotypes consisting of symbolic expressions are presented as an attempt to surpass the limitations of fixed-length genotypes with predefined expression rules. It is proposed that artificial evolution has potential as a powerful tool for achieving flexible complexity with a minimum of user input and knowledge of details.

The presented simulation model of surface tension and wettability based on physical properties of liquids is designed for use in computer graphics. Due to the relatively small surface tension forces the model is useful for simulating liquid of small volume such as droplets. This model can be used in conjunction with various fluid simulation methods, one of the most popular - Marker and Cell - has been selected for this paper. The paper describes also a simple and rapid method of determining the liquid surface as a mesh of triangles. The presented method improves the final visual effect and is well suited for determining the surface of the droplets. The simulation method was applied to create realistic animations of flowing liquid droplets of different types.

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